Bug Summary

File:clang/lib/AST/ExprConstant.cpp
Warning:line 3183, column 27
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name ExprConstant.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/clang/lib/AST -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D CLANG_ROUND_TRIP_CC1_ARGS=ON -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/clang/lib/AST -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/clang/lib/AST -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-08-28-193554-24367-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp
1//===--- ExprConstant.cpp - Expression Constant Evaluator -----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the Expr constant evaluator.
10//
11// Constant expression evaluation produces four main results:
12//
13// * A success/failure flag indicating whether constant folding was successful.
14// This is the 'bool' return value used by most of the code in this file. A
15// 'false' return value indicates that constant folding has failed, and any
16// appropriate diagnostic has already been produced.
17//
18// * An evaluated result, valid only if constant folding has not failed.
19//
20// * A flag indicating if evaluation encountered (unevaluated) side-effects.
21// These arise in cases such as (sideEffect(), 0) and (sideEffect() || 1),
22// where it is possible to determine the evaluated result regardless.
23//
24// * A set of notes indicating why the evaluation was not a constant expression
25// (under the C++11 / C++1y rules only, at the moment), or, if folding failed
26// too, why the expression could not be folded.
27//
28// If we are checking for a potential constant expression, failure to constant
29// fold a potential constant sub-expression will be indicated by a 'false'
30// return value (the expression could not be folded) and no diagnostic (the
31// expression is not necessarily non-constant).
32//
33//===----------------------------------------------------------------------===//
34
35#include "Interp/Context.h"
36#include "Interp/Frame.h"
37#include "Interp/State.h"
38#include "clang/AST/APValue.h"
39#include "clang/AST/ASTContext.h"
40#include "clang/AST/ASTDiagnostic.h"
41#include "clang/AST/ASTLambda.h"
42#include "clang/AST/Attr.h"
43#include "clang/AST/CXXInheritance.h"
44#include "clang/AST/CharUnits.h"
45#include "clang/AST/CurrentSourceLocExprScope.h"
46#include "clang/AST/Expr.h"
47#include "clang/AST/OSLog.h"
48#include "clang/AST/OptionalDiagnostic.h"
49#include "clang/AST/RecordLayout.h"
50#include "clang/AST/StmtVisitor.h"
51#include "clang/AST/TypeLoc.h"
52#include "clang/Basic/Builtins.h"
53#include "clang/Basic/TargetInfo.h"
54#include "llvm/ADT/APFixedPoint.h"
55#include "llvm/ADT/Optional.h"
56#include "llvm/ADT/SmallBitVector.h"
57#include "llvm/Support/Debug.h"
58#include "llvm/Support/SaveAndRestore.h"
59#include "llvm/Support/raw_ostream.h"
60#include <cstring>
61#include <functional>
62
63#define DEBUG_TYPE"exprconstant" "exprconstant"
64
65using namespace clang;
66using llvm::APFixedPoint;
67using llvm::APInt;
68using llvm::APSInt;
69using llvm::APFloat;
70using llvm::FixedPointSemantics;
71using llvm::Optional;
72
73namespace {
74 struct LValue;
75 class CallStackFrame;
76 class EvalInfo;
77
78 using SourceLocExprScopeGuard =
79 CurrentSourceLocExprScope::SourceLocExprScopeGuard;
80
81 static QualType getType(APValue::LValueBase B) {
82 return B.getType();
83 }
84
85 /// Get an LValue path entry, which is known to not be an array index, as a
86 /// field declaration.
87 static const FieldDecl *getAsField(APValue::LValuePathEntry E) {
88 return dyn_cast_or_null<FieldDecl>(E.getAsBaseOrMember().getPointer());
89 }
90 /// Get an LValue path entry, which is known to not be an array index, as a
91 /// base class declaration.
92 static const CXXRecordDecl *getAsBaseClass(APValue::LValuePathEntry E) {
93 return dyn_cast_or_null<CXXRecordDecl>(E.getAsBaseOrMember().getPointer());
94 }
95 /// Determine whether this LValue path entry for a base class names a virtual
96 /// base class.
97 static bool isVirtualBaseClass(APValue::LValuePathEntry E) {
98 return E.getAsBaseOrMember().getInt();
99 }
100
101 /// Given an expression, determine the type used to store the result of
102 /// evaluating that expression.
103 static QualType getStorageType(const ASTContext &Ctx, const Expr *E) {
104 if (E->isPRValue())
105 return E->getType();
106 return Ctx.getLValueReferenceType(E->getType());
107 }
108
109 /// Given a CallExpr, try to get the alloc_size attribute. May return null.
110 static const AllocSizeAttr *getAllocSizeAttr(const CallExpr *CE) {
111 if (const FunctionDecl *DirectCallee = CE->getDirectCallee())
112 return DirectCallee->getAttr<AllocSizeAttr>();
113 if (const Decl *IndirectCallee = CE->getCalleeDecl())
114 return IndirectCallee->getAttr<AllocSizeAttr>();
115 return nullptr;
116 }
117
118 /// Attempts to unwrap a CallExpr (with an alloc_size attribute) from an Expr.
119 /// This will look through a single cast.
120 ///
121 /// Returns null if we couldn't unwrap a function with alloc_size.
122 static const CallExpr *tryUnwrapAllocSizeCall(const Expr *E) {
123 if (!E->getType()->isPointerType())
124 return nullptr;
125
126 E = E->IgnoreParens();
127 // If we're doing a variable assignment from e.g. malloc(N), there will
128 // probably be a cast of some kind. In exotic cases, we might also see a
129 // top-level ExprWithCleanups. Ignore them either way.
130 if (const auto *FE = dyn_cast<FullExpr>(E))
131 E = FE->getSubExpr()->IgnoreParens();
132
133 if (const auto *Cast = dyn_cast<CastExpr>(E))
134 E = Cast->getSubExpr()->IgnoreParens();
135
136 if (const auto *CE = dyn_cast<CallExpr>(E))
137 return getAllocSizeAttr(CE) ? CE : nullptr;
138 return nullptr;
139 }
140
141 /// Determines whether or not the given Base contains a call to a function
142 /// with the alloc_size attribute.
143 static bool isBaseAnAllocSizeCall(APValue::LValueBase Base) {
144 const auto *E = Base.dyn_cast<const Expr *>();
145 return E && E->getType()->isPointerType() && tryUnwrapAllocSizeCall(E);
146 }
147
148 /// Determines whether the given kind of constant expression is only ever
149 /// used for name mangling. If so, it's permitted to reference things that we
150 /// can't generate code for (in particular, dllimported functions).
151 static bool isForManglingOnly(ConstantExprKind Kind) {
152 switch (Kind) {
153 case ConstantExprKind::Normal:
154 case ConstantExprKind::ClassTemplateArgument:
155 case ConstantExprKind::ImmediateInvocation:
156 // Note that non-type template arguments of class type are emitted as
157 // template parameter objects.
158 return false;
159
160 case ConstantExprKind::NonClassTemplateArgument:
161 return true;
162 }
163 llvm_unreachable("unknown ConstantExprKind")::llvm::llvm_unreachable_internal("unknown ConstantExprKind",
"/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 163)
;
164 }
165
166 static bool isTemplateArgument(ConstantExprKind Kind) {
167 switch (Kind) {
168 case ConstantExprKind::Normal:
169 case ConstantExprKind::ImmediateInvocation:
170 return false;
171
172 case ConstantExprKind::ClassTemplateArgument:
173 case ConstantExprKind::NonClassTemplateArgument:
174 return true;
175 }
176 llvm_unreachable("unknown ConstantExprKind")::llvm::llvm_unreachable_internal("unknown ConstantExprKind",
"/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 176)
;
177 }
178
179 /// The bound to claim that an array of unknown bound has.
180 /// The value in MostDerivedArraySize is undefined in this case. So, set it
181 /// to an arbitrary value that's likely to loudly break things if it's used.
182 static const uint64_t AssumedSizeForUnsizedArray =
183 std::numeric_limits<uint64_t>::max() / 2;
184
185 /// Determines if an LValue with the given LValueBase will have an unsized
186 /// array in its designator.
187 /// Find the path length and type of the most-derived subobject in the given
188 /// path, and find the size of the containing array, if any.
189 static unsigned
190 findMostDerivedSubobject(ASTContext &Ctx, APValue::LValueBase Base,
191 ArrayRef<APValue::LValuePathEntry> Path,
192 uint64_t &ArraySize, QualType &Type, bool &IsArray,
193 bool &FirstEntryIsUnsizedArray) {
194 // This only accepts LValueBases from APValues, and APValues don't support
195 // arrays that lack size info.
196 assert(!isBaseAnAllocSizeCall(Base) &&(static_cast <bool> (!isBaseAnAllocSizeCall(Base) &&
"Unsized arrays shouldn't appear here") ? void (0) : __assert_fail
("!isBaseAnAllocSizeCall(Base) && \"Unsized arrays shouldn't appear here\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 197, __extension__ __PRETTY_FUNCTION__))
197 "Unsized arrays shouldn't appear here")(static_cast <bool> (!isBaseAnAllocSizeCall(Base) &&
"Unsized arrays shouldn't appear here") ? void (0) : __assert_fail
("!isBaseAnAllocSizeCall(Base) && \"Unsized arrays shouldn't appear here\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 197, __extension__ __PRETTY_FUNCTION__))
;
198 unsigned MostDerivedLength = 0;
199 Type = getType(Base);
200
201 for (unsigned I = 0, N = Path.size(); I != N; ++I) {
202 if (Type->isArrayType()) {
203 const ArrayType *AT = Ctx.getAsArrayType(Type);
204 Type = AT->getElementType();
205 MostDerivedLength = I + 1;
206 IsArray = true;
207
208 if (auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
209 ArraySize = CAT->getSize().getZExtValue();
210 } else {
211 assert(I == 0 && "unexpected unsized array designator")(static_cast <bool> (I == 0 && "unexpected unsized array designator"
) ? void (0) : __assert_fail ("I == 0 && \"unexpected unsized array designator\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 211, __extension__ __PRETTY_FUNCTION__))
;
212 FirstEntryIsUnsizedArray = true;
213 ArraySize = AssumedSizeForUnsizedArray;
214 }
215 } else if (Type->isAnyComplexType()) {
216 const ComplexType *CT = Type->castAs<ComplexType>();
217 Type = CT->getElementType();
218 ArraySize = 2;
219 MostDerivedLength = I + 1;
220 IsArray = true;
221 } else if (const FieldDecl *FD = getAsField(Path[I])) {
222 Type = FD->getType();
223 ArraySize = 0;
224 MostDerivedLength = I + 1;
225 IsArray = false;
226 } else {
227 // Path[I] describes a base class.
228 ArraySize = 0;
229 IsArray = false;
230 }
231 }
232 return MostDerivedLength;
233 }
234
235 /// A path from a glvalue to a subobject of that glvalue.
236 struct SubobjectDesignator {
237 /// True if the subobject was named in a manner not supported by C++11. Such
238 /// lvalues can still be folded, but they are not core constant expressions
239 /// and we cannot perform lvalue-to-rvalue conversions on them.
240 unsigned Invalid : 1;
241
242 /// Is this a pointer one past the end of an object?
243 unsigned IsOnePastTheEnd : 1;
244
245 /// Indicator of whether the first entry is an unsized array.
246 unsigned FirstEntryIsAnUnsizedArray : 1;
247
248 /// Indicator of whether the most-derived object is an array element.
249 unsigned MostDerivedIsArrayElement : 1;
250
251 /// The length of the path to the most-derived object of which this is a
252 /// subobject.
253 unsigned MostDerivedPathLength : 28;
254
255 /// The size of the array of which the most-derived object is an element.
256 /// This will always be 0 if the most-derived object is not an array
257 /// element. 0 is not an indicator of whether or not the most-derived object
258 /// is an array, however, because 0-length arrays are allowed.
259 ///
260 /// If the current array is an unsized array, the value of this is
261 /// undefined.
262 uint64_t MostDerivedArraySize;
263
264 /// The type of the most derived object referred to by this address.
265 QualType MostDerivedType;
266
267 typedef APValue::LValuePathEntry PathEntry;
268
269 /// The entries on the path from the glvalue to the designated subobject.
270 SmallVector<PathEntry, 8> Entries;
271
272 SubobjectDesignator() : Invalid(true) {}
273
274 explicit SubobjectDesignator(QualType T)
275 : Invalid(false), IsOnePastTheEnd(false),
276 FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
277 MostDerivedPathLength(0), MostDerivedArraySize(0),
278 MostDerivedType(T) {}
279
280 SubobjectDesignator(ASTContext &Ctx, const APValue &V)
281 : Invalid(!V.isLValue() || !V.hasLValuePath()), IsOnePastTheEnd(false),
282 FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
283 MostDerivedPathLength(0), MostDerivedArraySize(0) {
284 assert(V.isLValue() && "Non-LValue used to make an LValue designator?")(static_cast <bool> (V.isLValue() && "Non-LValue used to make an LValue designator?"
) ? void (0) : __assert_fail ("V.isLValue() && \"Non-LValue used to make an LValue designator?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 284, __extension__ __PRETTY_FUNCTION__))
;
285 if (!Invalid) {
286 IsOnePastTheEnd = V.isLValueOnePastTheEnd();
287 ArrayRef<PathEntry> VEntries = V.getLValuePath();
288 Entries.insert(Entries.end(), VEntries.begin(), VEntries.end());
289 if (V.getLValueBase()) {
290 bool IsArray = false;
291 bool FirstIsUnsizedArray = false;
292 MostDerivedPathLength = findMostDerivedSubobject(
293 Ctx, V.getLValueBase(), V.getLValuePath(), MostDerivedArraySize,
294 MostDerivedType, IsArray, FirstIsUnsizedArray);
295 MostDerivedIsArrayElement = IsArray;
296 FirstEntryIsAnUnsizedArray = FirstIsUnsizedArray;
297 }
298 }
299 }
300
301 void truncate(ASTContext &Ctx, APValue::LValueBase Base,
302 unsigned NewLength) {
303 if (Invalid)
304 return;
305
306 assert(Base && "cannot truncate path for null pointer")(static_cast <bool> (Base && "cannot truncate path for null pointer"
) ? void (0) : __assert_fail ("Base && \"cannot truncate path for null pointer\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 306, __extension__ __PRETTY_FUNCTION__))
;
307 assert(NewLength <= Entries.size() && "not a truncation")(static_cast <bool> (NewLength <= Entries.size() &&
"not a truncation") ? void (0) : __assert_fail ("NewLength <= Entries.size() && \"not a truncation\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 307, __extension__ __PRETTY_FUNCTION__))
;
308
309 if (NewLength == Entries.size())
310 return;
311 Entries.resize(NewLength);
312
313 bool IsArray = false;
314 bool FirstIsUnsizedArray = false;
315 MostDerivedPathLength = findMostDerivedSubobject(
316 Ctx, Base, Entries, MostDerivedArraySize, MostDerivedType, IsArray,
317 FirstIsUnsizedArray);
318 MostDerivedIsArrayElement = IsArray;
319 FirstEntryIsAnUnsizedArray = FirstIsUnsizedArray;
320 }
321
322 void setInvalid() {
323 Invalid = true;
324 Entries.clear();
325 }
326
327 /// Determine whether the most derived subobject is an array without a
328 /// known bound.
329 bool isMostDerivedAnUnsizedArray() const {
330 assert(!Invalid && "Calling this makes no sense on invalid designators")(static_cast <bool> (!Invalid && "Calling this makes no sense on invalid designators"
) ? void (0) : __assert_fail ("!Invalid && \"Calling this makes no sense on invalid designators\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 330, __extension__ __PRETTY_FUNCTION__))
;
331 return Entries.size() == 1 && FirstEntryIsAnUnsizedArray;
332 }
333
334 /// Determine what the most derived array's size is. Results in an assertion
335 /// failure if the most derived array lacks a size.
336 uint64_t getMostDerivedArraySize() const {
337 assert(!isMostDerivedAnUnsizedArray() && "Unsized array has no size")(static_cast <bool> (!isMostDerivedAnUnsizedArray() &&
"Unsized array has no size") ? void (0) : __assert_fail ("!isMostDerivedAnUnsizedArray() && \"Unsized array has no size\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 337, __extension__ __PRETTY_FUNCTION__))
;
338 return MostDerivedArraySize;
339 }
340
341 /// Determine whether this is a one-past-the-end pointer.
342 bool isOnePastTheEnd() const {
343 assert(!Invalid)(static_cast <bool> (!Invalid) ? void (0) : __assert_fail
("!Invalid", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 343, __extension__ __PRETTY_FUNCTION__))
;
344 if (IsOnePastTheEnd)
345 return true;
346 if (!isMostDerivedAnUnsizedArray() && MostDerivedIsArrayElement &&
347 Entries[MostDerivedPathLength - 1].getAsArrayIndex() ==
348 MostDerivedArraySize)
349 return true;
350 return false;
351 }
352
353 /// Get the range of valid index adjustments in the form
354 /// {maximum value that can be subtracted from this pointer,
355 /// maximum value that can be added to this pointer}
356 std::pair<uint64_t, uint64_t> validIndexAdjustments() {
357 if (Invalid || isMostDerivedAnUnsizedArray())
358 return {0, 0};
359
360 // [expr.add]p4: For the purposes of these operators, a pointer to a
361 // nonarray object behaves the same as a pointer to the first element of
362 // an array of length one with the type of the object as its element type.
363 bool IsArray = MostDerivedPathLength == Entries.size() &&
364 MostDerivedIsArrayElement;
365 uint64_t ArrayIndex = IsArray ? Entries.back().getAsArrayIndex()
366 : (uint64_t)IsOnePastTheEnd;
367 uint64_t ArraySize =
368 IsArray ? getMostDerivedArraySize() : (uint64_t)1;
369 return {ArrayIndex, ArraySize - ArrayIndex};
370 }
371
372 /// Check that this refers to a valid subobject.
373 bool isValidSubobject() const {
374 if (Invalid)
375 return false;
376 return !isOnePastTheEnd();
377 }
378 /// Check that this refers to a valid subobject, and if not, produce a
379 /// relevant diagnostic and set the designator as invalid.
380 bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK);
381
382 /// Get the type of the designated object.
383 QualType getType(ASTContext &Ctx) const {
384 assert(!Invalid && "invalid designator has no subobject type")(static_cast <bool> (!Invalid && "invalid designator has no subobject type"
) ? void (0) : __assert_fail ("!Invalid && \"invalid designator has no subobject type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 384, __extension__ __PRETTY_FUNCTION__))
;
385 return MostDerivedPathLength == Entries.size()
386 ? MostDerivedType
387 : Ctx.getRecordType(getAsBaseClass(Entries.back()));
388 }
389
390 /// Update this designator to refer to the first element within this array.
391 void addArrayUnchecked(const ConstantArrayType *CAT) {
392 Entries.push_back(PathEntry::ArrayIndex(0));
393
394 // This is a most-derived object.
395 MostDerivedType = CAT->getElementType();
396 MostDerivedIsArrayElement = true;
397 MostDerivedArraySize = CAT->getSize().getZExtValue();
398 MostDerivedPathLength = Entries.size();
399 }
400 /// Update this designator to refer to the first element within the array of
401 /// elements of type T. This is an array of unknown size.
402 void addUnsizedArrayUnchecked(QualType ElemTy) {
403 Entries.push_back(PathEntry::ArrayIndex(0));
404
405 MostDerivedType = ElemTy;
406 MostDerivedIsArrayElement = true;
407 // The value in MostDerivedArraySize is undefined in this case. So, set it
408 // to an arbitrary value that's likely to loudly break things if it's
409 // used.
410 MostDerivedArraySize = AssumedSizeForUnsizedArray;
411 MostDerivedPathLength = Entries.size();
412 }
413 /// Update this designator to refer to the given base or member of this
414 /// object.
415 void addDeclUnchecked(const Decl *D, bool Virtual = false) {
416 Entries.push_back(APValue::BaseOrMemberType(D, Virtual));
417
418 // If this isn't a base class, it's a new most-derived object.
419 if (const FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
420 MostDerivedType = FD->getType();
421 MostDerivedIsArrayElement = false;
422 MostDerivedArraySize = 0;
423 MostDerivedPathLength = Entries.size();
424 }
425 }
426 /// Update this designator to refer to the given complex component.
427 void addComplexUnchecked(QualType EltTy, bool Imag) {
428 Entries.push_back(PathEntry::ArrayIndex(Imag));
429
430 // This is technically a most-derived object, though in practice this
431 // is unlikely to matter.
432 MostDerivedType = EltTy;
433 MostDerivedIsArrayElement = true;
434 MostDerivedArraySize = 2;
435 MostDerivedPathLength = Entries.size();
436 }
437 void diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info, const Expr *E);
438 void diagnosePointerArithmetic(EvalInfo &Info, const Expr *E,
439 const APSInt &N);
440 /// Add N to the address of this subobject.
441 void adjustIndex(EvalInfo &Info, const Expr *E, APSInt N) {
442 if (Invalid || !N) return;
443 uint64_t TruncatedN = N.extOrTrunc(64).getZExtValue();
444 if (isMostDerivedAnUnsizedArray()) {
445 diagnoseUnsizedArrayPointerArithmetic(Info, E);
446 // Can't verify -- trust that the user is doing the right thing (or if
447 // not, trust that the caller will catch the bad behavior).
448 // FIXME: Should we reject if this overflows, at least?
449 Entries.back() = PathEntry::ArrayIndex(
450 Entries.back().getAsArrayIndex() + TruncatedN);
451 return;
452 }
453
454 // [expr.add]p4: For the purposes of these operators, a pointer to a
455 // nonarray object behaves the same as a pointer to the first element of
456 // an array of length one with the type of the object as its element type.
457 bool IsArray = MostDerivedPathLength == Entries.size() &&
458 MostDerivedIsArrayElement;
459 uint64_t ArrayIndex = IsArray ? Entries.back().getAsArrayIndex()
460 : (uint64_t)IsOnePastTheEnd;
461 uint64_t ArraySize =
462 IsArray ? getMostDerivedArraySize() : (uint64_t)1;
463
464 if (N < -(int64_t)ArrayIndex || N > ArraySize - ArrayIndex) {
465 // Calculate the actual index in a wide enough type, so we can include
466 // it in the note.
467 N = N.extend(std::max<unsigned>(N.getBitWidth() + 1, 65));
468 (llvm::APInt&)N += ArrayIndex;
469 assert(N.ugt(ArraySize) && "bounds check failed for in-bounds index")(static_cast <bool> (N.ugt(ArraySize) && "bounds check failed for in-bounds index"
) ? void (0) : __assert_fail ("N.ugt(ArraySize) && \"bounds check failed for in-bounds index\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 469, __extension__ __PRETTY_FUNCTION__))
;
470 diagnosePointerArithmetic(Info, E, N);
471 setInvalid();
472 return;
473 }
474
475 ArrayIndex += TruncatedN;
476 assert(ArrayIndex <= ArraySize &&(static_cast <bool> (ArrayIndex <= ArraySize &&
"bounds check succeeded for out-of-bounds index") ? void (0)
: __assert_fail ("ArrayIndex <= ArraySize && \"bounds check succeeded for out-of-bounds index\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 477, __extension__ __PRETTY_FUNCTION__))
477 "bounds check succeeded for out-of-bounds index")(static_cast <bool> (ArrayIndex <= ArraySize &&
"bounds check succeeded for out-of-bounds index") ? void (0)
: __assert_fail ("ArrayIndex <= ArraySize && \"bounds check succeeded for out-of-bounds index\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 477, __extension__ __PRETTY_FUNCTION__))
;
478
479 if (IsArray)
480 Entries.back() = PathEntry::ArrayIndex(ArrayIndex);
481 else
482 IsOnePastTheEnd = (ArrayIndex != 0);
483 }
484 };
485
486 /// A scope at the end of which an object can need to be destroyed.
487 enum class ScopeKind {
488 Block,
489 FullExpression,
490 Call
491 };
492
493 /// A reference to a particular call and its arguments.
494 struct CallRef {
495 CallRef() : OrigCallee(), CallIndex(0), Version() {}
496 CallRef(const FunctionDecl *Callee, unsigned CallIndex, unsigned Version)
497 : OrigCallee(Callee), CallIndex(CallIndex), Version(Version) {}
498
499 explicit operator bool() const { return OrigCallee; }
500
501 /// Get the parameter that the caller initialized, corresponding to the
502 /// given parameter in the callee.
503 const ParmVarDecl *getOrigParam(const ParmVarDecl *PVD) const {
504 return OrigCallee ? OrigCallee->getParamDecl(PVD->getFunctionScopeIndex())
505 : PVD;
506 }
507
508 /// The callee at the point where the arguments were evaluated. This might
509 /// be different from the actual callee (a different redeclaration, or a
510 /// virtual override), but this function's parameters are the ones that
511 /// appear in the parameter map.
512 const FunctionDecl *OrigCallee;
513 /// The call index of the frame that holds the argument values.
514 unsigned CallIndex;
515 /// The version of the parameters corresponding to this call.
516 unsigned Version;
517 };
518
519 /// A stack frame in the constexpr call stack.
520 class CallStackFrame : public interp::Frame {
521 public:
522 EvalInfo &Info;
523
524 /// Parent - The caller of this stack frame.
525 CallStackFrame *Caller;
526
527 /// Callee - The function which was called.
528 const FunctionDecl *Callee;
529
530 /// This - The binding for the this pointer in this call, if any.
531 const LValue *This;
532
533 /// Information on how to find the arguments to this call. Our arguments
534 /// are stored in our parent's CallStackFrame, using the ParmVarDecl* as a
535 /// key and this value as the version.
536 CallRef Arguments;
537
538 /// Source location information about the default argument or default
539 /// initializer expression we're evaluating, if any.
540 CurrentSourceLocExprScope CurSourceLocExprScope;
541
542 // Note that we intentionally use std::map here so that references to
543 // values are stable.
544 typedef std::pair<const void *, unsigned> MapKeyTy;
545 typedef std::map<MapKeyTy, APValue> MapTy;
546 /// Temporaries - Temporary lvalues materialized within this stack frame.
547 MapTy Temporaries;
548
549 /// CallLoc - The location of the call expression for this call.
550 SourceLocation CallLoc;
551
552 /// Index - The call index of this call.
553 unsigned Index;
554
555 /// The stack of integers for tracking version numbers for temporaries.
556 SmallVector<unsigned, 2> TempVersionStack = {1};
557 unsigned CurTempVersion = TempVersionStack.back();
558
559 unsigned getTempVersion() const { return TempVersionStack.back(); }
560
561 void pushTempVersion() {
562 TempVersionStack.push_back(++CurTempVersion);
563 }
564
565 void popTempVersion() {
566 TempVersionStack.pop_back();
567 }
568
569 CallRef createCall(const FunctionDecl *Callee) {
570 return {Callee, Index, ++CurTempVersion};
571 }
572
573 // FIXME: Adding this to every 'CallStackFrame' may have a nontrivial impact
574 // on the overall stack usage of deeply-recursing constexpr evaluations.
575 // (We should cache this map rather than recomputing it repeatedly.)
576 // But let's try this and see how it goes; we can look into caching the map
577 // as a later change.
578
579 /// LambdaCaptureFields - Mapping from captured variables/this to
580 /// corresponding data members in the closure class.
581 llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
582 FieldDecl *LambdaThisCaptureField;
583
584 CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
585 const FunctionDecl *Callee, const LValue *This,
586 CallRef Arguments);
587 ~CallStackFrame();
588
589 // Return the temporary for Key whose version number is Version.
590 APValue *getTemporary(const void *Key, unsigned Version) {
591 MapKeyTy KV(Key, Version);
592 auto LB = Temporaries.lower_bound(KV);
593 if (LB != Temporaries.end() && LB->first == KV)
594 return &LB->second;
595 // Pair (Key,Version) wasn't found in the map. Check that no elements
596 // in the map have 'Key' as their key.
597 assert((LB == Temporaries.end() || LB->first.first != Key) &&(static_cast <bool> ((LB == Temporaries.end() || LB->
first.first != Key) && (LB == Temporaries.begin() || std
::prev(LB)->first.first != Key) && "Element with key 'Key' found in map"
) ? void (0) : __assert_fail ("(LB == Temporaries.end() || LB->first.first != Key) && (LB == Temporaries.begin() || std::prev(LB)->first.first != Key) && \"Element with key 'Key' found in map\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 599, __extension__ __PRETTY_FUNCTION__))
598 (LB == Temporaries.begin() || std::prev(LB)->first.first != Key) &&(static_cast <bool> ((LB == Temporaries.end() || LB->
first.first != Key) && (LB == Temporaries.begin() || std
::prev(LB)->first.first != Key) && "Element with key 'Key' found in map"
) ? void (0) : __assert_fail ("(LB == Temporaries.end() || LB->first.first != Key) && (LB == Temporaries.begin() || std::prev(LB)->first.first != Key) && \"Element with key 'Key' found in map\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 599, __extension__ __PRETTY_FUNCTION__))
599 "Element with key 'Key' found in map")(static_cast <bool> ((LB == Temporaries.end() || LB->
first.first != Key) && (LB == Temporaries.begin() || std
::prev(LB)->first.first != Key) && "Element with key 'Key' found in map"
) ? void (0) : __assert_fail ("(LB == Temporaries.end() || LB->first.first != Key) && (LB == Temporaries.begin() || std::prev(LB)->first.first != Key) && \"Element with key 'Key' found in map\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 599, __extension__ __PRETTY_FUNCTION__))
;
600 return nullptr;
601 }
602
603 // Return the current temporary for Key in the map.
604 APValue *getCurrentTemporary(const void *Key) {
605 auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX(2147483647 *2U +1U)));
606 if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
607 return &std::prev(UB)->second;
608 return nullptr;
609 }
610
611 // Return the version number of the current temporary for Key.
612 unsigned getCurrentTemporaryVersion(const void *Key) const {
613 auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX(2147483647 *2U +1U)));
614 if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
615 return std::prev(UB)->first.second;
616 return 0;
617 }
618
619 /// Allocate storage for an object of type T in this stack frame.
620 /// Populates LV with a handle to the created object. Key identifies
621 /// the temporary within the stack frame, and must not be reused without
622 /// bumping the temporary version number.
623 template<typename KeyT>
624 APValue &createTemporary(const KeyT *Key, QualType T,
625 ScopeKind Scope, LValue &LV);
626
627 /// Allocate storage for a parameter of a function call made in this frame.
628 APValue &createParam(CallRef Args, const ParmVarDecl *PVD, LValue &LV);
629
630 void describe(llvm::raw_ostream &OS) override;
631
632 Frame *getCaller() const override { return Caller; }
633 SourceLocation getCallLocation() const override { return CallLoc; }
634 const FunctionDecl *getCallee() const override { return Callee; }
635
636 bool isStdFunction() const {
637 for (const DeclContext *DC = Callee; DC; DC = DC->getParent())
638 if (DC->isStdNamespace())
639 return true;
640 return false;
641 }
642
643 private:
644 APValue &createLocal(APValue::LValueBase Base, const void *Key, QualType T,
645 ScopeKind Scope);
646 };
647
648 /// Temporarily override 'this'.
649 class ThisOverrideRAII {
650 public:
651 ThisOverrideRAII(CallStackFrame &Frame, const LValue *NewThis, bool Enable)
652 : Frame(Frame), OldThis(Frame.This) {
653 if (Enable)
654 Frame.This = NewThis;
655 }
656 ~ThisOverrideRAII() {
657 Frame.This = OldThis;
658 }
659 private:
660 CallStackFrame &Frame;
661 const LValue *OldThis;
662 };
663}
664
665static bool HandleDestruction(EvalInfo &Info, const Expr *E,
666 const LValue &This, QualType ThisType);
667static bool HandleDestruction(EvalInfo &Info, SourceLocation Loc,
668 APValue::LValueBase LVBase, APValue &Value,
669 QualType T);
670
671namespace {
672 /// A cleanup, and a flag indicating whether it is lifetime-extended.
673 class Cleanup {
674 llvm::PointerIntPair<APValue*, 2, ScopeKind> Value;
675 APValue::LValueBase Base;
676 QualType T;
677
678 public:
679 Cleanup(APValue *Val, APValue::LValueBase Base, QualType T,
680 ScopeKind Scope)
681 : Value(Val, Scope), Base(Base), T(T) {}
682
683 /// Determine whether this cleanup should be performed at the end of the
684 /// given kind of scope.
685 bool isDestroyedAtEndOf(ScopeKind K) const {
686 return (int)Value.getInt() >= (int)K;
687 }
688 bool endLifetime(EvalInfo &Info, bool RunDestructors) {
689 if (RunDestructors) {
690 SourceLocation Loc;
691 if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
692 Loc = VD->getLocation();
693 else if (const Expr *E = Base.dyn_cast<const Expr*>())
694 Loc = E->getExprLoc();
695 return HandleDestruction(Info, Loc, Base, *Value.getPointer(), T);
696 }
697 *Value.getPointer() = APValue();
698 return true;
699 }
700
701 bool hasSideEffect() {
702 return T.isDestructedType();
703 }
704 };
705
706 /// A reference to an object whose construction we are currently evaluating.
707 struct ObjectUnderConstruction {
708 APValue::LValueBase Base;
709 ArrayRef<APValue::LValuePathEntry> Path;
710 friend bool operator==(const ObjectUnderConstruction &LHS,
711 const ObjectUnderConstruction &RHS) {
712 return LHS.Base == RHS.Base && LHS.Path == RHS.Path;
713 }
714 friend llvm::hash_code hash_value(const ObjectUnderConstruction &Obj) {
715 return llvm::hash_combine(Obj.Base, Obj.Path);
716 }
717 };
718 enum class ConstructionPhase {
719 None,
720 Bases,
721 AfterBases,
722 AfterFields,
723 Destroying,
724 DestroyingBases
725 };
726}
727
728namespace llvm {
729template<> struct DenseMapInfo<ObjectUnderConstruction> {
730 using Base = DenseMapInfo<APValue::LValueBase>;
731 static ObjectUnderConstruction getEmptyKey() {
732 return {Base::getEmptyKey(), {}}; }
733 static ObjectUnderConstruction getTombstoneKey() {
734 return {Base::getTombstoneKey(), {}};
735 }
736 static unsigned getHashValue(const ObjectUnderConstruction &Object) {
737 return hash_value(Object);
738 }
739 static bool isEqual(const ObjectUnderConstruction &LHS,
740 const ObjectUnderConstruction &RHS) {
741 return LHS == RHS;
742 }
743};
744}
745
746namespace {
747 /// A dynamically-allocated heap object.
748 struct DynAlloc {
749 /// The value of this heap-allocated object.
750 APValue Value;
751 /// The allocating expression; used for diagnostics. Either a CXXNewExpr
752 /// or a CallExpr (the latter is for direct calls to operator new inside
753 /// std::allocator<T>::allocate).
754 const Expr *AllocExpr = nullptr;
755
756 enum Kind {
757 New,
758 ArrayNew,
759 StdAllocator
760 };
761
762 /// Get the kind of the allocation. This must match between allocation
763 /// and deallocation.
764 Kind getKind() const {
765 if (auto *NE = dyn_cast<CXXNewExpr>(AllocExpr))
766 return NE->isArray() ? ArrayNew : New;
767 assert(isa<CallExpr>(AllocExpr))(static_cast <bool> (isa<CallExpr>(AllocExpr)) ? void
(0) : __assert_fail ("isa<CallExpr>(AllocExpr)", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 767, __extension__ __PRETTY_FUNCTION__))
;
768 return StdAllocator;
769 }
770 };
771
772 struct DynAllocOrder {
773 bool operator()(DynamicAllocLValue L, DynamicAllocLValue R) const {
774 return L.getIndex() < R.getIndex();
775 }
776 };
777
778 /// EvalInfo - This is a private struct used by the evaluator to capture
779 /// information about a subexpression as it is folded. It retains information
780 /// about the AST context, but also maintains information about the folded
781 /// expression.
782 ///
783 /// If an expression could be evaluated, it is still possible it is not a C
784 /// "integer constant expression" or constant expression. If not, this struct
785 /// captures information about how and why not.
786 ///
787 /// One bit of information passed *into* the request for constant folding
788 /// indicates whether the subexpression is "evaluated" or not according to C
789 /// rules. For example, the RHS of (0 && foo()) is not evaluated. We can
790 /// evaluate the expression regardless of what the RHS is, but C only allows
791 /// certain things in certain situations.
792 class EvalInfo : public interp::State {
793 public:
794 ASTContext &Ctx;
795
796 /// EvalStatus - Contains information about the evaluation.
797 Expr::EvalStatus &EvalStatus;
798
799 /// CurrentCall - The top of the constexpr call stack.
800 CallStackFrame *CurrentCall;
801
802 /// CallStackDepth - The number of calls in the call stack right now.
803 unsigned CallStackDepth;
804
805 /// NextCallIndex - The next call index to assign.
806 unsigned NextCallIndex;
807
808 /// StepsLeft - The remaining number of evaluation steps we're permitted
809 /// to perform. This is essentially a limit for the number of statements
810 /// we will evaluate.
811 unsigned StepsLeft;
812
813 /// Enable the experimental new constant interpreter. If an expression is
814 /// not supported by the interpreter, an error is triggered.
815 bool EnableNewConstInterp;
816
817 /// BottomFrame - The frame in which evaluation started. This must be
818 /// initialized after CurrentCall and CallStackDepth.
819 CallStackFrame BottomFrame;
820
821 /// A stack of values whose lifetimes end at the end of some surrounding
822 /// evaluation frame.
823 llvm::SmallVector<Cleanup, 16> CleanupStack;
824
825 /// EvaluatingDecl - This is the declaration whose initializer is being
826 /// evaluated, if any.
827 APValue::LValueBase EvaluatingDecl;
828
829 enum class EvaluatingDeclKind {
830 None,
831 /// We're evaluating the construction of EvaluatingDecl.
832 Ctor,
833 /// We're evaluating the destruction of EvaluatingDecl.
834 Dtor,
835 };
836 EvaluatingDeclKind IsEvaluatingDecl = EvaluatingDeclKind::None;
837
838 /// EvaluatingDeclValue - This is the value being constructed for the
839 /// declaration whose initializer is being evaluated, if any.
840 APValue *EvaluatingDeclValue;
841
842 /// Set of objects that are currently being constructed.
843 llvm::DenseMap<ObjectUnderConstruction, ConstructionPhase>
844 ObjectsUnderConstruction;
845
846 /// Current heap allocations, along with the location where each was
847 /// allocated. We use std::map here because we need stable addresses
848 /// for the stored APValues.
849 std::map<DynamicAllocLValue, DynAlloc, DynAllocOrder> HeapAllocs;
850
851 /// The number of heap allocations performed so far in this evaluation.
852 unsigned NumHeapAllocs = 0;
853
854 struct EvaluatingConstructorRAII {
855 EvalInfo &EI;
856 ObjectUnderConstruction Object;
857 bool DidInsert;
858 EvaluatingConstructorRAII(EvalInfo &EI, ObjectUnderConstruction Object,
859 bool HasBases)
860 : EI(EI), Object(Object) {
861 DidInsert =
862 EI.ObjectsUnderConstruction
863 .insert({Object, HasBases ? ConstructionPhase::Bases
864 : ConstructionPhase::AfterBases})
865 .second;
866 }
867 void finishedConstructingBases() {
868 EI.ObjectsUnderConstruction[Object] = ConstructionPhase::AfterBases;
869 }
870 void finishedConstructingFields() {
871 EI.ObjectsUnderConstruction[Object] = ConstructionPhase::AfterFields;
872 }
873 ~EvaluatingConstructorRAII() {
874 if (DidInsert) EI.ObjectsUnderConstruction.erase(Object);
875 }
876 };
877
878 struct EvaluatingDestructorRAII {
879 EvalInfo &EI;
880 ObjectUnderConstruction Object;
881 bool DidInsert;
882 EvaluatingDestructorRAII(EvalInfo &EI, ObjectUnderConstruction Object)
883 : EI(EI), Object(Object) {
884 DidInsert = EI.ObjectsUnderConstruction
885 .insert({Object, ConstructionPhase::Destroying})
886 .second;
887 }
888 void startedDestroyingBases() {
889 EI.ObjectsUnderConstruction[Object] =
890 ConstructionPhase::DestroyingBases;
891 }
892 ~EvaluatingDestructorRAII() {
893 if (DidInsert)
894 EI.ObjectsUnderConstruction.erase(Object);
895 }
896 };
897
898 ConstructionPhase
899 isEvaluatingCtorDtor(APValue::LValueBase Base,
900 ArrayRef<APValue::LValuePathEntry> Path) {
901 return ObjectsUnderConstruction.lookup({Base, Path});
902 }
903
904 /// If we're currently speculatively evaluating, the outermost call stack
905 /// depth at which we can mutate state, otherwise 0.
906 unsigned SpeculativeEvaluationDepth = 0;
907
908 /// The current array initialization index, if we're performing array
909 /// initialization.
910 uint64_t ArrayInitIndex = -1;
911
912 /// HasActiveDiagnostic - Was the previous diagnostic stored? If so, further
913 /// notes attached to it will also be stored, otherwise they will not be.
914 bool HasActiveDiagnostic;
915
916 /// Have we emitted a diagnostic explaining why we couldn't constant
917 /// fold (not just why it's not strictly a constant expression)?
918 bool HasFoldFailureDiagnostic;
919
920 /// Whether or not we're in a context where the front end requires a
921 /// constant value.
922 bool InConstantContext;
923
924 /// Whether we're checking that an expression is a potential constant
925 /// expression. If so, do not fail on constructs that could become constant
926 /// later on (such as a use of an undefined global).
927 bool CheckingPotentialConstantExpression = false;
928
929 /// Whether we're checking for an expression that has undefined behavior.
930 /// If so, we will produce warnings if we encounter an operation that is
931 /// always undefined.
932 ///
933 /// Note that we still need to evaluate the expression normally when this
934 /// is set; this is used when evaluating ICEs in C.
935 bool CheckingForUndefinedBehavior = false;
936
937 enum EvaluationMode {
938 /// Evaluate as a constant expression. Stop if we find that the expression
939 /// is not a constant expression.
940 EM_ConstantExpression,
941
942 /// Evaluate as a constant expression. Stop if we find that the expression
943 /// is not a constant expression. Some expressions can be retried in the
944 /// optimizer if we don't constant fold them here, but in an unevaluated
945 /// context we try to fold them immediately since the optimizer never
946 /// gets a chance to look at it.
947 EM_ConstantExpressionUnevaluated,
948
949 /// Fold the expression to a constant. Stop if we hit a side-effect that
950 /// we can't model.
951 EM_ConstantFold,
952
953 /// Evaluate in any way we know how. Don't worry about side-effects that
954 /// can't be modeled.
955 EM_IgnoreSideEffects,
956 } EvalMode;
957
958 /// Are we checking whether the expression is a potential constant
959 /// expression?
960 bool checkingPotentialConstantExpression() const override {
961 return CheckingPotentialConstantExpression;
962 }
963
964 /// Are we checking an expression for overflow?
965 // FIXME: We should check for any kind of undefined or suspicious behavior
966 // in such constructs, not just overflow.
967 bool checkingForUndefinedBehavior() const override {
968 return CheckingForUndefinedBehavior;
969 }
970
971 EvalInfo(const ASTContext &C, Expr::EvalStatus &S, EvaluationMode Mode)
972 : Ctx(const_cast<ASTContext &>(C)), EvalStatus(S), CurrentCall(nullptr),
973 CallStackDepth(0), NextCallIndex(1),
974 StepsLeft(C.getLangOpts().ConstexprStepLimit),
975 EnableNewConstInterp(C.getLangOpts().EnableNewConstInterp),
976 BottomFrame(*this, SourceLocation(), nullptr, nullptr, CallRef()),
977 EvaluatingDecl((const ValueDecl *)nullptr),
978 EvaluatingDeclValue(nullptr), HasActiveDiagnostic(false),
979 HasFoldFailureDiagnostic(false), InConstantContext(false),
980 EvalMode(Mode) {}
981
982 ~EvalInfo() {
983 discardCleanups();
984 }
985
986 void setEvaluatingDecl(APValue::LValueBase Base, APValue &Value,
987 EvaluatingDeclKind EDK = EvaluatingDeclKind::Ctor) {
988 EvaluatingDecl = Base;
989 IsEvaluatingDecl = EDK;
990 EvaluatingDeclValue = &Value;
991 }
992
993 bool CheckCallLimit(SourceLocation Loc) {
994 // Don't perform any constexpr calls (other than the call we're checking)
995 // when checking a potential constant expression.
996 if (checkingPotentialConstantExpression() && CallStackDepth > 1)
997 return false;
998 if (NextCallIndex == 0) {
999 // NextCallIndex has wrapped around.
1000 FFDiag(Loc, diag::note_constexpr_call_limit_exceeded);
1001 return false;
1002 }
1003 if (CallStackDepth <= getLangOpts().ConstexprCallDepth)
1004 return true;
1005 FFDiag(Loc, diag::note_constexpr_depth_limit_exceeded)
1006 << getLangOpts().ConstexprCallDepth;
1007 return false;
1008 }
1009
1010 std::pair<CallStackFrame *, unsigned>
1011 getCallFrameAndDepth(unsigned CallIndex) {
1012 assert(CallIndex && "no call index in getCallFrameAndDepth")(static_cast <bool> (CallIndex && "no call index in getCallFrameAndDepth"
) ? void (0) : __assert_fail ("CallIndex && \"no call index in getCallFrameAndDepth\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1012, __extension__ __PRETTY_FUNCTION__))
;
1013 // We will eventually hit BottomFrame, which has Index 1, so Frame can't
1014 // be null in this loop.
1015 unsigned Depth = CallStackDepth;
1016 CallStackFrame *Frame = CurrentCall;
1017 while (Frame->Index > CallIndex) {
1018 Frame = Frame->Caller;
1019 --Depth;
1020 }
1021 if (Frame->Index == CallIndex)
1022 return {Frame, Depth};
1023 return {nullptr, 0};
1024 }
1025
1026 bool nextStep(const Stmt *S) {
1027 if (!StepsLeft) {
1028 FFDiag(S->getBeginLoc(), diag::note_constexpr_step_limit_exceeded);
1029 return false;
1030 }
1031 --StepsLeft;
1032 return true;
1033 }
1034
1035 APValue *createHeapAlloc(const Expr *E, QualType T, LValue &LV);
1036
1037 Optional<DynAlloc*> lookupDynamicAlloc(DynamicAllocLValue DA) {
1038 Optional<DynAlloc*> Result;
1039 auto It = HeapAllocs.find(DA);
1040 if (It != HeapAllocs.end())
1041 Result = &It->second;
1042 return Result;
1043 }
1044
1045 /// Get the allocated storage for the given parameter of the given call.
1046 APValue *getParamSlot(CallRef Call, const ParmVarDecl *PVD) {
1047 CallStackFrame *Frame = getCallFrameAndDepth(Call.CallIndex).first;
1048 return Frame ? Frame->getTemporary(Call.getOrigParam(PVD), Call.Version)
1049 : nullptr;
1050 }
1051
1052 /// Information about a stack frame for std::allocator<T>::[de]allocate.
1053 struct StdAllocatorCaller {
1054 unsigned FrameIndex;
1055 QualType ElemType;
1056 explicit operator bool() const { return FrameIndex != 0; };
1057 };
1058
1059 StdAllocatorCaller getStdAllocatorCaller(StringRef FnName) const {
1060 for (const CallStackFrame *Call = CurrentCall; Call != &BottomFrame;
1061 Call = Call->Caller) {
1062 const auto *MD = dyn_cast_or_null<CXXMethodDecl>(Call->Callee);
1063 if (!MD)
1064 continue;
1065 const IdentifierInfo *FnII = MD->getIdentifier();
1066 if (!FnII || !FnII->isStr(FnName))
1067 continue;
1068
1069 const auto *CTSD =
1070 dyn_cast<ClassTemplateSpecializationDecl>(MD->getParent());
1071 if (!CTSD)
1072 continue;
1073
1074 const IdentifierInfo *ClassII = CTSD->getIdentifier();
1075 const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
1076 if (CTSD->isInStdNamespace() && ClassII &&
1077 ClassII->isStr("allocator") && TAL.size() >= 1 &&
1078 TAL[0].getKind() == TemplateArgument::Type)
1079 return {Call->Index, TAL[0].getAsType()};
1080 }
1081
1082 return {};
1083 }
1084
1085 void performLifetimeExtension() {
1086 // Disable the cleanups for lifetime-extended temporaries.
1087 CleanupStack.erase(std::remove_if(CleanupStack.begin(),
1088 CleanupStack.end(),
1089 [](Cleanup &C) {
1090 return !C.isDestroyedAtEndOf(
1091 ScopeKind::FullExpression);
1092 }),
1093 CleanupStack.end());
1094 }
1095
1096 /// Throw away any remaining cleanups at the end of evaluation. If any
1097 /// cleanups would have had a side-effect, note that as an unmodeled
1098 /// side-effect and return false. Otherwise, return true.
1099 bool discardCleanups() {
1100 for (Cleanup &C : CleanupStack) {
1101 if (C.hasSideEffect() && !noteSideEffect()) {
1102 CleanupStack.clear();
1103 return false;
1104 }
1105 }
1106 CleanupStack.clear();
1107 return true;
1108 }
1109
1110 private:
1111 interp::Frame *getCurrentFrame() override { return CurrentCall; }
1112 const interp::Frame *getBottomFrame() const override { return &BottomFrame; }
1113
1114 bool hasActiveDiagnostic() override { return HasActiveDiagnostic; }
1115 void setActiveDiagnostic(bool Flag) override { HasActiveDiagnostic = Flag; }
1116
1117 void setFoldFailureDiagnostic(bool Flag) override {
1118 HasFoldFailureDiagnostic = Flag;
1119 }
1120
1121 Expr::EvalStatus &getEvalStatus() const override { return EvalStatus; }
1122
1123 ASTContext &getCtx() const override { return Ctx; }
1124
1125 // If we have a prior diagnostic, it will be noting that the expression
1126 // isn't a constant expression. This diagnostic is more important,
1127 // unless we require this evaluation to produce a constant expression.
1128 //
1129 // FIXME: We might want to show both diagnostics to the user in
1130 // EM_ConstantFold mode.
1131 bool hasPriorDiagnostic() override {
1132 if (!EvalStatus.Diag->empty()) {
1133 switch (EvalMode) {
1134 case EM_ConstantFold:
1135 case EM_IgnoreSideEffects:
1136 if (!HasFoldFailureDiagnostic)
1137 break;
1138 // We've already failed to fold something. Keep that diagnostic.
1139 LLVM_FALLTHROUGH[[gnu::fallthrough]];
1140 case EM_ConstantExpression:
1141 case EM_ConstantExpressionUnevaluated:
1142 setActiveDiagnostic(false);
1143 return true;
1144 }
1145 }
1146 return false;
1147 }
1148
1149 unsigned getCallStackDepth() override { return CallStackDepth; }
1150
1151 public:
1152 /// Should we continue evaluation after encountering a side-effect that we
1153 /// couldn't model?
1154 bool keepEvaluatingAfterSideEffect() {
1155 switch (EvalMode) {
1156 case EM_IgnoreSideEffects:
1157 return true;
1158
1159 case EM_ConstantExpression:
1160 case EM_ConstantExpressionUnevaluated:
1161 case EM_ConstantFold:
1162 // By default, assume any side effect might be valid in some other
1163 // evaluation of this expression from a different context.
1164 return checkingPotentialConstantExpression() ||
1165 checkingForUndefinedBehavior();
1166 }
1167 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1167)
;
1168 }
1169
1170 /// Note that we have had a side-effect, and determine whether we should
1171 /// keep evaluating.
1172 bool noteSideEffect() {
1173 EvalStatus.HasSideEffects = true;
1174 return keepEvaluatingAfterSideEffect();
1175 }
1176
1177 /// Should we continue evaluation after encountering undefined behavior?
1178 bool keepEvaluatingAfterUndefinedBehavior() {
1179 switch (EvalMode) {
1180 case EM_IgnoreSideEffects:
1181 case EM_ConstantFold:
1182 return true;
1183
1184 case EM_ConstantExpression:
1185 case EM_ConstantExpressionUnevaluated:
1186 return checkingForUndefinedBehavior();
1187 }
1188 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1188)
;
1189 }
1190
1191 /// Note that we hit something that was technically undefined behavior, but
1192 /// that we can evaluate past it (such as signed overflow or floating-point
1193 /// division by zero.)
1194 bool noteUndefinedBehavior() override {
1195 EvalStatus.HasUndefinedBehavior = true;
1196 return keepEvaluatingAfterUndefinedBehavior();
1197 }
1198
1199 /// Should we continue evaluation as much as possible after encountering a
1200 /// construct which can't be reduced to a value?
1201 bool keepEvaluatingAfterFailure() const override {
1202 if (!StepsLeft)
1203 return false;
1204
1205 switch (EvalMode) {
1206 case EM_ConstantExpression:
1207 case EM_ConstantExpressionUnevaluated:
1208 case EM_ConstantFold:
1209 case EM_IgnoreSideEffects:
1210 return checkingPotentialConstantExpression() ||
1211 checkingForUndefinedBehavior();
1212 }
1213 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1213)
;
1214 }
1215
1216 /// Notes that we failed to evaluate an expression that other expressions
1217 /// directly depend on, and determine if we should keep evaluating. This
1218 /// should only be called if we actually intend to keep evaluating.
1219 ///
1220 /// Call noteSideEffect() instead if we may be able to ignore the value that
1221 /// we failed to evaluate, e.g. if we failed to evaluate Foo() in:
1222 ///
1223 /// (Foo(), 1) // use noteSideEffect
1224 /// (Foo() || true) // use noteSideEffect
1225 /// Foo() + 1 // use noteFailure
1226 LLVM_NODISCARD[[clang::warn_unused_result]] bool noteFailure() {
1227 // Failure when evaluating some expression often means there is some
1228 // subexpression whose evaluation was skipped. Therefore, (because we
1229 // don't track whether we skipped an expression when unwinding after an
1230 // evaluation failure) every evaluation failure that bubbles up from a
1231 // subexpression implies that a side-effect has potentially happened. We
1232 // skip setting the HasSideEffects flag to true until we decide to
1233 // continue evaluating after that point, which happens here.
1234 bool KeepGoing = keepEvaluatingAfterFailure();
1235 EvalStatus.HasSideEffects |= KeepGoing;
1236 return KeepGoing;
1237 }
1238
1239 class ArrayInitLoopIndex {
1240 EvalInfo &Info;
1241 uint64_t OuterIndex;
1242
1243 public:
1244 ArrayInitLoopIndex(EvalInfo &Info)
1245 : Info(Info), OuterIndex(Info.ArrayInitIndex) {
1246 Info.ArrayInitIndex = 0;
1247 }
1248 ~ArrayInitLoopIndex() { Info.ArrayInitIndex = OuterIndex; }
1249
1250 operator uint64_t&() { return Info.ArrayInitIndex; }
1251 };
1252 };
1253
1254 /// Object used to treat all foldable expressions as constant expressions.
1255 struct FoldConstant {
1256 EvalInfo &Info;
1257 bool Enabled;
1258 bool HadNoPriorDiags;
1259 EvalInfo::EvaluationMode OldMode;
1260
1261 explicit FoldConstant(EvalInfo &Info, bool Enabled)
1262 : Info(Info),
1263 Enabled(Enabled),
1264 HadNoPriorDiags(Info.EvalStatus.Diag &&
1265 Info.EvalStatus.Diag->empty() &&
1266 !Info.EvalStatus.HasSideEffects),
1267 OldMode(Info.EvalMode) {
1268 if (Enabled)
1269 Info.EvalMode = EvalInfo::EM_ConstantFold;
1270 }
1271 void keepDiagnostics() { Enabled = false; }
1272 ~FoldConstant() {
1273 if (Enabled && HadNoPriorDiags && !Info.EvalStatus.Diag->empty() &&
1274 !Info.EvalStatus.HasSideEffects)
1275 Info.EvalStatus.Diag->clear();
1276 Info.EvalMode = OldMode;
1277 }
1278 };
1279
1280 /// RAII object used to set the current evaluation mode to ignore
1281 /// side-effects.
1282 struct IgnoreSideEffectsRAII {
1283 EvalInfo &Info;
1284 EvalInfo::EvaluationMode OldMode;
1285 explicit IgnoreSideEffectsRAII(EvalInfo &Info)
1286 : Info(Info), OldMode(Info.EvalMode) {
1287 Info.EvalMode = EvalInfo::EM_IgnoreSideEffects;
1288 }
1289
1290 ~IgnoreSideEffectsRAII() { Info.EvalMode = OldMode; }
1291 };
1292
1293 /// RAII object used to optionally suppress diagnostics and side-effects from
1294 /// a speculative evaluation.
1295 class SpeculativeEvaluationRAII {
1296 EvalInfo *Info = nullptr;
1297 Expr::EvalStatus OldStatus;
1298 unsigned OldSpeculativeEvaluationDepth;
1299
1300 void moveFromAndCancel(SpeculativeEvaluationRAII &&Other) {
1301 Info = Other.Info;
1302 OldStatus = Other.OldStatus;
1303 OldSpeculativeEvaluationDepth = Other.OldSpeculativeEvaluationDepth;
1304 Other.Info = nullptr;
1305 }
1306
1307 void maybeRestoreState() {
1308 if (!Info)
1309 return;
1310
1311 Info->EvalStatus = OldStatus;
1312 Info->SpeculativeEvaluationDepth = OldSpeculativeEvaluationDepth;
1313 }
1314
1315 public:
1316 SpeculativeEvaluationRAII() = default;
1317
1318 SpeculativeEvaluationRAII(
1319 EvalInfo &Info, SmallVectorImpl<PartialDiagnosticAt> *NewDiag = nullptr)
1320 : Info(&Info), OldStatus(Info.EvalStatus),
1321 OldSpeculativeEvaluationDepth(Info.SpeculativeEvaluationDepth) {
1322 Info.EvalStatus.Diag = NewDiag;
1323 Info.SpeculativeEvaluationDepth = Info.CallStackDepth + 1;
1324 }
1325
1326 SpeculativeEvaluationRAII(const SpeculativeEvaluationRAII &Other) = delete;
1327 SpeculativeEvaluationRAII(SpeculativeEvaluationRAII &&Other) {
1328 moveFromAndCancel(std::move(Other));
1329 }
1330
1331 SpeculativeEvaluationRAII &operator=(SpeculativeEvaluationRAII &&Other) {
1332 maybeRestoreState();
1333 moveFromAndCancel(std::move(Other));
1334 return *this;
1335 }
1336
1337 ~SpeculativeEvaluationRAII() { maybeRestoreState(); }
1338 };
1339
1340 /// RAII object wrapping a full-expression or block scope, and handling
1341 /// the ending of the lifetime of temporaries created within it.
1342 template<ScopeKind Kind>
1343 class ScopeRAII {
1344 EvalInfo &Info;
1345 unsigned OldStackSize;
1346 public:
1347 ScopeRAII(EvalInfo &Info)
1348 : Info(Info), OldStackSize(Info.CleanupStack.size()) {
1349 // Push a new temporary version. This is needed to distinguish between
1350 // temporaries created in different iterations of a loop.
1351 Info.CurrentCall->pushTempVersion();
1352 }
1353 bool destroy(bool RunDestructors = true) {
1354 bool OK = cleanup(Info, RunDestructors, OldStackSize);
1355 OldStackSize = -1U;
1356 return OK;
1357 }
1358 ~ScopeRAII() {
1359 if (OldStackSize != -1U)
1360 destroy(false);
1361 // Body moved to a static method to encourage the compiler to inline away
1362 // instances of this class.
1363 Info.CurrentCall->popTempVersion();
1364 }
1365 private:
1366 static bool cleanup(EvalInfo &Info, bool RunDestructors,
1367 unsigned OldStackSize) {
1368 assert(OldStackSize <= Info.CleanupStack.size() &&(static_cast <bool> (OldStackSize <= Info.CleanupStack
.size() && "running cleanups out of order?") ? void (
0) : __assert_fail ("OldStackSize <= Info.CleanupStack.size() && \"running cleanups out of order?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1369, __extension__ __PRETTY_FUNCTION__))
1369 "running cleanups out of order?")(static_cast <bool> (OldStackSize <= Info.CleanupStack
.size() && "running cleanups out of order?") ? void (
0) : __assert_fail ("OldStackSize <= Info.CleanupStack.size() && \"running cleanups out of order?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1369, __extension__ __PRETTY_FUNCTION__))
;
1370
1371 // Run all cleanups for a block scope, and non-lifetime-extended cleanups
1372 // for a full-expression scope.
1373 bool Success = true;
1374 for (unsigned I = Info.CleanupStack.size(); I > OldStackSize; --I) {
1375 if (Info.CleanupStack[I - 1].isDestroyedAtEndOf(Kind)) {
1376 if (!Info.CleanupStack[I - 1].endLifetime(Info, RunDestructors)) {
1377 Success = false;
1378 break;
1379 }
1380 }
1381 }
1382
1383 // Compact any retained cleanups.
1384 auto NewEnd = Info.CleanupStack.begin() + OldStackSize;
1385 if (Kind != ScopeKind::Block)
1386 NewEnd =
1387 std::remove_if(NewEnd, Info.CleanupStack.end(), [](Cleanup &C) {
1388 return C.isDestroyedAtEndOf(Kind);
1389 });
1390 Info.CleanupStack.erase(NewEnd, Info.CleanupStack.end());
1391 return Success;
1392 }
1393 };
1394 typedef ScopeRAII<ScopeKind::Block> BlockScopeRAII;
1395 typedef ScopeRAII<ScopeKind::FullExpression> FullExpressionRAII;
1396 typedef ScopeRAII<ScopeKind::Call> CallScopeRAII;
1397}
1398
1399bool SubobjectDesignator::checkSubobject(EvalInfo &Info, const Expr *E,
1400 CheckSubobjectKind CSK) {
1401 if (Invalid)
1402 return false;
1403 if (isOnePastTheEnd()) {
1404 Info.CCEDiag(E, diag::note_constexpr_past_end_subobject)
1405 << CSK;
1406 setInvalid();
1407 return false;
1408 }
1409 // Note, we do not diagnose if isMostDerivedAnUnsizedArray(), because there
1410 // must actually be at least one array element; even a VLA cannot have a
1411 // bound of zero. And if our index is nonzero, we already had a CCEDiag.
1412 return true;
1413}
1414
1415void SubobjectDesignator::diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info,
1416 const Expr *E) {
1417 Info.CCEDiag(E, diag::note_constexpr_unsized_array_indexed);
1418 // Do not set the designator as invalid: we can represent this situation,
1419 // and correct handling of __builtin_object_size requires us to do so.
1420}
1421
1422void SubobjectDesignator::diagnosePointerArithmetic(EvalInfo &Info,
1423 const Expr *E,
1424 const APSInt &N) {
1425 // If we're complaining, we must be able to statically determine the size of
1426 // the most derived array.
1427 if (MostDerivedPathLength == Entries.size() && MostDerivedIsArrayElement)
1428 Info.CCEDiag(E, diag::note_constexpr_array_index)
1429 << N << /*array*/ 0
1430 << static_cast<unsigned>(getMostDerivedArraySize());
1431 else
1432 Info.CCEDiag(E, diag::note_constexpr_array_index)
1433 << N << /*non-array*/ 1;
1434 setInvalid();
1435}
1436
1437CallStackFrame::CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
1438 const FunctionDecl *Callee, const LValue *This,
1439 CallRef Call)
1440 : Info(Info), Caller(Info.CurrentCall), Callee(Callee), This(This),
1441 Arguments(Call), CallLoc(CallLoc), Index(Info.NextCallIndex++) {
1442 Info.CurrentCall = this;
1443 ++Info.CallStackDepth;
1444}
1445
1446CallStackFrame::~CallStackFrame() {
1447 assert(Info.CurrentCall == this && "calls retired out of order")(static_cast <bool> (Info.CurrentCall == this &&
"calls retired out of order") ? void (0) : __assert_fail ("Info.CurrentCall == this && \"calls retired out of order\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1447, __extension__ __PRETTY_FUNCTION__))
;
1448 --Info.CallStackDepth;
1449 Info.CurrentCall = Caller;
1450}
1451
1452static bool isRead(AccessKinds AK) {
1453 return AK == AK_Read || AK == AK_ReadObjectRepresentation;
1454}
1455
1456static bool isModification(AccessKinds AK) {
1457 switch (AK) {
1458 case AK_Read:
1459 case AK_ReadObjectRepresentation:
1460 case AK_MemberCall:
1461 case AK_DynamicCast:
1462 case AK_TypeId:
1463 return false;
1464 case AK_Assign:
1465 case AK_Increment:
1466 case AK_Decrement:
1467 case AK_Construct:
1468 case AK_Destroy:
1469 return true;
1470 }
1471 llvm_unreachable("unknown access kind")::llvm::llvm_unreachable_internal("unknown access kind", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1471)
;
1472}
1473
1474static bool isAnyAccess(AccessKinds AK) {
1475 return isRead(AK) || isModification(AK);
1476}
1477
1478/// Is this an access per the C++ definition?
1479static bool isFormalAccess(AccessKinds AK) {
1480 return isAnyAccess(AK) && AK != AK_Construct && AK != AK_Destroy;
1481}
1482
1483/// Is this kind of axcess valid on an indeterminate object value?
1484static bool isValidIndeterminateAccess(AccessKinds AK) {
1485 switch (AK) {
1486 case AK_Read:
1487 case AK_Increment:
1488 case AK_Decrement:
1489 // These need the object's value.
1490 return false;
1491
1492 case AK_ReadObjectRepresentation:
1493 case AK_Assign:
1494 case AK_Construct:
1495 case AK_Destroy:
1496 // Construction and destruction don't need the value.
1497 return true;
1498
1499 case AK_MemberCall:
1500 case AK_DynamicCast:
1501 case AK_TypeId:
1502 // These aren't really meaningful on scalars.
1503 return true;
1504 }
1505 llvm_unreachable("unknown access kind")::llvm::llvm_unreachable_internal("unknown access kind", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1505)
;
1506}
1507
1508namespace {
1509 struct ComplexValue {
1510 private:
1511 bool IsInt;
1512
1513 public:
1514 APSInt IntReal, IntImag;
1515 APFloat FloatReal, FloatImag;
1516
1517 ComplexValue() : FloatReal(APFloat::Bogus()), FloatImag(APFloat::Bogus()) {}
1518
1519 void makeComplexFloat() { IsInt = false; }
1520 bool isComplexFloat() const { return !IsInt; }
1521 APFloat &getComplexFloatReal() { return FloatReal; }
1522 APFloat &getComplexFloatImag() { return FloatImag; }
1523
1524 void makeComplexInt() { IsInt = true; }
1525 bool isComplexInt() const { return IsInt; }
1526 APSInt &getComplexIntReal() { return IntReal; }
1527 APSInt &getComplexIntImag() { return IntImag; }
1528
1529 void moveInto(APValue &v) const {
1530 if (isComplexFloat())
1531 v = APValue(FloatReal, FloatImag);
1532 else
1533 v = APValue(IntReal, IntImag);
1534 }
1535 void setFrom(const APValue &v) {
1536 assert(v.isComplexFloat() || v.isComplexInt())(static_cast <bool> (v.isComplexFloat() || v.isComplexInt
()) ? void (0) : __assert_fail ("v.isComplexFloat() || v.isComplexInt()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1536, __extension__ __PRETTY_FUNCTION__))
;
1537 if (v.isComplexFloat()) {
1538 makeComplexFloat();
1539 FloatReal = v.getComplexFloatReal();
1540 FloatImag = v.getComplexFloatImag();
1541 } else {
1542 makeComplexInt();
1543 IntReal = v.getComplexIntReal();
1544 IntImag = v.getComplexIntImag();
1545 }
1546 }
1547 };
1548
1549 struct LValue {
1550 APValue::LValueBase Base;
1551 CharUnits Offset;
1552 SubobjectDesignator Designator;
1553 bool IsNullPtr : 1;
1554 bool InvalidBase : 1;
1555
1556 const APValue::LValueBase getLValueBase() const { return Base; }
1557 CharUnits &getLValueOffset() { return Offset; }
1558 const CharUnits &getLValueOffset() const { return Offset; }
1559 SubobjectDesignator &getLValueDesignator() { return Designator; }
1560 const SubobjectDesignator &getLValueDesignator() const { return Designator;}
1561 bool isNullPointer() const { return IsNullPtr;}
1562
1563 unsigned getLValueCallIndex() const { return Base.getCallIndex(); }
1564 unsigned getLValueVersion() const { return Base.getVersion(); }
1565
1566 void moveInto(APValue &V) const {
1567 if (Designator.Invalid)
1568 V = APValue(Base, Offset, APValue::NoLValuePath(), IsNullPtr);
1569 else {
1570 assert(!InvalidBase && "APValues can't handle invalid LValue bases")(static_cast <bool> (!InvalidBase && "APValues can't handle invalid LValue bases"
) ? void (0) : __assert_fail ("!InvalidBase && \"APValues can't handle invalid LValue bases\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1570, __extension__ __PRETTY_FUNCTION__))
;
1571 V = APValue(Base, Offset, Designator.Entries,
1572 Designator.IsOnePastTheEnd, IsNullPtr);
1573 }
1574 }
1575 void setFrom(ASTContext &Ctx, const APValue &V) {
1576 assert(V.isLValue() && "Setting LValue from a non-LValue?")(static_cast <bool> (V.isLValue() && "Setting LValue from a non-LValue?"
) ? void (0) : __assert_fail ("V.isLValue() && \"Setting LValue from a non-LValue?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1576, __extension__ __PRETTY_FUNCTION__))
;
1577 Base = V.getLValueBase();
1578 Offset = V.getLValueOffset();
1579 InvalidBase = false;
1580 Designator = SubobjectDesignator(Ctx, V);
1581 IsNullPtr = V.isNullPointer();
1582 }
1583
1584 void set(APValue::LValueBase B, bool BInvalid = false) {
1585#ifndef NDEBUG
1586 // We only allow a few types of invalid bases. Enforce that here.
1587 if (BInvalid) {
1588 const auto *E = B.get<const Expr *>();
1589 assert((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) &&(static_cast <bool> ((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall
(E)) && "Unexpected type of invalid base") ? void (0)
: __assert_fail ("(isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) && \"Unexpected type of invalid base\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1590, __extension__ __PRETTY_FUNCTION__))
1590 "Unexpected type of invalid base")(static_cast <bool> ((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall
(E)) && "Unexpected type of invalid base") ? void (0)
: __assert_fail ("(isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) && \"Unexpected type of invalid base\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1590, __extension__ __PRETTY_FUNCTION__))
;
1591 }
1592#endif
1593
1594 Base = B;
1595 Offset = CharUnits::fromQuantity(0);
1596 InvalidBase = BInvalid;
1597 Designator = SubobjectDesignator(getType(B));
1598 IsNullPtr = false;
1599 }
1600
1601 void setNull(ASTContext &Ctx, QualType PointerTy) {
1602 Base = (const ValueDecl *)nullptr;
1603 Offset =
1604 CharUnits::fromQuantity(Ctx.getTargetNullPointerValue(PointerTy));
1605 InvalidBase = false;
1606 Designator = SubobjectDesignator(PointerTy->getPointeeType());
1607 IsNullPtr = true;
1608 }
1609
1610 void setInvalid(APValue::LValueBase B, unsigned I = 0) {
1611 set(B, true);
1612 }
1613
1614 std::string toString(ASTContext &Ctx, QualType T) const {
1615 APValue Printable;
1616 moveInto(Printable);
1617 return Printable.getAsString(Ctx, T);
1618 }
1619
1620 private:
1621 // Check that this LValue is not based on a null pointer. If it is, produce
1622 // a diagnostic and mark the designator as invalid.
1623 template <typename GenDiagType>
1624 bool checkNullPointerDiagnosingWith(const GenDiagType &GenDiag) {
1625 if (Designator.Invalid)
1626 return false;
1627 if (IsNullPtr) {
1628 GenDiag();
1629 Designator.setInvalid();
1630 return false;
1631 }
1632 return true;
1633 }
1634
1635 public:
1636 bool checkNullPointer(EvalInfo &Info, const Expr *E,
1637 CheckSubobjectKind CSK) {
1638 return checkNullPointerDiagnosingWith([&Info, E, CSK] {
1639 Info.CCEDiag(E, diag::note_constexpr_null_subobject) << CSK;
1640 });
1641 }
1642
1643 bool checkNullPointerForFoldAccess(EvalInfo &Info, const Expr *E,
1644 AccessKinds AK) {
1645 return checkNullPointerDiagnosingWith([&Info, E, AK] {
1646 Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
1647 });
1648 }
1649
1650 // Check this LValue refers to an object. If not, set the designator to be
1651 // invalid and emit a diagnostic.
1652 bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK) {
1653 return (CSK == CSK_ArrayToPointer || checkNullPointer(Info, E, CSK)) &&
1654 Designator.checkSubobject(Info, E, CSK);
1655 }
1656
1657 void addDecl(EvalInfo &Info, const Expr *E,
1658 const Decl *D, bool Virtual = false) {
1659 if (checkSubobject(Info, E, isa<FieldDecl>(D) ? CSK_Field : CSK_Base))
1660 Designator.addDeclUnchecked(D, Virtual);
1661 }
1662 void addUnsizedArray(EvalInfo &Info, const Expr *E, QualType ElemTy) {
1663 if (!Designator.Entries.empty()) {
1664 Info.CCEDiag(E, diag::note_constexpr_unsupported_unsized_array);
1665 Designator.setInvalid();
1666 return;
1667 }
1668 if (checkSubobject(Info, E, CSK_ArrayToPointer)) {
1669 assert(getType(Base)->isPointerType() || getType(Base)->isArrayType())(static_cast <bool> (getType(Base)->isPointerType() ||
getType(Base)->isArrayType()) ? void (0) : __assert_fail (
"getType(Base)->isPointerType() || getType(Base)->isArrayType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1669, __extension__ __PRETTY_FUNCTION__))
;
1670 Designator.FirstEntryIsAnUnsizedArray = true;
1671 Designator.addUnsizedArrayUnchecked(ElemTy);
1672 }
1673 }
1674 void addArray(EvalInfo &Info, const Expr *E, const ConstantArrayType *CAT) {
1675 if (checkSubobject(Info, E, CSK_ArrayToPointer))
1676 Designator.addArrayUnchecked(CAT);
1677 }
1678 void addComplex(EvalInfo &Info, const Expr *E, QualType EltTy, bool Imag) {
1679 if (checkSubobject(Info, E, Imag ? CSK_Imag : CSK_Real))
1680 Designator.addComplexUnchecked(EltTy, Imag);
1681 }
1682 void clearIsNullPointer() {
1683 IsNullPtr = false;
1684 }
1685 void adjustOffsetAndIndex(EvalInfo &Info, const Expr *E,
1686 const APSInt &Index, CharUnits ElementSize) {
1687 // An index of 0 has no effect. (In C, adding 0 to a null pointer is UB,
1688 // but we're not required to diagnose it and it's valid in C++.)
1689 if (!Index)
1690 return;
1691
1692 // Compute the new offset in the appropriate width, wrapping at 64 bits.
1693 // FIXME: When compiling for a 32-bit target, we should use 32-bit
1694 // offsets.
1695 uint64_t Offset64 = Offset.getQuantity();
1696 uint64_t ElemSize64 = ElementSize.getQuantity();
1697 uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
1698 Offset = CharUnits::fromQuantity(Offset64 + ElemSize64 * Index64);
1699
1700 if (checkNullPointer(Info, E, CSK_ArrayIndex))
1701 Designator.adjustIndex(Info, E, Index);
1702 clearIsNullPointer();
1703 }
1704 void adjustOffset(CharUnits N) {
1705 Offset += N;
1706 if (N.getQuantity())
1707 clearIsNullPointer();
1708 }
1709 };
1710
1711 struct MemberPtr {
1712 MemberPtr() {}
1713 explicit MemberPtr(const ValueDecl *Decl) :
1714 DeclAndIsDerivedMember(Decl, false), Path() {}
1715
1716 /// The member or (direct or indirect) field referred to by this member
1717 /// pointer, or 0 if this is a null member pointer.
1718 const ValueDecl *getDecl() const {
1719 return DeclAndIsDerivedMember.getPointer();
1720 }
1721 /// Is this actually a member of some type derived from the relevant class?
1722 bool isDerivedMember() const {
1723 return DeclAndIsDerivedMember.getInt();
1724 }
1725 /// Get the class which the declaration actually lives in.
1726 const CXXRecordDecl *getContainingRecord() const {
1727 return cast<CXXRecordDecl>(
1728 DeclAndIsDerivedMember.getPointer()->getDeclContext());
1729 }
1730
1731 void moveInto(APValue &V) const {
1732 V = APValue(getDecl(), isDerivedMember(), Path);
1733 }
1734 void setFrom(const APValue &V) {
1735 assert(V.isMemberPointer())(static_cast <bool> (V.isMemberPointer()) ? void (0) : __assert_fail
("V.isMemberPointer()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1735, __extension__ __PRETTY_FUNCTION__))
;
1736 DeclAndIsDerivedMember.setPointer(V.getMemberPointerDecl());
1737 DeclAndIsDerivedMember.setInt(V.isMemberPointerToDerivedMember());
1738 Path.clear();
1739 ArrayRef<const CXXRecordDecl*> P = V.getMemberPointerPath();
1740 Path.insert(Path.end(), P.begin(), P.end());
1741 }
1742
1743 /// DeclAndIsDerivedMember - The member declaration, and a flag indicating
1744 /// whether the member is a member of some class derived from the class type
1745 /// of the member pointer.
1746 llvm::PointerIntPair<const ValueDecl*, 1, bool> DeclAndIsDerivedMember;
1747 /// Path - The path of base/derived classes from the member declaration's
1748 /// class (exclusive) to the class type of the member pointer (inclusive).
1749 SmallVector<const CXXRecordDecl*, 4> Path;
1750
1751 /// Perform a cast towards the class of the Decl (either up or down the
1752 /// hierarchy).
1753 bool castBack(const CXXRecordDecl *Class) {
1754 assert(!Path.empty())(static_cast <bool> (!Path.empty()) ? void (0) : __assert_fail
("!Path.empty()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1754, __extension__ __PRETTY_FUNCTION__))
;
1755 const CXXRecordDecl *Expected;
1756 if (Path.size() >= 2)
1757 Expected = Path[Path.size() - 2];
1758 else
1759 Expected = getContainingRecord();
1760 if (Expected->getCanonicalDecl() != Class->getCanonicalDecl()) {
1761 // C++11 [expr.static.cast]p12: In a conversion from (D::*) to (B::*),
1762 // if B does not contain the original member and is not a base or
1763 // derived class of the class containing the original member, the result
1764 // of the cast is undefined.
1765 // C++11 [conv.mem]p2 does not cover this case for a cast from (B::*) to
1766 // (D::*). We consider that to be a language defect.
1767 return false;
1768 }
1769 Path.pop_back();
1770 return true;
1771 }
1772 /// Perform a base-to-derived member pointer cast.
1773 bool castToDerived(const CXXRecordDecl *Derived) {
1774 if (!getDecl())
1775 return true;
1776 if (!isDerivedMember()) {
1777 Path.push_back(Derived);
1778 return true;
1779 }
1780 if (!castBack(Derived))
1781 return false;
1782 if (Path.empty())
1783 DeclAndIsDerivedMember.setInt(false);
1784 return true;
1785 }
1786 /// Perform a derived-to-base member pointer cast.
1787 bool castToBase(const CXXRecordDecl *Base) {
1788 if (!getDecl())
1789 return true;
1790 if (Path.empty())
1791 DeclAndIsDerivedMember.setInt(true);
1792 if (isDerivedMember()) {
1793 Path.push_back(Base);
1794 return true;
1795 }
1796 return castBack(Base);
1797 }
1798 };
1799
1800 /// Compare two member pointers, which are assumed to be of the same type.
1801 static bool operator==(const MemberPtr &LHS, const MemberPtr &RHS) {
1802 if (!LHS.getDecl() || !RHS.getDecl())
1803 return !LHS.getDecl() && !RHS.getDecl();
1804 if (LHS.getDecl()->getCanonicalDecl() != RHS.getDecl()->getCanonicalDecl())
1805 return false;
1806 return LHS.Path == RHS.Path;
1807 }
1808}
1809
1810static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E);
1811static bool EvaluateInPlace(APValue &Result, EvalInfo &Info,
1812 const LValue &This, const Expr *E,
1813 bool AllowNonLiteralTypes = false);
1814static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
1815 bool InvalidBaseOK = false);
1816static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info,
1817 bool InvalidBaseOK = false);
1818static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
1819 EvalInfo &Info);
1820static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info);
1821static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info);
1822static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
1823 EvalInfo &Info);
1824static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info);
1825static bool EvaluateComplex(const Expr *E, ComplexValue &Res, EvalInfo &Info);
1826static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
1827 EvalInfo &Info);
1828static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result);
1829static bool EvaluateBuiltinStrLen(const Expr *E, uint64_t &Result,
1830 EvalInfo &Info);
1831
1832/// Evaluate an integer or fixed point expression into an APResult.
1833static bool EvaluateFixedPointOrInteger(const Expr *E, APFixedPoint &Result,
1834 EvalInfo &Info);
1835
1836/// Evaluate only a fixed point expression into an APResult.
1837static bool EvaluateFixedPoint(const Expr *E, APFixedPoint &Result,
1838 EvalInfo &Info);
1839
1840//===----------------------------------------------------------------------===//
1841// Misc utilities
1842//===----------------------------------------------------------------------===//
1843
1844/// Negate an APSInt in place, converting it to a signed form if necessary, and
1845/// preserving its value (by extending by up to one bit as needed).
1846static void negateAsSigned(APSInt &Int) {
1847 if (Int.isUnsigned() || Int.isMinSignedValue()) {
1848 Int = Int.extend(Int.getBitWidth() + 1);
1849 Int.setIsSigned(true);
1850 }
1851 Int = -Int;
1852}
1853
1854template<typename KeyT>
1855APValue &CallStackFrame::createTemporary(const KeyT *Key, QualType T,
1856 ScopeKind Scope, LValue &LV) {
1857 unsigned Version = getTempVersion();
1858 APValue::LValueBase Base(Key, Index, Version);
1859 LV.set(Base);
1860 return createLocal(Base, Key, T, Scope);
1861}
1862
1863/// Allocate storage for a parameter of a function call made in this frame.
1864APValue &CallStackFrame::createParam(CallRef Args, const ParmVarDecl *PVD,
1865 LValue &LV) {
1866 assert(Args.CallIndex == Index && "creating parameter in wrong frame")(static_cast <bool> (Args.CallIndex == Index &&
"creating parameter in wrong frame") ? void (0) : __assert_fail
("Args.CallIndex == Index && \"creating parameter in wrong frame\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1866, __extension__ __PRETTY_FUNCTION__))
;
1867 APValue::LValueBase Base(PVD, Index, Args.Version);
1868 LV.set(Base);
1869 // We always destroy parameters at the end of the call, even if we'd allow
1870 // them to live to the end of the full-expression at runtime, in order to
1871 // give portable results and match other compilers.
1872 return createLocal(Base, PVD, PVD->getType(), ScopeKind::Call);
1873}
1874
1875APValue &CallStackFrame::createLocal(APValue::LValueBase Base, const void *Key,
1876 QualType T, ScopeKind Scope) {
1877 assert(Base.getCallIndex() == Index && "lvalue for wrong frame")(static_cast <bool> (Base.getCallIndex() == Index &&
"lvalue for wrong frame") ? void (0) : __assert_fail ("Base.getCallIndex() == Index && \"lvalue for wrong frame\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1877, __extension__ __PRETTY_FUNCTION__))
;
1878 unsigned Version = Base.getVersion();
1879 APValue &Result = Temporaries[MapKeyTy(Key, Version)];
1880 assert(Result.isAbsent() && "local created multiple times")(static_cast <bool> (Result.isAbsent() && "local created multiple times"
) ? void (0) : __assert_fail ("Result.isAbsent() && \"local created multiple times\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1880, __extension__ __PRETTY_FUNCTION__))
;
1881
1882 // If we're creating a local immediately in the operand of a speculative
1883 // evaluation, don't register a cleanup to be run outside the speculative
1884 // evaluation context, since we won't actually be able to initialize this
1885 // object.
1886 if (Index <= Info.SpeculativeEvaluationDepth) {
1887 if (T.isDestructedType())
1888 Info.noteSideEffect();
1889 } else {
1890 Info.CleanupStack.push_back(Cleanup(&Result, Base, T, Scope));
1891 }
1892 return Result;
1893}
1894
1895APValue *EvalInfo::createHeapAlloc(const Expr *E, QualType T, LValue &LV) {
1896 if (NumHeapAllocs > DynamicAllocLValue::getMaxIndex()) {
1897 FFDiag(E, diag::note_constexpr_heap_alloc_limit_exceeded);
1898 return nullptr;
1899 }
1900
1901 DynamicAllocLValue DA(NumHeapAllocs++);
1902 LV.set(APValue::LValueBase::getDynamicAlloc(DA, T));
1903 auto Result = HeapAllocs.emplace(std::piecewise_construct,
1904 std::forward_as_tuple(DA), std::tuple<>());
1905 assert(Result.second && "reused a heap alloc index?")(static_cast <bool> (Result.second && "reused a heap alloc index?"
) ? void (0) : __assert_fail ("Result.second && \"reused a heap alloc index?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1905, __extension__ __PRETTY_FUNCTION__))
;
1906 Result.first->second.AllocExpr = E;
1907 return &Result.first->second.Value;
1908}
1909
1910/// Produce a string describing the given constexpr call.
1911void CallStackFrame::describe(raw_ostream &Out) {
1912 unsigned ArgIndex = 0;
1913 bool IsMemberCall = isa<CXXMethodDecl>(Callee) &&
1914 !isa<CXXConstructorDecl>(Callee) &&
1915 cast<CXXMethodDecl>(Callee)->isInstance();
1916
1917 if (!IsMemberCall)
1918 Out << *Callee << '(';
1919
1920 if (This && IsMemberCall) {
1921 APValue Val;
1922 This->moveInto(Val);
1923 Val.printPretty(Out, Info.Ctx,
1924 This->Designator.MostDerivedType);
1925 // FIXME: Add parens around Val if needed.
1926 Out << "->" << *Callee << '(';
1927 IsMemberCall = false;
1928 }
1929
1930 for (FunctionDecl::param_const_iterator I = Callee->param_begin(),
1931 E = Callee->param_end(); I != E; ++I, ++ArgIndex) {
1932 if (ArgIndex > (unsigned)IsMemberCall)
1933 Out << ", ";
1934
1935 const ParmVarDecl *Param = *I;
1936 APValue *V = Info.getParamSlot(Arguments, Param);
1937 if (V)
1938 V->printPretty(Out, Info.Ctx, Param->getType());
1939 else
1940 Out << "<...>";
1941
1942 if (ArgIndex == 0 && IsMemberCall)
1943 Out << "->" << *Callee << '(';
1944 }
1945
1946 Out << ')';
1947}
1948
1949/// Evaluate an expression to see if it had side-effects, and discard its
1950/// result.
1951/// \return \c true if the caller should keep evaluating.
1952static bool EvaluateIgnoredValue(EvalInfo &Info, const Expr *E) {
1953 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 1953, __extension__ __PRETTY_FUNCTION__))
;
1954 APValue Scratch;
1955 if (!Evaluate(Scratch, Info, E))
1956 // We don't need the value, but we might have skipped a side effect here.
1957 return Info.noteSideEffect();
1958 return true;
1959}
1960
1961/// Should this call expression be treated as a string literal?
1962static bool IsStringLiteralCall(const CallExpr *E) {
1963 unsigned Builtin = E->getBuiltinCallee();
1964 return (Builtin == Builtin::BI__builtin___CFStringMakeConstantString ||
1965 Builtin == Builtin::BI__builtin___NSStringMakeConstantString);
1966}
1967
1968static bool IsGlobalLValue(APValue::LValueBase B) {
1969 // C++11 [expr.const]p3 An address constant expression is a prvalue core
1970 // constant expression of pointer type that evaluates to...
1971
1972 // ... a null pointer value, or a prvalue core constant expression of type
1973 // std::nullptr_t.
1974 if (!B) return true;
1975
1976 if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
1977 // ... the address of an object with static storage duration,
1978 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
1979 return VD->hasGlobalStorage();
1980 if (isa<TemplateParamObjectDecl>(D))
1981 return true;
1982 // ... the address of a function,
1983 // ... the address of a GUID [MS extension],
1984 return isa<FunctionDecl>(D) || isa<MSGuidDecl>(D);
1985 }
1986
1987 if (B.is<TypeInfoLValue>() || B.is<DynamicAllocLValue>())
1988 return true;
1989
1990 const Expr *E = B.get<const Expr*>();
1991 switch (E->getStmtClass()) {
1992 default:
1993 return false;
1994 case Expr::CompoundLiteralExprClass: {
1995 const CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E);
1996 return CLE->isFileScope() && CLE->isLValue();
1997 }
1998 case Expr::MaterializeTemporaryExprClass:
1999 // A materialized temporary might have been lifetime-extended to static
2000 // storage duration.
2001 return cast<MaterializeTemporaryExpr>(E)->getStorageDuration() == SD_Static;
2002 // A string literal has static storage duration.
2003 case Expr::StringLiteralClass:
2004 case Expr::PredefinedExprClass:
2005 case Expr::ObjCStringLiteralClass:
2006 case Expr::ObjCEncodeExprClass:
2007 return true;
2008 case Expr::ObjCBoxedExprClass:
2009 return cast<ObjCBoxedExpr>(E)->isExpressibleAsConstantInitializer();
2010 case Expr::CallExprClass:
2011 return IsStringLiteralCall(cast<CallExpr>(E));
2012 // For GCC compatibility, &&label has static storage duration.
2013 case Expr::AddrLabelExprClass:
2014 return true;
2015 // A Block literal expression may be used as the initialization value for
2016 // Block variables at global or local static scope.
2017 case Expr::BlockExprClass:
2018 return !cast<BlockExpr>(E)->getBlockDecl()->hasCaptures();
2019 case Expr::ImplicitValueInitExprClass:
2020 // FIXME:
2021 // We can never form an lvalue with an implicit value initialization as its
2022 // base through expression evaluation, so these only appear in one case: the
2023 // implicit variable declaration we invent when checking whether a constexpr
2024 // constructor can produce a constant expression. We must assume that such
2025 // an expression might be a global lvalue.
2026 return true;
2027 }
2028}
2029
2030static const ValueDecl *GetLValueBaseDecl(const LValue &LVal) {
2031 return LVal.Base.dyn_cast<const ValueDecl*>();
2032}
2033
2034static bool IsLiteralLValue(const LValue &Value) {
2035 if (Value.getLValueCallIndex())
2036 return false;
2037 const Expr *E = Value.Base.dyn_cast<const Expr*>();
2038 return E && !isa<MaterializeTemporaryExpr>(E);
2039}
2040
2041static bool IsWeakLValue(const LValue &Value) {
2042 const ValueDecl *Decl = GetLValueBaseDecl(Value);
2043 return Decl && Decl->isWeak();
2044}
2045
2046static bool isZeroSized(const LValue &Value) {
2047 const ValueDecl *Decl = GetLValueBaseDecl(Value);
2048 if (Decl && isa<VarDecl>(Decl)) {
2049 QualType Ty = Decl->getType();
2050 if (Ty->isArrayType())
2051 return Ty->isIncompleteType() ||
2052 Decl->getASTContext().getTypeSize(Ty) == 0;
2053 }
2054 return false;
2055}
2056
2057static bool HasSameBase(const LValue &A, const LValue &B) {
2058 if (!A.getLValueBase())
2059 return !B.getLValueBase();
2060 if (!B.getLValueBase())
2061 return false;
2062
2063 if (A.getLValueBase().getOpaqueValue() !=
2064 B.getLValueBase().getOpaqueValue())
2065 return false;
2066
2067 return A.getLValueCallIndex() == B.getLValueCallIndex() &&
2068 A.getLValueVersion() == B.getLValueVersion();
2069}
2070
2071static void NoteLValueLocation(EvalInfo &Info, APValue::LValueBase Base) {
2072 assert(Base && "no location for a null lvalue")(static_cast <bool> (Base && "no location for a null lvalue"
) ? void (0) : __assert_fail ("Base && \"no location for a null lvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2072, __extension__ __PRETTY_FUNCTION__))
;
2073 const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
2074
2075 // For a parameter, find the corresponding call stack frame (if it still
2076 // exists), and point at the parameter of the function definition we actually
2077 // invoked.
2078 if (auto *PVD = dyn_cast_or_null<ParmVarDecl>(VD)) {
2079 unsigned Idx = PVD->getFunctionScopeIndex();
2080 for (CallStackFrame *F = Info.CurrentCall; F; F = F->Caller) {
2081 if (F->Arguments.CallIndex == Base.getCallIndex() &&
2082 F->Arguments.Version == Base.getVersion() && F->Callee &&
2083 Idx < F->Callee->getNumParams()) {
2084 VD = F->Callee->getParamDecl(Idx);
2085 break;
2086 }
2087 }
2088 }
2089
2090 if (VD)
2091 Info.Note(VD->getLocation(), diag::note_declared_at);
2092 else if (const Expr *E = Base.dyn_cast<const Expr*>())
2093 Info.Note(E->getExprLoc(), diag::note_constexpr_temporary_here);
2094 else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
2095 // FIXME: Produce a note for dangling pointers too.
2096 if (Optional<DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA))
2097 Info.Note((*Alloc)->AllocExpr->getExprLoc(),
2098 diag::note_constexpr_dynamic_alloc_here);
2099 }
2100 // We have no information to show for a typeid(T) object.
2101}
2102
2103enum class CheckEvaluationResultKind {
2104 ConstantExpression,
2105 FullyInitialized,
2106};
2107
2108/// Materialized temporaries that we've already checked to determine if they're
2109/// initializsed by a constant expression.
2110using CheckedTemporaries =
2111 llvm::SmallPtrSet<const MaterializeTemporaryExpr *, 8>;
2112
2113static bool CheckEvaluationResult(CheckEvaluationResultKind CERK,
2114 EvalInfo &Info, SourceLocation DiagLoc,
2115 QualType Type, const APValue &Value,
2116 ConstantExprKind Kind,
2117 SourceLocation SubobjectLoc,
2118 CheckedTemporaries &CheckedTemps);
2119
2120/// Check that this reference or pointer core constant expression is a valid
2121/// value for an address or reference constant expression. Return true if we
2122/// can fold this expression, whether or not it's a constant expression.
2123static bool CheckLValueConstantExpression(EvalInfo &Info, SourceLocation Loc,
2124 QualType Type, const LValue &LVal,
2125 ConstantExprKind Kind,
2126 CheckedTemporaries &CheckedTemps) {
2127 bool IsReferenceType = Type->isReferenceType();
2128
2129 APValue::LValueBase Base = LVal.getLValueBase();
2130 const SubobjectDesignator &Designator = LVal.getLValueDesignator();
2131
2132 const Expr *BaseE = Base.dyn_cast<const Expr *>();
2133 const ValueDecl *BaseVD = Base.dyn_cast<const ValueDecl*>();
2134
2135 // Additional restrictions apply in a template argument. We only enforce the
2136 // C++20 restrictions here; additional syntactic and semantic restrictions
2137 // are applied elsewhere.
2138 if (isTemplateArgument(Kind)) {
2139 int InvalidBaseKind = -1;
2140 StringRef Ident;
2141 if (Base.is<TypeInfoLValue>())
2142 InvalidBaseKind = 0;
2143 else if (isa_and_nonnull<StringLiteral>(BaseE))
2144 InvalidBaseKind = 1;
2145 else if (isa_and_nonnull<MaterializeTemporaryExpr>(BaseE) ||
2146 isa_and_nonnull<LifetimeExtendedTemporaryDecl>(BaseVD))
2147 InvalidBaseKind = 2;
2148 else if (auto *PE = dyn_cast_or_null<PredefinedExpr>(BaseE)) {
2149 InvalidBaseKind = 3;
2150 Ident = PE->getIdentKindName();
2151 }
2152
2153 if (InvalidBaseKind != -1) {
2154 Info.FFDiag(Loc, diag::note_constexpr_invalid_template_arg)
2155 << IsReferenceType << !Designator.Entries.empty() << InvalidBaseKind
2156 << Ident;
2157 return false;
2158 }
2159 }
2160
2161 if (auto *FD = dyn_cast_or_null<FunctionDecl>(BaseVD)) {
2162 if (FD->isConsteval()) {
2163 Info.FFDiag(Loc, diag::note_consteval_address_accessible)
2164 << !Type->isAnyPointerType();
2165 Info.Note(FD->getLocation(), diag::note_declared_at);
2166 return false;
2167 }
2168 }
2169
2170 // Check that the object is a global. Note that the fake 'this' object we
2171 // manufacture when checking potential constant expressions is conservatively
2172 // assumed to be global here.
2173 if (!IsGlobalLValue(Base)) {
2174 if (Info.getLangOpts().CPlusPlus11) {
2175 const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
2176 Info.FFDiag(Loc, diag::note_constexpr_non_global, 1)
2177 << IsReferenceType << !Designator.Entries.empty()
2178 << !!VD << VD;
2179
2180 auto *VarD = dyn_cast_or_null<VarDecl>(VD);
2181 if (VarD && VarD->isConstexpr()) {
2182 // Non-static local constexpr variables have unintuitive semantics:
2183 // constexpr int a = 1;
2184 // constexpr const int *p = &a;
2185 // ... is invalid because the address of 'a' is not constant. Suggest
2186 // adding a 'static' in this case.
2187 Info.Note(VarD->getLocation(), diag::note_constexpr_not_static)
2188 << VarD
2189 << FixItHint::CreateInsertion(VarD->getBeginLoc(), "static ");
2190 } else {
2191 NoteLValueLocation(Info, Base);
2192 }
2193 } else {
2194 Info.FFDiag(Loc);
2195 }
2196 // Don't allow references to temporaries to escape.
2197 return false;
2198 }
2199 assert((Info.checkingPotentialConstantExpression() ||(static_cast <bool> ((Info.checkingPotentialConstantExpression
() || LVal.getLValueCallIndex() == 0) && "have call index for global lvalue"
) ? void (0) : __assert_fail ("(Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex() == 0) && \"have call index for global lvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2201, __extension__ __PRETTY_FUNCTION__))
2200 LVal.getLValueCallIndex() == 0) &&(static_cast <bool> ((Info.checkingPotentialConstantExpression
() || LVal.getLValueCallIndex() == 0) && "have call index for global lvalue"
) ? void (0) : __assert_fail ("(Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex() == 0) && \"have call index for global lvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2201, __extension__ __PRETTY_FUNCTION__))
2201 "have call index for global lvalue")(static_cast <bool> ((Info.checkingPotentialConstantExpression
() || LVal.getLValueCallIndex() == 0) && "have call index for global lvalue"
) ? void (0) : __assert_fail ("(Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex() == 0) && \"have call index for global lvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2201, __extension__ __PRETTY_FUNCTION__))
;
2202
2203 if (Base.is<DynamicAllocLValue>()) {
2204 Info.FFDiag(Loc, diag::note_constexpr_dynamic_alloc)
2205 << IsReferenceType << !Designator.Entries.empty();
2206 NoteLValueLocation(Info, Base);
2207 return false;
2208 }
2209
2210 if (BaseVD) {
2211 if (const VarDecl *Var = dyn_cast<const VarDecl>(BaseVD)) {
2212 // Check if this is a thread-local variable.
2213 if (Var->getTLSKind())
2214 // FIXME: Diagnostic!
2215 return false;
2216
2217 // A dllimport variable never acts like a constant, unless we're
2218 // evaluating a value for use only in name mangling.
2219 if (!isForManglingOnly(Kind) && Var->hasAttr<DLLImportAttr>())
2220 // FIXME: Diagnostic!
2221 return false;
2222 }
2223 if (const auto *FD = dyn_cast<const FunctionDecl>(BaseVD)) {
2224 // __declspec(dllimport) must be handled very carefully:
2225 // We must never initialize an expression with the thunk in C++.
2226 // Doing otherwise would allow the same id-expression to yield
2227 // different addresses for the same function in different translation
2228 // units. However, this means that we must dynamically initialize the
2229 // expression with the contents of the import address table at runtime.
2230 //
2231 // The C language has no notion of ODR; furthermore, it has no notion of
2232 // dynamic initialization. This means that we are permitted to
2233 // perform initialization with the address of the thunk.
2234 if (Info.getLangOpts().CPlusPlus && !isForManglingOnly(Kind) &&
2235 FD->hasAttr<DLLImportAttr>())
2236 // FIXME: Diagnostic!
2237 return false;
2238 }
2239 } else if (const auto *MTE =
2240 dyn_cast_or_null<MaterializeTemporaryExpr>(BaseE)) {
2241 if (CheckedTemps.insert(MTE).second) {
2242 QualType TempType = getType(Base);
2243 if (TempType.isDestructedType()) {
2244 Info.FFDiag(MTE->getExprLoc(),
2245 diag::note_constexpr_unsupported_temporary_nontrivial_dtor)
2246 << TempType;
2247 return false;
2248 }
2249
2250 APValue *V = MTE->getOrCreateValue(false);
2251 assert(V && "evasluation result refers to uninitialised temporary")(static_cast <bool> (V && "evasluation result refers to uninitialised temporary"
) ? void (0) : __assert_fail ("V && \"evasluation result refers to uninitialised temporary\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2251, __extension__ __PRETTY_FUNCTION__))
;
2252 if (!CheckEvaluationResult(CheckEvaluationResultKind::ConstantExpression,
2253 Info, MTE->getExprLoc(), TempType, *V,
2254 Kind, SourceLocation(), CheckedTemps))
2255 return false;
2256 }
2257 }
2258
2259 // Allow address constant expressions to be past-the-end pointers. This is
2260 // an extension: the standard requires them to point to an object.
2261 if (!IsReferenceType)
2262 return true;
2263
2264 // A reference constant expression must refer to an object.
2265 if (!Base) {
2266 // FIXME: diagnostic
2267 Info.CCEDiag(Loc);
2268 return true;
2269 }
2270
2271 // Does this refer one past the end of some object?
2272 if (!Designator.Invalid && Designator.isOnePastTheEnd()) {
2273 Info.FFDiag(Loc, diag::note_constexpr_past_end, 1)
2274 << !Designator.Entries.empty() << !!BaseVD << BaseVD;
2275 NoteLValueLocation(Info, Base);
2276 }
2277
2278 return true;
2279}
2280
2281/// Member pointers are constant expressions unless they point to a
2282/// non-virtual dllimport member function.
2283static bool CheckMemberPointerConstantExpression(EvalInfo &Info,
2284 SourceLocation Loc,
2285 QualType Type,
2286 const APValue &Value,
2287 ConstantExprKind Kind) {
2288 const ValueDecl *Member = Value.getMemberPointerDecl();
2289 const auto *FD = dyn_cast_or_null<CXXMethodDecl>(Member);
2290 if (!FD)
2291 return true;
2292 if (FD->isConsteval()) {
2293 Info.FFDiag(Loc, diag::note_consteval_address_accessible) << /*pointer*/ 0;
2294 Info.Note(FD->getLocation(), diag::note_declared_at);
2295 return false;
2296 }
2297 return isForManglingOnly(Kind) || FD->isVirtual() ||
2298 !FD->hasAttr<DLLImportAttr>();
2299}
2300
2301/// Check that this core constant expression is of literal type, and if not,
2302/// produce an appropriate diagnostic.
2303static bool CheckLiteralType(EvalInfo &Info, const Expr *E,
2304 const LValue *This = nullptr) {
2305 if (!E->isPRValue() || E->getType()->isLiteralType(Info.Ctx))
2306 return true;
2307
2308 // C++1y: A constant initializer for an object o [...] may also invoke
2309 // constexpr constructors for o and its subobjects even if those objects
2310 // are of non-literal class types.
2311 //
2312 // C++11 missed this detail for aggregates, so classes like this:
2313 // struct foo_t { union { int i; volatile int j; } u; };
2314 // are not (obviously) initializable like so:
2315 // __attribute__((__require_constant_initialization__))
2316 // static const foo_t x = {{0}};
2317 // because "i" is a subobject with non-literal initialization (due to the
2318 // volatile member of the union). See:
2319 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1677
2320 // Therefore, we use the C++1y behavior.
2321 if (This && Info.EvaluatingDecl == This->getLValueBase())
2322 return true;
2323
2324 // Prvalue constant expressions must be of literal types.
2325 if (Info.getLangOpts().CPlusPlus11)
2326 Info.FFDiag(E, diag::note_constexpr_nonliteral)
2327 << E->getType();
2328 else
2329 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2330 return false;
2331}
2332
2333static bool CheckEvaluationResult(CheckEvaluationResultKind CERK,
2334 EvalInfo &Info, SourceLocation DiagLoc,
2335 QualType Type, const APValue &Value,
2336 ConstantExprKind Kind,
2337 SourceLocation SubobjectLoc,
2338 CheckedTemporaries &CheckedTemps) {
2339 if (!Value.hasValue()) {
2340 Info.FFDiag(DiagLoc, diag::note_constexpr_uninitialized)
2341 << true << Type;
2342 if (SubobjectLoc.isValid())
2343 Info.Note(SubobjectLoc, diag::note_constexpr_subobject_declared_here);
2344 return false;
2345 }
2346
2347 // We allow _Atomic(T) to be initialized from anything that T can be
2348 // initialized from.
2349 if (const AtomicType *AT = Type->getAs<AtomicType>())
2350 Type = AT->getValueType();
2351
2352 // Core issue 1454: For a literal constant expression of array or class type,
2353 // each subobject of its value shall have been initialized by a constant
2354 // expression.
2355 if (Value.isArray()) {
2356 QualType EltTy = Type->castAsArrayTypeUnsafe()->getElementType();
2357 for (unsigned I = 0, N = Value.getArrayInitializedElts(); I != N; ++I) {
2358 if (!CheckEvaluationResult(CERK, Info, DiagLoc, EltTy,
2359 Value.getArrayInitializedElt(I), Kind,
2360 SubobjectLoc, CheckedTemps))
2361 return false;
2362 }
2363 if (!Value.hasArrayFiller())
2364 return true;
2365 return CheckEvaluationResult(CERK, Info, DiagLoc, EltTy,
2366 Value.getArrayFiller(), Kind, SubobjectLoc,
2367 CheckedTemps);
2368 }
2369 if (Value.isUnion() && Value.getUnionField()) {
2370 return CheckEvaluationResult(
2371 CERK, Info, DiagLoc, Value.getUnionField()->getType(),
2372 Value.getUnionValue(), Kind, Value.getUnionField()->getLocation(),
2373 CheckedTemps);
2374 }
2375 if (Value.isStruct()) {
2376 RecordDecl *RD = Type->castAs<RecordType>()->getDecl();
2377 if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
2378 unsigned BaseIndex = 0;
2379 for (const CXXBaseSpecifier &BS : CD->bases()) {
2380 if (!CheckEvaluationResult(CERK, Info, DiagLoc, BS.getType(),
2381 Value.getStructBase(BaseIndex), Kind,
2382 BS.getBeginLoc(), CheckedTemps))
2383 return false;
2384 ++BaseIndex;
2385 }
2386 }
2387 for (const auto *I : RD->fields()) {
2388 if (I->isUnnamedBitfield())
2389 continue;
2390
2391 if (!CheckEvaluationResult(CERK, Info, DiagLoc, I->getType(),
2392 Value.getStructField(I->getFieldIndex()),
2393 Kind, I->getLocation(), CheckedTemps))
2394 return false;
2395 }
2396 }
2397
2398 if (Value.isLValue() &&
2399 CERK == CheckEvaluationResultKind::ConstantExpression) {
2400 LValue LVal;
2401 LVal.setFrom(Info.Ctx, Value);
2402 return CheckLValueConstantExpression(Info, DiagLoc, Type, LVal, Kind,
2403 CheckedTemps);
2404 }
2405
2406 if (Value.isMemberPointer() &&
2407 CERK == CheckEvaluationResultKind::ConstantExpression)
2408 return CheckMemberPointerConstantExpression(Info, DiagLoc, Type, Value, Kind);
2409
2410 // Everything else is fine.
2411 return true;
2412}
2413
2414/// Check that this core constant expression value is a valid value for a
2415/// constant expression. If not, report an appropriate diagnostic. Does not
2416/// check that the expression is of literal type.
2417static bool CheckConstantExpression(EvalInfo &Info, SourceLocation DiagLoc,
2418 QualType Type, const APValue &Value,
2419 ConstantExprKind Kind) {
2420 // Nothing to check for a constant expression of type 'cv void'.
2421 if (Type->isVoidType())
2422 return true;
2423
2424 CheckedTemporaries CheckedTemps;
2425 return CheckEvaluationResult(CheckEvaluationResultKind::ConstantExpression,
2426 Info, DiagLoc, Type, Value, Kind,
2427 SourceLocation(), CheckedTemps);
2428}
2429
2430/// Check that this evaluated value is fully-initialized and can be loaded by
2431/// an lvalue-to-rvalue conversion.
2432static bool CheckFullyInitialized(EvalInfo &Info, SourceLocation DiagLoc,
2433 QualType Type, const APValue &Value) {
2434 CheckedTemporaries CheckedTemps;
2435 return CheckEvaluationResult(
2436 CheckEvaluationResultKind::FullyInitialized, Info, DiagLoc, Type, Value,
2437 ConstantExprKind::Normal, SourceLocation(), CheckedTemps);
2438}
2439
2440/// Enforce C++2a [expr.const]/4.17, which disallows new-expressions unless
2441/// "the allocated storage is deallocated within the evaluation".
2442static bool CheckMemoryLeaks(EvalInfo &Info) {
2443 if (!Info.HeapAllocs.empty()) {
2444 // We can still fold to a constant despite a compile-time memory leak,
2445 // so long as the heap allocation isn't referenced in the result (we check
2446 // that in CheckConstantExpression).
2447 Info.CCEDiag(Info.HeapAllocs.begin()->second.AllocExpr,
2448 diag::note_constexpr_memory_leak)
2449 << unsigned(Info.HeapAllocs.size() - 1);
2450 }
2451 return true;
2452}
2453
2454static bool EvalPointerValueAsBool(const APValue &Value, bool &Result) {
2455 // A null base expression indicates a null pointer. These are always
2456 // evaluatable, and they are false unless the offset is zero.
2457 if (!Value.getLValueBase()) {
2458 Result = !Value.getLValueOffset().isZero();
2459 return true;
2460 }
2461
2462 // We have a non-null base. These are generally known to be true, but if it's
2463 // a weak declaration it can be null at runtime.
2464 Result = true;
2465 const ValueDecl *Decl = Value.getLValueBase().dyn_cast<const ValueDecl*>();
2466 return !Decl || !Decl->isWeak();
2467}
2468
2469static bool HandleConversionToBool(const APValue &Val, bool &Result) {
2470 switch (Val.getKind()) {
2471 case APValue::None:
2472 case APValue::Indeterminate:
2473 return false;
2474 case APValue::Int:
2475 Result = Val.getInt().getBoolValue();
2476 return true;
2477 case APValue::FixedPoint:
2478 Result = Val.getFixedPoint().getBoolValue();
2479 return true;
2480 case APValue::Float:
2481 Result = !Val.getFloat().isZero();
2482 return true;
2483 case APValue::ComplexInt:
2484 Result = Val.getComplexIntReal().getBoolValue() ||
2485 Val.getComplexIntImag().getBoolValue();
2486 return true;
2487 case APValue::ComplexFloat:
2488 Result = !Val.getComplexFloatReal().isZero() ||
2489 !Val.getComplexFloatImag().isZero();
2490 return true;
2491 case APValue::LValue:
2492 return EvalPointerValueAsBool(Val, Result);
2493 case APValue::MemberPointer:
2494 Result = Val.getMemberPointerDecl();
2495 return true;
2496 case APValue::Vector:
2497 case APValue::Array:
2498 case APValue::Struct:
2499 case APValue::Union:
2500 case APValue::AddrLabelDiff:
2501 return false;
2502 }
2503
2504 llvm_unreachable("unknown APValue kind")::llvm::llvm_unreachable_internal("unknown APValue kind", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2504)
;
2505}
2506
2507static bool EvaluateAsBooleanCondition(const Expr *E, bool &Result,
2508 EvalInfo &Info) {
2509 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2509, __extension__ __PRETTY_FUNCTION__))
;
2510 assert(E->isPRValue() && "missing lvalue-to-rvalue conv in bool condition")(static_cast <bool> (E->isPRValue() && "missing lvalue-to-rvalue conv in bool condition"
) ? void (0) : __assert_fail ("E->isPRValue() && \"missing lvalue-to-rvalue conv in bool condition\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2510, __extension__ __PRETTY_FUNCTION__))
;
2511 APValue Val;
2512 if (!Evaluate(Val, Info, E))
2513 return false;
2514 return HandleConversionToBool(Val, Result);
2515}
2516
2517template<typename T>
2518static bool HandleOverflow(EvalInfo &Info, const Expr *E,
2519 const T &SrcValue, QualType DestType) {
2520 Info.CCEDiag(E, diag::note_constexpr_overflow)
2521 << SrcValue << DestType;
2522 return Info.noteUndefinedBehavior();
2523}
2524
2525static bool HandleFloatToIntCast(EvalInfo &Info, const Expr *E,
2526 QualType SrcType, const APFloat &Value,
2527 QualType DestType, APSInt &Result) {
2528 unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
2529 // Determine whether we are converting to unsigned or signed.
2530 bool DestSigned = DestType->isSignedIntegerOrEnumerationType();
2531
2532 Result = APSInt(DestWidth, !DestSigned);
2533 bool ignored;
2534 if (Value.convertToInteger(Result, llvm::APFloat::rmTowardZero, &ignored)
2535 & APFloat::opInvalidOp)
2536 return HandleOverflow(Info, E, Value, DestType);
2537 return true;
2538}
2539
2540/// Get rounding mode used for evaluation of the specified expression.
2541/// \param[out] DynamicRM Is set to true is the requested rounding mode is
2542/// dynamic.
2543/// If rounding mode is unknown at compile time, still try to evaluate the
2544/// expression. If the result is exact, it does not depend on rounding mode.
2545/// So return "tonearest" mode instead of "dynamic".
2546static llvm::RoundingMode getActiveRoundingMode(EvalInfo &Info, const Expr *E,
2547 bool &DynamicRM) {
2548 llvm::RoundingMode RM =
2549 E->getFPFeaturesInEffect(Info.Ctx.getLangOpts()).getRoundingMode();
2550 DynamicRM = (RM == llvm::RoundingMode::Dynamic);
2551 if (DynamicRM)
2552 RM = llvm::RoundingMode::NearestTiesToEven;
2553 return RM;
2554}
2555
2556/// Check if the given evaluation result is allowed for constant evaluation.
2557static bool checkFloatingPointResult(EvalInfo &Info, const Expr *E,
2558 APFloat::opStatus St) {
2559 // In a constant context, assume that any dynamic rounding mode or FP
2560 // exception state matches the default floating-point environment.
2561 if (Info.InConstantContext)
2562 return true;
2563
2564 FPOptions FPO = E->getFPFeaturesInEffect(Info.Ctx.getLangOpts());
2565 if ((St & APFloat::opInexact) &&
2566 FPO.getRoundingMode() == llvm::RoundingMode::Dynamic) {
2567 // Inexact result means that it depends on rounding mode. If the requested
2568 // mode is dynamic, the evaluation cannot be made in compile time.
2569 Info.FFDiag(E, diag::note_constexpr_dynamic_rounding);
2570 return false;
2571 }
2572
2573 if ((St != APFloat::opOK) &&
2574 (FPO.getRoundingMode() == llvm::RoundingMode::Dynamic ||
2575 FPO.getFPExceptionMode() != LangOptions::FPE_Ignore ||
2576 FPO.getAllowFEnvAccess())) {
2577 Info.FFDiag(E, diag::note_constexpr_float_arithmetic_strict);
2578 return false;
2579 }
2580
2581 if ((St & APFloat::opStatus::opInvalidOp) &&
2582 FPO.getFPExceptionMode() != LangOptions::FPE_Ignore) {
2583 // There is no usefully definable result.
2584 Info.FFDiag(E);
2585 return false;
2586 }
2587
2588 // FIXME: if:
2589 // - evaluation triggered other FP exception, and
2590 // - exception mode is not "ignore", and
2591 // - the expression being evaluated is not a part of global variable
2592 // initializer,
2593 // the evaluation probably need to be rejected.
2594 return true;
2595}
2596
2597static bool HandleFloatToFloatCast(EvalInfo &Info, const Expr *E,
2598 QualType SrcType, QualType DestType,
2599 APFloat &Result) {
2600 assert(isa<CastExpr>(E) || isa<CompoundAssignOperator>(E))(static_cast <bool> (isa<CastExpr>(E) || isa<CompoundAssignOperator
>(E)) ? void (0) : __assert_fail ("isa<CastExpr>(E) || isa<CompoundAssignOperator>(E)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2600, __extension__ __PRETTY_FUNCTION__))
;
2601 bool DynamicRM;
2602 llvm::RoundingMode RM = getActiveRoundingMode(Info, E, DynamicRM);
2603 APFloat::opStatus St;
2604 APFloat Value = Result;
2605 bool ignored;
2606 St = Result.convert(Info.Ctx.getFloatTypeSemantics(DestType), RM, &ignored);
2607 return checkFloatingPointResult(Info, E, St);
2608}
2609
2610static APSInt HandleIntToIntCast(EvalInfo &Info, const Expr *E,
2611 QualType DestType, QualType SrcType,
2612 const APSInt &Value) {
2613 unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
2614 // Figure out if this is a truncate, extend or noop cast.
2615 // If the input is signed, do a sign extend, noop, or truncate.
2616 APSInt Result = Value.extOrTrunc(DestWidth);
2617 Result.setIsUnsigned(DestType->isUnsignedIntegerOrEnumerationType());
2618 if (DestType->isBooleanType())
2619 Result = Value.getBoolValue();
2620 return Result;
2621}
2622
2623static bool HandleIntToFloatCast(EvalInfo &Info, const Expr *E,
2624 const FPOptions FPO,
2625 QualType SrcType, const APSInt &Value,
2626 QualType DestType, APFloat &Result) {
2627 Result = APFloat(Info.Ctx.getFloatTypeSemantics(DestType), 1);
2628 APFloat::opStatus St = Result.convertFromAPInt(Value, Value.isSigned(),
2629 APFloat::rmNearestTiesToEven);
2630 if (!Info.InConstantContext && St != llvm::APFloatBase::opOK &&
2631 FPO.isFPConstrained()) {
2632 Info.FFDiag(E, diag::note_constexpr_float_arithmetic_strict);
2633 return false;
2634 }
2635 return true;
2636}
2637
2638static bool truncateBitfieldValue(EvalInfo &Info, const Expr *E,
2639 APValue &Value, const FieldDecl *FD) {
2640 assert(FD->isBitField() && "truncateBitfieldValue on non-bitfield")(static_cast <bool> (FD->isBitField() && "truncateBitfieldValue on non-bitfield"
) ? void (0) : __assert_fail ("FD->isBitField() && \"truncateBitfieldValue on non-bitfield\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2640, __extension__ __PRETTY_FUNCTION__))
;
2641
2642 if (!Value.isInt()) {
2643 // Trying to store a pointer-cast-to-integer into a bitfield.
2644 // FIXME: In this case, we should provide the diagnostic for casting
2645 // a pointer to an integer.
2646 assert(Value.isLValue() && "integral value neither int nor lvalue?")(static_cast <bool> (Value.isLValue() && "integral value neither int nor lvalue?"
) ? void (0) : __assert_fail ("Value.isLValue() && \"integral value neither int nor lvalue?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2646, __extension__ __PRETTY_FUNCTION__))
;
2647 Info.FFDiag(E);
2648 return false;
2649 }
2650
2651 APSInt &Int = Value.getInt();
2652 unsigned OldBitWidth = Int.getBitWidth();
2653 unsigned NewBitWidth = FD->getBitWidthValue(Info.Ctx);
2654 if (NewBitWidth < OldBitWidth)
2655 Int = Int.trunc(NewBitWidth).extend(OldBitWidth);
2656 return true;
2657}
2658
2659static bool EvalAndBitcastToAPInt(EvalInfo &Info, const Expr *E,
2660 llvm::APInt &Res) {
2661 APValue SVal;
2662 if (!Evaluate(SVal, Info, E))
2663 return false;
2664 if (SVal.isInt()) {
2665 Res = SVal.getInt();
2666 return true;
2667 }
2668 if (SVal.isFloat()) {
2669 Res = SVal.getFloat().bitcastToAPInt();
2670 return true;
2671 }
2672 if (SVal.isVector()) {
2673 QualType VecTy = E->getType();
2674 unsigned VecSize = Info.Ctx.getTypeSize(VecTy);
2675 QualType EltTy = VecTy->castAs<VectorType>()->getElementType();
2676 unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
2677 bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
2678 Res = llvm::APInt::getNullValue(VecSize);
2679 for (unsigned i = 0; i < SVal.getVectorLength(); i++) {
2680 APValue &Elt = SVal.getVectorElt(i);
2681 llvm::APInt EltAsInt;
2682 if (Elt.isInt()) {
2683 EltAsInt = Elt.getInt();
2684 } else if (Elt.isFloat()) {
2685 EltAsInt = Elt.getFloat().bitcastToAPInt();
2686 } else {
2687 // Don't try to handle vectors of anything other than int or float
2688 // (not sure if it's possible to hit this case).
2689 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2690 return false;
2691 }
2692 unsigned BaseEltSize = EltAsInt.getBitWidth();
2693 if (BigEndian)
2694 Res |= EltAsInt.zextOrTrunc(VecSize).rotr(i*EltSize+BaseEltSize);
2695 else
2696 Res |= EltAsInt.zextOrTrunc(VecSize).rotl(i*EltSize);
2697 }
2698 return true;
2699 }
2700 // Give up if the input isn't an int, float, or vector. For example, we
2701 // reject "(v4i16)(intptr_t)&a".
2702 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2703 return false;
2704}
2705
2706/// Perform the given integer operation, which is known to need at most BitWidth
2707/// bits, and check for overflow in the original type (if that type was not an
2708/// unsigned type).
2709template<typename Operation>
2710static bool CheckedIntArithmetic(EvalInfo &Info, const Expr *E,
2711 const APSInt &LHS, const APSInt &RHS,
2712 unsigned BitWidth, Operation Op,
2713 APSInt &Result) {
2714 if (LHS.isUnsigned()) {
2715 Result = Op(LHS, RHS);
2716 return true;
2717 }
2718
2719 APSInt Value(Op(LHS.extend(BitWidth), RHS.extend(BitWidth)), false);
2720 Result = Value.trunc(LHS.getBitWidth());
2721 if (Result.extend(BitWidth) != Value) {
2722 if (Info.checkingForUndefinedBehavior())
2723 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
2724 diag::warn_integer_constant_overflow)
2725 << toString(Result, 10) << E->getType();
2726 return HandleOverflow(Info, E, Value, E->getType());
2727 }
2728 return true;
2729}
2730
2731/// Perform the given binary integer operation.
2732static bool handleIntIntBinOp(EvalInfo &Info, const Expr *E, const APSInt &LHS,
2733 BinaryOperatorKind Opcode, APSInt RHS,
2734 APSInt &Result) {
2735 switch (Opcode) {
2736 default:
2737 Info.FFDiag(E);
2738 return false;
2739 case BO_Mul:
2740 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() * 2,
2741 std::multiplies<APSInt>(), Result);
2742 case BO_Add:
2743 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
2744 std::plus<APSInt>(), Result);
2745 case BO_Sub:
2746 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
2747 std::minus<APSInt>(), Result);
2748 case BO_And: Result = LHS & RHS; return true;
2749 case BO_Xor: Result = LHS ^ RHS; return true;
2750 case BO_Or: Result = LHS | RHS; return true;
2751 case BO_Div:
2752 case BO_Rem:
2753 if (RHS == 0) {
2754 Info.FFDiag(E, diag::note_expr_divide_by_zero);
2755 return false;
2756 }
2757 Result = (Opcode == BO_Rem ? LHS % RHS : LHS / RHS);
2758 // Check for overflow case: INT_MIN / -1 or INT_MIN % -1. APSInt supports
2759 // this operation and gives the two's complement result.
2760 if (RHS.isNegative() && RHS.isAllOnesValue() &&
2761 LHS.isSigned() && LHS.isMinSignedValue())
2762 return HandleOverflow(Info, E, -LHS.extend(LHS.getBitWidth() + 1),
2763 E->getType());
2764 return true;
2765 case BO_Shl: {
2766 if (Info.getLangOpts().OpenCL)
2767 // OpenCL 6.3j: shift values are effectively % word size of LHS.
2768 RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
2769 static_cast<uint64_t>(LHS.getBitWidth() - 1)),
2770 RHS.isUnsigned());
2771 else if (RHS.isSigned() && RHS.isNegative()) {
2772 // During constant-folding, a negative shift is an opposite shift. Such
2773 // a shift is not a constant expression.
2774 Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
2775 RHS = -RHS;
2776 goto shift_right;
2777 }
2778 shift_left:
2779 // C++11 [expr.shift]p1: Shift width must be less than the bit width of
2780 // the shifted type.
2781 unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
2782 if (SA != RHS) {
2783 Info.CCEDiag(E, diag::note_constexpr_large_shift)
2784 << RHS << E->getType() << LHS.getBitWidth();
2785 } else if (LHS.isSigned() && !Info.getLangOpts().CPlusPlus20) {
2786 // C++11 [expr.shift]p2: A signed left shift must have a non-negative
2787 // operand, and must not overflow the corresponding unsigned type.
2788 // C++2a [expr.shift]p2: E1 << E2 is the unique value congruent to
2789 // E1 x 2^E2 module 2^N.
2790 if (LHS.isNegative())
2791 Info.CCEDiag(E, diag::note_constexpr_lshift_of_negative) << LHS;
2792 else if (LHS.countLeadingZeros() < SA)
2793 Info.CCEDiag(E, diag::note_constexpr_lshift_discards);
2794 }
2795 Result = LHS << SA;
2796 return true;
2797 }
2798 case BO_Shr: {
2799 if (Info.getLangOpts().OpenCL)
2800 // OpenCL 6.3j: shift values are effectively % word size of LHS.
2801 RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
2802 static_cast<uint64_t>(LHS.getBitWidth() - 1)),
2803 RHS.isUnsigned());
2804 else if (RHS.isSigned() && RHS.isNegative()) {
2805 // During constant-folding, a negative shift is an opposite shift. Such a
2806 // shift is not a constant expression.
2807 Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
2808 RHS = -RHS;
2809 goto shift_left;
2810 }
2811 shift_right:
2812 // C++11 [expr.shift]p1: Shift width must be less than the bit width of the
2813 // shifted type.
2814 unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
2815 if (SA != RHS)
2816 Info.CCEDiag(E, diag::note_constexpr_large_shift)
2817 << RHS << E->getType() << LHS.getBitWidth();
2818 Result = LHS >> SA;
2819 return true;
2820 }
2821
2822 case BO_LT: Result = LHS < RHS; return true;
2823 case BO_GT: Result = LHS > RHS; return true;
2824 case BO_LE: Result = LHS <= RHS; return true;
2825 case BO_GE: Result = LHS >= RHS; return true;
2826 case BO_EQ: Result = LHS == RHS; return true;
2827 case BO_NE: Result = LHS != RHS; return true;
2828 case BO_Cmp:
2829 llvm_unreachable("BO_Cmp should be handled elsewhere")::llvm::llvm_unreachable_internal("BO_Cmp should be handled elsewhere"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2829)
;
2830 }
2831}
2832
2833/// Perform the given binary floating-point operation, in-place, on LHS.
2834static bool handleFloatFloatBinOp(EvalInfo &Info, const BinaryOperator *E,
2835 APFloat &LHS, BinaryOperatorKind Opcode,
2836 const APFloat &RHS) {
2837 bool DynamicRM;
2838 llvm::RoundingMode RM = getActiveRoundingMode(Info, E, DynamicRM);
2839 APFloat::opStatus St;
2840 switch (Opcode) {
2841 default:
2842 Info.FFDiag(E);
2843 return false;
2844 case BO_Mul:
2845 St = LHS.multiply(RHS, RM);
2846 break;
2847 case BO_Add:
2848 St = LHS.add(RHS, RM);
2849 break;
2850 case BO_Sub:
2851 St = LHS.subtract(RHS, RM);
2852 break;
2853 case BO_Div:
2854 // [expr.mul]p4:
2855 // If the second operand of / or % is zero the behavior is undefined.
2856 if (RHS.isZero())
2857 Info.CCEDiag(E, diag::note_expr_divide_by_zero);
2858 St = LHS.divide(RHS, RM);
2859 break;
2860 }
2861
2862 // [expr.pre]p4:
2863 // If during the evaluation of an expression, the result is not
2864 // mathematically defined [...], the behavior is undefined.
2865 // FIXME: C++ rules require us to not conform to IEEE 754 here.
2866 if (LHS.isNaN()) {
2867 Info.CCEDiag(E, diag::note_constexpr_float_arithmetic) << LHS.isNaN();
2868 return Info.noteUndefinedBehavior();
2869 }
2870
2871 return checkFloatingPointResult(Info, E, St);
2872}
2873
2874static bool handleLogicalOpForVector(const APInt &LHSValue,
2875 BinaryOperatorKind Opcode,
2876 const APInt &RHSValue, APInt &Result) {
2877 bool LHS = (LHSValue != 0);
2878 bool RHS = (RHSValue != 0);
2879
2880 if (Opcode == BO_LAnd)
2881 Result = LHS && RHS;
2882 else
2883 Result = LHS || RHS;
2884 return true;
2885}
2886static bool handleLogicalOpForVector(const APFloat &LHSValue,
2887 BinaryOperatorKind Opcode,
2888 const APFloat &RHSValue, APInt &Result) {
2889 bool LHS = !LHSValue.isZero();
2890 bool RHS = !RHSValue.isZero();
2891
2892 if (Opcode == BO_LAnd)
2893 Result = LHS && RHS;
2894 else
2895 Result = LHS || RHS;
2896 return true;
2897}
2898
2899static bool handleLogicalOpForVector(const APValue &LHSValue,
2900 BinaryOperatorKind Opcode,
2901 const APValue &RHSValue, APInt &Result) {
2902 // The result is always an int type, however operands match the first.
2903 if (LHSValue.getKind() == APValue::Int)
2904 return handleLogicalOpForVector(LHSValue.getInt(), Opcode,
2905 RHSValue.getInt(), Result);
2906 assert(LHSValue.getKind() == APValue::Float && "Should be no other options")(static_cast <bool> (LHSValue.getKind() == APValue::Float
&& "Should be no other options") ? void (0) : __assert_fail
("LHSValue.getKind() == APValue::Float && \"Should be no other options\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2906, __extension__ __PRETTY_FUNCTION__))
;
2907 return handleLogicalOpForVector(LHSValue.getFloat(), Opcode,
2908 RHSValue.getFloat(), Result);
2909}
2910
2911template <typename APTy>
2912static bool
2913handleCompareOpForVectorHelper(const APTy &LHSValue, BinaryOperatorKind Opcode,
2914 const APTy &RHSValue, APInt &Result) {
2915 switch (Opcode) {
2916 default:
2917 llvm_unreachable("unsupported binary operator")::llvm::llvm_unreachable_internal("unsupported binary operator"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2917)
;
2918 case BO_EQ:
2919 Result = (LHSValue == RHSValue);
2920 break;
2921 case BO_NE:
2922 Result = (LHSValue != RHSValue);
2923 break;
2924 case BO_LT:
2925 Result = (LHSValue < RHSValue);
2926 break;
2927 case BO_GT:
2928 Result = (LHSValue > RHSValue);
2929 break;
2930 case BO_LE:
2931 Result = (LHSValue <= RHSValue);
2932 break;
2933 case BO_GE:
2934 Result = (LHSValue >= RHSValue);
2935 break;
2936 }
2937
2938 return true;
2939}
2940
2941static bool handleCompareOpForVector(const APValue &LHSValue,
2942 BinaryOperatorKind Opcode,
2943 const APValue &RHSValue, APInt &Result) {
2944 // The result is always an int type, however operands match the first.
2945 if (LHSValue.getKind() == APValue::Int)
2946 return handleCompareOpForVectorHelper(LHSValue.getInt(), Opcode,
2947 RHSValue.getInt(), Result);
2948 assert(LHSValue.getKind() == APValue::Float && "Should be no other options")(static_cast <bool> (LHSValue.getKind() == APValue::Float
&& "Should be no other options") ? void (0) : __assert_fail
("LHSValue.getKind() == APValue::Float && \"Should be no other options\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2948, __extension__ __PRETTY_FUNCTION__))
;
2949 return handleCompareOpForVectorHelper(LHSValue.getFloat(), Opcode,
2950 RHSValue.getFloat(), Result);
2951}
2952
2953// Perform binary operations for vector types, in place on the LHS.
2954static bool handleVectorVectorBinOp(EvalInfo &Info, const BinaryOperator *E,
2955 BinaryOperatorKind Opcode,
2956 APValue &LHSValue,
2957 const APValue &RHSValue) {
2958 assert(Opcode != BO_PtrMemD && Opcode != BO_PtrMemI &&(static_cast <bool> (Opcode != BO_PtrMemD && Opcode
!= BO_PtrMemI && "Operation not supported on vector types"
) ? void (0) : __assert_fail ("Opcode != BO_PtrMemD && Opcode != BO_PtrMemI && \"Operation not supported on vector types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2959, __extension__ __PRETTY_FUNCTION__))
2959 "Operation not supported on vector types")(static_cast <bool> (Opcode != BO_PtrMemD && Opcode
!= BO_PtrMemI && "Operation not supported on vector types"
) ? void (0) : __assert_fail ("Opcode != BO_PtrMemD && Opcode != BO_PtrMemI && \"Operation not supported on vector types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2959, __extension__ __PRETTY_FUNCTION__))
;
2960
2961 const auto *VT = E->getType()->castAs<VectorType>();
2962 unsigned NumElements = VT->getNumElements();
2963 QualType EltTy = VT->getElementType();
2964
2965 // In the cases (typically C as I've observed) where we aren't evaluating
2966 // constexpr but are checking for cases where the LHS isn't yet evaluatable,
2967 // just give up.
2968 if (!LHSValue.isVector()) {
2969 assert(LHSValue.isLValue() &&(static_cast <bool> (LHSValue.isLValue() && "A vector result that isn't a vector OR uncalculated LValue"
) ? void (0) : __assert_fail ("LHSValue.isLValue() && \"A vector result that isn't a vector OR uncalculated LValue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2970, __extension__ __PRETTY_FUNCTION__))
2970 "A vector result that isn't a vector OR uncalculated LValue")(static_cast <bool> (LHSValue.isLValue() && "A vector result that isn't a vector OR uncalculated LValue"
) ? void (0) : __assert_fail ("LHSValue.isLValue() && \"A vector result that isn't a vector OR uncalculated LValue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2970, __extension__ __PRETTY_FUNCTION__))
;
2971 Info.FFDiag(E);
2972 return false;
2973 }
2974
2975 assert(LHSValue.getVectorLength() == NumElements &&(static_cast <bool> (LHSValue.getVectorLength() == NumElements
&& RHSValue.getVectorLength() == NumElements &&
"Different vector sizes") ? void (0) : __assert_fail ("LHSValue.getVectorLength() == NumElements && RHSValue.getVectorLength() == NumElements && \"Different vector sizes\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2976, __extension__ __PRETTY_FUNCTION__))
2976 RHSValue.getVectorLength() == NumElements && "Different vector sizes")(static_cast <bool> (LHSValue.getVectorLength() == NumElements
&& RHSValue.getVectorLength() == NumElements &&
"Different vector sizes") ? void (0) : __assert_fail ("LHSValue.getVectorLength() == NumElements && RHSValue.getVectorLength() == NumElements && \"Different vector sizes\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 2976, __extension__ __PRETTY_FUNCTION__))
;
2977
2978 SmallVector<APValue, 4> ResultElements;
2979
2980 for (unsigned EltNum = 0; EltNum < NumElements; ++EltNum) {
2981 APValue LHSElt = LHSValue.getVectorElt(EltNum);
2982 APValue RHSElt = RHSValue.getVectorElt(EltNum);
2983
2984 if (EltTy->isIntegerType()) {
2985 APSInt EltResult{Info.Ctx.getIntWidth(EltTy),
2986 EltTy->isUnsignedIntegerType()};
2987 bool Success = true;
2988
2989 if (BinaryOperator::isLogicalOp(Opcode))
2990 Success = handleLogicalOpForVector(LHSElt, Opcode, RHSElt, EltResult);
2991 else if (BinaryOperator::isComparisonOp(Opcode))
2992 Success = handleCompareOpForVector(LHSElt, Opcode, RHSElt, EltResult);
2993 else
2994 Success = handleIntIntBinOp(Info, E, LHSElt.getInt(), Opcode,
2995 RHSElt.getInt(), EltResult);
2996
2997 if (!Success) {
2998 Info.FFDiag(E);
2999 return false;
3000 }
3001 ResultElements.emplace_back(EltResult);
3002
3003 } else if (EltTy->isFloatingType()) {
3004 assert(LHSElt.getKind() == APValue::Float &&(static_cast <bool> (LHSElt.getKind() == APValue::Float
&& RHSElt.getKind() == APValue::Float && "Mismatched LHS/RHS/Result Type"
) ? void (0) : __assert_fail ("LHSElt.getKind() == APValue::Float && RHSElt.getKind() == APValue::Float && \"Mismatched LHS/RHS/Result Type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3006, __extension__ __PRETTY_FUNCTION__))
3005 RHSElt.getKind() == APValue::Float &&(static_cast <bool> (LHSElt.getKind() == APValue::Float
&& RHSElt.getKind() == APValue::Float && "Mismatched LHS/RHS/Result Type"
) ? void (0) : __assert_fail ("LHSElt.getKind() == APValue::Float && RHSElt.getKind() == APValue::Float && \"Mismatched LHS/RHS/Result Type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3006, __extension__ __PRETTY_FUNCTION__))
3006 "Mismatched LHS/RHS/Result Type")(static_cast <bool> (LHSElt.getKind() == APValue::Float
&& RHSElt.getKind() == APValue::Float && "Mismatched LHS/RHS/Result Type"
) ? void (0) : __assert_fail ("LHSElt.getKind() == APValue::Float && RHSElt.getKind() == APValue::Float && \"Mismatched LHS/RHS/Result Type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3006, __extension__ __PRETTY_FUNCTION__))
;
3007 APFloat LHSFloat = LHSElt.getFloat();
3008
3009 if (!handleFloatFloatBinOp(Info, E, LHSFloat, Opcode,
3010 RHSElt.getFloat())) {
3011 Info.FFDiag(E);
3012 return false;
3013 }
3014
3015 ResultElements.emplace_back(LHSFloat);
3016 }
3017 }
3018
3019 LHSValue = APValue(ResultElements.data(), ResultElements.size());
3020 return true;
3021}
3022
3023/// Cast an lvalue referring to a base subobject to a derived class, by
3024/// truncating the lvalue's path to the given length.
3025static bool CastToDerivedClass(EvalInfo &Info, const Expr *E, LValue &Result,
3026 const RecordDecl *TruncatedType,
3027 unsigned TruncatedElements) {
3028 SubobjectDesignator &D = Result.Designator;
3029
3030 // Check we actually point to a derived class object.
3031 if (TruncatedElements == D.Entries.size())
3032 return true;
3033 assert(TruncatedElements >= D.MostDerivedPathLength &&(static_cast <bool> (TruncatedElements >= D.MostDerivedPathLength
&& "not casting to a derived class") ? void (0) : __assert_fail
("TruncatedElements >= D.MostDerivedPathLength && \"not casting to a derived class\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3034, __extension__ __PRETTY_FUNCTION__))
3034 "not casting to a derived class")(static_cast <bool> (TruncatedElements >= D.MostDerivedPathLength
&& "not casting to a derived class") ? void (0) : __assert_fail
("TruncatedElements >= D.MostDerivedPathLength && \"not casting to a derived class\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3034, __extension__ __PRETTY_FUNCTION__))
;
3035 if (!Result.checkSubobject(Info, E, CSK_Derived))
3036 return false;
3037
3038 // Truncate the path to the subobject, and remove any derived-to-base offsets.
3039 const RecordDecl *RD = TruncatedType;
3040 for (unsigned I = TruncatedElements, N = D.Entries.size(); I != N; ++I) {
3041 if (RD->isInvalidDecl()) return false;
3042 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
3043 const CXXRecordDecl *Base = getAsBaseClass(D.Entries[I]);
3044 if (isVirtualBaseClass(D.Entries[I]))
3045 Result.Offset -= Layout.getVBaseClassOffset(Base);
3046 else
3047 Result.Offset -= Layout.getBaseClassOffset(Base);
3048 RD = Base;
3049 }
3050 D.Entries.resize(TruncatedElements);
3051 return true;
3052}
3053
3054static bool HandleLValueDirectBase(EvalInfo &Info, const Expr *E, LValue &Obj,
3055 const CXXRecordDecl *Derived,
3056 const CXXRecordDecl *Base,
3057 const ASTRecordLayout *RL = nullptr) {
3058 if (!RL) {
3059 if (Derived->isInvalidDecl()) return false;
3060 RL = &Info.Ctx.getASTRecordLayout(Derived);
3061 }
3062
3063 Obj.getLValueOffset() += RL->getBaseClassOffset(Base);
3064 Obj.addDecl(Info, E, Base, /*Virtual*/ false);
3065 return true;
3066}
3067
3068static bool HandleLValueBase(EvalInfo &Info, const Expr *E, LValue &Obj,
3069 const CXXRecordDecl *DerivedDecl,
3070 const CXXBaseSpecifier *Base) {
3071 const CXXRecordDecl *BaseDecl = Base->getType()->getAsCXXRecordDecl();
3072
3073 if (!Base->isVirtual())
3074 return HandleLValueDirectBase(Info, E, Obj, DerivedDecl, BaseDecl);
3075
3076 SubobjectDesignator &D = Obj.Designator;
3077 if (D.Invalid)
3078 return false;
3079
3080 // Extract most-derived object and corresponding type.
3081 DerivedDecl = D.MostDerivedType->getAsCXXRecordDecl();
3082 if (!CastToDerivedClass(Info, E, Obj, DerivedDecl, D.MostDerivedPathLength))
3083 return false;
3084
3085 // Find the virtual base class.
3086 if (DerivedDecl->isInvalidDecl()) return false;
3087 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(DerivedDecl);
3088 Obj.getLValueOffset() += Layout.getVBaseClassOffset(BaseDecl);
3089 Obj.addDecl(Info, E, BaseDecl, /*Virtual*/ true);
3090 return true;
3091}
3092
3093static bool HandleLValueBasePath(EvalInfo &Info, const CastExpr *E,
3094 QualType Type, LValue &Result) {
3095 for (CastExpr::path_const_iterator PathI = E->path_begin(),
3096 PathE = E->path_end();
3097 PathI != PathE; ++PathI) {
3098 if (!HandleLValueBase(Info, E, Result, Type->getAsCXXRecordDecl(),
3099 *PathI))
3100 return false;
3101 Type = (*PathI)->getType();
3102 }
3103 return true;
3104}
3105
3106/// Cast an lvalue referring to a derived class to a known base subobject.
3107static bool CastToBaseClass(EvalInfo &Info, const Expr *E, LValue &Result,
3108 const CXXRecordDecl *DerivedRD,
3109 const CXXRecordDecl *BaseRD) {
3110 CXXBasePaths Paths(/*FindAmbiguities=*/false,
3111 /*RecordPaths=*/true, /*DetectVirtual=*/false);
3112 if (!DerivedRD->isDerivedFrom(BaseRD, Paths))
3113 llvm_unreachable("Class must be derived from the passed in base class!")::llvm::llvm_unreachable_internal("Class must be derived from the passed in base class!"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3113)
;
3114
3115 for (CXXBasePathElement &Elem : Paths.front())
3116 if (!HandleLValueBase(Info, E, Result, Elem.Class, Elem.Base))
3117 return false;
3118 return true;
3119}
3120
3121/// Update LVal to refer to the given field, which must be a member of the type
3122/// currently described by LVal.
3123static bool HandleLValueMember(EvalInfo &Info, const Expr *E, LValue &LVal,
3124 const FieldDecl *FD,
3125 const ASTRecordLayout *RL = nullptr) {
3126 if (!RL) {
3127 if (FD->getParent()->isInvalidDecl()) return false;
3128 RL = &Info.Ctx.getASTRecordLayout(FD->getParent());
3129 }
3130
3131 unsigned I = FD->getFieldIndex();
3132 LVal.adjustOffset(Info.Ctx.toCharUnitsFromBits(RL->getFieldOffset(I)));
3133 LVal.addDecl(Info, E, FD);
3134 return true;
3135}
3136
3137/// Update LVal to refer to the given indirect field.
3138static bool HandleLValueIndirectMember(EvalInfo &Info, const Expr *E,
3139 LValue &LVal,
3140 const IndirectFieldDecl *IFD) {
3141 for (const auto *C : IFD->chain())
3142 if (!HandleLValueMember(Info, E, LVal, cast<FieldDecl>(C)))
3143 return false;
3144 return true;
3145}
3146
3147/// Get the size of the given type in char units.
3148static bool HandleSizeof(EvalInfo &Info, SourceLocation Loc,
3149 QualType Type, CharUnits &Size) {
3150 // sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc
3151 // extension.
3152 if (Type->isVoidType() || Type->isFunctionType()) {
3153 Size = CharUnits::One();
3154 return true;
3155 }
3156
3157 if (Type->isDependentType()) {
3158 Info.FFDiag(Loc);
3159 return false;
3160 }
3161
3162 if (!Type->isConstantSizeType()) {
3163 // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
3164 // FIXME: Better diagnostic.
3165 Info.FFDiag(Loc);
3166 return false;
3167 }
3168
3169 Size = Info.Ctx.getTypeSizeInChars(Type);
3170 return true;
3171}
3172
3173/// Update a pointer value to model pointer arithmetic.
3174/// \param Info - Information about the ongoing evaluation.
3175/// \param E - The expression being evaluated, for diagnostic purposes.
3176/// \param LVal - The pointer value to be updated.
3177/// \param EltTy - The pointee type represented by LVal.
3178/// \param Adjustment - The adjustment, in objects of type EltTy, to add.
3179static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
3180 LValue &LVal, QualType EltTy,
3181 APSInt Adjustment) {
3182 CharUnits SizeOfPointee;
3183 if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfPointee))
29
Called C++ object pointer is null
3184 return false;
3185
3186 LVal.adjustOffsetAndIndex(Info, E, Adjustment, SizeOfPointee);
3187 return true;
3188}
3189
3190static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
3191 LValue &LVal, QualType EltTy,
3192 int64_t Adjustment) {
3193 return HandleLValueArrayAdjustment(Info, E, LVal, EltTy,
27
Passing null pointer value via 2nd parameter 'E'
28
Calling 'HandleLValueArrayAdjustment'
3194 APSInt::get(Adjustment));
3195}
3196
3197/// Update an lvalue to refer to a component of a complex number.
3198/// \param Info - Information about the ongoing evaluation.
3199/// \param LVal - The lvalue to be updated.
3200/// \param EltTy - The complex number's component type.
3201/// \param Imag - False for the real component, true for the imaginary.
3202static bool HandleLValueComplexElement(EvalInfo &Info, const Expr *E,
3203 LValue &LVal, QualType EltTy,
3204 bool Imag) {
3205 if (Imag) {
3206 CharUnits SizeOfComponent;
3207 if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfComponent))
3208 return false;
3209 LVal.Offset += SizeOfComponent;
3210 }
3211 LVal.addComplex(Info, E, EltTy, Imag);
3212 return true;
3213}
3214
3215/// Try to evaluate the initializer for a variable declaration.
3216///
3217/// \param Info Information about the ongoing evaluation.
3218/// \param E An expression to be used when printing diagnostics.
3219/// \param VD The variable whose initializer should be obtained.
3220/// \param Version The version of the variable within the frame.
3221/// \param Frame The frame in which the variable was created. Must be null
3222/// if this variable is not local to the evaluation.
3223/// \param Result Filled in with a pointer to the value of the variable.
3224static bool evaluateVarDeclInit(EvalInfo &Info, const Expr *E,
3225 const VarDecl *VD, CallStackFrame *Frame,
3226 unsigned Version, APValue *&Result) {
3227 APValue::LValueBase Base(VD, Frame ? Frame->Index : 0, Version);
3228
3229 // If this is a local variable, dig out its value.
3230 if (Frame) {
3231 Result = Frame->getTemporary(VD, Version);
3232 if (Result)
3233 return true;
3234
3235 if (!isa<ParmVarDecl>(VD)) {
3236 // Assume variables referenced within a lambda's call operator that were
3237 // not declared within the call operator are captures and during checking
3238 // of a potential constant expression, assume they are unknown constant
3239 // expressions.
3240 assert(isLambdaCallOperator(Frame->Callee) &&(static_cast <bool> (isLambdaCallOperator(Frame->Callee
) && (VD->getDeclContext() != Frame->Callee || VD
->isInitCapture()) && "missing value for local variable"
) ? void (0) : __assert_fail ("isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) && \"missing value for local variable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3242, __extension__ __PRETTY_FUNCTION__))
3241 (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) &&(static_cast <bool> (isLambdaCallOperator(Frame->Callee
) && (VD->getDeclContext() != Frame->Callee || VD
->isInitCapture()) && "missing value for local variable"
) ? void (0) : __assert_fail ("isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) && \"missing value for local variable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3242, __extension__ __PRETTY_FUNCTION__))
3242 "missing value for local variable")(static_cast <bool> (isLambdaCallOperator(Frame->Callee
) && (VD->getDeclContext() != Frame->Callee || VD
->isInitCapture()) && "missing value for local variable"
) ? void (0) : __assert_fail ("isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) && \"missing value for local variable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3242, __extension__ __PRETTY_FUNCTION__))
;
3243 if (Info.checkingPotentialConstantExpression())
3244 return false;
3245 // FIXME: This diagnostic is bogus; we do support captures. Is this code
3246 // still reachable at all?
3247 Info.FFDiag(E->getBeginLoc(),
3248 diag::note_unimplemented_constexpr_lambda_feature_ast)
3249 << "captures not currently allowed";
3250 return false;
3251 }
3252 }
3253
3254 // If we're currently evaluating the initializer of this declaration, use that
3255 // in-flight value.
3256 if (Info.EvaluatingDecl == Base) {
3257 Result = Info.EvaluatingDeclValue;
3258 return true;
3259 }
3260
3261 if (isa<ParmVarDecl>(VD)) {
3262 // Assume parameters of a potential constant expression are usable in
3263 // constant expressions.
3264 if (!Info.checkingPotentialConstantExpression() ||
3265 !Info.CurrentCall->Callee ||
3266 !Info.CurrentCall->Callee->Equals(VD->getDeclContext())) {
3267 if (Info.getLangOpts().CPlusPlus11) {
3268 Info.FFDiag(E, diag::note_constexpr_function_param_value_unknown)
3269 << VD;
3270 NoteLValueLocation(Info, Base);
3271 } else {
3272 Info.FFDiag(E);
3273 }
3274 }
3275 return false;
3276 }
3277
3278 // Dig out the initializer, and use the declaration which it's attached to.
3279 // FIXME: We should eventually check whether the variable has a reachable
3280 // initializing declaration.
3281 const Expr *Init = VD->getAnyInitializer(VD);
3282 if (!Init) {
3283 // Don't diagnose during potential constant expression checking; an
3284 // initializer might be added later.
3285 if (!Info.checkingPotentialConstantExpression()) {
3286 Info.FFDiag(E, diag::note_constexpr_var_init_unknown, 1)
3287 << VD;
3288 NoteLValueLocation(Info, Base);
3289 }
3290 return false;
3291 }
3292
3293 if (Init->isValueDependent()) {
3294 // The DeclRefExpr is not value-dependent, but the variable it refers to
3295 // has a value-dependent initializer. This should only happen in
3296 // constant-folding cases, where the variable is not actually of a suitable
3297 // type for use in a constant expression (otherwise the DeclRefExpr would
3298 // have been value-dependent too), so diagnose that.
3299 assert(!VD->mightBeUsableInConstantExpressions(Info.Ctx))(static_cast <bool> (!VD->mightBeUsableInConstantExpressions
(Info.Ctx)) ? void (0) : __assert_fail ("!VD->mightBeUsableInConstantExpressions(Info.Ctx)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3299, __extension__ __PRETTY_FUNCTION__))
;
3300 if (!Info.checkingPotentialConstantExpression()) {
3301 Info.FFDiag(E, Info.getLangOpts().CPlusPlus11
3302 ? diag::note_constexpr_ltor_non_constexpr
3303 : diag::note_constexpr_ltor_non_integral, 1)
3304 << VD << VD->getType();
3305 NoteLValueLocation(Info, Base);
3306 }
3307 return false;
3308 }
3309
3310 // Check that we can fold the initializer. In C++, we will have already done
3311 // this in the cases where it matters for conformance.
3312 if (!VD->evaluateValue()) {
3313 Info.FFDiag(E, diag::note_constexpr_var_init_non_constant, 1) << VD;
3314 NoteLValueLocation(Info, Base);
3315 return false;
3316 }
3317
3318 // Check that the variable is actually usable in constant expressions. For a
3319 // const integral variable or a reference, we might have a non-constant
3320 // initializer that we can nonetheless evaluate the initializer for. Such
3321 // variables are not usable in constant expressions. In C++98, the
3322 // initializer also syntactically needs to be an ICE.
3323 //
3324 // FIXME: We don't diagnose cases that aren't potentially usable in constant
3325 // expressions here; doing so would regress diagnostics for things like
3326 // reading from a volatile constexpr variable.
3327 if ((Info.getLangOpts().CPlusPlus && !VD->hasConstantInitialization() &&
3328 VD->mightBeUsableInConstantExpressions(Info.Ctx)) ||
3329 ((Info.getLangOpts().CPlusPlus || Info.getLangOpts().OpenCL) &&
3330 !Info.getLangOpts().CPlusPlus11 && !VD->hasICEInitializer(Info.Ctx))) {
3331 Info.CCEDiag(E, diag::note_constexpr_var_init_non_constant, 1) << VD;
3332 NoteLValueLocation(Info, Base);
3333 }
3334
3335 // Never use the initializer of a weak variable, not even for constant
3336 // folding. We can't be sure that this is the definition that will be used.
3337 if (VD->isWeak()) {
3338 Info.FFDiag(E, diag::note_constexpr_var_init_weak) << VD;
3339 NoteLValueLocation(Info, Base);
3340 return false;
3341 }
3342
3343 Result = VD->getEvaluatedValue();
3344 return true;
3345}
3346
3347/// Get the base index of the given base class within an APValue representing
3348/// the given derived class.
3349static unsigned getBaseIndex(const CXXRecordDecl *Derived,
3350 const CXXRecordDecl *Base) {
3351 Base = Base->getCanonicalDecl();
3352 unsigned Index = 0;
3353 for (CXXRecordDecl::base_class_const_iterator I = Derived->bases_begin(),
3354 E = Derived->bases_end(); I != E; ++I, ++Index) {
3355 if (I->getType()->getAsCXXRecordDecl()->getCanonicalDecl() == Base)
3356 return Index;
3357 }
3358
3359 llvm_unreachable("base class missing from derived class's bases list")::llvm::llvm_unreachable_internal("base class missing from derived class's bases list"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3359)
;
3360}
3361
3362/// Extract the value of a character from a string literal.
3363static APSInt extractStringLiteralCharacter(EvalInfo &Info, const Expr *Lit,
3364 uint64_t Index) {
3365 assert(!isa<SourceLocExpr>(Lit) &&(static_cast <bool> (!isa<SourceLocExpr>(Lit) &&
"SourceLocExpr should have already been converted to a StringLiteral"
) ? void (0) : __assert_fail ("!isa<SourceLocExpr>(Lit) && \"SourceLocExpr should have already been converted to a StringLiteral\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3366, __extension__ __PRETTY_FUNCTION__))
3366 "SourceLocExpr should have already been converted to a StringLiteral")(static_cast <bool> (!isa<SourceLocExpr>(Lit) &&
"SourceLocExpr should have already been converted to a StringLiteral"
) ? void (0) : __assert_fail ("!isa<SourceLocExpr>(Lit) && \"SourceLocExpr should have already been converted to a StringLiteral\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3366, __extension__ __PRETTY_FUNCTION__))
;
3367
3368 // FIXME: Support MakeStringConstant
3369 if (const auto *ObjCEnc = dyn_cast<ObjCEncodeExpr>(Lit)) {
3370 std::string Str;
3371 Info.Ctx.getObjCEncodingForType(ObjCEnc->getEncodedType(), Str);
3372 assert(Index <= Str.size() && "Index too large")(static_cast <bool> (Index <= Str.size() && "Index too large"
) ? void (0) : __assert_fail ("Index <= Str.size() && \"Index too large\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3372, __extension__ __PRETTY_FUNCTION__))
;
3373 return APSInt::getUnsigned(Str.c_str()[Index]);
3374 }
3375
3376 if (auto PE = dyn_cast<PredefinedExpr>(Lit))
3377 Lit = PE->getFunctionName();
3378 const StringLiteral *S = cast<StringLiteral>(Lit);
3379 const ConstantArrayType *CAT =
3380 Info.Ctx.getAsConstantArrayType(S->getType());
3381 assert(CAT && "string literal isn't an array")(static_cast <bool> (CAT && "string literal isn't an array"
) ? void (0) : __assert_fail ("CAT && \"string literal isn't an array\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3381, __extension__ __PRETTY_FUNCTION__))
;
3382 QualType CharType = CAT->getElementType();
3383 assert(CharType->isIntegerType() && "unexpected character type")(static_cast <bool> (CharType->isIntegerType() &&
"unexpected character type") ? void (0) : __assert_fail ("CharType->isIntegerType() && \"unexpected character type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3383, __extension__ __PRETTY_FUNCTION__))
;
3384
3385 APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
3386 CharType->isUnsignedIntegerType());
3387 if (Index < S->getLength())
3388 Value = S->getCodeUnit(Index);
3389 return Value;
3390}
3391
3392// Expand a string literal into an array of characters.
3393//
3394// FIXME: This is inefficient; we should probably introduce something similar
3395// to the LLVM ConstantDataArray to make this cheaper.
3396static void expandStringLiteral(EvalInfo &Info, const StringLiteral *S,
3397 APValue &Result,
3398 QualType AllocType = QualType()) {
3399 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(
3400 AllocType.isNull() ? S->getType() : AllocType);
3401 assert(CAT && "string literal isn't an array")(static_cast <bool> (CAT && "string literal isn't an array"
) ? void (0) : __assert_fail ("CAT && \"string literal isn't an array\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3401, __extension__ __PRETTY_FUNCTION__))
;
3402 QualType CharType = CAT->getElementType();
3403 assert(CharType->isIntegerType() && "unexpected character type")(static_cast <bool> (CharType->isIntegerType() &&
"unexpected character type") ? void (0) : __assert_fail ("CharType->isIntegerType() && \"unexpected character type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3403, __extension__ __PRETTY_FUNCTION__))
;
3404
3405 unsigned Elts = CAT->getSize().getZExtValue();
3406 Result = APValue(APValue::UninitArray(),
3407 std::min(S->getLength(), Elts), Elts);
3408 APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
3409 CharType->isUnsignedIntegerType());
3410 if (Result.hasArrayFiller())
3411 Result.getArrayFiller() = APValue(Value);
3412 for (unsigned I = 0, N = Result.getArrayInitializedElts(); I != N; ++I) {
3413 Value = S->getCodeUnit(I);
3414 Result.getArrayInitializedElt(I) = APValue(Value);
3415 }
3416}
3417
3418// Expand an array so that it has more than Index filled elements.
3419static void expandArray(APValue &Array, unsigned Index) {
3420 unsigned Size = Array.getArraySize();
3421 assert(Index < Size)(static_cast <bool> (Index < Size) ? void (0) : __assert_fail
("Index < Size", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3421, __extension__ __PRETTY_FUNCTION__))
;
3422
3423 // Always at least double the number of elements for which we store a value.
3424 unsigned OldElts = Array.getArrayInitializedElts();
3425 unsigned NewElts = std::max(Index+1, OldElts * 2);
3426 NewElts = std::min(Size, std::max(NewElts, 8u));
3427
3428 // Copy the data across.
3429 APValue NewValue(APValue::UninitArray(), NewElts, Size);
3430 for (unsigned I = 0; I != OldElts; ++I)
3431 NewValue.getArrayInitializedElt(I).swap(Array.getArrayInitializedElt(I));
3432 for (unsigned I = OldElts; I != NewElts; ++I)
3433 NewValue.getArrayInitializedElt(I) = Array.getArrayFiller();
3434 if (NewValue.hasArrayFiller())
3435 NewValue.getArrayFiller() = Array.getArrayFiller();
3436 Array.swap(NewValue);
3437}
3438
3439/// Determine whether a type would actually be read by an lvalue-to-rvalue
3440/// conversion. If it's of class type, we may assume that the copy operation
3441/// is trivial. Note that this is never true for a union type with fields
3442/// (because the copy always "reads" the active member) and always true for
3443/// a non-class type.
3444static bool isReadByLvalueToRvalueConversion(const CXXRecordDecl *RD);
3445static bool isReadByLvalueToRvalueConversion(QualType T) {
3446 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
3447 return !RD || isReadByLvalueToRvalueConversion(RD);
3448}
3449static bool isReadByLvalueToRvalueConversion(const CXXRecordDecl *RD) {
3450 // FIXME: A trivial copy of a union copies the object representation, even if
3451 // the union is empty.
3452 if (RD->isUnion())
3453 return !RD->field_empty();
3454 if (RD->isEmpty())
3455 return false;
3456
3457 for (auto *Field : RD->fields())
3458 if (!Field->isUnnamedBitfield() &&
3459 isReadByLvalueToRvalueConversion(Field->getType()))
3460 return true;
3461
3462 for (auto &BaseSpec : RD->bases())
3463 if (isReadByLvalueToRvalueConversion(BaseSpec.getType()))
3464 return true;
3465
3466 return false;
3467}
3468
3469/// Diagnose an attempt to read from any unreadable field within the specified
3470/// type, which might be a class type.
3471static bool diagnoseMutableFields(EvalInfo &Info, const Expr *E, AccessKinds AK,
3472 QualType T) {
3473 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
3474 if (!RD)
3475 return false;
3476
3477 if (!RD->hasMutableFields())
3478 return false;
3479
3480 for (auto *Field : RD->fields()) {
3481 // If we're actually going to read this field in some way, then it can't
3482 // be mutable. If we're in a union, then assigning to a mutable field
3483 // (even an empty one) can change the active member, so that's not OK.
3484 // FIXME: Add core issue number for the union case.
3485 if (Field->isMutable() &&
3486 (RD->isUnion() || isReadByLvalueToRvalueConversion(Field->getType()))) {
3487 Info.FFDiag(E, diag::note_constexpr_access_mutable, 1) << AK << Field;
3488 Info.Note(Field->getLocation(), diag::note_declared_at);
3489 return true;
3490 }
3491
3492 if (diagnoseMutableFields(Info, E, AK, Field->getType()))
3493 return true;
3494 }
3495
3496 for (auto &BaseSpec : RD->bases())
3497 if (diagnoseMutableFields(Info, E, AK, BaseSpec.getType()))
3498 return true;
3499
3500 // All mutable fields were empty, and thus not actually read.
3501 return false;
3502}
3503
3504static bool lifetimeStartedInEvaluation(EvalInfo &Info,
3505 APValue::LValueBase Base,
3506 bool MutableSubobject = false) {
3507 // A temporary or transient heap allocation we created.
3508 if (Base.getCallIndex() || Base.is<DynamicAllocLValue>())
3509 return true;
3510
3511 switch (Info.IsEvaluatingDecl) {
3512 case EvalInfo::EvaluatingDeclKind::None:
3513 return false;
3514
3515 case EvalInfo::EvaluatingDeclKind::Ctor:
3516 // The variable whose initializer we're evaluating.
3517 if (Info.EvaluatingDecl == Base)
3518 return true;
3519
3520 // A temporary lifetime-extended by the variable whose initializer we're
3521 // evaluating.
3522 if (auto *BaseE = Base.dyn_cast<const Expr *>())
3523 if (auto *BaseMTE = dyn_cast<MaterializeTemporaryExpr>(BaseE))
3524 return Info.EvaluatingDecl == BaseMTE->getExtendingDecl();
3525 return false;
3526
3527 case EvalInfo::EvaluatingDeclKind::Dtor:
3528 // C++2a [expr.const]p6:
3529 // [during constant destruction] the lifetime of a and its non-mutable
3530 // subobjects (but not its mutable subobjects) [are] considered to start
3531 // within e.
3532 if (MutableSubobject || Base != Info.EvaluatingDecl)
3533 return false;
3534 // FIXME: We can meaningfully extend this to cover non-const objects, but
3535 // we will need special handling: we should be able to access only
3536 // subobjects of such objects that are themselves declared const.
3537 QualType T = getType(Base);
3538 return T.isConstQualified() || T->isReferenceType();
3539 }
3540
3541 llvm_unreachable("unknown evaluating decl kind")::llvm::llvm_unreachable_internal("unknown evaluating decl kind"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3541)
;
3542}
3543
3544namespace {
3545/// A handle to a complete object (an object that is not a subobject of
3546/// another object).
3547struct CompleteObject {
3548 /// The identity of the object.
3549 APValue::LValueBase Base;
3550 /// The value of the complete object.
3551 APValue *Value;
3552 /// The type of the complete object.
3553 QualType Type;
3554
3555 CompleteObject() : Value(nullptr) {}
3556 CompleteObject(APValue::LValueBase Base, APValue *Value, QualType Type)
3557 : Base(Base), Value(Value), Type(Type) {}
3558
3559 bool mayAccessMutableMembers(EvalInfo &Info, AccessKinds AK) const {
3560 // If this isn't a "real" access (eg, if it's just accessing the type
3561 // info), allow it. We assume the type doesn't change dynamically for
3562 // subobjects of constexpr objects (even though we'd hit UB here if it
3563 // did). FIXME: Is this right?
3564 if (!isAnyAccess(AK))
3565 return true;
3566
3567 // In C++14 onwards, it is permitted to read a mutable member whose
3568 // lifetime began within the evaluation.
3569 // FIXME: Should we also allow this in C++11?
3570 if (!Info.getLangOpts().CPlusPlus14)
3571 return false;
3572 return lifetimeStartedInEvaluation(Info, Base, /*MutableSubobject*/true);
3573 }
3574
3575 explicit operator bool() const { return !Type.isNull(); }
3576};
3577} // end anonymous namespace
3578
3579static QualType getSubobjectType(QualType ObjType, QualType SubobjType,
3580 bool IsMutable = false) {
3581 // C++ [basic.type.qualifier]p1:
3582 // - A const object is an object of type const T or a non-mutable subobject
3583 // of a const object.
3584 if (ObjType.isConstQualified() && !IsMutable)
3585 SubobjType.addConst();
3586 // - A volatile object is an object of type const T or a subobject of a
3587 // volatile object.
3588 if (ObjType.isVolatileQualified())
3589 SubobjType.addVolatile();
3590 return SubobjType;
3591}
3592
3593/// Find the designated sub-object of an rvalue.
3594template<typename SubobjectHandler>
3595typename SubobjectHandler::result_type
3596findSubobject(EvalInfo &Info, const Expr *E, const CompleteObject &Obj,
3597 const SubobjectDesignator &Sub, SubobjectHandler &handler) {
3598 if (Sub.Invalid)
3599 // A diagnostic will have already been produced.
3600 return handler.failed();
3601 if (Sub.isOnePastTheEnd() || Sub.isMostDerivedAnUnsizedArray()) {
3602 if (Info.getLangOpts().CPlusPlus11)
3603 Info.FFDiag(E, Sub.isOnePastTheEnd()
3604 ? diag::note_constexpr_access_past_end
3605 : diag::note_constexpr_access_unsized_array)
3606 << handler.AccessKind;
3607 else
3608 Info.FFDiag(E);
3609 return handler.failed();
3610 }
3611
3612 APValue *O = Obj.Value;
3613 QualType ObjType = Obj.Type;
3614 const FieldDecl *LastField = nullptr;
3615 const FieldDecl *VolatileField = nullptr;
3616
3617 // Walk the designator's path to find the subobject.
3618 for (unsigned I = 0, N = Sub.Entries.size(); /**/; ++I) {
3619 // Reading an indeterminate value is undefined, but assigning over one is OK.
3620 if ((O->isAbsent() && !(handler.AccessKind == AK_Construct && I == N)) ||
3621 (O->isIndeterminate() &&
3622 !isValidIndeterminateAccess(handler.AccessKind))) {
3623 if (!Info.checkingPotentialConstantExpression())
3624 Info.FFDiag(E, diag::note_constexpr_access_uninit)
3625 << handler.AccessKind << O->isIndeterminate();
3626 return handler.failed();
3627 }
3628
3629 // C++ [class.ctor]p5, C++ [class.dtor]p5:
3630 // const and volatile semantics are not applied on an object under
3631 // {con,de}struction.
3632 if ((ObjType.isConstQualified() || ObjType.isVolatileQualified()) &&
3633 ObjType->isRecordType() &&
3634 Info.isEvaluatingCtorDtor(
3635 Obj.Base, llvm::makeArrayRef(Sub.Entries.begin(),
3636 Sub.Entries.begin() + I)) !=
3637 ConstructionPhase::None) {
3638 ObjType = Info.Ctx.getCanonicalType(ObjType);
3639 ObjType.removeLocalConst();
3640 ObjType.removeLocalVolatile();
3641 }
3642
3643 // If this is our last pass, check that the final object type is OK.
3644 if (I == N || (I == N - 1 && ObjType->isAnyComplexType())) {
3645 // Accesses to volatile objects are prohibited.
3646 if (ObjType.isVolatileQualified() && isFormalAccess(handler.AccessKind)) {
3647 if (Info.getLangOpts().CPlusPlus) {
3648 int DiagKind;
3649 SourceLocation Loc;
3650 const NamedDecl *Decl = nullptr;
3651 if (VolatileField) {
3652 DiagKind = 2;
3653 Loc = VolatileField->getLocation();
3654 Decl = VolatileField;
3655 } else if (auto *VD = Obj.Base.dyn_cast<const ValueDecl*>()) {
3656 DiagKind = 1;
3657 Loc = VD->getLocation();
3658 Decl = VD;
3659 } else {
3660 DiagKind = 0;
3661 if (auto *E = Obj.Base.dyn_cast<const Expr *>())
3662 Loc = E->getExprLoc();
3663 }
3664 Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
3665 << handler.AccessKind << DiagKind << Decl;
3666 Info.Note(Loc, diag::note_constexpr_volatile_here) << DiagKind;
3667 } else {
3668 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
3669 }
3670 return handler.failed();
3671 }
3672
3673 // If we are reading an object of class type, there may still be more
3674 // things we need to check: if there are any mutable subobjects, we
3675 // cannot perform this read. (This only happens when performing a trivial
3676 // copy or assignment.)
3677 if (ObjType->isRecordType() &&
3678 !Obj.mayAccessMutableMembers(Info, handler.AccessKind) &&
3679 diagnoseMutableFields(Info, E, handler.AccessKind, ObjType))
3680 return handler.failed();
3681 }
3682
3683 if (I == N) {
3684 if (!handler.found(*O, ObjType))
3685 return false;
3686
3687 // If we modified a bit-field, truncate it to the right width.
3688 if (isModification(handler.AccessKind) &&
3689 LastField && LastField->isBitField() &&
3690 !truncateBitfieldValue(Info, E, *O, LastField))
3691 return false;
3692
3693 return true;
3694 }
3695
3696 LastField = nullptr;
3697 if (ObjType->isArrayType()) {
3698 // Next subobject is an array element.
3699 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(ObjType);
3700 assert(CAT && "vla in literal type?")(static_cast <bool> (CAT && "vla in literal type?"
) ? void (0) : __assert_fail ("CAT && \"vla in literal type?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3700, __extension__ __PRETTY_FUNCTION__))
;
3701 uint64_t Index = Sub.Entries[I].getAsArrayIndex();
3702 if (CAT->getSize().ule(Index)) {
3703 // Note, it should not be possible to form a pointer with a valid
3704 // designator which points more than one past the end of the array.
3705 if (Info.getLangOpts().CPlusPlus11)
3706 Info.FFDiag(E, diag::note_constexpr_access_past_end)
3707 << handler.AccessKind;
3708 else
3709 Info.FFDiag(E);
3710 return handler.failed();
3711 }
3712
3713 ObjType = CAT->getElementType();
3714
3715 if (O->getArrayInitializedElts() > Index)
3716 O = &O->getArrayInitializedElt(Index);
3717 else if (!isRead(handler.AccessKind)) {
3718 expandArray(*O, Index);
3719 O = &O->getArrayInitializedElt(Index);
3720 } else
3721 O = &O->getArrayFiller();
3722 } else if (ObjType->isAnyComplexType()) {
3723 // Next subobject is a complex number.
3724 uint64_t Index = Sub.Entries[I].getAsArrayIndex();
3725 if (Index > 1) {
3726 if (Info.getLangOpts().CPlusPlus11)
3727 Info.FFDiag(E, diag::note_constexpr_access_past_end)
3728 << handler.AccessKind;
3729 else
3730 Info.FFDiag(E);
3731 return handler.failed();
3732 }
3733
3734 ObjType = getSubobjectType(
3735 ObjType, ObjType->castAs<ComplexType>()->getElementType());
3736
3737 assert(I == N - 1 && "extracting subobject of scalar?")(static_cast <bool> (I == N - 1 && "extracting subobject of scalar?"
) ? void (0) : __assert_fail ("I == N - 1 && \"extracting subobject of scalar?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3737, __extension__ __PRETTY_FUNCTION__))
;
3738 if (O->isComplexInt()) {
3739 return handler.found(Index ? O->getComplexIntImag()
3740 : O->getComplexIntReal(), ObjType);
3741 } else {
3742 assert(O->isComplexFloat())(static_cast <bool> (O->isComplexFloat()) ? void (0)
: __assert_fail ("O->isComplexFloat()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3742, __extension__ __PRETTY_FUNCTION__))
;
3743 return handler.found(Index ? O->getComplexFloatImag()
3744 : O->getComplexFloatReal(), ObjType);
3745 }
3746 } else if (const FieldDecl *Field = getAsField(Sub.Entries[I])) {
3747 if (Field->isMutable() &&
3748 !Obj.mayAccessMutableMembers(Info, handler.AccessKind)) {
3749 Info.FFDiag(E, diag::note_constexpr_access_mutable, 1)
3750 << handler.AccessKind << Field;
3751 Info.Note(Field->getLocation(), diag::note_declared_at);
3752 return handler.failed();
3753 }
3754
3755 // Next subobject is a class, struct or union field.
3756 RecordDecl *RD = ObjType->castAs<RecordType>()->getDecl();
3757 if (RD->isUnion()) {
3758 const FieldDecl *UnionField = O->getUnionField();
3759 if (!UnionField ||
3760 UnionField->getCanonicalDecl() != Field->getCanonicalDecl()) {
3761 if (I == N - 1 && handler.AccessKind == AK_Construct) {
3762 // Placement new onto an inactive union member makes it active.
3763 O->setUnion(Field, APValue());
3764 } else {
3765 // FIXME: If O->getUnionValue() is absent, report that there's no
3766 // active union member rather than reporting the prior active union
3767 // member. We'll need to fix nullptr_t to not use APValue() as its
3768 // representation first.
3769 Info.FFDiag(E, diag::note_constexpr_access_inactive_union_member)
3770 << handler.AccessKind << Field << !UnionField << UnionField;
3771 return handler.failed();
3772 }
3773 }
3774 O = &O->getUnionValue();
3775 } else
3776 O = &O->getStructField(Field->getFieldIndex());
3777
3778 ObjType = getSubobjectType(ObjType, Field->getType(), Field->isMutable());
3779 LastField = Field;
3780 if (Field->getType().isVolatileQualified())
3781 VolatileField = Field;
3782 } else {
3783 // Next subobject is a base class.
3784 const CXXRecordDecl *Derived = ObjType->getAsCXXRecordDecl();
3785 const CXXRecordDecl *Base = getAsBaseClass(Sub.Entries[I]);
3786 O = &O->getStructBase(getBaseIndex(Derived, Base));
3787
3788 ObjType = getSubobjectType(ObjType, Info.Ctx.getRecordType(Base));
3789 }
3790 }
3791}
3792
3793namespace {
3794struct ExtractSubobjectHandler {
3795 EvalInfo &Info;
3796 const Expr *E;
3797 APValue &Result;
3798 const AccessKinds AccessKind;
3799
3800 typedef bool result_type;
3801 bool failed() { return false; }
3802 bool found(APValue &Subobj, QualType SubobjType) {
3803 Result = Subobj;
3804 if (AccessKind == AK_ReadObjectRepresentation)
3805 return true;
3806 return CheckFullyInitialized(Info, E->getExprLoc(), SubobjType, Result);
3807 }
3808 bool found(APSInt &Value, QualType SubobjType) {
3809 Result = APValue(Value);
3810 return true;
3811 }
3812 bool found(APFloat &Value, QualType SubobjType) {
3813 Result = APValue(Value);
3814 return true;
3815 }
3816};
3817} // end anonymous namespace
3818
3819/// Extract the designated sub-object of an rvalue.
3820static bool extractSubobject(EvalInfo &Info, const Expr *E,
3821 const CompleteObject &Obj,
3822 const SubobjectDesignator &Sub, APValue &Result,
3823 AccessKinds AK = AK_Read) {
3824 assert(AK == AK_Read || AK == AK_ReadObjectRepresentation)(static_cast <bool> (AK == AK_Read || AK == AK_ReadObjectRepresentation
) ? void (0) : __assert_fail ("AK == AK_Read || AK == AK_ReadObjectRepresentation"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 3824, __extension__ __PRETTY_FUNCTION__))
;
3825 ExtractSubobjectHandler Handler = {Info, E, Result, AK};
3826 return findSubobject(Info, E, Obj, Sub, Handler);
3827}
3828
3829namespace {
3830struct ModifySubobjectHandler {
3831 EvalInfo &Info;
3832 APValue &NewVal;
3833 const Expr *E;
3834
3835 typedef bool result_type;
3836 static const AccessKinds AccessKind = AK_Assign;
3837
3838 bool checkConst(QualType QT) {
3839 // Assigning to a const object has undefined behavior.
3840 if (QT.isConstQualified()) {
3841 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
3842 return false;
3843 }
3844 return true;
3845 }
3846
3847 bool failed() { return false; }
3848 bool found(APValue &Subobj, QualType SubobjType) {
3849 if (!checkConst(SubobjType))
3850 return false;
3851 // We've been given ownership of NewVal, so just swap it in.
3852 Subobj.swap(NewVal);
3853 return true;
3854 }
3855 bool found(APSInt &Value, QualType SubobjType) {
3856 if (!checkConst(SubobjType))
3857 return false;
3858 if (!NewVal.isInt()) {
3859 // Maybe trying to write a cast pointer value into a complex?
3860 Info.FFDiag(E);
3861 return false;
3862 }
3863 Value = NewVal.getInt();
3864 return true;
3865 }
3866 bool found(APFloat &Value, QualType SubobjType) {
3867 if (!checkConst(SubobjType))
3868 return false;
3869 Value = NewVal.getFloat();
3870 return true;
3871 }
3872};
3873} // end anonymous namespace
3874
3875const AccessKinds ModifySubobjectHandler::AccessKind;
3876
3877/// Update the designated sub-object of an rvalue to the given value.
3878static bool modifySubobject(EvalInfo &Info, const Expr *E,
3879 const CompleteObject &Obj,
3880 const SubobjectDesignator &Sub,
3881 APValue &NewVal) {
3882 ModifySubobjectHandler Handler = { Info, NewVal, E };
3883 return findSubobject(Info, E, Obj, Sub, Handler);
3884}
3885
3886/// Find the position where two subobject designators diverge, or equivalently
3887/// the length of the common initial subsequence.
3888static unsigned FindDesignatorMismatch(QualType ObjType,
3889 const SubobjectDesignator &A,
3890 const SubobjectDesignator &B,
3891 bool &WasArrayIndex) {
3892 unsigned I = 0, N = std::min(A.Entries.size(), B.Entries.size());
3893 for (/**/; I != N; ++I) {
3894 if (!ObjType.isNull() &&
3895 (ObjType->isArrayType() || ObjType->isAnyComplexType())) {
3896 // Next subobject is an array element.
3897 if (A.Entries[I].getAsArrayIndex() != B.Entries[I].getAsArrayIndex()) {
3898 WasArrayIndex = true;
3899 return I;
3900 }
3901 if (ObjType->isAnyComplexType())
3902 ObjType = ObjType->castAs<ComplexType>()->getElementType();
3903 else
3904 ObjType = ObjType->castAsArrayTypeUnsafe()->getElementType();
3905 } else {
3906 if (A.Entries[I].getAsBaseOrMember() !=
3907 B.Entries[I].getAsBaseOrMember()) {
3908 WasArrayIndex = false;
3909 return I;
3910 }
3911 if (const FieldDecl *FD = getAsField(A.Entries[I]))
3912 // Next subobject is a field.
3913 ObjType = FD->getType();
3914 else
3915 // Next subobject is a base class.
3916 ObjType = QualType();
3917 }
3918 }
3919 WasArrayIndex = false;
3920 return I;
3921}
3922
3923/// Determine whether the given subobject designators refer to elements of the
3924/// same array object.
3925static bool AreElementsOfSameArray(QualType ObjType,
3926 const SubobjectDesignator &A,
3927 const SubobjectDesignator &B) {
3928 if (A.Entries.size() != B.Entries.size())
3929 return false;
3930
3931 bool IsArray = A.MostDerivedIsArrayElement;
3932 if (IsArray && A.MostDerivedPathLength != A.Entries.size())
3933 // A is a subobject of the array element.
3934 return false;
3935
3936 // If A (and B) designates an array element, the last entry will be the array
3937 // index. That doesn't have to match. Otherwise, we're in the 'implicit array
3938 // of length 1' case, and the entire path must match.
3939 bool WasArrayIndex;
3940 unsigned CommonLength = FindDesignatorMismatch(ObjType, A, B, WasArrayIndex);
3941 return CommonLength >= A.Entries.size() - IsArray;
3942}
3943
3944/// Find the complete object to which an LValue refers.
3945static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
3946 AccessKinds AK, const LValue &LVal,
3947 QualType LValType) {
3948 if (LVal.InvalidBase) {
3949 Info.FFDiag(E);
3950 return CompleteObject();
3951 }
3952
3953 if (!LVal.Base) {
3954 Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
3955 return CompleteObject();
3956 }
3957
3958 CallStackFrame *Frame = nullptr;
3959 unsigned Depth = 0;
3960 if (LVal.getLValueCallIndex()) {
3961 std::tie(Frame, Depth) =
3962 Info.getCallFrameAndDepth(LVal.getLValueCallIndex());
3963 if (!Frame) {
3964 Info.FFDiag(E, diag::note_constexpr_lifetime_ended, 1)
3965 << AK << LVal.Base.is<const ValueDecl*>();
3966 NoteLValueLocation(Info, LVal.Base);
3967 return CompleteObject();
3968 }
3969 }
3970
3971 bool IsAccess = isAnyAccess(AK);
3972
3973 // C++11 DR1311: An lvalue-to-rvalue conversion on a volatile-qualified type
3974 // is not a constant expression (even if the object is non-volatile). We also
3975 // apply this rule to C++98, in order to conform to the expected 'volatile'
3976 // semantics.
3977 if (isFormalAccess(AK) && LValType.isVolatileQualified()) {
3978 if (Info.getLangOpts().CPlusPlus)
3979 Info.FFDiag(E, diag::note_constexpr_access_volatile_type)
3980 << AK << LValType;
3981 else
3982 Info.FFDiag(E);
3983 return CompleteObject();
3984 }
3985
3986 // Compute value storage location and type of base object.
3987 APValue *BaseVal = nullptr;
3988 QualType BaseType = getType(LVal.Base);
3989
3990 if (Info.getLangOpts().CPlusPlus14 && LVal.Base == Info.EvaluatingDecl &&
3991 lifetimeStartedInEvaluation(Info, LVal.Base)) {
3992 // This is the object whose initializer we're evaluating, so its lifetime
3993 // started in the current evaluation.
3994 BaseVal = Info.EvaluatingDeclValue;
3995 } else if (const ValueDecl *D = LVal.Base.dyn_cast<const ValueDecl *>()) {
3996 // Allow reading from a GUID declaration.
3997 if (auto *GD = dyn_cast<MSGuidDecl>(D)) {
3998 if (isModification(AK)) {
3999 // All the remaining cases do not permit modification of the object.
4000 Info.FFDiag(E, diag::note_constexpr_modify_global);
4001 return CompleteObject();
4002 }
4003 APValue &V = GD->getAsAPValue();
4004 if (V.isAbsent()) {
4005 Info.FFDiag(E, diag::note_constexpr_unsupported_layout)
4006 << GD->getType();
4007 return CompleteObject();
4008 }
4009 return CompleteObject(LVal.Base, &V, GD->getType());
4010 }
4011
4012 // Allow reading from template parameter objects.
4013 if (auto *TPO = dyn_cast<TemplateParamObjectDecl>(D)) {
4014 if (isModification(AK)) {
4015 Info.FFDiag(E, diag::note_constexpr_modify_global);
4016 return CompleteObject();
4017 }
4018 return CompleteObject(LVal.Base, const_cast<APValue *>(&TPO->getValue()),
4019 TPO->getType());
4020 }
4021
4022 // In C++98, const, non-volatile integers initialized with ICEs are ICEs.
4023 // In C++11, constexpr, non-volatile variables initialized with constant
4024 // expressions are constant expressions too. Inside constexpr functions,
4025 // parameters are constant expressions even if they're non-const.
4026 // In C++1y, objects local to a constant expression (those with a Frame) are
4027 // both readable and writable inside constant expressions.
4028 // In C, such things can also be folded, although they are not ICEs.
4029 const VarDecl *VD = dyn_cast<VarDecl>(D);
4030 if (VD) {
4031 if (const VarDecl *VDef = VD->getDefinition(Info.Ctx))
4032 VD = VDef;
4033 }
4034 if (!VD || VD->isInvalidDecl()) {
4035 Info.FFDiag(E);
4036 return CompleteObject();
4037 }
4038
4039 bool IsConstant = BaseType.isConstant(Info.Ctx);
4040
4041 // Unless we're looking at a local variable or argument in a constexpr call,
4042 // the variable we're reading must be const.
4043 if (!Frame) {
4044 if (IsAccess && isa<ParmVarDecl>(VD)) {
4045 // Access of a parameter that's not associated with a frame isn't going
4046 // to work out, but we can leave it to evaluateVarDeclInit to provide a
4047 // suitable diagnostic.
4048 } else if (Info.getLangOpts().CPlusPlus14 &&
4049 lifetimeStartedInEvaluation(Info, LVal.Base)) {
4050 // OK, we can read and modify an object if we're in the process of
4051 // evaluating its initializer, because its lifetime began in this
4052 // evaluation.
4053 } else if (isModification(AK)) {
4054 // All the remaining cases do not permit modification of the object.
4055 Info.FFDiag(E, diag::note_constexpr_modify_global);
4056 return CompleteObject();
4057 } else if (VD->isConstexpr()) {
4058 // OK, we can read this variable.
4059 } else if (BaseType->isIntegralOrEnumerationType()) {
4060 if (!IsConstant) {
4061 if (!IsAccess)
4062 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
4063 if (Info.getLangOpts().CPlusPlus) {
4064 Info.FFDiag(E, diag::note_constexpr_ltor_non_const_int, 1) << VD;
4065 Info.Note(VD->getLocation(), diag::note_declared_at);
4066 } else {
4067 Info.FFDiag(E);
4068 }
4069 return CompleteObject();
4070 }
4071 } else if (!IsAccess) {
4072 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
4073 } else if (IsConstant && Info.checkingPotentialConstantExpression() &&
4074 BaseType->isLiteralType(Info.Ctx) && !VD->hasDefinition()) {
4075 // This variable might end up being constexpr. Don't diagnose it yet.
4076 } else if (IsConstant) {
4077 // Keep evaluating to see what we can do. In particular, we support
4078 // folding of const floating-point types, in order to make static const
4079 // data members of such types (supported as an extension) more useful.
4080 if (Info.getLangOpts().CPlusPlus) {
4081 Info.CCEDiag(E, Info.getLangOpts().CPlusPlus11
4082 ? diag::note_constexpr_ltor_non_constexpr
4083 : diag::note_constexpr_ltor_non_integral, 1)
4084 << VD << BaseType;
4085 Info.Note(VD->getLocation(), diag::note_declared_at);
4086 } else {
4087 Info.CCEDiag(E);
4088 }
4089 } else {
4090 // Never allow reading a non-const value.
4091 if (Info.getLangOpts().CPlusPlus) {
4092 Info.FFDiag(E, Info.getLangOpts().CPlusPlus11
4093 ? diag::note_constexpr_ltor_non_constexpr
4094 : diag::note_constexpr_ltor_non_integral, 1)
4095 << VD << BaseType;
4096 Info.Note(VD->getLocation(), diag::note_declared_at);
4097 } else {
4098 Info.FFDiag(E);
4099 }
4100 return CompleteObject();
4101 }
4102 }
4103
4104 if (!evaluateVarDeclInit(Info, E, VD, Frame, LVal.getLValueVersion(), BaseVal))
4105 return CompleteObject();
4106 } else if (DynamicAllocLValue DA = LVal.Base.dyn_cast<DynamicAllocLValue>()) {
4107 Optional<DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA);
4108 if (!Alloc) {
4109 Info.FFDiag(E, diag::note_constexpr_access_deleted_object) << AK;
4110 return CompleteObject();
4111 }
4112 return CompleteObject(LVal.Base, &(*Alloc)->Value,
4113 LVal.Base.getDynamicAllocType());
4114 } else {
4115 const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
4116
4117 if (!Frame) {
4118 if (const MaterializeTemporaryExpr *MTE =
4119 dyn_cast_or_null<MaterializeTemporaryExpr>(Base)) {
4120 assert(MTE->getStorageDuration() == SD_Static &&(static_cast <bool> (MTE->getStorageDuration() == SD_Static
&& "should have a frame for a non-global materialized temporary"
) ? void (0) : __assert_fail ("MTE->getStorageDuration() == SD_Static && \"should have a frame for a non-global materialized temporary\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4121, __extension__ __PRETTY_FUNCTION__))
4121 "should have a frame for a non-global materialized temporary")(static_cast <bool> (MTE->getStorageDuration() == SD_Static
&& "should have a frame for a non-global materialized temporary"
) ? void (0) : __assert_fail ("MTE->getStorageDuration() == SD_Static && \"should have a frame for a non-global materialized temporary\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4121, __extension__ __PRETTY_FUNCTION__))
;
4122
4123 // C++20 [expr.const]p4: [DR2126]
4124 // An object or reference is usable in constant expressions if it is
4125 // - a temporary object of non-volatile const-qualified literal type
4126 // whose lifetime is extended to that of a variable that is usable
4127 // in constant expressions
4128 //
4129 // C++20 [expr.const]p5:
4130 // an lvalue-to-rvalue conversion [is not allowed unless it applies to]
4131 // - a non-volatile glvalue that refers to an object that is usable
4132 // in constant expressions, or
4133 // - a non-volatile glvalue of literal type that refers to a
4134 // non-volatile object whose lifetime began within the evaluation
4135 // of E;
4136 //
4137 // C++11 misses the 'began within the evaluation of e' check and
4138 // instead allows all temporaries, including things like:
4139 // int &&r = 1;
4140 // int x = ++r;
4141 // constexpr int k = r;
4142 // Therefore we use the C++14-onwards rules in C++11 too.
4143 //
4144 // Note that temporaries whose lifetimes began while evaluating a
4145 // variable's constructor are not usable while evaluating the
4146 // corresponding destructor, not even if they're of const-qualified
4147 // types.
4148 if (!MTE->isUsableInConstantExpressions(Info.Ctx) &&
4149 !lifetimeStartedInEvaluation(Info, LVal.Base)) {
4150 if (!IsAccess)
4151 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
4152 Info.FFDiag(E, diag::note_constexpr_access_static_temporary, 1) << AK;
4153 Info.Note(MTE->getExprLoc(), diag::note_constexpr_temporary_here);
4154 return CompleteObject();
4155 }
4156
4157 BaseVal = MTE->getOrCreateValue(false);
4158 assert(BaseVal && "got reference to unevaluated temporary")(static_cast <bool> (BaseVal && "got reference to unevaluated temporary"
) ? void (0) : __assert_fail ("BaseVal && \"got reference to unevaluated temporary\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4158, __extension__ __PRETTY_FUNCTION__))
;
4159 } else {
4160 if (!IsAccess)
4161 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
4162 APValue Val;
4163 LVal.moveInto(Val);
4164 Info.FFDiag(E, diag::note_constexpr_access_unreadable_object)
4165 << AK
4166 << Val.getAsString(Info.Ctx,
4167 Info.Ctx.getLValueReferenceType(LValType));
4168 NoteLValueLocation(Info, LVal.Base);
4169 return CompleteObject();
4170 }
4171 } else {
4172 BaseVal = Frame->getTemporary(Base, LVal.Base.getVersion());
4173 assert(BaseVal && "missing value for temporary")(static_cast <bool> (BaseVal && "missing value for temporary"
) ? void (0) : __assert_fail ("BaseVal && \"missing value for temporary\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4173, __extension__ __PRETTY_FUNCTION__))
;
4174 }
4175 }
4176
4177 // In C++14, we can't safely access any mutable state when we might be
4178 // evaluating after an unmodeled side effect. Parameters are modeled as state
4179 // in the caller, but aren't visible once the call returns, so they can be
4180 // modified in a speculatively-evaluated call.
4181 //
4182 // FIXME: Not all local state is mutable. Allow local constant subobjects
4183 // to be read here (but take care with 'mutable' fields).
4184 unsigned VisibleDepth = Depth;
4185 if (llvm::isa_and_nonnull<ParmVarDecl>(
4186 LVal.Base.dyn_cast<const ValueDecl *>()))
4187 ++VisibleDepth;
4188 if ((Frame && Info.getLangOpts().CPlusPlus14 &&
4189 Info.EvalStatus.HasSideEffects) ||
4190 (isModification(AK) && VisibleDepth < Info.SpeculativeEvaluationDepth))
4191 return CompleteObject();
4192
4193 return CompleteObject(LVal.getLValueBase(), BaseVal, BaseType);
4194}
4195
4196/// Perform an lvalue-to-rvalue conversion on the given glvalue. This
4197/// can also be used for 'lvalue-to-lvalue' conversions for looking up the
4198/// glvalue referred to by an entity of reference type.
4199///
4200/// \param Info - Information about the ongoing evaluation.
4201/// \param Conv - The expression for which we are performing the conversion.
4202/// Used for diagnostics.
4203/// \param Type - The type of the glvalue (before stripping cv-qualifiers in the
4204/// case of a non-class type).
4205/// \param LVal - The glvalue on which we are attempting to perform this action.
4206/// \param RVal - The produced value will be placed here.
4207/// \param WantObjectRepresentation - If true, we're looking for the object
4208/// representation rather than the value, and in particular,
4209/// there is no requirement that the result be fully initialized.
4210static bool
4211handleLValueToRValueConversion(EvalInfo &Info, const Expr *Conv, QualType Type,
4212 const LValue &LVal, APValue &RVal,
4213 bool WantObjectRepresentation = false) {
4214 if (LVal.Designator.Invalid)
4215 return false;
4216
4217 // Check for special cases where there is no existing APValue to look at.
4218 const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
4219
4220 AccessKinds AK =
4221 WantObjectRepresentation ? AK_ReadObjectRepresentation : AK_Read;
4222
4223 if (Base && !LVal.getLValueCallIndex() && !Type.isVolatileQualified()) {
4224 if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(Base)) {
4225 // In C99, a CompoundLiteralExpr is an lvalue, and we defer evaluating the
4226 // initializer until now for such expressions. Such an expression can't be
4227 // an ICE in C, so this only matters for fold.
4228 if (Type.isVolatileQualified()) {
4229 Info.FFDiag(Conv);
4230 return false;
4231 }
4232 APValue Lit;
4233 if (!Evaluate(Lit, Info, CLE->getInitializer()))
4234 return false;
4235 CompleteObject LitObj(LVal.Base, &Lit, Base->getType());
4236 return extractSubobject(Info, Conv, LitObj, LVal.Designator, RVal, AK);
4237 } else if (isa<StringLiteral>(Base) || isa<PredefinedExpr>(Base)) {
4238 // Special-case character extraction so we don't have to construct an
4239 // APValue for the whole string.
4240 assert(LVal.Designator.Entries.size() <= 1 &&(static_cast <bool> (LVal.Designator.Entries.size() <=
1 && "Can only read characters from string literals"
) ? void (0) : __assert_fail ("LVal.Designator.Entries.size() <= 1 && \"Can only read characters from string literals\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4241, __extension__ __PRETTY_FUNCTION__))
4241 "Can only read characters from string literals")(static_cast <bool> (LVal.Designator.Entries.size() <=
1 && "Can only read characters from string literals"
) ? void (0) : __assert_fail ("LVal.Designator.Entries.size() <= 1 && \"Can only read characters from string literals\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4241, __extension__ __PRETTY_FUNCTION__))
;
4242 if (LVal.Designator.Entries.empty()) {
4243 // Fail for now for LValue to RValue conversion of an array.
4244 // (This shouldn't show up in C/C++, but it could be triggered by a
4245 // weird EvaluateAsRValue call from a tool.)
4246 Info.FFDiag(Conv);
4247 return false;
4248 }
4249 if (LVal.Designator.isOnePastTheEnd()) {
4250 if (Info.getLangOpts().CPlusPlus11)
4251 Info.FFDiag(Conv, diag::note_constexpr_access_past_end) << AK;
4252 else
4253 Info.FFDiag(Conv);
4254 return false;
4255 }
4256 uint64_t CharIndex = LVal.Designator.Entries[0].getAsArrayIndex();
4257 RVal = APValue(extractStringLiteralCharacter(Info, Base, CharIndex));
4258 return true;
4259 }
4260 }
4261
4262 CompleteObject Obj = findCompleteObject(Info, Conv, AK, LVal, Type);
4263 return Obj && extractSubobject(Info, Conv, Obj, LVal.Designator, RVal, AK);
4264}
4265
4266/// Perform an assignment of Val to LVal. Takes ownership of Val.
4267static bool handleAssignment(EvalInfo &Info, const Expr *E, const LValue &LVal,
4268 QualType LValType, APValue &Val) {
4269 if (LVal.Designator.Invalid)
4270 return false;
4271
4272 if (!Info.getLangOpts().CPlusPlus14) {
4273 Info.FFDiag(E);
4274 return false;
4275 }
4276
4277 CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
4278 return Obj && modifySubobject(Info, E, Obj, LVal.Designator, Val);
4279}
4280
4281namespace {
4282struct CompoundAssignSubobjectHandler {
4283 EvalInfo &Info;
4284 const CompoundAssignOperator *E;
4285 QualType PromotedLHSType;
4286 BinaryOperatorKind Opcode;
4287 const APValue &RHS;
4288
4289 static const AccessKinds AccessKind = AK_Assign;
4290
4291 typedef bool result_type;
4292
4293 bool checkConst(QualType QT) {
4294 // Assigning to a const object has undefined behavior.
4295 if (QT.isConstQualified()) {
4296 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
4297 return false;
4298 }
4299 return true;
4300 }
4301
4302 bool failed() { return false; }
4303 bool found(APValue &Subobj, QualType SubobjType) {
4304 switch (Subobj.getKind()) {
4305 case APValue::Int:
4306 return found(Subobj.getInt(), SubobjType);
4307 case APValue::Float:
4308 return found(Subobj.getFloat(), SubobjType);
4309 case APValue::ComplexInt:
4310 case APValue::ComplexFloat:
4311 // FIXME: Implement complex compound assignment.
4312 Info.FFDiag(E);
4313 return false;
4314 case APValue::LValue:
4315 return foundPointer(Subobj, SubobjType);
4316 case APValue::Vector:
4317 return foundVector(Subobj, SubobjType);
4318 default:
4319 // FIXME: can this happen?
4320 Info.FFDiag(E);
4321 return false;
4322 }
4323 }
4324
4325 bool foundVector(APValue &Value, QualType SubobjType) {
4326 if (!checkConst(SubobjType))
4327 return false;
4328
4329 if (!SubobjType->isVectorType()) {
4330 Info.FFDiag(E);
4331 return false;
4332 }
4333 return handleVectorVectorBinOp(Info, E, Opcode, Value, RHS);
4334 }
4335
4336 bool found(APSInt &Value, QualType SubobjType) {
4337 if (!checkConst(SubobjType))
4338 return false;
4339
4340 if (!SubobjType->isIntegerType()) {
4341 // We don't support compound assignment on integer-cast-to-pointer
4342 // values.
4343 Info.FFDiag(E);
4344 return false;
4345 }
4346
4347 if (RHS.isInt()) {
4348 APSInt LHS =
4349 HandleIntToIntCast(Info, E, PromotedLHSType, SubobjType, Value);
4350 if (!handleIntIntBinOp(Info, E, LHS, Opcode, RHS.getInt(), LHS))
4351 return false;
4352 Value = HandleIntToIntCast(Info, E, SubobjType, PromotedLHSType, LHS);
4353 return true;
4354 } else if (RHS.isFloat()) {
4355 const FPOptions FPO = E->getFPFeaturesInEffect(
4356 Info.Ctx.getLangOpts());
4357 APFloat FValue(0.0);
4358 return HandleIntToFloatCast(Info, E, FPO, SubobjType, Value,
4359 PromotedLHSType, FValue) &&
4360 handleFloatFloatBinOp(Info, E, FValue, Opcode, RHS.getFloat()) &&
4361 HandleFloatToIntCast(Info, E, PromotedLHSType, FValue, SubobjType,
4362 Value);
4363 }
4364
4365 Info.FFDiag(E);
4366 return false;
4367 }
4368 bool found(APFloat &Value, QualType SubobjType) {
4369 return checkConst(SubobjType) &&
4370 HandleFloatToFloatCast(Info, E, SubobjType, PromotedLHSType,
4371 Value) &&
4372 handleFloatFloatBinOp(Info, E, Value, Opcode, RHS.getFloat()) &&
4373 HandleFloatToFloatCast(Info, E, PromotedLHSType, SubobjType, Value);
4374 }
4375 bool foundPointer(APValue &Subobj, QualType SubobjType) {
4376 if (!checkConst(SubobjType))
4377 return false;
4378
4379 QualType PointeeType;
4380 if (const PointerType *PT = SubobjType->getAs<PointerType>())
4381 PointeeType = PT->getPointeeType();
4382
4383 if (PointeeType.isNull() || !RHS.isInt() ||
4384 (Opcode != BO_Add && Opcode != BO_Sub)) {
4385 Info.FFDiag(E);
4386 return false;
4387 }
4388
4389 APSInt Offset = RHS.getInt();
4390 if (Opcode == BO_Sub)
4391 negateAsSigned(Offset);
4392
4393 LValue LVal;
4394 LVal.setFrom(Info.Ctx, Subobj);
4395 if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType, Offset))
4396 return false;
4397 LVal.moveInto(Subobj);
4398 return true;
4399 }
4400};
4401} // end anonymous namespace
4402
4403const AccessKinds CompoundAssignSubobjectHandler::AccessKind;
4404
4405/// Perform a compound assignment of LVal <op>= RVal.
4406static bool handleCompoundAssignment(EvalInfo &Info,
4407 const CompoundAssignOperator *E,
4408 const LValue &LVal, QualType LValType,
4409 QualType PromotedLValType,
4410 BinaryOperatorKind Opcode,
4411 const APValue &RVal) {
4412 if (LVal.Designator.Invalid)
4413 return false;
4414
4415 if (!Info.getLangOpts().CPlusPlus14) {
4416 Info.FFDiag(E);
4417 return false;
4418 }
4419
4420 CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
4421 CompoundAssignSubobjectHandler Handler = { Info, E, PromotedLValType, Opcode,
4422 RVal };
4423 return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
4424}
4425
4426namespace {
4427struct IncDecSubobjectHandler {
4428 EvalInfo &Info;
4429 const UnaryOperator *E;
4430 AccessKinds AccessKind;
4431 APValue *Old;
4432
4433 typedef bool result_type;
4434
4435 bool checkConst(QualType QT) {
4436 // Assigning to a const object has undefined behavior.
4437 if (QT.isConstQualified()) {
4438 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
4439 return false;
4440 }
4441 return true;
4442 }
4443
4444 bool failed() { return false; }
4445 bool found(APValue &Subobj, QualType SubobjType) {
4446 // Stash the old value. Also clear Old, so we don't clobber it later
4447 // if we're post-incrementing a complex.
4448 if (Old) {
4449 *Old = Subobj;
4450 Old = nullptr;
4451 }
4452
4453 switch (Subobj.getKind()) {
4454 case APValue::Int:
4455 return found(Subobj.getInt(), SubobjType);
4456 case APValue::Float:
4457 return found(Subobj.getFloat(), SubobjType);
4458 case APValue::ComplexInt:
4459 return found(Subobj.getComplexIntReal(),
4460 SubobjType->castAs<ComplexType>()->getElementType()
4461 .withCVRQualifiers(SubobjType.getCVRQualifiers()));
4462 case APValue::ComplexFloat:
4463 return found(Subobj.getComplexFloatReal(),
4464 SubobjType->castAs<ComplexType>()->getElementType()
4465 .withCVRQualifiers(SubobjType.getCVRQualifiers()));
4466 case APValue::LValue:
4467 return foundPointer(Subobj, SubobjType);
4468 default:
4469 // FIXME: can this happen?
4470 Info.FFDiag(E);
4471 return false;
4472 }
4473 }
4474 bool found(APSInt &Value, QualType SubobjType) {
4475 if (!checkConst(SubobjType))
4476 return false;
4477
4478 if (!SubobjType->isIntegerType()) {
4479 // We don't support increment / decrement on integer-cast-to-pointer
4480 // values.
4481 Info.FFDiag(E);
4482 return false;
4483 }
4484
4485 if (Old) *Old = APValue(Value);
4486
4487 // bool arithmetic promotes to int, and the conversion back to bool
4488 // doesn't reduce mod 2^n, so special-case it.
4489 if (SubobjType->isBooleanType()) {
4490 if (AccessKind == AK_Increment)
4491 Value = 1;
4492 else
4493 Value = !Value;
4494 return true;
4495 }
4496
4497 bool WasNegative = Value.isNegative();
4498 if (AccessKind == AK_Increment) {
4499 ++Value;
4500
4501 if (!WasNegative && Value.isNegative() && E->canOverflow()) {
4502 APSInt ActualValue(Value, /*IsUnsigned*/true);
4503 return HandleOverflow(Info, E, ActualValue, SubobjType);
4504 }
4505 } else {
4506 --Value;
4507
4508 if (WasNegative && !Value.isNegative() && E->canOverflow()) {
4509 unsigned BitWidth = Value.getBitWidth();
4510 APSInt ActualValue(Value.sext(BitWidth + 1), /*IsUnsigned*/false);
4511 ActualValue.setBit(BitWidth);
4512 return HandleOverflow(Info, E, ActualValue, SubobjType);
4513 }
4514 }
4515 return true;
4516 }
4517 bool found(APFloat &Value, QualType SubobjType) {
4518 if (!checkConst(SubobjType))
4519 return false;
4520
4521 if (Old) *Old = APValue(Value);
4522
4523 APFloat One(Value.getSemantics(), 1);
4524 if (AccessKind == AK_Increment)
4525 Value.add(One, APFloat::rmNearestTiesToEven);
4526 else
4527 Value.subtract(One, APFloat::rmNearestTiesToEven);
4528 return true;
4529 }
4530 bool foundPointer(APValue &Subobj, QualType SubobjType) {
4531 if (!checkConst(SubobjType))
4532 return false;
4533
4534 QualType PointeeType;
4535 if (const PointerType *PT = SubobjType->getAs<PointerType>())
4536 PointeeType = PT->getPointeeType();
4537 else {
4538 Info.FFDiag(E);
4539 return false;
4540 }
4541
4542 LValue LVal;
4543 LVal.setFrom(Info.Ctx, Subobj);
4544 if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType,
4545 AccessKind == AK_Increment ? 1 : -1))
4546 return false;
4547 LVal.moveInto(Subobj);
4548 return true;
4549 }
4550};
4551} // end anonymous namespace
4552
4553/// Perform an increment or decrement on LVal.
4554static bool handleIncDec(EvalInfo &Info, const Expr *E, const LValue &LVal,
4555 QualType LValType, bool IsIncrement, APValue *Old) {
4556 if (LVal.Designator.Invalid)
4557 return false;
4558
4559 if (!Info.getLangOpts().CPlusPlus14) {
4560 Info.FFDiag(E);
4561 return false;
4562 }
4563
4564 AccessKinds AK = IsIncrement ? AK_Increment : AK_Decrement;
4565 CompleteObject Obj = findCompleteObject(Info, E, AK, LVal, LValType);
4566 IncDecSubobjectHandler Handler = {Info, cast<UnaryOperator>(E), AK, Old};
4567 return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
4568}
4569
4570/// Build an lvalue for the object argument of a member function call.
4571static bool EvaluateObjectArgument(EvalInfo &Info, const Expr *Object,
4572 LValue &This) {
4573 if (Object->getType()->isPointerType() && Object->isPRValue())
4574 return EvaluatePointer(Object, This, Info);
4575
4576 if (Object->isGLValue())
4577 return EvaluateLValue(Object, This, Info);
4578
4579 if (Object->getType()->isLiteralType(Info.Ctx))
4580 return EvaluateTemporary(Object, This, Info);
4581
4582 Info.FFDiag(Object, diag::note_constexpr_nonliteral) << Object->getType();
4583 return false;
4584}
4585
4586/// HandleMemberPointerAccess - Evaluate a member access operation and build an
4587/// lvalue referring to the result.
4588///
4589/// \param Info - Information about the ongoing evaluation.
4590/// \param LV - An lvalue referring to the base of the member pointer.
4591/// \param RHS - The member pointer expression.
4592/// \param IncludeMember - Specifies whether the member itself is included in
4593/// the resulting LValue subobject designator. This is not possible when
4594/// creating a bound member function.
4595/// \return The field or method declaration to which the member pointer refers,
4596/// or 0 if evaluation fails.
4597static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
4598 QualType LVType,
4599 LValue &LV,
4600 const Expr *RHS,
4601 bool IncludeMember = true) {
4602 MemberPtr MemPtr;
4603 if (!EvaluateMemberPointer(RHS, MemPtr, Info))
4604 return nullptr;
4605
4606 // C++11 [expr.mptr.oper]p6: If the second operand is the null pointer to
4607 // member value, the behavior is undefined.
4608 if (!MemPtr.getDecl()) {
4609 // FIXME: Specific diagnostic.
4610 Info.FFDiag(RHS);
4611 return nullptr;
4612 }
4613
4614 if (MemPtr.isDerivedMember()) {
4615 // This is a member of some derived class. Truncate LV appropriately.
4616 // The end of the derived-to-base path for the base object must match the
4617 // derived-to-base path for the member pointer.
4618 if (LV.Designator.MostDerivedPathLength + MemPtr.Path.size() >
4619 LV.Designator.Entries.size()) {
4620 Info.FFDiag(RHS);
4621 return nullptr;
4622 }
4623 unsigned PathLengthToMember =
4624 LV.Designator.Entries.size() - MemPtr.Path.size();
4625 for (unsigned I = 0, N = MemPtr.Path.size(); I != N; ++I) {
4626 const CXXRecordDecl *LVDecl = getAsBaseClass(
4627 LV.Designator.Entries[PathLengthToMember + I]);
4628 const CXXRecordDecl *MPDecl = MemPtr.Path[I];
4629 if (LVDecl->getCanonicalDecl() != MPDecl->getCanonicalDecl()) {
4630 Info.FFDiag(RHS);
4631 return nullptr;
4632 }
4633 }
4634
4635 // Truncate the lvalue to the appropriate derived class.
4636 if (!CastToDerivedClass(Info, RHS, LV, MemPtr.getContainingRecord(),
4637 PathLengthToMember))
4638 return nullptr;
4639 } else if (!MemPtr.Path.empty()) {
4640 // Extend the LValue path with the member pointer's path.
4641 LV.Designator.Entries.reserve(LV.Designator.Entries.size() +
4642 MemPtr.Path.size() + IncludeMember);
4643
4644 // Walk down to the appropriate base class.
4645 if (const PointerType *PT = LVType->getAs<PointerType>())
4646 LVType = PT->getPointeeType();
4647 const CXXRecordDecl *RD = LVType->getAsCXXRecordDecl();
4648 assert(RD && "member pointer access on non-class-type expression")(static_cast <bool> (RD && "member pointer access on non-class-type expression"
) ? void (0) : __assert_fail ("RD && \"member pointer access on non-class-type expression\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4648, __extension__ __PRETTY_FUNCTION__))
;
4649 // The first class in the path is that of the lvalue.
4650 for (unsigned I = 1, N = MemPtr.Path.size(); I != N; ++I) {
4651 const CXXRecordDecl *Base = MemPtr.Path[N - I - 1];
4652 if (!HandleLValueDirectBase(Info, RHS, LV, RD, Base))
4653 return nullptr;
4654 RD = Base;
4655 }
4656 // Finally cast to the class containing the member.
4657 if (!HandleLValueDirectBase(Info, RHS, LV, RD,
4658 MemPtr.getContainingRecord()))
4659 return nullptr;
4660 }
4661
4662 // Add the member. Note that we cannot build bound member functions here.
4663 if (IncludeMember) {
4664 if (const FieldDecl *FD = dyn_cast<FieldDecl>(MemPtr.getDecl())) {
4665 if (!HandleLValueMember(Info, RHS, LV, FD))
4666 return nullptr;
4667 } else if (const IndirectFieldDecl *IFD =
4668 dyn_cast<IndirectFieldDecl>(MemPtr.getDecl())) {
4669 if (!HandleLValueIndirectMember(Info, RHS, LV, IFD))
4670 return nullptr;
4671 } else {
4672 llvm_unreachable("can't construct reference to bound member function")::llvm::llvm_unreachable_internal("can't construct reference to bound member function"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4672)
;
4673 }
4674 }
4675
4676 return MemPtr.getDecl();
4677}
4678
4679static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
4680 const BinaryOperator *BO,
4681 LValue &LV,
4682 bool IncludeMember = true) {
4683 assert(BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI)(static_cast <bool> (BO->getOpcode() == BO_PtrMemD ||
BO->getOpcode() == BO_PtrMemI) ? void (0) : __assert_fail
("BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4683, __extension__ __PRETTY_FUNCTION__))
;
4684
4685 if (!EvaluateObjectArgument(Info, BO->getLHS(), LV)) {
4686 if (Info.noteFailure()) {
4687 MemberPtr MemPtr;
4688 EvaluateMemberPointer(BO->getRHS(), MemPtr, Info);
4689 }
4690 return nullptr;
4691 }
4692
4693 return HandleMemberPointerAccess(Info, BO->getLHS()->getType(), LV,
4694 BO->getRHS(), IncludeMember);
4695}
4696
4697/// HandleBaseToDerivedCast - Apply the given base-to-derived cast operation on
4698/// the provided lvalue, which currently refers to the base object.
4699static bool HandleBaseToDerivedCast(EvalInfo &Info, const CastExpr *E,
4700 LValue &Result) {
4701 SubobjectDesignator &D = Result.Designator;
4702 if (D.Invalid || !Result.checkNullPointer(Info, E, CSK_Derived))
4703 return false;
4704
4705 QualType TargetQT = E->getType();
4706 if (const PointerType *PT = TargetQT->getAs<PointerType>())
4707 TargetQT = PT->getPointeeType();
4708
4709 // Check this cast lands within the final derived-to-base subobject path.
4710 if (D.MostDerivedPathLength + E->path_size() > D.Entries.size()) {
4711 Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
4712 << D.MostDerivedType << TargetQT;
4713 return false;
4714 }
4715
4716 // Check the type of the final cast. We don't need to check the path,
4717 // since a cast can only be formed if the path is unique.
4718 unsigned NewEntriesSize = D.Entries.size() - E->path_size();
4719 const CXXRecordDecl *TargetType = TargetQT->getAsCXXRecordDecl();
4720 const CXXRecordDecl *FinalType;
4721 if (NewEntriesSize == D.MostDerivedPathLength)
4722 FinalType = D.MostDerivedType->getAsCXXRecordDecl();
4723 else
4724 FinalType = getAsBaseClass(D.Entries[NewEntriesSize - 1]);
4725 if (FinalType->getCanonicalDecl() != TargetType->getCanonicalDecl()) {
4726 Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
4727 << D.MostDerivedType << TargetQT;
4728 return false;
4729 }
4730
4731 // Truncate the lvalue to the appropriate derived class.
4732 return CastToDerivedClass(Info, E, Result, TargetType, NewEntriesSize);
4733}
4734
4735/// Get the value to use for a default-initialized object of type T.
4736/// Return false if it encounters something invalid.
4737static bool getDefaultInitValue(QualType T, APValue &Result) {
4738 bool Success = true;
4739 if (auto *RD = T->getAsCXXRecordDecl()) {
4740 if (RD->isInvalidDecl()) {
4741 Result = APValue();
4742 return false;
4743 }
4744 if (RD->isUnion()) {
4745 Result = APValue((const FieldDecl *)nullptr);
4746 return true;
4747 }
4748 Result = APValue(APValue::UninitStruct(), RD->getNumBases(),
4749 std::distance(RD->field_begin(), RD->field_end()));
4750
4751 unsigned Index = 0;
4752 for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
4753 End = RD->bases_end();
4754 I != End; ++I, ++Index)
4755 Success &= getDefaultInitValue(I->getType(), Result.getStructBase(Index));
4756
4757 for (const auto *I : RD->fields()) {
4758 if (I->isUnnamedBitfield())
4759 continue;
4760 Success &= getDefaultInitValue(I->getType(),
4761 Result.getStructField(I->getFieldIndex()));
4762 }
4763 return Success;
4764 }
4765
4766 if (auto *AT =
4767 dyn_cast_or_null<ConstantArrayType>(T->getAsArrayTypeUnsafe())) {
4768 Result = APValue(APValue::UninitArray(), 0, AT->getSize().getZExtValue());
4769 if (Result.hasArrayFiller())
4770 Success &=
4771 getDefaultInitValue(AT->getElementType(), Result.getArrayFiller());
4772
4773 return Success;
4774 }
4775
4776 Result = APValue::IndeterminateValue();
4777 return true;
4778}
4779
4780namespace {
4781enum EvalStmtResult {
4782 /// Evaluation failed.
4783 ESR_Failed,
4784 /// Hit a 'return' statement.
4785 ESR_Returned,
4786 /// Evaluation succeeded.
4787 ESR_Succeeded,
4788 /// Hit a 'continue' statement.
4789 ESR_Continue,
4790 /// Hit a 'break' statement.
4791 ESR_Break,
4792 /// Still scanning for 'case' or 'default' statement.
4793 ESR_CaseNotFound
4794};
4795}
4796
4797static bool EvaluateVarDecl(EvalInfo &Info, const VarDecl *VD) {
4798 // We don't need to evaluate the initializer for a static local.
4799 if (!VD->hasLocalStorage())
4800 return true;
4801
4802 LValue Result;
4803 APValue &Val = Info.CurrentCall->createTemporary(VD, VD->getType(),
4804 ScopeKind::Block, Result);
4805
4806 const Expr *InitE = VD->getInit();
4807 if (!InitE) {
4808 if (VD->getType()->isDependentType())
4809 return Info.noteSideEffect();
4810 return getDefaultInitValue(VD->getType(), Val);
4811 }
4812 if (InitE->isValueDependent())
4813 return false;
4814
4815 if (!EvaluateInPlace(Val, Info, Result, InitE)) {
4816 // Wipe out any partially-computed value, to allow tracking that this
4817 // evaluation failed.
4818 Val = APValue();
4819 return false;
4820 }
4821
4822 return true;
4823}
4824
4825static bool EvaluateDecl(EvalInfo &Info, const Decl *D) {
4826 bool OK = true;
4827
4828 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
4829 OK &= EvaluateVarDecl(Info, VD);
4830
4831 if (const DecompositionDecl *DD = dyn_cast<DecompositionDecl>(D))
4832 for (auto *BD : DD->bindings())
4833 if (auto *VD = BD->getHoldingVar())
4834 OK &= EvaluateDecl(Info, VD);
4835
4836 return OK;
4837}
4838
4839static bool EvaluateDependentExpr(const Expr *E, EvalInfo &Info) {
4840 assert(E->isValueDependent())(static_cast <bool> (E->isValueDependent()) ? void (
0) : __assert_fail ("E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4840, __extension__ __PRETTY_FUNCTION__))
;
4841 if (Info.noteSideEffect())
4842 return true;
4843 assert(E->containsErrors() && "valid value-dependent expression should never "(static_cast <bool> (E->containsErrors() && "valid value-dependent expression should never "
"reach invalid code path.") ? void (0) : __assert_fail ("E->containsErrors() && \"valid value-dependent expression should never \" \"reach invalid code path.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4844, __extension__ __PRETTY_FUNCTION__))
4844 "reach invalid code path.")(static_cast <bool> (E->containsErrors() && "valid value-dependent expression should never "
"reach invalid code path.") ? void (0) : __assert_fail ("E->containsErrors() && \"valid value-dependent expression should never \" \"reach invalid code path.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4844, __extension__ __PRETTY_FUNCTION__))
;
4845 return false;
4846}
4847
4848/// Evaluate a condition (either a variable declaration or an expression).
4849static bool EvaluateCond(EvalInfo &Info, const VarDecl *CondDecl,
4850 const Expr *Cond, bool &Result) {
4851 if (Cond->isValueDependent())
4852 return false;
4853 FullExpressionRAII Scope(Info);
4854 if (CondDecl && !EvaluateDecl(Info, CondDecl))
4855 return false;
4856 if (!EvaluateAsBooleanCondition(Cond, Result, Info))
4857 return false;
4858 return Scope.destroy();
4859}
4860
4861namespace {
4862/// A location where the result (returned value) of evaluating a
4863/// statement should be stored.
4864struct StmtResult {
4865 /// The APValue that should be filled in with the returned value.
4866 APValue &Value;
4867 /// The location containing the result, if any (used to support RVO).
4868 const LValue *Slot;
4869};
4870
4871struct TempVersionRAII {
4872 CallStackFrame &Frame;
4873
4874 TempVersionRAII(CallStackFrame &Frame) : Frame(Frame) {
4875 Frame.pushTempVersion();
4876 }
4877
4878 ~TempVersionRAII() {
4879 Frame.popTempVersion();
4880 }
4881};
4882
4883}
4884
4885static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
4886 const Stmt *S,
4887 const SwitchCase *SC = nullptr);
4888
4889/// Evaluate the body of a loop, and translate the result as appropriate.
4890static EvalStmtResult EvaluateLoopBody(StmtResult &Result, EvalInfo &Info,
4891 const Stmt *Body,
4892 const SwitchCase *Case = nullptr) {
4893 BlockScopeRAII Scope(Info);
4894
4895 EvalStmtResult ESR = EvaluateStmt(Result, Info, Body, Case);
4896 if (ESR != ESR_Failed && ESR != ESR_CaseNotFound && !Scope.destroy())
4897 ESR = ESR_Failed;
4898
4899 switch (ESR) {
4900 case ESR_Break:
4901 return ESR_Succeeded;
4902 case ESR_Succeeded:
4903 case ESR_Continue:
4904 return ESR_Continue;
4905 case ESR_Failed:
4906 case ESR_Returned:
4907 case ESR_CaseNotFound:
4908 return ESR;
4909 }
4910 llvm_unreachable("Invalid EvalStmtResult!")::llvm::llvm_unreachable_internal("Invalid EvalStmtResult!", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4910)
;
4911}
4912
4913/// Evaluate a switch statement.
4914static EvalStmtResult EvaluateSwitch(StmtResult &Result, EvalInfo &Info,
4915 const SwitchStmt *SS) {
4916 BlockScopeRAII Scope(Info);
4917
4918 // Evaluate the switch condition.
4919 APSInt Value;
4920 {
4921 if (const Stmt *Init = SS->getInit()) {
4922 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
4923 if (ESR != ESR_Succeeded) {
4924 if (ESR != ESR_Failed && !Scope.destroy())
4925 ESR = ESR_Failed;
4926 return ESR;
4927 }
4928 }
4929
4930 FullExpressionRAII CondScope(Info);
4931 if (SS->getConditionVariable() &&
4932 !EvaluateDecl(Info, SS->getConditionVariable()))
4933 return ESR_Failed;
4934 if (!EvaluateInteger(SS->getCond(), Value, Info))
4935 return ESR_Failed;
4936 if (!CondScope.destroy())
4937 return ESR_Failed;
4938 }
4939
4940 // Find the switch case corresponding to the value of the condition.
4941 // FIXME: Cache this lookup.
4942 const SwitchCase *Found = nullptr;
4943 for (const SwitchCase *SC = SS->getSwitchCaseList(); SC;
4944 SC = SC->getNextSwitchCase()) {
4945 if (isa<DefaultStmt>(SC)) {
4946 Found = SC;
4947 continue;
4948 }
4949
4950 const CaseStmt *CS = cast<CaseStmt>(SC);
4951 APSInt LHS = CS->getLHS()->EvaluateKnownConstInt(Info.Ctx);
4952 APSInt RHS = CS->getRHS() ? CS->getRHS()->EvaluateKnownConstInt(Info.Ctx)
4953 : LHS;
4954 if (LHS <= Value && Value <= RHS) {
4955 Found = SC;
4956 break;
4957 }
4958 }
4959
4960 if (!Found)
4961 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
4962
4963 // Search the switch body for the switch case and evaluate it from there.
4964 EvalStmtResult ESR = EvaluateStmt(Result, Info, SS->getBody(), Found);
4965 if (ESR != ESR_Failed && ESR != ESR_CaseNotFound && !Scope.destroy())
4966 return ESR_Failed;
4967
4968 switch (ESR) {
4969 case ESR_Break:
4970 return ESR_Succeeded;
4971 case ESR_Succeeded:
4972 case ESR_Continue:
4973 case ESR_Failed:
4974 case ESR_Returned:
4975 return ESR;
4976 case ESR_CaseNotFound:
4977 // This can only happen if the switch case is nested within a statement
4978 // expression. We have no intention of supporting that.
4979 Info.FFDiag(Found->getBeginLoc(),
4980 diag::note_constexpr_stmt_expr_unsupported);
4981 return ESR_Failed;
4982 }
4983 llvm_unreachable("Invalid EvalStmtResult!")::llvm::llvm_unreachable_internal("Invalid EvalStmtResult!", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 4983)
;
4984}
4985
4986// Evaluate a statement.
4987static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
4988 const Stmt *S, const SwitchCase *Case) {
4989 if (!Info.nextStep(S))
4990 return ESR_Failed;
4991
4992 // If we're hunting down a 'case' or 'default' label, recurse through
4993 // substatements until we hit the label.
4994 if (Case) {
4995 switch (S->getStmtClass()) {
4996 case Stmt::CompoundStmtClass:
4997 // FIXME: Precompute which substatement of a compound statement we
4998 // would jump to, and go straight there rather than performing a
4999 // linear scan each time.
5000 case Stmt::LabelStmtClass:
5001 case Stmt::AttributedStmtClass:
5002 case Stmt::DoStmtClass:
5003 break;
5004
5005 case Stmt::CaseStmtClass:
5006 case Stmt::DefaultStmtClass:
5007 if (Case == S)
5008 Case = nullptr;
5009 break;
5010
5011 case Stmt::IfStmtClass: {
5012 // FIXME: Precompute which side of an 'if' we would jump to, and go
5013 // straight there rather than scanning both sides.
5014 const IfStmt *IS = cast<IfStmt>(S);
5015
5016 // Wrap the evaluation in a block scope, in case it's a DeclStmt
5017 // preceded by our switch label.
5018 BlockScopeRAII Scope(Info);
5019
5020 // Step into the init statement in case it brings an (uninitialized)
5021 // variable into scope.
5022 if (const Stmt *Init = IS->getInit()) {
5023 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init, Case);
5024 if (ESR != ESR_CaseNotFound) {
5025 assert(ESR != ESR_Succeeded)(static_cast <bool> (ESR != ESR_Succeeded) ? void (0) :
__assert_fail ("ESR != ESR_Succeeded", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5025, __extension__ __PRETTY_FUNCTION__))
;
5026 return ESR;
5027 }
5028 }
5029
5030 // Condition variable must be initialized if it exists.
5031 // FIXME: We can skip evaluating the body if there's a condition
5032 // variable, as there can't be any case labels within it.
5033 // (The same is true for 'for' statements.)
5034
5035 EvalStmtResult ESR = EvaluateStmt(Result, Info, IS->getThen(), Case);
5036 if (ESR == ESR_Failed)
5037 return ESR;
5038 if (ESR != ESR_CaseNotFound)
5039 return Scope.destroy() ? ESR : ESR_Failed;
5040 if (!IS->getElse())
5041 return ESR_CaseNotFound;
5042
5043 ESR = EvaluateStmt(Result, Info, IS->getElse(), Case);
5044 if (ESR == ESR_Failed)
5045 return ESR;
5046 if (ESR != ESR_CaseNotFound)
5047 return Scope.destroy() ? ESR : ESR_Failed;
5048 return ESR_CaseNotFound;
5049 }
5050
5051 case Stmt::WhileStmtClass: {
5052 EvalStmtResult ESR =
5053 EvaluateLoopBody(Result, Info, cast<WhileStmt>(S)->getBody(), Case);
5054 if (ESR != ESR_Continue)
5055 return ESR;
5056 break;
5057 }
5058
5059 case Stmt::ForStmtClass: {
5060 const ForStmt *FS = cast<ForStmt>(S);
5061 BlockScopeRAII Scope(Info);
5062
5063 // Step into the init statement in case it brings an (uninitialized)
5064 // variable into scope.
5065 if (const Stmt *Init = FS->getInit()) {
5066 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init, Case);
5067 if (ESR != ESR_CaseNotFound) {
5068 assert(ESR != ESR_Succeeded)(static_cast <bool> (ESR != ESR_Succeeded) ? void (0) :
__assert_fail ("ESR != ESR_Succeeded", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5068, __extension__ __PRETTY_FUNCTION__))
;
5069 return ESR;
5070 }
5071 }
5072
5073 EvalStmtResult ESR =
5074 EvaluateLoopBody(Result, Info, FS->getBody(), Case);
5075 if (ESR != ESR_Continue)
5076 return ESR;
5077 if (const auto *Inc = FS->getInc()) {
5078 if (Inc->isValueDependent()) {
5079 if (!EvaluateDependentExpr(Inc, Info))
5080 return ESR_Failed;
5081 } else {
5082 FullExpressionRAII IncScope(Info);
5083 if (!EvaluateIgnoredValue(Info, Inc) || !IncScope.destroy())
5084 return ESR_Failed;
5085 }
5086 }
5087 break;
5088 }
5089
5090 case Stmt::DeclStmtClass: {
5091 // Start the lifetime of any uninitialized variables we encounter. They
5092 // might be used by the selected branch of the switch.
5093 const DeclStmt *DS = cast<DeclStmt>(S);
5094 for (const auto *D : DS->decls()) {
5095 if (const auto *VD = dyn_cast<VarDecl>(D)) {
5096 if (VD->hasLocalStorage() && !VD->getInit())
5097 if (!EvaluateVarDecl(Info, VD))
5098 return ESR_Failed;
5099 // FIXME: If the variable has initialization that can't be jumped
5100 // over, bail out of any immediately-surrounding compound-statement
5101 // too. There can't be any case labels here.
5102 }
5103 }
5104 return ESR_CaseNotFound;
5105 }
5106
5107 default:
5108 return ESR_CaseNotFound;
5109 }
5110 }
5111
5112 switch (S->getStmtClass()) {
5113 default:
5114 if (const Expr *E = dyn_cast<Expr>(S)) {
5115 if (E->isValueDependent()) {
5116 if (!EvaluateDependentExpr(E, Info))
5117 return ESR_Failed;
5118 } else {
5119 // Don't bother evaluating beyond an expression-statement which couldn't
5120 // be evaluated.
5121 // FIXME: Do we need the FullExpressionRAII object here?
5122 // VisitExprWithCleanups should create one when necessary.
5123 FullExpressionRAII Scope(Info);
5124 if (!EvaluateIgnoredValue(Info, E) || !Scope.destroy())
5125 return ESR_Failed;
5126 }
5127 return ESR_Succeeded;
5128 }
5129
5130 Info.FFDiag(S->getBeginLoc());
5131 return ESR_Failed;
5132
5133 case Stmt::NullStmtClass:
5134 return ESR_Succeeded;
5135
5136 case Stmt::DeclStmtClass: {
5137 const DeclStmt *DS = cast<DeclStmt>(S);
5138 for (const auto *D : DS->decls()) {
5139 // Each declaration initialization is its own full-expression.
5140 FullExpressionRAII Scope(Info);
5141 if (!EvaluateDecl(Info, D) && !Info.noteFailure())
5142 return ESR_Failed;
5143 if (!Scope.destroy())
5144 return ESR_Failed;
5145 }
5146 return ESR_Succeeded;
5147 }
5148
5149 case Stmt::ReturnStmtClass: {
5150 const Expr *RetExpr = cast<ReturnStmt>(S)->getRetValue();
5151 FullExpressionRAII Scope(Info);
5152 if (RetExpr && RetExpr->isValueDependent()) {
5153 EvaluateDependentExpr(RetExpr, Info);
5154 // We know we returned, but we don't know what the value is.
5155 return ESR_Failed;
5156 }
5157 if (RetExpr &&
5158 !(Result.Slot
5159 ? EvaluateInPlace(Result.Value, Info, *Result.Slot, RetExpr)
5160 : Evaluate(Result.Value, Info, RetExpr)))
5161 return ESR_Failed;
5162 return Scope.destroy() ? ESR_Returned : ESR_Failed;
5163 }
5164
5165 case Stmt::CompoundStmtClass: {
5166 BlockScopeRAII Scope(Info);
5167
5168 const CompoundStmt *CS = cast<CompoundStmt>(S);
5169 for (const auto *BI : CS->body()) {
5170 EvalStmtResult ESR = EvaluateStmt(Result, Info, BI, Case);
5171 if (ESR == ESR_Succeeded)
5172 Case = nullptr;
5173 else if (ESR != ESR_CaseNotFound) {
5174 if (ESR != ESR_Failed && !Scope.destroy())
5175 return ESR_Failed;
5176 return ESR;
5177 }
5178 }
5179 if (Case)
5180 return ESR_CaseNotFound;
5181 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
5182 }
5183
5184 case Stmt::IfStmtClass: {
5185 const IfStmt *IS = cast<IfStmt>(S);
5186
5187 // Evaluate the condition, as either a var decl or as an expression.
5188 BlockScopeRAII Scope(Info);
5189 if (const Stmt *Init = IS->getInit()) {
5190 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
5191 if (ESR != ESR_Succeeded) {
5192 if (ESR != ESR_Failed && !Scope.destroy())
5193 return ESR_Failed;
5194 return ESR;
5195 }
5196 }
5197 bool Cond;
5198 if (!EvaluateCond(Info, IS->getConditionVariable(), IS->getCond(), Cond))
5199 return ESR_Failed;
5200
5201 if (const Stmt *SubStmt = Cond ? IS->getThen() : IS->getElse()) {
5202 EvalStmtResult ESR = EvaluateStmt(Result, Info, SubStmt);
5203 if (ESR != ESR_Succeeded) {
5204 if (ESR != ESR_Failed && !Scope.destroy())
5205 return ESR_Failed;
5206 return ESR;
5207 }
5208 }
5209 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
5210 }
5211
5212 case Stmt::WhileStmtClass: {
5213 const WhileStmt *WS = cast<WhileStmt>(S);
5214 while (true) {
5215 BlockScopeRAII Scope(Info);
5216 bool Continue;
5217 if (!EvaluateCond(Info, WS->getConditionVariable(), WS->getCond(),
5218 Continue))
5219 return ESR_Failed;
5220 if (!Continue)
5221 break;
5222
5223 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, WS->getBody());
5224 if (ESR != ESR_Continue) {
5225 if (ESR != ESR_Failed && !Scope.destroy())
5226 return ESR_Failed;
5227 return ESR;
5228 }
5229 if (!Scope.destroy())
5230 return ESR_Failed;
5231 }
5232 return ESR_Succeeded;
5233 }
5234
5235 case Stmt::DoStmtClass: {
5236 const DoStmt *DS = cast<DoStmt>(S);
5237 bool Continue;
5238 do {
5239 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, DS->getBody(), Case);
5240 if (ESR != ESR_Continue)
5241 return ESR;
5242 Case = nullptr;
5243
5244 if (DS->getCond()->isValueDependent()) {
5245 EvaluateDependentExpr(DS->getCond(), Info);
5246 // Bailout as we don't know whether to keep going or terminate the loop.
5247 return ESR_Failed;
5248 }
5249 FullExpressionRAII CondScope(Info);
5250 if (!EvaluateAsBooleanCondition(DS->getCond(), Continue, Info) ||
5251 !CondScope.destroy())
5252 return ESR_Failed;
5253 } while (Continue);
5254 return ESR_Succeeded;
5255 }
5256
5257 case Stmt::ForStmtClass: {
5258 const ForStmt *FS = cast<ForStmt>(S);
5259 BlockScopeRAII ForScope(Info);
5260 if (FS->getInit()) {
5261 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
5262 if (ESR != ESR_Succeeded) {
5263 if (ESR != ESR_Failed && !ForScope.destroy())
5264 return ESR_Failed;
5265 return ESR;
5266 }
5267 }
5268 while (true) {
5269 BlockScopeRAII IterScope(Info);
5270 bool Continue = true;
5271 if (FS->getCond() && !EvaluateCond(Info, FS->getConditionVariable(),
5272 FS->getCond(), Continue))
5273 return ESR_Failed;
5274 if (!Continue)
5275 break;
5276
5277 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, FS->getBody());
5278 if (ESR != ESR_Continue) {
5279 if (ESR != ESR_Failed && (!IterScope.destroy() || !ForScope.destroy()))
5280 return ESR_Failed;
5281 return ESR;
5282 }
5283
5284 if (const auto *Inc = FS->getInc()) {
5285 if (Inc->isValueDependent()) {
5286 if (!EvaluateDependentExpr(Inc, Info))
5287 return ESR_Failed;
5288 } else {
5289 FullExpressionRAII IncScope(Info);
5290 if (!EvaluateIgnoredValue(Info, Inc) || !IncScope.destroy())
5291 return ESR_Failed;
5292 }
5293 }
5294
5295 if (!IterScope.destroy())
5296 return ESR_Failed;
5297 }
5298 return ForScope.destroy() ? ESR_Succeeded : ESR_Failed;
5299 }
5300
5301 case Stmt::CXXForRangeStmtClass: {
5302 const CXXForRangeStmt *FS = cast<CXXForRangeStmt>(S);
5303 BlockScopeRAII Scope(Info);
5304
5305 // Evaluate the init-statement if present.
5306 if (FS->getInit()) {
5307 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
5308 if (ESR != ESR_Succeeded) {
5309 if (ESR != ESR_Failed && !Scope.destroy())
5310 return ESR_Failed;
5311 return ESR;
5312 }
5313 }
5314
5315 // Initialize the __range variable.
5316 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getRangeStmt());
5317 if (ESR != ESR_Succeeded) {
5318 if (ESR != ESR_Failed && !Scope.destroy())
5319 return ESR_Failed;
5320 return ESR;
5321 }
5322
5323 // Create the __begin and __end iterators.
5324 ESR = EvaluateStmt(Result, Info, FS->getBeginStmt());
5325 if (ESR != ESR_Succeeded) {
5326 if (ESR != ESR_Failed && !Scope.destroy())
5327 return ESR_Failed;
5328 return ESR;
5329 }
5330 ESR = EvaluateStmt(Result, Info, FS->getEndStmt());
5331 if (ESR != ESR_Succeeded) {
5332 if (ESR != ESR_Failed && !Scope.destroy())
5333 return ESR_Failed;
5334 return ESR;
5335 }
5336
5337 while (true) {
5338 // Condition: __begin != __end.
5339 {
5340 if (FS->getCond()->isValueDependent()) {
5341 EvaluateDependentExpr(FS->getCond(), Info);
5342 // We don't know whether to keep going or terminate the loop.
5343 return ESR_Failed;
5344 }
5345 bool Continue = true;
5346 FullExpressionRAII CondExpr(Info);
5347 if (!EvaluateAsBooleanCondition(FS->getCond(), Continue, Info))
5348 return ESR_Failed;
5349 if (!Continue)
5350 break;
5351 }
5352
5353 // User's variable declaration, initialized by *__begin.
5354 BlockScopeRAII InnerScope(Info);
5355 ESR = EvaluateStmt(Result, Info, FS->getLoopVarStmt());
5356 if (ESR != ESR_Succeeded) {
5357 if (ESR != ESR_Failed && (!InnerScope.destroy() || !Scope.destroy()))
5358 return ESR_Failed;
5359 return ESR;
5360 }
5361
5362 // Loop body.
5363 ESR = EvaluateLoopBody(Result, Info, FS->getBody());
5364 if (ESR != ESR_Continue) {
5365 if (ESR != ESR_Failed && (!InnerScope.destroy() || !Scope.destroy()))
5366 return ESR_Failed;
5367 return ESR;
5368 }
5369 if (FS->getInc()->isValueDependent()) {
5370 if (!EvaluateDependentExpr(FS->getInc(), Info))
5371 return ESR_Failed;
5372 } else {
5373 // Increment: ++__begin
5374 if (!EvaluateIgnoredValue(Info, FS->getInc()))
5375 return ESR_Failed;
5376 }
5377
5378 if (!InnerScope.destroy())
5379 return ESR_Failed;
5380 }
5381
5382 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
5383 }
5384
5385 case Stmt::SwitchStmtClass:
5386 return EvaluateSwitch(Result, Info, cast<SwitchStmt>(S));
5387
5388 case Stmt::ContinueStmtClass:
5389 return ESR_Continue;
5390
5391 case Stmt::BreakStmtClass:
5392 return ESR_Break;
5393
5394 case Stmt::LabelStmtClass:
5395 return EvaluateStmt(Result, Info, cast<LabelStmt>(S)->getSubStmt(), Case);
5396
5397 case Stmt::AttributedStmtClass:
5398 // As a general principle, C++11 attributes can be ignored without
5399 // any semantic impact.
5400 return EvaluateStmt(Result, Info, cast<AttributedStmt>(S)->getSubStmt(),
5401 Case);
5402
5403 case Stmt::CaseStmtClass:
5404 case Stmt::DefaultStmtClass:
5405 return EvaluateStmt(Result, Info, cast<SwitchCase>(S)->getSubStmt(), Case);
5406 case Stmt::CXXTryStmtClass:
5407 // Evaluate try blocks by evaluating all sub statements.
5408 return EvaluateStmt(Result, Info, cast<CXXTryStmt>(S)->getTryBlock(), Case);
5409 }
5410}
5411
5412/// CheckTrivialDefaultConstructor - Check whether a constructor is a trivial
5413/// default constructor. If so, we'll fold it whether or not it's marked as
5414/// constexpr. If it is marked as constexpr, we will never implicitly define it,
5415/// so we need special handling.
5416static bool CheckTrivialDefaultConstructor(EvalInfo &Info, SourceLocation Loc,
5417 const CXXConstructorDecl *CD,
5418 bool IsValueInitialization) {
5419 if (!CD->isTrivial() || !CD->isDefaultConstructor())
5420 return false;
5421
5422 // Value-initialization does not call a trivial default constructor, so such a
5423 // call is a core constant expression whether or not the constructor is
5424 // constexpr.
5425 if (!CD->isConstexpr() && !IsValueInitialization) {
5426 if (Info.getLangOpts().CPlusPlus11) {
5427 // FIXME: If DiagDecl is an implicitly-declared special member function,
5428 // we should be much more explicit about why it's not constexpr.
5429 Info.CCEDiag(Loc, diag::note_constexpr_invalid_function, 1)
5430 << /*IsConstexpr*/0 << /*IsConstructor*/1 << CD;
5431 Info.Note(CD->getLocation(), diag::note_declared_at);
5432 } else {
5433 Info.CCEDiag(Loc, diag::note_invalid_subexpr_in_const_expr);
5434 }
5435 }
5436 return true;
5437}
5438
5439/// CheckConstexprFunction - Check that a function can be called in a constant
5440/// expression.
5441static bool CheckConstexprFunction(EvalInfo &Info, SourceLocation CallLoc,
5442 const FunctionDecl *Declaration,
5443 const FunctionDecl *Definition,
5444 const Stmt *Body) {
5445 // Potential constant expressions can contain calls to declared, but not yet
5446 // defined, constexpr functions.
5447 if (Info.checkingPotentialConstantExpression() && !Definition &&
5448 Declaration->isConstexpr())
5449 return false;
5450
5451 // Bail out if the function declaration itself is invalid. We will
5452 // have produced a relevant diagnostic while parsing it, so just
5453 // note the problematic sub-expression.
5454 if (Declaration->isInvalidDecl()) {
5455 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
5456 return false;
5457 }
5458
5459 // DR1872: An instantiated virtual constexpr function can't be called in a
5460 // constant expression (prior to C++20). We can still constant-fold such a
5461 // call.
5462 if (!Info.Ctx.getLangOpts().CPlusPlus20 && isa<CXXMethodDecl>(Declaration) &&
5463 cast<CXXMethodDecl>(Declaration)->isVirtual())
5464 Info.CCEDiag(CallLoc, diag::note_constexpr_virtual_call);
5465
5466 if (Definition && Definition->isInvalidDecl()) {
5467 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
5468 return false;
5469 }
5470
5471 // Can we evaluate this function call?
5472 if (Definition && Definition->isConstexpr() && Body)
5473 return true;
5474
5475 if (Info.getLangOpts().CPlusPlus11) {
5476 const FunctionDecl *DiagDecl = Definition ? Definition : Declaration;
5477
5478 // If this function is not constexpr because it is an inherited
5479 // non-constexpr constructor, diagnose that directly.
5480 auto *CD = dyn_cast<CXXConstructorDecl>(DiagDecl);
5481 if (CD && CD->isInheritingConstructor()) {
5482 auto *Inherited = CD->getInheritedConstructor().getConstructor();
5483 if (!Inherited->isConstexpr())
5484 DiagDecl = CD = Inherited;
5485 }
5486
5487 // FIXME: If DiagDecl is an implicitly-declared special member function
5488 // or an inheriting constructor, we should be much more explicit about why
5489 // it's not constexpr.
5490 if (CD && CD->isInheritingConstructor())
5491 Info.FFDiag(CallLoc, diag::note_constexpr_invalid_inhctor, 1)
5492 << CD->getInheritedConstructor().getConstructor()->getParent();
5493 else
5494 Info.FFDiag(CallLoc, diag::note_constexpr_invalid_function, 1)
5495 << DiagDecl->isConstexpr() << (bool)CD << DiagDecl;
5496 Info.Note(DiagDecl->getLocation(), diag::note_declared_at);
5497 } else {
5498 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
5499 }
5500 return false;
5501}
5502
5503namespace {
5504struct CheckDynamicTypeHandler {
5505 AccessKinds AccessKind;
5506 typedef bool result_type;
5507 bool failed() { return false; }
5508 bool found(APValue &Subobj, QualType SubobjType) { return true; }
5509 bool found(APSInt &Value, QualType SubobjType) { return true; }
5510 bool found(APFloat &Value, QualType SubobjType) { return true; }
5511};
5512} // end anonymous namespace
5513
5514/// Check that we can access the notional vptr of an object / determine its
5515/// dynamic type.
5516static bool checkDynamicType(EvalInfo &Info, const Expr *E, const LValue &This,
5517 AccessKinds AK, bool Polymorphic) {
5518 if (This.Designator.Invalid)
5519 return false;
5520
5521 CompleteObject Obj = findCompleteObject(Info, E, AK, This, QualType());
5522
5523 if (!Obj)
5524 return false;
5525
5526 if (!Obj.Value) {
5527 // The object is not usable in constant expressions, so we can't inspect
5528 // its value to see if it's in-lifetime or what the active union members
5529 // are. We can still check for a one-past-the-end lvalue.
5530 if (This.Designator.isOnePastTheEnd() ||
5531 This.Designator.isMostDerivedAnUnsizedArray()) {
5532 Info.FFDiag(E, This.Designator.isOnePastTheEnd()
5533 ? diag::note_constexpr_access_past_end
5534 : diag::note_constexpr_access_unsized_array)
5535 << AK;
5536 return false;
5537 } else if (Polymorphic) {
5538 // Conservatively refuse to perform a polymorphic operation if we would
5539 // not be able to read a notional 'vptr' value.
5540 APValue Val;
5541 This.moveInto(Val);
5542 QualType StarThisType =
5543 Info.Ctx.getLValueReferenceType(This.Designator.getType(Info.Ctx));
5544 Info.FFDiag(E, diag::note_constexpr_polymorphic_unknown_dynamic_type)
5545 << AK << Val.getAsString(Info.Ctx, StarThisType);
5546 return false;
5547 }
5548 return true;
5549 }
5550
5551 CheckDynamicTypeHandler Handler{AK};
5552 return Obj && findSubobject(Info, E, Obj, This.Designator, Handler);
5553}
5554
5555/// Check that the pointee of the 'this' pointer in a member function call is
5556/// either within its lifetime or in its period of construction or destruction.
5557static bool
5558checkNonVirtualMemberCallThisPointer(EvalInfo &Info, const Expr *E,
5559 const LValue &This,
5560 const CXXMethodDecl *NamedMember) {
5561 return checkDynamicType(
5562 Info, E, This,
5563 isa<CXXDestructorDecl>(NamedMember) ? AK_Destroy : AK_MemberCall, false);
5564}
5565
5566struct DynamicType {
5567 /// The dynamic class type of the object.
5568 const CXXRecordDecl *Type;
5569 /// The corresponding path length in the lvalue.
5570 unsigned PathLength;
5571};
5572
5573static const CXXRecordDecl *getBaseClassType(SubobjectDesignator &Designator,
5574 unsigned PathLength) {
5575 assert(PathLength >= Designator.MostDerivedPathLength && PathLength <=(static_cast <bool> (PathLength >= Designator.MostDerivedPathLength
&& PathLength <= Designator.Entries.size() &&
"invalid path length") ? void (0) : __assert_fail ("PathLength >= Designator.MostDerivedPathLength && PathLength <= Designator.Entries.size() && \"invalid path length\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5576, __extension__ __PRETTY_FUNCTION__))
5576 Designator.Entries.size() && "invalid path length")(static_cast <bool> (PathLength >= Designator.MostDerivedPathLength
&& PathLength <= Designator.Entries.size() &&
"invalid path length") ? void (0) : __assert_fail ("PathLength >= Designator.MostDerivedPathLength && PathLength <= Designator.Entries.size() && \"invalid path length\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5576, __extension__ __PRETTY_FUNCTION__))
;
5577 return (PathLength == Designator.MostDerivedPathLength)
5578 ? Designator.MostDerivedType->getAsCXXRecordDecl()
5579 : getAsBaseClass(Designator.Entries[PathLength - 1]);
5580}
5581
5582/// Determine the dynamic type of an object.
5583static Optional<DynamicType> ComputeDynamicType(EvalInfo &Info, const Expr *E,
5584 LValue &This, AccessKinds AK) {
5585 // If we don't have an lvalue denoting an object of class type, there is no
5586 // meaningful dynamic type. (We consider objects of non-class type to have no
5587 // dynamic type.)
5588 if (!checkDynamicType(Info, E, This, AK, true))
5589 return None;
5590
5591 // Refuse to compute a dynamic type in the presence of virtual bases. This
5592 // shouldn't happen other than in constant-folding situations, since literal
5593 // types can't have virtual bases.
5594 //
5595 // Note that consumers of DynamicType assume that the type has no virtual
5596 // bases, and will need modifications if this restriction is relaxed.
5597 const CXXRecordDecl *Class =
5598 This.Designator.MostDerivedType->getAsCXXRecordDecl();
5599 if (!Class || Class->getNumVBases()) {
5600 Info.FFDiag(E);
5601 return None;
5602 }
5603
5604 // FIXME: For very deep class hierarchies, it might be beneficial to use a
5605 // binary search here instead. But the overwhelmingly common case is that
5606 // we're not in the middle of a constructor, so it probably doesn't matter
5607 // in practice.
5608 ArrayRef<APValue::LValuePathEntry> Path = This.Designator.Entries;
5609 for (unsigned PathLength = This.Designator.MostDerivedPathLength;
5610 PathLength <= Path.size(); ++PathLength) {
5611 switch (Info.isEvaluatingCtorDtor(This.getLValueBase(),
5612 Path.slice(0, PathLength))) {
5613 case ConstructionPhase::Bases:
5614 case ConstructionPhase::DestroyingBases:
5615 // We're constructing or destroying a base class. This is not the dynamic
5616 // type.
5617 break;
5618
5619 case ConstructionPhase::None:
5620 case ConstructionPhase::AfterBases:
5621 case ConstructionPhase::AfterFields:
5622 case ConstructionPhase::Destroying:
5623 // We've finished constructing the base classes and not yet started
5624 // destroying them again, so this is the dynamic type.
5625 return DynamicType{getBaseClassType(This.Designator, PathLength),
5626 PathLength};
5627 }
5628 }
5629
5630 // CWG issue 1517: we're constructing a base class of the object described by
5631 // 'This', so that object has not yet begun its period of construction and
5632 // any polymorphic operation on it results in undefined behavior.
5633 Info.FFDiag(E);
5634 return None;
5635}
5636
5637/// Perform virtual dispatch.
5638static const CXXMethodDecl *HandleVirtualDispatch(
5639 EvalInfo &Info, const Expr *E, LValue &This, const CXXMethodDecl *Found,
5640 llvm::SmallVectorImpl<QualType> &CovariantAdjustmentPath) {
5641 Optional<DynamicType> DynType = ComputeDynamicType(
5642 Info, E, This,
5643 isa<CXXDestructorDecl>(Found) ? AK_Destroy : AK_MemberCall);
5644 if (!DynType)
5645 return nullptr;
5646
5647 // Find the final overrider. It must be declared in one of the classes on the
5648 // path from the dynamic type to the static type.
5649 // FIXME: If we ever allow literal types to have virtual base classes, that
5650 // won't be true.
5651 const CXXMethodDecl *Callee = Found;
5652 unsigned PathLength = DynType->PathLength;
5653 for (/**/; PathLength <= This.Designator.Entries.size(); ++PathLength) {
5654 const CXXRecordDecl *Class = getBaseClassType(This.Designator, PathLength);
5655 const CXXMethodDecl *Overrider =
5656 Found->getCorrespondingMethodDeclaredInClass(Class, false);
5657 if (Overrider) {
5658 Callee = Overrider;
5659 break;
5660 }
5661 }
5662
5663 // C++2a [class.abstract]p6:
5664 // the effect of making a virtual call to a pure virtual function [...] is
5665 // undefined
5666 if (Callee->isPure()) {
5667 Info.FFDiag(E, diag::note_constexpr_pure_virtual_call, 1) << Callee;
5668 Info.Note(Callee->getLocation(), diag::note_declared_at);
5669 return nullptr;
5670 }
5671
5672 // If necessary, walk the rest of the path to determine the sequence of
5673 // covariant adjustment steps to apply.
5674 if (!Info.Ctx.hasSameUnqualifiedType(Callee->getReturnType(),
5675 Found->getReturnType())) {
5676 CovariantAdjustmentPath.push_back(Callee->getReturnType());
5677 for (unsigned CovariantPathLength = PathLength + 1;
5678 CovariantPathLength != This.Designator.Entries.size();
5679 ++CovariantPathLength) {
5680 const CXXRecordDecl *NextClass =
5681 getBaseClassType(This.Designator, CovariantPathLength);
5682 const CXXMethodDecl *Next =
5683 Found->getCorrespondingMethodDeclaredInClass(NextClass, false);
5684 if (Next && !Info.Ctx.hasSameUnqualifiedType(
5685 Next->getReturnType(), CovariantAdjustmentPath.back()))
5686 CovariantAdjustmentPath.push_back(Next->getReturnType());
5687 }
5688 if (!Info.Ctx.hasSameUnqualifiedType(Found->getReturnType(),
5689 CovariantAdjustmentPath.back()))
5690 CovariantAdjustmentPath.push_back(Found->getReturnType());
5691 }
5692
5693 // Perform 'this' adjustment.
5694 if (!CastToDerivedClass(Info, E, This, Callee->getParent(), PathLength))
5695 return nullptr;
5696
5697 return Callee;
5698}
5699
5700/// Perform the adjustment from a value returned by a virtual function to
5701/// a value of the statically expected type, which may be a pointer or
5702/// reference to a base class of the returned type.
5703static bool HandleCovariantReturnAdjustment(EvalInfo &Info, const Expr *E,
5704 APValue &Result,
5705 ArrayRef<QualType> Path) {
5706 assert(Result.isLValue() &&(static_cast <bool> (Result.isLValue() && "unexpected kind of APValue for covariant return"
) ? void (0) : __assert_fail ("Result.isLValue() && \"unexpected kind of APValue for covariant return\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5707, __extension__ __PRETTY_FUNCTION__))
5707 "unexpected kind of APValue for covariant return")(static_cast <bool> (Result.isLValue() && "unexpected kind of APValue for covariant return"
) ? void (0) : __assert_fail ("Result.isLValue() && \"unexpected kind of APValue for covariant return\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5707, __extension__ __PRETTY_FUNCTION__))
;
5708 if (Result.isNullPointer())
5709 return true;
5710
5711 LValue LVal;
5712 LVal.setFrom(Info.Ctx, Result);
5713
5714 const CXXRecordDecl *OldClass = Path[0]->getPointeeCXXRecordDecl();
5715 for (unsigned I = 1; I != Path.size(); ++I) {
5716 const CXXRecordDecl *NewClass = Path[I]->getPointeeCXXRecordDecl();
5717 assert(OldClass && NewClass && "unexpected kind of covariant return")(static_cast <bool> (OldClass && NewClass &&
"unexpected kind of covariant return") ? void (0) : __assert_fail
("OldClass && NewClass && \"unexpected kind of covariant return\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5717, __extension__ __PRETTY_FUNCTION__))
;
5718 if (OldClass != NewClass &&
5719 !CastToBaseClass(Info, E, LVal, OldClass, NewClass))
5720 return false;
5721 OldClass = NewClass;
5722 }
5723
5724 LVal.moveInto(Result);
5725 return true;
5726}
5727
5728/// Determine whether \p Base, which is known to be a direct base class of
5729/// \p Derived, is a public base class.
5730static bool isBaseClassPublic(const CXXRecordDecl *Derived,
5731 const CXXRecordDecl *Base) {
5732 for (const CXXBaseSpecifier &BaseSpec : Derived->bases()) {
5733 auto *BaseClass = BaseSpec.getType()->getAsCXXRecordDecl();
5734 if (BaseClass && declaresSameEntity(BaseClass, Base))
5735 return BaseSpec.getAccessSpecifier() == AS_public;
5736 }
5737 llvm_unreachable("Base is not a direct base of Derived")::llvm::llvm_unreachable_internal("Base is not a direct base of Derived"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5737)
;
5738}
5739
5740/// Apply the given dynamic cast operation on the provided lvalue.
5741///
5742/// This implements the hard case of dynamic_cast, requiring a "runtime check"
5743/// to find a suitable target subobject.
5744static bool HandleDynamicCast(EvalInfo &Info, const ExplicitCastExpr *E,
5745 LValue &Ptr) {
5746 // We can't do anything with a non-symbolic pointer value.
5747 SubobjectDesignator &D = Ptr.Designator;
5748 if (D.Invalid)
5749 return false;
5750
5751 // C++ [expr.dynamic.cast]p6:
5752 // If v is a null pointer value, the result is a null pointer value.
5753 if (Ptr.isNullPointer() && !E->isGLValue())
5754 return true;
5755
5756 // For all the other cases, we need the pointer to point to an object within
5757 // its lifetime / period of construction / destruction, and we need to know
5758 // its dynamic type.
5759 Optional<DynamicType> DynType =
5760 ComputeDynamicType(Info, E, Ptr, AK_DynamicCast);
5761 if (!DynType)
5762 return false;
5763
5764 // C++ [expr.dynamic.cast]p7:
5765 // If T is "pointer to cv void", then the result is a pointer to the most
5766 // derived object
5767 if (E->getType()->isVoidPointerType())
5768 return CastToDerivedClass(Info, E, Ptr, DynType->Type, DynType->PathLength);
5769
5770 const CXXRecordDecl *C = E->getTypeAsWritten()->getPointeeCXXRecordDecl();
5771 assert(C && "dynamic_cast target is not void pointer nor class")(static_cast <bool> (C && "dynamic_cast target is not void pointer nor class"
) ? void (0) : __assert_fail ("C && \"dynamic_cast target is not void pointer nor class\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5771, __extension__ __PRETTY_FUNCTION__))
;
5772 CanQualType CQT = Info.Ctx.getCanonicalType(Info.Ctx.getRecordType(C));
5773
5774 auto RuntimeCheckFailed = [&] (CXXBasePaths *Paths) {
5775 // C++ [expr.dynamic.cast]p9:
5776 if (!E->isGLValue()) {
5777 // The value of a failed cast to pointer type is the null pointer value
5778 // of the required result type.
5779 Ptr.setNull(Info.Ctx, E->getType());
5780 return true;
5781 }
5782
5783 // A failed cast to reference type throws [...] std::bad_cast.
5784 unsigned DiagKind;
5785 if (!Paths && (declaresSameEntity(DynType->Type, C) ||
5786 DynType->Type->isDerivedFrom(C)))
5787 DiagKind = 0;
5788 else if (!Paths || Paths->begin() == Paths->end())
5789 DiagKind = 1;
5790 else if (Paths->isAmbiguous(CQT))
5791 DiagKind = 2;
5792 else {
5793 assert(Paths->front().Access != AS_public && "why did the cast fail?")(static_cast <bool> (Paths->front().Access != AS_public
&& "why did the cast fail?") ? void (0) : __assert_fail
("Paths->front().Access != AS_public && \"why did the cast fail?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5793, __extension__ __PRETTY_FUNCTION__))
;
5794 DiagKind = 3;
5795 }
5796 Info.FFDiag(E, diag::note_constexpr_dynamic_cast_to_reference_failed)
5797 << DiagKind << Ptr.Designator.getType(Info.Ctx)
5798 << Info.Ctx.getRecordType(DynType->Type)
5799 << E->getType().getUnqualifiedType();
5800 return false;
5801 };
5802
5803 // Runtime check, phase 1:
5804 // Walk from the base subobject towards the derived object looking for the
5805 // target type.
5806 for (int PathLength = Ptr.Designator.Entries.size();
5807 PathLength >= (int)DynType->PathLength; --PathLength) {
5808 const CXXRecordDecl *Class = getBaseClassType(Ptr.Designator, PathLength);
5809 if (declaresSameEntity(Class, C))
5810 return CastToDerivedClass(Info, E, Ptr, Class, PathLength);
5811 // We can only walk across public inheritance edges.
5812 if (PathLength > (int)DynType->PathLength &&
5813 !isBaseClassPublic(getBaseClassType(Ptr.Designator, PathLength - 1),
5814 Class))
5815 return RuntimeCheckFailed(nullptr);
5816 }
5817
5818 // Runtime check, phase 2:
5819 // Search the dynamic type for an unambiguous public base of type C.
5820 CXXBasePaths Paths(/*FindAmbiguities=*/true,
5821 /*RecordPaths=*/true, /*DetectVirtual=*/false);
5822 if (DynType->Type->isDerivedFrom(C, Paths) && !Paths.isAmbiguous(CQT) &&
5823 Paths.front().Access == AS_public) {
5824 // Downcast to the dynamic type...
5825 if (!CastToDerivedClass(Info, E, Ptr, DynType->Type, DynType->PathLength))
5826 return false;
5827 // ... then upcast to the chosen base class subobject.
5828 for (CXXBasePathElement &Elem : Paths.front())
5829 if (!HandleLValueBase(Info, E, Ptr, Elem.Class, Elem.Base))
5830 return false;
5831 return true;
5832 }
5833
5834 // Otherwise, the runtime check fails.
5835 return RuntimeCheckFailed(&Paths);
5836}
5837
5838namespace {
5839struct StartLifetimeOfUnionMemberHandler {
5840 EvalInfo &Info;
5841 const Expr *LHSExpr;
5842 const FieldDecl *Field;
5843 bool DuringInit;
5844 bool Failed = false;
5845 static const AccessKinds AccessKind = AK_Assign;
5846
5847 typedef bool result_type;
5848 bool failed() { return Failed; }
5849 bool found(APValue &Subobj, QualType SubobjType) {
5850 // We are supposed to perform no initialization but begin the lifetime of
5851 // the object. We interpret that as meaning to do what default
5852 // initialization of the object would do if all constructors involved were
5853 // trivial:
5854 // * All base, non-variant member, and array element subobjects' lifetimes
5855 // begin
5856 // * No variant members' lifetimes begin
5857 // * All scalar subobjects whose lifetimes begin have indeterminate values
5858 assert(SubobjType->isUnionType())(static_cast <bool> (SubobjType->isUnionType()) ? void
(0) : __assert_fail ("SubobjType->isUnionType()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5858, __extension__ __PRETTY_FUNCTION__))
;
5859 if (declaresSameEntity(Subobj.getUnionField(), Field)) {
5860 // This union member is already active. If it's also in-lifetime, there's
5861 // nothing to do.
5862 if (Subobj.getUnionValue().hasValue())
5863 return true;
5864 } else if (DuringInit) {
5865 // We're currently in the process of initializing a different union
5866 // member. If we carried on, that initialization would attempt to
5867 // store to an inactive union member, resulting in undefined behavior.
5868 Info.FFDiag(LHSExpr,
5869 diag::note_constexpr_union_member_change_during_init);
5870 return false;
5871 }
5872 APValue Result;
5873 Failed = !getDefaultInitValue(Field->getType(), Result);
5874 Subobj.setUnion(Field, Result);
5875 return true;
5876 }
5877 bool found(APSInt &Value, QualType SubobjType) {
5878 llvm_unreachable("wrong value kind for union object")::llvm::llvm_unreachable_internal("wrong value kind for union object"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5878)
;
5879 }
5880 bool found(APFloat &Value, QualType SubobjType) {
5881 llvm_unreachable("wrong value kind for union object")::llvm::llvm_unreachable_internal("wrong value kind for union object"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5881)
;
5882 }
5883};
5884} // end anonymous namespace
5885
5886const AccessKinds StartLifetimeOfUnionMemberHandler::AccessKind;
5887
5888/// Handle a builtin simple-assignment or a call to a trivial assignment
5889/// operator whose left-hand side might involve a union member access. If it
5890/// does, implicitly start the lifetime of any accessed union elements per
5891/// C++20 [class.union]5.
5892static bool HandleUnionActiveMemberChange(EvalInfo &Info, const Expr *LHSExpr,
5893 const LValue &LHS) {
5894 if (LHS.InvalidBase || LHS.Designator.Invalid)
5895 return false;
5896
5897 llvm::SmallVector<std::pair<unsigned, const FieldDecl*>, 4> UnionPathLengths;
5898 // C++ [class.union]p5:
5899 // define the set S(E) of subexpressions of E as follows:
5900 unsigned PathLength = LHS.Designator.Entries.size();
5901 for (const Expr *E = LHSExpr; E != nullptr;) {
5902 // -- If E is of the form A.B, S(E) contains the elements of S(A)...
5903 if (auto *ME = dyn_cast<MemberExpr>(E)) {
5904 auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
5905 // Note that we can't implicitly start the lifetime of a reference,
5906 // so we don't need to proceed any further if we reach one.
5907 if (!FD || FD->getType()->isReferenceType())
5908 break;
5909
5910 // ... and also contains A.B if B names a union member ...
5911 if (FD->getParent()->isUnion()) {
5912 // ... of a non-class, non-array type, or of a class type with a
5913 // trivial default constructor that is not deleted, or an array of
5914 // such types.
5915 auto *RD =
5916 FD->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
5917 if (!RD || RD->hasTrivialDefaultConstructor())
5918 UnionPathLengths.push_back({PathLength - 1, FD});
5919 }
5920
5921 E = ME->getBase();
5922 --PathLength;
5923 assert(declaresSameEntity(FD,(static_cast <bool> (declaresSameEntity(FD, LHS.Designator
.Entries[PathLength] .getAsBaseOrMember().getPointer())) ? void
(0) : __assert_fail ("declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5925, __extension__ __PRETTY_FUNCTION__))
5924 LHS.Designator.Entries[PathLength](static_cast <bool> (declaresSameEntity(FD, LHS.Designator
.Entries[PathLength] .getAsBaseOrMember().getPointer())) ? void
(0) : __assert_fail ("declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5925, __extension__ __PRETTY_FUNCTION__))
5925 .getAsBaseOrMember().getPointer()))(static_cast <bool> (declaresSameEntity(FD, LHS.Designator
.Entries[PathLength] .getAsBaseOrMember().getPointer())) ? void
(0) : __assert_fail ("declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5925, __extension__ __PRETTY_FUNCTION__))
;
5926
5927 // -- If E is of the form A[B] and is interpreted as a built-in array
5928 // subscripting operator, S(E) is [S(the array operand, if any)].
5929 } else if (auto *ASE = dyn_cast<ArraySubscriptExpr>(E)) {
5930 // Step over an ArrayToPointerDecay implicit cast.
5931 auto *Base = ASE->getBase()->IgnoreImplicit();
5932 if (!Base->getType()->isArrayType())
5933 break;
5934
5935 E = Base;
5936 --PathLength;
5937
5938 } else if (auto *ICE = dyn_cast<ImplicitCastExpr>(E)) {
5939 // Step over a derived-to-base conversion.
5940 E = ICE->getSubExpr();
5941 if (ICE->getCastKind() == CK_NoOp)
5942 continue;
5943 if (ICE->getCastKind() != CK_DerivedToBase &&
5944 ICE->getCastKind() != CK_UncheckedDerivedToBase)
5945 break;
5946 // Walk path backwards as we walk up from the base to the derived class.
5947 for (const CXXBaseSpecifier *Elt : llvm::reverse(ICE->path())) {
5948 --PathLength;
5949 (void)Elt;
5950 assert(declaresSameEntity(Elt->getType()->getAsCXXRecordDecl(),(static_cast <bool> (declaresSameEntity(Elt->getType
()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength
] .getAsBaseOrMember().getPointer())) ? void (0) : __assert_fail
("declaresSameEntity(Elt->getType()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5952, __extension__ __PRETTY_FUNCTION__))
5951 LHS.Designator.Entries[PathLength](static_cast <bool> (declaresSameEntity(Elt->getType
()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength
] .getAsBaseOrMember().getPointer())) ? void (0) : __assert_fail
("declaresSameEntity(Elt->getType()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5952, __extension__ __PRETTY_FUNCTION__))
5952 .getAsBaseOrMember().getPointer()))(static_cast <bool> (declaresSameEntity(Elt->getType
()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength
] .getAsBaseOrMember().getPointer())) ? void (0) : __assert_fail
("declaresSameEntity(Elt->getType()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 5952, __extension__ __PRETTY_FUNCTION__))
;
5953 }
5954
5955 // -- Otherwise, S(E) is empty.
5956 } else {
5957 break;
5958 }
5959 }
5960
5961 // Common case: no unions' lifetimes are started.
5962 if (UnionPathLengths.empty())
5963 return true;
5964
5965 // if modification of X [would access an inactive union member], an object
5966 // of the type of X is implicitly created
5967 CompleteObject Obj =
5968 findCompleteObject(Info, LHSExpr, AK_Assign, LHS, LHSExpr->getType());
5969 if (!Obj)
5970 return false;
5971 for (std::pair<unsigned, const FieldDecl *> LengthAndField :
5972 llvm::reverse(UnionPathLengths)) {
5973 // Form a designator for the union object.
5974 SubobjectDesignator D = LHS.Designator;
5975 D.truncate(Info.Ctx, LHS.Base, LengthAndField.first);
5976
5977 bool DuringInit = Info.isEvaluatingCtorDtor(LHS.Base, D.Entries) ==
5978 ConstructionPhase::AfterBases;
5979 StartLifetimeOfUnionMemberHandler StartLifetime{
5980 Info, LHSExpr, LengthAndField.second, DuringInit};
5981 if (!findSubobject(Info, LHSExpr, Obj, D, StartLifetime))
5982 return false;
5983 }
5984
5985 return true;
5986}
5987
5988static bool EvaluateCallArg(const ParmVarDecl *PVD, const Expr *Arg,
5989 CallRef Call, EvalInfo &Info,
5990 bool NonNull = false) {
5991 LValue LV;
5992 // Create the parameter slot and register its destruction. For a vararg
5993 // argument, create a temporary.
5994 // FIXME: For calling conventions that destroy parameters in the callee,
5995 // should we consider performing destruction when the function returns
5996 // instead?
5997 APValue &V = PVD ? Info.CurrentCall->createParam(Call, PVD, LV)
5998 : Info.CurrentCall->createTemporary(Arg, Arg->getType(),
5999 ScopeKind::Call, LV);
6000 if (!EvaluateInPlace(V, Info, LV, Arg))
6001 return false;
6002
6003 // Passing a null pointer to an __attribute__((nonnull)) parameter results in
6004 // undefined behavior, so is non-constant.
6005 if (NonNull && V.isLValue() && V.isNullPointer()) {
6006 Info.CCEDiag(Arg, diag::note_non_null_attribute_failed);
6007 return false;
6008 }
6009
6010 return true;
6011}
6012
6013/// Evaluate the arguments to a function call.
6014static bool EvaluateArgs(ArrayRef<const Expr *> Args, CallRef Call,
6015 EvalInfo &Info, const FunctionDecl *Callee,
6016 bool RightToLeft = false) {
6017 bool Success = true;
6018 llvm::SmallBitVector ForbiddenNullArgs;
6019 if (Callee->hasAttr<NonNullAttr>()) {
6020 ForbiddenNullArgs.resize(Args.size());
6021 for (const auto *Attr : Callee->specific_attrs<NonNullAttr>()) {
6022 if (!Attr->args_size()) {
6023 ForbiddenNullArgs.set();
6024 break;
6025 } else
6026 for (auto Idx : Attr->args()) {
6027 unsigned ASTIdx = Idx.getASTIndex();
6028 if (ASTIdx >= Args.size())
6029 continue;
6030 ForbiddenNullArgs[ASTIdx] = 1;
6031 }
6032 }
6033 }
6034 for (unsigned I = 0; I < Args.size(); I++) {
6035 unsigned Idx = RightToLeft ? Args.size() - I - 1 : I;
6036 const ParmVarDecl *PVD =
6037 Idx < Callee->getNumParams() ? Callee->getParamDecl(Idx) : nullptr;
6038 bool NonNull = !ForbiddenNullArgs.empty() && ForbiddenNullArgs[Idx];
6039 if (!EvaluateCallArg(PVD, Args[Idx], Call, Info, NonNull)) {
6040 // If we're checking for a potential constant expression, evaluate all
6041 // initializers even if some of them fail.
6042 if (!Info.noteFailure())
6043 return false;
6044 Success = false;
6045 }
6046 }
6047 return Success;
6048}
6049
6050/// Perform a trivial copy from Param, which is the parameter of a copy or move
6051/// constructor or assignment operator.
6052static bool handleTrivialCopy(EvalInfo &Info, const ParmVarDecl *Param,
6053 const Expr *E, APValue &Result,
6054 bool CopyObjectRepresentation) {
6055 // Find the reference argument.
6056 CallStackFrame *Frame = Info.CurrentCall;
6057 APValue *RefValue = Info.getParamSlot(Frame->Arguments, Param);
6058 if (!RefValue) {
6059 Info.FFDiag(E);
6060 return false;
6061 }
6062
6063 // Copy out the contents of the RHS object.
6064 LValue RefLValue;
6065 RefLValue.setFrom(Info.Ctx, *RefValue);
6066 return handleLValueToRValueConversion(
6067 Info, E, Param->getType().getNonReferenceType(), RefLValue, Result,
6068 CopyObjectRepresentation);
6069}
6070
6071/// Evaluate a function call.
6072static bool HandleFunctionCall(SourceLocation CallLoc,
6073 const FunctionDecl *Callee, const LValue *This,
6074 ArrayRef<const Expr *> Args, CallRef Call,
6075 const Stmt *Body, EvalInfo &Info,
6076 APValue &Result, const LValue *ResultSlot) {
6077 if (!Info.CheckCallLimit(CallLoc))
6078 return false;
6079
6080 CallStackFrame Frame(Info, CallLoc, Callee, This, Call);
6081
6082 // For a trivial copy or move assignment, perform an APValue copy. This is
6083 // essential for unions, where the operations performed by the assignment
6084 // operator cannot be represented as statements.
6085 //
6086 // Skip this for non-union classes with no fields; in that case, the defaulted
6087 // copy/move does not actually read the object.
6088 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Callee);
6089 if (MD && MD->isDefaulted() &&
6090 (MD->getParent()->isUnion() ||
6091 (MD->isTrivial() &&
6092 isReadByLvalueToRvalueConversion(MD->getParent())))) {
6093 assert(This &&(static_cast <bool> (This && (MD->isCopyAssignmentOperator
() || MD->isMoveAssignmentOperator())) ? void (0) : __assert_fail
("This && (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6094, __extension__ __PRETTY_FUNCTION__))
6094 (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()))(static_cast <bool> (This && (MD->isCopyAssignmentOperator
() || MD->isMoveAssignmentOperator())) ? void (0) : __assert_fail
("This && (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6094, __extension__ __PRETTY_FUNCTION__))
;
6095 APValue RHSValue;
6096 if (!handleTrivialCopy(Info, MD->getParamDecl(0), Args[0], RHSValue,
6097 MD->getParent()->isUnion()))
6098 return false;
6099 if (Info.getLangOpts().CPlusPlus20 && MD->isTrivial() &&
6100 !HandleUnionActiveMemberChange(Info, Args[0], *This))
6101 return false;
6102 if (!handleAssignment(Info, Args[0], *This, MD->getThisType(),
6103 RHSValue))
6104 return false;
6105 This->moveInto(Result);
6106 return true;
6107 } else if (MD && isLambdaCallOperator(MD)) {
6108 // We're in a lambda; determine the lambda capture field maps unless we're
6109 // just constexpr checking a lambda's call operator. constexpr checking is
6110 // done before the captures have been added to the closure object (unless
6111 // we're inferring constexpr-ness), so we don't have access to them in this
6112 // case. But since we don't need the captures to constexpr check, we can
6113 // just ignore them.
6114 if (!Info.checkingPotentialConstantExpression())
6115 MD->getParent()->getCaptureFields(Frame.LambdaCaptureFields,
6116 Frame.LambdaThisCaptureField);
6117 }
6118
6119 StmtResult Ret = {Result, ResultSlot};
6120 EvalStmtResult ESR = EvaluateStmt(Ret, Info, Body);
6121 if (ESR == ESR_Succeeded) {
6122 if (Callee->getReturnType()->isVoidType())
6123 return true;
6124 Info.FFDiag(Callee->getEndLoc(), diag::note_constexpr_no_return);
6125 }
6126 return ESR == ESR_Returned;
6127}
6128
6129/// Evaluate a constructor call.
6130static bool HandleConstructorCall(const Expr *E, const LValue &This,
6131 CallRef Call,
6132 const CXXConstructorDecl *Definition,
6133 EvalInfo &Info, APValue &Result) {
6134 SourceLocation CallLoc = E->getExprLoc();
6135 if (!Info.CheckCallLimit(CallLoc))
6136 return false;
6137
6138 const CXXRecordDecl *RD = Definition->getParent();
6139 if (RD->getNumVBases()) {
6140 Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD;
6141 return false;
6142 }
6143
6144 EvalInfo::EvaluatingConstructorRAII EvalObj(
6145 Info,
6146 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries},
6147 RD->getNumBases());
6148 CallStackFrame Frame(Info, CallLoc, Definition, &This, Call);
6149
6150 // FIXME: Creating an APValue just to hold a nonexistent return value is
6151 // wasteful.
6152 APValue RetVal;
6153 StmtResult Ret = {RetVal, nullptr};
6154
6155 // If it's a delegating constructor, delegate.
6156 if (Definition->isDelegatingConstructor()) {
6157 CXXConstructorDecl::init_const_iterator I = Definition->init_begin();
6158 if ((*I)->getInit()->isValueDependent()) {
6159 if (!EvaluateDependentExpr((*I)->getInit(), Info))
6160 return false;
6161 } else {
6162 FullExpressionRAII InitScope(Info);
6163 if (!EvaluateInPlace(Result, Info, This, (*I)->getInit()) ||
6164 !InitScope.destroy())
6165 return false;
6166 }
6167 return EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed;
6168 }
6169
6170 // For a trivial copy or move constructor, perform an APValue copy. This is
6171 // essential for unions (or classes with anonymous union members), where the
6172 // operations performed by the constructor cannot be represented by
6173 // ctor-initializers.
6174 //
6175 // Skip this for empty non-union classes; we should not perform an
6176 // lvalue-to-rvalue conversion on them because their copy constructor does not
6177 // actually read them.
6178 if (Definition->isDefaulted() && Definition->isCopyOrMoveConstructor() &&
6179 (Definition->getParent()->isUnion() ||
6180 (Definition->isTrivial() &&
6181 isReadByLvalueToRvalueConversion(Definition->getParent())))) {
6182 return handleTrivialCopy(Info, Definition->getParamDecl(0), E, Result,
6183 Definition->getParent()->isUnion());
6184 }
6185
6186 // Reserve space for the struct members.
6187 if (!Result.hasValue()) {
6188 if (!RD->isUnion())
6189 Result = APValue(APValue::UninitStruct(), RD->getNumBases(),
6190 std::distance(RD->field_begin(), RD->field_end()));
6191 else
6192 // A union starts with no active member.
6193 Result = APValue((const FieldDecl*)nullptr);
6194 }
6195
6196 if (RD->isInvalidDecl()) return false;
6197 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
6198
6199 // A scope for temporaries lifetime-extended by reference members.
6200 BlockScopeRAII LifetimeExtendedScope(Info);
6201
6202 bool Success = true;
6203 unsigned BasesSeen = 0;
6204#ifndef NDEBUG
6205 CXXRecordDecl::base_class_const_iterator BaseIt = RD->bases_begin();
6206#endif
6207 CXXRecordDecl::field_iterator FieldIt = RD->field_begin();
6208 auto SkipToField = [&](FieldDecl *FD, bool Indirect) {
6209 // We might be initializing the same field again if this is an indirect
6210 // field initialization.
6211 if (FieldIt == RD->field_end() ||
6212 FieldIt->getFieldIndex() > FD->getFieldIndex()) {
6213 assert(Indirect && "fields out of order?")(static_cast <bool> (Indirect && "fields out of order?"
) ? void (0) : __assert_fail ("Indirect && \"fields out of order?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6213, __extension__ __PRETTY_FUNCTION__))
;
6214 return;
6215 }
6216
6217 // Default-initialize any fields with no explicit initializer.
6218 for (; !declaresSameEntity(*FieldIt, FD); ++FieldIt) {
6219 assert(FieldIt != RD->field_end() && "missing field?")(static_cast <bool> (FieldIt != RD->field_end() &&
"missing field?") ? void (0) : __assert_fail ("FieldIt != RD->field_end() && \"missing field?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6219, __extension__ __PRETTY_FUNCTION__))
;
6220 if (!FieldIt->isUnnamedBitfield())
6221 Success &= getDefaultInitValue(
6222 FieldIt->getType(),
6223 Result.getStructField(FieldIt->getFieldIndex()));
6224 }
6225 ++FieldIt;
6226 };
6227 for (const auto *I : Definition->inits()) {
6228 LValue Subobject = This;
6229 LValue SubobjectParent = This;
6230 APValue *Value = &Result;
6231
6232 // Determine the subobject to initialize.
6233 FieldDecl *FD = nullptr;
6234 if (I->isBaseInitializer()) {
6235 QualType BaseType(I->getBaseClass(), 0);
6236#ifndef NDEBUG
6237 // Non-virtual base classes are initialized in the order in the class
6238 // definition. We have already checked for virtual base classes.
6239 assert(!BaseIt->isVirtual() && "virtual base for literal type")(static_cast <bool> (!BaseIt->isVirtual() &&
"virtual base for literal type") ? void (0) : __assert_fail (
"!BaseIt->isVirtual() && \"virtual base for literal type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6239, __extension__ __PRETTY_FUNCTION__))
;
6240 assert(Info.Ctx.hasSameType(BaseIt->getType(), BaseType) &&(static_cast <bool> (Info.Ctx.hasSameType(BaseIt->getType
(), BaseType) && "base class initializers not in expected order"
) ? void (0) : __assert_fail ("Info.Ctx.hasSameType(BaseIt->getType(), BaseType) && \"base class initializers not in expected order\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6241, __extension__ __PRETTY_FUNCTION__))
6241 "base class initializers not in expected order")(static_cast <bool> (Info.Ctx.hasSameType(BaseIt->getType
(), BaseType) && "base class initializers not in expected order"
) ? void (0) : __assert_fail ("Info.Ctx.hasSameType(BaseIt->getType(), BaseType) && \"base class initializers not in expected order\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6241, __extension__ __PRETTY_FUNCTION__))
;
6242 ++BaseIt;
6243#endif
6244 if (!HandleLValueDirectBase(Info, I->getInit(), Subobject, RD,
6245 BaseType->getAsCXXRecordDecl(), &Layout))
6246 return false;
6247 Value = &Result.getStructBase(BasesSeen++);
6248 } else if ((FD = I->getMember())) {
6249 if (!HandleLValueMember(Info, I->getInit(), Subobject, FD, &Layout))
6250 return false;
6251 if (RD->isUnion()) {
6252 Result = APValue(FD);
6253 Value = &Result.getUnionValue();
6254 } else {
6255 SkipToField(FD, false);
6256 Value = &Result.getStructField(FD->getFieldIndex());
6257 }
6258 } else if (IndirectFieldDecl *IFD = I->getIndirectMember()) {
6259 // Walk the indirect field decl's chain to find the object to initialize,
6260 // and make sure we've initialized every step along it.
6261 auto IndirectFieldChain = IFD->chain();
6262 for (auto *C : IndirectFieldChain) {
6263 FD = cast<FieldDecl>(C);
6264 CXXRecordDecl *CD = cast<CXXRecordDecl>(FD->getParent());
6265 // Switch the union field if it differs. This happens if we had
6266 // preceding zero-initialization, and we're now initializing a union
6267 // subobject other than the first.
6268 // FIXME: In this case, the values of the other subobjects are
6269 // specified, since zero-initialization sets all padding bits to zero.
6270 if (!Value->hasValue() ||
6271 (Value->isUnion() && Value->getUnionField() != FD)) {
6272 if (CD->isUnion())
6273 *Value = APValue(FD);
6274 else
6275 // FIXME: This immediately starts the lifetime of all members of
6276 // an anonymous struct. It would be preferable to strictly start
6277 // member lifetime in initialization order.
6278 Success &= getDefaultInitValue(Info.Ctx.getRecordType(CD), *Value);
6279 }
6280 // Store Subobject as its parent before updating it for the last element
6281 // in the chain.
6282 if (C == IndirectFieldChain.back())
6283 SubobjectParent = Subobject;
6284 if (!HandleLValueMember(Info, I->getInit(), Subobject, FD))
6285 return false;
6286 if (CD->isUnion())
6287 Value = &Value->getUnionValue();
6288 else {
6289 if (C == IndirectFieldChain.front() && !RD->isUnion())
6290 SkipToField(FD, true);
6291 Value = &Value->getStructField(FD->getFieldIndex());
6292 }
6293 }
6294 } else {
6295 llvm_unreachable("unknown base initializer kind")::llvm::llvm_unreachable_internal("unknown base initializer kind"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6295)
;
6296 }
6297
6298 // Need to override This for implicit field initializers as in this case
6299 // This refers to innermost anonymous struct/union containing initializer,
6300 // not to currently constructed class.
6301 const Expr *Init = I->getInit();
6302 if (Init->isValueDependent()) {
6303 if (!EvaluateDependentExpr(Init, Info))
6304 return false;
6305 } else {
6306 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &SubobjectParent,
6307 isa<CXXDefaultInitExpr>(Init));
6308 FullExpressionRAII InitScope(Info);
6309 if (!EvaluateInPlace(*Value, Info, Subobject, Init) ||
6310 (FD && FD->isBitField() &&
6311 !truncateBitfieldValue(Info, Init, *Value, FD))) {
6312 // If we're checking for a potential constant expression, evaluate all
6313 // initializers even if some of them fail.
6314 if (!Info.noteFailure())
6315 return false;
6316 Success = false;
6317 }
6318 }
6319
6320 // This is the point at which the dynamic type of the object becomes this
6321 // class type.
6322 if (I->isBaseInitializer() && BasesSeen == RD->getNumBases())
6323 EvalObj.finishedConstructingBases();
6324 }
6325
6326 // Default-initialize any remaining fields.
6327 if (!RD->isUnion()) {
6328 for (; FieldIt != RD->field_end(); ++FieldIt) {
6329 if (!FieldIt->isUnnamedBitfield())
6330 Success &= getDefaultInitValue(
6331 FieldIt->getType(),
6332 Result.getStructField(FieldIt->getFieldIndex()));
6333 }
6334 }
6335
6336 EvalObj.finishedConstructingFields();
6337
6338 return Success &&
6339 EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed &&
6340 LifetimeExtendedScope.destroy();
6341}
6342
6343static bool HandleConstructorCall(const Expr *E, const LValue &This,
6344 ArrayRef<const Expr*> Args,
6345 const CXXConstructorDecl *Definition,
6346 EvalInfo &Info, APValue &Result) {
6347 CallScopeRAII CallScope(Info);
6348 CallRef Call = Info.CurrentCall->createCall(Definition);
6349 if (!EvaluateArgs(Args, Call, Info, Definition))
6350 return false;
6351
6352 return HandleConstructorCall(E, This, Call, Definition, Info, Result) &&
6353 CallScope.destroy();
6354}
6355
6356static bool HandleDestructionImpl(EvalInfo &Info, SourceLocation CallLoc,
6357 const LValue &This, APValue &Value,
6358 QualType T) {
6359 // Objects can only be destroyed while they're within their lifetimes.
6360 // FIXME: We have no representation for whether an object of type nullptr_t
6361 // is in its lifetime; it usually doesn't matter. Perhaps we should model it
6362 // as indeterminate instead?
6363 if (Value.isAbsent() && !T->isNullPtrType()) {
6364 APValue Printable;
6365 This.moveInto(Printable);
6366 Info.FFDiag(CallLoc, diag::note_constexpr_destroy_out_of_lifetime)
6367 << Printable.getAsString(Info.Ctx, Info.Ctx.getLValueReferenceType(T));
6368 return false;
6369 }
6370
6371 // Invent an expression for location purposes.
6372 // FIXME: We shouldn't need to do this.
6373 OpaqueValueExpr LocE(CallLoc, Info.Ctx.IntTy, VK_PRValue);
6374
6375 // For arrays, destroy elements right-to-left.
6376 if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(T)) {
6377 uint64_t Size = CAT->getSize().getZExtValue();
6378 QualType ElemT = CAT->getElementType();
6379
6380 LValue ElemLV = This;
6381 ElemLV.addArray(Info, &LocE, CAT);
6382 if (!HandleLValueArrayAdjustment(Info, &LocE, ElemLV, ElemT, Size))
6383 return false;
6384
6385 // Ensure that we have actual array elements available to destroy; the
6386 // destructors might mutate the value, so we can't run them on the array
6387 // filler.
6388 if (Size && Size > Value.getArrayInitializedElts())
6389 expandArray(Value, Value.getArraySize() - 1);
6390
6391 for (; Size != 0; --Size) {
6392 APValue &Elem = Value.getArrayInitializedElt(Size - 1);
6393 if (!HandleLValueArrayAdjustment(Info, &LocE, ElemLV, ElemT, -1) ||
6394 !HandleDestructionImpl(Info, CallLoc, ElemLV, Elem, ElemT))
6395 return false;
6396 }
6397
6398 // End the lifetime of this array now.
6399 Value = APValue();
6400 return true;
6401 }
6402
6403 const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
6404 if (!RD) {
6405 if (T.isDestructedType()) {
6406 Info.FFDiag(CallLoc, diag::note_constexpr_unsupported_destruction) << T;
6407 return false;
6408 }
6409
6410 Value = APValue();
6411 return true;
6412 }
6413
6414 if (RD->getNumVBases()) {
6415 Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD;
6416 return false;
6417 }
6418
6419 const CXXDestructorDecl *DD = RD->getDestructor();
6420 if (!DD && !RD->hasTrivialDestructor()) {
6421 Info.FFDiag(CallLoc);
6422 return false;
6423 }
6424
6425 if (!DD || DD->isTrivial() ||
6426 (RD->isAnonymousStructOrUnion() && RD->isUnion())) {
6427 // A trivial destructor just ends the lifetime of the object. Check for
6428 // this case before checking for a body, because we might not bother
6429 // building a body for a trivial destructor. Note that it doesn't matter
6430 // whether the destructor is constexpr in this case; all trivial
6431 // destructors are constexpr.
6432 //
6433 // If an anonymous union would be destroyed, some enclosing destructor must
6434 // have been explicitly defined, and the anonymous union destruction should
6435 // have no effect.
6436 Value = APValue();
6437 return true;
6438 }
6439
6440 if (!Info.CheckCallLimit(CallLoc))
6441 return false;
6442
6443 const FunctionDecl *Definition = nullptr;
6444 const Stmt *Body = DD->getBody(Definition);
6445
6446 if (!CheckConstexprFunction(Info, CallLoc, DD, Definition, Body))
6447 return false;
6448
6449 CallStackFrame Frame(Info, CallLoc, Definition, &This, CallRef());
6450
6451 // We're now in the period of destruction of this object.
6452 unsigned BasesLeft = RD->getNumBases();
6453 EvalInfo::EvaluatingDestructorRAII EvalObj(
6454 Info,
6455 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries});
6456 if (!EvalObj.DidInsert) {
6457 // C++2a [class.dtor]p19:
6458 // the behavior is undefined if the destructor is invoked for an object
6459 // whose lifetime has ended
6460 // (Note that formally the lifetime ends when the period of destruction
6461 // begins, even though certain uses of the object remain valid until the
6462 // period of destruction ends.)
6463 Info.FFDiag(CallLoc, diag::note_constexpr_double_destroy);
6464 return false;
6465 }
6466
6467 // FIXME: Creating an APValue just to hold a nonexistent return value is
6468 // wasteful.
6469 APValue RetVal;
6470 StmtResult Ret = {RetVal, nullptr};
6471 if (EvaluateStmt(Ret, Info, Definition->getBody()) == ESR_Failed)
6472 return false;
6473
6474 // A union destructor does not implicitly destroy its members.
6475 if (RD->isUnion())
6476 return true;
6477
6478 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
6479
6480 // We don't have a good way to iterate fields in reverse, so collect all the
6481 // fields first and then walk them backwards.
6482 SmallVector<FieldDecl*, 16> Fields(RD->field_begin(), RD->field_end());
6483 for (const FieldDecl *FD : llvm::reverse(Fields)) {
6484 if (FD->isUnnamedBitfield())
6485 continue;
6486
6487 LValue Subobject = This;
6488 if (!HandleLValueMember(Info, &LocE, Subobject, FD, &Layout))
6489 return false;
6490
6491 APValue *SubobjectValue = &Value.getStructField(FD->getFieldIndex());
6492 if (!HandleDestructionImpl(Info, CallLoc, Subobject, *SubobjectValue,
6493 FD->getType()))
6494 return false;
6495 }
6496
6497 if (BasesLeft != 0)
6498 EvalObj.startedDestroyingBases();
6499
6500 // Destroy base classes in reverse order.
6501 for (const CXXBaseSpecifier &Base : llvm::reverse(RD->bases())) {
6502 --BasesLeft;
6503
6504 QualType BaseType = Base.getType();
6505 LValue Subobject = This;
6506 if (!HandleLValueDirectBase(Info, &LocE, Subobject, RD,
6507 BaseType->getAsCXXRecordDecl(), &Layout))
6508 return false;
6509
6510 APValue *SubobjectValue = &Value.getStructBase(BasesLeft);
6511 if (!HandleDestructionImpl(Info, CallLoc, Subobject, *SubobjectValue,
6512 BaseType))
6513 return false;
6514 }
6515 assert(BasesLeft == 0 && "NumBases was wrong?")(static_cast <bool> (BasesLeft == 0 && "NumBases was wrong?"
) ? void (0) : __assert_fail ("BasesLeft == 0 && \"NumBases was wrong?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6515, __extension__ __PRETTY_FUNCTION__))
;
6516
6517 // The period of destruction ends now. The object is gone.
6518 Value = APValue();
6519 return true;
6520}
6521
6522namespace {
6523struct DestroyObjectHandler {
6524 EvalInfo &Info;
6525 const Expr *E;
6526 const LValue &This;
6527 const AccessKinds AccessKind;
6528
6529 typedef bool result_type;
6530 bool failed() { return false; }
6531 bool found(APValue &Subobj, QualType SubobjType) {
6532 return HandleDestructionImpl(Info, E->getExprLoc(), This, Subobj,
6533 SubobjType);
6534 }
6535 bool found(APSInt &Value, QualType SubobjType) {
6536 Info.FFDiag(E, diag::note_constexpr_destroy_complex_elem);
6537 return false;
6538 }
6539 bool found(APFloat &Value, QualType SubobjType) {
6540 Info.FFDiag(E, diag::note_constexpr_destroy_complex_elem);
6541 return false;
6542 }
6543};
6544}
6545
6546/// Perform a destructor or pseudo-destructor call on the given object, which
6547/// might in general not be a complete object.
6548static bool HandleDestruction(EvalInfo &Info, const Expr *E,
6549 const LValue &This, QualType ThisType) {
6550 CompleteObject Obj = findCompleteObject(Info, E, AK_Destroy, This, ThisType);
6551 DestroyObjectHandler Handler = {Info, E, This, AK_Destroy};
6552 return Obj && findSubobject(Info, E, Obj, This.Designator, Handler);
6553}
6554
6555/// Destroy and end the lifetime of the given complete object.
6556static bool HandleDestruction(EvalInfo &Info, SourceLocation Loc,
6557 APValue::LValueBase LVBase, APValue &Value,
6558 QualType T) {
6559 // If we've had an unmodeled side-effect, we can't rely on mutable state
6560 // (such as the object we're about to destroy) being correct.
6561 if (Info.EvalStatus.HasSideEffects)
6562 return false;
6563
6564 LValue LV;
6565 LV.set({LVBase});
6566 return HandleDestructionImpl(Info, Loc, LV, Value, T);
6567}
6568
6569/// Perform a call to 'perator new' or to `__builtin_operator_new'.
6570static bool HandleOperatorNewCall(EvalInfo &Info, const CallExpr *E,
6571 LValue &Result) {
6572 if (Info.checkingPotentialConstantExpression() ||
6573 Info.SpeculativeEvaluationDepth)
6574 return false;
6575
6576 // This is permitted only within a call to std::allocator<T>::allocate.
6577 auto Caller = Info.getStdAllocatorCaller("allocate");
6578 if (!Caller) {
6579 Info.FFDiag(E->getExprLoc(), Info.getLangOpts().CPlusPlus20
6580 ? diag::note_constexpr_new_untyped
6581 : diag::note_constexpr_new);
6582 return false;
6583 }
6584
6585 QualType ElemType = Caller.ElemType;
6586 if (ElemType->isIncompleteType() || ElemType->isFunctionType()) {
6587 Info.FFDiag(E->getExprLoc(),
6588 diag::note_constexpr_new_not_complete_object_type)
6589 << (ElemType->isIncompleteType() ? 0 : 1) << ElemType;
6590 return false;
6591 }
6592
6593 APSInt ByteSize;
6594 if (!EvaluateInteger(E->getArg(0), ByteSize, Info))
6595 return false;
6596 bool IsNothrow = false;
6597 for (unsigned I = 1, N = E->getNumArgs(); I != N; ++I) {
6598 EvaluateIgnoredValue(Info, E->getArg(I));
6599 IsNothrow |= E->getType()->isNothrowT();
6600 }
6601
6602 CharUnits ElemSize;
6603 if (!HandleSizeof(Info, E->getExprLoc(), ElemType, ElemSize))
6604 return false;
6605 APInt Size, Remainder;
6606 APInt ElemSizeAP(ByteSize.getBitWidth(), ElemSize.getQuantity());
6607 APInt::udivrem(ByteSize, ElemSizeAP, Size, Remainder);
6608 if (Remainder != 0) {
6609 // This likely indicates a bug in the implementation of 'std::allocator'.
6610 Info.FFDiag(E->getExprLoc(), diag::note_constexpr_operator_new_bad_size)
6611 << ByteSize << APSInt(ElemSizeAP, true) << ElemType;
6612 return false;
6613 }
6614
6615 if (ByteSize.getActiveBits() > ConstantArrayType::getMaxSizeBits(Info.Ctx)) {
6616 if (IsNothrow) {
6617 Result.setNull(Info.Ctx, E->getType());
6618 return true;
6619 }
6620
6621 Info.FFDiag(E, diag::note_constexpr_new_too_large) << APSInt(Size, true);
6622 return false;
6623 }
6624
6625 QualType AllocType = Info.Ctx.getConstantArrayType(ElemType, Size, nullptr,
6626 ArrayType::Normal, 0);
6627 APValue *Val = Info.createHeapAlloc(E, AllocType, Result);
6628 *Val = APValue(APValue::UninitArray(), 0, Size.getZExtValue());
6629 Result.addArray(Info, E, cast<ConstantArrayType>(AllocType));
6630 return true;
6631}
6632
6633static bool hasVirtualDestructor(QualType T) {
6634 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
6635 if (CXXDestructorDecl *DD = RD->getDestructor())
6636 return DD->isVirtual();
6637 return false;
6638}
6639
6640static const FunctionDecl *getVirtualOperatorDelete(QualType T) {
6641 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
6642 if (CXXDestructorDecl *DD = RD->getDestructor())
6643 return DD->isVirtual() ? DD->getOperatorDelete() : nullptr;
6644 return nullptr;
6645}
6646
6647/// Check that the given object is a suitable pointer to a heap allocation that
6648/// still exists and is of the right kind for the purpose of a deletion.
6649///
6650/// On success, returns the heap allocation to deallocate. On failure, produces
6651/// a diagnostic and returns None.
6652static Optional<DynAlloc *> CheckDeleteKind(EvalInfo &Info, const Expr *E,
6653 const LValue &Pointer,
6654 DynAlloc::Kind DeallocKind) {
6655 auto PointerAsString = [&] {
6656 return Pointer.toString(Info.Ctx, Info.Ctx.VoidPtrTy);
6657 };
6658
6659 DynamicAllocLValue DA = Pointer.Base.dyn_cast<DynamicAllocLValue>();
6660 if (!DA) {
6661 Info.FFDiag(E, diag::note_constexpr_delete_not_heap_alloc)
6662 << PointerAsString();
6663 if (Pointer.Base)
6664 NoteLValueLocation(Info, Pointer.Base);
6665 return None;
6666 }
6667
6668 Optional<DynAlloc *> Alloc = Info.lookupDynamicAlloc(DA);
6669 if (!Alloc) {
6670 Info.FFDiag(E, diag::note_constexpr_double_delete);
6671 return None;
6672 }
6673
6674 QualType AllocType = Pointer.Base.getDynamicAllocType();
6675 if (DeallocKind != (*Alloc)->getKind()) {
6676 Info.FFDiag(E, diag::note_constexpr_new_delete_mismatch)
6677 << DeallocKind << (*Alloc)->getKind() << AllocType;
6678 NoteLValueLocation(Info, Pointer.Base);
6679 return None;
6680 }
6681
6682 bool Subobject = false;
6683 if (DeallocKind == DynAlloc::New) {
6684 Subobject = Pointer.Designator.MostDerivedPathLength != 0 ||
6685 Pointer.Designator.isOnePastTheEnd();
6686 } else {
6687 Subobject = Pointer.Designator.Entries.size() != 1 ||
6688 Pointer.Designator.Entries[0].getAsArrayIndex() != 0;
6689 }
6690 if (Subobject) {
6691 Info.FFDiag(E, diag::note_constexpr_delete_subobject)
6692 << PointerAsString() << Pointer.Designator.isOnePastTheEnd();
6693 return None;
6694 }
6695
6696 return Alloc;
6697}
6698
6699// Perform a call to 'operator delete' or '__builtin_operator_delete'.
6700bool HandleOperatorDeleteCall(EvalInfo &Info, const CallExpr *E) {
6701 if (Info.checkingPotentialConstantExpression() ||
6702 Info.SpeculativeEvaluationDepth)
6703 return false;
6704
6705 // This is permitted only within a call to std::allocator<T>::deallocate.
6706 if (!Info.getStdAllocatorCaller("deallocate")) {
6707 Info.FFDiag(E->getExprLoc());
6708 return true;
6709 }
6710
6711 LValue Pointer;
6712 if (!EvaluatePointer(E->getArg(0), Pointer, Info))
6713 return false;
6714 for (unsigned I = 1, N = E->getNumArgs(); I != N; ++I)
6715 EvaluateIgnoredValue(Info, E->getArg(I));
6716
6717 if (Pointer.Designator.Invalid)
6718 return false;
6719
6720 // Deleting a null pointer would have no effect, but it's not permitted by
6721 // std::allocator<T>::deallocate's contract.
6722 if (Pointer.isNullPointer()) {
6723 Info.CCEDiag(E->getExprLoc(), diag::note_constexpr_deallocate_null);
6724 return true;
6725 }
6726
6727 if (!CheckDeleteKind(Info, E, Pointer, DynAlloc::StdAllocator))
6728 return false;
6729
6730 Info.HeapAllocs.erase(Pointer.Base.get<DynamicAllocLValue>());
6731 return true;
6732}
6733
6734//===----------------------------------------------------------------------===//
6735// Generic Evaluation
6736//===----------------------------------------------------------------------===//
6737namespace {
6738
6739class BitCastBuffer {
6740 // FIXME: We're going to need bit-level granularity when we support
6741 // bit-fields.
6742 // FIXME: Its possible under the C++ standard for 'char' to not be 8 bits, but
6743 // we don't support a host or target where that is the case. Still, we should
6744 // use a more generic type in case we ever do.
6745 SmallVector<Optional<unsigned char>, 32> Bytes;
6746
6747 static_assert(std::numeric_limits<unsigned char>::digits >= 8,
6748 "Need at least 8 bit unsigned char");
6749
6750 bool TargetIsLittleEndian;
6751
6752public:
6753 BitCastBuffer(CharUnits Width, bool TargetIsLittleEndian)
6754 : Bytes(Width.getQuantity()),
6755 TargetIsLittleEndian(TargetIsLittleEndian) {}
6756
6757 LLVM_NODISCARD[[clang::warn_unused_result]]
6758 bool readObject(CharUnits Offset, CharUnits Width,
6759 SmallVectorImpl<unsigned char> &Output) const {
6760 for (CharUnits I = Offset, E = Offset + Width; I != E; ++I) {
6761 // If a byte of an integer is uninitialized, then the whole integer is
6762 // uninitalized.
6763 if (!Bytes[I.getQuantity()])
6764 return false;
6765 Output.push_back(*Bytes[I.getQuantity()]);
6766 }
6767 if (llvm::sys::IsLittleEndianHost != TargetIsLittleEndian)
6768 std::reverse(Output.begin(), Output.end());
6769 return true;
6770 }
6771
6772 void writeObject(CharUnits Offset, SmallVectorImpl<unsigned char> &Input) {
6773 if (llvm::sys::IsLittleEndianHost != TargetIsLittleEndian)
6774 std::reverse(Input.begin(), Input.end());
6775
6776 size_t Index = 0;
6777 for (unsigned char Byte : Input) {
6778 assert(!Bytes[Offset.getQuantity() + Index] && "overwriting a byte?")(static_cast <bool> (!Bytes[Offset.getQuantity() + Index
] && "overwriting a byte?") ? void (0) : __assert_fail
("!Bytes[Offset.getQuantity() + Index] && \"overwriting a byte?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6778, __extension__ __PRETTY_FUNCTION__))
;
6779 Bytes[Offset.getQuantity() + Index] = Byte;
6780 ++Index;
6781 }
6782 }
6783
6784 size_t size() { return Bytes.size(); }
6785};
6786
6787/// Traverse an APValue to produce an BitCastBuffer, emulating how the current
6788/// target would represent the value at runtime.
6789class APValueToBufferConverter {
6790 EvalInfo &Info;
6791 BitCastBuffer Buffer;
6792 const CastExpr *BCE;
6793
6794 APValueToBufferConverter(EvalInfo &Info, CharUnits ObjectWidth,
6795 const CastExpr *BCE)
6796 : Info(Info),
6797 Buffer(ObjectWidth, Info.Ctx.getTargetInfo().isLittleEndian()),
6798 BCE(BCE) {}
6799
6800 bool visit(const APValue &Val, QualType Ty) {
6801 return visit(Val, Ty, CharUnits::fromQuantity(0));
6802 }
6803
6804 // Write out Val with type Ty into Buffer starting at Offset.
6805 bool visit(const APValue &Val, QualType Ty, CharUnits Offset) {
6806 assert((size_t)Offset.getQuantity() <= Buffer.size())(static_cast <bool> ((size_t)Offset.getQuantity() <=
Buffer.size()) ? void (0) : __assert_fail ("(size_t)Offset.getQuantity() <= Buffer.size()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6806, __extension__ __PRETTY_FUNCTION__))
;
6807
6808 // As a special case, nullptr_t has an indeterminate value.
6809 if (Ty->isNullPtrType())
6810 return true;
6811
6812 // Dig through Src to find the byte at SrcOffset.
6813 switch (Val.getKind()) {
6814 case APValue::Indeterminate:
6815 case APValue::None:
6816 return true;
6817
6818 case APValue::Int:
6819 return visitInt(Val.getInt(), Ty, Offset);
6820 case APValue::Float:
6821 return visitFloat(Val.getFloat(), Ty, Offset);
6822 case APValue::Array:
6823 return visitArray(Val, Ty, Offset);
6824 case APValue::Struct:
6825 return visitRecord(Val, Ty, Offset);
6826
6827 case APValue::ComplexInt:
6828 case APValue::ComplexFloat:
6829 case APValue::Vector:
6830 case APValue::FixedPoint:
6831 // FIXME: We should support these.
6832
6833 case APValue::Union:
6834 case APValue::MemberPointer:
6835 case APValue::AddrLabelDiff: {
6836 Info.FFDiag(BCE->getBeginLoc(),
6837 diag::note_constexpr_bit_cast_unsupported_type)
6838 << Ty;
6839 return false;
6840 }
6841
6842 case APValue::LValue:
6843 llvm_unreachable("LValue subobject in bit_cast?")::llvm::llvm_unreachable_internal("LValue subobject in bit_cast?"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6843)
;
6844 }
6845 llvm_unreachable("Unhandled APValue::ValueKind")::llvm::llvm_unreachable_internal("Unhandled APValue::ValueKind"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6845)
;
6846 }
6847
6848 bool visitRecord(const APValue &Val, QualType Ty, CharUnits Offset) {
6849 const RecordDecl *RD = Ty->getAsRecordDecl();
6850 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
6851
6852 // Visit the base classes.
6853 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
6854 for (size_t I = 0, E = CXXRD->getNumBases(); I != E; ++I) {
6855 const CXXBaseSpecifier &BS = CXXRD->bases_begin()[I];
6856 CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
6857
6858 if (!visitRecord(Val.getStructBase(I), BS.getType(),
6859 Layout.getBaseClassOffset(BaseDecl) + Offset))
6860 return false;
6861 }
6862 }
6863
6864 // Visit the fields.
6865 unsigned FieldIdx = 0;
6866 for (FieldDecl *FD : RD->fields()) {
6867 if (FD->isBitField()) {
6868 Info.FFDiag(BCE->getBeginLoc(),
6869 diag::note_constexpr_bit_cast_unsupported_bitfield);
6870 return false;
6871 }
6872
6873 uint64_t FieldOffsetBits = Layout.getFieldOffset(FieldIdx);
6874
6875 assert(FieldOffsetBits % Info.Ctx.getCharWidth() == 0 &&(static_cast <bool> (FieldOffsetBits % Info.Ctx.getCharWidth
() == 0 && "only bit-fields can have sub-char alignment"
) ? void (0) : __assert_fail ("FieldOffsetBits % Info.Ctx.getCharWidth() == 0 && \"only bit-fields can have sub-char alignment\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6876, __extension__ __PRETTY_FUNCTION__))
6876 "only bit-fields can have sub-char alignment")(static_cast <bool> (FieldOffsetBits % Info.Ctx.getCharWidth
() == 0 && "only bit-fields can have sub-char alignment"
) ? void (0) : __assert_fail ("FieldOffsetBits % Info.Ctx.getCharWidth() == 0 && \"only bit-fields can have sub-char alignment\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6876, __extension__ __PRETTY_FUNCTION__))
;
6877 CharUnits FieldOffset =
6878 Info.Ctx.toCharUnitsFromBits(FieldOffsetBits) + Offset;
6879 QualType FieldTy = FD->getType();
6880 if (!visit(Val.getStructField(FieldIdx), FieldTy, FieldOffset))
6881 return false;
6882 ++FieldIdx;
6883 }
6884
6885 return true;
6886 }
6887
6888 bool visitArray(const APValue &Val, QualType Ty, CharUnits Offset) {
6889 const auto *CAT =
6890 dyn_cast_or_null<ConstantArrayType>(Ty->getAsArrayTypeUnsafe());
6891 if (!CAT)
6892 return false;
6893
6894 CharUnits ElemWidth = Info.Ctx.getTypeSizeInChars(CAT->getElementType());
6895 unsigned NumInitializedElts = Val.getArrayInitializedElts();
6896 unsigned ArraySize = Val.getArraySize();
6897 // First, initialize the initialized elements.
6898 for (unsigned I = 0; I != NumInitializedElts; ++I) {
6899 const APValue &SubObj = Val.getArrayInitializedElt(I);
6900 if (!visit(SubObj, CAT->getElementType(), Offset + I * ElemWidth))
6901 return false;
6902 }
6903
6904 // Next, initialize the rest of the array using the filler.
6905 if (Val.hasArrayFiller()) {
6906 const APValue &Filler = Val.getArrayFiller();
6907 for (unsigned I = NumInitializedElts; I != ArraySize; ++I) {
6908 if (!visit(Filler, CAT->getElementType(), Offset + I * ElemWidth))
6909 return false;
6910 }
6911 }
6912
6913 return true;
6914 }
6915
6916 bool visitInt(const APSInt &Val, QualType Ty, CharUnits Offset) {
6917 APSInt AdjustedVal = Val;
6918 unsigned Width = AdjustedVal.getBitWidth();
6919 if (Ty->isBooleanType()) {
6920 Width = Info.Ctx.getTypeSize(Ty);
6921 AdjustedVal = AdjustedVal.extend(Width);
6922 }
6923
6924 SmallVector<unsigned char, 8> Bytes(Width / 8);
6925 llvm::StoreIntToMemory(AdjustedVal, &*Bytes.begin(), Width / 8);
6926 Buffer.writeObject(Offset, Bytes);
6927 return true;
6928 }
6929
6930 bool visitFloat(const APFloat &Val, QualType Ty, CharUnits Offset) {
6931 APSInt AsInt(Val.bitcastToAPInt());
6932 return visitInt(AsInt, Ty, Offset);
6933 }
6934
6935public:
6936 static Optional<BitCastBuffer> convert(EvalInfo &Info, const APValue &Src,
6937 const CastExpr *BCE) {
6938 CharUnits DstSize = Info.Ctx.getTypeSizeInChars(BCE->getType());
6939 APValueToBufferConverter Converter(Info, DstSize, BCE);
6940 if (!Converter.visit(Src, BCE->getSubExpr()->getType()))
6941 return None;
6942 return Converter.Buffer;
6943 }
6944};
6945
6946/// Write an BitCastBuffer into an APValue.
6947class BufferToAPValueConverter {
6948 EvalInfo &Info;
6949 const BitCastBuffer &Buffer;
6950 const CastExpr *BCE;
6951
6952 BufferToAPValueConverter(EvalInfo &Info, const BitCastBuffer &Buffer,
6953 const CastExpr *BCE)
6954 : Info(Info), Buffer(Buffer), BCE(BCE) {}
6955
6956 // Emit an unsupported bit_cast type error. Sema refuses to build a bit_cast
6957 // with an invalid type, so anything left is a deficiency on our part (FIXME).
6958 // Ideally this will be unreachable.
6959 llvm::NoneType unsupportedType(QualType Ty) {
6960 Info.FFDiag(BCE->getBeginLoc(),
6961 diag::note_constexpr_bit_cast_unsupported_type)
6962 << Ty;
6963 return None;
6964 }
6965
6966 llvm::NoneType unrepresentableValue(QualType Ty, const APSInt &Val) {
6967 Info.FFDiag(BCE->getBeginLoc(),
6968 diag::note_constexpr_bit_cast_unrepresentable_value)
6969 << Ty << toString(Val, /*Radix=*/10);
6970 return None;
6971 }
6972
6973 Optional<APValue> visit(const BuiltinType *T, CharUnits Offset,
6974 const EnumType *EnumSugar = nullptr) {
6975 if (T->isNullPtrType()) {
6976 uint64_t NullValue = Info.Ctx.getTargetNullPointerValue(QualType(T, 0));
6977 return APValue((Expr *)nullptr,
6978 /*Offset=*/CharUnits::fromQuantity(NullValue),
6979 APValue::NoLValuePath{}, /*IsNullPtr=*/true);
6980 }
6981
6982 CharUnits SizeOf = Info.Ctx.getTypeSizeInChars(T);
6983
6984 // Work around floating point types that contain unused padding bytes. This
6985 // is really just `long double` on x86, which is the only fundamental type
6986 // with padding bytes.
6987 if (T->isRealFloatingType()) {
6988 const llvm::fltSemantics &Semantics =
6989 Info.Ctx.getFloatTypeSemantics(QualType(T, 0));
6990 unsigned NumBits = llvm::APFloatBase::getSizeInBits(Semantics);
6991 assert(NumBits % 8 == 0)(static_cast <bool> (NumBits % 8 == 0) ? void (0) : __assert_fail
("NumBits % 8 == 0", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 6991, __extension__ __PRETTY_FUNCTION__))
;
6992 CharUnits NumBytes = CharUnits::fromQuantity(NumBits / 8);
6993 if (NumBytes != SizeOf)
6994 SizeOf = NumBytes;
6995 }
6996
6997 SmallVector<uint8_t, 8> Bytes;
6998 if (!Buffer.readObject(Offset, SizeOf, Bytes)) {
6999 // If this is std::byte or unsigned char, then its okay to store an
7000 // indeterminate value.
7001 bool IsStdByte = EnumSugar && EnumSugar->isStdByteType();
7002 bool IsUChar =
7003 !EnumSugar && (T->isSpecificBuiltinType(BuiltinType::UChar) ||
7004 T->isSpecificBuiltinType(BuiltinType::Char_U));
7005 if (!IsStdByte && !IsUChar) {
7006 QualType DisplayType(EnumSugar ? (const Type *)EnumSugar : T, 0);
7007 Info.FFDiag(BCE->getExprLoc(),
7008 diag::note_constexpr_bit_cast_indet_dest)
7009 << DisplayType << Info.Ctx.getLangOpts().CharIsSigned;
7010 return None;
7011 }
7012
7013 return APValue::IndeterminateValue();
7014 }
7015
7016 APSInt Val(SizeOf.getQuantity() * Info.Ctx.getCharWidth(), true);
7017 llvm::LoadIntFromMemory(Val, &*Bytes.begin(), Bytes.size());
7018
7019 if (T->isIntegralOrEnumerationType()) {
7020 Val.setIsSigned(T->isSignedIntegerOrEnumerationType());
7021
7022 unsigned IntWidth = Info.Ctx.getIntWidth(QualType(T, 0));
7023 if (IntWidth != Val.getBitWidth()) {
7024 APSInt Truncated = Val.trunc(IntWidth);
7025 if (Truncated.extend(Val.getBitWidth()) != Val)
7026 return unrepresentableValue(QualType(T, 0), Val);
7027 Val = Truncated;
7028 }
7029
7030 return APValue(Val);
7031 }
7032
7033 if (T->isRealFloatingType()) {
7034 const llvm::fltSemantics &Semantics =
7035 Info.Ctx.getFloatTypeSemantics(QualType(T, 0));
7036 return APValue(APFloat(Semantics, Val));
7037 }
7038
7039 return unsupportedType(QualType(T, 0));
7040 }
7041
7042 Optional<APValue> visit(const RecordType *RTy, CharUnits Offset) {
7043 const RecordDecl *RD = RTy->getAsRecordDecl();
7044 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
7045
7046 unsigned NumBases = 0;
7047 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
7048 NumBases = CXXRD->getNumBases();
7049
7050 APValue ResultVal(APValue::UninitStruct(), NumBases,
7051 std::distance(RD->field_begin(), RD->field_end()));
7052
7053 // Visit the base classes.
7054 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
7055 for (size_t I = 0, E = CXXRD->getNumBases(); I != E; ++I) {
7056 const CXXBaseSpecifier &BS = CXXRD->bases_begin()[I];
7057 CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
7058 if (BaseDecl->isEmpty() ||
7059 Info.Ctx.getASTRecordLayout(BaseDecl).getNonVirtualSize().isZero())
7060 continue;
7061
7062 Optional<APValue> SubObj = visitType(
7063 BS.getType(), Layout.getBaseClassOffset(BaseDecl) + Offset);
7064 if (!SubObj)
7065 return None;
7066 ResultVal.getStructBase(I) = *SubObj;
7067 }
7068 }
7069
7070 // Visit the fields.
7071 unsigned FieldIdx = 0;
7072 for (FieldDecl *FD : RD->fields()) {
7073 // FIXME: We don't currently support bit-fields. A lot of the logic for
7074 // this is in CodeGen, so we need to factor it around.
7075 if (FD->isBitField()) {
7076 Info.FFDiag(BCE->getBeginLoc(),
7077 diag::note_constexpr_bit_cast_unsupported_bitfield);
7078 return None;
7079 }
7080
7081 uint64_t FieldOffsetBits = Layout.getFieldOffset(FieldIdx);
7082 assert(FieldOffsetBits % Info.Ctx.getCharWidth() == 0)(static_cast <bool> (FieldOffsetBits % Info.Ctx.getCharWidth
() == 0) ? void (0) : __assert_fail ("FieldOffsetBits % Info.Ctx.getCharWidth() == 0"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7082, __extension__ __PRETTY_FUNCTION__))
;
7083
7084 CharUnits FieldOffset =
7085 CharUnits::fromQuantity(FieldOffsetBits / Info.Ctx.getCharWidth()) +
7086 Offset;
7087 QualType FieldTy = FD->getType();
7088 Optional<APValue> SubObj = visitType(FieldTy, FieldOffset);
7089 if (!SubObj)
7090 return None;
7091 ResultVal.getStructField(FieldIdx) = *SubObj;
7092 ++FieldIdx;
7093 }
7094
7095 return ResultVal;
7096 }
7097
7098 Optional<APValue> visit(const EnumType *Ty, CharUnits Offset) {
7099 QualType RepresentationType = Ty->getDecl()->getIntegerType();
7100 assert(!RepresentationType.isNull() &&(static_cast <bool> (!RepresentationType.isNull() &&
"enum forward decl should be caught by Sema") ? void (0) : __assert_fail
("!RepresentationType.isNull() && \"enum forward decl should be caught by Sema\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7101, __extension__ __PRETTY_FUNCTION__))
7101 "enum forward decl should be caught by Sema")(static_cast <bool> (!RepresentationType.isNull() &&
"enum forward decl should be caught by Sema") ? void (0) : __assert_fail
("!RepresentationType.isNull() && \"enum forward decl should be caught by Sema\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7101, __extension__ __PRETTY_FUNCTION__))
;
7102 const auto *AsBuiltin =
7103 RepresentationType.getCanonicalType()->castAs<BuiltinType>();
7104 // Recurse into the underlying type. Treat std::byte transparently as
7105 // unsigned char.
7106 return visit(AsBuiltin, Offset, /*EnumTy=*/Ty);
7107 }
7108
7109 Optional<APValue> visit(const ConstantArrayType *Ty, CharUnits Offset) {
7110 size_t Size = Ty->getSize().getLimitedValue();
7111 CharUnits ElementWidth = Info.Ctx.getTypeSizeInChars(Ty->getElementType());
7112
7113 APValue ArrayValue(APValue::UninitArray(), Size, Size);
7114 for (size_t I = 0; I != Size; ++I) {
7115 Optional<APValue> ElementValue =
7116 visitType(Ty->getElementType(), Offset + I * ElementWidth);
7117 if (!ElementValue)
7118 return None;
7119 ArrayValue.getArrayInitializedElt(I) = std::move(*ElementValue);
7120 }
7121
7122 return ArrayValue;
7123 }
7124
7125 Optional<APValue> visit(const Type *Ty, CharUnits Offset) {
7126 return unsupportedType(QualType(Ty, 0));
7127 }
7128
7129 Optional<APValue> visitType(QualType Ty, CharUnits Offset) {
7130 QualType Can = Ty.getCanonicalType();
7131
7132 switch (Can->getTypeClass()) {
7133#define TYPE(Class, Base) \
7134 case Type::Class: \
7135 return visit(cast<Class##Type>(Can.getTypePtr()), Offset);
7136#define ABSTRACT_TYPE(Class, Base)
7137#define NON_CANONICAL_TYPE(Class, Base) \
7138 case Type::Class: \
7139 llvm_unreachable("non-canonical type should be impossible!")::llvm::llvm_unreachable_internal("non-canonical type should be impossible!"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7139)
;
7140#define DEPENDENT_TYPE(Class, Base) \
7141 case Type::Class: \
7142 llvm_unreachable( \::llvm::llvm_unreachable_internal("dependent types aren't supported in the constant evaluator!"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7143)
7143 "dependent types aren't supported in the constant evaluator!")::llvm::llvm_unreachable_internal("dependent types aren't supported in the constant evaluator!"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7143)
;
7144#define NON_CANONICAL_UNLESS_DEPENDENT(Class, Base)case Type::Class: ::llvm::llvm_unreachable_internal("either dependent or not canonical!"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7144);
\
7145 case Type::Class: \
7146 llvm_unreachable("either dependent or not canonical!")::llvm::llvm_unreachable_internal("either dependent or not canonical!"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7146)
;
7147#include "clang/AST/TypeNodes.inc"
7148 }
7149 llvm_unreachable("Unhandled Type::TypeClass")::llvm::llvm_unreachable_internal("Unhandled Type::TypeClass"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7149)
;
7150 }
7151
7152public:
7153 // Pull out a full value of type DstType.
7154 static Optional<APValue> convert(EvalInfo &Info, BitCastBuffer &Buffer,
7155 const CastExpr *BCE) {
7156 BufferToAPValueConverter Converter(Info, Buffer, BCE);
7157 return Converter.visitType(BCE->getType(), CharUnits::fromQuantity(0));
7158 }
7159};
7160
7161static bool checkBitCastConstexprEligibilityType(SourceLocation Loc,
7162 QualType Ty, EvalInfo *Info,
7163 const ASTContext &Ctx,
7164 bool CheckingDest) {
7165 Ty = Ty.getCanonicalType();
7166
7167 auto diag = [&](int Reason) {
7168 if (Info)
7169 Info->FFDiag(Loc, diag::note_constexpr_bit_cast_invalid_type)
7170 << CheckingDest << (Reason == 4) << Reason;
7171 return false;
7172 };
7173 auto note = [&](int Construct, QualType NoteTy, SourceLocation NoteLoc) {
7174 if (Info)
7175 Info->Note(NoteLoc, diag::note_constexpr_bit_cast_invalid_subtype)
7176 << NoteTy << Construct << Ty;
7177 return false;
7178 };
7179
7180 if (Ty->isUnionType())
7181 return diag(0);
7182 if (Ty->isPointerType())
7183 return diag(1);
7184 if (Ty->isMemberPointerType())
7185 return diag(2);
7186 if (Ty.isVolatileQualified())
7187 return diag(3);
7188
7189 if (RecordDecl *Record = Ty->getAsRecordDecl()) {
7190 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(Record)) {
7191 for (CXXBaseSpecifier &BS : CXXRD->bases())
7192 if (!checkBitCastConstexprEligibilityType(Loc, BS.getType(), Info, Ctx,
7193 CheckingDest))
7194 return note(1, BS.getType(), BS.getBeginLoc());
7195 }
7196 for (FieldDecl *FD : Record->fields()) {
7197 if (FD->getType()->isReferenceType())
7198 return diag(4);
7199 if (!checkBitCastConstexprEligibilityType(Loc, FD->getType(), Info, Ctx,
7200 CheckingDest))
7201 return note(0, FD->getType(), FD->getBeginLoc());
7202 }
7203 }
7204
7205 if (Ty->isArrayType() &&
7206 !checkBitCastConstexprEligibilityType(Loc, Ctx.getBaseElementType(Ty),
7207 Info, Ctx, CheckingDest))
7208 return false;
7209
7210 return true;
7211}
7212
7213static bool checkBitCastConstexprEligibility(EvalInfo *Info,
7214 const ASTContext &Ctx,
7215 const CastExpr *BCE) {
7216 bool DestOK = checkBitCastConstexprEligibilityType(
7217 BCE->getBeginLoc(), BCE->getType(), Info, Ctx, true);
7218 bool SourceOK = DestOK && checkBitCastConstexprEligibilityType(
7219 BCE->getBeginLoc(),
7220 BCE->getSubExpr()->getType(), Info, Ctx, false);
7221 return SourceOK;
7222}
7223
7224static bool handleLValueToRValueBitCast(EvalInfo &Info, APValue &DestValue,
7225 APValue &SourceValue,
7226 const CastExpr *BCE) {
7227 assert(CHAR_BIT == 8 && Info.Ctx.getTargetInfo().getCharWidth() == 8 &&(static_cast <bool> (8 == 8 && Info.Ctx.getTargetInfo
().getCharWidth() == 8 && "no host or target supports non 8-bit chars"
) ? void (0) : __assert_fail ("CHAR_BIT == 8 && Info.Ctx.getTargetInfo().getCharWidth() == 8 && \"no host or target supports non 8-bit chars\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7228, __extension__ __PRETTY_FUNCTION__))
7228 "no host or target supports non 8-bit chars")(static_cast <bool> (8 == 8 && Info.Ctx.getTargetInfo
().getCharWidth() == 8 && "no host or target supports non 8-bit chars"
) ? void (0) : __assert_fail ("CHAR_BIT == 8 && Info.Ctx.getTargetInfo().getCharWidth() == 8 && \"no host or target supports non 8-bit chars\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7228, __extension__ __PRETTY_FUNCTION__))
;
7229 assert(SourceValue.isLValue() &&(static_cast <bool> (SourceValue.isLValue() && "LValueToRValueBitcast requires an lvalue operand!"
) ? void (0) : __assert_fail ("SourceValue.isLValue() && \"LValueToRValueBitcast requires an lvalue operand!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7230, __extension__ __PRETTY_FUNCTION__))
7230 "LValueToRValueBitcast requires an lvalue operand!")(static_cast <bool> (SourceValue.isLValue() && "LValueToRValueBitcast requires an lvalue operand!"
) ? void (0) : __assert_fail ("SourceValue.isLValue() && \"LValueToRValueBitcast requires an lvalue operand!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7230, __extension__ __PRETTY_FUNCTION__))
;
7231
7232 if (!checkBitCastConstexprEligibility(&Info, Info.Ctx, BCE))
7233 return false;
7234
7235 LValue SourceLValue;
7236 APValue SourceRValue;
7237 SourceLValue.setFrom(Info.Ctx, SourceValue);
7238 if (!handleLValueToRValueConversion(
7239 Info, BCE, BCE->getSubExpr()->getType().withConst(), SourceLValue,
7240 SourceRValue, /*WantObjectRepresentation=*/true))
7241 return false;
7242
7243 // Read out SourceValue into a char buffer.
7244 Optional<BitCastBuffer> Buffer =
7245 APValueToBufferConverter::convert(Info, SourceRValue, BCE);
7246 if (!Buffer)
7247 return false;
7248
7249 // Write out the buffer into a new APValue.
7250 Optional<APValue> MaybeDestValue =
7251 BufferToAPValueConverter::convert(Info, *Buffer, BCE);
7252 if (!MaybeDestValue)
7253 return false;
7254
7255 DestValue = std::move(*MaybeDestValue);
7256 return true;
7257}
7258
7259template <class Derived>
7260class ExprEvaluatorBase
7261 : public ConstStmtVisitor<Derived, bool> {
7262private:
7263 Derived &getDerived() { return static_cast<Derived&>(*this); }
7264 bool DerivedSuccess(const APValue &V, const Expr *E) {
7265 return getDerived().Success(V, E);
7266 }
7267 bool DerivedZeroInitialization(const Expr *E) {
7268 return getDerived().ZeroInitialization(E);
7269 }
7270
7271 // Check whether a conditional operator with a non-constant condition is a
7272 // potential constant expression. If neither arm is a potential constant
7273 // expression, then the conditional operator is not either.
7274 template<typename ConditionalOperator>
7275 void CheckPotentialConstantConditional(const ConditionalOperator *E) {
7276 assert(Info.checkingPotentialConstantExpression())(static_cast <bool> (Info.checkingPotentialConstantExpression
()) ? void (0) : __assert_fail ("Info.checkingPotentialConstantExpression()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7276, __extension__ __PRETTY_FUNCTION__))
;
7277
7278 // Speculatively evaluate both arms.
7279 SmallVector<PartialDiagnosticAt, 8> Diag;
7280 {
7281 SpeculativeEvaluationRAII Speculate(Info, &Diag);
7282 StmtVisitorTy::Visit(E->getFalseExpr());
7283 if (Diag.empty())
7284 return;
7285 }
7286
7287 {
7288 SpeculativeEvaluationRAII Speculate(Info, &Diag);
7289 Diag.clear();
7290 StmtVisitorTy::Visit(E->getTrueExpr());
7291 if (Diag.empty())
7292 return;
7293 }
7294
7295 Error(E, diag::note_constexpr_conditional_never_const);
7296 }
7297
7298
7299 template<typename ConditionalOperator>
7300 bool HandleConditionalOperator(const ConditionalOperator *E) {
7301 bool BoolResult;
7302 if (!EvaluateAsBooleanCondition(E->getCond(), BoolResult, Info)) {
7303 if (Info.checkingPotentialConstantExpression() && Info.noteFailure()) {
7304 CheckPotentialConstantConditional(E);
7305 return false;
7306 }
7307 if (Info.noteFailure()) {
7308 StmtVisitorTy::Visit(E->getTrueExpr());
7309 StmtVisitorTy::Visit(E->getFalseExpr());
7310 }
7311 return false;
7312 }
7313
7314 Expr *EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr();
7315 return StmtVisitorTy::Visit(EvalExpr);
7316 }
7317
7318protected:
7319 EvalInfo &Info;
7320 typedef ConstStmtVisitor<Derived, bool> StmtVisitorTy;
7321 typedef ExprEvaluatorBase ExprEvaluatorBaseTy;
7322
7323 OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
7324 return Info.CCEDiag(E, D);
7325 }
7326
7327 bool ZeroInitialization(const Expr *E) { return Error(E); }
7328
7329public:
7330 ExprEvaluatorBase(EvalInfo &Info) : Info(Info) {}
7331
7332 EvalInfo &getEvalInfo() { return Info; }
7333
7334 /// Report an evaluation error. This should only be called when an error is
7335 /// first discovered. When propagating an error, just return false.
7336 bool Error(const Expr *E, diag::kind D) {
7337 Info.FFDiag(E, D);
7338 return false;
7339 }
7340 bool Error(const Expr *E) {
7341 return Error(E, diag::note_invalid_subexpr_in_const_expr);
7342 }
7343
7344 bool VisitStmt(const Stmt *) {
7345 llvm_unreachable("Expression evaluator should not be called on stmts")::llvm::llvm_unreachable_internal("Expression evaluator should not be called on stmts"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7345)
;
7346 }
7347 bool VisitExpr(const Expr *E) {
7348 return Error(E);
7349 }
7350
7351 bool VisitConstantExpr(const ConstantExpr *E) {
7352 if (E->hasAPValueResult())
7353 return DerivedSuccess(E->getAPValueResult(), E);
7354
7355 return StmtVisitorTy::Visit(E->getSubExpr());
7356 }
7357
7358 bool VisitParenExpr(const ParenExpr *E)
7359 { return StmtVisitorTy::Visit(E->getSubExpr()); }
7360 bool VisitUnaryExtension(const UnaryOperator *E)
7361 { return StmtVisitorTy::Visit(E->getSubExpr()); }
7362 bool VisitUnaryPlus(const UnaryOperator *E)
7363 { return StmtVisitorTy::Visit(E->getSubExpr()); }
7364 bool VisitChooseExpr(const ChooseExpr *E)
7365 { return StmtVisitorTy::Visit(E->getChosenSubExpr()); }
7366 bool VisitGenericSelectionExpr(const GenericSelectionExpr *E)
7367 { return StmtVisitorTy::Visit(E->getResultExpr()); }
7368 bool VisitSubstNonTypeTemplateParmExpr(const SubstNonTypeTemplateParmExpr *E)
7369 { return StmtVisitorTy::Visit(E->getReplacement()); }
7370 bool VisitCXXDefaultArgExpr(const CXXDefaultArgExpr *E) {
7371 TempVersionRAII RAII(*Info.CurrentCall);
7372 SourceLocExprScopeGuard Guard(E, Info.CurrentCall->CurSourceLocExprScope);
7373 return StmtVisitorTy::Visit(E->getExpr());
7374 }
7375 bool VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *E) {
7376 TempVersionRAII RAII(*Info.CurrentCall);
7377 // The initializer may not have been parsed yet, or might be erroneous.
7378 if (!E->getExpr())
7379 return Error(E);
7380 SourceLocExprScopeGuard Guard(E, Info.CurrentCall->CurSourceLocExprScope);
7381 return StmtVisitorTy::Visit(E->getExpr());
7382 }
7383
7384 bool VisitExprWithCleanups(const ExprWithCleanups *E) {
7385 FullExpressionRAII Scope(Info);
7386 return StmtVisitorTy::Visit(E->getSubExpr()) && Scope.destroy();
7387 }
7388
7389 // Temporaries are registered when created, so we don't care about
7390 // CXXBindTemporaryExpr.
7391 bool VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *E) {
7392 return StmtVisitorTy::Visit(E->getSubExpr());
7393 }
7394
7395 bool VisitCXXReinterpretCastExpr(const CXXReinterpretCastExpr *E) {
7396 CCEDiag(E, diag::note_constexpr_invalid_cast) << 0;
7397 return static_cast<Derived*>(this)->VisitCastExpr(E);
7398 }
7399 bool VisitCXXDynamicCastExpr(const CXXDynamicCastExpr *E) {
7400 if (!Info.Ctx.getLangOpts().CPlusPlus20)
7401 CCEDiag(E, diag::note_constexpr_invalid_cast) << 1;
7402 return static_cast<Derived*>(this)->VisitCastExpr(E);
7403 }
7404 bool VisitBuiltinBitCastExpr(const BuiltinBitCastExpr *E) {
7405 return static_cast<Derived*>(this)->VisitCastExpr(E);
7406 }
7407
7408 bool VisitBinaryOperator(const BinaryOperator *E) {
7409 switch (E->getOpcode()) {
7410 default:
7411 return Error(E);
7412
7413 case BO_Comma:
7414 VisitIgnoredValue(E->getLHS());
7415 return StmtVisitorTy::Visit(E->getRHS());
7416
7417 case BO_PtrMemD:
7418 case BO_PtrMemI: {
7419 LValue Obj;
7420 if (!HandleMemberPointerAccess(Info, E, Obj))
7421 return false;
7422 APValue Result;
7423 if (!handleLValueToRValueConversion(Info, E, E->getType(), Obj, Result))
7424 return false;
7425 return DerivedSuccess(Result, E);
7426 }
7427 }
7428 }
7429
7430 bool VisitCXXRewrittenBinaryOperator(const CXXRewrittenBinaryOperator *E) {
7431 return StmtVisitorTy::Visit(E->getSemanticForm());
7432 }
7433
7434 bool VisitBinaryConditionalOperator(const BinaryConditionalOperator *E) {
7435 // Evaluate and cache the common expression. We treat it as a temporary,
7436 // even though it's not quite the same thing.
7437 LValue CommonLV;
7438 if (!Evaluate(Info.CurrentCall->createTemporary(
7439 E->getOpaqueValue(),
7440 getStorageType(Info.Ctx, E->getOpaqueValue()),
7441 ScopeKind::FullExpression, CommonLV),
7442 Info, E->getCommon()))
7443 return false;
7444
7445 return HandleConditionalOperator(E);
7446 }
7447
7448 bool VisitConditionalOperator(const ConditionalOperator *E) {
7449 bool IsBcpCall = false;
7450 // If the condition (ignoring parens) is a __builtin_constant_p call,
7451 // the result is a constant expression if it can be folded without
7452 // side-effects. This is an important GNU extension. See GCC PR38377
7453 // for discussion.
7454 if (const CallExpr *CallCE =
7455 dyn_cast<CallExpr>(E->getCond()->IgnoreParenCasts()))
7456 if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
7457 IsBcpCall = true;
7458
7459 // Always assume __builtin_constant_p(...) ? ... : ... is a potential
7460 // constant expression; we can't check whether it's potentially foldable.
7461 // FIXME: We should instead treat __builtin_constant_p as non-constant if
7462 // it would return 'false' in this mode.
7463 if (Info.checkingPotentialConstantExpression() && IsBcpCall)
7464 return false;
7465
7466 FoldConstant Fold(Info, IsBcpCall);
7467 if (!HandleConditionalOperator(E)) {
7468 Fold.keepDiagnostics();
7469 return false;
7470 }
7471
7472 return true;
7473 }
7474
7475 bool VisitOpaqueValueExpr(const OpaqueValueExpr *E) {
7476 if (APValue *Value = Info.CurrentCall->getCurrentTemporary(E))
7477 return DerivedSuccess(*Value, E);
7478
7479 const Expr *Source = E->getSourceExpr();
7480 if (!Source)
7481 return Error(E);
7482 if (Source == E) { // sanity checking.
7483 assert(0 && "OpaqueValueExpr recursively refers to itself")(static_cast <bool> (0 && "OpaqueValueExpr recursively refers to itself"
) ? void (0) : __assert_fail ("0 && \"OpaqueValueExpr recursively refers to itself\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7483, __extension__ __PRETTY_FUNCTION__))
;
7484 return Error(E);
7485 }
7486 return StmtVisitorTy::Visit(Source);
7487 }
7488
7489 bool VisitPseudoObjectExpr(const PseudoObjectExpr *E) {
7490 for (const Expr *SemE : E->semantics()) {
7491 if (auto *OVE = dyn_cast<OpaqueValueExpr>(SemE)) {
7492 // FIXME: We can't handle the case where an OpaqueValueExpr is also the
7493 // result expression: there could be two different LValues that would
7494 // refer to the same object in that case, and we can't model that.
7495 if (SemE == E->getResultExpr())
7496 return Error(E);
7497
7498 // Unique OVEs get evaluated if and when we encounter them when
7499 // emitting the rest of the semantic form, rather than eagerly.
7500 if (OVE->isUnique())
7501 continue;
7502
7503 LValue LV;
7504 if (!Evaluate(Info.CurrentCall->createTemporary(
7505 OVE, getStorageType(Info.Ctx, OVE),
7506 ScopeKind::FullExpression, LV),
7507 Info, OVE->getSourceExpr()))
7508 return false;
7509 } else if (SemE == E->getResultExpr()) {
7510 if (!StmtVisitorTy::Visit(SemE))
7511 return false;
7512 } else {
7513 if (!EvaluateIgnoredValue(Info, SemE))
7514 return false;
7515 }
7516 }
7517 return true;
7518 }
7519
7520 bool VisitCallExpr(const CallExpr *E) {
7521 APValue Result;
7522 if (!handleCallExpr(E, Result, nullptr))
7523 return false;
7524 return DerivedSuccess(Result, E);
7525 }
7526
7527 bool handleCallExpr(const CallExpr *E, APValue &Result,
7528 const LValue *ResultSlot) {
7529 CallScopeRAII CallScope(Info);
7530
7531 const Expr *Callee = E->getCallee()->IgnoreParens();
7532 QualType CalleeType = Callee->getType();
7533
7534 const FunctionDecl *FD = nullptr;
7535 LValue *This = nullptr, ThisVal;
7536 auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
7537 bool HasQualifier = false;
7538
7539 CallRef Call;
7540
7541 // Extract function decl and 'this' pointer from the callee.
7542 if (CalleeType->isSpecificBuiltinType(BuiltinType::BoundMember)) {
7543 const CXXMethodDecl *Member = nullptr;
7544 if (const MemberExpr *ME = dyn_cast<MemberExpr>(Callee)) {
7545 // Explicit bound member calls, such as x.f() or p->g();
7546 if (!EvaluateObjectArgument(Info, ME->getBase(), ThisVal))
7547 return false;
7548 Member = dyn_cast<CXXMethodDecl>(ME->getMemberDecl());
7549 if (!Member)
7550 return Error(Callee);
7551 This = &ThisVal;
7552 HasQualifier = ME->hasQualifier();
7553 } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(Callee)) {
7554 // Indirect bound member calls ('.*' or '->*').
7555 const ValueDecl *D =
7556 HandleMemberPointerAccess(Info, BE, ThisVal, false);
7557 if (!D)
7558 return false;
7559 Member = dyn_cast<CXXMethodDecl>(D);
7560 if (!Member)
7561 return Error(Callee);
7562 This = &ThisVal;
7563 } else if (const auto *PDE = dyn_cast<CXXPseudoDestructorExpr>(Callee)) {
7564 if (!Info.getLangOpts().CPlusPlus20)
7565 Info.CCEDiag(PDE, diag::note_constexpr_pseudo_destructor);
7566 return EvaluateObjectArgument(Info, PDE->getBase(), ThisVal) &&
7567 HandleDestruction(Info, PDE, ThisVal, PDE->getDestroyedType());
7568 } else
7569 return Error(Callee);
7570 FD = Member;
7571 } else if (CalleeType->isFunctionPointerType()) {
7572 LValue CalleeLV;
7573 if (!EvaluatePointer(Callee, CalleeLV, Info))
7574 return false;
7575
7576 if (!CalleeLV.getLValueOffset().isZero())
7577 return Error(Callee);
7578 FD = dyn_cast_or_null<FunctionDecl>(
7579 CalleeLV.getLValueBase().dyn_cast<const ValueDecl *>());
7580 if (!FD)
7581 return Error(Callee);
7582 // Don't call function pointers which have been cast to some other type.
7583 // Per DR (no number yet), the caller and callee can differ in noexcept.
7584 if (!Info.Ctx.hasSameFunctionTypeIgnoringExceptionSpec(
7585 CalleeType->getPointeeType(), FD->getType())) {
7586 return Error(E);
7587 }
7588
7589 // For an (overloaded) assignment expression, evaluate the RHS before the
7590 // LHS.
7591 auto *OCE = dyn_cast<CXXOperatorCallExpr>(E);
7592 if (OCE && OCE->isAssignmentOp()) {
7593 assert(Args.size() == 2 && "wrong number of arguments in assignment")(static_cast <bool> (Args.size() == 2 && "wrong number of arguments in assignment"
) ? void (0) : __assert_fail ("Args.size() == 2 && \"wrong number of arguments in assignment\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7593, __extension__ __PRETTY_FUNCTION__))
;
7594 Call = Info.CurrentCall->createCall(FD);
7595 if (!EvaluateArgs(isa<CXXMethodDecl>(FD) ? Args.slice(1) : Args, Call,
7596 Info, FD, /*RightToLeft=*/true))
7597 return false;
7598 }
7599
7600 // Overloaded operator calls to member functions are represented as normal
7601 // calls with '*this' as the first argument.
7602 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
7603 if (MD && !MD->isStatic()) {
7604 // FIXME: When selecting an implicit conversion for an overloaded
7605 // operator delete, we sometimes try to evaluate calls to conversion
7606 // operators without a 'this' parameter!
7607 if (Args.empty())
7608 return Error(E);
7609
7610 if (!EvaluateObjectArgument(Info, Args[0], ThisVal))
7611 return false;
7612 This = &ThisVal;
7613 Args = Args.slice(1);
7614 } else if (MD && MD->isLambdaStaticInvoker()) {
7615 // Map the static invoker for the lambda back to the call operator.
7616 // Conveniently, we don't have to slice out the 'this' argument (as is
7617 // being done for the non-static case), since a static member function
7618 // doesn't have an implicit argument passed in.
7619 const CXXRecordDecl *ClosureClass = MD->getParent();
7620 assert((static_cast <bool> (ClosureClass->captures_begin() ==
ClosureClass->captures_end() && "Number of captures must be zero for conversion to function-ptr"
) ? void (0) : __assert_fail ("ClosureClass->captures_begin() == ClosureClass->captures_end() && \"Number of captures must be zero for conversion to function-ptr\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7622, __extension__ __PRETTY_FUNCTION__))
7621 ClosureClass->captures_begin() == ClosureClass->captures_end() &&(static_cast <bool> (ClosureClass->captures_begin() ==
ClosureClass->captures_end() && "Number of captures must be zero for conversion to function-ptr"
) ? void (0) : __assert_fail ("ClosureClass->captures_begin() == ClosureClass->captures_end() && \"Number of captures must be zero for conversion to function-ptr\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7622, __extension__ __PRETTY_FUNCTION__))
7622 "Number of captures must be zero for conversion to function-ptr")(static_cast <bool> (ClosureClass->captures_begin() ==
ClosureClass->captures_end() && "Number of captures must be zero for conversion to function-ptr"
) ? void (0) : __assert_fail ("ClosureClass->captures_begin() == ClosureClass->captures_end() && \"Number of captures must be zero for conversion to function-ptr\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7622, __extension__ __PRETTY_FUNCTION__))
;
7623
7624 const CXXMethodDecl *LambdaCallOp =
7625 ClosureClass->getLambdaCallOperator();
7626
7627 // Set 'FD', the function that will be called below, to the call
7628 // operator. If the closure object represents a generic lambda, find
7629 // the corresponding specialization of the call operator.
7630
7631 if (ClosureClass->isGenericLambda()) {
7632 assert(MD->isFunctionTemplateSpecialization() &&(static_cast <bool> (MD->isFunctionTemplateSpecialization
() && "A generic lambda's static-invoker function must be a "
"template specialization") ? void (0) : __assert_fail ("MD->isFunctionTemplateSpecialization() && \"A generic lambda's static-invoker function must be a \" \"template specialization\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7634, __extension__ __PRETTY_FUNCTION__))
7633 "A generic lambda's static-invoker function must be a "(static_cast <bool> (MD->isFunctionTemplateSpecialization
() && "A generic lambda's static-invoker function must be a "
"template specialization") ? void (0) : __assert_fail ("MD->isFunctionTemplateSpecialization() && \"A generic lambda's static-invoker function must be a \" \"template specialization\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7634, __extension__ __PRETTY_FUNCTION__))
7634 "template specialization")(static_cast <bool> (MD->isFunctionTemplateSpecialization
() && "A generic lambda's static-invoker function must be a "
"template specialization") ? void (0) : __assert_fail ("MD->isFunctionTemplateSpecialization() && \"A generic lambda's static-invoker function must be a \" \"template specialization\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7634, __extension__ __PRETTY_FUNCTION__))
;
7635 const TemplateArgumentList *TAL = MD->getTemplateSpecializationArgs();
7636 FunctionTemplateDecl *CallOpTemplate =
7637 LambdaCallOp->getDescribedFunctionTemplate();
7638 void *InsertPos = nullptr;
7639 FunctionDecl *CorrespondingCallOpSpecialization =
7640 CallOpTemplate->findSpecialization(TAL->asArray(), InsertPos);
7641 assert(CorrespondingCallOpSpecialization &&(static_cast <bool> (CorrespondingCallOpSpecialization &&
"We must always have a function call operator specialization "
"that corresponds to our static invoker specialization") ? void
(0) : __assert_fail ("CorrespondingCallOpSpecialization && \"We must always have a function call operator specialization \" \"that corresponds to our static invoker specialization\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7643, __extension__ __PRETTY_FUNCTION__))
7642 "We must always have a function call operator specialization "(static_cast <bool> (CorrespondingCallOpSpecialization &&
"We must always have a function call operator specialization "
"that corresponds to our static invoker specialization") ? void
(0) : __assert_fail ("CorrespondingCallOpSpecialization && \"We must always have a function call operator specialization \" \"that corresponds to our static invoker specialization\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7643, __extension__ __PRETTY_FUNCTION__))
7643 "that corresponds to our static invoker specialization")(static_cast <bool> (CorrespondingCallOpSpecialization &&
"We must always have a function call operator specialization "
"that corresponds to our static invoker specialization") ? void
(0) : __assert_fail ("CorrespondingCallOpSpecialization && \"We must always have a function call operator specialization \" \"that corresponds to our static invoker specialization\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7643, __extension__ __PRETTY_FUNCTION__))
;
7644 FD = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
7645 } else
7646 FD = LambdaCallOp;
7647 } else if (FD->isReplaceableGlobalAllocationFunction()) {
7648 if (FD->getDeclName().getCXXOverloadedOperator() == OO_New ||
7649 FD->getDeclName().getCXXOverloadedOperator() == OO_Array_New) {
7650 LValue Ptr;
7651 if (!HandleOperatorNewCall(Info, E, Ptr))
7652 return false;
7653 Ptr.moveInto(Result);
7654 return CallScope.destroy();
7655 } else {
7656 return HandleOperatorDeleteCall(Info, E) && CallScope.destroy();
7657 }
7658 }
7659 } else
7660 return Error(E);
7661
7662 // Evaluate the arguments now if we've not already done so.
7663 if (!Call) {
7664 Call = Info.CurrentCall->createCall(FD);
7665 if (!EvaluateArgs(Args, Call, Info, FD))
7666 return false;
7667 }
7668
7669 SmallVector<QualType, 4> CovariantAdjustmentPath;
7670 if (This) {
7671 auto *NamedMember = dyn_cast<CXXMethodDecl>(FD);
7672 if (NamedMember && NamedMember->isVirtual() && !HasQualifier) {
7673 // Perform virtual dispatch, if necessary.
7674 FD = HandleVirtualDispatch(Info, E, *This, NamedMember,
7675 CovariantAdjustmentPath);
7676 if (!FD)
7677 return false;
7678 } else {
7679 // Check that the 'this' pointer points to an object of the right type.
7680 // FIXME: If this is an assignment operator call, we may need to change
7681 // the active union member before we check this.
7682 if (!checkNonVirtualMemberCallThisPointer(Info, E, *This, NamedMember))
7683 return false;
7684 }
7685 }
7686
7687 // Destructor calls are different enough that they have their own codepath.
7688 if (auto *DD = dyn_cast<CXXDestructorDecl>(FD)) {
7689 assert(This && "no 'this' pointer for destructor call")(static_cast <bool> (This && "no 'this' pointer for destructor call"
) ? void (0) : __assert_fail ("This && \"no 'this' pointer for destructor call\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7689, __extension__ __PRETTY_FUNCTION__))
;
7690 return HandleDestruction(Info, E, *This,
7691 Info.Ctx.getRecordType(DD->getParent())) &&
7692 CallScope.destroy();
7693 }
7694
7695 const FunctionDecl *Definition = nullptr;
7696 Stmt *Body = FD->getBody(Definition);
7697
7698 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body) ||
7699 !HandleFunctionCall(E->getExprLoc(), Definition, This, Args, Call,
7700 Body, Info, Result, ResultSlot))
7701 return false;
7702
7703 if (!CovariantAdjustmentPath.empty() &&
7704 !HandleCovariantReturnAdjustment(Info, E, Result,
7705 CovariantAdjustmentPath))
7706 return false;
7707
7708 return CallScope.destroy();
7709 }
7710
7711 bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
7712 return StmtVisitorTy::Visit(E->getInitializer());
7713 }
7714 bool VisitInitListExpr(const InitListExpr *E) {
7715 if (E->getNumInits() == 0)
7716 return DerivedZeroInitialization(E);
7717 if (E->getNumInits() == 1)
7718 return StmtVisitorTy::Visit(E->getInit(0));
7719 return Error(E);
7720 }
7721 bool VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
7722 return DerivedZeroInitialization(E);
7723 }
7724 bool VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
7725 return DerivedZeroInitialization(E);
7726 }
7727 bool VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
7728 return DerivedZeroInitialization(E);
7729 }
7730
7731 /// A member expression where the object is a prvalue is itself a prvalue.
7732 bool VisitMemberExpr(const MemberExpr *E) {
7733 assert(!Info.Ctx.getLangOpts().CPlusPlus11 &&(static_cast <bool> (!Info.Ctx.getLangOpts().CPlusPlus11
&& "missing temporary materialization conversion") ?
void (0) : __assert_fail ("!Info.Ctx.getLangOpts().CPlusPlus11 && \"missing temporary materialization conversion\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7734, __extension__ __PRETTY_FUNCTION__))
7734 "missing temporary materialization conversion")(static_cast <bool> (!Info.Ctx.getLangOpts().CPlusPlus11
&& "missing temporary materialization conversion") ?
void (0) : __assert_fail ("!Info.Ctx.getLangOpts().CPlusPlus11 && \"missing temporary materialization conversion\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7734, __extension__ __PRETTY_FUNCTION__))
;
7735 assert(!E->isArrow() && "missing call to bound member function?")(static_cast <bool> (!E->isArrow() && "missing call to bound member function?"
) ? void (0) : __assert_fail ("!E->isArrow() && \"missing call to bound member function?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7735, __extension__ __PRETTY_FUNCTION__))
;
7736
7737 APValue Val;
7738 if (!Evaluate(Val, Info, E->getBase()))
7739 return false;
7740
7741 QualType BaseTy = E->getBase()->getType();
7742
7743 const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl());
7744 if (!FD) return Error(E);
7745 assert(!FD->getType()->isReferenceType() && "prvalue reference?")(static_cast <bool> (!FD->getType()->isReferenceType
() && "prvalue reference?") ? void (0) : __assert_fail
("!FD->getType()->isReferenceType() && \"prvalue reference?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7745, __extension__ __PRETTY_FUNCTION__))
;
7746 assert(BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() ==(static_cast <bool> (BaseTy->castAs<RecordType>
()->getDecl()->getCanonicalDecl() == FD->getParent()
->getCanonicalDecl() && "record / field mismatch")
? void (0) : __assert_fail ("BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7747, __extension__ __PRETTY_FUNCTION__))
7747 FD->getParent()->getCanonicalDecl() && "record / field mismatch")(static_cast <bool> (BaseTy->castAs<RecordType>
()->getDecl()->getCanonicalDecl() == FD->getParent()
->getCanonicalDecl() && "record / field mismatch")
? void (0) : __assert_fail ("BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7747, __extension__ __PRETTY_FUNCTION__))
;
7748
7749 // Note: there is no lvalue base here. But this case should only ever
7750 // happen in C or in C++98, where we cannot be evaluating a constexpr
7751 // constructor, which is the only case the base matters.
7752 CompleteObject Obj(APValue::LValueBase(), &Val, BaseTy);
7753 SubobjectDesignator Designator(BaseTy);
7754 Designator.addDeclUnchecked(FD);
7755
7756 APValue Result;
7757 return extractSubobject(Info, E, Obj, Designator, Result) &&
7758 DerivedSuccess(Result, E);
7759 }
7760
7761 bool VisitExtVectorElementExpr(const ExtVectorElementExpr *E) {
7762 APValue Val;
7763 if (!Evaluate(Val, Info, E->getBase()))
7764 return false;
7765
7766 if (Val.isVector()) {
7767 SmallVector<uint32_t, 4> Indices;
7768 E->getEncodedElementAccess(Indices);
7769 if (Indices.size() == 1) {
7770 // Return scalar.
7771 return DerivedSuccess(Val.getVectorElt(Indices[0]), E);
7772 } else {
7773 // Construct new APValue vector.
7774 SmallVector<APValue, 4> Elts;
7775 for (unsigned I = 0; I < Indices.size(); ++I) {
7776 Elts.push_back(Val.getVectorElt(Indices[I]));
7777 }
7778 APValue VecResult(Elts.data(), Indices.size());
7779 return DerivedSuccess(VecResult, E);
7780 }
7781 }
7782
7783 return false;
7784 }
7785
7786 bool VisitCastExpr(const CastExpr *E) {
7787 switch (E->getCastKind()) {
7788 default:
7789 break;
7790
7791 case CK_AtomicToNonAtomic: {
7792 APValue AtomicVal;
7793 // This does not need to be done in place even for class/array types:
7794 // atomic-to-non-atomic conversion implies copying the object
7795 // representation.
7796 if (!Evaluate(AtomicVal, Info, E->getSubExpr()))
7797 return false;
7798 return DerivedSuccess(AtomicVal, E);
7799 }
7800
7801 case CK_NoOp:
7802 case CK_UserDefinedConversion:
7803 return StmtVisitorTy::Visit(E->getSubExpr());
7804
7805 case CK_LValueToRValue: {
7806 LValue LVal;
7807 if (!EvaluateLValue(E->getSubExpr(), LVal, Info))
7808 return false;
7809 APValue RVal;
7810 // Note, we use the subexpression's type in order to retain cv-qualifiers.
7811 if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
7812 LVal, RVal))
7813 return false;
7814 return DerivedSuccess(RVal, E);
7815 }
7816 case CK_LValueToRValueBitCast: {
7817 APValue DestValue, SourceValue;
7818 if (!Evaluate(SourceValue, Info, E->getSubExpr()))
7819 return false;
7820 if (!handleLValueToRValueBitCast(Info, DestValue, SourceValue, E))
7821 return false;
7822 return DerivedSuccess(DestValue, E);
7823 }
7824
7825 case CK_AddressSpaceConversion: {
7826 APValue Value;
7827 if (!Evaluate(Value, Info, E->getSubExpr()))
7828 return false;
7829 return DerivedSuccess(Value, E);
7830 }
7831 }
7832
7833 return Error(E);
7834 }
7835
7836 bool VisitUnaryPostInc(const UnaryOperator *UO) {
7837 return VisitUnaryPostIncDec(UO);
7838 }
7839 bool VisitUnaryPostDec(const UnaryOperator *UO) {
7840 return VisitUnaryPostIncDec(UO);
7841 }
7842 bool VisitUnaryPostIncDec(const UnaryOperator *UO) {
7843 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
7844 return Error(UO);
7845
7846 LValue LVal;
7847 if (!EvaluateLValue(UO->getSubExpr(), LVal, Info))
7848 return false;
7849 APValue RVal;
7850 if (!handleIncDec(this->Info, UO, LVal, UO->getSubExpr()->getType(),
7851 UO->isIncrementOp(), &RVal))
7852 return false;
7853 return DerivedSuccess(RVal, UO);
7854 }
7855
7856 bool VisitStmtExpr(const StmtExpr *E) {
7857 // We will have checked the full-expressions inside the statement expression
7858 // when they were completed, and don't need to check them again now.
7859 llvm::SaveAndRestore<bool> NotCheckingForUB(
7860 Info.CheckingForUndefinedBehavior, false);
7861
7862 const CompoundStmt *CS = E->getSubStmt();
7863 if (CS->body_empty())
7864 return true;
7865
7866 BlockScopeRAII Scope(Info);
7867 for (CompoundStmt::const_body_iterator BI = CS->body_begin(),
7868 BE = CS->body_end();
7869 /**/; ++BI) {
7870 if (BI + 1 == BE) {
7871 const Expr *FinalExpr = dyn_cast<Expr>(*BI);
7872 if (!FinalExpr) {
7873 Info.FFDiag((*BI)->getBeginLoc(),
7874 diag::note_constexpr_stmt_expr_unsupported);
7875 return false;
7876 }
7877 return this->Visit(FinalExpr) && Scope.destroy();
7878 }
7879
7880 APValue ReturnValue;
7881 StmtResult Result = { ReturnValue, nullptr };
7882 EvalStmtResult ESR = EvaluateStmt(Result, Info, *BI);
7883 if (ESR != ESR_Succeeded) {
7884 // FIXME: If the statement-expression terminated due to 'return',
7885 // 'break', or 'continue', it would be nice to propagate that to
7886 // the outer statement evaluation rather than bailing out.
7887 if (ESR != ESR_Failed)
7888 Info.FFDiag((*BI)->getBeginLoc(),
7889 diag::note_constexpr_stmt_expr_unsupported);
7890 return false;
7891 }
7892 }
7893
7894 llvm_unreachable("Return from function from the loop above.")::llvm::llvm_unreachable_internal("Return from function from the loop above."
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7894)
;
7895 }
7896
7897 /// Visit a value which is evaluated, but whose value is ignored.
7898 void VisitIgnoredValue(const Expr *E) {
7899 EvaluateIgnoredValue(Info, E);
7900 }
7901
7902 /// Potentially visit a MemberExpr's base expression.
7903 void VisitIgnoredBaseExpression(const Expr *E) {
7904 // While MSVC doesn't evaluate the base expression, it does diagnose the
7905 // presence of side-effecting behavior.
7906 if (Info.getLangOpts().MSVCCompat && !E->HasSideEffects(Info.Ctx))
7907 return;
7908 VisitIgnoredValue(E);
7909 }
7910};
7911
7912} // namespace
7913
7914//===----------------------------------------------------------------------===//
7915// Common base class for lvalue and temporary evaluation.
7916//===----------------------------------------------------------------------===//
7917namespace {
7918template<class Derived>
7919class LValueExprEvaluatorBase
7920 : public ExprEvaluatorBase<Derived> {
7921protected:
7922 LValue &Result;
7923 bool InvalidBaseOK;
7924 typedef LValueExprEvaluatorBase LValueExprEvaluatorBaseTy;
7925 typedef ExprEvaluatorBase<Derived> ExprEvaluatorBaseTy;
7926
7927 bool Success(APValue::LValueBase B) {
7928 Result.set(B);
7929 return true;
7930 }
7931
7932 bool evaluatePointer(const Expr *E, LValue &Result) {
7933 return EvaluatePointer(E, Result, this->Info, InvalidBaseOK);
7934 }
7935
7936public:
7937 LValueExprEvaluatorBase(EvalInfo &Info, LValue &Result, bool InvalidBaseOK)
7938 : ExprEvaluatorBaseTy(Info), Result(Result),
7939 InvalidBaseOK(InvalidBaseOK) {}
7940
7941 bool Success(const APValue &V, const Expr *E) {
7942 Result.setFrom(this->Info.Ctx, V);
7943 return true;
7944 }
7945
7946 bool VisitMemberExpr(const MemberExpr *E) {
7947 // Handle non-static data members.
7948 QualType BaseTy;
7949 bool EvalOK;
7950 if (E->isArrow()) {
7951 EvalOK = evaluatePointer(E->getBase(), Result);
7952 BaseTy = E->getBase()->getType()->castAs<PointerType>()->getPointeeType();
7953 } else if (E->getBase()->isPRValue()) {
7954 assert(E->getBase()->getType()->isRecordType())(static_cast <bool> (E->getBase()->getType()->
isRecordType()) ? void (0) : __assert_fail ("E->getBase()->getType()->isRecordType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7954, __extension__ __PRETTY_FUNCTION__))
;
7955 EvalOK = EvaluateTemporary(E->getBase(), Result, this->Info);
7956 BaseTy = E->getBase()->getType();
7957 } else {
7958 EvalOK = this->Visit(E->getBase());
7959 BaseTy = E->getBase()->getType();
7960 }
7961 if (!EvalOK) {
7962 if (!InvalidBaseOK)
7963 return false;
7964 Result.setInvalid(E);
7965 return true;
7966 }
7967
7968 const ValueDecl *MD = E->getMemberDecl();
7969 if (const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl())) {
7970 assert(BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() ==(static_cast <bool> (BaseTy->castAs<RecordType>
()->getDecl()->getCanonicalDecl() == FD->getParent()
->getCanonicalDecl() && "record / field mismatch")
? void (0) : __assert_fail ("BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7971, __extension__ __PRETTY_FUNCTION__))
7971 FD->getParent()->getCanonicalDecl() && "record / field mismatch")(static_cast <bool> (BaseTy->castAs<RecordType>
()->getDecl()->getCanonicalDecl() == FD->getParent()
->getCanonicalDecl() && "record / field mismatch")
? void (0) : __assert_fail ("BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 7971, __extension__ __PRETTY_FUNCTION__))
;
7972 (void)BaseTy;
7973 if (!HandleLValueMember(this->Info, E, Result, FD))
7974 return false;
7975 } else if (const IndirectFieldDecl *IFD = dyn_cast<IndirectFieldDecl>(MD)) {
7976 if (!HandleLValueIndirectMember(this->Info, E, Result, IFD))
7977 return false;
7978 } else
7979 return this->Error(E);
7980
7981 if (MD->getType()->isReferenceType()) {
7982 APValue RefValue;
7983 if (!handleLValueToRValueConversion(this->Info, E, MD->getType(), Result,
7984 RefValue))
7985 return false;
7986 return Success(RefValue, E);
7987 }
7988 return true;
7989 }
7990
7991 bool VisitBinaryOperator(const BinaryOperator *E) {
7992 switch (E->getOpcode()) {
7993 default:
7994 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
7995
7996 case BO_PtrMemD:
7997 case BO_PtrMemI:
7998 return HandleMemberPointerAccess(this->Info, E, Result);
7999 }
8000 }
8001
8002 bool VisitCastExpr(const CastExpr *E) {
8003 switch (E->getCastKind()) {
8004 default:
8005 return ExprEvaluatorBaseTy::VisitCastExpr(E);
8006
8007 case CK_DerivedToBase:
8008 case CK_UncheckedDerivedToBase:
8009 if (!this->Visit(E->getSubExpr()))
8010 return false;
8011
8012 // Now figure out the necessary offset to add to the base LV to get from
8013 // the derived class to the base class.
8014 return HandleLValueBasePath(this->Info, E, E->getSubExpr()->getType(),
8015 Result);
8016 }
8017 }
8018};
8019}
8020
8021//===----------------------------------------------------------------------===//
8022// LValue Evaluation
8023//
8024// This is used for evaluating lvalues (in C and C++), xvalues (in C++11),
8025// function designators (in C), decl references to void objects (in C), and
8026// temporaries (if building with -Wno-address-of-temporary).
8027//
8028// LValue evaluation produces values comprising a base expression of one of the
8029// following types:
8030// - Declarations
8031// * VarDecl
8032// * FunctionDecl
8033// - Literals
8034// * CompoundLiteralExpr in C (and in global scope in C++)
8035// * StringLiteral
8036// * PredefinedExpr
8037// * ObjCStringLiteralExpr
8038// * ObjCEncodeExpr
8039// * AddrLabelExpr
8040// * BlockExpr
8041// * CallExpr for a MakeStringConstant builtin
8042// - typeid(T) expressions, as TypeInfoLValues
8043// - Locals and temporaries
8044// * MaterializeTemporaryExpr
8045// * Any Expr, with a CallIndex indicating the function in which the temporary
8046// was evaluated, for cases where the MaterializeTemporaryExpr is missing
8047// from the AST (FIXME).
8048// * A MaterializeTemporaryExpr that has static storage duration, with no
8049// CallIndex, for a lifetime-extended temporary.
8050// * The ConstantExpr that is currently being evaluated during evaluation of an
8051// immediate invocation.
8052// plus an offset in bytes.
8053//===----------------------------------------------------------------------===//
8054namespace {
8055class LValueExprEvaluator
8056 : public LValueExprEvaluatorBase<LValueExprEvaluator> {
8057public:
8058 LValueExprEvaluator(EvalInfo &Info, LValue &Result, bool InvalidBaseOK) :
8059 LValueExprEvaluatorBaseTy(Info, Result, InvalidBaseOK) {}
8060
8061 bool VisitVarDecl(const Expr *E, const VarDecl *VD);
8062 bool VisitUnaryPreIncDec(const UnaryOperator *UO);
8063
8064 bool VisitDeclRefExpr(const DeclRefExpr *E);
8065 bool VisitPredefinedExpr(const PredefinedExpr *E) { return Success(E); }
8066 bool VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
8067 bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
8068 bool VisitMemberExpr(const MemberExpr *E);
8069 bool VisitStringLiteral(const StringLiteral *E) { return Success(E); }
8070 bool VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { return Success(E); }
8071 bool VisitCXXTypeidExpr(const CXXTypeidExpr *E);
8072 bool VisitCXXUuidofExpr(const CXXUuidofExpr *E);
8073 bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E);
8074 bool VisitUnaryDeref(const UnaryOperator *E);
8075 bool VisitUnaryReal(const UnaryOperator *E);
8076 bool VisitUnaryImag(const UnaryOperator *E);
8077 bool VisitUnaryPreInc(const UnaryOperator *UO) {
8078 return VisitUnaryPreIncDec(UO);
8079 }
8080 bool VisitUnaryPreDec(const UnaryOperator *UO) {
8081 return VisitUnaryPreIncDec(UO);
8082 }
8083 bool VisitBinAssign(const BinaryOperator *BO);
8084 bool VisitCompoundAssignOperator(const CompoundAssignOperator *CAO);
8085
8086 bool VisitCastExpr(const CastExpr *E) {
8087 switch (E->getCastKind()) {
8088 default:
8089 return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
8090
8091 case CK_LValueBitCast:
8092 this->CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
8093 if (!Visit(E->getSubExpr()))
8094 return false;
8095 Result.Designator.setInvalid();
8096 return true;
8097
8098 case CK_BaseToDerived:
8099 if (!Visit(E->getSubExpr()))
8100 return false;
8101 return HandleBaseToDerivedCast(Info, E, Result);
8102
8103 case CK_Dynamic:
8104 if (!Visit(E->getSubExpr()))
8105 return false;
8106 return HandleDynamicCast(Info, cast<ExplicitCastExpr>(E), Result);
8107 }
8108 }
8109};
8110} // end anonymous namespace
8111
8112/// Evaluate an expression as an lvalue. This can be legitimately called on
8113/// expressions which are not glvalues, in three cases:
8114/// * function designators in C, and
8115/// * "extern void" objects
8116/// * @selector() expressions in Objective-C
8117static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
8118 bool InvalidBaseOK) {
8119 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8119, __extension__ __PRETTY_FUNCTION__))
;
8120 assert(E->isGLValue() || E->getType()->isFunctionType() ||(static_cast <bool> (E->isGLValue() || E->getType
()->isFunctionType() || E->getType()->isVoidType() ||
isa<ObjCSelectorExpr>(E)) ? void (0) : __assert_fail (
"E->isGLValue() || E->getType()->isFunctionType() || E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8121, __extension__ __PRETTY_FUNCTION__))
8121 E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E))(static_cast <bool> (E->isGLValue() || E->getType
()->isFunctionType() || E->getType()->isVoidType() ||
isa<ObjCSelectorExpr>(E)) ? void (0) : __assert_fail (
"E->isGLValue() || E->getType()->isFunctionType() || E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8121, __extension__ __PRETTY_FUNCTION__))
;
8122 return LValueExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
8123}
8124
8125bool LValueExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
8126 const NamedDecl *D = E->getDecl();
8127 if (isa<FunctionDecl, MSGuidDecl, TemplateParamObjectDecl>(D))
8128 return Success(cast<ValueDecl>(D));
8129 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
8130 return VisitVarDecl(E, VD);
8131 if (const BindingDecl *BD = dyn_cast<BindingDecl>(D))
8132 return Visit(BD->getBinding());
8133 return Error(E);
8134}
8135
8136
8137bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
8138
8139 // If we are within a lambda's call operator, check whether the 'VD' referred
8140 // to within 'E' actually represents a lambda-capture that maps to a
8141 // data-member/field within the closure object, and if so, evaluate to the
8142 // field or what the field refers to.
8143 if (Info.CurrentCall && isLambdaCallOperator(Info.CurrentCall->Callee) &&
8144 isa<DeclRefExpr>(E) &&
8145 cast<DeclRefExpr>(E)->refersToEnclosingVariableOrCapture()) {
8146 // We don't always have a complete capture-map when checking or inferring if
8147 // the function call operator meets the requirements of a constexpr function
8148 // - but we don't need to evaluate the captures to determine constexprness
8149 // (dcl.constexpr C++17).
8150 if (Info.checkingPotentialConstantExpression())
8151 return false;
8152
8153 if (auto *FD = Info.CurrentCall->LambdaCaptureFields.lookup(VD)) {
8154 // Start with 'Result' referring to the complete closure object...
8155 Result = *Info.CurrentCall->This;
8156 // ... then update it to refer to the field of the closure object
8157 // that represents the capture.
8158 if (!HandleLValueMember(Info, E, Result, FD))
8159 return false;
8160 // And if the field is of reference type, update 'Result' to refer to what
8161 // the field refers to.
8162 if (FD->getType()->isReferenceType()) {
8163 APValue RVal;
8164 if (!handleLValueToRValueConversion(Info, E, FD->getType(), Result,
8165 RVal))
8166 return false;
8167 Result.setFrom(Info.Ctx, RVal);
8168 }
8169 return true;
8170 }
8171 }
8172
8173 CallStackFrame *Frame = nullptr;
8174 unsigned Version = 0;
8175 if (VD->hasLocalStorage()) {
8176 // Only if a local variable was declared in the function currently being
8177 // evaluated, do we expect to be able to find its value in the current
8178 // frame. (Otherwise it was likely declared in an enclosing context and
8179 // could either have a valid evaluatable value (for e.g. a constexpr
8180 // variable) or be ill-formed (and trigger an appropriate evaluation
8181 // diagnostic)).
8182 CallStackFrame *CurrFrame = Info.CurrentCall;
8183 if (CurrFrame->Callee && CurrFrame->Callee->Equals(VD->getDeclContext())) {
8184 // Function parameters are stored in some caller's frame. (Usually the
8185 // immediate caller, but for an inherited constructor they may be more
8186 // distant.)
8187 if (auto *PVD = dyn_cast<ParmVarDecl>(VD)) {
8188 if (CurrFrame->Arguments) {
8189 VD = CurrFrame->Arguments.getOrigParam(PVD);
8190 Frame =
8191 Info.getCallFrameAndDepth(CurrFrame->Arguments.CallIndex).first;
8192 Version = CurrFrame->Arguments.Version;
8193 }
8194 } else {
8195 Frame = CurrFrame;
8196 Version = CurrFrame->getCurrentTemporaryVersion(VD);
8197 }
8198 }
8199 }
8200
8201 if (!VD->getType()->isReferenceType()) {
8202 if (Frame) {
8203 Result.set({VD, Frame->Index, Version});
8204 return true;
8205 }
8206 return Success(VD);
8207 }
8208
8209 if (!Info.getLangOpts().CPlusPlus11) {
8210 Info.CCEDiag(E, diag::note_constexpr_ltor_non_integral, 1)
8211 << VD << VD->getType();
8212 Info.Note(VD->getLocation(), diag::note_declared_at);
8213 }
8214
8215 APValue *V;
8216 if (!evaluateVarDeclInit(Info, E, VD, Frame, Version, V))
8217 return false;
8218 if (!V->hasValue()) {
8219 // FIXME: Is it possible for V to be indeterminate here? If so, we should
8220 // adjust the diagnostic to say that.
8221 if (!Info.checkingPotentialConstantExpression())
8222 Info.FFDiag(E, diag::note_constexpr_use_uninit_reference);
8223 return false;
8224 }
8225 return Success(*V, E);
8226}
8227
8228bool LValueExprEvaluator::VisitMaterializeTemporaryExpr(
8229 const MaterializeTemporaryExpr *E) {
8230 // Walk through the expression to find the materialized temporary itself.
8231 SmallVector<const Expr *, 2> CommaLHSs;
8232 SmallVector<SubobjectAdjustment, 2> Adjustments;
8233 const Expr *Inner =
8234 E->getSubExpr()->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
8235
8236 // If we passed any comma operators, evaluate their LHSs.
8237 for (unsigned I = 0, N = CommaLHSs.size(); I != N; ++I)
8238 if (!EvaluateIgnoredValue(Info, CommaLHSs[I]))
8239 return false;
8240
8241 // A materialized temporary with static storage duration can appear within the
8242 // result of a constant expression evaluation, so we need to preserve its
8243 // value for use outside this evaluation.
8244 APValue *Value;
8245 if (E->getStorageDuration() == SD_Static) {
8246 // FIXME: What about SD_Thread?
8247 Value = E->getOrCreateValue(true);
8248 *Value = APValue();
8249 Result.set(E);
8250 } else {
8251 Value = &Info.CurrentCall->createTemporary(
8252 E, E->getType(),
8253 E->getStorageDuration() == SD_FullExpression ? ScopeKind::FullExpression
8254 : ScopeKind::Block,
8255 Result);
8256 }
8257
8258 QualType Type = Inner->getType();
8259
8260 // Materialize the temporary itself.
8261 if (!EvaluateInPlace(*Value, Info, Result, Inner)) {
8262 *Value = APValue();
8263 return false;
8264 }
8265
8266 // Adjust our lvalue to refer to the desired subobject.
8267 for (unsigned I = Adjustments.size(); I != 0; /**/) {
8268 --I;
8269 switch (Adjustments[I].Kind) {
8270 case SubobjectAdjustment::DerivedToBaseAdjustment:
8271 if (!HandleLValueBasePath(Info, Adjustments[I].DerivedToBase.BasePath,
8272 Type, Result))
8273 return false;
8274 Type = Adjustments[I].DerivedToBase.BasePath->getType();
8275 break;
8276
8277 case SubobjectAdjustment::FieldAdjustment:
8278 if (!HandleLValueMember(Info, E, Result, Adjustments[I].Field))
8279 return false;
8280 Type = Adjustments[I].Field->getType();
8281 break;
8282
8283 case SubobjectAdjustment::MemberPointerAdjustment:
8284 if (!HandleMemberPointerAccess(this->Info, Type, Result,
8285 Adjustments[I].Ptr.RHS))
8286 return false;
8287 Type = Adjustments[I].Ptr.MPT->getPointeeType();
8288 break;
8289 }
8290 }
8291
8292 return true;
8293}
8294
8295bool
8296LValueExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
8297 assert((!Info.getLangOpts().CPlusPlus || E->isFileScope()) &&(static_cast <bool> ((!Info.getLangOpts().CPlusPlus || E
->isFileScope()) && "lvalue compound literal in c++?"
) ? void (0) : __assert_fail ("(!Info.getLangOpts().CPlusPlus || E->isFileScope()) && \"lvalue compound literal in c++?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8298, __extension__ __PRETTY_FUNCTION__))
8298 "lvalue compound literal in c++?")(static_cast <bool> ((!Info.getLangOpts().CPlusPlus || E
->isFileScope()) && "lvalue compound literal in c++?"
) ? void (0) : __assert_fail ("(!Info.getLangOpts().CPlusPlus || E->isFileScope()) && \"lvalue compound literal in c++?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8298, __extension__ __PRETTY_FUNCTION__))
;
8299 // Defer visiting the literal until the lvalue-to-rvalue conversion. We can
8300 // only see this when folding in C, so there's no standard to follow here.
8301 return Success(E);
8302}
8303
8304bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
8305 TypeInfoLValue TypeInfo;
8306
8307 if (!E->isPotentiallyEvaluated()) {
8308 if (E->isTypeOperand())
8309 TypeInfo = TypeInfoLValue(E->getTypeOperand(Info.Ctx).getTypePtr());
8310 else
8311 TypeInfo = TypeInfoLValue(E->getExprOperand()->getType().getTypePtr());
8312 } else {
8313 if (!Info.Ctx.getLangOpts().CPlusPlus20) {
8314 Info.CCEDiag(E, diag::note_constexpr_typeid_polymorphic)
8315 << E->getExprOperand()->getType()
8316 << E->getExprOperand()->getSourceRange();
8317 }
8318
8319 if (!Visit(E->getExprOperand()))
8320 return false;
8321
8322 Optional<DynamicType> DynType =
8323 ComputeDynamicType(Info, E, Result, AK_TypeId);
8324 if (!DynType)
8325 return false;
8326
8327 TypeInfo =
8328 TypeInfoLValue(Info.Ctx.getRecordType(DynType->Type).getTypePtr());
8329 }
8330
8331 return Success(APValue::LValueBase::getTypeInfo(TypeInfo, E->getType()));
8332}
8333
8334bool LValueExprEvaluator::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
8335 return Success(E->getGuidDecl());
8336}
8337
8338bool LValueExprEvaluator::VisitMemberExpr(const MemberExpr *E) {
8339 // Handle static data members.
8340 if (const VarDecl *VD = dyn_cast<VarDecl>(E->getMemberDecl())) {
8341 VisitIgnoredBaseExpression(E->getBase());
8342 return VisitVarDecl(E, VD);
8343 }
8344
8345 // Handle static member functions.
8346 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl())) {
8347 if (MD->isStatic()) {
8348 VisitIgnoredBaseExpression(E->getBase());
8349 return Success(MD);
8350 }
8351 }
8352
8353 // Handle non-static data members.
8354 return LValueExprEvaluatorBaseTy::VisitMemberExpr(E);
8355}
8356
8357bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
8358 // FIXME: Deal with vectors as array subscript bases.
8359 if (E->getBase()->getType()->isVectorType())
8360 return Error(E);
8361
8362 APSInt Index;
8363 bool Success = true;
8364
8365 // C++17's rules require us to evaluate the LHS first, regardless of which
8366 // side is the base.
8367 for (const Expr *SubExpr : {E->getLHS(), E->getRHS()}) {
8368 if (SubExpr == E->getBase() ? !evaluatePointer(SubExpr, Result)
8369 : !EvaluateInteger(SubExpr, Index, Info)) {
8370 if (!Info.noteFailure())
8371 return false;
8372 Success = false;
8373 }
8374 }
8375
8376 return Success &&
8377 HandleLValueArrayAdjustment(Info, E, Result, E->getType(), Index);
8378}
8379
8380bool LValueExprEvaluator::VisitUnaryDeref(const UnaryOperator *E) {
8381 return evaluatePointer(E->getSubExpr(), Result);
8382}
8383
8384bool LValueExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
8385 if (!Visit(E->getSubExpr()))
8386 return false;
8387 // __real is a no-op on scalar lvalues.
8388 if (E->getSubExpr()->getType()->isAnyComplexType())
8389 HandleLValueComplexElement(Info, E, Result, E->getType(), false);
8390 return true;
8391}
8392
8393bool LValueExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
8394 assert(E->getSubExpr()->getType()->isAnyComplexType() &&(static_cast <bool> (E->getSubExpr()->getType()->
isAnyComplexType() && "lvalue __imag__ on scalar?") ?
void (0) : __assert_fail ("E->getSubExpr()->getType()->isAnyComplexType() && \"lvalue __imag__ on scalar?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8395, __extension__ __PRETTY_FUNCTION__))
8395 "lvalue __imag__ on scalar?")(static_cast <bool> (E->getSubExpr()->getType()->
isAnyComplexType() && "lvalue __imag__ on scalar?") ?
void (0) : __assert_fail ("E->getSubExpr()->getType()->isAnyComplexType() && \"lvalue __imag__ on scalar?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8395, __extension__ __PRETTY_FUNCTION__))
;
8396 if (!Visit(E->getSubExpr()))
8397 return false;
8398 HandleLValueComplexElement(Info, E, Result, E->getType(), true);
8399 return true;
8400}
8401
8402bool LValueExprEvaluator::VisitUnaryPreIncDec(const UnaryOperator *UO) {
8403 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
8404 return Error(UO);
8405
8406 if (!this->Visit(UO->getSubExpr()))
8407 return false;
8408
8409 return handleIncDec(
8410 this->Info, UO, Result, UO->getSubExpr()->getType(),
8411 UO->isIncrementOp(), nullptr);
8412}
8413
8414bool LValueExprEvaluator::VisitCompoundAssignOperator(
8415 const CompoundAssignOperator *CAO) {
8416 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
8417 return Error(CAO);
8418
8419 bool Success = true;
8420
8421 // C++17 onwards require that we evaluate the RHS first.
8422 APValue RHS;
8423 if (!Evaluate(RHS, this->Info, CAO->getRHS())) {
8424 if (!Info.noteFailure())
8425 return false;
8426 Success = false;
8427 }
8428
8429 // The overall lvalue result is the result of evaluating the LHS.
8430 if (!this->Visit(CAO->getLHS()) || !Success)
8431 return false;
8432
8433 return handleCompoundAssignment(
8434 this->Info, CAO,
8435 Result, CAO->getLHS()->getType(), CAO->getComputationLHSType(),
8436 CAO->getOpForCompoundAssignment(CAO->getOpcode()), RHS);
8437}
8438
8439bool LValueExprEvaluator::VisitBinAssign(const BinaryOperator *E) {
8440 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
8441 return Error(E);
8442
8443 bool Success = true;
8444
8445 // C++17 onwards require that we evaluate the RHS first.
8446 APValue NewVal;
8447 if (!Evaluate(NewVal, this->Info, E->getRHS())) {
8448 if (!Info.noteFailure())
8449 return false;
8450 Success = false;
8451 }
8452
8453 if (!this->Visit(E->getLHS()) || !Success)
8454 return false;
8455
8456 if (Info.getLangOpts().CPlusPlus20 &&
8457 !HandleUnionActiveMemberChange(Info, E->getLHS(), Result))
8458 return false;
8459
8460 return handleAssignment(this->Info, E, Result, E->getLHS()->getType(),
8461 NewVal);
8462}
8463
8464//===----------------------------------------------------------------------===//
8465// Pointer Evaluation
8466//===----------------------------------------------------------------------===//
8467
8468/// Attempts to compute the number of bytes available at the pointer
8469/// returned by a function with the alloc_size attribute. Returns true if we
8470/// were successful. Places an unsigned number into `Result`.
8471///
8472/// This expects the given CallExpr to be a call to a function with an
8473/// alloc_size attribute.
8474static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
8475 const CallExpr *Call,
8476 llvm::APInt &Result) {
8477 const AllocSizeAttr *AllocSize = getAllocSizeAttr(Call);
8478
8479 assert(AllocSize && AllocSize->getElemSizeParam().isValid())(static_cast <bool> (AllocSize && AllocSize->
getElemSizeParam().isValid()) ? void (0) : __assert_fail ("AllocSize && AllocSize->getElemSizeParam().isValid()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8479, __extension__ __PRETTY_FUNCTION__))
;
8480 unsigned SizeArgNo = AllocSize->getElemSizeParam().getASTIndex();
8481 unsigned BitsInSizeT = Ctx.getTypeSize(Ctx.getSizeType());
8482 if (Call->getNumArgs() <= SizeArgNo)
8483 return false;
8484
8485 auto EvaluateAsSizeT = [&](const Expr *E, APSInt &Into) {
8486 Expr::EvalResult ExprResult;
8487 if (!E->EvaluateAsInt(ExprResult, Ctx, Expr::SE_AllowSideEffects))
8488 return false;
8489 Into = ExprResult.Val.getInt();
8490 if (Into.isNegative() || !Into.isIntN(BitsInSizeT))
8491 return false;
8492 Into = Into.zextOrSelf(BitsInSizeT);
8493 return true;
8494 };
8495
8496 APSInt SizeOfElem;
8497 if (!EvaluateAsSizeT(Call->getArg(SizeArgNo), SizeOfElem))
8498 return false;
8499
8500 if (!AllocSize->getNumElemsParam().isValid()) {
8501 Result = std::move(SizeOfElem);
8502 return true;
8503 }
8504
8505 APSInt NumberOfElems;
8506 unsigned NumArgNo = AllocSize->getNumElemsParam().getASTIndex();
8507 if (!EvaluateAsSizeT(Call->getArg(NumArgNo), NumberOfElems))
8508 return false;
8509
8510 bool Overflow;
8511 llvm::APInt BytesAvailable = SizeOfElem.umul_ov(NumberOfElems, Overflow);
8512 if (Overflow)
8513 return false;
8514
8515 Result = std::move(BytesAvailable);
8516 return true;
8517}
8518
8519/// Convenience function. LVal's base must be a call to an alloc_size
8520/// function.
8521static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
8522 const LValue &LVal,
8523 llvm::APInt &Result) {
8524 assert(isBaseAnAllocSizeCall(LVal.getLValueBase()) &&(static_cast <bool> (isBaseAnAllocSizeCall(LVal.getLValueBase
()) && "Can't get the size of a non alloc_size function"
) ? void (0) : __assert_fail ("isBaseAnAllocSizeCall(LVal.getLValueBase()) && \"Can't get the size of a non alloc_size function\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8525, __extension__ __PRETTY_FUNCTION__))
8525 "Can't get the size of a non alloc_size function")(static_cast <bool> (isBaseAnAllocSizeCall(LVal.getLValueBase
()) && "Can't get the size of a non alloc_size function"
) ? void (0) : __assert_fail ("isBaseAnAllocSizeCall(LVal.getLValueBase()) && \"Can't get the size of a non alloc_size function\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8525, __extension__ __PRETTY_FUNCTION__))
;
8526 const auto *Base = LVal.getLValueBase().get<const Expr *>();
8527 const CallExpr *CE = tryUnwrapAllocSizeCall(Base);
8528 return getBytesReturnedByAllocSizeCall(Ctx, CE, Result);
8529}
8530
8531/// Attempts to evaluate the given LValueBase as the result of a call to
8532/// a function with the alloc_size attribute. If it was possible to do so, this
8533/// function will return true, make Result's Base point to said function call,
8534/// and mark Result's Base as invalid.
8535static bool evaluateLValueAsAllocSize(EvalInfo &Info, APValue::LValueBase Base,
8536 LValue &Result) {
8537 if (Base.isNull())
8538 return false;
8539
8540 // Because we do no form of static analysis, we only support const variables.
8541 //
8542 // Additionally, we can't support parameters, nor can we support static
8543 // variables (in the latter case, use-before-assign isn't UB; in the former,
8544 // we have no clue what they'll be assigned to).
8545 const auto *VD =
8546 dyn_cast_or_null<VarDecl>(Base.dyn_cast<const ValueDecl *>());
8547 if (!VD || !VD->isLocalVarDecl() || !VD->getType().isConstQualified())
8548 return false;
8549
8550 const Expr *Init = VD->getAnyInitializer();
8551 if (!Init)
8552 return false;
8553
8554 const Expr *E = Init->IgnoreParens();
8555 if (!tryUnwrapAllocSizeCall(E))
8556 return false;
8557
8558 // Store E instead of E unwrapped so that the type of the LValue's base is
8559 // what the user wanted.
8560 Result.setInvalid(E);
8561
8562 QualType Pointee = E->getType()->castAs<PointerType>()->getPointeeType();
8563 Result.addUnsizedArray(Info, E, Pointee);
8564 return true;
8565}
8566
8567namespace {
8568class PointerExprEvaluator
8569 : public ExprEvaluatorBase<PointerExprEvaluator> {
8570 LValue &Result;
8571 bool InvalidBaseOK;
8572
8573 bool Success(const Expr *E) {
8574 Result.set(E);
8575 return true;
8576 }
8577
8578 bool evaluateLValue(const Expr *E, LValue &Result) {
8579 return EvaluateLValue(E, Result, Info, InvalidBaseOK);
8580 }
8581
8582 bool evaluatePointer(const Expr *E, LValue &Result) {
8583 return EvaluatePointer(E, Result, Info, InvalidBaseOK);
8584 }
8585
8586 bool visitNonBuiltinCallExpr(const CallExpr *E);
8587public:
8588
8589 PointerExprEvaluator(EvalInfo &info, LValue &Result, bool InvalidBaseOK)
8590 : ExprEvaluatorBaseTy(info), Result(Result),
8591 InvalidBaseOK(InvalidBaseOK) {}
8592
8593 bool Success(const APValue &V, const Expr *E) {
8594 Result.setFrom(Info.Ctx, V);
8595 return true;
8596 }
8597 bool ZeroInitialization(const Expr *E) {
8598 Result.setNull(Info.Ctx, E->getType());
8599 return true;
8600 }
8601
8602 bool VisitBinaryOperator(const BinaryOperator *E);
8603 bool VisitCastExpr(const CastExpr* E);
8604 bool VisitUnaryAddrOf(const UnaryOperator *E);
8605 bool VisitObjCStringLiteral(const ObjCStringLiteral *E)
8606 { return Success(E); }
8607 bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
8608 if (E->isExpressibleAsConstantInitializer())
8609 return Success(E);
8610 if (Info.noteFailure())
8611 EvaluateIgnoredValue(Info, E->getSubExpr());
8612 return Error(E);
8613 }
8614 bool VisitAddrLabelExpr(const AddrLabelExpr *E)
8615 { return Success(E); }
8616 bool VisitCallExpr(const CallExpr *E);
8617 bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
8618 bool VisitBlockExpr(const BlockExpr *E) {
8619 if (!E->getBlockDecl()->hasCaptures())
8620 return Success(E);
8621 return Error(E);
8622 }
8623 bool VisitCXXThisExpr(const CXXThisExpr *E) {
8624 // Can't look at 'this' when checking a potential constant expression.
8625 if (Info.checkingPotentialConstantExpression())
8626 return false;
8627 if (!Info.CurrentCall->This) {
8628 if (Info.getLangOpts().CPlusPlus11)
8629 Info.FFDiag(E, diag::note_constexpr_this) << E->isImplicit();
8630 else
8631 Info.FFDiag(E);
8632 return false;
8633 }
8634 Result = *Info.CurrentCall->This;
8635 // If we are inside a lambda's call operator, the 'this' expression refers
8636 // to the enclosing '*this' object (either by value or reference) which is
8637 // either copied into the closure object's field that represents the '*this'
8638 // or refers to '*this'.
8639 if (isLambdaCallOperator(Info.CurrentCall->Callee)) {
8640 // Ensure we actually have captured 'this'. (an error will have
8641 // been previously reported if not).
8642 if (!Info.CurrentCall->LambdaThisCaptureField)
8643 return false;
8644
8645 // Update 'Result' to refer to the data member/field of the closure object
8646 // that represents the '*this' capture.
8647 if (!HandleLValueMember(Info, E, Result,
8648 Info.CurrentCall->LambdaThisCaptureField))
8649 return false;
8650 // If we captured '*this' by reference, replace the field with its referent.
8651 if (Info.CurrentCall->LambdaThisCaptureField->getType()
8652 ->isPointerType()) {
8653 APValue RVal;
8654 if (!handleLValueToRValueConversion(Info, E, E->getType(), Result,
8655 RVal))
8656 return false;
8657
8658 Result.setFrom(Info.Ctx, RVal);
8659 }
8660 }
8661 return true;
8662 }
8663
8664 bool VisitCXXNewExpr(const CXXNewExpr *E);
8665
8666 bool VisitSourceLocExpr(const SourceLocExpr *E) {
8667 assert(E->isStringType() && "SourceLocExpr isn't a pointer type?")(static_cast <bool> (E->isStringType() && "SourceLocExpr isn't a pointer type?"
) ? void (0) : __assert_fail ("E->isStringType() && \"SourceLocExpr isn't a pointer type?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8667, __extension__ __PRETTY_FUNCTION__))
;
8668 APValue LValResult = E->EvaluateInContext(
8669 Info.Ctx, Info.CurrentCall->CurSourceLocExprScope.getDefaultExpr());
8670 Result.setFrom(Info.Ctx, LValResult);
8671 return true;
8672 }
8673
8674 bool VisitSYCLUniqueStableNameExpr(const SYCLUniqueStableNameExpr *E) {
8675 std::string ResultStr = E->ComputeName(Info.Ctx);
8676
8677 Info.Ctx.SYCLUniqueStableNameEvaluatedValues[E] = ResultStr;
8678
8679 QualType CharTy = Info.Ctx.CharTy.withConst();
8680 APInt Size(Info.Ctx.getTypeSize(Info.Ctx.getSizeType()),
8681 ResultStr.size() + 1);
8682 QualType ArrayTy = Info.Ctx.getConstantArrayType(CharTy, Size, nullptr,
8683 ArrayType::Normal, 0);
8684
8685 StringLiteral *SL =
8686 StringLiteral::Create(Info.Ctx, ResultStr, StringLiteral::Ascii,
8687 /*Pascal*/ false, ArrayTy, E->getLocation());
8688
8689 evaluateLValue(SL, Result);
8690 Result.addArray(Info, E, cast<ConstantArrayType>(ArrayTy));
8691 return true;
8692 }
8693
8694 // FIXME: Missing: @protocol, @selector
8695};
8696} // end anonymous namespace
8697
8698static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info,
8699 bool InvalidBaseOK) {
8700 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8700, __extension__ __PRETTY_FUNCTION__))
;
8701 assert(E->isPRValue() && E->getType()->hasPointerRepresentation())(static_cast <bool> (E->isPRValue() && E->
getType()->hasPointerRepresentation()) ? void (0) : __assert_fail
("E->isPRValue() && E->getType()->hasPointerRepresentation()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8701, __extension__ __PRETTY_FUNCTION__))
;
8702 return PointerExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
8703}
8704
8705bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
8706 if (E->getOpcode() != BO_Add &&
8707 E->getOpcode() != BO_Sub)
8708 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
8709
8710 const Expr *PExp = E->getLHS();
8711 const Expr *IExp = E->getRHS();
8712 if (IExp->getType()->isPointerType())
8713 std::swap(PExp, IExp);
8714
8715 bool EvalPtrOK = evaluatePointer(PExp, Result);
8716 if (!EvalPtrOK && !Info.noteFailure())
8717 return false;
8718
8719 llvm::APSInt Offset;
8720 if (!EvaluateInteger(IExp, Offset, Info) || !EvalPtrOK)
8721 return false;
8722
8723 if (E->getOpcode() == BO_Sub)
8724 negateAsSigned(Offset);
8725
8726 QualType Pointee = PExp->getType()->castAs<PointerType>()->getPointeeType();
8727 return HandleLValueArrayAdjustment(Info, E, Result, Pointee, Offset);
8728}
8729
8730bool PointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
8731 return evaluateLValue(E->getSubExpr(), Result);
8732}
8733
8734bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
8735 const Expr *SubExpr = E->getSubExpr();
8736
8737 switch (E->getCastKind()) {
8738 default:
8739 break;
8740 case CK_BitCast:
8741 case CK_CPointerToObjCPointerCast:
8742 case CK_BlockPointerToObjCPointerCast:
8743 case CK_AnyPointerToBlockPointerCast:
8744 case CK_AddressSpaceConversion:
8745 if (!Visit(SubExpr))
8746 return false;
8747 // Bitcasts to cv void* are static_casts, not reinterpret_casts, so are
8748 // permitted in constant expressions in C++11. Bitcasts from cv void* are
8749 // also static_casts, but we disallow them as a resolution to DR1312.
8750 if (!E->getType()->isVoidPointerType()) {
8751 if (!Result.InvalidBase && !Result.Designator.Invalid &&
8752 !Result.IsNullPtr &&
8753 Info.Ctx.hasSameUnqualifiedType(Result.Designator.getType(Info.Ctx),
8754 E->getType()->getPointeeType()) &&
8755 Info.getStdAllocatorCaller("allocate")) {
8756 // Inside a call to std::allocator::allocate and friends, we permit
8757 // casting from void* back to cv1 T* for a pointer that points to a
8758 // cv2 T.
8759 } else {
8760 Result.Designator.setInvalid();
8761 if (SubExpr->getType()->isVoidPointerType())
8762 CCEDiag(E, diag::note_constexpr_invalid_cast)
8763 << 3 << SubExpr->getType();
8764 else
8765 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
8766 }
8767 }
8768 if (E->getCastKind() == CK_AddressSpaceConversion && Result.IsNullPtr)
8769 ZeroInitialization(E);
8770 return true;
8771
8772 case CK_DerivedToBase:
8773 case CK_UncheckedDerivedToBase:
8774 if (!evaluatePointer(E->getSubExpr(), Result))
8775 return false;
8776 if (!Result.Base && Result.Offset.isZero())
8777 return true;
8778
8779 // Now figure out the necessary offset to add to the base LV to get from
8780 // the derived class to the base class.
8781 return HandleLValueBasePath(Info, E, E->getSubExpr()->getType()->
8782 castAs<PointerType>()->getPointeeType(),
8783 Result);
8784
8785 case CK_BaseToDerived:
8786 if (!Visit(E->getSubExpr()))
8787 return false;
8788 if (!Result.Base && Result.Offset.isZero())
8789 return true;
8790 return HandleBaseToDerivedCast(Info, E, Result);
8791
8792 case CK_Dynamic:
8793 if (!Visit(E->getSubExpr()))
8794 return false;
8795 return HandleDynamicCast(Info, cast<ExplicitCastExpr>(E), Result);
8796
8797 case CK_NullToPointer:
8798 VisitIgnoredValue(E->getSubExpr());
8799 return ZeroInitialization(E);
8800
8801 case CK_IntegralToPointer: {
8802 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
8803
8804 APValue Value;
8805 if (!EvaluateIntegerOrLValue(SubExpr, Value, Info))
8806 break;
8807
8808 if (Value.isInt()) {
8809 unsigned Size = Info.Ctx.getTypeSize(E->getType());
8810 uint64_t N = Value.getInt().extOrTrunc(Size).getZExtValue();
8811 Result.Base = (Expr*)nullptr;
8812 Result.InvalidBase = false;
8813 Result.Offset = CharUnits::fromQuantity(N);
8814 Result.Designator.setInvalid();
8815 Result.IsNullPtr = false;
8816 return true;
8817 } else {
8818 // Cast is of an lvalue, no need to change value.
8819 Result.setFrom(Info.Ctx, Value);
8820 return true;
8821 }
8822 }
8823
8824 case CK_ArrayToPointerDecay: {
8825 if (SubExpr->isGLValue()) {
8826 if (!evaluateLValue(SubExpr, Result))
8827 return false;
8828 } else {
8829 APValue &Value = Info.CurrentCall->createTemporary(
8830 SubExpr, SubExpr->getType(), ScopeKind::FullExpression, Result);
8831 if (!EvaluateInPlace(Value, Info, Result, SubExpr))
8832 return false;
8833 }
8834 // The result is a pointer to the first element of the array.
8835 auto *AT = Info.Ctx.getAsArrayType(SubExpr->getType());
8836 if (auto *CAT = dyn_cast<ConstantArrayType>(AT))
8837 Result.addArray(Info, E, CAT);
8838 else
8839 Result.addUnsizedArray(Info, E, AT->getElementType());
8840 return true;
8841 }
8842
8843 case CK_FunctionToPointerDecay:
8844 return evaluateLValue(SubExpr, Result);
8845
8846 case CK_LValueToRValue: {
8847 LValue LVal;
8848 if (!evaluateLValue(E->getSubExpr(), LVal))
8849 return false;
8850
8851 APValue RVal;
8852 // Note, we use the subexpression's type in order to retain cv-qualifiers.
8853 if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
8854 LVal, RVal))
8855 return InvalidBaseOK &&
8856 evaluateLValueAsAllocSize(Info, LVal.Base, Result);
8857 return Success(RVal, E);
8858 }
8859 }
8860
8861 return ExprEvaluatorBaseTy::VisitCastExpr(E);
8862}
8863
8864static CharUnits GetAlignOfType(EvalInfo &Info, QualType T,
8865 UnaryExprOrTypeTrait ExprKind) {
8866 // C++ [expr.alignof]p3:
8867 // When alignof is applied to a reference type, the result is the
8868 // alignment of the referenced type.
8869 if (const ReferenceType *Ref = T->getAs<ReferenceType>())
8870 T = Ref->getPointeeType();
8871
8872 if (T.getQualifiers().hasUnaligned())
8873 return CharUnits::One();
8874
8875 const bool AlignOfReturnsPreferred =
8876 Info.Ctx.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver7;
8877
8878 // __alignof is defined to return the preferred alignment.
8879 // Before 8, clang returned the preferred alignment for alignof and _Alignof
8880 // as well.
8881 if (ExprKind == UETT_PreferredAlignOf || AlignOfReturnsPreferred)
8882 return Info.Ctx.toCharUnitsFromBits(
8883 Info.Ctx.getPreferredTypeAlign(T.getTypePtr()));
8884 // alignof and _Alignof are defined to return the ABI alignment.
8885 else if (ExprKind == UETT_AlignOf)
8886 return Info.Ctx.getTypeAlignInChars(T.getTypePtr());
8887 else
8888 llvm_unreachable("GetAlignOfType on a non-alignment ExprKind")::llvm::llvm_unreachable_internal("GetAlignOfType on a non-alignment ExprKind"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8888)
;
8889}
8890
8891static CharUnits GetAlignOfExpr(EvalInfo &Info, const Expr *E,
8892 UnaryExprOrTypeTrait ExprKind) {
8893 E = E->IgnoreParens();
8894
8895 // The kinds of expressions that we have special-case logic here for
8896 // should be kept up to date with the special checks for those
8897 // expressions in Sema.
8898
8899 // alignof decl is always accepted, even if it doesn't make sense: we default
8900 // to 1 in those cases.
8901 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
8902 return Info.Ctx.getDeclAlign(DRE->getDecl(),
8903 /*RefAsPointee*/true);
8904
8905 if (const MemberExpr *ME = dyn_cast<MemberExpr>(E))
8906 return Info.Ctx.getDeclAlign(ME->getMemberDecl(),
8907 /*RefAsPointee*/true);
8908
8909 return GetAlignOfType(Info, E->getType(), ExprKind);
8910}
8911
8912static CharUnits getBaseAlignment(EvalInfo &Info, const LValue &Value) {
8913 if (const auto *VD = Value.Base.dyn_cast<const ValueDecl *>())
8914 return Info.Ctx.getDeclAlign(VD);
8915 if (const auto *E = Value.Base.dyn_cast<const Expr *>())
8916 return GetAlignOfExpr(Info, E, UETT_AlignOf);
8917 return GetAlignOfType(Info, Value.Base.getTypeInfoType(), UETT_AlignOf);
8918}
8919
8920/// Evaluate the value of the alignment argument to __builtin_align_{up,down},
8921/// __builtin_is_aligned and __builtin_assume_aligned.
8922static bool getAlignmentArgument(const Expr *E, QualType ForType,
8923 EvalInfo &Info, APSInt &Alignment) {
8924 if (!EvaluateInteger(E, Alignment, Info))
8925 return false;
8926 if (Alignment < 0 || !Alignment.isPowerOf2()) {
8927 Info.FFDiag(E, diag::note_constexpr_invalid_alignment) << Alignment;
8928 return false;
8929 }
8930 unsigned SrcWidth = Info.Ctx.getIntWidth(ForType);
8931 APSInt MaxValue(APInt::getOneBitSet(SrcWidth, SrcWidth - 1));
8932 if (APSInt::compareValues(Alignment, MaxValue) > 0) {
8933 Info.FFDiag(E, diag::note_constexpr_alignment_too_big)
8934 << MaxValue << ForType << Alignment;
8935 return false;
8936 }
8937 // Ensure both alignment and source value have the same bit width so that we
8938 // don't assert when computing the resulting value.
8939 APSInt ExtAlignment =
8940 APSInt(Alignment.zextOrTrunc(SrcWidth), /*isUnsigned=*/true);
8941 assert(APSInt::compareValues(Alignment, ExtAlignment) == 0 &&(static_cast <bool> (APSInt::compareValues(Alignment, ExtAlignment
) == 0 && "Alignment should not be changed by ext/trunc"
) ? void (0) : __assert_fail ("APSInt::compareValues(Alignment, ExtAlignment) == 0 && \"Alignment should not be changed by ext/trunc\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8942, __extension__ __PRETTY_FUNCTION__))
8942 "Alignment should not be changed by ext/trunc")(static_cast <bool> (APSInt::compareValues(Alignment, ExtAlignment
) == 0 && "Alignment should not be changed by ext/trunc"
) ? void (0) : __assert_fail ("APSInt::compareValues(Alignment, ExtAlignment) == 0 && \"Alignment should not be changed by ext/trunc\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8942, __extension__ __PRETTY_FUNCTION__))
;
8943 Alignment = ExtAlignment;
8944 assert(Alignment.getBitWidth() == SrcWidth)(static_cast <bool> (Alignment.getBitWidth() == SrcWidth
) ? void (0) : __assert_fail ("Alignment.getBitWidth() == SrcWidth"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 8944, __extension__ __PRETTY_FUNCTION__))
;
8945 return true;
8946}
8947
8948// To be clear: this happily visits unsupported builtins. Better name welcomed.
8949bool PointerExprEvaluator::visitNonBuiltinCallExpr(const CallExpr *E) {
8950 if (ExprEvaluatorBaseTy::VisitCallExpr(E))
8951 return true;
8952
8953 if (!(InvalidBaseOK && getAllocSizeAttr(E)))
8954 return false;
8955
8956 Result.setInvalid(E);
8957 QualType PointeeTy = E->getType()->castAs<PointerType>()->getPointeeType();
8958 Result.addUnsizedArray(Info, E, PointeeTy);
8959 return true;
8960}
8961
8962bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) {
8963 if (IsStringLiteralCall(E))
8964 return Success(E);
8965
8966 if (unsigned BuiltinOp = E->getBuiltinCallee())
8967 return VisitBuiltinCallExpr(E, BuiltinOp);
8968
8969 return visitNonBuiltinCallExpr(E);
8970}
8971
8972// Determine if T is a character type for which we guarantee that
8973// sizeof(T) == 1.
8974static bool isOneByteCharacterType(QualType T) {
8975 return T->isCharType() || T->isChar8Type();
8976}
8977
8978bool PointerExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
8979 unsigned BuiltinOp) {
8980 switch (BuiltinOp) {
8981 case Builtin::BI__builtin_addressof:
8982 return evaluateLValue(E->getArg(0), Result);
8983 case Builtin::BI__builtin_assume_aligned: {
8984 // We need to be very careful here because: if the pointer does not have the
8985 // asserted alignment, then the behavior is undefined, and undefined
8986 // behavior is non-constant.
8987 if (!evaluatePointer(E->getArg(0), Result))
8988 return false;
8989
8990 LValue OffsetResult(Result);
8991 APSInt Alignment;
8992 if (!getAlignmentArgument(E->getArg(1), E->getArg(0)->getType(), Info,
8993 Alignment))
8994 return false;
8995 CharUnits Align = CharUnits::fromQuantity(Alignment.getZExtValue());
8996
8997 if (E->getNumArgs() > 2) {
8998 APSInt Offset;
8999 if (!EvaluateInteger(E->getArg(2), Offset, Info))
9000 return false;
9001
9002 int64_t AdditionalOffset = -Offset.getZExtValue();
9003 OffsetResult.Offset += CharUnits::fromQuantity(AdditionalOffset);
9004 }
9005
9006 // If there is a base object, then it must have the correct alignment.
9007 if (OffsetResult.Base) {
9008 CharUnits BaseAlignment = getBaseAlignment(Info, OffsetResult);
9009
9010 if (BaseAlignment < Align) {
9011 Result.Designator.setInvalid();
9012 // FIXME: Add support to Diagnostic for long / long long.
9013 CCEDiag(E->getArg(0),
9014 diag::note_constexpr_baa_insufficient_alignment) << 0
9015 << (unsigned)BaseAlignment.getQuantity()
9016 << (unsigned)Align.getQuantity();
9017 return false;
9018 }
9019 }
9020
9021 // The offset must also have the correct alignment.
9022 if (OffsetResult.Offset.alignTo(Align) != OffsetResult.Offset) {
9023 Result.Designator.setInvalid();
9024
9025 (OffsetResult.Base
9026 ? CCEDiag(E->getArg(0),
9027 diag::note_constexpr_baa_insufficient_alignment) << 1
9028 : CCEDiag(E->getArg(0),
9029 diag::note_constexpr_baa_value_insufficient_alignment))
9030 << (int)OffsetResult.Offset.getQuantity()
9031 << (unsigned)Align.getQuantity();
9032 return false;
9033 }
9034
9035 return true;
9036 }
9037 case Builtin::BI__builtin_align_up:
9038 case Builtin::BI__builtin_align_down: {
9039 if (!evaluatePointer(E->getArg(0), Result))
9040 return false;
9041 APSInt Alignment;
9042 if (!getAlignmentArgument(E->getArg(1), E->getArg(0)->getType(), Info,
9043 Alignment))
9044 return false;
9045 CharUnits BaseAlignment = getBaseAlignment(Info, Result);
9046 CharUnits PtrAlign = BaseAlignment.alignmentAtOffset(Result.Offset);
9047 // For align_up/align_down, we can return the same value if the alignment
9048 // is known to be greater or equal to the requested value.
9049 if (PtrAlign.getQuantity() >= Alignment)
9050 return true;
9051
9052 // The alignment could be greater than the minimum at run-time, so we cannot
9053 // infer much about the resulting pointer value. One case is possible:
9054 // For `_Alignas(32) char buf[N]; __builtin_align_down(&buf[idx], 32)` we
9055 // can infer the correct index if the requested alignment is smaller than
9056 // the base alignment so we can perform the computation on the offset.
9057 if (BaseAlignment.getQuantity() >= Alignment) {
9058 assert(Alignment.getBitWidth() <= 64 &&(static_cast <bool> (Alignment.getBitWidth() <= 64 &&
"Cannot handle > 64-bit address-space") ? void (0) : __assert_fail
("Alignment.getBitWidth() <= 64 && \"Cannot handle > 64-bit address-space\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9059, __extension__ __PRETTY_FUNCTION__))
9059 "Cannot handle > 64-bit address-space")(static_cast <bool> (Alignment.getBitWidth() <= 64 &&
"Cannot handle > 64-bit address-space") ? void (0) : __assert_fail
("Alignment.getBitWidth() <= 64 && \"Cannot handle > 64-bit address-space\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9059, __extension__ __PRETTY_FUNCTION__))
;
9060 uint64_t Alignment64 = Alignment.getZExtValue();
9061 CharUnits NewOffset = CharUnits::fromQuantity(
9062 BuiltinOp == Builtin::BI__builtin_align_down
9063 ? llvm::alignDown(Result.Offset.getQuantity(), Alignment64)
9064 : llvm::alignTo(Result.Offset.getQuantity(), Alignment64));
9065 Result.adjustOffset(NewOffset - Result.Offset);
9066 // TODO: diagnose out-of-bounds values/only allow for arrays?
9067 return true;
9068 }
9069 // Otherwise, we cannot constant-evaluate the result.
9070 Info.FFDiag(E->getArg(0), diag::note_constexpr_alignment_adjust)
9071 << Alignment;
9072 return false;
9073 }
9074 case Builtin::BI__builtin_operator_new:
9075 return HandleOperatorNewCall(Info, E, Result);
9076 case Builtin::BI__builtin_launder:
9077 return evaluatePointer(E->getArg(0), Result);
9078 case Builtin::BIstrchr:
9079 case Builtin::BIwcschr:
9080 case Builtin::BImemchr:
9081 case Builtin::BIwmemchr:
9082 if (Info.getLangOpts().CPlusPlus11)
9083 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
9084 << /*isConstexpr*/0 << /*isConstructor*/0
9085 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
9086 else
9087 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
9088 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9089 case Builtin::BI__builtin_strchr:
9090 case Builtin::BI__builtin_wcschr:
9091 case Builtin::BI__builtin_memchr:
9092 case Builtin::BI__builtin_char_memchr:
9093 case Builtin::BI__builtin_wmemchr: {
9094 if (!Visit(E->getArg(0)))
9095 return false;
9096 APSInt Desired;
9097 if (!EvaluateInteger(E->getArg(1), Desired, Info))
9098 return false;
9099 uint64_t MaxLength = uint64_t(-1);
9100 if (BuiltinOp != Builtin::BIstrchr &&
9101 BuiltinOp != Builtin::BIwcschr &&
9102 BuiltinOp != Builtin::BI__builtin_strchr &&
9103 BuiltinOp != Builtin::BI__builtin_wcschr) {
9104 APSInt N;
9105 if (!EvaluateInteger(E->getArg(2), N, Info))
9106 return false;
9107 MaxLength = N.getExtValue();
9108 }
9109 // We cannot find the value if there are no candidates to match against.
9110 if (MaxLength == 0u)
9111 return ZeroInitialization(E);
9112 if (!Result.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
9113 Result.Designator.Invalid)
9114 return false;
9115 QualType CharTy = Result.Designator.getType(Info.Ctx);
9116 bool IsRawByte = BuiltinOp == Builtin::BImemchr ||
9117 BuiltinOp == Builtin::BI__builtin_memchr;
9118 assert(IsRawByte ||(static_cast <bool> (IsRawByte || Info.Ctx.hasSameUnqualifiedType
( CharTy, E->getArg(0)->getType()->getPointeeType())
) ? void (0) : __assert_fail ("IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->getArg(0)->getType()->getPointeeType())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9120, __extension__ __PRETTY_FUNCTION__))
9119 Info.Ctx.hasSameUnqualifiedType((static_cast <bool> (IsRawByte || Info.Ctx.hasSameUnqualifiedType
( CharTy, E->getArg(0)->getType()->getPointeeType())
) ? void (0) : __assert_fail ("IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->getArg(0)->getType()->getPointeeType())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9120, __extension__ __PRETTY_FUNCTION__))
9120 CharTy, E->getArg(0)->getType()->getPointeeType()))(static_cast <bool> (IsRawByte || Info.Ctx.hasSameUnqualifiedType
( CharTy, E->getArg(0)->getType()->getPointeeType())
) ? void (0) : __assert_fail ("IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->getArg(0)->getType()->getPointeeType())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9120, __extension__ __PRETTY_FUNCTION__))
;
9121 // Pointers to const void may point to objects of incomplete type.
9122 if (IsRawByte && CharTy->isIncompleteType()) {
9123 Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy;
9124 return false;
9125 }
9126 // Give up on byte-oriented matching against multibyte elements.
9127 // FIXME: We can compare the bytes in the correct order.
9128 if (IsRawByte && !isOneByteCharacterType(CharTy)) {
9129 Info.FFDiag(E, diag::note_constexpr_memchr_unsupported)
9130 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'")
9131 << CharTy;
9132 return false;
9133 }
9134 // Figure out what value we're actually looking for (after converting to
9135 // the corresponding unsigned type if necessary).
9136 uint64_t DesiredVal;
9137 bool StopAtNull = false;
9138 switch (BuiltinOp) {
9139 case Builtin::BIstrchr:
9140 case Builtin::BI__builtin_strchr:
9141 // strchr compares directly to the passed integer, and therefore
9142 // always fails if given an int that is not a char.
9143 if (!APSInt::isSameValue(HandleIntToIntCast(Info, E, CharTy,
9144 E->getArg(1)->getType(),
9145 Desired),
9146 Desired))
9147 return ZeroInitialization(E);
9148 StopAtNull = true;
9149 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9150 case Builtin::BImemchr:
9151 case Builtin::BI__builtin_memchr:
9152 case Builtin::BI__builtin_char_memchr:
9153 // memchr compares by converting both sides to unsigned char. That's also
9154 // correct for strchr if we get this far (to cope with plain char being
9155 // unsigned in the strchr case).
9156 DesiredVal = Desired.trunc(Info.Ctx.getCharWidth()).getZExtValue();
9157 break;
9158
9159 case Builtin::BIwcschr:
9160 case Builtin::BI__builtin_wcschr:
9161 StopAtNull = true;
9162 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9163 case Builtin::BIwmemchr:
9164 case Builtin::BI__builtin_wmemchr:
9165 // wcschr and wmemchr are given a wchar_t to look for. Just use it.
9166 DesiredVal = Desired.getZExtValue();
9167 break;
9168 }
9169
9170 for (; MaxLength; --MaxLength) {
9171 APValue Char;
9172 if (!handleLValueToRValueConversion(Info, E, CharTy, Result, Char) ||
9173 !Char.isInt())
9174 return false;
9175 if (Char.getInt().getZExtValue() == DesiredVal)
9176 return true;
9177 if (StopAtNull && !Char.getInt())
9178 break;
9179 if (!HandleLValueArrayAdjustment(Info, E, Result, CharTy, 1))
9180 return false;
9181 }
9182 // Not found: return nullptr.
9183 return ZeroInitialization(E);
9184 }
9185
9186 case Builtin::BImemcpy:
9187 case Builtin::BImemmove:
9188 case Builtin::BIwmemcpy:
9189 case Builtin::BIwmemmove:
9190 if (Info.getLangOpts().CPlusPlus11)
9191 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
9192 << /*isConstexpr*/0 << /*isConstructor*/0
9193 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
9194 else
9195 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
9196 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9197 case Builtin::BI__builtin_memcpy:
9198 case Builtin::BI__builtin_memmove:
9199 case Builtin::BI__builtin_wmemcpy:
9200 case Builtin::BI__builtin_wmemmove: {
9201 bool WChar = BuiltinOp == Builtin::BIwmemcpy ||
9202 BuiltinOp == Builtin::BIwmemmove ||
9203 BuiltinOp == Builtin::BI__builtin_wmemcpy ||
9204 BuiltinOp == Builtin::BI__builtin_wmemmove;
9205 bool Move = BuiltinOp == Builtin::BImemmove ||
9206 BuiltinOp == Builtin::BIwmemmove ||
9207 BuiltinOp == Builtin::BI__builtin_memmove ||
9208 BuiltinOp == Builtin::BI__builtin_wmemmove;
9209
9210 // The result of mem* is the first argument.
9211 if (!Visit(E->getArg(0)))
9212 return false;
9213 LValue Dest = Result;
9214
9215 LValue Src;
9216 if (!EvaluatePointer(E->getArg(1), Src, Info))
9217 return false;
9218
9219 APSInt N;
9220 if (!EvaluateInteger(E->getArg(2), N, Info))
9221 return false;
9222 assert(!N.isSigned() && "memcpy and friends take an unsigned size")(static_cast <bool> (!N.isSigned() && "memcpy and friends take an unsigned size"
) ? void (0) : __assert_fail ("!N.isSigned() && \"memcpy and friends take an unsigned size\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9222, __extension__ __PRETTY_FUNCTION__))
;
9223
9224 // If the size is zero, we treat this as always being a valid no-op.
9225 // (Even if one of the src and dest pointers is null.)
9226 if (!N)
9227 return true;
9228
9229 // Otherwise, if either of the operands is null, we can't proceed. Don't
9230 // try to determine the type of the copied objects, because there aren't
9231 // any.
9232 if (!Src.Base || !Dest.Base) {
9233 APValue Val;
9234 (!Src.Base ? Src : Dest).moveInto(Val);
9235 Info.FFDiag(E, diag::note_constexpr_memcpy_null)
9236 << Move << WChar << !!Src.Base
9237 << Val.getAsString(Info.Ctx, E->getArg(0)->getType());
9238 return false;
9239 }
9240 if (Src.Designator.Invalid || Dest.Designator.Invalid)
9241 return false;
9242
9243 // We require that Src and Dest are both pointers to arrays of
9244 // trivially-copyable type. (For the wide version, the designator will be
9245 // invalid if the designated object is not a wchar_t.)
9246 QualType T = Dest.Designator.getType(Info.Ctx);
9247 QualType SrcT = Src.Designator.getType(Info.Ctx);
9248 if (!Info.Ctx.hasSameUnqualifiedType(T, SrcT)) {
9249 // FIXME: Consider using our bit_cast implementation to support this.
9250 Info.FFDiag(E, diag::note_constexpr_memcpy_type_pun) << Move << SrcT << T;
9251 return false;
9252 }
9253 if (T->isIncompleteType()) {
9254 Info.FFDiag(E, diag::note_constexpr_memcpy_incomplete_type) << Move << T;
9255 return false;
9256 }
9257 if (!T.isTriviallyCopyableType(Info.Ctx)) {
9258 Info.FFDiag(E, diag::note_constexpr_memcpy_nontrivial) << Move << T;
9259 return false;
9260 }
9261
9262 // Figure out how many T's we're copying.
9263 uint64_t TSize = Info.Ctx.getTypeSizeInChars(T).getQuantity();
9264 if (!WChar) {
9265 uint64_t Remainder;
9266 llvm::APInt OrigN = N;
9267 llvm::APInt::udivrem(OrigN, TSize, N, Remainder);
9268 if (Remainder) {
9269 Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
9270 << Move << WChar << 0 << T << toString(OrigN, 10, /*Signed*/false)
9271 << (unsigned)TSize;
9272 return false;
9273 }
9274 }
9275
9276 // Check that the copying will remain within the arrays, just so that we
9277 // can give a more meaningful diagnostic. This implicitly also checks that
9278 // N fits into 64 bits.
9279 uint64_t RemainingSrcSize = Src.Designator.validIndexAdjustments().second;
9280 uint64_t RemainingDestSize = Dest.Designator.validIndexAdjustments().second;
9281 if (N.ugt(RemainingSrcSize) || N.ugt(RemainingDestSize)) {
9282 Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
9283 << Move << WChar << (N.ugt(RemainingSrcSize) ? 1 : 2) << T
9284 << toString(N, 10, /*Signed*/false);
9285 return false;
9286 }
9287 uint64_t NElems = N.getZExtValue();
9288 uint64_t NBytes = NElems * TSize;
9289
9290 // Check for overlap.
9291 int Direction = 1;
9292 if (HasSameBase(Src, Dest)) {
9293 uint64_t SrcOffset = Src.getLValueOffset().getQuantity();
9294 uint64_t DestOffset = Dest.getLValueOffset().getQuantity();
9295 if (DestOffset >= SrcOffset && DestOffset - SrcOffset < NBytes) {
9296 // Dest is inside the source region.
9297 if (!Move) {
9298 Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
9299 return false;
9300 }
9301 // For memmove and friends, copy backwards.
9302 if (!HandleLValueArrayAdjustment(Info, E, Src, T, NElems - 1) ||
9303 !HandleLValueArrayAdjustment(Info, E, Dest, T, NElems - 1))
9304 return false;
9305 Direction = -1;
9306 } else if (!Move && SrcOffset >= DestOffset &&
9307 SrcOffset - DestOffset < NBytes) {
9308 // Src is inside the destination region for memcpy: invalid.
9309 Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
9310 return false;
9311 }
9312 }
9313
9314 while (true) {
9315 APValue Val;
9316 // FIXME: Set WantObjectRepresentation to true if we're copying a
9317 // char-like type?
9318 if (!handleLValueToRValueConversion(Info, E, T, Src, Val) ||
9319 !handleAssignment(Info, E, Dest, T, Val))
9320 return false;
9321 // Do not iterate past the last element; if we're copying backwards, that
9322 // might take us off the start of the array.
9323 if (--NElems == 0)
9324 return true;
9325 if (!HandleLValueArrayAdjustment(Info, E, Src, T, Direction) ||
9326 !HandleLValueArrayAdjustment(Info, E, Dest, T, Direction))
9327 return false;
9328 }
9329 }
9330
9331 default:
9332 break;
9333 }
9334
9335 return visitNonBuiltinCallExpr(E);
9336}
9337
9338static bool EvaluateArrayNewInitList(EvalInfo &Info, LValue &This,
9339 APValue &Result, const InitListExpr *ILE,
9340 QualType AllocType);
9341static bool EvaluateArrayNewConstructExpr(EvalInfo &Info, LValue &This,
9342 APValue &Result,
9343 const CXXConstructExpr *CCE,
9344 QualType AllocType);
9345
9346bool PointerExprEvaluator::VisitCXXNewExpr(const CXXNewExpr *E) {
9347 if (!Info.getLangOpts().CPlusPlus20)
9348 Info.CCEDiag(E, diag::note_constexpr_new);
9349
9350 // We cannot speculatively evaluate a delete expression.
9351 if (Info.SpeculativeEvaluationDepth)
9352 return false;
9353
9354 FunctionDecl *OperatorNew = E->getOperatorNew();
9355
9356 bool IsNothrow = false;
9357 bool IsPlacement = false;
9358 if (OperatorNew->isReservedGlobalPlacementOperator() &&
9359 Info.CurrentCall->isStdFunction() && !E->isArray()) {
9360 // FIXME Support array placement new.
9361 assert(E->getNumPlacementArgs() == 1)(static_cast <bool> (E->getNumPlacementArgs() == 1) ?
void (0) : __assert_fail ("E->getNumPlacementArgs() == 1"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9361, __extension__ __PRETTY_FUNCTION__))
;
9362 if (!EvaluatePointer(E->getPlacementArg(0), Result, Info))
9363 return false;
9364 if (Result.Designator.Invalid)
9365 return false;
9366 IsPlacement = true;
9367 } else if (!OperatorNew->isReplaceableGlobalAllocationFunction()) {
9368 Info.FFDiag(E, diag::note_constexpr_new_non_replaceable)
9369 << isa<CXXMethodDecl>(OperatorNew) << OperatorNew;
9370 return false;
9371 } else if (E->getNumPlacementArgs()) {
9372 // The only new-placement list we support is of the form (std::nothrow).
9373 //
9374 // FIXME: There is no restriction on this, but it's not clear that any
9375 // other form makes any sense. We get here for cases such as:
9376 //
9377 // new (std::align_val_t{N}) X(int)
9378 //
9379 // (which should presumably be valid only if N is a multiple of
9380 // alignof(int), and in any case can't be deallocated unless N is
9381 // alignof(X) and X has new-extended alignment).
9382 if (E->getNumPlacementArgs() != 1 ||
9383 !E->getPlacementArg(0)->getType()->isNothrowT())
9384 return Error(E, diag::note_constexpr_new_placement);
9385
9386 LValue Nothrow;
9387 if (!EvaluateLValue(E->getPlacementArg(0), Nothrow, Info))
9388 return false;
9389 IsNothrow = true;
9390 }
9391
9392 const Expr *Init = E->getInitializer();
9393 const InitListExpr *ResizedArrayILE = nullptr;
9394 const CXXConstructExpr *ResizedArrayCCE = nullptr;
9395 bool ValueInit = false;
9396
9397 QualType AllocType = E->getAllocatedType();
9398 if (Optional<const Expr*> ArraySize = E->getArraySize()) {
9399 const Expr *Stripped = *ArraySize;
9400 for (; auto *ICE = dyn_cast<ImplicitCastExpr>(Stripped);
9401 Stripped = ICE->getSubExpr())
9402 if (ICE->getCastKind() != CK_NoOp &&
9403 ICE->getCastKind() != CK_IntegralCast)
9404 break;
9405
9406 llvm::APSInt ArrayBound;
9407 if (!EvaluateInteger(Stripped, ArrayBound, Info))
9408 return false;
9409
9410 // C++ [expr.new]p9:
9411 // The expression is erroneous if:
9412 // -- [...] its value before converting to size_t [or] applying the
9413 // second standard conversion sequence is less than zero
9414 if (ArrayBound.isSigned() && ArrayBound.isNegative()) {
9415 if (IsNothrow)
9416 return ZeroInitialization(E);
9417
9418 Info.FFDiag(*ArraySize, diag::note_constexpr_new_negative)
9419 << ArrayBound << (*ArraySize)->getSourceRange();
9420 return false;
9421 }
9422
9423 // -- its value is such that the size of the allocated object would
9424 // exceed the implementation-defined limit
9425 if (ConstantArrayType::getNumAddressingBits(Info.Ctx, AllocType,
9426 ArrayBound) >
9427 ConstantArrayType::getMaxSizeBits(Info.Ctx)) {
9428 if (IsNothrow)
9429 return ZeroInitialization(E);
9430
9431 Info.FFDiag(*ArraySize, diag::note_constexpr_new_too_large)
9432 << ArrayBound << (*ArraySize)->getSourceRange();
9433 return false;
9434 }
9435
9436 // -- the new-initializer is a braced-init-list and the number of
9437 // array elements for which initializers are provided [...]
9438 // exceeds the number of elements to initialize
9439 if (!Init) {
9440 // No initialization is performed.
9441 } else if (isa<CXXScalarValueInitExpr>(Init) ||
9442 isa<ImplicitValueInitExpr>(Init)) {
9443 ValueInit = true;
9444 } else if (auto *CCE = dyn_cast<CXXConstructExpr>(Init)) {
9445 ResizedArrayCCE = CCE;
9446 } else {
9447 auto *CAT = Info.Ctx.getAsConstantArrayType(Init->getType());
9448 assert(CAT && "unexpected type for array initializer")(static_cast <bool> (CAT && "unexpected type for array initializer"
) ? void (0) : __assert_fail ("CAT && \"unexpected type for array initializer\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9448, __extension__ __PRETTY_FUNCTION__))
;
9449
9450 unsigned Bits =
9451 std::max(CAT->getSize().getBitWidth(), ArrayBound.getBitWidth());
9452 llvm::APInt InitBound = CAT->getSize().zextOrSelf(Bits);
9453 llvm::APInt AllocBound = ArrayBound.zextOrSelf(Bits);
9454 if (InitBound.ugt(AllocBound)) {
9455 if (IsNothrow)
9456 return ZeroInitialization(E);
9457
9458 Info.FFDiag(*ArraySize, diag::note_constexpr_new_too_small)
9459 << toString(AllocBound, 10, /*Signed=*/false)
9460 << toString(InitBound, 10, /*Signed=*/false)
9461 << (*ArraySize)->getSourceRange();
9462 return false;
9463 }
9464
9465 // If the sizes differ, we must have an initializer list, and we need
9466 // special handling for this case when we initialize.
9467 if (InitBound != AllocBound)
9468 ResizedArrayILE = cast<InitListExpr>(Init);
9469 }
9470
9471 AllocType = Info.Ctx.getConstantArrayType(AllocType, ArrayBound, nullptr,
9472 ArrayType::Normal, 0);
9473 } else {
9474 assert(!AllocType->isArrayType() &&(static_cast <bool> (!AllocType->isArrayType() &&
"array allocation with non-array new") ? void (0) : __assert_fail
("!AllocType->isArrayType() && \"array allocation with non-array new\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9475, __extension__ __PRETTY_FUNCTION__))
9475 "array allocation with non-array new")(static_cast <bool> (!AllocType->isArrayType() &&
"array allocation with non-array new") ? void (0) : __assert_fail
("!AllocType->isArrayType() && \"array allocation with non-array new\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9475, __extension__ __PRETTY_FUNCTION__))
;
9476 }
9477
9478 APValue *Val;
9479 if (IsPlacement) {
9480 AccessKinds AK = AK_Construct;
9481 struct FindObjectHandler {
9482 EvalInfo &Info;
9483 const Expr *E;
9484 QualType AllocType;
9485 const AccessKinds AccessKind;
9486 APValue *Value;
9487
9488 typedef bool result_type;
9489 bool failed() { return false; }
9490 bool found(APValue &Subobj, QualType SubobjType) {
9491 // FIXME: Reject the cases where [basic.life]p8 would not permit the
9492 // old name of the object to be used to name the new object.
9493 if (!Info.Ctx.hasSameUnqualifiedType(SubobjType, AllocType)) {
9494 Info.FFDiag(E, diag::note_constexpr_placement_new_wrong_type) <<
9495 SubobjType << AllocType;
9496 return false;
9497 }
9498 Value = &Subobj;
9499 return true;
9500 }
9501 bool found(APSInt &Value, QualType SubobjType) {
9502 Info.FFDiag(E, diag::note_constexpr_construct_complex_elem);
9503 return false;
9504 }
9505 bool found(APFloat &Value, QualType SubobjType) {
9506 Info.FFDiag(E, diag::note_constexpr_construct_complex_elem);
9507 return false;
9508 }
9509 } Handler = {Info, E, AllocType, AK, nullptr};
9510
9511 CompleteObject Obj = findCompleteObject(Info, E, AK, Result, AllocType);
9512 if (!Obj || !findSubobject(Info, E, Obj, Result.Designator, Handler))
9513 return false;
9514
9515 Val = Handler.Value;
9516
9517 // [basic.life]p1:
9518 // The lifetime of an object o of type T ends when [...] the storage
9519 // which the object occupies is [...] reused by an object that is not
9520 // nested within o (6.6.2).
9521 *Val = APValue();
9522 } else {
9523 // Perform the allocation and obtain a pointer to the resulting object.
9524 Val = Info.createHeapAlloc(E, AllocType, Result);
9525 if (!Val)
9526 return false;
9527 }
9528
9529 if (ValueInit) {
9530 ImplicitValueInitExpr VIE(AllocType);
9531 if (!EvaluateInPlace(*Val, Info, Result, &VIE))
9532 return false;
9533 } else if (ResizedArrayILE) {
9534 if (!EvaluateArrayNewInitList(Info, Result, *Val, ResizedArrayILE,
9535 AllocType))
9536 return false;
9537 } else if (ResizedArrayCCE) {
9538 if (!EvaluateArrayNewConstructExpr(Info, Result, *Val, ResizedArrayCCE,
9539 AllocType))
9540 return false;
9541 } else if (Init) {
9542 if (!EvaluateInPlace(*Val, Info, Result, Init))
9543 return false;
9544 } else if (!getDefaultInitValue(AllocType, *Val)) {
9545 return false;
9546 }
9547
9548 // Array new returns a pointer to the first element, not a pointer to the
9549 // array.
9550 if (auto *AT = AllocType->getAsArrayTypeUnsafe())
9551 Result.addArray(Info, E, cast<ConstantArrayType>(AT));
9552
9553 return true;
9554}
9555//===----------------------------------------------------------------------===//
9556// Member Pointer Evaluation
9557//===----------------------------------------------------------------------===//
9558
9559namespace {
9560class MemberPointerExprEvaluator
9561 : public ExprEvaluatorBase<MemberPointerExprEvaluator> {
9562 MemberPtr &Result;
9563
9564 bool Success(const ValueDecl *D) {
9565 Result = MemberPtr(D);
9566 return true;
9567 }
9568public:
9569
9570 MemberPointerExprEvaluator(EvalInfo &Info, MemberPtr &Result)
9571 : ExprEvaluatorBaseTy(Info), Result(Result) {}
9572
9573 bool Success(const APValue &V, const Expr *E) {
9574 Result.setFrom(V);
9575 return true;
9576 }
9577 bool ZeroInitialization(const Expr *E) {
9578 return Success((const ValueDecl*)nullptr);
9579 }
9580
9581 bool VisitCastExpr(const CastExpr *E);
9582 bool VisitUnaryAddrOf(const UnaryOperator *E);
9583};
9584} // end anonymous namespace
9585
9586static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
9587 EvalInfo &Info) {
9588 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9588, __extension__ __PRETTY_FUNCTION__))
;
9589 assert(E->isPRValue() && E->getType()->isMemberPointerType())(static_cast <bool> (E->isPRValue() && E->
getType()->isMemberPointerType()) ? void (0) : __assert_fail
("E->isPRValue() && E->getType()->isMemberPointerType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9589, __extension__ __PRETTY_FUNCTION__))
;
9590 return MemberPointerExprEvaluator(Info, Result).Visit(E);
9591}
9592
9593bool MemberPointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
9594 switch (E->getCastKind()) {
9595 default:
9596 return ExprEvaluatorBaseTy::VisitCastExpr(E);
9597
9598 case CK_NullToMemberPointer:
9599 VisitIgnoredValue(E->getSubExpr());
9600 return ZeroInitialization(E);
9601
9602 case CK_BaseToDerivedMemberPointer: {
9603 if (!Visit(E->getSubExpr()))
9604 return false;
9605 if (E->path_empty())
9606 return true;
9607 // Base-to-derived member pointer casts store the path in derived-to-base
9608 // order, so iterate backwards. The CXXBaseSpecifier also provides us with
9609 // the wrong end of the derived->base arc, so stagger the path by one class.
9610 typedef std::reverse_iterator<CastExpr::path_const_iterator> ReverseIter;
9611 for (ReverseIter PathI(E->path_end() - 1), PathE(E->path_begin());
9612 PathI != PathE; ++PathI) {
9613 assert(!(*PathI)->isVirtual() && "memptr cast through vbase")(static_cast <bool> (!(*PathI)->isVirtual() &&
"memptr cast through vbase") ? void (0) : __assert_fail ("!(*PathI)->isVirtual() && \"memptr cast through vbase\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9613, __extension__ __PRETTY_FUNCTION__))
;
9614 const CXXRecordDecl *Derived = (*PathI)->getType()->getAsCXXRecordDecl();
9615 if (!Result.castToDerived(Derived))
9616 return Error(E);
9617 }
9618 const Type *FinalTy = E->getType()->castAs<MemberPointerType>()->getClass();
9619 if (!Result.castToDerived(FinalTy->getAsCXXRecordDecl()))
9620 return Error(E);
9621 return true;
9622 }
9623
9624 case CK_DerivedToBaseMemberPointer:
9625 if (!Visit(E->getSubExpr()))
9626 return false;
9627 for (CastExpr::path_const_iterator PathI = E->path_begin(),
9628 PathE = E->path_end(); PathI != PathE; ++PathI) {
9629 assert(!(*PathI)->isVirtual() && "memptr cast through vbase")(static_cast <bool> (!(*PathI)->isVirtual() &&
"memptr cast through vbase") ? void (0) : __assert_fail ("!(*PathI)->isVirtual() && \"memptr cast through vbase\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9629, __extension__ __PRETTY_FUNCTION__))
;
9630 const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
9631 if (!Result.castToBase(Base))
9632 return Error(E);
9633 }
9634 return true;
9635 }
9636}
9637
9638bool MemberPointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
9639 // C++11 [expr.unary.op]p3 has very strict rules on how the address of a
9640 // member can be formed.
9641 return Success(cast<DeclRefExpr>(E->getSubExpr())->getDecl());
9642}
9643
9644//===----------------------------------------------------------------------===//
9645// Record Evaluation
9646//===----------------------------------------------------------------------===//
9647
9648namespace {
9649 class RecordExprEvaluator
9650 : public ExprEvaluatorBase<RecordExprEvaluator> {
9651 const LValue &This;
9652 APValue &Result;
9653 public:
9654
9655 RecordExprEvaluator(EvalInfo &info, const LValue &This, APValue &Result)
9656 : ExprEvaluatorBaseTy(info), This(This), Result(Result) {}
9657
9658 bool Success(const APValue &V, const Expr *E) {
9659 Result = V;
9660 return true;
9661 }
9662 bool ZeroInitialization(const Expr *E) {
9663 return ZeroInitialization(E, E->getType());
9664 }
9665 bool ZeroInitialization(const Expr *E, QualType T);
9666
9667 bool VisitCallExpr(const CallExpr *E) {
9668 return handleCallExpr(E, Result, &This);
9669 }
9670 bool VisitCastExpr(const CastExpr *E);
9671 bool VisitInitListExpr(const InitListExpr *E);
9672 bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
9673 return VisitCXXConstructExpr(E, E->getType());
9674 }
9675 bool VisitLambdaExpr(const LambdaExpr *E);
9676 bool VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
9677 bool VisitCXXConstructExpr(const CXXConstructExpr *E, QualType T);
9678 bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E);
9679 bool VisitBinCmp(const BinaryOperator *E);
9680 };
9681}
9682
9683/// Perform zero-initialization on an object of non-union class type.
9684/// C++11 [dcl.init]p5:
9685/// To zero-initialize an object or reference of type T means:
9686/// [...]
9687/// -- if T is a (possibly cv-qualified) non-union class type,
9688/// each non-static data member and each base-class subobject is
9689/// zero-initialized
9690static bool HandleClassZeroInitialization(EvalInfo &Info, const Expr *E,
9691 const RecordDecl *RD,
9692 const LValue &This, APValue &Result) {
9693 assert(!RD->isUnion() && "Expected non-union class type")(static_cast <bool> (!RD->isUnion() && "Expected non-union class type"
) ? void (0) : __assert_fail ("!RD->isUnion() && \"Expected non-union class type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9693, __extension__ __PRETTY_FUNCTION__))
;
9694 const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
9695 Result = APValue(APValue::UninitStruct(), CD ? CD->getNumBases() : 0,
9696 std::distance(RD->field_begin(), RD->field_end()));
9697
9698 if (RD->isInvalidDecl()) return false;
9699 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
9700
9701 if (CD) {
9702 unsigned Index = 0;
9703 for (CXXRecordDecl::base_class_const_iterator I = CD->bases_begin(),
9704 End = CD->bases_end(); I != End; ++I, ++Index) {
9705 const CXXRecordDecl *Base = I->getType()->getAsCXXRecordDecl();
9706 LValue Subobject = This;
9707 if (!HandleLValueDirectBase(Info, E, Subobject, CD, Base, &Layout))
9708 return false;
9709 if (!HandleClassZeroInitialization(Info, E, Base, Subobject,
9710 Result.getStructBase(Index)))
9711 return false;
9712 }
9713 }
9714
9715 for (const auto *I : RD->fields()) {
9716 // -- if T is a reference type, no initialization is performed.
9717 if (I->isUnnamedBitfield() || I->getType()->isReferenceType())
9718 continue;
9719
9720 LValue Subobject = This;
9721 if (!HandleLValueMember(Info, E, Subobject, I, &Layout))
9722 return false;
9723
9724 ImplicitValueInitExpr VIE(I->getType());
9725 if (!EvaluateInPlace(
9726 Result.getStructField(I->getFieldIndex()), Info, Subobject, &VIE))
9727 return false;
9728 }
9729
9730 return true;
9731}
9732
9733bool RecordExprEvaluator::ZeroInitialization(const Expr *E, QualType T) {
9734 const RecordDecl *RD = T->castAs<RecordType>()->getDecl();
9735 if (RD->isInvalidDecl()) return false;
9736 if (RD->isUnion()) {
9737 // C++11 [dcl.init]p5: If T is a (possibly cv-qualified) union type, the
9738 // object's first non-static named data member is zero-initialized
9739 RecordDecl::field_iterator I = RD->field_begin();
9740 while (I != RD->field_end() && (*I)->isUnnamedBitfield())
9741 ++I;
9742 if (I == RD->field_end()) {
9743 Result = APValue((const FieldDecl*)nullptr);
9744 return true;
9745 }
9746
9747 LValue Subobject = This;
9748 if (!HandleLValueMember(Info, E, Subobject, *I))
9749 return false;
9750 Result = APValue(*I);
9751 ImplicitValueInitExpr VIE(I->getType());
9752 return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, &VIE);
9753 }
9754
9755 if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->getNumVBases()) {
9756 Info.FFDiag(E, diag::note_constexpr_virtual_base) << RD;
9757 return false;
9758 }
9759
9760 return HandleClassZeroInitialization(Info, E, RD, This, Result);
9761}
9762
9763bool RecordExprEvaluator::VisitCastExpr(const CastExpr *E) {
9764 switch (E->getCastKind()) {
9765 default:
9766 return ExprEvaluatorBaseTy::VisitCastExpr(E);
9767
9768 case CK_ConstructorConversion:
9769 return Visit(E->getSubExpr());
9770
9771 case CK_DerivedToBase:
9772 case CK_UncheckedDerivedToBase: {
9773 APValue DerivedObject;
9774 if (!Evaluate(DerivedObject, Info, E->getSubExpr()))
9775 return false;
9776 if (!DerivedObject.isStruct())
9777 return Error(E->getSubExpr());
9778
9779 // Derived-to-base rvalue conversion: just slice off the derived part.
9780 APValue *Value = &DerivedObject;
9781 const CXXRecordDecl *RD = E->getSubExpr()->getType()->getAsCXXRecordDecl();
9782 for (CastExpr::path_const_iterator PathI = E->path_begin(),
9783 PathE = E->path_end(); PathI != PathE; ++PathI) {
9784 assert(!(*PathI)->isVirtual() && "record rvalue with virtual base")(static_cast <bool> (!(*PathI)->isVirtual() &&
"record rvalue with virtual base") ? void (0) : __assert_fail
("!(*PathI)->isVirtual() && \"record rvalue with virtual base\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9784, __extension__ __PRETTY_FUNCTION__))
;
9785 const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
9786 Value = &Value->getStructBase(getBaseIndex(RD, Base));
9787 RD = Base;
9788 }
9789 Result = *Value;
9790 return true;
9791 }
9792 }
9793}
9794
9795bool RecordExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
9796 if (E->isTransparent())
9797 return Visit(E->getInit(0));
9798
9799 const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
9800 if (RD->isInvalidDecl()) return false;
9801 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
9802 auto *CXXRD = dyn_cast<CXXRecordDecl>(RD);
9803
9804 EvalInfo::EvaluatingConstructorRAII EvalObj(
9805 Info,
9806 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries},
9807 CXXRD && CXXRD->getNumBases());
9808
9809 if (RD->isUnion()) {
9810 const FieldDecl *Field = E->getInitializedFieldInUnion();
9811 Result = APValue(Field);
9812 if (!Field)
9813 return true;
9814
9815 // If the initializer list for a union does not contain any elements, the
9816 // first element of the union is value-initialized.
9817 // FIXME: The element should be initialized from an initializer list.
9818 // Is this difference ever observable for initializer lists which
9819 // we don't build?
9820 ImplicitValueInitExpr VIE(Field->getType());
9821 const Expr *InitExpr = E->getNumInits() ? E->getInit(0) : &VIE;
9822
9823 LValue Subobject = This;
9824 if (!HandleLValueMember(Info, InitExpr, Subobject, Field, &Layout))
9825 return false;
9826
9827 // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
9828 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
9829 isa<CXXDefaultInitExpr>(InitExpr));
9830
9831 if (EvaluateInPlace(Result.getUnionValue(), Info, Subobject, InitExpr)) {
9832 if (Field->isBitField())
9833 return truncateBitfieldValue(Info, InitExpr, Result.getUnionValue(),
9834 Field);
9835 return true;
9836 }
9837
9838 return false;
9839 }
9840
9841 if (!Result.hasValue())
9842 Result = APValue(APValue::UninitStruct(), CXXRD ? CXXRD->getNumBases() : 0,
9843 std::distance(RD->field_begin(), RD->field_end()));
9844 unsigned ElementNo = 0;
9845 bool Success = true;
9846
9847 // Initialize base classes.
9848 if (CXXRD && CXXRD->getNumBases()) {
9849 for (const auto &Base : CXXRD->bases()) {
9850 assert(ElementNo < E->getNumInits() && "missing init for base class")(static_cast <bool> (ElementNo < E->getNumInits()
&& "missing init for base class") ? void (0) : __assert_fail
("ElementNo < E->getNumInits() && \"missing init for base class\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9850, __extension__ __PRETTY_FUNCTION__))
;
9851 const Expr *Init = E->getInit(ElementNo);
9852
9853 LValue Subobject = This;
9854 if (!HandleLValueBase(Info, Init, Subobject, CXXRD, &Base))
9855 return false;
9856
9857 APValue &FieldVal = Result.getStructBase(ElementNo);
9858 if (!EvaluateInPlace(FieldVal, Info, Subobject, Init)) {
9859 if (!Info.noteFailure())
9860 return false;
9861 Success = false;
9862 }
9863 ++ElementNo;
9864 }
9865
9866 EvalObj.finishedConstructingBases();
9867 }
9868
9869 // Initialize members.
9870 for (const auto *Field : RD->fields()) {
9871 // Anonymous bit-fields are not considered members of the class for
9872 // purposes of aggregate initialization.
9873 if (Field->isUnnamedBitfield())
9874 continue;
9875
9876 LValue Subobject = This;
9877
9878 bool HaveInit = ElementNo < E->getNumInits();
9879
9880 // FIXME: Diagnostics here should point to the end of the initializer
9881 // list, not the start.
9882 if (!HandleLValueMember(Info, HaveInit ? E->getInit(ElementNo) : E,
9883 Subobject, Field, &Layout))
9884 return false;
9885
9886 // Perform an implicit value-initialization for members beyond the end of
9887 // the initializer list.
9888 ImplicitValueInitExpr VIE(HaveInit ? Info.Ctx.IntTy : Field->getType());
9889 const Expr *Init = HaveInit ? E->getInit(ElementNo++) : &VIE;
9890
9891 // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
9892 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
9893 isa<CXXDefaultInitExpr>(Init));
9894
9895 APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
9896 if (!EvaluateInPlace(FieldVal, Info, Subobject, Init) ||
9897 (Field->isBitField() && !truncateBitfieldValue(Info, Init,
9898 FieldVal, Field))) {
9899 if (!Info.noteFailure())
9900 return false;
9901 Success = false;
9902 }
9903 }
9904
9905 EvalObj.finishedConstructingFields();
9906
9907 return Success;
9908}
9909
9910bool RecordExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
9911 QualType T) {
9912 // Note that E's type is not necessarily the type of our class here; we might
9913 // be initializing an array element instead.
9914 const CXXConstructorDecl *FD = E->getConstructor();
9915 if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl()) return false;
9916
9917 bool ZeroInit = E->requiresZeroInitialization();
9918 if (CheckTrivialDefaultConstructor(Info, E->getExprLoc(), FD, ZeroInit)) {
9919 // If we've already performed zero-initialization, we're already done.
9920 if (Result.hasValue())
9921 return true;
9922
9923 if (ZeroInit)
9924 return ZeroInitialization(E, T);
9925
9926 return getDefaultInitValue(T, Result);
9927 }
9928
9929 const FunctionDecl *Definition = nullptr;
9930 auto Body = FD->getBody(Definition);
9931
9932 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
9933 return false;
9934
9935 // Avoid materializing a temporary for an elidable copy/move constructor.
9936 if (E->isElidable() && !ZeroInit)
9937 if (const MaterializeTemporaryExpr *ME
9938 = dyn_cast<MaterializeTemporaryExpr>(E->getArg(0)))
9939 return Visit(ME->getSubExpr());
9940
9941 if (ZeroInit && !ZeroInitialization(E, T))
9942 return false;
9943
9944 auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
9945 return HandleConstructorCall(E, This, Args,
9946 cast<CXXConstructorDecl>(Definition), Info,
9947 Result);
9948}
9949
9950bool RecordExprEvaluator::VisitCXXInheritedCtorInitExpr(
9951 const CXXInheritedCtorInitExpr *E) {
9952 if (!Info.CurrentCall) {
9953 assert(Info.checkingPotentialConstantExpression())(static_cast <bool> (Info.checkingPotentialConstantExpression
()) ? void (0) : __assert_fail ("Info.checkingPotentialConstantExpression()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 9953, __extension__ __PRETTY_FUNCTION__))
;
9954 return false;
9955 }
9956
9957 const CXXConstructorDecl *FD = E->getConstructor();
9958 if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl())
9959 return false;
9960
9961 const FunctionDecl *Definition = nullptr;
9962 auto Body = FD->getBody(Definition);
9963
9964 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
9965 return false;
9966
9967 return HandleConstructorCall(E, This, Info.CurrentCall->Arguments,
9968 cast<CXXConstructorDecl>(Definition), Info,
9969 Result);
9970}
9971
9972bool RecordExprEvaluator::VisitCXXStdInitializerListExpr(
9973 const CXXStdInitializerListExpr *E) {
9974 const ConstantArrayType *ArrayType =
9975 Info.Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
9976
9977 LValue Array;
9978 if (!EvaluateLValue(E->getSubExpr(), Array, Info))
9979 return false;
9980
9981 // Get a pointer to the first element of the array.
9982 Array.addArray(Info, E, ArrayType);
9983
9984 auto InvalidType = [&] {
9985 Info.FFDiag(E, diag::note_constexpr_unsupported_layout)
9986 << E->getType();
9987 return false;
9988 };
9989
9990 // FIXME: Perform the checks on the field types in SemaInit.
9991 RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
9992 RecordDecl::field_iterator Field = Record->field_begin();
9993 if (Field == Record->field_end())
9994 return InvalidType();
9995
9996 // Start pointer.
9997 if (!Field->getType()->isPointerType() ||
9998 !Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
9999 ArrayType->getElementType()))
10000 return InvalidType();
10001
10002 // FIXME: What if the initializer_list type has base classes, etc?
10003 Result = APValue(APValue::UninitStruct(), 0, 2);
10004 Array.moveInto(Result.getStructField(0));
10005
10006 if (++Field == Record->field_end())
10007 return InvalidType();
10008
10009 if (Field->getType()->isPointerType() &&
10010 Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
10011 ArrayType->getElementType())) {
10012 // End pointer.
10013 if (!HandleLValueArrayAdjustment(Info, E, Array,
10014 ArrayType->getElementType(),
10015 ArrayType->getSize().getZExtValue()))
10016 return false;
10017 Array.moveInto(Result.getStructField(1));
10018 } else if (Info.Ctx.hasSameType(Field->getType(), Info.Ctx.getSizeType()))
10019 // Length.
10020 Result.getStructField(1) = APValue(APSInt(ArrayType->getSize()));
10021 else
10022 return InvalidType();
10023
10024 if (++Field != Record->field_end())
10025 return InvalidType();
10026
10027 return true;
10028}
10029
10030bool RecordExprEvaluator::VisitLambdaExpr(const LambdaExpr *E) {
10031 const CXXRecordDecl *ClosureClass = E->getLambdaClass();
10032 if (ClosureClass->isInvalidDecl())
10033 return false;
10034
10035 const size_t NumFields =
10036 std::distance(ClosureClass->field_begin(), ClosureClass->field_end());
10037
10038 assert(NumFields == (size_t)std::distance(E->capture_init_begin(),(static_cast <bool> (NumFields == (size_t)std::distance
(E->capture_init_begin(), E->capture_init_end()) &&
"The number of lambda capture initializers should equal the number of "
"fields within the closure type") ? void (0) : __assert_fail
("NumFields == (size_t)std::distance(E->capture_init_begin(), E->capture_init_end()) && \"The number of lambda capture initializers should equal the number of \" \"fields within the closure type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10041, __extension__ __PRETTY_FUNCTION__))
10039 E->capture_init_end()) &&(static_cast <bool> (NumFields == (size_t)std::distance
(E->capture_init_begin(), E->capture_init_end()) &&
"The number of lambda capture initializers should equal the number of "
"fields within the closure type") ? void (0) : __assert_fail
("NumFields == (size_t)std::distance(E->capture_init_begin(), E->capture_init_end()) && \"The number of lambda capture initializers should equal the number of \" \"fields within the closure type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10041, __extension__ __PRETTY_FUNCTION__))
10040 "The number of lambda capture initializers should equal the number of "(static_cast <bool> (NumFields == (size_t)std::distance
(E->capture_init_begin(), E->capture_init_end()) &&
"The number of lambda capture initializers should equal the number of "
"fields within the closure type") ? void (0) : __assert_fail
("NumFields == (size_t)std::distance(E->capture_init_begin(), E->capture_init_end()) && \"The number of lambda capture initializers should equal the number of \" \"fields within the closure type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10041, __extension__ __PRETTY_FUNCTION__))
10041 "fields within the closure type")(static_cast <bool> (NumFields == (size_t)std::distance
(E->capture_init_begin(), E->capture_init_end()) &&
"The number of lambda capture initializers should equal the number of "
"fields within the closure type") ? void (0) : __assert_fail
("NumFields == (size_t)std::distance(E->capture_init_begin(), E->capture_init_end()) && \"The number of lambda capture initializers should equal the number of \" \"fields within the closure type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10041, __extension__ __PRETTY_FUNCTION__))
;
10042
10043 Result = APValue(APValue::UninitStruct(), /*NumBases*/0, NumFields);
10044 // Iterate through all the lambda's closure object's fields and initialize
10045 // them.
10046 auto *CaptureInitIt = E->capture_init_begin();
10047 const LambdaCapture *CaptureIt = ClosureClass->captures_begin();
10048 bool Success = true;
10049 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(ClosureClass);
10050 for (const auto *Field : ClosureClass->fields()) {
10051 assert(CaptureInitIt != E->capture_init_end())(static_cast <bool> (CaptureInitIt != E->capture_init_end
()) ? void (0) : __assert_fail ("CaptureInitIt != E->capture_init_end()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10051, __extension__ __PRETTY_FUNCTION__))
;
10052 // Get the initializer for this field
10053 Expr *const CurFieldInit = *CaptureInitIt++;
10054
10055 // If there is no initializer, either this is a VLA or an error has
10056 // occurred.
10057 if (!CurFieldInit)
10058 return Error(E);
10059
10060 LValue Subobject = This;
10061
10062 if (!HandleLValueMember(Info, E, Subobject, Field, &Layout))
10063 return false;
10064
10065 APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
10066 if (!EvaluateInPlace(FieldVal, Info, Subobject, CurFieldInit)) {
10067 if (!Info.keepEvaluatingAfterFailure())
10068 return false;
10069 Success = false;
10070 }
10071 ++CaptureIt;
10072 }
10073 return Success;
10074}
10075
10076static bool EvaluateRecord(const Expr *E, const LValue &This,
10077 APValue &Result, EvalInfo &Info) {
10078 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10078, __extension__ __PRETTY_FUNCTION__))
;
10079 assert(E->isPRValue() && E->getType()->isRecordType() &&(static_cast <bool> (E->isPRValue() && E->
getType()->isRecordType() && "can't evaluate expression as a record rvalue"
) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isRecordType() && \"can't evaluate expression as a record rvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10080, __extension__ __PRETTY_FUNCTION__))
10080 "can't evaluate expression as a record rvalue")(static_cast <bool> (E->isPRValue() && E->
getType()->isRecordType() && "can't evaluate expression as a record rvalue"
) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isRecordType() && \"can't evaluate expression as a record rvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10080, __extension__ __PRETTY_FUNCTION__))
;
10081 return RecordExprEvaluator(Info, This, Result).Visit(E);
10082}
10083
10084//===----------------------------------------------------------------------===//
10085// Temporary Evaluation
10086//
10087// Temporaries are represented in the AST as rvalues, but generally behave like
10088// lvalues. The full-object of which the temporary is a subobject is implicitly
10089// materialized so that a reference can bind to it.
10090//===----------------------------------------------------------------------===//
10091namespace {
10092class TemporaryExprEvaluator
10093 : public LValueExprEvaluatorBase<TemporaryExprEvaluator> {
10094public:
10095 TemporaryExprEvaluator(EvalInfo &Info, LValue &Result) :
10096 LValueExprEvaluatorBaseTy(Info, Result, false) {}
10097
10098 /// Visit an expression which constructs the value of this temporary.
10099 bool VisitConstructExpr(const Expr *E) {
10100 APValue &Value = Info.CurrentCall->createTemporary(
10101 E, E->getType(), ScopeKind::FullExpression, Result);
10102 return EvaluateInPlace(Value, Info, Result, E);
10103 }
10104
10105 bool VisitCastExpr(const CastExpr *E) {
10106 switch (E->getCastKind()) {
10107 default:
10108 return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
10109
10110 case CK_ConstructorConversion:
10111 return VisitConstructExpr(E->getSubExpr());
10112 }
10113 }
10114 bool VisitInitListExpr(const InitListExpr *E) {
10115 return VisitConstructExpr(E);
10116 }
10117 bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
10118 return VisitConstructExpr(E);
10119 }
10120 bool VisitCallExpr(const CallExpr *E) {
10121 return VisitConstructExpr(E);
10122 }
10123 bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E) {
10124 return VisitConstructExpr(E);
10125 }
10126 bool VisitLambdaExpr(const LambdaExpr *E) {
10127 return VisitConstructExpr(E);
10128 }
10129};
10130} // end anonymous namespace
10131
10132/// Evaluate an expression of record type as a temporary.
10133static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info) {
10134 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10134, __extension__ __PRETTY_FUNCTION__))
;
10135 assert(E->isPRValue() && E->getType()->isRecordType())(static_cast <bool> (E->isPRValue() && E->
getType()->isRecordType()) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isRecordType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10135, __extension__ __PRETTY_FUNCTION__))
;
10136 return TemporaryExprEvaluator(Info, Result).Visit(E);
10137}
10138
10139//===----------------------------------------------------------------------===//
10140// Vector Evaluation
10141//===----------------------------------------------------------------------===//
10142
10143namespace {
10144 class VectorExprEvaluator
10145 : public ExprEvaluatorBase<VectorExprEvaluator> {
10146 APValue &Result;
10147 public:
10148
10149 VectorExprEvaluator(EvalInfo &info, APValue &Result)
10150 : ExprEvaluatorBaseTy(info), Result(Result) {}
10151
10152 bool Success(ArrayRef<APValue> V, const Expr *E) {
10153 assert(V.size() == E->getType()->castAs<VectorType>()->getNumElements())(static_cast <bool> (V.size() == E->getType()->castAs
<VectorType>()->getNumElements()) ? void (0) : __assert_fail
("V.size() == E->getType()->castAs<VectorType>()->getNumElements()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10153, __extension__ __PRETTY_FUNCTION__))
;
10154 // FIXME: remove this APValue copy.
10155 Result = APValue(V.data(), V.size());
10156 return true;
10157 }
10158 bool Success(const APValue &V, const Expr *E) {
10159 assert(V.isVector())(static_cast <bool> (V.isVector()) ? void (0) : __assert_fail
("V.isVector()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10159, __extension__ __PRETTY_FUNCTION__))
;
10160 Result = V;
10161 return true;
10162 }
10163 bool ZeroInitialization(const Expr *E);
10164
10165 bool VisitUnaryReal(const UnaryOperator *E)
10166 { return Visit(E->getSubExpr()); }
10167 bool VisitCastExpr(const CastExpr* E);
10168 bool VisitInitListExpr(const InitListExpr *E);
10169 bool VisitUnaryImag(const UnaryOperator *E);
10170 bool VisitBinaryOperator(const BinaryOperator *E);
10171 // FIXME: Missing: unary -, unary ~, conditional operator (for GNU
10172 // conditional select), shufflevector, ExtVectorElementExpr
10173 };
10174} // end anonymous namespace
10175
10176static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) {
10177 assert(E->isPRValue() && E->getType()->isVectorType() &&(static_cast <bool> (E->isPRValue() && E->
getType()->isVectorType() && "not a vector prvalue"
) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isVectorType() && \"not a vector prvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10178, __extension__ __PRETTY_FUNCTION__))
10178 "not a vector prvalue")(static_cast <bool> (E->isPRValue() && E->
getType()->isVectorType() && "not a vector prvalue"
) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isVectorType() && \"not a vector prvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10178, __extension__ __PRETTY_FUNCTION__))
;
10179 return VectorExprEvaluator(Info, Result).Visit(E);
10180}
10181
10182bool VectorExprEvaluator::VisitCastExpr(const CastExpr *E) {
10183 const VectorType *VTy = E->getType()->castAs<VectorType>();
10184 unsigned NElts = VTy->getNumElements();
10185
10186 const Expr *SE = E->getSubExpr();
10187 QualType SETy = SE->getType();
10188
10189 switch (E->getCastKind()) {
10190 case CK_VectorSplat: {
10191 APValue Val = APValue();
10192 if (SETy->isIntegerType()) {
10193 APSInt IntResult;
10194 if (!EvaluateInteger(SE, IntResult, Info))
10195 return false;
10196 Val = APValue(std::move(IntResult));
10197 } else if (SETy->isRealFloatingType()) {
10198 APFloat FloatResult(0.0);
10199 if (!EvaluateFloat(SE, FloatResult, Info))
10200 return false;
10201 Val = APValue(std::move(FloatResult));
10202 } else {
10203 return Error(E);
10204 }
10205
10206 // Splat and create vector APValue.
10207 SmallVector<APValue, 4> Elts(NElts, Val);
10208 return Success(Elts, E);
10209 }
10210 case CK_BitCast: {
10211 // Evaluate the operand into an APInt we can extract from.
10212 llvm::APInt SValInt;
10213 if (!EvalAndBitcastToAPInt(Info, SE, SValInt))
10214 return false;
10215 // Extract the elements
10216 QualType EltTy = VTy->getElementType();
10217 unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
10218 bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
10219 SmallVector<APValue, 4> Elts;
10220 if (EltTy->isRealFloatingType()) {
10221 const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(EltTy);
10222 unsigned FloatEltSize = EltSize;
10223 if (&Sem == &APFloat::x87DoubleExtended())
10224 FloatEltSize = 80;
10225 for (unsigned i = 0; i < NElts; i++) {
10226 llvm::APInt Elt;
10227 if (BigEndian)
10228 Elt = SValInt.rotl(i*EltSize+FloatEltSize).trunc(FloatEltSize);
10229 else
10230 Elt = SValInt.rotr(i*EltSize).trunc(FloatEltSize);
10231 Elts.push_back(APValue(APFloat(Sem, Elt)));
10232 }
10233 } else if (EltTy->isIntegerType()) {
10234 for (unsigned i = 0; i < NElts; i++) {
10235 llvm::APInt Elt;
10236 if (BigEndian)
10237 Elt = SValInt.rotl(i*EltSize+EltSize).zextOrTrunc(EltSize);
10238 else
10239 Elt = SValInt.rotr(i*EltSize).zextOrTrunc(EltSize);
10240 Elts.push_back(APValue(APSInt(Elt, !EltTy->isSignedIntegerType())));
10241 }
10242 } else {
10243 return Error(E);
10244 }
10245 return Success(Elts, E);
10246 }
10247 default:
10248 return ExprEvaluatorBaseTy::VisitCastExpr(E);
10249 }
10250}
10251
10252bool
10253VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
10254 const VectorType *VT = E->getType()->castAs<VectorType>();
10255 unsigned NumInits = E->getNumInits();
10256 unsigned NumElements = VT->getNumElements();
10257
10258 QualType EltTy = VT->getElementType();
10259 SmallVector<APValue, 4> Elements;
10260
10261 // The number of initializers can be less than the number of
10262 // vector elements. For OpenCL, this can be due to nested vector
10263 // initialization. For GCC compatibility, missing trailing elements
10264 // should be initialized with zeroes.
10265 unsigned CountInits = 0, CountElts = 0;
10266 while (CountElts < NumElements) {
10267 // Handle nested vector initialization.
10268 if (CountInits < NumInits
10269 && E->getInit(CountInits)->getType()->isVectorType()) {
10270 APValue v;
10271 if (!EvaluateVector(E->getInit(CountInits), v, Info))
10272 return Error(E);
10273 unsigned vlen = v.getVectorLength();
10274 for (unsigned j = 0; j < vlen; j++)
10275 Elements.push_back(v.getVectorElt(j));
10276 CountElts += vlen;
10277 } else if (EltTy->isIntegerType()) {
10278 llvm::APSInt sInt(32);
10279 if (CountInits < NumInits) {
10280 if (!EvaluateInteger(E->getInit(CountInits), sInt, Info))
10281 return false;
10282 } else // trailing integer zero.
10283 sInt = Info.Ctx.MakeIntValue(0, EltTy);
10284 Elements.push_back(APValue(sInt));
10285 CountElts++;
10286 } else {
10287 llvm::APFloat f(0.0);
10288 if (CountInits < NumInits) {
10289 if (!EvaluateFloat(E->getInit(CountInits), f, Info))
10290 return false;
10291 } else // trailing float zero.
10292 f = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy));
10293 Elements.push_back(APValue(f));
10294 CountElts++;
10295 }
10296 CountInits++;
10297 }
10298 return Success(Elements, E);
10299}
10300
10301bool
10302VectorExprEvaluator::ZeroInitialization(const Expr *E) {
10303 const auto *VT = E->getType()->castAs<VectorType>();
10304 QualType EltTy = VT->getElementType();
10305 APValue ZeroElement;
10306 if (EltTy->isIntegerType())
10307 ZeroElement = APValue(Info.Ctx.MakeIntValue(0, EltTy));
10308 else
10309 ZeroElement =
10310 APValue(APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy)));
10311
10312 SmallVector<APValue, 4> Elements(VT->getNumElements(), ZeroElement);
10313 return Success(Elements, E);
10314}
10315
10316bool VectorExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
10317 VisitIgnoredValue(E->getSubExpr());
10318 return ZeroInitialization(E);
10319}
10320
10321bool VectorExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
10322 BinaryOperatorKind Op = E->getOpcode();
10323 assert(Op != BO_PtrMemD && Op != BO_PtrMemI && Op != BO_Cmp &&(static_cast <bool> (Op != BO_PtrMemD && Op != BO_PtrMemI
&& Op != BO_Cmp && "Operation not supported on vector types"
) ? void (0) : __assert_fail ("Op != BO_PtrMemD && Op != BO_PtrMemI && Op != BO_Cmp && \"Operation not supported on vector types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10324, __extension__ __PRETTY_FUNCTION__))
10324 "Operation not supported on vector types")(static_cast <bool> (Op != BO_PtrMemD && Op != BO_PtrMemI
&& Op != BO_Cmp && "Operation not supported on vector types"
) ? void (0) : __assert_fail ("Op != BO_PtrMemD && Op != BO_PtrMemI && Op != BO_Cmp && \"Operation not supported on vector types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10324, __extension__ __PRETTY_FUNCTION__))
;
10325
10326 if (Op == BO_Comma)
10327 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
10328
10329 Expr *LHS = E->getLHS();
10330 Expr *RHS = E->getRHS();
10331
10332 assert(LHS->getType()->isVectorType() && RHS->getType()->isVectorType() &&(static_cast <bool> (LHS->getType()->isVectorType
() && RHS->getType()->isVectorType() &&
"Must both be vector types") ? void (0) : __assert_fail ("LHS->getType()->isVectorType() && RHS->getType()->isVectorType() && \"Must both be vector types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10333, __extension__ __PRETTY_FUNCTION__))
10333 "Must both be vector types")(static_cast <bool> (LHS->getType()->isVectorType
() && RHS->getType()->isVectorType() &&
"Must both be vector types") ? void (0) : __assert_fail ("LHS->getType()->isVectorType() && RHS->getType()->isVectorType() && \"Must both be vector types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10333, __extension__ __PRETTY_FUNCTION__))
;
10334 // Checking JUST the types are the same would be fine, except shifts don't
10335 // need to have their types be the same (since you always shift by an int).
10336 assert(LHS->getType()->castAs<VectorType>()->getNumElements() ==(static_cast <bool> (LHS->getType()->castAs<VectorType
>()->getNumElements() == E->getType()->castAs<
VectorType>()->getNumElements() && RHS->getType
()->castAs<VectorType>()->getNumElements() == E->
getType()->castAs<VectorType>()->getNumElements()
&& "All operands must be the same size.") ? void (0)
: __assert_fail ("LHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && RHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10340, __extension__ __PRETTY_FUNCTION__))
10337 E->getType()->castAs<VectorType>()->getNumElements() &&(static_cast <bool> (LHS->getType()->castAs<VectorType
>()->getNumElements() == E->getType()->castAs<
VectorType>()->getNumElements() && RHS->getType
()->castAs<VectorType>()->getNumElements() == E->
getType()->castAs<VectorType>()->getNumElements()
&& "All operands must be the same size.") ? void (0)
: __assert_fail ("LHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && RHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10340, __extension__ __PRETTY_FUNCTION__))
10338 RHS->getType()->castAs<VectorType>()->getNumElements() ==(static_cast <bool> (LHS->getType()->castAs<VectorType
>()->getNumElements() == E->getType()->castAs<
VectorType>()->getNumElements() && RHS->getType
()->castAs<VectorType>()->getNumElements() == E->
getType()->castAs<VectorType>()->getNumElements()
&& "All operands must be the same size.") ? void (0)
: __assert_fail ("LHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && RHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10340, __extension__ __PRETTY_FUNCTION__))
10339 E->getType()->castAs<VectorType>()->getNumElements() &&(static_cast <bool> (LHS->getType()->castAs<VectorType
>()->getNumElements() == E->getType()->castAs<
VectorType>()->getNumElements() && RHS->getType
()->castAs<VectorType>()->getNumElements() == E->
getType()->castAs<VectorType>()->getNumElements()
&& "All operands must be the same size.") ? void (0)
: __assert_fail ("LHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && RHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10340, __extension__ __PRETTY_FUNCTION__))
10340 "All operands must be the same size.")(static_cast <bool> (LHS->getType()->castAs<VectorType
>()->getNumElements() == E->getType()->castAs<
VectorType>()->getNumElements() && RHS->getType
()->castAs<VectorType>()->getNumElements() == E->
getType()->castAs<VectorType>()->getNumElements()
&& "All operands must be the same size.") ? void (0)
: __assert_fail ("LHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && RHS->getType()->castAs<VectorType>()->getNumElements() == E->getType()->castAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10340, __extension__ __PRETTY_FUNCTION__))
;
10341
10342 APValue LHSValue;
10343 APValue RHSValue;
10344 bool LHSOK = Evaluate(LHSValue, Info, LHS);
10345 if (!LHSOK && !Info.noteFailure())
10346 return false;
10347 if (!Evaluate(RHSValue, Info, RHS) || !LHSOK)
10348 return false;
10349
10350 if (!handleVectorVectorBinOp(Info, E, Op, LHSValue, RHSValue))
10351 return false;
10352
10353 return Success(LHSValue, E);
10354}
10355
10356//===----------------------------------------------------------------------===//
10357// Array Evaluation
10358//===----------------------------------------------------------------------===//
10359
10360namespace {
10361 class ArrayExprEvaluator
10362 : public ExprEvaluatorBase<ArrayExprEvaluator> {
10363 const LValue &This;
10364 APValue &Result;
10365 public:
10366
10367 ArrayExprEvaluator(EvalInfo &Info, const LValue &This, APValue &Result)
10368 : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
10369
10370 bool Success(const APValue &V, const Expr *E) {
10371 assert(V.isArray() && "expected array")(static_cast <bool> (V.isArray() && "expected array"
) ? void (0) : __assert_fail ("V.isArray() && \"expected array\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10371, __extension__ __PRETTY_FUNCTION__))
;
10372 Result = V;
10373 return true;
10374 }
10375
10376 bool ZeroInitialization(const Expr *E) {
10377 const ConstantArrayType *CAT =
10378 Info.Ctx.getAsConstantArrayType(E->getType());
10379 if (!CAT) {
10380 if (E->getType()->isIncompleteArrayType()) {
10381 // We can be asked to zero-initialize a flexible array member; this
10382 // is represented as an ImplicitValueInitExpr of incomplete array
10383 // type. In this case, the array has zero elements.
10384 Result = APValue(APValue::UninitArray(), 0, 0);
10385 return true;
10386 }
10387 // FIXME: We could handle VLAs here.
10388 return Error(E);
10389 }
10390
10391 Result = APValue(APValue::UninitArray(), 0,
10392 CAT->getSize().getZExtValue());
10393 if (!Result.hasArrayFiller())
10394 return true;
10395
10396 // Zero-initialize all elements.
10397 LValue Subobject = This;
10398 Subobject.addArray(Info, E, CAT);
10399 ImplicitValueInitExpr VIE(CAT->getElementType());
10400 return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject, &VIE);
10401 }
10402
10403 bool VisitCallExpr(const CallExpr *E) {
10404 return handleCallExpr(E, Result, &This);
10405 }
10406 bool VisitInitListExpr(const InitListExpr *E,
10407 QualType AllocType = QualType());
10408 bool VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E);
10409 bool VisitCXXConstructExpr(const CXXConstructExpr *E);
10410 bool VisitCXXConstructExpr(const CXXConstructExpr *E,
10411 const LValue &Subobject,
10412 APValue *Value, QualType Type);
10413 bool VisitStringLiteral(const StringLiteral *E,
10414 QualType AllocType = QualType()) {
10415 expandStringLiteral(Info, E, Result, AllocType);
10416 return true;
10417 }
10418 };
10419} // end anonymous namespace
10420
10421static bool EvaluateArray(const Expr *E, const LValue &This,
10422 APValue &Result, EvalInfo &Info) {
10423 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10423, __extension__ __PRETTY_FUNCTION__))
;
10424 assert(E->isPRValue() && E->getType()->isArrayType() &&(static_cast <bool> (E->isPRValue() && E->
getType()->isArrayType() && "not an array prvalue"
) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isArrayType() && \"not an array prvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10425, __extension__ __PRETTY_FUNCTION__))
10425 "not an array prvalue")(static_cast <bool> (E->isPRValue() && E->
getType()->isArrayType() && "not an array prvalue"
) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isArrayType() && \"not an array prvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10425, __extension__ __PRETTY_FUNCTION__))
;
10426 return ArrayExprEvaluator(Info, This, Result).Visit(E);
10427}
10428
10429static bool EvaluateArrayNewInitList(EvalInfo &Info, LValue &This,
10430 APValue &Result, const InitListExpr *ILE,
10431 QualType AllocType) {
10432 assert(!ILE->isValueDependent())(static_cast <bool> (!ILE->isValueDependent()) ? void
(0) : __assert_fail ("!ILE->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10432, __extension__ __PRETTY_FUNCTION__))
;
1
Assuming the condition is true
2
'?' condition is true
10433 assert(ILE->isPRValue() && ILE->getType()->isArrayType() &&(static_cast <bool> (ILE->isPRValue() && ILE
->getType()->isArrayType() && "not an array prvalue"
) ? void (0) : __assert_fail ("ILE->isPRValue() && ILE->getType()->isArrayType() && \"not an array prvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10434, __extension__ __PRETTY_FUNCTION__))
3
'?' condition is true
10434 "not an array prvalue")(static_cast <bool> (ILE->isPRValue() && ILE
->getType()->isArrayType() && "not an array prvalue"
) ? void (0) : __assert_fail ("ILE->isPRValue() && ILE->getType()->isArrayType() && \"not an array prvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10434, __extension__ __PRETTY_FUNCTION__))
;
10435 return ArrayExprEvaluator(Info, This, Result)
4
Calling 'ArrayExprEvaluator::VisitInitListExpr'
10436 .VisitInitListExpr(ILE, AllocType);
10437}
10438
10439static bool EvaluateArrayNewConstructExpr(EvalInfo &Info, LValue &This,
10440 APValue &Result,
10441 const CXXConstructExpr *CCE,
10442 QualType AllocType) {
10443 assert(!CCE->isValueDependent())(static_cast <bool> (!CCE->isValueDependent()) ? void
(0) : __assert_fail ("!CCE->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10443, __extension__ __PRETTY_FUNCTION__))
;
10444 assert(CCE->isPRValue() && CCE->getType()->isArrayType() &&(static_cast <bool> (CCE->isPRValue() && CCE
->getType()->isArrayType() && "not an array prvalue"
) ? void (0) : __assert_fail ("CCE->isPRValue() && CCE->getType()->isArrayType() && \"not an array prvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10445, __extension__ __PRETTY_FUNCTION__))
10445 "not an array prvalue")(static_cast <bool> (CCE->isPRValue() && CCE
->getType()->isArrayType() && "not an array prvalue"
) ? void (0) : __assert_fail ("CCE->isPRValue() && CCE->getType()->isArrayType() && \"not an array prvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10445, __extension__ __PRETTY_FUNCTION__))
;
10446 return ArrayExprEvaluator(Info, This, Result)
10447 .VisitCXXConstructExpr(CCE, This, &Result, AllocType);
10448}
10449
10450// Return true iff the given array filler may depend on the element index.
10451static bool MaybeElementDependentArrayFiller(const Expr *FillerExpr) {
10452 // For now, just allow non-class value-initialization and initialization
10453 // lists comprised of them.
10454 if (isa<ImplicitValueInitExpr>(FillerExpr))
10455 return false;
10456 if (const InitListExpr *ILE = dyn_cast<InitListExpr>(FillerExpr)) {
10457 for (unsigned I = 0, E = ILE->getNumInits(); I != E; ++I) {
10458 if (MaybeElementDependentArrayFiller(ILE->getInit(I)))
10459 return true;
10460 }
10461 return false;
10462 }
10463 return true;
10464}
10465
10466bool ArrayExprEvaluator::VisitInitListExpr(const InitListExpr *E,
10467 QualType AllocType) {
10468 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(
10469 AllocType.isNull() ? E->getType() : AllocType);
5
'?' condition is false
10470 if (!CAT
5.1
'CAT' is non-null
)
6
Taking false branch
10471 return Error(E);
10472
10473 // C++11 [dcl.init.string]p1: A char array [...] can be initialized by [...]
10474 // an appropriately-typed string literal enclosed in braces.
10475 if (E->isStringLiteralInit()) {
7
Assuming the condition is false
10476 auto *SL = dyn_cast<StringLiteral>(E->getInit(0)->IgnoreParenImpCasts());
10477 // FIXME: Support ObjCEncodeExpr here once we support it in
10478 // ArrayExprEvaluator generally.
10479 if (!SL)
10480 return Error(E);
10481 return VisitStringLiteral(SL, AllocType);
10482 }
10483 // Any other transparent list init will need proper handling of the
10484 // AllocType; we can't just recurse to the inner initializer.
10485 assert(!E->isTransparent() &&(static_cast <bool> (!E->isTransparent() && "transparent array list initialization is not string literal init?"
) ? void (0) : __assert_fail ("!E->isTransparent() && \"transparent array list initialization is not string literal init?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10486, __extension__ __PRETTY_FUNCTION__))
8
Taking false branch
9
Assuming the condition is true
10
'?' condition is true
10486 "transparent array list initialization is not string literal init?")(static_cast <bool> (!E->isTransparent() && "transparent array list initialization is not string literal init?"
) ? void (0) : __assert_fail ("!E->isTransparent() && \"transparent array list initialization is not string literal init?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10486, __extension__ __PRETTY_FUNCTION__))
;
10487
10488 bool Success = true;
10489
10490 assert((!Result.isArray() || Result.getArrayInitializedElts() == 0) &&(static_cast <bool> ((!Result.isArray() || Result.getArrayInitializedElts
() == 0) && "zero-initialized array shouldn't have any initialized elts"
) ? void (0) : __assert_fail ("(!Result.isArray() || Result.getArrayInitializedElts() == 0) && \"zero-initialized array shouldn't have any initialized elts\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10491, __extension__ __PRETTY_FUNCTION__))
11
'?' condition is true
10491 "zero-initialized array shouldn't have any initialized elts")(static_cast <bool> ((!Result.isArray() || Result.getArrayInitializedElts
() == 0) && "zero-initialized array shouldn't have any initialized elts"
) ? void (0) : __assert_fail ("(!Result.isArray() || Result.getArrayInitializedElts() == 0) && \"zero-initialized array shouldn't have any initialized elts\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10491, __extension__ __PRETTY_FUNCTION__))
;
10492 APValue Filler;
10493 if (Result.isArray() && Result.hasArrayFiller())
10494 Filler = Result.getArrayFiller();
10495
10496 unsigned NumEltsToInit = E->getNumInits();
10497 unsigned NumElts = CAT->getSize().getZExtValue();
10498 const Expr *FillerExpr = E->hasArrayFiller() ? E->getArrayFiller() : nullptr;
12
Assuming the condition is false
13
'?' condition is false
14
'FillerExpr' initialized to a null pointer value
10499
10500 // If the initializer might depend on the array index, run it for each
10501 // array element.
10502 if (NumEltsToInit != NumElts && MaybeElementDependentArrayFiller(FillerExpr))
15
Assuming 'NumEltsToInit' is equal to 'NumElts'
10503 NumEltsToInit = NumElts;
10504
10505 LLVM_DEBUG(llvm::dbgs() << "The number of elements to initialize: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("exprconstant")) { llvm::dbgs() << "The number of elements to initialize: "
<< NumEltsToInit << ".\n"; } } while (false)
16
Assuming 'DebugFlag' is false
17
Loop condition is false. Exiting loop
10506 << NumEltsToInit << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("exprconstant")) { llvm::dbgs() << "The number of elements to initialize: "
<< NumEltsToInit << ".\n"; } } while (false)
;
10507
10508 Result = APValue(APValue::UninitArray(), NumEltsToInit, NumElts);
10509
10510 // If the array was previously zero-initialized, preserve the
10511 // zero-initialized values.
10512 if (Filler.hasValue()) {
18
Taking false branch
10513 for (unsigned I = 0, E = Result.getArrayInitializedElts(); I != E; ++I)
10514 Result.getArrayInitializedElt(I) = Filler;
10515 if (Result.hasArrayFiller())
10516 Result.getArrayFiller() = Filler;
10517 }
10518
10519 LValue Subobject = This;
10520 Subobject.addArray(Info, E, CAT);
10521 for (unsigned Index = 0; Index != NumEltsToInit; ++Index) {
19
Assuming 'Index' is not equal to 'NumEltsToInit'
10522 const Expr *Init =
20
Loop condition is true. Entering loop body
23
'Init' initialized to a null pointer value
10523 Index < E->getNumInits() ? E->getInit(Index) : FillerExpr;
21
Assuming the condition is false
22
'?' condition is false
10524 if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
24
Assuming the condition is false
10525 Info, Subobject, Init) ||
10526 !HandleLValueArrayAdjustment(Info, Init, Subobject,
25
Passing null pointer value via 2nd parameter 'E'
26
Calling 'HandleLValueArrayAdjustment'
10527 CAT->getElementType(), 1)) {
10528 if (!Info.noteFailure())
10529 return false;
10530 Success = false;
10531 }
10532 }
10533
10534 if (!Result.hasArrayFiller())
10535 return Success;
10536
10537 // If we get here, we have a trivial filler, which we can just evaluate
10538 // once and splat over the rest of the array elements.
10539 assert(FillerExpr && "no array filler for incomplete init list")(static_cast <bool> (FillerExpr && "no array filler for incomplete init list"
) ? void (0) : __assert_fail ("FillerExpr && \"no array filler for incomplete init list\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10539, __extension__ __PRETTY_FUNCTION__))
;
10540 return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject,
10541 FillerExpr) && Success;
10542}
10543
10544bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
10545 LValue CommonLV;
10546 if (E->getCommonExpr() &&
10547 !Evaluate(Info.CurrentCall->createTemporary(
10548 E->getCommonExpr(),
10549 getStorageType(Info.Ctx, E->getCommonExpr()),
10550 ScopeKind::FullExpression, CommonLV),
10551 Info, E->getCommonExpr()->getSourceExpr()))
10552 return false;
10553
10554 auto *CAT = cast<ConstantArrayType>(E->getType()->castAsArrayTypeUnsafe());
10555
10556 uint64_t Elements = CAT->getSize().getZExtValue();
10557 Result = APValue(APValue::UninitArray(), Elements, Elements);
10558
10559 LValue Subobject = This;
10560 Subobject.addArray(Info, E, CAT);
10561
10562 bool Success = true;
10563 for (EvalInfo::ArrayInitLoopIndex Index(Info); Index != Elements; ++Index) {
10564 if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
10565 Info, Subobject, E->getSubExpr()) ||
10566 !HandleLValueArrayAdjustment(Info, E, Subobject,
10567 CAT->getElementType(), 1)) {
10568 if (!Info.noteFailure())
10569 return false;
10570 Success = false;
10571 }
10572 }
10573
10574 return Success;
10575}
10576
10577bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
10578 return VisitCXXConstructExpr(E, This, &Result, E->getType());
10579}
10580
10581bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
10582 const LValue &Subobject,
10583 APValue *Value,
10584 QualType Type) {
10585 bool HadZeroInit = Value->hasValue();
10586
10587 if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(Type)) {
10588 unsigned N = CAT->getSize().getZExtValue();
10589
10590 // Preserve the array filler if we had prior zero-initialization.
10591 APValue Filler =
10592 HadZeroInit && Value->hasArrayFiller() ? Value->getArrayFiller()
10593 : APValue();
10594
10595 *Value = APValue(APValue::UninitArray(), N, N);
10596
10597 if (HadZeroInit)
10598 for (unsigned I = 0; I != N; ++I)
10599 Value->getArrayInitializedElt(I) = Filler;
10600
10601 // Initialize the elements.
10602 LValue ArrayElt = Subobject;
10603 ArrayElt.addArray(Info, E, CAT);
10604 for (unsigned I = 0; I != N; ++I)
10605 if (!VisitCXXConstructExpr(E, ArrayElt, &Value->getArrayInitializedElt(I),
10606 CAT->getElementType()) ||
10607 !HandleLValueArrayAdjustment(Info, E, ArrayElt,
10608 CAT->getElementType(), 1))
10609 return false;
10610
10611 return true;
10612 }
10613
10614 if (!Type->isRecordType())
10615 return Error(E);
10616
10617 return RecordExprEvaluator(Info, Subobject, *Value)
10618 .VisitCXXConstructExpr(E, Type);
10619}
10620
10621//===----------------------------------------------------------------------===//
10622// Integer Evaluation
10623//
10624// As a GNU extension, we support casting pointers to sufficiently-wide integer
10625// types and back in constant folding. Integer values are thus represented
10626// either as an integer-valued APValue, or as an lvalue-valued APValue.
10627//===----------------------------------------------------------------------===//
10628
10629namespace {
10630class IntExprEvaluator
10631 : public ExprEvaluatorBase<IntExprEvaluator> {
10632 APValue &Result;
10633public:
10634 IntExprEvaluator(EvalInfo &info, APValue &result)
10635 : ExprEvaluatorBaseTy(info), Result(result) {}
10636
10637 bool Success(const llvm::APSInt &SI, const Expr *E, APValue &Result) {
10638 assert(E->getType()->isIntegralOrEnumerationType() &&(static_cast <bool> (E->getType()->isIntegralOrEnumerationType
() && "Invalid evaluation result.") ? void (0) : __assert_fail
("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10639, __extension__ __PRETTY_FUNCTION__))
10639 "Invalid evaluation result.")(static_cast <bool> (E->getType()->isIntegralOrEnumerationType
() && "Invalid evaluation result.") ? void (0) : __assert_fail
("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10639, __extension__ __PRETTY_FUNCTION__))
;
10640 assert(SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() &&(static_cast <bool> (SI.isSigned() == E->getType()->
isSignedIntegerOrEnumerationType() && "Invalid evaluation result."
) ? void (0) : __assert_fail ("SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10641, __extension__ __PRETTY_FUNCTION__))
10641 "Invalid evaluation result.")(static_cast <bool> (SI.isSigned() == E->getType()->
isSignedIntegerOrEnumerationType() && "Invalid evaluation result."
) ? void (0) : __assert_fail ("SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10641, __extension__ __PRETTY_FUNCTION__))
;
10642 assert(SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&(static_cast <bool> (SI.getBitWidth() == Info.Ctx.getIntWidth
(E->getType()) && "Invalid evaluation result.") ? void
(0) : __assert_fail ("SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10643, __extension__ __PRETTY_FUNCTION__))
10643 "Invalid evaluation result.")(static_cast <bool> (SI.getBitWidth() == Info.Ctx.getIntWidth
(E->getType()) && "Invalid evaluation result.") ? void
(0) : __assert_fail ("SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10643, __extension__ __PRETTY_FUNCTION__))
;
10644 Result = APValue(SI);
10645 return true;
10646 }
10647 bool Success(const llvm::APSInt &SI, const Expr *E) {
10648 return Success(SI, E, Result);
10649 }
10650
10651 bool Success(const llvm::APInt &I, const Expr *E, APValue &Result) {
10652 assert(E->getType()->isIntegralOrEnumerationType() &&(static_cast <bool> (E->getType()->isIntegralOrEnumerationType
() && "Invalid evaluation result.") ? void (0) : __assert_fail
("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10653, __extension__ __PRETTY_FUNCTION__))
10653 "Invalid evaluation result.")(static_cast <bool> (E->getType()->isIntegralOrEnumerationType
() && "Invalid evaluation result.") ? void (0) : __assert_fail
("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10653, __extension__ __PRETTY_FUNCTION__))
;
10654 assert(I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&(static_cast <bool> (I.getBitWidth() == Info.Ctx.getIntWidth
(E->getType()) && "Invalid evaluation result.") ? void
(0) : __assert_fail ("I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10655, __extension__ __PRETTY_FUNCTION__))
10655 "Invalid evaluation result.")(static_cast <bool> (I.getBitWidth() == Info.Ctx.getIntWidth
(E->getType()) && "Invalid evaluation result.") ? void
(0) : __assert_fail ("I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10655, __extension__ __PRETTY_FUNCTION__))
;
10656 Result = APValue(APSInt(I));
10657 Result.getInt().setIsUnsigned(
10658 E->getType()->isUnsignedIntegerOrEnumerationType());
10659 return true;
10660 }
10661 bool Success(const llvm::APInt &I, const Expr *E) {
10662 return Success(I, E, Result);
10663 }
10664
10665 bool Success(uint64_t Value, const Expr *E, APValue &Result) {
10666 assert(E->getType()->isIntegralOrEnumerationType() &&(static_cast <bool> (E->getType()->isIntegralOrEnumerationType
() && "Invalid evaluation result.") ? void (0) : __assert_fail
("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10667, __extension__ __PRETTY_FUNCTION__))
10667 "Invalid evaluation result.")(static_cast <bool> (E->getType()->isIntegralOrEnumerationType
() && "Invalid evaluation result.") ? void (0) : __assert_fail
("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10667, __extension__ __PRETTY_FUNCTION__))
;
10668 Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType()));
10669 return true;
10670 }
10671 bool Success(uint64_t Value, const Expr *E) {
10672 return Success(Value, E, Result);
10673 }
10674
10675 bool Success(CharUnits Size, const Expr *E) {
10676 return Success(Size.getQuantity(), E);
10677 }
10678
10679 bool Success(const APValue &V, const Expr *E) {
10680 if (V.isLValue() || V.isAddrLabelDiff() || V.isIndeterminate()) {
10681 Result = V;
10682 return true;
10683 }
10684 return Success(V.getInt(), E);
10685 }
10686
10687 bool ZeroInitialization(const Expr *E) { return Success(0, E); }
10688
10689 //===--------------------------------------------------------------------===//
10690 // Visitor Methods
10691 //===--------------------------------------------------------------------===//
10692
10693 bool VisitIntegerLiteral(const IntegerLiteral *E) {
10694 return Success(E->getValue(), E);
10695 }
10696 bool VisitCharacterLiteral(const CharacterLiteral *E) {
10697 return Success(E->getValue(), E);
10698 }
10699
10700 bool CheckReferencedDecl(const Expr *E, const Decl *D);
10701 bool VisitDeclRefExpr(const DeclRefExpr *E) {
10702 if (CheckReferencedDecl(E, E->getDecl()))
10703 return true;
10704
10705 return ExprEvaluatorBaseTy::VisitDeclRefExpr(E);
10706 }
10707 bool VisitMemberExpr(const MemberExpr *E) {
10708 if (CheckReferencedDecl(E, E->getMemberDecl())) {
10709 VisitIgnoredBaseExpression(E->getBase());
10710 return true;
10711 }
10712
10713 return ExprEvaluatorBaseTy::VisitMemberExpr(E);
10714 }
10715
10716 bool VisitCallExpr(const CallExpr *E);
10717 bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
10718 bool VisitBinaryOperator(const BinaryOperator *E);
10719 bool VisitOffsetOfExpr(const OffsetOfExpr *E);
10720 bool VisitUnaryOperator(const UnaryOperator *E);
10721
10722 bool VisitCastExpr(const CastExpr* E);
10723 bool VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
10724
10725 bool VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
10726 return Success(E->getValue(), E);
10727 }
10728
10729 bool VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) {
10730 return Success(E->getValue(), E);
10731 }
10732
10733 bool VisitArrayInitIndexExpr(const ArrayInitIndexExpr *E) {
10734 if (Info.ArrayInitIndex == uint64_t(-1)) {
10735 // We were asked to evaluate this subexpression independent of the
10736 // enclosing ArrayInitLoopExpr. We can't do that.
10737 Info.FFDiag(E);
10738 return false;
10739 }
10740 return Success(Info.ArrayInitIndex, E);
10741 }
10742
10743 // Note, GNU defines __null as an integer, not a pointer.
10744 bool VisitGNUNullExpr(const GNUNullExpr *E) {
10745 return ZeroInitialization(E);
10746 }
10747
10748 bool VisitTypeTraitExpr(const TypeTraitExpr *E) {
10749 return Success(E->getValue(), E);
10750 }
10751
10752 bool VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
10753 return Success(E->getValue(), E);
10754 }
10755
10756 bool VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
10757 return Success(E->getValue(), E);
10758 }
10759
10760 bool VisitUnaryReal(const UnaryOperator *E);
10761 bool VisitUnaryImag(const UnaryOperator *E);
10762
10763 bool VisitCXXNoexceptExpr(const CXXNoexceptExpr *E);
10764 bool VisitSizeOfPackExpr(const SizeOfPackExpr *E);
10765 bool VisitSourceLocExpr(const SourceLocExpr *E);
10766 bool VisitConceptSpecializationExpr(const ConceptSpecializationExpr *E);
10767 bool VisitRequiresExpr(const RequiresExpr *E);
10768 // FIXME: Missing: array subscript of vector, member of vector
10769};
10770
10771class FixedPointExprEvaluator
10772 : public ExprEvaluatorBase<FixedPointExprEvaluator> {
10773 APValue &Result;
10774
10775 public:
10776 FixedPointExprEvaluator(EvalInfo &info, APValue &result)
10777 : ExprEvaluatorBaseTy(info), Result(result) {}
10778
10779 bool Success(const llvm::APInt &I, const Expr *E) {
10780 return Success(
10781 APFixedPoint(I, Info.Ctx.getFixedPointSemantics(E->getType())), E);
10782 }
10783
10784 bool Success(uint64_t Value, const Expr *E) {
10785 return Success(
10786 APFixedPoint(Value, Info.Ctx.getFixedPointSemantics(E->getType())), E);
10787 }
10788
10789 bool Success(const APValue &V, const Expr *E) {
10790 return Success(V.getFixedPoint(), E);
10791 }
10792
10793 bool Success(const APFixedPoint &V, const Expr *E) {
10794 assert(E->getType()->isFixedPointType() && "Invalid evaluation result.")(static_cast <bool> (E->getType()->isFixedPointType
() && "Invalid evaluation result.") ? void (0) : __assert_fail
("E->getType()->isFixedPointType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10794, __extension__ __PRETTY_FUNCTION__))
;
10795 assert(V.getWidth() == Info.Ctx.getIntWidth(E->getType()) &&(static_cast <bool> (V.getWidth() == Info.Ctx.getIntWidth
(E->getType()) && "Invalid evaluation result.") ? void
(0) : __assert_fail ("V.getWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10796, __extension__ __PRETTY_FUNCTION__))
10796 "Invalid evaluation result.")(static_cast <bool> (V.getWidth() == Info.Ctx.getIntWidth
(E->getType()) && "Invalid evaluation result.") ? void
(0) : __assert_fail ("V.getWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10796, __extension__ __PRETTY_FUNCTION__))
;
10797 Result = APValue(V);
10798 return true;
10799 }
10800
10801 //===--------------------------------------------------------------------===//
10802 // Visitor Methods
10803 //===--------------------------------------------------------------------===//
10804
10805 bool VisitFixedPointLiteral(const FixedPointLiteral *E) {
10806 return Success(E->getValue(), E);
10807 }
10808
10809 bool VisitCastExpr(const CastExpr *E);
10810 bool VisitUnaryOperator(const UnaryOperator *E);
10811 bool VisitBinaryOperator(const BinaryOperator *E);
10812};
10813} // end anonymous namespace
10814
10815/// EvaluateIntegerOrLValue - Evaluate an rvalue integral-typed expression, and
10816/// produce either the integer value or a pointer.
10817///
10818/// GCC has a heinous extension which folds casts between pointer types and
10819/// pointer-sized integral types. We support this by allowing the evaluation of
10820/// an integer rvalue to produce a pointer (represented as an lvalue) instead.
10821/// Some simple arithmetic on such values is supported (they are treated much
10822/// like char*).
10823static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
10824 EvalInfo &Info) {
10825 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10825, __extension__ __PRETTY_FUNCTION__))
;
10826 assert(E->isPRValue() && E->getType()->isIntegralOrEnumerationType())(static_cast <bool> (E->isPRValue() && E->
getType()->isIntegralOrEnumerationType()) ? void (0) : __assert_fail
("E->isPRValue() && E->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10826, __extension__ __PRETTY_FUNCTION__))
;
10827 return IntExprEvaluator(Info, Result).Visit(E);
10828}
10829
10830static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info) {
10831 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10831, __extension__ __PRETTY_FUNCTION__))
;
10832 APValue Val;
10833 if (!EvaluateIntegerOrLValue(E, Val, Info))
10834 return false;
10835 if (!Val.isInt()) {
10836 // FIXME: It would be better to produce the diagnostic for casting
10837 // a pointer to an integer.
10838 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
10839 return false;
10840 }
10841 Result = Val.getInt();
10842 return true;
10843}
10844
10845bool IntExprEvaluator::VisitSourceLocExpr(const SourceLocExpr *E) {
10846 APValue Evaluated = E->EvaluateInContext(
10847 Info.Ctx, Info.CurrentCall->CurSourceLocExprScope.getDefaultExpr());
10848 return Success(Evaluated, E);
10849}
10850
10851static bool EvaluateFixedPoint(const Expr *E, APFixedPoint &Result,
10852 EvalInfo &Info) {
10853 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10853, __extension__ __PRETTY_FUNCTION__))
;
10854 if (E->getType()->isFixedPointType()) {
10855 APValue Val;
10856 if (!FixedPointExprEvaluator(Info, Val).Visit(E))
10857 return false;
10858 if (!Val.isFixedPoint())
10859 return false;
10860
10861 Result = Val.getFixedPoint();
10862 return true;
10863 }
10864 return false;
10865}
10866
10867static bool EvaluateFixedPointOrInteger(const Expr *E, APFixedPoint &Result,
10868 EvalInfo &Info) {
10869 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10869, __extension__ __PRETTY_FUNCTION__))
;
10870 if (E->getType()->isIntegerType()) {
10871 auto FXSema = Info.Ctx.getFixedPointSemantics(E->getType());
10872 APSInt Val;
10873 if (!EvaluateInteger(E, Val, Info))
10874 return false;
10875 Result = APFixedPoint(Val, FXSema);
10876 return true;
10877 } else if (E->getType()->isFixedPointType()) {
10878 return EvaluateFixedPoint(E, Result, Info);
10879 }
10880 return false;
10881}
10882
10883/// Check whether the given declaration can be directly converted to an integral
10884/// rvalue. If not, no diagnostic is produced; there are other things we can
10885/// try.
10886bool IntExprEvaluator::CheckReferencedDecl(const Expr* E, const Decl* D) {
10887 // Enums are integer constant exprs.
10888 if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) {
10889 // Check for signedness/width mismatches between E type and ECD value.
10890 bool SameSign = (ECD->getInitVal().isSigned()
10891 == E->getType()->isSignedIntegerOrEnumerationType());
10892 bool SameWidth = (ECD->getInitVal().getBitWidth()
10893 == Info.Ctx.getIntWidth(E->getType()));
10894 if (SameSign && SameWidth)
10895 return Success(ECD->getInitVal(), E);
10896 else {
10897 // Get rid of mismatch (otherwise Success assertions will fail)
10898 // by computing a new value matching the type of E.
10899 llvm::APSInt Val = ECD->getInitVal();
10900 if (!SameSign)
10901 Val.setIsSigned(!ECD->getInitVal().isSigned());
10902 if (!SameWidth)
10903 Val = Val.extOrTrunc(Info.Ctx.getIntWidth(E->getType()));
10904 return Success(Val, E);
10905 }
10906 }
10907 return false;
10908}
10909
10910/// Values returned by __builtin_classify_type, chosen to match the values
10911/// produced by GCC's builtin.
10912enum class GCCTypeClass {
10913 None = -1,
10914 Void = 0,
10915 Integer = 1,
10916 // GCC reserves 2 for character types, but instead classifies them as
10917 // integers.
10918 Enum = 3,
10919 Bool = 4,
10920 Pointer = 5,
10921 // GCC reserves 6 for references, but appears to never use it (because
10922 // expressions never have reference type, presumably).
10923 PointerToDataMember = 7,
10924 RealFloat = 8,
10925 Complex = 9,
10926 // GCC reserves 10 for functions, but does not use it since GCC version 6 due
10927 // to decay to pointer. (Prior to version 6 it was only used in C++ mode).
10928 // GCC claims to reserve 11 for pointers to member functions, but *actually*
10929 // uses 12 for that purpose, same as for a class or struct. Maybe it
10930 // internally implements a pointer to member as a struct? Who knows.
10931 PointerToMemberFunction = 12, // Not a bug, see above.
10932 ClassOrStruct = 12,
10933 Union = 13,
10934 // GCC reserves 14 for arrays, but does not use it since GCC version 6 due to
10935 // decay to pointer. (Prior to version 6 it was only used in C++ mode).
10936 // GCC reserves 15 for strings, but actually uses 5 (pointer) for string
10937 // literals.
10938};
10939
10940/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
10941/// as GCC.
10942static GCCTypeClass
10943EvaluateBuiltinClassifyType(QualType T, const LangOptions &LangOpts) {
10944 assert(!T->isDependentType() && "unexpected dependent type")(static_cast <bool> (!T->isDependentType() &&
"unexpected dependent type") ? void (0) : __assert_fail ("!T->isDependentType() && \"unexpected dependent type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10944, __extension__ __PRETTY_FUNCTION__))
;
10945
10946 QualType CanTy = T.getCanonicalType();
10947 const BuiltinType *BT = dyn_cast<BuiltinType>(CanTy);
10948
10949 switch (CanTy->getTypeClass()) {
10950#define TYPE(ID, BASE)
10951#define DEPENDENT_TYPE(ID, BASE) case Type::ID:
10952#define NON_CANONICAL_TYPE(ID, BASE) case Type::ID:
10953#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(ID, BASE) case Type::ID:
10954#include "clang/AST/TypeNodes.inc"
10955 case Type::Auto:
10956 case Type::DeducedTemplateSpecialization:
10957 llvm_unreachable("unexpected non-canonical or dependent type")::llvm::llvm_unreachable_internal("unexpected non-canonical or dependent type"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 10957)
;
10958
10959 case Type::Builtin:
10960 switch (BT->getKind()) {
10961#define BUILTIN_TYPE(ID, SINGLETON_ID)
10962#define SIGNED_TYPE(ID, SINGLETON_ID) \
10963 case BuiltinType::ID: return GCCTypeClass::Integer;
10964#define FLOATING_TYPE(ID, SINGLETON_ID) \
10965 case BuiltinType::ID: return GCCTypeClass::RealFloat;
10966#define PLACEHOLDER_TYPE(ID, SINGLETON_ID) \
10967 case BuiltinType::ID: break;
10968#include "clang/AST/BuiltinTypes.def"
10969 case BuiltinType::Void:
10970 return GCCTypeClass::Void;
10971
10972 case BuiltinType::Bool:
10973 return GCCTypeClass::Bool;
10974
10975 case BuiltinType::Char_U:
10976 case BuiltinType::UChar:
10977 case BuiltinType::WChar_U:
10978 case BuiltinType::Char8:
10979 case BuiltinType::Char16:
10980 case BuiltinType::Char32:
10981 case BuiltinType::UShort:
10982 case BuiltinType::UInt:
10983 case BuiltinType::ULong:
10984 case BuiltinType::ULongLong:
10985 case BuiltinType::UInt128:
10986 return GCCTypeClass::Integer;
10987
10988 case BuiltinType::UShortAccum:
10989 case BuiltinType::UAccum:
10990 case BuiltinType::ULongAccum:
10991 case BuiltinType::UShortFract:
10992 case BuiltinType::UFract:
10993 case BuiltinType::ULongFract:
10994 case BuiltinType::SatUShortAccum:
10995 case BuiltinType::SatUAccum:
10996 case BuiltinType::SatULongAccum:
10997 case BuiltinType::SatUShortFract:
10998 case BuiltinType::SatUFract:
10999 case BuiltinType::SatULongFract:
11000 return GCCTypeClass::None;
11001
11002 case BuiltinType::NullPtr:
11003
11004 case BuiltinType::ObjCId:
11005 case BuiltinType::ObjCClass:
11006 case BuiltinType::ObjCSel:
11007#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
11008 case BuiltinType::Id:
11009#include "clang/Basic/OpenCLImageTypes.def"
11010#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
11011 case BuiltinType::Id:
11012#include "clang/Basic/OpenCLExtensionTypes.def"
11013 case BuiltinType::OCLSampler:
11014 case BuiltinType::OCLEvent:
11015 case BuiltinType::OCLClkEvent:
11016 case BuiltinType::OCLQueue:
11017 case BuiltinType::OCLReserveID:
11018#define SVE_TYPE(Name, Id, SingletonId) \
11019 case BuiltinType::Id:
11020#include "clang/Basic/AArch64SVEACLETypes.def"
11021#define PPC_VECTOR_TYPE(Name, Id, Size) \
11022 case BuiltinType::Id:
11023#include "clang/Basic/PPCTypes.def"
11024#define RVV_TYPE(Name, Id, SingletonId) case BuiltinType::Id:
11025#include "clang/Basic/RISCVVTypes.def"
11026 return GCCTypeClass::None;
11027
11028 case BuiltinType::Dependent:
11029 llvm_unreachable("unexpected dependent type")::llvm::llvm_unreachable_internal("unexpected dependent type"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11029)
;
11030 };
11031 llvm_unreachable("unexpected placeholder type")::llvm::llvm_unreachable_internal("unexpected placeholder type"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11031)
;
11032
11033 case Type::Enum:
11034 return LangOpts.CPlusPlus ? GCCTypeClass::Enum : GCCTypeClass::Integer;
11035
11036 case Type::Pointer:
11037 case Type::ConstantArray:
11038 case Type::VariableArray:
11039 case Type::IncompleteArray:
11040 case Type::FunctionNoProto:
11041 case Type::FunctionProto:
11042 return GCCTypeClass::Pointer;
11043
11044 case Type::MemberPointer:
11045 return CanTy->isMemberDataPointerType()
11046 ? GCCTypeClass::PointerToDataMember
11047 : GCCTypeClass::PointerToMemberFunction;
11048
11049 case Type::Complex:
11050 return GCCTypeClass::Complex;
11051
11052 case Type::Record:
11053 return CanTy->isUnionType() ? GCCTypeClass::Union
11054 : GCCTypeClass::ClassOrStruct;
11055
11056 case Type::Atomic:
11057 // GCC classifies _Atomic T the same as T.
11058 return EvaluateBuiltinClassifyType(
11059 CanTy->castAs<AtomicType>()->getValueType(), LangOpts);
11060
11061 case Type::BlockPointer:
11062 case Type::Vector:
11063 case Type::ExtVector:
11064 case Type::ConstantMatrix:
11065 case Type::ObjCObject:
11066 case Type::ObjCInterface:
11067 case Type::ObjCObjectPointer:
11068 case Type::Pipe:
11069 case Type::ExtInt:
11070 // GCC classifies vectors as None. We follow its lead and classify all
11071 // other types that don't fit into the regular classification the same way.
11072 return GCCTypeClass::None;
11073
11074 case Type::LValueReference:
11075 case Type::RValueReference:
11076 llvm_unreachable("invalid type for expression")::llvm::llvm_unreachable_internal("invalid type for expression"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11076)
;
11077 }
11078
11079 llvm_unreachable("unexpected type class")::llvm::llvm_unreachable_internal("unexpected type class", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11079)
;
11080}
11081
11082/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
11083/// as GCC.
11084static GCCTypeClass
11085EvaluateBuiltinClassifyType(const CallExpr *E, const LangOptions &LangOpts) {
11086 // If no argument was supplied, default to None. This isn't
11087 // ideal, however it is what gcc does.
11088 if (E->getNumArgs() == 0)
11089 return GCCTypeClass::None;
11090
11091 // FIXME: Bizarrely, GCC treats a call with more than one argument as not
11092 // being an ICE, but still folds it to a constant using the type of the first
11093 // argument.
11094 return EvaluateBuiltinClassifyType(E->getArg(0)->getType(), LangOpts);
11095}
11096
11097/// EvaluateBuiltinConstantPForLValue - Determine the result of
11098/// __builtin_constant_p when applied to the given pointer.
11099///
11100/// A pointer is only "constant" if it is null (or a pointer cast to integer)
11101/// or it points to the first character of a string literal.
11102static bool EvaluateBuiltinConstantPForLValue(const APValue &LV) {
11103 APValue::LValueBase Base = LV.getLValueBase();
11104 if (Base.isNull()) {
11105 // A null base is acceptable.
11106 return true;
11107 } else if (const Expr *E = Base.dyn_cast<const Expr *>()) {
11108 if (!isa<StringLiteral>(E))
11109 return false;
11110 return LV.getLValueOffset().isZero();
11111 } else if (Base.is<TypeInfoLValue>()) {
11112 // Surprisingly, GCC considers __builtin_constant_p(&typeid(int)) to
11113 // evaluate to true.
11114 return true;
11115 } else {
11116 // Any other base is not constant enough for GCC.
11117 return false;
11118 }
11119}
11120
11121/// EvaluateBuiltinConstantP - Evaluate __builtin_constant_p as similarly to
11122/// GCC as we can manage.
11123static bool EvaluateBuiltinConstantP(EvalInfo &Info, const Expr *Arg) {
11124 // This evaluation is not permitted to have side-effects, so evaluate it in
11125 // a speculative evaluation context.
11126 SpeculativeEvaluationRAII SpeculativeEval(Info);
11127
11128 // Constant-folding is always enabled for the operand of __builtin_constant_p
11129 // (even when the enclosing evaluation context otherwise requires a strict
11130 // language-specific constant expression).
11131 FoldConstant Fold(Info, true);
11132
11133 QualType ArgType = Arg->getType();
11134
11135 // __builtin_constant_p always has one operand. The rules which gcc follows
11136 // are not precisely documented, but are as follows:
11137 //
11138 // - If the operand is of integral, floating, complex or enumeration type,
11139 // and can be folded to a known value of that type, it returns 1.
11140 // - If the operand can be folded to a pointer to the first character
11141 // of a string literal (or such a pointer cast to an integral type)
11142 // or to a null pointer or an integer cast to a pointer, it returns 1.
11143 //
11144 // Otherwise, it returns 0.
11145 //
11146 // FIXME: GCC also intends to return 1 for literals of aggregate types, but
11147 // its support for this did not work prior to GCC 9 and is not yet well
11148 // understood.
11149 if (ArgType->isIntegralOrEnumerationType() || ArgType->isFloatingType() ||
11150 ArgType->isAnyComplexType() || ArgType->isPointerType() ||
11151 ArgType->isNullPtrType()) {
11152 APValue V;
11153 if (!::EvaluateAsRValue(Info, Arg, V) || Info.EvalStatus.HasSideEffects) {
11154 Fold.keepDiagnostics();
11155 return false;
11156 }
11157
11158 // For a pointer (possibly cast to integer), there are special rules.
11159 if (V.getKind() == APValue::LValue)
11160 return EvaluateBuiltinConstantPForLValue(V);
11161
11162 // Otherwise, any constant value is good enough.
11163 return V.hasValue();
11164 }
11165
11166 // Anything else isn't considered to be sufficiently constant.
11167 return false;
11168}
11169
11170/// Retrieves the "underlying object type" of the given expression,
11171/// as used by __builtin_object_size.
11172static QualType getObjectType(APValue::LValueBase B) {
11173 if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
11174 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
11175 return VD->getType();
11176 } else if (const Expr *E = B.dyn_cast<const Expr*>()) {
11177 if (isa<CompoundLiteralExpr>(E))
11178 return E->getType();
11179 } else if (B.is<TypeInfoLValue>()) {
11180 return B.getTypeInfoType();
11181 } else if (B.is<DynamicAllocLValue>()) {
11182 return B.getDynamicAllocType();
11183 }
11184
11185 return QualType();
11186}
11187
11188/// A more selective version of E->IgnoreParenCasts for
11189/// tryEvaluateBuiltinObjectSize. This ignores some casts/parens that serve only
11190/// to change the type of E.
11191/// Ex. For E = `(short*)((char*)(&foo))`, returns `&foo`
11192///
11193/// Always returns an RValue with a pointer representation.
11194static const Expr *ignorePointerCastsAndParens(const Expr *E) {
11195 assert(E->isPRValue() && E->getType()->hasPointerRepresentation())(static_cast <bool> (E->isPRValue() && E->
getType()->hasPointerRepresentation()) ? void (0) : __assert_fail
("E->isPRValue() && E->getType()->hasPointerRepresentation()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11195, __extension__ __PRETTY_FUNCTION__))
;
11196
11197 auto *NoParens = E->IgnoreParens();
11198 auto *Cast = dyn_cast<CastExpr>(NoParens);
11199 if (Cast == nullptr)
11200 return NoParens;
11201
11202 // We only conservatively allow a few kinds of casts, because this code is
11203 // inherently a simple solution that seeks to support the common case.
11204 auto CastKind = Cast->getCastKind();
11205 if (CastKind != CK_NoOp && CastKind != CK_BitCast &&
11206 CastKind != CK_AddressSpaceConversion)
11207 return NoParens;
11208
11209 auto *SubExpr = Cast->getSubExpr();
11210 if (!SubExpr->getType()->hasPointerRepresentation() || !SubExpr->isPRValue())
11211 return NoParens;
11212 return ignorePointerCastsAndParens(SubExpr);
11213}
11214
11215/// Checks to see if the given LValue's Designator is at the end of the LValue's
11216/// record layout. e.g.
11217/// struct { struct { int a, b; } fst, snd; } obj;
11218/// obj.fst // no
11219/// obj.snd // yes
11220/// obj.fst.a // no
11221/// obj.fst.b // no
11222/// obj.snd.a // no
11223/// obj.snd.b // yes
11224///
11225/// Please note: this function is specialized for how __builtin_object_size
11226/// views "objects".
11227///
11228/// If this encounters an invalid RecordDecl or otherwise cannot determine the
11229/// correct result, it will always return true.
11230static bool isDesignatorAtObjectEnd(const ASTContext &Ctx, const LValue &LVal) {
11231 assert(!LVal.Designator.Invalid)(static_cast <bool> (!LVal.Designator.Invalid) ? void (
0) : __assert_fail ("!LVal.Designator.Invalid", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11231, __extension__ __PRETTY_FUNCTION__))
;
11232
11233 auto IsLastOrInvalidFieldDecl = [&Ctx](const FieldDecl *FD, bool &Invalid) {
11234 const RecordDecl *Parent = FD->getParent();
11235 Invalid = Parent->isInvalidDecl();
11236 if (Invalid || Parent->isUnion())
11237 return true;
11238 const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(Parent);
11239 return FD->getFieldIndex() + 1 == Layout.getFieldCount();
11240 };
11241
11242 auto &Base = LVal.getLValueBase();
11243 if (auto *ME = dyn_cast_or_null<MemberExpr>(Base.dyn_cast<const Expr *>())) {
11244 if (auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
11245 bool Invalid;
11246 if (!IsLastOrInvalidFieldDecl(FD, Invalid))
11247 return Invalid;
11248 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(ME->getMemberDecl())) {
11249 for (auto *FD : IFD->chain()) {
11250 bool Invalid;
11251 if (!IsLastOrInvalidFieldDecl(cast<FieldDecl>(FD), Invalid))
11252 return Invalid;
11253 }
11254 }
11255 }
11256
11257 unsigned I = 0;
11258 QualType BaseType = getType(Base);
11259 if (LVal.Designator.FirstEntryIsAnUnsizedArray) {
11260 // If we don't know the array bound, conservatively assume we're looking at
11261 // the final array element.
11262 ++I;
11263 if (BaseType->isIncompleteArrayType())
11264 BaseType = Ctx.getAsArrayType(BaseType)->getElementType();
11265 else
11266 BaseType = BaseType->castAs<PointerType>()->getPointeeType();
11267 }
11268
11269 for (unsigned E = LVal.Designator.Entries.size(); I != E; ++I) {
11270 const auto &Entry = LVal.Designator.Entries[I];
11271 if (BaseType->isArrayType()) {
11272 // Because __builtin_object_size treats arrays as objects, we can ignore
11273 // the index iff this is the last array in the Designator.
11274 if (I + 1 == E)
11275 return true;
11276 const auto *CAT = cast<ConstantArrayType>(Ctx.getAsArrayType(BaseType));
11277 uint64_t Index = Entry.getAsArrayIndex();
11278 if (Index + 1 != CAT->getSize())
11279 return false;
11280 BaseType = CAT->getElementType();
11281 } else if (BaseType->isAnyComplexType()) {
11282 const auto *CT = BaseType->castAs<ComplexType>();
11283 uint64_t Index = Entry.getAsArrayIndex();
11284 if (Index != 1)
11285 return false;
11286 BaseType = CT->getElementType();
11287 } else if (auto *FD = getAsField(Entry)) {
11288 bool Invalid;
11289 if (!IsLastOrInvalidFieldDecl(FD, Invalid))
11290 return Invalid;
11291 BaseType = FD->getType();
11292 } else {
11293 assert(getAsBaseClass(Entry) && "Expecting cast to a base class")(static_cast <bool> (getAsBaseClass(Entry) && "Expecting cast to a base class"
) ? void (0) : __assert_fail ("getAsBaseClass(Entry) && \"Expecting cast to a base class\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11293, __extension__ __PRETTY_FUNCTION__))
;
11294 return false;
11295 }
11296 }
11297 return true;
11298}
11299
11300/// Tests to see if the LValue has a user-specified designator (that isn't
11301/// necessarily valid). Note that this always returns 'true' if the LValue has
11302/// an unsized array as its first designator entry, because there's currently no
11303/// way to tell if the user typed *foo or foo[0].
11304static bool refersToCompleteObject(const LValue &LVal) {
11305 if (LVal.Designator.Invalid)
11306 return false;
11307
11308 if (!LVal.Designator.Entries.empty())
11309 return LVal.Designator.isMostDerivedAnUnsizedArray();
11310
11311 if (!LVal.InvalidBase)
11312 return true;
11313
11314 // If `E` is a MemberExpr, then the first part of the designator is hiding in
11315 // the LValueBase.
11316 const auto *E = LVal.Base.dyn_cast<const Expr *>();
11317 return !E || !isa<MemberExpr>(E);
11318}
11319
11320/// Attempts to detect a user writing into a piece of memory that's impossible
11321/// to figure out the size of by just using types.
11322static bool isUserWritingOffTheEnd(const ASTContext &Ctx, const LValue &LVal) {
11323 const SubobjectDesignator &Designator = LVal.Designator;
11324 // Notes:
11325 // - Users can only write off of the end when we have an invalid base. Invalid
11326 // bases imply we don't know where the memory came from.
11327 // - We used to be a bit more aggressive here; we'd only be conservative if
11328 // the array at the end was flexible, or if it had 0 or 1 elements. This
11329 // broke some common standard library extensions (PR30346), but was
11330 // otherwise seemingly fine. It may be useful to reintroduce this behavior
11331 // with some sort of list. OTOH, it seems that GCC is always
11332 // conservative with the last element in structs (if it's an array), so our
11333 // current behavior is more compatible than an explicit list approach would
11334 // be.
11335 return LVal.InvalidBase &&
11336 Designator.Entries.size() == Designator.MostDerivedPathLength &&
11337 Designator.MostDerivedIsArrayElement &&
11338 isDesignatorAtObjectEnd(Ctx, LVal);
11339}
11340
11341/// Converts the given APInt to CharUnits, assuming the APInt is unsigned.
11342/// Fails if the conversion would cause loss of precision.
11343static bool convertUnsignedAPIntToCharUnits(const llvm::APInt &Int,
11344 CharUnits &Result) {
11345 auto CharUnitsMax = std::numeric_limits<CharUnits::QuantityType>::max();
11346 if (Int.ugt(CharUnitsMax))
11347 return false;
11348 Result = CharUnits::fromQuantity(Int.getZExtValue());
11349 return true;
11350}
11351
11352/// Helper for tryEvaluateBuiltinObjectSize -- Given an LValue, this will
11353/// determine how many bytes exist from the beginning of the object to either
11354/// the end of the current subobject, or the end of the object itself, depending
11355/// on what the LValue looks like + the value of Type.
11356///
11357/// If this returns false, the value of Result is undefined.
11358static bool determineEndOffset(EvalInfo &Info, SourceLocation ExprLoc,
11359 unsigned Type, const LValue &LVal,
11360 CharUnits &EndOffset) {
11361 bool DetermineForCompleteObject = refersToCompleteObject(LVal);
11362
11363 auto CheckedHandleSizeof = [&](QualType Ty, CharUnits &Result) {
11364 if (Ty.isNull() || Ty->isIncompleteType() || Ty->isFunctionType())
11365 return false;
11366 return HandleSizeof(Info, ExprLoc, Ty, Result);
11367 };
11368
11369 // We want to evaluate the size of the entire object. This is a valid fallback
11370 // for when Type=1 and the designator is invalid, because we're asked for an
11371 // upper-bound.
11372 if (!(Type & 1) || LVal.Designator.Invalid || DetermineForCompleteObject) {
11373 // Type=3 wants a lower bound, so we can't fall back to this.
11374 if (Type == 3 && !DetermineForCompleteObject)
11375 return false;
11376
11377 llvm::APInt APEndOffset;
11378 if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
11379 getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
11380 return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
11381
11382 if (LVal.InvalidBase)
11383 return false;
11384
11385 QualType BaseTy = getObjectType(LVal.getLValueBase());
11386 return CheckedHandleSizeof(BaseTy, EndOffset);
11387 }
11388
11389 // We want to evaluate the size of a subobject.
11390 const SubobjectDesignator &Designator = LVal.Designator;
11391
11392 // The following is a moderately common idiom in C:
11393 //
11394 // struct Foo { int a; char c[1]; };
11395 // struct Foo *F = (struct Foo *)malloc(sizeof(struct Foo) + strlen(Bar));
11396 // strcpy(&F->c[0], Bar);
11397 //
11398 // In order to not break too much legacy code, we need to support it.
11399 if (isUserWritingOffTheEnd(Info.Ctx, LVal)) {
11400 // If we can resolve this to an alloc_size call, we can hand that back,
11401 // because we know for certain how many bytes there are to write to.
11402 llvm::APInt APEndOffset;
11403 if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
11404 getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
11405 return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
11406
11407 // If we cannot determine the size of the initial allocation, then we can't
11408 // given an accurate upper-bound. However, we are still able to give
11409 // conservative lower-bounds for Type=3.
11410 if (Type == 1)
11411 return false;
11412 }
11413
11414 CharUnits BytesPerElem;
11415 if (!CheckedHandleSizeof(Designator.MostDerivedType, BytesPerElem))
11416 return false;
11417
11418 // According to the GCC documentation, we want the size of the subobject
11419 // denoted by the pointer. But that's not quite right -- what we actually
11420 // want is the size of the immediately-enclosing array, if there is one.
11421 int64_t ElemsRemaining;
11422 if (Designator.MostDerivedIsArrayElement &&
11423 Designator.Entries.size() == Designator.MostDerivedPathLength) {
11424 uint64_t ArraySize = Designator.getMostDerivedArraySize();
11425 uint64_t ArrayIndex = Designator.Entries.back().getAsArrayIndex();
11426 ElemsRemaining = ArraySize <= ArrayIndex ? 0 : ArraySize - ArrayIndex;
11427 } else {
11428 ElemsRemaining = Designator.isOnePastTheEnd() ? 0 : 1;
11429 }
11430
11431 EndOffset = LVal.getLValueOffset() + BytesPerElem * ElemsRemaining;
11432 return true;
11433}
11434
11435/// Tries to evaluate the __builtin_object_size for @p E. If successful,
11436/// returns true and stores the result in @p Size.
11437///
11438/// If @p WasError is non-null, this will report whether the failure to evaluate
11439/// is to be treated as an Error in IntExprEvaluator.
11440static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
11441 EvalInfo &Info, uint64_t &Size) {
11442 // Determine the denoted object.
11443 LValue LVal;
11444 {
11445 // The operand of __builtin_object_size is never evaluated for side-effects.
11446 // If there are any, but we can determine the pointed-to object anyway, then
11447 // ignore the side-effects.
11448 SpeculativeEvaluationRAII SpeculativeEval(Info);
11449 IgnoreSideEffectsRAII Fold(Info);
11450
11451 if (E->isGLValue()) {
11452 // It's possible for us to be given GLValues if we're called via
11453 // Expr::tryEvaluateObjectSize.
11454 APValue RVal;
11455 if (!EvaluateAsRValue(Info, E, RVal))
11456 return false;
11457 LVal.setFrom(Info.Ctx, RVal);
11458 } else if (!EvaluatePointer(ignorePointerCastsAndParens(E), LVal, Info,
11459 /*InvalidBaseOK=*/true))
11460 return false;
11461 }
11462
11463 // If we point to before the start of the object, there are no accessible
11464 // bytes.
11465 if (LVal.getLValueOffset().isNegative()) {
11466 Size = 0;
11467 return true;
11468 }
11469
11470 CharUnits EndOffset;
11471 if (!determineEndOffset(Info, E->getExprLoc(), Type, LVal, EndOffset))
11472 return false;
11473
11474 // If we've fallen outside of the end offset, just pretend there's nothing to
11475 // write to/read from.
11476 if (EndOffset <= LVal.getLValueOffset())
11477 Size = 0;
11478 else
11479 Size = (EndOffset - LVal.getLValueOffset()).getQuantity();
11480 return true;
11481}
11482
11483bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
11484 if (unsigned BuiltinOp = E->getBuiltinCallee())
11485 return VisitBuiltinCallExpr(E, BuiltinOp);
11486
11487 return ExprEvaluatorBaseTy::VisitCallExpr(E);
11488}
11489
11490static bool getBuiltinAlignArguments(const CallExpr *E, EvalInfo &Info,
11491 APValue &Val, APSInt &Alignment) {
11492 QualType SrcTy = E->getArg(0)->getType();
11493 if (!getAlignmentArgument(E->getArg(1), SrcTy, Info, Alignment))
11494 return false;
11495 // Even though we are evaluating integer expressions we could get a pointer
11496 // argument for the __builtin_is_aligned() case.
11497 if (SrcTy->isPointerType()) {
11498 LValue Ptr;
11499 if (!EvaluatePointer(E->getArg(0), Ptr, Info))
11500 return false;
11501 Ptr.moveInto(Val);
11502 } else if (!SrcTy->isIntegralOrEnumerationType()) {
11503 Info.FFDiag(E->getArg(0));
11504 return false;
11505 } else {
11506 APSInt SrcInt;
11507 if (!EvaluateInteger(E->getArg(0), SrcInt, Info))
11508 return false;
11509 assert(SrcInt.getBitWidth() >= Alignment.getBitWidth() &&(static_cast <bool> (SrcInt.getBitWidth() >= Alignment
.getBitWidth() && "Bit widths must be the same") ? void
(0) : __assert_fail ("SrcInt.getBitWidth() >= Alignment.getBitWidth() && \"Bit widths must be the same\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11510, __extension__ __PRETTY_FUNCTION__))
11510 "Bit widths must be the same")(static_cast <bool> (SrcInt.getBitWidth() >= Alignment
.getBitWidth() && "Bit widths must be the same") ? void
(0) : __assert_fail ("SrcInt.getBitWidth() >= Alignment.getBitWidth() && \"Bit widths must be the same\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11510, __extension__ __PRETTY_FUNCTION__))
;
11511 Val = APValue(SrcInt);
11512 }
11513 assert(Val.hasValue())(static_cast <bool> (Val.hasValue()) ? void (0) : __assert_fail
("Val.hasValue()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11513, __extension__ __PRETTY_FUNCTION__))
;
11514 return true;
11515}
11516
11517bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
11518 unsigned BuiltinOp) {
11519 switch (BuiltinOp) {
11520 default:
11521 return ExprEvaluatorBaseTy::VisitCallExpr(E);
11522
11523 case Builtin::BI__builtin_dynamic_object_size:
11524 case Builtin::BI__builtin_object_size: {
11525 // The type was checked when we built the expression.
11526 unsigned Type =
11527 E->getArg(1)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
11528 assert(Type <= 3 && "unexpected type")(static_cast <bool> (Type <= 3 && "unexpected type"
) ? void (0) : __assert_fail ("Type <= 3 && \"unexpected type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11528, __extension__ __PRETTY_FUNCTION__))
;
11529
11530 uint64_t Size;
11531 if (tryEvaluateBuiltinObjectSize(E->getArg(0), Type, Info, Size))
11532 return Success(Size, E);
11533
11534 if (E->getArg(0)->HasSideEffects(Info.Ctx))
11535 return Success((Type & 2) ? 0 : -1, E);
11536
11537 // Expression had no side effects, but we couldn't statically determine the
11538 // size of the referenced object.
11539 switch (Info.EvalMode) {
11540 case EvalInfo::EM_ConstantExpression:
11541 case EvalInfo::EM_ConstantFold:
11542 case EvalInfo::EM_IgnoreSideEffects:
11543 // Leave it to IR generation.
11544 return Error(E);
11545 case EvalInfo::EM_ConstantExpressionUnevaluated:
11546 // Reduce it to a constant now.
11547 return Success((Type & 2) ? 0 : -1, E);
11548 }
11549
11550 llvm_unreachable("unexpected EvalMode")::llvm::llvm_unreachable_internal("unexpected EvalMode", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11550)
;
11551 }
11552
11553 case Builtin::BI__builtin_os_log_format_buffer_size: {
11554 analyze_os_log::OSLogBufferLayout Layout;
11555 analyze_os_log::computeOSLogBufferLayout(Info.Ctx, E, Layout);
11556 return Success(Layout.size().getQuantity(), E);
11557 }
11558
11559 case Builtin::BI__builtin_is_aligned: {
11560 APValue Src;
11561 APSInt Alignment;
11562 if (!getBuiltinAlignArguments(E, Info, Src, Alignment))
11563 return false;
11564 if (Src.isLValue()) {
11565 // If we evaluated a pointer, check the minimum known alignment.
11566 LValue Ptr;
11567 Ptr.setFrom(Info.Ctx, Src);
11568 CharUnits BaseAlignment = getBaseAlignment(Info, Ptr);
11569 CharUnits PtrAlign = BaseAlignment.alignmentAtOffset(Ptr.Offset);
11570 // We can return true if the known alignment at the computed offset is
11571 // greater than the requested alignment.
11572 assert(PtrAlign.isPowerOfTwo())(static_cast <bool> (PtrAlign.isPowerOfTwo()) ? void (0
) : __assert_fail ("PtrAlign.isPowerOfTwo()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11572, __extension__ __PRETTY_FUNCTION__))
;
11573 assert(Alignment.isPowerOf2())(static_cast <bool> (Alignment.isPowerOf2()) ? void (0)
: __assert_fail ("Alignment.isPowerOf2()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11573, __extension__ __PRETTY_FUNCTION__))
;
11574 if (PtrAlign.getQuantity() >= Alignment)
11575 return Success(1, E);
11576 // If the alignment is not known to be sufficient, some cases could still
11577 // be aligned at run time. However, if the requested alignment is less or
11578 // equal to the base alignment and the offset is not aligned, we know that
11579 // the run-time value can never be aligned.
11580 if (BaseAlignment.getQuantity() >= Alignment &&
11581 PtrAlign.getQuantity() < Alignment)
11582 return Success(0, E);
11583 // Otherwise we can't infer whether the value is sufficiently aligned.
11584 // TODO: __builtin_is_aligned(__builtin_align_{down,up{(expr, N), N)
11585 // in cases where we can't fully evaluate the pointer.
11586 Info.FFDiag(E->getArg(0), diag::note_constexpr_alignment_compute)
11587 << Alignment;
11588 return false;
11589 }
11590 assert(Src.isInt())(static_cast <bool> (Src.isInt()) ? void (0) : __assert_fail
("Src.isInt()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11590, __extension__ __PRETTY_FUNCTION__))
;
11591 return Success((Src.getInt() & (Alignment - 1)) == 0 ? 1 : 0, E);
11592 }
11593 case Builtin::BI__builtin_align_up: {
11594 APValue Src;
11595 APSInt Alignment;
11596 if (!getBuiltinAlignArguments(E, Info, Src, Alignment))
11597 return false;
11598 if (!Src.isInt())
11599 return Error(E);
11600 APSInt AlignedVal =
11601 APSInt((Src.getInt() + (Alignment - 1)) & ~(Alignment - 1),
11602 Src.getInt().isUnsigned());
11603 assert(AlignedVal.getBitWidth() == Src.getInt().getBitWidth())(static_cast <bool> (AlignedVal.getBitWidth() == Src.getInt
().getBitWidth()) ? void (0) : __assert_fail ("AlignedVal.getBitWidth() == Src.getInt().getBitWidth()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11603, __extension__ __PRETTY_FUNCTION__))
;
11604 return Success(AlignedVal, E);
11605 }
11606 case Builtin::BI__builtin_align_down: {
11607 APValue Src;
11608 APSInt Alignment;
11609 if (!getBuiltinAlignArguments(E, Info, Src, Alignment))
11610 return false;
11611 if (!Src.isInt())
11612 return Error(E);
11613 APSInt AlignedVal =
11614 APSInt(Src.getInt() & ~(Alignment - 1), Src.getInt().isUnsigned());
11615 assert(AlignedVal.getBitWidth() == Src.getInt().getBitWidth())(static_cast <bool> (AlignedVal.getBitWidth() == Src.getInt
().getBitWidth()) ? void (0) : __assert_fail ("AlignedVal.getBitWidth() == Src.getInt().getBitWidth()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11615, __extension__ __PRETTY_FUNCTION__))
;
11616 return Success(AlignedVal, E);
11617 }
11618
11619 case Builtin::BI__builtin_bitreverse8:
11620 case Builtin::BI__builtin_bitreverse16:
11621 case Builtin::BI__builtin_bitreverse32:
11622 case Builtin::BI__builtin_bitreverse64: {
11623 APSInt Val;
11624 if (!EvaluateInteger(E->getArg(0), Val, Info))
11625 return false;
11626
11627 return Success(Val.reverseBits(), E);
11628 }
11629
11630 case Builtin::BI__builtin_bswap16:
11631 case Builtin::BI__builtin_bswap32:
11632 case Builtin::BI__builtin_bswap64: {
11633 APSInt Val;
11634 if (!EvaluateInteger(E->getArg(0), Val, Info))
11635 return false;
11636
11637 return Success(Val.byteSwap(), E);
11638 }
11639
11640 case Builtin::BI__builtin_classify_type:
11641 return Success((int)EvaluateBuiltinClassifyType(E, Info.getLangOpts()), E);
11642
11643 case Builtin::BI__builtin_clrsb:
11644 case Builtin::BI__builtin_clrsbl:
11645 case Builtin::BI__builtin_clrsbll: {
11646 APSInt Val;
11647 if (!EvaluateInteger(E->getArg(0), Val, Info))
11648 return false;
11649
11650 return Success(Val.getBitWidth() - Val.getMinSignedBits(), E);
11651 }
11652
11653 case Builtin::BI__builtin_clz:
11654 case Builtin::BI__builtin_clzl:
11655 case Builtin::BI__builtin_clzll:
11656 case Builtin::BI__builtin_clzs: {
11657 APSInt Val;
11658 if (!EvaluateInteger(E->getArg(0), Val, Info))
11659 return false;
11660 if (!Val)
11661 return Error(E);
11662
11663 return Success(Val.countLeadingZeros(), E);
11664 }
11665
11666 case Builtin::BI__builtin_constant_p: {
11667 const Expr *Arg = E->getArg(0);
11668 if (EvaluateBuiltinConstantP(Info, Arg))
11669 return Success(true, E);
11670 if (Info.InConstantContext || Arg->HasSideEffects(Info.Ctx)) {
11671 // Outside a constant context, eagerly evaluate to false in the presence
11672 // of side-effects in order to avoid -Wunsequenced false-positives in
11673 // a branch on __builtin_constant_p(expr).
11674 return Success(false, E);
11675 }
11676 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
11677 return false;
11678 }
11679
11680 case Builtin::BI__builtin_is_constant_evaluated: {
11681 const auto *Callee = Info.CurrentCall->getCallee();
11682 if (Info.InConstantContext && !Info.CheckingPotentialConstantExpression &&
11683 (Info.CallStackDepth == 1 ||
11684 (Info.CallStackDepth == 2 && Callee->isInStdNamespace() &&
11685 Callee->getIdentifier() &&
11686 Callee->getIdentifier()->isStr("is_constant_evaluated")))) {
11687 // FIXME: Find a better way to avoid duplicated diagnostics.
11688 if (Info.EvalStatus.Diag)
11689 Info.report((Info.CallStackDepth == 1) ? E->getExprLoc()
11690 : Info.CurrentCall->CallLoc,
11691 diag::warn_is_constant_evaluated_always_true_constexpr)
11692 << (Info.CallStackDepth == 1 ? "__builtin_is_constant_evaluated"
11693 : "std::is_constant_evaluated");
11694 }
11695
11696 return Success(Info.InConstantContext, E);
11697 }
11698
11699 case Builtin::BI__builtin_ctz:
11700 case Builtin::BI__builtin_ctzl:
11701 case Builtin::BI__builtin_ctzll:
11702 case Builtin::BI__builtin_ctzs: {
11703 APSInt Val;
11704 if (!EvaluateInteger(E->getArg(0), Val, Info))
11705 return false;
11706 if (!Val)
11707 return Error(E);
11708
11709 return Success(Val.countTrailingZeros(), E);
11710 }
11711
11712 case Builtin::BI__builtin_eh_return_data_regno: {
11713 int Operand = E->getArg(0)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
11714 Operand = Info.Ctx.getTargetInfo().getEHDataRegisterNumber(Operand);
11715 return Success(Operand, E);
11716 }
11717
11718 case Builtin::BI__builtin_expect:
11719 case Builtin::BI__builtin_expect_with_probability:
11720 return Visit(E->getArg(0));
11721
11722 case Builtin::BI__builtin_ffs:
11723 case Builtin::BI__builtin_ffsl:
11724 case Builtin::BI__builtin_ffsll: {
11725 APSInt Val;
11726 if (!EvaluateInteger(E->getArg(0), Val, Info))
11727 return false;
11728
11729 unsigned N = Val.countTrailingZeros();
11730 return Success(N == Val.getBitWidth() ? 0 : N + 1, E);
11731 }
11732
11733 case Builtin::BI__builtin_fpclassify: {
11734 APFloat Val(0.0);
11735 if (!EvaluateFloat(E->getArg(5), Val, Info))
11736 return false;
11737 unsigned Arg;
11738 switch (Val.getCategory()) {
11739 case APFloat::fcNaN: Arg = 0; break;
11740 case APFloat::fcInfinity: Arg = 1; break;
11741 case APFloat::fcNormal: Arg = Val.isDenormal() ? 3 : 2; break;
11742 case APFloat::fcZero: Arg = 4; break;
11743 }
11744 return Visit(E->getArg(Arg));
11745 }
11746
11747 case Builtin::BI__builtin_isinf_sign: {
11748 APFloat Val(0.0);
11749 return EvaluateFloat(E->getArg(0), Val, Info) &&
11750 Success(Val.isInfinity() ? (Val.isNegative() ? -1 : 1) : 0, E);
11751 }
11752
11753 case Builtin::BI__builtin_isinf: {
11754 APFloat Val(0.0);
11755 return EvaluateFloat(E->getArg(0), Val, Info) &&
11756 Success(Val.isInfinity() ? 1 : 0, E);
11757 }
11758
11759 case Builtin::BI__builtin_isfinite: {
11760 APFloat Val(0.0);
11761 return EvaluateFloat(E->getArg(0), Val, Info) &&
11762 Success(Val.isFinite() ? 1 : 0, E);
11763 }
11764
11765 case Builtin::BI__builtin_isnan: {
11766 APFloat Val(0.0);
11767 return EvaluateFloat(E->getArg(0), Val, Info) &&
11768 Success(Val.isNaN() ? 1 : 0, E);
11769 }
11770
11771 case Builtin::BI__builtin_isnormal: {
11772 APFloat Val(0.0);
11773 return EvaluateFloat(E->getArg(0), Val, Info) &&
11774 Success(Val.isNormal() ? 1 : 0, E);
11775 }
11776
11777 case Builtin::BI__builtin_parity:
11778 case Builtin::BI__builtin_parityl:
11779 case Builtin::BI__builtin_parityll: {
11780 APSInt Val;
11781 if (!EvaluateInteger(E->getArg(0), Val, Info))
11782 return false;
11783
11784 return Success(Val.countPopulation() % 2, E);
11785 }
11786
11787 case Builtin::BI__builtin_popcount:
11788 case Builtin::BI__builtin_popcountl:
11789 case Builtin::BI__builtin_popcountll: {
11790 APSInt Val;
11791 if (!EvaluateInteger(E->getArg(0), Val, Info))
11792 return false;
11793
11794 return Success(Val.countPopulation(), E);
11795 }
11796
11797 case Builtin::BI__builtin_rotateleft8:
11798 case Builtin::BI__builtin_rotateleft16:
11799 case Builtin::BI__builtin_rotateleft32:
11800 case Builtin::BI__builtin_rotateleft64:
11801 case Builtin::BI_rotl8: // Microsoft variants of rotate right
11802 case Builtin::BI_rotl16:
11803 case Builtin::BI_rotl:
11804 case Builtin::BI_lrotl:
11805 case Builtin::BI_rotl64: {
11806 APSInt Val, Amt;
11807 if (!EvaluateInteger(E->getArg(0), Val, Info) ||
11808 !EvaluateInteger(E->getArg(1), Amt, Info))
11809 return false;
11810
11811 return Success(Val.rotl(Amt.urem(Val.getBitWidth())), E);
11812 }
11813
11814 case Builtin::BI__builtin_rotateright8:
11815 case Builtin::BI__builtin_rotateright16:
11816 case Builtin::BI__builtin_rotateright32:
11817 case Builtin::BI__builtin_rotateright64:
11818 case Builtin::BI_rotr8: // Microsoft variants of rotate right
11819 case Builtin::BI_rotr16:
11820 case Builtin::BI_rotr:
11821 case Builtin::BI_lrotr:
11822 case Builtin::BI_rotr64: {
11823 APSInt Val, Amt;
11824 if (!EvaluateInteger(E->getArg(0), Val, Info) ||
11825 !EvaluateInteger(E->getArg(1), Amt, Info))
11826 return false;
11827
11828 return Success(Val.rotr(Amt.urem(Val.getBitWidth())), E);
11829 }
11830
11831 case Builtin::BIstrlen:
11832 case Builtin::BIwcslen:
11833 // A call to strlen is not a constant expression.
11834 if (Info.getLangOpts().CPlusPlus11)
11835 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
11836 << /*isConstexpr*/0 << /*isConstructor*/0
11837 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
11838 else
11839 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
11840 LLVM_FALLTHROUGH[[gnu::fallthrough]];
11841 case Builtin::BI__builtin_strlen:
11842 case Builtin::BI__builtin_wcslen: {
11843 // As an extension, we support __builtin_strlen() as a constant expression,
11844 // and support folding strlen() to a constant.
11845 uint64_t StrLen;
11846 if (EvaluateBuiltinStrLen(E->getArg(0), StrLen, Info))
11847 return Success(StrLen, E);
11848 return false;
11849 }
11850
11851 case Builtin::BIstrcmp:
11852 case Builtin::BIwcscmp:
11853 case Builtin::BIstrncmp:
11854 case Builtin::BIwcsncmp:
11855 case Builtin::BImemcmp:
11856 case Builtin::BIbcmp:
11857 case Builtin::BIwmemcmp:
11858 // A call to strlen is not a constant expression.
11859 if (Info.getLangOpts().CPlusPlus11)
11860 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
11861 << /*isConstexpr*/0 << /*isConstructor*/0
11862 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
11863 else
11864 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
11865 LLVM_FALLTHROUGH[[gnu::fallthrough]];
11866 case Builtin::BI__builtin_strcmp:
11867 case Builtin::BI__builtin_wcscmp:
11868 case Builtin::BI__builtin_strncmp:
11869 case Builtin::BI__builtin_wcsncmp:
11870 case Builtin::BI__builtin_memcmp:
11871 case Builtin::BI__builtin_bcmp:
11872 case Builtin::BI__builtin_wmemcmp: {
11873 LValue String1, String2;
11874 if (!EvaluatePointer(E->getArg(0), String1, Info) ||
11875 !EvaluatePointer(E->getArg(1), String2, Info))
11876 return false;
11877
11878 uint64_t MaxLength = uint64_t(-1);
11879 if (BuiltinOp != Builtin::BIstrcmp &&
11880 BuiltinOp != Builtin::BIwcscmp &&
11881 BuiltinOp != Builtin::BI__builtin_strcmp &&
11882 BuiltinOp != Builtin::BI__builtin_wcscmp) {
11883 APSInt N;
11884 if (!EvaluateInteger(E->getArg(2), N, Info))
11885 return false;
11886 MaxLength = N.getExtValue();
11887 }
11888
11889 // Empty substrings compare equal by definition.
11890 if (MaxLength == 0u)
11891 return Success(0, E);
11892
11893 if (!String1.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
11894 !String2.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
11895 String1.Designator.Invalid || String2.Designator.Invalid)
11896 return false;
11897
11898 QualType CharTy1 = String1.Designator.getType(Info.Ctx);
11899 QualType CharTy2 = String2.Designator.getType(Info.Ctx);
11900
11901 bool IsRawByte = BuiltinOp == Builtin::BImemcmp ||
11902 BuiltinOp == Builtin::BIbcmp ||
11903 BuiltinOp == Builtin::BI__builtin_memcmp ||
11904 BuiltinOp == Builtin::BI__builtin_bcmp;
11905
11906 assert(IsRawByte ||(static_cast <bool> (IsRawByte || (Info.Ctx.hasSameUnqualifiedType
( CharTy1, E->getArg(0)->getType()->getPointeeType()
) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2
))) ? void (0) : __assert_fail ("IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->getArg(0)->getType()->getPointeeType()) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11909, __extension__ __PRETTY_FUNCTION__))
11907 (Info.Ctx.hasSameUnqualifiedType((static_cast <bool> (IsRawByte || (Info.Ctx.hasSameUnqualifiedType
( CharTy1, E->getArg(0)->getType()->getPointeeType()
) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2
))) ? void (0) : __assert_fail ("IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->getArg(0)->getType()->getPointeeType()) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11909, __extension__ __PRETTY_FUNCTION__))
11908 CharTy1, E->getArg(0)->getType()->getPointeeType()) &&(static_cast <bool> (IsRawByte || (Info.Ctx.hasSameUnqualifiedType
( CharTy1, E->getArg(0)->getType()->getPointeeType()
) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2
))) ? void (0) : __assert_fail ("IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->getArg(0)->getType()->getPointeeType()) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11909, __extension__ __PRETTY_FUNCTION__))
11909 Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2)))(static_cast <bool> (IsRawByte || (Info.Ctx.hasSameUnqualifiedType
( CharTy1, E->getArg(0)->getType()->getPointeeType()
) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2
))) ? void (0) : __assert_fail ("IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->getArg(0)->getType()->getPointeeType()) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11909, __extension__ __PRETTY_FUNCTION__))
;
11910
11911 // For memcmp, allow comparing any arrays of '[[un]signed] char' or
11912 // 'char8_t', but no other types.
11913 if (IsRawByte &&
11914 !(isOneByteCharacterType(CharTy1) && isOneByteCharacterType(CharTy2))) {
11915 // FIXME: Consider using our bit_cast implementation to support this.
11916 Info.FFDiag(E, diag::note_constexpr_memcmp_unsupported)
11917 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'")
11918 << CharTy1 << CharTy2;
11919 return false;
11920 }
11921
11922 const auto &ReadCurElems = [&](APValue &Char1, APValue &Char2) {
11923 return handleLValueToRValueConversion(Info, E, CharTy1, String1, Char1) &&
11924 handleLValueToRValueConversion(Info, E, CharTy2, String2, Char2) &&
11925 Char1.isInt() && Char2.isInt();
11926 };
11927 const auto &AdvanceElems = [&] {
11928 return HandleLValueArrayAdjustment(Info, E, String1, CharTy1, 1) &&
11929 HandleLValueArrayAdjustment(Info, E, String2, CharTy2, 1);
11930 };
11931
11932 bool StopAtNull =
11933 (BuiltinOp != Builtin::BImemcmp && BuiltinOp != Builtin::BIbcmp &&
11934 BuiltinOp != Builtin::BIwmemcmp &&
11935 BuiltinOp != Builtin::BI__builtin_memcmp &&
11936 BuiltinOp != Builtin::BI__builtin_bcmp &&
11937 BuiltinOp != Builtin::BI__builtin_wmemcmp);
11938 bool IsWide = BuiltinOp == Builtin::BIwcscmp ||
11939 BuiltinOp == Builtin::BIwcsncmp ||
11940 BuiltinOp == Builtin::BIwmemcmp ||
11941 BuiltinOp == Builtin::BI__builtin_wcscmp ||
11942 BuiltinOp == Builtin::BI__builtin_wcsncmp ||
11943 BuiltinOp == Builtin::BI__builtin_wmemcmp;
11944
11945 for (; MaxLength; --MaxLength) {
11946 APValue Char1, Char2;
11947 if (!ReadCurElems(Char1, Char2))
11948 return false;
11949 if (Char1.getInt().ne(Char2.getInt())) {
11950 if (IsWide) // wmemcmp compares with wchar_t signedness.
11951 return Success(Char1.getInt() < Char2.getInt() ? -1 : 1, E);
11952 // memcmp always compares unsigned chars.
11953 return Success(Char1.getInt().ult(Char2.getInt()) ? -1 : 1, E);
11954 }
11955 if (StopAtNull && !Char1.getInt())
11956 return Success(0, E);
11957 assert(!(StopAtNull && !Char2.getInt()))(static_cast <bool> (!(StopAtNull && !Char2.getInt
())) ? void (0) : __assert_fail ("!(StopAtNull && !Char2.getInt())"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 11957, __extension__ __PRETTY_FUNCTION__))
;
11958 if (!AdvanceElems())
11959 return false;
11960 }
11961 // We hit the strncmp / memcmp limit.
11962 return Success(0, E);
11963 }
11964
11965 case Builtin::BI__atomic_always_lock_free:
11966 case Builtin::BI__atomic_is_lock_free:
11967 case Builtin::BI__c11_atomic_is_lock_free: {
11968 APSInt SizeVal;
11969 if (!EvaluateInteger(E->getArg(0), SizeVal, Info))
11970 return false;
11971
11972 // For __atomic_is_lock_free(sizeof(_Atomic(T))), if the size is a power
11973 // of two less than or equal to the maximum inline atomic width, we know it
11974 // is lock-free. If the size isn't a power of two, or greater than the
11975 // maximum alignment where we promote atomics, we know it is not lock-free
11976 // (at least not in the sense of atomic_is_lock_free). Otherwise,
11977 // the answer can only be determined at runtime; for example, 16-byte
11978 // atomics have lock-free implementations on some, but not all,
11979 // x86-64 processors.
11980
11981 // Check power-of-two.
11982 CharUnits Size = CharUnits::fromQuantity(SizeVal.getZExtValue());
11983 if (Size.isPowerOfTwo()) {
11984 // Check against inlining width.
11985 unsigned InlineWidthBits =
11986 Info.Ctx.getTargetInfo().getMaxAtomicInlineWidth();
11987 if (Size <= Info.Ctx.toCharUnitsFromBits(InlineWidthBits)) {
11988 if (BuiltinOp == Builtin::BI__c11_atomic_is_lock_free ||
11989 Size == CharUnits::One() ||
11990 E->getArg(1)->isNullPointerConstant(Info.Ctx,
11991 Expr::NPC_NeverValueDependent))
11992 // OK, we will inline appropriately-aligned operations of this size,
11993 // and _Atomic(T) is appropriately-aligned.
11994 return Success(1, E);
11995
11996 QualType PointeeType = E->getArg(1)->IgnoreImpCasts()->getType()->
11997 castAs<PointerType>()->getPointeeType();
11998 if (!PointeeType->isIncompleteType() &&
11999 Info.Ctx.getTypeAlignInChars(PointeeType) >= Size) {
12000 // OK, we will inline operations on this object.
12001 return Success(1, E);
12002 }
12003 }
12004 }
12005
12006 return BuiltinOp == Builtin::BI__atomic_always_lock_free ?
12007 Success(0, E) : Error(E);
12008 }
12009 case Builtin::BI__builtin_add_overflow:
12010 case Builtin::BI__builtin_sub_overflow:
12011 case Builtin::BI__builtin_mul_overflow:
12012 case Builtin::BI__builtin_sadd_overflow:
12013 case Builtin::BI__builtin_uadd_overflow:
12014 case Builtin::BI__builtin_uaddl_overflow:
12015 case Builtin::BI__builtin_uaddll_overflow:
12016 case Builtin::BI__builtin_usub_overflow:
12017 case Builtin::BI__builtin_usubl_overflow:
12018 case Builtin::BI__builtin_usubll_overflow:
12019 case Builtin::BI__builtin_umul_overflow:
12020 case Builtin::BI__builtin_umull_overflow:
12021 case Builtin::BI__builtin_umulll_overflow:
12022 case Builtin::BI__builtin_saddl_overflow:
12023 case Builtin::BI__builtin_saddll_overflow:
12024 case Builtin::BI__builtin_ssub_overflow:
12025 case Builtin::BI__builtin_ssubl_overflow:
12026 case Builtin::BI__builtin_ssubll_overflow:
12027 case Builtin::BI__builtin_smul_overflow:
12028 case Builtin::BI__builtin_smull_overflow:
12029 case Builtin::BI__builtin_smulll_overflow: {
12030 LValue ResultLValue;
12031 APSInt LHS, RHS;
12032
12033 QualType ResultType = E->getArg(2)->getType()->getPointeeType();
12034 if (!EvaluateInteger(E->getArg(0), LHS, Info) ||
12035 !EvaluateInteger(E->getArg(1), RHS, Info) ||
12036 !EvaluatePointer(E->getArg(2), ResultLValue, Info))
12037 return false;
12038
12039 APSInt Result;
12040 bool DidOverflow = false;
12041
12042 // If the types don't have to match, enlarge all 3 to the largest of them.
12043 if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
12044 BuiltinOp == Builtin::BI__builtin_sub_overflow ||
12045 BuiltinOp == Builtin::BI__builtin_mul_overflow) {
12046 bool IsSigned = LHS.isSigned() || RHS.isSigned() ||
12047 ResultType->isSignedIntegerOrEnumerationType();
12048 bool AllSigned = LHS.isSigned() && RHS.isSigned() &&
12049 ResultType->isSignedIntegerOrEnumerationType();
12050 uint64_t LHSSize = LHS.getBitWidth();
12051 uint64_t RHSSize = RHS.getBitWidth();
12052 uint64_t ResultSize = Info.Ctx.getTypeSize(ResultType);
12053 uint64_t MaxBits = std::max(std::max(LHSSize, RHSSize), ResultSize);
12054
12055 // Add an additional bit if the signedness isn't uniformly agreed to. We
12056 // could do this ONLY if there is a signed and an unsigned that both have
12057 // MaxBits, but the code to check that is pretty nasty. The issue will be
12058 // caught in the shrink-to-result later anyway.
12059 if (IsSigned && !AllSigned)
12060 ++MaxBits;
12061
12062 LHS = APSInt(LHS.extOrTrunc(MaxBits), !IsSigned);
12063 RHS = APSInt(RHS.extOrTrunc(MaxBits), !IsSigned);
12064 Result = APSInt(MaxBits, !IsSigned);
12065 }
12066
12067 // Find largest int.
12068 switch (BuiltinOp) {
12069 default:
12070 llvm_unreachable("Invalid value for BuiltinOp")::llvm::llvm_unreachable_internal("Invalid value for BuiltinOp"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12070)
;
12071 case Builtin::BI__builtin_add_overflow:
12072 case Builtin::BI__builtin_sadd_overflow:
12073 case Builtin::BI__builtin_saddl_overflow:
12074 case Builtin::BI__builtin_saddll_overflow:
12075 case Builtin::BI__builtin_uadd_overflow:
12076 case Builtin::BI__builtin_uaddl_overflow:
12077 case Builtin::BI__builtin_uaddll_overflow:
12078 Result = LHS.isSigned() ? LHS.sadd_ov(RHS, DidOverflow)
12079 : LHS.uadd_ov(RHS, DidOverflow);
12080 break;
12081 case Builtin::BI__builtin_sub_overflow:
12082 case Builtin::BI__builtin_ssub_overflow:
12083 case Builtin::BI__builtin_ssubl_overflow:
12084 case Builtin::BI__builtin_ssubll_overflow:
12085 case Builtin::BI__builtin_usub_overflow:
12086 case Builtin::BI__builtin_usubl_overflow:
12087 case Builtin::BI__builtin_usubll_overflow:
12088 Result = LHS.isSigned() ? LHS.ssub_ov(RHS, DidOverflow)
12089 : LHS.usub_ov(RHS, DidOverflow);
12090 break;
12091 case Builtin::BI__builtin_mul_overflow:
12092 case Builtin::BI__builtin_smul_overflow:
12093 case Builtin::BI__builtin_smull_overflow:
12094 case Builtin::BI__builtin_smulll_overflow:
12095 case Builtin::BI__builtin_umul_overflow:
12096 case Builtin::BI__builtin_umull_overflow:
12097 case Builtin::BI__builtin_umulll_overflow:
12098 Result = LHS.isSigned() ? LHS.smul_ov(RHS, DidOverflow)
12099 : LHS.umul_ov(RHS, DidOverflow);
12100 break;
12101 }
12102
12103 // In the case where multiple sizes are allowed, truncate and see if
12104 // the values are the same.
12105 if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
12106 BuiltinOp == Builtin::BI__builtin_sub_overflow ||
12107 BuiltinOp == Builtin::BI__builtin_mul_overflow) {
12108 // APSInt doesn't have a TruncOrSelf, so we use extOrTrunc instead,
12109 // since it will give us the behavior of a TruncOrSelf in the case where
12110 // its parameter <= its size. We previously set Result to be at least the
12111 // type-size of the result, so getTypeSize(ResultType) <= Result.BitWidth
12112 // will work exactly like TruncOrSelf.
12113 APSInt Temp = Result.extOrTrunc(Info.Ctx.getTypeSize(ResultType));
12114 Temp.setIsSigned(ResultType->isSignedIntegerOrEnumerationType());
12115
12116 if (!APSInt::isSameValue(Temp, Result))
12117 DidOverflow = true;
12118 Result = Temp;
12119 }
12120
12121 APValue APV{Result};
12122 if (!handleAssignment(Info, E, ResultLValue, ResultType, APV))
12123 return false;
12124 return Success(DidOverflow, E);
12125 }
12126 }
12127}
12128
12129/// Determine whether this is a pointer past the end of the complete
12130/// object referred to by the lvalue.
12131static bool isOnePastTheEndOfCompleteObject(const ASTContext &Ctx,
12132 const LValue &LV) {
12133 // A null pointer can be viewed as being "past the end" but we don't
12134 // choose to look at it that way here.
12135 if (!LV.getLValueBase())
12136 return false;
12137
12138 // If the designator is valid and refers to a subobject, we're not pointing
12139 // past the end.
12140 if (!LV.getLValueDesignator().Invalid &&
12141 !LV.getLValueDesignator().isOnePastTheEnd())
12142 return false;
12143
12144 // A pointer to an incomplete type might be past-the-end if the type's size is
12145 // zero. We cannot tell because the type is incomplete.
12146 QualType Ty = getType(LV.getLValueBase());
12147 if (Ty->isIncompleteType())
12148 return true;
12149
12150 // We're a past-the-end pointer if we point to the byte after the object,
12151 // no matter what our type or path is.
12152 auto Size = Ctx.getTypeSizeInChars(Ty);
12153 return LV.getLValueOffset() == Size;
12154}
12155
12156namespace {
12157
12158/// Data recursive integer evaluator of certain binary operators.
12159///
12160/// We use a data recursive algorithm for binary operators so that we are able
12161/// to handle extreme cases of chained binary operators without causing stack
12162/// overflow.
12163class DataRecursiveIntBinOpEvaluator {
12164 struct EvalResult {
12165 APValue Val;
12166 bool Failed;
12167
12168 EvalResult() : Failed(false) { }
12169
12170 void swap(EvalResult &RHS) {
12171 Val.swap(RHS.Val);
12172 Failed = RHS.Failed;
12173 RHS.Failed = false;
12174 }
12175 };
12176
12177 struct Job {
12178 const Expr *E;
12179 EvalResult LHSResult; // meaningful only for binary operator expression.
12180 enum { AnyExprKind, BinOpKind, BinOpVisitedLHSKind } Kind;
12181
12182 Job() = default;
12183 Job(Job &&) = default;
12184
12185 void startSpeculativeEval(EvalInfo &Info) {
12186 SpecEvalRAII = SpeculativeEvaluationRAII(Info);
12187 }
12188
12189 private:
12190 SpeculativeEvaluationRAII SpecEvalRAII;
12191 };
12192
12193 SmallVector<Job, 16> Queue;
12194
12195 IntExprEvaluator &IntEval;
12196 EvalInfo &Info;
12197 APValue &FinalResult;
12198
12199public:
12200 DataRecursiveIntBinOpEvaluator(IntExprEvaluator &IntEval, APValue &Result)
12201 : IntEval(IntEval), Info(IntEval.getEvalInfo()), FinalResult(Result) { }
12202
12203 /// True if \param E is a binary operator that we are going to handle
12204 /// data recursively.
12205 /// We handle binary operators that are comma, logical, or that have operands
12206 /// with integral or enumeration type.
12207 static bool shouldEnqueue(const BinaryOperator *E) {
12208 return E->getOpcode() == BO_Comma || E->isLogicalOp() ||
12209 (E->isPRValue() && E->getType()->isIntegralOrEnumerationType() &&
12210 E->getLHS()->getType()->isIntegralOrEnumerationType() &&
12211 E->getRHS()->getType()->isIntegralOrEnumerationType());
12212 }
12213
12214 bool Traverse(const BinaryOperator *E) {
12215 enqueue(E);
12216 EvalResult PrevResult;
12217 while (!Queue.empty())
12218 process(PrevResult);
12219
12220 if (PrevResult.Failed) return false;
12221
12222 FinalResult.swap(PrevResult.Val);
12223 return true;
12224 }
12225
12226private:
12227 bool Success(uint64_t Value, const Expr *E, APValue &Result) {
12228 return IntEval.Success(Value, E, Result);
12229 }
12230 bool Success(const APSInt &Value, const Expr *E, APValue &Result) {
12231 return IntEval.Success(Value, E, Result);
12232 }
12233 bool Error(const Expr *E) {
12234 return IntEval.Error(E);
12235 }
12236 bool Error(const Expr *E, diag::kind D) {
12237 return IntEval.Error(E, D);
12238 }
12239
12240 OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
12241 return Info.CCEDiag(E, D);
12242 }
12243
12244 // Returns true if visiting the RHS is necessary, false otherwise.
12245 bool VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
12246 bool &SuppressRHSDiags);
12247
12248 bool VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
12249 const BinaryOperator *E, APValue &Result);
12250
12251 void EvaluateExpr(const Expr *E, EvalResult &Result) {
12252 Result.Failed = !Evaluate(Result.Val, Info, E);
12253 if (Result.Failed)
12254 Result.Val = APValue();
12255 }
12256
12257 void process(EvalResult &Result);
12258
12259 void enqueue(const Expr *E) {
12260 E = E->IgnoreParens();
12261 Queue.resize(Queue.size()+1);
12262 Queue.back().E = E;
12263 Queue.back().Kind = Job::AnyExprKind;
12264 }
12265};
12266
12267}
12268
12269bool DataRecursiveIntBinOpEvaluator::
12270 VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
12271 bool &SuppressRHSDiags) {
12272 if (E->getOpcode() == BO_Comma) {
12273 // Ignore LHS but note if we could not evaluate it.
12274 if (LHSResult.Failed)
12275 return Info.noteSideEffect();
12276 return true;
12277 }
12278
12279 if (E->isLogicalOp()) {
12280 bool LHSAsBool;
12281 if (!LHSResult.Failed && HandleConversionToBool(LHSResult.Val, LHSAsBool)) {
12282 // We were able to evaluate the LHS, see if we can get away with not
12283 // evaluating the RHS: 0 && X -> 0, 1 || X -> 1
12284 if (LHSAsBool == (E->getOpcode() == BO_LOr)) {
12285 Success(LHSAsBool, E, LHSResult.Val);
12286 return false; // Ignore RHS
12287 }
12288 } else {
12289 LHSResult.Failed = true;
12290
12291 // Since we weren't able to evaluate the left hand side, it
12292 // might have had side effects.
12293 if (!Info.noteSideEffect())
12294 return false;
12295
12296 // We can't evaluate the LHS; however, sometimes the result
12297 // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
12298 // Don't ignore RHS and suppress diagnostics from this arm.
12299 SuppressRHSDiags = true;
12300 }
12301
12302 return true;
12303 }
12304
12305 assert(E->getLHS()->getType()->isIntegralOrEnumerationType() &&(static_cast <bool> (E->getLHS()->getType()->isIntegralOrEnumerationType
() && E->getRHS()->getType()->isIntegralOrEnumerationType
()) ? void (0) : __assert_fail ("E->getLHS()->getType()->isIntegralOrEnumerationType() && E->getRHS()->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12306, __extension__ __PRETTY_FUNCTION__))
12306 E->getRHS()->getType()->isIntegralOrEnumerationType())(static_cast <bool> (E->getLHS()->getType()->isIntegralOrEnumerationType
() && E->getRHS()->getType()->isIntegralOrEnumerationType
()) ? void (0) : __assert_fail ("E->getLHS()->getType()->isIntegralOrEnumerationType() && E->getRHS()->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12306, __extension__ __PRETTY_FUNCTION__))
;
12307
12308 if (LHSResult.Failed && !Info.noteFailure())
12309 return false; // Ignore RHS;
12310
12311 return true;
12312}
12313
12314static void addOrSubLValueAsInteger(APValue &LVal, const APSInt &Index,
12315 bool IsSub) {
12316 // Compute the new offset in the appropriate width, wrapping at 64 bits.
12317 // FIXME: When compiling for a 32-bit target, we should use 32-bit
12318 // offsets.
12319 assert(!LVal.hasLValuePath() && "have designator for integer lvalue")(static_cast <bool> (!LVal.hasLValuePath() && "have designator for integer lvalue"
) ? void (0) : __assert_fail ("!LVal.hasLValuePath() && \"have designator for integer lvalue\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12319, __extension__ __PRETTY_FUNCTION__))
;
12320 CharUnits &Offset = LVal.getLValueOffset();
12321 uint64_t Offset64 = Offset.getQuantity();
12322 uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
12323 Offset = CharUnits::fromQuantity(IsSub ? Offset64 - Index64
12324 : Offset64 + Index64);
12325}
12326
12327bool DataRecursiveIntBinOpEvaluator::
12328 VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
12329 const BinaryOperator *E, APValue &Result) {
12330 if (E->getOpcode() == BO_Comma) {
12331 if (RHSResult.Failed)
12332 return false;
12333 Result = RHSResult.Val;
12334 return true;
12335 }
12336
12337 if (E->isLogicalOp()) {
12338 bool lhsResult, rhsResult;
12339 bool LHSIsOK = HandleConversionToBool(LHSResult.Val, lhsResult);
12340 bool RHSIsOK = HandleConversionToBool(RHSResult.Val, rhsResult);
12341
12342 if (LHSIsOK) {
12343 if (RHSIsOK) {
12344 if (E->getOpcode() == BO_LOr)
12345 return Success(lhsResult || rhsResult, E, Result);
12346 else
12347 return Success(lhsResult && rhsResult, E, Result);
12348 }
12349 } else {
12350 if (RHSIsOK) {
12351 // We can't evaluate the LHS; however, sometimes the result
12352 // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
12353 if (rhsResult == (E->getOpcode() == BO_LOr))
12354 return Success(rhsResult, E, Result);
12355 }
12356 }
12357
12358 return false;
12359 }
12360
12361 assert(E->getLHS()->getType()->isIntegralOrEnumerationType() &&(static_cast <bool> (E->getLHS()->getType()->isIntegralOrEnumerationType
() && E->getRHS()->getType()->isIntegralOrEnumerationType
()) ? void (0) : __assert_fail ("E->getLHS()->getType()->isIntegralOrEnumerationType() && E->getRHS()->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12362, __extension__ __PRETTY_FUNCTION__))
12362 E->getRHS()->getType()->isIntegralOrEnumerationType())(static_cast <bool> (E->getLHS()->getType()->isIntegralOrEnumerationType
() && E->getRHS()->getType()->isIntegralOrEnumerationType
()) ? void (0) : __assert_fail ("E->getLHS()->getType()->isIntegralOrEnumerationType() && E->getRHS()->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12362, __extension__ __PRETTY_FUNCTION__))
;
12363
12364 if (LHSResult.Failed || RHSResult.Failed)
12365 return false;
12366
12367 const APValue &LHSVal = LHSResult.Val;
12368 const APValue &RHSVal = RHSResult.Val;
12369
12370 // Handle cases like (unsigned long)&a + 4.
12371 if (E->isAdditiveOp() && LHSVal.isLValue() && RHSVal.isInt()) {
12372 Result = LHSVal;
12373 addOrSubLValueAsInteger(Result, RHSVal.getInt(), E->getOpcode() == BO_Sub);
12374 return true;
12375 }
12376
12377 // Handle cases like 4 + (unsigned long)&a
12378 if (E->getOpcode() == BO_Add &&
12379 RHSVal.isLValue() && LHSVal.isInt()) {
12380 Result = RHSVal;
12381 addOrSubLValueAsInteger(Result, LHSVal.getInt(), /*IsSub*/false);
12382 return true;
12383 }
12384
12385 if (E->getOpcode() == BO_Sub && LHSVal.isLValue() && RHSVal.isLValue()) {
12386 // Handle (intptr_t)&&A - (intptr_t)&&B.
12387 if (!LHSVal.getLValueOffset().isZero() ||
12388 !RHSVal.getLValueOffset().isZero())
12389 return false;
12390 const Expr *LHSExpr = LHSVal.getLValueBase().dyn_cast<const Expr*>();
12391 const Expr *RHSExpr = RHSVal.getLValueBase().dyn_cast<const Expr*>();
12392 if (!LHSExpr || !RHSExpr)
12393 return false;
12394 const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
12395 const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
12396 if (!LHSAddrExpr || !RHSAddrExpr)
12397 return false;
12398 // Make sure both labels come from the same function.
12399 if (LHSAddrExpr->getLabel()->getDeclContext() !=
12400 RHSAddrExpr->getLabel()->getDeclContext())
12401 return false;
12402 Result = APValue(LHSAddrExpr, RHSAddrExpr);
12403 return true;
12404 }
12405
12406 // All the remaining cases expect both operands to be an integer
12407 if (!LHSVal.isInt() || !RHSVal.isInt())
12408 return Error(E);
12409
12410 // Set up the width and signedness manually, in case it can't be deduced
12411 // from the operation we're performing.
12412 // FIXME: Don't do this in the cases where we can deduce it.
12413 APSInt Value(Info.Ctx.getIntWidth(E->getType()),
12414 E->getType()->isUnsignedIntegerOrEnumerationType());
12415 if (!handleIntIntBinOp(Info, E, LHSVal.getInt(), E->getOpcode(),
12416 RHSVal.getInt(), Value))
12417 return false;
12418 return Success(Value, E, Result);
12419}
12420
12421void DataRecursiveIntBinOpEvaluator::process(EvalResult &Result) {
12422 Job &job = Queue.back();
12423
12424 switch (job.Kind) {
12425 case Job::AnyExprKind: {
12426 if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(job.E)) {
12427 if (shouldEnqueue(Bop)) {
12428 job.Kind = Job::BinOpKind;
12429 enqueue(Bop->getLHS());
12430 return;
12431 }
12432 }
12433
12434 EvaluateExpr(job.E, Result);
12435 Queue.pop_back();
12436 return;
12437 }
12438
12439 case Job::BinOpKind: {
12440 const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
12441 bool SuppressRHSDiags = false;
12442 if (!VisitBinOpLHSOnly(Result, Bop, SuppressRHSDiags)) {
12443 Queue.pop_back();
12444 return;
12445 }
12446 if (SuppressRHSDiags)
12447 job.startSpeculativeEval(Info);
12448 job.LHSResult.swap(Result);
12449 job.Kind = Job::BinOpVisitedLHSKind;
12450 enqueue(Bop->getRHS());
12451 return;
12452 }
12453
12454 case Job::BinOpVisitedLHSKind: {
12455 const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
12456 EvalResult RHS;
12457 RHS.swap(Result);
12458 Result.Failed = !VisitBinOp(job.LHSResult, RHS, Bop, Result.Val);
12459 Queue.pop_back();
12460 return;
12461 }
12462 }
12463
12464 llvm_unreachable("Invalid Job::Kind!")::llvm::llvm_unreachable_internal("Invalid Job::Kind!", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12464)
;
12465}
12466
12467namespace {
12468enum class CmpResult {
12469 Unequal,
12470 Less,
12471 Equal,
12472 Greater,
12473 Unordered,
12474};
12475}
12476
12477template <class SuccessCB, class AfterCB>
12478static bool
12479EvaluateComparisonBinaryOperator(EvalInfo &Info, const BinaryOperator *E,
12480 SuccessCB &&Success, AfterCB &&DoAfter) {
12481 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12481, __extension__ __PRETTY_FUNCTION__))
;
12482 assert(E->isComparisonOp() && "expected comparison operator")(static_cast <bool> (E->isComparisonOp() && "expected comparison operator"
) ? void (0) : __assert_fail ("E->isComparisonOp() && \"expected comparison operator\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12482, __extension__ __PRETTY_FUNCTION__))
;
12483 assert((E->getOpcode() == BO_Cmp ||(static_cast <bool> ((E->getOpcode() == BO_Cmp || E->
getType()->isIntegralOrEnumerationType()) && "unsupported binary expression evaluation"
) ? void (0) : __assert_fail ("(E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType()) && \"unsupported binary expression evaluation\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12485, __extension__ __PRETTY_FUNCTION__))
12484 E->getType()->isIntegralOrEnumerationType()) &&(static_cast <bool> ((E->getOpcode() == BO_Cmp || E->
getType()->isIntegralOrEnumerationType()) && "unsupported binary expression evaluation"
) ? void (0) : __assert_fail ("(E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType()) && \"unsupported binary expression evaluation\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12485, __extension__ __PRETTY_FUNCTION__))
12485 "unsupported binary expression evaluation")(static_cast <bool> ((E->getOpcode() == BO_Cmp || E->
getType()->isIntegralOrEnumerationType()) && "unsupported binary expression evaluation"
) ? void (0) : __assert_fail ("(E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType()) && \"unsupported binary expression evaluation\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12485, __extension__ __PRETTY_FUNCTION__))
;
12486 auto Error = [&](const Expr *E) {
12487 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
12488 return false;
12489 };
12490
12491 bool IsRelational = E->isRelationalOp() || E->getOpcode() == BO_Cmp;
12492 bool IsEquality = E->isEqualityOp();
12493
12494 QualType LHSTy = E->getLHS()->getType();
12495 QualType RHSTy = E->getRHS()->getType();
12496
12497 if (LHSTy->isIntegralOrEnumerationType() &&
12498 RHSTy->isIntegralOrEnumerationType()) {
12499 APSInt LHS, RHS;
12500 bool LHSOK = EvaluateInteger(E->getLHS(), LHS, Info);
12501 if (!LHSOK && !Info.noteFailure())
12502 return false;
12503 if (!EvaluateInteger(E->getRHS(), RHS, Info) || !LHSOK)
12504 return false;
12505 if (LHS < RHS)
12506 return Success(CmpResult::Less, E);
12507 if (LHS > RHS)
12508 return Success(CmpResult::Greater, E);
12509 return Success(CmpResult::Equal, E);
12510 }
12511
12512 if (LHSTy->isFixedPointType() || RHSTy->isFixedPointType()) {
12513 APFixedPoint LHSFX(Info.Ctx.getFixedPointSemantics(LHSTy));
12514 APFixedPoint RHSFX(Info.Ctx.getFixedPointSemantics(RHSTy));
12515
12516 bool LHSOK = EvaluateFixedPointOrInteger(E->getLHS(), LHSFX, Info);
12517 if (!LHSOK && !Info.noteFailure())
12518 return false;
12519 if (!EvaluateFixedPointOrInteger(E->getRHS(), RHSFX, Info) || !LHSOK)
12520 return false;
12521 if (LHSFX < RHSFX)
12522 return Success(CmpResult::Less, E);
12523 if (LHSFX > RHSFX)
12524 return Success(CmpResult::Greater, E);
12525 return Success(CmpResult::Equal, E);
12526 }
12527
12528 if (LHSTy->isAnyComplexType() || RHSTy->isAnyComplexType()) {
12529 ComplexValue LHS, RHS;
12530 bool LHSOK;
12531 if (E->isAssignmentOp()) {
12532 LValue LV;
12533 EvaluateLValue(E->getLHS(), LV, Info);
12534 LHSOK = false;
12535 } else if (LHSTy->isRealFloatingType()) {
12536 LHSOK = EvaluateFloat(E->getLHS(), LHS.FloatReal, Info);
12537 if (LHSOK) {
12538 LHS.makeComplexFloat();
12539 LHS.FloatImag = APFloat(LHS.FloatReal.getSemantics());
12540 }
12541 } else {
12542 LHSOK = EvaluateComplex(E->getLHS(), LHS, Info);
12543 }
12544 if (!LHSOK && !Info.noteFailure())
12545 return false;
12546
12547 if (E->getRHS()->getType()->isRealFloatingType()) {
12548 if (!EvaluateFloat(E->getRHS(), RHS.FloatReal, Info) || !LHSOK)
12549 return false;
12550 RHS.makeComplexFloat();
12551 RHS.FloatImag = APFloat(RHS.FloatReal.getSemantics());
12552 } else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
12553 return false;
12554
12555 if (LHS.isComplexFloat()) {
12556 APFloat::cmpResult CR_r =
12557 LHS.getComplexFloatReal().compare(RHS.getComplexFloatReal());
12558 APFloat::cmpResult CR_i =
12559 LHS.getComplexFloatImag().compare(RHS.getComplexFloatImag());
12560 bool IsEqual = CR_r == APFloat::cmpEqual && CR_i == APFloat::cmpEqual;
12561 return Success(IsEqual ? CmpResult::Equal : CmpResult::Unequal, E);
12562 } else {
12563 assert(IsEquality && "invalid complex comparison")(static_cast <bool> (IsEquality && "invalid complex comparison"
) ? void (0) : __assert_fail ("IsEquality && \"invalid complex comparison\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12563, __extension__ __PRETTY_FUNCTION__))
;
12564 bool IsEqual = LHS.getComplexIntReal() == RHS.getComplexIntReal() &&
12565 LHS.getComplexIntImag() == RHS.getComplexIntImag();
12566 return Success(IsEqual ? CmpResult::Equal : CmpResult::Unequal, E);
12567 }
12568 }
12569
12570 if (LHSTy->isRealFloatingType() &&
12571 RHSTy->isRealFloatingType()) {
12572 APFloat RHS(0.0), LHS(0.0);
12573
12574 bool LHSOK = EvaluateFloat(E->getRHS(), RHS, Info);
12575 if (!LHSOK && !Info.noteFailure())
12576 return false;
12577
12578 if (!EvaluateFloat(E->getLHS(), LHS, Info) || !LHSOK)
12579 return false;
12580
12581 assert(E->isComparisonOp() && "Invalid binary operator!")(static_cast <bool> (E->isComparisonOp() && "Invalid binary operator!"
) ? void (0) : __assert_fail ("E->isComparisonOp() && \"Invalid binary operator!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12581, __extension__ __PRETTY_FUNCTION__))
;
12582 llvm::APFloatBase::cmpResult APFloatCmpResult = LHS.compare(RHS);
12583 if (!Info.InConstantContext &&
12584 APFloatCmpResult == APFloat::cmpUnordered &&
12585 E->getFPFeaturesInEffect(Info.Ctx.getLangOpts()).isFPConstrained()) {
12586 // Note: Compares may raise invalid in some cases involving NaN or sNaN.
12587 Info.FFDiag(E, diag::note_constexpr_float_arithmetic_strict);
12588 return false;
12589 }
12590 auto GetCmpRes = [&]() {
12591 switch (APFloatCmpResult) {
12592 case APFloat::cmpEqual:
12593 return CmpResult::Equal;
12594 case APFloat::cmpLessThan:
12595 return CmpResult::Less;
12596 case APFloat::cmpGreaterThan:
12597 return CmpResult::Greater;
12598 case APFloat::cmpUnordered:
12599 return CmpResult::Unordered;
12600 }
12601 llvm_unreachable("Unrecognised APFloat::cmpResult enum")::llvm::llvm_unreachable_internal("Unrecognised APFloat::cmpResult enum"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12601)
;
12602 };
12603 return Success(GetCmpRes(), E);
12604 }
12605
12606 if (LHSTy->isPointerType() && RHSTy->isPointerType()) {
12607 LValue LHSValue, RHSValue;
12608
12609 bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
12610 if (!LHSOK && !Info.noteFailure())
12611 return false;
12612
12613 if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
12614 return false;
12615
12616 // Reject differing bases from the normal codepath; we special-case
12617 // comparisons to null.
12618 if (!HasSameBase(LHSValue, RHSValue)) {
12619 // Inequalities and subtractions between unrelated pointers have
12620 // unspecified or undefined behavior.
12621 if (!IsEquality) {
12622 Info.FFDiag(E, diag::note_constexpr_pointer_comparison_unspecified);
12623 return false;
12624 }
12625 // A constant address may compare equal to the address of a symbol.
12626 // The one exception is that address of an object cannot compare equal
12627 // to a null pointer constant.
12628 if ((!LHSValue.Base && !LHSValue.Offset.isZero()) ||
12629 (!RHSValue.Base && !RHSValue.Offset.isZero()))
12630 return Error(E);
12631 // It's implementation-defined whether distinct literals will have
12632 // distinct addresses. In clang, the result of such a comparison is
12633 // unspecified, so it is not a constant expression. However, we do know
12634 // that the address of a literal will be non-null.
12635 if ((IsLiteralLValue(LHSValue) || IsLiteralLValue(RHSValue)) &&
12636 LHSValue.Base && RHSValue.Base)
12637 return Error(E);
12638 // We can't tell whether weak symbols will end up pointing to the same
12639 // object.
12640 if (IsWeakLValue(LHSValue) || IsWeakLValue(RHSValue))
12641 return Error(E);
12642 // We can't compare the address of the start of one object with the
12643 // past-the-end address of another object, per C++ DR1652.
12644 if ((LHSValue.Base && LHSValue.Offset.isZero() &&
12645 isOnePastTheEndOfCompleteObject(Info.Ctx, RHSValue)) ||
12646 (RHSValue.Base && RHSValue.Offset.isZero() &&
12647 isOnePastTheEndOfCompleteObject(Info.Ctx, LHSValue)))
12648 return Error(E);
12649 // We can't tell whether an object is at the same address as another
12650 // zero sized object.
12651 if ((RHSValue.Base && isZeroSized(LHSValue)) ||
12652 (LHSValue.Base && isZeroSized(RHSValue)))
12653 return Error(E);
12654 return Success(CmpResult::Unequal, E);
12655 }
12656
12657 const CharUnits &LHSOffset = LHSValue.getLValueOffset();
12658 const CharUnits &RHSOffset = RHSValue.getLValueOffset();
12659
12660 SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
12661 SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
12662
12663 // C++11 [expr.rel]p3:
12664 // Pointers to void (after pointer conversions) can be compared, with a
12665 // result defined as follows: If both pointers represent the same
12666 // address or are both the null pointer value, the result is true if the
12667 // operator is <= or >= and false otherwise; otherwise the result is
12668 // unspecified.
12669 // We interpret this as applying to pointers to *cv* void.
12670 if (LHSTy->isVoidPointerType() && LHSOffset != RHSOffset && IsRelational)
12671 Info.CCEDiag(E, diag::note_constexpr_void_comparison);
12672
12673 // C++11 [expr.rel]p2:
12674 // - If two pointers point to non-static data members of the same object,
12675 // or to subobjects or array elements fo such members, recursively, the
12676 // pointer to the later declared member compares greater provided the
12677 // two members have the same access control and provided their class is
12678 // not a union.
12679 // [...]
12680 // - Otherwise pointer comparisons are unspecified.
12681 if (!LHSDesignator.Invalid && !RHSDesignator.Invalid && IsRelational) {
12682 bool WasArrayIndex;
12683 unsigned Mismatch = FindDesignatorMismatch(
12684 getType(LHSValue.Base), LHSDesignator, RHSDesignator, WasArrayIndex);
12685 // At the point where the designators diverge, the comparison has a
12686 // specified value if:
12687 // - we are comparing array indices
12688 // - we are comparing fields of a union, or fields with the same access
12689 // Otherwise, the result is unspecified and thus the comparison is not a
12690 // constant expression.
12691 if (!WasArrayIndex && Mismatch < LHSDesignator.Entries.size() &&
12692 Mismatch < RHSDesignator.Entries.size()) {
12693 const FieldDecl *LF = getAsField(LHSDesignator.Entries[Mismatch]);
12694 const FieldDecl *RF = getAsField(RHSDesignator.Entries[Mismatch]);
12695 if (!LF && !RF)
12696 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_classes);
12697 else if (!LF)
12698 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
12699 << getAsBaseClass(LHSDesignator.Entries[Mismatch])
12700 << RF->getParent() << RF;
12701 else if (!RF)
12702 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
12703 << getAsBaseClass(RHSDesignator.Entries[Mismatch])
12704 << LF->getParent() << LF;
12705 else if (!LF->getParent()->isUnion() &&
12706 LF->getAccess() != RF->getAccess())
12707 Info.CCEDiag(E,
12708 diag::note_constexpr_pointer_comparison_differing_access)
12709 << LF << LF->getAccess() << RF << RF->getAccess()
12710 << LF->getParent();
12711 }
12712 }
12713
12714 // The comparison here must be unsigned, and performed with the same
12715 // width as the pointer.
12716 unsigned PtrSize = Info.Ctx.getTypeSize(LHSTy);
12717 uint64_t CompareLHS = LHSOffset.getQuantity();
12718 uint64_t CompareRHS = RHSOffset.getQuantity();
12719 assert(PtrSize <= 64 && "Unexpected pointer width")(static_cast <bool> (PtrSize <= 64 && "Unexpected pointer width"
) ? void (0) : __assert_fail ("PtrSize <= 64 && \"Unexpected pointer width\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12719, __extension__ __PRETTY_FUNCTION__))
;
12720 uint64_t Mask = ~0ULL >> (64 - PtrSize);
12721 CompareLHS &= Mask;
12722 CompareRHS &= Mask;
12723
12724 // If there is a base and this is a relational operator, we can only
12725 // compare pointers within the object in question; otherwise, the result
12726 // depends on where the object is located in memory.
12727 if (!LHSValue.Base.isNull() && IsRelational) {
12728 QualType BaseTy = getType(LHSValue.Base);
12729 if (BaseTy->isIncompleteType())
12730 return Error(E);
12731 CharUnits Size = Info.Ctx.getTypeSizeInChars(BaseTy);
12732 uint64_t OffsetLimit = Size.getQuantity();
12733 if (CompareLHS > OffsetLimit || CompareRHS > OffsetLimit)
12734 return Error(E);
12735 }
12736
12737 if (CompareLHS < CompareRHS)
12738 return Success(CmpResult::Less, E);
12739 if (CompareLHS > CompareRHS)
12740 return Success(CmpResult::Greater, E);
12741 return Success(CmpResult::Equal, E);
12742 }
12743
12744 if (LHSTy->isMemberPointerType()) {
12745 assert(IsEquality && "unexpected member pointer operation")(static_cast <bool> (IsEquality && "unexpected member pointer operation"
) ? void (0) : __assert_fail ("IsEquality && \"unexpected member pointer operation\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12745, __extension__ __PRETTY_FUNCTION__))
;
12746 assert(RHSTy->isMemberPointerType() && "invalid comparison")(static_cast <bool> (RHSTy->isMemberPointerType() &&
"invalid comparison") ? void (0) : __assert_fail ("RHSTy->isMemberPointerType() && \"invalid comparison\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12746, __extension__ __PRETTY_FUNCTION__))
;
12747
12748 MemberPtr LHSValue, RHSValue;
12749
12750 bool LHSOK = EvaluateMemberPointer(E->getLHS(), LHSValue, Info);
12751 if (!LHSOK && !Info.noteFailure())
12752 return false;
12753
12754 if (!EvaluateMemberPointer(E->getRHS(), RHSValue, Info) || !LHSOK)
12755 return false;
12756
12757 // C++11 [expr.eq]p2:
12758 // If both operands are null, they compare equal. Otherwise if only one is
12759 // null, they compare unequal.
12760 if (!LHSValue.getDecl() || !RHSValue.getDecl()) {
12761 bool Equal = !LHSValue.getDecl() && !RHSValue.getDecl();
12762 return Success(Equal ? CmpResult::Equal : CmpResult::Unequal, E);
12763 }
12764
12765 // Otherwise if either is a pointer to a virtual member function, the
12766 // result is unspecified.
12767 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(LHSValue.getDecl()))
12768 if (MD->isVirtual())
12769 Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
12770 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(RHSValue.getDecl()))
12771 if (MD->isVirtual())
12772 Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
12773
12774 // Otherwise they compare equal if and only if they would refer to the
12775 // same member of the same most derived object or the same subobject if
12776 // they were dereferenced with a hypothetical object of the associated
12777 // class type.
12778 bool Equal = LHSValue == RHSValue;
12779 return Success(Equal ? CmpResult::Equal : CmpResult::Unequal, E);
12780 }
12781
12782 if (LHSTy->isNullPtrType()) {
12783 assert(E->isComparisonOp() && "unexpected nullptr operation")(static_cast <bool> (E->isComparisonOp() && "unexpected nullptr operation"
) ? void (0) : __assert_fail ("E->isComparisonOp() && \"unexpected nullptr operation\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12783, __extension__ __PRETTY_FUNCTION__))
;
12784 assert(RHSTy->isNullPtrType() && "missing pointer conversion")(static_cast <bool> (RHSTy->isNullPtrType() &&
"missing pointer conversion") ? void (0) : __assert_fail ("RHSTy->isNullPtrType() && \"missing pointer conversion\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12784, __extension__ __PRETTY_FUNCTION__))
;
12785 // C++11 [expr.rel]p4, [expr.eq]p3: If two operands of type std::nullptr_t
12786 // are compared, the result is true of the operator is <=, >= or ==, and
12787 // false otherwise.
12788 return Success(CmpResult::Equal, E);
12789 }
12790
12791 return DoAfter();
12792}
12793
12794bool RecordExprEvaluator::VisitBinCmp(const BinaryOperator *E) {
12795 if (!CheckLiteralType(Info, E))
12796 return false;
12797
12798 auto OnSuccess = [&](CmpResult CR, const BinaryOperator *E) {
12799 ComparisonCategoryResult CCR;
12800 switch (CR) {
12801 case CmpResult::Unequal:
12802 llvm_unreachable("should never produce Unequal for three-way comparison")::llvm::llvm_unreachable_internal("should never produce Unequal for three-way comparison"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12802)
;
12803 case CmpResult::Less:
12804 CCR = ComparisonCategoryResult::Less;
12805 break;
12806 case CmpResult::Equal:
12807 CCR = ComparisonCategoryResult::Equal;
12808 break;
12809 case CmpResult::Greater:
12810 CCR = ComparisonCategoryResult::Greater;
12811 break;
12812 case CmpResult::Unordered:
12813 CCR = ComparisonCategoryResult::Unordered;
12814 break;
12815 }
12816 // Evaluation succeeded. Lookup the information for the comparison category
12817 // type and fetch the VarDecl for the result.
12818 const ComparisonCategoryInfo &CmpInfo =
12819 Info.Ctx.CompCategories.getInfoForType(E->getType());
12820 const VarDecl *VD = CmpInfo.getValueInfo(CmpInfo.makeWeakResult(CCR))->VD;
12821 // Check and evaluate the result as a constant expression.
12822 LValue LV;
12823 LV.set(VD);
12824 if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
12825 return false;
12826 return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result,
12827 ConstantExprKind::Normal);
12828 };
12829 return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
12830 return ExprEvaluatorBaseTy::VisitBinCmp(E);
12831 });
12832}
12833
12834bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
12835 // We don't support assignment in C. C++ assignments don't get here because
12836 // assignment is an lvalue in C++.
12837 if (E->isAssignmentOp()) {
12838 Error(E);
12839 if (!Info.noteFailure())
12840 return false;
12841 }
12842
12843 if (DataRecursiveIntBinOpEvaluator::shouldEnqueue(E))
12844 return DataRecursiveIntBinOpEvaluator(*this, Result).Traverse(E);
12845
12846 assert((!E->getLHS()->getType()->isIntegralOrEnumerationType() ||(static_cast <bool> ((!E->getLHS()->getType()->
isIntegralOrEnumerationType() || !E->getRHS()->getType(
)->isIntegralOrEnumerationType()) && "DataRecursiveIntBinOpEvaluator should have handled integral types"
) ? void (0) : __assert_fail ("(!E->getLHS()->getType()->isIntegralOrEnumerationType() || !E->getRHS()->getType()->isIntegralOrEnumerationType()) && \"DataRecursiveIntBinOpEvaluator should have handled integral types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12848, __extension__ __PRETTY_FUNCTION__))
12847 !E->getRHS()->getType()->isIntegralOrEnumerationType()) &&(static_cast <bool> ((!E->getLHS()->getType()->
isIntegralOrEnumerationType() || !E->getRHS()->getType(
)->isIntegralOrEnumerationType()) && "DataRecursiveIntBinOpEvaluator should have handled integral types"
) ? void (0) : __assert_fail ("(!E->getLHS()->getType()->isIntegralOrEnumerationType() || !E->getRHS()->getType()->isIntegralOrEnumerationType()) && \"DataRecursiveIntBinOpEvaluator should have handled integral types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12848, __extension__ __PRETTY_FUNCTION__))
12848 "DataRecursiveIntBinOpEvaluator should have handled integral types")(static_cast <bool> ((!E->getLHS()->getType()->
isIntegralOrEnumerationType() || !E->getRHS()->getType(
)->isIntegralOrEnumerationType()) && "DataRecursiveIntBinOpEvaluator should have handled integral types"
) ? void (0) : __assert_fail ("(!E->getLHS()->getType()->isIntegralOrEnumerationType() || !E->getRHS()->getType()->isIntegralOrEnumerationType()) && \"DataRecursiveIntBinOpEvaluator should have handled integral types\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12848, __extension__ __PRETTY_FUNCTION__))
;
12849
12850 if (E->isComparisonOp()) {
12851 // Evaluate builtin binary comparisons by evaluating them as three-way
12852 // comparisons and then translating the result.
12853 auto OnSuccess = [&](CmpResult CR, const BinaryOperator *E) {
12854 assert((CR != CmpResult::Unequal || E->isEqualityOp()) &&(static_cast <bool> ((CR != CmpResult::Unequal || E->
isEqualityOp()) && "should only produce Unequal for equality comparisons"
) ? void (0) : __assert_fail ("(CR != CmpResult::Unequal || E->isEqualityOp()) && \"should only produce Unequal for equality comparisons\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12855, __extension__ __PRETTY_FUNCTION__))
12855 "should only produce Unequal for equality comparisons")(static_cast <bool> ((CR != CmpResult::Unequal || E->
isEqualityOp()) && "should only produce Unequal for equality comparisons"
) ? void (0) : __assert_fail ("(CR != CmpResult::Unequal || E->isEqualityOp()) && \"should only produce Unequal for equality comparisons\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12855, __extension__ __PRETTY_FUNCTION__))
;
12856 bool IsEqual = CR == CmpResult::Equal,
12857 IsLess = CR == CmpResult::Less,
12858 IsGreater = CR == CmpResult::Greater;
12859 auto Op = E->getOpcode();
12860 switch (Op) {
12861 default:
12862 llvm_unreachable("unsupported binary operator")::llvm::llvm_unreachable_internal("unsupported binary operator"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 12862)
;
12863 case BO_EQ:
12864 case BO_NE:
12865 return Success(IsEqual == (Op == BO_EQ), E);
12866 case BO_LT:
12867 return Success(IsLess, E);
12868 case BO_GT:
12869 return Success(IsGreater, E);
12870 case BO_LE:
12871 return Success(IsEqual || IsLess, E);
12872 case BO_GE:
12873 return Success(IsEqual || IsGreater, E);
12874 }
12875 };
12876 return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
12877 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
12878 });
12879 }
12880
12881 QualType LHSTy = E->getLHS()->getType();
12882 QualType RHSTy = E->getRHS()->getType();
12883
12884 if (LHSTy->isPointerType() && RHSTy->isPointerType() &&
12885 E->getOpcode() == BO_Sub) {
12886 LValue LHSValue, RHSValue;
12887
12888 bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
12889 if (!LHSOK && !Info.noteFailure())
12890 return false;
12891
12892 if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
12893 return false;
12894
12895 // Reject differing bases from the normal codepath; we special-case
12896 // comparisons to null.
12897 if (!HasSameBase(LHSValue, RHSValue)) {
12898 // Handle &&A - &&B.
12899 if (!LHSValue.Offset.isZero() || !RHSValue.Offset.isZero())
12900 return Error(E);
12901 const Expr *LHSExpr = LHSValue.Base.dyn_cast<const Expr *>();
12902 const Expr *RHSExpr = RHSValue.Base.dyn_cast<const Expr *>();
12903 if (!LHSExpr || !RHSExpr)
12904 return Error(E);
12905 const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
12906 const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
12907 if (!LHSAddrExpr || !RHSAddrExpr)
12908 return Error(E);
12909 // Make sure both labels come from the same function.
12910 if (LHSAddrExpr->getLabel()->getDeclContext() !=
12911 RHSAddrExpr->getLabel()->getDeclContext())
12912 return Error(E);
12913 return Success(APValue(LHSAddrExpr, RHSAddrExpr), E);
12914 }
12915 const CharUnits &LHSOffset = LHSValue.getLValueOffset();
12916 const CharUnits &RHSOffset = RHSValue.getLValueOffset();
12917
12918 SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
12919 SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
12920
12921 // C++11 [expr.add]p6:
12922 // Unless both pointers point to elements of the same array object, or
12923 // one past the last element of the array object, the behavior is
12924 // undefined.
12925 if (!LHSDesignator.Invalid && !RHSDesignator.Invalid &&
12926 !AreElementsOfSameArray(getType(LHSValue.Base), LHSDesignator,
12927 RHSDesignator))
12928 Info.CCEDiag(E, diag::note_constexpr_pointer_subtraction_not_same_array);
12929
12930 QualType Type = E->getLHS()->getType();
12931 QualType ElementType = Type->castAs<PointerType>()->getPointeeType();
12932
12933 CharUnits ElementSize;
12934 if (!HandleSizeof(Info, E->getExprLoc(), ElementType, ElementSize))
12935 return false;
12936
12937 // As an extension, a type may have zero size (empty struct or union in
12938 // C, array of zero length). Pointer subtraction in such cases has
12939 // undefined behavior, so is not constant.
12940 if (ElementSize.isZero()) {
12941 Info.FFDiag(E, diag::note_constexpr_pointer_subtraction_zero_size)
12942 << ElementType;
12943 return false;
12944 }
12945
12946 // FIXME: LLVM and GCC both compute LHSOffset - RHSOffset at runtime,
12947 // and produce incorrect results when it overflows. Such behavior
12948 // appears to be non-conforming, but is common, so perhaps we should
12949 // assume the standard intended for such cases to be undefined behavior
12950 // and check for them.
12951
12952 // Compute (LHSOffset - RHSOffset) / Size carefully, checking for
12953 // overflow in the final conversion to ptrdiff_t.
12954 APSInt LHS(llvm::APInt(65, (int64_t)LHSOffset.getQuantity(), true), false);
12955 APSInt RHS(llvm::APInt(65, (int64_t)RHSOffset.getQuantity(), true), false);
12956 APSInt ElemSize(llvm::APInt(65, (int64_t)ElementSize.getQuantity(), true),
12957 false);
12958 APSInt TrueResult = (LHS - RHS) / ElemSize;
12959 APSInt Result = TrueResult.trunc(Info.Ctx.getIntWidth(E->getType()));
12960
12961 if (Result.extend(65) != TrueResult &&
12962 !HandleOverflow(Info, E, TrueResult, E->getType()))
12963 return false;
12964 return Success(Result, E);
12965 }
12966
12967 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
12968}
12969
12970/// VisitUnaryExprOrTypeTraitExpr - Evaluate a sizeof, alignof or vec_step with
12971/// a result as the expression's type.
12972bool IntExprEvaluator::VisitUnaryExprOrTypeTraitExpr(
12973 const UnaryExprOrTypeTraitExpr *E) {
12974 switch(E->getKind()) {
12975 case UETT_PreferredAlignOf:
12976 case UETT_AlignOf: {
12977 if (E->isArgumentType())
12978 return Success(GetAlignOfType(Info, E->getArgumentType(), E->getKind()),
12979 E);
12980 else
12981 return Success(GetAlignOfExpr(Info, E->getArgumentExpr(), E->getKind()),
12982 E);
12983 }
12984
12985 case UETT_VecStep: {
12986 QualType Ty = E->getTypeOfArgument();
12987
12988 if (Ty->isVectorType()) {
12989 unsigned n = Ty->castAs<VectorType>()->getNumElements();
12990
12991 // The vec_step built-in functions that take a 3-component
12992 // vector return 4. (OpenCL 1.1 spec 6.11.12)
12993 if (n == 3)
12994 n = 4;
12995
12996 return Success(n, E);
12997 } else
12998 return Success(1, E);
12999 }
13000
13001 case UETT_SizeOf: {
13002 QualType SrcTy = E->getTypeOfArgument();
13003 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
13004 // the result is the size of the referenced type."
13005 if (const ReferenceType *Ref = SrcTy->getAs<ReferenceType>())
13006 SrcTy = Ref->getPointeeType();
13007
13008 CharUnits Sizeof;
13009 if (!HandleSizeof(Info, E->getExprLoc(), SrcTy, Sizeof))
13010 return false;
13011 return Success(Sizeof, E);
13012 }
13013 case UETT_OpenMPRequiredSimdAlign:
13014 assert(E->isArgumentType())(static_cast <bool> (E->isArgumentType()) ? void (0)
: __assert_fail ("E->isArgumentType()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13014, __extension__ __PRETTY_FUNCTION__))
;
13015 return Success(
13016 Info.Ctx.toCharUnitsFromBits(
13017 Info.Ctx.getOpenMPDefaultSimdAlign(E->getArgumentType()))
13018 .getQuantity(),
13019 E);
13020 }
13021
13022 llvm_unreachable("unknown expr/type trait")::llvm::llvm_unreachable_internal("unknown expr/type trait", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13022)
;
13023}
13024
13025bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *OOE) {
13026 CharUnits Result;
13027 unsigned n = OOE->getNumComponents();
13028 if (n == 0)
13029 return Error(OOE);
13030 QualType CurrentType = OOE->getTypeSourceInfo()->getType();
13031 for (unsigned i = 0; i != n; ++i) {
13032 OffsetOfNode ON = OOE->getComponent(i);
13033 switch (ON.getKind()) {
13034 case OffsetOfNode::Array: {
13035 const Expr *Idx = OOE->getIndexExpr(ON.getArrayExprIndex());
13036 APSInt IdxResult;
13037 if (!EvaluateInteger(Idx, IdxResult, Info))
13038 return false;
13039 const ArrayType *AT = Info.Ctx.getAsArrayType(CurrentType);
13040 if (!AT)
13041 return Error(OOE);
13042 CurrentType = AT->getElementType();
13043 CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(CurrentType);
13044 Result += IdxResult.getSExtValue() * ElementSize;
13045 break;
13046 }
13047
13048 case OffsetOfNode::Field: {
13049 FieldDecl *MemberDecl = ON.getField();
13050 const RecordType *RT = CurrentType->getAs<RecordType>();
13051 if (!RT)
13052 return Error(OOE);
13053 RecordDecl *RD = RT->getDecl();
13054 if (RD->isInvalidDecl()) return false;
13055 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
13056 unsigned i = MemberDecl->getFieldIndex();
13057 assert(i < RL.getFieldCount() && "offsetof field in wrong type")(static_cast <bool> (i < RL.getFieldCount() &&
"offsetof field in wrong type") ? void (0) : __assert_fail (
"i < RL.getFieldCount() && \"offsetof field in wrong type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13057, __extension__ __PRETTY_FUNCTION__))
;
13058 Result += Info.Ctx.toCharUnitsFromBits(RL.getFieldOffset(i));
13059 CurrentType = MemberDecl->getType().getNonReferenceType();
13060 break;
13061 }
13062
13063 case OffsetOfNode::Identifier:
13064 llvm_unreachable("dependent __builtin_offsetof")::llvm::llvm_unreachable_internal("dependent __builtin_offsetof"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13064)
;
13065
13066 case OffsetOfNode::Base: {
13067 CXXBaseSpecifier *BaseSpec = ON.getBase();
13068 if (BaseSpec->isVirtual())
13069 return Error(OOE);
13070
13071 // Find the layout of the class whose base we are looking into.
13072 const RecordType *RT = CurrentType->getAs<RecordType>();
13073 if (!RT)
13074 return Error(OOE);
13075 RecordDecl *RD = RT->getDecl();
13076 if (RD->isInvalidDecl()) return false;
13077 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
13078
13079 // Find the base class itself.
13080 CurrentType = BaseSpec->getType();
13081 const RecordType *BaseRT = CurrentType->getAs<RecordType>();
13082 if (!BaseRT)
13083 return Error(OOE);
13084
13085 // Add the offset to the base.
13086 Result += RL.getBaseClassOffset(cast<CXXRecordDecl>(BaseRT->getDecl()));
13087 break;
13088 }
13089 }
13090 }
13091 return Success(Result, OOE);
13092}
13093
13094bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
13095 switch (E->getOpcode()) {
13096 default:
13097 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
13098 // See C99 6.6p3.
13099 return Error(E);
13100 case UO_Extension:
13101 // FIXME: Should extension allow i-c-e extension expressions in its scope?
13102 // If so, we could clear the diagnostic ID.
13103 return Visit(E->getSubExpr());
13104 case UO_Plus:
13105 // The result is just the value.
13106 return Visit(E->getSubExpr());
13107 case UO_Minus: {
13108 if (!Visit(E->getSubExpr()))
13109 return false;
13110 if (!Result.isInt()) return Error(E);
13111 const APSInt &Value = Result.getInt();
13112 if (Value.isSigned() && Value.isMinSignedValue() && E->canOverflow() &&
13113 !HandleOverflow(Info, E, -Value.extend(Value.getBitWidth() + 1),
13114 E->getType()))
13115 return false;
13116 return Success(-Value, E);
13117 }
13118 case UO_Not: {
13119 if (!Visit(E->getSubExpr()))
13120 return false;
13121 if (!Result.isInt()) return Error(E);
13122 return Success(~Result.getInt(), E);
13123 }
13124 case UO_LNot: {
13125 bool bres;
13126 if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
13127 return false;
13128 return Success(!bres, E);
13129 }
13130 }
13131}
13132
13133/// HandleCast - This is used to evaluate implicit or explicit casts where the
13134/// result type is integer.
13135bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
13136 const Expr *SubExpr = E->getSubExpr();
13137 QualType DestType = E->getType();
13138 QualType SrcType = SubExpr->getType();
13139
13140 switch (E->getCastKind()) {
13141 case CK_BaseToDerived:
13142 case CK_DerivedToBase:
13143 case CK_UncheckedDerivedToBase:
13144 case CK_Dynamic:
13145 case CK_ToUnion:
13146 case CK_ArrayToPointerDecay:
13147 case CK_FunctionToPointerDecay:
13148 case CK_NullToPointer:
13149 case CK_NullToMemberPointer:
13150 case CK_BaseToDerivedMemberPointer:
13151 case CK_DerivedToBaseMemberPointer:
13152 case CK_ReinterpretMemberPointer:
13153 case CK_ConstructorConversion:
13154 case CK_IntegralToPointer:
13155 case CK_ToVoid:
13156 case CK_VectorSplat:
13157 case CK_IntegralToFloating:
13158 case CK_FloatingCast:
13159 case CK_CPointerToObjCPointerCast:
13160 case CK_BlockPointerToObjCPointerCast:
13161 case CK_AnyPointerToBlockPointerCast:
13162 case CK_ObjCObjectLValueCast:
13163 case CK_FloatingRealToComplex:
13164 case CK_FloatingComplexToReal:
13165 case CK_FloatingComplexCast:
13166 case CK_FloatingComplexToIntegralComplex:
13167 case CK_IntegralRealToComplex:
13168 case CK_IntegralComplexCast:
13169 case CK_IntegralComplexToFloatingComplex:
13170 case CK_BuiltinFnToFnPtr:
13171 case CK_ZeroToOCLOpaqueType:
13172 case CK_NonAtomicToAtomic:
13173 case CK_AddressSpaceConversion:
13174 case CK_IntToOCLSampler:
13175 case CK_FloatingToFixedPoint:
13176 case CK_FixedPointToFloating:
13177 case CK_FixedPointCast:
13178 case CK_IntegralToFixedPoint:
13179 case CK_MatrixCast:
13180 llvm_unreachable("invalid cast kind for integral value")::llvm::llvm_unreachable_internal("invalid cast kind for integral value"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13180)
;
13181
13182 case CK_BitCast:
13183 case CK_Dependent:
13184 case CK_LValueBitCast:
13185 case CK_ARCProduceObject:
13186 case CK_ARCConsumeObject:
13187 case CK_ARCReclaimReturnedObject:
13188 case CK_ARCExtendBlockObject:
13189 case CK_CopyAndAutoreleaseBlockObject:
13190 return Error(E);
13191
13192 case CK_UserDefinedConversion:
13193 case CK_LValueToRValue:
13194 case CK_AtomicToNonAtomic:
13195 case CK_NoOp:
13196 case CK_LValueToRValueBitCast:
13197 return ExprEvaluatorBaseTy::VisitCastExpr(E);
13198
13199 case CK_MemberPointerToBoolean:
13200 case CK_PointerToBoolean:
13201 case CK_IntegralToBoolean:
13202 case CK_FloatingToBoolean:
13203 case CK_BooleanToSignedIntegral:
13204 case CK_FloatingComplexToBoolean:
13205 case CK_IntegralComplexToBoolean: {
13206 bool BoolResult;
13207 if (!EvaluateAsBooleanCondition(SubExpr, BoolResult, Info))
13208 return false;
13209 uint64_t IntResult = BoolResult;
13210 if (BoolResult && E->getCastKind() == CK_BooleanToSignedIntegral)
13211 IntResult = (uint64_t)-1;
13212 return Success(IntResult, E);
13213 }
13214
13215 case CK_FixedPointToIntegral: {
13216 APFixedPoint Src(Info.Ctx.getFixedPointSemantics(SrcType));
13217 if (!EvaluateFixedPoint(SubExpr, Src, Info))
13218 return false;
13219 bool Overflowed;
13220 llvm::APSInt Result = Src.convertToInt(
13221 Info.Ctx.getIntWidth(DestType),
13222 DestType->isSignedIntegerOrEnumerationType(), &Overflowed);
13223 if (Overflowed && !HandleOverflow(Info, E, Result, DestType))
13224 return false;
13225 return Success(Result, E);
13226 }
13227
13228 case CK_FixedPointToBoolean: {
13229 // Unsigned padding does not affect this.
13230 APValue Val;
13231 if (!Evaluate(Val, Info, SubExpr))
13232 return false;
13233 return Success(Val.getFixedPoint().getBoolValue(), E);
13234 }
13235
13236 case CK_IntegralCast: {
13237 if (!Visit(SubExpr))
13238 return false;
13239
13240 if (!Result.isInt()) {
13241 // Allow casts of address-of-label differences if they are no-ops
13242 // or narrowing. (The narrowing case isn't actually guaranteed to
13243 // be constant-evaluatable except in some narrow cases which are hard
13244 // to detect here. We let it through on the assumption the user knows
13245 // what they are doing.)
13246 if (Result.isAddrLabelDiff())
13247 return Info.Ctx.getTypeSize(DestType) <= Info.Ctx.getTypeSize(SrcType);
13248 // Only allow casts of lvalues if they are lossless.
13249 return Info.Ctx.getTypeSize(DestType) == Info.Ctx.getTypeSize(SrcType);
13250 }
13251
13252 return Success(HandleIntToIntCast(Info, E, DestType, SrcType,
13253 Result.getInt()), E);
13254 }
13255
13256 case CK_PointerToIntegral: {
13257 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
13258
13259 LValue LV;
13260 if (!EvaluatePointer(SubExpr, LV, Info))
13261 return false;
13262
13263 if (LV.getLValueBase()) {
13264 // Only allow based lvalue casts if they are lossless.
13265 // FIXME: Allow a larger integer size than the pointer size, and allow
13266 // narrowing back down to pointer width in subsequent integral casts.
13267 // FIXME: Check integer type's active bits, not its type size.
13268 if (Info.Ctx.getTypeSize(DestType) != Info.Ctx.getTypeSize(SrcType))
13269 return Error(E);
13270
13271 LV.Designator.setInvalid();
13272 LV.moveInto(Result);
13273 return true;
13274 }
13275
13276 APSInt AsInt;
13277 APValue V;
13278 LV.moveInto(V);
13279 if (!V.toIntegralConstant(AsInt, SrcType, Info.Ctx))
13280 llvm_unreachable("Can't cast this!")::llvm::llvm_unreachable_internal("Can't cast this!", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13280)
;
13281
13282 return Success(HandleIntToIntCast(Info, E, DestType, SrcType, AsInt), E);
13283 }
13284
13285 case CK_IntegralComplexToReal: {
13286 ComplexValue C;
13287 if (!EvaluateComplex(SubExpr, C, Info))
13288 return false;
13289 return Success(C.getComplexIntReal(), E);
13290 }
13291
13292 case CK_FloatingToIntegral: {
13293 APFloat F(0.0);
13294 if (!EvaluateFloat(SubExpr, F, Info))
13295 return false;
13296
13297 APSInt Value;
13298 if (!HandleFloatToIntCast(Info, E, SrcType, F, DestType, Value))
13299 return false;
13300 return Success(Value, E);
13301 }
13302 }
13303
13304 llvm_unreachable("unknown cast resulting in integral value")::llvm::llvm_unreachable_internal("unknown cast resulting in integral value"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13304)
;
13305}
13306
13307bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
13308 if (E->getSubExpr()->getType()->isAnyComplexType()) {
13309 ComplexValue LV;
13310 if (!EvaluateComplex(E->getSubExpr(), LV, Info))
13311 return false;
13312 if (!LV.isComplexInt())
13313 return Error(E);
13314 return Success(LV.getComplexIntReal(), E);
13315 }
13316
13317 return Visit(E->getSubExpr());
13318}
13319
13320bool IntExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
13321 if (E->getSubExpr()->getType()->isComplexIntegerType()) {
13322 ComplexValue LV;
13323 if (!EvaluateComplex(E->getSubExpr(), LV, Info))
13324 return false;
13325 if (!LV.isComplexInt())
13326 return Error(E);
13327 return Success(LV.getComplexIntImag(), E);
13328 }
13329
13330 VisitIgnoredValue(E->getSubExpr());
13331 return Success(0, E);
13332}
13333
13334bool IntExprEvaluator::VisitSizeOfPackExpr(const SizeOfPackExpr *E) {
13335 return Success(E->getPackLength(), E);
13336}
13337
13338bool IntExprEvaluator::VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
13339 return Success(E->getValue(), E);
13340}
13341
13342bool IntExprEvaluator::VisitConceptSpecializationExpr(
13343 const ConceptSpecializationExpr *E) {
13344 return Success(E->isSatisfied(), E);
13345}
13346
13347bool IntExprEvaluator::VisitRequiresExpr(const RequiresExpr *E) {
13348 return Success(E->isSatisfied(), E);
13349}
13350
13351bool FixedPointExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
13352 switch (E->getOpcode()) {
13353 default:
13354 // Invalid unary operators
13355 return Error(E);
13356 case UO_Plus:
13357 // The result is just the value.
13358 return Visit(E->getSubExpr());
13359 case UO_Minus: {
13360 if (!Visit(E->getSubExpr())) return false;
13361 if (!Result.isFixedPoint())
13362 return Error(E);
13363 bool Overflowed;
13364 APFixedPoint Negated = Result.getFixedPoint().negate(&Overflowed);
13365 if (Overflowed && !HandleOverflow(Info, E, Negated, E->getType()))
13366 return false;
13367 return Success(Negated, E);
13368 }
13369 case UO_LNot: {
13370 bool bres;
13371 if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
13372 return false;
13373 return Success(!bres, E);
13374 }
13375 }
13376}
13377
13378bool FixedPointExprEvaluator::VisitCastExpr(const CastExpr *E) {
13379 const Expr *SubExpr = E->getSubExpr();
13380 QualType DestType = E->getType();
13381 assert(DestType->isFixedPointType() &&(static_cast <bool> (DestType->isFixedPointType() &&
"Expected destination type to be a fixed point type") ? void
(0) : __assert_fail ("DestType->isFixedPointType() && \"Expected destination type to be a fixed point type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13382, __extension__ __PRETTY_FUNCTION__))
13382 "Expected destination type to be a fixed point type")(static_cast <bool> (DestType->isFixedPointType() &&
"Expected destination type to be a fixed point type") ? void
(0) : __assert_fail ("DestType->isFixedPointType() && \"Expected destination type to be a fixed point type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13382, __extension__ __PRETTY_FUNCTION__))
;
13383 auto DestFXSema = Info.Ctx.getFixedPointSemantics(DestType);
13384
13385 switch (E->getCastKind()) {
13386 case CK_FixedPointCast: {
13387 APFixedPoint Src(Info.Ctx.getFixedPointSemantics(SubExpr->getType()));
13388 if (!EvaluateFixedPoint(SubExpr, Src, Info))
13389 return false;
13390 bool Overflowed;
13391 APFixedPoint Result = Src.convert(DestFXSema, &Overflowed);
13392 if (Overflowed) {
13393 if (Info.checkingForUndefinedBehavior())
13394 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
13395 diag::warn_fixedpoint_constant_overflow)
13396 << Result.toString() << E->getType();
13397 if (!HandleOverflow(Info, E, Result, E->getType()))
13398 return false;
13399 }
13400 return Success(Result, E);
13401 }
13402 case CK_IntegralToFixedPoint: {
13403 APSInt Src;
13404 if (!EvaluateInteger(SubExpr, Src, Info))
13405 return false;
13406
13407 bool Overflowed;
13408 APFixedPoint IntResult = APFixedPoint::getFromIntValue(
13409 Src, Info.Ctx.getFixedPointSemantics(DestType), &Overflowed);
13410
13411 if (Overflowed) {
13412 if (Info.checkingForUndefinedBehavior())
13413 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
13414 diag::warn_fixedpoint_constant_overflow)
13415 << IntResult.toString() << E->getType();
13416 if (!HandleOverflow(Info, E, IntResult, E->getType()))
13417 return false;
13418 }
13419
13420 return Success(IntResult, E);
13421 }
13422 case CK_FloatingToFixedPoint: {
13423 APFloat Src(0.0);
13424 if (!EvaluateFloat(SubExpr, Src, Info))
13425 return false;
13426
13427 bool Overflowed;
13428 APFixedPoint Result = APFixedPoint::getFromFloatValue(
13429 Src, Info.Ctx.getFixedPointSemantics(DestType), &Overflowed);
13430
13431 if (Overflowed) {
13432 if (Info.checkingForUndefinedBehavior())
13433 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
13434 diag::warn_fixedpoint_constant_overflow)
13435 << Result.toString() << E->getType();
13436 if (!HandleOverflow(Info, E, Result, E->getType()))
13437 return false;
13438 }
13439
13440 return Success(Result, E);
13441 }
13442 case CK_NoOp:
13443 case CK_LValueToRValue:
13444 return ExprEvaluatorBaseTy::VisitCastExpr(E);
13445 default:
13446 return Error(E);
13447 }
13448}
13449
13450bool FixedPointExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
13451 if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
13452 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
13453
13454 const Expr *LHS = E->getLHS();
13455 const Expr *RHS = E->getRHS();
13456 FixedPointSemantics ResultFXSema =
13457 Info.Ctx.getFixedPointSemantics(E->getType());
13458
13459 APFixedPoint LHSFX(Info.Ctx.getFixedPointSemantics(LHS->getType()));
13460 if (!EvaluateFixedPointOrInteger(LHS, LHSFX, Info))
13461 return false;
13462 APFixedPoint RHSFX(Info.Ctx.getFixedPointSemantics(RHS->getType()));
13463 if (!EvaluateFixedPointOrInteger(RHS, RHSFX, Info))
13464 return false;
13465
13466 bool OpOverflow = false, ConversionOverflow = false;
13467 APFixedPoint Result(LHSFX.getSemantics());
13468 switch (E->getOpcode()) {
13469 case BO_Add: {
13470 Result = LHSFX.add(RHSFX, &OpOverflow)
13471 .convert(ResultFXSema, &ConversionOverflow);
13472 break;
13473 }
13474 case BO_Sub: {
13475 Result = LHSFX.sub(RHSFX, &OpOverflow)
13476 .convert(ResultFXSema, &ConversionOverflow);
13477 break;
13478 }
13479 case BO_Mul: {
13480 Result = LHSFX.mul(RHSFX, &OpOverflow)
13481 .convert(ResultFXSema, &ConversionOverflow);
13482 break;
13483 }
13484 case BO_Div: {
13485 if (RHSFX.getValue() == 0) {
13486 Info.FFDiag(E, diag::note_expr_divide_by_zero);
13487 return false;
13488 }
13489 Result = LHSFX.div(RHSFX, &OpOverflow)
13490 .convert(ResultFXSema, &ConversionOverflow);
13491 break;
13492 }
13493 case BO_Shl:
13494 case BO_Shr: {
13495 FixedPointSemantics LHSSema = LHSFX.getSemantics();
13496 llvm::APSInt RHSVal = RHSFX.getValue();
13497
13498 unsigned ShiftBW =
13499 LHSSema.getWidth() - (unsigned)LHSSema.hasUnsignedPadding();
13500 unsigned Amt = RHSVal.getLimitedValue(ShiftBW - 1);
13501 // Embedded-C 4.1.6.2.2:
13502 // The right operand must be nonnegative and less than the total number
13503 // of (nonpadding) bits of the fixed-point operand ...
13504 if (RHSVal.isNegative())
13505 Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHSVal;
13506 else if (Amt != RHSVal)
13507 Info.CCEDiag(E, diag::note_constexpr_large_shift)
13508 << RHSVal << E->getType() << ShiftBW;
13509
13510 if (E->getOpcode() == BO_Shl)
13511 Result = LHSFX.shl(Amt, &OpOverflow);
13512 else
13513 Result = LHSFX.shr(Amt, &OpOverflow);
13514 break;
13515 }
13516 default:
13517 return false;
13518 }
13519 if (OpOverflow || ConversionOverflow) {
13520 if (Info.checkingForUndefinedBehavior())
13521 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
13522 diag::warn_fixedpoint_constant_overflow)
13523 << Result.toString() << E->getType();
13524 if (!HandleOverflow(Info, E, Result, E->getType()))
13525 return false;
13526 }
13527 return Success(Result, E);
13528}
13529
13530//===----------------------------------------------------------------------===//
13531// Float Evaluation
13532//===----------------------------------------------------------------------===//
13533
13534namespace {
13535class FloatExprEvaluator
13536 : public ExprEvaluatorBase<FloatExprEvaluator> {
13537 APFloat &Result;
13538public:
13539 FloatExprEvaluator(EvalInfo &info, APFloat &result)
13540 : ExprEvaluatorBaseTy(info), Result(result) {}
13541
13542 bool Success(const APValue &V, const Expr *e) {
13543 Result = V.getFloat();
13544 return true;
13545 }
13546
13547 bool ZeroInitialization(const Expr *E) {
13548 Result = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(E->getType()));
13549 return true;
13550 }
13551
13552 bool VisitCallExpr(const CallExpr *E);
13553
13554 bool VisitUnaryOperator(const UnaryOperator *E);
13555 bool VisitBinaryOperator(const BinaryOperator *E);
13556 bool VisitFloatingLiteral(const FloatingLiteral *E);
13557 bool VisitCastExpr(const CastExpr *E);
13558
13559 bool VisitUnaryReal(const UnaryOperator *E);
13560 bool VisitUnaryImag(const UnaryOperator *E);
13561
13562 // FIXME: Missing: array subscript of vector, member of vector
13563};
13564} // end anonymous namespace
13565
13566static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) {
13567 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13567, __extension__ __PRETTY_FUNCTION__))
;
13568 assert(E->isPRValue() && E->getType()->isRealFloatingType())(static_cast <bool> (E->isPRValue() && E->
getType()->isRealFloatingType()) ? void (0) : __assert_fail
("E->isPRValue() && E->getType()->isRealFloatingType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13568, __extension__ __PRETTY_FUNCTION__))
;
13569 return FloatExprEvaluator(Info, Result).Visit(E);
13570}
13571
13572static bool TryEvaluateBuiltinNaN(const ASTContext &Context,
13573 QualType ResultTy,
13574 const Expr *Arg,
13575 bool SNaN,
13576 llvm::APFloat &Result) {
13577 const StringLiteral *S = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts());
13578 if (!S) return false;
13579
13580 const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(ResultTy);
13581
13582 llvm::APInt fill;
13583
13584 // Treat empty strings as if they were zero.
13585 if (S->getString().empty())
13586 fill = llvm::APInt(32, 0);
13587 else if (S->getString().getAsInteger(0, fill))
13588 return false;
13589
13590 if (Context.getTargetInfo().isNan2008()) {
13591 if (SNaN)
13592 Result = llvm::APFloat::getSNaN(Sem, false, &fill);
13593 else
13594 Result = llvm::APFloat::getQNaN(Sem, false, &fill);
13595 } else {
13596 // Prior to IEEE 754-2008, architectures were allowed to choose whether
13597 // the first bit of their significand was set for qNaN or sNaN. MIPS chose
13598 // a different encoding to what became a standard in 2008, and for pre-
13599 // 2008 revisions, MIPS interpreted sNaN-2008 as qNan and qNaN-2008 as
13600 // sNaN. This is now known as "legacy NaN" encoding.
13601 if (SNaN)
13602 Result = llvm::APFloat::getQNaN(Sem, false, &fill);
13603 else
13604 Result = llvm::APFloat::getSNaN(Sem, false, &fill);
13605 }
13606
13607 return true;
13608}
13609
13610bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
13611 switch (E->getBuiltinCallee()) {
13612 default:
13613 return ExprEvaluatorBaseTy::VisitCallExpr(E);
13614
13615 case Builtin::BI__builtin_huge_val:
13616 case Builtin::BI__builtin_huge_valf:
13617 case Builtin::BI__builtin_huge_vall:
13618 case Builtin::BI__builtin_huge_valf128:
13619 case Builtin::BI__builtin_inf:
13620 case Builtin::BI__builtin_inff:
13621 case Builtin::BI__builtin_infl:
13622 case Builtin::BI__builtin_inff128: {
13623 const llvm::fltSemantics &Sem =
13624 Info.Ctx.getFloatTypeSemantics(E->getType());
13625 Result = llvm::APFloat::getInf(Sem);
13626 return true;
13627 }
13628
13629 case Builtin::BI__builtin_nans:
13630 case Builtin::BI__builtin_nansf:
13631 case Builtin::BI__builtin_nansl:
13632 case Builtin::BI__builtin_nansf128:
13633 if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
13634 true, Result))
13635 return Error(E);
13636 return true;
13637
13638 case Builtin::BI__builtin_nan:
13639 case Builtin::BI__builtin_nanf:
13640 case Builtin::BI__builtin_nanl:
13641 case Builtin::BI__builtin_nanf128:
13642 // If this is __builtin_nan() turn this into a nan, otherwise we
13643 // can't constant fold it.
13644 if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
13645 false, Result))
13646 return Error(E);
13647 return true;
13648
13649 case Builtin::BI__builtin_fabs:
13650 case Builtin::BI__builtin_fabsf:
13651 case Builtin::BI__builtin_fabsl:
13652 case Builtin::BI__builtin_fabsf128:
13653 // The C standard says "fabs raises no floating-point exceptions,
13654 // even if x is a signaling NaN. The returned value is independent of
13655 // the current rounding direction mode." Therefore constant folding can
13656 // proceed without regard to the floating point settings.
13657 // Reference, WG14 N2478 F.10.4.3
13658 if (!EvaluateFloat(E->getArg(0), Result, Info))
13659 return false;
13660
13661 if (Result.isNegative())
13662 Result.changeSign();
13663 return true;
13664
13665 case Builtin::BI__arithmetic_fence:
13666 return EvaluateFloat(E->getArg(0), Result, Info);
13667
13668 // FIXME: Builtin::BI__builtin_powi
13669 // FIXME: Builtin::BI__builtin_powif
13670 // FIXME: Builtin::BI__builtin_powil
13671
13672 case Builtin::BI__builtin_copysign:
13673 case Builtin::BI__builtin_copysignf:
13674 case Builtin::BI__builtin_copysignl:
13675 case Builtin::BI__builtin_copysignf128: {
13676 APFloat RHS(0.);
13677 if (!EvaluateFloat(E->getArg(0), Result, Info) ||
13678 !EvaluateFloat(E->getArg(1), RHS, Info))
13679 return false;
13680 Result.copySign(RHS);
13681 return true;
13682 }
13683 }
13684}
13685
13686bool FloatExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
13687 if (E->getSubExpr()->getType()->isAnyComplexType()) {
13688 ComplexValue CV;
13689 if (!EvaluateComplex(E->getSubExpr(), CV, Info))
13690 return false;
13691 Result = CV.FloatReal;
13692 return true;
13693 }
13694
13695 return Visit(E->getSubExpr());
13696}
13697
13698bool FloatExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
13699 if (E->getSubExpr()->getType()->isAnyComplexType()) {
13700 ComplexValue CV;
13701 if (!EvaluateComplex(E->getSubExpr(), CV, Info))
13702 return false;
13703 Result = CV.FloatImag;
13704 return true;
13705 }
13706
13707 VisitIgnoredValue(E->getSubExpr());
13708 const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(E->getType());
13709 Result = llvm::APFloat::getZero(Sem);
13710 return true;
13711}
13712
13713bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
13714 switch (E->getOpcode()) {
13715 default: return Error(E);
13716 case UO_Plus:
13717 return EvaluateFloat(E->getSubExpr(), Result, Info);
13718 case UO_Minus:
13719 // In C standard, WG14 N2478 F.3 p4
13720 // "the unary - raises no floating point exceptions,
13721 // even if the operand is signalling."
13722 if (!EvaluateFloat(E->getSubExpr(), Result, Info))
13723 return false;
13724 Result.changeSign();
13725 return true;
13726 }
13727}
13728
13729bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
13730 if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
13731 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
13732
13733 APFloat RHS(0.0);
13734 bool LHSOK = EvaluateFloat(E->getLHS(), Result, Info);
13735 if (!LHSOK && !Info.noteFailure())
13736 return false;
13737 return EvaluateFloat(E->getRHS(), RHS, Info) && LHSOK &&
13738 handleFloatFloatBinOp(Info, E, Result, E->getOpcode(), RHS);
13739}
13740
13741bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) {
13742 Result = E->getValue();
13743 return true;
13744}
13745
13746bool FloatExprEvaluator::VisitCastExpr(const CastExpr *E) {
13747 const Expr* SubExpr = E->getSubExpr();
13748
13749 switch (E->getCastKind()) {
13750 default:
13751 return ExprEvaluatorBaseTy::VisitCastExpr(E);
13752
13753 case CK_IntegralToFloating: {
13754 APSInt IntResult;
13755 const FPOptions FPO = E->getFPFeaturesInEffect(
13756 Info.Ctx.getLangOpts());
13757 return EvaluateInteger(SubExpr, IntResult, Info) &&
13758 HandleIntToFloatCast(Info, E, FPO, SubExpr->getType(),
13759 IntResult, E->getType(), Result);
13760 }
13761
13762 case CK_FixedPointToFloating: {
13763 APFixedPoint FixResult(Info.Ctx.getFixedPointSemantics(SubExpr->getType()));
13764 if (!EvaluateFixedPoint(SubExpr, FixResult, Info))
13765 return false;
13766 Result =
13767 FixResult.convertToFloat(Info.Ctx.getFloatTypeSemantics(E->getType()));
13768 return true;
13769 }
13770
13771 case CK_FloatingCast: {
13772 if (!Visit(SubExpr))
13773 return false;
13774 return HandleFloatToFloatCast(Info, E, SubExpr->getType(), E->getType(),
13775 Result);
13776 }
13777
13778 case CK_FloatingComplexToReal: {
13779 ComplexValue V;
13780 if (!EvaluateComplex(SubExpr, V, Info))
13781 return false;
13782 Result = V.getComplexFloatReal();
13783 return true;
13784 }
13785 }
13786}
13787
13788//===----------------------------------------------------------------------===//
13789// Complex Evaluation (for float and integer)
13790//===----------------------------------------------------------------------===//
13791
13792namespace {
13793class ComplexExprEvaluator
13794 : public ExprEvaluatorBase<ComplexExprEvaluator> {
13795 ComplexValue &Result;
13796
13797public:
13798 ComplexExprEvaluator(EvalInfo &info, ComplexValue &Result)
13799 : ExprEvaluatorBaseTy(info), Result(Result) {}
13800
13801 bool Success(const APValue &V, const Expr *e) {
13802 Result.setFrom(V);
13803 return true;
13804 }
13805
13806 bool ZeroInitialization(const Expr *E);
13807
13808 //===--------------------------------------------------------------------===//
13809 // Visitor Methods
13810 //===--------------------------------------------------------------------===//
13811
13812 bool VisitImaginaryLiteral(const ImaginaryLiteral *E);
13813 bool VisitCastExpr(const CastExpr *E);
13814 bool VisitBinaryOperator(const BinaryOperator *E);
13815 bool VisitUnaryOperator(const UnaryOperator *E);
13816 bool VisitInitListExpr(const InitListExpr *E);
13817 bool VisitCallExpr(const CallExpr *E);
13818};
13819} // end anonymous namespace
13820
13821static bool EvaluateComplex(const Expr *E, ComplexValue &Result,
13822 EvalInfo &Info) {
13823 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13823, __extension__ __PRETTY_FUNCTION__))
;
13824 assert(E->isPRValue() && E->getType()->isAnyComplexType())(static_cast <bool> (E->isPRValue() && E->
getType()->isAnyComplexType()) ? void (0) : __assert_fail (
"E->isPRValue() && E->getType()->isAnyComplexType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13824, __extension__ __PRETTY_FUNCTION__))
;
13825 return ComplexExprEvaluator(Info, Result).Visit(E);
13826}
13827
13828bool ComplexExprEvaluator::ZeroInitialization(const Expr *E) {
13829 QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
13830 if (ElemTy->isRealFloatingType()) {
13831 Result.makeComplexFloat();
13832 APFloat Zero = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(ElemTy));
13833 Result.FloatReal = Zero;
13834 Result.FloatImag = Zero;
13835 } else {
13836 Result.makeComplexInt();
13837 APSInt Zero = Info.Ctx.MakeIntValue(0, ElemTy);
13838 Result.IntReal = Zero;
13839 Result.IntImag = Zero;
13840 }
13841 return true;
13842}
13843
13844bool ComplexExprEvaluator::VisitImaginaryLiteral(const ImaginaryLiteral *E) {
13845 const Expr* SubExpr = E->getSubExpr();
13846
13847 if (SubExpr->getType()->isRealFloatingType()) {
13848 Result.makeComplexFloat();
13849 APFloat &Imag = Result.FloatImag;
13850 if (!EvaluateFloat(SubExpr, Imag, Info))
13851 return false;
13852
13853 Result.FloatReal = APFloat(Imag.getSemantics());
13854 return true;
13855 } else {
13856 assert(SubExpr->getType()->isIntegerType() &&(static_cast <bool> (SubExpr->getType()->isIntegerType
() && "Unexpected imaginary literal.") ? void (0) : __assert_fail
("SubExpr->getType()->isIntegerType() && \"Unexpected imaginary literal.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13857, __extension__ __PRETTY_FUNCTION__))
13857 "Unexpected imaginary literal.")(static_cast <bool> (SubExpr->getType()->isIntegerType
() && "Unexpected imaginary literal.") ? void (0) : __assert_fail
("SubExpr->getType()->isIntegerType() && \"Unexpected imaginary literal.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13857, __extension__ __PRETTY_FUNCTION__))
;
13858
13859 Result.makeComplexInt();
13860 APSInt &Imag = Result.IntImag;
13861 if (!EvaluateInteger(SubExpr, Imag, Info))
13862 return false;
13863
13864 Result.IntReal = APSInt(Imag.getBitWidth(), !Imag.isSigned());
13865 return true;
13866 }
13867}
13868
13869bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
13870
13871 switch (E->getCastKind()) {
13872 case CK_BitCast:
13873 case CK_BaseToDerived:
13874 case CK_DerivedToBase:
13875 case CK_UncheckedDerivedToBase:
13876 case CK_Dynamic:
13877 case CK_ToUnion:
13878 case CK_ArrayToPointerDecay:
13879 case CK_FunctionToPointerDecay:
13880 case CK_NullToPointer:
13881 case CK_NullToMemberPointer:
13882 case CK_BaseToDerivedMemberPointer:
13883 case CK_DerivedToBaseMemberPointer:
13884 case CK_MemberPointerToBoolean:
13885 case CK_ReinterpretMemberPointer:
13886 case CK_ConstructorConversion:
13887 case CK_IntegralToPointer:
13888 case CK_PointerToIntegral:
13889 case CK_PointerToBoolean:
13890 case CK_ToVoid:
13891 case CK_VectorSplat:
13892 case CK_IntegralCast:
13893 case CK_BooleanToSignedIntegral:
13894 case CK_IntegralToBoolean:
13895 case CK_IntegralToFloating:
13896 case CK_FloatingToIntegral:
13897 case CK_FloatingToBoolean:
13898 case CK_FloatingCast:
13899 case CK_CPointerToObjCPointerCast:
13900 case CK_BlockPointerToObjCPointerCast:
13901 case CK_AnyPointerToBlockPointerCast:
13902 case CK_ObjCObjectLValueCast:
13903 case CK_FloatingComplexToReal:
13904 case CK_FloatingComplexToBoolean:
13905 case CK_IntegralComplexToReal:
13906 case CK_IntegralComplexToBoolean:
13907 case CK_ARCProduceObject:
13908 case CK_ARCConsumeObject:
13909 case CK_ARCReclaimReturnedObject:
13910 case CK_ARCExtendBlockObject:
13911 case CK_CopyAndAutoreleaseBlockObject:
13912 case CK_BuiltinFnToFnPtr:
13913 case CK_ZeroToOCLOpaqueType:
13914 case CK_NonAtomicToAtomic:
13915 case CK_AddressSpaceConversion:
13916 case CK_IntToOCLSampler:
13917 case CK_FloatingToFixedPoint:
13918 case CK_FixedPointToFloating:
13919 case CK_FixedPointCast:
13920 case CK_FixedPointToBoolean:
13921 case CK_FixedPointToIntegral:
13922 case CK_IntegralToFixedPoint:
13923 case CK_MatrixCast:
13924 llvm_unreachable("invalid cast kind for complex value")::llvm::llvm_unreachable_internal("invalid cast kind for complex value"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 13924)
;
13925
13926 case CK_LValueToRValue:
13927 case CK_AtomicToNonAtomic:
13928 case CK_NoOp:
13929 case CK_LValueToRValueBitCast:
13930 return ExprEvaluatorBaseTy::VisitCastExpr(E);
13931
13932 case CK_Dependent:
13933 case CK_LValueBitCast:
13934 case CK_UserDefinedConversion:
13935 return Error(E);
13936
13937 case CK_FloatingRealToComplex: {
13938 APFloat &Real = Result.FloatReal;
13939 if (!EvaluateFloat(E->getSubExpr(), Real, Info))
13940 return false;
13941
13942 Result.makeComplexFloat();
13943 Result.FloatImag = APFloat(Real.getSemantics());
13944 return true;
13945 }
13946
13947 case CK_FloatingComplexCast: {
13948 if (!Visit(E->getSubExpr()))
13949 return false;
13950
13951 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
13952 QualType From
13953 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
13954
13955 return HandleFloatToFloatCast(Info, E, From, To, Result.FloatReal) &&
13956 HandleFloatToFloatCast(Info, E, From, To, Result.FloatImag);
13957 }
13958
13959 case CK_FloatingComplexToIntegralComplex: {
13960 if (!Visit(E->getSubExpr()))
13961 return false;
13962
13963 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
13964 QualType From
13965 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
13966 Result.makeComplexInt();
13967 return HandleFloatToIntCast(Info, E, From, Result.FloatReal,
13968 To, Result.IntReal) &&
13969 HandleFloatToIntCast(Info, E, From, Result.FloatImag,
13970 To, Result.IntImag);
13971 }
13972
13973 case CK_IntegralRealToComplex: {
13974 APSInt &Real = Result.IntReal;
13975 if (!EvaluateInteger(E->getSubExpr(), Real, Info))
13976 return false;
13977
13978 Result.makeComplexInt();
13979 Result.IntImag = APSInt(Real.getBitWidth(), !Real.isSigned());
13980 return true;
13981 }
13982
13983 case CK_IntegralComplexCast: {
13984 if (!Visit(E->getSubExpr()))
13985 return false;
13986
13987 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
13988 QualType From
13989 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
13990
13991 Result.IntReal = HandleIntToIntCast(Info, E, To, From, Result.IntReal);
13992 Result.IntImag = HandleIntToIntCast(Info, E, To, From, Result.IntImag);
13993 return true;
13994 }
13995
13996 case CK_IntegralComplexToFloatingComplex: {
13997 if (!Visit(E->getSubExpr()))
13998 return false;
13999
14000 const FPOptions FPO = E->getFPFeaturesInEffect(
14001 Info.Ctx.getLangOpts());
14002 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
14003 QualType From
14004 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
14005 Result.makeComplexFloat();
14006 return HandleIntToFloatCast(Info, E, FPO, From, Result.IntReal,
14007 To, Result.FloatReal) &&
14008 HandleIntToFloatCast(Info, E, FPO, From, Result.IntImag,
14009 To, Result.FloatImag);
14010 }
14011 }
14012
14013 llvm_unreachable("unknown cast resulting in complex value")::llvm::llvm_unreachable_internal("unknown cast resulting in complex value"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14013)
;
14014}
14015
14016bool ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
14017 if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
14018 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
14019
14020 // Track whether the LHS or RHS is real at the type system level. When this is
14021 // the case we can simplify our evaluation strategy.
14022 bool LHSReal = false, RHSReal = false;
14023
14024 bool LHSOK;
14025 if (E->getLHS()->getType()->isRealFloatingType()) {
14026 LHSReal = true;
14027 APFloat &Real = Result.FloatReal;
14028 LHSOK = EvaluateFloat(E->getLHS(), Real, Info);
14029 if (LHSOK) {
14030 Result.makeComplexFloat();
14031 Result.FloatImag = APFloat(Real.getSemantics());
14032 }
14033 } else {
14034 LHSOK = Visit(E->getLHS());
14035 }
14036 if (!LHSOK && !Info.noteFailure())
14037 return false;
14038
14039 ComplexValue RHS;
14040 if (E->getRHS()->getType()->isRealFloatingType()) {
14041 RHSReal = true;
14042 APFloat &Real = RHS.FloatReal;
14043 if (!EvaluateFloat(E->getRHS(), Real, Info) || !LHSOK)
14044 return false;
14045 RHS.makeComplexFloat();
14046 RHS.FloatImag = APFloat(Real.getSemantics());
14047 } else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
14048 return false;
14049
14050 assert(!(LHSReal && RHSReal) &&(static_cast <bool> (!(LHSReal && RHSReal) &&
"Cannot have both operands of a complex operation be real.")
? void (0) : __assert_fail ("!(LHSReal && RHSReal) && \"Cannot have both operands of a complex operation be real.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14051, __extension__ __PRETTY_FUNCTION__))
14051 "Cannot have both operands of a complex operation be real.")(static_cast <bool> (!(LHSReal && RHSReal) &&
"Cannot have both operands of a complex operation be real.")
? void (0) : __assert_fail ("!(LHSReal && RHSReal) && \"Cannot have both operands of a complex operation be real.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14051, __extension__ __PRETTY_FUNCTION__))
;
14052 switch (E->getOpcode()) {
14053 default: return Error(E);
14054 case BO_Add:
14055 if (Result.isComplexFloat()) {
14056 Result.getComplexFloatReal().add(RHS.getComplexFloatReal(),
14057 APFloat::rmNearestTiesToEven);
14058 if (LHSReal)
14059 Result.getComplexFloatImag() = RHS.getComplexFloatImag();
14060 else if (!RHSReal)
14061 Result.getComplexFloatImag().add(RHS.getComplexFloatImag(),
14062 APFloat::rmNearestTiesToEven);
14063 } else {
14064 Result.getComplexIntReal() += RHS.getComplexIntReal();
14065 Result.getComplexIntImag() += RHS.getComplexIntImag();
14066 }
14067 break;
14068 case BO_Sub:
14069 if (Result.isComplexFloat()) {
14070 Result.getComplexFloatReal().subtract(RHS.getComplexFloatReal(),
14071 APFloat::rmNearestTiesToEven);
14072 if (LHSReal) {
14073 Result.getComplexFloatImag() = RHS.getComplexFloatImag();
14074 Result.getComplexFloatImag().changeSign();
14075 } else if (!RHSReal) {
14076 Result.getComplexFloatImag().subtract(RHS.getComplexFloatImag(),
14077 APFloat::rmNearestTiesToEven);
14078 }
14079 } else {
14080 Result.getComplexIntReal() -= RHS.getComplexIntReal();
14081 Result.getComplexIntImag() -= RHS.getComplexIntImag();
14082 }
14083 break;
14084 case BO_Mul:
14085 if (Result.isComplexFloat()) {
14086 // This is an implementation of complex multiplication according to the
14087 // constraints laid out in C11 Annex G. The implementation uses the
14088 // following naming scheme:
14089 // (a + ib) * (c + id)
14090 ComplexValue LHS = Result;
14091 APFloat &A = LHS.getComplexFloatReal();
14092 APFloat &B = LHS.getComplexFloatImag();
14093 APFloat &C = RHS.getComplexFloatReal();
14094 APFloat &D = RHS.getComplexFloatImag();
14095 APFloat &ResR = Result.getComplexFloatReal();
14096 APFloat &ResI = Result.getComplexFloatImag();
14097 if (LHSReal) {
14098 assert(!RHSReal && "Cannot have two real operands for a complex op!")(static_cast <bool> (!RHSReal && "Cannot have two real operands for a complex op!"
) ? void (0) : __assert_fail ("!RHSReal && \"Cannot have two real operands for a complex op!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14098, __extension__ __PRETTY_FUNCTION__))
;
14099 ResR = A * C;
14100 ResI = A * D;
14101 } else if (RHSReal) {
14102 ResR = C * A;
14103 ResI = C * B;
14104 } else {
14105 // In the fully general case, we need to handle NaNs and infinities
14106 // robustly.
14107 APFloat AC = A * C;
14108 APFloat BD = B * D;
14109 APFloat AD = A * D;
14110 APFloat BC = B * C;
14111 ResR = AC - BD;
14112 ResI = AD + BC;
14113 if (ResR.isNaN() && ResI.isNaN()) {
14114 bool Recalc = false;
14115 if (A.isInfinity() || B.isInfinity()) {
14116 A = APFloat::copySign(
14117 APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
14118 B = APFloat::copySign(
14119 APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
14120 if (C.isNaN())
14121 C = APFloat::copySign(APFloat(C.getSemantics()), C);
14122 if (D.isNaN())
14123 D = APFloat::copySign(APFloat(D.getSemantics()), D);
14124 Recalc = true;
14125 }
14126 if (C.isInfinity() || D.isInfinity()) {
14127 C = APFloat::copySign(
14128 APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
14129 D = APFloat::copySign(
14130 APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
14131 if (A.isNaN())
14132 A = APFloat::copySign(APFloat(A.getSemantics()), A);
14133 if (B.isNaN())
14134 B = APFloat::copySign(APFloat(B.getSemantics()), B);
14135 Recalc = true;
14136 }
14137 if (!Recalc && (AC.isInfinity() || BD.isInfinity() ||
14138 AD.isInfinity() || BC.isInfinity())) {
14139 if (A.isNaN())
14140 A = APFloat::copySign(APFloat(A.getSemantics()), A);
14141 if (B.isNaN())
14142 B = APFloat::copySign(APFloat(B.getSemantics()), B);
14143 if (C.isNaN())
14144 C = APFloat::copySign(APFloat(C.getSemantics()), C);
14145 if (D.isNaN())
14146 D = APFloat::copySign(APFloat(D.getSemantics()), D);
14147 Recalc = true;
14148 }
14149 if (Recalc) {
14150 ResR = APFloat::getInf(A.getSemantics()) * (A * C - B * D);
14151 ResI = APFloat::getInf(A.getSemantics()) * (A * D + B * C);
14152 }
14153 }
14154 }
14155 } else {
14156 ComplexValue LHS = Result;
14157 Result.getComplexIntReal() =
14158 (LHS.getComplexIntReal() * RHS.getComplexIntReal() -
14159 LHS.getComplexIntImag() * RHS.getComplexIntImag());
14160 Result.getComplexIntImag() =
14161 (LHS.getComplexIntReal() * RHS.getComplexIntImag() +
14162 LHS.getComplexIntImag() * RHS.getComplexIntReal());
14163 }
14164 break;
14165 case BO_Div:
14166 if (Result.isComplexFloat()) {
14167 // This is an implementation of complex division according to the
14168 // constraints laid out in C11 Annex G. The implementation uses the
14169 // following naming scheme:
14170 // (a + ib) / (c + id)
14171 ComplexValue LHS = Result;
14172 APFloat &A = LHS.getComplexFloatReal();
14173 APFloat &B = LHS.getComplexFloatImag();
14174 APFloat &C = RHS.getComplexFloatReal();
14175 APFloat &D = RHS.getComplexFloatImag();
14176 APFloat &ResR = Result.getComplexFloatReal();
14177 APFloat &ResI = Result.getComplexFloatImag();
14178 if (RHSReal) {
14179 ResR = A / C;
14180 ResI = B / C;
14181 } else {
14182 if (LHSReal) {
14183 // No real optimizations we can do here, stub out with zero.
14184 B = APFloat::getZero(A.getSemantics());
14185 }
14186 int DenomLogB = 0;
14187 APFloat MaxCD = maxnum(abs(C), abs(D));
14188 if (MaxCD.isFinite()) {
14189 DenomLogB = ilogb(MaxCD);
14190 C = scalbn(C, -DenomLogB, APFloat::rmNearestTiesToEven);
14191 D = scalbn(D, -DenomLogB, APFloat::rmNearestTiesToEven);
14192 }
14193 APFloat Denom = C * C + D * D;
14194 ResR = scalbn((A * C + B * D) / Denom, -DenomLogB,
14195 APFloat::rmNearestTiesToEven);
14196 ResI = scalbn((B * C - A * D) / Denom, -DenomLogB,
14197 APFloat::rmNearestTiesToEven);
14198 if (ResR.isNaN() && ResI.isNaN()) {
14199 if (Denom.isPosZero() && (!A.isNaN() || !B.isNaN())) {
14200 ResR = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * A;
14201 ResI = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * B;
14202 } else if ((A.isInfinity() || B.isInfinity()) && C.isFinite() &&
14203 D.isFinite()) {
14204 A = APFloat::copySign(
14205 APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
14206 B = APFloat::copySign(
14207 APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
14208 ResR = APFloat::getInf(ResR.getSemantics()) * (A * C + B * D);
14209 ResI = APFloat::getInf(ResI.getSemantics()) * (B * C - A * D);
14210 } else if (MaxCD.isInfinity() && A.isFinite() && B.isFinite()) {
14211 C = APFloat::copySign(
14212 APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
14213 D = APFloat::copySign(
14214 APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
14215 ResR = APFloat::getZero(ResR.getSemantics()) * (A * C + B * D);
14216 ResI = APFloat::getZero(ResI.getSemantics()) * (B * C - A * D);
14217 }
14218 }
14219 }
14220 } else {
14221 if (RHS.getComplexIntReal() == 0 && RHS.getComplexIntImag() == 0)
14222 return Error(E, diag::note_expr_divide_by_zero);
14223
14224 ComplexValue LHS = Result;
14225 APSInt Den = RHS.getComplexIntReal() * RHS.getComplexIntReal() +
14226 RHS.getComplexIntImag() * RHS.getComplexIntImag();
14227 Result.getComplexIntReal() =
14228 (LHS.getComplexIntReal() * RHS.getComplexIntReal() +
14229 LHS.getComplexIntImag() * RHS.getComplexIntImag()) / Den;
14230 Result.getComplexIntImag() =
14231 (LHS.getComplexIntImag() * RHS.getComplexIntReal() -
14232 LHS.getComplexIntReal() * RHS.getComplexIntImag()) / Den;
14233 }
14234 break;
14235 }
14236
14237 return true;
14238}
14239
14240bool ComplexExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
14241 // Get the operand value into 'Result'.
14242 if (!Visit(E->getSubExpr()))
14243 return false;
14244
14245 switch (E->getOpcode()) {
14246 default:
14247 return Error(E);
14248 case UO_Extension:
14249 return true;
14250 case UO_Plus:
14251 // The result is always just the subexpr.
14252 return true;
14253 case UO_Minus:
14254 if (Result.isComplexFloat()) {
14255 Result.getComplexFloatReal().changeSign();
14256 Result.getComplexFloatImag().changeSign();
14257 }
14258 else {
14259 Result.getComplexIntReal() = -Result.getComplexIntReal();
14260 Result.getComplexIntImag() = -Result.getComplexIntImag();
14261 }
14262 return true;
14263 case UO_Not:
14264 if (Result.isComplexFloat())
14265 Result.getComplexFloatImag().changeSign();
14266 else
14267 Result.getComplexIntImag() = -Result.getComplexIntImag();
14268 return true;
14269 }
14270}
14271
14272bool ComplexExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
14273 if (E->getNumInits() == 2) {
14274 if (E->getType()->isComplexType()) {
14275 Result.makeComplexFloat();
14276 if (!EvaluateFloat(E->getInit(0), Result.FloatReal, Info))
14277 return false;
14278 if (!EvaluateFloat(E->getInit(1), Result.FloatImag, Info))
14279 return false;
14280 } else {
14281 Result.makeComplexInt();
14282 if (!EvaluateInteger(E->getInit(0), Result.IntReal, Info))
14283 return false;
14284 if (!EvaluateInteger(E->getInit(1), Result.IntImag, Info))
14285 return false;
14286 }
14287 return true;
14288 }
14289 return ExprEvaluatorBaseTy::VisitInitListExpr(E);
14290}
14291
14292bool ComplexExprEvaluator::VisitCallExpr(const CallExpr *E) {
14293 switch (E->getBuiltinCallee()) {
14294 case Builtin::BI__builtin_complex:
14295 Result.makeComplexFloat();
14296 if (!EvaluateFloat(E->getArg(0), Result.FloatReal, Info))
14297 return false;
14298 if (!EvaluateFloat(E->getArg(1), Result.FloatImag, Info))
14299 return false;
14300 return true;
14301
14302 default:
14303 break;
14304 }
14305
14306 return ExprEvaluatorBaseTy::VisitCallExpr(E);
14307}
14308
14309//===----------------------------------------------------------------------===//
14310// Atomic expression evaluation, essentially just handling the NonAtomicToAtomic
14311// implicit conversion.
14312//===----------------------------------------------------------------------===//
14313
14314namespace {
14315class AtomicExprEvaluator :
14316 public ExprEvaluatorBase<AtomicExprEvaluator> {
14317 const LValue *This;
14318 APValue &Result;
14319public:
14320 AtomicExprEvaluator(EvalInfo &Info, const LValue *This, APValue &Result)
14321 : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
14322
14323 bool Success(const APValue &V, const Expr *E) {
14324 Result = V;
14325 return true;
14326 }
14327
14328 bool ZeroInitialization(const Expr *E) {
14329 ImplicitValueInitExpr VIE(
14330 E->getType()->castAs<AtomicType>()->getValueType());
14331 // For atomic-qualified class (and array) types in C++, initialize the
14332 // _Atomic-wrapped subobject directly, in-place.
14333 return This ? EvaluateInPlace(Result, Info, *This, &VIE)
14334 : Evaluate(Result, Info, &VIE);
14335 }
14336
14337 bool VisitCastExpr(const CastExpr *E) {
14338 switch (E->getCastKind()) {
14339 default:
14340 return ExprEvaluatorBaseTy::VisitCastExpr(E);
14341 case CK_NonAtomicToAtomic:
14342 return This ? EvaluateInPlace(Result, Info, *This, E->getSubExpr())
14343 : Evaluate(Result, Info, E->getSubExpr());
14344 }
14345 }
14346};
14347} // end anonymous namespace
14348
14349static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
14350 EvalInfo &Info) {
14351 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14351, __extension__ __PRETTY_FUNCTION__))
;
14352 assert(E->isPRValue() && E->getType()->isAtomicType())(static_cast <bool> (E->isPRValue() && E->
getType()->isAtomicType()) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isAtomicType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14352, __extension__ __PRETTY_FUNCTION__))
;
14353 return AtomicExprEvaluator(Info, This, Result).Visit(E);
14354}
14355
14356//===----------------------------------------------------------------------===//
14357// Void expression evaluation, primarily for a cast to void on the LHS of a
14358// comma operator
14359//===----------------------------------------------------------------------===//
14360
14361namespace {
14362class VoidExprEvaluator
14363 : public ExprEvaluatorBase<VoidExprEvaluator> {
14364public:
14365 VoidExprEvaluator(EvalInfo &Info) : ExprEvaluatorBaseTy(Info) {}
14366
14367 bool Success(const APValue &V, const Expr *e) { return true; }
14368
14369 bool ZeroInitialization(const Expr *E) { return true; }
14370
14371 bool VisitCastExpr(const CastExpr *E) {
14372 switch (E->getCastKind()) {
14373 default:
14374 return ExprEvaluatorBaseTy::VisitCastExpr(E);
14375 case CK_ToVoid:
14376 VisitIgnoredValue(E->getSubExpr());
14377 return true;
14378 }
14379 }
14380
14381 bool VisitCallExpr(const CallExpr *E) {
14382 switch (E->getBuiltinCallee()) {
14383 case Builtin::BI__assume:
14384 case Builtin::BI__builtin_assume:
14385 // The argument is not evaluated!
14386 return true;
14387
14388 case Builtin::BI__builtin_operator_delete:
14389 return HandleOperatorDeleteCall(Info, E);
14390
14391 default:
14392 break;
14393 }
14394
14395 return ExprEvaluatorBaseTy::VisitCallExpr(E);
14396 }
14397
14398 bool VisitCXXDeleteExpr(const CXXDeleteExpr *E);
14399};
14400} // end anonymous namespace
14401
14402bool VoidExprEvaluator::VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
14403 // We cannot speculatively evaluate a delete expression.
14404 if (Info.SpeculativeEvaluationDepth)
14405 return false;
14406
14407 FunctionDecl *OperatorDelete = E->getOperatorDelete();
14408 if (!OperatorDelete->isReplaceableGlobalAllocationFunction()) {
14409 Info.FFDiag(E, diag::note_constexpr_new_non_replaceable)
14410 << isa<CXXMethodDecl>(OperatorDelete) << OperatorDelete;
14411 return false;
14412 }
14413
14414 const Expr *Arg = E->getArgument();
14415
14416 LValue Pointer;
14417 if (!EvaluatePointer(Arg, Pointer, Info))
14418 return false;
14419 if (Pointer.Designator.Invalid)
14420 return false;
14421
14422 // Deleting a null pointer has no effect.
14423 if (Pointer.isNullPointer()) {
14424 // This is the only case where we need to produce an extension warning:
14425 // the only other way we can succeed is if we find a dynamic allocation,
14426 // and we will have warned when we allocated it in that case.
14427 if (!Info.getLangOpts().CPlusPlus20)
14428 Info.CCEDiag(E, diag::note_constexpr_new);
14429 return true;
14430 }
14431
14432 Optional<DynAlloc *> Alloc = CheckDeleteKind(
14433 Info, E, Pointer, E->isArrayForm() ? DynAlloc::ArrayNew : DynAlloc::New);
14434 if (!Alloc)
14435 return false;
14436 QualType AllocType = Pointer.Base.getDynamicAllocType();
14437
14438 // For the non-array case, the designator must be empty if the static type
14439 // does not have a virtual destructor.
14440 if (!E->isArrayForm() && Pointer.Designator.Entries.size() != 0 &&
14441 !hasVirtualDestructor(Arg->getType()->getPointeeType())) {
14442 Info.FFDiag(E, diag::note_constexpr_delete_base_nonvirt_dtor)
14443 << Arg->getType()->getPointeeType() << AllocType;
14444 return false;
14445 }
14446
14447 // For a class type with a virtual destructor, the selected operator delete
14448 // is the one looked up when building the destructor.
14449 if (!E->isArrayForm() && !E->isGlobalDelete()) {
14450 const FunctionDecl *VirtualDelete = getVirtualOperatorDelete(AllocType);
14451 if (VirtualDelete &&
14452 !VirtualDelete->isReplaceableGlobalAllocationFunction()) {
14453 Info.FFDiag(E, diag::note_constexpr_new_non_replaceable)
14454 << isa<CXXMethodDecl>(VirtualDelete) << VirtualDelete;
14455 return false;
14456 }
14457 }
14458
14459 if (!HandleDestruction(Info, E->getExprLoc(), Pointer.getLValueBase(),
14460 (*Alloc)->Value, AllocType))
14461 return false;
14462
14463 if (!Info.HeapAllocs.erase(Pointer.Base.dyn_cast<DynamicAllocLValue>())) {
14464 // The element was already erased. This means the destructor call also
14465 // deleted the object.
14466 // FIXME: This probably results in undefined behavior before we get this
14467 // far, and should be diagnosed elsewhere first.
14468 Info.FFDiag(E, diag::note_constexpr_double_delete);
14469 return false;
14470 }
14471
14472 return true;
14473}
14474
14475static bool EvaluateVoid(const Expr *E, EvalInfo &Info) {
14476 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14476, __extension__ __PRETTY_FUNCTION__))
;
14477 assert(E->isPRValue() && E->getType()->isVoidType())(static_cast <bool> (E->isPRValue() && E->
getType()->isVoidType()) ? void (0) : __assert_fail ("E->isPRValue() && E->getType()->isVoidType()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14477, __extension__ __PRETTY_FUNCTION__))
;
14478 return VoidExprEvaluator(Info).Visit(E);
14479}
14480
14481//===----------------------------------------------------------------------===//
14482// Top level Expr::EvaluateAsRValue method.
14483//===----------------------------------------------------------------------===//
14484
14485static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) {
14486 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14486, __extension__ __PRETTY_FUNCTION__))
;
14487 // In C, function designators are not lvalues, but we evaluate them as if they
14488 // are.
14489 QualType T = E->getType();
14490 if (E->isGLValue() || T->isFunctionType()) {
14491 LValue LV;
14492 if (!EvaluateLValue(E, LV, Info))
14493 return false;
14494 LV.moveInto(Result);
14495 } else if (T->isVectorType()) {
14496 if (!EvaluateVector(E, Result, Info))
14497 return false;
14498 } else if (T->isIntegralOrEnumerationType()) {
14499 if (!IntExprEvaluator(Info, Result).Visit(E))
14500 return false;
14501 } else if (T->hasPointerRepresentation()) {
14502 LValue LV;
14503 if (!EvaluatePointer(E, LV, Info))
14504 return false;
14505 LV.moveInto(Result);
14506 } else if (T->isRealFloatingType()) {
14507 llvm::APFloat F(0.0);
14508 if (!EvaluateFloat(E, F, Info))
14509 return false;
14510 Result = APValue(F);
14511 } else if (T->isAnyComplexType()) {
14512 ComplexValue C;
14513 if (!EvaluateComplex(E, C, Info))
14514 return false;
14515 C.moveInto(Result);
14516 } else if (T->isFixedPointType()) {
14517 if (!FixedPointExprEvaluator(Info, Result).Visit(E)) return false;
14518 } else if (T->isMemberPointerType()) {
14519 MemberPtr P;
14520 if (!EvaluateMemberPointer(E, P, Info))
14521 return false;
14522 P.moveInto(Result);
14523 return true;
14524 } else if (T->isArrayType()) {
14525 LValue LV;
14526 APValue &Value =
14527 Info.CurrentCall->createTemporary(E, T, ScopeKind::FullExpression, LV);
14528 if (!EvaluateArray(E, LV, Value, Info))
14529 return false;
14530 Result = Value;
14531 } else if (T->isRecordType()) {
14532 LValue LV;
14533 APValue &Value =
14534 Info.CurrentCall->createTemporary(E, T, ScopeKind::FullExpression, LV);
14535 if (!EvaluateRecord(E, LV, Value, Info))
14536 return false;
14537 Result = Value;
14538 } else if (T->isVoidType()) {
14539 if (!Info.getLangOpts().CPlusPlus11)
14540 Info.CCEDiag(E, diag::note_constexpr_nonliteral)
14541 << E->getType();
14542 if (!EvaluateVoid(E, Info))
14543 return false;
14544 } else if (T->isAtomicType()) {
14545 QualType Unqual = T.getAtomicUnqualifiedType();
14546 if (Unqual->isArrayType() || Unqual->isRecordType()) {
14547 LValue LV;
14548 APValue &Value = Info.CurrentCall->createTemporary(
14549 E, Unqual, ScopeKind::FullExpression, LV);
14550 if (!EvaluateAtomic(E, &LV, Value, Info))
14551 return false;
14552 } else {
14553 if (!EvaluateAtomic(E, nullptr, Result, Info))
14554 return false;
14555 }
14556 } else if (Info.getLangOpts().CPlusPlus11) {
14557 Info.FFDiag(E, diag::note_constexpr_nonliteral) << E->getType();
14558 return false;
14559 } else {
14560 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
14561 return false;
14562 }
14563
14564 return true;
14565}
14566
14567/// EvaluateInPlace - Evaluate an expression in-place in an APValue. In some
14568/// cases, the in-place evaluation is essential, since later initializers for
14569/// an object can indirectly refer to subobjects which were initialized earlier.
14570static bool EvaluateInPlace(APValue &Result, EvalInfo &Info, const LValue &This,
14571 const Expr *E, bool AllowNonLiteralTypes) {
14572 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14572, __extension__ __PRETTY_FUNCTION__))
;
14573
14574 if (!AllowNonLiteralTypes && !CheckLiteralType(Info, E, &This))
14575 return false;
14576
14577 if (E->isPRValue()) {
14578 // Evaluate arrays and record types in-place, so that later initializers can
14579 // refer to earlier-initialized members of the object.
14580 QualType T = E->getType();
14581 if (T->isArrayType())
14582 return EvaluateArray(E, This, Result, Info);
14583 else if (T->isRecordType())
14584 return EvaluateRecord(E, This, Result, Info);
14585 else if (T->isAtomicType()) {
14586 QualType Unqual = T.getAtomicUnqualifiedType();
14587 if (Unqual->isArrayType() || Unqual->isRecordType())
14588 return EvaluateAtomic(E, &This, Result, Info);
14589 }
14590 }
14591
14592 // For any other type, in-place evaluation is unimportant.
14593 return Evaluate(Result, Info, E);
14594}
14595
14596/// EvaluateAsRValue - Try to evaluate this expression, performing an implicit
14597/// lvalue-to-rvalue cast if it is an lvalue.
14598static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result) {
14599 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14599, __extension__ __PRETTY_FUNCTION__))
;
14600 if (Info.EnableNewConstInterp) {
14601 if (!Info.Ctx.getInterpContext().evaluateAsRValue(Info, E, Result))
14602 return false;
14603 } else {
14604 if (E->getType().isNull())
14605 return false;
14606
14607 if (!CheckLiteralType(Info, E))
14608 return false;
14609
14610 if (!::Evaluate(Result, Info, E))
14611 return false;
14612
14613 if (E->isGLValue()) {
14614 LValue LV;
14615 LV.setFrom(Info.Ctx, Result);
14616 if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
14617 return false;
14618 }
14619 }
14620
14621 // Check this core constant expression is a constant expression.
14622 return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result,
14623 ConstantExprKind::Normal) &&
14624 CheckMemoryLeaks(Info);
14625}
14626
14627static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
14628 const ASTContext &Ctx, bool &IsConst) {
14629 // Fast-path evaluations of integer literals, since we sometimes see files
14630 // containing vast quantities of these.
14631 if (const IntegerLiteral *L = dyn_cast<IntegerLiteral>(Exp)) {
14632 Result.Val = APValue(APSInt(L->getValue(),
14633 L->getType()->isUnsignedIntegerType()));
14634 IsConst = true;
14635 return true;
14636 }
14637
14638 // This case should be rare, but we need to check it before we check on
14639 // the type below.
14640 if (Exp->getType().isNull()) {
14641 IsConst = false;
14642 return true;
14643 }
14644
14645 // FIXME: Evaluating values of large array and record types can cause
14646 // performance problems. Only do so in C++11 for now.
14647 if (Exp->isPRValue() &&
14648 (Exp->getType()->isArrayType() || Exp->getType()->isRecordType()) &&
14649 !Ctx.getLangOpts().CPlusPlus11) {
14650 IsConst = false;
14651 return true;
14652 }
14653 return false;
14654}
14655
14656static bool hasUnacceptableSideEffect(Expr::EvalStatus &Result,
14657 Expr::SideEffectsKind SEK) {
14658 return (SEK < Expr::SE_AllowSideEffects && Result.HasSideEffects) ||
14659 (SEK < Expr::SE_AllowUndefinedBehavior && Result.HasUndefinedBehavior);
14660}
14661
14662static bool EvaluateAsRValue(const Expr *E, Expr::EvalResult &Result,
14663 const ASTContext &Ctx, EvalInfo &Info) {
14664 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14664, __extension__ __PRETTY_FUNCTION__))
;
14665 bool IsConst;
14666 if (FastEvaluateAsRValue(E, Result, Ctx, IsConst))
14667 return IsConst;
14668
14669 return EvaluateAsRValue(Info, E, Result.Val);
14670}
14671
14672static bool EvaluateAsInt(const Expr *E, Expr::EvalResult &ExprResult,
14673 const ASTContext &Ctx,
14674 Expr::SideEffectsKind AllowSideEffects,
14675 EvalInfo &Info) {
14676 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14676, __extension__ __PRETTY_FUNCTION__))
;
14677 if (!E->getType()->isIntegralOrEnumerationType())
14678 return false;
14679
14680 if (!::EvaluateAsRValue(E, ExprResult, Ctx, Info) ||
14681 !ExprResult.Val.isInt() ||
14682 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
14683 return false;
14684
14685 return true;
14686}
14687
14688static bool EvaluateAsFixedPoint(const Expr *E, Expr::EvalResult &ExprResult,
14689 const ASTContext &Ctx,
14690 Expr::SideEffectsKind AllowSideEffects,
14691 EvalInfo &Info) {
14692 assert(!E->isValueDependent())(static_cast <bool> (!E->isValueDependent()) ? void (
0) : __assert_fail ("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14692, __extension__ __PRETTY_FUNCTION__))
;
14693 if (!E->getType()->isFixedPointType())
14694 return false;
14695
14696 if (!::EvaluateAsRValue(E, ExprResult, Ctx, Info))
14697 return false;
14698
14699 if (!ExprResult.Val.isFixedPoint() ||
14700 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
14701 return false;
14702
14703 return true;
14704}
14705
14706/// EvaluateAsRValue - Return true if this is a constant which we can fold using
14707/// any crazy technique (that has nothing to do with language standards) that
14708/// we want to. If this function returns true, it returns the folded constant
14709/// in Result. If this expression is a glvalue, an lvalue-to-rvalue conversion
14710/// will be applied to the result.
14711bool Expr::EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx,
14712 bool InConstantContext) const {
14713 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14714, __extension__ __PRETTY_FUNCTION__))
14714 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14714, __extension__ __PRETTY_FUNCTION__))
;
14715 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
14716 Info.InConstantContext = InConstantContext;
14717 return ::EvaluateAsRValue(this, Result, Ctx, Info);
14718}
14719
14720bool Expr::EvaluateAsBooleanCondition(bool &Result, const ASTContext &Ctx,
14721 bool InConstantContext) const {
14722 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14723, __extension__ __PRETTY_FUNCTION__))
14723 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14723, __extension__ __PRETTY_FUNCTION__))
;
14724 EvalResult Scratch;
14725 return EvaluateAsRValue(Scratch, Ctx, InConstantContext) &&
14726 HandleConversionToBool(Scratch.Val, Result);
14727}
14728
14729bool Expr::EvaluateAsInt(EvalResult &Result, const ASTContext &Ctx,
14730 SideEffectsKind AllowSideEffects,
14731 bool InConstantContext) const {
14732 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14733, __extension__ __PRETTY_FUNCTION__))
14733 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14733, __extension__ __PRETTY_FUNCTION__))
;
14734 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
14735 Info.InConstantContext = InConstantContext;
14736 return ::EvaluateAsInt(this, Result, Ctx, AllowSideEffects, Info);
14737}
14738
14739bool Expr::EvaluateAsFixedPoint(EvalResult &Result, const ASTContext &Ctx,
14740 SideEffectsKind AllowSideEffects,
14741 bool InConstantContext) const {
14742 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14743, __extension__ __PRETTY_FUNCTION__))
14743 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14743, __extension__ __PRETTY_FUNCTION__))
;
14744 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
14745 Info.InConstantContext = InConstantContext;
14746 return ::EvaluateAsFixedPoint(this, Result, Ctx, AllowSideEffects, Info);
14747}
14748
14749bool Expr::EvaluateAsFloat(APFloat &Result, const ASTContext &Ctx,
14750 SideEffectsKind AllowSideEffects,
14751 bool InConstantContext) const {
14752 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14753, __extension__ __PRETTY_FUNCTION__))
14753 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14753, __extension__ __PRETTY_FUNCTION__))
;
14754
14755 if (!getType()->isRealFloatingType())
14756 return false;
14757
14758 EvalResult ExprResult;
14759 if (!EvaluateAsRValue(ExprResult, Ctx, InConstantContext) ||
14760 !ExprResult.Val.isFloat() ||
14761 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
14762 return false;
14763
14764 Result = ExprResult.Val.getFloat();
14765 return true;
14766}
14767
14768bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx,
14769 bool InConstantContext) const {
14770 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14771, __extension__ __PRETTY_FUNCTION__))
14771 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14771, __extension__ __PRETTY_FUNCTION__))
;
14772
14773 EvalInfo Info(Ctx, Result, EvalInfo::EM_ConstantFold);
14774 Info.InConstantContext = InConstantContext;
14775 LValue LV;
14776 CheckedTemporaries CheckedTemps;
14777 if (!EvaluateLValue(this, LV, Info) || !Info.discardCleanups() ||
14778 Result.HasSideEffects ||
14779 !CheckLValueConstantExpression(Info, getExprLoc(),
14780 Ctx.getLValueReferenceType(getType()), LV,
14781 ConstantExprKind::Normal, CheckedTemps))
14782 return false;
14783
14784 LV.moveInto(Result.Val);
14785 return true;
14786}
14787
14788static bool EvaluateDestruction(const ASTContext &Ctx, APValue::LValueBase Base,
14789 APValue DestroyedValue, QualType Type,
14790 SourceLocation Loc, Expr::EvalStatus &EStatus,
14791 bool IsConstantDestruction) {
14792 EvalInfo Info(Ctx, EStatus,
14793 IsConstantDestruction ? EvalInfo::EM_ConstantExpression
14794 : EvalInfo::EM_ConstantFold);
14795 Info.setEvaluatingDecl(Base, DestroyedValue,
14796 EvalInfo::EvaluatingDeclKind::Dtor);
14797 Info.InConstantContext = IsConstantDestruction;
14798
14799 LValue LVal;
14800 LVal.set(Base);
14801
14802 if (!HandleDestruction(Info, Loc, Base, DestroyedValue, Type) ||
14803 EStatus.HasSideEffects)
14804 return false;
14805
14806 if (!Info.discardCleanups())
14807 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14807)
;
14808
14809 return true;
14810}
14811
14812bool Expr::EvaluateAsConstantExpr(EvalResult &Result, const ASTContext &Ctx,
14813 ConstantExprKind Kind) const {
14814 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14815, __extension__ __PRETTY_FUNCTION__))
14815 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14815, __extension__ __PRETTY_FUNCTION__))
;
14816
14817 EvalInfo::EvaluationMode EM = EvalInfo::EM_ConstantExpression;
14818 EvalInfo Info(Ctx, Result, EM);
14819 Info.InConstantContext = true;
14820
14821 // The type of the object we're initializing is 'const T' for a class NTTP.
14822 QualType T = getType();
14823 if (Kind == ConstantExprKind::ClassTemplateArgument)
14824 T.addConst();
14825
14826 // If we're evaluating a prvalue, fake up a MaterializeTemporaryExpr to
14827 // represent the result of the evaluation. CheckConstantExpression ensures
14828 // this doesn't escape.
14829 MaterializeTemporaryExpr BaseMTE(T, const_cast<Expr*>(this), true);
14830 APValue::LValueBase Base(&BaseMTE);
14831
14832 Info.setEvaluatingDecl(Base, Result.Val);
14833 LValue LVal;
14834 LVal.set(Base);
14835
14836 if (!::EvaluateInPlace(Result.Val, Info, LVal, this) || Result.HasSideEffects)
14837 return false;
14838
14839 if (!Info.discardCleanups())
14840 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14840)
;
14841
14842 if (!CheckConstantExpression(Info, getExprLoc(), getStorageType(Ctx, this),
14843 Result.Val, Kind))
14844 return false;
14845 if (!CheckMemoryLeaks(Info))
14846 return false;
14847
14848 // If this is a class template argument, it's required to have constant
14849 // destruction too.
14850 if (Kind == ConstantExprKind::ClassTemplateArgument &&
14851 (!EvaluateDestruction(Ctx, Base, Result.Val, T, getBeginLoc(), Result,
14852 true) ||
14853 Result.HasSideEffects)) {
14854 // FIXME: Prefix a note to indicate that the problem is lack of constant
14855 // destruction.
14856 return false;
14857 }
14858
14859 return true;
14860}
14861
14862bool Expr::EvaluateAsInitializer(APValue &Value, const ASTContext &Ctx,
14863 const VarDecl *VD,
14864 SmallVectorImpl<PartialDiagnosticAt> &Notes,
14865 bool IsConstantInitialization) const {
14866 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14867, __extension__ __PRETTY_FUNCTION__))
14867 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14867, __extension__ __PRETTY_FUNCTION__))
;
14868
14869 // FIXME: Evaluating initializers for large array and record types can cause
14870 // performance problems. Only do so in C++11 for now.
14871 if (isPRValue() && (getType()->isArrayType() || getType()->isRecordType()) &&
14872 !Ctx.getLangOpts().CPlusPlus11)
14873 return false;
14874
14875 Expr::EvalStatus EStatus;
14876 EStatus.Diag = &Notes;
14877
14878 EvalInfo Info(Ctx, EStatus,
14879 (IsConstantInitialization && Ctx.getLangOpts().CPlusPlus11)
14880 ? EvalInfo::EM_ConstantExpression
14881 : EvalInfo::EM_ConstantFold);
14882 Info.setEvaluatingDecl(VD, Value);
14883 Info.InConstantContext = IsConstantInitialization;
14884
14885 SourceLocation DeclLoc = VD->getLocation();
14886 QualType DeclTy = VD->getType();
14887
14888 if (Info.EnableNewConstInterp) {
14889 auto &InterpCtx = const_cast<ASTContext &>(Ctx).getInterpContext();
14890 if (!InterpCtx.evaluateAsInitializer(Info, VD, Value))
14891 return false;
14892 } else {
14893 LValue LVal;
14894 LVal.set(VD);
14895
14896 if (!EvaluateInPlace(Value, Info, LVal, this,
14897 /*AllowNonLiteralTypes=*/true) ||
14898 EStatus.HasSideEffects)
14899 return false;
14900
14901 // At this point, any lifetime-extended temporaries are completely
14902 // initialized.
14903 Info.performLifetimeExtension();
14904
14905 if (!Info.discardCleanups())
14906 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14906)
;
14907 }
14908 return CheckConstantExpression(Info, DeclLoc, DeclTy, Value,
14909 ConstantExprKind::Normal) &&
14910 CheckMemoryLeaks(Info);
14911}
14912
14913bool VarDecl::evaluateDestruction(
14914 SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
14915 Expr::EvalStatus EStatus;
14916 EStatus.Diag = &Notes;
14917
14918 // Only treat the destruction as constant destruction if we formally have
14919 // constant initialization (or are usable in a constant expression).
14920 bool IsConstantDestruction = hasConstantInitialization();
14921
14922 // Make a copy of the value for the destructor to mutate, if we know it.
14923 // Otherwise, treat the value as default-initialized; if the destructor works
14924 // anyway, then the destruction is constant (and must be essentially empty).
14925 APValue DestroyedValue;
14926 if (getEvaluatedValue() && !getEvaluatedValue()->isAbsent())
14927 DestroyedValue = *getEvaluatedValue();
14928 else if (!getDefaultInitValue(getType(), DestroyedValue))
14929 return false;
14930
14931 if (!EvaluateDestruction(getASTContext(), this, std::move(DestroyedValue),
14932 getType(), getLocation(), EStatus,
14933 IsConstantDestruction) ||
14934 EStatus.HasSideEffects)
14935 return false;
14936
14937 ensureEvaluatedStmt()->HasConstantDestruction = true;
14938 return true;
14939}
14940
14941/// isEvaluatable - Call EvaluateAsRValue to see if this expression can be
14942/// constant folded, but discard the result.
14943bool Expr::isEvaluatable(const ASTContext &Ctx, SideEffectsKind SEK) const {
14944 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14945, __extension__ __PRETTY_FUNCTION__))
14945 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14945, __extension__ __PRETTY_FUNCTION__))
;
14946
14947 EvalResult Result;
14948 return EvaluateAsRValue(Result, Ctx, /* in constant context */ true) &&
14949 !hasUnacceptableSideEffect(Result, SEK);
14950}
14951
14952APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx,
14953 SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
14954 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14955, __extension__ __PRETTY_FUNCTION__))
14955 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14955, __extension__ __PRETTY_FUNCTION__))
;
14956
14957 EvalResult EVResult;
14958 EVResult.Diag = Diag;
14959 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
14960 Info.InConstantContext = true;
14961
14962 bool Result = ::EvaluateAsRValue(this, EVResult, Ctx, Info);
14963 (void)Result;
14964 assert(Result && "Could not evaluate expression")(static_cast <bool> (Result && "Could not evaluate expression"
) ? void (0) : __assert_fail ("Result && \"Could not evaluate expression\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14964, __extension__ __PRETTY_FUNCTION__))
;
14965 assert(EVResult.Val.isInt() && "Expression did not evaluate to integer")(static_cast <bool> (EVResult.Val.isInt() && "Expression did not evaluate to integer"
) ? void (0) : __assert_fail ("EVResult.Val.isInt() && \"Expression did not evaluate to integer\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14965, __extension__ __PRETTY_FUNCTION__))
;
14966
14967 return EVResult.Val.getInt();
14968}
14969
14970APSInt Expr::EvaluateKnownConstIntCheckOverflow(
14971 const ASTContext &Ctx, SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
14972 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14973, __extension__ __PRETTY_FUNCTION__))
14973 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14973, __extension__ __PRETTY_FUNCTION__))
;
14974
14975 EvalResult EVResult;
14976 EVResult.Diag = Diag;
14977 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
14978 Info.InConstantContext = true;
14979 Info.CheckingForUndefinedBehavior = true;
14980
14981 bool Result = ::EvaluateAsRValue(Info, this, EVResult.Val);
14982 (void)Result;
14983 assert(Result && "Could not evaluate expression")(static_cast <bool> (Result && "Could not evaluate expression"
) ? void (0) : __assert_fail ("Result && \"Could not evaluate expression\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14983, __extension__ __PRETTY_FUNCTION__))
;
14984 assert(EVResult.Val.isInt() && "Expression did not evaluate to integer")(static_cast <bool> (EVResult.Val.isInt() && "Expression did not evaluate to integer"
) ? void (0) : __assert_fail ("EVResult.Val.isInt() && \"Expression did not evaluate to integer\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14984, __extension__ __PRETTY_FUNCTION__))
;
14985
14986 return EVResult.Val.getInt();
14987}
14988
14989void Expr::EvaluateForOverflow(const ASTContext &Ctx) const {
14990 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14991, __extension__ __PRETTY_FUNCTION__))
14991 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 14991, __extension__ __PRETTY_FUNCTION__))
;
14992
14993 bool IsConst;
14994 EvalResult EVResult;
14995 if (!FastEvaluateAsRValue(this, EVResult, Ctx, IsConst)) {
14996 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
14997 Info.CheckingForUndefinedBehavior = true;
14998 (void)::EvaluateAsRValue(Info, this, EVResult.Val);
14999 }
15000}
15001
15002bool Expr::EvalResult::isGlobalLValue() const {
15003 assert(Val.isLValue())(static_cast <bool> (Val.isLValue()) ? void (0) : __assert_fail
("Val.isLValue()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15003, __extension__ __PRETTY_FUNCTION__))
;
15004 return IsGlobalLValue(Val.getLValueBase());
15005}
15006
15007/// isIntegerConstantExpr - this recursive routine will test if an expression is
15008/// an integer constant expression.
15009
15010/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
15011/// comma, etc
15012
15013// CheckICE - This function does the fundamental ICE checking: the returned
15014// ICEDiag contains an ICEKind indicating whether the expression is an ICE,
15015// and a (possibly null) SourceLocation indicating the location of the problem.
15016//
15017// Note that to reduce code duplication, this helper does no evaluation
15018// itself; the caller checks whether the expression is evaluatable, and
15019// in the rare cases where CheckICE actually cares about the evaluated
15020// value, it calls into Evaluate.
15021
15022namespace {
15023
15024enum ICEKind {
15025 /// This expression is an ICE.
15026 IK_ICE,
15027 /// This expression is not an ICE, but if it isn't evaluated, it's
15028 /// a legal subexpression for an ICE. This return value is used to handle
15029 /// the comma operator in C99 mode, and non-constant subexpressions.
15030 IK_ICEIfUnevaluated,
15031 /// This expression is not an ICE, and is not a legal subexpression for one.
15032 IK_NotICE
15033};
15034
15035struct ICEDiag {
15036 ICEKind Kind;
15037 SourceLocation Loc;
15038
15039 ICEDiag(ICEKind IK, SourceLocation l) : Kind(IK), Loc(l) {}
15040};
15041
15042}
15043
15044static ICEDiag NoDiag() { return ICEDiag(IK_ICE, SourceLocation()); }
15045
15046static ICEDiag Worst(ICEDiag A, ICEDiag B) { return A.Kind >= B.Kind ? A : B; }
15047
15048static ICEDiag CheckEvalInICE(const Expr* E, const ASTContext &Ctx) {
15049 Expr::EvalResult EVResult;
15050 Expr::EvalStatus Status;
15051 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
15052
15053 Info.InConstantContext = true;
15054 if (!::EvaluateAsRValue(E, EVResult, Ctx, Info) || EVResult.HasSideEffects ||
15055 !EVResult.Val.isInt())
15056 return ICEDiag(IK_NotICE, E->getBeginLoc());
15057
15058 return NoDiag();
15059}
15060
15061static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
15062 assert(!E->isValueDependent() && "Should not see value dependent exprs!")(static_cast <bool> (!E->isValueDependent() &&
"Should not see value dependent exprs!") ? void (0) : __assert_fail
("!E->isValueDependent() && \"Should not see value dependent exprs!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15062, __extension__ __PRETTY_FUNCTION__))
;
15063 if (!E->getType()->isIntegralOrEnumerationType())
15064 return ICEDiag(IK_NotICE, E->getBeginLoc());
15065
15066 switch (E->getStmtClass()) {
15067#define ABSTRACT_STMT(Node)
15068#define STMT(Node, Base) case Expr::Node##Class:
15069#define EXPR(Node, Base)
15070#include "clang/AST/StmtNodes.inc"
15071 case Expr::PredefinedExprClass:
15072 case Expr::FloatingLiteralClass:
15073 case Expr::ImaginaryLiteralClass:
15074 case Expr::StringLiteralClass:
15075 case Expr::ArraySubscriptExprClass:
15076 case Expr::MatrixSubscriptExprClass:
15077 case Expr::OMPArraySectionExprClass:
15078 case Expr::OMPArrayShapingExprClass:
15079 case Expr::OMPIteratorExprClass:
15080 case Expr::MemberExprClass:
15081 case Expr::CompoundAssignOperatorClass:
15082 case Expr::CompoundLiteralExprClass:
15083 case Expr::ExtVectorElementExprClass:
15084 case Expr::DesignatedInitExprClass:
15085 case Expr::ArrayInitLoopExprClass:
15086 case Expr::ArrayInitIndexExprClass:
15087 case Expr::NoInitExprClass:
15088 case Expr::DesignatedInitUpdateExprClass:
15089 case Expr::ImplicitValueInitExprClass:
15090 case Expr::ParenListExprClass:
15091 case Expr::VAArgExprClass:
15092 case Expr::AddrLabelExprClass:
15093 case Expr::StmtExprClass:
15094 case Expr::CXXMemberCallExprClass:
15095 case Expr::CUDAKernelCallExprClass:
15096 case Expr::CXXAddrspaceCastExprClass:
15097 case Expr::CXXDynamicCastExprClass:
15098 case Expr::CXXTypeidExprClass:
15099 case Expr::CXXUuidofExprClass:
15100 case Expr::MSPropertyRefExprClass:
15101 case Expr::MSPropertySubscriptExprClass:
15102 case Expr::CXXNullPtrLiteralExprClass:
15103 case Expr::UserDefinedLiteralClass:
15104 case Expr::CXXThisExprClass:
15105 case Expr::CXXThrowExprClass:
15106 case Expr::CXXNewExprClass:
15107 case Expr::CXXDeleteExprClass:
15108 case Expr::CXXPseudoDestructorExprClass:
15109 case Expr::UnresolvedLookupExprClass:
15110 case Expr::TypoExprClass:
15111 case Expr::RecoveryExprClass:
15112 case Expr::DependentScopeDeclRefExprClass:
15113 case Expr::CXXConstructExprClass:
15114 case Expr::CXXInheritedCtorInitExprClass:
15115 case Expr::CXXStdInitializerListExprClass:
15116 case Expr::CXXBindTemporaryExprClass:
15117 case Expr::ExprWithCleanupsClass:
15118 case Expr::CXXTemporaryObjectExprClass:
15119 case Expr::CXXUnresolvedConstructExprClass:
15120 case Expr::CXXDependentScopeMemberExprClass:
15121 case Expr::UnresolvedMemberExprClass:
15122 case Expr::ObjCStringLiteralClass:
15123 case Expr::ObjCBoxedExprClass:
15124 case Expr::ObjCArrayLiteralClass:
15125 case Expr::ObjCDictionaryLiteralClass:
15126 case Expr::ObjCEncodeExprClass:
15127 case Expr::ObjCMessageExprClass:
15128 case Expr::ObjCSelectorExprClass:
15129 case Expr::ObjCProtocolExprClass:
15130 case Expr::ObjCIvarRefExprClass:
15131 case Expr::ObjCPropertyRefExprClass:
15132 case Expr::ObjCSubscriptRefExprClass:
15133 case Expr::ObjCIsaExprClass:
15134 case Expr::ObjCAvailabilityCheckExprClass:
15135 case Expr::ShuffleVectorExprClass:
15136 case Expr::ConvertVectorExprClass:
15137 case Expr::BlockExprClass:
15138 case Expr::NoStmtClass:
15139 case Expr::OpaqueValueExprClass:
15140 case Expr::PackExpansionExprClass:
15141 case Expr::SubstNonTypeTemplateParmPackExprClass:
15142 case Expr::FunctionParmPackExprClass:
15143 case Expr::AsTypeExprClass:
15144 case Expr::ObjCIndirectCopyRestoreExprClass:
15145 case Expr::MaterializeTemporaryExprClass:
15146 case Expr::PseudoObjectExprClass:
15147 case Expr::AtomicExprClass:
15148 case Expr::LambdaExprClass:
15149 case Expr::CXXFoldExprClass:
15150 case Expr::CoawaitExprClass:
15151 case Expr::DependentCoawaitExprClass:
15152 case Expr::CoyieldExprClass:
15153 case Expr::SYCLUniqueStableNameExprClass:
15154 return ICEDiag(IK_NotICE, E->getBeginLoc());
15155
15156 case Expr::InitListExprClass: {
15157 // C++03 [dcl.init]p13: If T is a scalar type, then a declaration of the
15158 // form "T x = { a };" is equivalent to "T x = a;".
15159 // Unless we're initializing a reference, T is a scalar as it is known to be
15160 // of integral or enumeration type.
15161 if (E->isPRValue())
15162 if (cast<InitListExpr>(E)->getNumInits() == 1)
15163 return CheckICE(cast<InitListExpr>(E)->getInit(0), Ctx);
15164 return ICEDiag(IK_NotICE, E->getBeginLoc());
15165 }
15166
15167 case Expr::SizeOfPackExprClass:
15168 case Expr::GNUNullExprClass:
15169 case Expr::SourceLocExprClass:
15170 return NoDiag();
15171
15172 case Expr::SubstNonTypeTemplateParmExprClass:
15173 return
15174 CheckICE(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(), Ctx);
15175
15176 case Expr::ConstantExprClass:
15177 return CheckICE(cast<ConstantExpr>(E)->getSubExpr(), Ctx);
15178
15179 case Expr::ParenExprClass:
15180 return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
15181 case Expr::GenericSelectionExprClass:
15182 return CheckICE(cast<GenericSelectionExpr>(E)->getResultExpr(), Ctx);
15183 case Expr::IntegerLiteralClass:
15184 case Expr::FixedPointLiteralClass:
15185 case Expr::CharacterLiteralClass:
15186 case Expr::ObjCBoolLiteralExprClass:
15187 case Expr::CXXBoolLiteralExprClass:
15188 case Expr::CXXScalarValueInitExprClass:
15189 case Expr::TypeTraitExprClass:
15190 case Expr::ConceptSpecializationExprClass:
15191 case Expr::RequiresExprClass:
15192 case Expr::ArrayTypeTraitExprClass:
15193 case Expr::ExpressionTraitExprClass:
15194 case Expr::CXXNoexceptExprClass:
15195 return NoDiag();
15196 case Expr::CallExprClass:
15197 case Expr::CXXOperatorCallExprClass: {
15198 // C99 6.6/3 allows function calls within unevaluated subexpressions of
15199 // constant expressions, but they can never be ICEs because an ICE cannot
15200 // contain an operand of (pointer to) function type.
15201 const CallExpr *CE = cast<CallExpr>(E);
15202 if (CE->getBuiltinCallee())
15203 return CheckEvalInICE(E, Ctx);
15204 return ICEDiag(IK_NotICE, E->getBeginLoc());
15205 }
15206 case Expr::CXXRewrittenBinaryOperatorClass:
15207 return CheckICE(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm(),
15208 Ctx);
15209 case Expr::DeclRefExprClass: {
15210 const NamedDecl *D = cast<DeclRefExpr>(E)->getDecl();
15211 if (isa<EnumConstantDecl>(D))
15212 return NoDiag();
15213
15214 // C++ and OpenCL (FIXME: spec reference?) allow reading const-qualified
15215 // integer variables in constant expressions:
15216 //
15217 // C++ 7.1.5.1p2
15218 // A variable of non-volatile const-qualified integral or enumeration
15219 // type initialized by an ICE can be used in ICEs.
15220 //
15221 // We sometimes use CheckICE to check the C++98 rules in C++11 mode. In
15222 // that mode, use of reference variables should not be allowed.
15223 const VarDecl *VD = dyn_cast<VarDecl>(D);
15224 if (VD && VD->isUsableInConstantExpressions(Ctx) &&
15225 !VD->getType()->isReferenceType())
15226 return NoDiag();
15227
15228 return ICEDiag(IK_NotICE, E->getBeginLoc());
15229 }
15230 case Expr::UnaryOperatorClass: {
15231 const UnaryOperator *Exp = cast<UnaryOperator>(E);
15232 switch (Exp->getOpcode()) {
15233 case UO_PostInc:
15234 case UO_PostDec:
15235 case UO_PreInc:
15236 case UO_PreDec:
15237 case UO_AddrOf:
15238 case UO_Deref:
15239 case UO_Coawait:
15240 // C99 6.6/3 allows increment and decrement within unevaluated
15241 // subexpressions of constant expressions, but they can never be ICEs
15242 // because an ICE cannot contain an lvalue operand.
15243 return ICEDiag(IK_NotICE, E->getBeginLoc());
15244 case UO_Extension:
15245 case UO_LNot:
15246 case UO_Plus:
15247 case UO_Minus:
15248 case UO_Not:
15249 case UO_Real:
15250 case UO_Imag:
15251 return CheckICE(Exp->getSubExpr(), Ctx);
15252 }
15253 llvm_unreachable("invalid unary operator class")::llvm::llvm_unreachable_internal("invalid unary operator class"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15253)
;
15254 }
15255 case Expr::OffsetOfExprClass: {
15256 // Note that per C99, offsetof must be an ICE. And AFAIK, using
15257 // EvaluateAsRValue matches the proposed gcc behavior for cases like
15258 // "offsetof(struct s{int x[4];}, x[1.0])". This doesn't affect
15259 // compliance: we should warn earlier for offsetof expressions with
15260 // array subscripts that aren't ICEs, and if the array subscripts
15261 // are ICEs, the value of the offsetof must be an integer constant.
15262 return CheckEvalInICE(E, Ctx);
15263 }
15264 case Expr::UnaryExprOrTypeTraitExprClass: {
15265 const UnaryExprOrTypeTraitExpr *Exp = cast<UnaryExprOrTypeTraitExpr>(E);
15266 if ((Exp->getKind() == UETT_SizeOf) &&
15267 Exp->getTypeOfArgument()->isVariableArrayType())
15268 return ICEDiag(IK_NotICE, E->getBeginLoc());
15269 return NoDiag();
15270 }
15271 case Expr::BinaryOperatorClass: {
15272 const BinaryOperator *Exp = cast<BinaryOperator>(E);
15273 switch (Exp->getOpcode()) {
15274 case BO_PtrMemD:
15275 case BO_PtrMemI:
15276 case BO_Assign:
15277 case BO_MulAssign:
15278 case BO_DivAssign:
15279 case BO_RemAssign:
15280 case BO_AddAssign:
15281 case BO_SubAssign:
15282 case BO_ShlAssign:
15283 case BO_ShrAssign:
15284 case BO_AndAssign:
15285 case BO_XorAssign:
15286 case BO_OrAssign:
15287 // C99 6.6/3 allows assignments within unevaluated subexpressions of
15288 // constant expressions, but they can never be ICEs because an ICE cannot
15289 // contain an lvalue operand.
15290 return ICEDiag(IK_NotICE, E->getBeginLoc());
15291
15292 case BO_Mul:
15293 case BO_Div:
15294 case BO_Rem:
15295 case BO_Add:
15296 case BO_Sub:
15297 case BO_Shl:
15298 case BO_Shr:
15299 case BO_LT:
15300 case BO_GT:
15301 case BO_LE:
15302 case BO_GE:
15303 case BO_EQ:
15304 case BO_NE:
15305 case BO_And:
15306 case BO_Xor:
15307 case BO_Or:
15308 case BO_Comma:
15309 case BO_Cmp: {
15310 ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
15311 ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
15312 if (Exp->getOpcode() == BO_Div ||
15313 Exp->getOpcode() == BO_Rem) {
15314 // EvaluateAsRValue gives an error for undefined Div/Rem, so make sure
15315 // we don't evaluate one.
15316 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE) {
15317 llvm::APSInt REval = Exp->getRHS()->EvaluateKnownConstInt(Ctx);
15318 if (REval == 0)
15319 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
15320 if (REval.isSigned() && REval.isAllOnesValue()) {
15321 llvm::APSInt LEval = Exp->getLHS()->EvaluateKnownConstInt(Ctx);
15322 if (LEval.isMinSignedValue())
15323 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
15324 }
15325 }
15326 }
15327 if (Exp->getOpcode() == BO_Comma) {
15328 if (Ctx.getLangOpts().C99) {
15329 // C99 6.6p3 introduces a strange edge case: comma can be in an ICE
15330 // if it isn't evaluated.
15331 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE)
15332 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
15333 } else {
15334 // In both C89 and C++, commas in ICEs are illegal.
15335 return ICEDiag(IK_NotICE, E->getBeginLoc());
15336 }
15337 }
15338 return Worst(LHSResult, RHSResult);
15339 }
15340 case BO_LAnd:
15341 case BO_LOr: {
15342 ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
15343 ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
15344 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICEIfUnevaluated) {
15345 // Rare case where the RHS has a comma "side-effect"; we need
15346 // to actually check the condition to see whether the side
15347 // with the comma is evaluated.
15348 if ((Exp->getOpcode() == BO_LAnd) !=
15349 (Exp->getLHS()->EvaluateKnownConstInt(Ctx) == 0))
15350 return RHSResult;
15351 return NoDiag();
15352 }
15353
15354 return Worst(LHSResult, RHSResult);
15355 }
15356 }
15357 llvm_unreachable("invalid binary operator kind")::llvm::llvm_unreachable_internal("invalid binary operator kind"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15357)
;
15358 }
15359 case Expr::ImplicitCastExprClass:
15360 case Expr::CStyleCastExprClass:
15361 case Expr::CXXFunctionalCastExprClass:
15362 case Expr::CXXStaticCastExprClass:
15363 case Expr::CXXReinterpretCastExprClass:
15364 case Expr::CXXConstCastExprClass:
15365 case Expr::ObjCBridgedCastExprClass: {
15366 const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr();
15367 if (isa<ExplicitCastExpr>(E)) {
15368 if (const FloatingLiteral *FL
15369 = dyn_cast<FloatingLiteral>(SubExpr->IgnoreParenImpCasts())) {
15370 unsigned DestWidth = Ctx.getIntWidth(E->getType());
15371 bool DestSigned = E->getType()->isSignedIntegerOrEnumerationType();
15372 APSInt IgnoredVal(DestWidth, !DestSigned);
15373 bool Ignored;
15374 // If the value does not fit in the destination type, the behavior is
15375 // undefined, so we are not required to treat it as a constant
15376 // expression.
15377 if (FL->getValue().convertToInteger(IgnoredVal,
15378 llvm::APFloat::rmTowardZero,
15379 &Ignored) & APFloat::opInvalidOp)
15380 return ICEDiag(IK_NotICE, E->getBeginLoc());
15381 return NoDiag();
15382 }
15383 }
15384 switch (cast<CastExpr>(E)->getCastKind()) {
15385 case CK_LValueToRValue:
15386 case CK_AtomicToNonAtomic:
15387 case CK_NonAtomicToAtomic:
15388 case CK_NoOp:
15389 case CK_IntegralToBoolean:
15390 case CK_IntegralCast:
15391 return CheckICE(SubExpr, Ctx);
15392 default:
15393 return ICEDiag(IK_NotICE, E->getBeginLoc());
15394 }
15395 }
15396 case Expr::BinaryConditionalOperatorClass: {
15397 const BinaryConditionalOperator *Exp = cast<BinaryConditionalOperator>(E);
15398 ICEDiag CommonResult = CheckICE(Exp->getCommon(), Ctx);
15399 if (CommonResult.Kind == IK_NotICE) return CommonResult;
15400 ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
15401 if (FalseResult.Kind == IK_NotICE) return FalseResult;
15402 if (CommonResult.Kind == IK_ICEIfUnevaluated) return CommonResult;
15403 if (FalseResult.Kind == IK_ICEIfUnevaluated &&
15404 Exp->getCommon()->EvaluateKnownConstInt(Ctx) != 0) return NoDiag();
15405 return FalseResult;
15406 }
15407 case Expr::ConditionalOperatorClass: {
15408 const ConditionalOperator *Exp = cast<ConditionalOperator>(E);
15409 // If the condition (ignoring parens) is a __builtin_constant_p call,
15410 // then only the true side is actually considered in an integer constant
15411 // expression, and it is fully evaluated. This is an important GNU
15412 // extension. See GCC PR38377 for discussion.
15413 if (const CallExpr *CallCE
15414 = dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts()))
15415 if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
15416 return CheckEvalInICE(E, Ctx);
15417 ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
15418 if (CondResult.Kind == IK_NotICE)
15419 return CondResult;
15420
15421 ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
15422 ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
15423
15424 if (TrueResult.Kind == IK_NotICE)
15425 return TrueResult;
15426 if (FalseResult.Kind == IK_NotICE)
15427 return FalseResult;
15428 if (CondResult.Kind == IK_ICEIfUnevaluated)
15429 return CondResult;
15430 if (TrueResult.Kind == IK_ICE && FalseResult.Kind == IK_ICE)
15431 return NoDiag();
15432 // Rare case where the diagnostics depend on which side is evaluated
15433 // Note that if we get here, CondResult is 0, and at least one of
15434 // TrueResult and FalseResult is non-zero.
15435 if (Exp->getCond()->EvaluateKnownConstInt(Ctx) == 0)
15436 return FalseResult;
15437 return TrueResult;
15438 }
15439 case Expr::CXXDefaultArgExprClass:
15440 return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx);
15441 case Expr::CXXDefaultInitExprClass:
15442 return CheckICE(cast<CXXDefaultInitExpr>(E)->getExpr(), Ctx);
15443 case Expr::ChooseExprClass: {
15444 return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(), Ctx);
15445 }
15446 case Expr::BuiltinBitCastExprClass: {
15447 if (!checkBitCastConstexprEligibility(nullptr, Ctx, cast<CastExpr>(E)))
15448 return ICEDiag(IK_NotICE, E->getBeginLoc());
15449 return CheckICE(cast<CastExpr>(E)->getSubExpr(), Ctx);
15450 }
15451 }
15452
15453 llvm_unreachable("Invalid StmtClass!")::llvm::llvm_unreachable_internal("Invalid StmtClass!", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15453)
;
15454}
15455
15456/// Evaluate an expression as a C++11 integral constant expression.
15457static bool EvaluateCPlusPlus11IntegralConstantExpr(const ASTContext &Ctx,
15458 const Expr *E,
15459 llvm::APSInt *Value,
15460 SourceLocation *Loc) {
15461 if (!E->getType()->isIntegralOrUnscopedEnumerationType()) {
15462 if (Loc) *Loc = E->getExprLoc();
15463 return false;
15464 }
15465
15466 APValue Result;
15467 if (!E->isCXX11ConstantExpr(Ctx, &Result, Loc))
15468 return false;
15469
15470 if (!Result.isInt()) {
15471 if (Loc) *Loc = E->getExprLoc();
15472 return false;
15473 }
15474
15475 if (Value) *Value = Result.getInt();
15476 return true;
15477}
15478
15479bool Expr::isIntegerConstantExpr(const ASTContext &Ctx,
15480 SourceLocation *Loc) const {
15481 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15482, __extension__ __PRETTY_FUNCTION__))
15482 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15482, __extension__ __PRETTY_FUNCTION__))
;
15483
15484 if (Ctx.getLangOpts().CPlusPlus11)
15485 return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, nullptr, Loc);
15486
15487 ICEDiag D = CheckICE(this, Ctx);
15488 if (D.Kind != IK_ICE) {
15489 if (Loc) *Loc = D.Loc;
15490 return false;
15491 }
15492 return true;
15493}
15494
15495Optional<llvm::APSInt> Expr::getIntegerConstantExpr(const ASTContext &Ctx,
15496 SourceLocation *Loc,
15497 bool isEvaluated) const {
15498 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15499, __extension__ __PRETTY_FUNCTION__))
15499 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15499, __extension__ __PRETTY_FUNCTION__))
;
15500
15501 APSInt Value;
15502
15503 if (Ctx.getLangOpts().CPlusPlus11) {
15504 if (EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, &Value, Loc))
15505 return Value;
15506 return None;
15507 }
15508
15509 if (!isIntegerConstantExpr(Ctx, Loc))
15510 return None;
15511
15512 // The only possible side-effects here are due to UB discovered in the
15513 // evaluation (for instance, INT_MAX + 1). In such a case, we are still
15514 // required to treat the expression as an ICE, so we produce the folded
15515 // value.
15516 EvalResult ExprResult;
15517 Expr::EvalStatus Status;
15518 EvalInfo Info(Ctx, Status, EvalInfo::EM_IgnoreSideEffects);
15519 Info.InConstantContext = true;
15520
15521 if (!::EvaluateAsInt(this, ExprResult, Ctx, SE_AllowSideEffects, Info))
15522 llvm_unreachable("ICE cannot be evaluated!")::llvm::llvm_unreachable_internal("ICE cannot be evaluated!",
"/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15522)
;
15523
15524 return ExprResult.Val.getInt();
15525}
15526
15527bool Expr::isCXX98IntegralConstantExpr(const ASTContext &Ctx) const {
15528 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15529, __extension__ __PRETTY_FUNCTION__))
15529 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15529, __extension__ __PRETTY_FUNCTION__))
;
15530
15531 return CheckICE(this, Ctx).Kind == IK_ICE;
15532}
15533
15534bool Expr::isCXX11ConstantExpr(const ASTContext &Ctx, APValue *Result,
15535 SourceLocation *Loc) const {
15536 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15537, __extension__ __PRETTY_FUNCTION__))
15537 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15537, __extension__ __PRETTY_FUNCTION__))
;
15538
15539 // We support this checking in C++98 mode in order to diagnose compatibility
15540 // issues.
15541 assert(Ctx.getLangOpts().CPlusPlus)(static_cast <bool> (Ctx.getLangOpts().CPlusPlus) ? void
(0) : __assert_fail ("Ctx.getLangOpts().CPlusPlus", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15541, __extension__ __PRETTY_FUNCTION__))
;
15542
15543 // Build evaluation settings.
15544 Expr::EvalStatus Status;
15545 SmallVector<PartialDiagnosticAt, 8> Diags;
15546 Status.Diag = &Diags;
15547 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
15548
15549 APValue Scratch;
15550 bool IsConstExpr =
15551 ::EvaluateAsRValue(Info, this, Result ? *Result : Scratch) &&
15552 // FIXME: We don't produce a diagnostic for this, but the callers that
15553 // call us on arbitrary full-expressions should generally not care.
15554 Info.discardCleanups() && !Status.HasSideEffects;
15555
15556 if (!Diags.empty()) {
15557 IsConstExpr = false;
15558 if (Loc) *Loc = Diags[0].first;
15559 } else if (!IsConstExpr) {
15560 // FIXME: This shouldn't happen.
15561 if (Loc) *Loc = getExprLoc();
15562 }
15563
15564 return IsConstExpr;
15565}
15566
15567bool Expr::EvaluateWithSubstitution(APValue &Value, ASTContext &Ctx,
15568 const FunctionDecl *Callee,
15569 ArrayRef<const Expr*> Args,
15570 const Expr *This) const {
15571 assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15572, __extension__ __PRETTY_FUNCTION__))
15572 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15572, __extension__ __PRETTY_FUNCTION__))
;
15573
15574 Expr::EvalStatus Status;
15575 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpressionUnevaluated);
15576 Info.InConstantContext = true;
15577
15578 LValue ThisVal;
15579 const LValue *ThisPtr = nullptr;
15580 if (This) {
15581#ifndef NDEBUG
15582 auto *MD = dyn_cast<CXXMethodDecl>(Callee);
15583 assert(MD && "Don't provide `this` for non-methods.")(static_cast <bool> (MD && "Don't provide `this` for non-methods."
) ? void (0) : __assert_fail ("MD && \"Don't provide `this` for non-methods.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15583, __extension__ __PRETTY_FUNCTION__))
;
15584 assert(!MD->isStatic() && "Don't provide `this` for static methods.")(static_cast <bool> (!MD->isStatic() && "Don't provide `this` for static methods."
) ? void (0) : __assert_fail ("!MD->isStatic() && \"Don't provide `this` for static methods.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15584, __extension__ __PRETTY_FUNCTION__))
;
15585#endif
15586 if (!This->isValueDependent() &&
15587 EvaluateObjectArgument(Info, This, ThisVal) &&
15588 !Info.EvalStatus.HasSideEffects)
15589 ThisPtr = &ThisVal;
15590
15591 // Ignore any side-effects from a failed evaluation. This is safe because
15592 // they can't interfere with any other argument evaluation.
15593 Info.EvalStatus.HasSideEffects = false;
15594 }
15595
15596 CallRef Call = Info.CurrentCall->createCall(Callee);
15597 for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
15598 I != E; ++I) {
15599 unsigned Idx = I - Args.begin();
15600 if (Idx >= Callee->getNumParams())
15601 break;
15602 const ParmVarDecl *PVD = Callee->getParamDecl(Idx);
15603 if ((*I)->isValueDependent() ||
15604 !EvaluateCallArg(PVD, *I, Call, Info) ||
15605 Info.EvalStatus.HasSideEffects) {
15606 // If evaluation fails, throw away the argument entirely.
15607 if (APValue *Slot = Info.getParamSlot(Call, PVD))
15608 *Slot = APValue();
15609 }
15610
15611 // Ignore any side-effects from a failed evaluation. This is safe because
15612 // they can't interfere with any other argument evaluation.
15613 Info.EvalStatus.HasSideEffects = false;
15614 }
15615
15616 // Parameter cleanups happen in the caller and are not part of this
15617 // evaluation.
15618 Info.discardCleanups();
15619 Info.EvalStatus.HasSideEffects = false;
15620
15621 // Build fake call to Callee.
15622 CallStackFrame Frame(Info, Callee->getLocation(), Callee, ThisPtr, Call);
15623 // FIXME: Missing ExprWithCleanups in enable_if conditions?
15624 FullExpressionRAII Scope(Info);
15625 return Evaluate(Value, Info, this) && Scope.destroy() &&
15626 !Info.EvalStatus.HasSideEffects;
15627}
15628
15629bool Expr::isPotentialConstantExpr(const FunctionDecl *FD,
15630 SmallVectorImpl<
15631 PartialDiagnosticAt> &Diags) {
15632 // FIXME: It would be useful to check constexpr function templates, but at the
15633 // moment the constant expression evaluator cannot cope with the non-rigorous
15634 // ASTs which we build for dependent expressions.
15635 if (FD->isDependentContext())
15636 return true;
15637
15638 Expr::EvalStatus Status;
15639 Status.Diag = &Diags;
15640
15641 EvalInfo Info(FD->getASTContext(), Status, EvalInfo::EM_ConstantExpression);
15642 Info.InConstantContext = true;
15643 Info.CheckingPotentialConstantExpression = true;
15644
15645 // The constexpr VM attempts to compile all methods to bytecode here.
15646 if (Info.EnableNewConstInterp) {
15647 Info.Ctx.getInterpContext().isPotentialConstantExpr(Info, FD);
15648 return Diags.empty();
15649 }
15650
15651 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
15652 const CXXRecordDecl *RD = MD ? MD->getParent()->getCanonicalDecl() : nullptr;
15653
15654 // Fabricate an arbitrary expression on the stack and pretend that it
15655 // is a temporary being used as the 'this' pointer.
15656 LValue This;
15657 ImplicitValueInitExpr VIE(RD ? Info.Ctx.getRecordType(RD) : Info.Ctx.IntTy);
15658 This.set({&VIE, Info.CurrentCall->Index});
15659
15660 ArrayRef<const Expr*> Args;
15661
15662 APValue Scratch;
15663 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) {
15664 // Evaluate the call as a constant initializer, to allow the construction
15665 // of objects of non-literal types.
15666 Info.setEvaluatingDecl(This.getLValueBase(), Scratch);
15667 HandleConstructorCall(&VIE, This, Args, CD, Info, Scratch);
15668 } else {
15669 SourceLocation Loc = FD->getLocation();
15670 HandleFunctionCall(Loc, FD, (MD && MD->isInstance()) ? &This : nullptr,
15671 Args, CallRef(), FD->getBody(), Info, Scratch, nullptr);
15672 }
15673
15674 return Diags.empty();
15675}
15676
15677bool Expr::isPotentialConstantExprUnevaluated(Expr *E,
15678 const FunctionDecl *FD,
15679 SmallVectorImpl<
15680 PartialDiagnosticAt> &Diags) {
15681 assert(!E->isValueDependent() &&(static_cast <bool> (!E->isValueDependent() &&
"Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!E->isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15682, __extension__ __PRETTY_FUNCTION__))
15682 "Expression evaluator can't be called on a dependent expression.")(static_cast <bool> (!E->isValueDependent() &&
"Expression evaluator can't be called on a dependent expression."
) ? void (0) : __assert_fail ("!E->isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/AST/ExprConstant.cpp"
, 15682, __extension__ __PRETTY_FUNCTION__))
;
15683
15684 Expr::EvalStatus Status;
15685 Status.Diag = &Diags;
15686
15687 EvalInfo Info(FD->getASTContext(), Status,
15688 EvalInfo::EM_ConstantExpressionUnevaluated);
15689 Info.InConstantContext = true;
15690 Info.CheckingPotentialConstantExpression = true;
15691
15692 // Fabricate a call stack frame to give the arguments a plausible cover story.
15693 CallStackFrame Frame(Info, SourceLocation(), FD, /*This*/ nullptr, CallRef());
15694
15695 APValue ResultScratch;
15696 Evaluate(ResultScratch, Info, E);
15697 return Diags.empty();
15698}
15699
15700bool Expr::tryEvaluateObjectSize(uint64_t &Result, ASTContext &Ctx,
15701 unsigned Type) const {
15702 if (!getType()->isPointerType())
15703 return false;
15704
15705 Expr::EvalStatus Status;
15706 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
15707 return tryEvaluateBuiltinObjectSize(this, Type, Info, Result);
15708}
15709
15710static bool EvaluateBuiltinStrLen(const Expr *E, uint64_t &Result,
15711 EvalInfo &Info) {
15712 if (!E->getType()->hasPointerRepresentation() || !E->isPRValue())
15713 return false;
15714
15715 LValue String;
15716
15717 if (!EvaluatePointer(E, String, Info))
15718 return false;
15719
15720 QualType CharTy = E->getType()->getPointeeType();
15721
15722 // Fast path: if it's a string literal, search the string value.
15723 if (const StringLiteral *S = dyn_cast_or_null<StringLiteral>(
15724 String.getLValueBase().dyn_cast<const Expr *>())) {
15725 StringRef Str = S->getBytes();
15726 int64_t Off = String.Offset.getQuantity();
15727 if (Off >= 0 && (uint64_t)Off <= (uint64_t)Str.size() &&
15728 S->getCharByteWidth() == 1 &&
15729 // FIXME: Add fast-path for wchar_t too.
15730 Info.Ctx.hasSameUnqualifiedType(CharTy, Info.Ctx.CharTy)) {
15731 Str = Str.substr(Off);
15732
15733 StringRef::size_type Pos = Str.find(0);
15734 if (Pos != StringRef::npos)
15735 Str = Str.substr(0, Pos);
15736
15737 Result = Str.size();
15738 return true;
15739 }
15740
15741 // Fall through to slow path.
15742 }
15743
15744 // Slow path: scan the bytes of the string looking for the terminating 0.
15745 for (uint64_t Strlen = 0; /**/; ++Strlen) {
15746 APValue Char;
15747 if (!handleLValueToRValueConversion(Info, E, CharTy, String, Char) ||
15748 !Char.isInt())
15749 return false;
15750 if (!Char.getInt()) {
15751 Result = Strlen;
15752 return true;
15753 }
15754 if (!HandleLValueArrayAdjustment(Info, E, String, CharTy, 1))
15755 return false;
15756 }
15757}
15758
15759bool Expr::tryEvaluateStrLen(uint64_t &Result, ASTContext &Ctx) const {
15760 Expr::EvalStatus Status;
15761 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
15762 return EvaluateBuiltinStrLen(this, Result, Info);
15763}