Bug Summary

File:clang/lib/AST/ExprConstant.cpp
Warning:line 10310, column 3
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 -fhalf-no-semantic-interposition -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-13~++20210405022414+5f57793c4fe4/build-llvm/tools/clang/lib/AST -resource-dir /usr/lib/llvm-13/lib/clang/13.0.0 -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-13~++20210405022414+5f57793c4fe4/build-llvm/tools/clang/lib/AST -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/build-llvm/include -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../x86_64-linux-gnu/include -internal-isystem /usr/lib/llvm-13/lib/clang/13.0.0/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-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/build-llvm/tools/clang/lib/AST -fdebug-prefix-map=/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4=. -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-2021-04-05-202135-9119-1 -x c++ /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/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->isRValue())
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 const FunctionDecl *Callee = CE->getDirectCallee();
112 return Callee ? Callee->getAttr<AllocSizeAttr>() : nullptr;
113 }
114
115 /// Attempts to unwrap a CallExpr (with an alloc_size attribute) from an Expr.
116 /// This will look through a single cast.
117 ///
118 /// Returns null if we couldn't unwrap a function with alloc_size.
119 static const CallExpr *tryUnwrapAllocSizeCall(const Expr *E) {
120 if (!E->getType()->isPointerType())
121 return nullptr;
122
123 E = E->IgnoreParens();
124 // If we're doing a variable assignment from e.g. malloc(N), there will
125 // probably be a cast of some kind. In exotic cases, we might also see a
126 // top-level ExprWithCleanups. Ignore them either way.
127 if (const auto *FE = dyn_cast<FullExpr>(E))
128 E = FE->getSubExpr()->IgnoreParens();
129
130 if (const auto *Cast = dyn_cast<CastExpr>(E))
131 E = Cast->getSubExpr()->IgnoreParens();
132
133 if (const auto *CE = dyn_cast<CallExpr>(E))
134 return getAllocSizeAttr(CE) ? CE : nullptr;
135 return nullptr;
136 }
137
138 /// Determines whether or not the given Base contains a call to a function
139 /// with the alloc_size attribute.
140 static bool isBaseAnAllocSizeCall(APValue::LValueBase Base) {
141 const auto *E = Base.dyn_cast<const Expr *>();
142 return E && E->getType()->isPointerType() && tryUnwrapAllocSizeCall(E);
143 }
144
145 /// Determines whether the given kind of constant expression is only ever
146 /// used for name mangling. If so, it's permitted to reference things that we
147 /// can't generate code for (in particular, dllimported functions).
148 static bool isForManglingOnly(ConstantExprKind Kind) {
149 switch (Kind) {
150 case ConstantExprKind::Normal:
151 case ConstantExprKind::ClassTemplateArgument:
152 case ConstantExprKind::ImmediateInvocation:
153 // Note that non-type template arguments of class type are emitted as
154 // template parameter objects.
155 return false;
156
157 case ConstantExprKind::NonClassTemplateArgument:
158 return true;
159 }
160 llvm_unreachable("unknown ConstantExprKind")::llvm::llvm_unreachable_internal("unknown ConstantExprKind",
"/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 160)
;
161 }
162
163 static bool isTemplateArgument(ConstantExprKind Kind) {
164 switch (Kind) {
165 case ConstantExprKind::Normal:
166 case ConstantExprKind::ImmediateInvocation:
167 return false;
168
169 case ConstantExprKind::ClassTemplateArgument:
170 case ConstantExprKind::NonClassTemplateArgument:
171 return true;
172 }
173 llvm_unreachable("unknown ConstantExprKind")::llvm::llvm_unreachable_internal("unknown ConstantExprKind",
"/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 173)
;
174 }
175
176 /// The bound to claim that an array of unknown bound has.
177 /// The value in MostDerivedArraySize is undefined in this case. So, set it
178 /// to an arbitrary value that's likely to loudly break things if it's used.
179 static const uint64_t AssumedSizeForUnsizedArray =
180 std::numeric_limits<uint64_t>::max() / 2;
181
182 /// Determines if an LValue with the given LValueBase will have an unsized
183 /// array in its designator.
184 /// Find the path length and type of the most-derived subobject in the given
185 /// path, and find the size of the containing array, if any.
186 static unsigned
187 findMostDerivedSubobject(ASTContext &Ctx, APValue::LValueBase Base,
188 ArrayRef<APValue::LValuePathEntry> Path,
189 uint64_t &ArraySize, QualType &Type, bool &IsArray,
190 bool &FirstEntryIsUnsizedArray) {
191 // This only accepts LValueBases from APValues, and APValues don't support
192 // arrays that lack size info.
193 assert(!isBaseAnAllocSizeCall(Base) &&((!isBaseAnAllocSizeCall(Base) && "Unsized arrays shouldn't appear here"
) ? static_cast<void> (0) : __assert_fail ("!isBaseAnAllocSizeCall(Base) && \"Unsized arrays shouldn't appear here\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 194, __PRETTY_FUNCTION__))
194 "Unsized arrays shouldn't appear here")((!isBaseAnAllocSizeCall(Base) && "Unsized arrays shouldn't appear here"
) ? static_cast<void> (0) : __assert_fail ("!isBaseAnAllocSizeCall(Base) && \"Unsized arrays shouldn't appear here\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 194, __PRETTY_FUNCTION__))
;
195 unsigned MostDerivedLength = 0;
196 Type = getType(Base);
197
198 for (unsigned I = 0, N = Path.size(); I != N; ++I) {
199 if (Type->isArrayType()) {
200 const ArrayType *AT = Ctx.getAsArrayType(Type);
201 Type = AT->getElementType();
202 MostDerivedLength = I + 1;
203 IsArray = true;
204
205 if (auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
206 ArraySize = CAT->getSize().getZExtValue();
207 } else {
208 assert(I == 0 && "unexpected unsized array designator")((I == 0 && "unexpected unsized array designator") ? static_cast
<void> (0) : __assert_fail ("I == 0 && \"unexpected unsized array designator\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 208, __PRETTY_FUNCTION__))
;
209 FirstEntryIsUnsizedArray = true;
210 ArraySize = AssumedSizeForUnsizedArray;
211 }
212 } else if (Type->isAnyComplexType()) {
213 const ComplexType *CT = Type->castAs<ComplexType>();
214 Type = CT->getElementType();
215 ArraySize = 2;
216 MostDerivedLength = I + 1;
217 IsArray = true;
218 } else if (const FieldDecl *FD = getAsField(Path[I])) {
219 Type = FD->getType();
220 ArraySize = 0;
221 MostDerivedLength = I + 1;
222 IsArray = false;
223 } else {
224 // Path[I] describes a base class.
225 ArraySize = 0;
226 IsArray = false;
227 }
228 }
229 return MostDerivedLength;
230 }
231
232 /// A path from a glvalue to a subobject of that glvalue.
233 struct SubobjectDesignator {
234 /// True if the subobject was named in a manner not supported by C++11. Such
235 /// lvalues can still be folded, but they are not core constant expressions
236 /// and we cannot perform lvalue-to-rvalue conversions on them.
237 unsigned Invalid : 1;
238
239 /// Is this a pointer one past the end of an object?
240 unsigned IsOnePastTheEnd : 1;
241
242 /// Indicator of whether the first entry is an unsized array.
243 unsigned FirstEntryIsAnUnsizedArray : 1;
244
245 /// Indicator of whether the most-derived object is an array element.
246 unsigned MostDerivedIsArrayElement : 1;
247
248 /// The length of the path to the most-derived object of which this is a
249 /// subobject.
250 unsigned MostDerivedPathLength : 28;
251
252 /// The size of the array of which the most-derived object is an element.
253 /// This will always be 0 if the most-derived object is not an array
254 /// element. 0 is not an indicator of whether or not the most-derived object
255 /// is an array, however, because 0-length arrays are allowed.
256 ///
257 /// If the current array is an unsized array, the value of this is
258 /// undefined.
259 uint64_t MostDerivedArraySize;
260
261 /// The type of the most derived object referred to by this address.
262 QualType MostDerivedType;
263
264 typedef APValue::LValuePathEntry PathEntry;
265
266 /// The entries on the path from the glvalue to the designated subobject.
267 SmallVector<PathEntry, 8> Entries;
268
269 SubobjectDesignator() : Invalid(true) {}
270
271 explicit SubobjectDesignator(QualType T)
272 : Invalid(false), IsOnePastTheEnd(false),
273 FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
274 MostDerivedPathLength(0), MostDerivedArraySize(0),
275 MostDerivedType(T) {}
276
277 SubobjectDesignator(ASTContext &Ctx, const APValue &V)
278 : Invalid(!V.isLValue() || !V.hasLValuePath()), IsOnePastTheEnd(false),
279 FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
280 MostDerivedPathLength(0), MostDerivedArraySize(0) {
281 assert(V.isLValue() && "Non-LValue used to make an LValue designator?")((V.isLValue() && "Non-LValue used to make an LValue designator?"
) ? static_cast<void> (0) : __assert_fail ("V.isLValue() && \"Non-LValue used to make an LValue designator?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 281, __PRETTY_FUNCTION__))
;
282 if (!Invalid) {
283 IsOnePastTheEnd = V.isLValueOnePastTheEnd();
284 ArrayRef<PathEntry> VEntries = V.getLValuePath();
285 Entries.insert(Entries.end(), VEntries.begin(), VEntries.end());
286 if (V.getLValueBase()) {
287 bool IsArray = false;
288 bool FirstIsUnsizedArray = false;
289 MostDerivedPathLength = findMostDerivedSubobject(
290 Ctx, V.getLValueBase(), V.getLValuePath(), MostDerivedArraySize,
291 MostDerivedType, IsArray, FirstIsUnsizedArray);
292 MostDerivedIsArrayElement = IsArray;
293 FirstEntryIsAnUnsizedArray = FirstIsUnsizedArray;
294 }
295 }
296 }
297
298 void truncate(ASTContext &Ctx, APValue::LValueBase Base,
299 unsigned NewLength) {
300 if (Invalid)
301 return;
302
303 assert(Base && "cannot truncate path for null pointer")((Base && "cannot truncate path for null pointer") ? static_cast
<void> (0) : __assert_fail ("Base && \"cannot truncate path for null pointer\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 303, __PRETTY_FUNCTION__))
;
304 assert(NewLength <= Entries.size() && "not a truncation")((NewLength <= Entries.size() && "not a truncation"
) ? static_cast<void> (0) : __assert_fail ("NewLength <= Entries.size() && \"not a truncation\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 304, __PRETTY_FUNCTION__))
;
305
306 if (NewLength == Entries.size())
307 return;
308 Entries.resize(NewLength);
309
310 bool IsArray = false;
311 bool FirstIsUnsizedArray = false;
312 MostDerivedPathLength = findMostDerivedSubobject(
313 Ctx, Base, Entries, MostDerivedArraySize, MostDerivedType, IsArray,
314 FirstIsUnsizedArray);
315 MostDerivedIsArrayElement = IsArray;
316 FirstEntryIsAnUnsizedArray = FirstIsUnsizedArray;
317 }
318
319 void setInvalid() {
320 Invalid = true;
321 Entries.clear();
322 }
323
324 /// Determine whether the most derived subobject is an array without a
325 /// known bound.
326 bool isMostDerivedAnUnsizedArray() const {
327 assert(!Invalid && "Calling this makes no sense on invalid designators")((!Invalid && "Calling this makes no sense on invalid designators"
) ? static_cast<void> (0) : __assert_fail ("!Invalid && \"Calling this makes no sense on invalid designators\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 327, __PRETTY_FUNCTION__))
;
328 return Entries.size() == 1 && FirstEntryIsAnUnsizedArray;
329 }
330
331 /// Determine what the most derived array's size is. Results in an assertion
332 /// failure if the most derived array lacks a size.
333 uint64_t getMostDerivedArraySize() const {
334 assert(!isMostDerivedAnUnsizedArray() && "Unsized array has no size")((!isMostDerivedAnUnsizedArray() && "Unsized array has no size"
) ? static_cast<void> (0) : __assert_fail ("!isMostDerivedAnUnsizedArray() && \"Unsized array has no size\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 334, __PRETTY_FUNCTION__))
;
335 return MostDerivedArraySize;
336 }
337
338 /// Determine whether this is a one-past-the-end pointer.
339 bool isOnePastTheEnd() const {
340 assert(!Invalid)((!Invalid) ? static_cast<void> (0) : __assert_fail ("!Invalid"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 340, __PRETTY_FUNCTION__))
;
341 if (IsOnePastTheEnd)
342 return true;
343 if (!isMostDerivedAnUnsizedArray() && MostDerivedIsArrayElement &&
344 Entries[MostDerivedPathLength - 1].getAsArrayIndex() ==
345 MostDerivedArraySize)
346 return true;
347 return false;
348 }
349
350 /// Get the range of valid index adjustments in the form
351 /// {maximum value that can be subtracted from this pointer,
352 /// maximum value that can be added to this pointer}
353 std::pair<uint64_t, uint64_t> validIndexAdjustments() {
354 if (Invalid || isMostDerivedAnUnsizedArray())
355 return {0, 0};
356
357 // [expr.add]p4: For the purposes of these operators, a pointer to a
358 // nonarray object behaves the same as a pointer to the first element of
359 // an array of length one with the type of the object as its element type.
360 bool IsArray = MostDerivedPathLength == Entries.size() &&
361 MostDerivedIsArrayElement;
362 uint64_t ArrayIndex = IsArray ? Entries.back().getAsArrayIndex()
363 : (uint64_t)IsOnePastTheEnd;
364 uint64_t ArraySize =
365 IsArray ? getMostDerivedArraySize() : (uint64_t)1;
366 return {ArrayIndex, ArraySize - ArrayIndex};
367 }
368
369 /// Check that this refers to a valid subobject.
370 bool isValidSubobject() const {
371 if (Invalid)
372 return false;
373 return !isOnePastTheEnd();
374 }
375 /// Check that this refers to a valid subobject, and if not, produce a
376 /// relevant diagnostic and set the designator as invalid.
377 bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK);
378
379 /// Get the type of the designated object.
380 QualType getType(ASTContext &Ctx) const {
381 assert(!Invalid && "invalid designator has no subobject type")((!Invalid && "invalid designator has no subobject type"
) ? static_cast<void> (0) : __assert_fail ("!Invalid && \"invalid designator has no subobject type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 381, __PRETTY_FUNCTION__))
;
382 return MostDerivedPathLength == Entries.size()
383 ? MostDerivedType
384 : Ctx.getRecordType(getAsBaseClass(Entries.back()));
385 }
386
387 /// Update this designator to refer to the first element within this array.
388 void addArrayUnchecked(const ConstantArrayType *CAT) {
389 Entries.push_back(PathEntry::ArrayIndex(0));
390
391 // This is a most-derived object.
392 MostDerivedType = CAT->getElementType();
393 MostDerivedIsArrayElement = true;
394 MostDerivedArraySize = CAT->getSize().getZExtValue();
395 MostDerivedPathLength = Entries.size();
396 }
397 /// Update this designator to refer to the first element within the array of
398 /// elements of type T. This is an array of unknown size.
399 void addUnsizedArrayUnchecked(QualType ElemTy) {
400 Entries.push_back(PathEntry::ArrayIndex(0));
401
402 MostDerivedType = ElemTy;
403 MostDerivedIsArrayElement = true;
404 // The value in MostDerivedArraySize is undefined in this case. So, set it
405 // to an arbitrary value that's likely to loudly break things if it's
406 // used.
407 MostDerivedArraySize = AssumedSizeForUnsizedArray;
408 MostDerivedPathLength = Entries.size();
409 }
410 /// Update this designator to refer to the given base or member of this
411 /// object.
412 void addDeclUnchecked(const Decl *D, bool Virtual = false) {
413 Entries.push_back(APValue::BaseOrMemberType(D, Virtual));
414
415 // If this isn't a base class, it's a new most-derived object.
416 if (const FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
417 MostDerivedType = FD->getType();
418 MostDerivedIsArrayElement = false;
419 MostDerivedArraySize = 0;
420 MostDerivedPathLength = Entries.size();
421 }
422 }
423 /// Update this designator to refer to the given complex component.
424 void addComplexUnchecked(QualType EltTy, bool Imag) {
425 Entries.push_back(PathEntry::ArrayIndex(Imag));
426
427 // This is technically a most-derived object, though in practice this
428 // is unlikely to matter.
429 MostDerivedType = EltTy;
430 MostDerivedIsArrayElement = true;
431 MostDerivedArraySize = 2;
432 MostDerivedPathLength = Entries.size();
433 }
434 void diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info, const Expr *E);
435 void diagnosePointerArithmetic(EvalInfo &Info, const Expr *E,
436 const APSInt &N);
437 /// Add N to the address of this subobject.
438 void adjustIndex(EvalInfo &Info, const Expr *E, APSInt N) {
439 if (Invalid || !N) return;
440 uint64_t TruncatedN = N.extOrTrunc(64).getZExtValue();
441 if (isMostDerivedAnUnsizedArray()) {
442 diagnoseUnsizedArrayPointerArithmetic(Info, E);
443 // Can't verify -- trust that the user is doing the right thing (or if
444 // not, trust that the caller will catch the bad behavior).
445 // FIXME: Should we reject if this overflows, at least?
446 Entries.back() = PathEntry::ArrayIndex(
447 Entries.back().getAsArrayIndex() + TruncatedN);
448 return;
449 }
450
451 // [expr.add]p4: For the purposes of these operators, a pointer to a
452 // nonarray object behaves the same as a pointer to the first element of
453 // an array of length one with the type of the object as its element type.
454 bool IsArray = MostDerivedPathLength == Entries.size() &&
455 MostDerivedIsArrayElement;
456 uint64_t ArrayIndex = IsArray ? Entries.back().getAsArrayIndex()
457 : (uint64_t)IsOnePastTheEnd;
458 uint64_t ArraySize =
459 IsArray ? getMostDerivedArraySize() : (uint64_t)1;
460
461 if (N < -(int64_t)ArrayIndex || N > ArraySize - ArrayIndex) {
462 // Calculate the actual index in a wide enough type, so we can include
463 // it in the note.
464 N = N.extend(std::max<unsigned>(N.getBitWidth() + 1, 65));
465 (llvm::APInt&)N += ArrayIndex;
466 assert(N.ugt(ArraySize) && "bounds check failed for in-bounds index")((N.ugt(ArraySize) && "bounds check failed for in-bounds index"
) ? static_cast<void> (0) : __assert_fail ("N.ugt(ArraySize) && \"bounds check failed for in-bounds index\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 466, __PRETTY_FUNCTION__))
;
467 diagnosePointerArithmetic(Info, E, N);
468 setInvalid();
469 return;
470 }
471
472 ArrayIndex += TruncatedN;
473 assert(ArrayIndex <= ArraySize &&((ArrayIndex <= ArraySize && "bounds check succeeded for out-of-bounds index"
) ? static_cast<void> (0) : __assert_fail ("ArrayIndex <= ArraySize && \"bounds check succeeded for out-of-bounds index\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 474, __PRETTY_FUNCTION__))
474 "bounds check succeeded for out-of-bounds index")((ArrayIndex <= ArraySize && "bounds check succeeded for out-of-bounds index"
) ? static_cast<void> (0) : __assert_fail ("ArrayIndex <= ArraySize && \"bounds check succeeded for out-of-bounds index\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 474, __PRETTY_FUNCTION__))
;
475
476 if (IsArray)
477 Entries.back() = PathEntry::ArrayIndex(ArrayIndex);
478 else
479 IsOnePastTheEnd = (ArrayIndex != 0);
480 }
481 };
482
483 /// A scope at the end of which an object can need to be destroyed.
484 enum class ScopeKind {
485 Block,
486 FullExpression,
487 Call
488 };
489
490 /// A reference to a particular call and its arguments.
491 struct CallRef {
492 CallRef() : OrigCallee(), CallIndex(0), Version() {}
493 CallRef(const FunctionDecl *Callee, unsigned CallIndex, unsigned Version)
494 : OrigCallee(Callee), CallIndex(CallIndex), Version(Version) {}
495
496 explicit operator bool() const { return OrigCallee; }
497
498 /// Get the parameter that the caller initialized, corresponding to the
499 /// given parameter in the callee.
500 const ParmVarDecl *getOrigParam(const ParmVarDecl *PVD) const {
501 return OrigCallee ? OrigCallee->getParamDecl(PVD->getFunctionScopeIndex())
502 : PVD;
503 }
504
505 /// The callee at the point where the arguments were evaluated. This might
506 /// be different from the actual callee (a different redeclaration, or a
507 /// virtual override), but this function's parameters are the ones that
508 /// appear in the parameter map.
509 const FunctionDecl *OrigCallee;
510 /// The call index of the frame that holds the argument values.
511 unsigned CallIndex;
512 /// The version of the parameters corresponding to this call.
513 unsigned Version;
514 };
515
516 /// A stack frame in the constexpr call stack.
517 class CallStackFrame : public interp::Frame {
518 public:
519 EvalInfo &Info;
520
521 /// Parent - The caller of this stack frame.
522 CallStackFrame *Caller;
523
524 /// Callee - The function which was called.
525 const FunctionDecl *Callee;
526
527 /// This - The binding for the this pointer in this call, if any.
528 const LValue *This;
529
530 /// Information on how to find the arguments to this call. Our arguments
531 /// are stored in our parent's CallStackFrame, using the ParmVarDecl* as a
532 /// key and this value as the version.
533 CallRef Arguments;
534
535 /// Source location information about the default argument or default
536 /// initializer expression we're evaluating, if any.
537 CurrentSourceLocExprScope CurSourceLocExprScope;
538
539 // Note that we intentionally use std::map here so that references to
540 // values are stable.
541 typedef std::pair<const void *, unsigned> MapKeyTy;
542 typedef std::map<MapKeyTy, APValue> MapTy;
543 /// Temporaries - Temporary lvalues materialized within this stack frame.
544 MapTy Temporaries;
545
546 /// CallLoc - The location of the call expression for this call.
547 SourceLocation CallLoc;
548
549 /// Index - The call index of this call.
550 unsigned Index;
551
552 /// The stack of integers for tracking version numbers for temporaries.
553 SmallVector<unsigned, 2> TempVersionStack = {1};
554 unsigned CurTempVersion = TempVersionStack.back();
555
556 unsigned getTempVersion() const { return TempVersionStack.back(); }
557
558 void pushTempVersion() {
559 TempVersionStack.push_back(++CurTempVersion);
560 }
561
562 void popTempVersion() {
563 TempVersionStack.pop_back();
564 }
565
566 CallRef createCall(const FunctionDecl *Callee) {
567 return {Callee, Index, ++CurTempVersion};
568 }
569
570 // FIXME: Adding this to every 'CallStackFrame' may have a nontrivial impact
571 // on the overall stack usage of deeply-recursing constexpr evaluations.
572 // (We should cache this map rather than recomputing it repeatedly.)
573 // But let's try this and see how it goes; we can look into caching the map
574 // as a later change.
575
576 /// LambdaCaptureFields - Mapping from captured variables/this to
577 /// corresponding data members in the closure class.
578 llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
579 FieldDecl *LambdaThisCaptureField;
580
581 CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
582 const FunctionDecl *Callee, const LValue *This,
583 CallRef Arguments);
584 ~CallStackFrame();
585
586 // Return the temporary for Key whose version number is Version.
587 APValue *getTemporary(const void *Key, unsigned Version) {
588 MapKeyTy KV(Key, Version);
589 auto LB = Temporaries.lower_bound(KV);
590 if (LB != Temporaries.end() && LB->first == KV)
591 return &LB->second;
592 // Pair (Key,Version) wasn't found in the map. Check that no elements
593 // in the map have 'Key' as their key.
594 assert((LB == Temporaries.end() || LB->first.first != Key) &&(((LB == Temporaries.end() || LB->first.first != Key) &&
(LB == Temporaries.begin() || std::prev(LB)->first.first !=
Key) && "Element with key 'Key' found in map") ? static_cast
<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 596, __PRETTY_FUNCTION__))
595 (LB == Temporaries.begin() || std::prev(LB)->first.first != Key) &&(((LB == Temporaries.end() || LB->first.first != Key) &&
(LB == Temporaries.begin() || std::prev(LB)->first.first !=
Key) && "Element with key 'Key' found in map") ? static_cast
<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 596, __PRETTY_FUNCTION__))
596 "Element with key 'Key' found in map")(((LB == Temporaries.end() || LB->first.first != Key) &&
(LB == Temporaries.begin() || std::prev(LB)->first.first !=
Key) && "Element with key 'Key' found in map") ? static_cast
<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 596, __PRETTY_FUNCTION__))
;
597 return nullptr;
598 }
599
600 // Return the current temporary for Key in the map.
601 APValue *getCurrentTemporary(const void *Key) {
602 auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX(2147483647 *2U +1U)));
603 if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
604 return &std::prev(UB)->second;
605 return nullptr;
606 }
607
608 // Return the version number of the current temporary for Key.
609 unsigned getCurrentTemporaryVersion(const void *Key) const {
610 auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX(2147483647 *2U +1U)));
611 if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
612 return std::prev(UB)->first.second;
613 return 0;
614 }
615
616 /// Allocate storage for an object of type T in this stack frame.
617 /// Populates LV with a handle to the created object. Key identifies
618 /// the temporary within the stack frame, and must not be reused without
619 /// bumping the temporary version number.
620 template<typename KeyT>
621 APValue &createTemporary(const KeyT *Key, QualType T,
622 ScopeKind Scope, LValue &LV);
623
624 /// Allocate storage for a parameter of a function call made in this frame.
625 APValue &createParam(CallRef Args, const ParmVarDecl *PVD, LValue &LV);
626
627 void describe(llvm::raw_ostream &OS) override;
628
629 Frame *getCaller() const override { return Caller; }
630 SourceLocation getCallLocation() const override { return CallLoc; }
631 const FunctionDecl *getCallee() const override { return Callee; }
632
633 bool isStdFunction() const {
634 for (const DeclContext *DC = Callee; DC; DC = DC->getParent())
635 if (DC->isStdNamespace())
636 return true;
637 return false;
638 }
639
640 private:
641 APValue &createLocal(APValue::LValueBase Base, const void *Key, QualType T,
642 ScopeKind Scope);
643 };
644
645 /// Temporarily override 'this'.
646 class ThisOverrideRAII {
647 public:
648 ThisOverrideRAII(CallStackFrame &Frame, const LValue *NewThis, bool Enable)
649 : Frame(Frame), OldThis(Frame.This) {
650 if (Enable)
651 Frame.This = NewThis;
652 }
653 ~ThisOverrideRAII() {
654 Frame.This = OldThis;
655 }
656 private:
657 CallStackFrame &Frame;
658 const LValue *OldThis;
659 };
660}
661
662static bool HandleDestruction(EvalInfo &Info, const Expr *E,
663 const LValue &This, QualType ThisType);
664static bool HandleDestruction(EvalInfo &Info, SourceLocation Loc,
665 APValue::LValueBase LVBase, APValue &Value,
666 QualType T);
667
668namespace {
669 /// A cleanup, and a flag indicating whether it is lifetime-extended.
670 class Cleanup {
671 llvm::PointerIntPair<APValue*, 2, ScopeKind> Value;
672 APValue::LValueBase Base;
673 QualType T;
674
675 public:
676 Cleanup(APValue *Val, APValue::LValueBase Base, QualType T,
677 ScopeKind Scope)
678 : Value(Val, Scope), Base(Base), T(T) {}
679
680 /// Determine whether this cleanup should be performed at the end of the
681 /// given kind of scope.
682 bool isDestroyedAtEndOf(ScopeKind K) const {
683 return (int)Value.getInt() >= (int)K;
684 }
685 bool endLifetime(EvalInfo &Info, bool RunDestructors) {
686 if (RunDestructors) {
687 SourceLocation Loc;
688 if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
689 Loc = VD->getLocation();
690 else if (const Expr *E = Base.dyn_cast<const Expr*>())
691 Loc = E->getExprLoc();
692 return HandleDestruction(Info, Loc, Base, *Value.getPointer(), T);
693 }
694 *Value.getPointer() = APValue();
695 return true;
696 }
697
698 bool hasSideEffect() {
699 return T.isDestructedType();
700 }
701 };
702
703 /// A reference to an object whose construction we are currently evaluating.
704 struct ObjectUnderConstruction {
705 APValue::LValueBase Base;
706 ArrayRef<APValue::LValuePathEntry> Path;
707 friend bool operator==(const ObjectUnderConstruction &LHS,
708 const ObjectUnderConstruction &RHS) {
709 return LHS.Base == RHS.Base && LHS.Path == RHS.Path;
710 }
711 friend llvm::hash_code hash_value(const ObjectUnderConstruction &Obj) {
712 return llvm::hash_combine(Obj.Base, Obj.Path);
713 }
714 };
715 enum class ConstructionPhase {
716 None,
717 Bases,
718 AfterBases,
719 AfterFields,
720 Destroying,
721 DestroyingBases
722 };
723}
724
725namespace llvm {
726template<> struct DenseMapInfo<ObjectUnderConstruction> {
727 using Base = DenseMapInfo<APValue::LValueBase>;
728 static ObjectUnderConstruction getEmptyKey() {
729 return {Base::getEmptyKey(), {}}; }
730 static ObjectUnderConstruction getTombstoneKey() {
731 return {Base::getTombstoneKey(), {}};
732 }
733 static unsigned getHashValue(const ObjectUnderConstruction &Object) {
734 return hash_value(Object);
735 }
736 static bool isEqual(const ObjectUnderConstruction &LHS,
737 const ObjectUnderConstruction &RHS) {
738 return LHS == RHS;
739 }
740};
741}
742
743namespace {
744 /// A dynamically-allocated heap object.
745 struct DynAlloc {
746 /// The value of this heap-allocated object.
747 APValue Value;
748 /// The allocating expression; used for diagnostics. Either a CXXNewExpr
749 /// or a CallExpr (the latter is for direct calls to operator new inside
750 /// std::allocator<T>::allocate).
751 const Expr *AllocExpr = nullptr;
752
753 enum Kind {
754 New,
755 ArrayNew,
756 StdAllocator
757 };
758
759 /// Get the kind of the allocation. This must match between allocation
760 /// and deallocation.
761 Kind getKind() const {
762 if (auto *NE = dyn_cast<CXXNewExpr>(AllocExpr))
763 return NE->isArray() ? ArrayNew : New;
764 assert(isa<CallExpr>(AllocExpr))((isa<CallExpr>(AllocExpr)) ? static_cast<void> (
0) : __assert_fail ("isa<CallExpr>(AllocExpr)", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 764, __PRETTY_FUNCTION__))
;
765 return StdAllocator;
766 }
767 };
768
769 struct DynAllocOrder {
770 bool operator()(DynamicAllocLValue L, DynamicAllocLValue R) const {
771 return L.getIndex() < R.getIndex();
772 }
773 };
774
775 /// EvalInfo - This is a private struct used by the evaluator to capture
776 /// information about a subexpression as it is folded. It retains information
777 /// about the AST context, but also maintains information about the folded
778 /// expression.
779 ///
780 /// If an expression could be evaluated, it is still possible it is not a C
781 /// "integer constant expression" or constant expression. If not, this struct
782 /// captures information about how and why not.
783 ///
784 /// One bit of information passed *into* the request for constant folding
785 /// indicates whether the subexpression is "evaluated" or not according to C
786 /// rules. For example, the RHS of (0 && foo()) is not evaluated. We can
787 /// evaluate the expression regardless of what the RHS is, but C only allows
788 /// certain things in certain situations.
789 class EvalInfo : public interp::State {
790 public:
791 ASTContext &Ctx;
792
793 /// EvalStatus - Contains information about the evaluation.
794 Expr::EvalStatus &EvalStatus;
795
796 /// CurrentCall - The top of the constexpr call stack.
797 CallStackFrame *CurrentCall;
798
799 /// CallStackDepth - The number of calls in the call stack right now.
800 unsigned CallStackDepth;
801
802 /// NextCallIndex - The next call index to assign.
803 unsigned NextCallIndex;
804
805 /// StepsLeft - The remaining number of evaluation steps we're permitted
806 /// to perform. This is essentially a limit for the number of statements
807 /// we will evaluate.
808 unsigned StepsLeft;
809
810 /// Enable the experimental new constant interpreter. If an expression is
811 /// not supported by the interpreter, an error is triggered.
812 bool EnableNewConstInterp;
813
814 /// BottomFrame - The frame in which evaluation started. This must be
815 /// initialized after CurrentCall and CallStackDepth.
816 CallStackFrame BottomFrame;
817
818 /// A stack of values whose lifetimes end at the end of some surrounding
819 /// evaluation frame.
820 llvm::SmallVector<Cleanup, 16> CleanupStack;
821
822 /// EvaluatingDecl - This is the declaration whose initializer is being
823 /// evaluated, if any.
824 APValue::LValueBase EvaluatingDecl;
825
826 enum class EvaluatingDeclKind {
827 None,
828 /// We're evaluating the construction of EvaluatingDecl.
829 Ctor,
830 /// We're evaluating the destruction of EvaluatingDecl.
831 Dtor,
832 };
833 EvaluatingDeclKind IsEvaluatingDecl = EvaluatingDeclKind::None;
834
835 /// EvaluatingDeclValue - This is the value being constructed for the
836 /// declaration whose initializer is being evaluated, if any.
837 APValue *EvaluatingDeclValue;
838
839 /// Set of objects that are currently being constructed.
840 llvm::DenseMap<ObjectUnderConstruction, ConstructionPhase>
841 ObjectsUnderConstruction;
842
843 /// Current heap allocations, along with the location where each was
844 /// allocated. We use std::map here because we need stable addresses
845 /// for the stored APValues.
846 std::map<DynamicAllocLValue, DynAlloc, DynAllocOrder> HeapAllocs;
847
848 /// The number of heap allocations performed so far in this evaluation.
849 unsigned NumHeapAllocs = 0;
850
851 struct EvaluatingConstructorRAII {
852 EvalInfo &EI;
853 ObjectUnderConstruction Object;
854 bool DidInsert;
855 EvaluatingConstructorRAII(EvalInfo &EI, ObjectUnderConstruction Object,
856 bool HasBases)
857 : EI(EI), Object(Object) {
858 DidInsert =
859 EI.ObjectsUnderConstruction
860 .insert({Object, HasBases ? ConstructionPhase::Bases
861 : ConstructionPhase::AfterBases})
862 .second;
863 }
864 void finishedConstructingBases() {
865 EI.ObjectsUnderConstruction[Object] = ConstructionPhase::AfterBases;
866 }
867 void finishedConstructingFields() {
868 EI.ObjectsUnderConstruction[Object] = ConstructionPhase::AfterFields;
869 }
870 ~EvaluatingConstructorRAII() {
871 if (DidInsert) EI.ObjectsUnderConstruction.erase(Object);
872 }
873 };
874
875 struct EvaluatingDestructorRAII {
876 EvalInfo &EI;
877 ObjectUnderConstruction Object;
878 bool DidInsert;
879 EvaluatingDestructorRAII(EvalInfo &EI, ObjectUnderConstruction Object)
880 : EI(EI), Object(Object) {
881 DidInsert = EI.ObjectsUnderConstruction
882 .insert({Object, ConstructionPhase::Destroying})
883 .second;
884 }
885 void startedDestroyingBases() {
886 EI.ObjectsUnderConstruction[Object] =
887 ConstructionPhase::DestroyingBases;
888 }
889 ~EvaluatingDestructorRAII() {
890 if (DidInsert)
891 EI.ObjectsUnderConstruction.erase(Object);
892 }
893 };
894
895 ConstructionPhase
896 isEvaluatingCtorDtor(APValue::LValueBase Base,
897 ArrayRef<APValue::LValuePathEntry> Path) {
898 return ObjectsUnderConstruction.lookup({Base, Path});
899 }
900
901 /// If we're currently speculatively evaluating, the outermost call stack
902 /// depth at which we can mutate state, otherwise 0.
903 unsigned SpeculativeEvaluationDepth = 0;
904
905 /// The current array initialization index, if we're performing array
906 /// initialization.
907 uint64_t ArrayInitIndex = -1;
908
909 /// HasActiveDiagnostic - Was the previous diagnostic stored? If so, further
910 /// notes attached to it will also be stored, otherwise they will not be.
911 bool HasActiveDiagnostic;
912
913 /// Have we emitted a diagnostic explaining why we couldn't constant
914 /// fold (not just why it's not strictly a constant expression)?
915 bool HasFoldFailureDiagnostic;
916
917 /// Whether or not we're in a context where the front end requires a
918 /// constant value.
919 bool InConstantContext;
920
921 /// Whether we're checking that an expression is a potential constant
922 /// expression. If so, do not fail on constructs that could become constant
923 /// later on (such as a use of an undefined global).
924 bool CheckingPotentialConstantExpression = false;
925
926 /// Whether we're checking for an expression that has undefined behavior.
927 /// If so, we will produce warnings if we encounter an operation that is
928 /// always undefined.
929 ///
930 /// Note that we still need to evaluate the expression normally when this
931 /// is set; this is used when evaluating ICEs in C.
932 bool CheckingForUndefinedBehavior = false;
933
934 enum EvaluationMode {
935 /// Evaluate as a constant expression. Stop if we find that the expression
936 /// is not a constant expression.
937 EM_ConstantExpression,
938
939 /// Evaluate as a constant expression. Stop if we find that the expression
940 /// is not a constant expression. Some expressions can be retried in the
941 /// optimizer if we don't constant fold them here, but in an unevaluated
942 /// context we try to fold them immediately since the optimizer never
943 /// gets a chance to look at it.
944 EM_ConstantExpressionUnevaluated,
945
946 /// Fold the expression to a constant. Stop if we hit a side-effect that
947 /// we can't model.
948 EM_ConstantFold,
949
950 /// Evaluate in any way we know how. Don't worry about side-effects that
951 /// can't be modeled.
952 EM_IgnoreSideEffects,
953 } EvalMode;
954
955 /// Are we checking whether the expression is a potential constant
956 /// expression?
957 bool checkingPotentialConstantExpression() const override {
958 return CheckingPotentialConstantExpression;
959 }
960
961 /// Are we checking an expression for overflow?
962 // FIXME: We should check for any kind of undefined or suspicious behavior
963 // in such constructs, not just overflow.
964 bool checkingForUndefinedBehavior() const override {
965 return CheckingForUndefinedBehavior;
966 }
967
968 EvalInfo(const ASTContext &C, Expr::EvalStatus &S, EvaluationMode Mode)
969 : Ctx(const_cast<ASTContext &>(C)), EvalStatus(S), CurrentCall(nullptr),
970 CallStackDepth(0), NextCallIndex(1),
971 StepsLeft(C.getLangOpts().ConstexprStepLimit),
972 EnableNewConstInterp(C.getLangOpts().EnableNewConstInterp),
973 BottomFrame(*this, SourceLocation(), nullptr, nullptr, CallRef()),
974 EvaluatingDecl((const ValueDecl *)nullptr),
975 EvaluatingDeclValue(nullptr), HasActiveDiagnostic(false),
976 HasFoldFailureDiagnostic(false), InConstantContext(false),
977 EvalMode(Mode) {}
978
979 ~EvalInfo() {
980 discardCleanups();
981 }
982
983 void setEvaluatingDecl(APValue::LValueBase Base, APValue &Value,
984 EvaluatingDeclKind EDK = EvaluatingDeclKind::Ctor) {
985 EvaluatingDecl = Base;
986 IsEvaluatingDecl = EDK;
987 EvaluatingDeclValue = &Value;
988 }
989
990 bool CheckCallLimit(SourceLocation Loc) {
991 // Don't perform any constexpr calls (other than the call we're checking)
992 // when checking a potential constant expression.
993 if (checkingPotentialConstantExpression() && CallStackDepth > 1)
994 return false;
995 if (NextCallIndex == 0) {
996 // NextCallIndex has wrapped around.
997 FFDiag(Loc, diag::note_constexpr_call_limit_exceeded);
998 return false;
999 }
1000 if (CallStackDepth <= getLangOpts().ConstexprCallDepth)
1001 return true;
1002 FFDiag(Loc, diag::note_constexpr_depth_limit_exceeded)
1003 << getLangOpts().ConstexprCallDepth;
1004 return false;
1005 }
1006
1007 std::pair<CallStackFrame *, unsigned>
1008 getCallFrameAndDepth(unsigned CallIndex) {
1009 assert(CallIndex && "no call index in getCallFrameAndDepth")((CallIndex && "no call index in getCallFrameAndDepth"
) ? static_cast<void> (0) : __assert_fail ("CallIndex && \"no call index in getCallFrameAndDepth\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1009, __PRETTY_FUNCTION__))
;
1010 // We will eventually hit BottomFrame, which has Index 1, so Frame can't
1011 // be null in this loop.
1012 unsigned Depth = CallStackDepth;
1013 CallStackFrame *Frame = CurrentCall;
1014 while (Frame->Index > CallIndex) {
1015 Frame = Frame->Caller;
1016 --Depth;
1017 }
1018 if (Frame->Index == CallIndex)
1019 return {Frame, Depth};
1020 return {nullptr, 0};
1021 }
1022
1023 bool nextStep(const Stmt *S) {
1024 if (!StepsLeft) {
1025 FFDiag(S->getBeginLoc(), diag::note_constexpr_step_limit_exceeded);
1026 return false;
1027 }
1028 --StepsLeft;
1029 return true;
1030 }
1031
1032 APValue *createHeapAlloc(const Expr *E, QualType T, LValue &LV);
1033
1034 Optional<DynAlloc*> lookupDynamicAlloc(DynamicAllocLValue DA) {
1035 Optional<DynAlloc*> Result;
1036 auto It = HeapAllocs.find(DA);
1037 if (It != HeapAllocs.end())
1038 Result = &It->second;
1039 return Result;
1040 }
1041
1042 /// Get the allocated storage for the given parameter of the given call.
1043 APValue *getParamSlot(CallRef Call, const ParmVarDecl *PVD) {
1044 CallStackFrame *Frame = getCallFrameAndDepth(Call.CallIndex).first;
1045 return Frame ? Frame->getTemporary(Call.getOrigParam(PVD), Call.Version)
1046 : nullptr;
1047 }
1048
1049 /// Information about a stack frame for std::allocator<T>::[de]allocate.
1050 struct StdAllocatorCaller {
1051 unsigned FrameIndex;
1052 QualType ElemType;
1053 explicit operator bool() const { return FrameIndex != 0; };
1054 };
1055
1056 StdAllocatorCaller getStdAllocatorCaller(StringRef FnName) const {
1057 for (const CallStackFrame *Call = CurrentCall; Call != &BottomFrame;
1058 Call = Call->Caller) {
1059 const auto *MD = dyn_cast_or_null<CXXMethodDecl>(Call->Callee);
1060 if (!MD)
1061 continue;
1062 const IdentifierInfo *FnII = MD->getIdentifier();
1063 if (!FnII || !FnII->isStr(FnName))
1064 continue;
1065
1066 const auto *CTSD =
1067 dyn_cast<ClassTemplateSpecializationDecl>(MD->getParent());
1068 if (!CTSD)
1069 continue;
1070
1071 const IdentifierInfo *ClassII = CTSD->getIdentifier();
1072 const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
1073 if (CTSD->isInStdNamespace() && ClassII &&
1074 ClassII->isStr("allocator") && TAL.size() >= 1 &&
1075 TAL[0].getKind() == TemplateArgument::Type)
1076 return {Call->Index, TAL[0].getAsType()};
1077 }
1078
1079 return {};
1080 }
1081
1082 void performLifetimeExtension() {
1083 // Disable the cleanups for lifetime-extended temporaries.
1084 CleanupStack.erase(std::remove_if(CleanupStack.begin(),
1085 CleanupStack.end(),
1086 [](Cleanup &C) {
1087 return !C.isDestroyedAtEndOf(
1088 ScopeKind::FullExpression);
1089 }),
1090 CleanupStack.end());
1091 }
1092
1093 /// Throw away any remaining cleanups at the end of evaluation. If any
1094 /// cleanups would have had a side-effect, note that as an unmodeled
1095 /// side-effect and return false. Otherwise, return true.
1096 bool discardCleanups() {
1097 for (Cleanup &C : CleanupStack) {
1098 if (C.hasSideEffect() && !noteSideEffect()) {
1099 CleanupStack.clear();
1100 return false;
1101 }
1102 }
1103 CleanupStack.clear();
1104 return true;
1105 }
1106
1107 private:
1108 interp::Frame *getCurrentFrame() override { return CurrentCall; }
1109 const interp::Frame *getBottomFrame() const override { return &BottomFrame; }
1110
1111 bool hasActiveDiagnostic() override { return HasActiveDiagnostic; }
1112 void setActiveDiagnostic(bool Flag) override { HasActiveDiagnostic = Flag; }
1113
1114 void setFoldFailureDiagnostic(bool Flag) override {
1115 HasFoldFailureDiagnostic = Flag;
1116 }
1117
1118 Expr::EvalStatus &getEvalStatus() const override { return EvalStatus; }
1119
1120 ASTContext &getCtx() const override { return Ctx; }
1121
1122 // If we have a prior diagnostic, it will be noting that the expression
1123 // isn't a constant expression. This diagnostic is more important,
1124 // unless we require this evaluation to produce a constant expression.
1125 //
1126 // FIXME: We might want to show both diagnostics to the user in
1127 // EM_ConstantFold mode.
1128 bool hasPriorDiagnostic() override {
1129 if (!EvalStatus.Diag->empty()) {
1130 switch (EvalMode) {
1131 case EM_ConstantFold:
1132 case EM_IgnoreSideEffects:
1133 if (!HasFoldFailureDiagnostic)
1134 break;
1135 // We've already failed to fold something. Keep that diagnostic.
1136 LLVM_FALLTHROUGH[[gnu::fallthrough]];
1137 case EM_ConstantExpression:
1138 case EM_ConstantExpressionUnevaluated:
1139 setActiveDiagnostic(false);
1140 return true;
1141 }
1142 }
1143 return false;
1144 }
1145
1146 unsigned getCallStackDepth() override { return CallStackDepth; }
1147
1148 public:
1149 /// Should we continue evaluation after encountering a side-effect that we
1150 /// couldn't model?
1151 bool keepEvaluatingAfterSideEffect() {
1152 switch (EvalMode) {
1153 case EM_IgnoreSideEffects:
1154 return true;
1155
1156 case EM_ConstantExpression:
1157 case EM_ConstantExpressionUnevaluated:
1158 case EM_ConstantFold:
1159 // By default, assume any side effect might be valid in some other
1160 // evaluation of this expression from a different context.
1161 return checkingPotentialConstantExpression() ||
1162 checkingForUndefinedBehavior();
1163 }
1164 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1164)
;
1165 }
1166
1167 /// Note that we have had a side-effect, and determine whether we should
1168 /// keep evaluating.
1169 bool noteSideEffect() {
1170 EvalStatus.HasSideEffects = true;
1171 return keepEvaluatingAfterSideEffect();
1172 }
1173
1174 /// Should we continue evaluation after encountering undefined behavior?
1175 bool keepEvaluatingAfterUndefinedBehavior() {
1176 switch (EvalMode) {
1177 case EM_IgnoreSideEffects:
1178 case EM_ConstantFold:
1179 return true;
1180
1181 case EM_ConstantExpression:
1182 case EM_ConstantExpressionUnevaluated:
1183 return checkingForUndefinedBehavior();
1184 }
1185 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1185)
;
1186 }
1187
1188 /// Note that we hit something that was technically undefined behavior, but
1189 /// that we can evaluate past it (such as signed overflow or floating-point
1190 /// division by zero.)
1191 bool noteUndefinedBehavior() override {
1192 EvalStatus.HasUndefinedBehavior = true;
1193 return keepEvaluatingAfterUndefinedBehavior();
1194 }
1195
1196 /// Should we continue evaluation as much as possible after encountering a
1197 /// construct which can't be reduced to a value?
1198 bool keepEvaluatingAfterFailure() const override {
1199 if (!StepsLeft)
1200 return false;
1201
1202 switch (EvalMode) {
1203 case EM_ConstantExpression:
1204 case EM_ConstantExpressionUnevaluated:
1205 case EM_ConstantFold:
1206 case EM_IgnoreSideEffects:
1207 return checkingPotentialConstantExpression() ||
1208 checkingForUndefinedBehavior();
1209 }
1210 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1210)
;
1211 }
1212
1213 /// Notes that we failed to evaluate an expression that other expressions
1214 /// directly depend on, and determine if we should keep evaluating. This
1215 /// should only be called if we actually intend to keep evaluating.
1216 ///
1217 /// Call noteSideEffect() instead if we may be able to ignore the value that
1218 /// we failed to evaluate, e.g. if we failed to evaluate Foo() in:
1219 ///
1220 /// (Foo(), 1) // use noteSideEffect
1221 /// (Foo() || true) // use noteSideEffect
1222 /// Foo() + 1 // use noteFailure
1223 LLVM_NODISCARD[[clang::warn_unused_result]] bool noteFailure() {
1224 // Failure when evaluating some expression often means there is some
1225 // subexpression whose evaluation was skipped. Therefore, (because we
1226 // don't track whether we skipped an expression when unwinding after an
1227 // evaluation failure) every evaluation failure that bubbles up from a
1228 // subexpression implies that a side-effect has potentially happened. We
1229 // skip setting the HasSideEffects flag to true until we decide to
1230 // continue evaluating after that point, which happens here.
1231 bool KeepGoing = keepEvaluatingAfterFailure();
1232 EvalStatus.HasSideEffects |= KeepGoing;
1233 return KeepGoing;
1234 }
1235
1236 class ArrayInitLoopIndex {
1237 EvalInfo &Info;
1238 uint64_t OuterIndex;
1239
1240 public:
1241 ArrayInitLoopIndex(EvalInfo &Info)
1242 : Info(Info), OuterIndex(Info.ArrayInitIndex) {
1243 Info.ArrayInitIndex = 0;
1244 }
1245 ~ArrayInitLoopIndex() { Info.ArrayInitIndex = OuterIndex; }
1246
1247 operator uint64_t&() { return Info.ArrayInitIndex; }
1248 };
1249 };
1250
1251 /// Object used to treat all foldable expressions as constant expressions.
1252 struct FoldConstant {
1253 EvalInfo &Info;
1254 bool Enabled;
1255 bool HadNoPriorDiags;
1256 EvalInfo::EvaluationMode OldMode;
1257
1258 explicit FoldConstant(EvalInfo &Info, bool Enabled)
1259 : Info(Info),
1260 Enabled(Enabled),
1261 HadNoPriorDiags(Info.EvalStatus.Diag &&
1262 Info.EvalStatus.Diag->empty() &&
1263 !Info.EvalStatus.HasSideEffects),
1264 OldMode(Info.EvalMode) {
1265 if (Enabled)
1266 Info.EvalMode = EvalInfo::EM_ConstantFold;
1267 }
1268 void keepDiagnostics() { Enabled = false; }
1269 ~FoldConstant() {
1270 if (Enabled && HadNoPriorDiags && !Info.EvalStatus.Diag->empty() &&
1271 !Info.EvalStatus.HasSideEffects)
1272 Info.EvalStatus.Diag->clear();
1273 Info.EvalMode = OldMode;
1274 }
1275 };
1276
1277 /// RAII object used to set the current evaluation mode to ignore
1278 /// side-effects.
1279 struct IgnoreSideEffectsRAII {
1280 EvalInfo &Info;
1281 EvalInfo::EvaluationMode OldMode;
1282 explicit IgnoreSideEffectsRAII(EvalInfo &Info)
1283 : Info(Info), OldMode(Info.EvalMode) {
1284 Info.EvalMode = EvalInfo::EM_IgnoreSideEffects;
1285 }
1286
1287 ~IgnoreSideEffectsRAII() { Info.EvalMode = OldMode; }
1288 };
1289
1290 /// RAII object used to optionally suppress diagnostics and side-effects from
1291 /// a speculative evaluation.
1292 class SpeculativeEvaluationRAII {
1293 EvalInfo *Info = nullptr;
1294 Expr::EvalStatus OldStatus;
1295 unsigned OldSpeculativeEvaluationDepth;
1296
1297 void moveFromAndCancel(SpeculativeEvaluationRAII &&Other) {
1298 Info = Other.Info;
1299 OldStatus = Other.OldStatus;
1300 OldSpeculativeEvaluationDepth = Other.OldSpeculativeEvaluationDepth;
1301 Other.Info = nullptr;
1302 }
1303
1304 void maybeRestoreState() {
1305 if (!Info)
1306 return;
1307
1308 Info->EvalStatus = OldStatus;
1309 Info->SpeculativeEvaluationDepth = OldSpeculativeEvaluationDepth;
1310 }
1311
1312 public:
1313 SpeculativeEvaluationRAII() = default;
1314
1315 SpeculativeEvaluationRAII(
1316 EvalInfo &Info, SmallVectorImpl<PartialDiagnosticAt> *NewDiag = nullptr)
1317 : Info(&Info), OldStatus(Info.EvalStatus),
1318 OldSpeculativeEvaluationDepth(Info.SpeculativeEvaluationDepth) {
1319 Info.EvalStatus.Diag = NewDiag;
1320 Info.SpeculativeEvaluationDepth = Info.CallStackDepth + 1;
1321 }
1322
1323 SpeculativeEvaluationRAII(const SpeculativeEvaluationRAII &Other) = delete;
1324 SpeculativeEvaluationRAII(SpeculativeEvaluationRAII &&Other) {
1325 moveFromAndCancel(std::move(Other));
1326 }
1327
1328 SpeculativeEvaluationRAII &operator=(SpeculativeEvaluationRAII &&Other) {
1329 maybeRestoreState();
1330 moveFromAndCancel(std::move(Other));
1331 return *this;
1332 }
1333
1334 ~SpeculativeEvaluationRAII() { maybeRestoreState(); }
1335 };
1336
1337 /// RAII object wrapping a full-expression or block scope, and handling
1338 /// the ending of the lifetime of temporaries created within it.
1339 template<ScopeKind Kind>
1340 class ScopeRAII {
1341 EvalInfo &Info;
1342 unsigned OldStackSize;
1343 public:
1344 ScopeRAII(EvalInfo &Info)
1345 : Info(Info), OldStackSize(Info.CleanupStack.size()) {
1346 // Push a new temporary version. This is needed to distinguish between
1347 // temporaries created in different iterations of a loop.
1348 Info.CurrentCall->pushTempVersion();
1349 }
1350 bool destroy(bool RunDestructors = true) {
1351 bool OK = cleanup(Info, RunDestructors, OldStackSize);
1352 OldStackSize = -1U;
1353 return OK;
1354 }
1355 ~ScopeRAII() {
1356 if (OldStackSize != -1U)
1357 destroy(false);
1358 // Body moved to a static method to encourage the compiler to inline away
1359 // instances of this class.
1360 Info.CurrentCall->popTempVersion();
1361 }
1362 private:
1363 static bool cleanup(EvalInfo &Info, bool RunDestructors,
1364 unsigned OldStackSize) {
1365 assert(OldStackSize <= Info.CleanupStack.size() &&((OldStackSize <= Info.CleanupStack.size() && "running cleanups out of order?"
) ? static_cast<void> (0) : __assert_fail ("OldStackSize <= Info.CleanupStack.size() && \"running cleanups out of order?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1366, __PRETTY_FUNCTION__))
1366 "running cleanups out of order?")((OldStackSize <= Info.CleanupStack.size() && "running cleanups out of order?"
) ? static_cast<void> (0) : __assert_fail ("OldStackSize <= Info.CleanupStack.size() && \"running cleanups out of order?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1366, __PRETTY_FUNCTION__))
;
1367
1368 // Run all cleanups for a block scope, and non-lifetime-extended cleanups
1369 // for a full-expression scope.
1370 bool Success = true;
1371 for (unsigned I = Info.CleanupStack.size(); I > OldStackSize; --I) {
1372 if (Info.CleanupStack[I - 1].isDestroyedAtEndOf(Kind)) {
1373 if (!Info.CleanupStack[I - 1].endLifetime(Info, RunDestructors)) {
1374 Success = false;
1375 break;
1376 }
1377 }
1378 }
1379
1380 // Compact any retained cleanups.
1381 auto NewEnd = Info.CleanupStack.begin() + OldStackSize;
1382 if (Kind != ScopeKind::Block)
1383 NewEnd =
1384 std::remove_if(NewEnd, Info.CleanupStack.end(), [](Cleanup &C) {
1385 return C.isDestroyedAtEndOf(Kind);
1386 });
1387 Info.CleanupStack.erase(NewEnd, Info.CleanupStack.end());
1388 return Success;
1389 }
1390 };
1391 typedef ScopeRAII<ScopeKind::Block> BlockScopeRAII;
1392 typedef ScopeRAII<ScopeKind::FullExpression> FullExpressionRAII;
1393 typedef ScopeRAII<ScopeKind::Call> CallScopeRAII;
1394}
1395
1396bool SubobjectDesignator::checkSubobject(EvalInfo &Info, const Expr *E,
1397 CheckSubobjectKind CSK) {
1398 if (Invalid)
1399 return false;
1400 if (isOnePastTheEnd()) {
1401 Info.CCEDiag(E, diag::note_constexpr_past_end_subobject)
1402 << CSK;
1403 setInvalid();
1404 return false;
1405 }
1406 // Note, we do not diagnose if isMostDerivedAnUnsizedArray(), because there
1407 // must actually be at least one array element; even a VLA cannot have a
1408 // bound of zero. And if our index is nonzero, we already had a CCEDiag.
1409 return true;
1410}
1411
1412void SubobjectDesignator::diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info,
1413 const Expr *E) {
1414 Info.CCEDiag(E, diag::note_constexpr_unsized_array_indexed);
1415 // Do not set the designator as invalid: we can represent this situation,
1416 // and correct handling of __builtin_object_size requires us to do so.
1417}
1418
1419void SubobjectDesignator::diagnosePointerArithmetic(EvalInfo &Info,
1420 const Expr *E,
1421 const APSInt &N) {
1422 // If we're complaining, we must be able to statically determine the size of
1423 // the most derived array.
1424 if (MostDerivedPathLength == Entries.size() && MostDerivedIsArrayElement)
1425 Info.CCEDiag(E, diag::note_constexpr_array_index)
1426 << N << /*array*/ 0
1427 << static_cast<unsigned>(getMostDerivedArraySize());
1428 else
1429 Info.CCEDiag(E, diag::note_constexpr_array_index)
1430 << N << /*non-array*/ 1;
1431 setInvalid();
1432}
1433
1434CallStackFrame::CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
1435 const FunctionDecl *Callee, const LValue *This,
1436 CallRef Call)
1437 : Info(Info), Caller(Info.CurrentCall), Callee(Callee), This(This),
1438 Arguments(Call), CallLoc(CallLoc), Index(Info.NextCallIndex++) {
1439 Info.CurrentCall = this;
1440 ++Info.CallStackDepth;
1441}
1442
1443CallStackFrame::~CallStackFrame() {
1444 assert(Info.CurrentCall == this && "calls retired out of order")((Info.CurrentCall == this && "calls retired out of order"
) ? static_cast<void> (0) : __assert_fail ("Info.CurrentCall == this && \"calls retired out of order\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1444, __PRETTY_FUNCTION__))
;
1445 --Info.CallStackDepth;
1446 Info.CurrentCall = Caller;
1447}
1448
1449static bool isRead(AccessKinds AK) {
1450 return AK == AK_Read || AK == AK_ReadObjectRepresentation;
1451}
1452
1453static bool isModification(AccessKinds AK) {
1454 switch (AK) {
1455 case AK_Read:
1456 case AK_ReadObjectRepresentation:
1457 case AK_MemberCall:
1458 case AK_DynamicCast:
1459 case AK_TypeId:
1460 return false;
1461 case AK_Assign:
1462 case AK_Increment:
1463 case AK_Decrement:
1464 case AK_Construct:
1465 case AK_Destroy:
1466 return true;
1467 }
1468 llvm_unreachable("unknown access kind")::llvm::llvm_unreachable_internal("unknown access kind", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1468)
;
1469}
1470
1471static bool isAnyAccess(AccessKinds AK) {
1472 return isRead(AK) || isModification(AK);
1473}
1474
1475/// Is this an access per the C++ definition?
1476static bool isFormalAccess(AccessKinds AK) {
1477 return isAnyAccess(AK) && AK != AK_Construct && AK != AK_Destroy;
1478}
1479
1480/// Is this kind of axcess valid on an indeterminate object value?
1481static bool isValidIndeterminateAccess(AccessKinds AK) {
1482 switch (AK) {
1483 case AK_Read:
1484 case AK_Increment:
1485 case AK_Decrement:
1486 // These need the object's value.
1487 return false;
1488
1489 case AK_ReadObjectRepresentation:
1490 case AK_Assign:
1491 case AK_Construct:
1492 case AK_Destroy:
1493 // Construction and destruction don't need the value.
1494 return true;
1495
1496 case AK_MemberCall:
1497 case AK_DynamicCast:
1498 case AK_TypeId:
1499 // These aren't really meaningful on scalars.
1500 return true;
1501 }
1502 llvm_unreachable("unknown access kind")::llvm::llvm_unreachable_internal("unknown access kind", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1502)
;
1503}
1504
1505namespace {
1506 struct ComplexValue {
1507 private:
1508 bool IsInt;
1509
1510 public:
1511 APSInt IntReal, IntImag;
1512 APFloat FloatReal, FloatImag;
1513
1514 ComplexValue() : FloatReal(APFloat::Bogus()), FloatImag(APFloat::Bogus()) {}
1515
1516 void makeComplexFloat() { IsInt = false; }
1517 bool isComplexFloat() const { return !IsInt; }
1518 APFloat &getComplexFloatReal() { return FloatReal; }
1519 APFloat &getComplexFloatImag() { return FloatImag; }
1520
1521 void makeComplexInt() { IsInt = true; }
1522 bool isComplexInt() const { return IsInt; }
1523 APSInt &getComplexIntReal() { return IntReal; }
1524 APSInt &getComplexIntImag() { return IntImag; }
1525
1526 void moveInto(APValue &v) const {
1527 if (isComplexFloat())
1528 v = APValue(FloatReal, FloatImag);
1529 else
1530 v = APValue(IntReal, IntImag);
1531 }
1532 void setFrom(const APValue &v) {
1533 assert(v.isComplexFloat() || v.isComplexInt())((v.isComplexFloat() || v.isComplexInt()) ? static_cast<void
> (0) : __assert_fail ("v.isComplexFloat() || v.isComplexInt()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1533, __PRETTY_FUNCTION__))
;
1534 if (v.isComplexFloat()) {
1535 makeComplexFloat();
1536 FloatReal = v.getComplexFloatReal();
1537 FloatImag = v.getComplexFloatImag();
1538 } else {
1539 makeComplexInt();
1540 IntReal = v.getComplexIntReal();
1541 IntImag = v.getComplexIntImag();
1542 }
1543 }
1544 };
1545
1546 struct LValue {
1547 APValue::LValueBase Base;
1548 CharUnits Offset;
1549 SubobjectDesignator Designator;
1550 bool IsNullPtr : 1;
1551 bool InvalidBase : 1;
1552
1553 const APValue::LValueBase getLValueBase() const { return Base; }
1554 CharUnits &getLValueOffset() { return Offset; }
1555 const CharUnits &getLValueOffset() const { return Offset; }
1556 SubobjectDesignator &getLValueDesignator() { return Designator; }
1557 const SubobjectDesignator &getLValueDesignator() const { return Designator;}
1558 bool isNullPointer() const { return IsNullPtr;}
1559
1560 unsigned getLValueCallIndex() const { return Base.getCallIndex(); }
1561 unsigned getLValueVersion() const { return Base.getVersion(); }
1562
1563 void moveInto(APValue &V) const {
1564 if (Designator.Invalid)
1565 V = APValue(Base, Offset, APValue::NoLValuePath(), IsNullPtr);
1566 else {
1567 assert(!InvalidBase && "APValues can't handle invalid LValue bases")((!InvalidBase && "APValues can't handle invalid LValue bases"
) ? static_cast<void> (0) : __assert_fail ("!InvalidBase && \"APValues can't handle invalid LValue bases\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1567, __PRETTY_FUNCTION__))
;
1568 V = APValue(Base, Offset, Designator.Entries,
1569 Designator.IsOnePastTheEnd, IsNullPtr);
1570 }
1571 }
1572 void setFrom(ASTContext &Ctx, const APValue &V) {
1573 assert(V.isLValue() && "Setting LValue from a non-LValue?")((V.isLValue() && "Setting LValue from a non-LValue?"
) ? static_cast<void> (0) : __assert_fail ("V.isLValue() && \"Setting LValue from a non-LValue?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1573, __PRETTY_FUNCTION__))
;
1574 Base = V.getLValueBase();
1575 Offset = V.getLValueOffset();
1576 InvalidBase = false;
1577 Designator = SubobjectDesignator(Ctx, V);
1578 IsNullPtr = V.isNullPointer();
1579 }
1580
1581 void set(APValue::LValueBase B, bool BInvalid = false) {
1582#ifndef NDEBUG
1583 // We only allow a few types of invalid bases. Enforce that here.
1584 if (BInvalid) {
1585 const auto *E = B.get<const Expr *>();
1586 assert((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) &&(((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) &&
"Unexpected type of invalid base") ? static_cast<void>
(0) : __assert_fail ("(isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) && \"Unexpected type of invalid base\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1587, __PRETTY_FUNCTION__))
1587 "Unexpected type of invalid base")(((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) &&
"Unexpected type of invalid base") ? static_cast<void>
(0) : __assert_fail ("(isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) && \"Unexpected type of invalid base\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1587, __PRETTY_FUNCTION__))
;
1588 }
1589#endif
1590
1591 Base = B;
1592 Offset = CharUnits::fromQuantity(0);
1593 InvalidBase = BInvalid;
1594 Designator = SubobjectDesignator(getType(B));
1595 IsNullPtr = false;
1596 }
1597
1598 void setNull(ASTContext &Ctx, QualType PointerTy) {
1599 Base = (const ValueDecl *)nullptr;
1600 Offset =
1601 CharUnits::fromQuantity(Ctx.getTargetNullPointerValue(PointerTy));
1602 InvalidBase = false;
1603 Designator = SubobjectDesignator(PointerTy->getPointeeType());
1604 IsNullPtr = true;
1605 }
1606
1607 void setInvalid(APValue::LValueBase B, unsigned I = 0) {
1608 set(B, true);
1609 }
1610
1611 std::string toString(ASTContext &Ctx, QualType T) const {
1612 APValue Printable;
1613 moveInto(Printable);
1614 return Printable.getAsString(Ctx, T);
1615 }
1616
1617 private:
1618 // Check that this LValue is not based on a null pointer. If it is, produce
1619 // a diagnostic and mark the designator as invalid.
1620 template <typename GenDiagType>
1621 bool checkNullPointerDiagnosingWith(const GenDiagType &GenDiag) {
1622 if (Designator.Invalid)
1623 return false;
1624 if (IsNullPtr) {
1625 GenDiag();
1626 Designator.setInvalid();
1627 return false;
1628 }
1629 return true;
1630 }
1631
1632 public:
1633 bool checkNullPointer(EvalInfo &Info, const Expr *E,
1634 CheckSubobjectKind CSK) {
1635 return checkNullPointerDiagnosingWith([&Info, E, CSK] {
1636 Info.CCEDiag(E, diag::note_constexpr_null_subobject) << CSK;
1637 });
1638 }
1639
1640 bool checkNullPointerForFoldAccess(EvalInfo &Info, const Expr *E,
1641 AccessKinds AK) {
1642 return checkNullPointerDiagnosingWith([&Info, E, AK] {
1643 Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
1644 });
1645 }
1646
1647 // Check this LValue refers to an object. If not, set the designator to be
1648 // invalid and emit a diagnostic.
1649 bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK) {
1650 return (CSK == CSK_ArrayToPointer || checkNullPointer(Info, E, CSK)) &&
1651 Designator.checkSubobject(Info, E, CSK);
1652 }
1653
1654 void addDecl(EvalInfo &Info, const Expr *E,
1655 const Decl *D, bool Virtual = false) {
1656 if (checkSubobject(Info, E, isa<FieldDecl>(D) ? CSK_Field : CSK_Base))
1657 Designator.addDeclUnchecked(D, Virtual);
1658 }
1659 void addUnsizedArray(EvalInfo &Info, const Expr *E, QualType ElemTy) {
1660 if (!Designator.Entries.empty()) {
1661 Info.CCEDiag(E, diag::note_constexpr_unsupported_unsized_array);
1662 Designator.setInvalid();
1663 return;
1664 }
1665 if (checkSubobject(Info, E, CSK_ArrayToPointer)) {
1666 assert(getType(Base)->isPointerType() || getType(Base)->isArrayType())((getType(Base)->isPointerType() || getType(Base)->isArrayType
()) ? static_cast<void> (0) : __assert_fail ("getType(Base)->isPointerType() || getType(Base)->isArrayType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1666, __PRETTY_FUNCTION__))
;
1667 Designator.FirstEntryIsAnUnsizedArray = true;
1668 Designator.addUnsizedArrayUnchecked(ElemTy);
1669 }
1670 }
1671 void addArray(EvalInfo &Info, const Expr *E, const ConstantArrayType *CAT) {
1672 if (checkSubobject(Info, E, CSK_ArrayToPointer))
1673 Designator.addArrayUnchecked(CAT);
1674 }
1675 void addComplex(EvalInfo &Info, const Expr *E, QualType EltTy, bool Imag) {
1676 if (checkSubobject(Info, E, Imag ? CSK_Imag : CSK_Real))
1677 Designator.addComplexUnchecked(EltTy, Imag);
1678 }
1679 void clearIsNullPointer() {
1680 IsNullPtr = false;
1681 }
1682 void adjustOffsetAndIndex(EvalInfo &Info, const Expr *E,
1683 const APSInt &Index, CharUnits ElementSize) {
1684 // An index of 0 has no effect. (In C, adding 0 to a null pointer is UB,
1685 // but we're not required to diagnose it and it's valid in C++.)
1686 if (!Index)
1687 return;
1688
1689 // Compute the new offset in the appropriate width, wrapping at 64 bits.
1690 // FIXME: When compiling for a 32-bit target, we should use 32-bit
1691 // offsets.
1692 uint64_t Offset64 = Offset.getQuantity();
1693 uint64_t ElemSize64 = ElementSize.getQuantity();
1694 uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
1695 Offset = CharUnits::fromQuantity(Offset64 + ElemSize64 * Index64);
1696
1697 if (checkNullPointer(Info, E, CSK_ArrayIndex))
1698 Designator.adjustIndex(Info, E, Index);
1699 clearIsNullPointer();
1700 }
1701 void adjustOffset(CharUnits N) {
1702 Offset += N;
1703 if (N.getQuantity())
1704 clearIsNullPointer();
1705 }
1706 };
1707
1708 struct MemberPtr {
1709 MemberPtr() {}
1710 explicit MemberPtr(const ValueDecl *Decl) :
1711 DeclAndIsDerivedMember(Decl, false), Path() {}
1712
1713 /// The member or (direct or indirect) field referred to by this member
1714 /// pointer, or 0 if this is a null member pointer.
1715 const ValueDecl *getDecl() const {
1716 return DeclAndIsDerivedMember.getPointer();
1717 }
1718 /// Is this actually a member of some type derived from the relevant class?
1719 bool isDerivedMember() const {
1720 return DeclAndIsDerivedMember.getInt();
1721 }
1722 /// Get the class which the declaration actually lives in.
1723 const CXXRecordDecl *getContainingRecord() const {
1724 return cast<CXXRecordDecl>(
1725 DeclAndIsDerivedMember.getPointer()->getDeclContext());
1726 }
1727
1728 void moveInto(APValue &V) const {
1729 V = APValue(getDecl(), isDerivedMember(), Path);
1730 }
1731 void setFrom(const APValue &V) {
1732 assert(V.isMemberPointer())((V.isMemberPointer()) ? static_cast<void> (0) : __assert_fail
("V.isMemberPointer()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1732, __PRETTY_FUNCTION__))
;
1733 DeclAndIsDerivedMember.setPointer(V.getMemberPointerDecl());
1734 DeclAndIsDerivedMember.setInt(V.isMemberPointerToDerivedMember());
1735 Path.clear();
1736 ArrayRef<const CXXRecordDecl*> P = V.getMemberPointerPath();
1737 Path.insert(Path.end(), P.begin(), P.end());
1738 }
1739
1740 /// DeclAndIsDerivedMember - The member declaration, and a flag indicating
1741 /// whether the member is a member of some class derived from the class type
1742 /// of the member pointer.
1743 llvm::PointerIntPair<const ValueDecl*, 1, bool> DeclAndIsDerivedMember;
1744 /// Path - The path of base/derived classes from the member declaration's
1745 /// class (exclusive) to the class type of the member pointer (inclusive).
1746 SmallVector<const CXXRecordDecl*, 4> Path;
1747
1748 /// Perform a cast towards the class of the Decl (either up or down the
1749 /// hierarchy).
1750 bool castBack(const CXXRecordDecl *Class) {
1751 assert(!Path.empty())((!Path.empty()) ? static_cast<void> (0) : __assert_fail
("!Path.empty()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1751, __PRETTY_FUNCTION__))
;
1752 const CXXRecordDecl *Expected;
1753 if (Path.size() >= 2)
1754 Expected = Path[Path.size() - 2];
1755 else
1756 Expected = getContainingRecord();
1757 if (Expected->getCanonicalDecl() != Class->getCanonicalDecl()) {
1758 // C++11 [expr.static.cast]p12: In a conversion from (D::*) to (B::*),
1759 // if B does not contain the original member and is not a base or
1760 // derived class of the class containing the original member, the result
1761 // of the cast is undefined.
1762 // C++11 [conv.mem]p2 does not cover this case for a cast from (B::*) to
1763 // (D::*). We consider that to be a language defect.
1764 return false;
1765 }
1766 Path.pop_back();
1767 return true;
1768 }
1769 /// Perform a base-to-derived member pointer cast.
1770 bool castToDerived(const CXXRecordDecl *Derived) {
1771 if (!getDecl())
1772 return true;
1773 if (!isDerivedMember()) {
1774 Path.push_back(Derived);
1775 return true;
1776 }
1777 if (!castBack(Derived))
1778 return false;
1779 if (Path.empty())
1780 DeclAndIsDerivedMember.setInt(false);
1781 return true;
1782 }
1783 /// Perform a derived-to-base member pointer cast.
1784 bool castToBase(const CXXRecordDecl *Base) {
1785 if (!getDecl())
1786 return true;
1787 if (Path.empty())
1788 DeclAndIsDerivedMember.setInt(true);
1789 if (isDerivedMember()) {
1790 Path.push_back(Base);
1791 return true;
1792 }
1793 return castBack(Base);
1794 }
1795 };
1796
1797 /// Compare two member pointers, which are assumed to be of the same type.
1798 static bool operator==(const MemberPtr &LHS, const MemberPtr &RHS) {
1799 if (!LHS.getDecl() || !RHS.getDecl())
1800 return !LHS.getDecl() && !RHS.getDecl();
1801 if (LHS.getDecl()->getCanonicalDecl() != RHS.getDecl()->getCanonicalDecl())
1802 return false;
1803 return LHS.Path == RHS.Path;
1804 }
1805}
1806
1807static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E);
1808static bool EvaluateInPlace(APValue &Result, EvalInfo &Info,
1809 const LValue &This, const Expr *E,
1810 bool AllowNonLiteralTypes = false);
1811static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
1812 bool InvalidBaseOK = false);
1813static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info,
1814 bool InvalidBaseOK = false);
1815static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
1816 EvalInfo &Info);
1817static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info);
1818static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info);
1819static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
1820 EvalInfo &Info);
1821static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info);
1822static bool EvaluateComplex(const Expr *E, ComplexValue &Res, EvalInfo &Info);
1823static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
1824 EvalInfo &Info);
1825static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result);
1826
1827/// Evaluate an integer or fixed point expression into an APResult.
1828static bool EvaluateFixedPointOrInteger(const Expr *E, APFixedPoint &Result,
1829 EvalInfo &Info);
1830
1831/// Evaluate only a fixed point expression into an APResult.
1832static bool EvaluateFixedPoint(const Expr *E, APFixedPoint &Result,
1833 EvalInfo &Info);
1834
1835//===----------------------------------------------------------------------===//
1836// Misc utilities
1837//===----------------------------------------------------------------------===//
1838
1839/// Negate an APSInt in place, converting it to a signed form if necessary, and
1840/// preserving its value (by extending by up to one bit as needed).
1841static void negateAsSigned(APSInt &Int) {
1842 if (Int.isUnsigned() || Int.isMinSignedValue()) {
1843 Int = Int.extend(Int.getBitWidth() + 1);
1844 Int.setIsSigned(true);
1845 }
1846 Int = -Int;
1847}
1848
1849template<typename KeyT>
1850APValue &CallStackFrame::createTemporary(const KeyT *Key, QualType T,
1851 ScopeKind Scope, LValue &LV) {
1852 unsigned Version = getTempVersion();
1853 APValue::LValueBase Base(Key, Index, Version);
1854 LV.set(Base);
1855 return createLocal(Base, Key, T, Scope);
1856}
1857
1858/// Allocate storage for a parameter of a function call made in this frame.
1859APValue &CallStackFrame::createParam(CallRef Args, const ParmVarDecl *PVD,
1860 LValue &LV) {
1861 assert(Args.CallIndex == Index && "creating parameter in wrong frame")((Args.CallIndex == Index && "creating parameter in wrong frame"
) ? static_cast<void> (0) : __assert_fail ("Args.CallIndex == Index && \"creating parameter in wrong frame\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1861, __PRETTY_FUNCTION__))
;
1862 APValue::LValueBase Base(PVD, Index, Args.Version);
1863 LV.set(Base);
1864 // We always destroy parameters at the end of the call, even if we'd allow
1865 // them to live to the end of the full-expression at runtime, in order to
1866 // give portable results and match other compilers.
1867 return createLocal(Base, PVD, PVD->getType(), ScopeKind::Call);
1868}
1869
1870APValue &CallStackFrame::createLocal(APValue::LValueBase Base, const void *Key,
1871 QualType T, ScopeKind Scope) {
1872 assert(Base.getCallIndex() == Index && "lvalue for wrong frame")((Base.getCallIndex() == Index && "lvalue for wrong frame"
) ? static_cast<void> (0) : __assert_fail ("Base.getCallIndex() == Index && \"lvalue for wrong frame\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1872, __PRETTY_FUNCTION__))
;
1873 unsigned Version = Base.getVersion();
1874 APValue &Result = Temporaries[MapKeyTy(Key, Version)];
1875 assert(Result.isAbsent() && "local created multiple times")((Result.isAbsent() && "local created multiple times"
) ? static_cast<void> (0) : __assert_fail ("Result.isAbsent() && \"local created multiple times\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1875, __PRETTY_FUNCTION__))
;
1876
1877 // If we're creating a local immediately in the operand of a speculative
1878 // evaluation, don't register a cleanup to be run outside the speculative
1879 // evaluation context, since we won't actually be able to initialize this
1880 // object.
1881 if (Index <= Info.SpeculativeEvaluationDepth) {
1882 if (T.isDestructedType())
1883 Info.noteSideEffect();
1884 } else {
1885 Info.CleanupStack.push_back(Cleanup(&Result, Base, T, Scope));
1886 }
1887 return Result;
1888}
1889
1890APValue *EvalInfo::createHeapAlloc(const Expr *E, QualType T, LValue &LV) {
1891 if (NumHeapAllocs > DynamicAllocLValue::getMaxIndex()) {
1892 FFDiag(E, diag::note_constexpr_heap_alloc_limit_exceeded);
1893 return nullptr;
1894 }
1895
1896 DynamicAllocLValue DA(NumHeapAllocs++);
1897 LV.set(APValue::LValueBase::getDynamicAlloc(DA, T));
1898 auto Result = HeapAllocs.emplace(std::piecewise_construct,
1899 std::forward_as_tuple(DA), std::tuple<>());
1900 assert(Result.second && "reused a heap alloc index?")((Result.second && "reused a heap alloc index?") ? static_cast
<void> (0) : __assert_fail ("Result.second && \"reused a heap alloc index?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1900, __PRETTY_FUNCTION__))
;
1901 Result.first->second.AllocExpr = E;
1902 return &Result.first->second.Value;
1903}
1904
1905/// Produce a string describing the given constexpr call.
1906void CallStackFrame::describe(raw_ostream &Out) {
1907 unsigned ArgIndex = 0;
1908 bool IsMemberCall = isa<CXXMethodDecl>(Callee) &&
1909 !isa<CXXConstructorDecl>(Callee) &&
1910 cast<CXXMethodDecl>(Callee)->isInstance();
1911
1912 if (!IsMemberCall)
1913 Out << *Callee << '(';
1914
1915 if (This && IsMemberCall) {
1916 APValue Val;
1917 This->moveInto(Val);
1918 Val.printPretty(Out, Info.Ctx,
1919 This->Designator.MostDerivedType);
1920 // FIXME: Add parens around Val if needed.
1921 Out << "->" << *Callee << '(';
1922 IsMemberCall = false;
1923 }
1924
1925 for (FunctionDecl::param_const_iterator I = Callee->param_begin(),
1926 E = Callee->param_end(); I != E; ++I, ++ArgIndex) {
1927 if (ArgIndex > (unsigned)IsMemberCall)
1928 Out << ", ";
1929
1930 const ParmVarDecl *Param = *I;
1931 APValue *V = Info.getParamSlot(Arguments, Param);
1932 if (V)
1933 V->printPretty(Out, Info.Ctx, Param->getType());
1934 else
1935 Out << "<...>";
1936
1937 if (ArgIndex == 0 && IsMemberCall)
1938 Out << "->" << *Callee << '(';
1939 }
1940
1941 Out << ')';
1942}
1943
1944/// Evaluate an expression to see if it had side-effects, and discard its
1945/// result.
1946/// \return \c true if the caller should keep evaluating.
1947static bool EvaluateIgnoredValue(EvalInfo &Info, const Expr *E) {
1948 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 1948, __PRETTY_FUNCTION__))
;
1949 APValue Scratch;
1950 if (!Evaluate(Scratch, Info, E))
1951 // We don't need the value, but we might have skipped a side effect here.
1952 return Info.noteSideEffect();
1953 return true;
1954}
1955
1956/// Should this call expression be treated as a string literal?
1957static bool IsStringLiteralCall(const CallExpr *E) {
1958 unsigned Builtin = E->getBuiltinCallee();
1959 return (Builtin == Builtin::BI__builtin___CFStringMakeConstantString ||
1960 Builtin == Builtin::BI__builtin___NSStringMakeConstantString);
1961}
1962
1963static bool IsGlobalLValue(APValue::LValueBase B) {
1964 // C++11 [expr.const]p3 An address constant expression is a prvalue core
1965 // constant expression of pointer type that evaluates to...
1966
1967 // ... a null pointer value, or a prvalue core constant expression of type
1968 // std::nullptr_t.
1969 if (!B) return true;
1970
1971 if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
1972 // ... the address of an object with static storage duration,
1973 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
1974 return VD->hasGlobalStorage();
1975 if (isa<TemplateParamObjectDecl>(D))
1976 return true;
1977 // ... the address of a function,
1978 // ... the address of a GUID [MS extension],
1979 return isa<FunctionDecl>(D) || isa<MSGuidDecl>(D);
1980 }
1981
1982 if (B.is<TypeInfoLValue>() || B.is<DynamicAllocLValue>())
1983 return true;
1984
1985 const Expr *E = B.get<const Expr*>();
1986 switch (E->getStmtClass()) {
1987 default:
1988 return false;
1989 case Expr::CompoundLiteralExprClass: {
1990 const CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E);
1991 return CLE->isFileScope() && CLE->isLValue();
1992 }
1993 case Expr::MaterializeTemporaryExprClass:
1994 // A materialized temporary might have been lifetime-extended to static
1995 // storage duration.
1996 return cast<MaterializeTemporaryExpr>(E)->getStorageDuration() == SD_Static;
1997 // A string literal has static storage duration.
1998 case Expr::StringLiteralClass:
1999 case Expr::PredefinedExprClass:
2000 case Expr::ObjCStringLiteralClass:
2001 case Expr::ObjCEncodeExprClass:
2002 return true;
2003 case Expr::ObjCBoxedExprClass:
2004 return cast<ObjCBoxedExpr>(E)->isExpressibleAsConstantInitializer();
2005 case Expr::CallExprClass:
2006 return IsStringLiteralCall(cast<CallExpr>(E));
2007 // For GCC compatibility, &&label has static storage duration.
2008 case Expr::AddrLabelExprClass:
2009 return true;
2010 // A Block literal expression may be used as the initialization value for
2011 // Block variables at global or local static scope.
2012 case Expr::BlockExprClass:
2013 return !cast<BlockExpr>(E)->getBlockDecl()->hasCaptures();
2014 case Expr::ImplicitValueInitExprClass:
2015 // FIXME:
2016 // We can never form an lvalue with an implicit value initialization as its
2017 // base through expression evaluation, so these only appear in one case: the
2018 // implicit variable declaration we invent when checking whether a constexpr
2019 // constructor can produce a constant expression. We must assume that such
2020 // an expression might be a global lvalue.
2021 return true;
2022 }
2023}
2024
2025static const ValueDecl *GetLValueBaseDecl(const LValue &LVal) {
2026 return LVal.Base.dyn_cast<const ValueDecl*>();
2027}
2028
2029static bool IsLiteralLValue(const LValue &Value) {
2030 if (Value.getLValueCallIndex())
2031 return false;
2032 const Expr *E = Value.Base.dyn_cast<const Expr*>();
2033 return E && !isa<MaterializeTemporaryExpr>(E);
2034}
2035
2036static bool IsWeakLValue(const LValue &Value) {
2037 const ValueDecl *Decl = GetLValueBaseDecl(Value);
2038 return Decl && Decl->isWeak();
2039}
2040
2041static bool isZeroSized(const LValue &Value) {
2042 const ValueDecl *Decl = GetLValueBaseDecl(Value);
2043 if (Decl && isa<VarDecl>(Decl)) {
2044 QualType Ty = Decl->getType();
2045 if (Ty->isArrayType())
2046 return Ty->isIncompleteType() ||
2047 Decl->getASTContext().getTypeSize(Ty) == 0;
2048 }
2049 return false;
2050}
2051
2052static bool HasSameBase(const LValue &A, const LValue &B) {
2053 if (!A.getLValueBase())
2054 return !B.getLValueBase();
2055 if (!B.getLValueBase())
2056 return false;
2057
2058 if (A.getLValueBase().getOpaqueValue() !=
2059 B.getLValueBase().getOpaqueValue())
2060 return false;
2061
2062 return A.getLValueCallIndex() == B.getLValueCallIndex() &&
2063 A.getLValueVersion() == B.getLValueVersion();
2064}
2065
2066static void NoteLValueLocation(EvalInfo &Info, APValue::LValueBase Base) {
2067 assert(Base && "no location for a null lvalue")((Base && "no location for a null lvalue") ? static_cast
<void> (0) : __assert_fail ("Base && \"no location for a null lvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2067, __PRETTY_FUNCTION__))
;
2068 const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
2069
2070 // For a parameter, find the corresponding call stack frame (if it still
2071 // exists), and point at the parameter of the function definition we actually
2072 // invoked.
2073 if (auto *PVD = dyn_cast_or_null<ParmVarDecl>(VD)) {
2074 unsigned Idx = PVD->getFunctionScopeIndex();
2075 for (CallStackFrame *F = Info.CurrentCall; F; F = F->Caller) {
2076 if (F->Arguments.CallIndex == Base.getCallIndex() &&
2077 F->Arguments.Version == Base.getVersion() && F->Callee &&
2078 Idx < F->Callee->getNumParams()) {
2079 VD = F->Callee->getParamDecl(Idx);
2080 break;
2081 }
2082 }
2083 }
2084
2085 if (VD)
2086 Info.Note(VD->getLocation(), diag::note_declared_at);
2087 else if (const Expr *E = Base.dyn_cast<const Expr*>())
2088 Info.Note(E->getExprLoc(), diag::note_constexpr_temporary_here);
2089 else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
2090 // FIXME: Produce a note for dangling pointers too.
2091 if (Optional<DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA))
2092 Info.Note((*Alloc)->AllocExpr->getExprLoc(),
2093 diag::note_constexpr_dynamic_alloc_here);
2094 }
2095 // We have no information to show for a typeid(T) object.
2096}
2097
2098enum class CheckEvaluationResultKind {
2099 ConstantExpression,
2100 FullyInitialized,
2101};
2102
2103/// Materialized temporaries that we've already checked to determine if they're
2104/// initializsed by a constant expression.
2105using CheckedTemporaries =
2106 llvm::SmallPtrSet<const MaterializeTemporaryExpr *, 8>;
2107
2108static bool CheckEvaluationResult(CheckEvaluationResultKind CERK,
2109 EvalInfo &Info, SourceLocation DiagLoc,
2110 QualType Type, const APValue &Value,
2111 ConstantExprKind Kind,
2112 SourceLocation SubobjectLoc,
2113 CheckedTemporaries &CheckedTemps);
2114
2115/// Check that this reference or pointer core constant expression is a valid
2116/// value for an address or reference constant expression. Return true if we
2117/// can fold this expression, whether or not it's a constant expression.
2118static bool CheckLValueConstantExpression(EvalInfo &Info, SourceLocation Loc,
2119 QualType Type, const LValue &LVal,
2120 ConstantExprKind Kind,
2121 CheckedTemporaries &CheckedTemps) {
2122 bool IsReferenceType = Type->isReferenceType();
2123
2124 APValue::LValueBase Base = LVal.getLValueBase();
2125 const SubobjectDesignator &Designator = LVal.getLValueDesignator();
2126
2127 const Expr *BaseE = Base.dyn_cast<const Expr *>();
2128 const ValueDecl *BaseVD = Base.dyn_cast<const ValueDecl*>();
2129
2130 // Additional restrictions apply in a template argument. We only enforce the
2131 // C++20 restrictions here; additional syntactic and semantic restrictions
2132 // are applied elsewhere.
2133 if (isTemplateArgument(Kind)) {
2134 int InvalidBaseKind = -1;
2135 StringRef Ident;
2136 if (Base.is<TypeInfoLValue>())
2137 InvalidBaseKind = 0;
2138 else if (isa_and_nonnull<StringLiteral>(BaseE))
2139 InvalidBaseKind = 1;
2140 else if (isa_and_nonnull<MaterializeTemporaryExpr>(BaseE) ||
2141 isa_and_nonnull<LifetimeExtendedTemporaryDecl>(BaseVD))
2142 InvalidBaseKind = 2;
2143 else if (auto *PE = dyn_cast_or_null<PredefinedExpr>(BaseE)) {
2144 InvalidBaseKind = 3;
2145 Ident = PE->getIdentKindName();
2146 }
2147
2148 if (InvalidBaseKind != -1) {
2149 Info.FFDiag(Loc, diag::note_constexpr_invalid_template_arg)
2150 << IsReferenceType << !Designator.Entries.empty() << InvalidBaseKind
2151 << Ident;
2152 return false;
2153 }
2154 }
2155
2156 if (auto *FD = dyn_cast_or_null<FunctionDecl>(BaseVD)) {
2157 if (FD->isConsteval()) {
2158 Info.FFDiag(Loc, diag::note_consteval_address_accessible)
2159 << !Type->isAnyPointerType();
2160 Info.Note(FD->getLocation(), diag::note_declared_at);
2161 return false;
2162 }
2163 }
2164
2165 // Check that the object is a global. Note that the fake 'this' object we
2166 // manufacture when checking potential constant expressions is conservatively
2167 // assumed to be global here.
2168 if (!IsGlobalLValue(Base)) {
2169 if (Info.getLangOpts().CPlusPlus11) {
2170 const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
2171 Info.FFDiag(Loc, diag::note_constexpr_non_global, 1)
2172 << IsReferenceType << !Designator.Entries.empty()
2173 << !!VD << VD;
2174
2175 auto *VarD = dyn_cast_or_null<VarDecl>(VD);
2176 if (VarD && VarD->isConstexpr()) {
2177 // Non-static local constexpr variables have unintuitive semantics:
2178 // constexpr int a = 1;
2179 // constexpr const int *p = &a;
2180 // ... is invalid because the address of 'a' is not constant. Suggest
2181 // adding a 'static' in this case.
2182 Info.Note(VarD->getLocation(), diag::note_constexpr_not_static)
2183 << VarD
2184 << FixItHint::CreateInsertion(VarD->getBeginLoc(), "static ");
2185 } else {
2186 NoteLValueLocation(Info, Base);
2187 }
2188 } else {
2189 Info.FFDiag(Loc);
2190 }
2191 // Don't allow references to temporaries to escape.
2192 return false;
2193 }
2194 assert((Info.checkingPotentialConstantExpression() ||(((Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex
() == 0) && "have call index for global lvalue") ? static_cast
<void> (0) : __assert_fail ("(Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex() == 0) && \"have call index for global lvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2196, __PRETTY_FUNCTION__))
2195 LVal.getLValueCallIndex() == 0) &&(((Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex
() == 0) && "have call index for global lvalue") ? static_cast
<void> (0) : __assert_fail ("(Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex() == 0) && \"have call index for global lvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2196, __PRETTY_FUNCTION__))
2196 "have call index for global lvalue")(((Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex
() == 0) && "have call index for global lvalue") ? static_cast
<void> (0) : __assert_fail ("(Info.checkingPotentialConstantExpression() || LVal.getLValueCallIndex() == 0) && \"have call index for global lvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2196, __PRETTY_FUNCTION__))
;
2197
2198 if (Base.is<DynamicAllocLValue>()) {
2199 Info.FFDiag(Loc, diag::note_constexpr_dynamic_alloc)
2200 << IsReferenceType << !Designator.Entries.empty();
2201 NoteLValueLocation(Info, Base);
2202 return false;
2203 }
2204
2205 if (BaseVD) {
2206 if (const VarDecl *Var = dyn_cast<const VarDecl>(BaseVD)) {
2207 // Check if this is a thread-local variable.
2208 if (Var->getTLSKind())
2209 // FIXME: Diagnostic!
2210 return false;
2211
2212 // A dllimport variable never acts like a constant, unless we're
2213 // evaluating a value for use only in name mangling.
2214 if (!isForManglingOnly(Kind) && Var->hasAttr<DLLImportAttr>())
2215 // FIXME: Diagnostic!
2216 return false;
2217 }
2218 if (const auto *FD = dyn_cast<const FunctionDecl>(BaseVD)) {
2219 // __declspec(dllimport) must be handled very carefully:
2220 // We must never initialize an expression with the thunk in C++.
2221 // Doing otherwise would allow the same id-expression to yield
2222 // different addresses for the same function in different translation
2223 // units. However, this means that we must dynamically initialize the
2224 // expression with the contents of the import address table at runtime.
2225 //
2226 // The C language has no notion of ODR; furthermore, it has no notion of
2227 // dynamic initialization. This means that we are permitted to
2228 // perform initialization with the address of the thunk.
2229 if (Info.getLangOpts().CPlusPlus && !isForManglingOnly(Kind) &&
2230 FD->hasAttr<DLLImportAttr>())
2231 // FIXME: Diagnostic!
2232 return false;
2233 }
2234 } else if (const auto *MTE =
2235 dyn_cast_or_null<MaterializeTemporaryExpr>(BaseE)) {
2236 if (CheckedTemps.insert(MTE).second) {
2237 QualType TempType = getType(Base);
2238 if (TempType.isDestructedType()) {
2239 Info.FFDiag(MTE->getExprLoc(),
2240 diag::note_constexpr_unsupported_temporary_nontrivial_dtor)
2241 << TempType;
2242 return false;
2243 }
2244
2245 APValue *V = MTE->getOrCreateValue(false);
2246 assert(V && "evasluation result refers to uninitialised temporary")((V && "evasluation result refers to uninitialised temporary"
) ? static_cast<void> (0) : __assert_fail ("V && \"evasluation result refers to uninitialised temporary\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2246, __PRETTY_FUNCTION__))
;
2247 if (!CheckEvaluationResult(CheckEvaluationResultKind::ConstantExpression,
2248 Info, MTE->getExprLoc(), TempType, *V,
2249 Kind, SourceLocation(), CheckedTemps))
2250 return false;
2251 }
2252 }
2253
2254 // Allow address constant expressions to be past-the-end pointers. This is
2255 // an extension: the standard requires them to point to an object.
2256 if (!IsReferenceType)
2257 return true;
2258
2259 // A reference constant expression must refer to an object.
2260 if (!Base) {
2261 // FIXME: diagnostic
2262 Info.CCEDiag(Loc);
2263 return true;
2264 }
2265
2266 // Does this refer one past the end of some object?
2267 if (!Designator.Invalid && Designator.isOnePastTheEnd()) {
2268 Info.FFDiag(Loc, diag::note_constexpr_past_end, 1)
2269 << !Designator.Entries.empty() << !!BaseVD << BaseVD;
2270 NoteLValueLocation(Info, Base);
2271 }
2272
2273 return true;
2274}
2275
2276/// Member pointers are constant expressions unless they point to a
2277/// non-virtual dllimport member function.
2278static bool CheckMemberPointerConstantExpression(EvalInfo &Info,
2279 SourceLocation Loc,
2280 QualType Type,
2281 const APValue &Value,
2282 ConstantExprKind Kind) {
2283 const ValueDecl *Member = Value.getMemberPointerDecl();
2284 const auto *FD = dyn_cast_or_null<CXXMethodDecl>(Member);
2285 if (!FD)
2286 return true;
2287 if (FD->isConsteval()) {
2288 Info.FFDiag(Loc, diag::note_consteval_address_accessible) << /*pointer*/ 0;
2289 Info.Note(FD->getLocation(), diag::note_declared_at);
2290 return false;
2291 }
2292 return isForManglingOnly(Kind) || FD->isVirtual() ||
2293 !FD->hasAttr<DLLImportAttr>();
2294}
2295
2296/// Check that this core constant expression is of literal type, and if not,
2297/// produce an appropriate diagnostic.
2298static bool CheckLiteralType(EvalInfo &Info, const Expr *E,
2299 const LValue *This = nullptr) {
2300 if (!E->isRValue() || E->getType()->isLiteralType(Info.Ctx))
2301 return true;
2302
2303 // C++1y: A constant initializer for an object o [...] may also invoke
2304 // constexpr constructors for o and its subobjects even if those objects
2305 // are of non-literal class types.
2306 //
2307 // C++11 missed this detail for aggregates, so classes like this:
2308 // struct foo_t { union { int i; volatile int j; } u; };
2309 // are not (obviously) initializable like so:
2310 // __attribute__((__require_constant_initialization__))
2311 // static const foo_t x = {{0}};
2312 // because "i" is a subobject with non-literal initialization (due to the
2313 // volatile member of the union). See:
2314 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1677
2315 // Therefore, we use the C++1y behavior.
2316 if (This && Info.EvaluatingDecl == This->getLValueBase())
2317 return true;
2318
2319 // Prvalue constant expressions must be of literal types.
2320 if (Info.getLangOpts().CPlusPlus11)
2321 Info.FFDiag(E, diag::note_constexpr_nonliteral)
2322 << E->getType();
2323 else
2324 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2325 return false;
2326}
2327
2328static bool CheckEvaluationResult(CheckEvaluationResultKind CERK,
2329 EvalInfo &Info, SourceLocation DiagLoc,
2330 QualType Type, const APValue &Value,
2331 ConstantExprKind Kind,
2332 SourceLocation SubobjectLoc,
2333 CheckedTemporaries &CheckedTemps) {
2334 if (!Value.hasValue()) {
2335 Info.FFDiag(DiagLoc, diag::note_constexpr_uninitialized)
2336 << true << Type;
2337 if (SubobjectLoc.isValid())
2338 Info.Note(SubobjectLoc, diag::note_constexpr_subobject_declared_here);
2339 return false;
2340 }
2341
2342 // We allow _Atomic(T) to be initialized from anything that T can be
2343 // initialized from.
2344 if (const AtomicType *AT = Type->getAs<AtomicType>())
2345 Type = AT->getValueType();
2346
2347 // Core issue 1454: For a literal constant expression of array or class type,
2348 // each subobject of its value shall have been initialized by a constant
2349 // expression.
2350 if (Value.isArray()) {
2351 QualType EltTy = Type->castAsArrayTypeUnsafe()->getElementType();
2352 for (unsigned I = 0, N = Value.getArrayInitializedElts(); I != N; ++I) {
2353 if (!CheckEvaluationResult(CERK, Info, DiagLoc, EltTy,
2354 Value.getArrayInitializedElt(I), Kind,
2355 SubobjectLoc, CheckedTemps))
2356 return false;
2357 }
2358 if (!Value.hasArrayFiller())
2359 return true;
2360 return CheckEvaluationResult(CERK, Info, DiagLoc, EltTy,
2361 Value.getArrayFiller(), Kind, SubobjectLoc,
2362 CheckedTemps);
2363 }
2364 if (Value.isUnion() && Value.getUnionField()) {
2365 return CheckEvaluationResult(
2366 CERK, Info, DiagLoc, Value.getUnionField()->getType(),
2367 Value.getUnionValue(), Kind, Value.getUnionField()->getLocation(),
2368 CheckedTemps);
2369 }
2370 if (Value.isStruct()) {
2371 RecordDecl *RD = Type->castAs<RecordType>()->getDecl();
2372 if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
2373 unsigned BaseIndex = 0;
2374 for (const CXXBaseSpecifier &BS : CD->bases()) {
2375 if (!CheckEvaluationResult(CERK, Info, DiagLoc, BS.getType(),
2376 Value.getStructBase(BaseIndex), Kind,
2377 BS.getBeginLoc(), CheckedTemps))
2378 return false;
2379 ++BaseIndex;
2380 }
2381 }
2382 for (const auto *I : RD->fields()) {
2383 if (I->isUnnamedBitfield())
2384 continue;
2385
2386 if (!CheckEvaluationResult(CERK, Info, DiagLoc, I->getType(),
2387 Value.getStructField(I->getFieldIndex()),
2388 Kind, I->getLocation(), CheckedTemps))
2389 return false;
2390 }
2391 }
2392
2393 if (Value.isLValue() &&
2394 CERK == CheckEvaluationResultKind::ConstantExpression) {
2395 LValue LVal;
2396 LVal.setFrom(Info.Ctx, Value);
2397 return CheckLValueConstantExpression(Info, DiagLoc, Type, LVal, Kind,
2398 CheckedTemps);
2399 }
2400
2401 if (Value.isMemberPointer() &&
2402 CERK == CheckEvaluationResultKind::ConstantExpression)
2403 return CheckMemberPointerConstantExpression(Info, DiagLoc, Type, Value, Kind);
2404
2405 // Everything else is fine.
2406 return true;
2407}
2408
2409/// Check that this core constant expression value is a valid value for a
2410/// constant expression. If not, report an appropriate diagnostic. Does not
2411/// check that the expression is of literal type.
2412static bool CheckConstantExpression(EvalInfo &Info, SourceLocation DiagLoc,
2413 QualType Type, const APValue &Value,
2414 ConstantExprKind Kind) {
2415 // Nothing to check for a constant expression of type 'cv void'.
2416 if (Type->isVoidType())
2417 return true;
2418
2419 CheckedTemporaries CheckedTemps;
2420 return CheckEvaluationResult(CheckEvaluationResultKind::ConstantExpression,
2421 Info, DiagLoc, Type, Value, Kind,
2422 SourceLocation(), CheckedTemps);
2423}
2424
2425/// Check that this evaluated value is fully-initialized and can be loaded by
2426/// an lvalue-to-rvalue conversion.
2427static bool CheckFullyInitialized(EvalInfo &Info, SourceLocation DiagLoc,
2428 QualType Type, const APValue &Value) {
2429 CheckedTemporaries CheckedTemps;
2430 return CheckEvaluationResult(
2431 CheckEvaluationResultKind::FullyInitialized, Info, DiagLoc, Type, Value,
2432 ConstantExprKind::Normal, SourceLocation(), CheckedTemps);
2433}
2434
2435/// Enforce C++2a [expr.const]/4.17, which disallows new-expressions unless
2436/// "the allocated storage is deallocated within the evaluation".
2437static bool CheckMemoryLeaks(EvalInfo &Info) {
2438 if (!Info.HeapAllocs.empty()) {
2439 // We can still fold to a constant despite a compile-time memory leak,
2440 // so long as the heap allocation isn't referenced in the result (we check
2441 // that in CheckConstantExpression).
2442 Info.CCEDiag(Info.HeapAllocs.begin()->second.AllocExpr,
2443 diag::note_constexpr_memory_leak)
2444 << unsigned(Info.HeapAllocs.size() - 1);
2445 }
2446 return true;
2447}
2448
2449static bool EvalPointerValueAsBool(const APValue &Value, bool &Result) {
2450 // A null base expression indicates a null pointer. These are always
2451 // evaluatable, and they are false unless the offset is zero.
2452 if (!Value.getLValueBase()) {
2453 Result = !Value.getLValueOffset().isZero();
2454 return true;
2455 }
2456
2457 // We have a non-null base. These are generally known to be true, but if it's
2458 // a weak declaration it can be null at runtime.
2459 Result = true;
2460 const ValueDecl *Decl = Value.getLValueBase().dyn_cast<const ValueDecl*>();
2461 return !Decl || !Decl->isWeak();
2462}
2463
2464static bool HandleConversionToBool(const APValue &Val, bool &Result) {
2465 switch (Val.getKind()) {
2466 case APValue::None:
2467 case APValue::Indeterminate:
2468 return false;
2469 case APValue::Int:
2470 Result = Val.getInt().getBoolValue();
2471 return true;
2472 case APValue::FixedPoint:
2473 Result = Val.getFixedPoint().getBoolValue();
2474 return true;
2475 case APValue::Float:
2476 Result = !Val.getFloat().isZero();
2477 return true;
2478 case APValue::ComplexInt:
2479 Result = Val.getComplexIntReal().getBoolValue() ||
2480 Val.getComplexIntImag().getBoolValue();
2481 return true;
2482 case APValue::ComplexFloat:
2483 Result = !Val.getComplexFloatReal().isZero() ||
2484 !Val.getComplexFloatImag().isZero();
2485 return true;
2486 case APValue::LValue:
2487 return EvalPointerValueAsBool(Val, Result);
2488 case APValue::MemberPointer:
2489 Result = Val.getMemberPointerDecl();
2490 return true;
2491 case APValue::Vector:
2492 case APValue::Array:
2493 case APValue::Struct:
2494 case APValue::Union:
2495 case APValue::AddrLabelDiff:
2496 return false;
2497 }
2498
2499 llvm_unreachable("unknown APValue kind")::llvm::llvm_unreachable_internal("unknown APValue kind", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2499)
;
2500}
2501
2502static bool EvaluateAsBooleanCondition(const Expr *E, bool &Result,
2503 EvalInfo &Info) {
2504 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2504, __PRETTY_FUNCTION__))
;
2505 assert(E->isRValue() && "missing lvalue-to-rvalue conv in bool condition")((E->isRValue() && "missing lvalue-to-rvalue conv in bool condition"
) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && \"missing lvalue-to-rvalue conv in bool condition\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2505, __PRETTY_FUNCTION__))
;
2506 APValue Val;
2507 if (!Evaluate(Val, Info, E))
2508 return false;
2509 return HandleConversionToBool(Val, Result);
2510}
2511
2512template<typename T>
2513static bool HandleOverflow(EvalInfo &Info, const Expr *E,
2514 const T &SrcValue, QualType DestType) {
2515 Info.CCEDiag(E, diag::note_constexpr_overflow)
2516 << SrcValue << DestType;
2517 return Info.noteUndefinedBehavior();
2518}
2519
2520static bool HandleFloatToIntCast(EvalInfo &Info, const Expr *E,
2521 QualType SrcType, const APFloat &Value,
2522 QualType DestType, APSInt &Result) {
2523 unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
2524 // Determine whether we are converting to unsigned or signed.
2525 bool DestSigned = DestType->isSignedIntegerOrEnumerationType();
2526
2527 Result = APSInt(DestWidth, !DestSigned);
2528 bool ignored;
2529 if (Value.convertToInteger(Result, llvm::APFloat::rmTowardZero, &ignored)
2530 & APFloat::opInvalidOp)
2531 return HandleOverflow(Info, E, Value, DestType);
2532 return true;
2533}
2534
2535/// Get rounding mode used for evaluation of the specified expression.
2536/// \param[out] DynamicRM Is set to true is the requested rounding mode is
2537/// dynamic.
2538/// If rounding mode is unknown at compile time, still try to evaluate the
2539/// expression. If the result is exact, it does not depend on rounding mode.
2540/// So return "tonearest" mode instead of "dynamic".
2541static llvm::RoundingMode getActiveRoundingMode(EvalInfo &Info, const Expr *E,
2542 bool &DynamicRM) {
2543 llvm::RoundingMode RM =
2544 E->getFPFeaturesInEffect(Info.Ctx.getLangOpts()).getRoundingMode();
2545 DynamicRM = (RM == llvm::RoundingMode::Dynamic);
2546 if (DynamicRM)
2547 RM = llvm::RoundingMode::NearestTiesToEven;
2548 return RM;
2549}
2550
2551/// Check if the given evaluation result is allowed for constant evaluation.
2552static bool checkFloatingPointResult(EvalInfo &Info, const Expr *E,
2553 APFloat::opStatus St) {
2554 // In a constant context, assume that any dynamic rounding mode or FP
2555 // exception state matches the default floating-point environment.
2556 if (Info.InConstantContext)
2557 return true;
2558
2559 FPOptions FPO = E->getFPFeaturesInEffect(Info.Ctx.getLangOpts());
2560 if ((St & APFloat::opInexact) &&
2561 FPO.getRoundingMode() == llvm::RoundingMode::Dynamic) {
2562 // Inexact result means that it depends on rounding mode. If the requested
2563 // mode is dynamic, the evaluation cannot be made in compile time.
2564 Info.FFDiag(E, diag::note_constexpr_dynamic_rounding);
2565 return false;
2566 }
2567
2568 if ((St != APFloat::opOK) &&
2569 (FPO.getRoundingMode() == llvm::RoundingMode::Dynamic ||
2570 FPO.getFPExceptionMode() != LangOptions::FPE_Ignore ||
2571 FPO.getAllowFEnvAccess())) {
2572 Info.FFDiag(E, diag::note_constexpr_float_arithmetic_strict);
2573 return false;
2574 }
2575
2576 if ((St & APFloat::opStatus::opInvalidOp) &&
2577 FPO.getFPExceptionMode() != LangOptions::FPE_Ignore) {
2578 // There is no usefully definable result.
2579 Info.FFDiag(E);
2580 return false;
2581 }
2582
2583 // FIXME: if:
2584 // - evaluation triggered other FP exception, and
2585 // - exception mode is not "ignore", and
2586 // - the expression being evaluated is not a part of global variable
2587 // initializer,
2588 // the evaluation probably need to be rejected.
2589 return true;
2590}
2591
2592static bool HandleFloatToFloatCast(EvalInfo &Info, const Expr *E,
2593 QualType SrcType, QualType DestType,
2594 APFloat &Result) {
2595 assert(isa<CastExpr>(E) || isa<CompoundAssignOperator>(E))((isa<CastExpr>(E) || isa<CompoundAssignOperator>
(E)) ? static_cast<void> (0) : __assert_fail ("isa<CastExpr>(E) || isa<CompoundAssignOperator>(E)"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2595, __PRETTY_FUNCTION__))
;
2596 bool DynamicRM;
2597 llvm::RoundingMode RM = getActiveRoundingMode(Info, E, DynamicRM);
2598 APFloat::opStatus St;
2599 APFloat Value = Result;
2600 bool ignored;
2601 St = Result.convert(Info.Ctx.getFloatTypeSemantics(DestType), RM, &ignored);
2602 return checkFloatingPointResult(Info, E, St);
2603}
2604
2605static APSInt HandleIntToIntCast(EvalInfo &Info, const Expr *E,
2606 QualType DestType, QualType SrcType,
2607 const APSInt &Value) {
2608 unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
2609 // Figure out if this is a truncate, extend or noop cast.
2610 // If the input is signed, do a sign extend, noop, or truncate.
2611 APSInt Result = Value.extOrTrunc(DestWidth);
2612 Result.setIsUnsigned(DestType->isUnsignedIntegerOrEnumerationType());
2613 if (DestType->isBooleanType())
2614 Result = Value.getBoolValue();
2615 return Result;
2616}
2617
2618static bool HandleIntToFloatCast(EvalInfo &Info, const Expr *E,
2619 const FPOptions FPO,
2620 QualType SrcType, const APSInt &Value,
2621 QualType DestType, APFloat &Result) {
2622 Result = APFloat(Info.Ctx.getFloatTypeSemantics(DestType), 1);
2623 APFloat::opStatus St = Result.convertFromAPInt(Value, Value.isSigned(),
2624 APFloat::rmNearestTiesToEven);
2625 if (!Info.InConstantContext && St != llvm::APFloatBase::opOK &&
2626 FPO.isFPConstrained()) {
2627 Info.FFDiag(E, diag::note_constexpr_float_arithmetic_strict);
2628 return false;
2629 }
2630 return true;
2631}
2632
2633static bool truncateBitfieldValue(EvalInfo &Info, const Expr *E,
2634 APValue &Value, const FieldDecl *FD) {
2635 assert(FD->isBitField() && "truncateBitfieldValue on non-bitfield")((FD->isBitField() && "truncateBitfieldValue on non-bitfield"
) ? static_cast<void> (0) : __assert_fail ("FD->isBitField() && \"truncateBitfieldValue on non-bitfield\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2635, __PRETTY_FUNCTION__))
;
2636
2637 if (!Value.isInt()) {
2638 // Trying to store a pointer-cast-to-integer into a bitfield.
2639 // FIXME: In this case, we should provide the diagnostic for casting
2640 // a pointer to an integer.
2641 assert(Value.isLValue() && "integral value neither int nor lvalue?")((Value.isLValue() && "integral value neither int nor lvalue?"
) ? static_cast<void> (0) : __assert_fail ("Value.isLValue() && \"integral value neither int nor lvalue?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2641, __PRETTY_FUNCTION__))
;
2642 Info.FFDiag(E);
2643 return false;
2644 }
2645
2646 APSInt &Int = Value.getInt();
2647 unsigned OldBitWidth = Int.getBitWidth();
2648 unsigned NewBitWidth = FD->getBitWidthValue(Info.Ctx);
2649 if (NewBitWidth < OldBitWidth)
2650 Int = Int.trunc(NewBitWidth).extend(OldBitWidth);
2651 return true;
2652}
2653
2654static bool EvalAndBitcastToAPInt(EvalInfo &Info, const Expr *E,
2655 llvm::APInt &Res) {
2656 APValue SVal;
2657 if (!Evaluate(SVal, Info, E))
2658 return false;
2659 if (SVal.isInt()) {
2660 Res = SVal.getInt();
2661 return true;
2662 }
2663 if (SVal.isFloat()) {
2664 Res = SVal.getFloat().bitcastToAPInt();
2665 return true;
2666 }
2667 if (SVal.isVector()) {
2668 QualType VecTy = E->getType();
2669 unsigned VecSize = Info.Ctx.getTypeSize(VecTy);
2670 QualType EltTy = VecTy->castAs<VectorType>()->getElementType();
2671 unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
2672 bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
2673 Res = llvm::APInt::getNullValue(VecSize);
2674 for (unsigned i = 0; i < SVal.getVectorLength(); i++) {
2675 APValue &Elt = SVal.getVectorElt(i);
2676 llvm::APInt EltAsInt;
2677 if (Elt.isInt()) {
2678 EltAsInt = Elt.getInt();
2679 } else if (Elt.isFloat()) {
2680 EltAsInt = Elt.getFloat().bitcastToAPInt();
2681 } else {
2682 // Don't try to handle vectors of anything other than int or float
2683 // (not sure if it's possible to hit this case).
2684 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2685 return false;
2686 }
2687 unsigned BaseEltSize = EltAsInt.getBitWidth();
2688 if (BigEndian)
2689 Res |= EltAsInt.zextOrTrunc(VecSize).rotr(i*EltSize+BaseEltSize);
2690 else
2691 Res |= EltAsInt.zextOrTrunc(VecSize).rotl(i*EltSize);
2692 }
2693 return true;
2694 }
2695 // Give up if the input isn't an int, float, or vector. For example, we
2696 // reject "(v4i16)(intptr_t)&a".
2697 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2698 return false;
2699}
2700
2701/// Perform the given integer operation, which is known to need at most BitWidth
2702/// bits, and check for overflow in the original type (if that type was not an
2703/// unsigned type).
2704template<typename Operation>
2705static bool CheckedIntArithmetic(EvalInfo &Info, const Expr *E,
2706 const APSInt &LHS, const APSInt &RHS,
2707 unsigned BitWidth, Operation Op,
2708 APSInt &Result) {
2709 if (LHS.isUnsigned()) {
2710 Result = Op(LHS, RHS);
2711 return true;
2712 }
2713
2714 APSInt Value(Op(LHS.extend(BitWidth), RHS.extend(BitWidth)), false);
2715 Result = Value.trunc(LHS.getBitWidth());
2716 if (Result.extend(BitWidth) != Value) {
2717 if (Info.checkingForUndefinedBehavior())
2718 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
2719 diag::warn_integer_constant_overflow)
2720 << Result.toString(10) << E->getType();
2721 return HandleOverflow(Info, E, Value, E->getType());
2722 }
2723 return true;
2724}
2725
2726/// Perform the given binary integer operation.
2727static bool handleIntIntBinOp(EvalInfo &Info, const Expr *E, const APSInt &LHS,
2728 BinaryOperatorKind Opcode, APSInt RHS,
2729 APSInt &Result) {
2730 switch (Opcode) {
2731 default:
2732 Info.FFDiag(E);
2733 return false;
2734 case BO_Mul:
2735 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() * 2,
2736 std::multiplies<APSInt>(), Result);
2737 case BO_Add:
2738 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
2739 std::plus<APSInt>(), Result);
2740 case BO_Sub:
2741 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
2742 std::minus<APSInt>(), Result);
2743 case BO_And: Result = LHS & RHS; return true;
2744 case BO_Xor: Result = LHS ^ RHS; return true;
2745 case BO_Or: Result = LHS | RHS; return true;
2746 case BO_Div:
2747 case BO_Rem:
2748 if (RHS == 0) {
2749 Info.FFDiag(E, diag::note_expr_divide_by_zero);
2750 return false;
2751 }
2752 Result = (Opcode == BO_Rem ? LHS % RHS : LHS / RHS);
2753 // Check for overflow case: INT_MIN / -1 or INT_MIN % -1. APSInt supports
2754 // this operation and gives the two's complement result.
2755 if (RHS.isNegative() && RHS.isAllOnesValue() &&
2756 LHS.isSigned() && LHS.isMinSignedValue())
2757 return HandleOverflow(Info, E, -LHS.extend(LHS.getBitWidth() + 1),
2758 E->getType());
2759 return true;
2760 case BO_Shl: {
2761 if (Info.getLangOpts().OpenCL)
2762 // OpenCL 6.3j: shift values are effectively % word size of LHS.
2763 RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
2764 static_cast<uint64_t>(LHS.getBitWidth() - 1)),
2765 RHS.isUnsigned());
2766 else if (RHS.isSigned() && RHS.isNegative()) {
2767 // During constant-folding, a negative shift is an opposite shift. Such
2768 // a shift is not a constant expression.
2769 Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
2770 RHS = -RHS;
2771 goto shift_right;
2772 }
2773 shift_left:
2774 // C++11 [expr.shift]p1: Shift width must be less than the bit width of
2775 // the shifted type.
2776 unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
2777 if (SA != RHS) {
2778 Info.CCEDiag(E, diag::note_constexpr_large_shift)
2779 << RHS << E->getType() << LHS.getBitWidth();
2780 } else if (LHS.isSigned() && !Info.getLangOpts().CPlusPlus20) {
2781 // C++11 [expr.shift]p2: A signed left shift must have a non-negative
2782 // operand, and must not overflow the corresponding unsigned type.
2783 // C++2a [expr.shift]p2: E1 << E2 is the unique value congruent to
2784 // E1 x 2^E2 module 2^N.
2785 if (LHS.isNegative())
2786 Info.CCEDiag(E, diag::note_constexpr_lshift_of_negative) << LHS;
2787 else if (LHS.countLeadingZeros() < SA)
2788 Info.CCEDiag(E, diag::note_constexpr_lshift_discards);
2789 }
2790 Result = LHS << SA;
2791 return true;
2792 }
2793 case BO_Shr: {
2794 if (Info.getLangOpts().OpenCL)
2795 // OpenCL 6.3j: shift values are effectively % word size of LHS.
2796 RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
2797 static_cast<uint64_t>(LHS.getBitWidth() - 1)),
2798 RHS.isUnsigned());
2799 else if (RHS.isSigned() && RHS.isNegative()) {
2800 // During constant-folding, a negative shift is an opposite shift. Such a
2801 // shift is not a constant expression.
2802 Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
2803 RHS = -RHS;
2804 goto shift_left;
2805 }
2806 shift_right:
2807 // C++11 [expr.shift]p1: Shift width must be less than the bit width of the
2808 // shifted type.
2809 unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
2810 if (SA != RHS)
2811 Info.CCEDiag(E, diag::note_constexpr_large_shift)
2812 << RHS << E->getType() << LHS.getBitWidth();
2813 Result = LHS >> SA;
2814 return true;
2815 }
2816
2817 case BO_LT: Result = LHS < RHS; return true;
2818 case BO_GT: Result = LHS > RHS; return true;
2819 case BO_LE: Result = LHS <= RHS; return true;
2820 case BO_GE: Result = LHS >= RHS; return true;
2821 case BO_EQ: Result = LHS == RHS; return true;
2822 case BO_NE: Result = LHS != RHS; return true;
2823 case BO_Cmp:
2824 llvm_unreachable("BO_Cmp should be handled elsewhere")::llvm::llvm_unreachable_internal("BO_Cmp should be handled elsewhere"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2824)
;
2825 }
2826}
2827
2828/// Perform the given binary floating-point operation, in-place, on LHS.
2829static bool handleFloatFloatBinOp(EvalInfo &Info, const BinaryOperator *E,
2830 APFloat &LHS, BinaryOperatorKind Opcode,
2831 const APFloat &RHS) {
2832 bool DynamicRM;
2833 llvm::RoundingMode RM = getActiveRoundingMode(Info, E, DynamicRM);
2834 APFloat::opStatus St;
2835 switch (Opcode) {
2836 default:
2837 Info.FFDiag(E);
2838 return false;
2839 case BO_Mul:
2840 St = LHS.multiply(RHS, RM);
2841 break;
2842 case BO_Add:
2843 St = LHS.add(RHS, RM);
2844 break;
2845 case BO_Sub:
2846 St = LHS.subtract(RHS, RM);
2847 break;
2848 case BO_Div:
2849 // [expr.mul]p4:
2850 // If the second operand of / or % is zero the behavior is undefined.
2851 if (RHS.isZero())
2852 Info.CCEDiag(E, diag::note_expr_divide_by_zero);
2853 St = LHS.divide(RHS, RM);
2854 break;
2855 }
2856
2857 // [expr.pre]p4:
2858 // If during the evaluation of an expression, the result is not
2859 // mathematically defined [...], the behavior is undefined.
2860 // FIXME: C++ rules require us to not conform to IEEE 754 here.
2861 if (LHS.isNaN()) {
2862 Info.CCEDiag(E, diag::note_constexpr_float_arithmetic) << LHS.isNaN();
2863 return Info.noteUndefinedBehavior();
2864 }
2865
2866 return checkFloatingPointResult(Info, E, St);
2867}
2868
2869static bool handleLogicalOpForVector(const APInt &LHSValue,
2870 BinaryOperatorKind Opcode,
2871 const APInt &RHSValue, APInt &Result) {
2872 bool LHS = (LHSValue != 0);
2873 bool RHS = (RHSValue != 0);
2874
2875 if (Opcode == BO_LAnd)
2876 Result = LHS && RHS;
2877 else
2878 Result = LHS || RHS;
2879 return true;
2880}
2881static bool handleLogicalOpForVector(const APFloat &LHSValue,
2882 BinaryOperatorKind Opcode,
2883 const APFloat &RHSValue, APInt &Result) {
2884 bool LHS = !LHSValue.isZero();
2885 bool RHS = !RHSValue.isZero();
2886
2887 if (Opcode == BO_LAnd)
2888 Result = LHS && RHS;
2889 else
2890 Result = LHS || RHS;
2891 return true;
2892}
2893
2894static bool handleLogicalOpForVector(const APValue &LHSValue,
2895 BinaryOperatorKind Opcode,
2896 const APValue &RHSValue, APInt &Result) {
2897 // The result is always an int type, however operands match the first.
2898 if (LHSValue.getKind() == APValue::Int)
2899 return handleLogicalOpForVector(LHSValue.getInt(), Opcode,
2900 RHSValue.getInt(), Result);
2901 assert(LHSValue.getKind() == APValue::Float && "Should be no other options")((LHSValue.getKind() == APValue::Float && "Should be no other options"
) ? static_cast<void> (0) : __assert_fail ("LHSValue.getKind() == APValue::Float && \"Should be no other options\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2901, __PRETTY_FUNCTION__))
;
2902 return handleLogicalOpForVector(LHSValue.getFloat(), Opcode,
2903 RHSValue.getFloat(), Result);
2904}
2905
2906template <typename APTy>
2907static bool
2908handleCompareOpForVectorHelper(const APTy &LHSValue, BinaryOperatorKind Opcode,
2909 const APTy &RHSValue, APInt &Result) {
2910 switch (Opcode) {
2911 default:
2912 llvm_unreachable("unsupported binary operator")::llvm::llvm_unreachable_internal("unsupported binary operator"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2912)
;
2913 case BO_EQ:
2914 Result = (LHSValue == RHSValue);
2915 break;
2916 case BO_NE:
2917 Result = (LHSValue != RHSValue);
2918 break;
2919 case BO_LT:
2920 Result = (LHSValue < RHSValue);
2921 break;
2922 case BO_GT:
2923 Result = (LHSValue > RHSValue);
2924 break;
2925 case BO_LE:
2926 Result = (LHSValue <= RHSValue);
2927 break;
2928 case BO_GE:
2929 Result = (LHSValue >= RHSValue);
2930 break;
2931 }
2932
2933 return true;
2934}
2935
2936static bool handleCompareOpForVector(const APValue &LHSValue,
2937 BinaryOperatorKind Opcode,
2938 const APValue &RHSValue, APInt &Result) {
2939 // The result is always an int type, however operands match the first.
2940 if (LHSValue.getKind() == APValue::Int)
2941 return handleCompareOpForVectorHelper(LHSValue.getInt(), Opcode,
2942 RHSValue.getInt(), Result);
2943 assert(LHSValue.getKind() == APValue::Float && "Should be no other options")((LHSValue.getKind() == APValue::Float && "Should be no other options"
) ? static_cast<void> (0) : __assert_fail ("LHSValue.getKind() == APValue::Float && \"Should be no other options\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2943, __PRETTY_FUNCTION__))
;
2944 return handleCompareOpForVectorHelper(LHSValue.getFloat(), Opcode,
2945 RHSValue.getFloat(), Result);
2946}
2947
2948// Perform binary operations for vector types, in place on the LHS.
2949static bool handleVectorVectorBinOp(EvalInfo &Info, const BinaryOperator *E,
2950 BinaryOperatorKind Opcode,
2951 APValue &LHSValue,
2952 const APValue &RHSValue) {
2953 assert(Opcode != BO_PtrMemD && Opcode != BO_PtrMemI &&((Opcode != BO_PtrMemD && Opcode != BO_PtrMemI &&
"Operation not supported on vector types") ? static_cast<
void> (0) : __assert_fail ("Opcode != BO_PtrMemD && Opcode != BO_PtrMemI && \"Operation not supported on vector types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2954, __PRETTY_FUNCTION__))
2954 "Operation not supported on vector types")((Opcode != BO_PtrMemD && Opcode != BO_PtrMemI &&
"Operation not supported on vector types") ? static_cast<
void> (0) : __assert_fail ("Opcode != BO_PtrMemD && Opcode != BO_PtrMemI && \"Operation not supported on vector types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2954, __PRETTY_FUNCTION__))
;
2955
2956 const auto *VT = E->getType()->castAs<VectorType>();
2957 unsigned NumElements = VT->getNumElements();
2958 QualType EltTy = VT->getElementType();
2959
2960 // In the cases (typically C as I've observed) where we aren't evaluating
2961 // constexpr but are checking for cases where the LHS isn't yet evaluatable,
2962 // just give up.
2963 if (!LHSValue.isVector()) {
2964 assert(LHSValue.isLValue() &&((LHSValue.isLValue() && "A vector result that isn't a vector OR uncalculated LValue"
) ? static_cast<void> (0) : __assert_fail ("LHSValue.isLValue() && \"A vector result that isn't a vector OR uncalculated LValue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2965, __PRETTY_FUNCTION__))
2965 "A vector result that isn't a vector OR uncalculated LValue")((LHSValue.isLValue() && "A vector result that isn't a vector OR uncalculated LValue"
) ? static_cast<void> (0) : __assert_fail ("LHSValue.isLValue() && \"A vector result that isn't a vector OR uncalculated LValue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2965, __PRETTY_FUNCTION__))
;
2966 Info.FFDiag(E);
2967 return false;
2968 }
2969
2970 assert(LHSValue.getVectorLength() == NumElements &&((LHSValue.getVectorLength() == NumElements && RHSValue
.getVectorLength() == NumElements && "Different vector sizes"
) ? static_cast<void> (0) : __assert_fail ("LHSValue.getVectorLength() == NumElements && RHSValue.getVectorLength() == NumElements && \"Different vector sizes\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2971, __PRETTY_FUNCTION__))
2971 RHSValue.getVectorLength() == NumElements && "Different vector sizes")((LHSValue.getVectorLength() == NumElements && RHSValue
.getVectorLength() == NumElements && "Different vector sizes"
) ? static_cast<void> (0) : __assert_fail ("LHSValue.getVectorLength() == NumElements && RHSValue.getVectorLength() == NumElements && \"Different vector sizes\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 2971, __PRETTY_FUNCTION__))
;
2972
2973 SmallVector<APValue, 4> ResultElements;
2974
2975 for (unsigned EltNum = 0; EltNum < NumElements; ++EltNum) {
2976 APValue LHSElt = LHSValue.getVectorElt(EltNum);
2977 APValue RHSElt = RHSValue.getVectorElt(EltNum);
2978
2979 if (EltTy->isIntegerType()) {
2980 APSInt EltResult{Info.Ctx.getIntWidth(EltTy),
2981 EltTy->isUnsignedIntegerType()};
2982 bool Success = true;
2983
2984 if (BinaryOperator::isLogicalOp(Opcode))
2985 Success = handleLogicalOpForVector(LHSElt, Opcode, RHSElt, EltResult);
2986 else if (BinaryOperator::isComparisonOp(Opcode))
2987 Success = handleCompareOpForVector(LHSElt, Opcode, RHSElt, EltResult);
2988 else
2989 Success = handleIntIntBinOp(Info, E, LHSElt.getInt(), Opcode,
2990 RHSElt.getInt(), EltResult);
2991
2992 if (!Success) {
2993 Info.FFDiag(E);
2994 return false;
2995 }
2996 ResultElements.emplace_back(EltResult);
2997
2998 } else if (EltTy->isFloatingType()) {
2999 assert(LHSElt.getKind() == APValue::Float &&((LHSElt.getKind() == APValue::Float && RHSElt.getKind
() == APValue::Float && "Mismatched LHS/RHS/Result Type"
) ? static_cast<void> (0) : __assert_fail ("LHSElt.getKind() == APValue::Float && RHSElt.getKind() == APValue::Float && \"Mismatched LHS/RHS/Result Type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3001, __PRETTY_FUNCTION__))
3000 RHSElt.getKind() == APValue::Float &&((LHSElt.getKind() == APValue::Float && RHSElt.getKind
() == APValue::Float && "Mismatched LHS/RHS/Result Type"
) ? static_cast<void> (0) : __assert_fail ("LHSElt.getKind() == APValue::Float && RHSElt.getKind() == APValue::Float && \"Mismatched LHS/RHS/Result Type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3001, __PRETTY_FUNCTION__))
3001 "Mismatched LHS/RHS/Result Type")((LHSElt.getKind() == APValue::Float && RHSElt.getKind
() == APValue::Float && "Mismatched LHS/RHS/Result Type"
) ? static_cast<void> (0) : __assert_fail ("LHSElt.getKind() == APValue::Float && RHSElt.getKind() == APValue::Float && \"Mismatched LHS/RHS/Result Type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3001, __PRETTY_FUNCTION__))
;
3002 APFloat LHSFloat = LHSElt.getFloat();
3003
3004 if (!handleFloatFloatBinOp(Info, E, LHSFloat, Opcode,
3005 RHSElt.getFloat())) {
3006 Info.FFDiag(E);
3007 return false;
3008 }
3009
3010 ResultElements.emplace_back(LHSFloat);
3011 }
3012 }
3013
3014 LHSValue = APValue(ResultElements.data(), ResultElements.size());
3015 return true;
3016}
3017
3018/// Cast an lvalue referring to a base subobject to a derived class, by
3019/// truncating the lvalue's path to the given length.
3020static bool CastToDerivedClass(EvalInfo &Info, const Expr *E, LValue &Result,
3021 const RecordDecl *TruncatedType,
3022 unsigned TruncatedElements) {
3023 SubobjectDesignator &D = Result.Designator;
3024
3025 // Check we actually point to a derived class object.
3026 if (TruncatedElements == D.Entries.size())
3027 return true;
3028 assert(TruncatedElements >= D.MostDerivedPathLength &&((TruncatedElements >= D.MostDerivedPathLength && "not casting to a derived class"
) ? static_cast<void> (0) : __assert_fail ("TruncatedElements >= D.MostDerivedPathLength && \"not casting to a derived class\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3029, __PRETTY_FUNCTION__))
3029 "not casting to a derived class")((TruncatedElements >= D.MostDerivedPathLength && "not casting to a derived class"
) ? static_cast<void> (0) : __assert_fail ("TruncatedElements >= D.MostDerivedPathLength && \"not casting to a derived class\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3029, __PRETTY_FUNCTION__))
;
3030 if (!Result.checkSubobject(Info, E, CSK_Derived))
3031 return false;
3032
3033 // Truncate the path to the subobject, and remove any derived-to-base offsets.
3034 const RecordDecl *RD = TruncatedType;
3035 for (unsigned I = TruncatedElements, N = D.Entries.size(); I != N; ++I) {
3036 if (RD->isInvalidDecl()) return false;
3037 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
3038 const CXXRecordDecl *Base = getAsBaseClass(D.Entries[I]);
3039 if (isVirtualBaseClass(D.Entries[I]))
3040 Result.Offset -= Layout.getVBaseClassOffset(Base);
3041 else
3042 Result.Offset -= Layout.getBaseClassOffset(Base);
3043 RD = Base;
3044 }
3045 D.Entries.resize(TruncatedElements);
3046 return true;
3047}
3048
3049static bool HandleLValueDirectBase(EvalInfo &Info, const Expr *E, LValue &Obj,
3050 const CXXRecordDecl *Derived,
3051 const CXXRecordDecl *Base,
3052 const ASTRecordLayout *RL = nullptr) {
3053 if (!RL) {
3054 if (Derived->isInvalidDecl()) return false;
3055 RL = &Info.Ctx.getASTRecordLayout(Derived);
3056 }
3057
3058 Obj.getLValueOffset() += RL->getBaseClassOffset(Base);
3059 Obj.addDecl(Info, E, Base, /*Virtual*/ false);
3060 return true;
3061}
3062
3063static bool HandleLValueBase(EvalInfo &Info, const Expr *E, LValue &Obj,
3064 const CXXRecordDecl *DerivedDecl,
3065 const CXXBaseSpecifier *Base) {
3066 const CXXRecordDecl *BaseDecl = Base->getType()->getAsCXXRecordDecl();
3067
3068 if (!Base->isVirtual())
3069 return HandleLValueDirectBase(Info, E, Obj, DerivedDecl, BaseDecl);
3070
3071 SubobjectDesignator &D = Obj.Designator;
3072 if (D.Invalid)
3073 return false;
3074
3075 // Extract most-derived object and corresponding type.
3076 DerivedDecl = D.MostDerivedType->getAsCXXRecordDecl();
3077 if (!CastToDerivedClass(Info, E, Obj, DerivedDecl, D.MostDerivedPathLength))
3078 return false;
3079
3080 // Find the virtual base class.
3081 if (DerivedDecl->isInvalidDecl()) return false;
3082 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(DerivedDecl);
3083 Obj.getLValueOffset() += Layout.getVBaseClassOffset(BaseDecl);
3084 Obj.addDecl(Info, E, BaseDecl, /*Virtual*/ true);
3085 return true;
3086}
3087
3088static bool HandleLValueBasePath(EvalInfo &Info, const CastExpr *E,
3089 QualType Type, LValue &Result) {
3090 for (CastExpr::path_const_iterator PathI = E->path_begin(),
3091 PathE = E->path_end();
3092 PathI != PathE; ++PathI) {
3093 if (!HandleLValueBase(Info, E, Result, Type->getAsCXXRecordDecl(),
3094 *PathI))
3095 return false;
3096 Type = (*PathI)->getType();
3097 }
3098 return true;
3099}
3100
3101/// Cast an lvalue referring to a derived class to a known base subobject.
3102static bool CastToBaseClass(EvalInfo &Info, const Expr *E, LValue &Result,
3103 const CXXRecordDecl *DerivedRD,
3104 const CXXRecordDecl *BaseRD) {
3105 CXXBasePaths Paths(/*FindAmbiguities=*/false,
3106 /*RecordPaths=*/true, /*DetectVirtual=*/false);
3107 if (!DerivedRD->isDerivedFrom(BaseRD, Paths))
3108 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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3108)
;
3109
3110 for (CXXBasePathElement &Elem : Paths.front())
3111 if (!HandleLValueBase(Info, E, Result, Elem.Class, Elem.Base))
3112 return false;
3113 return true;
3114}
3115
3116/// Update LVal to refer to the given field, which must be a member of the type
3117/// currently described by LVal.
3118static bool HandleLValueMember(EvalInfo &Info, const Expr *E, LValue &LVal,
3119 const FieldDecl *FD,
3120 const ASTRecordLayout *RL = nullptr) {
3121 if (!RL) {
3122 if (FD->getParent()->isInvalidDecl()) return false;
3123 RL = &Info.Ctx.getASTRecordLayout(FD->getParent());
3124 }
3125
3126 unsigned I = FD->getFieldIndex();
3127 LVal.adjustOffset(Info.Ctx.toCharUnitsFromBits(RL->getFieldOffset(I)));
3128 LVal.addDecl(Info, E, FD);
3129 return true;
3130}
3131
3132/// Update LVal to refer to the given indirect field.
3133static bool HandleLValueIndirectMember(EvalInfo &Info, const Expr *E,
3134 LValue &LVal,
3135 const IndirectFieldDecl *IFD) {
3136 for (const auto *C : IFD->chain())
3137 if (!HandleLValueMember(Info, E, LVal, cast<FieldDecl>(C)))
3138 return false;
3139 return true;
3140}
3141
3142/// Get the size of the given type in char units.
3143static bool HandleSizeof(EvalInfo &Info, SourceLocation Loc,
3144 QualType Type, CharUnits &Size) {
3145 // sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc
3146 // extension.
3147 if (Type->isVoidType() || Type->isFunctionType()) {
3148 Size = CharUnits::One();
3149 return true;
3150 }
3151
3152 if (Type->isDependentType()) {
3153 Info.FFDiag(Loc);
3154 return false;
3155 }
3156
3157 if (!Type->isConstantSizeType()) {
3158 // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
3159 // FIXME: Better diagnostic.
3160 Info.FFDiag(Loc);
3161 return false;
3162 }
3163
3164 Size = Info.Ctx.getTypeSizeInChars(Type);
3165 return true;
3166}
3167
3168/// Update a pointer value to model pointer arithmetic.
3169/// \param Info - Information about the ongoing evaluation.
3170/// \param E - The expression being evaluated, for diagnostic purposes.
3171/// \param LVal - The pointer value to be updated.
3172/// \param EltTy - The pointee type represented by LVal.
3173/// \param Adjustment - The adjustment, in objects of type EltTy, to add.
3174static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
3175 LValue &LVal, QualType EltTy,
3176 APSInt Adjustment) {
3177 CharUnits SizeOfPointee;
3178 if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfPointee))
3179 return false;
3180
3181 LVal.adjustOffsetAndIndex(Info, E, Adjustment, SizeOfPointee);
3182 return true;
3183}
3184
3185static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
3186 LValue &LVal, QualType EltTy,
3187 int64_t Adjustment) {
3188 return HandleLValueArrayAdjustment(Info, E, LVal, EltTy,
3189 APSInt::get(Adjustment));
3190}
3191
3192/// Update an lvalue to refer to a component of a complex number.
3193/// \param Info - Information about the ongoing evaluation.
3194/// \param LVal - The lvalue to be updated.
3195/// \param EltTy - The complex number's component type.
3196/// \param Imag - False for the real component, true for the imaginary.
3197static bool HandleLValueComplexElement(EvalInfo &Info, const Expr *E,
3198 LValue &LVal, QualType EltTy,
3199 bool Imag) {
3200 if (Imag) {
3201 CharUnits SizeOfComponent;
3202 if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfComponent))
3203 return false;
3204 LVal.Offset += SizeOfComponent;
3205 }
3206 LVal.addComplex(Info, E, EltTy, Imag);
3207 return true;
3208}
3209
3210/// Try to evaluate the initializer for a variable declaration.
3211///
3212/// \param Info Information about the ongoing evaluation.
3213/// \param E An expression to be used when printing diagnostics.
3214/// \param VD The variable whose initializer should be obtained.
3215/// \param Version The version of the variable within the frame.
3216/// \param Frame The frame in which the variable was created. Must be null
3217/// if this variable is not local to the evaluation.
3218/// \param Result Filled in with a pointer to the value of the variable.
3219static bool evaluateVarDeclInit(EvalInfo &Info, const Expr *E,
3220 const VarDecl *VD, CallStackFrame *Frame,
3221 unsigned Version, APValue *&Result) {
3222 APValue::LValueBase Base(VD, Frame ? Frame->Index : 0, Version);
3223
3224 // If this is a local variable, dig out its value.
3225 if (Frame) {
3226 Result = Frame->getTemporary(VD, Version);
3227 if (Result)
3228 return true;
3229
3230 if (!isa<ParmVarDecl>(VD)) {
3231 // Assume variables referenced within a lambda's call operator that were
3232 // not declared within the call operator are captures and during checking
3233 // of a potential constant expression, assume they are unknown constant
3234 // expressions.
3235 assert(isLambdaCallOperator(Frame->Callee) &&((isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext
() != Frame->Callee || VD->isInitCapture()) && "missing value for local variable"
) ? static_cast<void> (0) : __assert_fail ("isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) && \"missing value for local variable\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3237, __PRETTY_FUNCTION__))
3236 (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) &&((isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext
() != Frame->Callee || VD->isInitCapture()) && "missing value for local variable"
) ? static_cast<void> (0) : __assert_fail ("isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) && \"missing value for local variable\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3237, __PRETTY_FUNCTION__))
3237 "missing value for local variable")((isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext
() != Frame->Callee || VD->isInitCapture()) && "missing value for local variable"
) ? static_cast<void> (0) : __assert_fail ("isLambdaCallOperator(Frame->Callee) && (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) && \"missing value for local variable\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3237, __PRETTY_FUNCTION__))
;
3238 if (Info.checkingPotentialConstantExpression())
3239 return false;
3240 // FIXME: This diagnostic is bogus; we do support captures. Is this code
3241 // still reachable at all?
3242 Info.FFDiag(E->getBeginLoc(),
3243 diag::note_unimplemented_constexpr_lambda_feature_ast)
3244 << "captures not currently allowed";
3245 return false;
3246 }
3247 }
3248
3249 // If we're currently evaluating the initializer of this declaration, use that
3250 // in-flight value.
3251 if (Info.EvaluatingDecl == Base) {
3252 Result = Info.EvaluatingDeclValue;
3253 return true;
3254 }
3255
3256 if (isa<ParmVarDecl>(VD)) {
3257 // Assume parameters of a potential constant expression are usable in
3258 // constant expressions.
3259 if (!Info.checkingPotentialConstantExpression() ||
3260 !Info.CurrentCall->Callee ||
3261 !Info.CurrentCall->Callee->Equals(VD->getDeclContext())) {
3262 if (Info.getLangOpts().CPlusPlus11) {
3263 Info.FFDiag(E, diag::note_constexpr_function_param_value_unknown)
3264 << VD;
3265 NoteLValueLocation(Info, Base);
3266 } else {
3267 Info.FFDiag(E);
3268 }
3269 }
3270 return false;
3271 }
3272
3273 // Dig out the initializer, and use the declaration which it's attached to.
3274 // FIXME: We should eventually check whether the variable has a reachable
3275 // initializing declaration.
3276 const Expr *Init = VD->getAnyInitializer(VD);
3277 if (!Init) {
3278 // Don't diagnose during potential constant expression checking; an
3279 // initializer might be added later.
3280 if (!Info.checkingPotentialConstantExpression()) {
3281 Info.FFDiag(E, diag::note_constexpr_var_init_unknown, 1)
3282 << VD;
3283 NoteLValueLocation(Info, Base);
3284 }
3285 return false;
3286 }
3287
3288 if (Init->isValueDependent()) {
3289 // The DeclRefExpr is not value-dependent, but the variable it refers to
3290 // has a value-dependent initializer. This should only happen in
3291 // constant-folding cases, where the variable is not actually of a suitable
3292 // type for use in a constant expression (otherwise the DeclRefExpr would
3293 // have been value-dependent too), so diagnose that.
3294 assert(!VD->mightBeUsableInConstantExpressions(Info.Ctx))((!VD->mightBeUsableInConstantExpressions(Info.Ctx)) ? static_cast
<void> (0) : __assert_fail ("!VD->mightBeUsableInConstantExpressions(Info.Ctx)"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3294, __PRETTY_FUNCTION__))
;
3295 if (!Info.checkingPotentialConstantExpression()) {
3296 Info.FFDiag(E, Info.getLangOpts().CPlusPlus11
3297 ? diag::note_constexpr_ltor_non_constexpr
3298 : diag::note_constexpr_ltor_non_integral, 1)
3299 << VD << VD->getType();
3300 NoteLValueLocation(Info, Base);
3301 }
3302 return false;
3303 }
3304
3305 // Check that we can fold the initializer. In C++, we will have already done
3306 // this in the cases where it matters for conformance.
3307 if (!VD->evaluateValue()) {
3308 Info.FFDiag(E, diag::note_constexpr_var_init_non_constant, 1) << VD;
3309 NoteLValueLocation(Info, Base);
3310 return false;
3311 }
3312
3313 // Check that the variable is actually usable in constant expressions. For a
3314 // const integral variable or a reference, we might have a non-constant
3315 // initializer that we can nonetheless evaluate the initializer for. Such
3316 // variables are not usable in constant expressions. In C++98, the
3317 // initializer also syntactically needs to be an ICE.
3318 //
3319 // FIXME: We don't diagnose cases that aren't potentially usable in constant
3320 // expressions here; doing so would regress diagnostics for things like
3321 // reading from a volatile constexpr variable.
3322 if ((Info.getLangOpts().CPlusPlus && !VD->hasConstantInitialization() &&
3323 VD->mightBeUsableInConstantExpressions(Info.Ctx)) ||
3324 ((Info.getLangOpts().CPlusPlus || Info.getLangOpts().OpenCL) &&
3325 !Info.getLangOpts().CPlusPlus11 && !VD->hasICEInitializer(Info.Ctx))) {
3326 Info.CCEDiag(E, diag::note_constexpr_var_init_non_constant, 1) << VD;
3327 NoteLValueLocation(Info, Base);
3328 }
3329
3330 // Never use the initializer of a weak variable, not even for constant
3331 // folding. We can't be sure that this is the definition that will be used.
3332 if (VD->isWeak()) {
3333 Info.FFDiag(E, diag::note_constexpr_var_init_weak) << VD;
3334 NoteLValueLocation(Info, Base);
3335 return false;
3336 }
3337
3338 Result = VD->getEvaluatedValue();
3339 return true;
3340}
3341
3342/// Get the base index of the given base class within an APValue representing
3343/// the given derived class.
3344static unsigned getBaseIndex(const CXXRecordDecl *Derived,
3345 const CXXRecordDecl *Base) {
3346 Base = Base->getCanonicalDecl();
3347 unsigned Index = 0;
3348 for (CXXRecordDecl::base_class_const_iterator I = Derived->bases_begin(),
3349 E = Derived->bases_end(); I != E; ++I, ++Index) {
3350 if (I->getType()->getAsCXXRecordDecl()->getCanonicalDecl() == Base)
3351 return Index;
3352 }
3353
3354 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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3354)
;
3355}
3356
3357/// Extract the value of a character from a string literal.
3358static APSInt extractStringLiteralCharacter(EvalInfo &Info, const Expr *Lit,
3359 uint64_t Index) {
3360 assert(!isa<SourceLocExpr>(Lit) &&((!isa<SourceLocExpr>(Lit) && "SourceLocExpr should have already been converted to a StringLiteral"
) ? static_cast<void> (0) : __assert_fail ("!isa<SourceLocExpr>(Lit) && \"SourceLocExpr should have already been converted to a StringLiteral\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3361, __PRETTY_FUNCTION__))
3361 "SourceLocExpr should have already been converted to a StringLiteral")((!isa<SourceLocExpr>(Lit) && "SourceLocExpr should have already been converted to a StringLiteral"
) ? static_cast<void> (0) : __assert_fail ("!isa<SourceLocExpr>(Lit) && \"SourceLocExpr should have already been converted to a StringLiteral\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3361, __PRETTY_FUNCTION__))
;
3362
3363 // FIXME: Support MakeStringConstant
3364 if (const auto *ObjCEnc = dyn_cast<ObjCEncodeExpr>(Lit)) {
3365 std::string Str;
3366 Info.Ctx.getObjCEncodingForType(ObjCEnc->getEncodedType(), Str);
3367 assert(Index <= Str.size() && "Index too large")((Index <= Str.size() && "Index too large") ? static_cast
<void> (0) : __assert_fail ("Index <= Str.size() && \"Index too large\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3367, __PRETTY_FUNCTION__))
;
3368 return APSInt::getUnsigned(Str.c_str()[Index]);
3369 }
3370
3371 if (auto PE = dyn_cast<PredefinedExpr>(Lit))
3372 Lit = PE->getFunctionName();
3373 const StringLiteral *S = cast<StringLiteral>(Lit);
3374 const ConstantArrayType *CAT =
3375 Info.Ctx.getAsConstantArrayType(S->getType());
3376 assert(CAT && "string literal isn't an array")((CAT && "string literal isn't an array") ? static_cast
<void> (0) : __assert_fail ("CAT && \"string literal isn't an array\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3376, __PRETTY_FUNCTION__))
;
3377 QualType CharType = CAT->getElementType();
3378 assert(CharType->isIntegerType() && "unexpected character type")((CharType->isIntegerType() && "unexpected character type"
) ? static_cast<void> (0) : __assert_fail ("CharType->isIntegerType() && \"unexpected character type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3378, __PRETTY_FUNCTION__))
;
3379
3380 APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
3381 CharType->isUnsignedIntegerType());
3382 if (Index < S->getLength())
3383 Value = S->getCodeUnit(Index);
3384 return Value;
3385}
3386
3387// Expand a string literal into an array of characters.
3388//
3389// FIXME: This is inefficient; we should probably introduce something similar
3390// to the LLVM ConstantDataArray to make this cheaper.
3391static void expandStringLiteral(EvalInfo &Info, const StringLiteral *S,
3392 APValue &Result,
3393 QualType AllocType = QualType()) {
3394 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(
3395 AllocType.isNull() ? S->getType() : AllocType);
3396 assert(CAT && "string literal isn't an array")((CAT && "string literal isn't an array") ? static_cast
<void> (0) : __assert_fail ("CAT && \"string literal isn't an array\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3396, __PRETTY_FUNCTION__))
;
3397 QualType CharType = CAT->getElementType();
3398 assert(CharType->isIntegerType() && "unexpected character type")((CharType->isIntegerType() && "unexpected character type"
) ? static_cast<void> (0) : __assert_fail ("CharType->isIntegerType() && \"unexpected character type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3398, __PRETTY_FUNCTION__))
;
3399
3400 unsigned Elts = CAT->getSize().getZExtValue();
3401 Result = APValue(APValue::UninitArray(),
3402 std::min(S->getLength(), Elts), Elts);
3403 APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
3404 CharType->isUnsignedIntegerType());
3405 if (Result.hasArrayFiller())
3406 Result.getArrayFiller() = APValue(Value);
3407 for (unsigned I = 0, N = Result.getArrayInitializedElts(); I != N; ++I) {
3408 Value = S->getCodeUnit(I);
3409 Result.getArrayInitializedElt(I) = APValue(Value);
3410 }
3411}
3412
3413// Expand an array so that it has more than Index filled elements.
3414static void expandArray(APValue &Array, unsigned Index) {
3415 unsigned Size = Array.getArraySize();
3416 assert(Index < Size)((Index < Size) ? static_cast<void> (0) : __assert_fail
("Index < Size", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3416, __PRETTY_FUNCTION__))
;
3417
3418 // Always at least double the number of elements for which we store a value.
3419 unsigned OldElts = Array.getArrayInitializedElts();
3420 unsigned NewElts = std::max(Index+1, OldElts * 2);
3421 NewElts = std::min(Size, std::max(NewElts, 8u));
3422
3423 // Copy the data across.
3424 APValue NewValue(APValue::UninitArray(), NewElts, Size);
3425 for (unsigned I = 0; I != OldElts; ++I)
3426 NewValue.getArrayInitializedElt(I).swap(Array.getArrayInitializedElt(I));
3427 for (unsigned I = OldElts; I != NewElts; ++I)
3428 NewValue.getArrayInitializedElt(I) = Array.getArrayFiller();
3429 if (NewValue.hasArrayFiller())
3430 NewValue.getArrayFiller() = Array.getArrayFiller();
3431 Array.swap(NewValue);
3432}
3433
3434/// Determine whether a type would actually be read by an lvalue-to-rvalue
3435/// conversion. If it's of class type, we may assume that the copy operation
3436/// is trivial. Note that this is never true for a union type with fields
3437/// (because the copy always "reads" the active member) and always true for
3438/// a non-class type.
3439static bool isReadByLvalueToRvalueConversion(const CXXRecordDecl *RD);
3440static bool isReadByLvalueToRvalueConversion(QualType T) {
3441 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
3442 return !RD || isReadByLvalueToRvalueConversion(RD);
3443}
3444static bool isReadByLvalueToRvalueConversion(const CXXRecordDecl *RD) {
3445 // FIXME: A trivial copy of a union copies the object representation, even if
3446 // the union is empty.
3447 if (RD->isUnion())
3448 return !RD->field_empty();
3449 if (RD->isEmpty())
3450 return false;
3451
3452 for (auto *Field : RD->fields())
3453 if (!Field->isUnnamedBitfield() &&
3454 isReadByLvalueToRvalueConversion(Field->getType()))
3455 return true;
3456
3457 for (auto &BaseSpec : RD->bases())
3458 if (isReadByLvalueToRvalueConversion(BaseSpec.getType()))
3459 return true;
3460
3461 return false;
3462}
3463
3464/// Diagnose an attempt to read from any unreadable field within the specified
3465/// type, which might be a class type.
3466static bool diagnoseMutableFields(EvalInfo &Info, const Expr *E, AccessKinds AK,
3467 QualType T) {
3468 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
3469 if (!RD)
3470 return false;
3471
3472 if (!RD->hasMutableFields())
3473 return false;
3474
3475 for (auto *Field : RD->fields()) {
3476 // If we're actually going to read this field in some way, then it can't
3477 // be mutable. If we're in a union, then assigning to a mutable field
3478 // (even an empty one) can change the active member, so that's not OK.
3479 // FIXME: Add core issue number for the union case.
3480 if (Field->isMutable() &&
3481 (RD->isUnion() || isReadByLvalueToRvalueConversion(Field->getType()))) {
3482 Info.FFDiag(E, diag::note_constexpr_access_mutable, 1) << AK << Field;
3483 Info.Note(Field->getLocation(), diag::note_declared_at);
3484 return true;
3485 }
3486
3487 if (diagnoseMutableFields(Info, E, AK, Field->getType()))
3488 return true;
3489 }
3490
3491 for (auto &BaseSpec : RD->bases())
3492 if (diagnoseMutableFields(Info, E, AK, BaseSpec.getType()))
3493 return true;
3494
3495 // All mutable fields were empty, and thus not actually read.
3496 return false;
3497}
3498
3499static bool lifetimeStartedInEvaluation(EvalInfo &Info,
3500 APValue::LValueBase Base,
3501 bool MutableSubobject = false) {
3502 // A temporary or transient heap allocation we created.
3503 if (Base.getCallIndex() || Base.is<DynamicAllocLValue>())
3504 return true;
3505
3506 switch (Info.IsEvaluatingDecl) {
3507 case EvalInfo::EvaluatingDeclKind::None:
3508 return false;
3509
3510 case EvalInfo::EvaluatingDeclKind::Ctor:
3511 // The variable whose initializer we're evaluating.
3512 if (Info.EvaluatingDecl == Base)
3513 return true;
3514
3515 // A temporary lifetime-extended by the variable whose initializer we're
3516 // evaluating.
3517 if (auto *BaseE = Base.dyn_cast<const Expr *>())
3518 if (auto *BaseMTE = dyn_cast<MaterializeTemporaryExpr>(BaseE))
3519 return Info.EvaluatingDecl == BaseMTE->getExtendingDecl();
3520 return false;
3521
3522 case EvalInfo::EvaluatingDeclKind::Dtor:
3523 // C++2a [expr.const]p6:
3524 // [during constant destruction] the lifetime of a and its non-mutable
3525 // subobjects (but not its mutable subobjects) [are] considered to start
3526 // within e.
3527 if (MutableSubobject || Base != Info.EvaluatingDecl)
3528 return false;
3529 // FIXME: We can meaningfully extend this to cover non-const objects, but
3530 // we will need special handling: we should be able to access only
3531 // subobjects of such objects that are themselves declared const.
3532 QualType T = getType(Base);
3533 return T.isConstQualified() || T->isReferenceType();
3534 }
3535
3536 llvm_unreachable("unknown evaluating decl kind")::llvm::llvm_unreachable_internal("unknown evaluating decl kind"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3536)
;
3537}
3538
3539namespace {
3540/// A handle to a complete object (an object that is not a subobject of
3541/// another object).
3542struct CompleteObject {
3543 /// The identity of the object.
3544 APValue::LValueBase Base;
3545 /// The value of the complete object.
3546 APValue *Value;
3547 /// The type of the complete object.
3548 QualType Type;
3549
3550 CompleteObject() : Value(nullptr) {}
3551 CompleteObject(APValue::LValueBase Base, APValue *Value, QualType Type)
3552 : Base(Base), Value(Value), Type(Type) {}
3553
3554 bool mayAccessMutableMembers(EvalInfo &Info, AccessKinds AK) const {
3555 // If this isn't a "real" access (eg, if it's just accessing the type
3556 // info), allow it. We assume the type doesn't change dynamically for
3557 // subobjects of constexpr objects (even though we'd hit UB here if it
3558 // did). FIXME: Is this right?
3559 if (!isAnyAccess(AK))
3560 return true;
3561
3562 // In C++14 onwards, it is permitted to read a mutable member whose
3563 // lifetime began within the evaluation.
3564 // FIXME: Should we also allow this in C++11?
3565 if (!Info.getLangOpts().CPlusPlus14)
3566 return false;
3567 return lifetimeStartedInEvaluation(Info, Base, /*MutableSubobject*/true);
3568 }
3569
3570 explicit operator bool() const { return !Type.isNull(); }
3571};
3572} // end anonymous namespace
3573
3574static QualType getSubobjectType(QualType ObjType, QualType SubobjType,
3575 bool IsMutable = false) {
3576 // C++ [basic.type.qualifier]p1:
3577 // - A const object is an object of type const T or a non-mutable subobject
3578 // of a const object.
3579 if (ObjType.isConstQualified() && !IsMutable)
3580 SubobjType.addConst();
3581 // - A volatile object is an object of type const T or a subobject of a
3582 // volatile object.
3583 if (ObjType.isVolatileQualified())
3584 SubobjType.addVolatile();
3585 return SubobjType;
3586}
3587
3588/// Find the designated sub-object of an rvalue.
3589template<typename SubobjectHandler>
3590typename SubobjectHandler::result_type
3591findSubobject(EvalInfo &Info, const Expr *E, const CompleteObject &Obj,
3592 const SubobjectDesignator &Sub, SubobjectHandler &handler) {
3593 if (Sub.Invalid)
3594 // A diagnostic will have already been produced.
3595 return handler.failed();
3596 if (Sub.isOnePastTheEnd() || Sub.isMostDerivedAnUnsizedArray()) {
3597 if (Info.getLangOpts().CPlusPlus11)
3598 Info.FFDiag(E, Sub.isOnePastTheEnd()
3599 ? diag::note_constexpr_access_past_end
3600 : diag::note_constexpr_access_unsized_array)
3601 << handler.AccessKind;
3602 else
3603 Info.FFDiag(E);
3604 return handler.failed();
3605 }
3606
3607 APValue *O = Obj.Value;
3608 QualType ObjType = Obj.Type;
3609 const FieldDecl *LastField = nullptr;
3610 const FieldDecl *VolatileField = nullptr;
3611
3612 // Walk the designator's path to find the subobject.
3613 for (unsigned I = 0, N = Sub.Entries.size(); /**/; ++I) {
3614 // Reading an indeterminate value is undefined, but assigning over one is OK.
3615 if ((O->isAbsent() && !(handler.AccessKind == AK_Construct && I == N)) ||
3616 (O->isIndeterminate() &&
3617 !isValidIndeterminateAccess(handler.AccessKind))) {
3618 if (!Info.checkingPotentialConstantExpression())
3619 Info.FFDiag(E, diag::note_constexpr_access_uninit)
3620 << handler.AccessKind << O->isIndeterminate();
3621 return handler.failed();
3622 }
3623
3624 // C++ [class.ctor]p5, C++ [class.dtor]p5:
3625 // const and volatile semantics are not applied on an object under
3626 // {con,de}struction.
3627 if ((ObjType.isConstQualified() || ObjType.isVolatileQualified()) &&
3628 ObjType->isRecordType() &&
3629 Info.isEvaluatingCtorDtor(
3630 Obj.Base, llvm::makeArrayRef(Sub.Entries.begin(),
3631 Sub.Entries.begin() + I)) !=
3632 ConstructionPhase::None) {
3633 ObjType = Info.Ctx.getCanonicalType(ObjType);
3634 ObjType.removeLocalConst();
3635 ObjType.removeLocalVolatile();
3636 }
3637
3638 // If this is our last pass, check that the final object type is OK.
3639 if (I == N || (I == N - 1 && ObjType->isAnyComplexType())) {
3640 // Accesses to volatile objects are prohibited.
3641 if (ObjType.isVolatileQualified() && isFormalAccess(handler.AccessKind)) {
3642 if (Info.getLangOpts().CPlusPlus) {
3643 int DiagKind;
3644 SourceLocation Loc;
3645 const NamedDecl *Decl = nullptr;
3646 if (VolatileField) {
3647 DiagKind = 2;
3648 Loc = VolatileField->getLocation();
3649 Decl = VolatileField;
3650 } else if (auto *VD = Obj.Base.dyn_cast<const ValueDecl*>()) {
3651 DiagKind = 1;
3652 Loc = VD->getLocation();
3653 Decl = VD;
3654 } else {
3655 DiagKind = 0;
3656 if (auto *E = Obj.Base.dyn_cast<const Expr *>())
3657 Loc = E->getExprLoc();
3658 }
3659 Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
3660 << handler.AccessKind << DiagKind << Decl;
3661 Info.Note(Loc, diag::note_constexpr_volatile_here) << DiagKind;
3662 } else {
3663 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
3664 }
3665 return handler.failed();
3666 }
3667
3668 // If we are reading an object of class type, there may still be more
3669 // things we need to check: if there are any mutable subobjects, we
3670 // cannot perform this read. (This only happens when performing a trivial
3671 // copy or assignment.)
3672 if (ObjType->isRecordType() &&
3673 !Obj.mayAccessMutableMembers(Info, handler.AccessKind) &&
3674 diagnoseMutableFields(Info, E, handler.AccessKind, ObjType))
3675 return handler.failed();
3676 }
3677
3678 if (I == N) {
3679 if (!handler.found(*O, ObjType))
3680 return false;
3681
3682 // If we modified a bit-field, truncate it to the right width.
3683 if (isModification(handler.AccessKind) &&
3684 LastField && LastField->isBitField() &&
3685 !truncateBitfieldValue(Info, E, *O, LastField))
3686 return false;
3687
3688 return true;
3689 }
3690
3691 LastField = nullptr;
3692 if (ObjType->isArrayType()) {
3693 // Next subobject is an array element.
3694 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(ObjType);
3695 assert(CAT && "vla in literal type?")((CAT && "vla in literal type?") ? static_cast<void
> (0) : __assert_fail ("CAT && \"vla in literal type?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3695, __PRETTY_FUNCTION__))
;
3696 uint64_t Index = Sub.Entries[I].getAsArrayIndex();
3697 if (CAT->getSize().ule(Index)) {
3698 // Note, it should not be possible to form a pointer with a valid
3699 // designator which points more than one past the end of the array.
3700 if (Info.getLangOpts().CPlusPlus11)
3701 Info.FFDiag(E, diag::note_constexpr_access_past_end)
3702 << handler.AccessKind;
3703 else
3704 Info.FFDiag(E);
3705 return handler.failed();
3706 }
3707
3708 ObjType = CAT->getElementType();
3709
3710 if (O->getArrayInitializedElts() > Index)
3711 O = &O->getArrayInitializedElt(Index);
3712 else if (!isRead(handler.AccessKind)) {
3713 expandArray(*O, Index);
3714 O = &O->getArrayInitializedElt(Index);
3715 } else
3716 O = &O->getArrayFiller();
3717 } else if (ObjType->isAnyComplexType()) {
3718 // Next subobject is a complex number.
3719 uint64_t Index = Sub.Entries[I].getAsArrayIndex();
3720 if (Index > 1) {
3721 if (Info.getLangOpts().CPlusPlus11)
3722 Info.FFDiag(E, diag::note_constexpr_access_past_end)
3723 << handler.AccessKind;
3724 else
3725 Info.FFDiag(E);
3726 return handler.failed();
3727 }
3728
3729 ObjType = getSubobjectType(
3730 ObjType, ObjType->castAs<ComplexType>()->getElementType());
3731
3732 assert(I == N - 1 && "extracting subobject of scalar?")((I == N - 1 && "extracting subobject of scalar?") ? static_cast
<void> (0) : __assert_fail ("I == N - 1 && \"extracting subobject of scalar?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3732, __PRETTY_FUNCTION__))
;
3733 if (O->isComplexInt()) {
3734 return handler.found(Index ? O->getComplexIntImag()
3735 : O->getComplexIntReal(), ObjType);
3736 } else {
3737 assert(O->isComplexFloat())((O->isComplexFloat()) ? static_cast<void> (0) : __assert_fail
("O->isComplexFloat()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3737, __PRETTY_FUNCTION__))
;
3738 return handler.found(Index ? O->getComplexFloatImag()
3739 : O->getComplexFloatReal(), ObjType);
3740 }
3741 } else if (const FieldDecl *Field = getAsField(Sub.Entries[I])) {
3742 if (Field->isMutable() &&
3743 !Obj.mayAccessMutableMembers(Info, handler.AccessKind)) {
3744 Info.FFDiag(E, diag::note_constexpr_access_mutable, 1)
3745 << handler.AccessKind << Field;
3746 Info.Note(Field->getLocation(), diag::note_declared_at);
3747 return handler.failed();
3748 }
3749
3750 // Next subobject is a class, struct or union field.
3751 RecordDecl *RD = ObjType->castAs<RecordType>()->getDecl();
3752 if (RD->isUnion()) {
3753 const FieldDecl *UnionField = O->getUnionField();
3754 if (!UnionField ||
3755 UnionField->getCanonicalDecl() != Field->getCanonicalDecl()) {
3756 if (I == N - 1 && handler.AccessKind == AK_Construct) {
3757 // Placement new onto an inactive union member makes it active.
3758 O->setUnion(Field, APValue());
3759 } else {
3760 // FIXME: If O->getUnionValue() is absent, report that there's no
3761 // active union member rather than reporting the prior active union
3762 // member. We'll need to fix nullptr_t to not use APValue() as its
3763 // representation first.
3764 Info.FFDiag(E, diag::note_constexpr_access_inactive_union_member)
3765 << handler.AccessKind << Field << !UnionField << UnionField;
3766 return handler.failed();
3767 }
3768 }
3769 O = &O->getUnionValue();
3770 } else
3771 O = &O->getStructField(Field->getFieldIndex());
3772
3773 ObjType = getSubobjectType(ObjType, Field->getType(), Field->isMutable());
3774 LastField = Field;
3775 if (Field->getType().isVolatileQualified())
3776 VolatileField = Field;
3777 } else {
3778 // Next subobject is a base class.
3779 const CXXRecordDecl *Derived = ObjType->getAsCXXRecordDecl();
3780 const CXXRecordDecl *Base = getAsBaseClass(Sub.Entries[I]);
3781 O = &O->getStructBase(getBaseIndex(Derived, Base));
3782
3783 ObjType = getSubobjectType(ObjType, Info.Ctx.getRecordType(Base));
3784 }
3785 }
3786}
3787
3788namespace {
3789struct ExtractSubobjectHandler {
3790 EvalInfo &Info;
3791 const Expr *E;
3792 APValue &Result;
3793 const AccessKinds AccessKind;
3794
3795 typedef bool result_type;
3796 bool failed() { return false; }
3797 bool found(APValue &Subobj, QualType SubobjType) {
3798 Result = Subobj;
3799 if (AccessKind == AK_ReadObjectRepresentation)
3800 return true;
3801 return CheckFullyInitialized(Info, E->getExprLoc(), SubobjType, Result);
3802 }
3803 bool found(APSInt &Value, QualType SubobjType) {
3804 Result = APValue(Value);
3805 return true;
3806 }
3807 bool found(APFloat &Value, QualType SubobjType) {
3808 Result = APValue(Value);
3809 return true;
3810 }
3811};
3812} // end anonymous namespace
3813
3814/// Extract the designated sub-object of an rvalue.
3815static bool extractSubobject(EvalInfo &Info, const Expr *E,
3816 const CompleteObject &Obj,
3817 const SubobjectDesignator &Sub, APValue &Result,
3818 AccessKinds AK = AK_Read) {
3819 assert(AK == AK_Read || AK == AK_ReadObjectRepresentation)((AK == AK_Read || AK == AK_ReadObjectRepresentation) ? static_cast
<void> (0) : __assert_fail ("AK == AK_Read || AK == AK_ReadObjectRepresentation"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 3819, __PRETTY_FUNCTION__))
;
3820 ExtractSubobjectHandler Handler = {Info, E, Result, AK};
3821 return findSubobject(Info, E, Obj, Sub, Handler);
3822}
3823
3824namespace {
3825struct ModifySubobjectHandler {
3826 EvalInfo &Info;
3827 APValue &NewVal;
3828 const Expr *E;
3829
3830 typedef bool result_type;
3831 static const AccessKinds AccessKind = AK_Assign;
3832
3833 bool checkConst(QualType QT) {
3834 // Assigning to a const object has undefined behavior.
3835 if (QT.isConstQualified()) {
3836 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
3837 return false;
3838 }
3839 return true;
3840 }
3841
3842 bool failed() { return false; }
3843 bool found(APValue &Subobj, QualType SubobjType) {
3844 if (!checkConst(SubobjType))
3845 return false;
3846 // We've been given ownership of NewVal, so just swap it in.
3847 Subobj.swap(NewVal);
3848 return true;
3849 }
3850 bool found(APSInt &Value, QualType SubobjType) {
3851 if (!checkConst(SubobjType))
3852 return false;
3853 if (!NewVal.isInt()) {
3854 // Maybe trying to write a cast pointer value into a complex?
3855 Info.FFDiag(E);
3856 return false;
3857 }
3858 Value = NewVal.getInt();
3859 return true;
3860 }
3861 bool found(APFloat &Value, QualType SubobjType) {
3862 if (!checkConst(SubobjType))
3863 return false;
3864 Value = NewVal.getFloat();
3865 return true;
3866 }
3867};
3868} // end anonymous namespace
3869
3870const AccessKinds ModifySubobjectHandler::AccessKind;
3871
3872/// Update the designated sub-object of an rvalue to the given value.
3873static bool modifySubobject(EvalInfo &Info, const Expr *E,
3874 const CompleteObject &Obj,
3875 const SubobjectDesignator &Sub,
3876 APValue &NewVal) {
3877 ModifySubobjectHandler Handler = { Info, NewVal, E };
3878 return findSubobject(Info, E, Obj, Sub, Handler);
3879}
3880
3881/// Find the position where two subobject designators diverge, or equivalently
3882/// the length of the common initial subsequence.
3883static unsigned FindDesignatorMismatch(QualType ObjType,
3884 const SubobjectDesignator &A,
3885 const SubobjectDesignator &B,
3886 bool &WasArrayIndex) {
3887 unsigned I = 0, N = std::min(A.Entries.size(), B.Entries.size());
3888 for (/**/; I != N; ++I) {
3889 if (!ObjType.isNull() &&
3890 (ObjType->isArrayType() || ObjType->isAnyComplexType())) {
3891 // Next subobject is an array element.
3892 if (A.Entries[I].getAsArrayIndex() != B.Entries[I].getAsArrayIndex()) {
3893 WasArrayIndex = true;
3894 return I;
3895 }
3896 if (ObjType->isAnyComplexType())
3897 ObjType = ObjType->castAs<ComplexType>()->getElementType();
3898 else
3899 ObjType = ObjType->castAsArrayTypeUnsafe()->getElementType();
3900 } else {
3901 if (A.Entries[I].getAsBaseOrMember() !=
3902 B.Entries[I].getAsBaseOrMember()) {
3903 WasArrayIndex = false;
3904 return I;
3905 }
3906 if (const FieldDecl *FD = getAsField(A.Entries[I]))
3907 // Next subobject is a field.
3908 ObjType = FD->getType();
3909 else
3910 // Next subobject is a base class.
3911 ObjType = QualType();
3912 }
3913 }
3914 WasArrayIndex = false;
3915 return I;
3916}
3917
3918/// Determine whether the given subobject designators refer to elements of the
3919/// same array object.
3920static bool AreElementsOfSameArray(QualType ObjType,
3921 const SubobjectDesignator &A,
3922 const SubobjectDesignator &B) {
3923 if (A.Entries.size() != B.Entries.size())
3924 return false;
3925
3926 bool IsArray = A.MostDerivedIsArrayElement;
3927 if (IsArray && A.MostDerivedPathLength != A.Entries.size())
3928 // A is a subobject of the array element.
3929 return false;
3930
3931 // If A (and B) designates an array element, the last entry will be the array
3932 // index. That doesn't have to match. Otherwise, we're in the 'implicit array
3933 // of length 1' case, and the entire path must match.
3934 bool WasArrayIndex;
3935 unsigned CommonLength = FindDesignatorMismatch(ObjType, A, B, WasArrayIndex);
3936 return CommonLength >= A.Entries.size() - IsArray;
3937}
3938
3939/// Find the complete object to which an LValue refers.
3940static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
3941 AccessKinds AK, const LValue &LVal,
3942 QualType LValType) {
3943 if (LVal.InvalidBase) {
3944 Info.FFDiag(E);
3945 return CompleteObject();
3946 }
3947
3948 if (!LVal.Base) {
3949 Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
3950 return CompleteObject();
3951 }
3952
3953 CallStackFrame *Frame = nullptr;
3954 unsigned Depth = 0;
3955 if (LVal.getLValueCallIndex()) {
3956 std::tie(Frame, Depth) =
3957 Info.getCallFrameAndDepth(LVal.getLValueCallIndex());
3958 if (!Frame) {
3959 Info.FFDiag(E, diag::note_constexpr_lifetime_ended, 1)
3960 << AK << LVal.Base.is<const ValueDecl*>();
3961 NoteLValueLocation(Info, LVal.Base);
3962 return CompleteObject();
3963 }
3964 }
3965
3966 bool IsAccess = isAnyAccess(AK);
3967
3968 // C++11 DR1311: An lvalue-to-rvalue conversion on a volatile-qualified type
3969 // is not a constant expression (even if the object is non-volatile). We also
3970 // apply this rule to C++98, in order to conform to the expected 'volatile'
3971 // semantics.
3972 if (isFormalAccess(AK) && LValType.isVolatileQualified()) {
3973 if (Info.getLangOpts().CPlusPlus)
3974 Info.FFDiag(E, diag::note_constexpr_access_volatile_type)
3975 << AK << LValType;
3976 else
3977 Info.FFDiag(E);
3978 return CompleteObject();
3979 }
3980
3981 // Compute value storage location and type of base object.
3982 APValue *BaseVal = nullptr;
3983 QualType BaseType = getType(LVal.Base);
3984
3985 if (Info.getLangOpts().CPlusPlus14 && LVal.Base == Info.EvaluatingDecl &&
3986 lifetimeStartedInEvaluation(Info, LVal.Base)) {
3987 // This is the object whose initializer we're evaluating, so its lifetime
3988 // started in the current evaluation.
3989 BaseVal = Info.EvaluatingDeclValue;
3990 } else if (const ValueDecl *D = LVal.Base.dyn_cast<const ValueDecl *>()) {
3991 // Allow reading from a GUID declaration.
3992 if (auto *GD = dyn_cast<MSGuidDecl>(D)) {
3993 if (isModification(AK)) {
3994 // All the remaining cases do not permit modification of the object.
3995 Info.FFDiag(E, diag::note_constexpr_modify_global);
3996 return CompleteObject();
3997 }
3998 APValue &V = GD->getAsAPValue();
3999 if (V.isAbsent()) {
4000 Info.FFDiag(E, diag::note_constexpr_unsupported_layout)
4001 << GD->getType();
4002 return CompleteObject();
4003 }
4004 return CompleteObject(LVal.Base, &V, GD->getType());
4005 }
4006
4007 // Allow reading from template parameter objects.
4008 if (auto *TPO = dyn_cast<TemplateParamObjectDecl>(D)) {
4009 if (isModification(AK)) {
4010 Info.FFDiag(E, diag::note_constexpr_modify_global);
4011 return CompleteObject();
4012 }
4013 return CompleteObject(LVal.Base, const_cast<APValue *>(&TPO->getValue()),
4014 TPO->getType());
4015 }
4016
4017 // In C++98, const, non-volatile integers initialized with ICEs are ICEs.
4018 // In C++11, constexpr, non-volatile variables initialized with constant
4019 // expressions are constant expressions too. Inside constexpr functions,
4020 // parameters are constant expressions even if they're non-const.
4021 // In C++1y, objects local to a constant expression (those with a Frame) are
4022 // both readable and writable inside constant expressions.
4023 // In C, such things can also be folded, although they are not ICEs.
4024 const VarDecl *VD = dyn_cast<VarDecl>(D);
4025 if (VD) {
4026 if (const VarDecl *VDef = VD->getDefinition(Info.Ctx))
4027 VD = VDef;
4028 }
4029 if (!VD || VD->isInvalidDecl()) {
4030 Info.FFDiag(E);
4031 return CompleteObject();
4032 }
4033
4034 bool IsConstant = BaseType.isConstant(Info.Ctx);
4035
4036 // Unless we're looking at a local variable or argument in a constexpr call,
4037 // the variable we're reading must be const.
4038 if (!Frame) {
4039 if (IsAccess && isa<ParmVarDecl>(VD)) {
4040 // Access of a parameter that's not associated with a frame isn't going
4041 // to work out, but we can leave it to evaluateVarDeclInit to provide a
4042 // suitable diagnostic.
4043 } else if (Info.getLangOpts().CPlusPlus14 &&
4044 lifetimeStartedInEvaluation(Info, LVal.Base)) {
4045 // OK, we can read and modify an object if we're in the process of
4046 // evaluating its initializer, because its lifetime began in this
4047 // evaluation.
4048 } else if (isModification(AK)) {
4049 // All the remaining cases do not permit modification of the object.
4050 Info.FFDiag(E, diag::note_constexpr_modify_global);
4051 return CompleteObject();
4052 } else if (VD->isConstexpr()) {
4053 // OK, we can read this variable.
4054 } else if (BaseType->isIntegralOrEnumerationType()) {
4055 if (!IsConstant) {
4056 if (!IsAccess)
4057 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
4058 if (Info.getLangOpts().CPlusPlus) {
4059 Info.FFDiag(E, diag::note_constexpr_ltor_non_const_int, 1) << VD;
4060 Info.Note(VD->getLocation(), diag::note_declared_at);
4061 } else {
4062 Info.FFDiag(E);
4063 }
4064 return CompleteObject();
4065 }
4066 } else if (!IsAccess) {
4067 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
4068 } else if (IsConstant && Info.checkingPotentialConstantExpression() &&
4069 BaseType->isLiteralType(Info.Ctx) && !VD->hasDefinition()) {
4070 // This variable might end up being constexpr. Don't diagnose it yet.
4071 } else if (IsConstant) {
4072 // Keep evaluating to see what we can do. In particular, we support
4073 // folding of const floating-point types, in order to make static const
4074 // data members of such types (supported as an extension) more useful.
4075 if (Info.getLangOpts().CPlusPlus) {
4076 Info.CCEDiag(E, Info.getLangOpts().CPlusPlus11
4077 ? diag::note_constexpr_ltor_non_constexpr
4078 : diag::note_constexpr_ltor_non_integral, 1)
4079 << VD << BaseType;
4080 Info.Note(VD->getLocation(), diag::note_declared_at);
4081 } else {
4082 Info.CCEDiag(E);
4083 }
4084 } else {
4085 // Never allow reading a non-const value.
4086 if (Info.getLangOpts().CPlusPlus) {
4087 Info.FFDiag(E, Info.getLangOpts().CPlusPlus11
4088 ? diag::note_constexpr_ltor_non_constexpr
4089 : diag::note_constexpr_ltor_non_integral, 1)
4090 << VD << BaseType;
4091 Info.Note(VD->getLocation(), diag::note_declared_at);
4092 } else {
4093 Info.FFDiag(E);
4094 }
4095 return CompleteObject();
4096 }
4097 }
4098
4099 if (!evaluateVarDeclInit(Info, E, VD, Frame, LVal.getLValueVersion(), BaseVal))
4100 return CompleteObject();
4101 } else if (DynamicAllocLValue DA = LVal.Base.dyn_cast<DynamicAllocLValue>()) {
4102 Optional<DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA);
4103 if (!Alloc) {
4104 Info.FFDiag(E, diag::note_constexpr_access_deleted_object) << AK;
4105 return CompleteObject();
4106 }
4107 return CompleteObject(LVal.Base, &(*Alloc)->Value,
4108 LVal.Base.getDynamicAllocType());
4109 } else {
4110 const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
4111
4112 if (!Frame) {
4113 if (const MaterializeTemporaryExpr *MTE =
4114 dyn_cast_or_null<MaterializeTemporaryExpr>(Base)) {
4115 assert(MTE->getStorageDuration() == SD_Static &&((MTE->getStorageDuration() == SD_Static && "should have a frame for a non-global materialized temporary"
) ? static_cast<void> (0) : __assert_fail ("MTE->getStorageDuration() == SD_Static && \"should have a frame for a non-global materialized temporary\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4116, __PRETTY_FUNCTION__))
4116 "should have a frame for a non-global materialized temporary")((MTE->getStorageDuration() == SD_Static && "should have a frame for a non-global materialized temporary"
) ? static_cast<void> (0) : __assert_fail ("MTE->getStorageDuration() == SD_Static && \"should have a frame for a non-global materialized temporary\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4116, __PRETTY_FUNCTION__))
;
4117
4118 // C++20 [expr.const]p4: [DR2126]
4119 // An object or reference is usable in constant expressions if it is
4120 // - a temporary object of non-volatile const-qualified literal type
4121 // whose lifetime is extended to that of a variable that is usable
4122 // in constant expressions
4123 //
4124 // C++20 [expr.const]p5:
4125 // an lvalue-to-rvalue conversion [is not allowed unless it applies to]
4126 // - a non-volatile glvalue that refers to an object that is usable
4127 // in constant expressions, or
4128 // - a non-volatile glvalue of literal type that refers to a
4129 // non-volatile object whose lifetime began within the evaluation
4130 // of E;
4131 //
4132 // C++11 misses the 'began within the evaluation of e' check and
4133 // instead allows all temporaries, including things like:
4134 // int &&r = 1;
4135 // int x = ++r;
4136 // constexpr int k = r;
4137 // Therefore we use the C++14-onwards rules in C++11 too.
4138 //
4139 // Note that temporaries whose lifetimes began while evaluating a
4140 // variable's constructor are not usable while evaluating the
4141 // corresponding destructor, not even if they're of const-qualified
4142 // types.
4143 if (!MTE->isUsableInConstantExpressions(Info.Ctx) &&
4144 !lifetimeStartedInEvaluation(Info, LVal.Base)) {
4145 if (!IsAccess)
4146 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
4147 Info.FFDiag(E, diag::note_constexpr_access_static_temporary, 1) << AK;
4148 Info.Note(MTE->getExprLoc(), diag::note_constexpr_temporary_here);
4149 return CompleteObject();
4150 }
4151
4152 BaseVal = MTE->getOrCreateValue(false);
4153 assert(BaseVal && "got reference to unevaluated temporary")((BaseVal && "got reference to unevaluated temporary"
) ? static_cast<void> (0) : __assert_fail ("BaseVal && \"got reference to unevaluated temporary\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4153, __PRETTY_FUNCTION__))
;
4154 } else {
4155 if (!IsAccess)
4156 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
4157 APValue Val;
4158 LVal.moveInto(Val);
4159 Info.FFDiag(E, diag::note_constexpr_access_unreadable_object)
4160 << AK
4161 << Val.getAsString(Info.Ctx,
4162 Info.Ctx.getLValueReferenceType(LValType));
4163 NoteLValueLocation(Info, LVal.Base);
4164 return CompleteObject();
4165 }
4166 } else {
4167 BaseVal = Frame->getTemporary(Base, LVal.Base.getVersion());
4168 assert(BaseVal && "missing value for temporary")((BaseVal && "missing value for temporary") ? static_cast
<void> (0) : __assert_fail ("BaseVal && \"missing value for temporary\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4168, __PRETTY_FUNCTION__))
;
4169 }
4170 }
4171
4172 // In C++14, we can't safely access any mutable state when we might be
4173 // evaluating after an unmodeled side effect. Parameters are modeled as state
4174 // in the caller, but aren't visible once the call returns, so they can be
4175 // modified in a speculatively-evaluated call.
4176 //
4177 // FIXME: Not all local state is mutable. Allow local constant subobjects
4178 // to be read here (but take care with 'mutable' fields).
4179 unsigned VisibleDepth = Depth;
4180 if (llvm::isa_and_nonnull<ParmVarDecl>(
4181 LVal.Base.dyn_cast<const ValueDecl *>()))
4182 ++VisibleDepth;
4183 if ((Frame && Info.getLangOpts().CPlusPlus14 &&
4184 Info.EvalStatus.HasSideEffects) ||
4185 (isModification(AK) && VisibleDepth < Info.SpeculativeEvaluationDepth))
4186 return CompleteObject();
4187
4188 return CompleteObject(LVal.getLValueBase(), BaseVal, BaseType);
4189}
4190
4191/// Perform an lvalue-to-rvalue conversion on the given glvalue. This
4192/// can also be used for 'lvalue-to-lvalue' conversions for looking up the
4193/// glvalue referred to by an entity of reference type.
4194///
4195/// \param Info - Information about the ongoing evaluation.
4196/// \param Conv - The expression for which we are performing the conversion.
4197/// Used for diagnostics.
4198/// \param Type - The type of the glvalue (before stripping cv-qualifiers in the
4199/// case of a non-class type).
4200/// \param LVal - The glvalue on which we are attempting to perform this action.
4201/// \param RVal - The produced value will be placed here.
4202/// \param WantObjectRepresentation - If true, we're looking for the object
4203/// representation rather than the value, and in particular,
4204/// there is no requirement that the result be fully initialized.
4205static bool
4206handleLValueToRValueConversion(EvalInfo &Info, const Expr *Conv, QualType Type,
4207 const LValue &LVal, APValue &RVal,
4208 bool WantObjectRepresentation = false) {
4209 if (LVal.Designator.Invalid)
4210 return false;
4211
4212 // Check for special cases where there is no existing APValue to look at.
4213 const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
4214
4215 AccessKinds AK =
4216 WantObjectRepresentation ? AK_ReadObjectRepresentation : AK_Read;
4217
4218 if (Base && !LVal.getLValueCallIndex() && !Type.isVolatileQualified()) {
4219 if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(Base)) {
4220 // In C99, a CompoundLiteralExpr is an lvalue, and we defer evaluating the
4221 // initializer until now for such expressions. Such an expression can't be
4222 // an ICE in C, so this only matters for fold.
4223 if (Type.isVolatileQualified()) {
4224 Info.FFDiag(Conv);
4225 return false;
4226 }
4227 APValue Lit;
4228 if (!Evaluate(Lit, Info, CLE->getInitializer()))
4229 return false;
4230 CompleteObject LitObj(LVal.Base, &Lit, Base->getType());
4231 return extractSubobject(Info, Conv, LitObj, LVal.Designator, RVal, AK);
4232 } else if (isa<StringLiteral>(Base) || isa<PredefinedExpr>(Base)) {
4233 // Special-case character extraction so we don't have to construct an
4234 // APValue for the whole string.
4235 assert(LVal.Designator.Entries.size() <= 1 &&((LVal.Designator.Entries.size() <= 1 && "Can only read characters from string literals"
) ? static_cast<void> (0) : __assert_fail ("LVal.Designator.Entries.size() <= 1 && \"Can only read characters from string literals\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4236, __PRETTY_FUNCTION__))
4236 "Can only read characters from string literals")((LVal.Designator.Entries.size() <= 1 && "Can only read characters from string literals"
) ? static_cast<void> (0) : __assert_fail ("LVal.Designator.Entries.size() <= 1 && \"Can only read characters from string literals\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4236, __PRETTY_FUNCTION__))
;
4237 if (LVal.Designator.Entries.empty()) {
4238 // Fail for now for LValue to RValue conversion of an array.
4239 // (This shouldn't show up in C/C++, but it could be triggered by a
4240 // weird EvaluateAsRValue call from a tool.)
4241 Info.FFDiag(Conv);
4242 return false;
4243 }
4244 if (LVal.Designator.isOnePastTheEnd()) {
4245 if (Info.getLangOpts().CPlusPlus11)
4246 Info.FFDiag(Conv, diag::note_constexpr_access_past_end) << AK;
4247 else
4248 Info.FFDiag(Conv);
4249 return false;
4250 }
4251 uint64_t CharIndex = LVal.Designator.Entries[0].getAsArrayIndex();
4252 RVal = APValue(extractStringLiteralCharacter(Info, Base, CharIndex));
4253 return true;
4254 }
4255 }
4256
4257 CompleteObject Obj = findCompleteObject(Info, Conv, AK, LVal, Type);
4258 return Obj && extractSubobject(Info, Conv, Obj, LVal.Designator, RVal, AK);
4259}
4260
4261/// Perform an assignment of Val to LVal. Takes ownership of Val.
4262static bool handleAssignment(EvalInfo &Info, const Expr *E, const LValue &LVal,
4263 QualType LValType, APValue &Val) {
4264 if (LVal.Designator.Invalid)
4265 return false;
4266
4267 if (!Info.getLangOpts().CPlusPlus14) {
4268 Info.FFDiag(E);
4269 return false;
4270 }
4271
4272 CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
4273 return Obj && modifySubobject(Info, E, Obj, LVal.Designator, Val);
4274}
4275
4276namespace {
4277struct CompoundAssignSubobjectHandler {
4278 EvalInfo &Info;
4279 const CompoundAssignOperator *E;
4280 QualType PromotedLHSType;
4281 BinaryOperatorKind Opcode;
4282 const APValue &RHS;
4283
4284 static const AccessKinds AccessKind = AK_Assign;
4285
4286 typedef bool result_type;
4287
4288 bool checkConst(QualType QT) {
4289 // Assigning to a const object has undefined behavior.
4290 if (QT.isConstQualified()) {
4291 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
4292 return false;
4293 }
4294 return true;
4295 }
4296
4297 bool failed() { return false; }
4298 bool found(APValue &Subobj, QualType SubobjType) {
4299 switch (Subobj.getKind()) {
4300 case APValue::Int:
4301 return found(Subobj.getInt(), SubobjType);
4302 case APValue::Float:
4303 return found(Subobj.getFloat(), SubobjType);
4304 case APValue::ComplexInt:
4305 case APValue::ComplexFloat:
4306 // FIXME: Implement complex compound assignment.
4307 Info.FFDiag(E);
4308 return false;
4309 case APValue::LValue:
4310 return foundPointer(Subobj, SubobjType);
4311 case APValue::Vector:
4312 return foundVector(Subobj, SubobjType);
4313 default:
4314 // FIXME: can this happen?
4315 Info.FFDiag(E);
4316 return false;
4317 }
4318 }
4319
4320 bool foundVector(APValue &Value, QualType SubobjType) {
4321 if (!checkConst(SubobjType))
4322 return false;
4323
4324 if (!SubobjType->isVectorType()) {
4325 Info.FFDiag(E);
4326 return false;
4327 }
4328 return handleVectorVectorBinOp(Info, E, Opcode, Value, RHS);
4329 }
4330
4331 bool found(APSInt &Value, QualType SubobjType) {
4332 if (!checkConst(SubobjType))
4333 return false;
4334
4335 if (!SubobjType->isIntegerType()) {
4336 // We don't support compound assignment on integer-cast-to-pointer
4337 // values.
4338 Info.FFDiag(E);
4339 return false;
4340 }
4341
4342 if (RHS.isInt()) {
4343 APSInt LHS =
4344 HandleIntToIntCast(Info, E, PromotedLHSType, SubobjType, Value);
4345 if (!handleIntIntBinOp(Info, E, LHS, Opcode, RHS.getInt(), LHS))
4346 return false;
4347 Value = HandleIntToIntCast(Info, E, SubobjType, PromotedLHSType, LHS);
4348 return true;
4349 } else if (RHS.isFloat()) {
4350 const FPOptions FPO = E->getFPFeaturesInEffect(
4351 Info.Ctx.getLangOpts());
4352 APFloat FValue(0.0);
4353 return HandleIntToFloatCast(Info, E, FPO, SubobjType, Value,
4354 PromotedLHSType, FValue) &&
4355 handleFloatFloatBinOp(Info, E, FValue, Opcode, RHS.getFloat()) &&
4356 HandleFloatToIntCast(Info, E, PromotedLHSType, FValue, SubobjType,
4357 Value);
4358 }
4359
4360 Info.FFDiag(E);
4361 return false;
4362 }
4363 bool found(APFloat &Value, QualType SubobjType) {
4364 return checkConst(SubobjType) &&
4365 HandleFloatToFloatCast(Info, E, SubobjType, PromotedLHSType,
4366 Value) &&
4367 handleFloatFloatBinOp(Info, E, Value, Opcode, RHS.getFloat()) &&
4368 HandleFloatToFloatCast(Info, E, PromotedLHSType, SubobjType, Value);
4369 }
4370 bool foundPointer(APValue &Subobj, QualType SubobjType) {
4371 if (!checkConst(SubobjType))
4372 return false;
4373
4374 QualType PointeeType;
4375 if (const PointerType *PT = SubobjType->getAs<PointerType>())
4376 PointeeType = PT->getPointeeType();
4377
4378 if (PointeeType.isNull() || !RHS.isInt() ||
4379 (Opcode != BO_Add && Opcode != BO_Sub)) {
4380 Info.FFDiag(E);
4381 return false;
4382 }
4383
4384 APSInt Offset = RHS.getInt();
4385 if (Opcode == BO_Sub)
4386 negateAsSigned(Offset);
4387
4388 LValue LVal;
4389 LVal.setFrom(Info.Ctx, Subobj);
4390 if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType, Offset))
4391 return false;
4392 LVal.moveInto(Subobj);
4393 return true;
4394 }
4395};
4396} // end anonymous namespace
4397
4398const AccessKinds CompoundAssignSubobjectHandler::AccessKind;
4399
4400/// Perform a compound assignment of LVal <op>= RVal.
4401static bool handleCompoundAssignment(EvalInfo &Info,
4402 const CompoundAssignOperator *E,
4403 const LValue &LVal, QualType LValType,
4404 QualType PromotedLValType,
4405 BinaryOperatorKind Opcode,
4406 const APValue &RVal) {
4407 if (LVal.Designator.Invalid)
4408 return false;
4409
4410 if (!Info.getLangOpts().CPlusPlus14) {
4411 Info.FFDiag(E);
4412 return false;
4413 }
4414
4415 CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
4416 CompoundAssignSubobjectHandler Handler = { Info, E, PromotedLValType, Opcode,
4417 RVal };
4418 return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
4419}
4420
4421namespace {
4422struct IncDecSubobjectHandler {
4423 EvalInfo &Info;
4424 const UnaryOperator *E;
4425 AccessKinds AccessKind;
4426 APValue *Old;
4427
4428 typedef bool result_type;
4429
4430 bool checkConst(QualType QT) {
4431 // Assigning to a const object has undefined behavior.
4432 if (QT.isConstQualified()) {
4433 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
4434 return false;
4435 }
4436 return true;
4437 }
4438
4439 bool failed() { return false; }
4440 bool found(APValue &Subobj, QualType SubobjType) {
4441 // Stash the old value. Also clear Old, so we don't clobber it later
4442 // if we're post-incrementing a complex.
4443 if (Old) {
4444 *Old = Subobj;
4445 Old = nullptr;
4446 }
4447
4448 switch (Subobj.getKind()) {
4449 case APValue::Int:
4450 return found(Subobj.getInt(), SubobjType);
4451 case APValue::Float:
4452 return found(Subobj.getFloat(), SubobjType);
4453 case APValue::ComplexInt:
4454 return found(Subobj.getComplexIntReal(),
4455 SubobjType->castAs<ComplexType>()->getElementType()
4456 .withCVRQualifiers(SubobjType.getCVRQualifiers()));
4457 case APValue::ComplexFloat:
4458 return found(Subobj.getComplexFloatReal(),
4459 SubobjType->castAs<ComplexType>()->getElementType()
4460 .withCVRQualifiers(SubobjType.getCVRQualifiers()));
4461 case APValue::LValue:
4462 return foundPointer(Subobj, SubobjType);
4463 default:
4464 // FIXME: can this happen?
4465 Info.FFDiag(E);
4466 return false;
4467 }
4468 }
4469 bool found(APSInt &Value, QualType SubobjType) {
4470 if (!checkConst(SubobjType))
4471 return false;
4472
4473 if (!SubobjType->isIntegerType()) {
4474 // We don't support increment / decrement on integer-cast-to-pointer
4475 // values.
4476 Info.FFDiag(E);
4477 return false;
4478 }
4479
4480 if (Old) *Old = APValue(Value);
4481
4482 // bool arithmetic promotes to int, and the conversion back to bool
4483 // doesn't reduce mod 2^n, so special-case it.
4484 if (SubobjType->isBooleanType()) {
4485 if (AccessKind == AK_Increment)
4486 Value = 1;
4487 else
4488 Value = !Value;
4489 return true;
4490 }
4491
4492 bool WasNegative = Value.isNegative();
4493 if (AccessKind == AK_Increment) {
4494 ++Value;
4495
4496 if (!WasNegative && Value.isNegative() && E->canOverflow()) {
4497 APSInt ActualValue(Value, /*IsUnsigned*/true);
4498 return HandleOverflow(Info, E, ActualValue, SubobjType);
4499 }
4500 } else {
4501 --Value;
4502
4503 if (WasNegative && !Value.isNegative() && E->canOverflow()) {
4504 unsigned BitWidth = Value.getBitWidth();
4505 APSInt ActualValue(Value.sext(BitWidth + 1), /*IsUnsigned*/false);
4506 ActualValue.setBit(BitWidth);
4507 return HandleOverflow(Info, E, ActualValue, SubobjType);
4508 }
4509 }
4510 return true;
4511 }
4512 bool found(APFloat &Value, QualType SubobjType) {
4513 if (!checkConst(SubobjType))
4514 return false;
4515
4516 if (Old) *Old = APValue(Value);
4517
4518 APFloat One(Value.getSemantics(), 1);
4519 if (AccessKind == AK_Increment)
4520 Value.add(One, APFloat::rmNearestTiesToEven);
4521 else
4522 Value.subtract(One, APFloat::rmNearestTiesToEven);
4523 return true;
4524 }
4525 bool foundPointer(APValue &Subobj, QualType SubobjType) {
4526 if (!checkConst(SubobjType))
4527 return false;
4528
4529 QualType PointeeType;
4530 if (const PointerType *PT = SubobjType->getAs<PointerType>())
4531 PointeeType = PT->getPointeeType();
4532 else {
4533 Info.FFDiag(E);
4534 return false;
4535 }
4536
4537 LValue LVal;
4538 LVal.setFrom(Info.Ctx, Subobj);
4539 if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType,
4540 AccessKind == AK_Increment ? 1 : -1))
4541 return false;
4542 LVal.moveInto(Subobj);
4543 return true;
4544 }
4545};
4546} // end anonymous namespace
4547
4548/// Perform an increment or decrement on LVal.
4549static bool handleIncDec(EvalInfo &Info, const Expr *E, const LValue &LVal,
4550 QualType LValType, bool IsIncrement, APValue *Old) {
4551 if (LVal.Designator.Invalid)
4552 return false;
4553
4554 if (!Info.getLangOpts().CPlusPlus14) {
4555 Info.FFDiag(E);
4556 return false;
4557 }
4558
4559 AccessKinds AK = IsIncrement ? AK_Increment : AK_Decrement;
4560 CompleteObject Obj = findCompleteObject(Info, E, AK, LVal, LValType);
4561 IncDecSubobjectHandler Handler = {Info, cast<UnaryOperator>(E), AK, Old};
4562 return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
4563}
4564
4565/// Build an lvalue for the object argument of a member function call.
4566static bool EvaluateObjectArgument(EvalInfo &Info, const Expr *Object,
4567 LValue &This) {
4568 if (Object->getType()->isPointerType() && Object->isRValue())
4569 return EvaluatePointer(Object, This, Info);
4570
4571 if (Object->isGLValue())
4572 return EvaluateLValue(Object, This, Info);
4573
4574 if (Object->getType()->isLiteralType(Info.Ctx))
4575 return EvaluateTemporary(Object, This, Info);
4576
4577 Info.FFDiag(Object, diag::note_constexpr_nonliteral) << Object->getType();
4578 return false;
4579}
4580
4581/// HandleMemberPointerAccess - Evaluate a member access operation and build an
4582/// lvalue referring to the result.
4583///
4584/// \param Info - Information about the ongoing evaluation.
4585/// \param LV - An lvalue referring to the base of the member pointer.
4586/// \param RHS - The member pointer expression.
4587/// \param IncludeMember - Specifies whether the member itself is included in
4588/// the resulting LValue subobject designator. This is not possible when
4589/// creating a bound member function.
4590/// \return The field or method declaration to which the member pointer refers,
4591/// or 0 if evaluation fails.
4592static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
4593 QualType LVType,
4594 LValue &LV,
4595 const Expr *RHS,
4596 bool IncludeMember = true) {
4597 MemberPtr MemPtr;
4598 if (!EvaluateMemberPointer(RHS, MemPtr, Info))
4599 return nullptr;
4600
4601 // C++11 [expr.mptr.oper]p6: If the second operand is the null pointer to
4602 // member value, the behavior is undefined.
4603 if (!MemPtr.getDecl()) {
4604 // FIXME: Specific diagnostic.
4605 Info.FFDiag(RHS);
4606 return nullptr;
4607 }
4608
4609 if (MemPtr.isDerivedMember()) {
4610 // This is a member of some derived class. Truncate LV appropriately.
4611 // The end of the derived-to-base path for the base object must match the
4612 // derived-to-base path for the member pointer.
4613 if (LV.Designator.MostDerivedPathLength + MemPtr.Path.size() >
4614 LV.Designator.Entries.size()) {
4615 Info.FFDiag(RHS);
4616 return nullptr;
4617 }
4618 unsigned PathLengthToMember =
4619 LV.Designator.Entries.size() - MemPtr.Path.size();
4620 for (unsigned I = 0, N = MemPtr.Path.size(); I != N; ++I) {
4621 const CXXRecordDecl *LVDecl = getAsBaseClass(
4622 LV.Designator.Entries[PathLengthToMember + I]);
4623 const CXXRecordDecl *MPDecl = MemPtr.Path[I];
4624 if (LVDecl->getCanonicalDecl() != MPDecl->getCanonicalDecl()) {
4625 Info.FFDiag(RHS);
4626 return nullptr;
4627 }
4628 }
4629
4630 // Truncate the lvalue to the appropriate derived class.
4631 if (!CastToDerivedClass(Info, RHS, LV, MemPtr.getContainingRecord(),
4632 PathLengthToMember))
4633 return nullptr;
4634 } else if (!MemPtr.Path.empty()) {
4635 // Extend the LValue path with the member pointer's path.
4636 LV.Designator.Entries.reserve(LV.Designator.Entries.size() +
4637 MemPtr.Path.size() + IncludeMember);
4638
4639 // Walk down to the appropriate base class.
4640 if (const PointerType *PT = LVType->getAs<PointerType>())
4641 LVType = PT->getPointeeType();
4642 const CXXRecordDecl *RD = LVType->getAsCXXRecordDecl();
4643 assert(RD && "member pointer access on non-class-type expression")((RD && "member pointer access on non-class-type expression"
) ? static_cast<void> (0) : __assert_fail ("RD && \"member pointer access on non-class-type expression\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4643, __PRETTY_FUNCTION__))
;
4644 // The first class in the path is that of the lvalue.
4645 for (unsigned I = 1, N = MemPtr.Path.size(); I != N; ++I) {
4646 const CXXRecordDecl *Base = MemPtr.Path[N - I - 1];
4647 if (!HandleLValueDirectBase(Info, RHS, LV, RD, Base))
4648 return nullptr;
4649 RD = Base;
4650 }
4651 // Finally cast to the class containing the member.
4652 if (!HandleLValueDirectBase(Info, RHS, LV, RD,
4653 MemPtr.getContainingRecord()))
4654 return nullptr;
4655 }
4656
4657 // Add the member. Note that we cannot build bound member functions here.
4658 if (IncludeMember) {
4659 if (const FieldDecl *FD = dyn_cast<FieldDecl>(MemPtr.getDecl())) {
4660 if (!HandleLValueMember(Info, RHS, LV, FD))
4661 return nullptr;
4662 } else if (const IndirectFieldDecl *IFD =
4663 dyn_cast<IndirectFieldDecl>(MemPtr.getDecl())) {
4664 if (!HandleLValueIndirectMember(Info, RHS, LV, IFD))
4665 return nullptr;
4666 } else {
4667 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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4667)
;
4668 }
4669 }
4670
4671 return MemPtr.getDecl();
4672}
4673
4674static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
4675 const BinaryOperator *BO,
4676 LValue &LV,
4677 bool IncludeMember = true) {
4678 assert(BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI)((BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI
) ? static_cast<void> (0) : __assert_fail ("BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4678, __PRETTY_FUNCTION__))
;
4679
4680 if (!EvaluateObjectArgument(Info, BO->getLHS(), LV)) {
4681 if (Info.noteFailure()) {
4682 MemberPtr MemPtr;
4683 EvaluateMemberPointer(BO->getRHS(), MemPtr, Info);
4684 }
4685 return nullptr;
4686 }
4687
4688 return HandleMemberPointerAccess(Info, BO->getLHS()->getType(), LV,
4689 BO->getRHS(), IncludeMember);
4690}
4691
4692/// HandleBaseToDerivedCast - Apply the given base-to-derived cast operation on
4693/// the provided lvalue, which currently refers to the base object.
4694static bool HandleBaseToDerivedCast(EvalInfo &Info, const CastExpr *E,
4695 LValue &Result) {
4696 SubobjectDesignator &D = Result.Designator;
4697 if (D.Invalid || !Result.checkNullPointer(Info, E, CSK_Derived))
4698 return false;
4699
4700 QualType TargetQT = E->getType();
4701 if (const PointerType *PT = TargetQT->getAs<PointerType>())
4702 TargetQT = PT->getPointeeType();
4703
4704 // Check this cast lands within the final derived-to-base subobject path.
4705 if (D.MostDerivedPathLength + E->path_size() > D.Entries.size()) {
4706 Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
4707 << D.MostDerivedType << TargetQT;
4708 return false;
4709 }
4710
4711 // Check the type of the final cast. We don't need to check the path,
4712 // since a cast can only be formed if the path is unique.
4713 unsigned NewEntriesSize = D.Entries.size() - E->path_size();
4714 const CXXRecordDecl *TargetType = TargetQT->getAsCXXRecordDecl();
4715 const CXXRecordDecl *FinalType;
4716 if (NewEntriesSize == D.MostDerivedPathLength)
4717 FinalType = D.MostDerivedType->getAsCXXRecordDecl();
4718 else
4719 FinalType = getAsBaseClass(D.Entries[NewEntriesSize - 1]);
4720 if (FinalType->getCanonicalDecl() != TargetType->getCanonicalDecl()) {
4721 Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
4722 << D.MostDerivedType << TargetQT;
4723 return false;
4724 }
4725
4726 // Truncate the lvalue to the appropriate derived class.
4727 return CastToDerivedClass(Info, E, Result, TargetType, NewEntriesSize);
4728}
4729
4730/// Get the value to use for a default-initialized object of type T.
4731/// Return false if it encounters something invalid.
4732static bool getDefaultInitValue(QualType T, APValue &Result) {
4733 bool Success = true;
4734 if (auto *RD = T->getAsCXXRecordDecl()) {
4735 if (RD->isInvalidDecl()) {
4736 Result = APValue();
4737 return false;
4738 }
4739 if (RD->isUnion()) {
4740 Result = APValue((const FieldDecl *)nullptr);
4741 return true;
4742 }
4743 Result = APValue(APValue::UninitStruct(), RD->getNumBases(),
4744 std::distance(RD->field_begin(), RD->field_end()));
4745
4746 unsigned Index = 0;
4747 for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
4748 End = RD->bases_end();
4749 I != End; ++I, ++Index)
4750 Success &= getDefaultInitValue(I->getType(), Result.getStructBase(Index));
4751
4752 for (const auto *I : RD->fields()) {
4753 if (I->isUnnamedBitfield())
4754 continue;
4755 Success &= getDefaultInitValue(I->getType(),
4756 Result.getStructField(I->getFieldIndex()));
4757 }
4758 return Success;
4759 }
4760
4761 if (auto *AT =
4762 dyn_cast_or_null<ConstantArrayType>(T->getAsArrayTypeUnsafe())) {
4763 Result = APValue(APValue::UninitArray(), 0, AT->getSize().getZExtValue());
4764 if (Result.hasArrayFiller())
4765 Success &=
4766 getDefaultInitValue(AT->getElementType(), Result.getArrayFiller());
4767
4768 return Success;
4769 }
4770
4771 Result = APValue::IndeterminateValue();
4772 return true;
4773}
4774
4775namespace {
4776enum EvalStmtResult {
4777 /// Evaluation failed.
4778 ESR_Failed,
4779 /// Hit a 'return' statement.
4780 ESR_Returned,
4781 /// Evaluation succeeded.
4782 ESR_Succeeded,
4783 /// Hit a 'continue' statement.
4784 ESR_Continue,
4785 /// Hit a 'break' statement.
4786 ESR_Break,
4787 /// Still scanning for 'case' or 'default' statement.
4788 ESR_CaseNotFound
4789};
4790}
4791
4792static bool EvaluateVarDecl(EvalInfo &Info, const VarDecl *VD) {
4793 // We don't need to evaluate the initializer for a static local.
4794 if (!VD->hasLocalStorage())
4795 return true;
4796
4797 LValue Result;
4798 APValue &Val = Info.CurrentCall->createTemporary(VD, VD->getType(),
4799 ScopeKind::Block, Result);
4800
4801 const Expr *InitE = VD->getInit();
4802 if (!InitE) {
4803 if (VD->getType()->isDependentType())
4804 return Info.noteSideEffect();
4805 return getDefaultInitValue(VD->getType(), Val);
4806 }
4807 if (InitE->isValueDependent())
4808 return false;
4809
4810 if (!EvaluateInPlace(Val, Info, Result, InitE)) {
4811 // Wipe out any partially-computed value, to allow tracking that this
4812 // evaluation failed.
4813 Val = APValue();
4814 return false;
4815 }
4816
4817 return true;
4818}
4819
4820static bool EvaluateDecl(EvalInfo &Info, const Decl *D) {
4821 bool OK = true;
4822
4823 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
4824 OK &= EvaluateVarDecl(Info, VD);
4825
4826 if (const DecompositionDecl *DD = dyn_cast<DecompositionDecl>(D))
4827 for (auto *BD : DD->bindings())
4828 if (auto *VD = BD->getHoldingVar())
4829 OK &= EvaluateDecl(Info, VD);
4830
4831 return OK;
4832}
4833
4834static bool EvaluateDependentExpr(const Expr *E, EvalInfo &Info) {
4835 assert(E->isValueDependent())((E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4835, __PRETTY_FUNCTION__))
;
4836 if (Info.noteSideEffect())
4837 return true;
4838 assert(E->containsErrors() && "valid value-dependent expression should never "((E->containsErrors() && "valid value-dependent expression should never "
"reach invalid code path.") ? static_cast<void> (0) : __assert_fail
("E->containsErrors() && \"valid value-dependent expression should never \" \"reach invalid code path.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4839, __PRETTY_FUNCTION__))
4839 "reach invalid code path.")((E->containsErrors() && "valid value-dependent expression should never "
"reach invalid code path.") ? static_cast<void> (0) : __assert_fail
("E->containsErrors() && \"valid value-dependent expression should never \" \"reach invalid code path.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4839, __PRETTY_FUNCTION__))
;
4840 return false;
4841}
4842
4843/// Evaluate a condition (either a variable declaration or an expression).
4844static bool EvaluateCond(EvalInfo &Info, const VarDecl *CondDecl,
4845 const Expr *Cond, bool &Result) {
4846 if (Cond->isValueDependent())
4847 return false;
4848 FullExpressionRAII Scope(Info);
4849 if (CondDecl && !EvaluateDecl(Info, CondDecl))
4850 return false;
4851 if (!EvaluateAsBooleanCondition(Cond, Result, Info))
4852 return false;
4853 return Scope.destroy();
4854}
4855
4856namespace {
4857/// A location where the result (returned value) of evaluating a
4858/// statement should be stored.
4859struct StmtResult {
4860 /// The APValue that should be filled in with the returned value.
4861 APValue &Value;
4862 /// The location containing the result, if any (used to support RVO).
4863 const LValue *Slot;
4864};
4865
4866struct TempVersionRAII {
4867 CallStackFrame &Frame;
4868
4869 TempVersionRAII(CallStackFrame &Frame) : Frame(Frame) {
4870 Frame.pushTempVersion();
4871 }
4872
4873 ~TempVersionRAII() {
4874 Frame.popTempVersion();
4875 }
4876};
4877
4878}
4879
4880static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
4881 const Stmt *S,
4882 const SwitchCase *SC = nullptr);
4883
4884/// Evaluate the body of a loop, and translate the result as appropriate.
4885static EvalStmtResult EvaluateLoopBody(StmtResult &Result, EvalInfo &Info,
4886 const Stmt *Body,
4887 const SwitchCase *Case = nullptr) {
4888 BlockScopeRAII Scope(Info);
4889
4890 EvalStmtResult ESR = EvaluateStmt(Result, Info, Body, Case);
4891 if (ESR != ESR_Failed && ESR != ESR_CaseNotFound && !Scope.destroy())
4892 ESR = ESR_Failed;
4893
4894 switch (ESR) {
4895 case ESR_Break:
4896 return ESR_Succeeded;
4897 case ESR_Succeeded:
4898 case ESR_Continue:
4899 return ESR_Continue;
4900 case ESR_Failed:
4901 case ESR_Returned:
4902 case ESR_CaseNotFound:
4903 return ESR;
4904 }
4905 llvm_unreachable("Invalid EvalStmtResult!")::llvm::llvm_unreachable_internal("Invalid EvalStmtResult!", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4905)
;
4906}
4907
4908/// Evaluate a switch statement.
4909static EvalStmtResult EvaluateSwitch(StmtResult &Result, EvalInfo &Info,
4910 const SwitchStmt *SS) {
4911 BlockScopeRAII Scope(Info);
4912
4913 // Evaluate the switch condition.
4914 APSInt Value;
4915 {
4916 if (const Stmt *Init = SS->getInit()) {
4917 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
4918 if (ESR != ESR_Succeeded) {
4919 if (ESR != ESR_Failed && !Scope.destroy())
4920 ESR = ESR_Failed;
4921 return ESR;
4922 }
4923 }
4924
4925 FullExpressionRAII CondScope(Info);
4926 if (SS->getConditionVariable() &&
4927 !EvaluateDecl(Info, SS->getConditionVariable()))
4928 return ESR_Failed;
4929 if (!EvaluateInteger(SS->getCond(), Value, Info))
4930 return ESR_Failed;
4931 if (!CondScope.destroy())
4932 return ESR_Failed;
4933 }
4934
4935 // Find the switch case corresponding to the value of the condition.
4936 // FIXME: Cache this lookup.
4937 const SwitchCase *Found = nullptr;
4938 for (const SwitchCase *SC = SS->getSwitchCaseList(); SC;
4939 SC = SC->getNextSwitchCase()) {
4940 if (isa<DefaultStmt>(SC)) {
4941 Found = SC;
4942 continue;
4943 }
4944
4945 const CaseStmt *CS = cast<CaseStmt>(SC);
4946 APSInt LHS = CS->getLHS()->EvaluateKnownConstInt(Info.Ctx);
4947 APSInt RHS = CS->getRHS() ? CS->getRHS()->EvaluateKnownConstInt(Info.Ctx)
4948 : LHS;
4949 if (LHS <= Value && Value <= RHS) {
4950 Found = SC;
4951 break;
4952 }
4953 }
4954
4955 if (!Found)
4956 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
4957
4958 // Search the switch body for the switch case and evaluate it from there.
4959 EvalStmtResult ESR = EvaluateStmt(Result, Info, SS->getBody(), Found);
4960 if (ESR != ESR_Failed && ESR != ESR_CaseNotFound && !Scope.destroy())
4961 return ESR_Failed;
4962
4963 switch (ESR) {
4964 case ESR_Break:
4965 return ESR_Succeeded;
4966 case ESR_Succeeded:
4967 case ESR_Continue:
4968 case ESR_Failed:
4969 case ESR_Returned:
4970 return ESR;
4971 case ESR_CaseNotFound:
4972 // This can only happen if the switch case is nested within a statement
4973 // expression. We have no intention of supporting that.
4974 Info.FFDiag(Found->getBeginLoc(),
4975 diag::note_constexpr_stmt_expr_unsupported);
4976 return ESR_Failed;
4977 }
4978 llvm_unreachable("Invalid EvalStmtResult!")::llvm::llvm_unreachable_internal("Invalid EvalStmtResult!", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 4978)
;
4979}
4980
4981// Evaluate a statement.
4982static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
4983 const Stmt *S, const SwitchCase *Case) {
4984 if (!Info.nextStep(S))
4985 return ESR_Failed;
4986
4987 // If we're hunting down a 'case' or 'default' label, recurse through
4988 // substatements until we hit the label.
4989 if (Case) {
4990 switch (S->getStmtClass()) {
4991 case Stmt::CompoundStmtClass:
4992 // FIXME: Precompute which substatement of a compound statement we
4993 // would jump to, and go straight there rather than performing a
4994 // linear scan each time.
4995 case Stmt::LabelStmtClass:
4996 case Stmt::AttributedStmtClass:
4997 case Stmt::DoStmtClass:
4998 break;
4999
5000 case Stmt::CaseStmtClass:
5001 case Stmt::DefaultStmtClass:
5002 if (Case == S)
5003 Case = nullptr;
5004 break;
5005
5006 case Stmt::IfStmtClass: {
5007 // FIXME: Precompute which side of an 'if' we would jump to, and go
5008 // straight there rather than scanning both sides.
5009 const IfStmt *IS = cast<IfStmt>(S);
5010
5011 // Wrap the evaluation in a block scope, in case it's a DeclStmt
5012 // preceded by our switch label.
5013 BlockScopeRAII Scope(Info);
5014
5015 // Step into the init statement in case it brings an (uninitialized)
5016 // variable into scope.
5017 if (const Stmt *Init = IS->getInit()) {
5018 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init, Case);
5019 if (ESR != ESR_CaseNotFound) {
5020 assert(ESR != ESR_Succeeded)((ESR != ESR_Succeeded) ? static_cast<void> (0) : __assert_fail
("ESR != ESR_Succeeded", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5020, __PRETTY_FUNCTION__))
;
5021 return ESR;
5022 }
5023 }
5024
5025 // Condition variable must be initialized if it exists.
5026 // FIXME: We can skip evaluating the body if there's a condition
5027 // variable, as there can't be any case labels within it.
5028 // (The same is true for 'for' statements.)
5029
5030 EvalStmtResult ESR = EvaluateStmt(Result, Info, IS->getThen(), Case);
5031 if (ESR == ESR_Failed)
5032 return ESR;
5033 if (ESR != ESR_CaseNotFound)
5034 return Scope.destroy() ? ESR : ESR_Failed;
5035 if (!IS->getElse())
5036 return ESR_CaseNotFound;
5037
5038 ESR = EvaluateStmt(Result, Info, IS->getElse(), Case);
5039 if (ESR == ESR_Failed)
5040 return ESR;
5041 if (ESR != ESR_CaseNotFound)
5042 return Scope.destroy() ? ESR : ESR_Failed;
5043 return ESR_CaseNotFound;
5044 }
5045
5046 case Stmt::WhileStmtClass: {
5047 EvalStmtResult ESR =
5048 EvaluateLoopBody(Result, Info, cast<WhileStmt>(S)->getBody(), Case);
5049 if (ESR != ESR_Continue)
5050 return ESR;
5051 break;
5052 }
5053
5054 case Stmt::ForStmtClass: {
5055 const ForStmt *FS = cast<ForStmt>(S);
5056 BlockScopeRAII Scope(Info);
5057
5058 // Step into the init statement in case it brings an (uninitialized)
5059 // variable into scope.
5060 if (const Stmt *Init = FS->getInit()) {
5061 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init, Case);
5062 if (ESR != ESR_CaseNotFound) {
5063 assert(ESR != ESR_Succeeded)((ESR != ESR_Succeeded) ? static_cast<void> (0) : __assert_fail
("ESR != ESR_Succeeded", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5063, __PRETTY_FUNCTION__))
;
5064 return ESR;
5065 }
5066 }
5067
5068 EvalStmtResult ESR =
5069 EvaluateLoopBody(Result, Info, FS->getBody(), Case);
5070 if (ESR != ESR_Continue)
5071 return ESR;
5072 if (const auto *Inc = FS->getInc()) {
5073 if (Inc->isValueDependent()) {
5074 if (!EvaluateDependentExpr(Inc, Info))
5075 return ESR_Failed;
5076 } else {
5077 FullExpressionRAII IncScope(Info);
5078 if (!EvaluateIgnoredValue(Info, Inc) || !IncScope.destroy())
5079 return ESR_Failed;
5080 }
5081 }
5082 break;
5083 }
5084
5085 case Stmt::DeclStmtClass: {
5086 // Start the lifetime of any uninitialized variables we encounter. They
5087 // might be used by the selected branch of the switch.
5088 const DeclStmt *DS = cast<DeclStmt>(S);
5089 for (const auto *D : DS->decls()) {
5090 if (const auto *VD = dyn_cast<VarDecl>(D)) {
5091 if (VD->hasLocalStorage() && !VD->getInit())
5092 if (!EvaluateVarDecl(Info, VD))
5093 return ESR_Failed;
5094 // FIXME: If the variable has initialization that can't be jumped
5095 // over, bail out of any immediately-surrounding compound-statement
5096 // too. There can't be any case labels here.
5097 }
5098 }
5099 return ESR_CaseNotFound;
5100 }
5101
5102 default:
5103 return ESR_CaseNotFound;
5104 }
5105 }
5106
5107 switch (S->getStmtClass()) {
5108 default:
5109 if (const Expr *E = dyn_cast<Expr>(S)) {
5110 if (E->isValueDependent()) {
5111 if (!EvaluateDependentExpr(E, Info))
5112 return ESR_Failed;
5113 } else {
5114 // Don't bother evaluating beyond an expression-statement which couldn't
5115 // be evaluated.
5116 // FIXME: Do we need the FullExpressionRAII object here?
5117 // VisitExprWithCleanups should create one when necessary.
5118 FullExpressionRAII Scope(Info);
5119 if (!EvaluateIgnoredValue(Info, E) || !Scope.destroy())
5120 return ESR_Failed;
5121 }
5122 return ESR_Succeeded;
5123 }
5124
5125 Info.FFDiag(S->getBeginLoc());
5126 return ESR_Failed;
5127
5128 case Stmt::NullStmtClass:
5129 return ESR_Succeeded;
5130
5131 case Stmt::DeclStmtClass: {
5132 const DeclStmt *DS = cast<DeclStmt>(S);
5133 for (const auto *D : DS->decls()) {
5134 // Each declaration initialization is its own full-expression.
5135 FullExpressionRAII Scope(Info);
5136 if (!EvaluateDecl(Info, D) && !Info.noteFailure())
5137 return ESR_Failed;
5138 if (!Scope.destroy())
5139 return ESR_Failed;
5140 }
5141 return ESR_Succeeded;
5142 }
5143
5144 case Stmt::ReturnStmtClass: {
5145 const Expr *RetExpr = cast<ReturnStmt>(S)->getRetValue();
5146 FullExpressionRAII Scope(Info);
5147 if (RetExpr && RetExpr->isValueDependent()) {
5148 EvaluateDependentExpr(RetExpr, Info);
5149 // We know we returned, but we don't know what the value is.
5150 return ESR_Failed;
5151 }
5152 if (RetExpr &&
5153 !(Result.Slot
5154 ? EvaluateInPlace(Result.Value, Info, *Result.Slot, RetExpr)
5155 : Evaluate(Result.Value, Info, RetExpr)))
5156 return ESR_Failed;
5157 return Scope.destroy() ? ESR_Returned : ESR_Failed;
5158 }
5159
5160 case Stmt::CompoundStmtClass: {
5161 BlockScopeRAII Scope(Info);
5162
5163 const CompoundStmt *CS = cast<CompoundStmt>(S);
5164 for (const auto *BI : CS->body()) {
5165 EvalStmtResult ESR = EvaluateStmt(Result, Info, BI, Case);
5166 if (ESR == ESR_Succeeded)
5167 Case = nullptr;
5168 else if (ESR != ESR_CaseNotFound) {
5169 if (ESR != ESR_Failed && !Scope.destroy())
5170 return ESR_Failed;
5171 return ESR;
5172 }
5173 }
5174 if (Case)
5175 return ESR_CaseNotFound;
5176 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
5177 }
5178
5179 case Stmt::IfStmtClass: {
5180 const IfStmt *IS = cast<IfStmt>(S);
5181
5182 // Evaluate the condition, as either a var decl or as an expression.
5183 BlockScopeRAII Scope(Info);
5184 if (const Stmt *Init = IS->getInit()) {
5185 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
5186 if (ESR != ESR_Succeeded) {
5187 if (ESR != ESR_Failed && !Scope.destroy())
5188 return ESR_Failed;
5189 return ESR;
5190 }
5191 }
5192 bool Cond;
5193 if (!EvaluateCond(Info, IS->getConditionVariable(), IS->getCond(), Cond))
5194 return ESR_Failed;
5195
5196 if (const Stmt *SubStmt = Cond ? IS->getThen() : IS->getElse()) {
5197 EvalStmtResult ESR = EvaluateStmt(Result, Info, SubStmt);
5198 if (ESR != ESR_Succeeded) {
5199 if (ESR != ESR_Failed && !Scope.destroy())
5200 return ESR_Failed;
5201 return ESR;
5202 }
5203 }
5204 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
5205 }
5206
5207 case Stmt::WhileStmtClass: {
5208 const WhileStmt *WS = cast<WhileStmt>(S);
5209 while (true) {
5210 BlockScopeRAII Scope(Info);
5211 bool Continue;
5212 if (!EvaluateCond(Info, WS->getConditionVariable(), WS->getCond(),
5213 Continue))
5214 return ESR_Failed;
5215 if (!Continue)
5216 break;
5217
5218 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, WS->getBody());
5219 if (ESR != ESR_Continue) {
5220 if (ESR != ESR_Failed && !Scope.destroy())
5221 return ESR_Failed;
5222 return ESR;
5223 }
5224 if (!Scope.destroy())
5225 return ESR_Failed;
5226 }
5227 return ESR_Succeeded;
5228 }
5229
5230 case Stmt::DoStmtClass: {
5231 const DoStmt *DS = cast<DoStmt>(S);
5232 bool Continue;
5233 do {
5234 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, DS->getBody(), Case);
5235 if (ESR != ESR_Continue)
5236 return ESR;
5237 Case = nullptr;
5238
5239 if (DS->getCond()->isValueDependent()) {
5240 EvaluateDependentExpr(DS->getCond(), Info);
5241 // Bailout as we don't know whether to keep going or terminate the loop.
5242 return ESR_Failed;
5243 }
5244 FullExpressionRAII CondScope(Info);
5245 if (!EvaluateAsBooleanCondition(DS->getCond(), Continue, Info) ||
5246 !CondScope.destroy())
5247 return ESR_Failed;
5248 } while (Continue);
5249 return ESR_Succeeded;
5250 }
5251
5252 case Stmt::ForStmtClass: {
5253 const ForStmt *FS = cast<ForStmt>(S);
5254 BlockScopeRAII ForScope(Info);
5255 if (FS->getInit()) {
5256 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
5257 if (ESR != ESR_Succeeded) {
5258 if (ESR != ESR_Failed && !ForScope.destroy())
5259 return ESR_Failed;
5260 return ESR;
5261 }
5262 }
5263 while (true) {
5264 BlockScopeRAII IterScope(Info);
5265 bool Continue = true;
5266 if (FS->getCond() && !EvaluateCond(Info, FS->getConditionVariable(),
5267 FS->getCond(), Continue))
5268 return ESR_Failed;
5269 if (!Continue)
5270 break;
5271
5272 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, FS->getBody());
5273 if (ESR != ESR_Continue) {
5274 if (ESR != ESR_Failed && (!IterScope.destroy() || !ForScope.destroy()))
5275 return ESR_Failed;
5276 return ESR;
5277 }
5278
5279 if (const auto *Inc = FS->getInc()) {
5280 if (Inc->isValueDependent()) {
5281 if (!EvaluateDependentExpr(Inc, Info))
5282 return ESR_Failed;
5283 } else {
5284 FullExpressionRAII IncScope(Info);
5285 if (!EvaluateIgnoredValue(Info, Inc) || !IncScope.destroy())
5286 return ESR_Failed;
5287 }
5288 }
5289
5290 if (!IterScope.destroy())
5291 return ESR_Failed;
5292 }
5293 return ForScope.destroy() ? ESR_Succeeded : ESR_Failed;
5294 }
5295
5296 case Stmt::CXXForRangeStmtClass: {
5297 const CXXForRangeStmt *FS = cast<CXXForRangeStmt>(S);
5298 BlockScopeRAII Scope(Info);
5299
5300 // Evaluate the init-statement if present.
5301 if (FS->getInit()) {
5302 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
5303 if (ESR != ESR_Succeeded) {
5304 if (ESR != ESR_Failed && !Scope.destroy())
5305 return ESR_Failed;
5306 return ESR;
5307 }
5308 }
5309
5310 // Initialize the __range variable.
5311 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getRangeStmt());
5312 if (ESR != ESR_Succeeded) {
5313 if (ESR != ESR_Failed && !Scope.destroy())
5314 return ESR_Failed;
5315 return ESR;
5316 }
5317
5318 // Create the __begin and __end iterators.
5319 ESR = EvaluateStmt(Result, Info, FS->getBeginStmt());
5320 if (ESR != ESR_Succeeded) {
5321 if (ESR != ESR_Failed && !Scope.destroy())
5322 return ESR_Failed;
5323 return ESR;
5324 }
5325 ESR = EvaluateStmt(Result, Info, FS->getEndStmt());
5326 if (ESR != ESR_Succeeded) {
5327 if (ESR != ESR_Failed && !Scope.destroy())
5328 return ESR_Failed;
5329 return ESR;
5330 }
5331
5332 while (true) {
5333 // Condition: __begin != __end.
5334 {
5335 if (FS->getCond()->isValueDependent()) {
5336 EvaluateDependentExpr(FS->getCond(), Info);
5337 // We don't know whether to keep going or terminate the loop.
5338 return ESR_Failed;
5339 }
5340 bool Continue = true;
5341 FullExpressionRAII CondExpr(Info);
5342 if (!EvaluateAsBooleanCondition(FS->getCond(), Continue, Info))
5343 return ESR_Failed;
5344 if (!Continue)
5345 break;
5346 }
5347
5348 // User's variable declaration, initialized by *__begin.
5349 BlockScopeRAII InnerScope(Info);
5350 ESR = EvaluateStmt(Result, Info, FS->getLoopVarStmt());
5351 if (ESR != ESR_Succeeded) {
5352 if (ESR != ESR_Failed && (!InnerScope.destroy() || !Scope.destroy()))
5353 return ESR_Failed;
5354 return ESR;
5355 }
5356
5357 // Loop body.
5358 ESR = EvaluateLoopBody(Result, Info, FS->getBody());
5359 if (ESR != ESR_Continue) {
5360 if (ESR != ESR_Failed && (!InnerScope.destroy() || !Scope.destroy()))
5361 return ESR_Failed;
5362 return ESR;
5363 }
5364 if (FS->getInc()->isValueDependent()) {
5365 if (!EvaluateDependentExpr(FS->getInc(), Info))
5366 return ESR_Failed;
5367 } else {
5368 // Increment: ++__begin
5369 if (!EvaluateIgnoredValue(Info, FS->getInc()))
5370 return ESR_Failed;
5371 }
5372
5373 if (!InnerScope.destroy())
5374 return ESR_Failed;
5375 }
5376
5377 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
5378 }
5379
5380 case Stmt::SwitchStmtClass:
5381 return EvaluateSwitch(Result, Info, cast<SwitchStmt>(S));
5382
5383 case Stmt::ContinueStmtClass:
5384 return ESR_Continue;
5385
5386 case Stmt::BreakStmtClass:
5387 return ESR_Break;
5388
5389 case Stmt::LabelStmtClass:
5390 return EvaluateStmt(Result, Info, cast<LabelStmt>(S)->getSubStmt(), Case);
5391
5392 case Stmt::AttributedStmtClass:
5393 // As a general principle, C++11 attributes can be ignored without
5394 // any semantic impact.
5395 return EvaluateStmt(Result, Info, cast<AttributedStmt>(S)->getSubStmt(),
5396 Case);
5397
5398 case Stmt::CaseStmtClass:
5399 case Stmt::DefaultStmtClass:
5400 return EvaluateStmt(Result, Info, cast<SwitchCase>(S)->getSubStmt(), Case);
5401 case Stmt::CXXTryStmtClass:
5402 // Evaluate try blocks by evaluating all sub statements.
5403 return EvaluateStmt(Result, Info, cast<CXXTryStmt>(S)->getTryBlock(), Case);
5404 }
5405}
5406
5407/// CheckTrivialDefaultConstructor - Check whether a constructor is a trivial
5408/// default constructor. If so, we'll fold it whether or not it's marked as
5409/// constexpr. If it is marked as constexpr, we will never implicitly define it,
5410/// so we need special handling.
5411static bool CheckTrivialDefaultConstructor(EvalInfo &Info, SourceLocation Loc,
5412 const CXXConstructorDecl *CD,
5413 bool IsValueInitialization) {
5414 if (!CD->isTrivial() || !CD->isDefaultConstructor())
5415 return false;
5416
5417 // Value-initialization does not call a trivial default constructor, so such a
5418 // call is a core constant expression whether or not the constructor is
5419 // constexpr.
5420 if (!CD->isConstexpr() && !IsValueInitialization) {
5421 if (Info.getLangOpts().CPlusPlus11) {
5422 // FIXME: If DiagDecl is an implicitly-declared special member function,
5423 // we should be much more explicit about why it's not constexpr.
5424 Info.CCEDiag(Loc, diag::note_constexpr_invalid_function, 1)
5425 << /*IsConstexpr*/0 << /*IsConstructor*/1 << CD;
5426 Info.Note(CD->getLocation(), diag::note_declared_at);
5427 } else {
5428 Info.CCEDiag(Loc, diag::note_invalid_subexpr_in_const_expr);
5429 }
5430 }
5431 return true;
5432}
5433
5434/// CheckConstexprFunction - Check that a function can be called in a constant
5435/// expression.
5436static bool CheckConstexprFunction(EvalInfo &Info, SourceLocation CallLoc,
5437 const FunctionDecl *Declaration,
5438 const FunctionDecl *Definition,
5439 const Stmt *Body) {
5440 // Potential constant expressions can contain calls to declared, but not yet
5441 // defined, constexpr functions.
5442 if (Info.checkingPotentialConstantExpression() && !Definition &&
5443 Declaration->isConstexpr())
5444 return false;
5445
5446 // Bail out if the function declaration itself is invalid. We will
5447 // have produced a relevant diagnostic while parsing it, so just
5448 // note the problematic sub-expression.
5449 if (Declaration->isInvalidDecl()) {
5450 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
5451 return false;
5452 }
5453
5454 // DR1872: An instantiated virtual constexpr function can't be called in a
5455 // constant expression (prior to C++20). We can still constant-fold such a
5456 // call.
5457 if (!Info.Ctx.getLangOpts().CPlusPlus20 && isa<CXXMethodDecl>(Declaration) &&
5458 cast<CXXMethodDecl>(Declaration)->isVirtual())
5459 Info.CCEDiag(CallLoc, diag::note_constexpr_virtual_call);
5460
5461 if (Definition && Definition->isInvalidDecl()) {
5462 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
5463 return false;
5464 }
5465
5466 // Can we evaluate this function call?
5467 if (Definition && Definition->isConstexpr() && Body)
5468 return true;
5469
5470 if (Info.getLangOpts().CPlusPlus11) {
5471 const FunctionDecl *DiagDecl = Definition ? Definition : Declaration;
5472
5473 // If this function is not constexpr because it is an inherited
5474 // non-constexpr constructor, diagnose that directly.
5475 auto *CD = dyn_cast<CXXConstructorDecl>(DiagDecl);
5476 if (CD && CD->isInheritingConstructor()) {
5477 auto *Inherited = CD->getInheritedConstructor().getConstructor();
5478 if (!Inherited->isConstexpr())
5479 DiagDecl = CD = Inherited;
5480 }
5481
5482 // FIXME: If DiagDecl is an implicitly-declared special member function
5483 // or an inheriting constructor, we should be much more explicit about why
5484 // it's not constexpr.
5485 if (CD && CD->isInheritingConstructor())
5486 Info.FFDiag(CallLoc, diag::note_constexpr_invalid_inhctor, 1)
5487 << CD->getInheritedConstructor().getConstructor()->getParent();
5488 else
5489 Info.FFDiag(CallLoc, diag::note_constexpr_invalid_function, 1)
5490 << DiagDecl->isConstexpr() << (bool)CD << DiagDecl;
5491 Info.Note(DiagDecl->getLocation(), diag::note_declared_at);
5492 } else {
5493 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
5494 }
5495 return false;
5496}
5497
5498namespace {
5499struct CheckDynamicTypeHandler {
5500 AccessKinds AccessKind;
5501 typedef bool result_type;
5502 bool failed() { return false; }
5503 bool found(APValue &Subobj, QualType SubobjType) { return true; }
5504 bool found(APSInt &Value, QualType SubobjType) { return true; }
5505 bool found(APFloat &Value, QualType SubobjType) { return true; }
5506};
5507} // end anonymous namespace
5508
5509/// Check that we can access the notional vptr of an object / determine its
5510/// dynamic type.
5511static bool checkDynamicType(EvalInfo &Info, const Expr *E, const LValue &This,
5512 AccessKinds AK, bool Polymorphic) {
5513 if (This.Designator.Invalid)
5514 return false;
5515
5516 CompleteObject Obj = findCompleteObject(Info, E, AK, This, QualType());
5517
5518 if (!Obj)
5519 return false;
5520
5521 if (!Obj.Value) {
5522 // The object is not usable in constant expressions, so we can't inspect
5523 // its value to see if it's in-lifetime or what the active union members
5524 // are. We can still check for a one-past-the-end lvalue.
5525 if (This.Designator.isOnePastTheEnd() ||
5526 This.Designator.isMostDerivedAnUnsizedArray()) {
5527 Info.FFDiag(E, This.Designator.isOnePastTheEnd()
5528 ? diag::note_constexpr_access_past_end
5529 : diag::note_constexpr_access_unsized_array)
5530 << AK;
5531 return false;
5532 } else if (Polymorphic) {
5533 // Conservatively refuse to perform a polymorphic operation if we would
5534 // not be able to read a notional 'vptr' value.
5535 APValue Val;
5536 This.moveInto(Val);
5537 QualType StarThisType =
5538 Info.Ctx.getLValueReferenceType(This.Designator.getType(Info.Ctx));
5539 Info.FFDiag(E, diag::note_constexpr_polymorphic_unknown_dynamic_type)
5540 << AK << Val.getAsString(Info.Ctx, StarThisType);
5541 return false;
5542 }
5543 return true;
5544 }
5545
5546 CheckDynamicTypeHandler Handler{AK};
5547 return Obj && findSubobject(Info, E, Obj, This.Designator, Handler);
5548}
5549
5550/// Check that the pointee of the 'this' pointer in a member function call is
5551/// either within its lifetime or in its period of construction or destruction.
5552static bool
5553checkNonVirtualMemberCallThisPointer(EvalInfo &Info, const Expr *E,
5554 const LValue &This,
5555 const CXXMethodDecl *NamedMember) {
5556 return checkDynamicType(
5557 Info, E, This,
5558 isa<CXXDestructorDecl>(NamedMember) ? AK_Destroy : AK_MemberCall, false);
5559}
5560
5561struct DynamicType {
5562 /// The dynamic class type of the object.
5563 const CXXRecordDecl *Type;
5564 /// The corresponding path length in the lvalue.
5565 unsigned PathLength;
5566};
5567
5568static const CXXRecordDecl *getBaseClassType(SubobjectDesignator &Designator,
5569 unsigned PathLength) {
5570 assert(PathLength >= Designator.MostDerivedPathLength && PathLength <=((PathLength >= Designator.MostDerivedPathLength &&
PathLength <= Designator.Entries.size() && "invalid path length"
) ? static_cast<void> (0) : __assert_fail ("PathLength >= Designator.MostDerivedPathLength && PathLength <= Designator.Entries.size() && \"invalid path length\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5571, __PRETTY_FUNCTION__))
5571 Designator.Entries.size() && "invalid path length")((PathLength >= Designator.MostDerivedPathLength &&
PathLength <= Designator.Entries.size() && "invalid path length"
) ? static_cast<void> (0) : __assert_fail ("PathLength >= Designator.MostDerivedPathLength && PathLength <= Designator.Entries.size() && \"invalid path length\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5571, __PRETTY_FUNCTION__))
;
5572 return (PathLength == Designator.MostDerivedPathLength)
5573 ? Designator.MostDerivedType->getAsCXXRecordDecl()
5574 : getAsBaseClass(Designator.Entries[PathLength - 1]);
5575}
5576
5577/// Determine the dynamic type of an object.
5578static Optional<DynamicType> ComputeDynamicType(EvalInfo &Info, const Expr *E,
5579 LValue &This, AccessKinds AK) {
5580 // If we don't have an lvalue denoting an object of class type, there is no
5581 // meaningful dynamic type. (We consider objects of non-class type to have no
5582 // dynamic type.)
5583 if (!checkDynamicType(Info, E, This, AK, true))
5584 return None;
5585
5586 // Refuse to compute a dynamic type in the presence of virtual bases. This
5587 // shouldn't happen other than in constant-folding situations, since literal
5588 // types can't have virtual bases.
5589 //
5590 // Note that consumers of DynamicType assume that the type has no virtual
5591 // bases, and will need modifications if this restriction is relaxed.
5592 const CXXRecordDecl *Class =
5593 This.Designator.MostDerivedType->getAsCXXRecordDecl();
5594 if (!Class || Class->getNumVBases()) {
5595 Info.FFDiag(E);
5596 return None;
5597 }
5598
5599 // FIXME: For very deep class hierarchies, it might be beneficial to use a
5600 // binary search here instead. But the overwhelmingly common case is that
5601 // we're not in the middle of a constructor, so it probably doesn't matter
5602 // in practice.
5603 ArrayRef<APValue::LValuePathEntry> Path = This.Designator.Entries;
5604 for (unsigned PathLength = This.Designator.MostDerivedPathLength;
5605 PathLength <= Path.size(); ++PathLength) {
5606 switch (Info.isEvaluatingCtorDtor(This.getLValueBase(),
5607 Path.slice(0, PathLength))) {
5608 case ConstructionPhase::Bases:
5609 case ConstructionPhase::DestroyingBases:
5610 // We're constructing or destroying a base class. This is not the dynamic
5611 // type.
5612 break;
5613
5614 case ConstructionPhase::None:
5615 case ConstructionPhase::AfterBases:
5616 case ConstructionPhase::AfterFields:
5617 case ConstructionPhase::Destroying:
5618 // We've finished constructing the base classes and not yet started
5619 // destroying them again, so this is the dynamic type.
5620 return DynamicType{getBaseClassType(This.Designator, PathLength),
5621 PathLength};
5622 }
5623 }
5624
5625 // CWG issue 1517: we're constructing a base class of the object described by
5626 // 'This', so that object has not yet begun its period of construction and
5627 // any polymorphic operation on it results in undefined behavior.
5628 Info.FFDiag(E);
5629 return None;
5630}
5631
5632/// Perform virtual dispatch.
5633static const CXXMethodDecl *HandleVirtualDispatch(
5634 EvalInfo &Info, const Expr *E, LValue &This, const CXXMethodDecl *Found,
5635 llvm::SmallVectorImpl<QualType> &CovariantAdjustmentPath) {
5636 Optional<DynamicType> DynType = ComputeDynamicType(
5637 Info, E, This,
5638 isa<CXXDestructorDecl>(Found) ? AK_Destroy : AK_MemberCall);
5639 if (!DynType)
5640 return nullptr;
5641
5642 // Find the final overrider. It must be declared in one of the classes on the
5643 // path from the dynamic type to the static type.
5644 // FIXME: If we ever allow literal types to have virtual base classes, that
5645 // won't be true.
5646 const CXXMethodDecl *Callee = Found;
5647 unsigned PathLength = DynType->PathLength;
5648 for (/**/; PathLength <= This.Designator.Entries.size(); ++PathLength) {
5649 const CXXRecordDecl *Class = getBaseClassType(This.Designator, PathLength);
5650 const CXXMethodDecl *Overrider =
5651 Found->getCorrespondingMethodDeclaredInClass(Class, false);
5652 if (Overrider) {
5653 Callee = Overrider;
5654 break;
5655 }
5656 }
5657
5658 // C++2a [class.abstract]p6:
5659 // the effect of making a virtual call to a pure virtual function [...] is
5660 // undefined
5661 if (Callee->isPure()) {
5662 Info.FFDiag(E, diag::note_constexpr_pure_virtual_call, 1) << Callee;
5663 Info.Note(Callee->getLocation(), diag::note_declared_at);
5664 return nullptr;
5665 }
5666
5667 // If necessary, walk the rest of the path to determine the sequence of
5668 // covariant adjustment steps to apply.
5669 if (!Info.Ctx.hasSameUnqualifiedType(Callee->getReturnType(),
5670 Found->getReturnType())) {
5671 CovariantAdjustmentPath.push_back(Callee->getReturnType());
5672 for (unsigned CovariantPathLength = PathLength + 1;
5673 CovariantPathLength != This.Designator.Entries.size();
5674 ++CovariantPathLength) {
5675 const CXXRecordDecl *NextClass =
5676 getBaseClassType(This.Designator, CovariantPathLength);
5677 const CXXMethodDecl *Next =
5678 Found->getCorrespondingMethodDeclaredInClass(NextClass, false);
5679 if (Next && !Info.Ctx.hasSameUnqualifiedType(
5680 Next->getReturnType(), CovariantAdjustmentPath.back()))
5681 CovariantAdjustmentPath.push_back(Next->getReturnType());
5682 }
5683 if (!Info.Ctx.hasSameUnqualifiedType(Found->getReturnType(),
5684 CovariantAdjustmentPath.back()))
5685 CovariantAdjustmentPath.push_back(Found->getReturnType());
5686 }
5687
5688 // Perform 'this' adjustment.
5689 if (!CastToDerivedClass(Info, E, This, Callee->getParent(), PathLength))
5690 return nullptr;
5691
5692 return Callee;
5693}
5694
5695/// Perform the adjustment from a value returned by a virtual function to
5696/// a value of the statically expected type, which may be a pointer or
5697/// reference to a base class of the returned type.
5698static bool HandleCovariantReturnAdjustment(EvalInfo &Info, const Expr *E,
5699 APValue &Result,
5700 ArrayRef<QualType> Path) {
5701 assert(Result.isLValue() &&((Result.isLValue() && "unexpected kind of APValue for covariant return"
) ? static_cast<void> (0) : __assert_fail ("Result.isLValue() && \"unexpected kind of APValue for covariant return\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5702, __PRETTY_FUNCTION__))
5702 "unexpected kind of APValue for covariant return")((Result.isLValue() && "unexpected kind of APValue for covariant return"
) ? static_cast<void> (0) : __assert_fail ("Result.isLValue() && \"unexpected kind of APValue for covariant return\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5702, __PRETTY_FUNCTION__))
;
5703 if (Result.isNullPointer())
5704 return true;
5705
5706 LValue LVal;
5707 LVal.setFrom(Info.Ctx, Result);
5708
5709 const CXXRecordDecl *OldClass = Path[0]->getPointeeCXXRecordDecl();
5710 for (unsigned I = 1; I != Path.size(); ++I) {
5711 const CXXRecordDecl *NewClass = Path[I]->getPointeeCXXRecordDecl();
5712 assert(OldClass && NewClass && "unexpected kind of covariant return")((OldClass && NewClass && "unexpected kind of covariant return"
) ? static_cast<void> (0) : __assert_fail ("OldClass && NewClass && \"unexpected kind of covariant return\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5712, __PRETTY_FUNCTION__))
;
5713 if (OldClass != NewClass &&
5714 !CastToBaseClass(Info, E, LVal, OldClass, NewClass))
5715 return false;
5716 OldClass = NewClass;
5717 }
5718
5719 LVal.moveInto(Result);
5720 return true;
5721}
5722
5723/// Determine whether \p Base, which is known to be a direct base class of
5724/// \p Derived, is a public base class.
5725static bool isBaseClassPublic(const CXXRecordDecl *Derived,
5726 const CXXRecordDecl *Base) {
5727 for (const CXXBaseSpecifier &BaseSpec : Derived->bases()) {
5728 auto *BaseClass = BaseSpec.getType()->getAsCXXRecordDecl();
5729 if (BaseClass && declaresSameEntity(BaseClass, Base))
5730 return BaseSpec.getAccessSpecifier() == AS_public;
5731 }
5732 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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5732)
;
5733}
5734
5735/// Apply the given dynamic cast operation on the provided lvalue.
5736///
5737/// This implements the hard case of dynamic_cast, requiring a "runtime check"
5738/// to find a suitable target subobject.
5739static bool HandleDynamicCast(EvalInfo &Info, const ExplicitCastExpr *E,
5740 LValue &Ptr) {
5741 // We can't do anything with a non-symbolic pointer value.
5742 SubobjectDesignator &D = Ptr.Designator;
5743 if (D.Invalid)
5744 return false;
5745
5746 // C++ [expr.dynamic.cast]p6:
5747 // If v is a null pointer value, the result is a null pointer value.
5748 if (Ptr.isNullPointer() && !E->isGLValue())
5749 return true;
5750
5751 // For all the other cases, we need the pointer to point to an object within
5752 // its lifetime / period of construction / destruction, and we need to know
5753 // its dynamic type.
5754 Optional<DynamicType> DynType =
5755 ComputeDynamicType(Info, E, Ptr, AK_DynamicCast);
5756 if (!DynType)
5757 return false;
5758
5759 // C++ [expr.dynamic.cast]p7:
5760 // If T is "pointer to cv void", then the result is a pointer to the most
5761 // derived object
5762 if (E->getType()->isVoidPointerType())
5763 return CastToDerivedClass(Info, E, Ptr, DynType->Type, DynType->PathLength);
5764
5765 const CXXRecordDecl *C = E->getTypeAsWritten()->getPointeeCXXRecordDecl();
5766 assert(C && "dynamic_cast target is not void pointer nor class")((C && "dynamic_cast target is not void pointer nor class"
) ? static_cast<void> (0) : __assert_fail ("C && \"dynamic_cast target is not void pointer nor class\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5766, __PRETTY_FUNCTION__))
;
5767 CanQualType CQT = Info.Ctx.getCanonicalType(Info.Ctx.getRecordType(C));
5768
5769 auto RuntimeCheckFailed = [&] (CXXBasePaths *Paths) {
5770 // C++ [expr.dynamic.cast]p9:
5771 if (!E->isGLValue()) {
5772 // The value of a failed cast to pointer type is the null pointer value
5773 // of the required result type.
5774 Ptr.setNull(Info.Ctx, E->getType());
5775 return true;
5776 }
5777
5778 // A failed cast to reference type throws [...] std::bad_cast.
5779 unsigned DiagKind;
5780 if (!Paths && (declaresSameEntity(DynType->Type, C) ||
5781 DynType->Type->isDerivedFrom(C)))
5782 DiagKind = 0;
5783 else if (!Paths || Paths->begin() == Paths->end())
5784 DiagKind = 1;
5785 else if (Paths->isAmbiguous(CQT))
5786 DiagKind = 2;
5787 else {
5788 assert(Paths->front().Access != AS_public && "why did the cast fail?")((Paths->front().Access != AS_public && "why did the cast fail?"
) ? static_cast<void> (0) : __assert_fail ("Paths->front().Access != AS_public && \"why did the cast fail?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5788, __PRETTY_FUNCTION__))
;
5789 DiagKind = 3;
5790 }
5791 Info.FFDiag(E, diag::note_constexpr_dynamic_cast_to_reference_failed)
5792 << DiagKind << Ptr.Designator.getType(Info.Ctx)
5793 << Info.Ctx.getRecordType(DynType->Type)
5794 << E->getType().getUnqualifiedType();
5795 return false;
5796 };
5797
5798 // Runtime check, phase 1:
5799 // Walk from the base subobject towards the derived object looking for the
5800 // target type.
5801 for (int PathLength = Ptr.Designator.Entries.size();
5802 PathLength >= (int)DynType->PathLength; --PathLength) {
5803 const CXXRecordDecl *Class = getBaseClassType(Ptr.Designator, PathLength);
5804 if (declaresSameEntity(Class, C))
5805 return CastToDerivedClass(Info, E, Ptr, Class, PathLength);
5806 // We can only walk across public inheritance edges.
5807 if (PathLength > (int)DynType->PathLength &&
5808 !isBaseClassPublic(getBaseClassType(Ptr.Designator, PathLength - 1),
5809 Class))
5810 return RuntimeCheckFailed(nullptr);
5811 }
5812
5813 // Runtime check, phase 2:
5814 // Search the dynamic type for an unambiguous public base of type C.
5815 CXXBasePaths Paths(/*FindAmbiguities=*/true,
5816 /*RecordPaths=*/true, /*DetectVirtual=*/false);
5817 if (DynType->Type->isDerivedFrom(C, Paths) && !Paths.isAmbiguous(CQT) &&
5818 Paths.front().Access == AS_public) {
5819 // Downcast to the dynamic type...
5820 if (!CastToDerivedClass(Info, E, Ptr, DynType->Type, DynType->PathLength))
5821 return false;
5822 // ... then upcast to the chosen base class subobject.
5823 for (CXXBasePathElement &Elem : Paths.front())
5824 if (!HandleLValueBase(Info, E, Ptr, Elem.Class, Elem.Base))
5825 return false;
5826 return true;
5827 }
5828
5829 // Otherwise, the runtime check fails.
5830 return RuntimeCheckFailed(&Paths);
5831}
5832
5833namespace {
5834struct StartLifetimeOfUnionMemberHandler {
5835 EvalInfo &Info;
5836 const Expr *LHSExpr;
5837 const FieldDecl *Field;
5838 bool DuringInit;
5839 bool Failed = false;
5840 static const AccessKinds AccessKind = AK_Assign;
5841
5842 typedef bool result_type;
5843 bool failed() { return Failed; }
5844 bool found(APValue &Subobj, QualType SubobjType) {
5845 // We are supposed to perform no initialization but begin the lifetime of
5846 // the object. We interpret that as meaning to do what default
5847 // initialization of the object would do if all constructors involved were
5848 // trivial:
5849 // * All base, non-variant member, and array element subobjects' lifetimes
5850 // begin
5851 // * No variant members' lifetimes begin
5852 // * All scalar subobjects whose lifetimes begin have indeterminate values
5853 assert(SubobjType->isUnionType())((SubobjType->isUnionType()) ? static_cast<void> (0)
: __assert_fail ("SubobjType->isUnionType()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5853, __PRETTY_FUNCTION__))
;
5854 if (declaresSameEntity(Subobj.getUnionField(), Field)) {
5855 // This union member is already active. If it's also in-lifetime, there's
5856 // nothing to do.
5857 if (Subobj.getUnionValue().hasValue())
5858 return true;
5859 } else if (DuringInit) {
5860 // We're currently in the process of initializing a different union
5861 // member. If we carried on, that initialization would attempt to
5862 // store to an inactive union member, resulting in undefined behavior.
5863 Info.FFDiag(LHSExpr,
5864 diag::note_constexpr_union_member_change_during_init);
5865 return false;
5866 }
5867 APValue Result;
5868 Failed = !getDefaultInitValue(Field->getType(), Result);
5869 Subobj.setUnion(Field, Result);
5870 return true;
5871 }
5872 bool found(APSInt &Value, QualType SubobjType) {
5873 llvm_unreachable("wrong value kind for union object")::llvm::llvm_unreachable_internal("wrong value kind for union object"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5873)
;
5874 }
5875 bool found(APFloat &Value, QualType SubobjType) {
5876 llvm_unreachable("wrong value kind for union object")::llvm::llvm_unreachable_internal("wrong value kind for union object"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5876)
;
5877 }
5878};
5879} // end anonymous namespace
5880
5881const AccessKinds StartLifetimeOfUnionMemberHandler::AccessKind;
5882
5883/// Handle a builtin simple-assignment or a call to a trivial assignment
5884/// operator whose left-hand side might involve a union member access. If it
5885/// does, implicitly start the lifetime of any accessed union elements per
5886/// C++20 [class.union]5.
5887static bool HandleUnionActiveMemberChange(EvalInfo &Info, const Expr *LHSExpr,
5888 const LValue &LHS) {
5889 if (LHS.InvalidBase || LHS.Designator.Invalid)
5890 return false;
5891
5892 llvm::SmallVector<std::pair<unsigned, const FieldDecl*>, 4> UnionPathLengths;
5893 // C++ [class.union]p5:
5894 // define the set S(E) of subexpressions of E as follows:
5895 unsigned PathLength = LHS.Designator.Entries.size();
5896 for (const Expr *E = LHSExpr; E != nullptr;) {
5897 // -- If E is of the form A.B, S(E) contains the elements of S(A)...
5898 if (auto *ME = dyn_cast<MemberExpr>(E)) {
5899 auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
5900 // Note that we can't implicitly start the lifetime of a reference,
5901 // so we don't need to proceed any further if we reach one.
5902 if (!FD || FD->getType()->isReferenceType())
5903 break;
5904
5905 // ... and also contains A.B if B names a union member ...
5906 if (FD->getParent()->isUnion()) {
5907 // ... of a non-class, non-array type, or of a class type with a
5908 // trivial default constructor that is not deleted, or an array of
5909 // such types.
5910 auto *RD =
5911 FD->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
5912 if (!RD || RD->hasTrivialDefaultConstructor())
5913 UnionPathLengths.push_back({PathLength - 1, FD});
5914 }
5915
5916 E = ME->getBase();
5917 --PathLength;
5918 assert(declaresSameEntity(FD,((declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .
getAsBaseOrMember().getPointer())) ? static_cast<void> (
0) : __assert_fail ("declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5920, __PRETTY_FUNCTION__))
5919 LHS.Designator.Entries[PathLength]((declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .
getAsBaseOrMember().getPointer())) ? static_cast<void> (
0) : __assert_fail ("declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5920, __PRETTY_FUNCTION__))
5920 .getAsBaseOrMember().getPointer()))((declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .
getAsBaseOrMember().getPointer())) ? static_cast<void> (
0) : __assert_fail ("declaresSameEntity(FD, LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5920, __PRETTY_FUNCTION__))
;
5921
5922 // -- If E is of the form A[B] and is interpreted as a built-in array
5923 // subscripting operator, S(E) is [S(the array operand, if any)].
5924 } else if (auto *ASE = dyn_cast<ArraySubscriptExpr>(E)) {
5925 // Step over an ArrayToPointerDecay implicit cast.
5926 auto *Base = ASE->getBase()->IgnoreImplicit();
5927 if (!Base->getType()->isArrayType())
5928 break;
5929
5930 E = Base;
5931 --PathLength;
5932
5933 } else if (auto *ICE = dyn_cast<ImplicitCastExpr>(E)) {
5934 // Step over a derived-to-base conversion.
5935 E = ICE->getSubExpr();
5936 if (ICE->getCastKind() == CK_NoOp)
5937 continue;
5938 if (ICE->getCastKind() != CK_DerivedToBase &&
5939 ICE->getCastKind() != CK_UncheckedDerivedToBase)
5940 break;
5941 // Walk path backwards as we walk up from the base to the derived class.
5942 for (const CXXBaseSpecifier *Elt : llvm::reverse(ICE->path())) {
5943 --PathLength;
5944 (void)Elt;
5945 assert(declaresSameEntity(Elt->getType()->getAsCXXRecordDecl(),((declaresSameEntity(Elt->getType()->getAsCXXRecordDecl
(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer
())) ? static_cast<void> (0) : __assert_fail ("declaresSameEntity(Elt->getType()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5947, __PRETTY_FUNCTION__))
5946 LHS.Designator.Entries[PathLength]((declaresSameEntity(Elt->getType()->getAsCXXRecordDecl
(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer
())) ? static_cast<void> (0) : __assert_fail ("declaresSameEntity(Elt->getType()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5947, __PRETTY_FUNCTION__))
5947 .getAsBaseOrMember().getPointer()))((declaresSameEntity(Elt->getType()->getAsCXXRecordDecl
(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer
())) ? static_cast<void> (0) : __assert_fail ("declaresSameEntity(Elt->getType()->getAsCXXRecordDecl(), LHS.Designator.Entries[PathLength] .getAsBaseOrMember().getPointer())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 5947, __PRETTY_FUNCTION__))
;
5948 }
5949
5950 // -- Otherwise, S(E) is empty.
5951 } else {
5952 break;
5953 }
5954 }
5955
5956 // Common case: no unions' lifetimes are started.
5957 if (UnionPathLengths.empty())
5958 return true;
5959
5960 // if modification of X [would access an inactive union member], an object
5961 // of the type of X is implicitly created
5962 CompleteObject Obj =
5963 findCompleteObject(Info, LHSExpr, AK_Assign, LHS, LHSExpr->getType());
5964 if (!Obj)
5965 return false;
5966 for (std::pair<unsigned, const FieldDecl *> LengthAndField :
5967 llvm::reverse(UnionPathLengths)) {
5968 // Form a designator for the union object.
5969 SubobjectDesignator D = LHS.Designator;
5970 D.truncate(Info.Ctx, LHS.Base, LengthAndField.first);
5971
5972 bool DuringInit = Info.isEvaluatingCtorDtor(LHS.Base, D.Entries) ==
5973 ConstructionPhase::AfterBases;
5974 StartLifetimeOfUnionMemberHandler StartLifetime{
5975 Info, LHSExpr, LengthAndField.second, DuringInit};
5976 if (!findSubobject(Info, LHSExpr, Obj, D, StartLifetime))
5977 return false;
5978 }
5979
5980 return true;
5981}
5982
5983static bool EvaluateCallArg(const ParmVarDecl *PVD, const Expr *Arg,
5984 CallRef Call, EvalInfo &Info,
5985 bool NonNull = false) {
5986 LValue LV;
5987 // Create the parameter slot and register its destruction. For a vararg
5988 // argument, create a temporary.
5989 // FIXME: For calling conventions that destroy parameters in the callee,
5990 // should we consider performing destruction when the function returns
5991 // instead?
5992 APValue &V = PVD ? Info.CurrentCall->createParam(Call, PVD, LV)
5993 : Info.CurrentCall->createTemporary(Arg, Arg->getType(),
5994 ScopeKind::Call, LV);
5995 if (!EvaluateInPlace(V, Info, LV, Arg))
5996 return false;
5997
5998 // Passing a null pointer to an __attribute__((nonnull)) parameter results in
5999 // undefined behavior, so is non-constant.
6000 if (NonNull && V.isLValue() && V.isNullPointer()) {
6001 Info.CCEDiag(Arg, diag::note_non_null_attribute_failed);
6002 return false;
6003 }
6004
6005 return true;
6006}
6007
6008/// Evaluate the arguments to a function call.
6009static bool EvaluateArgs(ArrayRef<const Expr *> Args, CallRef Call,
6010 EvalInfo &Info, const FunctionDecl *Callee,
6011 bool RightToLeft = false) {
6012 bool Success = true;
6013 llvm::SmallBitVector ForbiddenNullArgs;
6014 if (Callee->hasAttr<NonNullAttr>()) {
6015 ForbiddenNullArgs.resize(Args.size());
6016 for (const auto *Attr : Callee->specific_attrs<NonNullAttr>()) {
6017 if (!Attr->args_size()) {
6018 ForbiddenNullArgs.set();
6019 break;
6020 } else
6021 for (auto Idx : Attr->args()) {
6022 unsigned ASTIdx = Idx.getASTIndex();
6023 if (ASTIdx >= Args.size())
6024 continue;
6025 ForbiddenNullArgs[ASTIdx] = 1;
6026 }
6027 }
6028 }
6029 for (unsigned I = 0; I < Args.size(); I++) {
6030 unsigned Idx = RightToLeft ? Args.size() - I - 1 : I;
6031 const ParmVarDecl *PVD =
6032 Idx < Callee->getNumParams() ? Callee->getParamDecl(Idx) : nullptr;
6033 bool NonNull = !ForbiddenNullArgs.empty() && ForbiddenNullArgs[Idx];
6034 if (!EvaluateCallArg(PVD, Args[Idx], Call, Info, NonNull)) {
6035 // If we're checking for a potential constant expression, evaluate all
6036 // initializers even if some of them fail.
6037 if (!Info.noteFailure())
6038 return false;
6039 Success = false;
6040 }
6041 }
6042 return Success;
6043}
6044
6045/// Perform a trivial copy from Param, which is the parameter of a copy or move
6046/// constructor or assignment operator.
6047static bool handleTrivialCopy(EvalInfo &Info, const ParmVarDecl *Param,
6048 const Expr *E, APValue &Result,
6049 bool CopyObjectRepresentation) {
6050 // Find the reference argument.
6051 CallStackFrame *Frame = Info.CurrentCall;
6052 APValue *RefValue = Info.getParamSlot(Frame->Arguments, Param);
6053 if (!RefValue) {
6054 Info.FFDiag(E);
6055 return false;
6056 }
6057
6058 // Copy out the contents of the RHS object.
6059 LValue RefLValue;
6060 RefLValue.setFrom(Info.Ctx, *RefValue);
6061 return handleLValueToRValueConversion(
6062 Info, E, Param->getType().getNonReferenceType(), RefLValue, Result,
6063 CopyObjectRepresentation);
6064}
6065
6066/// Evaluate a function call.
6067static bool HandleFunctionCall(SourceLocation CallLoc,
6068 const FunctionDecl *Callee, const LValue *This,
6069 ArrayRef<const Expr *> Args, CallRef Call,
6070 const Stmt *Body, EvalInfo &Info,
6071 APValue &Result, const LValue *ResultSlot) {
6072 if (!Info.CheckCallLimit(CallLoc))
6073 return false;
6074
6075 CallStackFrame Frame(Info, CallLoc, Callee, This, Call);
6076
6077 // For a trivial copy or move assignment, perform an APValue copy. This is
6078 // essential for unions, where the operations performed by the assignment
6079 // operator cannot be represented as statements.
6080 //
6081 // Skip this for non-union classes with no fields; in that case, the defaulted
6082 // copy/move does not actually read the object.
6083 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Callee);
6084 if (MD && MD->isDefaulted() &&
6085 (MD->getParent()->isUnion() ||
6086 (MD->isTrivial() &&
6087 isReadByLvalueToRvalueConversion(MD->getParent())))) {
6088 assert(This &&((This && (MD->isCopyAssignmentOperator() || MD->
isMoveAssignmentOperator())) ? static_cast<void> (0) : __assert_fail
("This && (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6089, __PRETTY_FUNCTION__))
6089 (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()))((This && (MD->isCopyAssignmentOperator() || MD->
isMoveAssignmentOperator())) ? static_cast<void> (0) : __assert_fail
("This && (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6089, __PRETTY_FUNCTION__))
;
6090 APValue RHSValue;
6091 if (!handleTrivialCopy(Info, MD->getParamDecl(0), Args[0], RHSValue,
6092 MD->getParent()->isUnion()))
6093 return false;
6094 if (Info.getLangOpts().CPlusPlus20 && MD->isTrivial() &&
6095 !HandleUnionActiveMemberChange(Info, Args[0], *This))
6096 return false;
6097 if (!handleAssignment(Info, Args[0], *This, MD->getThisType(),
6098 RHSValue))
6099 return false;
6100 This->moveInto(Result);
6101 return true;
6102 } else if (MD && isLambdaCallOperator(MD)) {
6103 // We're in a lambda; determine the lambda capture field maps unless we're
6104 // just constexpr checking a lambda's call operator. constexpr checking is
6105 // done before the captures have been added to the closure object (unless
6106 // we're inferring constexpr-ness), so we don't have access to them in this
6107 // case. But since we don't need the captures to constexpr check, we can
6108 // just ignore them.
6109 if (!Info.checkingPotentialConstantExpression())
6110 MD->getParent()->getCaptureFields(Frame.LambdaCaptureFields,
6111 Frame.LambdaThisCaptureField);
6112 }
6113
6114 StmtResult Ret = {Result, ResultSlot};
6115 EvalStmtResult ESR = EvaluateStmt(Ret, Info, Body);
6116 if (ESR == ESR_Succeeded) {
6117 if (Callee->getReturnType()->isVoidType())
6118 return true;
6119 Info.FFDiag(Callee->getEndLoc(), diag::note_constexpr_no_return);
6120 }
6121 return ESR == ESR_Returned;
6122}
6123
6124/// Evaluate a constructor call.
6125static bool HandleConstructorCall(const Expr *E, const LValue &This,
6126 CallRef Call,
6127 const CXXConstructorDecl *Definition,
6128 EvalInfo &Info, APValue &Result) {
6129 SourceLocation CallLoc = E->getExprLoc();
6130 if (!Info.CheckCallLimit(CallLoc))
6131 return false;
6132
6133 const CXXRecordDecl *RD = Definition->getParent();
6134 if (RD->getNumVBases()) {
6135 Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD;
6136 return false;
6137 }
6138
6139 EvalInfo::EvaluatingConstructorRAII EvalObj(
6140 Info,
6141 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries},
6142 RD->getNumBases());
6143 CallStackFrame Frame(Info, CallLoc, Definition, &This, Call);
6144
6145 // FIXME: Creating an APValue just to hold a nonexistent return value is
6146 // wasteful.
6147 APValue RetVal;
6148 StmtResult Ret = {RetVal, nullptr};
6149
6150 // If it's a delegating constructor, delegate.
6151 if (Definition->isDelegatingConstructor()) {
6152 CXXConstructorDecl::init_const_iterator I = Definition->init_begin();
6153 if ((*I)->getInit()->isValueDependent()) {
6154 if (!EvaluateDependentExpr((*I)->getInit(), Info))
6155 return false;
6156 } else {
6157 FullExpressionRAII InitScope(Info);
6158 if (!EvaluateInPlace(Result, Info, This, (*I)->getInit()) ||
6159 !InitScope.destroy())
6160 return false;
6161 }
6162 return EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed;
6163 }
6164
6165 // For a trivial copy or move constructor, perform an APValue copy. This is
6166 // essential for unions (or classes with anonymous union members), where the
6167 // operations performed by the constructor cannot be represented by
6168 // ctor-initializers.
6169 //
6170 // Skip this for empty non-union classes; we should not perform an
6171 // lvalue-to-rvalue conversion on them because their copy constructor does not
6172 // actually read them.
6173 if (Definition->isDefaulted() && Definition->isCopyOrMoveConstructor() &&
6174 (Definition->getParent()->isUnion() ||
6175 (Definition->isTrivial() &&
6176 isReadByLvalueToRvalueConversion(Definition->getParent())))) {
6177 return handleTrivialCopy(Info, Definition->getParamDecl(0), E, Result,
6178 Definition->getParent()->isUnion());
6179 }
6180
6181 // Reserve space for the struct members.
6182 if (!Result.hasValue()) {
6183 if (!RD->isUnion())
6184 Result = APValue(APValue::UninitStruct(), RD->getNumBases(),
6185 std::distance(RD->field_begin(), RD->field_end()));
6186 else
6187 // A union starts with no active member.
6188 Result = APValue((const FieldDecl*)nullptr);
6189 }
6190
6191 if (RD->isInvalidDecl()) return false;
6192 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
6193
6194 // A scope for temporaries lifetime-extended by reference members.
6195 BlockScopeRAII LifetimeExtendedScope(Info);
6196
6197 bool Success = true;
6198 unsigned BasesSeen = 0;
6199#ifndef NDEBUG
6200 CXXRecordDecl::base_class_const_iterator BaseIt = RD->bases_begin();
6201#endif
6202 CXXRecordDecl::field_iterator FieldIt = RD->field_begin();
6203 auto SkipToField = [&](FieldDecl *FD, bool Indirect) {
6204 // We might be initializing the same field again if this is an indirect
6205 // field initialization.
6206 if (FieldIt == RD->field_end() ||
6207 FieldIt->getFieldIndex() > FD->getFieldIndex()) {
6208 assert(Indirect && "fields out of order?")((Indirect && "fields out of order?") ? static_cast<
void> (0) : __assert_fail ("Indirect && \"fields out of order?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6208, __PRETTY_FUNCTION__))
;
6209 return;
6210 }
6211
6212 // Default-initialize any fields with no explicit initializer.
6213 for (; !declaresSameEntity(*FieldIt, FD); ++FieldIt) {
6214 assert(FieldIt != RD->field_end() && "missing field?")((FieldIt != RD->field_end() && "missing field?") ?
static_cast<void> (0) : __assert_fail ("FieldIt != RD->field_end() && \"missing field?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6214, __PRETTY_FUNCTION__))
;
6215 if (!FieldIt->isUnnamedBitfield())
6216 Success &= getDefaultInitValue(
6217 FieldIt->getType(),
6218 Result.getStructField(FieldIt->getFieldIndex()));
6219 }
6220 ++FieldIt;
6221 };
6222 for (const auto *I : Definition->inits()) {
6223 LValue Subobject = This;
6224 LValue SubobjectParent = This;
6225 APValue *Value = &Result;
6226
6227 // Determine the subobject to initialize.
6228 FieldDecl *FD = nullptr;
6229 if (I->isBaseInitializer()) {
6230 QualType BaseType(I->getBaseClass(), 0);
6231#ifndef NDEBUG
6232 // Non-virtual base classes are initialized in the order in the class
6233 // definition. We have already checked for virtual base classes.
6234 assert(!BaseIt->isVirtual() && "virtual base for literal type")((!BaseIt->isVirtual() && "virtual base for literal type"
) ? static_cast<void> (0) : __assert_fail ("!BaseIt->isVirtual() && \"virtual base for literal type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6234, __PRETTY_FUNCTION__))
;
6235 assert(Info.Ctx.hasSameType(BaseIt->getType(), BaseType) &&((Info.Ctx.hasSameType(BaseIt->getType(), BaseType) &&
"base class initializers not in expected order") ? static_cast
<void> (0) : __assert_fail ("Info.Ctx.hasSameType(BaseIt->getType(), BaseType) && \"base class initializers not in expected order\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6236, __PRETTY_FUNCTION__))
6236 "base class initializers not in expected order")((Info.Ctx.hasSameType(BaseIt->getType(), BaseType) &&
"base class initializers not in expected order") ? static_cast
<void> (0) : __assert_fail ("Info.Ctx.hasSameType(BaseIt->getType(), BaseType) && \"base class initializers not in expected order\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6236, __PRETTY_FUNCTION__))
;
6237 ++BaseIt;
6238#endif
6239 if (!HandleLValueDirectBase(Info, I->getInit(), Subobject, RD,
6240 BaseType->getAsCXXRecordDecl(), &Layout))
6241 return false;
6242 Value = &Result.getStructBase(BasesSeen++);
6243 } else if ((FD = I->getMember())) {
6244 if (!HandleLValueMember(Info, I->getInit(), Subobject, FD, &Layout))
6245 return false;
6246 if (RD->isUnion()) {
6247 Result = APValue(FD);
6248 Value = &Result.getUnionValue();
6249 } else {
6250 SkipToField(FD, false);
6251 Value = &Result.getStructField(FD->getFieldIndex());
6252 }
6253 } else if (IndirectFieldDecl *IFD = I->getIndirectMember()) {
6254 // Walk the indirect field decl's chain to find the object to initialize,
6255 // and make sure we've initialized every step along it.
6256 auto IndirectFieldChain = IFD->chain();
6257 for (auto *C : IndirectFieldChain) {
6258 FD = cast<FieldDecl>(C);
6259 CXXRecordDecl *CD = cast<CXXRecordDecl>(FD->getParent());
6260 // Switch the union field if it differs. This happens if we had
6261 // preceding zero-initialization, and we're now initializing a union
6262 // subobject other than the first.
6263 // FIXME: In this case, the values of the other subobjects are
6264 // specified, since zero-initialization sets all padding bits to zero.
6265 if (!Value->hasValue() ||
6266 (Value->isUnion() && Value->getUnionField() != FD)) {
6267 if (CD->isUnion())
6268 *Value = APValue(FD);
6269 else
6270 // FIXME: This immediately starts the lifetime of all members of
6271 // an anonymous struct. It would be preferable to strictly start
6272 // member lifetime in initialization order.
6273 Success &= getDefaultInitValue(Info.Ctx.getRecordType(CD), *Value);
6274 }
6275 // Store Subobject as its parent before updating it for the last element
6276 // in the chain.
6277 if (C == IndirectFieldChain.back())
6278 SubobjectParent = Subobject;
6279 if (!HandleLValueMember(Info, I->getInit(), Subobject, FD))
6280 return false;
6281 if (CD->isUnion())
6282 Value = &Value->getUnionValue();
6283 else {
6284 if (C == IndirectFieldChain.front() && !RD->isUnion())
6285 SkipToField(FD, true);
6286 Value = &Value->getStructField(FD->getFieldIndex());
6287 }
6288 }
6289 } else {
6290 llvm_unreachable("unknown base initializer kind")::llvm::llvm_unreachable_internal("unknown base initializer kind"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6290)
;
6291 }
6292
6293 // Need to override This for implicit field initializers as in this case
6294 // This refers to innermost anonymous struct/union containing initializer,
6295 // not to currently constructed class.
6296 const Expr *Init = I->getInit();
6297 if (Init->isValueDependent()) {
6298 if (!EvaluateDependentExpr(Init, Info))
6299 return false;
6300 } else {
6301 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &SubobjectParent,
6302 isa<CXXDefaultInitExpr>(Init));
6303 FullExpressionRAII InitScope(Info);
6304 if (!EvaluateInPlace(*Value, Info, Subobject, Init) ||
6305 (FD && FD->isBitField() &&
6306 !truncateBitfieldValue(Info, Init, *Value, FD))) {
6307 // If we're checking for a potential constant expression, evaluate all
6308 // initializers even if some of them fail.
6309 if (!Info.noteFailure())
6310 return false;
6311 Success = false;
6312 }
6313 }
6314
6315 // This is the point at which the dynamic type of the object becomes this
6316 // class type.
6317 if (I->isBaseInitializer() && BasesSeen == RD->getNumBases())
6318 EvalObj.finishedConstructingBases();
6319 }
6320
6321 // Default-initialize any remaining fields.
6322 if (!RD->isUnion()) {
6323 for (; FieldIt != RD->field_end(); ++FieldIt) {
6324 if (!FieldIt->isUnnamedBitfield())
6325 Success &= getDefaultInitValue(
6326 FieldIt->getType(),
6327 Result.getStructField(FieldIt->getFieldIndex()));
6328 }
6329 }
6330
6331 EvalObj.finishedConstructingFields();
6332
6333 return Success &&
6334 EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed &&
6335 LifetimeExtendedScope.destroy();
6336}
6337
6338static bool HandleConstructorCall(const Expr *E, const LValue &This,
6339 ArrayRef<const Expr*> Args,
6340 const CXXConstructorDecl *Definition,
6341 EvalInfo &Info, APValue &Result) {
6342 CallScopeRAII CallScope(Info);
6343 CallRef Call = Info.CurrentCall->createCall(Definition);
6344 if (!EvaluateArgs(Args, Call, Info, Definition))
6345 return false;
6346
6347 return HandleConstructorCall(E, This, Call, Definition, Info, Result) &&
6348 CallScope.destroy();
6349}
6350
6351static bool HandleDestructionImpl(EvalInfo &Info, SourceLocation CallLoc,
6352 const LValue &This, APValue &Value,
6353 QualType T) {
6354 // Objects can only be destroyed while they're within their lifetimes.
6355 // FIXME: We have no representation for whether an object of type nullptr_t
6356 // is in its lifetime; it usually doesn't matter. Perhaps we should model it
6357 // as indeterminate instead?
6358 if (Value.isAbsent() && !T->isNullPtrType()) {
6359 APValue Printable;
6360 This.moveInto(Printable);
6361 Info.FFDiag(CallLoc, diag::note_constexpr_destroy_out_of_lifetime)
6362 << Printable.getAsString(Info.Ctx, Info.Ctx.getLValueReferenceType(T));
6363 return false;
6364 }
6365
6366 // Invent an expression for location purposes.
6367 // FIXME: We shouldn't need to do this.
6368 OpaqueValueExpr LocE(CallLoc, Info.Ctx.IntTy, VK_RValue);
6369
6370 // For arrays, destroy elements right-to-left.
6371 if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(T)) {
6372 uint64_t Size = CAT->getSize().getZExtValue();
6373 QualType ElemT = CAT->getElementType();
6374
6375 LValue ElemLV = This;
6376 ElemLV.addArray(Info, &LocE, CAT);
6377 if (!HandleLValueArrayAdjustment(Info, &LocE, ElemLV, ElemT, Size))
6378 return false;
6379
6380 // Ensure that we have actual array elements available to destroy; the
6381 // destructors might mutate the value, so we can't run them on the array
6382 // filler.
6383 if (Size && Size > Value.getArrayInitializedElts())
6384 expandArray(Value, Value.getArraySize() - 1);
6385
6386 for (; Size != 0; --Size) {
6387 APValue &Elem = Value.getArrayInitializedElt(Size - 1);
6388 if (!HandleLValueArrayAdjustment(Info, &LocE, ElemLV, ElemT, -1) ||
6389 !HandleDestructionImpl(Info, CallLoc, ElemLV, Elem, ElemT))
6390 return false;
6391 }
6392
6393 // End the lifetime of this array now.
6394 Value = APValue();
6395 return true;
6396 }
6397
6398 const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
6399 if (!RD) {
6400 if (T.isDestructedType()) {
6401 Info.FFDiag(CallLoc, diag::note_constexpr_unsupported_destruction) << T;
6402 return false;
6403 }
6404
6405 Value = APValue();
6406 return true;
6407 }
6408
6409 if (RD->getNumVBases()) {
6410 Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD;
6411 return false;
6412 }
6413
6414 const CXXDestructorDecl *DD = RD->getDestructor();
6415 if (!DD && !RD->hasTrivialDestructor()) {
6416 Info.FFDiag(CallLoc);
6417 return false;
6418 }
6419
6420 if (!DD || DD->isTrivial() ||
6421 (RD->isAnonymousStructOrUnion() && RD->isUnion())) {
6422 // A trivial destructor just ends the lifetime of the object. Check for
6423 // this case before checking for a body, because we might not bother
6424 // building a body for a trivial destructor. Note that it doesn't matter
6425 // whether the destructor is constexpr in this case; all trivial
6426 // destructors are constexpr.
6427 //
6428 // If an anonymous union would be destroyed, some enclosing destructor must
6429 // have been explicitly defined, and the anonymous union destruction should
6430 // have no effect.
6431 Value = APValue();
6432 return true;
6433 }
6434
6435 if (!Info.CheckCallLimit(CallLoc))
6436 return false;
6437
6438 const FunctionDecl *Definition = nullptr;
6439 const Stmt *Body = DD->getBody(Definition);
6440
6441 if (!CheckConstexprFunction(Info, CallLoc, DD, Definition, Body))
6442 return false;
6443
6444 CallStackFrame Frame(Info, CallLoc, Definition, &This, CallRef());
6445
6446 // We're now in the period of destruction of this object.
6447 unsigned BasesLeft = RD->getNumBases();
6448 EvalInfo::EvaluatingDestructorRAII EvalObj(
6449 Info,
6450 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries});
6451 if (!EvalObj.DidInsert) {
6452 // C++2a [class.dtor]p19:
6453 // the behavior is undefined if the destructor is invoked for an object
6454 // whose lifetime has ended
6455 // (Note that formally the lifetime ends when the period of destruction
6456 // begins, even though certain uses of the object remain valid until the
6457 // period of destruction ends.)
6458 Info.FFDiag(CallLoc, diag::note_constexpr_double_destroy);
6459 return false;
6460 }
6461
6462 // FIXME: Creating an APValue just to hold a nonexistent return value is
6463 // wasteful.
6464 APValue RetVal;
6465 StmtResult Ret = {RetVal, nullptr};
6466 if (EvaluateStmt(Ret, Info, Definition->getBody()) == ESR_Failed)
6467 return false;
6468
6469 // A union destructor does not implicitly destroy its members.
6470 if (RD->isUnion())
6471 return true;
6472
6473 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
6474
6475 // We don't have a good way to iterate fields in reverse, so collect all the
6476 // fields first and then walk them backwards.
6477 SmallVector<FieldDecl*, 16> Fields(RD->field_begin(), RD->field_end());
6478 for (const FieldDecl *FD : llvm::reverse(Fields)) {
6479 if (FD->isUnnamedBitfield())
6480 continue;
6481
6482 LValue Subobject = This;
6483 if (!HandleLValueMember(Info, &LocE, Subobject, FD, &Layout))
6484 return false;
6485
6486 APValue *SubobjectValue = &Value.getStructField(FD->getFieldIndex());
6487 if (!HandleDestructionImpl(Info, CallLoc, Subobject, *SubobjectValue,
6488 FD->getType()))
6489 return false;
6490 }
6491
6492 if (BasesLeft != 0)
6493 EvalObj.startedDestroyingBases();
6494
6495 // Destroy base classes in reverse order.
6496 for (const CXXBaseSpecifier &Base : llvm::reverse(RD->bases())) {
6497 --BasesLeft;
6498
6499 QualType BaseType = Base.getType();
6500 LValue Subobject = This;
6501 if (!HandleLValueDirectBase(Info, &LocE, Subobject, RD,
6502 BaseType->getAsCXXRecordDecl(), &Layout))
6503 return false;
6504
6505 APValue *SubobjectValue = &Value.getStructBase(BasesLeft);
6506 if (!HandleDestructionImpl(Info, CallLoc, Subobject, *SubobjectValue,
6507 BaseType))
6508 return false;
6509 }
6510 assert(BasesLeft == 0 && "NumBases was wrong?")((BasesLeft == 0 && "NumBases was wrong?") ? static_cast
<void> (0) : __assert_fail ("BasesLeft == 0 && \"NumBases was wrong?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6510, __PRETTY_FUNCTION__))
;
6511
6512 // The period of destruction ends now. The object is gone.
6513 Value = APValue();
6514 return true;
6515}
6516
6517namespace {
6518struct DestroyObjectHandler {
6519 EvalInfo &Info;
6520 const Expr *E;
6521 const LValue &This;
6522 const AccessKinds AccessKind;
6523
6524 typedef bool result_type;
6525 bool failed() { return false; }
6526 bool found(APValue &Subobj, QualType SubobjType) {
6527 return HandleDestructionImpl(Info, E->getExprLoc(), This, Subobj,
6528 SubobjType);
6529 }
6530 bool found(APSInt &Value, QualType SubobjType) {
6531 Info.FFDiag(E, diag::note_constexpr_destroy_complex_elem);
6532 return false;
6533 }
6534 bool found(APFloat &Value, QualType SubobjType) {
6535 Info.FFDiag(E, diag::note_constexpr_destroy_complex_elem);
6536 return false;
6537 }
6538};
6539}
6540
6541/// Perform a destructor or pseudo-destructor call on the given object, which
6542/// might in general not be a complete object.
6543static bool HandleDestruction(EvalInfo &Info, const Expr *E,
6544 const LValue &This, QualType ThisType) {
6545 CompleteObject Obj = findCompleteObject(Info, E, AK_Destroy, This, ThisType);
6546 DestroyObjectHandler Handler = {Info, E, This, AK_Destroy};
6547 return Obj && findSubobject(Info, E, Obj, This.Designator, Handler);
6548}
6549
6550/// Destroy and end the lifetime of the given complete object.
6551static bool HandleDestruction(EvalInfo &Info, SourceLocation Loc,
6552 APValue::LValueBase LVBase, APValue &Value,
6553 QualType T) {
6554 // If we've had an unmodeled side-effect, we can't rely on mutable state
6555 // (such as the object we're about to destroy) being correct.
6556 if (Info.EvalStatus.HasSideEffects)
6557 return false;
6558
6559 LValue LV;
6560 LV.set({LVBase});
6561 return HandleDestructionImpl(Info, Loc, LV, Value, T);
6562}
6563
6564/// Perform a call to 'perator new' or to `__builtin_operator_new'.
6565static bool HandleOperatorNewCall(EvalInfo &Info, const CallExpr *E,
6566 LValue &Result) {
6567 if (Info.checkingPotentialConstantExpression() ||
6568 Info.SpeculativeEvaluationDepth)
6569 return false;
6570
6571 // This is permitted only within a call to std::allocator<T>::allocate.
6572 auto Caller = Info.getStdAllocatorCaller("allocate");
6573 if (!Caller) {
6574 Info.FFDiag(E->getExprLoc(), Info.getLangOpts().CPlusPlus20
6575 ? diag::note_constexpr_new_untyped
6576 : diag::note_constexpr_new);
6577 return false;
6578 }
6579
6580 QualType ElemType = Caller.ElemType;
6581 if (ElemType->isIncompleteType() || ElemType->isFunctionType()) {
6582 Info.FFDiag(E->getExprLoc(),
6583 diag::note_constexpr_new_not_complete_object_type)
6584 << (ElemType->isIncompleteType() ? 0 : 1) << ElemType;
6585 return false;
6586 }
6587
6588 APSInt ByteSize;
6589 if (!EvaluateInteger(E->getArg(0), ByteSize, Info))
6590 return false;
6591 bool IsNothrow = false;
6592 for (unsigned I = 1, N = E->getNumArgs(); I != N; ++I) {
6593 EvaluateIgnoredValue(Info, E->getArg(I));
6594 IsNothrow |= E->getType()->isNothrowT();
6595 }
6596
6597 CharUnits ElemSize;
6598 if (!HandleSizeof(Info, E->getExprLoc(), ElemType, ElemSize))
6599 return false;
6600 APInt Size, Remainder;
6601 APInt ElemSizeAP(ByteSize.getBitWidth(), ElemSize.getQuantity());
6602 APInt::udivrem(ByteSize, ElemSizeAP, Size, Remainder);
6603 if (Remainder != 0) {
6604 // This likely indicates a bug in the implementation of 'std::allocator'.
6605 Info.FFDiag(E->getExprLoc(), diag::note_constexpr_operator_new_bad_size)
6606 << ByteSize << APSInt(ElemSizeAP, true) << ElemType;
6607 return false;
6608 }
6609
6610 if (ByteSize.getActiveBits() > ConstantArrayType::getMaxSizeBits(Info.Ctx)) {
6611 if (IsNothrow) {
6612 Result.setNull(Info.Ctx, E->getType());
6613 return true;
6614 }
6615
6616 Info.FFDiag(E, diag::note_constexpr_new_too_large) << APSInt(Size, true);
6617 return false;
6618 }
6619
6620 QualType AllocType = Info.Ctx.getConstantArrayType(ElemType, Size, nullptr,
6621 ArrayType::Normal, 0);
6622 APValue *Val = Info.createHeapAlloc(E, AllocType, Result);
6623 *Val = APValue(APValue::UninitArray(), 0, Size.getZExtValue());
6624 Result.addArray(Info, E, cast<ConstantArrayType>(AllocType));
6625 return true;
6626}
6627
6628static bool hasVirtualDestructor(QualType T) {
6629 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
6630 if (CXXDestructorDecl *DD = RD->getDestructor())
6631 return DD->isVirtual();
6632 return false;
6633}
6634
6635static const FunctionDecl *getVirtualOperatorDelete(QualType T) {
6636 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
6637 if (CXXDestructorDecl *DD = RD->getDestructor())
6638 return DD->isVirtual() ? DD->getOperatorDelete() : nullptr;
6639 return nullptr;
6640}
6641
6642/// Check that the given object is a suitable pointer to a heap allocation that
6643/// still exists and is of the right kind for the purpose of a deletion.
6644///
6645/// On success, returns the heap allocation to deallocate. On failure, produces
6646/// a diagnostic and returns None.
6647static Optional<DynAlloc *> CheckDeleteKind(EvalInfo &Info, const Expr *E,
6648 const LValue &Pointer,
6649 DynAlloc::Kind DeallocKind) {
6650 auto PointerAsString = [&] {
6651 return Pointer.toString(Info.Ctx, Info.Ctx.VoidPtrTy);
6652 };
6653
6654 DynamicAllocLValue DA = Pointer.Base.dyn_cast<DynamicAllocLValue>();
6655 if (!DA) {
6656 Info.FFDiag(E, diag::note_constexpr_delete_not_heap_alloc)
6657 << PointerAsString();
6658 if (Pointer.Base)
6659 NoteLValueLocation(Info, Pointer.Base);
6660 return None;
6661 }
6662
6663 Optional<DynAlloc *> Alloc = Info.lookupDynamicAlloc(DA);
6664 if (!Alloc) {
6665 Info.FFDiag(E, diag::note_constexpr_double_delete);
6666 return None;
6667 }
6668
6669 QualType AllocType = Pointer.Base.getDynamicAllocType();
6670 if (DeallocKind != (*Alloc)->getKind()) {
6671 Info.FFDiag(E, diag::note_constexpr_new_delete_mismatch)
6672 << DeallocKind << (*Alloc)->getKind() << AllocType;
6673 NoteLValueLocation(Info, Pointer.Base);
6674 return None;
6675 }
6676
6677 bool Subobject = false;
6678 if (DeallocKind == DynAlloc::New) {
6679 Subobject = Pointer.Designator.MostDerivedPathLength != 0 ||
6680 Pointer.Designator.isOnePastTheEnd();
6681 } else {
6682 Subobject = Pointer.Designator.Entries.size() != 1 ||
6683 Pointer.Designator.Entries[0].getAsArrayIndex() != 0;
6684 }
6685 if (Subobject) {
6686 Info.FFDiag(E, diag::note_constexpr_delete_subobject)
6687 << PointerAsString() << Pointer.Designator.isOnePastTheEnd();
6688 return None;
6689 }
6690
6691 return Alloc;
6692}
6693
6694// Perform a call to 'operator delete' or '__builtin_operator_delete'.
6695bool HandleOperatorDeleteCall(EvalInfo &Info, const CallExpr *E) {
6696 if (Info.checkingPotentialConstantExpression() ||
6697 Info.SpeculativeEvaluationDepth)
6698 return false;
6699
6700 // This is permitted only within a call to std::allocator<T>::deallocate.
6701 if (!Info.getStdAllocatorCaller("deallocate")) {
6702 Info.FFDiag(E->getExprLoc());
6703 return true;
6704 }
6705
6706 LValue Pointer;
6707 if (!EvaluatePointer(E->getArg(0), Pointer, Info))
6708 return false;
6709 for (unsigned I = 1, N = E->getNumArgs(); I != N; ++I)
6710 EvaluateIgnoredValue(Info, E->getArg(I));
6711
6712 if (Pointer.Designator.Invalid)
6713 return false;
6714
6715 // Deleting a null pointer would have no effect, but it's not permitted by
6716 // std::allocator<T>::deallocate's contract.
6717 if (Pointer.isNullPointer()) {
6718 Info.CCEDiag(E->getExprLoc(), diag::note_constexpr_deallocate_null);
6719 return true;
6720 }
6721
6722 if (!CheckDeleteKind(Info, E, Pointer, DynAlloc::StdAllocator))
6723 return false;
6724
6725 Info.HeapAllocs.erase(Pointer.Base.get<DynamicAllocLValue>());
6726 return true;
6727}
6728
6729//===----------------------------------------------------------------------===//
6730// Generic Evaluation
6731//===----------------------------------------------------------------------===//
6732namespace {
6733
6734class BitCastBuffer {
6735 // FIXME: We're going to need bit-level granularity when we support
6736 // bit-fields.
6737 // FIXME: Its possible under the C++ standard for 'char' to not be 8 bits, but
6738 // we don't support a host or target where that is the case. Still, we should
6739 // use a more generic type in case we ever do.
6740 SmallVector<Optional<unsigned char>, 32> Bytes;
6741
6742 static_assert(std::numeric_limits<unsigned char>::digits >= 8,
6743 "Need at least 8 bit unsigned char");
6744
6745 bool TargetIsLittleEndian;
6746
6747public:
6748 BitCastBuffer(CharUnits Width, bool TargetIsLittleEndian)
6749 : Bytes(Width.getQuantity()),
6750 TargetIsLittleEndian(TargetIsLittleEndian) {}
6751
6752 LLVM_NODISCARD[[clang::warn_unused_result]]
6753 bool readObject(CharUnits Offset, CharUnits Width,
6754 SmallVectorImpl<unsigned char> &Output) const {
6755 for (CharUnits I = Offset, E = Offset + Width; I != E; ++I) {
6756 // If a byte of an integer is uninitialized, then the whole integer is
6757 // uninitalized.
6758 if (!Bytes[I.getQuantity()])
6759 return false;
6760 Output.push_back(*Bytes[I.getQuantity()]);
6761 }
6762 if (llvm::sys::IsLittleEndianHost != TargetIsLittleEndian)
6763 std::reverse(Output.begin(), Output.end());
6764 return true;
6765 }
6766
6767 void writeObject(CharUnits Offset, SmallVectorImpl<unsigned char> &Input) {
6768 if (llvm::sys::IsLittleEndianHost != TargetIsLittleEndian)
6769 std::reverse(Input.begin(), Input.end());
6770
6771 size_t Index = 0;
6772 for (unsigned char Byte : Input) {
6773 assert(!Bytes[Offset.getQuantity() + Index] && "overwriting a byte?")((!Bytes[Offset.getQuantity() + Index] && "overwriting a byte?"
) ? static_cast<void> (0) : __assert_fail ("!Bytes[Offset.getQuantity() + Index] && \"overwriting a byte?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6773, __PRETTY_FUNCTION__))
;
6774 Bytes[Offset.getQuantity() + Index] = Byte;
6775 ++Index;
6776 }
6777 }
6778
6779 size_t size() { return Bytes.size(); }
6780};
6781
6782/// Traverse an APValue to produce an BitCastBuffer, emulating how the current
6783/// target would represent the value at runtime.
6784class APValueToBufferConverter {
6785 EvalInfo &Info;
6786 BitCastBuffer Buffer;
6787 const CastExpr *BCE;
6788
6789 APValueToBufferConverter(EvalInfo &Info, CharUnits ObjectWidth,
6790 const CastExpr *BCE)
6791 : Info(Info),
6792 Buffer(ObjectWidth, Info.Ctx.getTargetInfo().isLittleEndian()),
6793 BCE(BCE) {}
6794
6795 bool visit(const APValue &Val, QualType Ty) {
6796 return visit(Val, Ty, CharUnits::fromQuantity(0));
6797 }
6798
6799 // Write out Val with type Ty into Buffer starting at Offset.
6800 bool visit(const APValue &Val, QualType Ty, CharUnits Offset) {
6801 assert((size_t)Offset.getQuantity() <= Buffer.size())(((size_t)Offset.getQuantity() <= Buffer.size()) ? static_cast
<void> (0) : __assert_fail ("(size_t)Offset.getQuantity() <= Buffer.size()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6801, __PRETTY_FUNCTION__))
;
6802
6803 // As a special case, nullptr_t has an indeterminate value.
6804 if (Ty->isNullPtrType())
6805 return true;
6806
6807 // Dig through Src to find the byte at SrcOffset.
6808 switch (Val.getKind()) {
6809 case APValue::Indeterminate:
6810 case APValue::None:
6811 return true;
6812
6813 case APValue::Int:
6814 return visitInt(Val.getInt(), Ty, Offset);
6815 case APValue::Float:
6816 return visitFloat(Val.getFloat(), Ty, Offset);
6817 case APValue::Array:
6818 return visitArray(Val, Ty, Offset);
6819 case APValue::Struct:
6820 return visitRecord(Val, Ty, Offset);
6821
6822 case APValue::ComplexInt:
6823 case APValue::ComplexFloat:
6824 case APValue::Vector:
6825 case APValue::FixedPoint:
6826 // FIXME: We should support these.
6827
6828 case APValue::Union:
6829 case APValue::MemberPointer:
6830 case APValue::AddrLabelDiff: {
6831 Info.FFDiag(BCE->getBeginLoc(),
6832 diag::note_constexpr_bit_cast_unsupported_type)
6833 << Ty;
6834 return false;
6835 }
6836
6837 case APValue::LValue:
6838 llvm_unreachable("LValue subobject in bit_cast?")::llvm::llvm_unreachable_internal("LValue subobject in bit_cast?"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6838)
;
6839 }
6840 llvm_unreachable("Unhandled APValue::ValueKind")::llvm::llvm_unreachable_internal("Unhandled APValue::ValueKind"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6840)
;
6841 }
6842
6843 bool visitRecord(const APValue &Val, QualType Ty, CharUnits Offset) {
6844 const RecordDecl *RD = Ty->getAsRecordDecl();
6845 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
6846
6847 // Visit the base classes.
6848 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
6849 for (size_t I = 0, E = CXXRD->getNumBases(); I != E; ++I) {
6850 const CXXBaseSpecifier &BS = CXXRD->bases_begin()[I];
6851 CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
6852
6853 if (!visitRecord(Val.getStructBase(I), BS.getType(),
6854 Layout.getBaseClassOffset(BaseDecl) + Offset))
6855 return false;
6856 }
6857 }
6858
6859 // Visit the fields.
6860 unsigned FieldIdx = 0;
6861 for (FieldDecl *FD : RD->fields()) {
6862 if (FD->isBitField()) {
6863 Info.FFDiag(BCE->getBeginLoc(),
6864 diag::note_constexpr_bit_cast_unsupported_bitfield);
6865 return false;
6866 }
6867
6868 uint64_t FieldOffsetBits = Layout.getFieldOffset(FieldIdx);
6869
6870 assert(FieldOffsetBits % Info.Ctx.getCharWidth() == 0 &&((FieldOffsetBits % Info.Ctx.getCharWidth() == 0 && "only bit-fields can have sub-char alignment"
) ? static_cast<void> (0) : __assert_fail ("FieldOffsetBits % Info.Ctx.getCharWidth() == 0 && \"only bit-fields can have sub-char alignment\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6871, __PRETTY_FUNCTION__))
6871 "only bit-fields can have sub-char alignment")((FieldOffsetBits % Info.Ctx.getCharWidth() == 0 && "only bit-fields can have sub-char alignment"
) ? static_cast<void> (0) : __assert_fail ("FieldOffsetBits % Info.Ctx.getCharWidth() == 0 && \"only bit-fields can have sub-char alignment\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6871, __PRETTY_FUNCTION__))
;
6872 CharUnits FieldOffset =
6873 Info.Ctx.toCharUnitsFromBits(FieldOffsetBits) + Offset;
6874 QualType FieldTy = FD->getType();
6875 if (!visit(Val.getStructField(FieldIdx), FieldTy, FieldOffset))
6876 return false;
6877 ++FieldIdx;
6878 }
6879
6880 return true;
6881 }
6882
6883 bool visitArray(const APValue &Val, QualType Ty, CharUnits Offset) {
6884 const auto *CAT =
6885 dyn_cast_or_null<ConstantArrayType>(Ty->getAsArrayTypeUnsafe());
6886 if (!CAT)
6887 return false;
6888
6889 CharUnits ElemWidth = Info.Ctx.getTypeSizeInChars(CAT->getElementType());
6890 unsigned NumInitializedElts = Val.getArrayInitializedElts();
6891 unsigned ArraySize = Val.getArraySize();
6892 // First, initialize the initialized elements.
6893 for (unsigned I = 0; I != NumInitializedElts; ++I) {
6894 const APValue &SubObj = Val.getArrayInitializedElt(I);
6895 if (!visit(SubObj, CAT->getElementType(), Offset + I * ElemWidth))
6896 return false;
6897 }
6898
6899 // Next, initialize the rest of the array using the filler.
6900 if (Val.hasArrayFiller()) {
6901 const APValue &Filler = Val.getArrayFiller();
6902 for (unsigned I = NumInitializedElts; I != ArraySize; ++I) {
6903 if (!visit(Filler, CAT->getElementType(), Offset + I * ElemWidth))
6904 return false;
6905 }
6906 }
6907
6908 return true;
6909 }
6910
6911 bool visitInt(const APSInt &Val, QualType Ty, CharUnits Offset) {
6912 APSInt AdjustedVal = Val;
6913 unsigned Width = AdjustedVal.getBitWidth();
6914 if (Ty->isBooleanType()) {
6915 Width = Info.Ctx.getTypeSize(Ty);
6916 AdjustedVal = AdjustedVal.extend(Width);
6917 }
6918
6919 SmallVector<unsigned char, 8> Bytes(Width / 8);
6920 llvm::StoreIntToMemory(AdjustedVal, &*Bytes.begin(), Width / 8);
6921 Buffer.writeObject(Offset, Bytes);
6922 return true;
6923 }
6924
6925 bool visitFloat(const APFloat &Val, QualType Ty, CharUnits Offset) {
6926 APSInt AsInt(Val.bitcastToAPInt());
6927 return visitInt(AsInt, Ty, Offset);
6928 }
6929
6930public:
6931 static Optional<BitCastBuffer> convert(EvalInfo &Info, const APValue &Src,
6932 const CastExpr *BCE) {
6933 CharUnits DstSize = Info.Ctx.getTypeSizeInChars(BCE->getType());
6934 APValueToBufferConverter Converter(Info, DstSize, BCE);
6935 if (!Converter.visit(Src, BCE->getSubExpr()->getType()))
6936 return None;
6937 return Converter.Buffer;
6938 }
6939};
6940
6941/// Write an BitCastBuffer into an APValue.
6942class BufferToAPValueConverter {
6943 EvalInfo &Info;
6944 const BitCastBuffer &Buffer;
6945 const CastExpr *BCE;
6946
6947 BufferToAPValueConverter(EvalInfo &Info, const BitCastBuffer &Buffer,
6948 const CastExpr *BCE)
6949 : Info(Info), Buffer(Buffer), BCE(BCE) {}
6950
6951 // Emit an unsupported bit_cast type error. Sema refuses to build a bit_cast
6952 // with an invalid type, so anything left is a deficiency on our part (FIXME).
6953 // Ideally this will be unreachable.
6954 llvm::NoneType unsupportedType(QualType Ty) {
6955 Info.FFDiag(BCE->getBeginLoc(),
6956 diag::note_constexpr_bit_cast_unsupported_type)
6957 << Ty;
6958 return None;
6959 }
6960
6961 llvm::NoneType unrepresentableValue(QualType Ty, const APSInt &Val) {
6962 Info.FFDiag(BCE->getBeginLoc(),
6963 diag::note_constexpr_bit_cast_unrepresentable_value)
6964 << Ty << Val.toString(/*Radix=*/10);
6965 return None;
6966 }
6967
6968 Optional<APValue> visit(const BuiltinType *T, CharUnits Offset,
6969 const EnumType *EnumSugar = nullptr) {
6970 if (T->isNullPtrType()) {
6971 uint64_t NullValue = Info.Ctx.getTargetNullPointerValue(QualType(T, 0));
6972 return APValue((Expr *)nullptr,
6973 /*Offset=*/CharUnits::fromQuantity(NullValue),
6974 APValue::NoLValuePath{}, /*IsNullPtr=*/true);
6975 }
6976
6977 CharUnits SizeOf = Info.Ctx.getTypeSizeInChars(T);
6978
6979 // Work around floating point types that contain unused padding bytes. This
6980 // is really just `long double` on x86, which is the only fundamental type
6981 // with padding bytes.
6982 if (T->isRealFloatingType()) {
6983 const llvm::fltSemantics &Semantics =
6984 Info.Ctx.getFloatTypeSemantics(QualType(T, 0));
6985 unsigned NumBits = llvm::APFloatBase::getSizeInBits(Semantics);
6986 assert(NumBits % 8 == 0)((NumBits % 8 == 0) ? static_cast<void> (0) : __assert_fail
("NumBits % 8 == 0", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 6986, __PRETTY_FUNCTION__))
;
6987 CharUnits NumBytes = CharUnits::fromQuantity(NumBits / 8);
6988 if (NumBytes != SizeOf)
6989 SizeOf = NumBytes;
6990 }
6991
6992 SmallVector<uint8_t, 8> Bytes;
6993 if (!Buffer.readObject(Offset, SizeOf, Bytes)) {
6994 // If this is std::byte or unsigned char, then its okay to store an
6995 // indeterminate value.
6996 bool IsStdByte = EnumSugar && EnumSugar->isStdByteType();
6997 bool IsUChar =
6998 !EnumSugar && (T->isSpecificBuiltinType(BuiltinType::UChar) ||
6999 T->isSpecificBuiltinType(BuiltinType::Char_U));
7000 if (!IsStdByte && !IsUChar) {
7001 QualType DisplayType(EnumSugar ? (const Type *)EnumSugar : T, 0);
7002 Info.FFDiag(BCE->getExprLoc(),
7003 diag::note_constexpr_bit_cast_indet_dest)
7004 << DisplayType << Info.Ctx.getLangOpts().CharIsSigned;
7005 return None;
7006 }
7007
7008 return APValue::IndeterminateValue();
7009 }
7010
7011 APSInt Val(SizeOf.getQuantity() * Info.Ctx.getCharWidth(), true);
7012 llvm::LoadIntFromMemory(Val, &*Bytes.begin(), Bytes.size());
7013
7014 if (T->isIntegralOrEnumerationType()) {
7015 Val.setIsSigned(T->isSignedIntegerOrEnumerationType());
7016
7017 unsigned IntWidth = Info.Ctx.getIntWidth(QualType(T, 0));
7018 if (IntWidth != Val.getBitWidth()) {
7019 APSInt Truncated = Val.trunc(IntWidth);
7020 if (Truncated.extend(Val.getBitWidth()) != Val)
7021 return unrepresentableValue(QualType(T, 0), Val);
7022 Val = Truncated;
7023 }
7024
7025 return APValue(Val);
7026 }
7027
7028 if (T->isRealFloatingType()) {
7029 const llvm::fltSemantics &Semantics =
7030 Info.Ctx.getFloatTypeSemantics(QualType(T, 0));
7031 return APValue(APFloat(Semantics, Val));
7032 }
7033
7034 return unsupportedType(QualType(T, 0));
7035 }
7036
7037 Optional<APValue> visit(const RecordType *RTy, CharUnits Offset) {
7038 const RecordDecl *RD = RTy->getAsRecordDecl();
7039 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
7040
7041 unsigned NumBases = 0;
7042 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
7043 NumBases = CXXRD->getNumBases();
7044
7045 APValue ResultVal(APValue::UninitStruct(), NumBases,
7046 std::distance(RD->field_begin(), RD->field_end()));
7047
7048 // Visit the base classes.
7049 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
7050 for (size_t I = 0, E = CXXRD->getNumBases(); I != E; ++I) {
7051 const CXXBaseSpecifier &BS = CXXRD->bases_begin()[I];
7052 CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
7053 if (BaseDecl->isEmpty() ||
7054 Info.Ctx.getASTRecordLayout(BaseDecl).getNonVirtualSize().isZero())
7055 continue;
7056
7057 Optional<APValue> SubObj = visitType(
7058 BS.getType(), Layout.getBaseClassOffset(BaseDecl) + Offset);
7059 if (!SubObj)
7060 return None;
7061 ResultVal.getStructBase(I) = *SubObj;
7062 }
7063 }
7064
7065 // Visit the fields.
7066 unsigned FieldIdx = 0;
7067 for (FieldDecl *FD : RD->fields()) {
7068 // FIXME: We don't currently support bit-fields. A lot of the logic for
7069 // this is in CodeGen, so we need to factor it around.
7070 if (FD->isBitField()) {
7071 Info.FFDiag(BCE->getBeginLoc(),
7072 diag::note_constexpr_bit_cast_unsupported_bitfield);
7073 return None;
7074 }
7075
7076 uint64_t FieldOffsetBits = Layout.getFieldOffset(FieldIdx);
7077 assert(FieldOffsetBits % Info.Ctx.getCharWidth() == 0)((FieldOffsetBits % Info.Ctx.getCharWidth() == 0) ? static_cast
<void> (0) : __assert_fail ("FieldOffsetBits % Info.Ctx.getCharWidth() == 0"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7077, __PRETTY_FUNCTION__))
;
7078
7079 CharUnits FieldOffset =
7080 CharUnits::fromQuantity(FieldOffsetBits / Info.Ctx.getCharWidth()) +
7081 Offset;
7082 QualType FieldTy = FD->getType();
7083 Optional<APValue> SubObj = visitType(FieldTy, FieldOffset);
7084 if (!SubObj)
7085 return None;
7086 ResultVal.getStructField(FieldIdx) = *SubObj;
7087 ++FieldIdx;
7088 }
7089
7090 return ResultVal;
7091 }
7092
7093 Optional<APValue> visit(const EnumType *Ty, CharUnits Offset) {
7094 QualType RepresentationType = Ty->getDecl()->getIntegerType();
7095 assert(!RepresentationType.isNull() &&((!RepresentationType.isNull() && "enum forward decl should be caught by Sema"
) ? static_cast<void> (0) : __assert_fail ("!RepresentationType.isNull() && \"enum forward decl should be caught by Sema\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7096, __PRETTY_FUNCTION__))
7096 "enum forward decl should be caught by Sema")((!RepresentationType.isNull() && "enum forward decl should be caught by Sema"
) ? static_cast<void> (0) : __assert_fail ("!RepresentationType.isNull() && \"enum forward decl should be caught by Sema\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7096, __PRETTY_FUNCTION__))
;
7097 const auto *AsBuiltin =
7098 RepresentationType.getCanonicalType()->castAs<BuiltinType>();
7099 // Recurse into the underlying type. Treat std::byte transparently as
7100 // unsigned char.
7101 return visit(AsBuiltin, Offset, /*EnumTy=*/Ty);
7102 }
7103
7104 Optional<APValue> visit(const ConstantArrayType *Ty, CharUnits Offset) {
7105 size_t Size = Ty->getSize().getLimitedValue();
7106 CharUnits ElementWidth = Info.Ctx.getTypeSizeInChars(Ty->getElementType());
7107
7108 APValue ArrayValue(APValue::UninitArray(), Size, Size);
7109 for (size_t I = 0; I != Size; ++I) {
7110 Optional<APValue> ElementValue =
7111 visitType(Ty->getElementType(), Offset + I * ElementWidth);
7112 if (!ElementValue)
7113 return None;
7114 ArrayValue.getArrayInitializedElt(I) = std::move(*ElementValue);
7115 }
7116
7117 return ArrayValue;
7118 }
7119
7120 Optional<APValue> visit(const Type *Ty, CharUnits Offset) {
7121 return unsupportedType(QualType(Ty, 0));
7122 }
7123
7124 Optional<APValue> visitType(QualType Ty, CharUnits Offset) {
7125 QualType Can = Ty.getCanonicalType();
7126
7127 switch (Can->getTypeClass()) {
7128#define TYPE(Class, Base) \
7129 case Type::Class: \
7130 return visit(cast<Class##Type>(Can.getTypePtr()), Offset);
7131#define ABSTRACT_TYPE(Class, Base)
7132#define NON_CANONICAL_TYPE(Class, Base) \
7133 case Type::Class: \
7134 llvm_unreachable("non-canonical type should be impossible!")::llvm::llvm_unreachable_internal("non-canonical type should be impossible!"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7134)
;
7135#define DEPENDENT_TYPE(Class, Base) \
7136 case Type::Class: \
7137 llvm_unreachable( \::llvm::llvm_unreachable_internal("dependent types aren't supported in the constant evaluator!"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7138)
7138 "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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7138)
;
7139#define NON_CANONICAL_UNLESS_DEPENDENT(Class, Base)case Type::Class: ::llvm::llvm_unreachable_internal("either dependent or not canonical!"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7139);
\
7140 case Type::Class: \
7141 llvm_unreachable("either dependent or not canonical!")::llvm::llvm_unreachable_internal("either dependent or not canonical!"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7141)
;
7142#include "clang/AST/TypeNodes.inc"
7143 }
7144 llvm_unreachable("Unhandled Type::TypeClass")::llvm::llvm_unreachable_internal("Unhandled Type::TypeClass"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7144)
;
7145 }
7146
7147public:
7148 // Pull out a full value of type DstType.
7149 static Optional<APValue> convert(EvalInfo &Info, BitCastBuffer &Buffer,
7150 const CastExpr *BCE) {
7151 BufferToAPValueConverter Converter(Info, Buffer, BCE);
7152 return Converter.visitType(BCE->getType(), CharUnits::fromQuantity(0));
7153 }
7154};
7155
7156static bool checkBitCastConstexprEligibilityType(SourceLocation Loc,
7157 QualType Ty, EvalInfo *Info,
7158 const ASTContext &Ctx,
7159 bool CheckingDest) {
7160 Ty = Ty.getCanonicalType();
7161
7162 auto diag = [&](int Reason) {
7163 if (Info)
7164 Info->FFDiag(Loc, diag::note_constexpr_bit_cast_invalid_type)
7165 << CheckingDest << (Reason == 4) << Reason;
7166 return false;
7167 };
7168 auto note = [&](int Construct, QualType NoteTy, SourceLocation NoteLoc) {
7169 if (Info)
7170 Info->Note(NoteLoc, diag::note_constexpr_bit_cast_invalid_subtype)
7171 << NoteTy << Construct << Ty;
7172 return false;
7173 };
7174
7175 if (Ty->isUnionType())
7176 return diag(0);
7177 if (Ty->isPointerType())
7178 return diag(1);
7179 if (Ty->isMemberPointerType())
7180 return diag(2);
7181 if (Ty.isVolatileQualified())
7182 return diag(3);
7183
7184 if (RecordDecl *Record = Ty->getAsRecordDecl()) {
7185 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(Record)) {
7186 for (CXXBaseSpecifier &BS : CXXRD->bases())
7187 if (!checkBitCastConstexprEligibilityType(Loc, BS.getType(), Info, Ctx,
7188 CheckingDest))
7189 return note(1, BS.getType(), BS.getBeginLoc());
7190 }
7191 for (FieldDecl *FD : Record->fields()) {
7192 if (FD->getType()->isReferenceType())
7193 return diag(4);
7194 if (!checkBitCastConstexprEligibilityType(Loc, FD->getType(), Info, Ctx,
7195 CheckingDest))
7196 return note(0, FD->getType(), FD->getBeginLoc());
7197 }
7198 }
7199
7200 if (Ty->isArrayType() &&
7201 !checkBitCastConstexprEligibilityType(Loc, Ctx.getBaseElementType(Ty),
7202 Info, Ctx, CheckingDest))
7203 return false;
7204
7205 return true;
7206}
7207
7208static bool checkBitCastConstexprEligibility(EvalInfo *Info,
7209 const ASTContext &Ctx,
7210 const CastExpr *BCE) {
7211 bool DestOK = checkBitCastConstexprEligibilityType(
7212 BCE->getBeginLoc(), BCE->getType(), Info, Ctx, true);
7213 bool SourceOK = DestOK && checkBitCastConstexprEligibilityType(
7214 BCE->getBeginLoc(),
7215 BCE->getSubExpr()->getType(), Info, Ctx, false);
7216 return SourceOK;
7217}
7218
7219static bool handleLValueToRValueBitCast(EvalInfo &Info, APValue &DestValue,
7220 APValue &SourceValue,
7221 const CastExpr *BCE) {
7222 assert(CHAR_BIT == 8 && Info.Ctx.getTargetInfo().getCharWidth() == 8 &&((8 == 8 && Info.Ctx.getTargetInfo().getCharWidth() ==
8 && "no host or target supports non 8-bit chars") ?
static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7223, __PRETTY_FUNCTION__))
7223 "no host or target supports non 8-bit chars")((8 == 8 && Info.Ctx.getTargetInfo().getCharWidth() ==
8 && "no host or target supports non 8-bit chars") ?
static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7223, __PRETTY_FUNCTION__))
;
7224 assert(SourceValue.isLValue() &&((SourceValue.isLValue() && "LValueToRValueBitcast requires an lvalue operand!"
) ? static_cast<void> (0) : __assert_fail ("SourceValue.isLValue() && \"LValueToRValueBitcast requires an lvalue operand!\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7225, __PRETTY_FUNCTION__))
7225 "LValueToRValueBitcast requires an lvalue operand!")((SourceValue.isLValue() && "LValueToRValueBitcast requires an lvalue operand!"
) ? static_cast<void> (0) : __assert_fail ("SourceValue.isLValue() && \"LValueToRValueBitcast requires an lvalue operand!\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7225, __PRETTY_FUNCTION__))
;
7226
7227 if (!checkBitCastConstexprEligibility(&Info, Info.Ctx, BCE))
7228 return false;
7229
7230 LValue SourceLValue;
7231 APValue SourceRValue;
7232 SourceLValue.setFrom(Info.Ctx, SourceValue);
7233 if (!handleLValueToRValueConversion(
7234 Info, BCE, BCE->getSubExpr()->getType().withConst(), SourceLValue,
7235 SourceRValue, /*WantObjectRepresentation=*/true))
7236 return false;
7237
7238 // Read out SourceValue into a char buffer.
7239 Optional<BitCastBuffer> Buffer =
7240 APValueToBufferConverter::convert(Info, SourceRValue, BCE);
7241 if (!Buffer)
7242 return false;
7243
7244 // Write out the buffer into a new APValue.
7245 Optional<APValue> MaybeDestValue =
7246 BufferToAPValueConverter::convert(Info, *Buffer, BCE);
7247 if (!MaybeDestValue)
7248 return false;
7249
7250 DestValue = std::move(*MaybeDestValue);
7251 return true;
7252}
7253
7254template <class Derived>
7255class ExprEvaluatorBase
7256 : public ConstStmtVisitor<Derived, bool> {
7257private:
7258 Derived &getDerived() { return static_cast<Derived&>(*this); }
7259 bool DerivedSuccess(const APValue &V, const Expr *E) {
7260 return getDerived().Success(V, E);
7261 }
7262 bool DerivedZeroInitialization(const Expr *E) {
7263 return getDerived().ZeroInitialization(E);
7264 }
7265
7266 // Check whether a conditional operator with a non-constant condition is a
7267 // potential constant expression. If neither arm is a potential constant
7268 // expression, then the conditional operator is not either.
7269 template<typename ConditionalOperator>
7270 void CheckPotentialConstantConditional(const ConditionalOperator *E) {
7271 assert(Info.checkingPotentialConstantExpression())((Info.checkingPotentialConstantExpression()) ? static_cast<
void> (0) : __assert_fail ("Info.checkingPotentialConstantExpression()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7271, __PRETTY_FUNCTION__))
;
7272
7273 // Speculatively evaluate both arms.
7274 SmallVector<PartialDiagnosticAt, 8> Diag;
7275 {
7276 SpeculativeEvaluationRAII Speculate(Info, &Diag);
7277 StmtVisitorTy::Visit(E->getFalseExpr());
7278 if (Diag.empty())
7279 return;
7280 }
7281
7282 {
7283 SpeculativeEvaluationRAII Speculate(Info, &Diag);
7284 Diag.clear();
7285 StmtVisitorTy::Visit(E->getTrueExpr());
7286 if (Diag.empty())
7287 return;
7288 }
7289
7290 Error(E, diag::note_constexpr_conditional_never_const);
7291 }
7292
7293
7294 template<typename ConditionalOperator>
7295 bool HandleConditionalOperator(const ConditionalOperator *E) {
7296 bool BoolResult;
7297 if (!EvaluateAsBooleanCondition(E->getCond(), BoolResult, Info)) {
7298 if (Info.checkingPotentialConstantExpression() && Info.noteFailure()) {
7299 CheckPotentialConstantConditional(E);
7300 return false;
7301 }
7302 if (Info.noteFailure()) {
7303 StmtVisitorTy::Visit(E->getTrueExpr());
7304 StmtVisitorTy::Visit(E->getFalseExpr());
7305 }
7306 return false;
7307 }
7308
7309 Expr *EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr();
7310 return StmtVisitorTy::Visit(EvalExpr);
7311 }
7312
7313protected:
7314 EvalInfo &Info;
7315 typedef ConstStmtVisitor<Derived, bool> StmtVisitorTy;
7316 typedef ExprEvaluatorBase ExprEvaluatorBaseTy;
7317
7318 OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
7319 return Info.CCEDiag(E, D);
7320 }
7321
7322 bool ZeroInitialization(const Expr *E) { return Error(E); }
7323
7324public:
7325 ExprEvaluatorBase(EvalInfo &Info) : Info(Info) {}
7326
7327 EvalInfo &getEvalInfo() { return Info; }
7328
7329 /// Report an evaluation error. This should only be called when an error is
7330 /// first discovered. When propagating an error, just return false.
7331 bool Error(const Expr *E, diag::kind D) {
7332 Info.FFDiag(E, D);
7333 return false;
7334 }
7335 bool Error(const Expr *E) {
7336 return Error(E, diag::note_invalid_subexpr_in_const_expr);
7337 }
7338
7339 bool VisitStmt(const Stmt *) {
7340 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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7340)
;
7341 }
7342 bool VisitExpr(const Expr *E) {
7343 return Error(E);
7344 }
7345
7346 bool VisitConstantExpr(const ConstantExpr *E) {
7347 if (E->hasAPValueResult())
7348 return DerivedSuccess(E->getAPValueResult(), E);
7349
7350 return StmtVisitorTy::Visit(E->getSubExpr());
7351 }
7352
7353 bool VisitParenExpr(const ParenExpr *E)
7354 { return StmtVisitorTy::Visit(E->getSubExpr()); }
7355 bool VisitUnaryExtension(const UnaryOperator *E)
7356 { return StmtVisitorTy::Visit(E->getSubExpr()); }
7357 bool VisitUnaryPlus(const UnaryOperator *E)
7358 { return StmtVisitorTy::Visit(E->getSubExpr()); }
7359 bool VisitChooseExpr(const ChooseExpr *E)
7360 { return StmtVisitorTy::Visit(E->getChosenSubExpr()); }
7361 bool VisitGenericSelectionExpr(const GenericSelectionExpr *E)
7362 { return StmtVisitorTy::Visit(E->getResultExpr()); }
7363 bool VisitSubstNonTypeTemplateParmExpr(const SubstNonTypeTemplateParmExpr *E)
7364 { return StmtVisitorTy::Visit(E->getReplacement()); }
7365 bool VisitCXXDefaultArgExpr(const CXXDefaultArgExpr *E) {
7366 TempVersionRAII RAII(*Info.CurrentCall);
7367 SourceLocExprScopeGuard Guard(E, Info.CurrentCall->CurSourceLocExprScope);
7368 return StmtVisitorTy::Visit(E->getExpr());
7369 }
7370 bool VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *E) {
7371 TempVersionRAII RAII(*Info.CurrentCall);
7372 // The initializer may not have been parsed yet, or might be erroneous.
7373 if (!E->getExpr())
7374 return Error(E);
7375 SourceLocExprScopeGuard Guard(E, Info.CurrentCall->CurSourceLocExprScope);
7376 return StmtVisitorTy::Visit(E->getExpr());
7377 }
7378
7379 bool VisitExprWithCleanups(const ExprWithCleanups *E) {
7380 FullExpressionRAII Scope(Info);
7381 return StmtVisitorTy::Visit(E->getSubExpr()) && Scope.destroy();
7382 }
7383
7384 // Temporaries are registered when created, so we don't care about
7385 // CXXBindTemporaryExpr.
7386 bool VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *E) {
7387 return StmtVisitorTy::Visit(E->getSubExpr());
7388 }
7389
7390 bool VisitCXXReinterpretCastExpr(const CXXReinterpretCastExpr *E) {
7391 CCEDiag(E, diag::note_constexpr_invalid_cast) << 0;
7392 return static_cast<Derived*>(this)->VisitCastExpr(E);
7393 }
7394 bool VisitCXXDynamicCastExpr(const CXXDynamicCastExpr *E) {
7395 if (!Info.Ctx.getLangOpts().CPlusPlus20)
7396 CCEDiag(E, diag::note_constexpr_invalid_cast) << 1;
7397 return static_cast<Derived*>(this)->VisitCastExpr(E);
7398 }
7399 bool VisitBuiltinBitCastExpr(const BuiltinBitCastExpr *E) {
7400 return static_cast<Derived*>(this)->VisitCastExpr(E);
7401 }
7402
7403 bool VisitBinaryOperator(const BinaryOperator *E) {
7404 switch (E->getOpcode()) {
7405 default:
7406 return Error(E);
7407
7408 case BO_Comma:
7409 VisitIgnoredValue(E->getLHS());
7410 return StmtVisitorTy::Visit(E->getRHS());
7411
7412 case BO_PtrMemD:
7413 case BO_PtrMemI: {
7414 LValue Obj;
7415 if (!HandleMemberPointerAccess(Info, E, Obj))
7416 return false;
7417 APValue Result;
7418 if (!handleLValueToRValueConversion(Info, E, E->getType(), Obj, Result))
7419 return false;
7420 return DerivedSuccess(Result, E);
7421 }
7422 }
7423 }
7424
7425 bool VisitCXXRewrittenBinaryOperator(const CXXRewrittenBinaryOperator *E) {
7426 return StmtVisitorTy::Visit(E->getSemanticForm());
7427 }
7428
7429 bool VisitBinaryConditionalOperator(const BinaryConditionalOperator *E) {
7430 // Evaluate and cache the common expression. We treat it as a temporary,
7431 // even though it's not quite the same thing.
7432 LValue CommonLV;
7433 if (!Evaluate(Info.CurrentCall->createTemporary(
7434 E->getOpaqueValue(),
7435 getStorageType(Info.Ctx, E->getOpaqueValue()),
7436 ScopeKind::FullExpression, CommonLV),
7437 Info, E->getCommon()))
7438 return false;
7439
7440 return HandleConditionalOperator(E);
7441 }
7442
7443 bool VisitConditionalOperator(const ConditionalOperator *E) {
7444 bool IsBcpCall = false;
7445 // If the condition (ignoring parens) is a __builtin_constant_p call,
7446 // the result is a constant expression if it can be folded without
7447 // side-effects. This is an important GNU extension. See GCC PR38377
7448 // for discussion.
7449 if (const CallExpr *CallCE =
7450 dyn_cast<CallExpr>(E->getCond()->IgnoreParenCasts()))
7451 if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
7452 IsBcpCall = true;
7453
7454 // Always assume __builtin_constant_p(...) ? ... : ... is a potential
7455 // constant expression; we can't check whether it's potentially foldable.
7456 // FIXME: We should instead treat __builtin_constant_p as non-constant if
7457 // it would return 'false' in this mode.
7458 if (Info.checkingPotentialConstantExpression() && IsBcpCall)
7459 return false;
7460
7461 FoldConstant Fold(Info, IsBcpCall);
7462 if (!HandleConditionalOperator(E)) {
7463 Fold.keepDiagnostics();
7464 return false;
7465 }
7466
7467 return true;
7468 }
7469
7470 bool VisitOpaqueValueExpr(const OpaqueValueExpr *E) {
7471 if (APValue *Value = Info.CurrentCall->getCurrentTemporary(E))
7472 return DerivedSuccess(*Value, E);
7473
7474 const Expr *Source = E->getSourceExpr();
7475 if (!Source)
7476 return Error(E);
7477 if (Source == E) { // sanity checking.
7478 assert(0 && "OpaqueValueExpr recursively refers to itself")((0 && "OpaqueValueExpr recursively refers to itself"
) ? static_cast<void> (0) : __assert_fail ("0 && \"OpaqueValueExpr recursively refers to itself\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7478, __PRETTY_FUNCTION__))
;
7479 return Error(E);
7480 }
7481 return StmtVisitorTy::Visit(Source);
7482 }
7483
7484 bool VisitPseudoObjectExpr(const PseudoObjectExpr *E) {
7485 for (const Expr *SemE : E->semantics()) {
7486 if (auto *OVE = dyn_cast<OpaqueValueExpr>(SemE)) {
7487 // FIXME: We can't handle the case where an OpaqueValueExpr is also the
7488 // result expression: there could be two different LValues that would
7489 // refer to the same object in that case, and we can't model that.
7490 if (SemE == E->getResultExpr())
7491 return Error(E);
7492
7493 // Unique OVEs get evaluated if and when we encounter them when
7494 // emitting the rest of the semantic form, rather than eagerly.
7495 if (OVE->isUnique())
7496 continue;
7497
7498 LValue LV;
7499 if (!Evaluate(Info.CurrentCall->createTemporary(
7500 OVE, getStorageType(Info.Ctx, OVE),
7501 ScopeKind::FullExpression, LV),
7502 Info, OVE->getSourceExpr()))
7503 return false;
7504 } else if (SemE == E->getResultExpr()) {
7505 if (!StmtVisitorTy::Visit(SemE))
7506 return false;
7507 } else {
7508 if (!EvaluateIgnoredValue(Info, SemE))
7509 return false;
7510 }
7511 }
7512 return true;
7513 }
7514
7515 bool VisitCallExpr(const CallExpr *E) {
7516 APValue Result;
7517 if (!handleCallExpr(E, Result, nullptr))
7518 return false;
7519 return DerivedSuccess(Result, E);
7520 }
7521
7522 bool handleCallExpr(const CallExpr *E, APValue &Result,
7523 const LValue *ResultSlot) {
7524 CallScopeRAII CallScope(Info);
7525
7526 const Expr *Callee = E->getCallee()->IgnoreParens();
7527 QualType CalleeType = Callee->getType();
7528
7529 const FunctionDecl *FD = nullptr;
7530 LValue *This = nullptr, ThisVal;
7531 auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
7532 bool HasQualifier = false;
7533
7534 CallRef Call;
7535
7536 // Extract function decl and 'this' pointer from the callee.
7537 if (CalleeType->isSpecificBuiltinType(BuiltinType::BoundMember)) {
7538 const CXXMethodDecl *Member = nullptr;
7539 if (const MemberExpr *ME = dyn_cast<MemberExpr>(Callee)) {
7540 // Explicit bound member calls, such as x.f() or p->g();
7541 if (!EvaluateObjectArgument(Info, ME->getBase(), ThisVal))
7542 return false;
7543 Member = dyn_cast<CXXMethodDecl>(ME->getMemberDecl());
7544 if (!Member)
7545 return Error(Callee);
7546 This = &ThisVal;
7547 HasQualifier = ME->hasQualifier();
7548 } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(Callee)) {
7549 // Indirect bound member calls ('.*' or '->*').
7550 const ValueDecl *D =
7551 HandleMemberPointerAccess(Info, BE, ThisVal, false);
7552 if (!D)
7553 return false;
7554 Member = dyn_cast<CXXMethodDecl>(D);
7555 if (!Member)
7556 return Error(Callee);
7557 This = &ThisVal;
7558 } else if (const auto *PDE = dyn_cast<CXXPseudoDestructorExpr>(Callee)) {
7559 if (!Info.getLangOpts().CPlusPlus20)
7560 Info.CCEDiag(PDE, diag::note_constexpr_pseudo_destructor);
7561 return EvaluateObjectArgument(Info, PDE->getBase(), ThisVal) &&
7562 HandleDestruction(Info, PDE, ThisVal, PDE->getDestroyedType());
7563 } else
7564 return Error(Callee);
7565 FD = Member;
7566 } else if (CalleeType->isFunctionPointerType()) {
7567 LValue CalleeLV;
7568 if (!EvaluatePointer(Callee, CalleeLV, Info))
7569 return false;
7570
7571 if (!CalleeLV.getLValueOffset().isZero())
7572 return Error(Callee);
7573 FD = dyn_cast_or_null<FunctionDecl>(
7574 CalleeLV.getLValueBase().dyn_cast<const ValueDecl *>());
7575 if (!FD)
7576 return Error(Callee);
7577 // Don't call function pointers which have been cast to some other type.
7578 // Per DR (no number yet), the caller and callee can differ in noexcept.
7579 if (!Info.Ctx.hasSameFunctionTypeIgnoringExceptionSpec(
7580 CalleeType->getPointeeType(), FD->getType())) {
7581 return Error(E);
7582 }
7583
7584 // For an (overloaded) assignment expression, evaluate the RHS before the
7585 // LHS.
7586 auto *OCE = dyn_cast<CXXOperatorCallExpr>(E);
7587 if (OCE && OCE->isAssignmentOp()) {
7588 assert(Args.size() == 2 && "wrong number of arguments in assignment")((Args.size() == 2 && "wrong number of arguments in assignment"
) ? static_cast<void> (0) : __assert_fail ("Args.size() == 2 && \"wrong number of arguments in assignment\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7588, __PRETTY_FUNCTION__))
;
7589 Call = Info.CurrentCall->createCall(FD);
7590 if (!EvaluateArgs(isa<CXXMethodDecl>(FD) ? Args.slice(1) : Args, Call,
7591 Info, FD, /*RightToLeft=*/true))
7592 return false;
7593 }
7594
7595 // Overloaded operator calls to member functions are represented as normal
7596 // calls with '*this' as the first argument.
7597 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
7598 if (MD && !MD->isStatic()) {
7599 // FIXME: When selecting an implicit conversion for an overloaded
7600 // operator delete, we sometimes try to evaluate calls to conversion
7601 // operators without a 'this' parameter!
7602 if (Args.empty())
7603 return Error(E);
7604
7605 if (!EvaluateObjectArgument(Info, Args[0], ThisVal))
7606 return false;
7607 This = &ThisVal;
7608 Args = Args.slice(1);
7609 } else if (MD && MD->isLambdaStaticInvoker()) {
7610 // Map the static invoker for the lambda back to the call operator.
7611 // Conveniently, we don't have to slice out the 'this' argument (as is
7612 // being done for the non-static case), since a static member function
7613 // doesn't have an implicit argument passed in.
7614 const CXXRecordDecl *ClosureClass = MD->getParent();
7615 assert(((ClosureClass->captures_begin() == ClosureClass->captures_end
() && "Number of captures must be zero for conversion to function-ptr"
) ? static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7617, __PRETTY_FUNCTION__))
7616 ClosureClass->captures_begin() == ClosureClass->captures_end() &&((ClosureClass->captures_begin() == ClosureClass->captures_end
() && "Number of captures must be zero for conversion to function-ptr"
) ? static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7617, __PRETTY_FUNCTION__))
7617 "Number of captures must be zero for conversion to function-ptr")((ClosureClass->captures_begin() == ClosureClass->captures_end
() && "Number of captures must be zero for conversion to function-ptr"
) ? static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7617, __PRETTY_FUNCTION__))
;
7618
7619 const CXXMethodDecl *LambdaCallOp =
7620 ClosureClass->getLambdaCallOperator();
7621
7622 // Set 'FD', the function that will be called below, to the call
7623 // operator. If the closure object represents a generic lambda, find
7624 // the corresponding specialization of the call operator.
7625
7626 if (ClosureClass->isGenericLambda()) {
7627 assert(MD->isFunctionTemplateSpecialization() &&((MD->isFunctionTemplateSpecialization() && "A generic lambda's static-invoker function must be a "
"template specialization") ? static_cast<void> (0) : __assert_fail
("MD->isFunctionTemplateSpecialization() && \"A generic lambda's static-invoker function must be a \" \"template specialization\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7629, __PRETTY_FUNCTION__))
7628 "A generic lambda's static-invoker function must be a "((MD->isFunctionTemplateSpecialization() && "A generic lambda's static-invoker function must be a "
"template specialization") ? static_cast<void> (0) : __assert_fail
("MD->isFunctionTemplateSpecialization() && \"A generic lambda's static-invoker function must be a \" \"template specialization\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7629, __PRETTY_FUNCTION__))
7629 "template specialization")((MD->isFunctionTemplateSpecialization() && "A generic lambda's static-invoker function must be a "
"template specialization") ? static_cast<void> (0) : __assert_fail
("MD->isFunctionTemplateSpecialization() && \"A generic lambda's static-invoker function must be a \" \"template specialization\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7629, __PRETTY_FUNCTION__))
;
7630 const TemplateArgumentList *TAL = MD->getTemplateSpecializationArgs();
7631 FunctionTemplateDecl *CallOpTemplate =
7632 LambdaCallOp->getDescribedFunctionTemplate();
7633 void *InsertPos = nullptr;
7634 FunctionDecl *CorrespondingCallOpSpecialization =
7635 CallOpTemplate->findSpecialization(TAL->asArray(), InsertPos);
7636 assert(CorrespondingCallOpSpecialization &&((CorrespondingCallOpSpecialization && "We must always have a function call operator specialization "
"that corresponds to our static invoker specialization") ? static_cast
<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7638, __PRETTY_FUNCTION__))
7637 "We must always have a function call operator specialization "((CorrespondingCallOpSpecialization && "We must always have a function call operator specialization "
"that corresponds to our static invoker specialization") ? static_cast
<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7638, __PRETTY_FUNCTION__))
7638 "that corresponds to our static invoker specialization")((CorrespondingCallOpSpecialization && "We must always have a function call operator specialization "
"that corresponds to our static invoker specialization") ? static_cast
<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7638, __PRETTY_FUNCTION__))
;
7639 FD = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
7640 } else
7641 FD = LambdaCallOp;
7642 } else if (FD->isReplaceableGlobalAllocationFunction()) {
7643 if (FD->getDeclName().getCXXOverloadedOperator() == OO_New ||
7644 FD->getDeclName().getCXXOverloadedOperator() == OO_Array_New) {
7645 LValue Ptr;
7646 if (!HandleOperatorNewCall(Info, E, Ptr))
7647 return false;
7648 Ptr.moveInto(Result);
7649 return CallScope.destroy();
7650 } else {
7651 return HandleOperatorDeleteCall(Info, E) && CallScope.destroy();
7652 }
7653 }
7654 } else
7655 return Error(E);
7656
7657 // Evaluate the arguments now if we've not already done so.
7658 if (!Call) {
7659 Call = Info.CurrentCall->createCall(FD);
7660 if (!EvaluateArgs(Args, Call, Info, FD))
7661 return false;
7662 }
7663
7664 SmallVector<QualType, 4> CovariantAdjustmentPath;
7665 if (This) {
7666 auto *NamedMember = dyn_cast<CXXMethodDecl>(FD);
7667 if (NamedMember && NamedMember->isVirtual() && !HasQualifier) {
7668 // Perform virtual dispatch, if necessary.
7669 FD = HandleVirtualDispatch(Info, E, *This, NamedMember,
7670 CovariantAdjustmentPath);
7671 if (!FD)
7672 return false;
7673 } else {
7674 // Check that the 'this' pointer points to an object of the right type.
7675 // FIXME: If this is an assignment operator call, we may need to change
7676 // the active union member before we check this.
7677 if (!checkNonVirtualMemberCallThisPointer(Info, E, *This, NamedMember))
7678 return false;
7679 }
7680 }
7681
7682 // Destructor calls are different enough that they have their own codepath.
7683 if (auto *DD = dyn_cast<CXXDestructorDecl>(FD)) {
7684 assert(This && "no 'this' pointer for destructor call")((This && "no 'this' pointer for destructor call") ? static_cast
<void> (0) : __assert_fail ("This && \"no 'this' pointer for destructor call\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7684, __PRETTY_FUNCTION__))
;
7685 return HandleDestruction(Info, E, *This,
7686 Info.Ctx.getRecordType(DD->getParent())) &&
7687 CallScope.destroy();
7688 }
7689
7690 const FunctionDecl *Definition = nullptr;
7691 Stmt *Body = FD->getBody(Definition);
7692
7693 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body) ||
7694 !HandleFunctionCall(E->getExprLoc(), Definition, This, Args, Call,
7695 Body, Info, Result, ResultSlot))
7696 return false;
7697
7698 if (!CovariantAdjustmentPath.empty() &&
7699 !HandleCovariantReturnAdjustment(Info, E, Result,
7700 CovariantAdjustmentPath))
7701 return false;
7702
7703 return CallScope.destroy();
7704 }
7705
7706 bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
7707 return StmtVisitorTy::Visit(E->getInitializer());
7708 }
7709 bool VisitInitListExpr(const InitListExpr *E) {
7710 if (E->getNumInits() == 0)
7711 return DerivedZeroInitialization(E);
7712 if (E->getNumInits() == 1)
7713 return StmtVisitorTy::Visit(E->getInit(0));
7714 return Error(E);
7715 }
7716 bool VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
7717 return DerivedZeroInitialization(E);
7718 }
7719 bool VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
7720 return DerivedZeroInitialization(E);
7721 }
7722 bool VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
7723 return DerivedZeroInitialization(E);
7724 }
7725
7726 /// A member expression where the object is a prvalue is itself a prvalue.
7727 bool VisitMemberExpr(const MemberExpr *E) {
7728 assert(!Info.Ctx.getLangOpts().CPlusPlus11 &&((!Info.Ctx.getLangOpts().CPlusPlus11 && "missing temporary materialization conversion"
) ? static_cast<void> (0) : __assert_fail ("!Info.Ctx.getLangOpts().CPlusPlus11 && \"missing temporary materialization conversion\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7729, __PRETTY_FUNCTION__))
7729 "missing temporary materialization conversion")((!Info.Ctx.getLangOpts().CPlusPlus11 && "missing temporary materialization conversion"
) ? static_cast<void> (0) : __assert_fail ("!Info.Ctx.getLangOpts().CPlusPlus11 && \"missing temporary materialization conversion\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7729, __PRETTY_FUNCTION__))
;
7730 assert(!E->isArrow() && "missing call to bound member function?")((!E->isArrow() && "missing call to bound member function?"
) ? static_cast<void> (0) : __assert_fail ("!E->isArrow() && \"missing call to bound member function?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7730, __PRETTY_FUNCTION__))
;
7731
7732 APValue Val;
7733 if (!Evaluate(Val, Info, E->getBase()))
7734 return false;
7735
7736 QualType BaseTy = E->getBase()->getType();
7737
7738 const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl());
7739 if (!FD) return Error(E);
7740 assert(!FD->getType()->isReferenceType() && "prvalue reference?")((!FD->getType()->isReferenceType() && "prvalue reference?"
) ? static_cast<void> (0) : __assert_fail ("!FD->getType()->isReferenceType() && \"prvalue reference?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7740, __PRETTY_FUNCTION__))
;
7741 assert(BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() ==((BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl
() == FD->getParent()->getCanonicalDecl() && "record / field mismatch"
) ? static_cast<void> (0) : __assert_fail ("BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7742, __PRETTY_FUNCTION__))
7742 FD->getParent()->getCanonicalDecl() && "record / field mismatch")((BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl
() == FD->getParent()->getCanonicalDecl() && "record / field mismatch"
) ? static_cast<void> (0) : __assert_fail ("BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7742, __PRETTY_FUNCTION__))
;
7743
7744 // Note: there is no lvalue base here. But this case should only ever
7745 // happen in C or in C++98, where we cannot be evaluating a constexpr
7746 // constructor, which is the only case the base matters.
7747 CompleteObject Obj(APValue::LValueBase(), &Val, BaseTy);
7748 SubobjectDesignator Designator(BaseTy);
7749 Designator.addDeclUnchecked(FD);
7750
7751 APValue Result;
7752 return extractSubobject(Info, E, Obj, Designator, Result) &&
7753 DerivedSuccess(Result, E);
7754 }
7755
7756 bool VisitExtVectorElementExpr(const ExtVectorElementExpr *E) {
7757 APValue Val;
7758 if (!Evaluate(Val, Info, E->getBase()))
7759 return false;
7760
7761 if (Val.isVector()) {
7762 SmallVector<uint32_t, 4> Indices;
7763 E->getEncodedElementAccess(Indices);
7764 if (Indices.size() == 1) {
7765 // Return scalar.
7766 return DerivedSuccess(Val.getVectorElt(Indices[0]), E);
7767 } else {
7768 // Construct new APValue vector.
7769 SmallVector<APValue, 4> Elts;
7770 for (unsigned I = 0; I < Indices.size(); ++I) {
7771 Elts.push_back(Val.getVectorElt(Indices[I]));
7772 }
7773 APValue VecResult(Elts.data(), Indices.size());
7774 return DerivedSuccess(VecResult, E);
7775 }
7776 }
7777
7778 return false;
7779 }
7780
7781 bool VisitCastExpr(const CastExpr *E) {
7782 switch (E->getCastKind()) {
7783 default:
7784 break;
7785
7786 case CK_AtomicToNonAtomic: {
7787 APValue AtomicVal;
7788 // This does not need to be done in place even for class/array types:
7789 // atomic-to-non-atomic conversion implies copying the object
7790 // representation.
7791 if (!Evaluate(AtomicVal, Info, E->getSubExpr()))
7792 return false;
7793 return DerivedSuccess(AtomicVal, E);
7794 }
7795
7796 case CK_NoOp:
7797 case CK_UserDefinedConversion:
7798 return StmtVisitorTy::Visit(E->getSubExpr());
7799
7800 case CK_LValueToRValue: {
7801 LValue LVal;
7802 if (!EvaluateLValue(E->getSubExpr(), LVal, Info))
7803 return false;
7804 APValue RVal;
7805 // Note, we use the subexpression's type in order to retain cv-qualifiers.
7806 if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
7807 LVal, RVal))
7808 return false;
7809 return DerivedSuccess(RVal, E);
7810 }
7811 case CK_LValueToRValueBitCast: {
7812 APValue DestValue, SourceValue;
7813 if (!Evaluate(SourceValue, Info, E->getSubExpr()))
7814 return false;
7815 if (!handleLValueToRValueBitCast(Info, DestValue, SourceValue, E))
7816 return false;
7817 return DerivedSuccess(DestValue, E);
7818 }
7819
7820 case CK_AddressSpaceConversion: {
7821 APValue Value;
7822 if (!Evaluate(Value, Info, E->getSubExpr()))
7823 return false;
7824 return DerivedSuccess(Value, E);
7825 }
7826 }
7827
7828 return Error(E);
7829 }
7830
7831 bool VisitUnaryPostInc(const UnaryOperator *UO) {
7832 return VisitUnaryPostIncDec(UO);
7833 }
7834 bool VisitUnaryPostDec(const UnaryOperator *UO) {
7835 return VisitUnaryPostIncDec(UO);
7836 }
7837 bool VisitUnaryPostIncDec(const UnaryOperator *UO) {
7838 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
7839 return Error(UO);
7840
7841 LValue LVal;
7842 if (!EvaluateLValue(UO->getSubExpr(), LVal, Info))
7843 return false;
7844 APValue RVal;
7845 if (!handleIncDec(this->Info, UO, LVal, UO->getSubExpr()->getType(),
7846 UO->isIncrementOp(), &RVal))
7847 return false;
7848 return DerivedSuccess(RVal, UO);
7849 }
7850
7851 bool VisitStmtExpr(const StmtExpr *E) {
7852 // We will have checked the full-expressions inside the statement expression
7853 // when they were completed, and don't need to check them again now.
7854 llvm::SaveAndRestore<bool> NotCheckingForUB(
7855 Info.CheckingForUndefinedBehavior, false);
7856
7857 const CompoundStmt *CS = E->getSubStmt();
7858 if (CS->body_empty())
7859 return true;
7860
7861 BlockScopeRAII Scope(Info);
7862 for (CompoundStmt::const_body_iterator BI = CS->body_begin(),
7863 BE = CS->body_end();
7864 /**/; ++BI) {
7865 if (BI + 1 == BE) {
7866 const Expr *FinalExpr = dyn_cast<Expr>(*BI);
7867 if (!FinalExpr) {
7868 Info.FFDiag((*BI)->getBeginLoc(),
7869 diag::note_constexpr_stmt_expr_unsupported);
7870 return false;
7871 }
7872 return this->Visit(FinalExpr) && Scope.destroy();
7873 }
7874
7875 APValue ReturnValue;
7876 StmtResult Result = { ReturnValue, nullptr };
7877 EvalStmtResult ESR = EvaluateStmt(Result, Info, *BI);
7878 if (ESR != ESR_Succeeded) {
7879 // FIXME: If the statement-expression terminated due to 'return',
7880 // 'break', or 'continue', it would be nice to propagate that to
7881 // the outer statement evaluation rather than bailing out.
7882 if (ESR != ESR_Failed)
7883 Info.FFDiag((*BI)->getBeginLoc(),
7884 diag::note_constexpr_stmt_expr_unsupported);
7885 return false;
7886 }
7887 }
7888
7889 llvm_unreachable("Return from function from the loop above.")::llvm::llvm_unreachable_internal("Return from function from the loop above."
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7889)
;
7890 }
7891
7892 /// Visit a value which is evaluated, but whose value is ignored.
7893 void VisitIgnoredValue(const Expr *E) {
7894 EvaluateIgnoredValue(Info, E);
7895 }
7896
7897 /// Potentially visit a MemberExpr's base expression.
7898 void VisitIgnoredBaseExpression(const Expr *E) {
7899 // While MSVC doesn't evaluate the base expression, it does diagnose the
7900 // presence of side-effecting behavior.
7901 if (Info.getLangOpts().MSVCCompat && !E->HasSideEffects(Info.Ctx))
7902 return;
7903 VisitIgnoredValue(E);
7904 }
7905};
7906
7907} // namespace
7908
7909//===----------------------------------------------------------------------===//
7910// Common base class for lvalue and temporary evaluation.
7911//===----------------------------------------------------------------------===//
7912namespace {
7913template<class Derived>
7914class LValueExprEvaluatorBase
7915 : public ExprEvaluatorBase<Derived> {
7916protected:
7917 LValue &Result;
7918 bool InvalidBaseOK;
7919 typedef LValueExprEvaluatorBase LValueExprEvaluatorBaseTy;
7920 typedef ExprEvaluatorBase<Derived> ExprEvaluatorBaseTy;
7921
7922 bool Success(APValue::LValueBase B) {
7923 Result.set(B);
7924 return true;
7925 }
7926
7927 bool evaluatePointer(const Expr *E, LValue &Result) {
7928 return EvaluatePointer(E, Result, this->Info, InvalidBaseOK);
7929 }
7930
7931public:
7932 LValueExprEvaluatorBase(EvalInfo &Info, LValue &Result, bool InvalidBaseOK)
7933 : ExprEvaluatorBaseTy(Info), Result(Result),
7934 InvalidBaseOK(InvalidBaseOK) {}
7935
7936 bool Success(const APValue &V, const Expr *E) {
7937 Result.setFrom(this->Info.Ctx, V);
7938 return true;
7939 }
7940
7941 bool VisitMemberExpr(const MemberExpr *E) {
7942 // Handle non-static data members.
7943 QualType BaseTy;
7944 bool EvalOK;
7945 if (E->isArrow()) {
7946 EvalOK = evaluatePointer(E->getBase(), Result);
7947 BaseTy = E->getBase()->getType()->castAs<PointerType>()->getPointeeType();
7948 } else if (E->getBase()->isRValue()) {
7949 assert(E->getBase()->getType()->isRecordType())((E->getBase()->getType()->isRecordType()) ? static_cast
<void> (0) : __assert_fail ("E->getBase()->getType()->isRecordType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7949, __PRETTY_FUNCTION__))
;
7950 EvalOK = EvaluateTemporary(E->getBase(), Result, this->Info);
7951 BaseTy = E->getBase()->getType();
7952 } else {
7953 EvalOK = this->Visit(E->getBase());
7954 BaseTy = E->getBase()->getType();
7955 }
7956 if (!EvalOK) {
7957 if (!InvalidBaseOK)
7958 return false;
7959 Result.setInvalid(E);
7960 return true;
7961 }
7962
7963 const ValueDecl *MD = E->getMemberDecl();
7964 if (const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl())) {
7965 assert(BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() ==((BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl
() == FD->getParent()->getCanonicalDecl() && "record / field mismatch"
) ? static_cast<void> (0) : __assert_fail ("BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7966, __PRETTY_FUNCTION__))
7966 FD->getParent()->getCanonicalDecl() && "record / field mismatch")((BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl
() == FD->getParent()->getCanonicalDecl() && "record / field mismatch"
) ? static_cast<void> (0) : __assert_fail ("BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 7966, __PRETTY_FUNCTION__))
;
7967 (void)BaseTy;
7968 if (!HandleLValueMember(this->Info, E, Result, FD))
7969 return false;
7970 } else if (const IndirectFieldDecl *IFD = dyn_cast<IndirectFieldDecl>(MD)) {
7971 if (!HandleLValueIndirectMember(this->Info, E, Result, IFD))
7972 return false;
7973 } else
7974 return this->Error(E);
7975
7976 if (MD->getType()->isReferenceType()) {
7977 APValue RefValue;
7978 if (!handleLValueToRValueConversion(this->Info, E, MD->getType(), Result,
7979 RefValue))
7980 return false;
7981 return Success(RefValue, E);
7982 }
7983 return true;
7984 }
7985
7986 bool VisitBinaryOperator(const BinaryOperator *E) {
7987 switch (E->getOpcode()) {
7988 default:
7989 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
7990
7991 case BO_PtrMemD:
7992 case BO_PtrMemI:
7993 return HandleMemberPointerAccess(this->Info, E, Result);
7994 }
7995 }
7996
7997 bool VisitCastExpr(const CastExpr *E) {
7998 switch (E->getCastKind()) {
7999 default:
8000 return ExprEvaluatorBaseTy::VisitCastExpr(E);
8001
8002 case CK_DerivedToBase:
8003 case CK_UncheckedDerivedToBase:
8004 if (!this->Visit(E->getSubExpr()))
8005 return false;
8006
8007 // Now figure out the necessary offset to add to the base LV to get from
8008 // the derived class to the base class.
8009 return HandleLValueBasePath(this->Info, E, E->getSubExpr()->getType(),
8010 Result);
8011 }
8012 }
8013};
8014}
8015
8016//===----------------------------------------------------------------------===//
8017// LValue Evaluation
8018//
8019// This is used for evaluating lvalues (in C and C++), xvalues (in C++11),
8020// function designators (in C), decl references to void objects (in C), and
8021// temporaries (if building with -Wno-address-of-temporary).
8022//
8023// LValue evaluation produces values comprising a base expression of one of the
8024// following types:
8025// - Declarations
8026// * VarDecl
8027// * FunctionDecl
8028// - Literals
8029// * CompoundLiteralExpr in C (and in global scope in C++)
8030// * StringLiteral
8031// * PredefinedExpr
8032// * ObjCStringLiteralExpr
8033// * ObjCEncodeExpr
8034// * AddrLabelExpr
8035// * BlockExpr
8036// * CallExpr for a MakeStringConstant builtin
8037// - typeid(T) expressions, as TypeInfoLValues
8038// - Locals and temporaries
8039// * MaterializeTemporaryExpr
8040// * Any Expr, with a CallIndex indicating the function in which the temporary
8041// was evaluated, for cases where the MaterializeTemporaryExpr is missing
8042// from the AST (FIXME).
8043// * A MaterializeTemporaryExpr that has static storage duration, with no
8044// CallIndex, for a lifetime-extended temporary.
8045// * The ConstantExpr that is currently being evaluated during evaluation of an
8046// immediate invocation.
8047// plus an offset in bytes.
8048//===----------------------------------------------------------------------===//
8049namespace {
8050class LValueExprEvaluator
8051 : public LValueExprEvaluatorBase<LValueExprEvaluator> {
8052public:
8053 LValueExprEvaluator(EvalInfo &Info, LValue &Result, bool InvalidBaseOK) :
8054 LValueExprEvaluatorBaseTy(Info, Result, InvalidBaseOK) {}
8055
8056 bool VisitVarDecl(const Expr *E, const VarDecl *VD);
8057 bool VisitUnaryPreIncDec(const UnaryOperator *UO);
8058
8059 bool VisitDeclRefExpr(const DeclRefExpr *E);
8060 bool VisitPredefinedExpr(const PredefinedExpr *E) { return Success(E); }
8061 bool VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
8062 bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
8063 bool VisitMemberExpr(const MemberExpr *E);
8064 bool VisitStringLiteral(const StringLiteral *E) { return Success(E); }
8065 bool VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { return Success(E); }
8066 bool VisitCXXTypeidExpr(const CXXTypeidExpr *E);
8067 bool VisitCXXUuidofExpr(const CXXUuidofExpr *E);
8068 bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E);
8069 bool VisitUnaryDeref(const UnaryOperator *E);
8070 bool VisitUnaryReal(const UnaryOperator *E);
8071 bool VisitUnaryImag(const UnaryOperator *E);
8072 bool VisitUnaryPreInc(const UnaryOperator *UO) {
8073 return VisitUnaryPreIncDec(UO);
8074 }
8075 bool VisitUnaryPreDec(const UnaryOperator *UO) {
8076 return VisitUnaryPreIncDec(UO);
8077 }
8078 bool VisitBinAssign(const BinaryOperator *BO);
8079 bool VisitCompoundAssignOperator(const CompoundAssignOperator *CAO);
8080
8081 bool VisitCastExpr(const CastExpr *E) {
8082 switch (E->getCastKind()) {
8083 default:
8084 return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
8085
8086 case CK_LValueBitCast:
8087 this->CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
8088 if (!Visit(E->getSubExpr()))
8089 return false;
8090 Result.Designator.setInvalid();
8091 return true;
8092
8093 case CK_BaseToDerived:
8094 if (!Visit(E->getSubExpr()))
8095 return false;
8096 return HandleBaseToDerivedCast(Info, E, Result);
8097
8098 case CK_Dynamic:
8099 if (!Visit(E->getSubExpr()))
8100 return false;
8101 return HandleDynamicCast(Info, cast<ExplicitCastExpr>(E), Result);
8102 }
8103 }
8104};
8105} // end anonymous namespace
8106
8107/// Evaluate an expression as an lvalue. This can be legitimately called on
8108/// expressions which are not glvalues, in three cases:
8109/// * function designators in C, and
8110/// * "extern void" objects
8111/// * @selector() expressions in Objective-C
8112static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
8113 bool InvalidBaseOK) {
8114 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8114, __PRETTY_FUNCTION__))
;
8115 assert(E->isGLValue() || E->getType()->isFunctionType() ||((E->isGLValue() || E->getType()->isFunctionType() ||
E->getType()->isVoidType() || isa<ObjCSelectorExpr>
(E)) ? static_cast<void> (0) : __assert_fail ("E->isGLValue() || E->getType()->isFunctionType() || E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E)"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8116, __PRETTY_FUNCTION__))
8116 E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E))((E->isGLValue() || E->getType()->isFunctionType() ||
E->getType()->isVoidType() || isa<ObjCSelectorExpr>
(E)) ? static_cast<void> (0) : __assert_fail ("E->isGLValue() || E->getType()->isFunctionType() || E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E)"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8116, __PRETTY_FUNCTION__))
;
8117 return LValueExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
8118}
8119
8120bool LValueExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
8121 const NamedDecl *D = E->getDecl();
8122 if (isa<FunctionDecl, MSGuidDecl, TemplateParamObjectDecl>(D))
8123 return Success(cast<ValueDecl>(D));
8124 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
8125 return VisitVarDecl(E, VD);
8126 if (const BindingDecl *BD = dyn_cast<BindingDecl>(D))
8127 return Visit(BD->getBinding());
8128 return Error(E);
8129}
8130
8131
8132bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
8133
8134 // If we are within a lambda's call operator, check whether the 'VD' referred
8135 // to within 'E' actually represents a lambda-capture that maps to a
8136 // data-member/field within the closure object, and if so, evaluate to the
8137 // field or what the field refers to.
8138 if (Info.CurrentCall && isLambdaCallOperator(Info.CurrentCall->Callee) &&
8139 isa<DeclRefExpr>(E) &&
8140 cast<DeclRefExpr>(E)->refersToEnclosingVariableOrCapture()) {
8141 // We don't always have a complete capture-map when checking or inferring if
8142 // the function call operator meets the requirements of a constexpr function
8143 // - but we don't need to evaluate the captures to determine constexprness
8144 // (dcl.constexpr C++17).
8145 if (Info.checkingPotentialConstantExpression())
8146 return false;
8147
8148 if (auto *FD = Info.CurrentCall->LambdaCaptureFields.lookup(VD)) {
8149 // Start with 'Result' referring to the complete closure object...
8150 Result = *Info.CurrentCall->This;
8151 // ... then update it to refer to the field of the closure object
8152 // that represents the capture.
8153 if (!HandleLValueMember(Info, E, Result, FD))
8154 return false;
8155 // And if the field is of reference type, update 'Result' to refer to what
8156 // the field refers to.
8157 if (FD->getType()->isReferenceType()) {
8158 APValue RVal;
8159 if (!handleLValueToRValueConversion(Info, E, FD->getType(), Result,
8160 RVal))
8161 return false;
8162 Result.setFrom(Info.Ctx, RVal);
8163 }
8164 return true;
8165 }
8166 }
8167
8168 CallStackFrame *Frame = nullptr;
8169 unsigned Version = 0;
8170 if (VD->hasLocalStorage()) {
8171 // Only if a local variable was declared in the function currently being
8172 // evaluated, do we expect to be able to find its value in the current
8173 // frame. (Otherwise it was likely declared in an enclosing context and
8174 // could either have a valid evaluatable value (for e.g. a constexpr
8175 // variable) or be ill-formed (and trigger an appropriate evaluation
8176 // diagnostic)).
8177 CallStackFrame *CurrFrame = Info.CurrentCall;
8178 if (CurrFrame->Callee && CurrFrame->Callee->Equals(VD->getDeclContext())) {
8179 // Function parameters are stored in some caller's frame. (Usually the
8180 // immediate caller, but for an inherited constructor they may be more
8181 // distant.)
8182 if (auto *PVD = dyn_cast<ParmVarDecl>(VD)) {
8183 if (CurrFrame->Arguments) {
8184 VD = CurrFrame->Arguments.getOrigParam(PVD);
8185 Frame =
8186 Info.getCallFrameAndDepth(CurrFrame->Arguments.CallIndex).first;
8187 Version = CurrFrame->Arguments.Version;
8188 }
8189 } else {
8190 Frame = CurrFrame;
8191 Version = CurrFrame->getCurrentTemporaryVersion(VD);
8192 }
8193 }
8194 }
8195
8196 if (!VD->getType()->isReferenceType()) {
8197 if (Frame) {
8198 Result.set({VD, Frame->Index, Version});
8199 return true;
8200 }
8201 return Success(VD);
8202 }
8203
8204 if (!Info.getLangOpts().CPlusPlus11) {
8205 Info.CCEDiag(E, diag::note_constexpr_ltor_non_integral, 1)
8206 << VD << VD->getType();
8207 Info.Note(VD->getLocation(), diag::note_declared_at);
8208 }
8209
8210 APValue *V;
8211 if (!evaluateVarDeclInit(Info, E, VD, Frame, Version, V))
8212 return false;
8213 if (!V->hasValue()) {
8214 // FIXME: Is it possible for V to be indeterminate here? If so, we should
8215 // adjust the diagnostic to say that.
8216 if (!Info.checkingPotentialConstantExpression())
8217 Info.FFDiag(E, diag::note_constexpr_use_uninit_reference);
8218 return false;
8219 }
8220 return Success(*V, E);
8221}
8222
8223bool LValueExprEvaluator::VisitMaterializeTemporaryExpr(
8224 const MaterializeTemporaryExpr *E) {
8225 // Walk through the expression to find the materialized temporary itself.
8226 SmallVector<const Expr *, 2> CommaLHSs;
8227 SmallVector<SubobjectAdjustment, 2> Adjustments;
8228 const Expr *Inner =
8229 E->getSubExpr()->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
8230
8231 // If we passed any comma operators, evaluate their LHSs.
8232 for (unsigned I = 0, N = CommaLHSs.size(); I != N; ++I)
8233 if (!EvaluateIgnoredValue(Info, CommaLHSs[I]))
8234 return false;
8235
8236 // A materialized temporary with static storage duration can appear within the
8237 // result of a constant expression evaluation, so we need to preserve its
8238 // value for use outside this evaluation.
8239 APValue *Value;
8240 if (E->getStorageDuration() == SD_Static) {
8241 // FIXME: What about SD_Thread?
8242 Value = E->getOrCreateValue(true);
8243 *Value = APValue();
8244 Result.set(E);
8245 } else {
8246 Value = &Info.CurrentCall->createTemporary(
8247 E, E->getType(),
8248 E->getStorageDuration() == SD_FullExpression ? ScopeKind::FullExpression
8249 : ScopeKind::Block,
8250 Result);
8251 }
8252
8253 QualType Type = Inner->getType();
8254
8255 // Materialize the temporary itself.
8256 if (!EvaluateInPlace(*Value, Info, Result, Inner)) {
8257 *Value = APValue();
8258 return false;
8259 }
8260
8261 // Adjust our lvalue to refer to the desired subobject.
8262 for (unsigned I = Adjustments.size(); I != 0; /**/) {
8263 --I;
8264 switch (Adjustments[I].Kind) {
8265 case SubobjectAdjustment::DerivedToBaseAdjustment:
8266 if (!HandleLValueBasePath(Info, Adjustments[I].DerivedToBase.BasePath,
8267 Type, Result))
8268 return false;
8269 Type = Adjustments[I].DerivedToBase.BasePath->getType();
8270 break;
8271
8272 case SubobjectAdjustment::FieldAdjustment:
8273 if (!HandleLValueMember(Info, E, Result, Adjustments[I].Field))
8274 return false;
8275 Type = Adjustments[I].Field->getType();
8276 break;
8277
8278 case SubobjectAdjustment::MemberPointerAdjustment:
8279 if (!HandleMemberPointerAccess(this->Info, Type, Result,
8280 Adjustments[I].Ptr.RHS))
8281 return false;
8282 Type = Adjustments[I].Ptr.MPT->getPointeeType();
8283 break;
8284 }
8285 }
8286
8287 return true;
8288}
8289
8290bool
8291LValueExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
8292 assert((!Info.getLangOpts().CPlusPlus || E->isFileScope()) &&(((!Info.getLangOpts().CPlusPlus || E->isFileScope()) &&
"lvalue compound literal in c++?") ? static_cast<void>
(0) : __assert_fail ("(!Info.getLangOpts().CPlusPlus || E->isFileScope()) && \"lvalue compound literal in c++?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8293, __PRETTY_FUNCTION__))
8293 "lvalue compound literal in c++?")(((!Info.getLangOpts().CPlusPlus || E->isFileScope()) &&
"lvalue compound literal in c++?") ? static_cast<void>
(0) : __assert_fail ("(!Info.getLangOpts().CPlusPlus || E->isFileScope()) && \"lvalue compound literal in c++?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8293, __PRETTY_FUNCTION__))
;
8294 // Defer visiting the literal until the lvalue-to-rvalue conversion. We can
8295 // only see this when folding in C, so there's no standard to follow here.
8296 return Success(E);
8297}
8298
8299bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
8300 TypeInfoLValue TypeInfo;
8301
8302 if (!E->isPotentiallyEvaluated()) {
8303 if (E->isTypeOperand())
8304 TypeInfo = TypeInfoLValue(E->getTypeOperand(Info.Ctx).getTypePtr());
8305 else
8306 TypeInfo = TypeInfoLValue(E->getExprOperand()->getType().getTypePtr());
8307 } else {
8308 if (!Info.Ctx.getLangOpts().CPlusPlus20) {
8309 Info.CCEDiag(E, diag::note_constexpr_typeid_polymorphic)
8310 << E->getExprOperand()->getType()
8311 << E->getExprOperand()->getSourceRange();
8312 }
8313
8314 if (!Visit(E->getExprOperand()))
8315 return false;
8316
8317 Optional<DynamicType> DynType =
8318 ComputeDynamicType(Info, E, Result, AK_TypeId);
8319 if (!DynType)
8320 return false;
8321
8322 TypeInfo =
8323 TypeInfoLValue(Info.Ctx.getRecordType(DynType->Type).getTypePtr());
8324 }
8325
8326 return Success(APValue::LValueBase::getTypeInfo(TypeInfo, E->getType()));
8327}
8328
8329bool LValueExprEvaluator::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
8330 return Success(E->getGuidDecl());
8331}
8332
8333bool LValueExprEvaluator::VisitMemberExpr(const MemberExpr *E) {
8334 // Handle static data members.
8335 if (const VarDecl *VD = dyn_cast<VarDecl>(E->getMemberDecl())) {
8336 VisitIgnoredBaseExpression(E->getBase());
8337 return VisitVarDecl(E, VD);
8338 }
8339
8340 // Handle static member functions.
8341 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl())) {
8342 if (MD->isStatic()) {
8343 VisitIgnoredBaseExpression(E->getBase());
8344 return Success(MD);
8345 }
8346 }
8347
8348 // Handle non-static data members.
8349 return LValueExprEvaluatorBaseTy::VisitMemberExpr(E);
8350}
8351
8352bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
8353 // FIXME: Deal with vectors as array subscript bases.
8354 if (E->getBase()->getType()->isVectorType())
8355 return Error(E);
8356
8357 APSInt Index;
8358 bool Success = true;
8359
8360 // C++17's rules require us to evaluate the LHS first, regardless of which
8361 // side is the base.
8362 for (const Expr *SubExpr : {E->getLHS(), E->getRHS()}) {
8363 if (SubExpr == E->getBase() ? !evaluatePointer(SubExpr, Result)
8364 : !EvaluateInteger(SubExpr, Index, Info)) {
8365 if (!Info.noteFailure())
8366 return false;
8367 Success = false;
8368 }
8369 }
8370
8371 return Success &&
8372 HandleLValueArrayAdjustment(Info, E, Result, E->getType(), Index);
8373}
8374
8375bool LValueExprEvaluator::VisitUnaryDeref(const UnaryOperator *E) {
8376 return evaluatePointer(E->getSubExpr(), Result);
8377}
8378
8379bool LValueExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
8380 if (!Visit(E->getSubExpr()))
8381 return false;
8382 // __real is a no-op on scalar lvalues.
8383 if (E->getSubExpr()->getType()->isAnyComplexType())
8384 HandleLValueComplexElement(Info, E, Result, E->getType(), false);
8385 return true;
8386}
8387
8388bool LValueExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
8389 assert(E->getSubExpr()->getType()->isAnyComplexType() &&((E->getSubExpr()->getType()->isAnyComplexType() &&
"lvalue __imag__ on scalar?") ? static_cast<void> (0) :
__assert_fail ("E->getSubExpr()->getType()->isAnyComplexType() && \"lvalue __imag__ on scalar?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8390, __PRETTY_FUNCTION__))
8390 "lvalue __imag__ on scalar?")((E->getSubExpr()->getType()->isAnyComplexType() &&
"lvalue __imag__ on scalar?") ? static_cast<void> (0) :
__assert_fail ("E->getSubExpr()->getType()->isAnyComplexType() && \"lvalue __imag__ on scalar?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8390, __PRETTY_FUNCTION__))
;
8391 if (!Visit(E->getSubExpr()))
8392 return false;
8393 HandleLValueComplexElement(Info, E, Result, E->getType(), true);
8394 return true;
8395}
8396
8397bool LValueExprEvaluator::VisitUnaryPreIncDec(const UnaryOperator *UO) {
8398 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
8399 return Error(UO);
8400
8401 if (!this->Visit(UO->getSubExpr()))
8402 return false;
8403
8404 return handleIncDec(
8405 this->Info, UO, Result, UO->getSubExpr()->getType(),
8406 UO->isIncrementOp(), nullptr);
8407}
8408
8409bool LValueExprEvaluator::VisitCompoundAssignOperator(
8410 const CompoundAssignOperator *CAO) {
8411 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
8412 return Error(CAO);
8413
8414 bool Success = true;
8415
8416 // C++17 onwards require that we evaluate the RHS first.
8417 APValue RHS;
8418 if (!Evaluate(RHS, this->Info, CAO->getRHS())) {
8419 if (!Info.noteFailure())
8420 return false;
8421 Success = false;
8422 }
8423
8424 // The overall lvalue result is the result of evaluating the LHS.
8425 if (!this->Visit(CAO->getLHS()) || !Success)
8426 return false;
8427
8428 return handleCompoundAssignment(
8429 this->Info, CAO,
8430 Result, CAO->getLHS()->getType(), CAO->getComputationLHSType(),
8431 CAO->getOpForCompoundAssignment(CAO->getOpcode()), RHS);
8432}
8433
8434bool LValueExprEvaluator::VisitBinAssign(const BinaryOperator *E) {
8435 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
8436 return Error(E);
8437
8438 bool Success = true;
8439
8440 // C++17 onwards require that we evaluate the RHS first.
8441 APValue NewVal;
8442 if (!Evaluate(NewVal, this->Info, E->getRHS())) {
8443 if (!Info.noteFailure())
8444 return false;
8445 Success = false;
8446 }
8447
8448 if (!this->Visit(E->getLHS()) || !Success)
8449 return false;
8450
8451 if (Info.getLangOpts().CPlusPlus20 &&
8452 !HandleUnionActiveMemberChange(Info, E->getLHS(), Result))
8453 return false;
8454
8455 return handleAssignment(this->Info, E, Result, E->getLHS()->getType(),
8456 NewVal);
8457}
8458
8459//===----------------------------------------------------------------------===//
8460// Pointer Evaluation
8461//===----------------------------------------------------------------------===//
8462
8463/// Attempts to compute the number of bytes available at the pointer
8464/// returned by a function with the alloc_size attribute. Returns true if we
8465/// were successful. Places an unsigned number into `Result`.
8466///
8467/// This expects the given CallExpr to be a call to a function with an
8468/// alloc_size attribute.
8469static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
8470 const CallExpr *Call,
8471 llvm::APInt &Result) {
8472 const AllocSizeAttr *AllocSize = getAllocSizeAttr(Call);
8473
8474 assert(AllocSize && AllocSize->getElemSizeParam().isValid())((AllocSize && AllocSize->getElemSizeParam().isValid
()) ? static_cast<void> (0) : __assert_fail ("AllocSize && AllocSize->getElemSizeParam().isValid()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8474, __PRETTY_FUNCTION__))
;
8475 unsigned SizeArgNo = AllocSize->getElemSizeParam().getASTIndex();
8476 unsigned BitsInSizeT = Ctx.getTypeSize(Ctx.getSizeType());
8477 if (Call->getNumArgs() <= SizeArgNo)
8478 return false;
8479
8480 auto EvaluateAsSizeT = [&](const Expr *E, APSInt &Into) {
8481 Expr::EvalResult ExprResult;
8482 if (!E->EvaluateAsInt(ExprResult, Ctx, Expr::SE_AllowSideEffects))
8483 return false;
8484 Into = ExprResult.Val.getInt();
8485 if (Into.isNegative() || !Into.isIntN(BitsInSizeT))
8486 return false;
8487 Into = Into.zextOrSelf(BitsInSizeT);
8488 return true;
8489 };
8490
8491 APSInt SizeOfElem;
8492 if (!EvaluateAsSizeT(Call->getArg(SizeArgNo), SizeOfElem))
8493 return false;
8494
8495 if (!AllocSize->getNumElemsParam().isValid()) {
8496 Result = std::move(SizeOfElem);
8497 return true;
8498 }
8499
8500 APSInt NumberOfElems;
8501 unsigned NumArgNo = AllocSize->getNumElemsParam().getASTIndex();
8502 if (!EvaluateAsSizeT(Call->getArg(NumArgNo), NumberOfElems))
8503 return false;
8504
8505 bool Overflow;
8506 llvm::APInt BytesAvailable = SizeOfElem.umul_ov(NumberOfElems, Overflow);
8507 if (Overflow)
8508 return false;
8509
8510 Result = std::move(BytesAvailable);
8511 return true;
8512}
8513
8514/// Convenience function. LVal's base must be a call to an alloc_size
8515/// function.
8516static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
8517 const LValue &LVal,
8518 llvm::APInt &Result) {
8519 assert(isBaseAnAllocSizeCall(LVal.getLValueBase()) &&((isBaseAnAllocSizeCall(LVal.getLValueBase()) && "Can't get the size of a non alloc_size function"
) ? static_cast<void> (0) : __assert_fail ("isBaseAnAllocSizeCall(LVal.getLValueBase()) && \"Can't get the size of a non alloc_size function\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8520, __PRETTY_FUNCTION__))
8520 "Can't get the size of a non alloc_size function")((isBaseAnAllocSizeCall(LVal.getLValueBase()) && "Can't get the size of a non alloc_size function"
) ? static_cast<void> (0) : __assert_fail ("isBaseAnAllocSizeCall(LVal.getLValueBase()) && \"Can't get the size of a non alloc_size function\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8520, __PRETTY_FUNCTION__))
;
8521 const auto *Base = LVal.getLValueBase().get<const Expr *>();
8522 const CallExpr *CE = tryUnwrapAllocSizeCall(Base);
8523 return getBytesReturnedByAllocSizeCall(Ctx, CE, Result);
8524}
8525
8526/// Attempts to evaluate the given LValueBase as the result of a call to
8527/// a function with the alloc_size attribute. If it was possible to do so, this
8528/// function will return true, make Result's Base point to said function call,
8529/// and mark Result's Base as invalid.
8530static bool evaluateLValueAsAllocSize(EvalInfo &Info, APValue::LValueBase Base,
8531 LValue &Result) {
8532 if (Base.isNull())
8533 return false;
8534
8535 // Because we do no form of static analysis, we only support const variables.
8536 //
8537 // Additionally, we can't support parameters, nor can we support static
8538 // variables (in the latter case, use-before-assign isn't UB; in the former,
8539 // we have no clue what they'll be assigned to).
8540 const auto *VD =
8541 dyn_cast_or_null<VarDecl>(Base.dyn_cast<const ValueDecl *>());
8542 if (!VD || !VD->isLocalVarDecl() || !VD->getType().isConstQualified())
8543 return false;
8544
8545 const Expr *Init = VD->getAnyInitializer();
8546 if (!Init)
8547 return false;
8548
8549 const Expr *E = Init->IgnoreParens();
8550 if (!tryUnwrapAllocSizeCall(E))
8551 return false;
8552
8553 // Store E instead of E unwrapped so that the type of the LValue's base is
8554 // what the user wanted.
8555 Result.setInvalid(E);
8556
8557 QualType Pointee = E->getType()->castAs<PointerType>()->getPointeeType();
8558 Result.addUnsizedArray(Info, E, Pointee);
8559 return true;
8560}
8561
8562namespace {
8563class PointerExprEvaluator
8564 : public ExprEvaluatorBase<PointerExprEvaluator> {
8565 LValue &Result;
8566 bool InvalidBaseOK;
8567
8568 bool Success(const Expr *E) {
8569 Result.set(E);
8570 return true;
8571 }
8572
8573 bool evaluateLValue(const Expr *E, LValue &Result) {
8574 return EvaluateLValue(E, Result, Info, InvalidBaseOK);
8575 }
8576
8577 bool evaluatePointer(const Expr *E, LValue &Result) {
8578 return EvaluatePointer(E, Result, Info, InvalidBaseOK);
8579 }
8580
8581 bool visitNonBuiltinCallExpr(const CallExpr *E);
8582public:
8583
8584 PointerExprEvaluator(EvalInfo &info, LValue &Result, bool InvalidBaseOK)
8585 : ExprEvaluatorBaseTy(info), Result(Result),
8586 InvalidBaseOK(InvalidBaseOK) {}
8587
8588 bool Success(const APValue &V, const Expr *E) {
8589 Result.setFrom(Info.Ctx, V);
8590 return true;
8591 }
8592 bool ZeroInitialization(const Expr *E) {
8593 Result.setNull(Info.Ctx, E->getType());
8594 return true;
8595 }
8596
8597 bool VisitBinaryOperator(const BinaryOperator *E);
8598 bool VisitCastExpr(const CastExpr* E);
8599 bool VisitUnaryAddrOf(const UnaryOperator *E);
8600 bool VisitObjCStringLiteral(const ObjCStringLiteral *E)
8601 { return Success(E); }
8602 bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
8603 if (E->isExpressibleAsConstantInitializer())
8604 return Success(E);
8605 if (Info.noteFailure())
8606 EvaluateIgnoredValue(Info, E->getSubExpr());
8607 return Error(E);
8608 }
8609 bool VisitAddrLabelExpr(const AddrLabelExpr *E)
8610 { return Success(E); }
8611 bool VisitCallExpr(const CallExpr *E);
8612 bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
8613 bool VisitBlockExpr(const BlockExpr *E) {
8614 if (!E->getBlockDecl()->hasCaptures())
8615 return Success(E);
8616 return Error(E);
8617 }
8618 bool VisitCXXThisExpr(const CXXThisExpr *E) {
8619 // Can't look at 'this' when checking a potential constant expression.
8620 if (Info.checkingPotentialConstantExpression())
8621 return false;
8622 if (!Info.CurrentCall->This) {
8623 if (Info.getLangOpts().CPlusPlus11)
8624 Info.FFDiag(E, diag::note_constexpr_this) << E->isImplicit();
8625 else
8626 Info.FFDiag(E);
8627 return false;
8628 }
8629 Result = *Info.CurrentCall->This;
8630 // If we are inside a lambda's call operator, the 'this' expression refers
8631 // to the enclosing '*this' object (either by value or reference) which is
8632 // either copied into the closure object's field that represents the '*this'
8633 // or refers to '*this'.
8634 if (isLambdaCallOperator(Info.CurrentCall->Callee)) {
8635 // Ensure we actually have captured 'this'. (an error will have
8636 // been previously reported if not).
8637 if (!Info.CurrentCall->LambdaThisCaptureField)
8638 return false;
8639
8640 // Update 'Result' to refer to the data member/field of the closure object
8641 // that represents the '*this' capture.
8642 if (!HandleLValueMember(Info, E, Result,
8643 Info.CurrentCall->LambdaThisCaptureField))
8644 return false;
8645 // If we captured '*this' by reference, replace the field with its referent.
8646 if (Info.CurrentCall->LambdaThisCaptureField->getType()
8647 ->isPointerType()) {
8648 APValue RVal;
8649 if (!handleLValueToRValueConversion(Info, E, E->getType(), Result,
8650 RVal))
8651 return false;
8652
8653 Result.setFrom(Info.Ctx, RVal);
8654 }
8655 }
8656 return true;
8657 }
8658
8659 bool VisitCXXNewExpr(const CXXNewExpr *E);
8660
8661 bool VisitSourceLocExpr(const SourceLocExpr *E) {
8662 assert(E->isStringType() && "SourceLocExpr isn't a pointer type?")((E->isStringType() && "SourceLocExpr isn't a pointer type?"
) ? static_cast<void> (0) : __assert_fail ("E->isStringType() && \"SourceLocExpr isn't a pointer type?\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8662, __PRETTY_FUNCTION__))
;
8663 APValue LValResult = E->EvaluateInContext(
8664 Info.Ctx, Info.CurrentCall->CurSourceLocExprScope.getDefaultExpr());
8665 Result.setFrom(Info.Ctx, LValResult);
8666 return true;
8667 }
8668
8669 // FIXME: Missing: @protocol, @selector
8670};
8671} // end anonymous namespace
8672
8673static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info,
8674 bool InvalidBaseOK) {
8675 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8675, __PRETTY_FUNCTION__))
;
8676 assert(E->isRValue() && E->getType()->hasPointerRepresentation())((E->isRValue() && E->getType()->hasPointerRepresentation
()) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->hasPointerRepresentation()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8676, __PRETTY_FUNCTION__))
;
8677 return PointerExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
8678}
8679
8680bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
8681 if (E->getOpcode() != BO_Add &&
8682 E->getOpcode() != BO_Sub)
8683 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
8684
8685 const Expr *PExp = E->getLHS();
8686 const Expr *IExp = E->getRHS();
8687 if (IExp->getType()->isPointerType())
8688 std::swap(PExp, IExp);
8689
8690 bool EvalPtrOK = evaluatePointer(PExp, Result);
8691 if (!EvalPtrOK && !Info.noteFailure())
8692 return false;
8693
8694 llvm::APSInt Offset;
8695 if (!EvaluateInteger(IExp, Offset, Info) || !EvalPtrOK)
8696 return false;
8697
8698 if (E->getOpcode() == BO_Sub)
8699 negateAsSigned(Offset);
8700
8701 QualType Pointee = PExp->getType()->castAs<PointerType>()->getPointeeType();
8702 return HandleLValueArrayAdjustment(Info, E, Result, Pointee, Offset);
8703}
8704
8705bool PointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
8706 return evaluateLValue(E->getSubExpr(), Result);
8707}
8708
8709bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
8710 const Expr *SubExpr = E->getSubExpr();
8711
8712 switch (E->getCastKind()) {
8713 default:
8714 break;
8715 case CK_BitCast:
8716 case CK_CPointerToObjCPointerCast:
8717 case CK_BlockPointerToObjCPointerCast:
8718 case CK_AnyPointerToBlockPointerCast:
8719 case CK_AddressSpaceConversion:
8720 if (!Visit(SubExpr))
8721 return false;
8722 // Bitcasts to cv void* are static_casts, not reinterpret_casts, so are
8723 // permitted in constant expressions in C++11. Bitcasts from cv void* are
8724 // also static_casts, but we disallow them as a resolution to DR1312.
8725 if (!E->getType()->isVoidPointerType()) {
8726 if (!Result.InvalidBase && !Result.Designator.Invalid &&
8727 !Result.IsNullPtr &&
8728 Info.Ctx.hasSameUnqualifiedType(Result.Designator.getType(Info.Ctx),
8729 E->getType()->getPointeeType()) &&
8730 Info.getStdAllocatorCaller("allocate")) {
8731 // Inside a call to std::allocator::allocate and friends, we permit
8732 // casting from void* back to cv1 T* for a pointer that points to a
8733 // cv2 T.
8734 } else {
8735 Result.Designator.setInvalid();
8736 if (SubExpr->getType()->isVoidPointerType())
8737 CCEDiag(E, diag::note_constexpr_invalid_cast)
8738 << 3 << SubExpr->getType();
8739 else
8740 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
8741 }
8742 }
8743 if (E->getCastKind() == CK_AddressSpaceConversion && Result.IsNullPtr)
8744 ZeroInitialization(E);
8745 return true;
8746
8747 case CK_DerivedToBase:
8748 case CK_UncheckedDerivedToBase:
8749 if (!evaluatePointer(E->getSubExpr(), Result))
8750 return false;
8751 if (!Result.Base && Result.Offset.isZero())
8752 return true;
8753
8754 // Now figure out the necessary offset to add to the base LV to get from
8755 // the derived class to the base class.
8756 return HandleLValueBasePath(Info, E, E->getSubExpr()->getType()->
8757 castAs<PointerType>()->getPointeeType(),
8758 Result);
8759
8760 case CK_BaseToDerived:
8761 if (!Visit(E->getSubExpr()))
8762 return false;
8763 if (!Result.Base && Result.Offset.isZero())
8764 return true;
8765 return HandleBaseToDerivedCast(Info, E, Result);
8766
8767 case CK_Dynamic:
8768 if (!Visit(E->getSubExpr()))
8769 return false;
8770 return HandleDynamicCast(Info, cast<ExplicitCastExpr>(E), Result);
8771
8772 case CK_NullToPointer:
8773 VisitIgnoredValue(E->getSubExpr());
8774 return ZeroInitialization(E);
8775
8776 case CK_IntegralToPointer: {
8777 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
8778
8779 APValue Value;
8780 if (!EvaluateIntegerOrLValue(SubExpr, Value, Info))
8781 break;
8782
8783 if (Value.isInt()) {
8784 unsigned Size = Info.Ctx.getTypeSize(E->getType());
8785 uint64_t N = Value.getInt().extOrTrunc(Size).getZExtValue();
8786 Result.Base = (Expr*)nullptr;
8787 Result.InvalidBase = false;
8788 Result.Offset = CharUnits::fromQuantity(N);
8789 Result.Designator.setInvalid();
8790 Result.IsNullPtr = false;
8791 return true;
8792 } else {
8793 // Cast is of an lvalue, no need to change value.
8794 Result.setFrom(Info.Ctx, Value);
8795 return true;
8796 }
8797 }
8798
8799 case CK_ArrayToPointerDecay: {
8800 if (SubExpr->isGLValue()) {
8801 if (!evaluateLValue(SubExpr, Result))
8802 return false;
8803 } else {
8804 APValue &Value = Info.CurrentCall->createTemporary(
8805 SubExpr, SubExpr->getType(), ScopeKind::FullExpression, Result);
8806 if (!EvaluateInPlace(Value, Info, Result, SubExpr))
8807 return false;
8808 }
8809 // The result is a pointer to the first element of the array.
8810 auto *AT = Info.Ctx.getAsArrayType(SubExpr->getType());
8811 if (auto *CAT = dyn_cast<ConstantArrayType>(AT))
8812 Result.addArray(Info, E, CAT);
8813 else
8814 Result.addUnsizedArray(Info, E, AT->getElementType());
8815 return true;
8816 }
8817
8818 case CK_FunctionToPointerDecay:
8819 return evaluateLValue(SubExpr, Result);
8820
8821 case CK_LValueToRValue: {
8822 LValue LVal;
8823 if (!evaluateLValue(E->getSubExpr(), LVal))
8824 return false;
8825
8826 APValue RVal;
8827 // Note, we use the subexpression's type in order to retain cv-qualifiers.
8828 if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
8829 LVal, RVal))
8830 return InvalidBaseOK &&
8831 evaluateLValueAsAllocSize(Info, LVal.Base, Result);
8832 return Success(RVal, E);
8833 }
8834 }
8835
8836 return ExprEvaluatorBaseTy::VisitCastExpr(E);
8837}
8838
8839static CharUnits GetAlignOfType(EvalInfo &Info, QualType T,
8840 UnaryExprOrTypeTrait ExprKind) {
8841 // C++ [expr.alignof]p3:
8842 // When alignof is applied to a reference type, the result is the
8843 // alignment of the referenced type.
8844 if (const ReferenceType *Ref = T->getAs<ReferenceType>())
8845 T = Ref->getPointeeType();
8846
8847 if (T.getQualifiers().hasUnaligned())
8848 return CharUnits::One();
8849
8850 const bool AlignOfReturnsPreferred =
8851 Info.Ctx.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver7;
8852
8853 // __alignof is defined to return the preferred alignment.
8854 // Before 8, clang returned the preferred alignment for alignof and _Alignof
8855 // as well.
8856 if (ExprKind == UETT_PreferredAlignOf || AlignOfReturnsPreferred)
8857 return Info.Ctx.toCharUnitsFromBits(
8858 Info.Ctx.getPreferredTypeAlign(T.getTypePtr()));
8859 // alignof and _Alignof are defined to return the ABI alignment.
8860 else if (ExprKind == UETT_AlignOf)
8861 return Info.Ctx.getTypeAlignInChars(T.getTypePtr());
8862 else
8863 llvm_unreachable("GetAlignOfType on a non-alignment ExprKind")::llvm::llvm_unreachable_internal("GetAlignOfType on a non-alignment ExprKind"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8863)
;
8864}
8865
8866static CharUnits GetAlignOfExpr(EvalInfo &Info, const Expr *E,
8867 UnaryExprOrTypeTrait ExprKind) {
8868 E = E->IgnoreParens();
8869
8870 // The kinds of expressions that we have special-case logic here for
8871 // should be kept up to date with the special checks for those
8872 // expressions in Sema.
8873
8874 // alignof decl is always accepted, even if it doesn't make sense: we default
8875 // to 1 in those cases.
8876 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
8877 return Info.Ctx.getDeclAlign(DRE->getDecl(),
8878 /*RefAsPointee*/true);
8879
8880 if (const MemberExpr *ME = dyn_cast<MemberExpr>(E))
8881 return Info.Ctx.getDeclAlign(ME->getMemberDecl(),
8882 /*RefAsPointee*/true);
8883
8884 return GetAlignOfType(Info, E->getType(), ExprKind);
8885}
8886
8887static CharUnits getBaseAlignment(EvalInfo &Info, const LValue &Value) {
8888 if (const auto *VD = Value.Base.dyn_cast<const ValueDecl *>())
8889 return Info.Ctx.getDeclAlign(VD);
8890 if (const auto *E = Value.Base.dyn_cast<const Expr *>())
8891 return GetAlignOfExpr(Info, E, UETT_AlignOf);
8892 return GetAlignOfType(Info, Value.Base.getTypeInfoType(), UETT_AlignOf);
8893}
8894
8895/// Evaluate the value of the alignment argument to __builtin_align_{up,down},
8896/// __builtin_is_aligned and __builtin_assume_aligned.
8897static bool getAlignmentArgument(const Expr *E, QualType ForType,
8898 EvalInfo &Info, APSInt &Alignment) {
8899 if (!EvaluateInteger(E, Alignment, Info))
8900 return false;
8901 if (Alignment < 0 || !Alignment.isPowerOf2()) {
8902 Info.FFDiag(E, diag::note_constexpr_invalid_alignment) << Alignment;
8903 return false;
8904 }
8905 unsigned SrcWidth = Info.Ctx.getIntWidth(ForType);
8906 APSInt MaxValue(APInt::getOneBitSet(SrcWidth, SrcWidth - 1));
8907 if (APSInt::compareValues(Alignment, MaxValue) > 0) {
8908 Info.FFDiag(E, diag::note_constexpr_alignment_too_big)
8909 << MaxValue << ForType << Alignment;
8910 return false;
8911 }
8912 // Ensure both alignment and source value have the same bit width so that we
8913 // don't assert when computing the resulting value.
8914 APSInt ExtAlignment =
8915 APSInt(Alignment.zextOrTrunc(SrcWidth), /*isUnsigned=*/true);
8916 assert(APSInt::compareValues(Alignment, ExtAlignment) == 0 &&((APSInt::compareValues(Alignment, ExtAlignment) == 0 &&
"Alignment should not be changed by ext/trunc") ? static_cast
<void> (0) : __assert_fail ("APSInt::compareValues(Alignment, ExtAlignment) == 0 && \"Alignment should not be changed by ext/trunc\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8917, __PRETTY_FUNCTION__))
8917 "Alignment should not be changed by ext/trunc")((APSInt::compareValues(Alignment, ExtAlignment) == 0 &&
"Alignment should not be changed by ext/trunc") ? static_cast
<void> (0) : __assert_fail ("APSInt::compareValues(Alignment, ExtAlignment) == 0 && \"Alignment should not be changed by ext/trunc\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8917, __PRETTY_FUNCTION__))
;
8918 Alignment = ExtAlignment;
8919 assert(Alignment.getBitWidth() == SrcWidth)((Alignment.getBitWidth() == SrcWidth) ? static_cast<void>
(0) : __assert_fail ("Alignment.getBitWidth() == SrcWidth", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 8919, __PRETTY_FUNCTION__))
;
8920 return true;
8921}
8922
8923// To be clear: this happily visits unsupported builtins. Better name welcomed.
8924bool PointerExprEvaluator::visitNonBuiltinCallExpr(const CallExpr *E) {
8925 if (ExprEvaluatorBaseTy::VisitCallExpr(E))
8926 return true;
8927
8928 if (!(InvalidBaseOK && getAllocSizeAttr(E)))
8929 return false;
8930
8931 Result.setInvalid(E);
8932 QualType PointeeTy = E->getType()->castAs<PointerType>()->getPointeeType();
8933 Result.addUnsizedArray(Info, E, PointeeTy);
8934 return true;
8935}
8936
8937bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) {
8938 if (IsStringLiteralCall(E))
8939 return Success(E);
8940
8941 if (unsigned BuiltinOp = E->getBuiltinCallee())
8942 return VisitBuiltinCallExpr(E, BuiltinOp);
8943
8944 return visitNonBuiltinCallExpr(E);
8945}
8946
8947// Determine if T is a character type for which we guarantee that
8948// sizeof(T) == 1.
8949static bool isOneByteCharacterType(QualType T) {
8950 return T->isCharType() || T->isChar8Type();
8951}
8952
8953bool PointerExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
8954 unsigned BuiltinOp) {
8955 switch (BuiltinOp) {
8956 case Builtin::BI__builtin_addressof:
8957 return evaluateLValue(E->getArg(0), Result);
8958 case Builtin::BI__builtin_assume_aligned: {
8959 // We need to be very careful here because: if the pointer does not have the
8960 // asserted alignment, then the behavior is undefined, and undefined
8961 // behavior is non-constant.
8962 if (!evaluatePointer(E->getArg(0), Result))
8963 return false;
8964
8965 LValue OffsetResult(Result);
8966 APSInt Alignment;
8967 if (!getAlignmentArgument(E->getArg(1), E->getArg(0)->getType(), Info,
8968 Alignment))
8969 return false;
8970 CharUnits Align = CharUnits::fromQuantity(Alignment.getZExtValue());
8971
8972 if (E->getNumArgs() > 2) {
8973 APSInt Offset;
8974 if (!EvaluateInteger(E->getArg(2), Offset, Info))
8975 return false;
8976
8977 int64_t AdditionalOffset = -Offset.getZExtValue();
8978 OffsetResult.Offset += CharUnits::fromQuantity(AdditionalOffset);
8979 }
8980
8981 // If there is a base object, then it must have the correct alignment.
8982 if (OffsetResult.Base) {
8983 CharUnits BaseAlignment = getBaseAlignment(Info, OffsetResult);
8984
8985 if (BaseAlignment < Align) {
8986 Result.Designator.setInvalid();
8987 // FIXME: Add support to Diagnostic for long / long long.
8988 CCEDiag(E->getArg(0),
8989 diag::note_constexpr_baa_insufficient_alignment) << 0
8990 << (unsigned)BaseAlignment.getQuantity()
8991 << (unsigned)Align.getQuantity();
8992 return false;
8993 }
8994 }
8995
8996 // The offset must also have the correct alignment.
8997 if (OffsetResult.Offset.alignTo(Align) != OffsetResult.Offset) {
8998 Result.Designator.setInvalid();
8999
9000 (OffsetResult.Base
9001 ? CCEDiag(E->getArg(0),
9002 diag::note_constexpr_baa_insufficient_alignment) << 1
9003 : CCEDiag(E->getArg(0),
9004 diag::note_constexpr_baa_value_insufficient_alignment))
9005 << (int)OffsetResult.Offset.getQuantity()
9006 << (unsigned)Align.getQuantity();
9007 return false;
9008 }
9009
9010 return true;
9011 }
9012 case Builtin::BI__builtin_align_up:
9013 case Builtin::BI__builtin_align_down: {
9014 if (!evaluatePointer(E->getArg(0), Result))
9015 return false;
9016 APSInt Alignment;
9017 if (!getAlignmentArgument(E->getArg(1), E->getArg(0)->getType(), Info,
9018 Alignment))
9019 return false;
9020 CharUnits BaseAlignment = getBaseAlignment(Info, Result);
9021 CharUnits PtrAlign = BaseAlignment.alignmentAtOffset(Result.Offset);
9022 // For align_up/align_down, we can return the same value if the alignment
9023 // is known to be greater or equal to the requested value.
9024 if (PtrAlign.getQuantity() >= Alignment)
9025 return true;
9026
9027 // The alignment could be greater than the minimum at run-time, so we cannot
9028 // infer much about the resulting pointer value. One case is possible:
9029 // For `_Alignas(32) char buf[N]; __builtin_align_down(&buf[idx], 32)` we
9030 // can infer the correct index if the requested alignment is smaller than
9031 // the base alignment so we can perform the computation on the offset.
9032 if (BaseAlignment.getQuantity() >= Alignment) {
9033 assert(Alignment.getBitWidth() <= 64 &&((Alignment.getBitWidth() <= 64 && "Cannot handle > 64-bit address-space"
) ? static_cast<void> (0) : __assert_fail ("Alignment.getBitWidth() <= 64 && \"Cannot handle > 64-bit address-space\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9034, __PRETTY_FUNCTION__))
9034 "Cannot handle > 64-bit address-space")((Alignment.getBitWidth() <= 64 && "Cannot handle > 64-bit address-space"
) ? static_cast<void> (0) : __assert_fail ("Alignment.getBitWidth() <= 64 && \"Cannot handle > 64-bit address-space\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9034, __PRETTY_FUNCTION__))
;
9035 uint64_t Alignment64 = Alignment.getZExtValue();
9036 CharUnits NewOffset = CharUnits::fromQuantity(
9037 BuiltinOp == Builtin::BI__builtin_align_down
9038 ? llvm::alignDown(Result.Offset.getQuantity(), Alignment64)
9039 : llvm::alignTo(Result.Offset.getQuantity(), Alignment64));
9040 Result.adjustOffset(NewOffset - Result.Offset);
9041 // TODO: diagnose out-of-bounds values/only allow for arrays?
9042 return true;
9043 }
9044 // Otherwise, we cannot constant-evaluate the result.
9045 Info.FFDiag(E->getArg(0), diag::note_constexpr_alignment_adjust)
9046 << Alignment;
9047 return false;
9048 }
9049 case Builtin::BI__builtin_operator_new:
9050 return HandleOperatorNewCall(Info, E, Result);
9051 case Builtin::BI__builtin_launder:
9052 return evaluatePointer(E->getArg(0), Result);
9053 case Builtin::BIstrchr:
9054 case Builtin::BIwcschr:
9055 case Builtin::BImemchr:
9056 case Builtin::BIwmemchr:
9057 if (Info.getLangOpts().CPlusPlus11)
9058 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
9059 << /*isConstexpr*/0 << /*isConstructor*/0
9060 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
9061 else
9062 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
9063 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9064 case Builtin::BI__builtin_strchr:
9065 case Builtin::BI__builtin_wcschr:
9066 case Builtin::BI__builtin_memchr:
9067 case Builtin::BI__builtin_char_memchr:
9068 case Builtin::BI__builtin_wmemchr: {
9069 if (!Visit(E->getArg(0)))
9070 return false;
9071 APSInt Desired;
9072 if (!EvaluateInteger(E->getArg(1), Desired, Info))
9073 return false;
9074 uint64_t MaxLength = uint64_t(-1);
9075 if (BuiltinOp != Builtin::BIstrchr &&
9076 BuiltinOp != Builtin::BIwcschr &&
9077 BuiltinOp != Builtin::BI__builtin_strchr &&
9078 BuiltinOp != Builtin::BI__builtin_wcschr) {
9079 APSInt N;
9080 if (!EvaluateInteger(E->getArg(2), N, Info))
9081 return false;
9082 MaxLength = N.getExtValue();
9083 }
9084 // We cannot find the value if there are no candidates to match against.
9085 if (MaxLength == 0u)
9086 return ZeroInitialization(E);
9087 if (!Result.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
9088 Result.Designator.Invalid)
9089 return false;
9090 QualType CharTy = Result.Designator.getType(Info.Ctx);
9091 bool IsRawByte = BuiltinOp == Builtin::BImemchr ||
9092 BuiltinOp == Builtin::BI__builtin_memchr;
9093 assert(IsRawByte ||((IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->
getArg(0)->getType()->getPointeeType())) ? static_cast<
void> (0) : __assert_fail ("IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->getArg(0)->getType()->getPointeeType())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9095, __PRETTY_FUNCTION__))
9094 Info.Ctx.hasSameUnqualifiedType(((IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->
getArg(0)->getType()->getPointeeType())) ? static_cast<
void> (0) : __assert_fail ("IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->getArg(0)->getType()->getPointeeType())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9095, __PRETTY_FUNCTION__))
9095 CharTy, E->getArg(0)->getType()->getPointeeType()))((IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->
getArg(0)->getType()->getPointeeType())) ? static_cast<
void> (0) : __assert_fail ("IsRawByte || Info.Ctx.hasSameUnqualifiedType( CharTy, E->getArg(0)->getType()->getPointeeType())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9095, __PRETTY_FUNCTION__))
;
9096 // Pointers to const void may point to objects of incomplete type.
9097 if (IsRawByte && CharTy->isIncompleteType()) {
9098 Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy;
9099 return false;
9100 }
9101 // Give up on byte-oriented matching against multibyte elements.
9102 // FIXME: We can compare the bytes in the correct order.
9103 if (IsRawByte && !isOneByteCharacterType(CharTy)) {
9104 Info.FFDiag(E, diag::note_constexpr_memchr_unsupported)
9105 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'")
9106 << CharTy;
9107 return false;
9108 }
9109 // Figure out what value we're actually looking for (after converting to
9110 // the corresponding unsigned type if necessary).
9111 uint64_t DesiredVal;
9112 bool StopAtNull = false;
9113 switch (BuiltinOp) {
9114 case Builtin::BIstrchr:
9115 case Builtin::BI__builtin_strchr:
9116 // strchr compares directly to the passed integer, and therefore
9117 // always fails if given an int that is not a char.
9118 if (!APSInt::isSameValue(HandleIntToIntCast(Info, E, CharTy,
9119 E->getArg(1)->getType(),
9120 Desired),
9121 Desired))
9122 return ZeroInitialization(E);
9123 StopAtNull = true;
9124 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9125 case Builtin::BImemchr:
9126 case Builtin::BI__builtin_memchr:
9127 case Builtin::BI__builtin_char_memchr:
9128 // memchr compares by converting both sides to unsigned char. That's also
9129 // correct for strchr if we get this far (to cope with plain char being
9130 // unsigned in the strchr case).
9131 DesiredVal = Desired.trunc(Info.Ctx.getCharWidth()).getZExtValue();
9132 break;
9133
9134 case Builtin::BIwcschr:
9135 case Builtin::BI__builtin_wcschr:
9136 StopAtNull = true;
9137 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9138 case Builtin::BIwmemchr:
9139 case Builtin::BI__builtin_wmemchr:
9140 // wcschr and wmemchr are given a wchar_t to look for. Just use it.
9141 DesiredVal = Desired.getZExtValue();
9142 break;
9143 }
9144
9145 for (; MaxLength; --MaxLength) {
9146 APValue Char;
9147 if (!handleLValueToRValueConversion(Info, E, CharTy, Result, Char) ||
9148 !Char.isInt())
9149 return false;
9150 if (Char.getInt().getZExtValue() == DesiredVal)
9151 return true;
9152 if (StopAtNull && !Char.getInt())
9153 break;
9154 if (!HandleLValueArrayAdjustment(Info, E, Result, CharTy, 1))
9155 return false;
9156 }
9157 // Not found: return nullptr.
9158 return ZeroInitialization(E);
9159 }
9160
9161 case Builtin::BImemcpy:
9162 case Builtin::BImemmove:
9163 case Builtin::BIwmemcpy:
9164 case Builtin::BIwmemmove:
9165 if (Info.getLangOpts().CPlusPlus11)
9166 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
9167 << /*isConstexpr*/0 << /*isConstructor*/0
9168 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
9169 else
9170 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
9171 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9172 case Builtin::BI__builtin_memcpy:
9173 case Builtin::BI__builtin_memmove:
9174 case Builtin::BI__builtin_wmemcpy:
9175 case Builtin::BI__builtin_wmemmove: {
9176 bool WChar = BuiltinOp == Builtin::BIwmemcpy ||
9177 BuiltinOp == Builtin::BIwmemmove ||
9178 BuiltinOp == Builtin::BI__builtin_wmemcpy ||
9179 BuiltinOp == Builtin::BI__builtin_wmemmove;
9180 bool Move = BuiltinOp == Builtin::BImemmove ||
9181 BuiltinOp == Builtin::BIwmemmove ||
9182 BuiltinOp == Builtin::BI__builtin_memmove ||
9183 BuiltinOp == Builtin::BI__builtin_wmemmove;
9184
9185 // The result of mem* is the first argument.
9186 if (!Visit(E->getArg(0)))
9187 return false;
9188 LValue Dest = Result;
9189
9190 LValue Src;
9191 if (!EvaluatePointer(E->getArg(1), Src, Info))
9192 return false;
9193
9194 APSInt N;
9195 if (!EvaluateInteger(E->getArg(2), N, Info))
9196 return false;
9197 assert(!N.isSigned() && "memcpy and friends take an unsigned size")((!N.isSigned() && "memcpy and friends take an unsigned size"
) ? static_cast<void> (0) : __assert_fail ("!N.isSigned() && \"memcpy and friends take an unsigned size\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9197, __PRETTY_FUNCTION__))
;
9198
9199 // If the size is zero, we treat this as always being a valid no-op.
9200 // (Even if one of the src and dest pointers is null.)
9201 if (!N)
9202 return true;
9203
9204 // Otherwise, if either of the operands is null, we can't proceed. Don't
9205 // try to determine the type of the copied objects, because there aren't
9206 // any.
9207 if (!Src.Base || !Dest.Base) {
9208 APValue Val;
9209 (!Src.Base ? Src : Dest).moveInto(Val);
9210 Info.FFDiag(E, diag::note_constexpr_memcpy_null)
9211 << Move << WChar << !!Src.Base
9212 << Val.getAsString(Info.Ctx, E->getArg(0)->getType());
9213 return false;
9214 }
9215 if (Src.Designator.Invalid || Dest.Designator.Invalid)
9216 return false;
9217
9218 // We require that Src and Dest are both pointers to arrays of
9219 // trivially-copyable type. (For the wide version, the designator will be
9220 // invalid if the designated object is not a wchar_t.)
9221 QualType T = Dest.Designator.getType(Info.Ctx);
9222 QualType SrcT = Src.Designator.getType(Info.Ctx);
9223 if (!Info.Ctx.hasSameUnqualifiedType(T, SrcT)) {
9224 // FIXME: Consider using our bit_cast implementation to support this.
9225 Info.FFDiag(E, diag::note_constexpr_memcpy_type_pun) << Move << SrcT << T;
9226 return false;
9227 }
9228 if (T->isIncompleteType()) {
9229 Info.FFDiag(E, diag::note_constexpr_memcpy_incomplete_type) << Move << T;
9230 return false;
9231 }
9232 if (!T.isTriviallyCopyableType(Info.Ctx)) {
9233 Info.FFDiag(E, diag::note_constexpr_memcpy_nontrivial) << Move << T;
9234 return false;
9235 }
9236
9237 // Figure out how many T's we're copying.
9238 uint64_t TSize = Info.Ctx.getTypeSizeInChars(T).getQuantity();
9239 if (!WChar) {
9240 uint64_t Remainder;
9241 llvm::APInt OrigN = N;
9242 llvm::APInt::udivrem(OrigN, TSize, N, Remainder);
9243 if (Remainder) {
9244 Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
9245 << Move << WChar << 0 << T << OrigN.toString(10, /*Signed*/false)
9246 << (unsigned)TSize;
9247 return false;
9248 }
9249 }
9250
9251 // Check that the copying will remain within the arrays, just so that we
9252 // can give a more meaningful diagnostic. This implicitly also checks that
9253 // N fits into 64 bits.
9254 uint64_t RemainingSrcSize = Src.Designator.validIndexAdjustments().second;
9255 uint64_t RemainingDestSize = Dest.Designator.validIndexAdjustments().second;
9256 if (N.ugt(RemainingSrcSize) || N.ugt(RemainingDestSize)) {
9257 Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
9258 << Move << WChar << (N.ugt(RemainingSrcSize) ? 1 : 2) << T
9259 << N.toString(10, /*Signed*/false);
9260 return false;
9261 }
9262 uint64_t NElems = N.getZExtValue();
9263 uint64_t NBytes = NElems * TSize;
9264
9265 // Check for overlap.
9266 int Direction = 1;
9267 if (HasSameBase(Src, Dest)) {
9268 uint64_t SrcOffset = Src.getLValueOffset().getQuantity();
9269 uint64_t DestOffset = Dest.getLValueOffset().getQuantity();
9270 if (DestOffset >= SrcOffset && DestOffset - SrcOffset < NBytes) {
9271 // Dest is inside the source region.
9272 if (!Move) {
9273 Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
9274 return false;
9275 }
9276 // For memmove and friends, copy backwards.
9277 if (!HandleLValueArrayAdjustment(Info, E, Src, T, NElems - 1) ||
9278 !HandleLValueArrayAdjustment(Info, E, Dest, T, NElems - 1))
9279 return false;
9280 Direction = -1;
9281 } else if (!Move && SrcOffset >= DestOffset &&
9282 SrcOffset - DestOffset < NBytes) {
9283 // Src is inside the destination region for memcpy: invalid.
9284 Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
9285 return false;
9286 }
9287 }
9288
9289 while (true) {
9290 APValue Val;
9291 // FIXME: Set WantObjectRepresentation to true if we're copying a
9292 // char-like type?
9293 if (!handleLValueToRValueConversion(Info, E, T, Src, Val) ||
9294 !handleAssignment(Info, E, Dest, T, Val))
9295 return false;
9296 // Do not iterate past the last element; if we're copying backwards, that
9297 // might take us off the start of the array.
9298 if (--NElems == 0)
9299 return true;
9300 if (!HandleLValueArrayAdjustment(Info, E, Src, T, Direction) ||
9301 !HandleLValueArrayAdjustment(Info, E, Dest, T, Direction))
9302 return false;
9303 }
9304 }
9305
9306 default:
9307 break;
9308 }
9309
9310 return visitNonBuiltinCallExpr(E);
9311}
9312
9313static bool EvaluateArrayNewInitList(EvalInfo &Info, LValue &This,
9314 APValue &Result, const InitListExpr *ILE,
9315 QualType AllocType);
9316static bool EvaluateArrayNewConstructExpr(EvalInfo &Info, LValue &This,
9317 APValue &Result,
9318 const CXXConstructExpr *CCE,
9319 QualType AllocType);
9320
9321bool PointerExprEvaluator::VisitCXXNewExpr(const CXXNewExpr *E) {
9322 if (!Info.getLangOpts().CPlusPlus20)
9323 Info.CCEDiag(E, diag::note_constexpr_new);
9324
9325 // We cannot speculatively evaluate a delete expression.
9326 if (Info.SpeculativeEvaluationDepth)
9327 return false;
9328
9329 FunctionDecl *OperatorNew = E->getOperatorNew();
9330
9331 bool IsNothrow = false;
9332 bool IsPlacement = false;
9333 if (OperatorNew->isReservedGlobalPlacementOperator() &&
9334 Info.CurrentCall->isStdFunction() && !E->isArray()) {
9335 // FIXME Support array placement new.
9336 assert(E->getNumPlacementArgs() == 1)((E->getNumPlacementArgs() == 1) ? static_cast<void>
(0) : __assert_fail ("E->getNumPlacementArgs() == 1", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9336, __PRETTY_FUNCTION__))
;
9337 if (!EvaluatePointer(E->getPlacementArg(0), Result, Info))
9338 return false;
9339 if (Result.Designator.Invalid)
9340 return false;
9341 IsPlacement = true;
9342 } else if (!OperatorNew->isReplaceableGlobalAllocationFunction()) {
9343 Info.FFDiag(E, diag::note_constexpr_new_non_replaceable)
9344 << isa<CXXMethodDecl>(OperatorNew) << OperatorNew;
9345 return false;
9346 } else if (E->getNumPlacementArgs()) {
9347 // The only new-placement list we support is of the form (std::nothrow).
9348 //
9349 // FIXME: There is no restriction on this, but it's not clear that any
9350 // other form makes any sense. We get here for cases such as:
9351 //
9352 // new (std::align_val_t{N}) X(int)
9353 //
9354 // (which should presumably be valid only if N is a multiple of
9355 // alignof(int), and in any case can't be deallocated unless N is
9356 // alignof(X) and X has new-extended alignment).
9357 if (E->getNumPlacementArgs() != 1 ||
9358 !E->getPlacementArg(0)->getType()->isNothrowT())
9359 return Error(E, diag::note_constexpr_new_placement);
9360
9361 LValue Nothrow;
9362 if (!EvaluateLValue(E->getPlacementArg(0), Nothrow, Info))
9363 return false;
9364 IsNothrow = true;
9365 }
9366
9367 const Expr *Init = E->getInitializer();
9368 const InitListExpr *ResizedArrayILE = nullptr;
9369 const CXXConstructExpr *ResizedArrayCCE = nullptr;
9370 bool ValueInit = false;
9371
9372 QualType AllocType = E->getAllocatedType();
9373 if (Optional<const Expr*> ArraySize = E->getArraySize()) {
9374 const Expr *Stripped = *ArraySize;
9375 for (; auto *ICE = dyn_cast<ImplicitCastExpr>(Stripped);
9376 Stripped = ICE->getSubExpr())
9377 if (ICE->getCastKind() != CK_NoOp &&
9378 ICE->getCastKind() != CK_IntegralCast)
9379 break;
9380
9381 llvm::APSInt ArrayBound;
9382 if (!EvaluateInteger(Stripped, ArrayBound, Info))
9383 return false;
9384
9385 // C++ [expr.new]p9:
9386 // The expression is erroneous if:
9387 // -- [...] its value before converting to size_t [or] applying the
9388 // second standard conversion sequence is less than zero
9389 if (ArrayBound.isSigned() && ArrayBound.isNegative()) {
9390 if (IsNothrow)
9391 return ZeroInitialization(E);
9392
9393 Info.FFDiag(*ArraySize, diag::note_constexpr_new_negative)
9394 << ArrayBound << (*ArraySize)->getSourceRange();
9395 return false;
9396 }
9397
9398 // -- its value is such that the size of the allocated object would
9399 // exceed the implementation-defined limit
9400 if (ConstantArrayType::getNumAddressingBits(Info.Ctx, AllocType,
9401 ArrayBound) >
9402 ConstantArrayType::getMaxSizeBits(Info.Ctx)) {
9403 if (IsNothrow)
9404 return ZeroInitialization(E);
9405
9406 Info.FFDiag(*ArraySize, diag::note_constexpr_new_too_large)
9407 << ArrayBound << (*ArraySize)->getSourceRange();
9408 return false;
9409 }
9410
9411 // -- the new-initializer is a braced-init-list and the number of
9412 // array elements for which initializers are provided [...]
9413 // exceeds the number of elements to initialize
9414 if (!Init) {
9415 // No initialization is performed.
9416 } else if (isa<CXXScalarValueInitExpr>(Init) ||
9417 isa<ImplicitValueInitExpr>(Init)) {
9418 ValueInit = true;
9419 } else if (auto *CCE = dyn_cast<CXXConstructExpr>(Init)) {
9420 ResizedArrayCCE = CCE;
9421 } else {
9422 auto *CAT = Info.Ctx.getAsConstantArrayType(Init->getType());
9423 assert(CAT && "unexpected type for array initializer")((CAT && "unexpected type for array initializer") ? static_cast
<void> (0) : __assert_fail ("CAT && \"unexpected type for array initializer\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9423, __PRETTY_FUNCTION__))
;
9424
9425 unsigned Bits =
9426 std::max(CAT->getSize().getBitWidth(), ArrayBound.getBitWidth());
9427 llvm::APInt InitBound = CAT->getSize().zextOrSelf(Bits);
9428 llvm::APInt AllocBound = ArrayBound.zextOrSelf(Bits);
9429 if (InitBound.ugt(AllocBound)) {
9430 if (IsNothrow)
9431 return ZeroInitialization(E);
9432
9433 Info.FFDiag(*ArraySize, diag::note_constexpr_new_too_small)
9434 << AllocBound.toString(10, /*Signed=*/false)
9435 << InitBound.toString(10, /*Signed=*/false)
9436 << (*ArraySize)->getSourceRange();
9437 return false;
9438 }
9439
9440 // If the sizes differ, we must have an initializer list, and we need
9441 // special handling for this case when we initialize.
9442 if (InitBound != AllocBound)
9443 ResizedArrayILE = cast<InitListExpr>(Init);
9444 }
9445
9446 AllocType = Info.Ctx.getConstantArrayType(AllocType, ArrayBound, nullptr,
9447 ArrayType::Normal, 0);
9448 } else {
9449 assert(!AllocType->isArrayType() &&((!AllocType->isArrayType() && "array allocation with non-array new"
) ? static_cast<void> (0) : __assert_fail ("!AllocType->isArrayType() && \"array allocation with non-array new\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9450, __PRETTY_FUNCTION__))
9450 "array allocation with non-array new")((!AllocType->isArrayType() && "array allocation with non-array new"
) ? static_cast<void> (0) : __assert_fail ("!AllocType->isArrayType() && \"array allocation with non-array new\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9450, __PRETTY_FUNCTION__))
;
9451 }
9452
9453 APValue *Val;
9454 if (IsPlacement) {
9455 AccessKinds AK = AK_Construct;
9456 struct FindObjectHandler {
9457 EvalInfo &Info;
9458 const Expr *E;
9459 QualType AllocType;
9460 const AccessKinds AccessKind;
9461 APValue *Value;
9462
9463 typedef bool result_type;
9464 bool failed() { return false; }
9465 bool found(APValue &Subobj, QualType SubobjType) {
9466 // FIXME: Reject the cases where [basic.life]p8 would not permit the
9467 // old name of the object to be used to name the new object.
9468 if (!Info.Ctx.hasSameUnqualifiedType(SubobjType, AllocType)) {
9469 Info.FFDiag(E, diag::note_constexpr_placement_new_wrong_type) <<
9470 SubobjType << AllocType;
9471 return false;
9472 }
9473 Value = &Subobj;
9474 return true;
9475 }
9476 bool found(APSInt &Value, QualType SubobjType) {
9477 Info.FFDiag(E, diag::note_constexpr_construct_complex_elem);
9478 return false;
9479 }
9480 bool found(APFloat &Value, QualType SubobjType) {
9481 Info.FFDiag(E, diag::note_constexpr_construct_complex_elem);
9482 return false;
9483 }
9484 } Handler = {Info, E, AllocType, AK, nullptr};
9485
9486 CompleteObject Obj = findCompleteObject(Info, E, AK, Result, AllocType);
9487 if (!Obj || !findSubobject(Info, E, Obj, Result.Designator, Handler))
9488 return false;
9489
9490 Val = Handler.Value;
9491
9492 // [basic.life]p1:
9493 // The lifetime of an object o of type T ends when [...] the storage
9494 // which the object occupies is [...] reused by an object that is not
9495 // nested within o (6.6.2).
9496 *Val = APValue();
9497 } else {
9498 // Perform the allocation and obtain a pointer to the resulting object.
9499 Val = Info.createHeapAlloc(E, AllocType, Result);
9500 if (!Val)
9501 return false;
9502 }
9503
9504 if (ValueInit) {
9505 ImplicitValueInitExpr VIE(AllocType);
9506 if (!EvaluateInPlace(*Val, Info, Result, &VIE))
9507 return false;
9508 } else if (ResizedArrayILE) {
9509 if (!EvaluateArrayNewInitList(Info, Result, *Val, ResizedArrayILE,
9510 AllocType))
9511 return false;
9512 } else if (ResizedArrayCCE) {
9513 if (!EvaluateArrayNewConstructExpr(Info, Result, *Val, ResizedArrayCCE,
9514 AllocType))
9515 return false;
9516 } else if (Init) {
9517 if (!EvaluateInPlace(*Val, Info, Result, Init))
9518 return false;
9519 } else if (!getDefaultInitValue(AllocType, *Val)) {
9520 return false;
9521 }
9522
9523 // Array new returns a pointer to the first element, not a pointer to the
9524 // array.
9525 if (auto *AT = AllocType->getAsArrayTypeUnsafe())
9526 Result.addArray(Info, E, cast<ConstantArrayType>(AT));
9527
9528 return true;
9529}
9530//===----------------------------------------------------------------------===//
9531// Member Pointer Evaluation
9532//===----------------------------------------------------------------------===//
9533
9534namespace {
9535class MemberPointerExprEvaluator
9536 : public ExprEvaluatorBase<MemberPointerExprEvaluator> {
9537 MemberPtr &Result;
9538
9539 bool Success(const ValueDecl *D) {
9540 Result = MemberPtr(D);
9541 return true;
9542 }
9543public:
9544
9545 MemberPointerExprEvaluator(EvalInfo &Info, MemberPtr &Result)
9546 : ExprEvaluatorBaseTy(Info), Result(Result) {}
9547
9548 bool Success(const APValue &V, const Expr *E) {
9549 Result.setFrom(V);
9550 return true;
9551 }
9552 bool ZeroInitialization(const Expr *E) {
9553 return Success((const ValueDecl*)nullptr);
9554 }
9555
9556 bool VisitCastExpr(const CastExpr *E);
9557 bool VisitUnaryAddrOf(const UnaryOperator *E);
9558};
9559} // end anonymous namespace
9560
9561static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
9562 EvalInfo &Info) {
9563 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9563, __PRETTY_FUNCTION__))
;
9564 assert(E->isRValue() && E->getType()->isMemberPointerType())((E->isRValue() && E->getType()->isMemberPointerType
()) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isMemberPointerType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9564, __PRETTY_FUNCTION__))
;
9565 return MemberPointerExprEvaluator(Info, Result).Visit(E);
9566}
9567
9568bool MemberPointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
9569 switch (E->getCastKind()) {
9570 default:
9571 return ExprEvaluatorBaseTy::VisitCastExpr(E);
9572
9573 case CK_NullToMemberPointer:
9574 VisitIgnoredValue(E->getSubExpr());
9575 return ZeroInitialization(E);
9576
9577 case CK_BaseToDerivedMemberPointer: {
9578 if (!Visit(E->getSubExpr()))
9579 return false;
9580 if (E->path_empty())
9581 return true;
9582 // Base-to-derived member pointer casts store the path in derived-to-base
9583 // order, so iterate backwards. The CXXBaseSpecifier also provides us with
9584 // the wrong end of the derived->base arc, so stagger the path by one class.
9585 typedef std::reverse_iterator<CastExpr::path_const_iterator> ReverseIter;
9586 for (ReverseIter PathI(E->path_end() - 1), PathE(E->path_begin());
9587 PathI != PathE; ++PathI) {
9588 assert(!(*PathI)->isVirtual() && "memptr cast through vbase")((!(*PathI)->isVirtual() && "memptr cast through vbase"
) ? static_cast<void> (0) : __assert_fail ("!(*PathI)->isVirtual() && \"memptr cast through vbase\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9588, __PRETTY_FUNCTION__))
;
9589 const CXXRecordDecl *Derived = (*PathI)->getType()->getAsCXXRecordDecl();
9590 if (!Result.castToDerived(Derived))
9591 return Error(E);
9592 }
9593 const Type *FinalTy = E->getType()->castAs<MemberPointerType>()->getClass();
9594 if (!Result.castToDerived(FinalTy->getAsCXXRecordDecl()))
9595 return Error(E);
9596 return true;
9597 }
9598
9599 case CK_DerivedToBaseMemberPointer:
9600 if (!Visit(E->getSubExpr()))
9601 return false;
9602 for (CastExpr::path_const_iterator PathI = E->path_begin(),
9603 PathE = E->path_end(); PathI != PathE; ++PathI) {
9604 assert(!(*PathI)->isVirtual() && "memptr cast through vbase")((!(*PathI)->isVirtual() && "memptr cast through vbase"
) ? static_cast<void> (0) : __assert_fail ("!(*PathI)->isVirtual() && \"memptr cast through vbase\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9604, __PRETTY_FUNCTION__))
;
9605 const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
9606 if (!Result.castToBase(Base))
9607 return Error(E);
9608 }
9609 return true;
9610 }
9611}
9612
9613bool MemberPointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
9614 // C++11 [expr.unary.op]p3 has very strict rules on how the address of a
9615 // member can be formed.
9616 return Success(cast<DeclRefExpr>(E->getSubExpr())->getDecl());
9617}
9618
9619//===----------------------------------------------------------------------===//
9620// Record Evaluation
9621//===----------------------------------------------------------------------===//
9622
9623namespace {
9624 class RecordExprEvaluator
9625 : public ExprEvaluatorBase<RecordExprEvaluator> {
9626 const LValue &This;
9627 APValue &Result;
9628 public:
9629
9630 RecordExprEvaluator(EvalInfo &info, const LValue &This, APValue &Result)
9631 : ExprEvaluatorBaseTy(info), This(This), Result(Result) {}
9632
9633 bool Success(const APValue &V, const Expr *E) {
9634 Result = V;
9635 return true;
9636 }
9637 bool ZeroInitialization(const Expr *E) {
9638 return ZeroInitialization(E, E->getType());
9639 }
9640 bool ZeroInitialization(const Expr *E, QualType T);
9641
9642 bool VisitCallExpr(const CallExpr *E) {
9643 return handleCallExpr(E, Result, &This);
9644 }
9645 bool VisitCastExpr(const CastExpr *E);
9646 bool VisitInitListExpr(const InitListExpr *E);
9647 bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
9648 return VisitCXXConstructExpr(E, E->getType());
9649 }
9650 bool VisitLambdaExpr(const LambdaExpr *E);
9651 bool VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
9652 bool VisitCXXConstructExpr(const CXXConstructExpr *E, QualType T);
9653 bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E);
9654 bool VisitBinCmp(const BinaryOperator *E);
9655 };
9656}
9657
9658/// Perform zero-initialization on an object of non-union class type.
9659/// C++11 [dcl.init]p5:
9660/// To zero-initialize an object or reference of type T means:
9661/// [...]
9662/// -- if T is a (possibly cv-qualified) non-union class type,
9663/// each non-static data member and each base-class subobject is
9664/// zero-initialized
9665static bool HandleClassZeroInitialization(EvalInfo &Info, const Expr *E,
9666 const RecordDecl *RD,
9667 const LValue &This, APValue &Result) {
9668 assert(!RD->isUnion() && "Expected non-union class type")((!RD->isUnion() && "Expected non-union class type"
) ? static_cast<void> (0) : __assert_fail ("!RD->isUnion() && \"Expected non-union class type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9668, __PRETTY_FUNCTION__))
;
9669 const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
9670 Result = APValue(APValue::UninitStruct(), CD ? CD->getNumBases() : 0,
9671 std::distance(RD->field_begin(), RD->field_end()));
9672
9673 if (RD->isInvalidDecl()) return false;
9674 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
9675
9676 if (CD) {
9677 unsigned Index = 0;
9678 for (CXXRecordDecl::base_class_const_iterator I = CD->bases_begin(),
9679 End = CD->bases_end(); I != End; ++I, ++Index) {
9680 const CXXRecordDecl *Base = I->getType()->getAsCXXRecordDecl();
9681 LValue Subobject = This;
9682 if (!HandleLValueDirectBase(Info, E, Subobject, CD, Base, &Layout))
9683 return false;
9684 if (!HandleClassZeroInitialization(Info, E, Base, Subobject,
9685 Result.getStructBase(Index)))
9686 return false;
9687 }
9688 }
9689
9690 for (const auto *I : RD->fields()) {
9691 // -- if T is a reference type, no initialization is performed.
9692 if (I->isUnnamedBitfield() || I->getType()->isReferenceType())
9693 continue;
9694
9695 LValue Subobject = This;
9696 if (!HandleLValueMember(Info, E, Subobject, I, &Layout))
9697 return false;
9698
9699 ImplicitValueInitExpr VIE(I->getType());
9700 if (!EvaluateInPlace(
9701 Result.getStructField(I->getFieldIndex()), Info, Subobject, &VIE))
9702 return false;
9703 }
9704
9705 return true;
9706}
9707
9708bool RecordExprEvaluator::ZeroInitialization(const Expr *E, QualType T) {
9709 const RecordDecl *RD = T->castAs<RecordType>()->getDecl();
9710 if (RD->isInvalidDecl()) return false;
9711 if (RD->isUnion()) {
9712 // C++11 [dcl.init]p5: If T is a (possibly cv-qualified) union type, the
9713 // object's first non-static named data member is zero-initialized
9714 RecordDecl::field_iterator I = RD->field_begin();
9715 while (I != RD->field_end() && (*I)->isUnnamedBitfield())
9716 ++I;
9717 if (I == RD->field_end()) {
9718 Result = APValue((const FieldDecl*)nullptr);
9719 return true;
9720 }
9721
9722 LValue Subobject = This;
9723 if (!HandleLValueMember(Info, E, Subobject, *I))
9724 return false;
9725 Result = APValue(*I);
9726 ImplicitValueInitExpr VIE(I->getType());
9727 return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, &VIE);
9728 }
9729
9730 if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->getNumVBases()) {
9731 Info.FFDiag(E, diag::note_constexpr_virtual_base) << RD;
9732 return false;
9733 }
9734
9735 return HandleClassZeroInitialization(Info, E, RD, This, Result);
9736}
9737
9738bool RecordExprEvaluator::VisitCastExpr(const CastExpr *E) {
9739 switch (E->getCastKind()) {
9740 default:
9741 return ExprEvaluatorBaseTy::VisitCastExpr(E);
9742
9743 case CK_ConstructorConversion:
9744 return Visit(E->getSubExpr());
9745
9746 case CK_DerivedToBase:
9747 case CK_UncheckedDerivedToBase: {
9748 APValue DerivedObject;
9749 if (!Evaluate(DerivedObject, Info, E->getSubExpr()))
9750 return false;
9751 if (!DerivedObject.isStruct())
9752 return Error(E->getSubExpr());
9753
9754 // Derived-to-base rvalue conversion: just slice off the derived part.
9755 APValue *Value = &DerivedObject;
9756 const CXXRecordDecl *RD = E->getSubExpr()->getType()->getAsCXXRecordDecl();
9757 for (CastExpr::path_const_iterator PathI = E->path_begin(),
9758 PathE = E->path_end(); PathI != PathE; ++PathI) {
9759 assert(!(*PathI)->isVirtual() && "record rvalue with virtual base")((!(*PathI)->isVirtual() && "record rvalue with virtual base"
) ? static_cast<void> (0) : __assert_fail ("!(*PathI)->isVirtual() && \"record rvalue with virtual base\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9759, __PRETTY_FUNCTION__))
;
9760 const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
9761 Value = &Value->getStructBase(getBaseIndex(RD, Base));
9762 RD = Base;
9763 }
9764 Result = *Value;
9765 return true;
9766 }
9767 }
9768}
9769
9770bool RecordExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
9771 if (E->isTransparent())
9772 return Visit(E->getInit(0));
9773
9774 const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
9775 if (RD->isInvalidDecl()) return false;
9776 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
9777 auto *CXXRD = dyn_cast<CXXRecordDecl>(RD);
9778
9779 EvalInfo::EvaluatingConstructorRAII EvalObj(
9780 Info,
9781 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries},
9782 CXXRD && CXXRD->getNumBases());
9783
9784 if (RD->isUnion()) {
9785 const FieldDecl *Field = E->getInitializedFieldInUnion();
9786 Result = APValue(Field);
9787 if (!Field)
9788 return true;
9789
9790 // If the initializer list for a union does not contain any elements, the
9791 // first element of the union is value-initialized.
9792 // FIXME: The element should be initialized from an initializer list.
9793 // Is this difference ever observable for initializer lists which
9794 // we don't build?
9795 ImplicitValueInitExpr VIE(Field->getType());
9796 const Expr *InitExpr = E->getNumInits() ? E->getInit(0) : &VIE;
9797
9798 LValue Subobject = This;
9799 if (!HandleLValueMember(Info, InitExpr, Subobject, Field, &Layout))
9800 return false;
9801
9802 // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
9803 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
9804 isa<CXXDefaultInitExpr>(InitExpr));
9805
9806 if (EvaluateInPlace(Result.getUnionValue(), Info, Subobject, InitExpr)) {
9807 if (Field->isBitField())
9808 return truncateBitfieldValue(Info, InitExpr, Result.getUnionValue(),
9809 Field);
9810 return true;
9811 }
9812
9813 return false;
9814 }
9815
9816 if (!Result.hasValue())
9817 Result = APValue(APValue::UninitStruct(), CXXRD ? CXXRD->getNumBases() : 0,
9818 std::distance(RD->field_begin(), RD->field_end()));
9819 unsigned ElementNo = 0;
9820 bool Success = true;
9821
9822 // Initialize base classes.
9823 if (CXXRD && CXXRD->getNumBases()) {
9824 for (const auto &Base : CXXRD->bases()) {
9825 assert(ElementNo < E->getNumInits() && "missing init for base class")((ElementNo < E->getNumInits() && "missing init for base class"
) ? static_cast<void> (0) : __assert_fail ("ElementNo < E->getNumInits() && \"missing init for base class\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9825, __PRETTY_FUNCTION__))
;
9826 const Expr *Init = E->getInit(ElementNo);
9827
9828 LValue Subobject = This;
9829 if (!HandleLValueBase(Info, Init, Subobject, CXXRD, &Base))
9830 return false;
9831
9832 APValue &FieldVal = Result.getStructBase(ElementNo);
9833 if (!EvaluateInPlace(FieldVal, Info, Subobject, Init)) {
9834 if (!Info.noteFailure())
9835 return false;
9836 Success = false;
9837 }
9838 ++ElementNo;
9839 }
9840
9841 EvalObj.finishedConstructingBases();
9842 }
9843
9844 // Initialize members.
9845 for (const auto *Field : RD->fields()) {
9846 // Anonymous bit-fields are not considered members of the class for
9847 // purposes of aggregate initialization.
9848 if (Field->isUnnamedBitfield())
9849 continue;
9850
9851 LValue Subobject = This;
9852
9853 bool HaveInit = ElementNo < E->getNumInits();
9854
9855 // FIXME: Diagnostics here should point to the end of the initializer
9856 // list, not the start.
9857 if (!HandleLValueMember(Info, HaveInit ? E->getInit(ElementNo) : E,
9858 Subobject, Field, &Layout))
9859 return false;
9860
9861 // Perform an implicit value-initialization for members beyond the end of
9862 // the initializer list.
9863 ImplicitValueInitExpr VIE(HaveInit ? Info.Ctx.IntTy : Field->getType());
9864 const Expr *Init = HaveInit ? E->getInit(ElementNo++) : &VIE;
9865
9866 // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
9867 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
9868 isa<CXXDefaultInitExpr>(Init));
9869
9870 APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
9871 if (!EvaluateInPlace(FieldVal, Info, Subobject, Init) ||
9872 (Field->isBitField() && !truncateBitfieldValue(Info, Init,
9873 FieldVal, Field))) {
9874 if (!Info.noteFailure())
9875 return false;
9876 Success = false;
9877 }
9878 }
9879
9880 EvalObj.finishedConstructingFields();
9881
9882 return Success;
9883}
9884
9885bool RecordExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
9886 QualType T) {
9887 // Note that E's type is not necessarily the type of our class here; we might
9888 // be initializing an array element instead.
9889 const CXXConstructorDecl *FD = E->getConstructor();
9890 if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl()) return false;
9891
9892 bool ZeroInit = E->requiresZeroInitialization();
9893 if (CheckTrivialDefaultConstructor(Info, E->getExprLoc(), FD, ZeroInit)) {
9894 // If we've already performed zero-initialization, we're already done.
9895 if (Result.hasValue())
9896 return true;
9897
9898 if (ZeroInit)
9899 return ZeroInitialization(E, T);
9900
9901 return getDefaultInitValue(T, Result);
9902 }
9903
9904 const FunctionDecl *Definition = nullptr;
9905 auto Body = FD->getBody(Definition);
9906
9907 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
9908 return false;
9909
9910 // Avoid materializing a temporary for an elidable copy/move constructor.
9911 if (E->isElidable() && !ZeroInit)
9912 if (const MaterializeTemporaryExpr *ME
9913 = dyn_cast<MaterializeTemporaryExpr>(E->getArg(0)))
9914 return Visit(ME->getSubExpr());
9915
9916 if (ZeroInit && !ZeroInitialization(E, T))
9917 return false;
9918
9919 auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
9920 return HandleConstructorCall(E, This, Args,
9921 cast<CXXConstructorDecl>(Definition), Info,
9922 Result);
9923}
9924
9925bool RecordExprEvaluator::VisitCXXInheritedCtorInitExpr(
9926 const CXXInheritedCtorInitExpr *E) {
9927 if (!Info.CurrentCall) {
9928 assert(Info.checkingPotentialConstantExpression())((Info.checkingPotentialConstantExpression()) ? static_cast<
void> (0) : __assert_fail ("Info.checkingPotentialConstantExpression()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 9928, __PRETTY_FUNCTION__))
;
9929 return false;
9930 }
9931
9932 const CXXConstructorDecl *FD = E->getConstructor();
9933 if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl())
9934 return false;
9935
9936 const FunctionDecl *Definition = nullptr;
9937 auto Body = FD->getBody(Definition);
9938
9939 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
9940 return false;
9941
9942 return HandleConstructorCall(E, This, Info.CurrentCall->Arguments,
9943 cast<CXXConstructorDecl>(Definition), Info,
9944 Result);
9945}
9946
9947bool RecordExprEvaluator::VisitCXXStdInitializerListExpr(
9948 const CXXStdInitializerListExpr *E) {
9949 const ConstantArrayType *ArrayType =
9950 Info.Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
9951
9952 LValue Array;
9953 if (!EvaluateLValue(E->getSubExpr(), Array, Info))
9954 return false;
9955
9956 // Get a pointer to the first element of the array.
9957 Array.addArray(Info, E, ArrayType);
9958
9959 auto InvalidType = [&] {
9960 Info.FFDiag(E, diag::note_constexpr_unsupported_layout)
9961 << E->getType();
9962 return false;
9963 };
9964
9965 // FIXME: Perform the checks on the field types in SemaInit.
9966 RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
9967 RecordDecl::field_iterator Field = Record->field_begin();
9968 if (Field == Record->field_end())
9969 return InvalidType();
9970
9971 // Start pointer.
9972 if (!Field->getType()->isPointerType() ||
9973 !Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
9974 ArrayType->getElementType()))
9975 return InvalidType();
9976
9977 // FIXME: What if the initializer_list type has base classes, etc?
9978 Result = APValue(APValue::UninitStruct(), 0, 2);
9979 Array.moveInto(Result.getStructField(0));
9980
9981 if (++Field == Record->field_end())
9982 return InvalidType();
9983
9984 if (Field->getType()->isPointerType() &&
9985 Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
9986 ArrayType->getElementType())) {
9987 // End pointer.
9988 if (!HandleLValueArrayAdjustment(Info, E, Array,
9989 ArrayType->getElementType(),
9990 ArrayType->getSize().getZExtValue()))
9991 return false;
9992 Array.moveInto(Result.getStructField(1));
9993 } else if (Info.Ctx.hasSameType(Field->getType(), Info.Ctx.getSizeType()))
9994 // Length.
9995 Result.getStructField(1) = APValue(APSInt(ArrayType->getSize()));
9996 else
9997 return InvalidType();
9998
9999 if (++Field != Record->field_end())
10000 return InvalidType();
10001
10002 return true;
10003}
10004
10005bool RecordExprEvaluator::VisitLambdaExpr(const LambdaExpr *E) {
10006 const CXXRecordDecl *ClosureClass = E->getLambdaClass();
10007 if (ClosureClass->isInvalidDecl())
10008 return false;
10009
10010 const size_t NumFields =
10011 std::distance(ClosureClass->field_begin(), ClosureClass->field_end());
10012
10013 assert(NumFields == (size_t)std::distance(E->capture_init_begin(),((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") ? static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10016, __PRETTY_FUNCTION__))
10014 E->capture_init_end()) &&((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") ? static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10016, __PRETTY_FUNCTION__))
10015 "The number of lambda capture initializers should equal the number of "((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") ? static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10016, __PRETTY_FUNCTION__))
10016 "fields within the closure type")((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") ? static_cast<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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10016, __PRETTY_FUNCTION__))
;
10017
10018 Result = APValue(APValue::UninitStruct(), /*NumBases*/0, NumFields);
10019 // Iterate through all the lambda's closure object's fields and initialize
10020 // them.
10021 auto *CaptureInitIt = E->capture_init_begin();
10022 const LambdaCapture *CaptureIt = ClosureClass->captures_begin();
10023 bool Success = true;
10024 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(ClosureClass);
10025 for (const auto *Field : ClosureClass->fields()) {
10026 assert(CaptureInitIt != E->capture_init_end())((CaptureInitIt != E->capture_init_end()) ? static_cast<
void> (0) : __assert_fail ("CaptureInitIt != E->capture_init_end()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10026, __PRETTY_FUNCTION__))
;
10027 // Get the initializer for this field
10028 Expr *const CurFieldInit = *CaptureInitIt++;
10029
10030 // If there is no initializer, either this is a VLA or an error has
10031 // occurred.
10032 if (!CurFieldInit)
10033 return Error(E);
10034
10035 LValue Subobject = This;
10036
10037 if (!HandleLValueMember(Info, E, Subobject, Field, &Layout))
10038 return false;
10039
10040 APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
10041 if (!EvaluateInPlace(FieldVal, Info, Subobject, CurFieldInit)) {
10042 if (!Info.keepEvaluatingAfterFailure())
10043 return false;
10044 Success = false;
10045 }
10046 ++CaptureIt;
10047 }
10048 return Success;
10049}
10050
10051static bool EvaluateRecord(const Expr *E, const LValue &This,
10052 APValue &Result, EvalInfo &Info) {
10053 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10053, __PRETTY_FUNCTION__))
;
10054 assert(E->isRValue() && E->getType()->isRecordType() &&((E->isRValue() && E->getType()->isRecordType
() && "can't evaluate expression as a record rvalue")
? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isRecordType() && \"can't evaluate expression as a record rvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10055, __PRETTY_FUNCTION__))
10055 "can't evaluate expression as a record rvalue")((E->isRValue() && E->getType()->isRecordType
() && "can't evaluate expression as a record rvalue")
? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isRecordType() && \"can't evaluate expression as a record rvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10055, __PRETTY_FUNCTION__))
;
10056 return RecordExprEvaluator(Info, This, Result).Visit(E);
10057}
10058
10059//===----------------------------------------------------------------------===//
10060// Temporary Evaluation
10061//
10062// Temporaries are represented in the AST as rvalues, but generally behave like
10063// lvalues. The full-object of which the temporary is a subobject is implicitly
10064// materialized so that a reference can bind to it.
10065//===----------------------------------------------------------------------===//
10066namespace {
10067class TemporaryExprEvaluator
10068 : public LValueExprEvaluatorBase<TemporaryExprEvaluator> {
10069public:
10070 TemporaryExprEvaluator(EvalInfo &Info, LValue &Result) :
10071 LValueExprEvaluatorBaseTy(Info, Result, false) {}
10072
10073 /// Visit an expression which constructs the value of this temporary.
10074 bool VisitConstructExpr(const Expr *E) {
10075 APValue &Value = Info.CurrentCall->createTemporary(
10076 E, E->getType(), ScopeKind::FullExpression, Result);
10077 return EvaluateInPlace(Value, Info, Result, E);
10078 }
10079
10080 bool VisitCastExpr(const CastExpr *E) {
10081 switch (E->getCastKind()) {
10082 default:
10083 return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
10084
10085 case CK_ConstructorConversion:
10086 return VisitConstructExpr(E->getSubExpr());
10087 }
10088 }
10089 bool VisitInitListExpr(const InitListExpr *E) {
10090 return VisitConstructExpr(E);
10091 }
10092 bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
10093 return VisitConstructExpr(E);
10094 }
10095 bool VisitCallExpr(const CallExpr *E) {
10096 return VisitConstructExpr(E);
10097 }
10098 bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E) {
10099 return VisitConstructExpr(E);
10100 }
10101 bool VisitLambdaExpr(const LambdaExpr *E) {
10102 return VisitConstructExpr(E);
10103 }
10104};
10105} // end anonymous namespace
10106
10107/// Evaluate an expression of record type as a temporary.
10108static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info) {
10109 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10109, __PRETTY_FUNCTION__))
;
10110 assert(E->isRValue() && E->getType()->isRecordType())((E->isRValue() && E->getType()->isRecordType
()) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isRecordType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10110, __PRETTY_FUNCTION__))
;
10111 return TemporaryExprEvaluator(Info, Result).Visit(E);
10112}
10113
10114//===----------------------------------------------------------------------===//
10115// Vector Evaluation
10116//===----------------------------------------------------------------------===//
10117
10118namespace {
10119 class VectorExprEvaluator
10120 : public ExprEvaluatorBase<VectorExprEvaluator> {
10121 APValue &Result;
10122 public:
10123
10124 VectorExprEvaluator(EvalInfo &info, APValue &Result)
10125 : ExprEvaluatorBaseTy(info), Result(Result) {}
10126
10127 bool Success(ArrayRef<APValue> V, const Expr *E) {
10128 assert(V.size() == E->getType()->castAs<VectorType>()->getNumElements())((V.size() == E->getType()->castAs<VectorType>()->
getNumElements()) ? static_cast<void> (0) : __assert_fail
("V.size() == E->getType()->castAs<VectorType>()->getNumElements()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10128, __PRETTY_FUNCTION__))
;
10129 // FIXME: remove this APValue copy.
10130 Result = APValue(V.data(), V.size());
10131 return true;
10132 }
10133 bool Success(const APValue &V, const Expr *E) {
10134 assert(V.isVector())((V.isVector()) ? static_cast<void> (0) : __assert_fail
("V.isVector()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10134, __PRETTY_FUNCTION__))
;
10135 Result = V;
10136 return true;
10137 }
10138 bool ZeroInitialization(const Expr *E);
10139
10140 bool VisitUnaryReal(const UnaryOperator *E)
10141 { return Visit(E->getSubExpr()); }
10142 bool VisitCastExpr(const CastExpr* E);
10143 bool VisitInitListExpr(const InitListExpr *E);
10144 bool VisitUnaryImag(const UnaryOperator *E);
10145 bool VisitBinaryOperator(const BinaryOperator *E);
10146 // FIXME: Missing: unary -, unary ~, conditional operator (for GNU
10147 // conditional select), shufflevector, ExtVectorElementExpr
10148 };
10149} // end anonymous namespace
10150
10151static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) {
10152 assert(E->isRValue() && E->getType()->isVectorType() &&"not a vector rvalue")((E->isRValue() && E->getType()->isVectorType
() &&"not a vector rvalue") ? static_cast<void>
(0) : __assert_fail ("E->isRValue() && E->getType()->isVectorType() &&\"not a vector rvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10152, __PRETTY_FUNCTION__))
;
10153 return VectorExprEvaluator(Info, Result).Visit(E);
10154}
10155
10156bool VectorExprEvaluator::VisitCastExpr(const CastExpr *E) {
10157 const VectorType *VTy = E->getType()->castAs<VectorType>();
10158 unsigned NElts = VTy->getNumElements();
10159
10160 const Expr *SE = E->getSubExpr();
10161 QualType SETy = SE->getType();
10162
10163 switch (E->getCastKind()) {
10164 case CK_VectorSplat: {
10165 APValue Val = APValue();
10166 if (SETy->isIntegerType()) {
10167 APSInt IntResult;
10168 if (!EvaluateInteger(SE, IntResult, Info))
10169 return false;
10170 Val = APValue(std::move(IntResult));
10171 } else if (SETy->isRealFloatingType()) {
10172 APFloat FloatResult(0.0);
10173 if (!EvaluateFloat(SE, FloatResult, Info))
10174 return false;
10175 Val = APValue(std::move(FloatResult));
10176 } else {
10177 return Error(E);
10178 }
10179
10180 // Splat and create vector APValue.
10181 SmallVector<APValue, 4> Elts(NElts, Val);
10182 return Success(Elts, E);
10183 }
10184 case CK_BitCast: {
10185 // Evaluate the operand into an APInt we can extract from.
10186 llvm::APInt SValInt;
10187 if (!EvalAndBitcastToAPInt(Info, SE, SValInt))
10188 return false;
10189 // Extract the elements
10190 QualType EltTy = VTy->getElementType();
10191 unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
10192 bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
10193 SmallVector<APValue, 4> Elts;
10194 if (EltTy->isRealFloatingType()) {
10195 const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(EltTy);
10196 unsigned FloatEltSize = EltSize;
10197 if (&Sem == &APFloat::x87DoubleExtended())
10198 FloatEltSize = 80;
10199 for (unsigned i = 0; i < NElts; i++) {
10200 llvm::APInt Elt;
10201 if (BigEndian)
10202 Elt = SValInt.rotl(i*EltSize+FloatEltSize).trunc(FloatEltSize);
10203 else
10204 Elt = SValInt.rotr(i*EltSize).trunc(FloatEltSize);
10205 Elts.push_back(APValue(APFloat(Sem, Elt)));
10206 }
10207 } else if (EltTy->isIntegerType()) {
10208 for (unsigned i = 0; i < NElts; i++) {
10209 llvm::APInt Elt;
10210 if (BigEndian)
10211 Elt = SValInt.rotl(i*EltSize+EltSize).zextOrTrunc(EltSize);
10212 else
10213 Elt = SValInt.rotr(i*EltSize).zextOrTrunc(EltSize);
10214 Elts.push_back(APValue(APSInt(Elt, !EltTy->isSignedIntegerType())));
10215 }
10216 } else {
10217 return Error(E);
10218 }
10219 return Success(Elts, E);
10220 }
10221 default:
10222 return ExprEvaluatorBaseTy::VisitCastExpr(E);
10223 }
10224}
10225
10226bool
10227VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
10228 const VectorType *VT = E->getType()->castAs<VectorType>();
10229 unsigned NumInits = E->getNumInits();
10230 unsigned NumElements = VT->getNumElements();
10231
10232 QualType EltTy = VT->getElementType();
10233 SmallVector<APValue, 4> Elements;
10234
10235 // The number of initializers can be less than the number of
10236 // vector elements. For OpenCL, this can be due to nested vector
10237 // initialization. For GCC compatibility, missing trailing elements
10238 // should be initialized with zeroes.
10239 unsigned CountInits = 0, CountElts = 0;
10240 while (CountElts < NumElements) {
10241 // Handle nested vector initialization.
10242 if (CountInits < NumInits
10243 && E->getInit(CountInits)->getType()->isVectorType()) {
10244 APValue v;
10245 if (!EvaluateVector(E->getInit(CountInits), v, Info))
10246 return Error(E);
10247 unsigned vlen = v.getVectorLength();
10248 for (unsigned j = 0; j < vlen; j++)
10249 Elements.push_back(v.getVectorElt(j));
10250 CountElts += vlen;
10251 } else if (EltTy->isIntegerType()) {
10252 llvm::APSInt sInt(32);
10253 if (CountInits < NumInits) {
10254 if (!EvaluateInteger(E->getInit(CountInits), sInt, Info))
10255 return false;
10256 } else // trailing integer zero.
10257 sInt = Info.Ctx.MakeIntValue(0, EltTy);
10258 Elements.push_back(APValue(sInt));
10259 CountElts++;
10260 } else {
10261 llvm::APFloat f(0.0);
10262 if (CountInits < NumInits) {
10263 if (!EvaluateFloat(E->getInit(CountInits), f, Info))
10264 return false;
10265 } else // trailing float zero.
10266 f = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy));
10267 Elements.push_back(APValue(f));
10268 CountElts++;
10269 }
10270 CountInits++;
10271 }
10272 return Success(Elements, E);
10273}
10274
10275bool
10276VectorExprEvaluator::ZeroInitialization(const Expr *E) {
10277 const auto *VT = E->getType()->castAs<VectorType>();
10278 QualType EltTy = VT->getElementType();
10279 APValue ZeroElement;
10280 if (EltTy->isIntegerType())
10281 ZeroElement = APValue(Info.Ctx.MakeIntValue(0, EltTy));
10282 else
10283 ZeroElement =
10284 APValue(APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy)));
10285
10286 SmallVector<APValue, 4> Elements(VT->getNumElements(), ZeroElement);
10287 return Success(Elements, E);
10288}
10289
10290bool VectorExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
10291 VisitIgnoredValue(E->getSubExpr());
10292 return ZeroInitialization(E);
10293}
10294
10295bool VectorExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
10296 BinaryOperatorKind Op = E->getOpcode();
10297 assert(Op != BO_PtrMemD && Op != BO_PtrMemI && Op != BO_Cmp &&((Op != BO_PtrMemD && Op != BO_PtrMemI && Op !=
BO_Cmp && "Operation not supported on vector types")
? static_cast<void> (0) : __assert_fail ("Op != BO_PtrMemD && Op != BO_PtrMemI && Op != BO_Cmp && \"Operation not supported on vector types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10298, __PRETTY_FUNCTION__))
1
Assuming 'Op' is not equal to BO_PtrMemD
2
Assuming 'Op' is not equal to BO_PtrMemI
3
Assuming 'Op' is not equal to BO_Cmp
4
'?' condition is true
10298 "Operation not supported on vector types")((Op != BO_PtrMemD && Op != BO_PtrMemI && Op !=
BO_Cmp && "Operation not supported on vector types")
? static_cast<void> (0) : __assert_fail ("Op != BO_PtrMemD && Op != BO_PtrMemI && Op != BO_Cmp && \"Operation not supported on vector types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10298, __PRETTY_FUNCTION__))
;
10299
10300 if (Op == BO_Comma)
5
Assuming 'Op' is not equal to BO_Comma
6
Taking false branch
10301 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
10302
10303 Expr *LHS = E->getLHS();
10304 Expr *RHS = E->getRHS();
10305
10306 assert(LHS->getType()->isVectorType() && RHS->getType()->isVectorType() &&((LHS->getType()->isVectorType() && RHS->getType
()->isVectorType() && "Must both be vector types")
? static_cast<void> (0) : __assert_fail ("LHS->getType()->isVectorType() && RHS->getType()->isVectorType() && \"Must both be vector types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10307, __PRETTY_FUNCTION__))
7
'?' condition is true
10307 "Must both be vector types")((LHS->getType()->isVectorType() && RHS->getType
()->isVectorType() && "Must both be vector types")
? static_cast<void> (0) : __assert_fail ("LHS->getType()->isVectorType() && RHS->getType()->isVectorType() && \"Must both be vector types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10307, __PRETTY_FUNCTION__))
;
10308 // Checking JUST the types are the same would be fine, except shifts don't
10309 // need to have their types be the same (since you always shift by an int).
10310 assert(LHS->getType()->getAs<VectorType>()->getNumElements() ==((LHS->getType()->getAs<VectorType>()->getNumElements
() == E->getType()->getAs<VectorType>()->getNumElements
() && RHS->getType()->getAs<VectorType>()
->getNumElements() == E->getType()->getAs<VectorType
>()->getNumElements() && "All operands must be the same size."
) ? static_cast<void> (0) : __assert_fail ("LHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && RHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10314, __PRETTY_FUNCTION__))
8
Assuming the object is not a 'VectorType'
9
Called C++ object pointer is null
10311 E->getType()->getAs<VectorType>()->getNumElements() &&((LHS->getType()->getAs<VectorType>()->getNumElements
() == E->getType()->getAs<VectorType>()->getNumElements
() && RHS->getType()->getAs<VectorType>()
->getNumElements() == E->getType()->getAs<VectorType
>()->getNumElements() && "All operands must be the same size."
) ? static_cast<void> (0) : __assert_fail ("LHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && RHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10314, __PRETTY_FUNCTION__))
10312 RHS->getType()->getAs<VectorType>()->getNumElements() ==((LHS->getType()->getAs<VectorType>()->getNumElements
() == E->getType()->getAs<VectorType>()->getNumElements
() && RHS->getType()->getAs<VectorType>()
->getNumElements() == E->getType()->getAs<VectorType
>()->getNumElements() && "All operands must be the same size."
) ? static_cast<void> (0) : __assert_fail ("LHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && RHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10314, __PRETTY_FUNCTION__))
10313 E->getType()->getAs<VectorType>()->getNumElements() &&((LHS->getType()->getAs<VectorType>()->getNumElements
() == E->getType()->getAs<VectorType>()->getNumElements
() && RHS->getType()->getAs<VectorType>()
->getNumElements() == E->getType()->getAs<VectorType
>()->getNumElements() && "All operands must be the same size."
) ? static_cast<void> (0) : __assert_fail ("LHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && RHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10314, __PRETTY_FUNCTION__))
10314 "All operands must be the same size.")((LHS->getType()->getAs<VectorType>()->getNumElements
() == E->getType()->getAs<VectorType>()->getNumElements
() && RHS->getType()->getAs<VectorType>()
->getNumElements() == E->getType()->getAs<VectorType
>()->getNumElements() && "All operands must be the same size."
) ? static_cast<void> (0) : __assert_fail ("LHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && RHS->getType()->getAs<VectorType>()->getNumElements() == E->getType()->getAs<VectorType>()->getNumElements() && \"All operands must be the same size.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10314, __PRETTY_FUNCTION__))
;
10315
10316 APValue LHSValue;
10317 APValue RHSValue;
10318 bool LHSOK = Evaluate(LHSValue, Info, LHS);
10319 if (!LHSOK && !Info.noteFailure())
10320 return false;
10321 if (!Evaluate(RHSValue, Info, RHS) || !LHSOK)
10322 return false;
10323
10324 if (!handleVectorVectorBinOp(Info, E, Op, LHSValue, RHSValue))
10325 return false;
10326
10327 return Success(LHSValue, E);
10328}
10329
10330//===----------------------------------------------------------------------===//
10331// Array Evaluation
10332//===----------------------------------------------------------------------===//
10333
10334namespace {
10335 class ArrayExprEvaluator
10336 : public ExprEvaluatorBase<ArrayExprEvaluator> {
10337 const LValue &This;
10338 APValue &Result;
10339 public:
10340
10341 ArrayExprEvaluator(EvalInfo &Info, const LValue &This, APValue &Result)
10342 : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
10343
10344 bool Success(const APValue &V, const Expr *E) {
10345 assert(V.isArray() && "expected array")((V.isArray() && "expected array") ? static_cast<void
> (0) : __assert_fail ("V.isArray() && \"expected array\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10345, __PRETTY_FUNCTION__))
;
10346 Result = V;
10347 return true;
10348 }
10349
10350 bool ZeroInitialization(const Expr *E) {
10351 const ConstantArrayType *CAT =
10352 Info.Ctx.getAsConstantArrayType(E->getType());
10353 if (!CAT) {
10354 if (E->getType()->isIncompleteArrayType()) {
10355 // We can be asked to zero-initialize a flexible array member; this
10356 // is represented as an ImplicitValueInitExpr of incomplete array
10357 // type. In this case, the array has zero elements.
10358 Result = APValue(APValue::UninitArray(), 0, 0);
10359 return true;
10360 }
10361 // FIXME: We could handle VLAs here.
10362 return Error(E);
10363 }
10364
10365 Result = APValue(APValue::UninitArray(), 0,
10366 CAT->getSize().getZExtValue());
10367 if (!Result.hasArrayFiller()) return true;
10368
10369 // Zero-initialize all elements.
10370 LValue Subobject = This;
10371 Subobject.addArray(Info, E, CAT);
10372 ImplicitValueInitExpr VIE(CAT->getElementType());
10373 return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject, &VIE);
10374 }
10375
10376 bool VisitCallExpr(const CallExpr *E) {
10377 return handleCallExpr(E, Result, &This);
10378 }
10379 bool VisitInitListExpr(const InitListExpr *E,
10380 QualType AllocType = QualType());
10381 bool VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E);
10382 bool VisitCXXConstructExpr(const CXXConstructExpr *E);
10383 bool VisitCXXConstructExpr(const CXXConstructExpr *E,
10384 const LValue &Subobject,
10385 APValue *Value, QualType Type);
10386 bool VisitStringLiteral(const StringLiteral *E,
10387 QualType AllocType = QualType()) {
10388 expandStringLiteral(Info, E, Result, AllocType);
10389 return true;
10390 }
10391 };
10392} // end anonymous namespace
10393
10394static bool EvaluateArray(const Expr *E, const LValue &This,
10395 APValue &Result, EvalInfo &Info) {
10396 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10396, __PRETTY_FUNCTION__))
;
10397 assert(E->isRValue() && E->getType()->isArrayType() && "not an array rvalue")((E->isRValue() && E->getType()->isArrayType
() && "not an array rvalue") ? static_cast<void>
(0) : __assert_fail ("E->isRValue() && E->getType()->isArrayType() && \"not an array rvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10397, __PRETTY_FUNCTION__))
;
10398 return ArrayExprEvaluator(Info, This, Result).Visit(E);
10399}
10400
10401static bool EvaluateArrayNewInitList(EvalInfo &Info, LValue &This,
10402 APValue &Result, const InitListExpr *ILE,
10403 QualType AllocType) {
10404 assert(!ILE->isValueDependent())((!ILE->isValueDependent()) ? static_cast<void> (0) :
__assert_fail ("!ILE->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10404, __PRETTY_FUNCTION__))
;
10405 assert(ILE->isRValue() && ILE->getType()->isArrayType() &&((ILE->isRValue() && ILE->getType()->isArrayType
() && "not an array rvalue") ? static_cast<void>
(0) : __assert_fail ("ILE->isRValue() && ILE->getType()->isArrayType() && \"not an array rvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10406, __PRETTY_FUNCTION__))
10406 "not an array rvalue")((ILE->isRValue() && ILE->getType()->isArrayType
() && "not an array rvalue") ? static_cast<void>
(0) : __assert_fail ("ILE->isRValue() && ILE->getType()->isArrayType() && \"not an array rvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10406, __PRETTY_FUNCTION__))
;
10407 return ArrayExprEvaluator(Info, This, Result)
10408 .VisitInitListExpr(ILE, AllocType);
10409}
10410
10411static bool EvaluateArrayNewConstructExpr(EvalInfo &Info, LValue &This,
10412 APValue &Result,
10413 const CXXConstructExpr *CCE,
10414 QualType AllocType) {
10415 assert(!CCE->isValueDependent())((!CCE->isValueDependent()) ? static_cast<void> (0) :
__assert_fail ("!CCE->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10415, __PRETTY_FUNCTION__))
;
10416 assert(CCE->isRValue() && CCE->getType()->isArrayType() &&((CCE->isRValue() && CCE->getType()->isArrayType
() && "not an array rvalue") ? static_cast<void>
(0) : __assert_fail ("CCE->isRValue() && CCE->getType()->isArrayType() && \"not an array rvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10417, __PRETTY_FUNCTION__))
10417 "not an array rvalue")((CCE->isRValue() && CCE->getType()->isArrayType
() && "not an array rvalue") ? static_cast<void>
(0) : __assert_fail ("CCE->isRValue() && CCE->getType()->isArrayType() && \"not an array rvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10417, __PRETTY_FUNCTION__))
;
10418 return ArrayExprEvaluator(Info, This, Result)
10419 .VisitCXXConstructExpr(CCE, This, &Result, AllocType);
10420}
10421
10422// Return true iff the given array filler may depend on the element index.
10423static bool MaybeElementDependentArrayFiller(const Expr *FillerExpr) {
10424 // For now, just allow non-class value-initialization and initialization
10425 // lists comprised of them.
10426 if (isa<ImplicitValueInitExpr>(FillerExpr))
10427 return false;
10428 if (const InitListExpr *ILE = dyn_cast<InitListExpr>(FillerExpr)) {
10429 for (unsigned I = 0, E = ILE->getNumInits(); I != E; ++I) {
10430 if (MaybeElementDependentArrayFiller(ILE->getInit(I)))
10431 return true;
10432 }
10433 return false;
10434 }
10435 return true;
10436}
10437
10438bool ArrayExprEvaluator::VisitInitListExpr(const InitListExpr *E,
10439 QualType AllocType) {
10440 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(
10441 AllocType.isNull() ? E->getType() : AllocType);
10442 if (!CAT)
10443 return Error(E);
10444
10445 // C++11 [dcl.init.string]p1: A char array [...] can be initialized by [...]
10446 // an appropriately-typed string literal enclosed in braces.
10447 if (E->isStringLiteralInit()) {
10448 auto *SL = dyn_cast<StringLiteral>(E->getInit(0)->IgnoreParens());
10449 // FIXME: Support ObjCEncodeExpr here once we support it in
10450 // ArrayExprEvaluator generally.
10451 if (!SL)
10452 return Error(E);
10453 return VisitStringLiteral(SL, AllocType);
10454 }
10455
10456 bool Success = true;
10457
10458 assert((!Result.isArray() || Result.getArrayInitializedElts() == 0) &&(((!Result.isArray() || Result.getArrayInitializedElts() == 0
) && "zero-initialized array shouldn't have any initialized elts"
) ? static_cast<void> (0) : __assert_fail ("(!Result.isArray() || Result.getArrayInitializedElts() == 0) && \"zero-initialized array shouldn't have any initialized elts\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10459, __PRETTY_FUNCTION__))
10459 "zero-initialized array shouldn't have any initialized elts")(((!Result.isArray() || Result.getArrayInitializedElts() == 0
) && "zero-initialized array shouldn't have any initialized elts"
) ? static_cast<void> (0) : __assert_fail ("(!Result.isArray() || Result.getArrayInitializedElts() == 0) && \"zero-initialized array shouldn't have any initialized elts\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10459, __PRETTY_FUNCTION__))
;
10460 APValue Filler;
10461 if (Result.isArray() && Result.hasArrayFiller())
10462 Filler = Result.getArrayFiller();
10463
10464 unsigned NumEltsToInit = E->getNumInits();
10465 unsigned NumElts = CAT->getSize().getZExtValue();
10466 const Expr *FillerExpr = E->hasArrayFiller() ? E->getArrayFiller() : nullptr;
10467
10468 // If the initializer might depend on the array index, run it for each
10469 // array element.
10470 if (NumEltsToInit != NumElts && MaybeElementDependentArrayFiller(FillerExpr))
10471 NumEltsToInit = NumElts;
10472
10473 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)
10474 << NumEltsToInit << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("exprconstant")) { llvm::dbgs() << "The number of elements to initialize: "
<< NumEltsToInit << ".\n"; } } while (false)
;
10475
10476 Result = APValue(APValue::UninitArray(), NumEltsToInit, NumElts);
10477
10478 // If the array was previously zero-initialized, preserve the
10479 // zero-initialized values.
10480 if (Filler.hasValue()) {
10481 for (unsigned I = 0, E = Result.getArrayInitializedElts(); I != E; ++I)
10482 Result.getArrayInitializedElt(I) = Filler;
10483 if (Result.hasArrayFiller())
10484 Result.getArrayFiller() = Filler;
10485 }
10486
10487 LValue Subobject = This;
10488 Subobject.addArray(Info, E, CAT);
10489 for (unsigned Index = 0; Index != NumEltsToInit; ++Index) {
10490 const Expr *Init =
10491 Index < E->getNumInits() ? E->getInit(Index) : FillerExpr;
10492 if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
10493 Info, Subobject, Init) ||
10494 !HandleLValueArrayAdjustment(Info, Init, Subobject,
10495 CAT->getElementType(), 1)) {
10496 if (!Info.noteFailure())
10497 return false;
10498 Success = false;
10499 }
10500 }
10501
10502 if (!Result.hasArrayFiller())
10503 return Success;
10504
10505 // If we get here, we have a trivial filler, which we can just evaluate
10506 // once and splat over the rest of the array elements.
10507 assert(FillerExpr && "no array filler for incomplete init list")((FillerExpr && "no array filler for incomplete init list"
) ? static_cast<void> (0) : __assert_fail ("FillerExpr && \"no array filler for incomplete init list\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10507, __PRETTY_FUNCTION__))
;
10508 return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject,
10509 FillerExpr) && Success;
10510}
10511
10512bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
10513 LValue CommonLV;
10514 if (E->getCommonExpr() &&
10515 !Evaluate(Info.CurrentCall->createTemporary(
10516 E->getCommonExpr(),
10517 getStorageType(Info.Ctx, E->getCommonExpr()),
10518 ScopeKind::FullExpression, CommonLV),
10519 Info, E->getCommonExpr()->getSourceExpr()))
10520 return false;
10521
10522 auto *CAT = cast<ConstantArrayType>(E->getType()->castAsArrayTypeUnsafe());
10523
10524 uint64_t Elements = CAT->getSize().getZExtValue();
10525 Result = APValue(APValue::UninitArray(), Elements, Elements);
10526
10527 LValue Subobject = This;
10528 Subobject.addArray(Info, E, CAT);
10529
10530 bool Success = true;
10531 for (EvalInfo::ArrayInitLoopIndex Index(Info); Index != Elements; ++Index) {
10532 if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
10533 Info, Subobject, E->getSubExpr()) ||
10534 !HandleLValueArrayAdjustment(Info, E, Subobject,
10535 CAT->getElementType(), 1)) {
10536 if (!Info.noteFailure())
10537 return false;
10538 Success = false;
10539 }
10540 }
10541
10542 return Success;
10543}
10544
10545bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
10546 return VisitCXXConstructExpr(E, This, &Result, E->getType());
10547}
10548
10549bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
10550 const LValue &Subobject,
10551 APValue *Value,
10552 QualType Type) {
10553 bool HadZeroInit = Value->hasValue();
10554
10555 if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(Type)) {
10556 unsigned N = CAT->getSize().getZExtValue();
10557
10558 // Preserve the array filler if we had prior zero-initialization.
10559 APValue Filler =
10560 HadZeroInit && Value->hasArrayFiller() ? Value->getArrayFiller()
10561 : APValue();
10562
10563 *Value = APValue(APValue::UninitArray(), N, N);
10564
10565 if (HadZeroInit)
10566 for (unsigned I = 0; I != N; ++I)
10567 Value->getArrayInitializedElt(I) = Filler;
10568
10569 // Initialize the elements.
10570 LValue ArrayElt = Subobject;
10571 ArrayElt.addArray(Info, E, CAT);
10572 for (unsigned I = 0; I != N; ++I)
10573 if (!VisitCXXConstructExpr(E, ArrayElt, &Value->getArrayInitializedElt(I),
10574 CAT->getElementType()) ||
10575 !HandleLValueArrayAdjustment(Info, E, ArrayElt,
10576 CAT->getElementType(), 1))
10577 return false;
10578
10579 return true;
10580 }
10581
10582 if (!Type->isRecordType())
10583 return Error(E);
10584
10585 return RecordExprEvaluator(Info, Subobject, *Value)
10586 .VisitCXXConstructExpr(E, Type);
10587}
10588
10589//===----------------------------------------------------------------------===//
10590// Integer Evaluation
10591//
10592// As a GNU extension, we support casting pointers to sufficiently-wide integer
10593// types and back in constant folding. Integer values are thus represented
10594// either as an integer-valued APValue, or as an lvalue-valued APValue.
10595//===----------------------------------------------------------------------===//
10596
10597namespace {
10598class IntExprEvaluator
10599 : public ExprEvaluatorBase<IntExprEvaluator> {
10600 APValue &Result;
10601public:
10602 IntExprEvaluator(EvalInfo &info, APValue &result)
10603 : ExprEvaluatorBaseTy(info), Result(result) {}
10604
10605 bool Success(const llvm::APSInt &SI, const Expr *E, APValue &Result) {
10606 assert(E->getType()->isIntegralOrEnumerationType() &&((E->getType()->isIntegralOrEnumerationType() &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10607, __PRETTY_FUNCTION__))
10607 "Invalid evaluation result.")((E->getType()->isIntegralOrEnumerationType() &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10607, __PRETTY_FUNCTION__))
;
10608 assert(SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() &&((SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType
() && "Invalid evaluation result.") ? static_cast<
void> (0) : __assert_fail ("SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10609, __PRETTY_FUNCTION__))
10609 "Invalid evaluation result.")((SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType
() && "Invalid evaluation result.") ? static_cast<
void> (0) : __assert_fail ("SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10609, __PRETTY_FUNCTION__))
;
10610 assert(SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&((SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10611, __PRETTY_FUNCTION__))
10611 "Invalid evaluation result.")((SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10611, __PRETTY_FUNCTION__))
;
10612 Result = APValue(SI);
10613 return true;
10614 }
10615 bool Success(const llvm::APSInt &SI, const Expr *E) {
10616 return Success(SI, E, Result);
10617 }
10618
10619 bool Success(const llvm::APInt &I, const Expr *E, APValue &Result) {
10620 assert(E->getType()->isIntegralOrEnumerationType() &&((E->getType()->isIntegralOrEnumerationType() &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10621, __PRETTY_FUNCTION__))
10621 "Invalid evaluation result.")((E->getType()->isIntegralOrEnumerationType() &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10621, __PRETTY_FUNCTION__))
;
10622 assert(I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&((I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10623, __PRETTY_FUNCTION__))
10623 "Invalid evaluation result.")((I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10623, __PRETTY_FUNCTION__))
;
10624 Result = APValue(APSInt(I));
10625 Result.getInt().setIsUnsigned(
10626 E->getType()->isUnsignedIntegerOrEnumerationType());
10627 return true;
10628 }
10629 bool Success(const llvm::APInt &I, const Expr *E) {
10630 return Success(I, E, Result);
10631 }
10632
10633 bool Success(uint64_t Value, const Expr *E, APValue &Result) {
10634 assert(E->getType()->isIntegralOrEnumerationType() &&((E->getType()->isIntegralOrEnumerationType() &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10635, __PRETTY_FUNCTION__))
10635 "Invalid evaluation result.")((E->getType()->isIntegralOrEnumerationType() &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("E->getType()->isIntegralOrEnumerationType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10635, __PRETTY_FUNCTION__))
;
10636 Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType()));
10637 return true;
10638 }
10639 bool Success(uint64_t Value, const Expr *E) {
10640 return Success(Value, E, Result);
10641 }
10642
10643 bool Success(CharUnits Size, const Expr *E) {
10644 return Success(Size.getQuantity(), E);
10645 }
10646
10647 bool Success(const APValue &V, const Expr *E) {
10648 if (V.isLValue() || V.isAddrLabelDiff() || V.isIndeterminate()) {
10649 Result = V;
10650 return true;
10651 }
10652 return Success(V.getInt(), E);
10653 }
10654
10655 bool ZeroInitialization(const Expr *E) { return Success(0, E); }
10656
10657 //===--------------------------------------------------------------------===//
10658 // Visitor Methods
10659 //===--------------------------------------------------------------------===//
10660
10661 bool VisitIntegerLiteral(const IntegerLiteral *E) {
10662 return Success(E->getValue(), E);
10663 }
10664 bool VisitCharacterLiteral(const CharacterLiteral *E) {
10665 return Success(E->getValue(), E);
10666 }
10667
10668 bool CheckReferencedDecl(const Expr *E, const Decl *D);
10669 bool VisitDeclRefExpr(const DeclRefExpr *E) {
10670 if (CheckReferencedDecl(E, E->getDecl()))
10671 return true;
10672
10673 return ExprEvaluatorBaseTy::VisitDeclRefExpr(E);
10674 }
10675 bool VisitMemberExpr(const MemberExpr *E) {
10676 if (CheckReferencedDecl(E, E->getMemberDecl())) {
10677 VisitIgnoredBaseExpression(E->getBase());
10678 return true;
10679 }
10680
10681 return ExprEvaluatorBaseTy::VisitMemberExpr(E);
10682 }
10683
10684 bool VisitCallExpr(const CallExpr *E);
10685 bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
10686 bool VisitBinaryOperator(const BinaryOperator *E);
10687 bool VisitOffsetOfExpr(const OffsetOfExpr *E);
10688 bool VisitUnaryOperator(const UnaryOperator *E);
10689
10690 bool VisitCastExpr(const CastExpr* E);
10691 bool VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
10692
10693 bool VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
10694 return Success(E->getValue(), E);
10695 }
10696
10697 bool VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) {
10698 return Success(E->getValue(), E);
10699 }
10700
10701 bool VisitArrayInitIndexExpr(const ArrayInitIndexExpr *E) {
10702 if (Info.ArrayInitIndex == uint64_t(-1)) {
10703 // We were asked to evaluate this subexpression independent of the
10704 // enclosing ArrayInitLoopExpr. We can't do that.
10705 Info.FFDiag(E);
10706 return false;
10707 }
10708 return Success(Info.ArrayInitIndex, E);
10709 }
10710
10711 // Note, GNU defines __null as an integer, not a pointer.
10712 bool VisitGNUNullExpr(const GNUNullExpr *E) {
10713 return ZeroInitialization(E);
10714 }
10715
10716 bool VisitTypeTraitExpr(const TypeTraitExpr *E) {
10717 return Success(E->getValue(), E);
10718 }
10719
10720 bool VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
10721 return Success(E->getValue(), E);
10722 }
10723
10724 bool VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
10725 return Success(E->getValue(), E);
10726 }
10727
10728 bool VisitUnaryReal(const UnaryOperator *E);
10729 bool VisitUnaryImag(const UnaryOperator *E);
10730
10731 bool VisitCXXNoexceptExpr(const CXXNoexceptExpr *E);
10732 bool VisitSizeOfPackExpr(const SizeOfPackExpr *E);
10733 bool VisitSourceLocExpr(const SourceLocExpr *E);
10734 bool VisitConceptSpecializationExpr(const ConceptSpecializationExpr *E);
10735 bool VisitRequiresExpr(const RequiresExpr *E);
10736 // FIXME: Missing: array subscript of vector, member of vector
10737};
10738
10739class FixedPointExprEvaluator
10740 : public ExprEvaluatorBase<FixedPointExprEvaluator> {
10741 APValue &Result;
10742
10743 public:
10744 FixedPointExprEvaluator(EvalInfo &info, APValue &result)
10745 : ExprEvaluatorBaseTy(info), Result(result) {}
10746
10747 bool Success(const llvm::APInt &I, const Expr *E) {
10748 return Success(
10749 APFixedPoint(I, Info.Ctx.getFixedPointSemantics(E->getType())), E);
10750 }
10751
10752 bool Success(uint64_t Value, const Expr *E) {
10753 return Success(
10754 APFixedPoint(Value, Info.Ctx.getFixedPointSemantics(E->getType())), E);
10755 }
10756
10757 bool Success(const APValue &V, const Expr *E) {
10758 return Success(V.getFixedPoint(), E);
10759 }
10760
10761 bool Success(const APFixedPoint &V, const Expr *E) {
10762 assert(E->getType()->isFixedPointType() && "Invalid evaluation result.")((E->getType()->isFixedPointType() && "Invalid evaluation result."
) ? static_cast<void> (0) : __assert_fail ("E->getType()->isFixedPointType() && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10762, __PRETTY_FUNCTION__))
;
10763 assert(V.getWidth() == Info.Ctx.getIntWidth(E->getType()) &&((V.getWidth() == Info.Ctx.getIntWidth(E->getType()) &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("V.getWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10764, __PRETTY_FUNCTION__))
10764 "Invalid evaluation result.")((V.getWidth() == Info.Ctx.getIntWidth(E->getType()) &&
"Invalid evaluation result.") ? static_cast<void> (0) :
__assert_fail ("V.getWidth() == Info.Ctx.getIntWidth(E->getType()) && \"Invalid evaluation result.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10764, __PRETTY_FUNCTION__))
;
10765 Result = APValue(V);
10766 return true;
10767 }
10768
10769 //===--------------------------------------------------------------------===//
10770 // Visitor Methods
10771 //===--------------------------------------------------------------------===//
10772
10773 bool VisitFixedPointLiteral(const FixedPointLiteral *E) {
10774 return Success(E->getValue(), E);
10775 }
10776
10777 bool VisitCastExpr(const CastExpr *E);
10778 bool VisitUnaryOperator(const UnaryOperator *E);
10779 bool VisitBinaryOperator(const BinaryOperator *E);
10780};
10781} // end anonymous namespace
10782
10783/// EvaluateIntegerOrLValue - Evaluate an rvalue integral-typed expression, and
10784/// produce either the integer value or a pointer.
10785///
10786/// GCC has a heinous extension which folds casts between pointer types and
10787/// pointer-sized integral types. We support this by allowing the evaluation of
10788/// an integer rvalue to produce a pointer (represented as an lvalue) instead.
10789/// Some simple arithmetic on such values is supported (they are treated much
10790/// like char*).
10791static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
10792 EvalInfo &Info) {
10793 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10793, __PRETTY_FUNCTION__))
;
10794 assert(E->isRValue() && E->getType()->isIntegralOrEnumerationType())((E->isRValue() && E->getType()->isIntegralOrEnumerationType
()) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10794, __PRETTY_FUNCTION__))
;
10795 return IntExprEvaluator(Info, Result).Visit(E);
10796}
10797
10798static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info) {
10799 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10799, __PRETTY_FUNCTION__))
;
10800 APValue Val;
10801 if (!EvaluateIntegerOrLValue(E, Val, Info))
10802 return false;
10803 if (!Val.isInt()) {
10804 // FIXME: It would be better to produce the diagnostic for casting
10805 // a pointer to an integer.
10806 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
10807 return false;
10808 }
10809 Result = Val.getInt();
10810 return true;
10811}
10812
10813bool IntExprEvaluator::VisitSourceLocExpr(const SourceLocExpr *E) {
10814 APValue Evaluated = E->EvaluateInContext(
10815 Info.Ctx, Info.CurrentCall->CurSourceLocExprScope.getDefaultExpr());
10816 return Success(Evaluated, E);
10817}
10818
10819static bool EvaluateFixedPoint(const Expr *E, APFixedPoint &Result,
10820 EvalInfo &Info) {
10821 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10821, __PRETTY_FUNCTION__))
;
10822 if (E->getType()->isFixedPointType()) {
10823 APValue Val;
10824 if (!FixedPointExprEvaluator(Info, Val).Visit(E))
10825 return false;
10826 if (!Val.isFixedPoint())
10827 return false;
10828
10829 Result = Val.getFixedPoint();
10830 return true;
10831 }
10832 return false;
10833}
10834
10835static bool EvaluateFixedPointOrInteger(const Expr *E, APFixedPoint &Result,
10836 EvalInfo &Info) {
10837 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10837, __PRETTY_FUNCTION__))
;
10838 if (E->getType()->isIntegerType()) {
10839 auto FXSema = Info.Ctx.getFixedPointSemantics(E->getType());
10840 APSInt Val;
10841 if (!EvaluateInteger(E, Val, Info))
10842 return false;
10843 Result = APFixedPoint(Val, FXSema);
10844 return true;
10845 } else if (E->getType()->isFixedPointType()) {
10846 return EvaluateFixedPoint(E, Result, Info);
10847 }
10848 return false;
10849}
10850
10851/// Check whether the given declaration can be directly converted to an integral
10852/// rvalue. If not, no diagnostic is produced; there are other things we can
10853/// try.
10854bool IntExprEvaluator::CheckReferencedDecl(const Expr* E, const Decl* D) {
10855 // Enums are integer constant exprs.
10856 if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) {
10857 // Check for signedness/width mismatches between E type and ECD value.
10858 bool SameSign = (ECD->getInitVal().isSigned()
10859 == E->getType()->isSignedIntegerOrEnumerationType());
10860 bool SameWidth = (ECD->getInitVal().getBitWidth()
10861 == Info.Ctx.getIntWidth(E->getType()));
10862 if (SameSign && SameWidth)
10863 return Success(ECD->getInitVal(), E);
10864 else {
10865 // Get rid of mismatch (otherwise Success assertions will fail)
10866 // by computing a new value matching the type of E.
10867 llvm::APSInt Val = ECD->getInitVal();
10868 if (!SameSign)
10869 Val.setIsSigned(!ECD->getInitVal().isSigned());
10870 if (!SameWidth)
10871 Val = Val.extOrTrunc(Info.Ctx.getIntWidth(E->getType()));
10872 return Success(Val, E);
10873 }
10874 }
10875 return false;
10876}
10877
10878/// Values returned by __builtin_classify_type, chosen to match the values
10879/// produced by GCC's builtin.
10880enum class GCCTypeClass {
10881 None = -1,
10882 Void = 0,
10883 Integer = 1,
10884 // GCC reserves 2 for character types, but instead classifies them as
10885 // integers.
10886 Enum = 3,
10887 Bool = 4,
10888 Pointer = 5,
10889 // GCC reserves 6 for references, but appears to never use it (because
10890 // expressions never have reference type, presumably).
10891 PointerToDataMember = 7,
10892 RealFloat = 8,
10893 Complex = 9,
10894 // GCC reserves 10 for functions, but does not use it since GCC version 6 due
10895 // to decay to pointer. (Prior to version 6 it was only used in C++ mode).
10896 // GCC claims to reserve 11 for pointers to member functions, but *actually*
10897 // uses 12 for that purpose, same as for a class or struct. Maybe it
10898 // internally implements a pointer to member as a struct? Who knows.
10899 PointerToMemberFunction = 12, // Not a bug, see above.
10900 ClassOrStruct = 12,
10901 Union = 13,
10902 // GCC reserves 14 for arrays, but does not use it since GCC version 6 due to
10903 // decay to pointer. (Prior to version 6 it was only used in C++ mode).
10904 // GCC reserves 15 for strings, but actually uses 5 (pointer) for string
10905 // literals.
10906};
10907
10908/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
10909/// as GCC.
10910static GCCTypeClass
10911EvaluateBuiltinClassifyType(QualType T, const LangOptions &LangOpts) {
10912 assert(!T->isDependentType() && "unexpected dependent type")((!T->isDependentType() && "unexpected dependent type"
) ? static_cast<void> (0) : __assert_fail ("!T->isDependentType() && \"unexpected dependent type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10912, __PRETTY_FUNCTION__))
;
10913
10914 QualType CanTy = T.getCanonicalType();
10915 const BuiltinType *BT = dyn_cast<BuiltinType>(CanTy);
10916
10917 switch (CanTy->getTypeClass()) {
10918#define TYPE(ID, BASE)
10919#define DEPENDENT_TYPE(ID, BASE) case Type::ID:
10920#define NON_CANONICAL_TYPE(ID, BASE) case Type::ID:
10921#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(ID, BASE) case Type::ID:
10922#include "clang/AST/TypeNodes.inc"
10923 case Type::Auto:
10924 case Type::DeducedTemplateSpecialization:
10925 llvm_unreachable("unexpected non-canonical or dependent type")::llvm::llvm_unreachable_internal("unexpected non-canonical or dependent type"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10925)
;
10926
10927 case Type::Builtin:
10928 switch (BT->getKind()) {
10929#define BUILTIN_TYPE(ID, SINGLETON_ID)
10930#define SIGNED_TYPE(ID, SINGLETON_ID) \
10931 case BuiltinType::ID: return GCCTypeClass::Integer;
10932#define FLOATING_TYPE(ID, SINGLETON_ID) \
10933 case BuiltinType::ID: return GCCTypeClass::RealFloat;
10934#define PLACEHOLDER_TYPE(ID, SINGLETON_ID) \
10935 case BuiltinType::ID: break;
10936#include "clang/AST/BuiltinTypes.def"
10937 case BuiltinType::Void:
10938 return GCCTypeClass::Void;
10939
10940 case BuiltinType::Bool:
10941 return GCCTypeClass::Bool;
10942
10943 case BuiltinType::Char_U:
10944 case BuiltinType::UChar:
10945 case BuiltinType::WChar_U:
10946 case BuiltinType::Char8:
10947 case BuiltinType::Char16:
10948 case BuiltinType::Char32:
10949 case BuiltinType::UShort:
10950 case BuiltinType::UInt:
10951 case BuiltinType::ULong:
10952 case BuiltinType::ULongLong:
10953 case BuiltinType::UInt128:
10954 return GCCTypeClass::Integer;
10955
10956 case BuiltinType::UShortAccum:
10957 case BuiltinType::UAccum:
10958 case BuiltinType::ULongAccum:
10959 case BuiltinType::UShortFract:
10960 case BuiltinType::UFract:
10961 case BuiltinType::ULongFract:
10962 case BuiltinType::SatUShortAccum:
10963 case BuiltinType::SatUAccum:
10964 case BuiltinType::SatULongAccum:
10965 case BuiltinType::SatUShortFract:
10966 case BuiltinType::SatUFract:
10967 case BuiltinType::SatULongFract:
10968 return GCCTypeClass::None;
10969
10970 case BuiltinType::NullPtr:
10971
10972 case BuiltinType::ObjCId:
10973 case BuiltinType::ObjCClass:
10974 case BuiltinType::ObjCSel:
10975#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
10976 case BuiltinType::Id:
10977#include "clang/Basic/OpenCLImageTypes.def"
10978#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
10979 case BuiltinType::Id:
10980#include "clang/Basic/OpenCLExtensionTypes.def"
10981 case BuiltinType::OCLSampler:
10982 case BuiltinType::OCLEvent:
10983 case BuiltinType::OCLClkEvent:
10984 case BuiltinType::OCLQueue:
10985 case BuiltinType::OCLReserveID:
10986#define SVE_TYPE(Name, Id, SingletonId) \
10987 case BuiltinType::Id:
10988#include "clang/Basic/AArch64SVEACLETypes.def"
10989#define PPC_VECTOR_TYPE(Name, Id, Size) \
10990 case BuiltinType::Id:
10991#include "clang/Basic/PPCTypes.def"
10992#define RVV_TYPE(Name, Id, SingletonId) case BuiltinType::Id:
10993#include "clang/Basic/RISCVVTypes.def"
10994 return GCCTypeClass::None;
10995
10996 case BuiltinType::Dependent:
10997 llvm_unreachable("unexpected dependent type")::llvm::llvm_unreachable_internal("unexpected dependent type"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10997)
;
10998 };
10999 llvm_unreachable("unexpected placeholder type")::llvm::llvm_unreachable_internal("unexpected placeholder type"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 10999)
;
11000
11001 case Type::Enum:
11002 return LangOpts.CPlusPlus ? GCCTypeClass::Enum : GCCTypeClass::Integer;
11003
11004 case Type::Pointer:
11005 case Type::ConstantArray:
11006 case Type::VariableArray:
11007 case Type::IncompleteArray:
11008 case Type::FunctionNoProto:
11009 case Type::FunctionProto:
11010 return GCCTypeClass::Pointer;
11011
11012 case Type::MemberPointer:
11013 return CanTy->isMemberDataPointerType()
11014 ? GCCTypeClass::PointerToDataMember
11015 : GCCTypeClass::PointerToMemberFunction;
11016
11017 case Type::Complex:
11018 return GCCTypeClass::Complex;
11019
11020 case Type::Record:
11021 return CanTy->isUnionType() ? GCCTypeClass::Union
11022 : GCCTypeClass::ClassOrStruct;
11023
11024 case Type::Atomic:
11025 // GCC classifies _Atomic T the same as T.
11026 return EvaluateBuiltinClassifyType(
11027 CanTy->castAs<AtomicType>()->getValueType(), LangOpts);
11028
11029 case Type::BlockPointer:
11030 case Type::Vector:
11031 case Type::ExtVector:
11032 case Type::ConstantMatrix:
11033 case Type::ObjCObject:
11034 case Type::ObjCInterface:
11035 case Type::ObjCObjectPointer:
11036 case Type::Pipe:
11037 case Type::ExtInt:
11038 // GCC classifies vectors as None. We follow its lead and classify all
11039 // other types that don't fit into the regular classification the same way.
11040 return GCCTypeClass::None;
11041
11042 case Type::LValueReference:
11043 case Type::RValueReference:
11044 llvm_unreachable("invalid type for expression")::llvm::llvm_unreachable_internal("invalid type for expression"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11044)
;
11045 }
11046
11047 llvm_unreachable("unexpected type class")::llvm::llvm_unreachable_internal("unexpected type class", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11047)
;
11048}
11049
11050/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
11051/// as GCC.
11052static GCCTypeClass
11053EvaluateBuiltinClassifyType(const CallExpr *E, const LangOptions &LangOpts) {
11054 // If no argument was supplied, default to None. This isn't
11055 // ideal, however it is what gcc does.
11056 if (E->getNumArgs() == 0)
11057 return GCCTypeClass::None;
11058
11059 // FIXME: Bizarrely, GCC treats a call with more than one argument as not
11060 // being an ICE, but still folds it to a constant using the type of the first
11061 // argument.
11062 return EvaluateBuiltinClassifyType(E->getArg(0)->getType(), LangOpts);
11063}
11064
11065/// EvaluateBuiltinConstantPForLValue - Determine the result of
11066/// __builtin_constant_p when applied to the given pointer.
11067///
11068/// A pointer is only "constant" if it is null (or a pointer cast to integer)
11069/// or it points to the first character of a string literal.
11070static bool EvaluateBuiltinConstantPForLValue(const APValue &LV) {
11071 APValue::LValueBase Base = LV.getLValueBase();
11072 if (Base.isNull()) {
11073 // A null base is acceptable.
11074 return true;
11075 } else if (const Expr *E = Base.dyn_cast<const Expr *>()) {
11076 if (!isa<StringLiteral>(E))
11077 return false;
11078 return LV.getLValueOffset().isZero();
11079 } else if (Base.is<TypeInfoLValue>()) {
11080 // Surprisingly, GCC considers __builtin_constant_p(&typeid(int)) to
11081 // evaluate to true.
11082 return true;
11083 } else {
11084 // Any other base is not constant enough for GCC.
11085 return false;
11086 }
11087}
11088
11089/// EvaluateBuiltinConstantP - Evaluate __builtin_constant_p as similarly to
11090/// GCC as we can manage.
11091static bool EvaluateBuiltinConstantP(EvalInfo &Info, const Expr *Arg) {
11092 // This evaluation is not permitted to have side-effects, so evaluate it in
11093 // a speculative evaluation context.
11094 SpeculativeEvaluationRAII SpeculativeEval(Info);
11095
11096 // Constant-folding is always enabled for the operand of __builtin_constant_p
11097 // (even when the enclosing evaluation context otherwise requires a strict
11098 // language-specific constant expression).
11099 FoldConstant Fold(Info, true);
11100
11101 QualType ArgType = Arg->getType();
11102
11103 // __builtin_constant_p always has one operand. The rules which gcc follows
11104 // are not precisely documented, but are as follows:
11105 //
11106 // - If the operand is of integral, floating, complex or enumeration type,
11107 // and can be folded to a known value of that type, it returns 1.
11108 // - If the operand can be folded to a pointer to the first character
11109 // of a string literal (or such a pointer cast to an integral type)
11110 // or to a null pointer or an integer cast to a pointer, it returns 1.
11111 //
11112 // Otherwise, it returns 0.
11113 //
11114 // FIXME: GCC also intends to return 1 for literals of aggregate types, but
11115 // its support for this did not work prior to GCC 9 and is not yet well
11116 // understood.
11117 if (ArgType->isIntegralOrEnumerationType() || ArgType->isFloatingType() ||
11118 ArgType->isAnyComplexType() || ArgType->isPointerType() ||
11119 ArgType->isNullPtrType()) {
11120 APValue V;
11121 if (!::EvaluateAsRValue(Info, Arg, V) || Info.EvalStatus.HasSideEffects) {
11122 Fold.keepDiagnostics();
11123 return false;
11124 }
11125
11126 // For a pointer (possibly cast to integer), there are special rules.
11127 if (V.getKind() == APValue::LValue)
11128 return EvaluateBuiltinConstantPForLValue(V);
11129
11130 // Otherwise, any constant value is good enough.
11131 return V.hasValue();
11132 }
11133
11134 // Anything else isn't considered to be sufficiently constant.
11135 return false;
11136}
11137
11138/// Retrieves the "underlying object type" of the given expression,
11139/// as used by __builtin_object_size.
11140static QualType getObjectType(APValue::LValueBase B) {
11141 if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
11142 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
11143 return VD->getType();
11144 } else if (const Expr *E = B.dyn_cast<const Expr*>()) {
11145 if (isa<CompoundLiteralExpr>(E))
11146 return E->getType();
11147 } else if (B.is<TypeInfoLValue>()) {
11148 return B.getTypeInfoType();
11149 } else if (B.is<DynamicAllocLValue>()) {
11150 return B.getDynamicAllocType();
11151 }
11152
11153 return QualType();
11154}
11155
11156/// A more selective version of E->IgnoreParenCasts for
11157/// tryEvaluateBuiltinObjectSize. This ignores some casts/parens that serve only
11158/// to change the type of E.
11159/// Ex. For E = `(short*)((char*)(&foo))`, returns `&foo`
11160///
11161/// Always returns an RValue with a pointer representation.
11162static const Expr *ignorePointerCastsAndParens(const Expr *E) {
11163 assert(E->isRValue() && E->getType()->hasPointerRepresentation())((E->isRValue() && E->getType()->hasPointerRepresentation
()) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->hasPointerRepresentation()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11163, __PRETTY_FUNCTION__))
;
11164
11165 auto *NoParens = E->IgnoreParens();
11166 auto *Cast = dyn_cast<CastExpr>(NoParens);
11167 if (Cast == nullptr)
11168 return NoParens;
11169
11170 // We only conservatively allow a few kinds of casts, because this code is
11171 // inherently a simple solution that seeks to support the common case.
11172 auto CastKind = Cast->getCastKind();
11173 if (CastKind != CK_NoOp && CastKind != CK_BitCast &&
11174 CastKind != CK_AddressSpaceConversion)
11175 return NoParens;
11176
11177 auto *SubExpr = Cast->getSubExpr();
11178 if (!SubExpr->getType()->hasPointerRepresentation() || !SubExpr->isRValue())
11179 return NoParens;
11180 return ignorePointerCastsAndParens(SubExpr);
11181}
11182
11183/// Checks to see if the given LValue's Designator is at the end of the LValue's
11184/// record layout. e.g.
11185/// struct { struct { int a, b; } fst, snd; } obj;
11186/// obj.fst // no
11187/// obj.snd // yes
11188/// obj.fst.a // no
11189/// obj.fst.b // no
11190/// obj.snd.a // no
11191/// obj.snd.b // yes
11192///
11193/// Please note: this function is specialized for how __builtin_object_size
11194/// views "objects".
11195///
11196/// If this encounters an invalid RecordDecl or otherwise cannot determine the
11197/// correct result, it will always return true.
11198static bool isDesignatorAtObjectEnd(const ASTContext &Ctx, const LValue &LVal) {
11199 assert(!LVal.Designator.Invalid)((!LVal.Designator.Invalid) ? static_cast<void> (0) : __assert_fail
("!LVal.Designator.Invalid", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11199, __PRETTY_FUNCTION__))
;
11200
11201 auto IsLastOrInvalidFieldDecl = [&Ctx](const FieldDecl *FD, bool &Invalid) {
11202 const RecordDecl *Parent = FD->getParent();
11203 Invalid = Parent->isInvalidDecl();
11204 if (Invalid || Parent->isUnion())
11205 return true;
11206 const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(Parent);
11207 return FD->getFieldIndex() + 1 == Layout.getFieldCount();
11208 };
11209
11210 auto &Base = LVal.getLValueBase();
11211 if (auto *ME = dyn_cast_or_null<MemberExpr>(Base.dyn_cast<const Expr *>())) {
11212 if (auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
11213 bool Invalid;
11214 if (!IsLastOrInvalidFieldDecl(FD, Invalid))
11215 return Invalid;
11216 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(ME->getMemberDecl())) {
11217 for (auto *FD : IFD->chain()) {
11218 bool Invalid;
11219 if (!IsLastOrInvalidFieldDecl(cast<FieldDecl>(FD), Invalid))
11220 return Invalid;
11221 }
11222 }
11223 }
11224
11225 unsigned I = 0;
11226 QualType BaseType = getType(Base);
11227 if (LVal.Designator.FirstEntryIsAnUnsizedArray) {
11228 // If we don't know the array bound, conservatively assume we're looking at
11229 // the final array element.
11230 ++I;
11231 if (BaseType->isIncompleteArrayType())
11232 BaseType = Ctx.getAsArrayType(BaseType)->getElementType();
11233 else
11234 BaseType = BaseType->castAs<PointerType>()->getPointeeType();
11235 }
11236
11237 for (unsigned E = LVal.Designator.Entries.size(); I != E; ++I) {
11238 const auto &Entry = LVal.Designator.Entries[I];
11239 if (BaseType->isArrayType()) {
11240 // Because __builtin_object_size treats arrays as objects, we can ignore
11241 // the index iff this is the last array in the Designator.
11242 if (I + 1 == E)
11243 return true;
11244 const auto *CAT = cast<ConstantArrayType>(Ctx.getAsArrayType(BaseType));
11245 uint64_t Index = Entry.getAsArrayIndex();
11246 if (Index + 1 != CAT->getSize())
11247 return false;
11248 BaseType = CAT->getElementType();
11249 } else if (BaseType->isAnyComplexType()) {
11250 const auto *CT = BaseType->castAs<ComplexType>();
11251 uint64_t Index = Entry.getAsArrayIndex();
11252 if (Index != 1)
11253 return false;
11254 BaseType = CT->getElementType();
11255 } else if (auto *FD = getAsField(Entry)) {
11256 bool Invalid;
11257 if (!IsLastOrInvalidFieldDecl(FD, Invalid))
11258 return Invalid;
11259 BaseType = FD->getType();
11260 } else {
11261 assert(getAsBaseClass(Entry) && "Expecting cast to a base class")((getAsBaseClass(Entry) && "Expecting cast to a base class"
) ? static_cast<void> (0) : __assert_fail ("getAsBaseClass(Entry) && \"Expecting cast to a base class\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11261, __PRETTY_FUNCTION__))
;
11262 return false;
11263 }
11264 }
11265 return true;
11266}
11267
11268/// Tests to see if the LValue has a user-specified designator (that isn't
11269/// necessarily valid). Note that this always returns 'true' if the LValue has
11270/// an unsized array as its first designator entry, because there's currently no
11271/// way to tell if the user typed *foo or foo[0].
11272static bool refersToCompleteObject(const LValue &LVal) {
11273 if (LVal.Designator.Invalid)
11274 return false;
11275
11276 if (!LVal.Designator.Entries.empty())
11277 return LVal.Designator.isMostDerivedAnUnsizedArray();
11278
11279 if (!LVal.InvalidBase)
11280 return true;
11281
11282 // If `E` is a MemberExpr, then the first part of the designator is hiding in
11283 // the LValueBase.
11284 const auto *E = LVal.Base.dyn_cast<const Expr *>();
11285 return !E || !isa<MemberExpr>(E);
11286}
11287
11288/// Attempts to detect a user writing into a piece of memory that's impossible
11289/// to figure out the size of by just using types.
11290static bool isUserWritingOffTheEnd(const ASTContext &Ctx, const LValue &LVal) {
11291 const SubobjectDesignator &Designator = LVal.Designator;
11292 // Notes:
11293 // - Users can only write off of the end when we have an invalid base. Invalid
11294 // bases imply we don't know where the memory came from.
11295 // - We used to be a bit more aggressive here; we'd only be conservative if
11296 // the array at the end was flexible, or if it had 0 or 1 elements. This
11297 // broke some common standard library extensions (PR30346), but was
11298 // otherwise seemingly fine. It may be useful to reintroduce this behavior
11299 // with some sort of list. OTOH, it seems that GCC is always
11300 // conservative with the last element in structs (if it's an array), so our
11301 // current behavior is more compatible than an explicit list approach would
11302 // be.
11303 return LVal.InvalidBase &&
11304 Designator.Entries.size() == Designator.MostDerivedPathLength &&
11305 Designator.MostDerivedIsArrayElement &&
11306 isDesignatorAtObjectEnd(Ctx, LVal);
11307}
11308
11309/// Converts the given APInt to CharUnits, assuming the APInt is unsigned.
11310/// Fails if the conversion would cause loss of precision.
11311static bool convertUnsignedAPIntToCharUnits(const llvm::APInt &Int,
11312 CharUnits &Result) {
11313 auto CharUnitsMax = std::numeric_limits<CharUnits::QuantityType>::max();
11314 if (Int.ugt(CharUnitsMax))
11315 return false;
11316 Result = CharUnits::fromQuantity(Int.getZExtValue());
11317 return true;
11318}
11319
11320/// Helper for tryEvaluateBuiltinObjectSize -- Given an LValue, this will
11321/// determine how many bytes exist from the beginning of the object to either
11322/// the end of the current subobject, or the end of the object itself, depending
11323/// on what the LValue looks like + the value of Type.
11324///
11325/// If this returns false, the value of Result is undefined.
11326static bool determineEndOffset(EvalInfo &Info, SourceLocation ExprLoc,
11327 unsigned Type, const LValue &LVal,
11328 CharUnits &EndOffset) {
11329 bool DetermineForCompleteObject = refersToCompleteObject(LVal);
11330
11331 auto CheckedHandleSizeof = [&](QualType Ty, CharUnits &Result) {
11332 if (Ty.isNull() || Ty->isIncompleteType() || Ty->isFunctionType())
11333 return false;
11334 return HandleSizeof(Info, ExprLoc, Ty, Result);
11335 };
11336
11337 // We want to evaluate the size of the entire object. This is a valid fallback
11338 // for when Type=1 and the designator is invalid, because we're asked for an
11339 // upper-bound.
11340 if (!(Type & 1) || LVal.Designator.Invalid || DetermineForCompleteObject) {
11341 // Type=3 wants a lower bound, so we can't fall back to this.
11342 if (Type == 3 && !DetermineForCompleteObject)
11343 return false;
11344
11345 llvm::APInt APEndOffset;
11346 if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
11347 getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
11348 return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
11349
11350 if (LVal.InvalidBase)
11351 return false;
11352
11353 QualType BaseTy = getObjectType(LVal.getLValueBase());
11354 return CheckedHandleSizeof(BaseTy, EndOffset);
11355 }
11356
11357 // We want to evaluate the size of a subobject.
11358 const SubobjectDesignator &Designator = LVal.Designator;
11359
11360 // The following is a moderately common idiom in C:
11361 //
11362 // struct Foo { int a; char c[1]; };
11363 // struct Foo *F = (struct Foo *)malloc(sizeof(struct Foo) + strlen(Bar));
11364 // strcpy(&F->c[0], Bar);
11365 //
11366 // In order to not break too much legacy code, we need to support it.
11367 if (isUserWritingOffTheEnd(Info.Ctx, LVal)) {
11368 // If we can resolve this to an alloc_size call, we can hand that back,
11369 // because we know for certain how many bytes there are to write to.
11370 llvm::APInt APEndOffset;
11371 if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
11372 getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
11373 return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
11374
11375 // If we cannot determine the size of the initial allocation, then we can't
11376 // given an accurate upper-bound. However, we are still able to give
11377 // conservative lower-bounds for Type=3.
11378 if (Type == 1)
11379 return false;
11380 }
11381
11382 CharUnits BytesPerElem;
11383 if (!CheckedHandleSizeof(Designator.MostDerivedType, BytesPerElem))
11384 return false;
11385
11386 // According to the GCC documentation, we want the size of the subobject
11387 // denoted by the pointer. But that's not quite right -- what we actually
11388 // want is the size of the immediately-enclosing array, if there is one.
11389 int64_t ElemsRemaining;
11390 if (Designator.MostDerivedIsArrayElement &&
11391 Designator.Entries.size() == Designator.MostDerivedPathLength) {
11392 uint64_t ArraySize = Designator.getMostDerivedArraySize();
11393 uint64_t ArrayIndex = Designator.Entries.back().getAsArrayIndex();
11394 ElemsRemaining = ArraySize <= ArrayIndex ? 0 : ArraySize - ArrayIndex;
11395 } else {
11396 ElemsRemaining = Designator.isOnePastTheEnd() ? 0 : 1;
11397 }
11398
11399 EndOffset = LVal.getLValueOffset() + BytesPerElem * ElemsRemaining;
11400 return true;
11401}
11402
11403/// Tries to evaluate the __builtin_object_size for @p E. If successful,
11404/// returns true and stores the result in @p Size.
11405///
11406/// If @p WasError is non-null, this will report whether the failure to evaluate
11407/// is to be treated as an Error in IntExprEvaluator.
11408static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
11409 EvalInfo &Info, uint64_t &Size) {
11410 // Determine the denoted object.
11411 LValue LVal;
11412 {
11413 // The operand of __builtin_object_size is never evaluated for side-effects.
11414 // If there are any, but we can determine the pointed-to object anyway, then
11415 // ignore the side-effects.
11416 SpeculativeEvaluationRAII SpeculativeEval(Info);
11417 IgnoreSideEffectsRAII Fold(Info);
11418
11419 if (E->isGLValue()) {
11420 // It's possible for us to be given GLValues if we're called via
11421 // Expr::tryEvaluateObjectSize.
11422 APValue RVal;
11423 if (!EvaluateAsRValue(Info, E, RVal))
11424 return false;
11425 LVal.setFrom(Info.Ctx, RVal);
11426 } else if (!EvaluatePointer(ignorePointerCastsAndParens(E), LVal, Info,
11427 /*InvalidBaseOK=*/true))
11428 return false;
11429 }
11430
11431 // If we point to before the start of the object, there are no accessible
11432 // bytes.
11433 if (LVal.getLValueOffset().isNegative()) {
11434 Size = 0;
11435 return true;
11436 }
11437
11438 CharUnits EndOffset;
11439 if (!determineEndOffset(Info, E->getExprLoc(), Type, LVal, EndOffset))
11440 return false;
11441
11442 // If we've fallen outside of the end offset, just pretend there's nothing to
11443 // write to/read from.
11444 if (EndOffset <= LVal.getLValueOffset())
11445 Size = 0;
11446 else
11447 Size = (EndOffset - LVal.getLValueOffset()).getQuantity();
11448 return true;
11449}
11450
11451bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
11452 if (unsigned BuiltinOp = E->getBuiltinCallee())
11453 return VisitBuiltinCallExpr(E, BuiltinOp);
11454
11455 return ExprEvaluatorBaseTy::VisitCallExpr(E);
11456}
11457
11458static bool getBuiltinAlignArguments(const CallExpr *E, EvalInfo &Info,
11459 APValue &Val, APSInt &Alignment) {
11460 QualType SrcTy = E->getArg(0)->getType();
11461 if (!getAlignmentArgument(E->getArg(1), SrcTy, Info, Alignment))
11462 return false;
11463 // Even though we are evaluating integer expressions we could get a pointer
11464 // argument for the __builtin_is_aligned() case.
11465 if (SrcTy->isPointerType()) {
11466 LValue Ptr;
11467 if (!EvaluatePointer(E->getArg(0), Ptr, Info))
11468 return false;
11469 Ptr.moveInto(Val);
11470 } else if (!SrcTy->isIntegralOrEnumerationType()) {
11471 Info.FFDiag(E->getArg(0));
11472 return false;
11473 } else {
11474 APSInt SrcInt;
11475 if (!EvaluateInteger(E->getArg(0), SrcInt, Info))
11476 return false;
11477 assert(SrcInt.getBitWidth() >= Alignment.getBitWidth() &&((SrcInt.getBitWidth() >= Alignment.getBitWidth() &&
"Bit widths must be the same") ? static_cast<void> (0)
: __assert_fail ("SrcInt.getBitWidth() >= Alignment.getBitWidth() && \"Bit widths must be the same\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11478, __PRETTY_FUNCTION__))
11478 "Bit widths must be the same")((SrcInt.getBitWidth() >= Alignment.getBitWidth() &&
"Bit widths must be the same") ? static_cast<void> (0)
: __assert_fail ("SrcInt.getBitWidth() >= Alignment.getBitWidth() && \"Bit widths must be the same\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11478, __PRETTY_FUNCTION__))
;
11479 Val = APValue(SrcInt);
11480 }
11481 assert(Val.hasValue())((Val.hasValue()) ? static_cast<void> (0) : __assert_fail
("Val.hasValue()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11481, __PRETTY_FUNCTION__))
;
11482 return true;
11483}
11484
11485bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
11486 unsigned BuiltinOp) {
11487 switch (BuiltinOp) {
11488 default:
11489 return ExprEvaluatorBaseTy::VisitCallExpr(E);
11490
11491 case Builtin::BI__builtin_dynamic_object_size:
11492 case Builtin::BI__builtin_object_size: {
11493 // The type was checked when we built the expression.
11494 unsigned Type =
11495 E->getArg(1)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
11496 assert(Type <= 3 && "unexpected type")((Type <= 3 && "unexpected type") ? static_cast<
void> (0) : __assert_fail ("Type <= 3 && \"unexpected type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11496, __PRETTY_FUNCTION__))
;
11497
11498 uint64_t Size;
11499 if (tryEvaluateBuiltinObjectSize(E->getArg(0), Type, Info, Size))
11500 return Success(Size, E);
11501
11502 if (E->getArg(0)->HasSideEffects(Info.Ctx))
11503 return Success((Type & 2) ? 0 : -1, E);
11504
11505 // Expression had no side effects, but we couldn't statically determine the
11506 // size of the referenced object.
11507 switch (Info.EvalMode) {
11508 case EvalInfo::EM_ConstantExpression:
11509 case EvalInfo::EM_ConstantFold:
11510 case EvalInfo::EM_IgnoreSideEffects:
11511 // Leave it to IR generation.
11512 return Error(E);
11513 case EvalInfo::EM_ConstantExpressionUnevaluated:
11514 // Reduce it to a constant now.
11515 return Success((Type & 2) ? 0 : -1, E);
11516 }
11517
11518 llvm_unreachable("unexpected EvalMode")::llvm::llvm_unreachable_internal("unexpected EvalMode", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11518)
;
11519 }
11520
11521 case Builtin::BI__builtin_os_log_format_buffer_size: {
11522 analyze_os_log::OSLogBufferLayout Layout;
11523 analyze_os_log::computeOSLogBufferLayout(Info.Ctx, E, Layout);
11524 return Success(Layout.size().getQuantity(), E);
11525 }
11526
11527 case Builtin::BI__builtin_is_aligned: {
11528 APValue Src;
11529 APSInt Alignment;
11530 if (!getBuiltinAlignArguments(E, Info, Src, Alignment))
11531 return false;
11532 if (Src.isLValue()) {
11533 // If we evaluated a pointer, check the minimum known alignment.
11534 LValue Ptr;
11535 Ptr.setFrom(Info.Ctx, Src);
11536 CharUnits BaseAlignment = getBaseAlignment(Info, Ptr);
11537 CharUnits PtrAlign = BaseAlignment.alignmentAtOffset(Ptr.Offset);
11538 // We can return true if the known alignment at the computed offset is
11539 // greater than the requested alignment.
11540 assert(PtrAlign.isPowerOfTwo())((PtrAlign.isPowerOfTwo()) ? static_cast<void> (0) : __assert_fail
("PtrAlign.isPowerOfTwo()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11540, __PRETTY_FUNCTION__))
;
11541 assert(Alignment.isPowerOf2())((Alignment.isPowerOf2()) ? static_cast<void> (0) : __assert_fail
("Alignment.isPowerOf2()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11541, __PRETTY_FUNCTION__))
;
11542 if (PtrAlign.getQuantity() >= Alignment)
11543 return Success(1, E);
11544 // If the alignment is not known to be sufficient, some cases could still
11545 // be aligned at run time. However, if the requested alignment is less or
11546 // equal to the base alignment and the offset is not aligned, we know that
11547 // the run-time value can never be aligned.
11548 if (BaseAlignment.getQuantity() >= Alignment &&
11549 PtrAlign.getQuantity() < Alignment)
11550 return Success(0, E);
11551 // Otherwise we can't infer whether the value is sufficiently aligned.
11552 // TODO: __builtin_is_aligned(__builtin_align_{down,up{(expr, N), N)
11553 // in cases where we can't fully evaluate the pointer.
11554 Info.FFDiag(E->getArg(0), diag::note_constexpr_alignment_compute)
11555 << Alignment;
11556 return false;
11557 }
11558 assert(Src.isInt())((Src.isInt()) ? static_cast<void> (0) : __assert_fail (
"Src.isInt()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11558, __PRETTY_FUNCTION__))
;
11559 return Success((Src.getInt() & (Alignment - 1)) == 0 ? 1 : 0, E);
11560 }
11561 case Builtin::BI__builtin_align_up: {
11562 APValue Src;
11563 APSInt Alignment;
11564 if (!getBuiltinAlignArguments(E, Info, Src, Alignment))
11565 return false;
11566 if (!Src.isInt())
11567 return Error(E);
11568 APSInt AlignedVal =
11569 APSInt((Src.getInt() + (Alignment - 1)) & ~(Alignment - 1),
11570 Src.getInt().isUnsigned());
11571 assert(AlignedVal.getBitWidth() == Src.getInt().getBitWidth())((AlignedVal.getBitWidth() == Src.getInt().getBitWidth()) ? static_cast
<void> (0) : __assert_fail ("AlignedVal.getBitWidth() == Src.getInt().getBitWidth()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11571, __PRETTY_FUNCTION__))
;
11572 return Success(AlignedVal, E);
11573 }
11574 case Builtin::BI__builtin_align_down: {
11575 APValue Src;
11576 APSInt Alignment;
11577 if (!getBuiltinAlignArguments(E, Info, Src, Alignment))
11578 return false;
11579 if (!Src.isInt())
11580 return Error(E);
11581 APSInt AlignedVal =
11582 APSInt(Src.getInt() & ~(Alignment - 1), Src.getInt().isUnsigned());
11583 assert(AlignedVal.getBitWidth() == Src.getInt().getBitWidth())((AlignedVal.getBitWidth() == Src.getInt().getBitWidth()) ? static_cast
<void> (0) : __assert_fail ("AlignedVal.getBitWidth() == Src.getInt().getBitWidth()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11583, __PRETTY_FUNCTION__))
;
11584 return Success(AlignedVal, E);
11585 }
11586
11587 case Builtin::BI__builtin_bitreverse8:
11588 case Builtin::BI__builtin_bitreverse16:
11589 case Builtin::BI__builtin_bitreverse32:
11590 case Builtin::BI__builtin_bitreverse64: {
11591 APSInt Val;
11592 if (!EvaluateInteger(E->getArg(0), Val, Info))
11593 return false;
11594
11595 return Success(Val.reverseBits(), E);
11596 }
11597
11598 case Builtin::BI__builtin_bswap16:
11599 case Builtin::BI__builtin_bswap32:
11600 case Builtin::BI__builtin_bswap64: {
11601 APSInt Val;
11602 if (!EvaluateInteger(E->getArg(0), Val, Info))
11603 return false;
11604
11605 return Success(Val.byteSwap(), E);
11606 }
11607
11608 case Builtin::BI__builtin_classify_type:
11609 return Success((int)EvaluateBuiltinClassifyType(E, Info.getLangOpts()), E);
11610
11611 case Builtin::BI__builtin_clrsb:
11612 case Builtin::BI__builtin_clrsbl:
11613 case Builtin::BI__builtin_clrsbll: {
11614 APSInt Val;
11615 if (!EvaluateInteger(E->getArg(0), Val, Info))
11616 return false;
11617
11618 return Success(Val.getBitWidth() - Val.getMinSignedBits(), E);
11619 }
11620
11621 case Builtin::BI__builtin_clz:
11622 case Builtin::BI__builtin_clzl:
11623 case Builtin::BI__builtin_clzll:
11624 case Builtin::BI__builtin_clzs: {
11625 APSInt Val;
11626 if (!EvaluateInteger(E->getArg(0), Val, Info))
11627 return false;
11628 if (!Val)
11629 return Error(E);
11630
11631 return Success(Val.countLeadingZeros(), E);
11632 }
11633
11634 case Builtin::BI__builtin_constant_p: {
11635 const Expr *Arg = E->getArg(0);
11636 if (EvaluateBuiltinConstantP(Info, Arg))
11637 return Success(true, E);
11638 if (Info.InConstantContext || Arg->HasSideEffects(Info.Ctx)) {
11639 // Outside a constant context, eagerly evaluate to false in the presence
11640 // of side-effects in order to avoid -Wunsequenced false-positives in
11641 // a branch on __builtin_constant_p(expr).
11642 return Success(false, E);
11643 }
11644 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
11645 return false;
11646 }
11647
11648 case Builtin::BI__builtin_is_constant_evaluated: {
11649 const auto *Callee = Info.CurrentCall->getCallee();
11650 if (Info.InConstantContext && !Info.CheckingPotentialConstantExpression &&
11651 (Info.CallStackDepth == 1 ||
11652 (Info.CallStackDepth == 2 && Callee->isInStdNamespace() &&
11653 Callee->getIdentifier() &&
11654 Callee->getIdentifier()->isStr("is_constant_evaluated")))) {
11655 // FIXME: Find a better way to avoid duplicated diagnostics.
11656 if (Info.EvalStatus.Diag)
11657 Info.report((Info.CallStackDepth == 1) ? E->getExprLoc()
11658 : Info.CurrentCall->CallLoc,
11659 diag::warn_is_constant_evaluated_always_true_constexpr)
11660 << (Info.CallStackDepth == 1 ? "__builtin_is_constant_evaluated"
11661 : "std::is_constant_evaluated");
11662 }
11663
11664 return Success(Info.InConstantContext, E);
11665 }
11666
11667 case Builtin::BI__builtin_ctz:
11668 case Builtin::BI__builtin_ctzl:
11669 case Builtin::BI__builtin_ctzll:
11670 case Builtin::BI__builtin_ctzs: {
11671 APSInt Val;
11672 if (!EvaluateInteger(E->getArg(0), Val, Info))
11673 return false;
11674 if (!Val)
11675 return Error(E);
11676
11677 return Success(Val.countTrailingZeros(), E);
11678 }
11679
11680 case Builtin::BI__builtin_eh_return_data_regno: {
11681 int Operand = E->getArg(0)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
11682 Operand = Info.Ctx.getTargetInfo().getEHDataRegisterNumber(Operand);
11683 return Success(Operand, E);
11684 }
11685
11686 case Builtin::BI__builtin_expect:
11687 case Builtin::BI__builtin_expect_with_probability:
11688 return Visit(E->getArg(0));
11689
11690 case Builtin::BI__builtin_ffs:
11691 case Builtin::BI__builtin_ffsl:
11692 case Builtin::BI__builtin_ffsll: {
11693 APSInt Val;
11694 if (!EvaluateInteger(E->getArg(0), Val, Info))
11695 return false;
11696
11697 unsigned N = Val.countTrailingZeros();
11698 return Success(N == Val.getBitWidth() ? 0 : N + 1, E);
11699 }
11700
11701 case Builtin::BI__builtin_fpclassify: {
11702 APFloat Val(0.0);
11703 if (!EvaluateFloat(E->getArg(5), Val, Info))
11704 return false;
11705 unsigned Arg;
11706 switch (Val.getCategory()) {
11707 case APFloat::fcNaN: Arg = 0; break;
11708 case APFloat::fcInfinity: Arg = 1; break;
11709 case APFloat::fcNormal: Arg = Val.isDenormal() ? 3 : 2; break;
11710 case APFloat::fcZero: Arg = 4; break;
11711 }
11712 return Visit(E->getArg(Arg));
11713 }
11714
11715 case Builtin::BI__builtin_isinf_sign: {
11716 APFloat Val(0.0);
11717 return EvaluateFloat(E->getArg(0), Val, Info) &&
11718 Success(Val.isInfinity() ? (Val.isNegative() ? -1 : 1) : 0, E);
11719 }
11720
11721 case Builtin::BI__builtin_isinf: {
11722 APFloat Val(0.0);
11723 return EvaluateFloat(E->getArg(0), Val, Info) &&
11724 Success(Val.isInfinity() ? 1 : 0, E);
11725 }
11726
11727 case Builtin::BI__builtin_isfinite: {
11728 APFloat Val(0.0);
11729 return EvaluateFloat(E->getArg(0), Val, Info) &&
11730 Success(Val.isFinite() ? 1 : 0, E);
11731 }
11732
11733 case Builtin::BI__builtin_isnan: {
11734 APFloat Val(0.0);
11735 return EvaluateFloat(E->getArg(0), Val, Info) &&
11736 Success(Val.isNaN() ? 1 : 0, E);
11737 }
11738
11739 case Builtin::BI__builtin_isnormal: {
11740 APFloat Val(0.0);
11741 return EvaluateFloat(E->getArg(0), Val, Info) &&
11742 Success(Val.isNormal() ? 1 : 0, E);
11743 }
11744
11745 case Builtin::BI__builtin_parity:
11746 case Builtin::BI__builtin_parityl:
11747 case Builtin::BI__builtin_parityll: {
11748 APSInt Val;
11749 if (!EvaluateInteger(E->getArg(0), Val, Info))
11750 return false;
11751
11752 return Success(Val.countPopulation() % 2, E);
11753 }
11754
11755 case Builtin::BI__builtin_popcount:
11756 case Builtin::BI__builtin_popcountl:
11757 case Builtin::BI__builtin_popcountll: {
11758 APSInt Val;
11759 if (!EvaluateInteger(E->getArg(0), Val, Info))
11760 return false;
11761
11762 return Success(Val.countPopulation(), E);
11763 }
11764
11765 case Builtin::BI__builtin_rotateleft8:
11766 case Builtin::BI__builtin_rotateleft16:
11767 case Builtin::BI__builtin_rotateleft32:
11768 case Builtin::BI__builtin_rotateleft64:
11769 case Builtin::BI_rotl8: // Microsoft variants of rotate right
11770 case Builtin::BI_rotl16:
11771 case Builtin::BI_rotl:
11772 case Builtin::BI_lrotl:
11773 case Builtin::BI_rotl64: {
11774 APSInt Val, Amt;
11775 if (!EvaluateInteger(E->getArg(0), Val, Info) ||
11776 !EvaluateInteger(E->getArg(1), Amt, Info))
11777 return false;
11778
11779 return Success(Val.rotl(Amt.urem(Val.getBitWidth())), E);
11780 }
11781
11782 case Builtin::BI__builtin_rotateright8:
11783 case Builtin::BI__builtin_rotateright16:
11784 case Builtin::BI__builtin_rotateright32:
11785 case Builtin::BI__builtin_rotateright64:
11786 case Builtin::BI_rotr8: // Microsoft variants of rotate right
11787 case Builtin::BI_rotr16:
11788 case Builtin::BI_rotr:
11789 case Builtin::BI_lrotr:
11790 case Builtin::BI_rotr64: {
11791 APSInt Val, Amt;
11792 if (!EvaluateInteger(E->getArg(0), Val, Info) ||
11793 !EvaluateInteger(E->getArg(1), Amt, Info))
11794 return false;
11795
11796 return Success(Val.rotr(Amt.urem(Val.getBitWidth())), E);
11797 }
11798
11799 case Builtin::BIstrlen:
11800 case Builtin::BIwcslen:
11801 // A call to strlen is not a constant expression.
11802 if (Info.getLangOpts().CPlusPlus11)
11803 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
11804 << /*isConstexpr*/0 << /*isConstructor*/0
11805 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
11806 else
11807 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
11808 LLVM_FALLTHROUGH[[gnu::fallthrough]];
11809 case Builtin::BI__builtin_strlen:
11810 case Builtin::BI__builtin_wcslen: {
11811 // As an extension, we support __builtin_strlen() as a constant expression,
11812 // and support folding strlen() to a constant.
11813 LValue String;
11814 if (!EvaluatePointer(E->getArg(0), String, Info))
11815 return false;
11816
11817 QualType CharTy = E->getArg(0)->getType()->getPointeeType();
11818
11819 // Fast path: if it's a string literal, search the string value.
11820 if (const StringLiteral *S = dyn_cast_or_null<StringLiteral>(
11821 String.getLValueBase().dyn_cast<const Expr *>())) {
11822 // The string literal may have embedded null characters. Find the first
11823 // one and truncate there.
11824 StringRef Str = S->getBytes();
11825 int64_t Off = String.Offset.getQuantity();
11826 if (Off >= 0 && (uint64_t)Off <= (uint64_t)Str.size() &&
11827 S->getCharByteWidth() == 1 &&
11828 // FIXME: Add fast-path for wchar_t too.
11829 Info.Ctx.hasSameUnqualifiedType(CharTy, Info.Ctx.CharTy)) {
11830 Str = Str.substr(Off);
11831
11832 StringRef::size_type Pos = Str.find(0);
11833 if (Pos != StringRef::npos)
11834 Str = Str.substr(0, Pos);
11835
11836 return Success(Str.size(), E);
11837 }
11838
11839 // Fall through to slow path to issue appropriate diagnostic.
11840 }
11841
11842 // Slow path: scan the bytes of the string looking for the terminating 0.
11843 for (uint64_t Strlen = 0; /**/; ++Strlen) {
11844 APValue Char;
11845 if (!handleLValueToRValueConversion(Info, E, CharTy, String, Char) ||
11846 !Char.isInt())
11847 return false;
11848 if (!Char.getInt())
11849 return Success(Strlen, E);
11850 if (!HandleLValueArrayAdjustment(Info, E, String, CharTy, 1))
11851 return false;
11852 }
11853 }
11854
11855 case Builtin::BIstrcmp:
11856 case Builtin::BIwcscmp:
11857 case Builtin::BIstrncmp:
11858 case Builtin::BIwcsncmp:
11859 case Builtin::BImemcmp:
11860 case Builtin::BIbcmp:
11861 case Builtin::BIwmemcmp:
11862 // A call to strlen is not a constant expression.
11863 if (Info.getLangOpts().CPlusPlus11)
11864 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
11865 << /*isConstexpr*/0 << /*isConstructor*/0
11866 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
11867 else
11868 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
11869 LLVM_FALLTHROUGH[[gnu::fallthrough]];
11870 case Builtin::BI__builtin_strcmp:
11871 case Builtin::BI__builtin_wcscmp:
11872 case Builtin::BI__builtin_strncmp:
11873 case Builtin::BI__builtin_wcsncmp:
11874 case Builtin::BI__builtin_memcmp:
11875 case Builtin::BI__builtin_bcmp:
11876 case Builtin::BI__builtin_wmemcmp: {
11877 LValue String1, String2;
11878 if (!EvaluatePointer(E->getArg(0), String1, Info) ||
11879 !EvaluatePointer(E->getArg(1), String2, Info))
11880 return false;
11881
11882 uint64_t MaxLength = uint64_t(-1);
11883 if (BuiltinOp != Builtin::BIstrcmp &&
11884 BuiltinOp != Builtin::BIwcscmp &&
11885 BuiltinOp != Builtin::BI__builtin_strcmp &&
11886 BuiltinOp != Builtin::BI__builtin_wcscmp) {
11887 APSInt N;
11888 if (!EvaluateInteger(E->getArg(2), N, Info))
11889 return false;
11890 MaxLength = N.getExtValue();
11891 }
11892
11893 // Empty substrings compare equal by definition.
11894 if (MaxLength == 0u)
11895 return Success(0, E);
11896
11897 if (!String1.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
11898 !String2.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
11899 String1.Designator.Invalid || String2.Designator.Invalid)
11900 return false;
11901
11902 QualType CharTy1 = String1.Designator.getType(Info.Ctx);
11903 QualType CharTy2 = String2.Designator.getType(Info.Ctx);
11904
11905 bool IsRawByte = BuiltinOp == Builtin::BImemcmp ||
11906 BuiltinOp == Builtin::BIbcmp ||
11907 BuiltinOp == Builtin::BI__builtin_memcmp ||
11908 BuiltinOp == Builtin::BI__builtin_bcmp;
11909
11910 assert(IsRawByte ||((IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->
getArg(0)->getType()->getPointeeType()) && Info
.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))) ? static_cast
<void> (0) : __assert_fail ("IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->getArg(0)->getType()->getPointeeType()) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11913, __PRETTY_FUNCTION__))
11911 (Info.Ctx.hasSameUnqualifiedType(((IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->
getArg(0)->getType()->getPointeeType()) && Info
.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))) ? static_cast
<void> (0) : __assert_fail ("IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->getArg(0)->getType()->getPointeeType()) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11913, __PRETTY_FUNCTION__))
11912 CharTy1, E->getArg(0)->getType()->getPointeeType()) &&((IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->
getArg(0)->getType()->getPointeeType()) && Info
.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))) ? static_cast
<void> (0) : __assert_fail ("IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->getArg(0)->getType()->getPointeeType()) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11913, __PRETTY_FUNCTION__))
11913 Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2)))((IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->
getArg(0)->getType()->getPointeeType()) && Info
.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))) ? static_cast
<void> (0) : __assert_fail ("IsRawByte || (Info.Ctx.hasSameUnqualifiedType( CharTy1, E->getArg(0)->getType()->getPointeeType()) && Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2))"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11913, __PRETTY_FUNCTION__))
;
11914
11915 // For memcmp, allow comparing any arrays of '[[un]signed] char' or
11916 // 'char8_t', but no other types.
11917 if (IsRawByte &&
11918 !(isOneByteCharacterType(CharTy1) && isOneByteCharacterType(CharTy2))) {
11919 // FIXME: Consider using our bit_cast implementation to support this.
11920 Info.FFDiag(E, diag::note_constexpr_memcmp_unsupported)
11921 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'")
11922 << CharTy1 << CharTy2;
11923 return false;
11924 }
11925
11926 const auto &ReadCurElems = [&](APValue &Char1, APValue &Char2) {
11927 return handleLValueToRValueConversion(Info, E, CharTy1, String1, Char1) &&
11928 handleLValueToRValueConversion(Info, E, CharTy2, String2, Char2) &&
11929 Char1.isInt() && Char2.isInt();
11930 };
11931 const auto &AdvanceElems = [&] {
11932 return HandleLValueArrayAdjustment(Info, E, String1, CharTy1, 1) &&
11933 HandleLValueArrayAdjustment(Info, E, String2, CharTy2, 1);
11934 };
11935
11936 bool StopAtNull =
11937 (BuiltinOp != Builtin::BImemcmp && BuiltinOp != Builtin::BIbcmp &&
11938 BuiltinOp != Builtin::BIwmemcmp &&
11939 BuiltinOp != Builtin::BI__builtin_memcmp &&
11940 BuiltinOp != Builtin::BI__builtin_bcmp &&
11941 BuiltinOp != Builtin::BI__builtin_wmemcmp);
11942 bool IsWide = BuiltinOp == Builtin::BIwcscmp ||
11943 BuiltinOp == Builtin::BIwcsncmp ||
11944 BuiltinOp == Builtin::BIwmemcmp ||
11945 BuiltinOp == Builtin::BI__builtin_wcscmp ||
11946 BuiltinOp == Builtin::BI__builtin_wcsncmp ||
11947 BuiltinOp == Builtin::BI__builtin_wmemcmp;
11948
11949 for (; MaxLength; --MaxLength) {
11950 APValue Char1, Char2;
11951 if (!ReadCurElems(Char1, Char2))
11952 return false;
11953 if (Char1.getInt().ne(Char2.getInt())) {
11954 if (IsWide) // wmemcmp compares with wchar_t signedness.
11955 return Success(Char1.getInt() < Char2.getInt() ? -1 : 1, E);
11956 // memcmp always compares unsigned chars.
11957 return Success(Char1.getInt().ult(Char2.getInt()) ? -1 : 1, E);
11958 }
11959 if (StopAtNull && !Char1.getInt())
11960 return Success(0, E);
11961 assert(!(StopAtNull && !Char2.getInt()))((!(StopAtNull && !Char2.getInt())) ? static_cast<
void> (0) : __assert_fail ("!(StopAtNull && !Char2.getInt())"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 11961, __PRETTY_FUNCTION__))
;
11962 if (!AdvanceElems())
11963 return false;
11964 }
11965 // We hit the strncmp / memcmp limit.
11966 return Success(0, E);
11967 }
11968
11969 case Builtin::BI__atomic_always_lock_free:
11970 case Builtin::BI__atomic_is_lock_free:
11971 case Builtin::BI__c11_atomic_is_lock_free: {
11972 APSInt SizeVal;
11973 if (!EvaluateInteger(E->getArg(0), SizeVal, Info))
11974 return false;
11975
11976 // For __atomic_is_lock_free(sizeof(_Atomic(T))), if the size is a power
11977 // of two less than or equal to the maximum inline atomic width, we know it
11978 // is lock-free. If the size isn't a power of two, or greater than the
11979 // maximum alignment where we promote atomics, we know it is not lock-free
11980 // (at least not in the sense of atomic_is_lock_free). Otherwise,
11981 // the answer can only be determined at runtime; for example, 16-byte
11982 // atomics have lock-free implementations on some, but not all,
11983 // x86-64 processors.
11984
11985 // Check power-of-two.
11986 CharUnits Size = CharUnits::fromQuantity(SizeVal.getZExtValue());
11987 if (Size.isPowerOfTwo()) {
11988 // Check against inlining width.
11989 unsigned InlineWidthBits =
11990 Info.Ctx.getTargetInfo().getMaxAtomicInlineWidth();
11991 if (Size <= Info.Ctx.toCharUnitsFromBits(InlineWidthBits)) {
11992 if (BuiltinOp == Builtin::BI__c11_atomic_is_lock_free ||
11993 Size == CharUnits::One() ||
11994 E->getArg(1)->isNullPointerConstant(Info.Ctx,
11995 Expr::NPC_NeverValueDependent))
11996 // OK, we will inline appropriately-aligned operations of this size,
11997 // and _Atomic(T) is appropriately-aligned.
11998 return Success(1, E);
11999
12000 QualType PointeeType = E->getArg(1)->IgnoreImpCasts()->getType()->
12001 castAs<PointerType>()->getPointeeType();
12002 if (!PointeeType->isIncompleteType() &&
12003 Info.Ctx.getTypeAlignInChars(PointeeType) >= Size) {
12004 // OK, we will inline operations on this object.
12005 return Success(1, E);
12006 }
12007 }
12008 }
12009
12010 return BuiltinOp == Builtin::BI__atomic_always_lock_free ?
12011 Success(0, E) : Error(E);
12012 }
12013 case Builtin::BIomp_is_initial_device:
12014 // We can decide statically which value the runtime would return if called.
12015 return Success(Info.getLangOpts().OpenMPIsDevice ? 0 : 1, E);
12016 case Builtin::BI__builtin_add_overflow:
12017 case Builtin::BI__builtin_sub_overflow:
12018 case Builtin::BI__builtin_mul_overflow:
12019 case Builtin::BI__builtin_sadd_overflow:
12020 case Builtin::BI__builtin_uadd_overflow:
12021 case Builtin::BI__builtin_uaddl_overflow:
12022 case Builtin::BI__builtin_uaddll_overflow:
12023 case Builtin::BI__builtin_usub_overflow:
12024 case Builtin::BI__builtin_usubl_overflow:
12025 case Builtin::BI__builtin_usubll_overflow:
12026 case Builtin::BI__builtin_umul_overflow:
12027 case Builtin::BI__builtin_umull_overflow:
12028 case Builtin::BI__builtin_umulll_overflow:
12029 case Builtin::BI__builtin_saddl_overflow:
12030 case Builtin::BI__builtin_saddll_overflow:
12031 case Builtin::BI__builtin_ssub_overflow:
12032 case Builtin::BI__builtin_ssubl_overflow:
12033 case Builtin::BI__builtin_ssubll_overflow:
12034 case Builtin::BI__builtin_smul_overflow:
12035 case Builtin::BI__builtin_smull_overflow:
12036 case Builtin::BI__builtin_smulll_overflow: {
12037 LValue ResultLValue;
12038 APSInt LHS, RHS;
12039
12040 QualType ResultType = E->getArg(2)->getType()->getPointeeType();
12041 if (!EvaluateInteger(E->getArg(0), LHS, Info) ||
12042 !EvaluateInteger(E->getArg(1), RHS, Info) ||
12043 !EvaluatePointer(E->getArg(2), ResultLValue, Info))
12044 return false;
12045
12046 APSInt Result;
12047 bool DidOverflow = false;
12048
12049 // If the types don't have to match, enlarge all 3 to the largest of them.
12050 if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
12051 BuiltinOp == Builtin::BI__builtin_sub_overflow ||
12052 BuiltinOp == Builtin::BI__builtin_mul_overflow) {
12053 bool IsSigned = LHS.isSigned() || RHS.isSigned() ||
12054 ResultType->isSignedIntegerOrEnumerationType();
12055 bool AllSigned = LHS.isSigned() && RHS.isSigned() &&
12056 ResultType->isSignedIntegerOrEnumerationType();
12057 uint64_t LHSSize = LHS.getBitWidth();
12058 uint64_t RHSSize = RHS.getBitWidth();
12059 uint64_t ResultSize = Info.Ctx.getTypeSize(ResultType);
12060 uint64_t MaxBits = std::max(std::max(LHSSize, RHSSize), ResultSize);
12061
12062 // Add an additional bit if the signedness isn't uniformly agreed to. We
12063 // could do this ONLY if there is a signed and an unsigned that both have
12064 // MaxBits, but the code to check that is pretty nasty. The issue will be
12065 // caught in the shrink-to-result later anyway.
12066 if (IsSigned && !AllSigned)
12067 ++MaxBits;
12068
12069 LHS = APSInt(LHS.extOrTrunc(MaxBits), !IsSigned);
12070 RHS = APSInt(RHS.extOrTrunc(MaxBits), !IsSigned);
12071 Result = APSInt(MaxBits, !IsSigned);
12072 }
12073
12074 // Find largest int.
12075 switch (BuiltinOp) {
12076 default:
12077 llvm_unreachable("Invalid value for BuiltinOp")::llvm::llvm_unreachable_internal("Invalid value for BuiltinOp"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12077)
;
12078 case Builtin::BI__builtin_add_overflow:
12079 case Builtin::BI__builtin_sadd_overflow:
12080 case Builtin::BI__builtin_saddl_overflow:
12081 case Builtin::BI__builtin_saddll_overflow:
12082 case Builtin::BI__builtin_uadd_overflow:
12083 case Builtin::BI__builtin_uaddl_overflow:
12084 case Builtin::BI__builtin_uaddll_overflow:
12085 Result = LHS.isSigned() ? LHS.sadd_ov(RHS, DidOverflow)
12086 : LHS.uadd_ov(RHS, DidOverflow);
12087 break;
12088 case Builtin::BI__builtin_sub_overflow:
12089 case Builtin::BI__builtin_ssub_overflow:
12090 case Builtin::BI__builtin_ssubl_overflow:
12091 case Builtin::BI__builtin_ssubll_overflow:
12092 case Builtin::BI__builtin_usub_overflow:
12093 case Builtin::BI__builtin_usubl_overflow:
12094 case Builtin::BI__builtin_usubll_overflow:
12095 Result = LHS.isSigned() ? LHS.ssub_ov(RHS, DidOverflow)
12096 : LHS.usub_ov(RHS, DidOverflow);
12097 break;
12098 case Builtin::BI__builtin_mul_overflow:
12099 case Builtin::BI__builtin_smul_overflow:
12100 case Builtin::BI__builtin_smull_overflow:
12101 case Builtin::BI__builtin_smulll_overflow:
12102 case Builtin::BI__builtin_umul_overflow:
12103 case Builtin::BI__builtin_umull_overflow:
12104 case Builtin::BI__builtin_umulll_overflow:
12105 Result = LHS.isSigned() ? LHS.smul_ov(RHS, DidOverflow)
12106 : LHS.umul_ov(RHS, DidOverflow);
12107 break;
12108 }
12109
12110 // In the case where multiple sizes are allowed, truncate and see if
12111 // the values are the same.
12112 if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
12113 BuiltinOp == Builtin::BI__builtin_sub_overflow ||
12114 BuiltinOp == Builtin::BI__builtin_mul_overflow) {
12115 // APSInt doesn't have a TruncOrSelf, so we use extOrTrunc instead,
12116 // since it will give us the behavior of a TruncOrSelf in the case where
12117 // its parameter <= its size. We previously set Result to be at least the
12118 // type-size of the result, so getTypeSize(ResultType) <= Result.BitWidth
12119 // will work exactly like TruncOrSelf.
12120 APSInt Temp = Result.extOrTrunc(Info.Ctx.getTypeSize(ResultType));
12121 Temp.setIsSigned(ResultType->isSignedIntegerOrEnumerationType());
12122
12123 if (!APSInt::isSameValue(Temp, Result))
12124 DidOverflow = true;
12125 Result = Temp;
12126 }
12127
12128 APValue APV{Result};
12129 if (!handleAssignment(Info, E, ResultLValue, ResultType, APV))
12130 return false;
12131 return Success(DidOverflow, E);
12132 }
12133 }
12134}
12135
12136/// Determine whether this is a pointer past the end of the complete
12137/// object referred to by the lvalue.
12138static bool isOnePastTheEndOfCompleteObject(const ASTContext &Ctx,
12139 const LValue &LV) {
12140 // A null pointer can be viewed as being "past the end" but we don't
12141 // choose to look at it that way here.
12142 if (!LV.getLValueBase())
12143 return false;
12144
12145 // If the designator is valid and refers to a subobject, we're not pointing
12146 // past the end.
12147 if (!LV.getLValueDesignator().Invalid &&
12148 !LV.getLValueDesignator().isOnePastTheEnd())
12149 return false;
12150
12151 // A pointer to an incomplete type might be past-the-end if the type's size is
12152 // zero. We cannot tell because the type is incomplete.
12153 QualType Ty = getType(LV.getLValueBase());
12154 if (Ty->isIncompleteType())
12155 return true;
12156
12157 // We're a past-the-end pointer if we point to the byte after the object,
12158 // no matter what our type or path is.
12159 auto Size = Ctx.getTypeSizeInChars(Ty);
12160 return LV.getLValueOffset() == Size;
12161}
12162
12163namespace {
12164
12165/// Data recursive integer evaluator of certain binary operators.
12166///
12167/// We use a data recursive algorithm for binary operators so that we are able
12168/// to handle extreme cases of chained binary operators without causing stack
12169/// overflow.
12170class DataRecursiveIntBinOpEvaluator {
12171 struct EvalResult {
12172 APValue Val;
12173 bool Failed;
12174
12175 EvalResult() : Failed(false) { }
12176
12177 void swap(EvalResult &RHS) {
12178 Val.swap(RHS.Val);
12179 Failed = RHS.Failed;
12180 RHS.Failed = false;
12181 }
12182 };
12183
12184 struct Job {
12185 const Expr *E;
12186 EvalResult LHSResult; // meaningful only for binary operator expression.
12187 enum { AnyExprKind, BinOpKind, BinOpVisitedLHSKind } Kind;
12188
12189 Job() = default;
12190 Job(Job &&) = default;
12191
12192 void startSpeculativeEval(EvalInfo &Info) {
12193 SpecEvalRAII = SpeculativeEvaluationRAII(Info);
12194 }
12195
12196 private:
12197 SpeculativeEvaluationRAII SpecEvalRAII;
12198 };
12199
12200 SmallVector<Job, 16> Queue;
12201
12202 IntExprEvaluator &IntEval;
12203 EvalInfo &Info;
12204 APValue &FinalResult;
12205
12206public:
12207 DataRecursiveIntBinOpEvaluator(IntExprEvaluator &IntEval, APValue &Result)
12208 : IntEval(IntEval), Info(IntEval.getEvalInfo()), FinalResult(Result) { }
12209
12210 /// True if \param E is a binary operator that we are going to handle
12211 /// data recursively.
12212 /// We handle binary operators that are comma, logical, or that have operands
12213 /// with integral or enumeration type.
12214 static bool shouldEnqueue(const BinaryOperator *E) {
12215 return E->getOpcode() == BO_Comma || E->isLogicalOp() ||
12216 (E->isRValue() && E->getType()->isIntegralOrEnumerationType() &&
12217 E->getLHS()->getType()->isIntegralOrEnumerationType() &&
12218 E->getRHS()->getType()->isIntegralOrEnumerationType());
12219 }
12220
12221 bool Traverse(const BinaryOperator *E) {
12222 enqueue(E);
12223 EvalResult PrevResult;
12224 while (!Queue.empty())
12225 process(PrevResult);
12226
12227 if (PrevResult.Failed) return false;
12228
12229 FinalResult.swap(PrevResult.Val);
12230 return true;
12231 }
12232
12233private:
12234 bool Success(uint64_t Value, const Expr *E, APValue &Result) {
12235 return IntEval.Success(Value, E, Result);
12236 }
12237 bool Success(const APSInt &Value, const Expr *E, APValue &Result) {
12238 return IntEval.Success(Value, E, Result);
12239 }
12240 bool Error(const Expr *E) {
12241 return IntEval.Error(E);
12242 }
12243 bool Error(const Expr *E, diag::kind D) {
12244 return IntEval.Error(E, D);
12245 }
12246
12247 OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
12248 return Info.CCEDiag(E, D);
12249 }
12250
12251 // Returns true if visiting the RHS is necessary, false otherwise.
12252 bool VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
12253 bool &SuppressRHSDiags);
12254
12255 bool VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
12256 const BinaryOperator *E, APValue &Result);
12257
12258 void EvaluateExpr(const Expr *E, EvalResult &Result) {
12259 Result.Failed = !Evaluate(Result.Val, Info, E);
12260 if (Result.Failed)
12261 Result.Val = APValue();
12262 }
12263
12264 void process(EvalResult &Result);
12265
12266 void enqueue(const Expr *E) {
12267 E = E->IgnoreParens();
12268 Queue.resize(Queue.size()+1);
12269 Queue.back().E = E;
12270 Queue.back().Kind = Job::AnyExprKind;
12271 }
12272};
12273
12274}
12275
12276bool DataRecursiveIntBinOpEvaluator::
12277 VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
12278 bool &SuppressRHSDiags) {
12279 if (E->getOpcode() == BO_Comma) {
12280 // Ignore LHS but note if we could not evaluate it.
12281 if (LHSResult.Failed)
12282 return Info.noteSideEffect();
12283 return true;
12284 }
12285
12286 if (E->isLogicalOp()) {
12287 bool LHSAsBool;
12288 if (!LHSResult.Failed && HandleConversionToBool(LHSResult.Val, LHSAsBool)) {
12289 // We were able to evaluate the LHS, see if we can get away with not
12290 // evaluating the RHS: 0 && X -> 0, 1 || X -> 1
12291 if (LHSAsBool == (E->getOpcode() == BO_LOr)) {
12292 Success(LHSAsBool, E, LHSResult.Val);
12293 return false; // Ignore RHS
12294 }
12295 } else {
12296 LHSResult.Failed = true;
12297
12298 // Since we weren't able to evaluate the left hand side, it
12299 // might have had side effects.
12300 if (!Info.noteSideEffect())
12301 return false;
12302
12303 // We can't evaluate the LHS; however, sometimes the result
12304 // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
12305 // Don't ignore RHS and suppress diagnostics from this arm.
12306 SuppressRHSDiags = true;
12307 }
12308
12309 return true;
12310 }
12311
12312 assert(E->getLHS()->getType()->isIntegralOrEnumerationType() &&((E->getLHS()->getType()->isIntegralOrEnumerationType
() && E->getRHS()->getType()->isIntegralOrEnumerationType
()) ? static_cast<void> (0) : __assert_fail ("E->getLHS()->getType()->isIntegralOrEnumerationType() && E->getRHS()->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12313, __PRETTY_FUNCTION__))
12313 E->getRHS()->getType()->isIntegralOrEnumerationType())((E->getLHS()->getType()->isIntegralOrEnumerationType
() && E->getRHS()->getType()->isIntegralOrEnumerationType
()) ? static_cast<void> (0) : __assert_fail ("E->getLHS()->getType()->isIntegralOrEnumerationType() && E->getRHS()->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12313, __PRETTY_FUNCTION__))
;
12314
12315 if (LHSResult.Failed && !Info.noteFailure())
12316 return false; // Ignore RHS;
12317
12318 return true;
12319}
12320
12321static void addOrSubLValueAsInteger(APValue &LVal, const APSInt &Index,
12322 bool IsSub) {
12323 // Compute the new offset in the appropriate width, wrapping at 64 bits.
12324 // FIXME: When compiling for a 32-bit target, we should use 32-bit
12325 // offsets.
12326 assert(!LVal.hasLValuePath() && "have designator for integer lvalue")((!LVal.hasLValuePath() && "have designator for integer lvalue"
) ? static_cast<void> (0) : __assert_fail ("!LVal.hasLValuePath() && \"have designator for integer lvalue\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12326, __PRETTY_FUNCTION__))
;
12327 CharUnits &Offset = LVal.getLValueOffset();
12328 uint64_t Offset64 = Offset.getQuantity();
12329 uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
12330 Offset = CharUnits::fromQuantity(IsSub ? Offset64 - Index64
12331 : Offset64 + Index64);
12332}
12333
12334bool DataRecursiveIntBinOpEvaluator::
12335 VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
12336 const BinaryOperator *E, APValue &Result) {
12337 if (E->getOpcode() == BO_Comma) {
12338 if (RHSResult.Failed)
12339 return false;
12340 Result = RHSResult.Val;
12341 return true;
12342 }
12343
12344 if (E->isLogicalOp()) {
12345 bool lhsResult, rhsResult;
12346 bool LHSIsOK = HandleConversionToBool(LHSResult.Val, lhsResult);
12347 bool RHSIsOK = HandleConversionToBool(RHSResult.Val, rhsResult);
12348
12349 if (LHSIsOK) {
12350 if (RHSIsOK) {
12351 if (E->getOpcode() == BO_LOr)
12352 return Success(lhsResult || rhsResult, E, Result);
12353 else
12354 return Success(lhsResult && rhsResult, E, Result);
12355 }
12356 } else {
12357 if (RHSIsOK) {
12358 // We can't evaluate the LHS; however, sometimes the result
12359 // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
12360 if (rhsResult == (E->getOpcode() == BO_LOr))
12361 return Success(rhsResult, E, Result);
12362 }
12363 }
12364
12365 return false;
12366 }
12367
12368 assert(E->getLHS()->getType()->isIntegralOrEnumerationType() &&((E->getLHS()->getType()->isIntegralOrEnumerationType
() && E->getRHS()->getType()->isIntegralOrEnumerationType
()) ? static_cast<void> (0) : __assert_fail ("E->getLHS()->getType()->isIntegralOrEnumerationType() && E->getRHS()->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12369, __PRETTY_FUNCTION__))
12369 E->getRHS()->getType()->isIntegralOrEnumerationType())((E->getLHS()->getType()->isIntegralOrEnumerationType
() && E->getRHS()->getType()->isIntegralOrEnumerationType
()) ? static_cast<void> (0) : __assert_fail ("E->getLHS()->getType()->isIntegralOrEnumerationType() && E->getRHS()->getType()->isIntegralOrEnumerationType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12369, __PRETTY_FUNCTION__))
;
12370
12371 if (LHSResult.Failed || RHSResult.Failed)
12372 return false;
12373
12374 const APValue &LHSVal = LHSResult.Val;
12375 const APValue &RHSVal = RHSResult.Val;
12376
12377 // Handle cases like (unsigned long)&a + 4.
12378 if (E->isAdditiveOp() && LHSVal.isLValue() && RHSVal.isInt()) {
12379 Result = LHSVal;
12380 addOrSubLValueAsInteger(Result, RHSVal.getInt(), E->getOpcode() == BO_Sub);
12381 return true;
12382 }
12383
12384 // Handle cases like 4 + (unsigned long)&a
12385 if (E->getOpcode() == BO_Add &&
12386 RHSVal.isLValue() && LHSVal.isInt()) {
12387 Result = RHSVal;
12388 addOrSubLValueAsInteger(Result, LHSVal.getInt(), /*IsSub*/false);
12389 return true;
12390 }
12391
12392 if (E->getOpcode() == BO_Sub && LHSVal.isLValue() && RHSVal.isLValue()) {
12393 // Handle (intptr_t)&&A - (intptr_t)&&B.
12394 if (!LHSVal.getLValueOffset().isZero() ||
12395 !RHSVal.getLValueOffset().isZero())
12396 return false;
12397 const Expr *LHSExpr = LHSVal.getLValueBase().dyn_cast<const Expr*>();
12398 const Expr *RHSExpr = RHSVal.getLValueBase().dyn_cast<const Expr*>();
12399 if (!LHSExpr || !RHSExpr)
12400 return false;
12401 const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
12402 const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
12403 if (!LHSAddrExpr || !RHSAddrExpr)
12404 return false;
12405 // Make sure both labels come from the same function.
12406 if (LHSAddrExpr->getLabel()->getDeclContext() !=
12407 RHSAddrExpr->getLabel()->getDeclContext())
12408 return false;
12409 Result = APValue(LHSAddrExpr, RHSAddrExpr);
12410 return true;
12411 }
12412
12413 // All the remaining cases expect both operands to be an integer
12414 if (!LHSVal.isInt() || !RHSVal.isInt())
12415 return Error(E);
12416
12417 // Set up the width and signedness manually, in case it can't be deduced
12418 // from the operation we're performing.
12419 // FIXME: Don't do this in the cases where we can deduce it.
12420 APSInt Value(Info.Ctx.getIntWidth(E->getType()),
12421 E->getType()->isUnsignedIntegerOrEnumerationType());
12422 if (!handleIntIntBinOp(Info, E, LHSVal.getInt(), E->getOpcode(),
12423 RHSVal.getInt(), Value))
12424 return false;
12425 return Success(Value, E, Result);
12426}
12427
12428void DataRecursiveIntBinOpEvaluator::process(EvalResult &Result) {
12429 Job &job = Queue.back();
12430
12431 switch (job.Kind) {
12432 case Job::AnyExprKind: {
12433 if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(job.E)) {
12434 if (shouldEnqueue(Bop)) {
12435 job.Kind = Job::BinOpKind;
12436 enqueue(Bop->getLHS());
12437 return;
12438 }
12439 }
12440
12441 EvaluateExpr(job.E, Result);
12442 Queue.pop_back();
12443 return;
12444 }
12445
12446 case Job::BinOpKind: {
12447 const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
12448 bool SuppressRHSDiags = false;
12449 if (!VisitBinOpLHSOnly(Result, Bop, SuppressRHSDiags)) {
12450 Queue.pop_back();
12451 return;
12452 }
12453 if (SuppressRHSDiags)
12454 job.startSpeculativeEval(Info);
12455 job.LHSResult.swap(Result);
12456 job.Kind = Job::BinOpVisitedLHSKind;
12457 enqueue(Bop->getRHS());
12458 return;
12459 }
12460
12461 case Job::BinOpVisitedLHSKind: {
12462 const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
12463 EvalResult RHS;
12464 RHS.swap(Result);
12465 Result.Failed = !VisitBinOp(job.LHSResult, RHS, Bop, Result.Val);
12466 Queue.pop_back();
12467 return;
12468 }
12469 }
12470
12471 llvm_unreachable("Invalid Job::Kind!")::llvm::llvm_unreachable_internal("Invalid Job::Kind!", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12471)
;
12472}
12473
12474namespace {
12475enum class CmpResult {
12476 Unequal,
12477 Less,
12478 Equal,
12479 Greater,
12480 Unordered,
12481};
12482}
12483
12484template <class SuccessCB, class AfterCB>
12485static bool
12486EvaluateComparisonBinaryOperator(EvalInfo &Info, const BinaryOperator *E,
12487 SuccessCB &&Success, AfterCB &&DoAfter) {
12488 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12488, __PRETTY_FUNCTION__))
;
12489 assert(E->isComparisonOp() && "expected comparison operator")((E->isComparisonOp() && "expected comparison operator"
) ? static_cast<void> (0) : __assert_fail ("E->isComparisonOp() && \"expected comparison operator\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12489, __PRETTY_FUNCTION__))
;
12490 assert((E->getOpcode() == BO_Cmp ||(((E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType
()) && "unsupported binary expression evaluation") ? static_cast
<void> (0) : __assert_fail ("(E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType()) && \"unsupported binary expression evaluation\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12492, __PRETTY_FUNCTION__))
12491 E->getType()->isIntegralOrEnumerationType()) &&(((E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType
()) && "unsupported binary expression evaluation") ? static_cast
<void> (0) : __assert_fail ("(E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType()) && \"unsupported binary expression evaluation\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12492, __PRETTY_FUNCTION__))
12492 "unsupported binary expression evaluation")(((E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType
()) && "unsupported binary expression evaluation") ? static_cast
<void> (0) : __assert_fail ("(E->getOpcode() == BO_Cmp || E->getType()->isIntegralOrEnumerationType()) && \"unsupported binary expression evaluation\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12492, __PRETTY_FUNCTION__))
;
12493 auto Error = [&](const Expr *E) {
12494 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
12495 return false;
12496 };
12497
12498 bool IsRelational = E->isRelationalOp() || E->getOpcode() == BO_Cmp;
12499 bool IsEquality = E->isEqualityOp();
12500
12501 QualType LHSTy = E->getLHS()->getType();
12502 QualType RHSTy = E->getRHS()->getType();
12503
12504 if (LHSTy->isIntegralOrEnumerationType() &&
12505 RHSTy->isIntegralOrEnumerationType()) {
12506 APSInt LHS, RHS;
12507 bool LHSOK = EvaluateInteger(E->getLHS(), LHS, Info);
12508 if (!LHSOK && !Info.noteFailure())
12509 return false;
12510 if (!EvaluateInteger(E->getRHS(), RHS, Info) || !LHSOK)
12511 return false;
12512 if (LHS < RHS)
12513 return Success(CmpResult::Less, E);
12514 if (LHS > RHS)
12515 return Success(CmpResult::Greater, E);
12516 return Success(CmpResult::Equal, E);
12517 }
12518
12519 if (LHSTy->isFixedPointType() || RHSTy->isFixedPointType()) {
12520 APFixedPoint LHSFX(Info.Ctx.getFixedPointSemantics(LHSTy));
12521 APFixedPoint RHSFX(Info.Ctx.getFixedPointSemantics(RHSTy));
12522
12523 bool LHSOK = EvaluateFixedPointOrInteger(E->getLHS(), LHSFX, Info);
12524 if (!LHSOK && !Info.noteFailure())
12525 return false;
12526 if (!EvaluateFixedPointOrInteger(E->getRHS(), RHSFX, Info) || !LHSOK)
12527 return false;
12528 if (LHSFX < RHSFX)
12529 return Success(CmpResult::Less, E);
12530 if (LHSFX > RHSFX)
12531 return Success(CmpResult::Greater, E);
12532 return Success(CmpResult::Equal, E);
12533 }
12534
12535 if (LHSTy->isAnyComplexType() || RHSTy->isAnyComplexType()) {
12536 ComplexValue LHS, RHS;
12537 bool LHSOK;
12538 if (E->isAssignmentOp()) {
12539 LValue LV;
12540 EvaluateLValue(E->getLHS(), LV, Info);
12541 LHSOK = false;
12542 } else if (LHSTy->isRealFloatingType()) {
12543 LHSOK = EvaluateFloat(E->getLHS(), LHS.FloatReal, Info);
12544 if (LHSOK) {
12545 LHS.makeComplexFloat();
12546 LHS.FloatImag = APFloat(LHS.FloatReal.getSemantics());
12547 }
12548 } else {
12549 LHSOK = EvaluateComplex(E->getLHS(), LHS, Info);
12550 }
12551 if (!LHSOK && !Info.noteFailure())
12552 return false;
12553
12554 if (E->getRHS()->getType()->isRealFloatingType()) {
12555 if (!EvaluateFloat(E->getRHS(), RHS.FloatReal, Info) || !LHSOK)
12556 return false;
12557 RHS.makeComplexFloat();
12558 RHS.FloatImag = APFloat(RHS.FloatReal.getSemantics());
12559 } else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
12560 return false;
12561
12562 if (LHS.isComplexFloat()) {
12563 APFloat::cmpResult CR_r =
12564 LHS.getComplexFloatReal().compare(RHS.getComplexFloatReal());
12565 APFloat::cmpResult CR_i =
12566 LHS.getComplexFloatImag().compare(RHS.getComplexFloatImag());
12567 bool IsEqual = CR_r == APFloat::cmpEqual && CR_i == APFloat::cmpEqual;
12568 return Success(IsEqual ? CmpResult::Equal : CmpResult::Unequal, E);
12569 } else {
12570 assert(IsEquality && "invalid complex comparison")((IsEquality && "invalid complex comparison") ? static_cast
<void> (0) : __assert_fail ("IsEquality && \"invalid complex comparison\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12570, __PRETTY_FUNCTION__))
;
12571 bool IsEqual = LHS.getComplexIntReal() == RHS.getComplexIntReal() &&
12572 LHS.getComplexIntImag() == RHS.getComplexIntImag();
12573 return Success(IsEqual ? CmpResult::Equal : CmpResult::Unequal, E);
12574 }
12575 }
12576
12577 if (LHSTy->isRealFloatingType() &&
12578 RHSTy->isRealFloatingType()) {
12579 APFloat RHS(0.0), LHS(0.0);
12580
12581 bool LHSOK = EvaluateFloat(E->getRHS(), RHS, Info);
12582 if (!LHSOK && !Info.noteFailure())
12583 return false;
12584
12585 if (!EvaluateFloat(E->getLHS(), LHS, Info) || !LHSOK)
12586 return false;
12587
12588 assert(E->isComparisonOp() && "Invalid binary operator!")((E->isComparisonOp() && "Invalid binary operator!"
) ? static_cast<void> (0) : __assert_fail ("E->isComparisonOp() && \"Invalid binary operator!\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12588, __PRETTY_FUNCTION__))
;
12589 llvm::APFloatBase::cmpResult APFloatCmpResult = LHS.compare(RHS);
12590 if (!Info.InConstantContext &&
12591 APFloatCmpResult == APFloat::cmpUnordered &&
12592 E->getFPFeaturesInEffect(Info.Ctx.getLangOpts()).isFPConstrained()) {
12593 // Note: Compares may raise invalid in some cases involving NaN or sNaN.
12594 Info.FFDiag(E, diag::note_constexpr_float_arithmetic_strict);
12595 return false;
12596 }
12597 auto GetCmpRes = [&]() {
12598 switch (APFloatCmpResult) {
12599 case APFloat::cmpEqual:
12600 return CmpResult::Equal;
12601 case APFloat::cmpLessThan:
12602 return CmpResult::Less;
12603 case APFloat::cmpGreaterThan:
12604 return CmpResult::Greater;
12605 case APFloat::cmpUnordered:
12606 return CmpResult::Unordered;
12607 }
12608 llvm_unreachable("Unrecognised APFloat::cmpResult enum")::llvm::llvm_unreachable_internal("Unrecognised APFloat::cmpResult enum"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12608)
;
12609 };
12610 return Success(GetCmpRes(), E);
12611 }
12612
12613 if (LHSTy->isPointerType() && RHSTy->isPointerType()) {
12614 LValue LHSValue, RHSValue;
12615
12616 bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
12617 if (!LHSOK && !Info.noteFailure())
12618 return false;
12619
12620 if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
12621 return false;
12622
12623 // Reject differing bases from the normal codepath; we special-case
12624 // comparisons to null.
12625 if (!HasSameBase(LHSValue, RHSValue)) {
12626 // Inequalities and subtractions between unrelated pointers have
12627 // unspecified or undefined behavior.
12628 if (!IsEquality) {
12629 Info.FFDiag(E, diag::note_constexpr_pointer_comparison_unspecified);
12630 return false;
12631 }
12632 // A constant address may compare equal to the address of a symbol.
12633 // The one exception is that address of an object cannot compare equal
12634 // to a null pointer constant.
12635 if ((!LHSValue.Base && !LHSValue.Offset.isZero()) ||
12636 (!RHSValue.Base && !RHSValue.Offset.isZero()))
12637 return Error(E);
12638 // It's implementation-defined whether distinct literals will have
12639 // distinct addresses. In clang, the result of such a comparison is
12640 // unspecified, so it is not a constant expression. However, we do know
12641 // that the address of a literal will be non-null.
12642 if ((IsLiteralLValue(LHSValue) || IsLiteralLValue(RHSValue)) &&
12643 LHSValue.Base && RHSValue.Base)
12644 return Error(E);
12645 // We can't tell whether weak symbols will end up pointing to the same
12646 // object.
12647 if (IsWeakLValue(LHSValue) || IsWeakLValue(RHSValue))
12648 return Error(E);
12649 // We can't compare the address of the start of one object with the
12650 // past-the-end address of another object, per C++ DR1652.
12651 if ((LHSValue.Base && LHSValue.Offset.isZero() &&
12652 isOnePastTheEndOfCompleteObject(Info.Ctx, RHSValue)) ||
12653 (RHSValue.Base && RHSValue.Offset.isZero() &&
12654 isOnePastTheEndOfCompleteObject(Info.Ctx, LHSValue)))
12655 return Error(E);
12656 // We can't tell whether an object is at the same address as another
12657 // zero sized object.
12658 if ((RHSValue.Base && isZeroSized(LHSValue)) ||
12659 (LHSValue.Base && isZeroSized(RHSValue)))
12660 return Error(E);
12661 return Success(CmpResult::Unequal, E);
12662 }
12663
12664 const CharUnits &LHSOffset = LHSValue.getLValueOffset();
12665 const CharUnits &RHSOffset = RHSValue.getLValueOffset();
12666
12667 SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
12668 SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
12669
12670 // C++11 [expr.rel]p3:
12671 // Pointers to void (after pointer conversions) can be compared, with a
12672 // result defined as follows: If both pointers represent the same
12673 // address or are both the null pointer value, the result is true if the
12674 // operator is <= or >= and false otherwise; otherwise the result is
12675 // unspecified.
12676 // We interpret this as applying to pointers to *cv* void.
12677 if (LHSTy->isVoidPointerType() && LHSOffset != RHSOffset && IsRelational)
12678 Info.CCEDiag(E, diag::note_constexpr_void_comparison);
12679
12680 // C++11 [expr.rel]p2:
12681 // - If two pointers point to non-static data members of the same object,
12682 // or to subobjects or array elements fo such members, recursively, the
12683 // pointer to the later declared member compares greater provided the
12684 // two members have the same access control and provided their class is
12685 // not a union.
12686 // [...]
12687 // - Otherwise pointer comparisons are unspecified.
12688 if (!LHSDesignator.Invalid && !RHSDesignator.Invalid && IsRelational) {
12689 bool WasArrayIndex;
12690 unsigned Mismatch = FindDesignatorMismatch(
12691 getType(LHSValue.Base), LHSDesignator, RHSDesignator, WasArrayIndex);
12692 // At the point where the designators diverge, the comparison has a
12693 // specified value if:
12694 // - we are comparing array indices
12695 // - we are comparing fields of a union, or fields with the same access
12696 // Otherwise, the result is unspecified and thus the comparison is not a
12697 // constant expression.
12698 if (!WasArrayIndex && Mismatch < LHSDesignator.Entries.size() &&
12699 Mismatch < RHSDesignator.Entries.size()) {
12700 const FieldDecl *LF = getAsField(LHSDesignator.Entries[Mismatch]);
12701 const FieldDecl *RF = getAsField(RHSDesignator.Entries[Mismatch]);
12702 if (!LF && !RF)
12703 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_classes);
12704 else if (!LF)
12705 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
12706 << getAsBaseClass(LHSDesignator.Entries[Mismatch])
12707 << RF->getParent() << RF;
12708 else if (!RF)
12709 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
12710 << getAsBaseClass(RHSDesignator.Entries[Mismatch])
12711 << LF->getParent() << LF;
12712 else if (!LF->getParent()->isUnion() &&
12713 LF->getAccess() != RF->getAccess())
12714 Info.CCEDiag(E,
12715 diag::note_constexpr_pointer_comparison_differing_access)
12716 << LF << LF->getAccess() << RF << RF->getAccess()
12717 << LF->getParent();
12718 }
12719 }
12720
12721 // The comparison here must be unsigned, and performed with the same
12722 // width as the pointer.
12723 unsigned PtrSize = Info.Ctx.getTypeSize(LHSTy);
12724 uint64_t CompareLHS = LHSOffset.getQuantity();
12725 uint64_t CompareRHS = RHSOffset.getQuantity();
12726 assert(PtrSize <= 64 && "Unexpected pointer width")((PtrSize <= 64 && "Unexpected pointer width") ? static_cast
<void> (0) : __assert_fail ("PtrSize <= 64 && \"Unexpected pointer width\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12726, __PRETTY_FUNCTION__))
;
12727 uint64_t Mask = ~0ULL >> (64 - PtrSize);
12728 CompareLHS &= Mask;
12729 CompareRHS &= Mask;
12730
12731 // If there is a base and this is a relational operator, we can only
12732 // compare pointers within the object in question; otherwise, the result
12733 // depends on where the object is located in memory.
12734 if (!LHSValue.Base.isNull() && IsRelational) {
12735 QualType BaseTy = getType(LHSValue.Base);
12736 if (BaseTy->isIncompleteType())
12737 return Error(E);
12738 CharUnits Size = Info.Ctx.getTypeSizeInChars(BaseTy);
12739 uint64_t OffsetLimit = Size.getQuantity();
12740 if (CompareLHS > OffsetLimit || CompareRHS > OffsetLimit)
12741 return Error(E);
12742 }
12743
12744 if (CompareLHS < CompareRHS)
12745 return Success(CmpResult::Less, E);
12746 if (CompareLHS > CompareRHS)
12747 return Success(CmpResult::Greater, E);
12748 return Success(CmpResult::Equal, E);
12749 }
12750
12751 if (LHSTy->isMemberPointerType()) {
12752 assert(IsEquality && "unexpected member pointer operation")((IsEquality && "unexpected member pointer operation"
) ? static_cast<void> (0) : __assert_fail ("IsEquality && \"unexpected member pointer operation\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12752, __PRETTY_FUNCTION__))
;
12753 assert(RHSTy->isMemberPointerType() && "invalid comparison")((RHSTy->isMemberPointerType() && "invalid comparison"
) ? static_cast<void> (0) : __assert_fail ("RHSTy->isMemberPointerType() && \"invalid comparison\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12753, __PRETTY_FUNCTION__))
;
12754
12755 MemberPtr LHSValue, RHSValue;
12756
12757 bool LHSOK = EvaluateMemberPointer(E->getLHS(), LHSValue, Info);
12758 if (!LHSOK && !Info.noteFailure())
12759 return false;
12760
12761 if (!EvaluateMemberPointer(E->getRHS(), RHSValue, Info) || !LHSOK)
12762 return false;
12763
12764 // C++11 [expr.eq]p2:
12765 // If both operands are null, they compare equal. Otherwise if only one is
12766 // null, they compare unequal.
12767 if (!LHSValue.getDecl() || !RHSValue.getDecl()) {
12768 bool Equal = !LHSValue.getDecl() && !RHSValue.getDecl();
12769 return Success(Equal ? CmpResult::Equal : CmpResult::Unequal, E);
12770 }
12771
12772 // Otherwise if either is a pointer to a virtual member function, the
12773 // result is unspecified.
12774 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(LHSValue.getDecl()))
12775 if (MD->isVirtual())
12776 Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
12777 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(RHSValue.getDecl()))
12778 if (MD->isVirtual())
12779 Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
12780
12781 // Otherwise they compare equal if and only if they would refer to the
12782 // same member of the same most derived object or the same subobject if
12783 // they were dereferenced with a hypothetical object of the associated
12784 // class type.
12785 bool Equal = LHSValue == RHSValue;
12786 return Success(Equal ? CmpResult::Equal : CmpResult::Unequal, E);
12787 }
12788
12789 if (LHSTy->isNullPtrType()) {
12790 assert(E->isComparisonOp() && "unexpected nullptr operation")((E->isComparisonOp() && "unexpected nullptr operation"
) ? static_cast<void> (0) : __assert_fail ("E->isComparisonOp() && \"unexpected nullptr operation\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12790, __PRETTY_FUNCTION__))
;
12791 assert(RHSTy->isNullPtrType() && "missing pointer conversion")((RHSTy->isNullPtrType() && "missing pointer conversion"
) ? static_cast<void> (0) : __assert_fail ("RHSTy->isNullPtrType() && \"missing pointer conversion\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12791, __PRETTY_FUNCTION__))
;
12792 // C++11 [expr.rel]p4, [expr.eq]p3: If two operands of type std::nullptr_t
12793 // are compared, the result is true of the operator is <=, >= or ==, and
12794 // false otherwise.
12795 return Success(CmpResult::Equal, E);
12796 }
12797
12798 return DoAfter();
12799}
12800
12801bool RecordExprEvaluator::VisitBinCmp(const BinaryOperator *E) {
12802 if (!CheckLiteralType(Info, E))
12803 return false;
12804
12805 auto OnSuccess = [&](CmpResult CR, const BinaryOperator *E) {
12806 ComparisonCategoryResult CCR;
12807 switch (CR) {
12808 case CmpResult::Unequal:
12809 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-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12809)
;
12810 case CmpResult::Less:
12811 CCR = ComparisonCategoryResult::Less;
12812 break;
12813 case CmpResult::Equal:
12814 CCR = ComparisonCategoryResult::Equal;
12815 break;
12816 case CmpResult::Greater:
12817 CCR = ComparisonCategoryResult::Greater;
12818 break;
12819 case CmpResult::Unordered:
12820 CCR = ComparisonCategoryResult::Unordered;
12821 break;
12822 }
12823 // Evaluation succeeded. Lookup the information for the comparison category
12824 // type and fetch the VarDecl for the result.
12825 const ComparisonCategoryInfo &CmpInfo =
12826 Info.Ctx.CompCategories.getInfoForType(E->getType());
12827 const VarDecl *VD = CmpInfo.getValueInfo(CmpInfo.makeWeakResult(CCR))->VD;
12828 // Check and evaluate the result as a constant expression.
12829 LValue LV;
12830 LV.set(VD);
12831 if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
12832 return false;
12833 return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result,
12834 ConstantExprKind::Normal);
12835 };
12836 return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
12837 return ExprEvaluatorBaseTy::VisitBinCmp(E);
12838 });
12839}
12840
12841bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
12842 // We don't support assignment in C. C++ assignments don't get here because
12843 // assignment is an lvalue in C++.
12844 if (E->isAssignmentOp()) {
12845 Error(E);
12846 if (!Info.noteFailure())
12847 return false;
12848 }
12849
12850 if (DataRecursiveIntBinOpEvaluator::shouldEnqueue(E))
12851 return DataRecursiveIntBinOpEvaluator(*this, Result).Traverse(E);
12852
12853 assert((!E->getLHS()->getType()->isIntegralOrEnumerationType() ||(((!E->getLHS()->getType()->isIntegralOrEnumerationType
() || !E->getRHS()->getType()->isIntegralOrEnumerationType
()) && "DataRecursiveIntBinOpEvaluator should have handled integral types"
) ? static_cast<void> (0) : __assert_fail ("(!E->getLHS()->getType()->isIntegralOrEnumerationType() || !E->getRHS()->getType()->isIntegralOrEnumerationType()) && \"DataRecursiveIntBinOpEvaluator should have handled integral types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12855, __PRETTY_FUNCTION__))
12854 !E->getRHS()->getType()->isIntegralOrEnumerationType()) &&(((!E->getLHS()->getType()->isIntegralOrEnumerationType
() || !E->getRHS()->getType()->isIntegralOrEnumerationType
()) && "DataRecursiveIntBinOpEvaluator should have handled integral types"
) ? static_cast<void> (0) : __assert_fail ("(!E->getLHS()->getType()->isIntegralOrEnumerationType() || !E->getRHS()->getType()->isIntegralOrEnumerationType()) && \"DataRecursiveIntBinOpEvaluator should have handled integral types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12855, __PRETTY_FUNCTION__))
12855 "DataRecursiveIntBinOpEvaluator should have handled integral types")(((!E->getLHS()->getType()->isIntegralOrEnumerationType
() || !E->getRHS()->getType()->isIntegralOrEnumerationType
()) && "DataRecursiveIntBinOpEvaluator should have handled integral types"
) ? static_cast<void> (0) : __assert_fail ("(!E->getLHS()->getType()->isIntegralOrEnumerationType() || !E->getRHS()->getType()->isIntegralOrEnumerationType()) && \"DataRecursiveIntBinOpEvaluator should have handled integral types\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12855, __PRETTY_FUNCTION__))
;
12856
12857 if (E->isComparisonOp()) {
12858 // Evaluate builtin binary comparisons by evaluating them as three-way
12859 // comparisons and then translating the result.
12860 auto OnSuccess = [&](CmpResult CR, const BinaryOperator *E) {
12861 assert((CR != CmpResult::Unequal || E->isEqualityOp()) &&(((CR != CmpResult::Unequal || E->isEqualityOp()) &&
"should only produce Unequal for equality comparisons") ? static_cast
<void> (0) : __assert_fail ("(CR != CmpResult::Unequal || E->isEqualityOp()) && \"should only produce Unequal for equality comparisons\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12862, __PRETTY_FUNCTION__))
12862 "should only produce Unequal for equality comparisons")(((CR != CmpResult::Unequal || E->isEqualityOp()) &&
"should only produce Unequal for equality comparisons") ? static_cast
<void> (0) : __assert_fail ("(CR != CmpResult::Unequal || E->isEqualityOp()) && \"should only produce Unequal for equality comparisons\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12862, __PRETTY_FUNCTION__))
;
12863 bool IsEqual = CR == CmpResult::Equal,
12864 IsLess = CR == CmpResult::Less,
12865 IsGreater = CR == CmpResult::Greater;
12866 auto Op = E->getOpcode();
12867 switch (Op) {
12868 default:
12869 llvm_unreachable("unsupported binary operator")::llvm::llvm_unreachable_internal("unsupported binary operator"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 12869)
;
12870 case BO_EQ:
12871 case BO_NE:
12872 return Success(IsEqual == (Op == BO_EQ), E);
12873 case BO_LT:
12874 return Success(IsLess, E);
12875 case BO_GT:
12876 return Success(IsGreater, E);
12877 case BO_LE:
12878 return Success(IsEqual || IsLess, E);
12879 case BO_GE:
12880 return Success(IsEqual || IsGreater, E);
12881 }
12882 };
12883 return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
12884 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
12885 });
12886 }
12887
12888 QualType LHSTy = E->getLHS()->getType();
12889 QualType RHSTy = E->getRHS()->getType();
12890
12891 if (LHSTy->isPointerType() && RHSTy->isPointerType() &&
12892 E->getOpcode() == BO_Sub) {
12893 LValue LHSValue, RHSValue;
12894
12895 bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
12896 if (!LHSOK && !Info.noteFailure())
12897 return false;
12898
12899 if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
12900 return false;
12901
12902 // Reject differing bases from the normal codepath; we special-case
12903 // comparisons to null.
12904 if (!HasSameBase(LHSValue, RHSValue)) {
12905 // Handle &&A - &&B.
12906 if (!LHSValue.Offset.isZero() || !RHSValue.Offset.isZero())
12907 return Error(E);
12908 const Expr *LHSExpr = LHSValue.Base.dyn_cast<const Expr *>();
12909 const Expr *RHSExpr = RHSValue.Base.dyn_cast<const Expr *>();
12910 if (!LHSExpr || !RHSExpr)
12911 return Error(E);
12912 const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
12913 const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
12914 if (!LHSAddrExpr || !RHSAddrExpr)
12915 return Error(E);
12916 // Make sure both labels come from the same function.
12917 if (LHSAddrExpr->getLabel()->getDeclContext() !=
12918 RHSAddrExpr->getLabel()->getDeclContext())
12919 return Error(E);
12920 return Success(APValue(LHSAddrExpr, RHSAddrExpr), E);
12921 }
12922 const CharUnits &LHSOffset = LHSValue.getLValueOffset();
12923 const CharUnits &RHSOffset = RHSValue.getLValueOffset();
12924
12925 SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
12926 SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
12927
12928 // C++11 [expr.add]p6:
12929 // Unless both pointers point to elements of the same array object, or
12930 // one past the last element of the array object, the behavior is
12931 // undefined.
12932 if (!LHSDesignator.Invalid && !RHSDesignator.Invalid &&
12933 !AreElementsOfSameArray(getType(LHSValue.Base), LHSDesignator,
12934 RHSDesignator))
12935 Info.CCEDiag(E, diag::note_constexpr_pointer_subtraction_not_same_array);
12936
12937 QualType Type = E->getLHS()->getType();
12938 QualType ElementType = Type->castAs<PointerType>()->getPointeeType();
12939
12940 CharUnits ElementSize;
12941 if (!HandleSizeof(Info, E->getExprLoc(), ElementType, ElementSize))
12942 return false;
12943
12944 // As an extension, a type may have zero size (empty struct or union in
12945 // C, array of zero length). Pointer subtraction in such cases has
12946 // undefined behavior, so is not constant.
12947 if (ElementSize.isZero()) {
12948 Info.FFDiag(E, diag::note_constexpr_pointer_subtraction_zero_size)
12949 << ElementType;
12950 return false;
12951 }
12952
12953 // FIXME: LLVM and GCC both compute LHSOffset - RHSOffset at runtime,
12954 // and produce incorrect results when it overflows. Such behavior
12955 // appears to be non-conforming, but is common, so perhaps we should
12956 // assume the standard intended for such cases to be undefined behavior
12957 // and check for them.
12958
12959 // Compute (LHSOffset - RHSOffset) / Size carefully, checking for
12960 // overflow in the final conversion to ptrdiff_t.
12961 APSInt LHS(llvm::APInt(65, (int64_t)LHSOffset.getQuantity(), true), false);
12962 APSInt RHS(llvm::APInt(65, (int64_t)RHSOffset.getQuantity(), true), false);
12963 APSInt ElemSize(llvm::APInt(65, (int64_t)ElementSize.getQuantity(), true),
12964 false);
12965 APSInt TrueResult = (LHS - RHS) / ElemSize;
12966 APSInt Result = TrueResult.trunc(Info.Ctx.getIntWidth(E->getType()));
12967
12968 if (Result.extend(65) != TrueResult &&
12969 !HandleOverflow(Info, E, TrueResult, E->getType()))
12970 return false;
12971 return Success(Result, E);
12972 }
12973
12974 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
12975}
12976
12977/// VisitUnaryExprOrTypeTraitExpr - Evaluate a sizeof, alignof or vec_step with
12978/// a result as the expression's type.
12979bool IntExprEvaluator::VisitUnaryExprOrTypeTraitExpr(
12980 const UnaryExprOrTypeTraitExpr *E) {
12981 switch(E->getKind()) {
12982 case UETT_PreferredAlignOf:
12983 case UETT_AlignOf: {
12984 if (E->isArgumentType())
12985 return Success(GetAlignOfType(Info, E->getArgumentType(), E->getKind()),
12986 E);
12987 else
12988 return Success(GetAlignOfExpr(Info, E->getArgumentExpr(), E->getKind()),
12989 E);
12990 }
12991
12992 case UETT_VecStep: {
12993 QualType Ty = E->getTypeOfArgument();
12994
12995 if (Ty->isVectorType()) {
12996 unsigned n = Ty->castAs<VectorType>()->getNumElements();
12997
12998 // The vec_step built-in functions that take a 3-component
12999 // vector return 4. (OpenCL 1.1 spec 6.11.12)
13000 if (n == 3)
13001 n = 4;
13002
13003 return Success(n, E);
13004 } else
13005 return Success(1, E);
13006 }
13007
13008 case UETT_SizeOf: {
13009 QualType SrcTy = E->getTypeOfArgument();
13010 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
13011 // the result is the size of the referenced type."
13012 if (const ReferenceType *Ref = SrcTy->getAs<ReferenceType>())
13013 SrcTy = Ref->getPointeeType();
13014
13015 CharUnits Sizeof;
13016 if (!HandleSizeof(Info, E->getExprLoc(), SrcTy, Sizeof))
13017 return false;
13018 return Success(Sizeof, E);
13019 }
13020 case UETT_OpenMPRequiredSimdAlign:
13021 assert(E->isArgumentType())((E->isArgumentType()) ? static_cast<void> (0) : __assert_fail
("E->isArgumentType()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13021, __PRETTY_FUNCTION__))
;
13022 return Success(
13023 Info.Ctx.toCharUnitsFromBits(
13024 Info.Ctx.getOpenMPDefaultSimdAlign(E->getArgumentType()))
13025 .getQuantity(),
13026 E);
13027 }
13028
13029 llvm_unreachable("unknown expr/type trait")::llvm::llvm_unreachable_internal("unknown expr/type trait", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13029)
;
13030}
13031
13032bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *OOE) {
13033 CharUnits Result;
13034 unsigned n = OOE->getNumComponents();
13035 if (n == 0)
13036 return Error(OOE);
13037 QualType CurrentType = OOE->getTypeSourceInfo()->getType();
13038 for (unsigned i = 0; i != n; ++i) {
13039 OffsetOfNode ON = OOE->getComponent(i);
13040 switch (ON.getKind()) {
13041 case OffsetOfNode::Array: {
13042 const Expr *Idx = OOE->getIndexExpr(ON.getArrayExprIndex());
13043 APSInt IdxResult;
13044 if (!EvaluateInteger(Idx, IdxResult, Info))
13045 return false;
13046 const ArrayType *AT = Info.Ctx.getAsArrayType(CurrentType);
13047 if (!AT)
13048 return Error(OOE);
13049 CurrentType = AT->getElementType();
13050 CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(CurrentType);
13051 Result += IdxResult.getSExtValue() * ElementSize;
13052 break;
13053 }
13054
13055 case OffsetOfNode::Field: {
13056 FieldDecl *MemberDecl = ON.getField();
13057 const RecordType *RT = CurrentType->getAs<RecordType>();
13058 if (!RT)
13059 return Error(OOE);
13060 RecordDecl *RD = RT->getDecl();
13061 if (RD->isInvalidDecl()) return false;
13062 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
13063 unsigned i = MemberDecl->getFieldIndex();
13064 assert(i < RL.getFieldCount() && "offsetof field in wrong type")((i < RL.getFieldCount() && "offsetof field in wrong type"
) ? static_cast<void> (0) : __assert_fail ("i < RL.getFieldCount() && \"offsetof field in wrong type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13064, __PRETTY_FUNCTION__))
;
13065 Result += Info.Ctx.toCharUnitsFromBits(RL.getFieldOffset(i));
13066 CurrentType = MemberDecl->getType().getNonReferenceType();
13067 break;
13068 }
13069
13070 case OffsetOfNode::Identifier:
13071 llvm_unreachable("dependent __builtin_offsetof")::llvm::llvm_unreachable_internal("dependent __builtin_offsetof"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13071)
;
13072
13073 case OffsetOfNode::Base: {
13074 CXXBaseSpecifier *BaseSpec = ON.getBase();
13075 if (BaseSpec->isVirtual())
13076 return Error(OOE);
13077
13078 // Find the layout of the class whose base we are looking into.
13079 const RecordType *RT = CurrentType->getAs<RecordType>();
13080 if (!RT)
13081 return Error(OOE);
13082 RecordDecl *RD = RT->getDecl();
13083 if (RD->isInvalidDecl()) return false;
13084 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
13085
13086 // Find the base class itself.
13087 CurrentType = BaseSpec->getType();
13088 const RecordType *BaseRT = CurrentType->getAs<RecordType>();
13089 if (!BaseRT)
13090 return Error(OOE);
13091
13092 // Add the offset to the base.
13093 Result += RL.getBaseClassOffset(cast<CXXRecordDecl>(BaseRT->getDecl()));
13094 break;
13095 }
13096 }
13097 }
13098 return Success(Result, OOE);
13099}
13100
13101bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
13102 switch (E->getOpcode()) {
13103 default:
13104 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
13105 // See C99 6.6p3.
13106 return Error(E);
13107 case UO_Extension:
13108 // FIXME: Should extension allow i-c-e extension expressions in its scope?
13109 // If so, we could clear the diagnostic ID.
13110 return Visit(E->getSubExpr());
13111 case UO_Plus:
13112 // The result is just the value.
13113 return Visit(E->getSubExpr());
13114 case UO_Minus: {
13115 if (!Visit(E->getSubExpr()))
13116 return false;
13117 if (!Result.isInt()) return Error(E);
13118 const APSInt &Value = Result.getInt();
13119 if (Value.isSigned() && Value.isMinSignedValue() && E->canOverflow() &&
13120 !HandleOverflow(Info, E, -Value.extend(Value.getBitWidth() + 1),
13121 E->getType()))
13122 return false;
13123 return Success(-Value, E);
13124 }
13125 case UO_Not: {
13126 if (!Visit(E->getSubExpr()))
13127 return false;
13128 if (!Result.isInt()) return Error(E);
13129 return Success(~Result.getInt(), E);
13130 }
13131 case UO_LNot: {
13132 bool bres;
13133 if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
13134 return false;
13135 return Success(!bres, E);
13136 }
13137 }
13138}
13139
13140/// HandleCast - This is used to evaluate implicit or explicit casts where the
13141/// result type is integer.
13142bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
13143 const Expr *SubExpr = E->getSubExpr();
13144 QualType DestType = E->getType();
13145 QualType SrcType = SubExpr->getType();
13146
13147 switch (E->getCastKind()) {
13148 case CK_BaseToDerived:
13149 case CK_DerivedToBase:
13150 case CK_UncheckedDerivedToBase:
13151 case CK_Dynamic:
13152 case CK_ToUnion:
13153 case CK_ArrayToPointerDecay:
13154 case CK_FunctionToPointerDecay:
13155 case CK_NullToPointer:
13156 case CK_NullToMemberPointer:
13157 case CK_BaseToDerivedMemberPointer:
13158 case CK_DerivedToBaseMemberPointer:
13159 case CK_ReinterpretMemberPointer:
13160 case CK_ConstructorConversion:
13161 case CK_IntegralToPointer:
13162 case CK_ToVoid:
13163 case CK_VectorSplat:
13164 case CK_IntegralToFloating:
13165 case CK_FloatingCast:
13166 case CK_CPointerToObjCPointerCast:
13167 case CK_BlockPointerToObjCPointerCast:
13168 case CK_AnyPointerToBlockPointerCast:
13169 case CK_ObjCObjectLValueCast:
13170 case CK_FloatingRealToComplex:
13171 case CK_FloatingComplexToReal:
13172 case CK_FloatingComplexCast:
13173 case CK_FloatingComplexToIntegralComplex:
13174 case CK_IntegralRealToComplex:
13175 case CK_IntegralComplexCast:
13176 case CK_IntegralComplexToFloatingComplex:
13177 case CK_BuiltinFnToFnPtr:
13178 case CK_ZeroToOCLOpaqueType:
13179 case CK_NonAtomicToAtomic:
13180 case CK_AddressSpaceConversion:
13181 case CK_IntToOCLSampler:
13182 case CK_FloatingToFixedPoint:
13183 case CK_FixedPointToFloating:
13184 case CK_FixedPointCast:
13185 case CK_IntegralToFixedPoint:
13186 llvm_unreachable("invalid cast kind for integral value")::llvm::llvm_unreachable_internal("invalid cast kind for integral value"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13186)
;
13187
13188 case CK_BitCast:
13189 case CK_Dependent:
13190 case CK_LValueBitCast:
13191 case CK_ARCProduceObject:
13192 case CK_ARCConsumeObject:
13193 case CK_ARCReclaimReturnedObject:
13194 case CK_ARCExtendBlockObject:
13195 case CK_CopyAndAutoreleaseBlockObject:
13196 return Error(E);
13197
13198 case CK_UserDefinedConversion:
13199 case CK_LValueToRValue:
13200 case CK_AtomicToNonAtomic:
13201 case CK_NoOp:
13202 case CK_LValueToRValueBitCast:
13203 return ExprEvaluatorBaseTy::VisitCastExpr(E);
13204
13205 case CK_MemberPointerToBoolean:
13206 case CK_PointerToBoolean:
13207 case CK_IntegralToBoolean:
13208 case CK_FloatingToBoolean:
13209 case CK_BooleanToSignedIntegral:
13210 case CK_FloatingComplexToBoolean:
13211 case CK_IntegralComplexToBoolean: {
13212 bool BoolResult;
13213 if (!EvaluateAsBooleanCondition(SubExpr, BoolResult, Info))
13214 return false;
13215 uint64_t IntResult = BoolResult;
13216 if (BoolResult && E->getCastKind() == CK_BooleanToSignedIntegral)
13217 IntResult = (uint64_t)-1;
13218 return Success(IntResult, E);
13219 }
13220
13221 case CK_FixedPointToIntegral: {
13222 APFixedPoint Src(Info.Ctx.getFixedPointSemantics(SrcType));
13223 if (!EvaluateFixedPoint(SubExpr, Src, Info))
13224 return false;
13225 bool Overflowed;
13226 llvm::APSInt Result = Src.convertToInt(
13227 Info.Ctx.getIntWidth(DestType),
13228 DestType->isSignedIntegerOrEnumerationType(), &Overflowed);
13229 if (Overflowed && !HandleOverflow(Info, E, Result, DestType))
13230 return false;
13231 return Success(Result, E);
13232 }
13233
13234 case CK_FixedPointToBoolean: {
13235 // Unsigned padding does not affect this.
13236 APValue Val;
13237 if (!Evaluate(Val, Info, SubExpr))
13238 return false;
13239 return Success(Val.getFixedPoint().getBoolValue(), E);
13240 }
13241
13242 case CK_IntegralCast: {
13243 if (!Visit(SubExpr))
13244 return false;
13245
13246 if (!Result.isInt()) {
13247 // Allow casts of address-of-label differences if they are no-ops
13248 // or narrowing. (The narrowing case isn't actually guaranteed to
13249 // be constant-evaluatable except in some narrow cases which are hard
13250 // to detect here. We let it through on the assumption the user knows
13251 // what they are doing.)
13252 if (Result.isAddrLabelDiff())
13253 return Info.Ctx.getTypeSize(DestType) <= Info.Ctx.getTypeSize(SrcType);
13254 // Only allow casts of lvalues if they are lossless.
13255 return Info.Ctx.getTypeSize(DestType) == Info.Ctx.getTypeSize(SrcType);
13256 }
13257
13258 return Success(HandleIntToIntCast(Info, E, DestType, SrcType,
13259 Result.getInt()), E);
13260 }
13261
13262 case CK_PointerToIntegral: {
13263 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
13264
13265 LValue LV;
13266 if (!EvaluatePointer(SubExpr, LV, Info))
13267 return false;
13268
13269 if (LV.getLValueBase()) {
13270 // Only allow based lvalue casts if they are lossless.
13271 // FIXME: Allow a larger integer size than the pointer size, and allow
13272 // narrowing back down to pointer width in subsequent integral casts.
13273 // FIXME: Check integer type's active bits, not its type size.
13274 if (Info.Ctx.getTypeSize(DestType) != Info.Ctx.getTypeSize(SrcType))
13275 return Error(E);
13276
13277 LV.Designator.setInvalid();
13278 LV.moveInto(Result);
13279 return true;
13280 }
13281
13282 APSInt AsInt;
13283 APValue V;
13284 LV.moveInto(V);
13285 if (!V.toIntegralConstant(AsInt, SrcType, Info.Ctx))
13286 llvm_unreachable("Can't cast this!")::llvm::llvm_unreachable_internal("Can't cast this!", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13286)
;
13287
13288 return Success(HandleIntToIntCast(Info, E, DestType, SrcType, AsInt), E);
13289 }
13290
13291 case CK_IntegralComplexToReal: {
13292 ComplexValue C;
13293 if (!EvaluateComplex(SubExpr, C, Info))
13294 return false;
13295 return Success(C.getComplexIntReal(), E);
13296 }
13297
13298 case CK_FloatingToIntegral: {
13299 APFloat F(0.0);
13300 if (!EvaluateFloat(SubExpr, F, Info))
13301 return false;
13302
13303 APSInt Value;
13304 if (!HandleFloatToIntCast(Info, E, SrcType, F, DestType, Value))
13305 return false;
13306 return Success(Value, E);
13307 }
13308 }
13309
13310 llvm_unreachable("unknown cast resulting in integral value")::llvm::llvm_unreachable_internal("unknown cast resulting in integral value"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13310)
;
13311}
13312
13313bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
13314 if (E->getSubExpr()->getType()->isAnyComplexType()) {
13315 ComplexValue LV;
13316 if (!EvaluateComplex(E->getSubExpr(), LV, Info))
13317 return false;
13318 if (!LV.isComplexInt())
13319 return Error(E);
13320 return Success(LV.getComplexIntReal(), E);
13321 }
13322
13323 return Visit(E->getSubExpr());
13324}
13325
13326bool IntExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
13327 if (E->getSubExpr()->getType()->isComplexIntegerType()) {
13328 ComplexValue LV;
13329 if (!EvaluateComplex(E->getSubExpr(), LV, Info))
13330 return false;
13331 if (!LV.isComplexInt())
13332 return Error(E);
13333 return Success(LV.getComplexIntImag(), E);
13334 }
13335
13336 VisitIgnoredValue(E->getSubExpr());
13337 return Success(0, E);
13338}
13339
13340bool IntExprEvaluator::VisitSizeOfPackExpr(const SizeOfPackExpr *E) {
13341 return Success(E->getPackLength(), E);
13342}
13343
13344bool IntExprEvaluator::VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
13345 return Success(E->getValue(), E);
13346}
13347
13348bool IntExprEvaluator::VisitConceptSpecializationExpr(
13349 const ConceptSpecializationExpr *E) {
13350 return Success(E->isSatisfied(), E);
13351}
13352
13353bool IntExprEvaluator::VisitRequiresExpr(const RequiresExpr *E) {
13354 return Success(E->isSatisfied(), E);
13355}
13356
13357bool FixedPointExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
13358 switch (E->getOpcode()) {
13359 default:
13360 // Invalid unary operators
13361 return Error(E);
13362 case UO_Plus:
13363 // The result is just the value.
13364 return Visit(E->getSubExpr());
13365 case UO_Minus: {
13366 if (!Visit(E->getSubExpr())) return false;
13367 if (!Result.isFixedPoint())
13368 return Error(E);
13369 bool Overflowed;
13370 APFixedPoint Negated = Result.getFixedPoint().negate(&Overflowed);
13371 if (Overflowed && !HandleOverflow(Info, E, Negated, E->getType()))
13372 return false;
13373 return Success(Negated, E);
13374 }
13375 case UO_LNot: {
13376 bool bres;
13377 if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
13378 return false;
13379 return Success(!bres, E);
13380 }
13381 }
13382}
13383
13384bool FixedPointExprEvaluator::VisitCastExpr(const CastExpr *E) {
13385 const Expr *SubExpr = E->getSubExpr();
13386 QualType DestType = E->getType();
13387 assert(DestType->isFixedPointType() &&((DestType->isFixedPointType() && "Expected destination type to be a fixed point type"
) ? static_cast<void> (0) : __assert_fail ("DestType->isFixedPointType() && \"Expected destination type to be a fixed point type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13388, __PRETTY_FUNCTION__))
13388 "Expected destination type to be a fixed point type")((DestType->isFixedPointType() && "Expected destination type to be a fixed point type"
) ? static_cast<void> (0) : __assert_fail ("DestType->isFixedPointType() && \"Expected destination type to be a fixed point type\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13388, __PRETTY_FUNCTION__))
;
13389 auto DestFXSema = Info.Ctx.getFixedPointSemantics(DestType);
13390
13391 switch (E->getCastKind()) {
13392 case CK_FixedPointCast: {
13393 APFixedPoint Src(Info.Ctx.getFixedPointSemantics(SubExpr->getType()));
13394 if (!EvaluateFixedPoint(SubExpr, Src, Info))
13395 return false;
13396 bool Overflowed;
13397 APFixedPoint Result = Src.convert(DestFXSema, &Overflowed);
13398 if (Overflowed) {
13399 if (Info.checkingForUndefinedBehavior())
13400 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
13401 diag::warn_fixedpoint_constant_overflow)
13402 << Result.toString() << E->getType();
13403 if (!HandleOverflow(Info, E, Result, E->getType()))
13404 return false;
13405 }
13406 return Success(Result, E);
13407 }
13408 case CK_IntegralToFixedPoint: {
13409 APSInt Src;
13410 if (!EvaluateInteger(SubExpr, Src, Info))
13411 return false;
13412
13413 bool Overflowed;
13414 APFixedPoint IntResult = APFixedPoint::getFromIntValue(
13415 Src, Info.Ctx.getFixedPointSemantics(DestType), &Overflowed);
13416
13417 if (Overflowed) {
13418 if (Info.checkingForUndefinedBehavior())
13419 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
13420 diag::warn_fixedpoint_constant_overflow)
13421 << IntResult.toString() << E->getType();
13422 if (!HandleOverflow(Info, E, IntResult, E->getType()))
13423 return false;
13424 }
13425
13426 return Success(IntResult, E);
13427 }
13428 case CK_FloatingToFixedPoint: {
13429 APFloat Src(0.0);
13430 if (!EvaluateFloat(SubExpr, Src, Info))
13431 return false;
13432
13433 bool Overflowed;
13434 APFixedPoint Result = APFixedPoint::getFromFloatValue(
13435 Src, Info.Ctx.getFixedPointSemantics(DestType), &Overflowed);
13436
13437 if (Overflowed) {
13438 if (Info.checkingForUndefinedBehavior())
13439 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
13440 diag::warn_fixedpoint_constant_overflow)
13441 << Result.toString() << E->getType();
13442 if (!HandleOverflow(Info, E, Result, E->getType()))
13443 return false;
13444 }
13445
13446 return Success(Result, E);
13447 }
13448 case CK_NoOp:
13449 case CK_LValueToRValue:
13450 return ExprEvaluatorBaseTy::VisitCastExpr(E);
13451 default:
13452 return Error(E);
13453 }
13454}
13455
13456bool FixedPointExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
13457 if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
13458 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
13459
13460 const Expr *LHS = E->getLHS();
13461 const Expr *RHS = E->getRHS();
13462 FixedPointSemantics ResultFXSema =
13463 Info.Ctx.getFixedPointSemantics(E->getType());
13464
13465 APFixedPoint LHSFX(Info.Ctx.getFixedPointSemantics(LHS->getType()));
13466 if (!EvaluateFixedPointOrInteger(LHS, LHSFX, Info))
13467 return false;
13468 APFixedPoint RHSFX(Info.Ctx.getFixedPointSemantics(RHS->getType()));
13469 if (!EvaluateFixedPointOrInteger(RHS, RHSFX, Info))
13470 return false;
13471
13472 bool OpOverflow = false, ConversionOverflow = false;
13473 APFixedPoint Result(LHSFX.getSemantics());
13474 switch (E->getOpcode()) {
13475 case BO_Add: {
13476 Result = LHSFX.add(RHSFX, &OpOverflow)
13477 .convert(ResultFXSema, &ConversionOverflow);
13478 break;
13479 }
13480 case BO_Sub: {
13481 Result = LHSFX.sub(RHSFX, &OpOverflow)
13482 .convert(ResultFXSema, &ConversionOverflow);
13483 break;
13484 }
13485 case BO_Mul: {
13486 Result = LHSFX.mul(RHSFX, &OpOverflow)
13487 .convert(ResultFXSema, &ConversionOverflow);
13488 break;
13489 }
13490 case BO_Div: {
13491 if (RHSFX.getValue() == 0) {
13492 Info.FFDiag(E, diag::note_expr_divide_by_zero);
13493 return false;
13494 }
13495 Result = LHSFX.div(RHSFX, &OpOverflow)
13496 .convert(ResultFXSema, &ConversionOverflow);
13497 break;
13498 }
13499 case BO_Shl:
13500 case BO_Shr: {
13501 FixedPointSemantics LHSSema = LHSFX.getSemantics();
13502 llvm::APSInt RHSVal = RHSFX.getValue();
13503
13504 unsigned ShiftBW =
13505 LHSSema.getWidth() - (unsigned)LHSSema.hasUnsignedPadding();
13506 unsigned Amt = RHSVal.getLimitedValue(ShiftBW - 1);
13507 // Embedded-C 4.1.6.2.2:
13508 // The right operand must be nonnegative and less than the total number
13509 // of (nonpadding) bits of the fixed-point operand ...
13510 if (RHSVal.isNegative())
13511 Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHSVal;
13512 else if (Amt != RHSVal)
13513 Info.CCEDiag(E, diag::note_constexpr_large_shift)
13514 << RHSVal << E->getType() << ShiftBW;
13515
13516 if (E->getOpcode() == BO_Shl)
13517 Result = LHSFX.shl(Amt, &OpOverflow);
13518 else
13519 Result = LHSFX.shr(Amt, &OpOverflow);
13520 break;
13521 }
13522 default:
13523 return false;
13524 }
13525 if (OpOverflow || ConversionOverflow) {
13526 if (Info.checkingForUndefinedBehavior())
13527 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
13528 diag::warn_fixedpoint_constant_overflow)
13529 << Result.toString() << E->getType();
13530 if (!HandleOverflow(Info, E, Result, E->getType()))
13531 return false;
13532 }
13533 return Success(Result, E);
13534}
13535
13536//===----------------------------------------------------------------------===//
13537// Float Evaluation
13538//===----------------------------------------------------------------------===//
13539
13540namespace {
13541class FloatExprEvaluator
13542 : public ExprEvaluatorBase<FloatExprEvaluator> {
13543 APFloat &Result;
13544public:
13545 FloatExprEvaluator(EvalInfo &info, APFloat &result)
13546 : ExprEvaluatorBaseTy(info), Result(result) {}
13547
13548 bool Success(const APValue &V, const Expr *e) {
13549 Result = V.getFloat();
13550 return true;
13551 }
13552
13553 bool ZeroInitialization(const Expr *E) {
13554 Result = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(E->getType()));
13555 return true;
13556 }
13557
13558 bool VisitCallExpr(const CallExpr *E);
13559
13560 bool VisitUnaryOperator(const UnaryOperator *E);
13561 bool VisitBinaryOperator(const BinaryOperator *E);
13562 bool VisitFloatingLiteral(const FloatingLiteral *E);
13563 bool VisitCastExpr(const CastExpr *E);
13564
13565 bool VisitUnaryReal(const UnaryOperator *E);
13566 bool VisitUnaryImag(const UnaryOperator *E);
13567
13568 // FIXME: Missing: array subscript of vector, member of vector
13569};
13570} // end anonymous namespace
13571
13572static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) {
13573 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13573, __PRETTY_FUNCTION__))
;
13574 assert(E->isRValue() && E->getType()->isRealFloatingType())((E->isRValue() && E->getType()->isRealFloatingType
()) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isRealFloatingType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13574, __PRETTY_FUNCTION__))
;
13575 return FloatExprEvaluator(Info, Result).Visit(E);
13576}
13577
13578static bool TryEvaluateBuiltinNaN(const ASTContext &Context,
13579 QualType ResultTy,
13580 const Expr *Arg,
13581 bool SNaN,
13582 llvm::APFloat &Result) {
13583 const StringLiteral *S = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts());
13584 if (!S) return false;
13585
13586 const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(ResultTy);
13587
13588 llvm::APInt fill;
13589
13590 // Treat empty strings as if they were zero.
13591 if (S->getString().empty())
13592 fill = llvm::APInt(32, 0);
13593 else if (S->getString().getAsInteger(0, fill))
13594 return false;
13595
13596 if (Context.getTargetInfo().isNan2008()) {
13597 if (SNaN)
13598 Result = llvm::APFloat::getSNaN(Sem, false, &fill);
13599 else
13600 Result = llvm::APFloat::getQNaN(Sem, false, &fill);
13601 } else {
13602 // Prior to IEEE 754-2008, architectures were allowed to choose whether
13603 // the first bit of their significand was set for qNaN or sNaN. MIPS chose
13604 // a different encoding to what became a standard in 2008, and for pre-
13605 // 2008 revisions, MIPS interpreted sNaN-2008 as qNan and qNaN-2008 as
13606 // sNaN. This is now known as "legacy NaN" encoding.
13607 if (SNaN)
13608 Result = llvm::APFloat::getQNaN(Sem, false, &fill);
13609 else
13610 Result = llvm::APFloat::getSNaN(Sem, false, &fill);
13611 }
13612
13613 return true;
13614}
13615
13616bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
13617 switch (E->getBuiltinCallee()) {
13618 default:
13619 return ExprEvaluatorBaseTy::VisitCallExpr(E);
13620
13621 case Builtin::BI__builtin_huge_val:
13622 case Builtin::BI__builtin_huge_valf:
13623 case Builtin::BI__builtin_huge_vall:
13624 case Builtin::BI__builtin_huge_valf128:
13625 case Builtin::BI__builtin_inf:
13626 case Builtin::BI__builtin_inff:
13627 case Builtin::BI__builtin_infl:
13628 case Builtin::BI__builtin_inff128: {
13629 const llvm::fltSemantics &Sem =
13630 Info.Ctx.getFloatTypeSemantics(E->getType());
13631 Result = llvm::APFloat::getInf(Sem);
13632 return true;
13633 }
13634
13635 case Builtin::BI__builtin_nans:
13636 case Builtin::BI__builtin_nansf:
13637 case Builtin::BI__builtin_nansl:
13638 case Builtin::BI__builtin_nansf128:
13639 if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
13640 true, Result))
13641 return Error(E);
13642 return true;
13643
13644 case Builtin::BI__builtin_nan:
13645 case Builtin::BI__builtin_nanf:
13646 case Builtin::BI__builtin_nanl:
13647 case Builtin::BI__builtin_nanf128:
13648 // If this is __builtin_nan() turn this into a nan, otherwise we
13649 // can't constant fold it.
13650 if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
13651 false, Result))
13652 return Error(E);
13653 return true;
13654
13655 case Builtin::BI__builtin_fabs:
13656 case Builtin::BI__builtin_fabsf:
13657 case Builtin::BI__builtin_fabsl:
13658 case Builtin::BI__builtin_fabsf128:
13659 // The C standard says "fabs raises no floating-point exceptions,
13660 // even if x is a signaling NaN. The returned value is independent of
13661 // the current rounding direction mode." Therefore constant folding can
13662 // proceed without regard to the floating point settings.
13663 // Reference, WG14 N2478 F.10.4.3
13664 if (!EvaluateFloat(E->getArg(0), Result, Info))
13665 return false;
13666
13667 if (Result.isNegative())
13668 Result.changeSign();
13669 return true;
13670
13671 // FIXME: Builtin::BI__builtin_powi
13672 // FIXME: Builtin::BI__builtin_powif
13673 // FIXME: Builtin::BI__builtin_powil
13674
13675 case Builtin::BI__builtin_copysign:
13676 case Builtin::BI__builtin_copysignf:
13677 case Builtin::BI__builtin_copysignl:
13678 case Builtin::BI__builtin_copysignf128: {
13679 APFloat RHS(0.);
13680 if (!EvaluateFloat(E->getArg(0), Result, Info) ||
13681 !EvaluateFloat(E->getArg(1), RHS, Info))
13682 return false;
13683 Result.copySign(RHS);
13684 return true;
13685 }
13686 }
13687}
13688
13689bool FloatExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
13690 if (E->getSubExpr()->getType()->isAnyComplexType()) {
13691 ComplexValue CV;
13692 if (!EvaluateComplex(E->getSubExpr(), CV, Info))
13693 return false;
13694 Result = CV.FloatReal;
13695 return true;
13696 }
13697
13698 return Visit(E->getSubExpr());
13699}
13700
13701bool FloatExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
13702 if (E->getSubExpr()->getType()->isAnyComplexType()) {
13703 ComplexValue CV;
13704 if (!EvaluateComplex(E->getSubExpr(), CV, Info))
13705 return false;
13706 Result = CV.FloatImag;
13707 return true;
13708 }
13709
13710 VisitIgnoredValue(E->getSubExpr());
13711 const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(E->getType());
13712 Result = llvm::APFloat::getZero(Sem);
13713 return true;
13714}
13715
13716bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
13717 switch (E->getOpcode()) {
13718 default: return Error(E);
13719 case UO_Plus:
13720 return EvaluateFloat(E->getSubExpr(), Result, Info);
13721 case UO_Minus:
13722 // In C standard, WG14 N2478 F.3 p4
13723 // "the unary - raises no floating point exceptions,
13724 // even if the operand is signalling."
13725 if (!EvaluateFloat(E->getSubExpr(), Result, Info))
13726 return false;
13727 Result.changeSign();
13728 return true;
13729 }
13730}
13731
13732bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
13733 if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
13734 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
13735
13736 APFloat RHS(0.0);
13737 bool LHSOK = EvaluateFloat(E->getLHS(), Result, Info);
13738 if (!LHSOK && !Info.noteFailure())
13739 return false;
13740 return EvaluateFloat(E->getRHS(), RHS, Info) && LHSOK &&
13741 handleFloatFloatBinOp(Info, E, Result, E->getOpcode(), RHS);
13742}
13743
13744bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) {
13745 Result = E->getValue();
13746 return true;
13747}
13748
13749bool FloatExprEvaluator::VisitCastExpr(const CastExpr *E) {
13750 const Expr* SubExpr = E->getSubExpr();
13751
13752 switch (E->getCastKind()) {
13753 default:
13754 return ExprEvaluatorBaseTy::VisitCastExpr(E);
13755
13756 case CK_IntegralToFloating: {
13757 APSInt IntResult;
13758 const FPOptions FPO = E->getFPFeaturesInEffect(
13759 Info.Ctx.getLangOpts());
13760 return EvaluateInteger(SubExpr, IntResult, Info) &&
13761 HandleIntToFloatCast(Info, E, FPO, SubExpr->getType(),
13762 IntResult, E->getType(), Result);
13763 }
13764
13765 case CK_FixedPointToFloating: {
13766 APFixedPoint FixResult(Info.Ctx.getFixedPointSemantics(SubExpr->getType()));
13767 if (!EvaluateFixedPoint(SubExpr, FixResult, Info))
13768 return false;
13769 Result =
13770 FixResult.convertToFloat(Info.Ctx.getFloatTypeSemantics(E->getType()));
13771 return true;
13772 }
13773
13774 case CK_FloatingCast: {
13775 if (!Visit(SubExpr))
13776 return false;
13777 return HandleFloatToFloatCast(Info, E, SubExpr->getType(), E->getType(),
13778 Result);
13779 }
13780
13781 case CK_FloatingComplexToReal: {
13782 ComplexValue V;
13783 if (!EvaluateComplex(SubExpr, V, Info))
13784 return false;
13785 Result = V.getComplexFloatReal();
13786 return true;
13787 }
13788 }
13789}
13790
13791//===----------------------------------------------------------------------===//
13792// Complex Evaluation (for float and integer)
13793//===----------------------------------------------------------------------===//
13794
13795namespace {
13796class ComplexExprEvaluator
13797 : public ExprEvaluatorBase<ComplexExprEvaluator> {
13798 ComplexValue &Result;
13799
13800public:
13801 ComplexExprEvaluator(EvalInfo &info, ComplexValue &Result)
13802 : ExprEvaluatorBaseTy(info), Result(Result) {}
13803
13804 bool Success(const APValue &V, const Expr *e) {
13805 Result.setFrom(V);
13806 return true;
13807 }
13808
13809 bool ZeroInitialization(const Expr *E);
13810
13811 //===--------------------------------------------------------------------===//
13812 // Visitor Methods
13813 //===--------------------------------------------------------------------===//
13814
13815 bool VisitImaginaryLiteral(const ImaginaryLiteral *E);
13816 bool VisitCastExpr(const CastExpr *E);
13817 bool VisitBinaryOperator(const BinaryOperator *E);
13818 bool VisitUnaryOperator(const UnaryOperator *E);
13819 bool VisitInitListExpr(const InitListExpr *E);
13820 bool VisitCallExpr(const CallExpr *E);
13821};
13822} // end anonymous namespace
13823
13824static bool EvaluateComplex(const Expr *E, ComplexValue &Result,
13825 EvalInfo &Info) {
13826 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13826, __PRETTY_FUNCTION__))
;
13827 assert(E->isRValue() && E->getType()->isAnyComplexType())((E->isRValue() && E->getType()->isAnyComplexType
()) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isAnyComplexType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13827, __PRETTY_FUNCTION__))
;
13828 return ComplexExprEvaluator(Info, Result).Visit(E);
13829}
13830
13831bool ComplexExprEvaluator::ZeroInitialization(const Expr *E) {
13832 QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
13833 if (ElemTy->isRealFloatingType()) {
13834 Result.makeComplexFloat();
13835 APFloat Zero = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(ElemTy));
13836 Result.FloatReal = Zero;
13837 Result.FloatImag = Zero;
13838 } else {
13839 Result.makeComplexInt();
13840 APSInt Zero = Info.Ctx.MakeIntValue(0, ElemTy);
13841 Result.IntReal = Zero;
13842 Result.IntImag = Zero;
13843 }
13844 return true;
13845}
13846
13847bool ComplexExprEvaluator::VisitImaginaryLiteral(const ImaginaryLiteral *E) {
13848 const Expr* SubExpr = E->getSubExpr();
13849
13850 if (SubExpr->getType()->isRealFloatingType()) {
13851 Result.makeComplexFloat();
13852 APFloat &Imag = Result.FloatImag;
13853 if (!EvaluateFloat(SubExpr, Imag, Info))
13854 return false;
13855
13856 Result.FloatReal = APFloat(Imag.getSemantics());
13857 return true;
13858 } else {
13859 assert(SubExpr->getType()->isIntegerType() &&((SubExpr->getType()->isIntegerType() && "Unexpected imaginary literal."
) ? static_cast<void> (0) : __assert_fail ("SubExpr->getType()->isIntegerType() && \"Unexpected imaginary literal.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13860, __PRETTY_FUNCTION__))
13860 "Unexpected imaginary literal.")((SubExpr->getType()->isIntegerType() && "Unexpected imaginary literal."
) ? static_cast<void> (0) : __assert_fail ("SubExpr->getType()->isIntegerType() && \"Unexpected imaginary literal.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13860, __PRETTY_FUNCTION__))
;
13861
13862 Result.makeComplexInt();
13863 APSInt &Imag = Result.IntImag;
13864 if (!EvaluateInteger(SubExpr, Imag, Info))
13865 return false;
13866
13867 Result.IntReal = APSInt(Imag.getBitWidth(), !Imag.isSigned());
13868 return true;
13869 }
13870}
13871
13872bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
13873
13874 switch (E->getCastKind()) {
13875 case CK_BitCast:
13876 case CK_BaseToDerived:
13877 case CK_DerivedToBase:
13878 case CK_UncheckedDerivedToBase:
13879 case CK_Dynamic:
13880 case CK_ToUnion:
13881 case CK_ArrayToPointerDecay:
13882 case CK_FunctionToPointerDecay:
13883 case CK_NullToPointer:
13884 case CK_NullToMemberPointer:
13885 case CK_BaseToDerivedMemberPointer:
13886 case CK_DerivedToBaseMemberPointer:
13887 case CK_MemberPointerToBoolean:
13888 case CK_ReinterpretMemberPointer:
13889 case CK_ConstructorConversion:
13890 case CK_IntegralToPointer:
13891 case CK_PointerToIntegral:
13892 case CK_PointerToBoolean:
13893 case CK_ToVoid:
13894 case CK_VectorSplat:
13895 case CK_IntegralCast:
13896 case CK_BooleanToSignedIntegral:
13897 case CK_IntegralToBoolean:
13898 case CK_IntegralToFloating:
13899 case CK_FloatingToIntegral:
13900 case CK_FloatingToBoolean:
13901 case CK_FloatingCast:
13902 case CK_CPointerToObjCPointerCast:
13903 case CK_BlockPointerToObjCPointerCast:
13904 case CK_AnyPointerToBlockPointerCast:
13905 case CK_ObjCObjectLValueCast:
13906 case CK_FloatingComplexToReal:
13907 case CK_FloatingComplexToBoolean:
13908 case CK_IntegralComplexToReal:
13909 case CK_IntegralComplexToBoolean:
13910 case CK_ARCProduceObject:
13911 case CK_ARCConsumeObject:
13912 case CK_ARCReclaimReturnedObject:
13913 case CK_ARCExtendBlockObject:
13914 case CK_CopyAndAutoreleaseBlockObject:
13915 case CK_BuiltinFnToFnPtr:
13916 case CK_ZeroToOCLOpaqueType:
13917 case CK_NonAtomicToAtomic:
13918 case CK_AddressSpaceConversion:
13919 case CK_IntToOCLSampler:
13920 case CK_FloatingToFixedPoint:
13921 case CK_FixedPointToFloating:
13922 case CK_FixedPointCast:
13923 case CK_FixedPointToBoolean:
13924 case CK_FixedPointToIntegral:
13925 case CK_IntegralToFixedPoint:
13926 llvm_unreachable("invalid cast kind for complex value")::llvm::llvm_unreachable_internal("invalid cast kind for complex value"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 13926)
;
13927
13928 case CK_LValueToRValue:
13929 case CK_AtomicToNonAtomic:
13930 case CK_NoOp:
13931 case CK_LValueToRValueBitCast:
13932 return ExprEvaluatorBaseTy::VisitCastExpr(E);
13933
13934 case CK_Dependent:
13935 case CK_LValueBitCast:
13936 case CK_UserDefinedConversion:
13937 return Error(E);
13938
13939 case CK_FloatingRealToComplex: {
13940 APFloat &Real = Result.FloatReal;
13941 if (!EvaluateFloat(E->getSubExpr(), Real, Info))
13942 return false;
13943
13944 Result.makeComplexFloat();
13945 Result.FloatImag = APFloat(Real.getSemantics());
13946 return true;
13947 }
13948
13949 case CK_FloatingComplexCast: {
13950 if (!Visit(E->getSubExpr()))
13951 return false;
13952
13953 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
13954 QualType From
13955 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
13956
13957 return HandleFloatToFloatCast(Info, E, From, To, Result.FloatReal) &&
13958 HandleFloatToFloatCast(Info, E, From, To, Result.FloatImag);
13959 }
13960
13961 case CK_FloatingComplexToIntegralComplex: {
13962 if (!Visit(E->getSubExpr()))
13963 return false;
13964
13965 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
13966 QualType From
13967 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
13968 Result.makeComplexInt();
13969 return HandleFloatToIntCast(Info, E, From, Result.FloatReal,
13970 To, Result.IntReal) &&
13971 HandleFloatToIntCast(Info, E, From, Result.FloatImag,
13972 To, Result.IntImag);
13973 }
13974
13975 case CK_IntegralRealToComplex: {
13976 APSInt &Real = Result.IntReal;
13977 if (!EvaluateInteger(E->getSubExpr(), Real, Info))
13978 return false;
13979
13980 Result.makeComplexInt();
13981 Result.IntImag = APSInt(Real.getBitWidth(), !Real.isSigned());
13982 return true;
13983 }
13984
13985 case CK_IntegralComplexCast: {
13986 if (!Visit(E->getSubExpr()))
13987 return false;
13988
13989 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
13990 QualType From
13991 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
13992
13993 Result.IntReal = HandleIntToIntCast(Info, E, To, From, Result.IntReal);
13994 Result.IntImag = HandleIntToIntCast(Info, E, To, From, Result.IntImag);
13995 return true;
13996 }
13997
13998 case CK_IntegralComplexToFloatingComplex: {
13999 if (!Visit(E->getSubExpr()))
14000 return false;
14001
14002 const FPOptions FPO = E->getFPFeaturesInEffect(
14003 Info.Ctx.getLangOpts());
14004 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
14005 QualType From
14006 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
14007 Result.makeComplexFloat();
14008 return HandleIntToFloatCast(Info, E, FPO, From, Result.IntReal,
14009 To, Result.FloatReal) &&
14010 HandleIntToFloatCast(Info, E, FPO, From, Result.IntImag,
14011 To, Result.FloatImag);
14012 }
14013 }
14014
14015 llvm_unreachable("unknown cast resulting in complex value")::llvm::llvm_unreachable_internal("unknown cast resulting in complex value"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14015)
;
14016}
14017
14018bool ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
14019 if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
14020 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
14021
14022 // Track whether the LHS or RHS is real at the type system level. When this is
14023 // the case we can simplify our evaluation strategy.
14024 bool LHSReal = false, RHSReal = false;
14025
14026 bool LHSOK;
14027 if (E->getLHS()->getType()->isRealFloatingType()) {
14028 LHSReal = true;
14029 APFloat &Real = Result.FloatReal;
14030 LHSOK = EvaluateFloat(E->getLHS(), Real, Info);
14031 if (LHSOK) {
14032 Result.makeComplexFloat();
14033 Result.FloatImag = APFloat(Real.getSemantics());
14034 }
14035 } else {
14036 LHSOK = Visit(E->getLHS());
14037 }
14038 if (!LHSOK && !Info.noteFailure())
14039 return false;
14040
14041 ComplexValue RHS;
14042 if (E->getRHS()->getType()->isRealFloatingType()) {
14043 RHSReal = true;
14044 APFloat &Real = RHS.FloatReal;
14045 if (!EvaluateFloat(E->getRHS(), Real, Info) || !LHSOK)
14046 return false;
14047 RHS.makeComplexFloat();
14048 RHS.FloatImag = APFloat(Real.getSemantics());
14049 } else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
14050 return false;
14051
14052 assert(!(LHSReal && RHSReal) &&((!(LHSReal && RHSReal) && "Cannot have both operands of a complex operation be real."
) ? static_cast<void> (0) : __assert_fail ("!(LHSReal && RHSReal) && \"Cannot have both operands of a complex operation be real.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14053, __PRETTY_FUNCTION__))
14053 "Cannot have both operands of a complex operation be real.")((!(LHSReal && RHSReal) && "Cannot have both operands of a complex operation be real."
) ? static_cast<void> (0) : __assert_fail ("!(LHSReal && RHSReal) && \"Cannot have both operands of a complex operation be real.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14053, __PRETTY_FUNCTION__))
;
14054 switch (E->getOpcode()) {
14055 default: return Error(E);
14056 case BO_Add:
14057 if (Result.isComplexFloat()) {
14058 Result.getComplexFloatReal().add(RHS.getComplexFloatReal(),
14059 APFloat::rmNearestTiesToEven);
14060 if (LHSReal)
14061 Result.getComplexFloatImag() = RHS.getComplexFloatImag();
14062 else if (!RHSReal)
14063 Result.getComplexFloatImag().add(RHS.getComplexFloatImag(),
14064 APFloat::rmNearestTiesToEven);
14065 } else {
14066 Result.getComplexIntReal() += RHS.getComplexIntReal();
14067 Result.getComplexIntImag() += RHS.getComplexIntImag();
14068 }
14069 break;
14070 case BO_Sub:
14071 if (Result.isComplexFloat()) {
14072 Result.getComplexFloatReal().subtract(RHS.getComplexFloatReal(),
14073 APFloat::rmNearestTiesToEven);
14074 if (LHSReal) {
14075 Result.getComplexFloatImag() = RHS.getComplexFloatImag();
14076 Result.getComplexFloatImag().changeSign();
14077 } else if (!RHSReal) {
14078 Result.getComplexFloatImag().subtract(RHS.getComplexFloatImag(),
14079 APFloat::rmNearestTiesToEven);
14080 }
14081 } else {
14082 Result.getComplexIntReal() -= RHS.getComplexIntReal();
14083 Result.getComplexIntImag() -= RHS.getComplexIntImag();
14084 }
14085 break;
14086 case BO_Mul:
14087 if (Result.isComplexFloat()) {
14088 // This is an implementation of complex multiplication according to the
14089 // constraints laid out in C11 Annex G. The implementation uses the
14090 // following naming scheme:
14091 // (a + ib) * (c + id)
14092 ComplexValue LHS = Result;
14093 APFloat &A = LHS.getComplexFloatReal();
14094 APFloat &B = LHS.getComplexFloatImag();
14095 APFloat &C = RHS.getComplexFloatReal();
14096 APFloat &D = RHS.getComplexFloatImag();
14097 APFloat &ResR = Result.getComplexFloatReal();
14098 APFloat &ResI = Result.getComplexFloatImag();
14099 if (LHSReal) {
14100 assert(!RHSReal && "Cannot have two real operands for a complex op!")((!RHSReal && "Cannot have two real operands for a complex op!"
) ? static_cast<void> (0) : __assert_fail ("!RHSReal && \"Cannot have two real operands for a complex op!\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14100, __PRETTY_FUNCTION__))
;
14101 ResR = A * C;
14102 ResI = A * D;
14103 } else if (RHSReal) {
14104 ResR = C * A;
14105 ResI = C * B;
14106 } else {
14107 // In the fully general case, we need to handle NaNs and infinities
14108 // robustly.
14109 APFloat AC = A * C;
14110 APFloat BD = B * D;
14111 APFloat AD = A * D;
14112 APFloat BC = B * C;
14113 ResR = AC - BD;
14114 ResI = AD + BC;
14115 if (ResR.isNaN() && ResI.isNaN()) {
14116 bool Recalc = false;
14117 if (A.isInfinity() || B.isInfinity()) {
14118 A = APFloat::copySign(
14119 APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
14120 B = APFloat::copySign(
14121 APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
14122 if (C.isNaN())
14123 C = APFloat::copySign(APFloat(C.getSemantics()), C);
14124 if (D.isNaN())
14125 D = APFloat::copySign(APFloat(D.getSemantics()), D);
14126 Recalc = true;
14127 }
14128 if (C.isInfinity() || D.isInfinity()) {
14129 C = APFloat::copySign(
14130 APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
14131 D = APFloat::copySign(
14132 APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
14133 if (A.isNaN())
14134 A = APFloat::copySign(APFloat(A.getSemantics()), A);
14135 if (B.isNaN())
14136 B = APFloat::copySign(APFloat(B.getSemantics()), B);
14137 Recalc = true;
14138 }
14139 if (!Recalc && (AC.isInfinity() || BD.isInfinity() ||
14140 AD.isInfinity() || BC.isInfinity())) {
14141 if (A.isNaN())
14142 A = APFloat::copySign(APFloat(A.getSemantics()), A);
14143 if (B.isNaN())
14144 B = APFloat::copySign(APFloat(B.getSemantics()), B);
14145 if (C.isNaN())
14146 C = APFloat::copySign(APFloat(C.getSemantics()), C);
14147 if (D.isNaN())
14148 D = APFloat::copySign(APFloat(D.getSemantics()), D);
14149 Recalc = true;
14150 }
14151 if (Recalc) {
14152 ResR = APFloat::getInf(A.getSemantics()) * (A * C - B * D);
14153 ResI = APFloat::getInf(A.getSemantics()) * (A * D + B * C);
14154 }
14155 }
14156 }
14157 } else {
14158 ComplexValue LHS = Result;
14159 Result.getComplexIntReal() =
14160 (LHS.getComplexIntReal() * RHS.getComplexIntReal() -
14161 LHS.getComplexIntImag() * RHS.getComplexIntImag());
14162 Result.getComplexIntImag() =
14163 (LHS.getComplexIntReal() * RHS.getComplexIntImag() +
14164 LHS.getComplexIntImag() * RHS.getComplexIntReal());
14165 }
14166 break;
14167 case BO_Div:
14168 if (Result.isComplexFloat()) {
14169 // This is an implementation of complex division according to the
14170 // constraints laid out in C11 Annex G. The implementation uses the
14171 // following naming scheme:
14172 // (a + ib) / (c + id)
14173 ComplexValue LHS = Result;
14174 APFloat &A = LHS.getComplexFloatReal();
14175 APFloat &B = LHS.getComplexFloatImag();
14176 APFloat &C = RHS.getComplexFloatReal();
14177 APFloat &D = RHS.getComplexFloatImag();
14178 APFloat &ResR = Result.getComplexFloatReal();
14179 APFloat &ResI = Result.getComplexFloatImag();
14180 if (RHSReal) {
14181 ResR = A / C;
14182 ResI = B / C;
14183 } else {
14184 if (LHSReal) {
14185 // No real optimizations we can do here, stub out with zero.
14186 B = APFloat::getZero(A.getSemantics());
14187 }
14188 int DenomLogB = 0;
14189 APFloat MaxCD = maxnum(abs(C), abs(D));
14190 if (MaxCD.isFinite()) {
14191 DenomLogB = ilogb(MaxCD);
14192 C = scalbn(C, -DenomLogB, APFloat::rmNearestTiesToEven);
14193 D = scalbn(D, -DenomLogB, APFloat::rmNearestTiesToEven);
14194 }
14195 APFloat Denom = C * C + D * D;
14196 ResR = scalbn((A * C + B * D) / Denom, -DenomLogB,
14197 APFloat::rmNearestTiesToEven);
14198 ResI = scalbn((B * C - A * D) / Denom, -DenomLogB,
14199 APFloat::rmNearestTiesToEven);
14200 if (ResR.isNaN() && ResI.isNaN()) {
14201 if (Denom.isPosZero() && (!A.isNaN() || !B.isNaN())) {
14202 ResR = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * A;
14203 ResI = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * B;
14204 } else if ((A.isInfinity() || B.isInfinity()) && C.isFinite() &&
14205 D.isFinite()) {
14206 A = APFloat::copySign(
14207 APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
14208 B = APFloat::copySign(
14209 APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
14210 ResR = APFloat::getInf(ResR.getSemantics()) * (A * C + B * D);
14211 ResI = APFloat::getInf(ResI.getSemantics()) * (B * C - A * D);
14212 } else if (MaxCD.isInfinity() && A.isFinite() && B.isFinite()) {
14213 C = APFloat::copySign(
14214 APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
14215 D = APFloat::copySign(
14216 APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
14217 ResR = APFloat::getZero(ResR.getSemantics()) * (A * C + B * D);
14218 ResI = APFloat::getZero(ResI.getSemantics()) * (B * C - A * D);
14219 }
14220 }
14221 }
14222 } else {
14223 if (RHS.getComplexIntReal() == 0 && RHS.getComplexIntImag() == 0)
14224 return Error(E, diag::note_expr_divide_by_zero);
14225
14226 ComplexValue LHS = Result;
14227 APSInt Den = RHS.getComplexIntReal() * RHS.getComplexIntReal() +
14228 RHS.getComplexIntImag() * RHS.getComplexIntImag();
14229 Result.getComplexIntReal() =
14230 (LHS.getComplexIntReal() * RHS.getComplexIntReal() +
14231 LHS.getComplexIntImag() * RHS.getComplexIntImag()) / Den;
14232 Result.getComplexIntImag() =
14233 (LHS.getComplexIntImag() * RHS.getComplexIntReal() -
14234 LHS.getComplexIntReal() * RHS.getComplexIntImag()) / Den;
14235 }
14236 break;
14237 }
14238
14239 return true;
14240}
14241
14242bool ComplexExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
14243 // Get the operand value into 'Result'.
14244 if (!Visit(E->getSubExpr()))
14245 return false;
14246
14247 switch (E->getOpcode()) {
14248 default:
14249 return Error(E);
14250 case UO_Extension:
14251 return true;
14252 case UO_Plus:
14253 // The result is always just the subexpr.
14254 return true;
14255 case UO_Minus:
14256 if (Result.isComplexFloat()) {
14257 Result.getComplexFloatReal().changeSign();
14258 Result.getComplexFloatImag().changeSign();
14259 }
14260 else {
14261 Result.getComplexIntReal() = -Result.getComplexIntReal();
14262 Result.getComplexIntImag() = -Result.getComplexIntImag();
14263 }
14264 return true;
14265 case UO_Not:
14266 if (Result.isComplexFloat())
14267 Result.getComplexFloatImag().changeSign();
14268 else
14269 Result.getComplexIntImag() = -Result.getComplexIntImag();
14270 return true;
14271 }
14272}
14273
14274bool ComplexExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
14275 if (E->getNumInits() == 2) {
14276 if (E->getType()->isComplexType()) {
14277 Result.makeComplexFloat();
14278 if (!EvaluateFloat(E->getInit(0), Result.FloatReal, Info))
14279 return false;
14280 if (!EvaluateFloat(E->getInit(1), Result.FloatImag, Info))
14281 return false;
14282 } else {
14283 Result.makeComplexInt();
14284 if (!EvaluateInteger(E->getInit(0), Result.IntReal, Info))
14285 return false;
14286 if (!EvaluateInteger(E->getInit(1), Result.IntImag, Info))
14287 return false;
14288 }
14289 return true;
14290 }
14291 return ExprEvaluatorBaseTy::VisitInitListExpr(E);
14292}
14293
14294bool ComplexExprEvaluator::VisitCallExpr(const CallExpr *E) {
14295 switch (E->getBuiltinCallee()) {
14296 case Builtin::BI__builtin_complex:
14297 Result.makeComplexFloat();
14298 if (!EvaluateFloat(E->getArg(0), Result.FloatReal, Info))
14299 return false;
14300 if (!EvaluateFloat(E->getArg(1), Result.FloatImag, Info))
14301 return false;
14302 return true;
14303
14304 default:
14305 break;
14306 }
14307
14308 return ExprEvaluatorBaseTy::VisitCallExpr(E);
14309}
14310
14311//===----------------------------------------------------------------------===//
14312// Atomic expression evaluation, essentially just handling the NonAtomicToAtomic
14313// implicit conversion.
14314//===----------------------------------------------------------------------===//
14315
14316namespace {
14317class AtomicExprEvaluator :
14318 public ExprEvaluatorBase<AtomicExprEvaluator> {
14319 const LValue *This;
14320 APValue &Result;
14321public:
14322 AtomicExprEvaluator(EvalInfo &Info, const LValue *This, APValue &Result)
14323 : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
14324
14325 bool Success(const APValue &V, const Expr *E) {
14326 Result = V;
14327 return true;
14328 }
14329
14330 bool ZeroInitialization(const Expr *E) {
14331 ImplicitValueInitExpr VIE(
14332 E->getType()->castAs<AtomicType>()->getValueType());
14333 // For atomic-qualified class (and array) types in C++, initialize the
14334 // _Atomic-wrapped subobject directly, in-place.
14335 return This ? EvaluateInPlace(Result, Info, *This, &VIE)
14336 : Evaluate(Result, Info, &VIE);
14337 }
14338
14339 bool VisitCastExpr(const CastExpr *E) {
14340 switch (E->getCastKind()) {
14341 default:
14342 return ExprEvaluatorBaseTy::VisitCastExpr(E);
14343 case CK_NonAtomicToAtomic:
14344 return This ? EvaluateInPlace(Result, Info, *This, E->getSubExpr())
14345 : Evaluate(Result, Info, E->getSubExpr());
14346 }
14347 }
14348};
14349} // end anonymous namespace
14350
14351static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
14352 EvalInfo &Info) {
14353 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14353, __PRETTY_FUNCTION__))
;
14354 assert(E->isRValue() && E->getType()->isAtomicType())((E->isRValue() && E->getType()->isAtomicType
()) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isAtomicType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14354, __PRETTY_FUNCTION__))
;
14355 return AtomicExprEvaluator(Info, This, Result).Visit(E);
14356}
14357
14358//===----------------------------------------------------------------------===//
14359// Void expression evaluation, primarily for a cast to void on the LHS of a
14360// comma operator
14361//===----------------------------------------------------------------------===//
14362
14363namespace {
14364class VoidExprEvaluator
14365 : public ExprEvaluatorBase<VoidExprEvaluator> {
14366public:
14367 VoidExprEvaluator(EvalInfo &Info) : ExprEvaluatorBaseTy(Info) {}
14368
14369 bool Success(const APValue &V, const Expr *e) { return true; }
14370
14371 bool ZeroInitialization(const Expr *E) { return true; }
14372
14373 bool VisitCastExpr(const CastExpr *E) {
14374 switch (E->getCastKind()) {
14375 default:
14376 return ExprEvaluatorBaseTy::VisitCastExpr(E);
14377 case CK_ToVoid:
14378 VisitIgnoredValue(E->getSubExpr());
14379 return true;
14380 }
14381 }
14382
14383 bool VisitCallExpr(const CallExpr *E) {
14384 switch (E->getBuiltinCallee()) {
14385 case Builtin::BI__assume:
14386 case Builtin::BI__builtin_assume:
14387 // The argument is not evaluated!
14388 return true;
14389
14390 case Builtin::BI__builtin_operator_delete:
14391 return HandleOperatorDeleteCall(Info, E);
14392
14393 default:
14394 break;
14395 }
14396
14397 return ExprEvaluatorBaseTy::VisitCallExpr(E);
14398 }
14399
14400 bool VisitCXXDeleteExpr(const CXXDeleteExpr *E);
14401};
14402} // end anonymous namespace
14403
14404bool VoidExprEvaluator::VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
14405 // We cannot speculatively evaluate a delete expression.
14406 if (Info.SpeculativeEvaluationDepth)
14407 return false;
14408
14409 FunctionDecl *OperatorDelete = E->getOperatorDelete();
14410 if (!OperatorDelete->isReplaceableGlobalAllocationFunction()) {
14411 Info.FFDiag(E, diag::note_constexpr_new_non_replaceable)
14412 << isa<CXXMethodDecl>(OperatorDelete) << OperatorDelete;
14413 return false;
14414 }
14415
14416 const Expr *Arg = E->getArgument();
14417
14418 LValue Pointer;
14419 if (!EvaluatePointer(Arg, Pointer, Info))
14420 return false;
14421 if (Pointer.Designator.Invalid)
14422 return false;
14423
14424 // Deleting a null pointer has no effect.
14425 if (Pointer.isNullPointer()) {
14426 // This is the only case where we need to produce an extension warning:
14427 // the only other way we can succeed is if we find a dynamic allocation,
14428 // and we will have warned when we allocated it in that case.
14429 if (!Info.getLangOpts().CPlusPlus20)
14430 Info.CCEDiag(E, diag::note_constexpr_new);
14431 return true;
14432 }
14433
14434 Optional<DynAlloc *> Alloc = CheckDeleteKind(
14435 Info, E, Pointer, E->isArrayForm() ? DynAlloc::ArrayNew : DynAlloc::New);
14436 if (!Alloc)
14437 return false;
14438 QualType AllocType = Pointer.Base.getDynamicAllocType();
14439
14440 // For the non-array case, the designator must be empty if the static type
14441 // does not have a virtual destructor.
14442 if (!E->isArrayForm() && Pointer.Designator.Entries.size() != 0 &&
14443 !hasVirtualDestructor(Arg->getType()->getPointeeType())) {
14444 Info.FFDiag(E, diag::note_constexpr_delete_base_nonvirt_dtor)
14445 << Arg->getType()->getPointeeType() << AllocType;
14446 return false;
14447 }
14448
14449 // For a class type with a virtual destructor, the selected operator delete
14450 // is the one looked up when building the destructor.
14451 if (!E->isArrayForm() && !E->isGlobalDelete()) {
14452 const FunctionDecl *VirtualDelete = getVirtualOperatorDelete(AllocType);
14453 if (VirtualDelete &&
14454 !VirtualDelete->isReplaceableGlobalAllocationFunction()) {
14455 Info.FFDiag(E, diag::note_constexpr_new_non_replaceable)
14456 << isa<CXXMethodDecl>(VirtualDelete) << VirtualDelete;
14457 return false;
14458 }
14459 }
14460
14461 if (!HandleDestruction(Info, E->getExprLoc(), Pointer.getLValueBase(),
14462 (*Alloc)->Value, AllocType))
14463 return false;
14464
14465 if (!Info.HeapAllocs.erase(Pointer.Base.dyn_cast<DynamicAllocLValue>())) {
14466 // The element was already erased. This means the destructor call also
14467 // deleted the object.
14468 // FIXME: This probably results in undefined behavior before we get this
14469 // far, and should be diagnosed elsewhere first.
14470 Info.FFDiag(E, diag::note_constexpr_double_delete);
14471 return false;
14472 }
14473
14474 return true;
14475}
14476
14477static bool EvaluateVoid(const Expr *E, EvalInfo &Info) {
14478 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14478, __PRETTY_FUNCTION__))
;
14479 assert(E->isRValue() && E->getType()->isVoidType())((E->isRValue() && E->getType()->isVoidType(
)) ? static_cast<void> (0) : __assert_fail ("E->isRValue() && E->getType()->isVoidType()"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14479, __PRETTY_FUNCTION__))
;
14480 return VoidExprEvaluator(Info).Visit(E);
14481}
14482
14483//===----------------------------------------------------------------------===//
14484// Top level Expr::EvaluateAsRValue method.
14485//===----------------------------------------------------------------------===//
14486
14487static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) {
14488 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14488, __PRETTY_FUNCTION__))
;
14489 // In C, function designators are not lvalues, but we evaluate them as if they
14490 // are.
14491 QualType T = E->getType();
14492 if (E->isGLValue() || T->isFunctionType()) {
14493 LValue LV;
14494 if (!EvaluateLValue(E, LV, Info))
14495 return false;
14496 LV.moveInto(Result);
14497 } else if (T->isVectorType()) {
14498 if (!EvaluateVector(E, Result, Info))
14499 return false;
14500 } else if (T->isIntegralOrEnumerationType()) {
14501 if (!IntExprEvaluator(Info, Result).Visit(E))
14502 return false;
14503 } else if (T->hasPointerRepresentation()) {
14504 LValue LV;
14505 if (!EvaluatePointer(E, LV, Info))
14506 return false;
14507 LV.moveInto(Result);
14508 } else if (T->isRealFloatingType()) {
14509 llvm::APFloat F(0.0);
14510 if (!EvaluateFloat(E, F, Info))
14511 return false;
14512 Result = APValue(F);
14513 } else if (T->isAnyComplexType()) {
14514 ComplexValue C;
14515 if (!EvaluateComplex(E, C, Info))
14516 return false;
14517 C.moveInto(Result);
14518 } else if (T->isFixedPointType()) {
14519 if (!FixedPointExprEvaluator(Info, Result).Visit(E)) return false;
14520 } else if (T->isMemberPointerType()) {
14521 MemberPtr P;
14522 if (!EvaluateMemberPointer(E, P, Info))
14523 return false;
14524 P.moveInto(Result);
14525 return true;
14526 } else if (T->isArrayType()) {
14527 LValue LV;
14528 APValue &Value =
14529 Info.CurrentCall->createTemporary(E, T, ScopeKind::FullExpression, LV);
14530 if (!EvaluateArray(E, LV, Value, Info))
14531 return false;
14532 Result = Value;
14533 } else if (T->isRecordType()) {
14534 LValue LV;
14535 APValue &Value =
14536 Info.CurrentCall->createTemporary(E, T, ScopeKind::FullExpression, LV);
14537 if (!EvaluateRecord(E, LV, Value, Info))
14538 return false;
14539 Result = Value;
14540 } else if (T->isVoidType()) {
14541 if (!Info.getLangOpts().CPlusPlus11)
14542 Info.CCEDiag(E, diag::note_constexpr_nonliteral)
14543 << E->getType();
14544 if (!EvaluateVoid(E, Info))
14545 return false;
14546 } else if (T->isAtomicType()) {
14547 QualType Unqual = T.getAtomicUnqualifiedType();
14548 if (Unqual->isArrayType() || Unqual->isRecordType()) {
14549 LValue LV;
14550 APValue &Value = Info.CurrentCall->createTemporary(
14551 E, Unqual, ScopeKind::FullExpression, LV);
14552 if (!EvaluateAtomic(E, &LV, Value, Info))
14553 return false;
14554 } else {
14555 if (!EvaluateAtomic(E, nullptr, Result, Info))
14556 return false;
14557 }
14558 } else if (Info.getLangOpts().CPlusPlus11) {
14559 Info.FFDiag(E, diag::note_constexpr_nonliteral) << E->getType();
14560 return false;
14561 } else {
14562 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
14563 return false;
14564 }
14565
14566 return true;
14567}
14568
14569/// EvaluateInPlace - Evaluate an expression in-place in an APValue. In some
14570/// cases, the in-place evaluation is essential, since later initializers for
14571/// an object can indirectly refer to subobjects which were initialized earlier.
14572static bool EvaluateInPlace(APValue &Result, EvalInfo &Info, const LValue &This,
14573 const Expr *E, bool AllowNonLiteralTypes) {
14574 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14574, __PRETTY_FUNCTION__))
;
14575
14576 if (!AllowNonLiteralTypes && !CheckLiteralType(Info, E, &This))
14577 return false;
14578
14579 if (E->isRValue()) {
14580 // Evaluate arrays and record types in-place, so that later initializers can
14581 // refer to earlier-initialized members of the object.
14582 QualType T = E->getType();
14583 if (T->isArrayType())
14584 return EvaluateArray(E, This, Result, Info);
14585 else if (T->isRecordType())
14586 return EvaluateRecord(E, This, Result, Info);
14587 else if (T->isAtomicType()) {
14588 QualType Unqual = T.getAtomicUnqualifiedType();
14589 if (Unqual->isArrayType() || Unqual->isRecordType())
14590 return EvaluateAtomic(E, &This, Result, Info);
14591 }
14592 }
14593
14594 // For any other type, in-place evaluation is unimportant.
14595 return Evaluate(Result, Info, E);
14596}
14597
14598/// EvaluateAsRValue - Try to evaluate this expression, performing an implicit
14599/// lvalue-to-rvalue cast if it is an lvalue.
14600static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result) {
14601 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14601, __PRETTY_FUNCTION__))
;
14602 if (Info.EnableNewConstInterp) {
14603 if (!Info.Ctx.getInterpContext().evaluateAsRValue(Info, E, Result))
14604 return false;
14605 } else {
14606 if (E->getType().isNull())
14607 return false;
14608
14609 if (!CheckLiteralType(Info, E))
14610 return false;
14611
14612 if (!::Evaluate(Result, Info, E))
14613 return false;
14614
14615 if (E->isGLValue()) {
14616 LValue LV;
14617 LV.setFrom(Info.Ctx, Result);
14618 if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
14619 return false;
14620 }
14621 }
14622
14623 // Check this core constant expression is a constant expression.
14624 return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result,
14625 ConstantExprKind::Normal) &&
14626 CheckMemoryLeaks(Info);
14627}
14628
14629static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
14630 const ASTContext &Ctx, bool &IsConst) {
14631 // Fast-path evaluations of integer literals, since we sometimes see files
14632 // containing vast quantities of these.
14633 if (const IntegerLiteral *L = dyn_cast<IntegerLiteral>(Exp)) {
14634 Result.Val = APValue(APSInt(L->getValue(),
14635 L->getType()->isUnsignedIntegerType()));
14636 IsConst = true;
14637 return true;
14638 }
14639
14640 // This case should be rare, but we need to check it before we check on
14641 // the type below.
14642 if (Exp->getType().isNull()) {
14643 IsConst = false;
14644 return true;
14645 }
14646
14647 // FIXME: Evaluating values of large array and record types can cause
14648 // performance problems. Only do so in C++11 for now.
14649 if (Exp->isRValue() && (Exp->getType()->isArrayType() ||
14650 Exp->getType()->isRecordType()) &&
14651 !Ctx.getLangOpts().CPlusPlus11) {
14652 IsConst = false;
14653 return true;
14654 }
14655 return false;
14656}
14657
14658static bool hasUnacceptableSideEffect(Expr::EvalStatus &Result,
14659 Expr::SideEffectsKind SEK) {
14660 return (SEK < Expr::SE_AllowSideEffects && Result.HasSideEffects) ||
14661 (SEK < Expr::SE_AllowUndefinedBehavior && Result.HasUndefinedBehavior);
14662}
14663
14664static bool EvaluateAsRValue(const Expr *E, Expr::EvalResult &Result,
14665 const ASTContext &Ctx, EvalInfo &Info) {
14666 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14666, __PRETTY_FUNCTION__))
;
14667 bool IsConst;
14668 if (FastEvaluateAsRValue(E, Result, Ctx, IsConst))
14669 return IsConst;
14670
14671 return EvaluateAsRValue(Info, E, Result.Val);
14672}
14673
14674static bool EvaluateAsInt(const Expr *E, Expr::EvalResult &ExprResult,
14675 const ASTContext &Ctx,
14676 Expr::SideEffectsKind AllowSideEffects,
14677 EvalInfo &Info) {
14678 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14678, __PRETTY_FUNCTION__))
;
14679 if (!E->getType()->isIntegralOrEnumerationType())
14680 return false;
14681
14682 if (!::EvaluateAsRValue(E, ExprResult, Ctx, Info) ||
14683 !ExprResult.Val.isInt() ||
14684 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
14685 return false;
14686
14687 return true;
14688}
14689
14690static bool EvaluateAsFixedPoint(const Expr *E, Expr::EvalResult &ExprResult,
14691 const ASTContext &Ctx,
14692 Expr::SideEffectsKind AllowSideEffects,
14693 EvalInfo &Info) {
14694 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14694, __PRETTY_FUNCTION__))
;
14695 if (!E->getType()->isFixedPointType())
14696 return false;
14697
14698 if (!::EvaluateAsRValue(E, ExprResult, Ctx, Info))
14699 return false;
14700
14701 if (!ExprResult.Val.isFixedPoint() ||
14702 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
14703 return false;
14704
14705 return true;
14706}
14707
14708/// EvaluateAsRValue - Return true if this is a constant which we can fold using
14709/// any crazy technique (that has nothing to do with language standards) that
14710/// we want to. If this function returns true, it returns the folded constant
14711/// in Result. If this expression is a glvalue, an lvalue-to-rvalue conversion
14712/// will be applied to the result.
14713bool Expr::EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx,
14714 bool InConstantContext) const {
14715 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14716, __PRETTY_FUNCTION__))
14716 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14716, __PRETTY_FUNCTION__))
;
14717 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
14718 Info.InConstantContext = InConstantContext;
14719 return ::EvaluateAsRValue(this, Result, Ctx, Info);
14720}
14721
14722bool Expr::EvaluateAsBooleanCondition(bool &Result, const ASTContext &Ctx,
14723 bool InConstantContext) const {
14724 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14725, __PRETTY_FUNCTION__))
14725 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14725, __PRETTY_FUNCTION__))
;
14726 EvalResult Scratch;
14727 return EvaluateAsRValue(Scratch, Ctx, InConstantContext) &&
14728 HandleConversionToBool(Scratch.Val, Result);
14729}
14730
14731bool Expr::EvaluateAsInt(EvalResult &Result, const ASTContext &Ctx,
14732 SideEffectsKind AllowSideEffects,
14733 bool InConstantContext) const {
14734 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14735, __PRETTY_FUNCTION__))
14735 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14735, __PRETTY_FUNCTION__))
;
14736 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
14737 Info.InConstantContext = InConstantContext;
14738 return ::EvaluateAsInt(this, Result, Ctx, AllowSideEffects, Info);
14739}
14740
14741bool Expr::EvaluateAsFixedPoint(EvalResult &Result, const ASTContext &Ctx,
14742 SideEffectsKind AllowSideEffects,
14743 bool InConstantContext) const {
14744 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14745, __PRETTY_FUNCTION__))
14745 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14745, __PRETTY_FUNCTION__))
;
14746 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
14747 Info.InConstantContext = InConstantContext;
14748 return ::EvaluateAsFixedPoint(this, Result, Ctx, AllowSideEffects, Info);
14749}
14750
14751bool Expr::EvaluateAsFloat(APFloat &Result, const ASTContext &Ctx,
14752 SideEffectsKind AllowSideEffects,
14753 bool InConstantContext) const {
14754 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14755, __PRETTY_FUNCTION__))
14755 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14755, __PRETTY_FUNCTION__))
;
14756
14757 if (!getType()->isRealFloatingType())
14758 return false;
14759
14760 EvalResult ExprResult;
14761 if (!EvaluateAsRValue(ExprResult, Ctx, InConstantContext) ||
14762 !ExprResult.Val.isFloat() ||
14763 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
14764 return false;
14765
14766 Result = ExprResult.Val.getFloat();
14767 return true;
14768}
14769
14770bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx,
14771 bool InConstantContext) const {
14772 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14773, __PRETTY_FUNCTION__))
14773 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14773, __PRETTY_FUNCTION__))
;
14774
14775 EvalInfo Info(Ctx, Result, EvalInfo::EM_ConstantFold);
14776 Info.InConstantContext = InConstantContext;
14777 LValue LV;
14778 CheckedTemporaries CheckedTemps;
14779 if (!EvaluateLValue(this, LV, Info) || !Info.discardCleanups() ||
14780 Result.HasSideEffects ||
14781 !CheckLValueConstantExpression(Info, getExprLoc(),
14782 Ctx.getLValueReferenceType(getType()), LV,
14783 ConstantExprKind::Normal, CheckedTemps))
14784 return false;
14785
14786 LV.moveInto(Result.Val);
14787 return true;
14788}
14789
14790static bool EvaluateDestruction(const ASTContext &Ctx, APValue::LValueBase Base,
14791 APValue DestroyedValue, QualType Type,
14792 SourceLocation Loc, Expr::EvalStatus &EStatus,
14793 bool IsConstantDestruction) {
14794 EvalInfo Info(Ctx, EStatus,
14795 IsConstantDestruction ? EvalInfo::EM_ConstantExpression
14796 : EvalInfo::EM_ConstantFold);
14797 Info.setEvaluatingDecl(Base, DestroyedValue,
14798 EvalInfo::EvaluatingDeclKind::Dtor);
14799 Info.InConstantContext = IsConstantDestruction;
14800
14801 LValue LVal;
14802 LVal.set(Base);
14803
14804 if (!HandleDestruction(Info, Loc, Base, DestroyedValue, Type) ||
14805 EStatus.HasSideEffects)
14806 return false;
14807
14808 if (!Info.discardCleanups())
14809 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14809)
;
14810
14811 return true;
14812}
14813
14814bool Expr::EvaluateAsConstantExpr(EvalResult &Result, const ASTContext &Ctx,
14815 ConstantExprKind Kind) const {
14816 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14817, __PRETTY_FUNCTION__))
14817 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14817, __PRETTY_FUNCTION__))
;
14818
14819 EvalInfo::EvaluationMode EM = EvalInfo::EM_ConstantExpression;
14820 EvalInfo Info(Ctx, Result, EM);
14821 Info.InConstantContext = true;
14822
14823 // The type of the object we're initializing is 'const T' for a class NTTP.
14824 QualType T = getType();
14825 if (Kind == ConstantExprKind::ClassTemplateArgument)
14826 T.addConst();
14827
14828 // If we're evaluating a prvalue, fake up a MaterializeTemporaryExpr to
14829 // represent the result of the evaluation. CheckConstantExpression ensures
14830 // this doesn't escape.
14831 MaterializeTemporaryExpr BaseMTE(T, const_cast<Expr*>(this), true);
14832 APValue::LValueBase Base(&BaseMTE);
14833
14834 Info.setEvaluatingDecl(Base, Result.Val);
14835 LValue LVal;
14836 LVal.set(Base);
14837
14838 if (!::EvaluateInPlace(Result.Val, Info, LVal, this) || Result.HasSideEffects)
14839 return false;
14840
14841 if (!Info.discardCleanups())
14842 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14842)
;
14843
14844 if (!CheckConstantExpression(Info, getExprLoc(), getStorageType(Ctx, this),
14845 Result.Val, Kind))
14846 return false;
14847 if (!CheckMemoryLeaks(Info))
14848 return false;
14849
14850 // If this is a class template argument, it's required to have constant
14851 // destruction too.
14852 if (Kind == ConstantExprKind::ClassTemplateArgument &&
14853 (!EvaluateDestruction(Ctx, Base, Result.Val, T, getBeginLoc(), Result,
14854 true) ||
14855 Result.HasSideEffects)) {
14856 // FIXME: Prefix a note to indicate that the problem is lack of constant
14857 // destruction.
14858 return false;
14859 }
14860
14861 return true;
14862}
14863
14864bool Expr::EvaluateAsInitializer(APValue &Value, const ASTContext &Ctx,
14865 const VarDecl *VD,
14866 SmallVectorImpl<PartialDiagnosticAt> &Notes,
14867 bool IsConstantInitialization) const {
14868 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14869, __PRETTY_FUNCTION__))
14869 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14869, __PRETTY_FUNCTION__))
;
14870
14871 // FIXME: Evaluating initializers for large array and record types can cause
14872 // performance problems. Only do so in C++11 for now.
14873 if (isRValue() && (getType()->isArrayType() || getType()->isRecordType()) &&
14874 !Ctx.getLangOpts().CPlusPlus11)
14875 return false;
14876
14877 Expr::EvalStatus EStatus;
14878 EStatus.Diag = &Notes;
14879
14880 EvalInfo Info(Ctx, EStatus,
14881 (IsConstantInitialization && Ctx.getLangOpts().CPlusPlus11)
14882 ? EvalInfo::EM_ConstantExpression
14883 : EvalInfo::EM_ConstantFold);
14884 Info.setEvaluatingDecl(VD, Value);
14885 Info.InConstantContext = IsConstantInitialization;
14886
14887 SourceLocation DeclLoc = VD->getLocation();
14888 QualType DeclTy = VD->getType();
14889
14890 if (Info.EnableNewConstInterp) {
14891 auto &InterpCtx = const_cast<ASTContext &>(Ctx).getInterpContext();
14892 if (!InterpCtx.evaluateAsInitializer(Info, VD, Value))
14893 return false;
14894 } else {
14895 LValue LVal;
14896 LVal.set(VD);
14897
14898 if (!EvaluateInPlace(Value, Info, LVal, this,
14899 /*AllowNonLiteralTypes=*/true) ||
14900 EStatus.HasSideEffects)
14901 return false;
14902
14903 // At this point, any lifetime-extended temporaries are completely
14904 // initialized.
14905 Info.performLifetimeExtension();
14906
14907 if (!Info.discardCleanups())
14908 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14908)
;
14909 }
14910 return CheckConstantExpression(Info, DeclLoc, DeclTy, Value,
14911 ConstantExprKind::Normal) &&
14912 CheckMemoryLeaks(Info);
14913}
14914
14915bool VarDecl::evaluateDestruction(
14916 SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
14917 Expr::EvalStatus EStatus;
14918 EStatus.Diag = &Notes;
14919
14920 // Only treat the destruction as constant destruction if we formally have
14921 // constant initialization (or are usable in a constant expression).
14922 bool IsConstantDestruction = hasConstantInitialization();
14923
14924 // Make a copy of the value for the destructor to mutate, if we know it.
14925 // Otherwise, treat the value as default-initialized; if the destructor works
14926 // anyway, then the destruction is constant (and must be essentially empty).
14927 APValue DestroyedValue;
14928 if (getEvaluatedValue() && !getEvaluatedValue()->isAbsent())
14929 DestroyedValue = *getEvaluatedValue();
14930 else if (!getDefaultInitValue(getType(), DestroyedValue))
14931 return false;
14932
14933 if (!EvaluateDestruction(getASTContext(), this, std::move(DestroyedValue),
14934 getType(), getLocation(), EStatus,
14935 IsConstantDestruction) ||
14936 EStatus.HasSideEffects)
14937 return false;
14938
14939 ensureEvaluatedStmt()->HasConstantDestruction = true;
14940 return true;
14941}
14942
14943/// isEvaluatable - Call EvaluateAsRValue to see if this expression can be
14944/// constant folded, but discard the result.
14945bool Expr::isEvaluatable(const ASTContext &Ctx, SideEffectsKind SEK) const {
14946 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14947, __PRETTY_FUNCTION__))
14947 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14947, __PRETTY_FUNCTION__))
;
14948
14949 EvalResult Result;
14950 return EvaluateAsRValue(Result, Ctx, /* in constant context */ true) &&
14951 !hasUnacceptableSideEffect(Result, SEK);
14952}
14953
14954APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx,
14955 SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
14956 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14957, __PRETTY_FUNCTION__))
14957 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14957, __PRETTY_FUNCTION__))
;
14958
14959 EvalResult EVResult;
14960 EVResult.Diag = Diag;
14961 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
14962 Info.InConstantContext = true;
14963
14964 bool Result = ::EvaluateAsRValue(this, EVResult, Ctx, Info);
14965 (void)Result;
14966 assert(Result && "Could not evaluate expression")((Result && "Could not evaluate expression") ? static_cast
<void> (0) : __assert_fail ("Result && \"Could not evaluate expression\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14966, __PRETTY_FUNCTION__))
;
14967 assert(EVResult.Val.isInt() && "Expression did not evaluate to integer")((EVResult.Val.isInt() && "Expression did not evaluate to integer"
) ? static_cast<void> (0) : __assert_fail ("EVResult.Val.isInt() && \"Expression did not evaluate to integer\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14967, __PRETTY_FUNCTION__))
;
14968
14969 return EVResult.Val.getInt();
14970}
14971
14972APSInt Expr::EvaluateKnownConstIntCheckOverflow(
14973 const ASTContext &Ctx, SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
14974 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14975, __PRETTY_FUNCTION__))
14975 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14975, __PRETTY_FUNCTION__))
;
14976
14977 EvalResult EVResult;
14978 EVResult.Diag = Diag;
14979 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
14980 Info.InConstantContext = true;
14981 Info.CheckingForUndefinedBehavior = true;
14982
14983 bool Result = ::EvaluateAsRValue(Info, this, EVResult.Val);
14984 (void)Result;
14985 assert(Result && "Could not evaluate expression")((Result && "Could not evaluate expression") ? static_cast
<void> (0) : __assert_fail ("Result && \"Could not evaluate expression\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14985, __PRETTY_FUNCTION__))
;
14986 assert(EVResult.Val.isInt() && "Expression did not evaluate to integer")((EVResult.Val.isInt() && "Expression did not evaluate to integer"
) ? static_cast<void> (0) : __assert_fail ("EVResult.Val.isInt() && \"Expression did not evaluate to integer\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14986, __PRETTY_FUNCTION__))
;
14987
14988 return EVResult.Val.getInt();
14989}
14990
14991void Expr::EvaluateForOverflow(const ASTContext &Ctx) const {
14992 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14993, __PRETTY_FUNCTION__))
14993 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 14993, __PRETTY_FUNCTION__))
;
14994
14995 bool IsConst;
14996 EvalResult EVResult;
14997 if (!FastEvaluateAsRValue(this, EVResult, Ctx, IsConst)) {
14998 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
14999 Info.CheckingForUndefinedBehavior = true;
15000 (void)::EvaluateAsRValue(Info, this, EVResult.Val);
15001 }
15002}
15003
15004bool Expr::EvalResult::isGlobalLValue() const {
15005 assert(Val.isLValue())((Val.isLValue()) ? static_cast<void> (0) : __assert_fail
("Val.isLValue()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15005, __PRETTY_FUNCTION__))
;
15006 return IsGlobalLValue(Val.getLValueBase());
15007}
15008
15009/// isIntegerConstantExpr - this recursive routine will test if an expression is
15010/// an integer constant expression.
15011
15012/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
15013/// comma, etc
15014
15015// CheckICE - This function does the fundamental ICE checking: the returned
15016// ICEDiag contains an ICEKind indicating whether the expression is an ICE,
15017// and a (possibly null) SourceLocation indicating the location of the problem.
15018//
15019// Note that to reduce code duplication, this helper does no evaluation
15020// itself; the caller checks whether the expression is evaluatable, and
15021// in the rare cases where CheckICE actually cares about the evaluated
15022// value, it calls into Evaluate.
15023
15024namespace {
15025
15026enum ICEKind {
15027 /// This expression is an ICE.
15028 IK_ICE,
15029 /// This expression is not an ICE, but if it isn't evaluated, it's
15030 /// a legal subexpression for an ICE. This return value is used to handle
15031 /// the comma operator in C99 mode, and non-constant subexpressions.
15032 IK_ICEIfUnevaluated,
15033 /// This expression is not an ICE, and is not a legal subexpression for one.
15034 IK_NotICE
15035};
15036
15037struct ICEDiag {
15038 ICEKind Kind;
15039 SourceLocation Loc;
15040
15041 ICEDiag(ICEKind IK, SourceLocation l) : Kind(IK), Loc(l) {}
15042};
15043
15044}
15045
15046static ICEDiag NoDiag() { return ICEDiag(IK_ICE, SourceLocation()); }
15047
15048static ICEDiag Worst(ICEDiag A, ICEDiag B) { return A.Kind >= B.Kind ? A : B; }
15049
15050static ICEDiag CheckEvalInICE(const Expr* E, const ASTContext &Ctx) {
15051 Expr::EvalResult EVResult;
15052 Expr::EvalStatus Status;
15053 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
15054
15055 Info.InConstantContext = true;
15056 if (!::EvaluateAsRValue(E, EVResult, Ctx, Info) || EVResult.HasSideEffects ||
15057 !EVResult.Val.isInt())
15058 return ICEDiag(IK_NotICE, E->getBeginLoc());
15059
15060 return NoDiag();
15061}
15062
15063static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
15064 assert(!E->isValueDependent() && "Should not see value dependent exprs!")((!E->isValueDependent() && "Should not see value dependent exprs!"
) ? static_cast<void> (0) : __assert_fail ("!E->isValueDependent() && \"Should not see value dependent exprs!\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15064, __PRETTY_FUNCTION__))
;
15065 if (!E->getType()->isIntegralOrEnumerationType())
15066 return ICEDiag(IK_NotICE, E->getBeginLoc());
15067
15068 switch (E->getStmtClass()) {
15069#define ABSTRACT_STMT(Node)
15070#define STMT(Node, Base) case Expr::Node##Class:
15071#define EXPR(Node, Base)
15072#include "clang/AST/StmtNodes.inc"
15073 case Expr::PredefinedExprClass:
15074 case Expr::FloatingLiteralClass:
15075 case Expr::ImaginaryLiteralClass:
15076 case Expr::StringLiteralClass:
15077 case Expr::ArraySubscriptExprClass:
15078 case Expr::MatrixSubscriptExprClass:
15079 case Expr::OMPArraySectionExprClass:
15080 case Expr::OMPArrayShapingExprClass:
15081 case Expr::OMPIteratorExprClass:
15082 case Expr::MemberExprClass:
15083 case Expr::CompoundAssignOperatorClass:
15084 case Expr::CompoundLiteralExprClass:
15085 case Expr::ExtVectorElementExprClass:
15086 case Expr::DesignatedInitExprClass:
15087 case Expr::ArrayInitLoopExprClass:
15088 case Expr::ArrayInitIndexExprClass:
15089 case Expr::NoInitExprClass:
15090 case Expr::DesignatedInitUpdateExprClass:
15091 case Expr::ImplicitValueInitExprClass:
15092 case Expr::ParenListExprClass:
15093 case Expr::VAArgExprClass:
15094 case Expr::AddrLabelExprClass:
15095 case Expr::StmtExprClass:
15096 case Expr::CXXMemberCallExprClass:
15097 case Expr::CUDAKernelCallExprClass:
15098 case Expr::CXXAddrspaceCastExprClass:
15099 case Expr::CXXDynamicCastExprClass:
15100 case Expr::CXXTypeidExprClass:
15101 case Expr::CXXUuidofExprClass:
15102 case Expr::MSPropertyRefExprClass:
15103 case Expr::MSPropertySubscriptExprClass:
15104 case Expr::CXXNullPtrLiteralExprClass:
15105 case Expr::UserDefinedLiteralClass:
15106 case Expr::CXXThisExprClass:
15107 case Expr::CXXThrowExprClass:
15108 case Expr::CXXNewExprClass:
15109 case Expr::CXXDeleteExprClass:
15110 case Expr::CXXPseudoDestructorExprClass:
15111 case Expr::UnresolvedLookupExprClass:
15112 case Expr::TypoExprClass:
15113 case Expr::RecoveryExprClass:
15114 case Expr::DependentScopeDeclRefExprClass:
15115 case Expr::CXXConstructExprClass:
15116 case Expr::CXXInheritedCtorInitExprClass:
15117 case Expr::CXXStdInitializerListExprClass:
15118 case Expr::CXXBindTemporaryExprClass:
15119 case Expr::ExprWithCleanupsClass:
15120 case Expr::CXXTemporaryObjectExprClass:
15121 case Expr::CXXUnresolvedConstructExprClass:
15122 case Expr::CXXDependentScopeMemberExprClass:
15123 case Expr::UnresolvedMemberExprClass:
15124 case Expr::ObjCStringLiteralClass:
15125 case Expr::ObjCBoxedExprClass:
15126 case Expr::ObjCArrayLiteralClass:
15127 case Expr::ObjCDictionaryLiteralClass:
15128 case Expr::ObjCEncodeExprClass:
15129 case Expr::ObjCMessageExprClass:
15130 case Expr::ObjCSelectorExprClass:
15131 case Expr::ObjCProtocolExprClass:
15132 case Expr::ObjCIvarRefExprClass:
15133 case Expr::ObjCPropertyRefExprClass:
15134 case Expr::ObjCSubscriptRefExprClass:
15135 case Expr::ObjCIsaExprClass:
15136 case Expr::ObjCAvailabilityCheckExprClass:
15137 case Expr::ShuffleVectorExprClass:
15138 case Expr::ConvertVectorExprClass:
15139 case Expr::BlockExprClass:
15140 case Expr::NoStmtClass:
15141 case Expr::OpaqueValueExprClass:
15142 case Expr::PackExpansionExprClass:
15143 case Expr::SubstNonTypeTemplateParmPackExprClass:
15144 case Expr::FunctionParmPackExprClass:
15145 case Expr::AsTypeExprClass:
15146 case Expr::ObjCIndirectCopyRestoreExprClass:
15147 case Expr::MaterializeTemporaryExprClass:
15148 case Expr::PseudoObjectExprClass:
15149 case Expr::AtomicExprClass:
15150 case Expr::LambdaExprClass:
15151 case Expr::CXXFoldExprClass:
15152 case Expr::CoawaitExprClass:
15153 case Expr::DependentCoawaitExprClass:
15154 case Expr::CoyieldExprClass:
15155 return ICEDiag(IK_NotICE, E->getBeginLoc());
15156
15157 case Expr::InitListExprClass: {
15158 // C++03 [dcl.init]p13: If T is a scalar type, then a declaration of the
15159 // form "T x = { a };" is equivalent to "T x = a;".
15160 // Unless we're initializing a reference, T is a scalar as it is known to be
15161 // of integral or enumeration type.
15162 if (E->isRValue())
15163 if (cast<InitListExpr>(E)->getNumInits() == 1)
15164 return CheckICE(cast<InitListExpr>(E)->getInit(0), Ctx);
15165 return ICEDiag(IK_NotICE, E->getBeginLoc());
15166 }
15167
15168 case Expr::SizeOfPackExprClass:
15169 case Expr::GNUNullExprClass:
15170 case Expr::SourceLocExprClass:
15171 return NoDiag();
15172
15173 case Expr::SubstNonTypeTemplateParmExprClass:
15174 return
15175 CheckICE(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(), Ctx);
15176
15177 case Expr::ConstantExprClass:
15178 return CheckICE(cast<ConstantExpr>(E)->getSubExpr(), Ctx);
15179
15180 case Expr::ParenExprClass:
15181 return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
15182 case Expr::GenericSelectionExprClass:
15183 return CheckICE(cast<GenericSelectionExpr>(E)->getResultExpr(), Ctx);
15184 case Expr::IntegerLiteralClass:
15185 case Expr::FixedPointLiteralClass:
15186 case Expr::CharacterLiteralClass:
15187 case Expr::ObjCBoolLiteralExprClass:
15188 case Expr::CXXBoolLiteralExprClass:
15189 case Expr::CXXScalarValueInitExprClass:
15190 case Expr::TypeTraitExprClass:
15191 case Expr::ConceptSpecializationExprClass:
15192 case Expr::RequiresExprClass:
15193 case Expr::ArrayTypeTraitExprClass:
15194 case Expr::ExpressionTraitExprClass:
15195 case Expr::CXXNoexceptExprClass:
15196 return NoDiag();
15197 case Expr::CallExprClass:
15198 case Expr::CXXOperatorCallExprClass: {
15199 // C99 6.6/3 allows function calls within unevaluated subexpressions of
15200 // constant expressions, but they can never be ICEs because an ICE cannot
15201 // contain an operand of (pointer to) function type.
15202 const CallExpr *CE = cast<CallExpr>(E);
15203 if (CE->getBuiltinCallee())
15204 return CheckEvalInICE(E, Ctx);
15205 return ICEDiag(IK_NotICE, E->getBeginLoc());
15206 }
15207 case Expr::CXXRewrittenBinaryOperatorClass:
15208 return CheckICE(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm(),
15209 Ctx);
15210 case Expr::DeclRefExprClass: {
15211 const NamedDecl *D = cast<DeclRefExpr>(E)->getDecl();
15212 if (isa<EnumConstantDecl>(D))
15213 return NoDiag();
15214
15215 // C++ and OpenCL (FIXME: spec reference?) allow reading const-qualified
15216 // integer variables in constant expressions:
15217 //
15218 // C++ 7.1.5.1p2
15219 // A variable of non-volatile const-qualified integral or enumeration
15220 // type initialized by an ICE can be used in ICEs.
15221 //
15222 // We sometimes use CheckICE to check the C++98 rules in C++11 mode. In
15223 // that mode, use of reference variables should not be allowed.
15224 const VarDecl *VD = dyn_cast<VarDecl>(D);
15225 if (VD && VD->isUsableInConstantExpressions(Ctx) &&
15226 !VD->getType()->isReferenceType())
15227 return NoDiag();
15228
15229 return ICEDiag(IK_NotICE, E->getBeginLoc());
15230 }
15231 case Expr::UnaryOperatorClass: {
15232 const UnaryOperator *Exp = cast<UnaryOperator>(E);
15233 switch (Exp->getOpcode()) {
15234 case UO_PostInc:
15235 case UO_PostDec:
15236 case UO_PreInc:
15237 case UO_PreDec:
15238 case UO_AddrOf:
15239 case UO_Deref:
15240 case UO_Coawait:
15241 // C99 6.6/3 allows increment and decrement within unevaluated
15242 // subexpressions of constant expressions, but they can never be ICEs
15243 // because an ICE cannot contain an lvalue operand.
15244 return ICEDiag(IK_NotICE, E->getBeginLoc());
15245 case UO_Extension:
15246 case UO_LNot:
15247 case UO_Plus:
15248 case UO_Minus:
15249 case UO_Not:
15250 case UO_Real:
15251 case UO_Imag:
15252 return CheckICE(Exp->getSubExpr(), Ctx);
15253 }
15254 llvm_unreachable("invalid unary operator class")::llvm::llvm_unreachable_internal("invalid unary operator class"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15254)
;
15255 }
15256 case Expr::OffsetOfExprClass: {
15257 // Note that per C99, offsetof must be an ICE. And AFAIK, using
15258 // EvaluateAsRValue matches the proposed gcc behavior for cases like
15259 // "offsetof(struct s{int x[4];}, x[1.0])". This doesn't affect
15260 // compliance: we should warn earlier for offsetof expressions with
15261 // array subscripts that aren't ICEs, and if the array subscripts
15262 // are ICEs, the value of the offsetof must be an integer constant.
15263 return CheckEvalInICE(E, Ctx);
15264 }
15265 case Expr::UnaryExprOrTypeTraitExprClass: {
15266 const UnaryExprOrTypeTraitExpr *Exp = cast<UnaryExprOrTypeTraitExpr>(E);
15267 if ((Exp->getKind() == UETT_SizeOf) &&
15268 Exp->getTypeOfArgument()->isVariableArrayType())
15269 return ICEDiag(IK_NotICE, E->getBeginLoc());
15270 return NoDiag();
15271 }
15272 case Expr::BinaryOperatorClass: {
15273 const BinaryOperator *Exp = cast<BinaryOperator>(E);
15274 switch (Exp->getOpcode()) {
15275 case BO_PtrMemD:
15276 case BO_PtrMemI:
15277 case BO_Assign:
15278 case BO_MulAssign:
15279 case BO_DivAssign:
15280 case BO_RemAssign:
15281 case BO_AddAssign:
15282 case BO_SubAssign:
15283 case BO_ShlAssign:
15284 case BO_ShrAssign:
15285 case BO_AndAssign:
15286 case BO_XorAssign:
15287 case BO_OrAssign:
15288 // C99 6.6/3 allows assignments within unevaluated subexpressions of
15289 // constant expressions, but they can never be ICEs because an ICE cannot
15290 // contain an lvalue operand.
15291 return ICEDiag(IK_NotICE, E->getBeginLoc());
15292
15293 case BO_Mul:
15294 case BO_Div:
15295 case BO_Rem:
15296 case BO_Add:
15297 case BO_Sub:
15298 case BO_Shl:
15299 case BO_Shr:
15300 case BO_LT:
15301 case BO_GT:
15302 case BO_LE:
15303 case BO_GE:
15304 case BO_EQ:
15305 case BO_NE:
15306 case BO_And:
15307 case BO_Xor:
15308 case BO_Or:
15309 case BO_Comma:
15310 case BO_Cmp: {
15311 ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
15312 ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
15313 if (Exp->getOpcode() == BO_Div ||
15314 Exp->getOpcode() == BO_Rem) {
15315 // EvaluateAsRValue gives an error for undefined Div/Rem, so make sure
15316 // we don't evaluate one.
15317 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE) {
15318 llvm::APSInt REval = Exp->getRHS()->EvaluateKnownConstInt(Ctx);
15319 if (REval == 0)
15320 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
15321 if (REval.isSigned() && REval.isAllOnesValue()) {
15322 llvm::APSInt LEval = Exp->getLHS()->EvaluateKnownConstInt(Ctx);
15323 if (LEval.isMinSignedValue())
15324 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
15325 }
15326 }
15327 }
15328 if (Exp->getOpcode() == BO_Comma) {
15329 if (Ctx.getLangOpts().C99) {
15330 // C99 6.6p3 introduces a strange edge case: comma can be in an ICE
15331 // if it isn't evaluated.
15332 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE)
15333 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
15334 } else {
15335 // In both C89 and C++, commas in ICEs are illegal.
15336 return ICEDiag(IK_NotICE, E->getBeginLoc());
15337 }
15338 }
15339 return Worst(LHSResult, RHSResult);
15340 }
15341 case BO_LAnd:
15342 case BO_LOr: {
15343 ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
15344 ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
15345 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICEIfUnevaluated) {
15346 // Rare case where the RHS has a comma "side-effect"; we need
15347 // to actually check the condition to see whether the side
15348 // with the comma is evaluated.
15349 if ((Exp->getOpcode() == BO_LAnd) !=
15350 (Exp->getLHS()->EvaluateKnownConstInt(Ctx) == 0))
15351 return RHSResult;
15352 return NoDiag();
15353 }
15354
15355 return Worst(LHSResult, RHSResult);
15356 }
15357 }
15358 llvm_unreachable("invalid binary operator kind")::llvm::llvm_unreachable_internal("invalid binary operator kind"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15358)
;
15359 }
15360 case Expr::ImplicitCastExprClass:
15361 case Expr::CStyleCastExprClass:
15362 case Expr::CXXFunctionalCastExprClass:
15363 case Expr::CXXStaticCastExprClass:
15364 case Expr::CXXReinterpretCastExprClass:
15365 case Expr::CXXConstCastExprClass:
15366 case Expr::ObjCBridgedCastExprClass: {
15367 const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr();
15368 if (isa<ExplicitCastExpr>(E)) {
15369 if (const FloatingLiteral *FL
15370 = dyn_cast<FloatingLiteral>(SubExpr->IgnoreParenImpCasts())) {
15371 unsigned DestWidth = Ctx.getIntWidth(E->getType());
15372 bool DestSigned = E->getType()->isSignedIntegerOrEnumerationType();
15373 APSInt IgnoredVal(DestWidth, !DestSigned);
15374 bool Ignored;
15375 // If the value does not fit in the destination type, the behavior is
15376 // undefined, so we are not required to treat it as a constant
15377 // expression.
15378 if (FL->getValue().convertToInteger(IgnoredVal,
15379 llvm::APFloat::rmTowardZero,
15380 &Ignored) & APFloat::opInvalidOp)
15381 return ICEDiag(IK_NotICE, E->getBeginLoc());
15382 return NoDiag();
15383 }
15384 }
15385 switch (cast<CastExpr>(E)->getCastKind()) {
15386 case CK_LValueToRValue:
15387 case CK_AtomicToNonAtomic:
15388 case CK_NonAtomicToAtomic:
15389 case CK_NoOp:
15390 case CK_IntegralToBoolean:
15391 case CK_IntegralCast:
15392 return CheckICE(SubExpr, Ctx);
15393 default:
15394 return ICEDiag(IK_NotICE, E->getBeginLoc());
15395 }
15396 }
15397 case Expr::BinaryConditionalOperatorClass: {
15398 const BinaryConditionalOperator *Exp = cast<BinaryConditionalOperator>(E);
15399 ICEDiag CommonResult = CheckICE(Exp->getCommon(), Ctx);
15400 if (CommonResult.Kind == IK_NotICE) return CommonResult;
15401 ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
15402 if (FalseResult.Kind == IK_NotICE) return FalseResult;
15403 if (CommonResult.Kind == IK_ICEIfUnevaluated) return CommonResult;
15404 if (FalseResult.Kind == IK_ICEIfUnevaluated &&
15405 Exp->getCommon()->EvaluateKnownConstInt(Ctx) != 0) return NoDiag();
15406 return FalseResult;
15407 }
15408 case Expr::ConditionalOperatorClass: {
15409 const ConditionalOperator *Exp = cast<ConditionalOperator>(E);
15410 // If the condition (ignoring parens) is a __builtin_constant_p call,
15411 // then only the true side is actually considered in an integer constant
15412 // expression, and it is fully evaluated. This is an important GNU
15413 // extension. See GCC PR38377 for discussion.
15414 if (const CallExpr *CallCE
15415 = dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts()))
15416 if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
15417 return CheckEvalInICE(E, Ctx);
15418 ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
15419 if (CondResult.Kind == IK_NotICE)
15420 return CondResult;
15421
15422 ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
15423 ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
15424
15425 if (TrueResult.Kind == IK_NotICE)
15426 return TrueResult;
15427 if (FalseResult.Kind == IK_NotICE)
15428 return FalseResult;
15429 if (CondResult.Kind == IK_ICEIfUnevaluated)
15430 return CondResult;
15431 if (TrueResult.Kind == IK_ICE && FalseResult.Kind == IK_ICE)
15432 return NoDiag();
15433 // Rare case where the diagnostics depend on which side is evaluated
15434 // Note that if we get here, CondResult is 0, and at least one of
15435 // TrueResult and FalseResult is non-zero.
15436 if (Exp->getCond()->EvaluateKnownConstInt(Ctx) == 0)
15437 return FalseResult;
15438 return TrueResult;
15439 }
15440 case Expr::CXXDefaultArgExprClass:
15441 return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx);
15442 case Expr::CXXDefaultInitExprClass:
15443 return CheckICE(cast<CXXDefaultInitExpr>(E)->getExpr(), Ctx);
15444 case Expr::ChooseExprClass: {
15445 return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(), Ctx);
15446 }
15447 case Expr::BuiltinBitCastExprClass: {
15448 if (!checkBitCastConstexprEligibility(nullptr, Ctx, cast<CastExpr>(E)))
15449 return ICEDiag(IK_NotICE, E->getBeginLoc());
15450 return CheckICE(cast<CastExpr>(E)->getSubExpr(), Ctx);
15451 }
15452 }
15453
15454 llvm_unreachable("Invalid StmtClass!")::llvm::llvm_unreachable_internal("Invalid StmtClass!", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15454)
;
15455}
15456
15457/// Evaluate an expression as a C++11 integral constant expression.
15458static bool EvaluateCPlusPlus11IntegralConstantExpr(const ASTContext &Ctx,
15459 const Expr *E,
15460 llvm::APSInt *Value,
15461 SourceLocation *Loc) {
15462 if (!E->getType()->isIntegralOrUnscopedEnumerationType()) {
15463 if (Loc) *Loc = E->getExprLoc();
15464 return false;
15465 }
15466
15467 APValue Result;
15468 if (!E->isCXX11ConstantExpr(Ctx, &Result, Loc))
15469 return false;
15470
15471 if (!Result.isInt()) {
15472 if (Loc) *Loc = E->getExprLoc();
15473 return false;
15474 }
15475
15476 if (Value) *Value = Result.getInt();
15477 return true;
15478}
15479
15480bool Expr::isIntegerConstantExpr(const ASTContext &Ctx,
15481 SourceLocation *Loc) const {
15482 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15483, __PRETTY_FUNCTION__))
15483 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15483, __PRETTY_FUNCTION__))
;
15484
15485 if (Ctx.getLangOpts().CPlusPlus11)
15486 return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, nullptr, Loc);
15487
15488 ICEDiag D = CheckICE(this, Ctx);
15489 if (D.Kind != IK_ICE) {
15490 if (Loc) *Loc = D.Loc;
15491 return false;
15492 }
15493 return true;
15494}
15495
15496Optional<llvm::APSInt> Expr::getIntegerConstantExpr(const ASTContext &Ctx,
15497 SourceLocation *Loc,
15498 bool isEvaluated) const {
15499 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15500, __PRETTY_FUNCTION__))
15500 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15500, __PRETTY_FUNCTION__))
;
15501
15502 APSInt Value;
15503
15504 if (Ctx.getLangOpts().CPlusPlus11) {
15505 if (EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, &Value, Loc))
15506 return Value;
15507 return None;
15508 }
15509
15510 if (!isIntegerConstantExpr(Ctx, Loc))
15511 return None;
15512
15513 // The only possible side-effects here are due to UB discovered in the
15514 // evaluation (for instance, INT_MAX + 1). In such a case, we are still
15515 // required to treat the expression as an ICE, so we produce the folded
15516 // value.
15517 EvalResult ExprResult;
15518 Expr::EvalStatus Status;
15519 EvalInfo Info(Ctx, Status, EvalInfo::EM_IgnoreSideEffects);
15520 Info.InConstantContext = true;
15521
15522 if (!::EvaluateAsInt(this, ExprResult, Ctx, SE_AllowSideEffects, Info))
15523 llvm_unreachable("ICE cannot be evaluated!")::llvm::llvm_unreachable_internal("ICE cannot be evaluated!",
"/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15523)
;
15524
15525 return ExprResult.Val.getInt();
15526}
15527
15528bool Expr::isCXX98IntegralConstantExpr(const ASTContext &Ctx) const {
15529 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15530, __PRETTY_FUNCTION__))
15530 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15530, __PRETTY_FUNCTION__))
;
15531
15532 return CheckICE(this, Ctx).Kind == IK_ICE;
15533}
15534
15535bool Expr::isCXX11ConstantExpr(const ASTContext &Ctx, APValue *Result,
15536 SourceLocation *Loc) const {
15537 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15538, __PRETTY_FUNCTION__))
15538 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15538, __PRETTY_FUNCTION__))
;
15539
15540 // We support this checking in C++98 mode in order to diagnose compatibility
15541 // issues.
15542 assert(Ctx.getLangOpts().CPlusPlus)((Ctx.getLangOpts().CPlusPlus) ? static_cast<void> (0) :
__assert_fail ("Ctx.getLangOpts().CPlusPlus", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15542, __PRETTY_FUNCTION__))
;
15543
15544 // Build evaluation settings.
15545 Expr::EvalStatus Status;
15546 SmallVector<PartialDiagnosticAt, 8> Diags;
15547 Status.Diag = &Diags;
15548 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
15549
15550 APValue Scratch;
15551 bool IsConstExpr =
15552 ::EvaluateAsRValue(Info, this, Result ? *Result : Scratch) &&
15553 // FIXME: We don't produce a diagnostic for this, but the callers that
15554 // call us on arbitrary full-expressions should generally not care.
15555 Info.discardCleanups() && !Status.HasSideEffects;
15556
15557 if (!Diags.empty()) {
15558 IsConstExpr = false;
15559 if (Loc) *Loc = Diags[0].first;
15560 } else if (!IsConstExpr) {
15561 // FIXME: This shouldn't happen.
15562 if (Loc) *Loc = getExprLoc();
15563 }
15564
15565 return IsConstExpr;
15566}
15567
15568bool Expr::EvaluateWithSubstitution(APValue &Value, ASTContext &Ctx,
15569 const FunctionDecl *Callee,
15570 ArrayRef<const Expr*> Args,
15571 const Expr *This) const {
15572 assert(!isValueDependent() &&((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15573, __PRETTY_FUNCTION__))
15573 "Expression evaluator can't be called on a dependent expression.")((!isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15573, __PRETTY_FUNCTION__))
;
15574
15575 Expr::EvalStatus Status;
15576 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpressionUnevaluated);
15577 Info.InConstantContext = true;
15578
15579 LValue ThisVal;
15580 const LValue *ThisPtr = nullptr;
15581 if (This) {
15582#ifndef NDEBUG
15583 auto *MD = dyn_cast<CXXMethodDecl>(Callee);
15584 assert(MD && "Don't provide `this` for non-methods.")((MD && "Don't provide `this` for non-methods.") ? static_cast
<void> (0) : __assert_fail ("MD && \"Don't provide `this` for non-methods.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15584, __PRETTY_FUNCTION__))
;
15585 assert(!MD->isStatic() && "Don't provide `this` for static methods.")((!MD->isStatic() && "Don't provide `this` for static methods."
) ? static_cast<void> (0) : __assert_fail ("!MD->isStatic() && \"Don't provide `this` for static methods.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15585, __PRETTY_FUNCTION__))
;
15586#endif
15587 if (!This->isValueDependent() &&
15588 EvaluateObjectArgument(Info, This, ThisVal) &&
15589 !Info.EvalStatus.HasSideEffects)
15590 ThisPtr = &ThisVal;
15591
15592 // Ignore any side-effects from a failed evaluation. This is safe because
15593 // they can't interfere with any other argument evaluation.
15594 Info.EvalStatus.HasSideEffects = false;
15595 }
15596
15597 CallRef Call = Info.CurrentCall->createCall(Callee);
15598 for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
15599 I != E; ++I) {
15600 unsigned Idx = I - Args.begin();
15601 if (Idx >= Callee->getNumParams())
15602 break;
15603 const ParmVarDecl *PVD = Callee->getParamDecl(Idx);
15604 if ((*I)->isValueDependent() ||
15605 !EvaluateCallArg(PVD, *I, Call, Info) ||
15606 Info.EvalStatus.HasSideEffects) {
15607 // If evaluation fails, throw away the argument entirely.
15608 if (APValue *Slot = Info.getParamSlot(Call, PVD))
15609 *Slot = APValue();
15610 }
15611
15612 // Ignore any side-effects from a failed evaluation. This is safe because
15613 // they can't interfere with any other argument evaluation.
15614 Info.EvalStatus.HasSideEffects = false;
15615 }
15616
15617 // Parameter cleanups happen in the caller and are not part of this
15618 // evaluation.
15619 Info.discardCleanups();
15620 Info.EvalStatus.HasSideEffects = false;
15621
15622 // Build fake call to Callee.
15623 CallStackFrame Frame(Info, Callee->getLocation(), Callee, ThisPtr, Call);
15624 // FIXME: Missing ExprWithCleanups in enable_if conditions?
15625 FullExpressionRAII Scope(Info);
15626 return Evaluate(Value, Info, this) && Scope.destroy() &&
15627 !Info.EvalStatus.HasSideEffects;
15628}
15629
15630bool Expr::isPotentialConstantExpr(const FunctionDecl *FD,
15631 SmallVectorImpl<
15632 PartialDiagnosticAt> &Diags) {
15633 // FIXME: It would be useful to check constexpr function templates, but at the
15634 // moment the constant expression evaluator cannot cope with the non-rigorous
15635 // ASTs which we build for dependent expressions.
15636 if (FD->isDependentContext())
15637 return true;
15638
15639 Expr::EvalStatus Status;
15640 Status.Diag = &Diags;
15641
15642 EvalInfo Info(FD->getASTContext(), Status, EvalInfo::EM_ConstantExpression);
15643 Info.InConstantContext = true;
15644 Info.CheckingPotentialConstantExpression = true;
15645
15646 // The constexpr VM attempts to compile all methods to bytecode here.
15647 if (Info.EnableNewConstInterp) {
15648 Info.Ctx.getInterpContext().isPotentialConstantExpr(Info, FD);
15649 return Diags.empty();
15650 }
15651
15652 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
15653 const CXXRecordDecl *RD = MD ? MD->getParent()->getCanonicalDecl() : nullptr;
15654
15655 // Fabricate an arbitrary expression on the stack and pretend that it
15656 // is a temporary being used as the 'this' pointer.
15657 LValue This;
15658 ImplicitValueInitExpr VIE(RD ? Info.Ctx.getRecordType(RD) : Info.Ctx.IntTy);
15659 This.set({&VIE, Info.CurrentCall->Index});
15660
15661 ArrayRef<const Expr*> Args;
15662
15663 APValue Scratch;
15664 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) {
15665 // Evaluate the call as a constant initializer, to allow the construction
15666 // of objects of non-literal types.
15667 Info.setEvaluatingDecl(This.getLValueBase(), Scratch);
15668 HandleConstructorCall(&VIE, This, Args, CD, Info, Scratch);
15669 } else {
15670 SourceLocation Loc = FD->getLocation();
15671 HandleFunctionCall(Loc, FD, (MD && MD->isInstance()) ? &This : nullptr,
15672 Args, CallRef(), FD->getBody(), Info, Scratch, nullptr);
15673 }
15674
15675 return Diags.empty();
15676}
15677
15678bool Expr::isPotentialConstantExprUnevaluated(Expr *E,
15679 const FunctionDecl *FD,
15680 SmallVectorImpl<
15681 PartialDiagnosticAt> &Diags) {
15682 assert(!E->isValueDependent() &&((!E->isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!E->isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15683, __PRETTY_FUNCTION__))
15683 "Expression evaluator can't be called on a dependent expression.")((!E->isValueDependent() && "Expression evaluator can't be called on a dependent expression."
) ? static_cast<void> (0) : __assert_fail ("!E->isValueDependent() && \"Expression evaluator can't be called on a dependent expression.\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/AST/ExprConstant.cpp"
, 15683, __PRETTY_FUNCTION__))
;
15684
15685 Expr::EvalStatus Status;
15686 Status.Diag = &Diags;
15687
15688 EvalInfo Info(FD->getASTContext(), Status,
15689 EvalInfo::EM_ConstantExpressionUnevaluated);
15690 Info.InConstantContext = true;
15691 Info.CheckingPotentialConstantExpression = true;
15692
15693 // Fabricate a call stack frame to give the arguments a plausible cover story.
15694 CallStackFrame Frame(Info, SourceLocation(), FD, /*This*/ nullptr, CallRef());
15695
15696 APValue ResultScratch;
15697 Evaluate(ResultScratch, Info, E);
15698 return Diags.empty();
15699}
15700
15701bool Expr::tryEvaluateObjectSize(uint64_t &Result, ASTContext &Ctx,
15702 unsigned Type) const {
15703 if (!getType()->isPointerType())
15704 return false;
15705
15706 Expr::EvalStatus Status;
15707 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
15708 return tryEvaluateBuiltinObjectSize(this, Type, Info, Result);
15709}