Bug Summary

File:tools/clang/lib/AST/ExprConstant.cpp
Warning:line 12467, column 9
Called C++ object pointer is null

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -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 -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~svn373517/build-llvm/tools/clang/lib/AST -I /build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST -I /build/llvm-toolchain-snapshot-10~svn373517/tools/clang/include -I /build/llvm-toolchain-snapshot-10~svn373517/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~svn373517/build-llvm/include -I /build/llvm-toolchain-snapshot-10~svn373517/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/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/llvm-10/lib/clang/10.0.0/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-10~svn373517/build-llvm/tools/clang/lib/AST -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~svn373517=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-10-02-234743-9763-1 -x c++ /build/llvm-toolchain-snapshot-10~svn373517/tools/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 <cstring>
36#include <functional>
37#include "Interp/Context.h"
38#include "Interp/Frame.h"
39#include "Interp/State.h"
40#include "clang/AST/APValue.h"
41#include "clang/AST/ASTContext.h"
42#include "clang/AST/ASTDiagnostic.h"
43#include "clang/AST/ASTLambda.h"
44#include "clang/AST/CXXInheritance.h"
45#include "clang/AST/CharUnits.h"
46#include "clang/AST/CurrentSourceLocExprScope.h"
47#include "clang/AST/Expr.h"
48#include "clang/AST/OSLog.h"
49#include "clang/AST/OptionalDiagnostic.h"
50#include "clang/AST/RecordLayout.h"
51#include "clang/AST/StmtVisitor.h"
52#include "clang/AST/TypeLoc.h"
53#include "clang/Basic/Builtins.h"
54#include "clang/Basic/FixedPoint.h"
55#include "clang/Basic/TargetInfo.h"
56#include "llvm/ADT/Optional.h"
57#include "llvm/ADT/SmallBitVector.h"
58#include "llvm/Support/SaveAndRestore.h"
59#include "llvm/Support/raw_ostream.h"
60
61#define DEBUG_TYPE"exprconstant" "exprconstant"
62
63using namespace clang;
64using llvm::APInt;
65using llvm::APSInt;
66using llvm::APFloat;
67using llvm::Optional;
68
69namespace {
70 struct LValue;
71 class CallStackFrame;
72 class EvalInfo;
73
74 using SourceLocExprScopeGuard =
75 CurrentSourceLocExprScope::SourceLocExprScopeGuard;
76
77 static QualType getType(APValue::LValueBase B) {
78 if (!B) return QualType();
79 if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
80 // FIXME: It's unclear where we're supposed to take the type from, and
81 // this actually matters for arrays of unknown bound. Eg:
82 //
83 // extern int arr[]; void f() { extern int arr[3]; };
84 // constexpr int *p = &arr[1]; // valid?
85 //
86 // For now, we take the array bound from the most recent declaration.
87 for (auto *Redecl = cast<ValueDecl>(D->getMostRecentDecl()); Redecl;
88 Redecl = cast_or_null<ValueDecl>(Redecl->getPreviousDecl())) {
89 QualType T = Redecl->getType();
90 if (!T->isIncompleteArrayType())
91 return T;
92 }
93 return D->getType();
94 }
95
96 if (B.is<TypeInfoLValue>())
97 return B.getTypeInfoType();
98
99 if (B.is<DynamicAllocLValue>())
100 return B.getDynamicAllocType();
101
102 const Expr *Base = B.get<const Expr*>();
103
104 // For a materialized temporary, the type of the temporary we materialized
105 // may not be the type of the expression.
106 if (const MaterializeTemporaryExpr *MTE =
107 dyn_cast<MaterializeTemporaryExpr>(Base)) {
108 SmallVector<const Expr *, 2> CommaLHSs;
109 SmallVector<SubobjectAdjustment, 2> Adjustments;
110 const Expr *Temp = MTE->GetTemporaryExpr();
111 const Expr *Inner = Temp->skipRValueSubobjectAdjustments(CommaLHSs,
112 Adjustments);
113 // Keep any cv-qualifiers from the reference if we generated a temporary
114 // for it directly. Otherwise use the type after adjustment.
115 if (!Adjustments.empty())
116 return Inner->getType();
117 }
118
119 return Base->getType();
120 }
121
122 /// Get an LValue path entry, which is known to not be an array index, as a
123 /// field declaration.
124 static const FieldDecl *getAsField(APValue::LValuePathEntry E) {
125 return dyn_cast_or_null<FieldDecl>(E.getAsBaseOrMember().getPointer());
126 }
127 /// Get an LValue path entry, which is known to not be an array index, as a
128 /// base class declaration.
129 static const CXXRecordDecl *getAsBaseClass(APValue::LValuePathEntry E) {
130 return dyn_cast_or_null<CXXRecordDecl>(E.getAsBaseOrMember().getPointer());
131 }
132 /// Determine whether this LValue path entry for a base class names a virtual
133 /// base class.
134 static bool isVirtualBaseClass(APValue::LValuePathEntry E) {
135 return E.getAsBaseOrMember().getInt();
136 }
137
138 /// Given an expression, determine the type used to store the result of
139 /// evaluating that expression.
140 static QualType getStorageType(ASTContext &Ctx, Expr *E) {
141 if (E->isRValue())
142 return E->getType();
143 return Ctx.getLValueReferenceType(E->getType());
144 }
145
146 /// Given a CallExpr, try to get the alloc_size attribute. May return null.
147 static const AllocSizeAttr *getAllocSizeAttr(const CallExpr *CE) {
148 const FunctionDecl *Callee = CE->getDirectCallee();
149 return Callee ? Callee->getAttr<AllocSizeAttr>() : nullptr;
150 }
151
152 /// Attempts to unwrap a CallExpr (with an alloc_size attribute) from an Expr.
153 /// This will look through a single cast.
154 ///
155 /// Returns null if we couldn't unwrap a function with alloc_size.
156 static const CallExpr *tryUnwrapAllocSizeCall(const Expr *E) {
157 if (!E->getType()->isPointerType())
158 return nullptr;
159
160 E = E->IgnoreParens();
161 // If we're doing a variable assignment from e.g. malloc(N), there will
162 // probably be a cast of some kind. In exotic cases, we might also see a
163 // top-level ExprWithCleanups. Ignore them either way.
164 if (const auto *FE = dyn_cast<FullExpr>(E))
165 E = FE->getSubExpr()->IgnoreParens();
166
167 if (const auto *Cast = dyn_cast<CastExpr>(E))
168 E = Cast->getSubExpr()->IgnoreParens();
169
170 if (const auto *CE = dyn_cast<CallExpr>(E))
171 return getAllocSizeAttr(CE) ? CE : nullptr;
172 return nullptr;
173 }
174
175 /// Determines whether or not the given Base contains a call to a function
176 /// with the alloc_size attribute.
177 static bool isBaseAnAllocSizeCall(APValue::LValueBase Base) {
178 const auto *E = Base.dyn_cast<const Expr *>();
179 return E && E->getType()->isPointerType() && tryUnwrapAllocSizeCall(E);
180 }
181
182 /// The bound to claim that an array of unknown bound has.
183 /// The value in MostDerivedArraySize is undefined in this case. So, set it
184 /// to an arbitrary value that's likely to loudly break things if it's used.
185 static const uint64_t AssumedSizeForUnsizedArray =
186 std::numeric_limits<uint64_t>::max() / 2;
187
188 /// Determines if an LValue with the given LValueBase will have an unsized
189 /// array in its designator.
190 /// Find the path length and type of the most-derived subobject in the given
191 /// path, and find the size of the containing array, if any.
192 static unsigned
193 findMostDerivedSubobject(ASTContext &Ctx, APValue::LValueBase Base,
194 ArrayRef<APValue::LValuePathEntry> Path,
195 uint64_t &ArraySize, QualType &Type, bool &IsArray,
196 bool &FirstEntryIsUnsizedArray) {
197 // This only accepts LValueBases from APValues, and APValues don't support
198 // arrays that lack size info.
199 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 200, __PRETTY_FUNCTION__))
200 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 200, __PRETTY_FUNCTION__))
;
201 unsigned MostDerivedLength = 0;
202 Type = getType(Base);
203
204 for (unsigned I = 0, N = Path.size(); I != N; ++I) {
205 if (Type->isArrayType()) {
206 const ArrayType *AT = Ctx.getAsArrayType(Type);
207 Type = AT->getElementType();
208 MostDerivedLength = I + 1;
209 IsArray = true;
210
211 if (auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
212 ArraySize = CAT->getSize().getZExtValue();
213 } else {
214 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 214, __PRETTY_FUNCTION__))
;
215 FirstEntryIsUnsizedArray = true;
216 ArraySize = AssumedSizeForUnsizedArray;
217 }
218 } else if (Type->isAnyComplexType()) {
219 const ComplexType *CT = Type->castAs<ComplexType>();
220 Type = CT->getElementType();
221 ArraySize = 2;
222 MostDerivedLength = I + 1;
223 IsArray = true;
224 } else if (const FieldDecl *FD = getAsField(Path[I])) {
225 Type = FD->getType();
226 ArraySize = 0;
227 MostDerivedLength = I + 1;
228 IsArray = false;
229 } else {
230 // Path[I] describes a base class.
231 ArraySize = 0;
232 IsArray = false;
233 }
234 }
235 return MostDerivedLength;
236 }
237
238 /// A path from a glvalue to a subobject of that glvalue.
239 struct SubobjectDesignator {
240 /// True if the subobject was named in a manner not supported by C++11. Such
241 /// lvalues can still be folded, but they are not core constant expressions
242 /// and we cannot perform lvalue-to-rvalue conversions on them.
243 unsigned Invalid : 1;
244
245 /// Is this a pointer one past the end of an object?
246 unsigned IsOnePastTheEnd : 1;
247
248 /// Indicator of whether the first entry is an unsized array.
249 unsigned FirstEntryIsAnUnsizedArray : 1;
250
251 /// Indicator of whether the most-derived object is an array element.
252 unsigned MostDerivedIsArrayElement : 1;
253
254 /// The length of the path to the most-derived object of which this is a
255 /// subobject.
256 unsigned MostDerivedPathLength : 28;
257
258 /// The size of the array of which the most-derived object is an element.
259 /// This will always be 0 if the most-derived object is not an array
260 /// element. 0 is not an indicator of whether or not the most-derived object
261 /// is an array, however, because 0-length arrays are allowed.
262 ///
263 /// If the current array is an unsized array, the value of this is
264 /// undefined.
265 uint64_t MostDerivedArraySize;
266
267 /// The type of the most derived object referred to by this address.
268 QualType MostDerivedType;
269
270 typedef APValue::LValuePathEntry PathEntry;
271
272 /// The entries on the path from the glvalue to the designated subobject.
273 SmallVector<PathEntry, 8> Entries;
274
275 SubobjectDesignator() : Invalid(true) {}
276
277 explicit SubobjectDesignator(QualType T)
278 : Invalid(false), IsOnePastTheEnd(false),
279 FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
280 MostDerivedPathLength(0), MostDerivedArraySize(0),
281 MostDerivedType(T) {}
282
283 SubobjectDesignator(ASTContext &Ctx, const APValue &V)
284 : Invalid(!V.isLValue() || !V.hasLValuePath()), IsOnePastTheEnd(false),
285 FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
286 MostDerivedPathLength(0), MostDerivedArraySize(0) {
287 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 287, __PRETTY_FUNCTION__))
;
288 if (!Invalid) {
289 IsOnePastTheEnd = V.isLValueOnePastTheEnd();
290 ArrayRef<PathEntry> VEntries = V.getLValuePath();
291 Entries.insert(Entries.end(), VEntries.begin(), VEntries.end());
292 if (V.getLValueBase()) {
293 bool IsArray = false;
294 bool FirstIsUnsizedArray = false;
295 MostDerivedPathLength = findMostDerivedSubobject(
296 Ctx, V.getLValueBase(), V.getLValuePath(), MostDerivedArraySize,
297 MostDerivedType, IsArray, FirstIsUnsizedArray);
298 MostDerivedIsArrayElement = IsArray;
299 FirstEntryIsAnUnsizedArray = FirstIsUnsizedArray;
300 }
301 }
302 }
303
304 void truncate(ASTContext &Ctx, APValue::LValueBase Base,
305 unsigned NewLength) {
306 if (Invalid)
307 return;
308
309 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 309, __PRETTY_FUNCTION__))
;
310 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 310, __PRETTY_FUNCTION__))
;
311
312 if (NewLength == Entries.size())
313 return;
314 Entries.resize(NewLength);
315
316 bool IsArray = false;
317 bool FirstIsUnsizedArray = false;
318 MostDerivedPathLength = findMostDerivedSubobject(
319 Ctx, Base, Entries, MostDerivedArraySize, MostDerivedType, IsArray,
320 FirstIsUnsizedArray);
321 MostDerivedIsArrayElement = IsArray;
322 FirstEntryIsAnUnsizedArray = FirstIsUnsizedArray;
323 }
324
325 void setInvalid() {
326 Invalid = true;
327 Entries.clear();
328 }
329
330 /// Determine whether the most derived subobject is an array without a
331 /// known bound.
332 bool isMostDerivedAnUnsizedArray() const {
333 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 333, __PRETTY_FUNCTION__))
;
334 return Entries.size() == 1 && FirstEntryIsAnUnsizedArray;
335 }
336
337 /// Determine what the most derived array's size is. Results in an assertion
338 /// failure if the most derived array lacks a size.
339 uint64_t getMostDerivedArraySize() const {
340 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 340, __PRETTY_FUNCTION__))
;
341 return MostDerivedArraySize;
342 }
343
344 /// Determine whether this is a one-past-the-end pointer.
345 bool isOnePastTheEnd() const {
346 assert(!Invalid)((!Invalid) ? static_cast<void> (0) : __assert_fail ("!Invalid"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 346, __PRETTY_FUNCTION__))
;
347 if (IsOnePastTheEnd)
348 return true;
349 if (!isMostDerivedAnUnsizedArray() && MostDerivedIsArrayElement &&
350 Entries[MostDerivedPathLength - 1].getAsArrayIndex() ==
351 MostDerivedArraySize)
352 return true;
353 return false;
354 }
355
356 /// Get the range of valid index adjustments in the form
357 /// {maximum value that can be subtracted from this pointer,
358 /// maximum value that can be added to this pointer}
359 std::pair<uint64_t, uint64_t> validIndexAdjustments() {
360 if (Invalid || isMostDerivedAnUnsizedArray())
361 return {0, 0};
362
363 // [expr.add]p4: For the purposes of these operators, a pointer to a
364 // nonarray object behaves the same as a pointer to the first element of
365 // an array of length one with the type of the object as its element type.
366 bool IsArray = MostDerivedPathLength == Entries.size() &&
367 MostDerivedIsArrayElement;
368 uint64_t ArrayIndex = IsArray ? Entries.back().getAsArrayIndex()
369 : (uint64_t)IsOnePastTheEnd;
370 uint64_t ArraySize =
371 IsArray ? getMostDerivedArraySize() : (uint64_t)1;
372 return {ArrayIndex, ArraySize - ArrayIndex};
373 }
374
375 /// Check that this refers to a valid subobject.
376 bool isValidSubobject() const {
377 if (Invalid)
378 return false;
379 return !isOnePastTheEnd();
380 }
381 /// Check that this refers to a valid subobject, and if not, produce a
382 /// relevant diagnostic and set the designator as invalid.
383 bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK);
384
385 /// Get the type of the designated object.
386 QualType getType(ASTContext &Ctx) const {
387 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 387, __PRETTY_FUNCTION__))
;
388 return MostDerivedPathLength == Entries.size()
389 ? MostDerivedType
390 : Ctx.getRecordType(getAsBaseClass(Entries.back()));
391 }
392
393 /// Update this designator to refer to the first element within this array.
394 void addArrayUnchecked(const ConstantArrayType *CAT) {
395 Entries.push_back(PathEntry::ArrayIndex(0));
396
397 // This is a most-derived object.
398 MostDerivedType = CAT->getElementType();
399 MostDerivedIsArrayElement = true;
400 MostDerivedArraySize = CAT->getSize().getZExtValue();
401 MostDerivedPathLength = Entries.size();
402 }
403 /// Update this designator to refer to the first element within the array of
404 /// elements of type T. This is an array of unknown size.
405 void addUnsizedArrayUnchecked(QualType ElemTy) {
406 Entries.push_back(PathEntry::ArrayIndex(0));
407
408 MostDerivedType = ElemTy;
409 MostDerivedIsArrayElement = true;
410 // The value in MostDerivedArraySize is undefined in this case. So, set it
411 // to an arbitrary value that's likely to loudly break things if it's
412 // used.
413 MostDerivedArraySize = AssumedSizeForUnsizedArray;
414 MostDerivedPathLength = Entries.size();
415 }
416 /// Update this designator to refer to the given base or member of this
417 /// object.
418 void addDeclUnchecked(const Decl *D, bool Virtual = false) {
419 Entries.push_back(APValue::BaseOrMemberType(D, Virtual));
420
421 // If this isn't a base class, it's a new most-derived object.
422 if (const FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
423 MostDerivedType = FD->getType();
424 MostDerivedIsArrayElement = false;
425 MostDerivedArraySize = 0;
426 MostDerivedPathLength = Entries.size();
427 }
428 }
429 /// Update this designator to refer to the given complex component.
430 void addComplexUnchecked(QualType EltTy, bool Imag) {
431 Entries.push_back(PathEntry::ArrayIndex(Imag));
432
433 // This is technically a most-derived object, though in practice this
434 // is unlikely to matter.
435 MostDerivedType = EltTy;
436 MostDerivedIsArrayElement = true;
437 MostDerivedArraySize = 2;
438 MostDerivedPathLength = Entries.size();
439 }
440 void diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info, const Expr *E);
441 void diagnosePointerArithmetic(EvalInfo &Info, const Expr *E,
442 const APSInt &N);
443 /// Add N to the address of this subobject.
444 void adjustIndex(EvalInfo &Info, const Expr *E, APSInt N) {
445 if (Invalid || !N) return;
446 uint64_t TruncatedN = N.extOrTrunc(64).getZExtValue();
447 if (isMostDerivedAnUnsizedArray()) {
448 diagnoseUnsizedArrayPointerArithmetic(Info, E);
449 // Can't verify -- trust that the user is doing the right thing (or if
450 // not, trust that the caller will catch the bad behavior).
451 // FIXME: Should we reject if this overflows, at least?
452 Entries.back() = PathEntry::ArrayIndex(
453 Entries.back().getAsArrayIndex() + TruncatedN);
454 return;
455 }
456
457 // [expr.add]p4: For the purposes of these operators, a pointer to a
458 // nonarray object behaves the same as a pointer to the first element of
459 // an array of length one with the type of the object as its element type.
460 bool IsArray = MostDerivedPathLength == Entries.size() &&
461 MostDerivedIsArrayElement;
462 uint64_t ArrayIndex = IsArray ? Entries.back().getAsArrayIndex()
463 : (uint64_t)IsOnePastTheEnd;
464 uint64_t ArraySize =
465 IsArray ? getMostDerivedArraySize() : (uint64_t)1;
466
467 if (N < -(int64_t)ArrayIndex || N > ArraySize - ArrayIndex) {
468 // Calculate the actual index in a wide enough type, so we can include
469 // it in the note.
470 N = N.extend(std::max<unsigned>(N.getBitWidth() + 1, 65));
471 (llvm::APInt&)N += ArrayIndex;
472 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 472, __PRETTY_FUNCTION__))
;
473 diagnosePointerArithmetic(Info, E, N);
474 setInvalid();
475 return;
476 }
477
478 ArrayIndex += TruncatedN;
479 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 480, __PRETTY_FUNCTION__))
480 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 480, __PRETTY_FUNCTION__))
;
481
482 if (IsArray)
483 Entries.back() = PathEntry::ArrayIndex(ArrayIndex);
484 else
485 IsOnePastTheEnd = (ArrayIndex != 0);
486 }
487 };
488
489 /// A stack frame in the constexpr call stack.
490 class CallStackFrame : public interp::Frame {
491 public:
492 EvalInfo &Info;
493
494 /// Parent - The caller of this stack frame.
495 CallStackFrame *Caller;
496
497 /// Callee - The function which was called.
498 const FunctionDecl *Callee;
499
500 /// This - The binding for the this pointer in this call, if any.
501 const LValue *This;
502
503 /// Arguments - Parameter bindings for this function call, indexed by
504 /// parameters' function scope indices.
505 APValue *Arguments;
506
507 /// Source location information about the default argument or default
508 /// initializer expression we're evaluating, if any.
509 CurrentSourceLocExprScope CurSourceLocExprScope;
510
511 // Note that we intentionally use std::map here so that references to
512 // values are stable.
513 typedef std::pair<const void *, unsigned> MapKeyTy;
514 typedef std::map<MapKeyTy, APValue> MapTy;
515 /// Temporaries - Temporary lvalues materialized within this stack frame.
516 MapTy Temporaries;
517
518 /// CallLoc - The location of the call expression for this call.
519 SourceLocation CallLoc;
520
521 /// Index - The call index of this call.
522 unsigned Index;
523
524 /// The stack of integers for tracking version numbers for temporaries.
525 SmallVector<unsigned, 2> TempVersionStack = {1};
526 unsigned CurTempVersion = TempVersionStack.back();
527
528 unsigned getTempVersion() const { return TempVersionStack.back(); }
529
530 void pushTempVersion() {
531 TempVersionStack.push_back(++CurTempVersion);
532 }
533
534 void popTempVersion() {
535 TempVersionStack.pop_back();
536 }
537
538 // FIXME: Adding this to every 'CallStackFrame' may have a nontrivial impact
539 // on the overall stack usage of deeply-recursing constexpr evaluations.
540 // (We should cache this map rather than recomputing it repeatedly.)
541 // But let's try this and see how it goes; we can look into caching the map
542 // as a later change.
543
544 /// LambdaCaptureFields - Mapping from captured variables/this to
545 /// corresponding data members in the closure class.
546 llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
547 FieldDecl *LambdaThisCaptureField;
548
549 CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
550 const FunctionDecl *Callee, const LValue *This,
551 APValue *Arguments);
552 ~CallStackFrame();
553
554 // Return the temporary for Key whose version number is Version.
555 APValue *getTemporary(const void *Key, unsigned Version) {
556 MapKeyTy KV(Key, Version);
557 auto LB = Temporaries.lower_bound(KV);
558 if (LB != Temporaries.end() && LB->first == KV)
559 return &LB->second;
560 // Pair (Key,Version) wasn't found in the map. Check that no elements
561 // in the map have 'Key' as their key.
562 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 564, __PRETTY_FUNCTION__))
563 (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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 564, __PRETTY_FUNCTION__))
564 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 564, __PRETTY_FUNCTION__))
;
565 return nullptr;
566 }
567
568 // Return the current temporary for Key in the map.
569 APValue *getCurrentTemporary(const void *Key) {
570 auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX(2147483647 *2U +1U)));
571 if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
572 return &std::prev(UB)->second;
573 return nullptr;
574 }
575
576 // Return the version number of the current temporary for Key.
577 unsigned getCurrentTemporaryVersion(const void *Key) const {
578 auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX(2147483647 *2U +1U)));
579 if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
580 return std::prev(UB)->first.second;
581 return 0;
582 }
583
584 /// Allocate storage for an object of type T in this stack frame.
585 /// Populates LV with a handle to the created object. Key identifies
586 /// the temporary within the stack frame, and must not be reused without
587 /// bumping the temporary version number.
588 template<typename KeyT>
589 APValue &createTemporary(const KeyT *Key, QualType T,
590 bool IsLifetimeExtended, LValue &LV);
591
592 void describe(llvm::raw_ostream &OS) override;
593
594 Frame *getCaller() const override { return Caller; }
595 SourceLocation getCallLocation() const override { return CallLoc; }
596 const FunctionDecl *getCallee() const override { return Callee; }
597 };
598
599 /// Temporarily override 'this'.
600 class ThisOverrideRAII {
601 public:
602 ThisOverrideRAII(CallStackFrame &Frame, const LValue *NewThis, bool Enable)
603 : Frame(Frame), OldThis(Frame.This) {
604 if (Enable)
605 Frame.This = NewThis;
606 }
607 ~ThisOverrideRAII() {
608 Frame.This = OldThis;
609 }
610 private:
611 CallStackFrame &Frame;
612 const LValue *OldThis;
613 };
614}
615
616static bool HandleDestruction(EvalInfo &Info, const Expr *E,
617 const LValue &This, QualType ThisType);
618static bool HandleDestruction(EvalInfo &Info, SourceLocation Loc,
619 APValue::LValueBase LVBase, APValue &Value,
620 QualType T);
621
622namespace {
623 /// A cleanup, and a flag indicating whether it is lifetime-extended.
624 class Cleanup {
625 llvm::PointerIntPair<APValue*, 1, bool> Value;
626 APValue::LValueBase Base;
627 QualType T;
628
629 public:
630 Cleanup(APValue *Val, APValue::LValueBase Base, QualType T,
631 bool IsLifetimeExtended)
632 : Value(Val, IsLifetimeExtended), Base(Base), T(T) {}
633
634 bool isLifetimeExtended() const { return Value.getInt(); }
635 bool endLifetime(EvalInfo &Info, bool RunDestructors) {
636 if (RunDestructors) {
637 SourceLocation Loc;
638 if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
639 Loc = VD->getLocation();
640 else if (const Expr *E = Base.dyn_cast<const Expr*>())
641 Loc = E->getExprLoc();
642 return HandleDestruction(Info, Loc, Base, *Value.getPointer(), T);
643 }
644 *Value.getPointer() = APValue();
645 return true;
646 }
647
648 bool hasSideEffect() {
649 return T.isDestructedType();
650 }
651 };
652
653 /// A reference to an object whose construction we are currently evaluating.
654 struct ObjectUnderConstruction {
655 APValue::LValueBase Base;
656 ArrayRef<APValue::LValuePathEntry> Path;
657 friend bool operator==(const ObjectUnderConstruction &LHS,
658 const ObjectUnderConstruction &RHS) {
659 return LHS.Base == RHS.Base && LHS.Path == RHS.Path;
660 }
661 friend llvm::hash_code hash_value(const ObjectUnderConstruction &Obj) {
662 return llvm::hash_combine(Obj.Base, Obj.Path);
663 }
664 };
665 enum class ConstructionPhase {
666 None,
667 Bases,
668 AfterBases,
669 Destroying,
670 DestroyingBases
671 };
672}
673
674namespace llvm {
675template<> struct DenseMapInfo<ObjectUnderConstruction> {
676 using Base = DenseMapInfo<APValue::LValueBase>;
677 static ObjectUnderConstruction getEmptyKey() {
678 return {Base::getEmptyKey(), {}}; }
679 static ObjectUnderConstruction getTombstoneKey() {
680 return {Base::getTombstoneKey(), {}};
681 }
682 static unsigned getHashValue(const ObjectUnderConstruction &Object) {
683 return hash_value(Object);
684 }
685 static bool isEqual(const ObjectUnderConstruction &LHS,
686 const ObjectUnderConstruction &RHS) {
687 return LHS == RHS;
688 }
689};
690}
691
692namespace {
693 /// EvalInfo - This is a private struct used by the evaluator to capture
694 /// information about a subexpression as it is folded. It retains information
695 /// about the AST context, but also maintains information about the folded
696 /// expression.
697 ///
698 /// If an expression could be evaluated, it is still possible it is not a C
699 /// "integer constant expression" or constant expression. If not, this struct
700 /// captures information about how and why not.
701 ///
702 /// One bit of information passed *into* the request for constant folding
703 /// indicates whether the subexpression is "evaluated" or not according to C
704 /// rules. For example, the RHS of (0 && foo()) is not evaluated. We can
705 /// evaluate the expression regardless of what the RHS is, but C only allows
706 /// certain things in certain situations.
707 class EvalInfo : public interp::State {
708 public:
709 ASTContext &Ctx;
710
711 /// EvalStatus - Contains information about the evaluation.
712 Expr::EvalStatus &EvalStatus;
713
714 /// CurrentCall - The top of the constexpr call stack.
715 CallStackFrame *CurrentCall;
716
717 /// CallStackDepth - The number of calls in the call stack right now.
718 unsigned CallStackDepth;
719
720 /// NextCallIndex - The next call index to assign.
721 unsigned NextCallIndex;
722
723 /// StepsLeft - The remaining number of evaluation steps we're permitted
724 /// to perform. This is essentially a limit for the number of statements
725 /// we will evaluate.
726 unsigned StepsLeft;
727
728 /// Force the use of the experimental new constant interpreter, bailing out
729 /// with an error if a feature is not supported.
730 bool ForceNewConstInterp;
731
732 /// Enable the experimental new constant interpreter.
733 bool EnableNewConstInterp;
734
735 /// BottomFrame - The frame in which evaluation started. This must be
736 /// initialized after CurrentCall and CallStackDepth.
737 CallStackFrame BottomFrame;
738
739 /// A stack of values whose lifetimes end at the end of some surrounding
740 /// evaluation frame.
741 llvm::SmallVector<Cleanup, 16> CleanupStack;
742
743 /// EvaluatingDecl - This is the declaration whose initializer is being
744 /// evaluated, if any.
745 APValue::LValueBase EvaluatingDecl;
746
747 enum class EvaluatingDeclKind {
748 None,
749 /// We're evaluating the construction of EvaluatingDecl.
750 Ctor,
751 /// We're evaluating the destruction of EvaluatingDecl.
752 Dtor,
753 };
754 EvaluatingDeclKind IsEvaluatingDecl = EvaluatingDeclKind::None;
755
756 /// EvaluatingDeclValue - This is the value being constructed for the
757 /// declaration whose initializer is being evaluated, if any.
758 APValue *EvaluatingDeclValue;
759
760 /// Set of objects that are currently being constructed.
761 llvm::DenseMap<ObjectUnderConstruction, ConstructionPhase>
762 ObjectsUnderConstruction;
763
764 /// A dynamically-allocated heap object.
765 struct DynAlloc {
766 /// The value of this heap-allocated object.
767 APValue Value;
768 /// The allocating expression; used for diagnostics.
769 const Expr *AllocExpr = nullptr;
770 };
771
772 struct DynAllocOrder {
773 bool operator()(DynamicAllocLValue L, DynamicAllocLValue R) const {
774 return L.getIndex() < R.getIndex();
775 }
776 };
777
778 /// Current heap allocations, along with the location where each was
779 /// allocated. We use std::map here because we need stable addresses
780 /// for the stored APValues.
781 std::map<DynamicAllocLValue, DynAlloc, DynAllocOrder> HeapAllocs;
782
783 /// The number of heap allocations performed so far in this evaluation.
784 unsigned NumHeapAllocs = 0;
785
786 struct EvaluatingConstructorRAII {
787 EvalInfo &EI;
788 ObjectUnderConstruction Object;
789 bool DidInsert;
790 EvaluatingConstructorRAII(EvalInfo &EI, ObjectUnderConstruction Object,
791 bool HasBases)
792 : EI(EI), Object(Object) {
793 DidInsert =
794 EI.ObjectsUnderConstruction
795 .insert({Object, HasBases ? ConstructionPhase::Bases
796 : ConstructionPhase::AfterBases})
797 .second;
798 }
799 void finishedConstructingBases() {
800 EI.ObjectsUnderConstruction[Object] = ConstructionPhase::AfterBases;
801 }
802 ~EvaluatingConstructorRAII() {
803 if (DidInsert) EI.ObjectsUnderConstruction.erase(Object);
804 }
805 };
806
807 struct EvaluatingDestructorRAII {
808 EvalInfo &EI;
809 ObjectUnderConstruction Object;
810 bool DidInsert;
811 EvaluatingDestructorRAII(EvalInfo &EI, ObjectUnderConstruction Object)
812 : EI(EI), Object(Object) {
813 DidInsert = EI.ObjectsUnderConstruction
814 .insert({Object, ConstructionPhase::Destroying})
815 .second;
816 }
817 void startedDestroyingBases() {
818 EI.ObjectsUnderConstruction[Object] =
819 ConstructionPhase::DestroyingBases;
820 }
821 ~EvaluatingDestructorRAII() {
822 if (DidInsert)
823 EI.ObjectsUnderConstruction.erase(Object);
824 }
825 };
826
827 ConstructionPhase
828 isEvaluatingCtorDtor(APValue::LValueBase Base,
829 ArrayRef<APValue::LValuePathEntry> Path) {
830 return ObjectsUnderConstruction.lookup({Base, Path});
831 }
832
833 /// If we're currently speculatively evaluating, the outermost call stack
834 /// depth at which we can mutate state, otherwise 0.
835 unsigned SpeculativeEvaluationDepth = 0;
836
837 /// The current array initialization index, if we're performing array
838 /// initialization.
839 uint64_t ArrayInitIndex = -1;
840
841 /// HasActiveDiagnostic - Was the previous diagnostic stored? If so, further
842 /// notes attached to it will also be stored, otherwise they will not be.
843 bool HasActiveDiagnostic;
844
845 /// Have we emitted a diagnostic explaining why we couldn't constant
846 /// fold (not just why it's not strictly a constant expression)?
847 bool HasFoldFailureDiagnostic;
848
849 /// Whether or not we're in a context where the front end requires a
850 /// constant value.
851 bool InConstantContext;
852
853 /// Whether we're checking that an expression is a potential constant
854 /// expression. If so, do not fail on constructs that could become constant
855 /// later on (such as a use of an undefined global).
856 bool CheckingPotentialConstantExpression = false;
857
858 /// Whether we're checking for an expression that has undefined behavior.
859 /// If so, we will produce warnings if we encounter an operation that is
860 /// always undefined.
861 bool CheckingForUndefinedBehavior = false;
862
863 enum EvaluationMode {
864 /// Evaluate as a constant expression. Stop if we find that the expression
865 /// is not a constant expression.
866 EM_ConstantExpression,
867
868 /// Evaluate as a constant expression. Stop if we find that the expression
869 /// is not a constant expression. Some expressions can be retried in the
870 /// optimizer if we don't constant fold them here, but in an unevaluated
871 /// context we try to fold them immediately since the optimizer never
872 /// gets a chance to look at it.
873 EM_ConstantExpressionUnevaluated,
874
875 /// Fold the expression to a constant. Stop if we hit a side-effect that
876 /// we can't model.
877 EM_ConstantFold,
878
879 /// Evaluate in any way we know how. Don't worry about side-effects that
880 /// can't be modeled.
881 EM_IgnoreSideEffects,
882 } EvalMode;
883
884 /// Are we checking whether the expression is a potential constant
885 /// expression?
886 bool checkingPotentialConstantExpression() const override {
887 return CheckingPotentialConstantExpression;
888 }
889
890 /// Are we checking an expression for overflow?
891 // FIXME: We should check for any kind of undefined or suspicious behavior
892 // in such constructs, not just overflow.
893 bool checkingForUndefinedBehavior() const override {
894 return CheckingForUndefinedBehavior;
895 }
896
897 EvalInfo(const ASTContext &C, Expr::EvalStatus &S, EvaluationMode Mode)
898 : Ctx(const_cast<ASTContext &>(C)), EvalStatus(S), CurrentCall(nullptr),
899 CallStackDepth(0), NextCallIndex(1),
900 StepsLeft(getLangOpts().ConstexprStepLimit),
901 ForceNewConstInterp(getLangOpts().ForceNewConstInterp),
902 EnableNewConstInterp(ForceNewConstInterp ||
903 getLangOpts().EnableNewConstInterp),
904 BottomFrame(*this, SourceLocation(), nullptr, nullptr, nullptr),
905 EvaluatingDecl((const ValueDecl *)nullptr),
906 EvaluatingDeclValue(nullptr), HasActiveDiagnostic(false),
907 HasFoldFailureDiagnostic(false), InConstantContext(false),
908 EvalMode(Mode) {}
909
910 ~EvalInfo() {
911 discardCleanups();
912 }
913
914 void setEvaluatingDecl(APValue::LValueBase Base, APValue &Value,
915 EvaluatingDeclKind EDK = EvaluatingDeclKind::Ctor) {
916 EvaluatingDecl = Base;
917 IsEvaluatingDecl = EDK;
918 EvaluatingDeclValue = &Value;
919 }
920
921 bool CheckCallLimit(SourceLocation Loc) {
922 // Don't perform any constexpr calls (other than the call we're checking)
923 // when checking a potential constant expression.
924 if (checkingPotentialConstantExpression() && CallStackDepth > 1)
925 return false;
926 if (NextCallIndex == 0) {
927 // NextCallIndex has wrapped around.
928 FFDiag(Loc, diag::note_constexpr_call_limit_exceeded);
929 return false;
930 }
931 if (CallStackDepth <= getLangOpts().ConstexprCallDepth)
932 return true;
933 FFDiag(Loc, diag::note_constexpr_depth_limit_exceeded)
934 << getLangOpts().ConstexprCallDepth;
935 return false;
936 }
937
938 std::pair<CallStackFrame *, unsigned>
939 getCallFrameAndDepth(unsigned CallIndex) {
940 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 940, __PRETTY_FUNCTION__))
;
941 // We will eventually hit BottomFrame, which has Index 1, so Frame can't
942 // be null in this loop.
943 unsigned Depth = CallStackDepth;
944 CallStackFrame *Frame = CurrentCall;
945 while (Frame->Index > CallIndex) {
946 Frame = Frame->Caller;
947 --Depth;
948 }
949 if (Frame->Index == CallIndex)
950 return {Frame, Depth};
951 return {nullptr, 0};
952 }
953
954 bool nextStep(const Stmt *S) {
955 if (!StepsLeft) {
956 FFDiag(S->getBeginLoc(), diag::note_constexpr_step_limit_exceeded);
957 return false;
958 }
959 --StepsLeft;
960 return true;
961 }
962
963 APValue *createHeapAlloc(const Expr *E, QualType T, LValue &LV);
964
965 Optional<DynAlloc*> lookupDynamicAlloc(DynamicAllocLValue DA) {
966 Optional<DynAlloc*> Result;
967 auto It = HeapAllocs.find(DA);
968 if (It != HeapAllocs.end())
969 Result = &It->second;
970 return Result;
971 }
972
973 void performLifetimeExtension() {
974 // Disable the cleanups for lifetime-extended temporaries.
975 CleanupStack.erase(
976 std::remove_if(CleanupStack.begin(), CleanupStack.end(),
977 [](Cleanup &C) { return C.isLifetimeExtended(); }),
978 CleanupStack.end());
979 }
980
981 /// Throw away any remaining cleanups at the end of evaluation. If any
982 /// cleanups would have had a side-effect, note that as an unmodeled
983 /// side-effect and return false. Otherwise, return true.
984 bool discardCleanups() {
985 for (Cleanup &C : CleanupStack)
986 if (C.hasSideEffect())
987 if (!noteSideEffect())
988 return false;
989 return true;
990 }
991
992 private:
993 interp::Frame *getCurrentFrame() override { return CurrentCall; }
994 const interp::Frame *getBottomFrame() const override { return &BottomFrame; }
995
996 bool hasActiveDiagnostic() override { return HasActiveDiagnostic; }
997 void setActiveDiagnostic(bool Flag) override { HasActiveDiagnostic = Flag; }
998
999 void setFoldFailureDiagnostic(bool Flag) override {
1000 HasFoldFailureDiagnostic = Flag;
1001 }
1002
1003 Expr::EvalStatus &getEvalStatus() const override { return EvalStatus; }
1004
1005 ASTContext &getCtx() const override { return Ctx; }
1006
1007 // If we have a prior diagnostic, it will be noting that the expression
1008 // isn't a constant expression. This diagnostic is more important,
1009 // unless we require this evaluation to produce a constant expression.
1010 //
1011 // FIXME: We might want to show both diagnostics to the user in
1012 // EM_ConstantFold mode.
1013 bool hasPriorDiagnostic() override {
1014 if (!EvalStatus.Diag->empty()) {
1015 switch (EvalMode) {
1016 case EM_ConstantFold:
1017 case EM_IgnoreSideEffects:
1018 if (!HasFoldFailureDiagnostic)
1019 break;
1020 // We've already failed to fold something. Keep that diagnostic.
1021 LLVM_FALLTHROUGH[[gnu::fallthrough]];
1022 case EM_ConstantExpression:
1023 case EM_ConstantExpressionUnevaluated:
1024 setActiveDiagnostic(false);
1025 return true;
1026 }
1027 }
1028 return false;
1029 }
1030
1031 unsigned getCallStackDepth() override { return CallStackDepth; }
1032
1033 public:
1034 /// Should we continue evaluation after encountering a side-effect that we
1035 /// couldn't model?
1036 bool keepEvaluatingAfterSideEffect() {
1037 switch (EvalMode) {
1038 case EM_IgnoreSideEffects:
1039 return true;
1040
1041 case EM_ConstantExpression:
1042 case EM_ConstantExpressionUnevaluated:
1043 case EM_ConstantFold:
1044 // By default, assume any side effect might be valid in some other
1045 // evaluation of this expression from a different context.
1046 return checkingPotentialConstantExpression() ||
1047 checkingForUndefinedBehavior();
1048 }
1049 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1049)
;
1050 }
1051
1052 /// Note that we have had a side-effect, and determine whether we should
1053 /// keep evaluating.
1054 bool noteSideEffect() {
1055 EvalStatus.HasSideEffects = true;
1056 return keepEvaluatingAfterSideEffect();
1057 }
1058
1059 /// Should we continue evaluation after encountering undefined behavior?
1060 bool keepEvaluatingAfterUndefinedBehavior() {
1061 switch (EvalMode) {
1062 case EM_IgnoreSideEffects:
1063 case EM_ConstantFold:
1064 return true;
1065
1066 case EM_ConstantExpression:
1067 case EM_ConstantExpressionUnevaluated:
1068 return checkingForUndefinedBehavior();
1069 }
1070 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1070)
;
1071 }
1072
1073 /// Note that we hit something that was technically undefined behavior, but
1074 /// that we can evaluate past it (such as signed overflow or floating-point
1075 /// division by zero.)
1076 bool noteUndefinedBehavior() override {
1077 EvalStatus.HasUndefinedBehavior = true;
1078 return keepEvaluatingAfterUndefinedBehavior();
1079 }
1080
1081 /// Should we continue evaluation as much as possible after encountering a
1082 /// construct which can't be reduced to a value?
1083 bool keepEvaluatingAfterFailure() const override {
1084 if (!StepsLeft)
1085 return false;
1086
1087 switch (EvalMode) {
1088 case EM_ConstantExpression:
1089 case EM_ConstantExpressionUnevaluated:
1090 case EM_ConstantFold:
1091 case EM_IgnoreSideEffects:
1092 return checkingPotentialConstantExpression() ||
1093 checkingForUndefinedBehavior();
1094 }
1095 llvm_unreachable("Missed EvalMode case")::llvm::llvm_unreachable_internal("Missed EvalMode case", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1095)
;
1096 }
1097
1098 /// Notes that we failed to evaluate an expression that other expressions
1099 /// directly depend on, and determine if we should keep evaluating. This
1100 /// should only be called if we actually intend to keep evaluating.
1101 ///
1102 /// Call noteSideEffect() instead if we may be able to ignore the value that
1103 /// we failed to evaluate, e.g. if we failed to evaluate Foo() in:
1104 ///
1105 /// (Foo(), 1) // use noteSideEffect
1106 /// (Foo() || true) // use noteSideEffect
1107 /// Foo() + 1 // use noteFailure
1108 LLVM_NODISCARD[[clang::warn_unused_result]] bool noteFailure() {
1109 // Failure when evaluating some expression often means there is some
1110 // subexpression whose evaluation was skipped. Therefore, (because we
1111 // don't track whether we skipped an expression when unwinding after an
1112 // evaluation failure) every evaluation failure that bubbles up from a
1113 // subexpression implies that a side-effect has potentially happened. We
1114 // skip setting the HasSideEffects flag to true until we decide to
1115 // continue evaluating after that point, which happens here.
1116 bool KeepGoing = keepEvaluatingAfterFailure();
1117 EvalStatus.HasSideEffects |= KeepGoing;
1118 return KeepGoing;
1119 }
1120
1121 class ArrayInitLoopIndex {
1122 EvalInfo &Info;
1123 uint64_t OuterIndex;
1124
1125 public:
1126 ArrayInitLoopIndex(EvalInfo &Info)
1127 : Info(Info), OuterIndex(Info.ArrayInitIndex) {
1128 Info.ArrayInitIndex = 0;
1129 }
1130 ~ArrayInitLoopIndex() { Info.ArrayInitIndex = OuterIndex; }
1131
1132 operator uint64_t&() { return Info.ArrayInitIndex; }
1133 };
1134 };
1135
1136 /// Object used to treat all foldable expressions as constant expressions.
1137 struct FoldConstant {
1138 EvalInfo &Info;
1139 bool Enabled;
1140 bool HadNoPriorDiags;
1141 EvalInfo::EvaluationMode OldMode;
1142
1143 explicit FoldConstant(EvalInfo &Info, bool Enabled)
1144 : Info(Info),
1145 Enabled(Enabled),
1146 HadNoPriorDiags(Info.EvalStatus.Diag &&
1147 Info.EvalStatus.Diag->empty() &&
1148 !Info.EvalStatus.HasSideEffects),
1149 OldMode(Info.EvalMode) {
1150 if (Enabled)
1151 Info.EvalMode = EvalInfo::EM_ConstantFold;
1152 }
1153 void keepDiagnostics() { Enabled = false; }
1154 ~FoldConstant() {
1155 if (Enabled && HadNoPriorDiags && !Info.EvalStatus.Diag->empty() &&
1156 !Info.EvalStatus.HasSideEffects)
1157 Info.EvalStatus.Diag->clear();
1158 Info.EvalMode = OldMode;
1159 }
1160 };
1161
1162 /// RAII object used to set the current evaluation mode to ignore
1163 /// side-effects.
1164 struct IgnoreSideEffectsRAII {
1165 EvalInfo &Info;
1166 EvalInfo::EvaluationMode OldMode;
1167 explicit IgnoreSideEffectsRAII(EvalInfo &Info)
1168 : Info(Info), OldMode(Info.EvalMode) {
1169 Info.EvalMode = EvalInfo::EM_IgnoreSideEffects;
1170 }
1171
1172 ~IgnoreSideEffectsRAII() { Info.EvalMode = OldMode; }
1173 };
1174
1175 /// RAII object used to optionally suppress diagnostics and side-effects from
1176 /// a speculative evaluation.
1177 class SpeculativeEvaluationRAII {
1178 EvalInfo *Info = nullptr;
1179 Expr::EvalStatus OldStatus;
1180 unsigned OldSpeculativeEvaluationDepth;
1181
1182 void moveFromAndCancel(SpeculativeEvaluationRAII &&Other) {
1183 Info = Other.Info;
1184 OldStatus = Other.OldStatus;
1185 OldSpeculativeEvaluationDepth = Other.OldSpeculativeEvaluationDepth;
1186 Other.Info = nullptr;
1187 }
1188
1189 void maybeRestoreState() {
1190 if (!Info)
1191 return;
1192
1193 Info->EvalStatus = OldStatus;
1194 Info->SpeculativeEvaluationDepth = OldSpeculativeEvaluationDepth;
1195 }
1196
1197 public:
1198 SpeculativeEvaluationRAII() = default;
1199
1200 SpeculativeEvaluationRAII(
1201 EvalInfo &Info, SmallVectorImpl<PartialDiagnosticAt> *NewDiag = nullptr)
1202 : Info(&Info), OldStatus(Info.EvalStatus),
1203 OldSpeculativeEvaluationDepth(Info.SpeculativeEvaluationDepth) {
1204 Info.EvalStatus.Diag = NewDiag;
1205 Info.SpeculativeEvaluationDepth = Info.CallStackDepth + 1;
1206 }
1207
1208 SpeculativeEvaluationRAII(const SpeculativeEvaluationRAII &Other) = delete;
1209 SpeculativeEvaluationRAII(SpeculativeEvaluationRAII &&Other) {
1210 moveFromAndCancel(std::move(Other));
1211 }
1212
1213 SpeculativeEvaluationRAII &operator=(SpeculativeEvaluationRAII &&Other) {
1214 maybeRestoreState();
1215 moveFromAndCancel(std::move(Other));
1216 return *this;
1217 }
1218
1219 ~SpeculativeEvaluationRAII() { maybeRestoreState(); }
1220 };
1221
1222 /// RAII object wrapping a full-expression or block scope, and handling
1223 /// the ending of the lifetime of temporaries created within it.
1224 template<bool IsFullExpression>
1225 class ScopeRAII {
1226 EvalInfo &Info;
1227 unsigned OldStackSize;
1228 public:
1229 ScopeRAII(EvalInfo &Info)
1230 : Info(Info), OldStackSize(Info.CleanupStack.size()) {
1231 // Push a new temporary version. This is needed to distinguish between
1232 // temporaries created in different iterations of a loop.
1233 Info.CurrentCall->pushTempVersion();
1234 }
1235 bool destroy(bool RunDestructors = true) {
1236 bool OK = cleanup(Info, RunDestructors, OldStackSize);
1237 OldStackSize = -1U;
1238 return OK;
1239 }
1240 ~ScopeRAII() {
1241 if (OldStackSize != -1U)
1242 destroy(false);
1243 // Body moved to a static method to encourage the compiler to inline away
1244 // instances of this class.
1245 Info.CurrentCall->popTempVersion();
1246 }
1247 private:
1248 static bool cleanup(EvalInfo &Info, bool RunDestructors,
1249 unsigned OldStackSize) {
1250 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1251, __PRETTY_FUNCTION__))
1251 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1251, __PRETTY_FUNCTION__))
;
1252
1253 // Run all cleanups for a block scope, and non-lifetime-extended cleanups
1254 // for a full-expression scope.
1255 bool Success = true;
1256 for (unsigned I = Info.CleanupStack.size(); I > OldStackSize; --I) {
1257 if (!(IsFullExpression &&
1258 Info.CleanupStack[I - 1].isLifetimeExtended())) {
1259 if (!Info.CleanupStack[I - 1].endLifetime(Info, RunDestructors)) {
1260 Success = false;
1261 break;
1262 }
1263 }
1264 }
1265
1266 // Compact lifetime-extended cleanups.
1267 auto NewEnd = Info.CleanupStack.begin() + OldStackSize;
1268 if (IsFullExpression)
1269 NewEnd =
1270 std::remove_if(NewEnd, Info.CleanupStack.end(),
1271 [](Cleanup &C) { return !C.isLifetimeExtended(); });
1272 Info.CleanupStack.erase(NewEnd, Info.CleanupStack.end());
1273 return Success;
1274 }
1275 };
1276 typedef ScopeRAII<false> BlockScopeRAII;
1277 typedef ScopeRAII<true> FullExpressionRAII;
1278}
1279
1280bool SubobjectDesignator::checkSubobject(EvalInfo &Info, const Expr *E,
1281 CheckSubobjectKind CSK) {
1282 if (Invalid)
1283 return false;
1284 if (isOnePastTheEnd()) {
1285 Info.CCEDiag(E, diag::note_constexpr_past_end_subobject)
1286 << CSK;
1287 setInvalid();
1288 return false;
1289 }
1290 // Note, we do not diagnose if isMostDerivedAnUnsizedArray(), because there
1291 // must actually be at least one array element; even a VLA cannot have a
1292 // bound of zero. And if our index is nonzero, we already had a CCEDiag.
1293 return true;
1294}
1295
1296void SubobjectDesignator::diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info,
1297 const Expr *E) {
1298 Info.CCEDiag(E, diag::note_constexpr_unsized_array_indexed);
1299 // Do not set the designator as invalid: we can represent this situation,
1300 // and correct handling of __builtin_object_size requires us to do so.
1301}
1302
1303void SubobjectDesignator::diagnosePointerArithmetic(EvalInfo &Info,
1304 const Expr *E,
1305 const APSInt &N) {
1306 // If we're complaining, we must be able to statically determine the size of
1307 // the most derived array.
1308 if (MostDerivedPathLength == Entries.size() && MostDerivedIsArrayElement)
1309 Info.CCEDiag(E, diag::note_constexpr_array_index)
1310 << N << /*array*/ 0
1311 << static_cast<unsigned>(getMostDerivedArraySize());
1312 else
1313 Info.CCEDiag(E, diag::note_constexpr_array_index)
1314 << N << /*non-array*/ 1;
1315 setInvalid();
1316}
1317
1318CallStackFrame::CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
1319 const FunctionDecl *Callee, const LValue *This,
1320 APValue *Arguments)
1321 : Info(Info), Caller(Info.CurrentCall), Callee(Callee), This(This),
1322 Arguments(Arguments), CallLoc(CallLoc), Index(Info.NextCallIndex++) {
1323 Info.CurrentCall = this;
1324 ++Info.CallStackDepth;
1325}
1326
1327CallStackFrame::~CallStackFrame() {
1328 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1328, __PRETTY_FUNCTION__))
;
1329 --Info.CallStackDepth;
1330 Info.CurrentCall = Caller;
1331}
1332
1333static bool isRead(AccessKinds AK) {
1334 return AK == AK_Read || AK == AK_ReadObjectRepresentation;
1335}
1336
1337static bool isModification(AccessKinds AK) {
1338 switch (AK) {
1339 case AK_Read:
1340 case AK_ReadObjectRepresentation:
1341 case AK_MemberCall:
1342 case AK_DynamicCast:
1343 case AK_TypeId:
1344 return false;
1345 case AK_Assign:
1346 case AK_Increment:
1347 case AK_Decrement:
1348 case AK_Destroy:
1349 return true;
1350 }
1351 llvm_unreachable("unknown access kind")::llvm::llvm_unreachable_internal("unknown access kind", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1351)
;
1352}
1353
1354static bool isAnyAccess(AccessKinds AK) {
1355 return isRead(AK) || isModification(AK);
1356}
1357
1358/// Is this an access per the C++ definition?
1359static bool isFormalAccess(AccessKinds AK) {
1360 return isAnyAccess(AK) && AK != AK_Destroy;
1361}
1362
1363namespace {
1364 struct ComplexValue {
1365 private:
1366 bool IsInt;
1367
1368 public:
1369 APSInt IntReal, IntImag;
1370 APFloat FloatReal, FloatImag;
1371
1372 ComplexValue() : FloatReal(APFloat::Bogus()), FloatImag(APFloat::Bogus()) {}
1373
1374 void makeComplexFloat() { IsInt = false; }
1375 bool isComplexFloat() const { return !IsInt; }
1376 APFloat &getComplexFloatReal() { return FloatReal; }
1377 APFloat &getComplexFloatImag() { return FloatImag; }
1378
1379 void makeComplexInt() { IsInt = true; }
1380 bool isComplexInt() const { return IsInt; }
1381 APSInt &getComplexIntReal() { return IntReal; }
1382 APSInt &getComplexIntImag() { return IntImag; }
1383
1384 void moveInto(APValue &v) const {
1385 if (isComplexFloat())
1386 v = APValue(FloatReal, FloatImag);
1387 else
1388 v = APValue(IntReal, IntImag);
1389 }
1390 void setFrom(const APValue &v) {
1391 assert(v.isComplexFloat() || v.isComplexInt())((v.isComplexFloat() || v.isComplexInt()) ? static_cast<void
> (0) : __assert_fail ("v.isComplexFloat() || v.isComplexInt()"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1391, __PRETTY_FUNCTION__))
;
1392 if (v.isComplexFloat()) {
1393 makeComplexFloat();
1394 FloatReal = v.getComplexFloatReal();
1395 FloatImag = v.getComplexFloatImag();
1396 } else {
1397 makeComplexInt();
1398 IntReal = v.getComplexIntReal();
1399 IntImag = v.getComplexIntImag();
1400 }
1401 }
1402 };
1403
1404 struct LValue {
1405 APValue::LValueBase Base;
1406 CharUnits Offset;
1407 SubobjectDesignator Designator;
1408 bool IsNullPtr : 1;
1409 bool InvalidBase : 1;
1410
1411 const APValue::LValueBase getLValueBase() const { return Base; }
1412 CharUnits &getLValueOffset() { return Offset; }
1413 const CharUnits &getLValueOffset() const { return Offset; }
1414 SubobjectDesignator &getLValueDesignator() { return Designator; }
1415 const SubobjectDesignator &getLValueDesignator() const { return Designator;}
1416 bool isNullPointer() const { return IsNullPtr;}
1417
1418 unsigned getLValueCallIndex() const { return Base.getCallIndex(); }
1419 unsigned getLValueVersion() const { return Base.getVersion(); }
1420
1421 void moveInto(APValue &V) const {
1422 if (Designator.Invalid)
1423 V = APValue(Base, Offset, APValue::NoLValuePath(), IsNullPtr);
1424 else {
1425 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1425, __PRETTY_FUNCTION__))
;
1426 V = APValue(Base, Offset, Designator.Entries,
1427 Designator.IsOnePastTheEnd, IsNullPtr);
1428 }
1429 }
1430 void setFrom(ASTContext &Ctx, const APValue &V) {
1431 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1431, __PRETTY_FUNCTION__))
;
1432 Base = V.getLValueBase();
1433 Offset = V.getLValueOffset();
1434 InvalidBase = false;
1435 Designator = SubobjectDesignator(Ctx, V);
1436 IsNullPtr = V.isNullPointer();
1437 }
1438
1439 void set(APValue::LValueBase B, bool BInvalid = false) {
1440#ifndef NDEBUG
1441 // We only allow a few types of invalid bases. Enforce that here.
1442 if (BInvalid) {
1443 const auto *E = B.get<const Expr *>();
1444 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1445, __PRETTY_FUNCTION__))
1445 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1445, __PRETTY_FUNCTION__))
;
1446 }
1447#endif
1448
1449 Base = B;
1450 Offset = CharUnits::fromQuantity(0);
1451 InvalidBase = BInvalid;
1452 Designator = SubobjectDesignator(getType(B));
1453 IsNullPtr = false;
1454 }
1455
1456 void setNull(QualType PointerTy, uint64_t TargetVal) {
1457 Base = (Expr *)nullptr;
1458 Offset = CharUnits::fromQuantity(TargetVal);
1459 InvalidBase = false;
1460 Designator = SubobjectDesignator(PointerTy->getPointeeType());
1461 IsNullPtr = true;
1462 }
1463
1464 void setInvalid(APValue::LValueBase B, unsigned I = 0) {
1465 set(B, true);
1466 }
1467
1468 private:
1469 // Check that this LValue is not based on a null pointer. If it is, produce
1470 // a diagnostic and mark the designator as invalid.
1471 template <typename GenDiagType>
1472 bool checkNullPointerDiagnosingWith(const GenDiagType &GenDiag) {
1473 if (Designator.Invalid)
1474 return false;
1475 if (IsNullPtr) {
1476 GenDiag();
1477 Designator.setInvalid();
1478 return false;
1479 }
1480 return true;
1481 }
1482
1483 public:
1484 bool checkNullPointer(EvalInfo &Info, const Expr *E,
1485 CheckSubobjectKind CSK) {
1486 return checkNullPointerDiagnosingWith([&Info, E, CSK] {
1487 Info.CCEDiag(E, diag::note_constexpr_null_subobject) << CSK;
1488 });
1489 }
1490
1491 bool checkNullPointerForFoldAccess(EvalInfo &Info, const Expr *E,
1492 AccessKinds AK) {
1493 return checkNullPointerDiagnosingWith([&Info, E, AK] {
1494 Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
1495 });
1496 }
1497
1498 // Check this LValue refers to an object. If not, set the designator to be
1499 // invalid and emit a diagnostic.
1500 bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK) {
1501 return (CSK == CSK_ArrayToPointer || checkNullPointer(Info, E, CSK)) &&
1502 Designator.checkSubobject(Info, E, CSK);
1503 }
1504
1505 void addDecl(EvalInfo &Info, const Expr *E,
1506 const Decl *D, bool Virtual = false) {
1507 if (checkSubobject(Info, E, isa<FieldDecl>(D) ? CSK_Field : CSK_Base))
1508 Designator.addDeclUnchecked(D, Virtual);
1509 }
1510 void addUnsizedArray(EvalInfo &Info, const Expr *E, QualType ElemTy) {
1511 if (!Designator.Entries.empty()) {
1512 Info.CCEDiag(E, diag::note_constexpr_unsupported_unsized_array);
1513 Designator.setInvalid();
1514 return;
1515 }
1516 if (checkSubobject(Info, E, CSK_ArrayToPointer)) {
1517 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1517, __PRETTY_FUNCTION__))
;
1518 Designator.FirstEntryIsAnUnsizedArray = true;
1519 Designator.addUnsizedArrayUnchecked(ElemTy);
1520 }
1521 }
1522 void addArray(EvalInfo &Info, const Expr *E, const ConstantArrayType *CAT) {
1523 if (checkSubobject(Info, E, CSK_ArrayToPointer))
1524 Designator.addArrayUnchecked(CAT);
1525 }
1526 void addComplex(EvalInfo &Info, const Expr *E, QualType EltTy, bool Imag) {
1527 if (checkSubobject(Info, E, Imag ? CSK_Imag : CSK_Real))
1528 Designator.addComplexUnchecked(EltTy, Imag);
1529 }
1530 void clearIsNullPointer() {
1531 IsNullPtr = false;
1532 }
1533 void adjustOffsetAndIndex(EvalInfo &Info, const Expr *E,
1534 const APSInt &Index, CharUnits ElementSize) {
1535 // An index of 0 has no effect. (In C, adding 0 to a null pointer is UB,
1536 // but we're not required to diagnose it and it's valid in C++.)
1537 if (!Index)
1538 return;
1539
1540 // Compute the new offset in the appropriate width, wrapping at 64 bits.
1541 // FIXME: When compiling for a 32-bit target, we should use 32-bit
1542 // offsets.
1543 uint64_t Offset64 = Offset.getQuantity();
1544 uint64_t ElemSize64 = ElementSize.getQuantity();
1545 uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
1546 Offset = CharUnits::fromQuantity(Offset64 + ElemSize64 * Index64);
1547
1548 if (checkNullPointer(Info, E, CSK_ArrayIndex))
1549 Designator.adjustIndex(Info, E, Index);
1550 clearIsNullPointer();
1551 }
1552 void adjustOffset(CharUnits N) {
1553 Offset += N;
1554 if (N.getQuantity())
1555 clearIsNullPointer();
1556 }
1557 };
1558
1559 struct MemberPtr {
1560 MemberPtr() {}
1561 explicit MemberPtr(const ValueDecl *Decl) :
1562 DeclAndIsDerivedMember(Decl, false), Path() {}
1563
1564 /// The member or (direct or indirect) field referred to by this member
1565 /// pointer, or 0 if this is a null member pointer.
1566 const ValueDecl *getDecl() const {
1567 return DeclAndIsDerivedMember.getPointer();
1568 }
1569 /// Is this actually a member of some type derived from the relevant class?
1570 bool isDerivedMember() const {
1571 return DeclAndIsDerivedMember.getInt();
1572 }
1573 /// Get the class which the declaration actually lives in.
1574 const CXXRecordDecl *getContainingRecord() const {
1575 return cast<CXXRecordDecl>(
1576 DeclAndIsDerivedMember.getPointer()->getDeclContext());
1577 }
1578
1579 void moveInto(APValue &V) const {
1580 V = APValue(getDecl(), isDerivedMember(), Path);
1581 }
1582 void setFrom(const APValue &V) {
1583 assert(V.isMemberPointer())((V.isMemberPointer()) ? static_cast<void> (0) : __assert_fail
("V.isMemberPointer()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1583, __PRETTY_FUNCTION__))
;
1584 DeclAndIsDerivedMember.setPointer(V.getMemberPointerDecl());
1585 DeclAndIsDerivedMember.setInt(V.isMemberPointerToDerivedMember());
1586 Path.clear();
1587 ArrayRef<const CXXRecordDecl*> P = V.getMemberPointerPath();
1588 Path.insert(Path.end(), P.begin(), P.end());
1589 }
1590
1591 /// DeclAndIsDerivedMember - The member declaration, and a flag indicating
1592 /// whether the member is a member of some class derived from the class type
1593 /// of the member pointer.
1594 llvm::PointerIntPair<const ValueDecl*, 1, bool> DeclAndIsDerivedMember;
1595 /// Path - The path of base/derived classes from the member declaration's
1596 /// class (exclusive) to the class type of the member pointer (inclusive).
1597 SmallVector<const CXXRecordDecl*, 4> Path;
1598
1599 /// Perform a cast towards the class of the Decl (either up or down the
1600 /// hierarchy).
1601 bool castBack(const CXXRecordDecl *Class) {
1602 assert(!Path.empty())((!Path.empty()) ? static_cast<void> (0) : __assert_fail
("!Path.empty()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1602, __PRETTY_FUNCTION__))
;
1603 const CXXRecordDecl *Expected;
1604 if (Path.size() >= 2)
1605 Expected = Path[Path.size() - 2];
1606 else
1607 Expected = getContainingRecord();
1608 if (Expected->getCanonicalDecl() != Class->getCanonicalDecl()) {
1609 // C++11 [expr.static.cast]p12: In a conversion from (D::*) to (B::*),
1610 // if B does not contain the original member and is not a base or
1611 // derived class of the class containing the original member, the result
1612 // of the cast is undefined.
1613 // C++11 [conv.mem]p2 does not cover this case for a cast from (B::*) to
1614 // (D::*). We consider that to be a language defect.
1615 return false;
1616 }
1617 Path.pop_back();
1618 return true;
1619 }
1620 /// Perform a base-to-derived member pointer cast.
1621 bool castToDerived(const CXXRecordDecl *Derived) {
1622 if (!getDecl())
1623 return true;
1624 if (!isDerivedMember()) {
1625 Path.push_back(Derived);
1626 return true;
1627 }
1628 if (!castBack(Derived))
1629 return false;
1630 if (Path.empty())
1631 DeclAndIsDerivedMember.setInt(false);
1632 return true;
1633 }
1634 /// Perform a derived-to-base member pointer cast.
1635 bool castToBase(const CXXRecordDecl *Base) {
1636 if (!getDecl())
1637 return true;
1638 if (Path.empty())
1639 DeclAndIsDerivedMember.setInt(true);
1640 if (isDerivedMember()) {
1641 Path.push_back(Base);
1642 return true;
1643 }
1644 return castBack(Base);
1645 }
1646 };
1647
1648 /// Compare two member pointers, which are assumed to be of the same type.
1649 static bool operator==(const MemberPtr &LHS, const MemberPtr &RHS) {
1650 if (!LHS.getDecl() || !RHS.getDecl())
1651 return !LHS.getDecl() && !RHS.getDecl();
1652 if (LHS.getDecl()->getCanonicalDecl() != RHS.getDecl()->getCanonicalDecl())
1653 return false;
1654 return LHS.Path == RHS.Path;
1655 }
1656}
1657
1658static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E);
1659static bool EvaluateInPlace(APValue &Result, EvalInfo &Info,
1660 const LValue &This, const Expr *E,
1661 bool AllowNonLiteralTypes = false);
1662static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
1663 bool InvalidBaseOK = false);
1664static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info,
1665 bool InvalidBaseOK = false);
1666static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
1667 EvalInfo &Info);
1668static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info);
1669static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info);
1670static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
1671 EvalInfo &Info);
1672static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info);
1673static bool EvaluateComplex(const Expr *E, ComplexValue &Res, EvalInfo &Info);
1674static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
1675 EvalInfo &Info);
1676static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result);
1677
1678/// Evaluate an integer or fixed point expression into an APResult.
1679static bool EvaluateFixedPointOrInteger(const Expr *E, APFixedPoint &Result,
1680 EvalInfo &Info);
1681
1682/// Evaluate only a fixed point expression into an APResult.
1683static bool EvaluateFixedPoint(const Expr *E, APFixedPoint &Result,
1684 EvalInfo &Info);
1685
1686//===----------------------------------------------------------------------===//
1687// Misc utilities
1688//===----------------------------------------------------------------------===//
1689
1690/// Negate an APSInt in place, converting it to a signed form if necessary, and
1691/// preserving its value (by extending by up to one bit as needed).
1692static void negateAsSigned(APSInt &Int) {
1693 if (Int.isUnsigned() || Int.isMinSignedValue()) {
1694 Int = Int.extend(Int.getBitWidth() + 1);
1695 Int.setIsSigned(true);
1696 }
1697 Int = -Int;
1698}
1699
1700template<typename KeyT>
1701APValue &CallStackFrame::createTemporary(const KeyT *Key, QualType T,
1702 bool IsLifetimeExtended, LValue &LV) {
1703 unsigned Version = getTempVersion();
1704 APValue::LValueBase Base(Key, Index, Version);
1705 LV.set(Base);
1706 APValue &Result = Temporaries[MapKeyTy(Key, Version)];
1707 assert(Result.isAbsent() && "temporary created multiple times")((Result.isAbsent() && "temporary created multiple times"
) ? static_cast<void> (0) : __assert_fail ("Result.isAbsent() && \"temporary created multiple times\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1707, __PRETTY_FUNCTION__))
;
1708
1709 // If we're creating a temporary immediately in the operand of a speculative
1710 // evaluation, don't register a cleanup to be run outside the speculative
1711 // evaluation context, since we won't actually be able to initialize this
1712 // object.
1713 if (Index <= Info.SpeculativeEvaluationDepth) {
1714 if (T.isDestructedType())
1715 Info.noteSideEffect();
1716 } else {
1717 Info.CleanupStack.push_back(Cleanup(&Result, Base, T, IsLifetimeExtended));
1718 }
1719 return Result;
1720}
1721
1722APValue *EvalInfo::createHeapAlloc(const Expr *E, QualType T, LValue &LV) {
1723 if (NumHeapAllocs > DynamicAllocLValue::getMaxIndex()) {
1724 FFDiag(E, diag::note_constexpr_heap_alloc_limit_exceeded);
1725 return nullptr;
1726 }
1727
1728 DynamicAllocLValue DA(NumHeapAllocs++);
1729 LV.set(APValue::LValueBase::getDynamicAlloc(DA, T));
1730 auto Result = HeapAllocs.emplace(std::piecewise_construct,
1731 std::forward_as_tuple(DA), std::tuple<>());
1732 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1732, __PRETTY_FUNCTION__))
;
1733 Result.first->second.AllocExpr = E;
1734 return &Result.first->second.Value;
1735}
1736
1737/// Produce a string describing the given constexpr call.
1738void CallStackFrame::describe(raw_ostream &Out) {
1739 unsigned ArgIndex = 0;
1740 bool IsMemberCall = isa<CXXMethodDecl>(Callee) &&
1741 !isa<CXXConstructorDecl>(Callee) &&
1742 cast<CXXMethodDecl>(Callee)->isInstance();
1743
1744 if (!IsMemberCall)
1745 Out << *Callee << '(';
1746
1747 if (This && IsMemberCall) {
1748 APValue Val;
1749 This->moveInto(Val);
1750 Val.printPretty(Out, Info.Ctx,
1751 This->Designator.MostDerivedType);
1752 // FIXME: Add parens around Val if needed.
1753 Out << "->" << *Callee << '(';
1754 IsMemberCall = false;
1755 }
1756
1757 for (FunctionDecl::param_const_iterator I = Callee->param_begin(),
1758 E = Callee->param_end(); I != E; ++I, ++ArgIndex) {
1759 if (ArgIndex > (unsigned)IsMemberCall)
1760 Out << ", ";
1761
1762 const ParmVarDecl *Param = *I;
1763 const APValue &Arg = Arguments[ArgIndex];
1764 Arg.printPretty(Out, Info.Ctx, Param->getType());
1765
1766 if (ArgIndex == 0 && IsMemberCall)
1767 Out << "->" << *Callee << '(';
1768 }
1769
1770 Out << ')';
1771}
1772
1773/// Evaluate an expression to see if it had side-effects, and discard its
1774/// result.
1775/// \return \c true if the caller should keep evaluating.
1776static bool EvaluateIgnoredValue(EvalInfo &Info, const Expr *E) {
1777 APValue Scratch;
1778 if (!Evaluate(Scratch, Info, E))
1779 // We don't need the value, but we might have skipped a side effect here.
1780 return Info.noteSideEffect();
1781 return true;
1782}
1783
1784/// Should this call expression be treated as a string literal?
1785static bool IsStringLiteralCall(const CallExpr *E) {
1786 unsigned Builtin = E->getBuiltinCallee();
1787 return (Builtin == Builtin::BI__builtin___CFStringMakeConstantString ||
1788 Builtin == Builtin::BI__builtin___NSStringMakeConstantString);
1789}
1790
1791static bool IsGlobalLValue(APValue::LValueBase B) {
1792 // C++11 [expr.const]p3 An address constant expression is a prvalue core
1793 // constant expression of pointer type that evaluates to...
1794
1795 // ... a null pointer value, or a prvalue core constant expression of type
1796 // std::nullptr_t.
1797 if (!B) return true;
1798
1799 if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
1800 // ... the address of an object with static storage duration,
1801 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
1802 return VD->hasGlobalStorage();
1803 // ... the address of a function,
1804 return isa<FunctionDecl>(D);
1805 }
1806
1807 if (B.is<TypeInfoLValue>() || B.is<DynamicAllocLValue>())
1808 return true;
1809
1810 const Expr *E = B.get<const Expr*>();
1811 switch (E->getStmtClass()) {
1812 default:
1813 return false;
1814 case Expr::CompoundLiteralExprClass: {
1815 const CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E);
1816 return CLE->isFileScope() && CLE->isLValue();
1817 }
1818 case Expr::MaterializeTemporaryExprClass:
1819 // A materialized temporary might have been lifetime-extended to static
1820 // storage duration.
1821 return cast<MaterializeTemporaryExpr>(E)->getStorageDuration() == SD_Static;
1822 // A string literal has static storage duration.
1823 case Expr::StringLiteralClass:
1824 case Expr::PredefinedExprClass:
1825 case Expr::ObjCStringLiteralClass:
1826 case Expr::ObjCEncodeExprClass:
1827 case Expr::CXXUuidofExprClass:
1828 return true;
1829 case Expr::ObjCBoxedExprClass:
1830 return cast<ObjCBoxedExpr>(E)->isExpressibleAsConstantInitializer();
1831 case Expr::CallExprClass:
1832 return IsStringLiteralCall(cast<CallExpr>(E));
1833 // For GCC compatibility, &&label has static storage duration.
1834 case Expr::AddrLabelExprClass:
1835 return true;
1836 // A Block literal expression may be used as the initialization value for
1837 // Block variables at global or local static scope.
1838 case Expr::BlockExprClass:
1839 return !cast<BlockExpr>(E)->getBlockDecl()->hasCaptures();
1840 case Expr::ImplicitValueInitExprClass:
1841 // FIXME:
1842 // We can never form an lvalue with an implicit value initialization as its
1843 // base through expression evaluation, so these only appear in one case: the
1844 // implicit variable declaration we invent when checking whether a constexpr
1845 // constructor can produce a constant expression. We must assume that such
1846 // an expression might be a global lvalue.
1847 return true;
1848 }
1849}
1850
1851static const ValueDecl *GetLValueBaseDecl(const LValue &LVal) {
1852 return LVal.Base.dyn_cast<const ValueDecl*>();
1853}
1854
1855static bool IsLiteralLValue(const LValue &Value) {
1856 if (Value.getLValueCallIndex())
1857 return false;
1858 const Expr *E = Value.Base.dyn_cast<const Expr*>();
1859 return E && !isa<MaterializeTemporaryExpr>(E);
1860}
1861
1862static bool IsWeakLValue(const LValue &Value) {
1863 const ValueDecl *Decl = GetLValueBaseDecl(Value);
1864 return Decl && Decl->isWeak();
1865}
1866
1867static bool isZeroSized(const LValue &Value) {
1868 const ValueDecl *Decl = GetLValueBaseDecl(Value);
1869 if (Decl && isa<VarDecl>(Decl)) {
1870 QualType Ty = Decl->getType();
1871 if (Ty->isArrayType())
1872 return Ty->isIncompleteType() ||
1873 Decl->getASTContext().getTypeSize(Ty) == 0;
1874 }
1875 return false;
1876}
1877
1878static bool HasSameBase(const LValue &A, const LValue &B) {
1879 if (!A.getLValueBase())
1880 return !B.getLValueBase();
1881 if (!B.getLValueBase())
1882 return false;
1883
1884 if (A.getLValueBase().getOpaqueValue() !=
1885 B.getLValueBase().getOpaqueValue()) {
1886 const Decl *ADecl = GetLValueBaseDecl(A);
1887 if (!ADecl)
1888 return false;
1889 const Decl *BDecl = GetLValueBaseDecl(B);
1890 if (!BDecl || ADecl->getCanonicalDecl() != BDecl->getCanonicalDecl())
1891 return false;
1892 }
1893
1894 return IsGlobalLValue(A.getLValueBase()) ||
1895 (A.getLValueCallIndex() == B.getLValueCallIndex() &&
1896 A.getLValueVersion() == B.getLValueVersion());
1897}
1898
1899static void NoteLValueLocation(EvalInfo &Info, APValue::LValueBase Base) {
1900 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1900, __PRETTY_FUNCTION__))
;
1901 const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
1902 if (VD)
1903 Info.Note(VD->getLocation(), diag::note_declared_at);
1904 else if (const Expr *E = Base.dyn_cast<const Expr*>())
1905 Info.Note(E->getExprLoc(), diag::note_constexpr_temporary_here);
1906 else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
1907 // FIXME: Produce a note for dangling pointers too.
1908 if (Optional<EvalInfo::DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA))
1909 Info.Note((*Alloc)->AllocExpr->getExprLoc(),
1910 diag::note_constexpr_dynamic_alloc_here);
1911 }
1912 // We have no information to show for a typeid(T) object.
1913}
1914
1915enum class CheckEvaluationResultKind {
1916 ConstantExpression,
1917 FullyInitialized,
1918};
1919
1920/// Materialized temporaries that we've already checked to determine if they're
1921/// initializsed by a constant expression.
1922using CheckedTemporaries =
1923 llvm::SmallPtrSet<const MaterializeTemporaryExpr *, 8>;
1924
1925static bool CheckEvaluationResult(CheckEvaluationResultKind CERK,
1926 EvalInfo &Info, SourceLocation DiagLoc,
1927 QualType Type, const APValue &Value,
1928 Expr::ConstExprUsage Usage,
1929 SourceLocation SubobjectLoc,
1930 CheckedTemporaries &CheckedTemps);
1931
1932/// Check that this reference or pointer core constant expression is a valid
1933/// value for an address or reference constant expression. Return true if we
1934/// can fold this expression, whether or not it's a constant expression.
1935static bool CheckLValueConstantExpression(EvalInfo &Info, SourceLocation Loc,
1936 QualType Type, const LValue &LVal,
1937 Expr::ConstExprUsage Usage,
1938 CheckedTemporaries &CheckedTemps) {
1939 bool IsReferenceType = Type->isReferenceType();
1940
1941 APValue::LValueBase Base = LVal.getLValueBase();
1942 const SubobjectDesignator &Designator = LVal.getLValueDesignator();
1943
1944 // Check that the object is a global. Note that the fake 'this' object we
1945 // manufacture when checking potential constant expressions is conservatively
1946 // assumed to be global here.
1947 if (!IsGlobalLValue(Base)) {
1948 if (Info.getLangOpts().CPlusPlus11) {
1949 const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
1950 Info.FFDiag(Loc, diag::note_constexpr_non_global, 1)
1951 << IsReferenceType << !Designator.Entries.empty()
1952 << !!VD << VD;
1953 NoteLValueLocation(Info, Base);
1954 } else {
1955 Info.FFDiag(Loc);
1956 }
1957 // Don't allow references to temporaries to escape.
1958 return false;
1959 }
1960 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1962, __PRETTY_FUNCTION__))
1961 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1962, __PRETTY_FUNCTION__))
1962 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 1962, __PRETTY_FUNCTION__))
;
1963
1964 if (Base.is<DynamicAllocLValue>()) {
1965 Info.FFDiag(Loc, diag::note_constexpr_dynamic_alloc)
1966 << IsReferenceType << !Designator.Entries.empty();
1967 NoteLValueLocation(Info, Base);
1968 return false;
1969 }
1970
1971 if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
1972 if (const VarDecl *Var = dyn_cast<const VarDecl>(VD)) {
1973 // Check if this is a thread-local variable.
1974 if (Var->getTLSKind())
1975 // FIXME: Diagnostic!
1976 return false;
1977
1978 // A dllimport variable never acts like a constant.
1979 if (Usage == Expr::EvaluateForCodeGen && Var->hasAttr<DLLImportAttr>())
1980 // FIXME: Diagnostic!
1981 return false;
1982 }
1983 if (const auto *FD = dyn_cast<const FunctionDecl>(VD)) {
1984 // __declspec(dllimport) must be handled very carefully:
1985 // We must never initialize an expression with the thunk in C++.
1986 // Doing otherwise would allow the same id-expression to yield
1987 // different addresses for the same function in different translation
1988 // units. However, this means that we must dynamically initialize the
1989 // expression with the contents of the import address table at runtime.
1990 //
1991 // The C language has no notion of ODR; furthermore, it has no notion of
1992 // dynamic initialization. This means that we are permitted to
1993 // perform initialization with the address of the thunk.
1994 if (Info.getLangOpts().CPlusPlus && Usage == Expr::EvaluateForCodeGen &&
1995 FD->hasAttr<DLLImportAttr>())
1996 // FIXME: Diagnostic!
1997 return false;
1998 }
1999 } else if (const auto *MTE = dyn_cast_or_null<MaterializeTemporaryExpr>(
2000 Base.dyn_cast<const Expr *>())) {
2001 if (CheckedTemps.insert(MTE).second) {
2002 QualType TempType = getType(Base);
2003 if (TempType.isDestructedType()) {
2004 Info.FFDiag(MTE->getExprLoc(),
2005 diag::note_constexpr_unsupported_tempoarary_nontrivial_dtor)
2006 << TempType;
2007 return false;
2008 }
2009
2010 APValue *V = Info.Ctx.getMaterializedTemporaryValue(MTE, false);
2011 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2011, __PRETTY_FUNCTION__))
;
2012 if (!CheckEvaluationResult(CheckEvaluationResultKind::ConstantExpression,
2013 Info, MTE->getExprLoc(), TempType, *V,
2014 Usage, SourceLocation(), CheckedTemps))
2015 return false;
2016 }
2017 }
2018
2019 // Allow address constant expressions to be past-the-end pointers. This is
2020 // an extension: the standard requires them to point to an object.
2021 if (!IsReferenceType)
2022 return true;
2023
2024 // A reference constant expression must refer to an object.
2025 if (!Base) {
2026 // FIXME: diagnostic
2027 Info.CCEDiag(Loc);
2028 return true;
2029 }
2030
2031 // Does this refer one past the end of some object?
2032 if (!Designator.Invalid && Designator.isOnePastTheEnd()) {
2033 const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
2034 Info.FFDiag(Loc, diag::note_constexpr_past_end, 1)
2035 << !Designator.Entries.empty() << !!VD << VD;
2036 NoteLValueLocation(Info, Base);
2037 }
2038
2039 return true;
2040}
2041
2042/// Member pointers are constant expressions unless they point to a
2043/// non-virtual dllimport member function.
2044static bool CheckMemberPointerConstantExpression(EvalInfo &Info,
2045 SourceLocation Loc,
2046 QualType Type,
2047 const APValue &Value,
2048 Expr::ConstExprUsage Usage) {
2049 const ValueDecl *Member = Value.getMemberPointerDecl();
2050 const auto *FD = dyn_cast_or_null<CXXMethodDecl>(Member);
2051 if (!FD)
2052 return true;
2053 return Usage == Expr::EvaluateForMangling || FD->isVirtual() ||
2054 !FD->hasAttr<DLLImportAttr>();
2055}
2056
2057/// Check that this core constant expression is of literal type, and if not,
2058/// produce an appropriate diagnostic.
2059static bool CheckLiteralType(EvalInfo &Info, const Expr *E,
2060 const LValue *This = nullptr) {
2061 if (!E->isRValue() || E->getType()->isLiteralType(Info.Ctx))
2062 return true;
2063
2064 // C++1y: A constant initializer for an object o [...] may also invoke
2065 // constexpr constructors for o and its subobjects even if those objects
2066 // are of non-literal class types.
2067 //
2068 // C++11 missed this detail for aggregates, so classes like this:
2069 // struct foo_t { union { int i; volatile int j; } u; };
2070 // are not (obviously) initializable like so:
2071 // __attribute__((__require_constant_initialization__))
2072 // static const foo_t x = {{0}};
2073 // because "i" is a subobject with non-literal initialization (due to the
2074 // volatile member of the union). See:
2075 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1677
2076 // Therefore, we use the C++1y behavior.
2077 if (This && Info.EvaluatingDecl == This->getLValueBase())
2078 return true;
2079
2080 // Prvalue constant expressions must be of literal types.
2081 if (Info.getLangOpts().CPlusPlus11)
2082 Info.FFDiag(E, diag::note_constexpr_nonliteral)
2083 << E->getType();
2084 else
2085 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2086 return false;
2087}
2088
2089static bool CheckEvaluationResult(CheckEvaluationResultKind CERK,
2090 EvalInfo &Info, SourceLocation DiagLoc,
2091 QualType Type, const APValue &Value,
2092 Expr::ConstExprUsage Usage,
2093 SourceLocation SubobjectLoc,
2094 CheckedTemporaries &CheckedTemps) {
2095 if (!Value.hasValue()) {
2096 Info.FFDiag(DiagLoc, diag::note_constexpr_uninitialized)
2097 << true << Type;
2098 if (SubobjectLoc.isValid())
2099 Info.Note(SubobjectLoc, diag::note_constexpr_subobject_declared_here);
2100 return false;
2101 }
2102
2103 // We allow _Atomic(T) to be initialized from anything that T can be
2104 // initialized from.
2105 if (const AtomicType *AT = Type->getAs<AtomicType>())
2106 Type = AT->getValueType();
2107
2108 // Core issue 1454: For a literal constant expression of array or class type,
2109 // each subobject of its value shall have been initialized by a constant
2110 // expression.
2111 if (Value.isArray()) {
2112 QualType EltTy = Type->castAsArrayTypeUnsafe()->getElementType();
2113 for (unsigned I = 0, N = Value.getArrayInitializedElts(); I != N; ++I) {
2114 if (!CheckEvaluationResult(CERK, Info, DiagLoc, EltTy,
2115 Value.getArrayInitializedElt(I), Usage,
2116 SubobjectLoc, CheckedTemps))
2117 return false;
2118 }
2119 if (!Value.hasArrayFiller())
2120 return true;
2121 return CheckEvaluationResult(CERK, Info, DiagLoc, EltTy,
2122 Value.getArrayFiller(), Usage, SubobjectLoc,
2123 CheckedTemps);
2124 }
2125 if (Value.isUnion() && Value.getUnionField()) {
2126 return CheckEvaluationResult(
2127 CERK, Info, DiagLoc, Value.getUnionField()->getType(),
2128 Value.getUnionValue(), Usage, Value.getUnionField()->getLocation(),
2129 CheckedTemps);
2130 }
2131 if (Value.isStruct()) {
2132 RecordDecl *RD = Type->castAs<RecordType>()->getDecl();
2133 if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
2134 unsigned BaseIndex = 0;
2135 for (const CXXBaseSpecifier &BS : CD->bases()) {
2136 if (!CheckEvaluationResult(CERK, Info, DiagLoc, BS.getType(),
2137 Value.getStructBase(BaseIndex), Usage,
2138 BS.getBeginLoc(), CheckedTemps))
2139 return false;
2140 ++BaseIndex;
2141 }
2142 }
2143 for (const auto *I : RD->fields()) {
2144 if (I->isUnnamedBitfield())
2145 continue;
2146
2147 if (!CheckEvaluationResult(CERK, Info, DiagLoc, I->getType(),
2148 Value.getStructField(I->getFieldIndex()),
2149 Usage, I->getLocation(), CheckedTemps))
2150 return false;
2151 }
2152 }
2153
2154 if (Value.isLValue() &&
2155 CERK == CheckEvaluationResultKind::ConstantExpression) {
2156 LValue LVal;
2157 LVal.setFrom(Info.Ctx, Value);
2158 return CheckLValueConstantExpression(Info, DiagLoc, Type, LVal, Usage,
2159 CheckedTemps);
2160 }
2161
2162 if (Value.isMemberPointer() &&
2163 CERK == CheckEvaluationResultKind::ConstantExpression)
2164 return CheckMemberPointerConstantExpression(Info, DiagLoc, Type, Value, Usage);
2165
2166 // Everything else is fine.
2167 return true;
2168}
2169
2170/// Check that this core constant expression value is a valid value for a
2171/// constant expression. If not, report an appropriate diagnostic. Does not
2172/// check that the expression is of literal type.
2173static bool
2174CheckConstantExpression(EvalInfo &Info, SourceLocation DiagLoc, QualType Type,
2175 const APValue &Value,
2176 Expr::ConstExprUsage Usage = Expr::EvaluateForCodeGen) {
2177 CheckedTemporaries CheckedTemps;
2178 return CheckEvaluationResult(CheckEvaluationResultKind::ConstantExpression,
2179 Info, DiagLoc, Type, Value, Usage,
2180 SourceLocation(), CheckedTemps);
2181}
2182
2183/// Check that this evaluated value is fully-initialized and can be loaded by
2184/// an lvalue-to-rvalue conversion.
2185static bool CheckFullyInitialized(EvalInfo &Info, SourceLocation DiagLoc,
2186 QualType Type, const APValue &Value) {
2187 CheckedTemporaries CheckedTemps;
2188 return CheckEvaluationResult(
2189 CheckEvaluationResultKind::FullyInitialized, Info, DiagLoc, Type, Value,
2190 Expr::EvaluateForCodeGen, SourceLocation(), CheckedTemps);
2191}
2192
2193/// Enforce C++2a [expr.const]/4.17, which disallows new-expressions unless
2194/// "the allocated storage is deallocated within the evaluation".
2195static bool CheckMemoryLeaks(EvalInfo &Info) {
2196 if (!Info.HeapAllocs.empty()) {
2197 // We can still fold to a constant despite a compile-time memory leak,
2198 // so long as the heap allocation isn't referenced in the result (we check
2199 // that in CheckConstantExpression).
2200 Info.CCEDiag(Info.HeapAllocs.begin()->second.AllocExpr,
2201 diag::note_constexpr_memory_leak)
2202 << unsigned(Info.HeapAllocs.size() - 1);
2203 }
2204 return true;
2205}
2206
2207static bool EvalPointerValueAsBool(const APValue &Value, bool &Result) {
2208 // A null base expression indicates a null pointer. These are always
2209 // evaluatable, and they are false unless the offset is zero.
2210 if (!Value.getLValueBase()) {
2211 Result = !Value.getLValueOffset().isZero();
2212 return true;
2213 }
2214
2215 // We have a non-null base. These are generally known to be true, but if it's
2216 // a weak declaration it can be null at runtime.
2217 Result = true;
2218 const ValueDecl *Decl = Value.getLValueBase().dyn_cast<const ValueDecl*>();
2219 return !Decl || !Decl->isWeak();
2220}
2221
2222static bool HandleConversionToBool(const APValue &Val, bool &Result) {
2223 switch (Val.getKind()) {
2224 case APValue::None:
2225 case APValue::Indeterminate:
2226 return false;
2227 case APValue::Int:
2228 Result = Val.getInt().getBoolValue();
2229 return true;
2230 case APValue::FixedPoint:
2231 Result = Val.getFixedPoint().getBoolValue();
2232 return true;
2233 case APValue::Float:
2234 Result = !Val.getFloat().isZero();
2235 return true;
2236 case APValue::ComplexInt:
2237 Result = Val.getComplexIntReal().getBoolValue() ||
2238 Val.getComplexIntImag().getBoolValue();
2239 return true;
2240 case APValue::ComplexFloat:
2241 Result = !Val.getComplexFloatReal().isZero() ||
2242 !Val.getComplexFloatImag().isZero();
2243 return true;
2244 case APValue::LValue:
2245 return EvalPointerValueAsBool(Val, Result);
2246 case APValue::MemberPointer:
2247 Result = Val.getMemberPointerDecl();
2248 return true;
2249 case APValue::Vector:
2250 case APValue::Array:
2251 case APValue::Struct:
2252 case APValue::Union:
2253 case APValue::AddrLabelDiff:
2254 return false;
2255 }
2256
2257 llvm_unreachable("unknown APValue kind")::llvm::llvm_unreachable_internal("unknown APValue kind", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2257)
;
2258}
2259
2260static bool EvaluateAsBooleanCondition(const Expr *E, bool &Result,
2261 EvalInfo &Info) {
2262 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2262, __PRETTY_FUNCTION__))
;
2263 APValue Val;
2264 if (!Evaluate(Val, Info, E))
2265 return false;
2266 return HandleConversionToBool(Val, Result);
2267}
2268
2269template<typename T>
2270static bool HandleOverflow(EvalInfo &Info, const Expr *E,
2271 const T &SrcValue, QualType DestType) {
2272 Info.CCEDiag(E, diag::note_constexpr_overflow)
2273 << SrcValue << DestType;
2274 return Info.noteUndefinedBehavior();
2275}
2276
2277static bool HandleFloatToIntCast(EvalInfo &Info, const Expr *E,
2278 QualType SrcType, const APFloat &Value,
2279 QualType DestType, APSInt &Result) {
2280 unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
2281 // Determine whether we are converting to unsigned or signed.
2282 bool DestSigned = DestType->isSignedIntegerOrEnumerationType();
2283
2284 Result = APSInt(DestWidth, !DestSigned);
2285 bool ignored;
2286 if (Value.convertToInteger(Result, llvm::APFloat::rmTowardZero, &ignored)
2287 & APFloat::opInvalidOp)
2288 return HandleOverflow(Info, E, Value, DestType);
2289 return true;
2290}
2291
2292static bool HandleFloatToFloatCast(EvalInfo &Info, const Expr *E,
2293 QualType SrcType, QualType DestType,
2294 APFloat &Result) {
2295 APFloat Value = Result;
2296 bool ignored;
2297 Result.convert(Info.Ctx.getFloatTypeSemantics(DestType),
2298 APFloat::rmNearestTiesToEven, &ignored);
2299 return true;
2300}
2301
2302static APSInt HandleIntToIntCast(EvalInfo &Info, const Expr *E,
2303 QualType DestType, QualType SrcType,
2304 const APSInt &Value) {
2305 unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
2306 // Figure out if this is a truncate, extend or noop cast.
2307 // If the input is signed, do a sign extend, noop, or truncate.
2308 APSInt Result = Value.extOrTrunc(DestWidth);
2309 Result.setIsUnsigned(DestType->isUnsignedIntegerOrEnumerationType());
2310 if (DestType->isBooleanType())
2311 Result = Value.getBoolValue();
2312 return Result;
2313}
2314
2315static bool HandleIntToFloatCast(EvalInfo &Info, const Expr *E,
2316 QualType SrcType, const APSInt &Value,
2317 QualType DestType, APFloat &Result) {
2318 Result = APFloat(Info.Ctx.getFloatTypeSemantics(DestType), 1);
2319 Result.convertFromAPInt(Value, Value.isSigned(),
2320 APFloat::rmNearestTiesToEven);
2321 return true;
2322}
2323
2324static bool truncateBitfieldValue(EvalInfo &Info, const Expr *E,
2325 APValue &Value, const FieldDecl *FD) {
2326 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2326, __PRETTY_FUNCTION__))
;
2327
2328 if (!Value.isInt()) {
2329 // Trying to store a pointer-cast-to-integer into a bitfield.
2330 // FIXME: In this case, we should provide the diagnostic for casting
2331 // a pointer to an integer.
2332 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2332, __PRETTY_FUNCTION__))
;
2333 Info.FFDiag(E);
2334 return false;
2335 }
2336
2337 APSInt &Int = Value.getInt();
2338 unsigned OldBitWidth = Int.getBitWidth();
2339 unsigned NewBitWidth = FD->getBitWidthValue(Info.Ctx);
2340 if (NewBitWidth < OldBitWidth)
2341 Int = Int.trunc(NewBitWidth).extend(OldBitWidth);
2342 return true;
2343}
2344
2345static bool EvalAndBitcastToAPInt(EvalInfo &Info, const Expr *E,
2346 llvm::APInt &Res) {
2347 APValue SVal;
2348 if (!Evaluate(SVal, Info, E))
2349 return false;
2350 if (SVal.isInt()) {
2351 Res = SVal.getInt();
2352 return true;
2353 }
2354 if (SVal.isFloat()) {
2355 Res = SVal.getFloat().bitcastToAPInt();
2356 return true;
2357 }
2358 if (SVal.isVector()) {
2359 QualType VecTy = E->getType();
2360 unsigned VecSize = Info.Ctx.getTypeSize(VecTy);
2361 QualType EltTy = VecTy->castAs<VectorType>()->getElementType();
2362 unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
2363 bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
2364 Res = llvm::APInt::getNullValue(VecSize);
2365 for (unsigned i = 0; i < SVal.getVectorLength(); i++) {
2366 APValue &Elt = SVal.getVectorElt(i);
2367 llvm::APInt EltAsInt;
2368 if (Elt.isInt()) {
2369 EltAsInt = Elt.getInt();
2370 } else if (Elt.isFloat()) {
2371 EltAsInt = Elt.getFloat().bitcastToAPInt();
2372 } else {
2373 // Don't try to handle vectors of anything other than int or float
2374 // (not sure if it's possible to hit this case).
2375 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2376 return false;
2377 }
2378 unsigned BaseEltSize = EltAsInt.getBitWidth();
2379 if (BigEndian)
2380 Res |= EltAsInt.zextOrTrunc(VecSize).rotr(i*EltSize+BaseEltSize);
2381 else
2382 Res |= EltAsInt.zextOrTrunc(VecSize).rotl(i*EltSize);
2383 }
2384 return true;
2385 }
2386 // Give up if the input isn't an int, float, or vector. For example, we
2387 // reject "(v4i16)(intptr_t)&a".
2388 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2389 return false;
2390}
2391
2392/// Perform the given integer operation, which is known to need at most BitWidth
2393/// bits, and check for overflow in the original type (if that type was not an
2394/// unsigned type).
2395template<typename Operation>
2396static bool CheckedIntArithmetic(EvalInfo &Info, const Expr *E,
2397 const APSInt &LHS, const APSInt &RHS,
2398 unsigned BitWidth, Operation Op,
2399 APSInt &Result) {
2400 if (LHS.isUnsigned()) {
2401 Result = Op(LHS, RHS);
2402 return true;
2403 }
2404
2405 APSInt Value(Op(LHS.extend(BitWidth), RHS.extend(BitWidth)), false);
2406 Result = Value.trunc(LHS.getBitWidth());
2407 if (Result.extend(BitWidth) != Value) {
2408 if (Info.checkingForUndefinedBehavior())
2409 Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
2410 diag::warn_integer_constant_overflow)
2411 << Result.toString(10) << E->getType();
2412 else
2413 return HandleOverflow(Info, E, Value, E->getType());
2414 }
2415 return true;
2416}
2417
2418/// Perform the given binary integer operation.
2419static bool handleIntIntBinOp(EvalInfo &Info, const Expr *E, const APSInt &LHS,
2420 BinaryOperatorKind Opcode, APSInt RHS,
2421 APSInt &Result) {
2422 switch (Opcode) {
2423 default:
2424 Info.FFDiag(E);
2425 return false;
2426 case BO_Mul:
2427 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() * 2,
2428 std::multiplies<APSInt>(), Result);
2429 case BO_Add:
2430 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
2431 std::plus<APSInt>(), Result);
2432 case BO_Sub:
2433 return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
2434 std::minus<APSInt>(), Result);
2435 case BO_And: Result = LHS & RHS; return true;
2436 case BO_Xor: Result = LHS ^ RHS; return true;
2437 case BO_Or: Result = LHS | RHS; return true;
2438 case BO_Div:
2439 case BO_Rem:
2440 if (RHS == 0) {
2441 Info.FFDiag(E, diag::note_expr_divide_by_zero);
2442 return false;
2443 }
2444 Result = (Opcode == BO_Rem ? LHS % RHS : LHS / RHS);
2445 // Check for overflow case: INT_MIN / -1 or INT_MIN % -1. APSInt supports
2446 // this operation and gives the two's complement result.
2447 if (RHS.isNegative() && RHS.isAllOnesValue() &&
2448 LHS.isSigned() && LHS.isMinSignedValue())
2449 return HandleOverflow(Info, E, -LHS.extend(LHS.getBitWidth() + 1),
2450 E->getType());
2451 return true;
2452 case BO_Shl: {
2453 if (Info.getLangOpts().OpenCL)
2454 // OpenCL 6.3j: shift values are effectively % word size of LHS.
2455 RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
2456 static_cast<uint64_t>(LHS.getBitWidth() - 1)),
2457 RHS.isUnsigned());
2458 else if (RHS.isSigned() && RHS.isNegative()) {
2459 // During constant-folding, a negative shift is an opposite shift. Such
2460 // a shift is not a constant expression.
2461 Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
2462 RHS = -RHS;
2463 goto shift_right;
2464 }
2465 shift_left:
2466 // C++11 [expr.shift]p1: Shift width must be less than the bit width of
2467 // the shifted type.
2468 unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
2469 if (SA != RHS) {
2470 Info.CCEDiag(E, diag::note_constexpr_large_shift)
2471 << RHS << E->getType() << LHS.getBitWidth();
2472 } else if (LHS.isSigned() && !Info.getLangOpts().CPlusPlus2a) {
2473 // C++11 [expr.shift]p2: A signed left shift must have a non-negative
2474 // operand, and must not overflow the corresponding unsigned type.
2475 // C++2a [expr.shift]p2: E1 << E2 is the unique value congruent to
2476 // E1 x 2^E2 module 2^N.
2477 if (LHS.isNegative())
2478 Info.CCEDiag(E, diag::note_constexpr_lshift_of_negative) << LHS;
2479 else if (LHS.countLeadingZeros() < SA)
2480 Info.CCEDiag(E, diag::note_constexpr_lshift_discards);
2481 }
2482 Result = LHS << SA;
2483 return true;
2484 }
2485 case BO_Shr: {
2486 if (Info.getLangOpts().OpenCL)
2487 // OpenCL 6.3j: shift values are effectively % word size of LHS.
2488 RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
2489 static_cast<uint64_t>(LHS.getBitWidth() - 1)),
2490 RHS.isUnsigned());
2491 else if (RHS.isSigned() && RHS.isNegative()) {
2492 // During constant-folding, a negative shift is an opposite shift. Such a
2493 // shift is not a constant expression.
2494 Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
2495 RHS = -RHS;
2496 goto shift_left;
2497 }
2498 shift_right:
2499 // C++11 [expr.shift]p1: Shift width must be less than the bit width of the
2500 // shifted type.
2501 unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
2502 if (SA != RHS)
2503 Info.CCEDiag(E, diag::note_constexpr_large_shift)
2504 << RHS << E->getType() << LHS.getBitWidth();
2505 Result = LHS >> SA;
2506 return true;
2507 }
2508
2509 case BO_LT: Result = LHS < RHS; return true;
2510 case BO_GT: Result = LHS > RHS; return true;
2511 case BO_LE: Result = LHS <= RHS; return true;
2512 case BO_GE: Result = LHS >= RHS; return true;
2513 case BO_EQ: Result = LHS == RHS; return true;
2514 case BO_NE: Result = LHS != RHS; return true;
2515 case BO_Cmp:
2516 llvm_unreachable("BO_Cmp should be handled elsewhere")::llvm::llvm_unreachable_internal("BO_Cmp should be handled elsewhere"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2516)
;
2517 }
2518}
2519
2520/// Perform the given binary floating-point operation, in-place, on LHS.
2521static bool handleFloatFloatBinOp(EvalInfo &Info, const Expr *E,
2522 APFloat &LHS, BinaryOperatorKind Opcode,
2523 const APFloat &RHS) {
2524 switch (Opcode) {
2525 default:
2526 Info.FFDiag(E);
2527 return false;
2528 case BO_Mul:
2529 LHS.multiply(RHS, APFloat::rmNearestTiesToEven);
2530 break;
2531 case BO_Add:
2532 LHS.add(RHS, APFloat::rmNearestTiesToEven);
2533 break;
2534 case BO_Sub:
2535 LHS.subtract(RHS, APFloat::rmNearestTiesToEven);
2536 break;
2537 case BO_Div:
2538 // [expr.mul]p4:
2539 // If the second operand of / or % is zero the behavior is undefined.
2540 if (RHS.isZero())
2541 Info.CCEDiag(E, diag::note_expr_divide_by_zero);
2542 LHS.divide(RHS, APFloat::rmNearestTiesToEven);
2543 break;
2544 }
2545
2546 // [expr.pre]p4:
2547 // If during the evaluation of an expression, the result is not
2548 // mathematically defined [...], the behavior is undefined.
2549 // FIXME: C++ rules require us to not conform to IEEE 754 here.
2550 if (LHS.isNaN()) {
2551 Info.CCEDiag(E, diag::note_constexpr_float_arithmetic) << LHS.isNaN();
2552 return Info.noteUndefinedBehavior();
2553 }
2554 return true;
2555}
2556
2557/// Cast an lvalue referring to a base subobject to a derived class, by
2558/// truncating the lvalue's path to the given length.
2559static bool CastToDerivedClass(EvalInfo &Info, const Expr *E, LValue &Result,
2560 const RecordDecl *TruncatedType,
2561 unsigned TruncatedElements) {
2562 SubobjectDesignator &D = Result.Designator;
2563
2564 // Check we actually point to a derived class object.
2565 if (TruncatedElements == D.Entries.size())
2566 return true;
2567 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2568, __PRETTY_FUNCTION__))
2568 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2568, __PRETTY_FUNCTION__))
;
2569 if (!Result.checkSubobject(Info, E, CSK_Derived))
2570 return false;
2571
2572 // Truncate the path to the subobject, and remove any derived-to-base offsets.
2573 const RecordDecl *RD = TruncatedType;
2574 for (unsigned I = TruncatedElements, N = D.Entries.size(); I != N; ++I) {
2575 if (RD->isInvalidDecl()) return false;
2576 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
2577 const CXXRecordDecl *Base = getAsBaseClass(D.Entries[I]);
2578 if (isVirtualBaseClass(D.Entries[I]))
2579 Result.Offset -= Layout.getVBaseClassOffset(Base);
2580 else
2581 Result.Offset -= Layout.getBaseClassOffset(Base);
2582 RD = Base;
2583 }
2584 D.Entries.resize(TruncatedElements);
2585 return true;
2586}
2587
2588static bool HandleLValueDirectBase(EvalInfo &Info, const Expr *E, LValue &Obj,
2589 const CXXRecordDecl *Derived,
2590 const CXXRecordDecl *Base,
2591 const ASTRecordLayout *RL = nullptr) {
2592 if (!RL) {
2593 if (Derived->isInvalidDecl()) return false;
2594 RL = &Info.Ctx.getASTRecordLayout(Derived);
2595 }
2596
2597 Obj.getLValueOffset() += RL->getBaseClassOffset(Base);
2598 Obj.addDecl(Info, E, Base, /*Virtual*/ false);
2599 return true;
2600}
2601
2602static bool HandleLValueBase(EvalInfo &Info, const Expr *E, LValue &Obj,
2603 const CXXRecordDecl *DerivedDecl,
2604 const CXXBaseSpecifier *Base) {
2605 const CXXRecordDecl *BaseDecl = Base->getType()->getAsCXXRecordDecl();
2606
2607 if (!Base->isVirtual())
2608 return HandleLValueDirectBase(Info, E, Obj, DerivedDecl, BaseDecl);
2609
2610 SubobjectDesignator &D = Obj.Designator;
2611 if (D.Invalid)
2612 return false;
2613
2614 // Extract most-derived object and corresponding type.
2615 DerivedDecl = D.MostDerivedType->getAsCXXRecordDecl();
2616 if (!CastToDerivedClass(Info, E, Obj, DerivedDecl, D.MostDerivedPathLength))
2617 return false;
2618
2619 // Find the virtual base class.
2620 if (DerivedDecl->isInvalidDecl()) return false;
2621 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(DerivedDecl);
2622 Obj.getLValueOffset() += Layout.getVBaseClassOffset(BaseDecl);
2623 Obj.addDecl(Info, E, BaseDecl, /*Virtual*/ true);
2624 return true;
2625}
2626
2627static bool HandleLValueBasePath(EvalInfo &Info, const CastExpr *E,
2628 QualType Type, LValue &Result) {
2629 for (CastExpr::path_const_iterator PathI = E->path_begin(),
2630 PathE = E->path_end();
2631 PathI != PathE; ++PathI) {
2632 if (!HandleLValueBase(Info, E, Result, Type->getAsCXXRecordDecl(),
2633 *PathI))
2634 return false;
2635 Type = (*PathI)->getType();
2636 }
2637 return true;
2638}
2639
2640/// Cast an lvalue referring to a derived class to a known base subobject.
2641static bool CastToBaseClass(EvalInfo &Info, const Expr *E, LValue &Result,
2642 const CXXRecordDecl *DerivedRD,
2643 const CXXRecordDecl *BaseRD) {
2644 CXXBasePaths Paths(/*FindAmbiguities=*/false,
2645 /*RecordPaths=*/true, /*DetectVirtual=*/false);
2646 if (!DerivedRD->isDerivedFrom(BaseRD, Paths))
2647 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2647)
;
2648
2649 for (CXXBasePathElement &Elem : Paths.front())
2650 if (!HandleLValueBase(Info, E, Result, Elem.Class, Elem.Base))
2651 return false;
2652 return true;
2653}
2654
2655/// Update LVal to refer to the given field, which must be a member of the type
2656/// currently described by LVal.
2657static bool HandleLValueMember(EvalInfo &Info, const Expr *E, LValue &LVal,
2658 const FieldDecl *FD,
2659 const ASTRecordLayout *RL = nullptr) {
2660 if (!RL) {
2661 if (FD->getParent()->isInvalidDecl()) return false;
2662 RL = &Info.Ctx.getASTRecordLayout(FD->getParent());
2663 }
2664
2665 unsigned I = FD->getFieldIndex();
2666 LVal.adjustOffset(Info.Ctx.toCharUnitsFromBits(RL->getFieldOffset(I)));
2667 LVal.addDecl(Info, E, FD);
2668 return true;
2669}
2670
2671/// Update LVal to refer to the given indirect field.
2672static bool HandleLValueIndirectMember(EvalInfo &Info, const Expr *E,
2673 LValue &LVal,
2674 const IndirectFieldDecl *IFD) {
2675 for (const auto *C : IFD->chain())
2676 if (!HandleLValueMember(Info, E, LVal, cast<FieldDecl>(C)))
2677 return false;
2678 return true;
2679}
2680
2681/// Get the size of the given type in char units.
2682static bool HandleSizeof(EvalInfo &Info, SourceLocation Loc,
2683 QualType Type, CharUnits &Size) {
2684 // sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc
2685 // extension.
2686 if (Type->isVoidType() || Type->isFunctionType()) {
2687 Size = CharUnits::One();
2688 return true;
2689 }
2690
2691 if (Type->isDependentType()) {
2692 Info.FFDiag(Loc);
2693 return false;
2694 }
2695
2696 if (!Type->isConstantSizeType()) {
2697 // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
2698 // FIXME: Better diagnostic.
2699 Info.FFDiag(Loc);
2700 return false;
2701 }
2702
2703 Size = Info.Ctx.getTypeSizeInChars(Type);
2704 return true;
2705}
2706
2707/// Update a pointer value to model pointer arithmetic.
2708/// \param Info - Information about the ongoing evaluation.
2709/// \param E - The expression being evaluated, for diagnostic purposes.
2710/// \param LVal - The pointer value to be updated.
2711/// \param EltTy - The pointee type represented by LVal.
2712/// \param Adjustment - The adjustment, in objects of type EltTy, to add.
2713static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
2714 LValue &LVal, QualType EltTy,
2715 APSInt Adjustment) {
2716 CharUnits SizeOfPointee;
2717 if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfPointee))
2718 return false;
2719
2720 LVal.adjustOffsetAndIndex(Info, E, Adjustment, SizeOfPointee);
2721 return true;
2722}
2723
2724static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
2725 LValue &LVal, QualType EltTy,
2726 int64_t Adjustment) {
2727 return HandleLValueArrayAdjustment(Info, E, LVal, EltTy,
2728 APSInt::get(Adjustment));
2729}
2730
2731/// Update an lvalue to refer to a component of a complex number.
2732/// \param Info - Information about the ongoing evaluation.
2733/// \param LVal - The lvalue to be updated.
2734/// \param EltTy - The complex number's component type.
2735/// \param Imag - False for the real component, true for the imaginary.
2736static bool HandleLValueComplexElement(EvalInfo &Info, const Expr *E,
2737 LValue &LVal, QualType EltTy,
2738 bool Imag) {
2739 if (Imag) {
2740 CharUnits SizeOfComponent;
2741 if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfComponent))
2742 return false;
2743 LVal.Offset += SizeOfComponent;
2744 }
2745 LVal.addComplex(Info, E, EltTy, Imag);
2746 return true;
2747}
2748
2749/// Try to evaluate the initializer for a variable declaration.
2750///
2751/// \param Info Information about the ongoing evaluation.
2752/// \param E An expression to be used when printing diagnostics.
2753/// \param VD The variable whose initializer should be obtained.
2754/// \param Frame The frame in which the variable was created. Must be null
2755/// if this variable is not local to the evaluation.
2756/// \param Result Filled in with a pointer to the value of the variable.
2757static bool evaluateVarDeclInit(EvalInfo &Info, const Expr *E,
2758 const VarDecl *VD, CallStackFrame *Frame,
2759 APValue *&Result, const LValue *LVal) {
2760
2761 // If this is a parameter to an active constexpr function call, perform
2762 // argument substitution.
2763 if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(VD)) {
2764 // Assume arguments of a potential constant expression are unknown
2765 // constant expressions.
2766 if (Info.checkingPotentialConstantExpression())
2767 return false;
2768 if (!Frame || !Frame->Arguments) {
2769 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2770 return false;
2771 }
2772 Result = &Frame->Arguments[PVD->getFunctionScopeIndex()];
2773 return true;
2774 }
2775
2776 // If this is a local variable, dig out its value.
2777 if (Frame) {
2778 Result = LVal ? Frame->getTemporary(VD, LVal->getLValueVersion())
2779 : Frame->getCurrentTemporary(VD);
2780 if (!Result) {
2781 // Assume variables referenced within a lambda's call operator that were
2782 // not declared within the call operator are captures and during checking
2783 // of a potential constant expression, assume they are unknown constant
2784 // expressions.
2785 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2787, __PRETTY_FUNCTION__))
2786 (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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2787, __PRETTY_FUNCTION__))
2787 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2787, __PRETTY_FUNCTION__))
;
2788 if (Info.checkingPotentialConstantExpression())
2789 return false;
2790 // FIXME: implement capture evaluation during constant expr evaluation.
2791 Info.FFDiag(E->getBeginLoc(),
2792 diag::note_unimplemented_constexpr_lambda_feature_ast)
2793 << "captures not currently allowed";
2794 return false;
2795 }
2796 return true;
2797 }
2798
2799 // Dig out the initializer, and use the declaration which it's attached to.
2800 const Expr *Init = VD->getAnyInitializer(VD);
2801 if (!Init || Init->isValueDependent()) {
2802 // If we're checking a potential constant expression, the variable could be
2803 // initialized later.
2804 if (!Info.checkingPotentialConstantExpression())
2805 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2806 return false;
2807 }
2808
2809 // If we're currently evaluating the initializer of this declaration, use that
2810 // in-flight value.
2811 if (Info.EvaluatingDecl.dyn_cast<const ValueDecl*>() == VD) {
2812 Result = Info.EvaluatingDeclValue;
2813 return true;
2814 }
2815
2816 // Never evaluate the initializer of a weak variable. We can't be sure that
2817 // this is the definition which will be used.
2818 if (VD->isWeak()) {
2819 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
2820 return false;
2821 }
2822
2823 // Check that we can fold the initializer. In C++, we will have already done
2824 // this in the cases where it matters for conformance.
2825 SmallVector<PartialDiagnosticAt, 8> Notes;
2826 if (!VD->evaluateValue(Notes)) {
2827 Info.FFDiag(E, diag::note_constexpr_var_init_non_constant,
2828 Notes.size() + 1) << VD;
2829 Info.Note(VD->getLocation(), diag::note_declared_at);
2830 Info.addNotes(Notes);
2831 return false;
2832 } else if (!VD->checkInitIsICE()) {
2833 Info.CCEDiag(E, diag::note_constexpr_var_init_non_constant,
2834 Notes.size() + 1) << VD;
2835 Info.Note(VD->getLocation(), diag::note_declared_at);
2836 Info.addNotes(Notes);
2837 }
2838
2839 Result = VD->getEvaluatedValue();
2840 return true;
2841}
2842
2843static bool IsConstNonVolatile(QualType T) {
2844 Qualifiers Quals = T.getQualifiers();
2845 return Quals.hasConst() && !Quals.hasVolatile();
2846}
2847
2848/// Get the base index of the given base class within an APValue representing
2849/// the given derived class.
2850static unsigned getBaseIndex(const CXXRecordDecl *Derived,
2851 const CXXRecordDecl *Base) {
2852 Base = Base->getCanonicalDecl();
2853 unsigned Index = 0;
2854 for (CXXRecordDecl::base_class_const_iterator I = Derived->bases_begin(),
2855 E = Derived->bases_end(); I != E; ++I, ++Index) {
2856 if (I->getType()->getAsCXXRecordDecl()->getCanonicalDecl() == Base)
2857 return Index;
2858 }
2859
2860 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2860)
;
2861}
2862
2863/// Extract the value of a character from a string literal.
2864static APSInt extractStringLiteralCharacter(EvalInfo &Info, const Expr *Lit,
2865 uint64_t Index) {
2866 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2867, __PRETTY_FUNCTION__))
2867 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2867, __PRETTY_FUNCTION__))
;
2868
2869 // FIXME: Support MakeStringConstant
2870 if (const auto *ObjCEnc = dyn_cast<ObjCEncodeExpr>(Lit)) {
2871 std::string Str;
2872 Info.Ctx.getObjCEncodingForType(ObjCEnc->getEncodedType(), Str);
2873 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2873, __PRETTY_FUNCTION__))
;
2874 return APSInt::getUnsigned(Str.c_str()[Index]);
2875 }
2876
2877 if (auto PE = dyn_cast<PredefinedExpr>(Lit))
2878 Lit = PE->getFunctionName();
2879 const StringLiteral *S = cast<StringLiteral>(Lit);
2880 const ConstantArrayType *CAT =
2881 Info.Ctx.getAsConstantArrayType(S->getType());
2882 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2882, __PRETTY_FUNCTION__))
;
2883 QualType CharType = CAT->getElementType();
2884 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2884, __PRETTY_FUNCTION__))
;
2885
2886 APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
2887 CharType->isUnsignedIntegerType());
2888 if (Index < S->getLength())
2889 Value = S->getCodeUnit(Index);
2890 return Value;
2891}
2892
2893// Expand a string literal into an array of characters.
2894//
2895// FIXME: This is inefficient; we should probably introduce something similar
2896// to the LLVM ConstantDataArray to make this cheaper.
2897static void expandStringLiteral(EvalInfo &Info, const StringLiteral *S,
2898 APValue &Result,
2899 QualType AllocType = QualType()) {
2900 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(
2901 AllocType.isNull() ? S->getType() : AllocType);
2902 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2902, __PRETTY_FUNCTION__))
;
2903 QualType CharType = CAT->getElementType();
2904 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2904, __PRETTY_FUNCTION__))
;
2905
2906 unsigned Elts = CAT->getSize().getZExtValue();
2907 Result = APValue(APValue::UninitArray(),
2908 std::min(S->getLength(), Elts), Elts);
2909 APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
2910 CharType->isUnsignedIntegerType());
2911 if (Result.hasArrayFiller())
2912 Result.getArrayFiller() = APValue(Value);
2913 for (unsigned I = 0, N = Result.getArrayInitializedElts(); I != N; ++I) {
2914 Value = S->getCodeUnit(I);
2915 Result.getArrayInitializedElt(I) = APValue(Value);
2916 }
2917}
2918
2919// Expand an array so that it has more than Index filled elements.
2920static void expandArray(APValue &Array, unsigned Index) {
2921 unsigned Size = Array.getArraySize();
2922 assert(Index < Size)((Index < Size) ? static_cast<void> (0) : __assert_fail
("Index < Size", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 2922, __PRETTY_FUNCTION__))
;
2923
2924 // Always at least double the number of elements for which we store a value.
2925 unsigned OldElts = Array.getArrayInitializedElts();
2926 unsigned NewElts = std::max(Index+1, OldElts * 2);
2927 NewElts = std::min(Size, std::max(NewElts, 8u));
2928
2929 // Copy the data across.
2930 APValue NewValue(APValue::UninitArray(), NewElts, Size);
2931 for (unsigned I = 0; I != OldElts; ++I)
2932 NewValue.getArrayInitializedElt(I).swap(Array.getArrayInitializedElt(I));
2933 for (unsigned I = OldElts; I != NewElts; ++I)
2934 NewValue.getArrayInitializedElt(I) = Array.getArrayFiller();
2935 if (NewValue.hasArrayFiller())
2936 NewValue.getArrayFiller() = Array.getArrayFiller();
2937 Array.swap(NewValue);
2938}
2939
2940/// Determine whether a type would actually be read by an lvalue-to-rvalue
2941/// conversion. If it's of class type, we may assume that the copy operation
2942/// is trivial. Note that this is never true for a union type with fields
2943/// (because the copy always "reads" the active member) and always true for
2944/// a non-class type.
2945static bool isReadByLvalueToRvalueConversion(QualType T) {
2946 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
2947 if (!RD || (RD->isUnion() && !RD->field_empty()))
2948 return true;
2949 if (RD->isEmpty())
2950 return false;
2951
2952 for (auto *Field : RD->fields())
2953 if (isReadByLvalueToRvalueConversion(Field->getType()))
2954 return true;
2955
2956 for (auto &BaseSpec : RD->bases())
2957 if (isReadByLvalueToRvalueConversion(BaseSpec.getType()))
2958 return true;
2959
2960 return false;
2961}
2962
2963/// Diagnose an attempt to read from any unreadable field within the specified
2964/// type, which might be a class type.
2965static bool diagnoseMutableFields(EvalInfo &Info, const Expr *E, AccessKinds AK,
2966 QualType T) {
2967 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
2968 if (!RD)
2969 return false;
2970
2971 if (!RD->hasMutableFields())
2972 return false;
2973
2974 for (auto *Field : RD->fields()) {
2975 // If we're actually going to read this field in some way, then it can't
2976 // be mutable. If we're in a union, then assigning to a mutable field
2977 // (even an empty one) can change the active member, so that's not OK.
2978 // FIXME: Add core issue number for the union case.
2979 if (Field->isMutable() &&
2980 (RD->isUnion() || isReadByLvalueToRvalueConversion(Field->getType()))) {
2981 Info.FFDiag(E, diag::note_constexpr_access_mutable, 1) << AK << Field;
2982 Info.Note(Field->getLocation(), diag::note_declared_at);
2983 return true;
2984 }
2985
2986 if (diagnoseMutableFields(Info, E, AK, Field->getType()))
2987 return true;
2988 }
2989
2990 for (auto &BaseSpec : RD->bases())
2991 if (diagnoseMutableFields(Info, E, AK, BaseSpec.getType()))
2992 return true;
2993
2994 // All mutable fields were empty, and thus not actually read.
2995 return false;
2996}
2997
2998static bool lifetimeStartedInEvaluation(EvalInfo &Info,
2999 APValue::LValueBase Base,
3000 bool MutableSubobject = false) {
3001 // A temporary we created.
3002 if (Base.getCallIndex())
3003 return true;
3004
3005 auto *Evaluating = Info.EvaluatingDecl.dyn_cast<const ValueDecl*>();
3006 if (!Evaluating)
3007 return false;
3008
3009 auto *BaseD = Base.dyn_cast<const ValueDecl*>();
3010
3011 switch (Info.IsEvaluatingDecl) {
3012 case EvalInfo::EvaluatingDeclKind::None:
3013 return false;
3014
3015 case EvalInfo::EvaluatingDeclKind::Ctor:
3016 // The variable whose initializer we're evaluating.
3017 if (BaseD)
3018 return declaresSameEntity(Evaluating, BaseD);
3019
3020 // A temporary lifetime-extended by the variable whose initializer we're
3021 // evaluating.
3022 if (auto *BaseE = Base.dyn_cast<const Expr *>())
3023 if (auto *BaseMTE = dyn_cast<MaterializeTemporaryExpr>(BaseE))
3024 return declaresSameEntity(BaseMTE->getExtendingDecl(), Evaluating);
3025 return false;
3026
3027 case EvalInfo::EvaluatingDeclKind::Dtor:
3028 // C++2a [expr.const]p6:
3029 // [during constant destruction] the lifetime of a and its non-mutable
3030 // subobjects (but not its mutable subobjects) [are] considered to start
3031 // within e.
3032 //
3033 // FIXME: We can meaningfully extend this to cover non-const objects, but
3034 // we will need special handling: we should be able to access only
3035 // subobjects of such objects that are themselves declared const.
3036 if (!BaseD ||
3037 !(BaseD->getType().isConstQualified() ||
3038 BaseD->getType()->isReferenceType()) ||
3039 MutableSubobject)
3040 return false;
3041 return declaresSameEntity(Evaluating, BaseD);
3042 }
3043
3044 llvm_unreachable("unknown evaluating decl kind")::llvm::llvm_unreachable_internal("unknown evaluating decl kind"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3044)
;
3045}
3046
3047namespace {
3048/// A handle to a complete object (an object that is not a subobject of
3049/// another object).
3050struct CompleteObject {
3051 /// The identity of the object.
3052 APValue::LValueBase Base;
3053 /// The value of the complete object.
3054 APValue *Value;
3055 /// The type of the complete object.
3056 QualType Type;
3057
3058 CompleteObject() : Value(nullptr) {}
3059 CompleteObject(APValue::LValueBase Base, APValue *Value, QualType Type)
3060 : Base(Base), Value(Value), Type(Type) {}
3061
3062 bool mayAccessMutableMembers(EvalInfo &Info, AccessKinds AK) const {
3063 // In C++14 onwards, it is permitted to read a mutable member whose
3064 // lifetime began within the evaluation.
3065 // FIXME: Should we also allow this in C++11?
3066 if (!Info.getLangOpts().CPlusPlus14)
3067 return false;
3068 return lifetimeStartedInEvaluation(Info, Base, /*MutableSubobject*/true);
3069 }
3070
3071 explicit operator bool() const { return !Type.isNull(); }
3072};
3073} // end anonymous namespace
3074
3075static QualType getSubobjectType(QualType ObjType, QualType SubobjType,
3076 bool IsMutable = false) {
3077 // C++ [basic.type.qualifier]p1:
3078 // - A const object is an object of type const T or a non-mutable subobject
3079 // of a const object.
3080 if (ObjType.isConstQualified() && !IsMutable)
3081 SubobjType.addConst();
3082 // - A volatile object is an object of type const T or a subobject of a
3083 // volatile object.
3084 if (ObjType.isVolatileQualified())
3085 SubobjType.addVolatile();
3086 return SubobjType;
3087}
3088
3089/// Find the designated sub-object of an rvalue.
3090template<typename SubobjectHandler>
3091typename SubobjectHandler::result_type
3092findSubobject(EvalInfo &Info, const Expr *E, const CompleteObject &Obj,
3093 const SubobjectDesignator &Sub, SubobjectHandler &handler) {
3094 if (Sub.Invalid)
3095 // A diagnostic will have already been produced.
3096 return handler.failed();
3097 if (Sub.isOnePastTheEnd() || Sub.isMostDerivedAnUnsizedArray()) {
3098 if (Info.getLangOpts().CPlusPlus11)
3099 Info.FFDiag(E, Sub.isOnePastTheEnd()
3100 ? diag::note_constexpr_access_past_end
3101 : diag::note_constexpr_access_unsized_array)
3102 << handler.AccessKind;
3103 else
3104 Info.FFDiag(E);
3105 return handler.failed();
3106 }
3107
3108 APValue *O = Obj.Value;
3109 QualType ObjType = Obj.Type;
3110 const FieldDecl *LastField = nullptr;
3111 const FieldDecl *VolatileField = nullptr;
3112
3113 // Walk the designator's path to find the subobject.
3114 for (unsigned I = 0, N = Sub.Entries.size(); /**/; ++I) {
3115 // Reading an indeterminate value is undefined, but assigning over one is OK.
3116 if (O->isAbsent() ||
3117 (O->isIndeterminate() && handler.AccessKind != AK_Assign &&
3118 handler.AccessKind != AK_ReadObjectRepresentation)) {
3119 if (!Info.checkingPotentialConstantExpression())
3120 Info.FFDiag(E, diag::note_constexpr_access_uninit)
3121 << handler.AccessKind << O->isIndeterminate();
3122 return handler.failed();
3123 }
3124
3125 // C++ [class.ctor]p5, C++ [class.dtor]p5:
3126 // const and volatile semantics are not applied on an object under
3127 // {con,de}struction.
3128 if ((ObjType.isConstQualified() || ObjType.isVolatileQualified()) &&
3129 ObjType->isRecordType() &&
3130 Info.isEvaluatingCtorDtor(
3131 Obj.Base, llvm::makeArrayRef(Sub.Entries.begin(),
3132 Sub.Entries.begin() + I)) !=
3133 ConstructionPhase::None) {
3134 ObjType = Info.Ctx.getCanonicalType(ObjType);
3135 ObjType.removeLocalConst();
3136 ObjType.removeLocalVolatile();
3137 }
3138
3139 // If this is our last pass, check that the final object type is OK.
3140 if (I == N || (I == N - 1 && ObjType->isAnyComplexType())) {
3141 // Accesses to volatile objects are prohibited.
3142 if (ObjType.isVolatileQualified() && isFormalAccess(handler.AccessKind)) {
3143 if (Info.getLangOpts().CPlusPlus) {
3144 int DiagKind;
3145 SourceLocation Loc;
3146 const NamedDecl *Decl = nullptr;
3147 if (VolatileField) {
3148 DiagKind = 2;
3149 Loc = VolatileField->getLocation();
3150 Decl = VolatileField;
3151 } else if (auto *VD = Obj.Base.dyn_cast<const ValueDecl*>()) {
3152 DiagKind = 1;
3153 Loc = VD->getLocation();
3154 Decl = VD;
3155 } else {
3156 DiagKind = 0;
3157 if (auto *E = Obj.Base.dyn_cast<const Expr *>())
3158 Loc = E->getExprLoc();
3159 }
3160 Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
3161 << handler.AccessKind << DiagKind << Decl;
3162 Info.Note(Loc, diag::note_constexpr_volatile_here) << DiagKind;
3163 } else {
3164 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
3165 }
3166 return handler.failed();
3167 }
3168
3169 // If we are reading an object of class type, there may still be more
3170 // things we need to check: if there are any mutable subobjects, we
3171 // cannot perform this read. (This only happens when performing a trivial
3172 // copy or assignment.)
3173 if (ObjType->isRecordType() &&
3174 !Obj.mayAccessMutableMembers(Info, handler.AccessKind) &&
3175 diagnoseMutableFields(Info, E, handler.AccessKind, ObjType))
3176 return handler.failed();
3177 }
3178
3179 if (I == N) {
3180 if (!handler.found(*O, ObjType))
3181 return false;
3182
3183 // If we modified a bit-field, truncate it to the right width.
3184 if (isModification(handler.AccessKind) &&
3185 LastField && LastField->isBitField() &&
3186 !truncateBitfieldValue(Info, E, *O, LastField))
3187 return false;
3188
3189 return true;
3190 }
3191
3192 LastField = nullptr;
3193 if (ObjType->isArrayType()) {
3194 // Next subobject is an array element.
3195 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(ObjType);
3196 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3196, __PRETTY_FUNCTION__))
;
3197 uint64_t Index = Sub.Entries[I].getAsArrayIndex();
3198 if (CAT->getSize().ule(Index)) {
3199 // Note, it should not be possible to form a pointer with a valid
3200 // designator which points more than one past the end of the array.
3201 if (Info.getLangOpts().CPlusPlus11)
3202 Info.FFDiag(E, diag::note_constexpr_access_past_end)
3203 << handler.AccessKind;
3204 else
3205 Info.FFDiag(E);
3206 return handler.failed();
3207 }
3208
3209 ObjType = CAT->getElementType();
3210
3211 if (O->getArrayInitializedElts() > Index)
3212 O = &O->getArrayInitializedElt(Index);
3213 else if (!isRead(handler.AccessKind)) {
3214 expandArray(*O, Index);
3215 O = &O->getArrayInitializedElt(Index);
3216 } else
3217 O = &O->getArrayFiller();
3218 } else if (ObjType->isAnyComplexType()) {
3219 // Next subobject is a complex number.
3220 uint64_t Index = Sub.Entries[I].getAsArrayIndex();
3221 if (Index > 1) {
3222 if (Info.getLangOpts().CPlusPlus11)
3223 Info.FFDiag(E, diag::note_constexpr_access_past_end)
3224 << handler.AccessKind;
3225 else
3226 Info.FFDiag(E);
3227 return handler.failed();
3228 }
3229
3230 ObjType = getSubobjectType(
3231 ObjType, ObjType->castAs<ComplexType>()->getElementType());
3232
3233 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3233, __PRETTY_FUNCTION__))
;
3234 if (O->isComplexInt()) {
3235 return handler.found(Index ? O->getComplexIntImag()
3236 : O->getComplexIntReal(), ObjType);
3237 } else {
3238 assert(O->isComplexFloat())((O->isComplexFloat()) ? static_cast<void> (0) : __assert_fail
("O->isComplexFloat()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3238, __PRETTY_FUNCTION__))
;
3239 return handler.found(Index ? O->getComplexFloatImag()
3240 : O->getComplexFloatReal(), ObjType);
3241 }
3242 } else if (const FieldDecl *Field = getAsField(Sub.Entries[I])) {
3243 if (Field->isMutable() &&
3244 !Obj.mayAccessMutableMembers(Info, handler.AccessKind)) {
3245 Info.FFDiag(E, diag::note_constexpr_access_mutable, 1)
3246 << handler.AccessKind << Field;
3247 Info.Note(Field->getLocation(), diag::note_declared_at);
3248 return handler.failed();
3249 }
3250
3251 // Next subobject is a class, struct or union field.
3252 RecordDecl *RD = ObjType->castAs<RecordType>()->getDecl();
3253 if (RD->isUnion()) {
3254 const FieldDecl *UnionField = O->getUnionField();
3255 if (!UnionField ||
3256 UnionField->getCanonicalDecl() != Field->getCanonicalDecl()) {
3257 // FIXME: If O->getUnionValue() is absent, report that there's no
3258 // active union member rather than reporting the prior active union
3259 // member. We'll need to fix nullptr_t to not use APValue() as its
3260 // representation first.
3261 Info.FFDiag(E, diag::note_constexpr_access_inactive_union_member)
3262 << handler.AccessKind << Field << !UnionField << UnionField;
3263 return handler.failed();
3264 }
3265 O = &O->getUnionValue();
3266 } else
3267 O = &O->getStructField(Field->getFieldIndex());
3268
3269 ObjType = getSubobjectType(ObjType, Field->getType(), Field->isMutable());
3270 LastField = Field;
3271 if (Field->getType().isVolatileQualified())
3272 VolatileField = Field;
3273 } else {
3274 // Next subobject is a base class.
3275 const CXXRecordDecl *Derived = ObjType->getAsCXXRecordDecl();
3276 const CXXRecordDecl *Base = getAsBaseClass(Sub.Entries[I]);
3277 O = &O->getStructBase(getBaseIndex(Derived, Base));
3278
3279 ObjType = getSubobjectType(ObjType, Info.Ctx.getRecordType(Base));
3280 }
3281 }
3282}
3283
3284namespace {
3285struct ExtractSubobjectHandler {
3286 EvalInfo &Info;
3287 const Expr *E;
3288 APValue &Result;
3289 const AccessKinds AccessKind;
3290
3291 typedef bool result_type;
3292 bool failed() { return false; }
3293 bool found(APValue &Subobj, QualType SubobjType) {
3294 Result = Subobj;
3295 if (AccessKind == AK_ReadObjectRepresentation)
3296 return true;
3297 return CheckFullyInitialized(Info, E->getExprLoc(), SubobjType, Result);
3298 }
3299 bool found(APSInt &Value, QualType SubobjType) {
3300 Result = APValue(Value);
3301 return true;
3302 }
3303 bool found(APFloat &Value, QualType SubobjType) {
3304 Result = APValue(Value);
3305 return true;
3306 }
3307};
3308} // end anonymous namespace
3309
3310/// Extract the designated sub-object of an rvalue.
3311static bool extractSubobject(EvalInfo &Info, const Expr *E,
3312 const CompleteObject &Obj,
3313 const SubobjectDesignator &Sub, APValue &Result,
3314 AccessKinds AK = AK_Read) {
3315 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3315, __PRETTY_FUNCTION__))
;
3316 ExtractSubobjectHandler Handler = {Info, E, Result, AK};
3317 return findSubobject(Info, E, Obj, Sub, Handler);
3318}
3319
3320namespace {
3321struct ModifySubobjectHandler {
3322 EvalInfo &Info;
3323 APValue &NewVal;
3324 const Expr *E;
3325
3326 typedef bool result_type;
3327 static const AccessKinds AccessKind = AK_Assign;
3328
3329 bool checkConst(QualType QT) {
3330 // Assigning to a const object has undefined behavior.
3331 if (QT.isConstQualified()) {
3332 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
3333 return false;
3334 }
3335 return true;
3336 }
3337
3338 bool failed() { return false; }
3339 bool found(APValue &Subobj, QualType SubobjType) {
3340 if (!checkConst(SubobjType))
3341 return false;
3342 // We've been given ownership of NewVal, so just swap it in.
3343 Subobj.swap(NewVal);
3344 return true;
3345 }
3346 bool found(APSInt &Value, QualType SubobjType) {
3347 if (!checkConst(SubobjType))
3348 return false;
3349 if (!NewVal.isInt()) {
3350 // Maybe trying to write a cast pointer value into a complex?
3351 Info.FFDiag(E);
3352 return false;
3353 }
3354 Value = NewVal.getInt();
3355 return true;
3356 }
3357 bool found(APFloat &Value, QualType SubobjType) {
3358 if (!checkConst(SubobjType))
3359 return false;
3360 Value = NewVal.getFloat();
3361 return true;
3362 }
3363};
3364} // end anonymous namespace
3365
3366const AccessKinds ModifySubobjectHandler::AccessKind;
3367
3368/// Update the designated sub-object of an rvalue to the given value.
3369static bool modifySubobject(EvalInfo &Info, const Expr *E,
3370 const CompleteObject &Obj,
3371 const SubobjectDesignator &Sub,
3372 APValue &NewVal) {
3373 ModifySubobjectHandler Handler = { Info, NewVal, E };
3374 return findSubobject(Info, E, Obj, Sub, Handler);
3375}
3376
3377/// Find the position where two subobject designators diverge, or equivalently
3378/// the length of the common initial subsequence.
3379static unsigned FindDesignatorMismatch(QualType ObjType,
3380 const SubobjectDesignator &A,
3381 const SubobjectDesignator &B,
3382 bool &WasArrayIndex) {
3383 unsigned I = 0, N = std::min(A.Entries.size(), B.Entries.size());
3384 for (/**/; I != N; ++I) {
3385 if (!ObjType.isNull() &&
3386 (ObjType->isArrayType() || ObjType->isAnyComplexType())) {
3387 // Next subobject is an array element.
3388 if (A.Entries[I].getAsArrayIndex() != B.Entries[I].getAsArrayIndex()) {
3389 WasArrayIndex = true;
3390 return I;
3391 }
3392 if (ObjType->isAnyComplexType())
3393 ObjType = ObjType->castAs<ComplexType>()->getElementType();
3394 else
3395 ObjType = ObjType->castAsArrayTypeUnsafe()->getElementType();
3396 } else {
3397 if (A.Entries[I].getAsBaseOrMember() !=
3398 B.Entries[I].getAsBaseOrMember()) {
3399 WasArrayIndex = false;
3400 return I;
3401 }
3402 if (const FieldDecl *FD = getAsField(A.Entries[I]))
3403 // Next subobject is a field.
3404 ObjType = FD->getType();
3405 else
3406 // Next subobject is a base class.
3407 ObjType = QualType();
3408 }
3409 }
3410 WasArrayIndex = false;
3411 return I;
3412}
3413
3414/// Determine whether the given subobject designators refer to elements of the
3415/// same array object.
3416static bool AreElementsOfSameArray(QualType ObjType,
3417 const SubobjectDesignator &A,
3418 const SubobjectDesignator &B) {
3419 if (A.Entries.size() != B.Entries.size())
3420 return false;
3421
3422 bool IsArray = A.MostDerivedIsArrayElement;
3423 if (IsArray && A.MostDerivedPathLength != A.Entries.size())
3424 // A is a subobject of the array element.
3425 return false;
3426
3427 // If A (and B) designates an array element, the last entry will be the array
3428 // index. That doesn't have to match. Otherwise, we're in the 'implicit array
3429 // of length 1' case, and the entire path must match.
3430 bool WasArrayIndex;
3431 unsigned CommonLength = FindDesignatorMismatch(ObjType, A, B, WasArrayIndex);
3432 return CommonLength >= A.Entries.size() - IsArray;
3433}
3434
3435/// Find the complete object to which an LValue refers.
3436static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
3437 AccessKinds AK, const LValue &LVal,
3438 QualType LValType) {
3439 if (LVal.InvalidBase) {
3440 Info.FFDiag(E);
3441 return CompleteObject();
3442 }
3443
3444 if (!LVal.Base) {
3445 Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
3446 return CompleteObject();
3447 }
3448
3449 CallStackFrame *Frame = nullptr;
3450 unsigned Depth = 0;
3451 if (LVal.getLValueCallIndex()) {
3452 std::tie(Frame, Depth) =
3453 Info.getCallFrameAndDepth(LVal.getLValueCallIndex());
3454 if (!Frame) {
3455 Info.FFDiag(E, diag::note_constexpr_lifetime_ended, 1)
3456 << AK << LVal.Base.is<const ValueDecl*>();
3457 NoteLValueLocation(Info, LVal.Base);
3458 return CompleteObject();
3459 }
3460 }
3461
3462 bool IsAccess = isAnyAccess(AK);
3463
3464 // C++11 DR1311: An lvalue-to-rvalue conversion on a volatile-qualified type
3465 // is not a constant expression (even if the object is non-volatile). We also
3466 // apply this rule to C++98, in order to conform to the expected 'volatile'
3467 // semantics.
3468 if (isFormalAccess(AK) && LValType.isVolatileQualified()) {
3469 if (Info.getLangOpts().CPlusPlus)
3470 Info.FFDiag(E, diag::note_constexpr_access_volatile_type)
3471 << AK << LValType;
3472 else
3473 Info.FFDiag(E);
3474 return CompleteObject();
3475 }
3476
3477 // Compute value storage location and type of base object.
3478 APValue *BaseVal = nullptr;
3479 QualType BaseType = getType(LVal.Base);
3480
3481 if (const ValueDecl *D = LVal.Base.dyn_cast<const ValueDecl*>()) {
3482 // In C++98, const, non-volatile integers initialized with ICEs are ICEs.
3483 // In C++11, constexpr, non-volatile variables initialized with constant
3484 // expressions are constant expressions too. Inside constexpr functions,
3485 // parameters are constant expressions even if they're non-const.
3486 // In C++1y, objects local to a constant expression (those with a Frame) are
3487 // both readable and writable inside constant expressions.
3488 // In C, such things can also be folded, although they are not ICEs.
3489 const VarDecl *VD = dyn_cast<VarDecl>(D);
3490 if (VD) {
3491 if (const VarDecl *VDef = VD->getDefinition(Info.Ctx))
3492 VD = VDef;
3493 }
3494 if (!VD || VD->isInvalidDecl()) {
3495 Info.FFDiag(E);
3496 return CompleteObject();
3497 }
3498
3499 // Unless we're looking at a local variable or argument in a constexpr call,
3500 // the variable we're reading must be const.
3501 if (!Frame) {
3502 if (Info.getLangOpts().CPlusPlus14 &&
3503 lifetimeStartedInEvaluation(Info, LVal.Base)) {
3504 // OK, we can read and modify an object if we're in the process of
3505 // evaluating its initializer, because its lifetime began in this
3506 // evaluation.
3507 } else if (isModification(AK)) {
3508 // All the remaining cases do not permit modification of the object.
3509 Info.FFDiag(E, diag::note_constexpr_modify_global);
3510 return CompleteObject();
3511 } else if (VD->isConstexpr()) {
3512 // OK, we can read this variable.
3513 } else if (BaseType->isIntegralOrEnumerationType()) {
3514 // In OpenCL if a variable is in constant address space it is a const
3515 // value.
3516 if (!(BaseType.isConstQualified() ||
3517 (Info.getLangOpts().OpenCL &&
3518 BaseType.getAddressSpace() == LangAS::opencl_constant))) {
3519 if (!IsAccess)
3520 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
3521 if (Info.getLangOpts().CPlusPlus) {
3522 Info.FFDiag(E, diag::note_constexpr_ltor_non_const_int, 1) << VD;
3523 Info.Note(VD->getLocation(), diag::note_declared_at);
3524 } else {
3525 Info.FFDiag(E);
3526 }
3527 return CompleteObject();
3528 }
3529 } else if (!IsAccess) {
3530 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
3531 } else if (BaseType->isFloatingType() && BaseType.isConstQualified()) {
3532 // We support folding of const floating-point types, in order to make
3533 // static const data members of such types (supported as an extension)
3534 // more useful.
3535 if (Info.getLangOpts().CPlusPlus11) {
3536 Info.CCEDiag(E, diag::note_constexpr_ltor_non_constexpr, 1) << VD;
3537 Info.Note(VD->getLocation(), diag::note_declared_at);
3538 } else {
3539 Info.CCEDiag(E);
3540 }
3541 } else if (BaseType.isConstQualified() && VD->hasDefinition(Info.Ctx)) {
3542 Info.CCEDiag(E, diag::note_constexpr_ltor_non_constexpr) << VD;
3543 // Keep evaluating to see what we can do.
3544 } else {
3545 // FIXME: Allow folding of values of any literal type in all languages.
3546 if (Info.checkingPotentialConstantExpression() &&
3547 VD->getType().isConstQualified() && !VD->hasDefinition(Info.Ctx)) {
3548 // The definition of this variable could be constexpr. We can't
3549 // access it right now, but may be able to in future.
3550 } else if (Info.getLangOpts().CPlusPlus11) {
3551 Info.FFDiag(E, diag::note_constexpr_ltor_non_constexpr, 1) << VD;
3552 Info.Note(VD->getLocation(), diag::note_declared_at);
3553 } else {
3554 Info.FFDiag(E);
3555 }
3556 return CompleteObject();
3557 }
3558 }
3559
3560 if (!evaluateVarDeclInit(Info, E, VD, Frame, BaseVal, &LVal))
3561 return CompleteObject();
3562 } else if (DynamicAllocLValue DA = LVal.Base.dyn_cast<DynamicAllocLValue>()) {
3563 Optional<EvalInfo::DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA);
3564 if (!Alloc) {
3565 Info.FFDiag(E, diag::note_constexpr_access_deleted_object) << AK;
3566 return CompleteObject();
3567 }
3568 return CompleteObject(LVal.Base, &(*Alloc)->Value,
3569 LVal.Base.getDynamicAllocType());
3570 } else {
3571 const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
3572
3573 if (!Frame) {
3574 if (const MaterializeTemporaryExpr *MTE =
3575 dyn_cast_or_null<MaterializeTemporaryExpr>(Base)) {
3576 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3577, __PRETTY_FUNCTION__))
3577 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3577, __PRETTY_FUNCTION__))
;
3578
3579 // Per C++1y [expr.const]p2:
3580 // an lvalue-to-rvalue conversion [is not allowed unless it applies to]
3581 // - a [...] glvalue of integral or enumeration type that refers to
3582 // a non-volatile const object [...]
3583 // [...]
3584 // - a [...] glvalue of literal type that refers to a non-volatile
3585 // object whose lifetime began within the evaluation of e.
3586 //
3587 // C++11 misses the 'began within the evaluation of e' check and
3588 // instead allows all temporaries, including things like:
3589 // int &&r = 1;
3590 // int x = ++r;
3591 // constexpr int k = r;
3592 // Therefore we use the C++14 rules in C++11 too.
3593 //
3594 // Note that temporaries whose lifetimes began while evaluating a
3595 // variable's constructor are not usable while evaluating the
3596 // corresponding destructor, not even if they're of const-qualified
3597 // types.
3598 if (!(BaseType.isConstQualified() &&
3599 BaseType->isIntegralOrEnumerationType()) &&
3600 !lifetimeStartedInEvaluation(Info, LVal.Base)) {
3601 if (!IsAccess)
3602 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
3603 Info.FFDiag(E, diag::note_constexpr_access_static_temporary, 1) << AK;
3604 Info.Note(MTE->getExprLoc(), diag::note_constexpr_temporary_here);
3605 return CompleteObject();
3606 }
3607
3608 BaseVal = Info.Ctx.getMaterializedTemporaryValue(MTE, false);
3609 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3609, __PRETTY_FUNCTION__))
;
3610 } else {
3611 if (!IsAccess)
3612 return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
3613 APValue Val;
3614 LVal.moveInto(Val);
3615 Info.FFDiag(E, diag::note_constexpr_access_unreadable_object)
3616 << AK
3617 << Val.getAsString(Info.Ctx,
3618 Info.Ctx.getLValueReferenceType(LValType));
3619 NoteLValueLocation(Info, LVal.Base);
3620 return CompleteObject();
3621 }
3622 } else {
3623 BaseVal = Frame->getTemporary(Base, LVal.Base.getVersion());
3624 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3624, __PRETTY_FUNCTION__))
;
3625 }
3626 }
3627
3628 // In C++14, we can't safely access any mutable state when we might be
3629 // evaluating after an unmodeled side effect.
3630 //
3631 // FIXME: Not all local state is mutable. Allow local constant subobjects
3632 // to be read here (but take care with 'mutable' fields).
3633 if ((Frame && Info.getLangOpts().CPlusPlus14 &&
3634 Info.EvalStatus.HasSideEffects) ||
3635 (isModification(AK) && Depth < Info.SpeculativeEvaluationDepth))
3636 return CompleteObject();
3637
3638 return CompleteObject(LVal.getLValueBase(), BaseVal, BaseType);
3639}
3640
3641/// Perform an lvalue-to-rvalue conversion on the given glvalue. This
3642/// can also be used for 'lvalue-to-lvalue' conversions for looking up the
3643/// glvalue referred to by an entity of reference type.
3644///
3645/// \param Info - Information about the ongoing evaluation.
3646/// \param Conv - The expression for which we are performing the conversion.
3647/// Used for diagnostics.
3648/// \param Type - The type of the glvalue (before stripping cv-qualifiers in the
3649/// case of a non-class type).
3650/// \param LVal - The glvalue on which we are attempting to perform this action.
3651/// \param RVal - The produced value will be placed here.
3652/// \param WantObjectRepresentation - If true, we're looking for the object
3653/// representation rather than the value, and in particular,
3654/// there is no requirement that the result be fully initialized.
3655static bool
3656handleLValueToRValueConversion(EvalInfo &Info, const Expr *Conv, QualType Type,
3657 const LValue &LVal, APValue &RVal,
3658 bool WantObjectRepresentation = false) {
3659 if (LVal.Designator.Invalid)
3660 return false;
3661
3662 // Check for special cases where there is no existing APValue to look at.
3663 const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
3664
3665 AccessKinds AK =
3666 WantObjectRepresentation ? AK_ReadObjectRepresentation : AK_Read;
3667
3668 if (Base && !LVal.getLValueCallIndex() && !Type.isVolatileQualified()) {
3669 if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(Base)) {
3670 // In C99, a CompoundLiteralExpr is an lvalue, and we defer evaluating the
3671 // initializer until now for such expressions. Such an expression can't be
3672 // an ICE in C, so this only matters for fold.
3673 if (Type.isVolatileQualified()) {
3674 Info.FFDiag(Conv);
3675 return false;
3676 }
3677 APValue Lit;
3678 if (!Evaluate(Lit, Info, CLE->getInitializer()))
3679 return false;
3680 CompleteObject LitObj(LVal.Base, &Lit, Base->getType());
3681 return extractSubobject(Info, Conv, LitObj, LVal.Designator, RVal, AK);
3682 } else if (isa<StringLiteral>(Base) || isa<PredefinedExpr>(Base)) {
3683 // Special-case character extraction so we don't have to construct an
3684 // APValue for the whole string.
3685 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3686, __PRETTY_FUNCTION__))
3686 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 3686, __PRETTY_FUNCTION__))
;
3687 if (LVal.Designator.Entries.empty()) {
3688 // Fail for now for LValue to RValue conversion of an array.
3689 // (This shouldn't show up in C/C++, but it could be triggered by a
3690 // weird EvaluateAsRValue call from a tool.)
3691 Info.FFDiag(Conv);
3692 return false;
3693 }
3694 if (LVal.Designator.isOnePastTheEnd()) {
3695 if (Info.getLangOpts().CPlusPlus11)
3696 Info.FFDiag(Conv, diag::note_constexpr_access_past_end) << AK;
3697 else
3698 Info.FFDiag(Conv);
3699 return false;
3700 }
3701 uint64_t CharIndex = LVal.Designator.Entries[0].getAsArrayIndex();
3702 RVal = APValue(extractStringLiteralCharacter(Info, Base, CharIndex));
3703 return true;
3704 }
3705 }
3706
3707 CompleteObject Obj = findCompleteObject(Info, Conv, AK, LVal, Type);
3708 return Obj && extractSubobject(Info, Conv, Obj, LVal.Designator, RVal, AK);
3709}
3710
3711/// Perform an assignment of Val to LVal. Takes ownership of Val.
3712static bool handleAssignment(EvalInfo &Info, const Expr *E, const LValue &LVal,
3713 QualType LValType, APValue &Val) {
3714 if (LVal.Designator.Invalid)
3715 return false;
3716
3717 if (!Info.getLangOpts().CPlusPlus14) {
3718 Info.FFDiag(E);
3719 return false;
3720 }
3721
3722 CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
3723 return Obj && modifySubobject(Info, E, Obj, LVal.Designator, Val);
3724}
3725
3726namespace {
3727struct CompoundAssignSubobjectHandler {
3728 EvalInfo &Info;
3729 const Expr *E;
3730 QualType PromotedLHSType;
3731 BinaryOperatorKind Opcode;
3732 const APValue &RHS;
3733
3734 static const AccessKinds AccessKind = AK_Assign;
3735
3736 typedef bool result_type;
3737
3738 bool checkConst(QualType QT) {
3739 // Assigning to a const object has undefined behavior.
3740 if (QT.isConstQualified()) {
3741 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
3742 return false;
3743 }
3744 return true;
3745 }
3746
3747 bool failed() { return false; }
3748 bool found(APValue &Subobj, QualType SubobjType) {
3749 switch (Subobj.getKind()) {
3750 case APValue::Int:
3751 return found(Subobj.getInt(), SubobjType);
3752 case APValue::Float:
3753 return found(Subobj.getFloat(), SubobjType);
3754 case APValue::ComplexInt:
3755 case APValue::ComplexFloat:
3756 // FIXME: Implement complex compound assignment.
3757 Info.FFDiag(E);
3758 return false;
3759 case APValue::LValue:
3760 return foundPointer(Subobj, SubobjType);
3761 default:
3762 // FIXME: can this happen?
3763 Info.FFDiag(E);
3764 return false;
3765 }
3766 }
3767 bool found(APSInt &Value, QualType SubobjType) {
3768 if (!checkConst(SubobjType))
3769 return false;
3770
3771 if (!SubobjType->isIntegerType()) {
3772 // We don't support compound assignment on integer-cast-to-pointer
3773 // values.
3774 Info.FFDiag(E);
3775 return false;
3776 }
3777
3778 if (RHS.isInt()) {
3779 APSInt LHS =
3780 HandleIntToIntCast(Info, E, PromotedLHSType, SubobjType, Value);
3781 if (!handleIntIntBinOp(Info, E, LHS, Opcode, RHS.getInt(), LHS))
3782 return false;
3783 Value = HandleIntToIntCast(Info, E, SubobjType, PromotedLHSType, LHS);
3784 return true;
3785 } else if (RHS.isFloat()) {
3786 APFloat FValue(0.0);
3787 return HandleIntToFloatCast(Info, E, SubobjType, Value, PromotedLHSType,
3788 FValue) &&
3789 handleFloatFloatBinOp(Info, E, FValue, Opcode, RHS.getFloat()) &&
3790 HandleFloatToIntCast(Info, E, PromotedLHSType, FValue, SubobjType,
3791 Value);
3792 }
3793
3794 Info.FFDiag(E);
3795 return false;
3796 }
3797 bool found(APFloat &Value, QualType SubobjType) {
3798 return checkConst(SubobjType) &&
3799 HandleFloatToFloatCast(Info, E, SubobjType, PromotedLHSType,
3800 Value) &&
3801 handleFloatFloatBinOp(Info, E, Value, Opcode, RHS.getFloat()) &&
3802 HandleFloatToFloatCast(Info, E, PromotedLHSType, SubobjType, Value);
3803 }
3804 bool foundPointer(APValue &Subobj, QualType SubobjType) {
3805 if (!checkConst(SubobjType))
3806 return false;
3807
3808 QualType PointeeType;
3809 if (const PointerType *PT = SubobjType->getAs<PointerType>())
3810 PointeeType = PT->getPointeeType();
3811
3812 if (PointeeType.isNull() || !RHS.isInt() ||
3813 (Opcode != BO_Add && Opcode != BO_Sub)) {
3814 Info.FFDiag(E);
3815 return false;
3816 }
3817
3818 APSInt Offset = RHS.getInt();
3819 if (Opcode == BO_Sub)
3820 negateAsSigned(Offset);
3821
3822 LValue LVal;
3823 LVal.setFrom(Info.Ctx, Subobj);
3824 if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType, Offset))
3825 return false;
3826 LVal.moveInto(Subobj);
3827 return true;
3828 }
3829};
3830} // end anonymous namespace
3831
3832const AccessKinds CompoundAssignSubobjectHandler::AccessKind;
3833
3834/// Perform a compound assignment of LVal <op>= RVal.
3835static bool handleCompoundAssignment(
3836 EvalInfo &Info, const Expr *E,
3837 const LValue &LVal, QualType LValType, QualType PromotedLValType,
3838 BinaryOperatorKind Opcode, const APValue &RVal) {
3839 if (LVal.Designator.Invalid)
3840 return false;
3841
3842 if (!Info.getLangOpts().CPlusPlus14) {
3843 Info.FFDiag(E);
3844 return false;
3845 }
3846
3847 CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
3848 CompoundAssignSubobjectHandler Handler = { Info, E, PromotedLValType, Opcode,
3849 RVal };
3850 return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
3851}
3852
3853namespace {
3854struct IncDecSubobjectHandler {
3855 EvalInfo &Info;
3856 const UnaryOperator *E;
3857 AccessKinds AccessKind;
3858 APValue *Old;
3859
3860 typedef bool result_type;
3861
3862 bool checkConst(QualType QT) {
3863 // Assigning to a const object has undefined behavior.
3864 if (QT.isConstQualified()) {
3865 Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
3866 return false;
3867 }
3868 return true;
3869 }
3870
3871 bool failed() { return false; }
3872 bool found(APValue &Subobj, QualType SubobjType) {
3873 // Stash the old value. Also clear Old, so we don't clobber it later
3874 // if we're post-incrementing a complex.
3875 if (Old) {
3876 *Old = Subobj;
3877 Old = nullptr;
3878 }
3879
3880 switch (Subobj.getKind()) {
3881 case APValue::Int:
3882 return found(Subobj.getInt(), SubobjType);
3883 case APValue::Float:
3884 return found(Subobj.getFloat(), SubobjType);
3885 case APValue::ComplexInt:
3886 return found(Subobj.getComplexIntReal(),
3887 SubobjType->castAs<ComplexType>()->getElementType()
3888 .withCVRQualifiers(SubobjType.getCVRQualifiers()));
3889 case APValue::ComplexFloat:
3890 return found(Subobj.getComplexFloatReal(),
3891 SubobjType->castAs<ComplexType>()->getElementType()
3892 .withCVRQualifiers(SubobjType.getCVRQualifiers()));
3893 case APValue::LValue:
3894 return foundPointer(Subobj, SubobjType);
3895 default:
3896 // FIXME: can this happen?
3897 Info.FFDiag(E);
3898 return false;
3899 }
3900 }
3901 bool found(APSInt &Value, QualType SubobjType) {
3902 if (!checkConst(SubobjType))
3903 return false;
3904
3905 if (!SubobjType->isIntegerType()) {
3906 // We don't support increment / decrement on integer-cast-to-pointer
3907 // values.
3908 Info.FFDiag(E);
3909 return false;
3910 }
3911
3912 if (Old) *Old = APValue(Value);
3913
3914 // bool arithmetic promotes to int, and the conversion back to bool
3915 // doesn't reduce mod 2^n, so special-case it.
3916 if (SubobjType->isBooleanType()) {
3917 if (AccessKind == AK_Increment)
3918 Value = 1;
3919 else
3920 Value = !Value;
3921 return true;
3922 }
3923
3924 bool WasNegative = Value.isNegative();
3925 if (AccessKind == AK_Increment) {
3926 ++Value;
3927
3928 if (!WasNegative && Value.isNegative() && E->canOverflow()) {
3929 APSInt ActualValue(Value, /*IsUnsigned*/true);
3930 return HandleOverflow(Info, E, ActualValue, SubobjType);
3931 }
3932 } else {
3933 --Value;
3934
3935 if (WasNegative && !Value.isNegative() && E->canOverflow()) {
3936 unsigned BitWidth = Value.getBitWidth();
3937 APSInt ActualValue(Value.sext(BitWidth + 1), /*IsUnsigned*/false);
3938 ActualValue.setBit(BitWidth);
3939 return HandleOverflow(Info, E, ActualValue, SubobjType);
3940 }
3941 }
3942 return true;
3943 }
3944 bool found(APFloat &Value, QualType SubobjType) {
3945 if (!checkConst(SubobjType))
3946 return false;
3947
3948 if (Old) *Old = APValue(Value);
3949
3950 APFloat One(Value.getSemantics(), 1);
3951 if (AccessKind == AK_Increment)
3952 Value.add(One, APFloat::rmNearestTiesToEven);
3953 else
3954 Value.subtract(One, APFloat::rmNearestTiesToEven);
3955 return true;
3956 }
3957 bool foundPointer(APValue &Subobj, QualType SubobjType) {
3958 if (!checkConst(SubobjType))
3959 return false;
3960
3961 QualType PointeeType;
3962 if (const PointerType *PT = SubobjType->getAs<PointerType>())
3963 PointeeType = PT->getPointeeType();
3964 else {
3965 Info.FFDiag(E);
3966 return false;
3967 }
3968
3969 LValue LVal;
3970 LVal.setFrom(Info.Ctx, Subobj);
3971 if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType,
3972 AccessKind == AK_Increment ? 1 : -1))
3973 return false;
3974 LVal.moveInto(Subobj);
3975 return true;
3976 }
3977};
3978} // end anonymous namespace
3979
3980/// Perform an increment or decrement on LVal.
3981static bool handleIncDec(EvalInfo &Info, const Expr *E, const LValue &LVal,
3982 QualType LValType, bool IsIncrement, APValue *Old) {
3983 if (LVal.Designator.Invalid)
3984 return false;
3985
3986 if (!Info.getLangOpts().CPlusPlus14) {
3987 Info.FFDiag(E);
3988 return false;
3989 }
3990
3991 AccessKinds AK = IsIncrement ? AK_Increment : AK_Decrement;
3992 CompleteObject Obj = findCompleteObject(Info, E, AK, LVal, LValType);
3993 IncDecSubobjectHandler Handler = {Info, cast<UnaryOperator>(E), AK, Old};
3994 return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
3995}
3996
3997/// Build an lvalue for the object argument of a member function call.
3998static bool EvaluateObjectArgument(EvalInfo &Info, const Expr *Object,
3999 LValue &This) {
4000 if (Object->getType()->isPointerType() && Object->isRValue())
4001 return EvaluatePointer(Object, This, Info);
4002
4003 if (Object->isGLValue())
4004 return EvaluateLValue(Object, This, Info);
4005
4006 if (Object->getType()->isLiteralType(Info.Ctx))
4007 return EvaluateTemporary(Object, This, Info);
4008
4009 Info.FFDiag(Object, diag::note_constexpr_nonliteral) << Object->getType();
4010 return false;
4011}
4012
4013/// HandleMemberPointerAccess - Evaluate a member access operation and build an
4014/// lvalue referring to the result.
4015///
4016/// \param Info - Information about the ongoing evaluation.
4017/// \param LV - An lvalue referring to the base of the member pointer.
4018/// \param RHS - The member pointer expression.
4019/// \param IncludeMember - Specifies whether the member itself is included in
4020/// the resulting LValue subobject designator. This is not possible when
4021/// creating a bound member function.
4022/// \return The field or method declaration to which the member pointer refers,
4023/// or 0 if evaluation fails.
4024static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
4025 QualType LVType,
4026 LValue &LV,
4027 const Expr *RHS,
4028 bool IncludeMember = true) {
4029 MemberPtr MemPtr;
4030 if (!EvaluateMemberPointer(RHS, MemPtr, Info))
4031 return nullptr;
4032
4033 // C++11 [expr.mptr.oper]p6: If the second operand is the null pointer to
4034 // member value, the behavior is undefined.
4035 if (!MemPtr.getDecl()) {
4036 // FIXME: Specific diagnostic.
4037 Info.FFDiag(RHS);
4038 return nullptr;
4039 }
4040
4041 if (MemPtr.isDerivedMember()) {
4042 // This is a member of some derived class. Truncate LV appropriately.
4043 // The end of the derived-to-base path for the base object must match the
4044 // derived-to-base path for the member pointer.
4045 if (LV.Designator.MostDerivedPathLength + MemPtr.Path.size() >
4046 LV.Designator.Entries.size()) {
4047 Info.FFDiag(RHS);
4048 return nullptr;
4049 }
4050 unsigned PathLengthToMember =
4051 LV.Designator.Entries.size() - MemPtr.Path.size();
4052 for (unsigned I = 0, N = MemPtr.Path.size(); I != N; ++I) {
4053 const CXXRecordDecl *LVDecl = getAsBaseClass(
4054 LV.Designator.Entries[PathLengthToMember + I]);
4055 const CXXRecordDecl *MPDecl = MemPtr.Path[I];
4056 if (LVDecl->getCanonicalDecl() != MPDecl->getCanonicalDecl()) {
4057 Info.FFDiag(RHS);
4058 return nullptr;
4059 }
4060 }
4061
4062 // Truncate the lvalue to the appropriate derived class.
4063 if (!CastToDerivedClass(Info, RHS, LV, MemPtr.getContainingRecord(),
4064 PathLengthToMember))
4065 return nullptr;
4066 } else if (!MemPtr.Path.empty()) {
4067 // Extend the LValue path with the member pointer's path.
4068 LV.Designator.Entries.reserve(LV.Designator.Entries.size() +
4069 MemPtr.Path.size() + IncludeMember);
4070
4071 // Walk down to the appropriate base class.
4072 if (const PointerType *PT = LVType->getAs<PointerType>())
4073 LVType = PT->getPointeeType();
4074 const CXXRecordDecl *RD = LVType->getAsCXXRecordDecl();
4075 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4075, __PRETTY_FUNCTION__))
;
4076 // The first class in the path is that of the lvalue.
4077 for (unsigned I = 1, N = MemPtr.Path.size(); I != N; ++I) {
4078 const CXXRecordDecl *Base = MemPtr.Path[N - I - 1];
4079 if (!HandleLValueDirectBase(Info, RHS, LV, RD, Base))
4080 return nullptr;
4081 RD = Base;
4082 }
4083 // Finally cast to the class containing the member.
4084 if (!HandleLValueDirectBase(Info, RHS, LV, RD,
4085 MemPtr.getContainingRecord()))
4086 return nullptr;
4087 }
4088
4089 // Add the member. Note that we cannot build bound member functions here.
4090 if (IncludeMember) {
4091 if (const FieldDecl *FD = dyn_cast<FieldDecl>(MemPtr.getDecl())) {
4092 if (!HandleLValueMember(Info, RHS, LV, FD))
4093 return nullptr;
4094 } else if (const IndirectFieldDecl *IFD =
4095 dyn_cast<IndirectFieldDecl>(MemPtr.getDecl())) {
4096 if (!HandleLValueIndirectMember(Info, RHS, LV, IFD))
4097 return nullptr;
4098 } else {
4099 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4099)
;
4100 }
4101 }
4102
4103 return MemPtr.getDecl();
4104}
4105
4106static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
4107 const BinaryOperator *BO,
4108 LValue &LV,
4109 bool IncludeMember = true) {
4110 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4110, __PRETTY_FUNCTION__))
;
4111
4112 if (!EvaluateObjectArgument(Info, BO->getLHS(), LV)) {
4113 if (Info.noteFailure()) {
4114 MemberPtr MemPtr;
4115 EvaluateMemberPointer(BO->getRHS(), MemPtr, Info);
4116 }
4117 return nullptr;
4118 }
4119
4120 return HandleMemberPointerAccess(Info, BO->getLHS()->getType(), LV,
4121 BO->getRHS(), IncludeMember);
4122}
4123
4124/// HandleBaseToDerivedCast - Apply the given base-to-derived cast operation on
4125/// the provided lvalue, which currently refers to the base object.
4126static bool HandleBaseToDerivedCast(EvalInfo &Info, const CastExpr *E,
4127 LValue &Result) {
4128 SubobjectDesignator &D = Result.Designator;
4129 if (D.Invalid || !Result.checkNullPointer(Info, E, CSK_Derived))
4130 return false;
4131
4132 QualType TargetQT = E->getType();
4133 if (const PointerType *PT = TargetQT->getAs<PointerType>())
4134 TargetQT = PT->getPointeeType();
4135
4136 // Check this cast lands within the final derived-to-base subobject path.
4137 if (D.MostDerivedPathLength + E->path_size() > D.Entries.size()) {
4138 Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
4139 << D.MostDerivedType << TargetQT;
4140 return false;
4141 }
4142
4143 // Check the type of the final cast. We don't need to check the path,
4144 // since a cast can only be formed if the path is unique.
4145 unsigned NewEntriesSize = D.Entries.size() - E->path_size();
4146 const CXXRecordDecl *TargetType = TargetQT->getAsCXXRecordDecl();
4147 const CXXRecordDecl *FinalType;
4148 if (NewEntriesSize == D.MostDerivedPathLength)
4149 FinalType = D.MostDerivedType->getAsCXXRecordDecl();
4150 else
4151 FinalType = getAsBaseClass(D.Entries[NewEntriesSize - 1]);
4152 if (FinalType->getCanonicalDecl() != TargetType->getCanonicalDecl()) {
4153 Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
4154 << D.MostDerivedType << TargetQT;
4155 return false;
4156 }
4157
4158 // Truncate the lvalue to the appropriate derived class.
4159 return CastToDerivedClass(Info, E, Result, TargetType, NewEntriesSize);
4160}
4161
4162/// Get the value to use for a default-initialized object of type T.
4163static APValue getDefaultInitValue(QualType T) {
4164 if (auto *RD = T->getAsCXXRecordDecl()) {
4165 if (RD->isUnion())
4166 return APValue((const FieldDecl*)nullptr);
4167
4168 APValue Struct(APValue::UninitStruct(), RD->getNumBases(),
4169 std::distance(RD->field_begin(), RD->field_end()));
4170
4171 unsigned Index = 0;
4172 for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
4173 End = RD->bases_end(); I != End; ++I, ++Index)
4174 Struct.getStructBase(Index) = getDefaultInitValue(I->getType());
4175
4176 for (const auto *I : RD->fields()) {
4177 if (I->isUnnamedBitfield())
4178 continue;
4179 Struct.getStructField(I->getFieldIndex()) =
4180 getDefaultInitValue(I->getType());
4181 }
4182 return Struct;
4183 }
4184
4185 if (auto *AT =
4186 dyn_cast_or_null<ConstantArrayType>(T->getAsArrayTypeUnsafe())) {
4187 APValue Array(APValue::UninitArray(), 0, AT->getSize().getZExtValue());
4188 if (Array.hasArrayFiller())
4189 Array.getArrayFiller() = getDefaultInitValue(AT->getElementType());
4190 return Array;
4191 }
4192
4193 return APValue::IndeterminateValue();
4194}
4195
4196namespace {
4197enum EvalStmtResult {
4198 /// Evaluation failed.
4199 ESR_Failed,
4200 /// Hit a 'return' statement.
4201 ESR_Returned,
4202 /// Evaluation succeeded.
4203 ESR_Succeeded,
4204 /// Hit a 'continue' statement.
4205 ESR_Continue,
4206 /// Hit a 'break' statement.
4207 ESR_Break,
4208 /// Still scanning for 'case' or 'default' statement.
4209 ESR_CaseNotFound
4210};
4211}
4212
4213static bool EvaluateVarDecl(EvalInfo &Info, const VarDecl *VD) {
4214 // We don't need to evaluate the initializer for a static local.
4215 if (!VD->hasLocalStorage())
4216 return true;
4217
4218 LValue Result;
4219 APValue &Val =
4220 Info.CurrentCall->createTemporary(VD, VD->getType(), true, Result);
4221
4222 const Expr *InitE = VD->getInit();
4223 if (!InitE) {
4224 Val = getDefaultInitValue(VD->getType());
4225 return true;
4226 }
4227
4228 if (InitE->isValueDependent())
4229 return false;
4230
4231 if (!EvaluateInPlace(Val, Info, Result, InitE)) {
4232 // Wipe out any partially-computed value, to allow tracking that this
4233 // evaluation failed.
4234 Val = APValue();
4235 return false;
4236 }
4237
4238 return true;
4239}
4240
4241static bool EvaluateDecl(EvalInfo &Info, const Decl *D) {
4242 bool OK = true;
4243
4244 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
4245 OK &= EvaluateVarDecl(Info, VD);
4246
4247 if (const DecompositionDecl *DD = dyn_cast<DecompositionDecl>(D))
4248 for (auto *BD : DD->bindings())
4249 if (auto *VD = BD->getHoldingVar())
4250 OK &= EvaluateDecl(Info, VD);
4251
4252 return OK;
4253}
4254
4255
4256/// Evaluate a condition (either a variable declaration or an expression).
4257static bool EvaluateCond(EvalInfo &Info, const VarDecl *CondDecl,
4258 const Expr *Cond, bool &Result) {
4259 FullExpressionRAII Scope(Info);
4260 if (CondDecl && !EvaluateDecl(Info, CondDecl))
4261 return false;
4262 if (!EvaluateAsBooleanCondition(Cond, Result, Info))
4263 return false;
4264 return Scope.destroy();
4265}
4266
4267namespace {
4268/// A location where the result (returned value) of evaluating a
4269/// statement should be stored.
4270struct StmtResult {
4271 /// The APValue that should be filled in with the returned value.
4272 APValue &Value;
4273 /// The location containing the result, if any (used to support RVO).
4274 const LValue *Slot;
4275};
4276
4277struct TempVersionRAII {
4278 CallStackFrame &Frame;
4279
4280 TempVersionRAII(CallStackFrame &Frame) : Frame(Frame) {
4281 Frame.pushTempVersion();
4282 }
4283
4284 ~TempVersionRAII() {
4285 Frame.popTempVersion();
4286 }
4287};
4288
4289}
4290
4291static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
4292 const Stmt *S,
4293 const SwitchCase *SC = nullptr);
4294
4295/// Evaluate the body of a loop, and translate the result as appropriate.
4296static EvalStmtResult EvaluateLoopBody(StmtResult &Result, EvalInfo &Info,
4297 const Stmt *Body,
4298 const SwitchCase *Case = nullptr) {
4299 BlockScopeRAII Scope(Info);
4300
4301 EvalStmtResult ESR = EvaluateStmt(Result, Info, Body, Case);
4302 if (ESR != ESR_Failed && ESR != ESR_CaseNotFound && !Scope.destroy())
4303 ESR = ESR_Failed;
4304
4305 switch (ESR) {
4306 case ESR_Break:
4307 return ESR_Succeeded;
4308 case ESR_Succeeded:
4309 case ESR_Continue:
4310 return ESR_Continue;
4311 case ESR_Failed:
4312 case ESR_Returned:
4313 case ESR_CaseNotFound:
4314 return ESR;
4315 }
4316 llvm_unreachable("Invalid EvalStmtResult!")::llvm::llvm_unreachable_internal("Invalid EvalStmtResult!", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4316)
;
4317}
4318
4319/// Evaluate a switch statement.
4320static EvalStmtResult EvaluateSwitch(StmtResult &Result, EvalInfo &Info,
4321 const SwitchStmt *SS) {
4322 BlockScopeRAII Scope(Info);
4323
4324 // Evaluate the switch condition.
4325 APSInt Value;
4326 {
4327 if (const Stmt *Init = SS->getInit()) {
4328 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
4329 if (ESR != ESR_Succeeded) {
4330 if (ESR != ESR_Failed && !Scope.destroy())
4331 ESR = ESR_Failed;
4332 return ESR;
4333 }
4334 }
4335
4336 FullExpressionRAII CondScope(Info);
4337 if (SS->getConditionVariable() &&
4338 !EvaluateDecl(Info, SS->getConditionVariable()))
4339 return ESR_Failed;
4340 if (!EvaluateInteger(SS->getCond(), Value, Info))
4341 return ESR_Failed;
4342 if (!CondScope.destroy())
4343 return ESR_Failed;
4344 }
4345
4346 // Find the switch case corresponding to the value of the condition.
4347 // FIXME: Cache this lookup.
4348 const SwitchCase *Found = nullptr;
4349 for (const SwitchCase *SC = SS->getSwitchCaseList(); SC;
4350 SC = SC->getNextSwitchCase()) {
4351 if (isa<DefaultStmt>(SC)) {
4352 Found = SC;
4353 continue;
4354 }
4355
4356 const CaseStmt *CS = cast<CaseStmt>(SC);
4357 APSInt LHS = CS->getLHS()->EvaluateKnownConstInt(Info.Ctx);
4358 APSInt RHS = CS->getRHS() ? CS->getRHS()->EvaluateKnownConstInt(Info.Ctx)
4359 : LHS;
4360 if (LHS <= Value && Value <= RHS) {
4361 Found = SC;
4362 break;
4363 }
4364 }
4365
4366 if (!Found)
4367 return Scope.destroy() ? ESR_Failed : ESR_Succeeded;
4368
4369 // Search the switch body for the switch case and evaluate it from there.
4370 EvalStmtResult ESR = EvaluateStmt(Result, Info, SS->getBody(), Found);
4371 if (ESR != ESR_Failed && ESR != ESR_CaseNotFound && !Scope.destroy())
4372 return ESR_Failed;
4373
4374 switch (ESR) {
4375 case ESR_Break:
4376 return ESR_Succeeded;
4377 case ESR_Succeeded:
4378 case ESR_Continue:
4379 case ESR_Failed:
4380 case ESR_Returned:
4381 return ESR;
4382 case ESR_CaseNotFound:
4383 // This can only happen if the switch case is nested within a statement
4384 // expression. We have no intention of supporting that.
4385 Info.FFDiag(Found->getBeginLoc(),
4386 diag::note_constexpr_stmt_expr_unsupported);
4387 return ESR_Failed;
4388 }
4389 llvm_unreachable("Invalid EvalStmtResult!")::llvm::llvm_unreachable_internal("Invalid EvalStmtResult!", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4389)
;
4390}
4391
4392// Evaluate a statement.
4393static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
4394 const Stmt *S, const SwitchCase *Case) {
4395 if (!Info.nextStep(S))
4396 return ESR_Failed;
4397
4398 // If we're hunting down a 'case' or 'default' label, recurse through
4399 // substatements until we hit the label.
4400 if (Case) {
4401 switch (S->getStmtClass()) {
4402 case Stmt::CompoundStmtClass:
4403 // FIXME: Precompute which substatement of a compound statement we
4404 // would jump to, and go straight there rather than performing a
4405 // linear scan each time.
4406 case Stmt::LabelStmtClass:
4407 case Stmt::AttributedStmtClass:
4408 case Stmt::DoStmtClass:
4409 break;
4410
4411 case Stmt::CaseStmtClass:
4412 case Stmt::DefaultStmtClass:
4413 if (Case == S)
4414 Case = nullptr;
4415 break;
4416
4417 case Stmt::IfStmtClass: {
4418 // FIXME: Precompute which side of an 'if' we would jump to, and go
4419 // straight there rather than scanning both sides.
4420 const IfStmt *IS = cast<IfStmt>(S);
4421
4422 // Wrap the evaluation in a block scope, in case it's a DeclStmt
4423 // preceded by our switch label.
4424 BlockScopeRAII Scope(Info);
4425
4426 // Step into the init statement in case it brings an (uninitialized)
4427 // variable into scope.
4428 if (const Stmt *Init = IS->getInit()) {
4429 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init, Case);
4430 if (ESR != ESR_CaseNotFound) {
4431 assert(ESR != ESR_Succeeded)((ESR != ESR_Succeeded) ? static_cast<void> (0) : __assert_fail
("ESR != ESR_Succeeded", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4431, __PRETTY_FUNCTION__))
;
4432 return ESR;
4433 }
4434 }
4435
4436 // Condition variable must be initialized if it exists.
4437 // FIXME: We can skip evaluating the body if there's a condition
4438 // variable, as there can't be any case labels within it.
4439 // (The same is true for 'for' statements.)
4440
4441 EvalStmtResult ESR = EvaluateStmt(Result, Info, IS->getThen(), Case);
4442 if (ESR == ESR_Failed)
4443 return ESR;
4444 if (ESR != ESR_CaseNotFound)
4445 return Scope.destroy() ? ESR : ESR_Failed;
4446 if (!IS->getElse())
4447 return ESR_CaseNotFound;
4448
4449 ESR = EvaluateStmt(Result, Info, IS->getElse(), Case);
4450 if (ESR == ESR_Failed)
4451 return ESR;
4452 if (ESR != ESR_CaseNotFound)
4453 return Scope.destroy() ? ESR : ESR_Failed;
4454 return ESR_CaseNotFound;
4455 }
4456
4457 case Stmt::WhileStmtClass: {
4458 EvalStmtResult ESR =
4459 EvaluateLoopBody(Result, Info, cast<WhileStmt>(S)->getBody(), Case);
4460 if (ESR != ESR_Continue)
4461 return ESR;
4462 break;
4463 }
4464
4465 case Stmt::ForStmtClass: {
4466 const ForStmt *FS = cast<ForStmt>(S);
4467 BlockScopeRAII Scope(Info);
4468
4469 // Step into the init statement in case it brings an (uninitialized)
4470 // variable into scope.
4471 if (const Stmt *Init = FS->getInit()) {
4472 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init, Case);
4473 if (ESR != ESR_CaseNotFound) {
4474 assert(ESR != ESR_Succeeded)((ESR != ESR_Succeeded) ? static_cast<void> (0) : __assert_fail
("ESR != ESR_Succeeded", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4474, __PRETTY_FUNCTION__))
;
4475 return ESR;
4476 }
4477 }
4478
4479 EvalStmtResult ESR =
4480 EvaluateLoopBody(Result, Info, FS->getBody(), Case);
4481 if (ESR != ESR_Continue)
4482 return ESR;
4483 if (FS->getInc()) {
4484 FullExpressionRAII IncScope(Info);
4485 if (!EvaluateIgnoredValue(Info, FS->getInc()) || !IncScope.destroy())
4486 return ESR_Failed;
4487 }
4488 break;
4489 }
4490
4491 case Stmt::DeclStmtClass: {
4492 // Start the lifetime of any uninitialized variables we encounter. They
4493 // might be used by the selected branch of the switch.
4494 const DeclStmt *DS = cast<DeclStmt>(S);
4495 for (const auto *D : DS->decls()) {
4496 if (const auto *VD = dyn_cast<VarDecl>(D)) {
4497 if (VD->hasLocalStorage() && !VD->getInit())
4498 if (!EvaluateVarDecl(Info, VD))
4499 return ESR_Failed;
4500 // FIXME: If the variable has initialization that can't be jumped
4501 // over, bail out of any immediately-surrounding compound-statement
4502 // too. There can't be any case labels here.
4503 }
4504 }
4505 return ESR_CaseNotFound;
4506 }
4507
4508 default:
4509 return ESR_CaseNotFound;
4510 }
4511 }
4512
4513 switch (S->getStmtClass()) {
4514 default:
4515 if (const Expr *E = dyn_cast<Expr>(S)) {
4516 // Don't bother evaluating beyond an expression-statement which couldn't
4517 // be evaluated.
4518 // FIXME: Do we need the FullExpressionRAII object here?
4519 // VisitExprWithCleanups should create one when necessary.
4520 FullExpressionRAII Scope(Info);
4521 if (!EvaluateIgnoredValue(Info, E) || !Scope.destroy())
4522 return ESR_Failed;
4523 return ESR_Succeeded;
4524 }
4525
4526 Info.FFDiag(S->getBeginLoc());
4527 return ESR_Failed;
4528
4529 case Stmt::NullStmtClass:
4530 return ESR_Succeeded;
4531
4532 case Stmt::DeclStmtClass: {
4533 const DeclStmt *DS = cast<DeclStmt>(S);
4534 for (const auto *D : DS->decls()) {
4535 // Each declaration initialization is its own full-expression.
4536 FullExpressionRAII Scope(Info);
4537 if (!EvaluateDecl(Info, D) && !Info.noteFailure())
4538 return ESR_Failed;
4539 if (!Scope.destroy())
4540 return ESR_Failed;
4541 }
4542 return ESR_Succeeded;
4543 }
4544
4545 case Stmt::ReturnStmtClass: {
4546 const Expr *RetExpr = cast<ReturnStmt>(S)->getRetValue();
4547 FullExpressionRAII Scope(Info);
4548 if (RetExpr &&
4549 !(Result.Slot
4550 ? EvaluateInPlace(Result.Value, Info, *Result.Slot, RetExpr)
4551 : Evaluate(Result.Value, Info, RetExpr)))
4552 return ESR_Failed;
4553 return Scope.destroy() ? ESR_Returned : ESR_Failed;
4554 }
4555
4556 case Stmt::CompoundStmtClass: {
4557 BlockScopeRAII Scope(Info);
4558
4559 const CompoundStmt *CS = cast<CompoundStmt>(S);
4560 for (const auto *BI : CS->body()) {
4561 EvalStmtResult ESR = EvaluateStmt(Result, Info, BI, Case);
4562 if (ESR == ESR_Succeeded)
4563 Case = nullptr;
4564 else if (ESR != ESR_CaseNotFound) {
4565 if (ESR != ESR_Failed && !Scope.destroy())
4566 return ESR_Failed;
4567 return ESR;
4568 }
4569 }
4570 if (Case)
4571 return ESR_CaseNotFound;
4572 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
4573 }
4574
4575 case Stmt::IfStmtClass: {
4576 const IfStmt *IS = cast<IfStmt>(S);
4577
4578 // Evaluate the condition, as either a var decl or as an expression.
4579 BlockScopeRAII Scope(Info);
4580 if (const Stmt *Init = IS->getInit()) {
4581 EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
4582 if (ESR != ESR_Succeeded) {
4583 if (ESR != ESR_Failed && !Scope.destroy())
4584 return ESR_Failed;
4585 return ESR;
4586 }
4587 }
4588 bool Cond;
4589 if (!EvaluateCond(Info, IS->getConditionVariable(), IS->getCond(), Cond))
4590 return ESR_Failed;
4591
4592 if (const Stmt *SubStmt = Cond ? IS->getThen() : IS->getElse()) {
4593 EvalStmtResult ESR = EvaluateStmt(Result, Info, SubStmt);
4594 if (ESR != ESR_Succeeded) {
4595 if (ESR != ESR_Failed && !Scope.destroy())
4596 return ESR_Failed;
4597 return ESR;
4598 }
4599 }
4600 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
4601 }
4602
4603 case Stmt::WhileStmtClass: {
4604 const WhileStmt *WS = cast<WhileStmt>(S);
4605 while (true) {
4606 BlockScopeRAII Scope(Info);
4607 bool Continue;
4608 if (!EvaluateCond(Info, WS->getConditionVariable(), WS->getCond(),
4609 Continue))
4610 return ESR_Failed;
4611 if (!Continue)
4612 break;
4613
4614 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, WS->getBody());
4615 if (ESR != ESR_Continue) {
4616 if (ESR != ESR_Failed && !Scope.destroy())
4617 return ESR_Failed;
4618 return ESR;
4619 }
4620 if (!Scope.destroy())
4621 return ESR_Failed;
4622 }
4623 return ESR_Succeeded;
4624 }
4625
4626 case Stmt::DoStmtClass: {
4627 const DoStmt *DS = cast<DoStmt>(S);
4628 bool Continue;
4629 do {
4630 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, DS->getBody(), Case);
4631 if (ESR != ESR_Continue)
4632 return ESR;
4633 Case = nullptr;
4634
4635 FullExpressionRAII CondScope(Info);
4636 if (!EvaluateAsBooleanCondition(DS->getCond(), Continue, Info) ||
4637 !CondScope.destroy())
4638 return ESR_Failed;
4639 } while (Continue);
4640 return ESR_Succeeded;
4641 }
4642
4643 case Stmt::ForStmtClass: {
4644 const ForStmt *FS = cast<ForStmt>(S);
4645 BlockScopeRAII ForScope(Info);
4646 if (FS->getInit()) {
4647 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
4648 if (ESR != ESR_Succeeded) {
4649 if (ESR != ESR_Failed && !ForScope.destroy())
4650 return ESR_Failed;
4651 return ESR;
4652 }
4653 }
4654 while (true) {
4655 BlockScopeRAII IterScope(Info);
4656 bool Continue = true;
4657 if (FS->getCond() && !EvaluateCond(Info, FS->getConditionVariable(),
4658 FS->getCond(), Continue))
4659 return ESR_Failed;
4660 if (!Continue)
4661 break;
4662
4663 EvalStmtResult ESR = EvaluateLoopBody(Result, Info, FS->getBody());
4664 if (ESR != ESR_Continue) {
4665 if (ESR != ESR_Failed && (!IterScope.destroy() || !ForScope.destroy()))
4666 return ESR_Failed;
4667 return ESR;
4668 }
4669
4670 if (FS->getInc()) {
4671 FullExpressionRAII IncScope(Info);
4672 if (!EvaluateIgnoredValue(Info, FS->getInc()) || !IncScope.destroy())
4673 return ESR_Failed;
4674 }
4675
4676 if (!IterScope.destroy())
4677 return ESR_Failed;
4678 }
4679 return ForScope.destroy() ? ESR_Succeeded : ESR_Failed;
4680 }
4681
4682 case Stmt::CXXForRangeStmtClass: {
4683 const CXXForRangeStmt *FS = cast<CXXForRangeStmt>(S);
4684 BlockScopeRAII Scope(Info);
4685
4686 // Evaluate the init-statement if present.
4687 if (FS->getInit()) {
4688 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
4689 if (ESR != ESR_Succeeded) {
4690 if (ESR != ESR_Failed && !Scope.destroy())
4691 return ESR_Failed;
4692 return ESR;
4693 }
4694 }
4695
4696 // Initialize the __range variable.
4697 EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getRangeStmt());
4698 if (ESR != ESR_Succeeded) {
4699 if (ESR != ESR_Failed && !Scope.destroy())
4700 return ESR_Failed;
4701 return ESR;
4702 }
4703
4704 // Create the __begin and __end iterators.
4705 ESR = EvaluateStmt(Result, Info, FS->getBeginStmt());
4706 if (ESR != ESR_Succeeded) {
4707 if (ESR != ESR_Failed && !Scope.destroy())
4708 return ESR_Failed;
4709 return ESR;
4710 }
4711 ESR = EvaluateStmt(Result, Info, FS->getEndStmt());
4712 if (ESR != ESR_Succeeded) {
4713 if (ESR != ESR_Failed && !Scope.destroy())
4714 return ESR_Failed;
4715 return ESR;
4716 }
4717
4718 while (true) {
4719 // Condition: __begin != __end.
4720 {
4721 bool Continue = true;
4722 FullExpressionRAII CondExpr(Info);
4723 if (!EvaluateAsBooleanCondition(FS->getCond(), Continue, Info))
4724 return ESR_Failed;
4725 if (!Continue)
4726 break;
4727 }
4728
4729 // User's variable declaration, initialized by *__begin.
4730 BlockScopeRAII InnerScope(Info);
4731 ESR = EvaluateStmt(Result, Info, FS->getLoopVarStmt());
4732 if (ESR != ESR_Succeeded) {
4733 if (ESR != ESR_Failed && (!InnerScope.destroy() || !Scope.destroy()))
4734 return ESR_Failed;
4735 return ESR;
4736 }
4737
4738 // Loop body.
4739 ESR = EvaluateLoopBody(Result, Info, FS->getBody());
4740 if (ESR != ESR_Continue) {
4741 if (ESR != ESR_Failed && (!InnerScope.destroy() || !Scope.destroy()))
4742 return ESR_Failed;
4743 return ESR;
4744 }
4745
4746 // Increment: ++__begin
4747 if (!EvaluateIgnoredValue(Info, FS->getInc()))
4748 return ESR_Failed;
4749
4750 if (!InnerScope.destroy())
4751 return ESR_Failed;
4752 }
4753
4754 return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
4755 }
4756
4757 case Stmt::SwitchStmtClass:
4758 return EvaluateSwitch(Result, Info, cast<SwitchStmt>(S));
4759
4760 case Stmt::ContinueStmtClass:
4761 return ESR_Continue;
4762
4763 case Stmt::BreakStmtClass:
4764 return ESR_Break;
4765
4766 case Stmt::LabelStmtClass:
4767 return EvaluateStmt(Result, Info, cast<LabelStmt>(S)->getSubStmt(), Case);
4768
4769 case Stmt::AttributedStmtClass:
4770 // As a general principle, C++11 attributes can be ignored without
4771 // any semantic impact.
4772 return EvaluateStmt(Result, Info, cast<AttributedStmt>(S)->getSubStmt(),
4773 Case);
4774
4775 case Stmt::CaseStmtClass:
4776 case Stmt::DefaultStmtClass:
4777 return EvaluateStmt(Result, Info, cast<SwitchCase>(S)->getSubStmt(), Case);
4778 case Stmt::CXXTryStmtClass:
4779 // Evaluate try blocks by evaluating all sub statements.
4780 return EvaluateStmt(Result, Info, cast<CXXTryStmt>(S)->getTryBlock(), Case);
4781 }
4782}
4783
4784/// CheckTrivialDefaultConstructor - Check whether a constructor is a trivial
4785/// default constructor. If so, we'll fold it whether or not it's marked as
4786/// constexpr. If it is marked as constexpr, we will never implicitly define it,
4787/// so we need special handling.
4788static bool CheckTrivialDefaultConstructor(EvalInfo &Info, SourceLocation Loc,
4789 const CXXConstructorDecl *CD,
4790 bool IsValueInitialization) {
4791 if (!CD->isTrivial() || !CD->isDefaultConstructor())
4792 return false;
4793
4794 // Value-initialization does not call a trivial default constructor, so such a
4795 // call is a core constant expression whether or not the constructor is
4796 // constexpr.
4797 if (!CD->isConstexpr() && !IsValueInitialization) {
4798 if (Info.getLangOpts().CPlusPlus11) {
4799 // FIXME: If DiagDecl is an implicitly-declared special member function,
4800 // we should be much more explicit about why it's not constexpr.
4801 Info.CCEDiag(Loc, diag::note_constexpr_invalid_function, 1)
4802 << /*IsConstexpr*/0 << /*IsConstructor*/1 << CD;
4803 Info.Note(CD->getLocation(), diag::note_declared_at);
4804 } else {
4805 Info.CCEDiag(Loc, diag::note_invalid_subexpr_in_const_expr);
4806 }
4807 }
4808 return true;
4809}
4810
4811/// CheckConstexprFunction - Check that a function can be called in a constant
4812/// expression.
4813static bool CheckConstexprFunction(EvalInfo &Info, SourceLocation CallLoc,
4814 const FunctionDecl *Declaration,
4815 const FunctionDecl *Definition,
4816 const Stmt *Body) {
4817 // Potential constant expressions can contain calls to declared, but not yet
4818 // defined, constexpr functions.
4819 if (Info.checkingPotentialConstantExpression() && !Definition &&
4820 Declaration->isConstexpr())
4821 return false;
4822
4823 // Bail out if the function declaration itself is invalid. We will
4824 // have produced a relevant diagnostic while parsing it, so just
4825 // note the problematic sub-expression.
4826 if (Declaration->isInvalidDecl()) {
4827 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
4828 return false;
4829 }
4830
4831 // DR1872: An instantiated virtual constexpr function can't be called in a
4832 // constant expression (prior to C++20). We can still constant-fold such a
4833 // call.
4834 if (!Info.Ctx.getLangOpts().CPlusPlus2a && isa<CXXMethodDecl>(Declaration) &&
4835 cast<CXXMethodDecl>(Declaration)->isVirtual())
4836 Info.CCEDiag(CallLoc, diag::note_constexpr_virtual_call);
4837
4838 if (Definition && Definition->isInvalidDecl()) {
4839 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
4840 return false;
4841 }
4842
4843 // Can we evaluate this function call?
4844 if (Definition && Definition->isConstexpr() && Body)
4845 return true;
4846
4847 if (Info.getLangOpts().CPlusPlus11) {
4848 const FunctionDecl *DiagDecl = Definition ? Definition : Declaration;
4849
4850 // If this function is not constexpr because it is an inherited
4851 // non-constexpr constructor, diagnose that directly.
4852 auto *CD = dyn_cast<CXXConstructorDecl>(DiagDecl);
4853 if (CD && CD->isInheritingConstructor()) {
4854 auto *Inherited = CD->getInheritedConstructor().getConstructor();
4855 if (!Inherited->isConstexpr())
4856 DiagDecl = CD = Inherited;
4857 }
4858
4859 // FIXME: If DiagDecl is an implicitly-declared special member function
4860 // or an inheriting constructor, we should be much more explicit about why
4861 // it's not constexpr.
4862 if (CD && CD->isInheritingConstructor())
4863 Info.FFDiag(CallLoc, diag::note_constexpr_invalid_inhctor, 1)
4864 << CD->getInheritedConstructor().getConstructor()->getParent();
4865 else
4866 Info.FFDiag(CallLoc, diag::note_constexpr_invalid_function, 1)
4867 << DiagDecl->isConstexpr() << (bool)CD << DiagDecl;
4868 Info.Note(DiagDecl->getLocation(), diag::note_declared_at);
4869 } else {
4870 Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
4871 }
4872 return false;
4873}
4874
4875namespace {
4876struct CheckDynamicTypeHandler {
4877 AccessKinds AccessKind;
4878 typedef bool result_type;
4879 bool failed() { return false; }
4880 bool found(APValue &Subobj, QualType SubobjType) { return true; }
4881 bool found(APSInt &Value, QualType SubobjType) { return true; }
4882 bool found(APFloat &Value, QualType SubobjType) { return true; }
4883};
4884} // end anonymous namespace
4885
4886/// Check that we can access the notional vptr of an object / determine its
4887/// dynamic type.
4888static bool checkDynamicType(EvalInfo &Info, const Expr *E, const LValue &This,
4889 AccessKinds AK, bool Polymorphic) {
4890 if (This.Designator.Invalid)
4891 return false;
4892
4893 CompleteObject Obj = findCompleteObject(Info, E, AK, This, QualType());
4894
4895 if (!Obj)
4896 return false;
4897
4898 if (!Obj.Value) {
4899 // The object is not usable in constant expressions, so we can't inspect
4900 // its value to see if it's in-lifetime or what the active union members
4901 // are. We can still check for a one-past-the-end lvalue.
4902 if (This.Designator.isOnePastTheEnd() ||
4903 This.Designator.isMostDerivedAnUnsizedArray()) {
4904 Info.FFDiag(E, This.Designator.isOnePastTheEnd()
4905 ? diag::note_constexpr_access_past_end
4906 : diag::note_constexpr_access_unsized_array)
4907 << AK;
4908 return false;
4909 } else if (Polymorphic) {
4910 // Conservatively refuse to perform a polymorphic operation if we would
4911 // not be able to read a notional 'vptr' value.
4912 APValue Val;
4913 This.moveInto(Val);
4914 QualType StarThisType =
4915 Info.Ctx.getLValueReferenceType(This.Designator.getType(Info.Ctx));
4916 Info.FFDiag(E, diag::note_constexpr_polymorphic_unknown_dynamic_type)
4917 << AK << Val.getAsString(Info.Ctx, StarThisType);
4918 return false;
4919 }
4920 return true;
4921 }
4922
4923 CheckDynamicTypeHandler Handler{AK};
4924 return Obj && findSubobject(Info, E, Obj, This.Designator, Handler);
4925}
4926
4927/// Check that the pointee of the 'this' pointer in a member function call is
4928/// either within its lifetime or in its period of construction or destruction.
4929static bool
4930checkNonVirtualMemberCallThisPointer(EvalInfo &Info, const Expr *E,
4931 const LValue &This,
4932 const CXXMethodDecl *NamedMember) {
4933 return checkDynamicType(
4934 Info, E, This,
4935 isa<CXXDestructorDecl>(NamedMember) ? AK_Destroy : AK_MemberCall, false);
4936}
4937
4938struct DynamicType {
4939 /// The dynamic class type of the object.
4940 const CXXRecordDecl *Type;
4941 /// The corresponding path length in the lvalue.
4942 unsigned PathLength;
4943};
4944
4945static const CXXRecordDecl *getBaseClassType(SubobjectDesignator &Designator,
4946 unsigned PathLength) {
4947 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4948, __PRETTY_FUNCTION__))
4948 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 4948, __PRETTY_FUNCTION__))
;
4949 return (PathLength == Designator.MostDerivedPathLength)
4950 ? Designator.MostDerivedType->getAsCXXRecordDecl()
4951 : getAsBaseClass(Designator.Entries[PathLength - 1]);
4952}
4953
4954/// Determine the dynamic type of an object.
4955static Optional<DynamicType> ComputeDynamicType(EvalInfo &Info, const Expr *E,
4956 LValue &This, AccessKinds AK) {
4957 // If we don't have an lvalue denoting an object of class type, there is no
4958 // meaningful dynamic type. (We consider objects of non-class type to have no
4959 // dynamic type.)
4960 if (!checkDynamicType(Info, E, This, AK, true))
4961 return None;
4962
4963 // Refuse to compute a dynamic type in the presence of virtual bases. This
4964 // shouldn't happen other than in constant-folding situations, since literal
4965 // types can't have virtual bases.
4966 //
4967 // Note that consumers of DynamicType assume that the type has no virtual
4968 // bases, and will need modifications if this restriction is relaxed.
4969 const CXXRecordDecl *Class =
4970 This.Designator.MostDerivedType->getAsCXXRecordDecl();
4971 if (!Class || Class->getNumVBases()) {
4972 Info.FFDiag(E);
4973 return None;
4974 }
4975
4976 // FIXME: For very deep class hierarchies, it might be beneficial to use a
4977 // binary search here instead. But the overwhelmingly common case is that
4978 // we're not in the middle of a constructor, so it probably doesn't matter
4979 // in practice.
4980 ArrayRef<APValue::LValuePathEntry> Path = This.Designator.Entries;
4981 for (unsigned PathLength = This.Designator.MostDerivedPathLength;
4982 PathLength <= Path.size(); ++PathLength) {
4983 switch (Info.isEvaluatingCtorDtor(This.getLValueBase(),
4984 Path.slice(0, PathLength))) {
4985 case ConstructionPhase::Bases:
4986 case ConstructionPhase::DestroyingBases:
4987 // We're constructing or destroying a base class. This is not the dynamic
4988 // type.
4989 break;
4990
4991 case ConstructionPhase::None:
4992 case ConstructionPhase::AfterBases:
4993 case ConstructionPhase::Destroying:
4994 // We've finished constructing the base classes and not yet started
4995 // destroying them again, so this is the dynamic type.
4996 return DynamicType{getBaseClassType(This.Designator, PathLength),
4997 PathLength};
4998 }
4999 }
5000
5001 // CWG issue 1517: we're constructing a base class of the object described by
5002 // 'This', so that object has not yet begun its period of construction and
5003 // any polymorphic operation on it results in undefined behavior.
5004 Info.FFDiag(E);
5005 return None;
5006}
5007
5008/// Perform virtual dispatch.
5009static const CXXMethodDecl *HandleVirtualDispatch(
5010 EvalInfo &Info, const Expr *E, LValue &This, const CXXMethodDecl *Found,
5011 llvm::SmallVectorImpl<QualType> &CovariantAdjustmentPath) {
5012 Optional<DynamicType> DynType = ComputeDynamicType(
5013 Info, E, This,
5014 isa<CXXDestructorDecl>(Found) ? AK_Destroy : AK_MemberCall);
5015 if (!DynType)
5016 return nullptr;
5017
5018 // Find the final overrider. It must be declared in one of the classes on the
5019 // path from the dynamic type to the static type.
5020 // FIXME: If we ever allow literal types to have virtual base classes, that
5021 // won't be true.
5022 const CXXMethodDecl *Callee = Found;
5023 unsigned PathLength = DynType->PathLength;
5024 for (/**/; PathLength <= This.Designator.Entries.size(); ++PathLength) {
5025 const CXXRecordDecl *Class = getBaseClassType(This.Designator, PathLength);
5026 const CXXMethodDecl *Overrider =
5027 Found->getCorrespondingMethodDeclaredInClass(Class, false);
5028 if (Overrider) {
5029 Callee = Overrider;
5030 break;
5031 }
5032 }
5033
5034 // C++2a [class.abstract]p6:
5035 // the effect of making a virtual call to a pure virtual function [...] is
5036 // undefined
5037 if (Callee->isPure()) {
5038 Info.FFDiag(E, diag::note_constexpr_pure_virtual_call, 1) << Callee;
5039 Info.Note(Callee->getLocation(), diag::note_declared_at);
5040 return nullptr;
5041 }
5042
5043 // If necessary, walk the rest of the path to determine the sequence of
5044 // covariant adjustment steps to apply.
5045 if (!Info.Ctx.hasSameUnqualifiedType(Callee->getReturnType(),
5046 Found->getReturnType())) {
5047 CovariantAdjustmentPath.push_back(Callee->getReturnType());
5048 for (unsigned CovariantPathLength = PathLength + 1;
5049 CovariantPathLength != This.Designator.Entries.size();
5050 ++CovariantPathLength) {
5051 const CXXRecordDecl *NextClass =
5052 getBaseClassType(This.Designator, CovariantPathLength);
5053 const CXXMethodDecl *Next =
5054 Found->getCorrespondingMethodDeclaredInClass(NextClass, false);
5055 if (Next && !Info.Ctx.hasSameUnqualifiedType(
5056 Next->getReturnType(), CovariantAdjustmentPath.back()))
5057 CovariantAdjustmentPath.push_back(Next->getReturnType());
5058 }
5059 if (!Info.Ctx.hasSameUnqualifiedType(Found->getReturnType(),
5060 CovariantAdjustmentPath.back()))
5061 CovariantAdjustmentPath.push_back(Found->getReturnType());
5062 }
5063
5064 // Perform 'this' adjustment.
5065 if (!CastToDerivedClass(Info, E, This, Callee->getParent(), PathLength))
5066 return nullptr;
5067
5068 return Callee;
5069}
5070
5071/// Perform the adjustment from a value returned by a virtual function to
5072/// a value of the statically expected type, which may be a pointer or
5073/// reference to a base class of the returned type.
5074static bool HandleCovariantReturnAdjustment(EvalInfo &Info, const Expr *E,
5075 APValue &Result,
5076 ArrayRef<QualType> Path) {
5077 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5078, __PRETTY_FUNCTION__))
5078 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5078, __PRETTY_FUNCTION__))
;
5079 if (Result.isNullPointer())
5080 return true;
5081
5082 LValue LVal;
5083 LVal.setFrom(Info.Ctx, Result);
5084
5085 const CXXRecordDecl *OldClass = Path[0]->getPointeeCXXRecordDecl();
5086 for (unsigned I = 1; I != Path.size(); ++I) {
5087 const CXXRecordDecl *NewClass = Path[I]->getPointeeCXXRecordDecl();
5088 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5088, __PRETTY_FUNCTION__))
;
5089 if (OldClass != NewClass &&
5090 !CastToBaseClass(Info, E, LVal, OldClass, NewClass))
5091 return false;
5092 OldClass = NewClass;
5093 }
5094
5095 LVal.moveInto(Result);
5096 return true;
5097}
5098
5099/// Determine whether \p Base, which is known to be a direct base class of
5100/// \p Derived, is a public base class.
5101static bool isBaseClassPublic(const CXXRecordDecl *Derived,
5102 const CXXRecordDecl *Base) {
5103 for (const CXXBaseSpecifier &BaseSpec : Derived->bases()) {
5104 auto *BaseClass = BaseSpec.getType()->getAsCXXRecordDecl();
5105 if (BaseClass && declaresSameEntity(BaseClass, Base))
5106 return BaseSpec.getAccessSpecifier() == AS_public;
5107 }
5108 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5108)
;
5109}
5110
5111/// Apply the given dynamic cast operation on the provided lvalue.
5112///
5113/// This implements the hard case of dynamic_cast, requiring a "runtime check"
5114/// to find a suitable target subobject.
5115static bool HandleDynamicCast(EvalInfo &Info, const ExplicitCastExpr *E,
5116 LValue &Ptr) {
5117 // We can't do anything with a non-symbolic pointer value.
5118 SubobjectDesignator &D = Ptr.Designator;
5119 if (D.Invalid)
5120 return false;
5121
5122 // C++ [expr.dynamic.cast]p6:
5123 // If v is a null pointer value, the result is a null pointer value.
5124 if (Ptr.isNullPointer() && !E->isGLValue())
5125 return true;
5126
5127 // For all the other cases, we need the pointer to point to an object within
5128 // its lifetime / period of construction / destruction, and we need to know
5129 // its dynamic type.
5130 Optional<DynamicType> DynType =
5131 ComputeDynamicType(Info, E, Ptr, AK_DynamicCast);
5132 if (!DynType)
5133 return false;
5134
5135 // C++ [expr.dynamic.cast]p7:
5136 // If T is "pointer to cv void", then the result is a pointer to the most
5137 // derived object
5138 if (E->getType()->isVoidPointerType())
5139 return CastToDerivedClass(Info, E, Ptr, DynType->Type, DynType->PathLength);
5140
5141 const CXXRecordDecl *C = E->getTypeAsWritten()->getPointeeCXXRecordDecl();
5142 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5142, __PRETTY_FUNCTION__))
;
5143 CanQualType CQT = Info.Ctx.getCanonicalType(Info.Ctx.getRecordType(C));
5144
5145 auto RuntimeCheckFailed = [&] (CXXBasePaths *Paths) {
5146 // C++ [expr.dynamic.cast]p9:
5147 if (!E->isGLValue()) {
5148 // The value of a failed cast to pointer type is the null pointer value
5149 // of the required result type.
5150 auto TargetVal = Info.Ctx.getTargetNullPointerValue(E->getType());
5151 Ptr.setNull(E->getType(), TargetVal);
5152 return true;
5153 }
5154
5155 // A failed cast to reference type throws [...] std::bad_cast.
5156 unsigned DiagKind;
5157 if (!Paths && (declaresSameEntity(DynType->Type, C) ||
5158 DynType->Type->isDerivedFrom(C)))
5159 DiagKind = 0;
5160 else if (!Paths || Paths->begin() == Paths->end())
5161 DiagKind = 1;
5162 else if (Paths->isAmbiguous(CQT))
5163 DiagKind = 2;
5164 else {
5165 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5165, __PRETTY_FUNCTION__))
;
5166 DiagKind = 3;
5167 }
5168 Info.FFDiag(E, diag::note_constexpr_dynamic_cast_to_reference_failed)
5169 << DiagKind << Ptr.Designator.getType(Info.Ctx)
5170 << Info.Ctx.getRecordType(DynType->Type)
5171 << E->getType().getUnqualifiedType();
5172 return false;
5173 };
5174
5175 // Runtime check, phase 1:
5176 // Walk from the base subobject towards the derived object looking for the
5177 // target type.
5178 for (int PathLength = Ptr.Designator.Entries.size();
5179 PathLength >= (int)DynType->PathLength; --PathLength) {
5180 const CXXRecordDecl *Class = getBaseClassType(Ptr.Designator, PathLength);
5181 if (declaresSameEntity(Class, C))
5182 return CastToDerivedClass(Info, E, Ptr, Class, PathLength);
5183 // We can only walk across public inheritance edges.
5184 if (PathLength > (int)DynType->PathLength &&
5185 !isBaseClassPublic(getBaseClassType(Ptr.Designator, PathLength - 1),
5186 Class))
5187 return RuntimeCheckFailed(nullptr);
5188 }
5189
5190 // Runtime check, phase 2:
5191 // Search the dynamic type for an unambiguous public base of type C.
5192 CXXBasePaths Paths(/*FindAmbiguities=*/true,
5193 /*RecordPaths=*/true, /*DetectVirtual=*/false);
5194 if (DynType->Type->isDerivedFrom(C, Paths) && !Paths.isAmbiguous(CQT) &&
5195 Paths.front().Access == AS_public) {
5196 // Downcast to the dynamic type...
5197 if (!CastToDerivedClass(Info, E, Ptr, DynType->Type, DynType->PathLength))
5198 return false;
5199 // ... then upcast to the chosen base class subobject.
5200 for (CXXBasePathElement &Elem : Paths.front())
5201 if (!HandleLValueBase(Info, E, Ptr, Elem.Class, Elem.Base))
5202 return false;
5203 return true;
5204 }
5205
5206 // Otherwise, the runtime check fails.
5207 return RuntimeCheckFailed(&Paths);
5208}
5209
5210namespace {
5211struct StartLifetimeOfUnionMemberHandler {
5212 const FieldDecl *Field;
5213
5214 static const AccessKinds AccessKind = AK_Assign;
5215
5216 typedef bool result_type;
5217 bool failed() { return false; }
5218 bool found(APValue &Subobj, QualType SubobjType) {
5219 // We are supposed to perform no initialization but begin the lifetime of
5220 // the object. We interpret that as meaning to do what default
5221 // initialization of the object would do if all constructors involved were
5222 // trivial:
5223 // * All base, non-variant member, and array element subobjects' lifetimes
5224 // begin
5225 // * No variant members' lifetimes begin
5226 // * All scalar subobjects whose lifetimes begin have indeterminate values
5227 assert(SubobjType->isUnionType())((SubobjType->isUnionType()) ? static_cast<void> (0)
: __assert_fail ("SubobjType->isUnionType()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5227, __PRETTY_FUNCTION__))
;
5228 if (!declaresSameEntity(Subobj.getUnionField(), Field) ||
5229 !Subobj.getUnionValue().hasValue())
5230 Subobj.setUnion(Field, getDefaultInitValue(Field->getType()));
5231 return true;
5232 }
5233 bool found(APSInt &Value, QualType SubobjType) {
5234 llvm_unreachable("wrong value kind for union object")::llvm::llvm_unreachable_internal("wrong value kind for union object"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5234)
;
5235 }
5236 bool found(APFloat &Value, QualType SubobjType) {
5237 llvm_unreachable("wrong value kind for union object")::llvm::llvm_unreachable_internal("wrong value kind for union object"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5237)
;
5238 }
5239};
5240} // end anonymous namespace
5241
5242const AccessKinds StartLifetimeOfUnionMemberHandler::AccessKind;
5243
5244/// Handle a builtin simple-assignment or a call to a trivial assignment
5245/// operator whose left-hand side might involve a union member access. If it
5246/// does, implicitly start the lifetime of any accessed union elements per
5247/// C++20 [class.union]5.
5248static bool HandleUnionActiveMemberChange(EvalInfo &Info, const Expr *LHSExpr,
5249 const LValue &LHS) {
5250 if (LHS.InvalidBase || LHS.Designator.Invalid)
5251 return false;
5252
5253 llvm::SmallVector<std::pair<unsigned, const FieldDecl*>, 4> UnionPathLengths;
5254 // C++ [class.union]p5:
5255 // define the set S(E) of subexpressions of E as follows:
5256 unsigned PathLength = LHS.Designator.Entries.size();
5257 for (const Expr *E = LHSExpr; E != nullptr;) {
5258 // -- If E is of the form A.B, S(E) contains the elements of S(A)...
5259 if (auto *ME = dyn_cast<MemberExpr>(E)) {
5260 auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
5261 // Note that we can't implicitly start the lifetime of a reference,
5262 // so we don't need to proceed any further if we reach one.
5263 if (!FD || FD->getType()->isReferenceType())
5264 break;
5265
5266 // ... and also contains A.B if B names a union member
5267 if (FD->getParent()->isUnion())
5268 UnionPathLengths.push_back({PathLength - 1, FD});
5269
5270 E = ME->getBase();
5271 --PathLength;
5272 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5274, __PRETTY_FUNCTION__))
5273 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5274, __PRETTY_FUNCTION__))
5274 .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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5274, __PRETTY_FUNCTION__))
;
5275
5276 // -- If E is of the form A[B] and is interpreted as a built-in array
5277 // subscripting operator, S(E) is [S(the array operand, if any)].
5278 } else if (auto *ASE = dyn_cast<ArraySubscriptExpr>(E)) {
5279 // Step over an ArrayToPointerDecay implicit cast.
5280 auto *Base = ASE->getBase()->IgnoreImplicit();
5281 if (!Base->getType()->isArrayType())
5282 break;
5283
5284 E = Base;
5285 --PathLength;
5286
5287 } else if (auto *ICE = dyn_cast<ImplicitCastExpr>(E)) {
5288 // Step over a derived-to-base conversion.
5289 E = ICE->getSubExpr();
5290 if (ICE->getCastKind() == CK_NoOp)
5291 continue;
5292 if (ICE->getCastKind() != CK_DerivedToBase &&
5293 ICE->getCastKind() != CK_UncheckedDerivedToBase)
5294 break;
5295 // Walk path backwards as we walk up from the base to the derived class.
5296 for (const CXXBaseSpecifier *Elt : llvm::reverse(ICE->path())) {
5297 --PathLength;
5298 (void)Elt;
5299 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5301, __PRETTY_FUNCTION__))
5300 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5301, __PRETTY_FUNCTION__))
5301 .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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5301, __PRETTY_FUNCTION__))
;
5302 }
5303
5304 // -- Otherwise, S(E) is empty.
5305 } else {
5306 break;
5307 }
5308 }
5309
5310 // Common case: no unions' lifetimes are started.
5311 if (UnionPathLengths.empty())
5312 return true;
5313
5314 // if modification of X [would access an inactive union member], an object
5315 // of the type of X is implicitly created
5316 CompleteObject Obj =
5317 findCompleteObject(Info, LHSExpr, AK_Assign, LHS, LHSExpr->getType());
5318 if (!Obj)
5319 return false;
5320 for (std::pair<unsigned, const FieldDecl *> LengthAndField :
5321 llvm::reverse(UnionPathLengths)) {
5322 // Form a designator for the union object.
5323 SubobjectDesignator D = LHS.Designator;
5324 D.truncate(Info.Ctx, LHS.Base, LengthAndField.first);
5325
5326 StartLifetimeOfUnionMemberHandler StartLifetime{LengthAndField.second};
5327 if (!findSubobject(Info, LHSExpr, Obj, D, StartLifetime))
5328 return false;
5329 }
5330
5331 return true;
5332}
5333
5334/// Determine if a class has any fields that might need to be copied by a
5335/// trivial copy or move operation.
5336static bool hasFields(const CXXRecordDecl *RD) {
5337 if (!RD || RD->isEmpty())
5338 return false;
5339 for (auto *FD : RD->fields()) {
5340 if (FD->isUnnamedBitfield())
5341 continue;
5342 return true;
5343 }
5344 for (auto &Base : RD->bases())
5345 if (hasFields(Base.getType()->getAsCXXRecordDecl()))
5346 return true;
5347 return false;
5348}
5349
5350namespace {
5351typedef SmallVector<APValue, 8> ArgVector;
5352}
5353
5354/// EvaluateArgs - Evaluate the arguments to a function call.
5355static bool EvaluateArgs(ArrayRef<const Expr *> Args, ArgVector &ArgValues,
5356 EvalInfo &Info, const FunctionDecl *Callee) {
5357 bool Success = true;
5358 llvm::SmallBitVector ForbiddenNullArgs;
5359 if (Callee->hasAttr<NonNullAttr>()) {
5360 ForbiddenNullArgs.resize(Args.size());
5361 for (const auto *Attr : Callee->specific_attrs<NonNullAttr>()) {
5362 if (!Attr->args_size()) {
5363 ForbiddenNullArgs.set();
5364 break;
5365 } else
5366 for (auto Idx : Attr->args()) {
5367 unsigned ASTIdx = Idx.getASTIndex();
5368 if (ASTIdx >= Args.size())
5369 continue;
5370 ForbiddenNullArgs[ASTIdx] = 1;
5371 }
5372 }
5373 }
5374 for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
5375 I != E; ++I) {
5376 if (!Evaluate(ArgValues[I - Args.begin()], Info, *I)) {
5377 // If we're checking for a potential constant expression, evaluate all
5378 // initializers even if some of them fail.
5379 if (!Info.noteFailure())
5380 return false;
5381 Success = false;
5382 } else if (!ForbiddenNullArgs.empty() &&
5383 ForbiddenNullArgs[I - Args.begin()] &&
5384 ArgValues[I - Args.begin()].isNullPointer()) {
5385 Info.CCEDiag(*I, diag::note_non_null_attribute_failed);
5386 if (!Info.noteFailure())
5387 return false;
5388 Success = false;
5389 }
5390 }
5391 return Success;
5392}
5393
5394/// Evaluate a function call.
5395static bool HandleFunctionCall(SourceLocation CallLoc,
5396 const FunctionDecl *Callee, const LValue *This,
5397 ArrayRef<const Expr*> Args, const Stmt *Body,
5398 EvalInfo &Info, APValue &Result,
5399 const LValue *ResultSlot) {
5400 ArgVector ArgValues(Args.size());
5401 if (!EvaluateArgs(Args, ArgValues, Info, Callee))
5402 return false;
5403
5404 if (!Info.CheckCallLimit(CallLoc))
5405 return false;
5406
5407 CallStackFrame Frame(Info, CallLoc, Callee, This, ArgValues.data());
5408
5409 // For a trivial copy or move assignment, perform an APValue copy. This is
5410 // essential for unions, where the operations performed by the assignment
5411 // operator cannot be represented as statements.
5412 //
5413 // Skip this for non-union classes with no fields; in that case, the defaulted
5414 // copy/move does not actually read the object.
5415 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Callee);
5416 if (MD && MD->isDefaulted() &&
5417 (MD->getParent()->isUnion() ||
5418 (MD->isTrivial() && hasFields(MD->getParent())))) {
5419 assert(This &&((This && (MD->isCopyAssignmentOperator() || MD->
isMoveAssignmentOperator())) ? static_cast<void> (0) : __assert_fail
("This && (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5420, __PRETTY_FUNCTION__))
5420 (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()))((This && (MD->isCopyAssignmentOperator() || MD->
isMoveAssignmentOperator())) ? static_cast<void> (0) : __assert_fail
("This && (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5420, __PRETTY_FUNCTION__))
;
5421 LValue RHS;
5422 RHS.setFrom(Info.Ctx, ArgValues[0]);
5423 APValue RHSValue;
5424 if (!handleLValueToRValueConversion(Info, Args[0], Args[0]->getType(), RHS,
5425 RHSValue, MD->getParent()->isUnion()))
5426 return false;
5427 if (Info.getLangOpts().CPlusPlus2a && MD->isTrivial() &&
5428 !HandleUnionActiveMemberChange(Info, Args[0], *This))
5429 return false;
5430 if (!handleAssignment(Info, Args[0], *This, MD->getThisType(),
5431 RHSValue))
5432 return false;
5433 This->moveInto(Result);
5434 return true;
5435 } else if (MD && isLambdaCallOperator(MD)) {
5436 // We're in a lambda; determine the lambda capture field maps unless we're
5437 // just constexpr checking a lambda's call operator. constexpr checking is
5438 // done before the captures have been added to the closure object (unless
5439 // we're inferring constexpr-ness), so we don't have access to them in this
5440 // case. But since we don't need the captures to constexpr check, we can
5441 // just ignore them.
5442 if (!Info.checkingPotentialConstantExpression())
5443 MD->getParent()->getCaptureFields(Frame.LambdaCaptureFields,
5444 Frame.LambdaThisCaptureField);
5445 }
5446
5447 StmtResult Ret = {Result, ResultSlot};
5448 EvalStmtResult ESR = EvaluateStmt(Ret, Info, Body);
5449 if (ESR == ESR_Succeeded) {
5450 if (Callee->getReturnType()->isVoidType())
5451 return true;
5452 Info.FFDiag(Callee->getEndLoc(), diag::note_constexpr_no_return);
5453 }
5454 return ESR == ESR_Returned;
5455}
5456
5457/// Evaluate a constructor call.
5458static bool HandleConstructorCall(const Expr *E, const LValue &This,
5459 APValue *ArgValues,
5460 const CXXConstructorDecl *Definition,
5461 EvalInfo &Info, APValue &Result) {
5462 SourceLocation CallLoc = E->getExprLoc();
5463 if (!Info.CheckCallLimit(CallLoc))
5464 return false;
5465
5466 const CXXRecordDecl *RD = Definition->getParent();
5467 if (RD->getNumVBases()) {
5468 Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD;
5469 return false;
5470 }
5471
5472 EvalInfo::EvaluatingConstructorRAII EvalObj(
5473 Info,
5474 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries},
5475 RD->getNumBases());
5476 CallStackFrame Frame(Info, CallLoc, Definition, &This, ArgValues);
5477
5478 // FIXME: Creating an APValue just to hold a nonexistent return value is
5479 // wasteful.
5480 APValue RetVal;
5481 StmtResult Ret = {RetVal, nullptr};
5482
5483 // If it's a delegating constructor, delegate.
5484 if (Definition->isDelegatingConstructor()) {
5485 CXXConstructorDecl::init_const_iterator I = Definition->init_begin();
5486 {
5487 FullExpressionRAII InitScope(Info);
5488 if (!EvaluateInPlace(Result, Info, This, (*I)->getInit()) ||
5489 !InitScope.destroy())
5490 return false;
5491 }
5492 return EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed;
5493 }
5494
5495 // For a trivial copy or move constructor, perform an APValue copy. This is
5496 // essential for unions (or classes with anonymous union members), where the
5497 // operations performed by the constructor cannot be represented by
5498 // ctor-initializers.
5499 //
5500 // Skip this for empty non-union classes; we should not perform an
5501 // lvalue-to-rvalue conversion on them because their copy constructor does not
5502 // actually read them.
5503 if (Definition->isDefaulted() && Definition->isCopyOrMoveConstructor() &&
5504 (Definition->getParent()->isUnion() ||
5505 (Definition->isTrivial() && hasFields(Definition->getParent())))) {
5506 LValue RHS;
5507 RHS.setFrom(Info.Ctx, ArgValues[0]);
5508 return handleLValueToRValueConversion(
5509 Info, E, Definition->getParamDecl(0)->getType().getNonReferenceType(),
5510 RHS, Result, Definition->getParent()->isUnion());
5511 }
5512
5513 // Reserve space for the struct members.
5514 if (!RD->isUnion() && !Result.hasValue())
5515 Result = APValue(APValue::UninitStruct(), RD->getNumBases(),
5516 std::distance(RD->field_begin(), RD->field_end()));
5517
5518 if (RD->isInvalidDecl()) return false;
5519 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
5520
5521 // A scope for temporaries lifetime-extended by reference members.
5522 BlockScopeRAII LifetimeExtendedScope(Info);
5523
5524 bool Success = true;
5525 unsigned BasesSeen = 0;
5526#ifndef NDEBUG
5527 CXXRecordDecl::base_class_const_iterator BaseIt = RD->bases_begin();
5528#endif
5529 CXXRecordDecl::field_iterator FieldIt = RD->field_begin();
5530 auto SkipToField = [&](FieldDecl *FD, bool Indirect) {
5531 // We might be initializing the same field again if this is an indirect
5532 // field initialization.
5533 if (FieldIt == RD->field_end() ||
5534 FieldIt->getFieldIndex() > FD->getFieldIndex()) {
5535 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5535, __PRETTY_FUNCTION__))
;
5536 return;
5537 }
5538
5539 // Default-initialize any fields with no explicit initializer.
5540 for (; !declaresSameEntity(*FieldIt, FD); ++FieldIt) {
5541 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5541, __PRETTY_FUNCTION__))
;
5542 if (!FieldIt->isUnnamedBitfield())
5543 Result.getStructField(FieldIt->getFieldIndex()) =
5544 getDefaultInitValue(FieldIt->getType());
5545 }
5546 ++FieldIt;
5547 };
5548 for (const auto *I : Definition->inits()) {
5549 LValue Subobject = This;
5550 LValue SubobjectParent = This;
5551 APValue *Value = &Result;
5552
5553 // Determine the subobject to initialize.
5554 FieldDecl *FD = nullptr;
5555 if (I->isBaseInitializer()) {
5556 QualType BaseType(I->getBaseClass(), 0);
5557#ifndef NDEBUG
5558 // Non-virtual base classes are initialized in the order in the class
5559 // definition. We have already checked for virtual base classes.
5560 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5560, __PRETTY_FUNCTION__))
;
5561 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5562, __PRETTY_FUNCTION__))
5562 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5562, __PRETTY_FUNCTION__))
;
5563 ++BaseIt;
5564#endif
5565 if (!HandleLValueDirectBase(Info, I->getInit(), Subobject, RD,
5566 BaseType->getAsCXXRecordDecl(), &Layout))
5567 return false;
5568 Value = &Result.getStructBase(BasesSeen++);
5569 } else if ((FD = I->getMember())) {
5570 if (!HandleLValueMember(Info, I->getInit(), Subobject, FD, &Layout))
5571 return false;
5572 if (RD->isUnion()) {
5573 Result = APValue(FD);
5574 Value = &Result.getUnionValue();
5575 } else {
5576 SkipToField(FD, false);
5577 Value = &Result.getStructField(FD->getFieldIndex());
5578 }
5579 } else if (IndirectFieldDecl *IFD = I->getIndirectMember()) {
5580 // Walk the indirect field decl's chain to find the object to initialize,
5581 // and make sure we've initialized every step along it.
5582 auto IndirectFieldChain = IFD->chain();
5583 for (auto *C : IndirectFieldChain) {
5584 FD = cast<FieldDecl>(C);
5585 CXXRecordDecl *CD = cast<CXXRecordDecl>(FD->getParent());
5586 // Switch the union field if it differs. This happens if we had
5587 // preceding zero-initialization, and we're now initializing a union
5588 // subobject other than the first.
5589 // FIXME: In this case, the values of the other subobjects are
5590 // specified, since zero-initialization sets all padding bits to zero.
5591 if (!Value->hasValue() ||
5592 (Value->isUnion() && Value->getUnionField() != FD)) {
5593 if (CD->isUnion())
5594 *Value = APValue(FD);
5595 else
5596 // FIXME: This immediately starts the lifetime of all members of an
5597 // anonymous struct. It would be preferable to strictly start member
5598 // lifetime in initialization order.
5599 *Value = getDefaultInitValue(Info.Ctx.getRecordType(CD));
5600 }
5601 // Store Subobject as its parent before updating it for the last element
5602 // in the chain.
5603 if (C == IndirectFieldChain.back())
5604 SubobjectParent = Subobject;
5605 if (!HandleLValueMember(Info, I->getInit(), Subobject, FD))
5606 return false;
5607 if (CD->isUnion())
5608 Value = &Value->getUnionValue();
5609 else {
5610 if (C == IndirectFieldChain.front() && !RD->isUnion())
5611 SkipToField(FD, true);
5612 Value = &Value->getStructField(FD->getFieldIndex());
5613 }
5614 }
5615 } else {
5616 llvm_unreachable("unknown base initializer kind")::llvm::llvm_unreachable_internal("unknown base initializer kind"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5616)
;
5617 }
5618
5619 // Need to override This for implicit field initializers as in this case
5620 // This refers to innermost anonymous struct/union containing initializer,
5621 // not to currently constructed class.
5622 const Expr *Init = I->getInit();
5623 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &SubobjectParent,
5624 isa<CXXDefaultInitExpr>(Init));
5625 FullExpressionRAII InitScope(Info);
5626 if (!EvaluateInPlace(*Value, Info, Subobject, Init) ||
5627 (FD && FD->isBitField() &&
5628 !truncateBitfieldValue(Info, Init, *Value, FD))) {
5629 // If we're checking for a potential constant expression, evaluate all
5630 // initializers even if some of them fail.
5631 if (!Info.noteFailure())
5632 return false;
5633 Success = false;
5634 }
5635
5636 // This is the point at which the dynamic type of the object becomes this
5637 // class type.
5638 if (I->isBaseInitializer() && BasesSeen == RD->getNumBases())
5639 EvalObj.finishedConstructingBases();
5640 }
5641
5642 // Default-initialize any remaining fields.
5643 if (!RD->isUnion()) {
5644 for (; FieldIt != RD->field_end(); ++FieldIt) {
5645 if (!FieldIt->isUnnamedBitfield())
5646 Result.getStructField(FieldIt->getFieldIndex()) =
5647 getDefaultInitValue(FieldIt->getType());
5648 }
5649 }
5650
5651 return Success &&
5652 EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed &&
5653 LifetimeExtendedScope.destroy();
5654}
5655
5656static bool HandleConstructorCall(const Expr *E, const LValue &This,
5657 ArrayRef<const Expr*> Args,
5658 const CXXConstructorDecl *Definition,
5659 EvalInfo &Info, APValue &Result) {
5660 ArgVector ArgValues(Args.size());
5661 if (!EvaluateArgs(Args, ArgValues, Info, Definition))
5662 return false;
5663
5664 return HandleConstructorCall(E, This, ArgValues.data(), Definition,
5665 Info, Result);
5666}
5667
5668static bool HandleDestructionImpl(EvalInfo &Info, SourceLocation CallLoc,
5669 const LValue &This, APValue &Value,
5670 QualType T) {
5671 // Objects can only be destroyed while they're within their lifetimes.
5672 // FIXME: We have no representation for whether an object of type nullptr_t
5673 // is in its lifetime; it usually doesn't matter. Perhaps we should model it
5674 // as indeterminate instead?
5675 if (Value.isAbsent() && !T->isNullPtrType()) {
5676 APValue Printable;
5677 This.moveInto(Printable);
5678 Info.FFDiag(CallLoc, diag::note_constexpr_destroy_out_of_lifetime)
5679 << Printable.getAsString(Info.Ctx, Info.Ctx.getLValueReferenceType(T));
5680 return false;
5681 }
5682
5683 // Invent an expression for location purposes.
5684 // FIXME: We shouldn't need to do this.
5685 OpaqueValueExpr LocE(CallLoc, Info.Ctx.IntTy, VK_RValue);
5686
5687 // For arrays, destroy elements right-to-left.
5688 if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(T)) {
5689 uint64_t Size = CAT->getSize().getZExtValue();
5690 QualType ElemT = CAT->getElementType();
5691
5692 LValue ElemLV = This;
5693 ElemLV.addArray(Info, &LocE, CAT);
5694 if (!HandleLValueArrayAdjustment(Info, &LocE, ElemLV, ElemT, Size))
5695 return false;
5696
5697 // Ensure that we have actual array elements available to destroy; the
5698 // destructors might mutate the value, so we can't run them on the array
5699 // filler.
5700 if (Size && Size > Value.getArrayInitializedElts())
5701 expandArray(Value, Value.getArraySize() - 1);
5702
5703 for (; Size != 0; --Size) {
5704 APValue &Elem = Value.getArrayInitializedElt(Size - 1);
5705 if (!HandleLValueArrayAdjustment(Info, &LocE, ElemLV, ElemT, -1) ||
5706 !HandleDestructionImpl(Info, CallLoc, ElemLV, Elem, ElemT))
5707 return false;
5708 }
5709
5710 // End the lifetime of this array now.
5711 Value = APValue();
5712 return true;
5713 }
5714
5715 const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
5716 if (!RD) {
5717 if (T.isDestructedType()) {
5718 Info.FFDiag(CallLoc, diag::note_constexpr_unsupported_destruction) << T;
5719 return false;
5720 }
5721
5722 Value = APValue();
5723 return true;
5724 }
5725
5726 if (RD->getNumVBases()) {
5727 Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD;
5728 return false;
5729 }
5730
5731 const CXXDestructorDecl *DD = RD->getDestructor();
5732 if (!DD && !RD->hasTrivialDestructor()) {
5733 Info.FFDiag(CallLoc);
5734 return false;
5735 }
5736
5737 if (!DD || DD->isTrivial() ||
5738 (RD->isAnonymousStructOrUnion() && RD->isUnion())) {
5739 // A trivial destructor just ends the lifetime of the object. Check for
5740 // this case before checking for a body, because we might not bother
5741 // building a body for a trivial destructor. Note that it doesn't matter
5742 // whether the destructor is constexpr in this case; all trivial
5743 // destructors are constexpr.
5744 //
5745 // If an anonymous union would be destroyed, some enclosing destructor must
5746 // have been explicitly defined, and the anonymous union destruction should
5747 // have no effect.
5748 Value = APValue();
5749 return true;
5750 }
5751
5752 if (!Info.CheckCallLimit(CallLoc))
5753 return false;
5754
5755 const FunctionDecl *Definition = nullptr;
5756 const Stmt *Body = DD->getBody(Definition);
5757
5758 if (!CheckConstexprFunction(Info, CallLoc, DD, Definition, Body))
5759 return false;
5760
5761 CallStackFrame Frame(Info, CallLoc, Definition, &This, nullptr);
5762
5763 // We're now in the period of destruction of this object.
5764 unsigned BasesLeft = RD->getNumBases();
5765 EvalInfo::EvaluatingDestructorRAII EvalObj(
5766 Info,
5767 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries});
5768 if (!EvalObj.DidInsert) {
5769 // C++2a [class.dtor]p19:
5770 // the behavior is undefined if the destructor is invoked for an object
5771 // whose lifetime has ended
5772 // (Note that formally the lifetime ends when the period of destruction
5773 // begins, even though certain uses of the object remain valid until the
5774 // period of destruction ends.)
5775 Info.FFDiag(CallLoc, diag::note_constexpr_double_destroy);
5776 return false;
5777 }
5778
5779 // FIXME: Creating an APValue just to hold a nonexistent return value is
5780 // wasteful.
5781 APValue RetVal;
5782 StmtResult Ret = {RetVal, nullptr};
5783 if (EvaluateStmt(Ret, Info, Definition->getBody()) == ESR_Failed)
5784 return false;
5785
5786 // A union destructor does not implicitly destroy its members.
5787 if (RD->isUnion())
5788 return true;
5789
5790 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
5791
5792 // We don't have a good way to iterate fields in reverse, so collect all the
5793 // fields first and then walk them backwards.
5794 SmallVector<FieldDecl*, 16> Fields(RD->field_begin(), RD->field_end());
5795 for (const FieldDecl *FD : llvm::reverse(Fields)) {
5796 if (FD->isUnnamedBitfield())
5797 continue;
5798
5799 LValue Subobject = This;
5800 if (!HandleLValueMember(Info, &LocE, Subobject, FD, &Layout))
5801 return false;
5802
5803 APValue *SubobjectValue = &Value.getStructField(FD->getFieldIndex());
5804 if (!HandleDestructionImpl(Info, CallLoc, Subobject, *SubobjectValue,
5805 FD->getType()))
5806 return false;
5807 }
5808
5809 if (BasesLeft != 0)
5810 EvalObj.startedDestroyingBases();
5811
5812 // Destroy base classes in reverse order.
5813 for (const CXXBaseSpecifier &Base : llvm::reverse(RD->bases())) {
5814 --BasesLeft;
5815
5816 QualType BaseType = Base.getType();
5817 LValue Subobject = This;
5818 if (!HandleLValueDirectBase(Info, &LocE, Subobject, RD,
5819 BaseType->getAsCXXRecordDecl(), &Layout))
5820 return false;
5821
5822 APValue *SubobjectValue = &Value.getStructBase(BasesLeft);
5823 if (!HandleDestructionImpl(Info, CallLoc, Subobject, *SubobjectValue,
5824 BaseType))
5825 return false;
5826 }
5827 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5827, __PRETTY_FUNCTION__))
;
5828
5829 // The period of destruction ends now. The object is gone.
5830 Value = APValue();
5831 return true;
5832}
5833
5834namespace {
5835struct DestroyObjectHandler {
5836 EvalInfo &Info;
5837 const Expr *E;
5838 const LValue &This;
5839 const AccessKinds AccessKind;
5840
5841 typedef bool result_type;
5842 bool failed() { return false; }
5843 bool found(APValue &Subobj, QualType SubobjType) {
5844 return HandleDestructionImpl(Info, E->getExprLoc(), This, Subobj,
5845 SubobjType);
5846 }
5847 bool found(APSInt &Value, QualType SubobjType) {
5848 Info.FFDiag(E, diag::note_constexpr_destroy_complex_elem);
5849 return false;
5850 }
5851 bool found(APFloat &Value, QualType SubobjType) {
5852 Info.FFDiag(E, diag::note_constexpr_destroy_complex_elem);
5853 return false;
5854 }
5855};
5856}
5857
5858/// Perform a destructor or pseudo-destructor call on the given object, which
5859/// might in general not be a complete object.
5860static bool HandleDestruction(EvalInfo &Info, const Expr *E,
5861 const LValue &This, QualType ThisType) {
5862 CompleteObject Obj = findCompleteObject(Info, E, AK_Destroy, This, ThisType);
5863 DestroyObjectHandler Handler = {Info, E, This, AK_Destroy};
5864 return Obj && findSubobject(Info, E, Obj, This.Designator, Handler);
5865}
5866
5867/// Destroy and end the lifetime of the given complete object.
5868static bool HandleDestruction(EvalInfo &Info, SourceLocation Loc,
5869 APValue::LValueBase LVBase, APValue &Value,
5870 QualType T) {
5871 // If we've had an unmodeled side-effect, we can't rely on mutable state
5872 // (such as the object we're about to destroy) being correct.
5873 if (Info.EvalStatus.HasSideEffects)
5874 return false;
5875
5876 LValue LV;
5877 LV.set({LVBase});
5878 return HandleDestructionImpl(Info, Loc, LV, Value, T);
5879}
5880
5881//===----------------------------------------------------------------------===//
5882// Generic Evaluation
5883//===----------------------------------------------------------------------===//
5884namespace {
5885
5886class BitCastBuffer {
5887 // FIXME: We're going to need bit-level granularity when we support
5888 // bit-fields.
5889 // FIXME: Its possible under the C++ standard for 'char' to not be 8 bits, but
5890 // we don't support a host or target where that is the case. Still, we should
5891 // use a more generic type in case we ever do.
5892 SmallVector<Optional<unsigned char>, 32> Bytes;
5893
5894 static_assert(std::numeric_limits<unsigned char>::digits >= 8,
5895 "Need at least 8 bit unsigned char");
5896
5897 bool TargetIsLittleEndian;
5898
5899public:
5900 BitCastBuffer(CharUnits Width, bool TargetIsLittleEndian)
5901 : Bytes(Width.getQuantity()),
5902 TargetIsLittleEndian(TargetIsLittleEndian) {}
5903
5904 LLVM_NODISCARD[[clang::warn_unused_result]]
5905 bool readObject(CharUnits Offset, CharUnits Width,
5906 SmallVectorImpl<unsigned char> &Output) const {
5907 for (CharUnits I = Offset, E = Offset + Width; I != E; ++I) {
5908 // If a byte of an integer is uninitialized, then the whole integer is
5909 // uninitalized.
5910 if (!Bytes[I.getQuantity()])
5911 return false;
5912 Output.push_back(*Bytes[I.getQuantity()]);
5913 }
5914 if (llvm::sys::IsLittleEndianHost != TargetIsLittleEndian)
5915 std::reverse(Output.begin(), Output.end());
5916 return true;
5917 }
5918
5919 void writeObject(CharUnits Offset, SmallVectorImpl<unsigned char> &Input) {
5920 if (llvm::sys::IsLittleEndianHost != TargetIsLittleEndian)
5921 std::reverse(Input.begin(), Input.end());
5922
5923 size_t Index = 0;
5924 for (unsigned char Byte : Input) {
5925 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5925, __PRETTY_FUNCTION__))
;
5926 Bytes[Offset.getQuantity() + Index] = Byte;
5927 ++Index;
5928 }
5929 }
5930
5931 size_t size() { return Bytes.size(); }
5932};
5933
5934/// Traverse an APValue to produce an BitCastBuffer, emulating how the current
5935/// target would represent the value at runtime.
5936class APValueToBufferConverter {
5937 EvalInfo &Info;
5938 BitCastBuffer Buffer;
5939 const CastExpr *BCE;
5940
5941 APValueToBufferConverter(EvalInfo &Info, CharUnits ObjectWidth,
5942 const CastExpr *BCE)
5943 : Info(Info),
5944 Buffer(ObjectWidth, Info.Ctx.getTargetInfo().isLittleEndian()),
5945 BCE(BCE) {}
5946
5947 bool visit(const APValue &Val, QualType Ty) {
5948 return visit(Val, Ty, CharUnits::fromQuantity(0));
5949 }
5950
5951 // Write out Val with type Ty into Buffer starting at Offset.
5952 bool visit(const APValue &Val, QualType Ty, CharUnits Offset) {
5953 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5953, __PRETTY_FUNCTION__))
;
5954
5955 // As a special case, nullptr_t has an indeterminate value.
5956 if (Ty->isNullPtrType())
5957 return true;
5958
5959 // Dig through Src to find the byte at SrcOffset.
5960 switch (Val.getKind()) {
5961 case APValue::Indeterminate:
5962 case APValue::None:
5963 return true;
5964
5965 case APValue::Int:
5966 return visitInt(Val.getInt(), Ty, Offset);
5967 case APValue::Float:
5968 return visitFloat(Val.getFloat(), Ty, Offset);
5969 case APValue::Array:
5970 return visitArray(Val, Ty, Offset);
5971 case APValue::Struct:
5972 return visitRecord(Val, Ty, Offset);
5973
5974 case APValue::ComplexInt:
5975 case APValue::ComplexFloat:
5976 case APValue::Vector:
5977 case APValue::FixedPoint:
5978 // FIXME: We should support these.
5979
5980 case APValue::Union:
5981 case APValue::MemberPointer:
5982 case APValue::AddrLabelDiff: {
5983 Info.FFDiag(BCE->getBeginLoc(),
5984 diag::note_constexpr_bit_cast_unsupported_type)
5985 << Ty;
5986 return false;
5987 }
5988
5989 case APValue::LValue:
5990 llvm_unreachable("LValue subobject in bit_cast?")::llvm::llvm_unreachable_internal("LValue subobject in bit_cast?"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5990)
;
5991 }
5992 llvm_unreachable("Unhandled APValue::ValueKind")::llvm::llvm_unreachable_internal("Unhandled APValue::ValueKind"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 5992)
;
5993 }
5994
5995 bool visitRecord(const APValue &Val, QualType Ty, CharUnits Offset) {
5996 const RecordDecl *RD = Ty->getAsRecordDecl();
5997 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
5998
5999 // Visit the base classes.
6000 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
6001 for (size_t I = 0, E = CXXRD->getNumBases(); I != E; ++I) {
6002 const CXXBaseSpecifier &BS = CXXRD->bases_begin()[I];
6003 CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
6004
6005 if (!visitRecord(Val.getStructBase(I), BS.getType(),
6006 Layout.getBaseClassOffset(BaseDecl) + Offset))
6007 return false;
6008 }
6009 }
6010
6011 // Visit the fields.
6012 unsigned FieldIdx = 0;
6013 for (FieldDecl *FD : RD->fields()) {
6014 if (FD->isBitField()) {
6015 Info.FFDiag(BCE->getBeginLoc(),
6016 diag::note_constexpr_bit_cast_unsupported_bitfield);
6017 return false;
6018 }
6019
6020 uint64_t FieldOffsetBits = Layout.getFieldOffset(FieldIdx);
6021
6022 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6023, __PRETTY_FUNCTION__))
6023 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6023, __PRETTY_FUNCTION__))
;
6024 CharUnits FieldOffset =
6025 Info.Ctx.toCharUnitsFromBits(FieldOffsetBits) + Offset;
6026 QualType FieldTy = FD->getType();
6027 if (!visit(Val.getStructField(FieldIdx), FieldTy, FieldOffset))
6028 return false;
6029 ++FieldIdx;
6030 }
6031
6032 return true;
6033 }
6034
6035 bool visitArray(const APValue &Val, QualType Ty, CharUnits Offset) {
6036 const auto *CAT =
6037 dyn_cast_or_null<ConstantArrayType>(Ty->getAsArrayTypeUnsafe());
6038 if (!CAT)
6039 return false;
6040
6041 CharUnits ElemWidth = Info.Ctx.getTypeSizeInChars(CAT->getElementType());
6042 unsigned NumInitializedElts = Val.getArrayInitializedElts();
6043 unsigned ArraySize = Val.getArraySize();
6044 // First, initialize the initialized elements.
6045 for (unsigned I = 0; I != NumInitializedElts; ++I) {
6046 const APValue &SubObj = Val.getArrayInitializedElt(I);
6047 if (!visit(SubObj, CAT->getElementType(), Offset + I * ElemWidth))
6048 return false;
6049 }
6050
6051 // Next, initialize the rest of the array using the filler.
6052 if (Val.hasArrayFiller()) {
6053 const APValue &Filler = Val.getArrayFiller();
6054 for (unsigned I = NumInitializedElts; I != ArraySize; ++I) {
6055 if (!visit(Filler, CAT->getElementType(), Offset + I * ElemWidth))
6056 return false;
6057 }
6058 }
6059
6060 return true;
6061 }
6062
6063 bool visitInt(const APSInt &Val, QualType Ty, CharUnits Offset) {
6064 CharUnits Width = Info.Ctx.getTypeSizeInChars(Ty);
6065 SmallVector<unsigned char, 8> Bytes(Width.getQuantity());
6066 llvm::StoreIntToMemory(Val, &*Bytes.begin(), Width.getQuantity());
6067 Buffer.writeObject(Offset, Bytes);
6068 return true;
6069 }
6070
6071 bool visitFloat(const APFloat &Val, QualType Ty, CharUnits Offset) {
6072 APSInt AsInt(Val.bitcastToAPInt());
6073 return visitInt(AsInt, Ty, Offset);
6074 }
6075
6076public:
6077 static Optional<BitCastBuffer> convert(EvalInfo &Info, const APValue &Src,
6078 const CastExpr *BCE) {
6079 CharUnits DstSize = Info.Ctx.getTypeSizeInChars(BCE->getType());
6080 APValueToBufferConverter Converter(Info, DstSize, BCE);
6081 if (!Converter.visit(Src, BCE->getSubExpr()->getType()))
6082 return None;
6083 return Converter.Buffer;
6084 }
6085};
6086
6087/// Write an BitCastBuffer into an APValue.
6088class BufferToAPValueConverter {
6089 EvalInfo &Info;
6090 const BitCastBuffer &Buffer;
6091 const CastExpr *BCE;
6092
6093 BufferToAPValueConverter(EvalInfo &Info, const BitCastBuffer &Buffer,
6094 const CastExpr *BCE)
6095 : Info(Info), Buffer(Buffer), BCE(BCE) {}
6096
6097 // Emit an unsupported bit_cast type error. Sema refuses to build a bit_cast
6098 // with an invalid type, so anything left is a deficiency on our part (FIXME).
6099 // Ideally this will be unreachable.
6100 llvm::NoneType unsupportedType(QualType Ty) {
6101 Info.FFDiag(BCE->getBeginLoc(),
6102 diag::note_constexpr_bit_cast_unsupported_type)
6103 << Ty;
6104 return None;
6105 }
6106
6107 Optional<APValue> visit(const BuiltinType *T, CharUnits Offset,
6108 const EnumType *EnumSugar = nullptr) {
6109 if (T->isNullPtrType()) {
6110 uint64_t NullValue = Info.Ctx.getTargetNullPointerValue(QualType(T, 0));
6111 return APValue((Expr *)nullptr,
6112 /*Offset=*/CharUnits::fromQuantity(NullValue),
6113 APValue::NoLValuePath{}, /*IsNullPtr=*/true);
6114 }
6115
6116 CharUnits SizeOf = Info.Ctx.getTypeSizeInChars(T);
6117 SmallVector<uint8_t, 8> Bytes;
6118 if (!Buffer.readObject(Offset, SizeOf, Bytes)) {
6119 // If this is std::byte or unsigned char, then its okay to store an
6120 // indeterminate value.
6121 bool IsStdByte = EnumSugar && EnumSugar->isStdByteType();
6122 bool IsUChar =
6123 !EnumSugar && (T->isSpecificBuiltinType(BuiltinType::UChar) ||
6124 T->isSpecificBuiltinType(BuiltinType::Char_U));
6125 if (!IsStdByte && !IsUChar) {
6126 QualType DisplayType(EnumSugar ? (const Type *)EnumSugar : T, 0);
6127 Info.FFDiag(BCE->getExprLoc(),
6128 diag::note_constexpr_bit_cast_indet_dest)
6129 << DisplayType << Info.Ctx.getLangOpts().CharIsSigned;
6130 return None;
6131 }
6132
6133 return APValue::IndeterminateValue();
6134 }
6135
6136 APSInt Val(SizeOf.getQuantity() * Info.Ctx.getCharWidth(), true);
6137 llvm::LoadIntFromMemory(Val, &*Bytes.begin(), Bytes.size());
6138
6139 if (T->isIntegralOrEnumerationType()) {
6140 Val.setIsSigned(T->isSignedIntegerOrEnumerationType());
6141 return APValue(Val);
6142 }
6143
6144 if (T->isRealFloatingType()) {
6145 const llvm::fltSemantics &Semantics =
6146 Info.Ctx.getFloatTypeSemantics(QualType(T, 0));
6147 return APValue(APFloat(Semantics, Val));
6148 }
6149
6150 return unsupportedType(QualType(T, 0));
6151 }
6152
6153 Optional<APValue> visit(const RecordType *RTy, CharUnits Offset) {
6154 const RecordDecl *RD = RTy->getAsRecordDecl();
6155 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
6156
6157 unsigned NumBases = 0;
6158 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
6159 NumBases = CXXRD->getNumBases();
6160
6161 APValue ResultVal(APValue::UninitStruct(), NumBases,
6162 std::distance(RD->field_begin(), RD->field_end()));
6163
6164 // Visit the base classes.
6165 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
6166 for (size_t I = 0, E = CXXRD->getNumBases(); I != E; ++I) {
6167 const CXXBaseSpecifier &BS = CXXRD->bases_begin()[I];
6168 CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
6169 if (BaseDecl->isEmpty() ||
6170 Info.Ctx.getASTRecordLayout(BaseDecl).getNonVirtualSize().isZero())
6171 continue;
6172
6173 Optional<APValue> SubObj = visitType(
6174 BS.getType(), Layout.getBaseClassOffset(BaseDecl) + Offset);
6175 if (!SubObj)
6176 return None;
6177 ResultVal.getStructBase(I) = *SubObj;
6178 }
6179 }
6180
6181 // Visit the fields.
6182 unsigned FieldIdx = 0;
6183 for (FieldDecl *FD : RD->fields()) {
6184 // FIXME: We don't currently support bit-fields. A lot of the logic for
6185 // this is in CodeGen, so we need to factor it around.
6186 if (FD->isBitField()) {
6187 Info.FFDiag(BCE->getBeginLoc(),
6188 diag::note_constexpr_bit_cast_unsupported_bitfield);
6189 return None;
6190 }
6191
6192 uint64_t FieldOffsetBits = Layout.getFieldOffset(FieldIdx);
6193 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6193, __PRETTY_FUNCTION__))
;
6194
6195 CharUnits FieldOffset =
6196 CharUnits::fromQuantity(FieldOffsetBits / Info.Ctx.getCharWidth()) +
6197 Offset;
6198 QualType FieldTy = FD->getType();
6199 Optional<APValue> SubObj = visitType(FieldTy, FieldOffset);
6200 if (!SubObj)
6201 return None;
6202 ResultVal.getStructField(FieldIdx) = *SubObj;
6203 ++FieldIdx;
6204 }
6205
6206 return ResultVal;
6207 }
6208
6209 Optional<APValue> visit(const EnumType *Ty, CharUnits Offset) {
6210 QualType RepresentationType = Ty->getDecl()->getIntegerType();
6211 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6212, __PRETTY_FUNCTION__))
6212 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6212, __PRETTY_FUNCTION__))
;
6213 const BuiltinType *AsBuiltin =
6214 RepresentationType.getCanonicalType()->getAs<BuiltinType>();
6215 assert(AsBuiltin && "non-integral enum underlying type?")((AsBuiltin && "non-integral enum underlying type?") ?
static_cast<void> (0) : __assert_fail ("AsBuiltin && \"non-integral enum underlying type?\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6215, __PRETTY_FUNCTION__))
;
6216 // Recurse into the underlying type. Treat std::byte transparently as
6217 // unsigned char.
6218 return visit(AsBuiltin, Offset, /*EnumTy=*/Ty);
6219 }
6220
6221 Optional<APValue> visit(const ConstantArrayType *Ty, CharUnits Offset) {
6222 size_t Size = Ty->getSize().getLimitedValue();
6223 CharUnits ElementWidth = Info.Ctx.getTypeSizeInChars(Ty->getElementType());
6224
6225 APValue ArrayValue(APValue::UninitArray(), Size, Size);
6226 for (size_t I = 0; I != Size; ++I) {
6227 Optional<APValue> ElementValue =
6228 visitType(Ty->getElementType(), Offset + I * ElementWidth);
6229 if (!ElementValue)
6230 return None;
6231 ArrayValue.getArrayInitializedElt(I) = std::move(*ElementValue);
6232 }
6233
6234 return ArrayValue;
6235 }
6236
6237 Optional<APValue> visit(const Type *Ty, CharUnits Offset) {
6238 return unsupportedType(QualType(Ty, 0));
6239 }
6240
6241 Optional<APValue> visitType(QualType Ty, CharUnits Offset) {
6242 QualType Can = Ty.getCanonicalType();
6243
6244 switch (Can->getTypeClass()) {
6245#define TYPE(Class, Base) \
6246 case Type::Class: \
6247 return visit(cast<Class##Type>(Can.getTypePtr()), Offset);
6248#define ABSTRACT_TYPE(Class, Base)
6249#define NON_CANONICAL_TYPE(Class, Base) \
6250 case Type::Class: \
6251 llvm_unreachable("non-canonical type should be impossible!")::llvm::llvm_unreachable_internal("non-canonical type should be impossible!"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6251)
;
6252#define DEPENDENT_TYPE(Class, Base) \
6253 case Type::Class: \
6254 llvm_unreachable( \::llvm::llvm_unreachable_internal("dependent types aren't supported in the constant evaluator!"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6255)
6255 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6255)
;
6256#define NON_CANONICAL_UNLESS_DEPENDENT(Class, Base)case Type::Class: ::llvm::llvm_unreachable_internal("either dependent or not canonical!"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6256);
\
6257 case Type::Class: \
6258 llvm_unreachable("either dependent or not canonical!")::llvm::llvm_unreachable_internal("either dependent or not canonical!"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6258)
;
6259#include "clang/AST/TypeNodes.inc"
6260 }
6261 llvm_unreachable("Unhandled Type::TypeClass")::llvm::llvm_unreachable_internal("Unhandled Type::TypeClass"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6261)
;
6262 }
6263
6264public:
6265 // Pull out a full value of type DstType.
6266 static Optional<APValue> convert(EvalInfo &Info, BitCastBuffer &Buffer,
6267 const CastExpr *BCE) {
6268 BufferToAPValueConverter Converter(Info, Buffer, BCE);
6269 return Converter.visitType(BCE->getType(), CharUnits::fromQuantity(0));
6270 }
6271};
6272
6273static bool checkBitCastConstexprEligibilityType(SourceLocation Loc,
6274 QualType Ty, EvalInfo *Info,
6275 const ASTContext &Ctx,
6276 bool CheckingDest) {
6277 Ty = Ty.getCanonicalType();
6278
6279 auto diag = [&](int Reason) {
6280 if (Info)
6281 Info->FFDiag(Loc, diag::note_constexpr_bit_cast_invalid_type)
6282 << CheckingDest << (Reason == 4) << Reason;
6283 return false;
6284 };
6285 auto note = [&](int Construct, QualType NoteTy, SourceLocation NoteLoc) {
6286 if (Info)
6287 Info->Note(NoteLoc, diag::note_constexpr_bit_cast_invalid_subtype)
6288 << NoteTy << Construct << Ty;
6289 return false;
6290 };
6291
6292 if (Ty->isUnionType())
6293 return diag(0);
6294 if (Ty->isPointerType())
6295 return diag(1);
6296 if (Ty->isMemberPointerType())
6297 return diag(2);
6298 if (Ty.isVolatileQualified())
6299 return diag(3);
6300
6301 if (RecordDecl *Record = Ty->getAsRecordDecl()) {
6302 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(Record)) {
6303 for (CXXBaseSpecifier &BS : CXXRD->bases())
6304 if (!checkBitCastConstexprEligibilityType(Loc, BS.getType(), Info, Ctx,
6305 CheckingDest))
6306 return note(1, BS.getType(), BS.getBeginLoc());
6307 }
6308 for (FieldDecl *FD : Record->fields()) {
6309 if (FD->getType()->isReferenceType())
6310 return diag(4);
6311 if (!checkBitCastConstexprEligibilityType(Loc, FD->getType(), Info, Ctx,
6312 CheckingDest))
6313 return note(0, FD->getType(), FD->getBeginLoc());
6314 }
6315 }
6316
6317 if (Ty->isArrayType() &&
6318 !checkBitCastConstexprEligibilityType(Loc, Ctx.getBaseElementType(Ty),
6319 Info, Ctx, CheckingDest))
6320 return false;
6321
6322 return true;
6323}
6324
6325static bool checkBitCastConstexprEligibility(EvalInfo *Info,
6326 const ASTContext &Ctx,
6327 const CastExpr *BCE) {
6328 bool DestOK = checkBitCastConstexprEligibilityType(
6329 BCE->getBeginLoc(), BCE->getType(), Info, Ctx, true);
6330 bool SourceOK = DestOK && checkBitCastConstexprEligibilityType(
6331 BCE->getBeginLoc(),
6332 BCE->getSubExpr()->getType(), Info, Ctx, false);
6333 return SourceOK;
6334}
6335
6336static bool handleLValueToRValueBitCast(EvalInfo &Info, APValue &DestValue,
6337 APValue &SourceValue,
6338 const CastExpr *BCE) {
6339 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6340, __PRETTY_FUNCTION__))
6340 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6340, __PRETTY_FUNCTION__))
;
6341 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6342, __PRETTY_FUNCTION__))
6342 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6342, __PRETTY_FUNCTION__))
;
6343
6344 if (!checkBitCastConstexprEligibility(&Info, Info.Ctx, BCE))
6345 return false;
6346
6347 LValue SourceLValue;
6348 APValue SourceRValue;
6349 SourceLValue.setFrom(Info.Ctx, SourceValue);
6350 if (!handleLValueToRValueConversion(
6351 Info, BCE, BCE->getSubExpr()->getType().withConst(), SourceLValue,
6352 SourceRValue, /*WantObjectRepresentation=*/true))
6353 return false;
6354
6355 // Read out SourceValue into a char buffer.
6356 Optional<BitCastBuffer> Buffer =
6357 APValueToBufferConverter::convert(Info, SourceRValue, BCE);
6358 if (!Buffer)
6359 return false;
6360
6361 // Write out the buffer into a new APValue.
6362 Optional<APValue> MaybeDestValue =
6363 BufferToAPValueConverter::convert(Info, *Buffer, BCE);
6364 if (!MaybeDestValue)
6365 return false;
6366
6367 DestValue = std::move(*MaybeDestValue);
6368 return true;
6369}
6370
6371template <class Derived>
6372class ExprEvaluatorBase
6373 : public ConstStmtVisitor<Derived, bool> {
6374private:
6375 Derived &getDerived() { return static_cast<Derived&>(*this); }
6376 bool DerivedSuccess(const APValue &V, const Expr *E) {
6377 return getDerived().Success(V, E);
6378 }
6379 bool DerivedZeroInitialization(const Expr *E) {
6380 return getDerived().ZeroInitialization(E);
6381 }
6382
6383 // Check whether a conditional operator with a non-constant condition is a
6384 // potential constant expression. If neither arm is a potential constant
6385 // expression, then the conditional operator is not either.
6386 template<typename ConditionalOperator>
6387 void CheckPotentialConstantConditional(const ConditionalOperator *E) {
6388 assert(Info.checkingPotentialConstantExpression())((Info.checkingPotentialConstantExpression()) ? static_cast<
void> (0) : __assert_fail ("Info.checkingPotentialConstantExpression()"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6388, __PRETTY_FUNCTION__))
;
6389
6390 // Speculatively evaluate both arms.
6391 SmallVector<PartialDiagnosticAt, 8> Diag;
6392 {
6393 SpeculativeEvaluationRAII Speculate(Info, &Diag);
6394 StmtVisitorTy::Visit(E->getFalseExpr());
6395 if (Diag.empty())
6396 return;
6397 }
6398
6399 {
6400 SpeculativeEvaluationRAII Speculate(Info, &Diag);
6401 Diag.clear();
6402 StmtVisitorTy::Visit(E->getTrueExpr());
6403 if (Diag.empty())
6404 return;
6405 }
6406
6407 Error(E, diag::note_constexpr_conditional_never_const);
6408 }
6409
6410
6411 template<typename ConditionalOperator>
6412 bool HandleConditionalOperator(const ConditionalOperator *E) {
6413 bool BoolResult;
6414 if (!EvaluateAsBooleanCondition(E->getCond(), BoolResult, Info)) {
6415 if (Info.checkingPotentialConstantExpression() && Info.noteFailure()) {
6416 CheckPotentialConstantConditional(E);
6417 return false;
6418 }
6419 if (Info.noteFailure()) {
6420 StmtVisitorTy::Visit(E->getTrueExpr());
6421 StmtVisitorTy::Visit(E->getFalseExpr());
6422 }
6423 return false;
6424 }
6425
6426 Expr *EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr();
6427 return StmtVisitorTy::Visit(EvalExpr);
6428 }
6429
6430protected:
6431 EvalInfo &Info;
6432 typedef ConstStmtVisitor<Derived, bool> StmtVisitorTy;
6433 typedef ExprEvaluatorBase ExprEvaluatorBaseTy;
6434
6435 OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
6436 return Info.CCEDiag(E, D);
6437 }
6438
6439 bool ZeroInitialization(const Expr *E) { return Error(E); }
6440
6441public:
6442 ExprEvaluatorBase(EvalInfo &Info) : Info(Info) {}
6443
6444 EvalInfo &getEvalInfo() { return Info; }
6445
6446 /// Report an evaluation error. This should only be called when an error is
6447 /// first discovered. When propagating an error, just return false.
6448 bool Error(const Expr *E, diag::kind D) {
6449 Info.FFDiag(E, D);
6450 return false;
6451 }
6452 bool Error(const Expr *E) {
6453 return Error(E, diag::note_invalid_subexpr_in_const_expr);
6454 }
6455
6456 bool VisitStmt(const Stmt *) {
6457 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6457)
;
6458 }
6459 bool VisitExpr(const Expr *E) {
6460 return Error(E);
6461 }
6462
6463 bool VisitConstantExpr(const ConstantExpr *E)
6464 { return StmtVisitorTy::Visit(E->getSubExpr()); }
6465 bool VisitParenExpr(const ParenExpr *E)
6466 { return StmtVisitorTy::Visit(E->getSubExpr()); }
6467 bool VisitUnaryExtension(const UnaryOperator *E)
6468 { return StmtVisitorTy::Visit(E->getSubExpr()); }
6469 bool VisitUnaryPlus(const UnaryOperator *E)
6470 { return StmtVisitorTy::Visit(E->getSubExpr()); }
6471 bool VisitChooseExpr(const ChooseExpr *E)
6472 { return StmtVisitorTy::Visit(E->getChosenSubExpr()); }
6473 bool VisitGenericSelectionExpr(const GenericSelectionExpr *E)
6474 { return StmtVisitorTy::Visit(E->getResultExpr()); }
6475 bool VisitSubstNonTypeTemplateParmExpr(const SubstNonTypeTemplateParmExpr *E)
6476 { return StmtVisitorTy::Visit(E->getReplacement()); }
6477 bool VisitCXXDefaultArgExpr(const CXXDefaultArgExpr *E) {
6478 TempVersionRAII RAII(*Info.CurrentCall);
6479 SourceLocExprScopeGuard Guard(E, Info.CurrentCall->CurSourceLocExprScope);
6480 return StmtVisitorTy::Visit(E->getExpr());
6481 }
6482 bool VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *E) {
6483 TempVersionRAII RAII(*Info.CurrentCall);
6484 // The initializer may not have been parsed yet, or might be erroneous.
6485 if (!E->getExpr())
6486 return Error(E);
6487 SourceLocExprScopeGuard Guard(E, Info.CurrentCall->CurSourceLocExprScope);
6488 return StmtVisitorTy::Visit(E->getExpr());
6489 }
6490
6491 bool VisitExprWithCleanups(const ExprWithCleanups *E) {
6492 FullExpressionRAII Scope(Info);
6493 return StmtVisitorTy::Visit(E->getSubExpr()) && Scope.destroy();
6494 }
6495
6496 // Temporaries are registered when created, so we don't care about
6497 // CXXBindTemporaryExpr.
6498 bool VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *E) {
6499 return StmtVisitorTy::Visit(E->getSubExpr());
6500 }
6501
6502 bool VisitCXXReinterpretCastExpr(const CXXReinterpretCastExpr *E) {
6503 CCEDiag(E, diag::note_constexpr_invalid_cast) << 0;
6504 return static_cast<Derived*>(this)->VisitCastExpr(E);
1
Calling 'ComplexExprEvaluator::VisitCastExpr'
6505 }
6506 bool VisitCXXDynamicCastExpr(const CXXDynamicCastExpr *E) {
6507 if (!Info.Ctx.getLangOpts().CPlusPlus2a)
6508 CCEDiag(E, diag::note_constexpr_invalid_cast) << 1;
6509 return static_cast<Derived*>(this)->VisitCastExpr(E);
6510 }
6511 bool VisitBuiltinBitCastExpr(const BuiltinBitCastExpr *E) {
6512 return static_cast<Derived*>(this)->VisitCastExpr(E);
6513 }
6514
6515 bool VisitBinaryOperator(const BinaryOperator *E) {
6516 switch (E->getOpcode()) {
6517 default:
6518 return Error(E);
6519
6520 case BO_Comma:
6521 VisitIgnoredValue(E->getLHS());
6522 return StmtVisitorTy::Visit(E->getRHS());
6523
6524 case BO_PtrMemD:
6525 case BO_PtrMemI: {
6526 LValue Obj;
6527 if (!HandleMemberPointerAccess(Info, E, Obj))
6528 return false;
6529 APValue Result;
6530 if (!handleLValueToRValueConversion(Info, E, E->getType(), Obj, Result))
6531 return false;
6532 return DerivedSuccess(Result, E);
6533 }
6534 }
6535 }
6536
6537 bool VisitBinaryConditionalOperator(const BinaryConditionalOperator *E) {
6538 // Evaluate and cache the common expression. We treat it as a temporary,
6539 // even though it's not quite the same thing.
6540 LValue CommonLV;
6541 if (!Evaluate(Info.CurrentCall->createTemporary(
6542 E->getOpaqueValue(),
6543 getStorageType(Info.Ctx, E->getOpaqueValue()), false,
6544 CommonLV),
6545 Info, E->getCommon()))
6546 return false;
6547
6548 return HandleConditionalOperator(E);
6549 }
6550
6551 bool VisitConditionalOperator(const ConditionalOperator *E) {
6552 bool IsBcpCall = false;
6553 // If the condition (ignoring parens) is a __builtin_constant_p call,
6554 // the result is a constant expression if it can be folded without
6555 // side-effects. This is an important GNU extension. See GCC PR38377
6556 // for discussion.
6557 if (const CallExpr *CallCE =
6558 dyn_cast<CallExpr>(E->getCond()->IgnoreParenCasts()))
6559 if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
6560 IsBcpCall = true;
6561
6562 // Always assume __builtin_constant_p(...) ? ... : ... is a potential
6563 // constant expression; we can't check whether it's potentially foldable.
6564 // FIXME: We should instead treat __builtin_constant_p as non-constant if
6565 // it would return 'false' in this mode.
6566 if (Info.checkingPotentialConstantExpression() && IsBcpCall)
6567 return false;
6568
6569 FoldConstant Fold(Info, IsBcpCall);
6570 if (!HandleConditionalOperator(E)) {
6571 Fold.keepDiagnostics();
6572 return false;
6573 }
6574
6575 return true;
6576 }
6577
6578 bool VisitOpaqueValueExpr(const OpaqueValueExpr *E) {
6579 if (APValue *Value = Info.CurrentCall->getCurrentTemporary(E))
6580 return DerivedSuccess(*Value, E);
6581
6582 const Expr *Source = E->getSourceExpr();
6583 if (!Source)
6584 return Error(E);
6585 if (Source == E) { // sanity checking.
6586 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6586, __PRETTY_FUNCTION__))
;
6587 return Error(E);
6588 }
6589 return StmtVisitorTy::Visit(Source);
6590 }
6591
6592 bool VisitCallExpr(const CallExpr *E) {
6593 APValue Result;
6594 if (!handleCallExpr(E, Result, nullptr))
6595 return false;
6596 return DerivedSuccess(Result, E);
6597 }
6598
6599 bool handleCallExpr(const CallExpr *E, APValue &Result,
6600 const LValue *ResultSlot) {
6601 const Expr *Callee = E->getCallee()->IgnoreParens();
6602 QualType CalleeType = Callee->getType();
6603
6604 const FunctionDecl *FD = nullptr;
6605 LValue *This = nullptr, ThisVal;
6606 auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
6607 bool HasQualifier = false;
6608
6609 // Extract function decl and 'this' pointer from the callee.
6610 if (CalleeType->isSpecificBuiltinType(BuiltinType::BoundMember)) {
6611 const CXXMethodDecl *Member = nullptr;
6612 if (const MemberExpr *ME = dyn_cast<MemberExpr>(Callee)) {
6613 // Explicit bound member calls, such as x.f() or p->g();
6614 if (!EvaluateObjectArgument(Info, ME->getBase(), ThisVal))
6615 return false;
6616 Member = dyn_cast<CXXMethodDecl>(ME->getMemberDecl());
6617 if (!Member)
6618 return Error(Callee);
6619 This = &ThisVal;
6620 HasQualifier = ME->hasQualifier();
6621 } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(Callee)) {
6622 // Indirect bound member calls ('.*' or '->*').
6623 Member = dyn_cast_or_null<CXXMethodDecl>(
6624 HandleMemberPointerAccess(Info, BE, ThisVal, false));
6625 if (!Member)
6626 return Error(Callee);
6627 This = &ThisVal;
6628 } else if (const auto *PDE = dyn_cast<CXXPseudoDestructorExpr>(Callee)) {
6629 if (!Info.getLangOpts().CPlusPlus2a)
6630 Info.CCEDiag(PDE, diag::note_constexpr_pseudo_destructor);
6631 // FIXME: If pseudo-destructor calls ever start ending the lifetime of
6632 // their callee, we should start calling HandleDestruction here.
6633 // For now, we just evaluate the object argument and discard it.
6634 return EvaluateObjectArgument(Info, PDE->getBase(), ThisVal);
6635 } else
6636 return Error(Callee);
6637 FD = Member;
6638 } else if (CalleeType->isFunctionPointerType()) {
6639 LValue Call;
6640 if (!EvaluatePointer(Callee, Call, Info))
6641 return false;
6642
6643 if (!Call.getLValueOffset().isZero())
6644 return Error(Callee);
6645 FD = dyn_cast_or_null<FunctionDecl>(
6646 Call.getLValueBase().dyn_cast<const ValueDecl*>());
6647 if (!FD)
6648 return Error(Callee);
6649 // Don't call function pointers which have been cast to some other type.
6650 // Per DR (no number yet), the caller and callee can differ in noexcept.
6651 if (!Info.Ctx.hasSameFunctionTypeIgnoringExceptionSpec(
6652 CalleeType->getPointeeType(), FD->getType())) {
6653 return Error(E);
6654 }
6655
6656 // Overloaded operator calls to member functions are represented as normal
6657 // calls with '*this' as the first argument.
6658 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
6659 if (MD && !MD->isStatic()) {
6660 // FIXME: When selecting an implicit conversion for an overloaded
6661 // operator delete, we sometimes try to evaluate calls to conversion
6662 // operators without a 'this' parameter!
6663 if (Args.empty())
6664 return Error(E);
6665
6666 if (!EvaluateObjectArgument(Info, Args[0], ThisVal))
6667 return false;
6668 This = &ThisVal;
6669 Args = Args.slice(1);
6670 } else if (MD && MD->isLambdaStaticInvoker()) {
6671 // Map the static invoker for the lambda back to the call operator.
6672 // Conveniently, we don't have to slice out the 'this' argument (as is
6673 // being done for the non-static case), since a static member function
6674 // doesn't have an implicit argument passed in.
6675 const CXXRecordDecl *ClosureClass = MD->getParent();
6676 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6678, __PRETTY_FUNCTION__))
6677 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6678, __PRETTY_FUNCTION__))
6678 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6678, __PRETTY_FUNCTION__))
;
6679
6680 const CXXMethodDecl *LambdaCallOp =
6681 ClosureClass->getLambdaCallOperator();
6682
6683 // Set 'FD', the function that will be called below, to the call
6684 // operator. If the closure object represents a generic lambda, find
6685 // the corresponding specialization of the call operator.
6686
6687 if (ClosureClass->isGenericLambda()) {
6688 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6690, __PRETTY_FUNCTION__))
6689 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6690, __PRETTY_FUNCTION__))
6690 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6690, __PRETTY_FUNCTION__))
;
6691 const TemplateArgumentList *TAL = MD->getTemplateSpecializationArgs();
6692 FunctionTemplateDecl *CallOpTemplate =
6693 LambdaCallOp->getDescribedFunctionTemplate();
6694 void *InsertPos = nullptr;
6695 FunctionDecl *CorrespondingCallOpSpecialization =
6696 CallOpTemplate->findSpecialization(TAL->asArray(), InsertPos);
6697 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6699, __PRETTY_FUNCTION__))
6698 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6699, __PRETTY_FUNCTION__))
6699 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6699, __PRETTY_FUNCTION__))
;
6700 FD = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
6701 } else
6702 FD = LambdaCallOp;
6703 }
6704 } else
6705 return Error(E);
6706
6707 SmallVector<QualType, 4> CovariantAdjustmentPath;
6708 if (This) {
6709 auto *NamedMember = dyn_cast<CXXMethodDecl>(FD);
6710 if (NamedMember && NamedMember->isVirtual() && !HasQualifier) {
6711 // Perform virtual dispatch, if necessary.
6712 FD = HandleVirtualDispatch(Info, E, *This, NamedMember,
6713 CovariantAdjustmentPath);
6714 if (!FD)
6715 return false;
6716 } else {
6717 // Check that the 'this' pointer points to an object of the right type.
6718 // FIXME: If this is an assignment operator call, we may need to change
6719 // the active union member before we check this.
6720 if (!checkNonVirtualMemberCallThisPointer(Info, E, *This, NamedMember))
6721 return false;
6722 }
6723 }
6724
6725 // Destructor calls are different enough that they have their own codepath.
6726 if (auto *DD = dyn_cast<CXXDestructorDecl>(FD)) {
6727 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6727, __PRETTY_FUNCTION__))
;
6728 return HandleDestruction(Info, E, *This,
6729 Info.Ctx.getRecordType(DD->getParent()));
6730 }
6731
6732 const FunctionDecl *Definition = nullptr;
6733 Stmt *Body = FD->getBody(Definition);
6734
6735 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body) ||
6736 !HandleFunctionCall(E->getExprLoc(), Definition, This, Args, Body, Info,
6737 Result, ResultSlot))
6738 return false;
6739
6740 if (!CovariantAdjustmentPath.empty() &&
6741 !HandleCovariantReturnAdjustment(Info, E, Result,
6742 CovariantAdjustmentPath))
6743 return false;
6744
6745 return true;
6746 }
6747
6748 bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
6749 return StmtVisitorTy::Visit(E->getInitializer());
6750 }
6751 bool VisitInitListExpr(const InitListExpr *E) {
6752 if (E->getNumInits() == 0)
6753 return DerivedZeroInitialization(E);
6754 if (E->getNumInits() == 1)
6755 return StmtVisitorTy::Visit(E->getInit(0));
6756 return Error(E);
6757 }
6758 bool VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
6759 return DerivedZeroInitialization(E);
6760 }
6761 bool VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
6762 return DerivedZeroInitialization(E);
6763 }
6764 bool VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
6765 return DerivedZeroInitialization(E);
6766 }
6767
6768 /// A member expression where the object is a prvalue is itself a prvalue.
6769 bool VisitMemberExpr(const MemberExpr *E) {
6770 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6771, __PRETTY_FUNCTION__))
6771 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6771, __PRETTY_FUNCTION__))
;
6772 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6772, __PRETTY_FUNCTION__))
;
6773
6774 APValue Val;
6775 if (!Evaluate(Val, Info, E->getBase()))
6776 return false;
6777
6778 QualType BaseTy = E->getBase()->getType();
6779
6780 const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl());
6781 if (!FD) return Error(E);
6782 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6782, __PRETTY_FUNCTION__))
;
6783 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6784, __PRETTY_FUNCTION__))
6784 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6784, __PRETTY_FUNCTION__))
;
6785
6786 // Note: there is no lvalue base here. But this case should only ever
6787 // happen in C or in C++98, where we cannot be evaluating a constexpr
6788 // constructor, which is the only case the base matters.
6789 CompleteObject Obj(APValue::LValueBase(), &Val, BaseTy);
6790 SubobjectDesignator Designator(BaseTy);
6791 Designator.addDeclUnchecked(FD);
6792
6793 APValue Result;
6794 return extractSubobject(Info, E, Obj, Designator, Result) &&
6795 DerivedSuccess(Result, E);
6796 }
6797
6798 bool VisitCastExpr(const CastExpr *E) {
6799 switch (E->getCastKind()) {
6800 default:
6801 break;
6802
6803 case CK_AtomicToNonAtomic: {
6804 APValue AtomicVal;
6805 // This does not need to be done in place even for class/array types:
6806 // atomic-to-non-atomic conversion implies copying the object
6807 // representation.
6808 if (!Evaluate(AtomicVal, Info, E->getSubExpr()))
6809 return false;
6810 return DerivedSuccess(AtomicVal, E);
6811 }
6812
6813 case CK_NoOp:
6814 case CK_UserDefinedConversion:
6815 return StmtVisitorTy::Visit(E->getSubExpr());
6816
6817 case CK_LValueToRValue: {
6818 LValue LVal;
6819 if (!EvaluateLValue(E->getSubExpr(), LVal, Info))
6820 return false;
6821 APValue RVal;
6822 // Note, we use the subexpression's type in order to retain cv-qualifiers.
6823 if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
6824 LVal, RVal))
6825 return false;
6826 return DerivedSuccess(RVal, E);
6827 }
6828 case CK_LValueToRValueBitCast: {
6829 APValue DestValue, SourceValue;
6830 if (!Evaluate(SourceValue, Info, E->getSubExpr()))
6831 return false;
6832 if (!handleLValueToRValueBitCast(Info, DestValue, SourceValue, E))
6833 return false;
6834 return DerivedSuccess(DestValue, E);
6835 }
6836 }
6837
6838 return Error(E);
6839 }
6840
6841 bool VisitUnaryPostInc(const UnaryOperator *UO) {
6842 return VisitUnaryPostIncDec(UO);
6843 }
6844 bool VisitUnaryPostDec(const UnaryOperator *UO) {
6845 return VisitUnaryPostIncDec(UO);
6846 }
6847 bool VisitUnaryPostIncDec(const UnaryOperator *UO) {
6848 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
6849 return Error(UO);
6850
6851 LValue LVal;
6852 if (!EvaluateLValue(UO->getSubExpr(), LVal, Info))
6853 return false;
6854 APValue RVal;
6855 if (!handleIncDec(this->Info, UO, LVal, UO->getSubExpr()->getType(),
6856 UO->isIncrementOp(), &RVal))
6857 return false;
6858 return DerivedSuccess(RVal, UO);
6859 }
6860
6861 bool VisitStmtExpr(const StmtExpr *E) {
6862 // We will have checked the full-expressions inside the statement expression
6863 // when they were completed, and don't need to check them again now.
6864 if (Info.checkingForUndefinedBehavior())
6865 return Error(E);
6866
6867 const CompoundStmt *CS = E->getSubStmt();
6868 if (CS->body_empty())
6869 return true;
6870
6871 BlockScopeRAII Scope(Info);
6872 for (CompoundStmt::const_body_iterator BI = CS->body_begin(),
6873 BE = CS->body_end();
6874 /**/; ++BI) {
6875 if (BI + 1 == BE) {
6876 const Expr *FinalExpr = dyn_cast<Expr>(*BI);
6877 if (!FinalExpr) {
6878 Info.FFDiag((*BI)->getBeginLoc(),
6879 diag::note_constexpr_stmt_expr_unsupported);
6880 return false;
6881 }
6882 return this->Visit(FinalExpr) && Scope.destroy();
6883 }
6884
6885 APValue ReturnValue;
6886 StmtResult Result = { ReturnValue, nullptr };
6887 EvalStmtResult ESR = EvaluateStmt(Result, Info, *BI);
6888 if (ESR != ESR_Succeeded) {
6889 // FIXME: If the statement-expression terminated due to 'return',
6890 // 'break', or 'continue', it would be nice to propagate that to
6891 // the outer statement evaluation rather than bailing out.
6892 if (ESR != ESR_Failed)
6893 Info.FFDiag((*BI)->getBeginLoc(),
6894 diag::note_constexpr_stmt_expr_unsupported);
6895 return false;
6896 }
6897 }
6898
6899 llvm_unreachable("Return from function from the loop above.")::llvm::llvm_unreachable_internal("Return from function from the loop above."
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6899)
;
6900 }
6901
6902 /// Visit a value which is evaluated, but whose value is ignored.
6903 void VisitIgnoredValue(const Expr *E) {
6904 EvaluateIgnoredValue(Info, E);
6905 }
6906
6907 /// Potentially visit a MemberExpr's base expression.
6908 void VisitIgnoredBaseExpression(const Expr *E) {
6909 // While MSVC doesn't evaluate the base expression, it does diagnose the
6910 // presence of side-effecting behavior.
6911 if (Info.getLangOpts().MSVCCompat && !E->HasSideEffects(Info.Ctx))
6912 return;
6913 VisitIgnoredValue(E);
6914 }
6915};
6916
6917} // namespace
6918
6919//===----------------------------------------------------------------------===//
6920// Common base class for lvalue and temporary evaluation.
6921//===----------------------------------------------------------------------===//
6922namespace {
6923template<class Derived>
6924class LValueExprEvaluatorBase
6925 : public ExprEvaluatorBase<Derived> {
6926protected:
6927 LValue &Result;
6928 bool InvalidBaseOK;
6929 typedef LValueExprEvaluatorBase LValueExprEvaluatorBaseTy;
6930 typedef ExprEvaluatorBase<Derived> ExprEvaluatorBaseTy;
6931
6932 bool Success(APValue::LValueBase B) {
6933 Result.set(B);
6934 return true;
6935 }
6936
6937 bool evaluatePointer(const Expr *E, LValue &Result) {
6938 return EvaluatePointer(E, Result, this->Info, InvalidBaseOK);
6939 }
6940
6941public:
6942 LValueExprEvaluatorBase(EvalInfo &Info, LValue &Result, bool InvalidBaseOK)
6943 : ExprEvaluatorBaseTy(Info), Result(Result),
6944 InvalidBaseOK(InvalidBaseOK) {}
6945
6946 bool Success(const APValue &V, const Expr *E) {
6947 Result.setFrom(this->Info.Ctx, V);
6948 return true;
6949 }
6950
6951 bool VisitMemberExpr(const MemberExpr *E) {
6952 // Handle non-static data members.
6953 QualType BaseTy;
6954 bool EvalOK;
6955 if (E->isArrow()) {
6956 EvalOK = evaluatePointer(E->getBase(), Result);
6957 BaseTy = E->getBase()->getType()->castAs<PointerType>()->getPointeeType();
6958 } else if (E->getBase()->isRValue()) {
6959 assert(E->getBase()->getType()->isRecordType())((E->getBase()->getType()->isRecordType()) ? static_cast
<void> (0) : __assert_fail ("E->getBase()->getType()->isRecordType()"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6959, __PRETTY_FUNCTION__))
;
6960 EvalOK = EvaluateTemporary(E->getBase(), Result, this->Info);
6961 BaseTy = E->getBase()->getType();
6962 } else {
6963 EvalOK = this->Visit(E->getBase());
6964 BaseTy = E->getBase()->getType();
6965 }
6966 if (!EvalOK) {
6967 if (!InvalidBaseOK)
6968 return false;
6969 Result.setInvalid(E);
6970 return true;
6971 }
6972
6973 const ValueDecl *MD = E->getMemberDecl();
6974 if (const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl())) {
6975 assert(BaseTy->getAs<RecordType>()->getDecl()->getCanonicalDecl() ==((BaseTy->getAs<RecordType>()->getDecl()->getCanonicalDecl
() == FD->getParent()->getCanonicalDecl() && "record / field mismatch"
) ? static_cast<void> (0) : __assert_fail ("BaseTy->getAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6976, __PRETTY_FUNCTION__))
6976 FD->getParent()->getCanonicalDecl() && "record / field mismatch")((BaseTy->getAs<RecordType>()->getDecl()->getCanonicalDecl
() == FD->getParent()->getCanonicalDecl() && "record / field mismatch"
) ? static_cast<void> (0) : __assert_fail ("BaseTy->getAs<RecordType>()->getDecl()->getCanonicalDecl() == FD->getParent()->getCanonicalDecl() && \"record / field mismatch\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 6976, __PRETTY_FUNCTION__))
;
6977 (void)BaseTy;
6978 if (!HandleLValueMember(this->Info, E, Result, FD))
6979 return false;
6980 } else if (const IndirectFieldDecl *IFD = dyn_cast<IndirectFieldDecl>(MD)) {
6981 if (!HandleLValueIndirectMember(this->Info, E, Result, IFD))
6982 return false;
6983 } else
6984 return this->Error(E);
6985
6986 if (MD->getType()->isReferenceType()) {
6987 APValue RefValue;
6988 if (!handleLValueToRValueConversion(this->Info, E, MD->getType(), Result,
6989 RefValue))
6990 return false;
6991 return Success(RefValue, E);
6992 }
6993 return true;
6994 }
6995
6996 bool VisitBinaryOperator(const BinaryOperator *E) {
6997 switch (E->getOpcode()) {
6998 default:
6999 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
7000
7001 case BO_PtrMemD:
7002 case BO_PtrMemI:
7003 return HandleMemberPointerAccess(this->Info, E, Result);
7004 }
7005 }
7006
7007 bool VisitCastExpr(const CastExpr *E) {
7008 switch (E->getCastKind()) {
7009 default:
7010 return ExprEvaluatorBaseTy::VisitCastExpr(E);
7011
7012 case CK_DerivedToBase:
7013 case CK_UncheckedDerivedToBase:
7014 if (!this->Visit(E->getSubExpr()))
7015 return false;
7016
7017 // Now figure out the necessary offset to add to the base LV to get from
7018 // the derived class to the base class.
7019 return HandleLValueBasePath(this->Info, E, E->getSubExpr()->getType(),
7020 Result);
7021 }
7022 }
7023};
7024}
7025
7026//===----------------------------------------------------------------------===//
7027// LValue Evaluation
7028//
7029// This is used for evaluating lvalues (in C and C++), xvalues (in C++11),
7030// function designators (in C), decl references to void objects (in C), and
7031// temporaries (if building with -Wno-address-of-temporary).
7032//
7033// LValue evaluation produces values comprising a base expression of one of the
7034// following types:
7035// - Declarations
7036// * VarDecl
7037// * FunctionDecl
7038// - Literals
7039// * CompoundLiteralExpr in C (and in global scope in C++)
7040// * StringLiteral
7041// * PredefinedExpr
7042// * ObjCStringLiteralExpr
7043// * ObjCEncodeExpr
7044// * AddrLabelExpr
7045// * BlockExpr
7046// * CallExpr for a MakeStringConstant builtin
7047// - typeid(T) expressions, as TypeInfoLValues
7048// - Locals and temporaries
7049// * MaterializeTemporaryExpr
7050// * Any Expr, with a CallIndex indicating the function in which the temporary
7051// was evaluated, for cases where the MaterializeTemporaryExpr is missing
7052// from the AST (FIXME).
7053// * A MaterializeTemporaryExpr that has static storage duration, with no
7054// CallIndex, for a lifetime-extended temporary.
7055// plus an offset in bytes.
7056//===----------------------------------------------------------------------===//
7057namespace {
7058class LValueExprEvaluator
7059 : public LValueExprEvaluatorBase<LValueExprEvaluator> {
7060public:
7061 LValueExprEvaluator(EvalInfo &Info, LValue &Result, bool InvalidBaseOK) :
7062 LValueExprEvaluatorBaseTy(Info, Result, InvalidBaseOK) {}
7063
7064 bool VisitVarDecl(const Expr *E, const VarDecl *VD);
7065 bool VisitUnaryPreIncDec(const UnaryOperator *UO);
7066
7067 bool VisitDeclRefExpr(const DeclRefExpr *E);
7068 bool VisitPredefinedExpr(const PredefinedExpr *E) { return Success(E); }
7069 bool VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
7070 bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
7071 bool VisitMemberExpr(const MemberExpr *E);
7072 bool VisitStringLiteral(const StringLiteral *E) { return Success(E); }
7073 bool VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { return Success(E); }
7074 bool VisitCXXTypeidExpr(const CXXTypeidExpr *E);
7075 bool VisitCXXUuidofExpr(const CXXUuidofExpr *E);
7076 bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E);
7077 bool VisitUnaryDeref(const UnaryOperator *E);
7078 bool VisitUnaryReal(const UnaryOperator *E);
7079 bool VisitUnaryImag(const UnaryOperator *E);
7080 bool VisitUnaryPreInc(const UnaryOperator *UO) {
7081 return VisitUnaryPreIncDec(UO);
7082 }
7083 bool VisitUnaryPreDec(const UnaryOperator *UO) {
7084 return VisitUnaryPreIncDec(UO);
7085 }
7086 bool VisitBinAssign(const BinaryOperator *BO);
7087 bool VisitCompoundAssignOperator(const CompoundAssignOperator *CAO);
7088
7089 bool VisitCastExpr(const CastExpr *E) {
7090 switch (E->getCastKind()) {
7091 default:
7092 return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
7093
7094 case CK_LValueBitCast:
7095 this->CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
7096 if (!Visit(E->getSubExpr()))
7097 return false;
7098 Result.Designator.setInvalid();
7099 return true;
7100
7101 case CK_BaseToDerived:
7102 if (!Visit(E->getSubExpr()))
7103 return false;
7104 return HandleBaseToDerivedCast(Info, E, Result);
7105
7106 case CK_Dynamic:
7107 if (!Visit(E->getSubExpr()))
7108 return false;
7109 return HandleDynamicCast(Info, cast<ExplicitCastExpr>(E), Result);
7110 }
7111 }
7112};
7113} // end anonymous namespace
7114
7115/// Evaluate an expression as an lvalue. This can be legitimately called on
7116/// expressions which are not glvalues, in three cases:
7117/// * function designators in C, and
7118/// * "extern void" objects
7119/// * @selector() expressions in Objective-C
7120static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
7121 bool InvalidBaseOK) {
7122 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7123, __PRETTY_FUNCTION__))
7123 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7123, __PRETTY_FUNCTION__))
;
7124 return LValueExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
7125}
7126
7127bool LValueExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
7128 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(E->getDecl()))
7129 return Success(FD);
7130 if (const VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()))
7131 return VisitVarDecl(E, VD);
7132 if (const BindingDecl *BD = dyn_cast<BindingDecl>(E->getDecl()))
7133 return Visit(BD->getBinding());
7134 return Error(E);
7135}
7136
7137
7138bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
7139
7140 // If we are within a lambda's call operator, check whether the 'VD' referred
7141 // to within 'E' actually represents a lambda-capture that maps to a
7142 // data-member/field within the closure object, and if so, evaluate to the
7143 // field or what the field refers to.
7144 if (Info.CurrentCall && isLambdaCallOperator(Info.CurrentCall->Callee) &&
7145 isa<DeclRefExpr>(E) &&
7146 cast<DeclRefExpr>(E)->refersToEnclosingVariableOrCapture()) {
7147 // We don't always have a complete capture-map when checking or inferring if
7148 // the function call operator meets the requirements of a constexpr function
7149 // - but we don't need to evaluate the captures to determine constexprness
7150 // (dcl.constexpr C++17).
7151 if (Info.checkingPotentialConstantExpression())
7152 return false;
7153
7154 if (auto *FD = Info.CurrentCall->LambdaCaptureFields.lookup(VD)) {
7155 // Start with 'Result' referring to the complete closure object...
7156 Result = *Info.CurrentCall->This;
7157 // ... then update it to refer to the field of the closure object
7158 // that represents the capture.
7159 if (!HandleLValueMember(Info, E, Result, FD))
7160 return false;
7161 // And if the field is of reference type, update 'Result' to refer to what
7162 // the field refers to.
7163 if (FD->getType()->isReferenceType()) {
7164 APValue RVal;
7165 if (!handleLValueToRValueConversion(Info, E, FD->getType(), Result,
7166 RVal))
7167 return false;
7168 Result.setFrom(Info.Ctx, RVal);
7169 }
7170 return true;
7171 }
7172 }
7173 CallStackFrame *Frame = nullptr;
7174 if (VD->hasLocalStorage() && Info.CurrentCall->Index > 1) {
7175 // Only if a local variable was declared in the function currently being
7176 // evaluated, do we expect to be able to find its value in the current
7177 // frame. (Otherwise it was likely declared in an enclosing context and
7178 // could either have a valid evaluatable value (for e.g. a constexpr
7179 // variable) or be ill-formed (and trigger an appropriate evaluation
7180 // diagnostic)).
7181 if (Info.CurrentCall->Callee &&
7182 Info.CurrentCall->Callee->Equals(VD->getDeclContext())) {
7183 Frame = Info.CurrentCall;
7184 }
7185 }
7186
7187 if (!VD->getType()->isReferenceType()) {
7188 if (Frame) {
7189 Result.set({VD, Frame->Index,
7190 Info.CurrentCall->getCurrentTemporaryVersion(VD)});
7191 return true;
7192 }
7193 return Success(VD);
7194 }
7195
7196 APValue *V;
7197 if (!evaluateVarDeclInit(Info, E, VD, Frame, V, nullptr))
7198 return false;
7199 if (!V->hasValue()) {
7200 // FIXME: Is it possible for V to be indeterminate here? If so, we should
7201 // adjust the diagnostic to say that.
7202 if (!Info.checkingPotentialConstantExpression())
7203 Info.FFDiag(E, diag::note_constexpr_use_uninit_reference);
7204 return false;
7205 }
7206 return Success(*V, E);
7207}
7208
7209bool LValueExprEvaluator::VisitMaterializeTemporaryExpr(
7210 const MaterializeTemporaryExpr *E) {
7211 // Walk through the expression to find the materialized temporary itself.
7212 SmallVector<const Expr *, 2> CommaLHSs;
7213 SmallVector<SubobjectAdjustment, 2> Adjustments;
7214 const Expr *Inner = E->GetTemporaryExpr()->
7215 skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
7216
7217 // If we passed any comma operators, evaluate their LHSs.
7218 for (unsigned I = 0, N = CommaLHSs.size(); I != N; ++I)
7219 if (!EvaluateIgnoredValue(Info, CommaLHSs[I]))
7220 return false;
7221
7222 // A materialized temporary with static storage duration can appear within the
7223 // result of a constant expression evaluation, so we need to preserve its
7224 // value for use outside this evaluation.
7225 APValue *Value;
7226 if (E->getStorageDuration() == SD_Static) {
7227 Value = Info.Ctx.getMaterializedTemporaryValue(E, true);
7228 *Value = APValue();
7229 Result.set(E);
7230 } else {
7231 Value = &Info.CurrentCall->createTemporary(
7232 E, E->getType(), E->getStorageDuration() == SD_Automatic, Result);
7233 }
7234
7235 QualType Type = Inner->getType();
7236
7237 // Materialize the temporary itself.
7238 if (!EvaluateInPlace(*Value, Info, Result, Inner)) {
7239 *Value = APValue();
7240 return false;
7241 }
7242
7243 // Adjust our lvalue to refer to the desired subobject.
7244 for (unsigned I = Adjustments.size(); I != 0; /**/) {
7245 --I;
7246 switch (Adjustments[I].Kind) {
7247 case SubobjectAdjustment::DerivedToBaseAdjustment:
7248 if (!HandleLValueBasePath(Info, Adjustments[I].DerivedToBase.BasePath,
7249 Type, Result))
7250 return false;
7251 Type = Adjustments[I].DerivedToBase.BasePath->getType();
7252 break;
7253
7254 case SubobjectAdjustment::FieldAdjustment:
7255 if (!HandleLValueMember(Info, E, Result, Adjustments[I].Field))
7256 return false;
7257 Type = Adjustments[I].Field->getType();
7258 break;
7259
7260 case SubobjectAdjustment::MemberPointerAdjustment:
7261 if (!HandleMemberPointerAccess(this->Info, Type, Result,
7262 Adjustments[I].Ptr.RHS))
7263 return false;
7264 Type = Adjustments[I].Ptr.MPT->getPointeeType();
7265 break;
7266 }
7267 }
7268
7269 return true;
7270}
7271
7272bool
7273LValueExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
7274 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7275, __PRETTY_FUNCTION__))
7275 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7275, __PRETTY_FUNCTION__))
;
7276 // Defer visiting the literal until the lvalue-to-rvalue conversion. We can
7277 // only see this when folding in C, so there's no standard to follow here.
7278 return Success(E);
7279}
7280
7281bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
7282 TypeInfoLValue TypeInfo;
7283
7284 if (!E->isPotentiallyEvaluated()) {
7285 if (E->isTypeOperand())
7286 TypeInfo = TypeInfoLValue(E->getTypeOperand(Info.Ctx).getTypePtr());
7287 else
7288 TypeInfo = TypeInfoLValue(E->getExprOperand()->getType().getTypePtr());
7289 } else {
7290 if (!Info.Ctx.getLangOpts().CPlusPlus2a) {
7291 Info.CCEDiag(E, diag::note_constexpr_typeid_polymorphic)
7292 << E->getExprOperand()->getType()
7293 << E->getExprOperand()->getSourceRange();
7294 }
7295
7296 if (!Visit(E->getExprOperand()))
7297 return false;
7298
7299 Optional<DynamicType> DynType =
7300 ComputeDynamicType(Info, E, Result, AK_TypeId);
7301 if (!DynType)
7302 return false;
7303
7304 TypeInfo =
7305 TypeInfoLValue(Info.Ctx.getRecordType(DynType->Type).getTypePtr());
7306 }
7307
7308 return Success(APValue::LValueBase::getTypeInfo(TypeInfo, E->getType()));
7309}
7310
7311bool LValueExprEvaluator::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
7312 return Success(E);
7313}
7314
7315bool LValueExprEvaluator::VisitMemberExpr(const MemberExpr *E) {
7316 // Handle static data members.
7317 if (const VarDecl *VD = dyn_cast<VarDecl>(E->getMemberDecl())) {
7318 VisitIgnoredBaseExpression(E->getBase());
7319 return VisitVarDecl(E, VD);
7320 }
7321
7322 // Handle static member functions.
7323 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl())) {
7324 if (MD->isStatic()) {
7325 VisitIgnoredBaseExpression(E->getBase());
7326 return Success(MD);
7327 }
7328 }
7329
7330 // Handle non-static data members.
7331 return LValueExprEvaluatorBaseTy::VisitMemberExpr(E);
7332}
7333
7334bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
7335 // FIXME: Deal with vectors as array subscript bases.
7336 if (E->getBase()->getType()->isVectorType())
7337 return Error(E);
7338
7339 bool Success = true;
7340 if (!evaluatePointer(E->getBase(), Result)) {
7341 if (!Info.noteFailure())
7342 return false;
7343 Success = false;
7344 }
7345
7346 APSInt Index;
7347 if (!EvaluateInteger(E->getIdx(), Index, Info))
7348 return false;
7349
7350 return Success &&
7351 HandleLValueArrayAdjustment(Info, E, Result, E->getType(), Index);
7352}
7353
7354bool LValueExprEvaluator::VisitUnaryDeref(const UnaryOperator *E) {
7355 return evaluatePointer(E->getSubExpr(), Result);
7356}
7357
7358bool LValueExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
7359 if (!Visit(E->getSubExpr()))
7360 return false;
7361 // __real is a no-op on scalar lvalues.
7362 if (E->getSubExpr()->getType()->isAnyComplexType())
7363 HandleLValueComplexElement(Info, E, Result, E->getType(), false);
7364 return true;
7365}
7366
7367bool LValueExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
7368 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7369, __PRETTY_FUNCTION__))
7369 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7369, __PRETTY_FUNCTION__))
;
7370 if (!Visit(E->getSubExpr()))
7371 return false;
7372 HandleLValueComplexElement(Info, E, Result, E->getType(), true);
7373 return true;
7374}
7375
7376bool LValueExprEvaluator::VisitUnaryPreIncDec(const UnaryOperator *UO) {
7377 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
7378 return Error(UO);
7379
7380 if (!this->Visit(UO->getSubExpr()))
7381 return false;
7382
7383 return handleIncDec(
7384 this->Info, UO, Result, UO->getSubExpr()->getType(),
7385 UO->isIncrementOp(), nullptr);
7386}
7387
7388bool LValueExprEvaluator::VisitCompoundAssignOperator(
7389 const CompoundAssignOperator *CAO) {
7390 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
7391 return Error(CAO);
7392
7393 APValue RHS;
7394
7395 // The overall lvalue result is the result of evaluating the LHS.
7396 if (!this->Visit(CAO->getLHS())) {
7397 if (Info.noteFailure())
7398 Evaluate(RHS, this->Info, CAO->getRHS());
7399 return false;
7400 }
7401
7402 if (!Evaluate(RHS, this->Info, CAO->getRHS()))
7403 return false;
7404
7405 return handleCompoundAssignment(
7406 this->Info, CAO,
7407 Result, CAO->getLHS()->getType(), CAO->getComputationLHSType(),
7408 CAO->getOpForCompoundAssignment(CAO->getOpcode()), RHS);
7409}
7410
7411bool LValueExprEvaluator::VisitBinAssign(const BinaryOperator *E) {
7412 if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
7413 return Error(E);
7414
7415 APValue NewVal;
7416
7417 if (!this->Visit(E->getLHS())) {
7418 if (Info.noteFailure())
7419 Evaluate(NewVal, this->Info, E->getRHS());
7420 return false;
7421 }
7422
7423 if (!Evaluate(NewVal, this->Info, E->getRHS()))
7424 return false;
7425
7426 if (Info.getLangOpts().CPlusPlus2a &&
7427 !HandleUnionActiveMemberChange(Info, E->getLHS(), Result))
7428 return false;
7429
7430 return handleAssignment(this->Info, E, Result, E->getLHS()->getType(),
7431 NewVal);
7432}
7433
7434//===----------------------------------------------------------------------===//
7435// Pointer Evaluation
7436//===----------------------------------------------------------------------===//
7437
7438/// Attempts to compute the number of bytes available at the pointer
7439/// returned by a function with the alloc_size attribute. Returns true if we
7440/// were successful. Places an unsigned number into `Result`.
7441///
7442/// This expects the given CallExpr to be a call to a function with an
7443/// alloc_size attribute.
7444static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
7445 const CallExpr *Call,
7446 llvm::APInt &Result) {
7447 const AllocSizeAttr *AllocSize = getAllocSizeAttr(Call);
7448
7449 assert(AllocSize && AllocSize->getElemSizeParam().isValid())((AllocSize && AllocSize->getElemSizeParam().isValid
()) ? static_cast<void> (0) : __assert_fail ("AllocSize && AllocSize->getElemSizeParam().isValid()"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7449, __PRETTY_FUNCTION__))
;
7450 unsigned SizeArgNo = AllocSize->getElemSizeParam().getASTIndex();
7451 unsigned BitsInSizeT = Ctx.getTypeSize(Ctx.getSizeType());
7452 if (Call->getNumArgs() <= SizeArgNo)
7453 return false;
7454
7455 auto EvaluateAsSizeT = [&](const Expr *E, APSInt &Into) {
7456 Expr::EvalResult ExprResult;
7457 if (!E->EvaluateAsInt(ExprResult, Ctx, Expr::SE_AllowSideEffects))
7458 return false;
7459 Into = ExprResult.Val.getInt();
7460 if (Into.isNegative() || !Into.isIntN(BitsInSizeT))
7461 return false;
7462 Into = Into.zextOrSelf(BitsInSizeT);
7463 return true;
7464 };
7465
7466 APSInt SizeOfElem;
7467 if (!EvaluateAsSizeT(Call->getArg(SizeArgNo), SizeOfElem))
7468 return false;
7469
7470 if (!AllocSize->getNumElemsParam().isValid()) {
7471 Result = std::move(SizeOfElem);
7472 return true;
7473 }
7474
7475 APSInt NumberOfElems;
7476 unsigned NumArgNo = AllocSize->getNumElemsParam().getASTIndex();
7477 if (!EvaluateAsSizeT(Call->getArg(NumArgNo), NumberOfElems))
7478 return false;
7479
7480 bool Overflow;
7481 llvm::APInt BytesAvailable = SizeOfElem.umul_ov(NumberOfElems, Overflow);
7482 if (Overflow)
7483 return false;
7484
7485 Result = std::move(BytesAvailable);
7486 return true;
7487}
7488
7489/// Convenience function. LVal's base must be a call to an alloc_size
7490/// function.
7491static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
7492 const LValue &LVal,
7493 llvm::APInt &Result) {
7494 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7495, __PRETTY_FUNCTION__))
7495 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7495, __PRETTY_FUNCTION__))
;
7496 const auto *Base = LVal.getLValueBase().get<const Expr *>();
7497 const CallExpr *CE = tryUnwrapAllocSizeCall(Base);
7498 return getBytesReturnedByAllocSizeCall(Ctx, CE, Result);
7499}
7500
7501/// Attempts to evaluate the given LValueBase as the result of a call to
7502/// a function with the alloc_size attribute. If it was possible to do so, this
7503/// function will return true, make Result's Base point to said function call,
7504/// and mark Result's Base as invalid.
7505static bool evaluateLValueAsAllocSize(EvalInfo &Info, APValue::LValueBase Base,
7506 LValue &Result) {
7507 if (Base.isNull())
7508 return false;
7509
7510 // Because we do no form of static analysis, we only support const variables.
7511 //
7512 // Additionally, we can't support parameters, nor can we support static
7513 // variables (in the latter case, use-before-assign isn't UB; in the former,
7514 // we have no clue what they'll be assigned to).
7515 const auto *VD =
7516 dyn_cast_or_null<VarDecl>(Base.dyn_cast<const ValueDecl *>());
7517 if (!VD || !VD->isLocalVarDecl() || !VD->getType().isConstQualified())
7518 return false;
7519
7520 const Expr *Init = VD->getAnyInitializer();
7521 if (!Init)
7522 return false;
7523
7524 const Expr *E = Init->IgnoreParens();
7525 if (!tryUnwrapAllocSizeCall(E))
7526 return false;
7527
7528 // Store E instead of E unwrapped so that the type of the LValue's base is
7529 // what the user wanted.
7530 Result.setInvalid(E);
7531
7532 QualType Pointee = E->getType()->castAs<PointerType>()->getPointeeType();
7533 Result.addUnsizedArray(Info, E, Pointee);
7534 return true;
7535}
7536
7537namespace {
7538class PointerExprEvaluator
7539 : public ExprEvaluatorBase<PointerExprEvaluator> {
7540 LValue &Result;
7541 bool InvalidBaseOK;
7542
7543 bool Success(const Expr *E) {
7544 Result.set(E);
7545 return true;
7546 }
7547
7548 bool evaluateLValue(const Expr *E, LValue &Result) {
7549 return EvaluateLValue(E, Result, Info, InvalidBaseOK);
7550 }
7551
7552 bool evaluatePointer(const Expr *E, LValue &Result) {
7553 return EvaluatePointer(E, Result, Info, InvalidBaseOK);
7554 }
7555
7556 bool visitNonBuiltinCallExpr(const CallExpr *E);
7557public:
7558
7559 PointerExprEvaluator(EvalInfo &info, LValue &Result, bool InvalidBaseOK)
7560 : ExprEvaluatorBaseTy(info), Result(Result),
7561 InvalidBaseOK(InvalidBaseOK) {}
7562
7563 bool Success(const APValue &V, const Expr *E) {
7564 Result.setFrom(Info.Ctx, V);
7565 return true;
7566 }
7567 bool ZeroInitialization(const Expr *E) {
7568 auto TargetVal = Info.Ctx.getTargetNullPointerValue(E->getType());
7569 Result.setNull(E->getType(), TargetVal);
7570 return true;
7571 }
7572
7573 bool VisitBinaryOperator(const BinaryOperator *E);
7574 bool VisitCastExpr(const CastExpr* E);
7575 bool VisitUnaryAddrOf(const UnaryOperator *E);
7576 bool VisitObjCStringLiteral(const ObjCStringLiteral *E)
7577 { return Success(E); }
7578 bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
7579 if (E->isExpressibleAsConstantInitializer())
7580 return Success(E);
7581 if (Info.noteFailure())
7582 EvaluateIgnoredValue(Info, E->getSubExpr());
7583 return Error(E);
7584 }
7585 bool VisitAddrLabelExpr(const AddrLabelExpr *E)
7586 { return Success(E); }
7587 bool VisitCallExpr(const CallExpr *E);
7588 bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
7589 bool VisitBlockExpr(const BlockExpr *E) {
7590 if (!E->getBlockDecl()->hasCaptures())
7591 return Success(E);
7592 return Error(E);
7593 }
7594 bool VisitCXXThisExpr(const CXXThisExpr *E) {
7595 // Can't look at 'this' when checking a potential constant expression.
7596 if (Info.checkingPotentialConstantExpression())
7597 return false;
7598 if (!Info.CurrentCall->This) {
7599 if (Info.getLangOpts().CPlusPlus11)
7600 Info.FFDiag(E, diag::note_constexpr_this) << E->isImplicit();
7601 else
7602 Info.FFDiag(E);
7603 return false;
7604 }
7605 Result = *Info.CurrentCall->This;
7606 // If we are inside a lambda's call operator, the 'this' expression refers
7607 // to the enclosing '*this' object (either by value or reference) which is
7608 // either copied into the closure object's field that represents the '*this'
7609 // or refers to '*this'.
7610 if (isLambdaCallOperator(Info.CurrentCall->Callee)) {
7611 // Update 'Result' to refer to the data member/field of the closure object
7612 // that represents the '*this' capture.
7613 if (!HandleLValueMember(Info, E, Result,
7614 Info.CurrentCall->LambdaThisCaptureField))
7615 return false;
7616 // If we captured '*this' by reference, replace the field with its referent.
7617 if (Info.CurrentCall->LambdaThisCaptureField->getType()
7618 ->isPointerType()) {
7619 APValue RVal;
7620 if (!handleLValueToRValueConversion(Info, E, E->getType(), Result,
7621 RVal))
7622 return false;
7623
7624 Result.setFrom(Info.Ctx, RVal);
7625 }
7626 }
7627 return true;
7628 }
7629
7630 bool VisitCXXNewExpr(const CXXNewExpr *E);
7631
7632 bool VisitSourceLocExpr(const SourceLocExpr *E) {
7633 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7633, __PRETTY_FUNCTION__))
;
7634 APValue LValResult = E->EvaluateInContext(
7635 Info.Ctx, Info.CurrentCall->CurSourceLocExprScope.getDefaultExpr());
7636 Result.setFrom(Info.Ctx, LValResult);
7637 return true;
7638 }
7639
7640 // FIXME: Missing: @protocol, @selector
7641};
7642} // end anonymous namespace
7643
7644static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info,
7645 bool InvalidBaseOK) {
7646 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7646, __PRETTY_FUNCTION__))
;
7647 return PointerExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
7648}
7649
7650bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
7651 if (E->getOpcode() != BO_Add &&
7652 E->getOpcode() != BO_Sub)
7653 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
7654
7655 const Expr *PExp = E->getLHS();
7656 const Expr *IExp = E->getRHS();
7657 if (IExp->getType()->isPointerType())
7658 std::swap(PExp, IExp);
7659
7660 bool EvalPtrOK = evaluatePointer(PExp, Result);
7661 if (!EvalPtrOK && !Info.noteFailure())
7662 return false;
7663
7664 llvm::APSInt Offset;
7665 if (!EvaluateInteger(IExp, Offset, Info) || !EvalPtrOK)
7666 return false;
7667
7668 if (E->getOpcode() == BO_Sub)
7669 negateAsSigned(Offset);
7670
7671 QualType Pointee = PExp->getType()->castAs<PointerType>()->getPointeeType();
7672 return HandleLValueArrayAdjustment(Info, E, Result, Pointee, Offset);
7673}
7674
7675bool PointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
7676 return evaluateLValue(E->getSubExpr(), Result);
7677}
7678
7679bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
7680 const Expr *SubExpr = E->getSubExpr();
7681
7682 switch (E->getCastKind()) {
7683 default:
7684 break;
7685 case CK_BitCast:
7686 case CK_CPointerToObjCPointerCast:
7687 case CK_BlockPointerToObjCPointerCast:
7688 case CK_AnyPointerToBlockPointerCast:
7689 case CK_AddressSpaceConversion:
7690 if (!Visit(SubExpr))
7691 return false;
7692 // Bitcasts to cv void* are static_casts, not reinterpret_casts, so are
7693 // permitted in constant expressions in C++11. Bitcasts from cv void* are
7694 // also static_casts, but we disallow them as a resolution to DR1312.
7695 if (!E->getType()->isVoidPointerType()) {
7696 Result.Designator.setInvalid();
7697 if (SubExpr->getType()->isVoidPointerType())
7698 CCEDiag(E, diag::note_constexpr_invalid_cast)
7699 << 3 << SubExpr->getType();
7700 else
7701 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
7702 }
7703 if (E->getCastKind() == CK_AddressSpaceConversion && Result.IsNullPtr)
7704 ZeroInitialization(E);
7705 return true;
7706
7707 case CK_DerivedToBase:
7708 case CK_UncheckedDerivedToBase:
7709 if (!evaluatePointer(E->getSubExpr(), Result))
7710 return false;
7711 if (!Result.Base && Result.Offset.isZero())
7712 return true;
7713
7714 // Now figure out the necessary offset to add to the base LV to get from
7715 // the derived class to the base class.
7716 return HandleLValueBasePath(Info, E, E->getSubExpr()->getType()->
7717 castAs<PointerType>()->getPointeeType(),
7718 Result);
7719
7720 case CK_BaseToDerived:
7721 if (!Visit(E->getSubExpr()))
7722 return false;
7723 if (!Result.Base && Result.Offset.isZero())
7724 return true;
7725 return HandleBaseToDerivedCast(Info, E, Result);
7726
7727 case CK_Dynamic:
7728 if (!Visit(E->getSubExpr()))
7729 return false;
7730 return HandleDynamicCast(Info, cast<ExplicitCastExpr>(E), Result);
7731
7732 case CK_NullToPointer:
7733 VisitIgnoredValue(E->getSubExpr());
7734 return ZeroInitialization(E);
7735
7736 case CK_IntegralToPointer: {
7737 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
7738
7739 APValue Value;
7740 if (!EvaluateIntegerOrLValue(SubExpr, Value, Info))
7741 break;
7742
7743 if (Value.isInt()) {
7744 unsigned Size = Info.Ctx.getTypeSize(E->getType());
7745 uint64_t N = Value.getInt().extOrTrunc(Size).getZExtValue();
7746 Result.Base = (Expr*)nullptr;
7747 Result.InvalidBase = false;
7748 Result.Offset = CharUnits::fromQuantity(N);
7749 Result.Designator.setInvalid();
7750 Result.IsNullPtr = false;
7751 return true;
7752 } else {
7753 // Cast is of an lvalue, no need to change value.
7754 Result.setFrom(Info.Ctx, Value);
7755 return true;
7756 }
7757 }
7758
7759 case CK_ArrayToPointerDecay: {
7760 if (SubExpr->isGLValue()) {
7761 if (!evaluateLValue(SubExpr, Result))
7762 return false;
7763 } else {
7764 APValue &Value = Info.CurrentCall->createTemporary(
7765 SubExpr, SubExpr->getType(), false, Result);
7766 if (!EvaluateInPlace(Value, Info, Result, SubExpr))
7767 return false;
7768 }
7769 // The result is a pointer to the first element of the array.
7770 auto *AT = Info.Ctx.getAsArrayType(SubExpr->getType());
7771 if (auto *CAT = dyn_cast<ConstantArrayType>(AT))
7772 Result.addArray(Info, E, CAT);
7773 else
7774 Result.addUnsizedArray(Info, E, AT->getElementType());
7775 return true;
7776 }
7777
7778 case CK_FunctionToPointerDecay:
7779 return evaluateLValue(SubExpr, Result);
7780
7781 case CK_LValueToRValue: {
7782 LValue LVal;
7783 if (!evaluateLValue(E->getSubExpr(), LVal))
7784 return false;
7785
7786 APValue RVal;
7787 // Note, we use the subexpression's type in order to retain cv-qualifiers.
7788 if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
7789 LVal, RVal))
7790 return InvalidBaseOK &&
7791 evaluateLValueAsAllocSize(Info, LVal.Base, Result);
7792 return Success(RVal, E);
7793 }
7794 }
7795
7796 return ExprEvaluatorBaseTy::VisitCastExpr(E);
7797}
7798
7799static CharUnits GetAlignOfType(EvalInfo &Info, QualType T,
7800 UnaryExprOrTypeTrait ExprKind) {
7801 // C++ [expr.alignof]p3:
7802 // When alignof is applied to a reference type, the result is the
7803 // alignment of the referenced type.
7804 if (const ReferenceType *Ref = T->getAs<ReferenceType>())
7805 T = Ref->getPointeeType();
7806
7807 if (T.getQualifiers().hasUnaligned())
7808 return CharUnits::One();
7809
7810 const bool AlignOfReturnsPreferred =
7811 Info.Ctx.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver7;
7812
7813 // __alignof is defined to return the preferred alignment.
7814 // Before 8, clang returned the preferred alignment for alignof and _Alignof
7815 // as well.
7816 if (ExprKind == UETT_PreferredAlignOf || AlignOfReturnsPreferred)
7817 return Info.Ctx.toCharUnitsFromBits(
7818 Info.Ctx.getPreferredTypeAlign(T.getTypePtr()));
7819 // alignof and _Alignof are defined to return the ABI alignment.
7820 else if (ExprKind == UETT_AlignOf)
7821 return Info.Ctx.getTypeAlignInChars(T.getTypePtr());
7822 else
7823 llvm_unreachable("GetAlignOfType on a non-alignment ExprKind")::llvm::llvm_unreachable_internal("GetAlignOfType on a non-alignment ExprKind"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7823)
;
7824}
7825
7826static CharUnits GetAlignOfExpr(EvalInfo &Info, const Expr *E,
7827 UnaryExprOrTypeTrait ExprKind) {
7828 E = E->IgnoreParens();
7829
7830 // The kinds of expressions that we have special-case logic here for
7831 // should be kept up to date with the special checks for those
7832 // expressions in Sema.
7833
7834 // alignof decl is always accepted, even if it doesn't make sense: we default
7835 // to 1 in those cases.
7836 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
7837 return Info.Ctx.getDeclAlign(DRE->getDecl(),
7838 /*RefAsPointee*/true);
7839
7840 if (const MemberExpr *ME = dyn_cast<MemberExpr>(E))
7841 return Info.Ctx.getDeclAlign(ME->getMemberDecl(),
7842 /*RefAsPointee*/true);
7843
7844 return GetAlignOfType(Info, E->getType(), ExprKind);
7845}
7846
7847// To be clear: this happily visits unsupported builtins. Better name welcomed.
7848bool PointerExprEvaluator::visitNonBuiltinCallExpr(const CallExpr *E) {
7849 if (ExprEvaluatorBaseTy::VisitCallExpr(E))
7850 return true;
7851
7852 if (!(InvalidBaseOK && getAllocSizeAttr(E)))
7853 return false;
7854
7855 Result.setInvalid(E);
7856 QualType PointeeTy = E->getType()->castAs<PointerType>()->getPointeeType();
7857 Result.addUnsizedArray(Info, E, PointeeTy);
7858 return true;
7859}
7860
7861bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) {
7862 if (IsStringLiteralCall(E))
7863 return Success(E);
7864
7865 if (unsigned BuiltinOp = E->getBuiltinCallee())
7866 return VisitBuiltinCallExpr(E, BuiltinOp);
7867
7868 return visitNonBuiltinCallExpr(E);
7869}
7870
7871bool PointerExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
7872 unsigned BuiltinOp) {
7873 switch (BuiltinOp) {
7874 case Builtin::BI__builtin_addressof:
7875 return evaluateLValue(E->getArg(0), Result);
7876 case Builtin::BI__builtin_assume_aligned: {
7877 // We need to be very careful here because: if the pointer does not have the
7878 // asserted alignment, then the behavior is undefined, and undefined
7879 // behavior is non-constant.
7880 if (!evaluatePointer(E->getArg(0), Result))
7881 return false;
7882
7883 LValue OffsetResult(Result);
7884 APSInt Alignment;
7885 if (!EvaluateInteger(E->getArg(1), Alignment, Info))
7886 return false;
7887 CharUnits Align = CharUnits::fromQuantity(Alignment.getZExtValue());
7888
7889 if (E->getNumArgs() > 2) {
7890 APSInt Offset;
7891 if (!EvaluateInteger(E->getArg(2), Offset, Info))
7892 return false;
7893
7894 int64_t AdditionalOffset = -Offset.getZExtValue();
7895 OffsetResult.Offset += CharUnits::fromQuantity(AdditionalOffset);
7896 }
7897
7898 // If there is a base object, then it must have the correct alignment.
7899 if (OffsetResult.Base) {
7900 CharUnits BaseAlignment;
7901 if (const ValueDecl *VD =
7902 OffsetResult.Base.dyn_cast<const ValueDecl*>()) {
7903 BaseAlignment = Info.Ctx.getDeclAlign(VD);
7904 } else if (const Expr *E = OffsetResult.Base.dyn_cast<const Expr *>()) {
7905 BaseAlignment = GetAlignOfExpr(Info, E, UETT_AlignOf);
7906 } else {
7907 BaseAlignment = GetAlignOfType(
7908 Info, OffsetResult.Base.getTypeInfoType(), UETT_AlignOf);
7909 }
7910
7911 if (BaseAlignment < Align) {
7912 Result.Designator.setInvalid();
7913 // FIXME: Add support to Diagnostic for long / long long.
7914 CCEDiag(E->getArg(0),
7915 diag::note_constexpr_baa_insufficient_alignment) << 0
7916 << (unsigned)BaseAlignment.getQuantity()
7917 << (unsigned)Align.getQuantity();
7918 return false;
7919 }
7920 }
7921
7922 // The offset must also have the correct alignment.
7923 if (OffsetResult.Offset.alignTo(Align) != OffsetResult.Offset) {
7924 Result.Designator.setInvalid();
7925
7926 (OffsetResult.Base
7927 ? CCEDiag(E->getArg(0),
7928 diag::note_constexpr_baa_insufficient_alignment) << 1
7929 : CCEDiag(E->getArg(0),
7930 diag::note_constexpr_baa_value_insufficient_alignment))
7931 << (int)OffsetResult.Offset.getQuantity()
7932 << (unsigned)Align.getQuantity();
7933 return false;
7934 }
7935
7936 return true;
7937 }
7938 case Builtin::BI__builtin_launder:
7939 return evaluatePointer(E->getArg(0), Result);
7940 case Builtin::BIstrchr:
7941 case Builtin::BIwcschr:
7942 case Builtin::BImemchr:
7943 case Builtin::BIwmemchr:
7944 if (Info.getLangOpts().CPlusPlus11)
7945 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
7946 << /*isConstexpr*/0 << /*isConstructor*/0
7947 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
7948 else
7949 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
7950 LLVM_FALLTHROUGH[[gnu::fallthrough]];
7951 case Builtin::BI__builtin_strchr:
7952 case Builtin::BI__builtin_wcschr:
7953 case Builtin::BI__builtin_memchr:
7954 case Builtin::BI__builtin_char_memchr:
7955 case Builtin::BI__builtin_wmemchr: {
7956 if (!Visit(E->getArg(0)))
7957 return false;
7958 APSInt Desired;
7959 if (!EvaluateInteger(E->getArg(1), Desired, Info))
7960 return false;
7961 uint64_t MaxLength = uint64_t(-1);
7962 if (BuiltinOp != Builtin::BIstrchr &&
7963 BuiltinOp != Builtin::BIwcschr &&
7964 BuiltinOp != Builtin::BI__builtin_strchr &&
7965 BuiltinOp != Builtin::BI__builtin_wcschr) {
7966 APSInt N;
7967 if (!EvaluateInteger(E->getArg(2), N, Info))
7968 return false;
7969 MaxLength = N.getExtValue();
7970 }
7971 // We cannot find the value if there are no candidates to match against.
7972 if (MaxLength == 0u)
7973 return ZeroInitialization(E);
7974 if (!Result.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
7975 Result.Designator.Invalid)
7976 return false;
7977 QualType CharTy = Result.Designator.getType(Info.Ctx);
7978 bool IsRawByte = BuiltinOp == Builtin::BImemchr ||
7979 BuiltinOp == Builtin::BI__builtin_memchr;
7980 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7982, __PRETTY_FUNCTION__))
7981 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7982, __PRETTY_FUNCTION__))
7982 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 7982, __PRETTY_FUNCTION__))
;
7983 // Pointers to const void may point to objects of incomplete type.
7984 if (IsRawByte && CharTy->isIncompleteType()) {
7985 Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy;
7986 return false;
7987 }
7988 // Give up on byte-oriented matching against multibyte elements.
7989 // FIXME: We can compare the bytes in the correct order.
7990 if (IsRawByte && Info.Ctx.getTypeSizeInChars(CharTy) != CharUnits::One())
7991 return false;
7992 // Figure out what value we're actually looking for (after converting to
7993 // the corresponding unsigned type if necessary).
7994 uint64_t DesiredVal;
7995 bool StopAtNull = false;
7996 switch (BuiltinOp) {
7997 case Builtin::BIstrchr:
7998 case Builtin::BI__builtin_strchr:
7999 // strchr compares directly to the passed integer, and therefore
8000 // always fails if given an int that is not a char.
8001 if (!APSInt::isSameValue(HandleIntToIntCast(Info, E, CharTy,
8002 E->getArg(1)->getType(),
8003 Desired),
8004 Desired))
8005 return ZeroInitialization(E);
8006 StopAtNull = true;
8007 LLVM_FALLTHROUGH[[gnu::fallthrough]];
8008 case Builtin::BImemchr:
8009 case Builtin::BI__builtin_memchr:
8010 case Builtin::BI__builtin_char_memchr:
8011 // memchr compares by converting both sides to unsigned char. That's also
8012 // correct for strchr if we get this far (to cope with plain char being
8013 // unsigned in the strchr case).
8014 DesiredVal = Desired.trunc(Info.Ctx.getCharWidth()).getZExtValue();
8015 break;
8016
8017 case Builtin::BIwcschr:
8018 case Builtin::BI__builtin_wcschr:
8019 StopAtNull = true;
8020 LLVM_FALLTHROUGH[[gnu::fallthrough]];
8021 case Builtin::BIwmemchr:
8022 case Builtin::BI__builtin_wmemchr:
8023 // wcschr and wmemchr are given a wchar_t to look for. Just use it.
8024 DesiredVal = Desired.getZExtValue();
8025 break;
8026 }
8027
8028 for (; MaxLength; --MaxLength) {
8029 APValue Char;
8030 if (!handleLValueToRValueConversion(Info, E, CharTy, Result, Char) ||
8031 !Char.isInt())
8032 return false;
8033 if (Char.getInt().getZExtValue() == DesiredVal)
8034 return true;
8035 if (StopAtNull && !Char.getInt())
8036 break;
8037 if (!HandleLValueArrayAdjustment(Info, E, Result, CharTy, 1))
8038 return false;
8039 }
8040 // Not found: return nullptr.
8041 return ZeroInitialization(E);
8042 }
8043
8044 case Builtin::BImemcpy:
8045 case Builtin::BImemmove:
8046 case Builtin::BIwmemcpy:
8047 case Builtin::BIwmemmove:
8048 if (Info.getLangOpts().CPlusPlus11)
8049 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
8050 << /*isConstexpr*/0 << /*isConstructor*/0
8051 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
8052 else
8053 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
8054 LLVM_FALLTHROUGH[[gnu::fallthrough]];
8055 case Builtin::BI__builtin_memcpy:
8056 case Builtin::BI__builtin_memmove:
8057 case Builtin::BI__builtin_wmemcpy:
8058 case Builtin::BI__builtin_wmemmove: {
8059 bool WChar = BuiltinOp == Builtin::BIwmemcpy ||
8060 BuiltinOp == Builtin::BIwmemmove ||
8061 BuiltinOp == Builtin::BI__builtin_wmemcpy ||
8062 BuiltinOp == Builtin::BI__builtin_wmemmove;
8063 bool Move = BuiltinOp == Builtin::BImemmove ||
8064 BuiltinOp == Builtin::BIwmemmove ||
8065 BuiltinOp == Builtin::BI__builtin_memmove ||
8066 BuiltinOp == Builtin::BI__builtin_wmemmove;
8067
8068 // The result of mem* is the first argument.
8069 if (!Visit(E->getArg(0)))
8070 return false;
8071 LValue Dest = Result;
8072
8073 LValue Src;
8074 if (!EvaluatePointer(E->getArg(1), Src, Info))
8075 return false;
8076
8077 APSInt N;
8078 if (!EvaluateInteger(E->getArg(2), N, Info))
8079 return false;
8080 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8080, __PRETTY_FUNCTION__))
;
8081
8082 // If the size is zero, we treat this as always being a valid no-op.
8083 // (Even if one of the src and dest pointers is null.)
8084 if (!N)
8085 return true;
8086
8087 // Otherwise, if either of the operands is null, we can't proceed. Don't
8088 // try to determine the type of the copied objects, because there aren't
8089 // any.
8090 if (!Src.Base || !Dest.Base) {
8091 APValue Val;
8092 (!Src.Base ? Src : Dest).moveInto(Val);
8093 Info.FFDiag(E, diag::note_constexpr_memcpy_null)
8094 << Move << WChar << !!Src.Base
8095 << Val.getAsString(Info.Ctx, E->getArg(0)->getType());
8096 return false;
8097 }
8098 if (Src.Designator.Invalid || Dest.Designator.Invalid)
8099 return false;
8100
8101 // We require that Src and Dest are both pointers to arrays of
8102 // trivially-copyable type. (For the wide version, the designator will be
8103 // invalid if the designated object is not a wchar_t.)
8104 QualType T = Dest.Designator.getType(Info.Ctx);
8105 QualType SrcT = Src.Designator.getType(Info.Ctx);
8106 if (!Info.Ctx.hasSameUnqualifiedType(T, SrcT)) {
8107 Info.FFDiag(E, diag::note_constexpr_memcpy_type_pun) << Move << SrcT << T;
8108 return false;
8109 }
8110 if (T->isIncompleteType()) {
8111 Info.FFDiag(E, diag::note_constexpr_memcpy_incomplete_type) << Move << T;
8112 return false;
8113 }
8114 if (!T.isTriviallyCopyableType(Info.Ctx)) {
8115 Info.FFDiag(E, diag::note_constexpr_memcpy_nontrivial) << Move << T;
8116 return false;
8117 }
8118
8119 // Figure out how many T's we're copying.
8120 uint64_t TSize = Info.Ctx.getTypeSizeInChars(T).getQuantity();
8121 if (!WChar) {
8122 uint64_t Remainder;
8123 llvm::APInt OrigN = N;
8124 llvm::APInt::udivrem(OrigN, TSize, N, Remainder);
8125 if (Remainder) {
8126 Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
8127 << Move << WChar << 0 << T << OrigN.toString(10, /*Signed*/false)
8128 << (unsigned)TSize;
8129 return false;
8130 }
8131 }
8132
8133 // Check that the copying will remain within the arrays, just so that we
8134 // can give a more meaningful diagnostic. This implicitly also checks that
8135 // N fits into 64 bits.
8136 uint64_t RemainingSrcSize = Src.Designator.validIndexAdjustments().second;
8137 uint64_t RemainingDestSize = Dest.Designator.validIndexAdjustments().second;
8138 if (N.ugt(RemainingSrcSize) || N.ugt(RemainingDestSize)) {
8139 Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
8140 << Move << WChar << (N.ugt(RemainingSrcSize) ? 1 : 2) << T
8141 << N.toString(10, /*Signed*/false);
8142 return false;
8143 }
8144 uint64_t NElems = N.getZExtValue();
8145 uint64_t NBytes = NElems * TSize;
8146
8147 // Check for overlap.
8148 int Direction = 1;
8149 if (HasSameBase(Src, Dest)) {
8150 uint64_t SrcOffset = Src.getLValueOffset().getQuantity();
8151 uint64_t DestOffset = Dest.getLValueOffset().getQuantity();
8152 if (DestOffset >= SrcOffset && DestOffset - SrcOffset < NBytes) {
8153 // Dest is inside the source region.
8154 if (!Move) {
8155 Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
8156 return false;
8157 }
8158 // For memmove and friends, copy backwards.
8159 if (!HandleLValueArrayAdjustment(Info, E, Src, T, NElems - 1) ||
8160 !HandleLValueArrayAdjustment(Info, E, Dest, T, NElems - 1))
8161 return false;
8162 Direction = -1;
8163 } else if (!Move && SrcOffset >= DestOffset &&
8164 SrcOffset - DestOffset < NBytes) {
8165 // Src is inside the destination region for memcpy: invalid.
8166 Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
8167 return false;
8168 }
8169 }
8170
8171 while (true) {
8172 APValue Val;
8173 // FIXME: Set WantObjectRepresentation to true if we're copying a
8174 // char-like type?
8175 if (!handleLValueToRValueConversion(Info, E, T, Src, Val) ||
8176 !handleAssignment(Info, E, Dest, T, Val))
8177 return false;
8178 // Do not iterate past the last element; if we're copying backwards, that
8179 // might take us off the start of the array.
8180 if (--NElems == 0)
8181 return true;
8182 if (!HandleLValueArrayAdjustment(Info, E, Src, T, Direction) ||
8183 !HandleLValueArrayAdjustment(Info, E, Dest, T, Direction))
8184 return false;
8185 }
8186 }
8187
8188 default:
8189 return visitNonBuiltinCallExpr(E);
8190 }
8191}
8192
8193static bool EvaluateArrayNewInitList(EvalInfo &Info, LValue &This,
8194 APValue &Result, const InitListExpr *ILE,
8195 QualType AllocType);
8196
8197bool PointerExprEvaluator::VisitCXXNewExpr(const CXXNewExpr *E) {
8198 if (!Info.getLangOpts().CPlusPlus2a)
8199 Info.CCEDiag(E, diag::note_constexpr_new);
8200
8201 // We cannot speculatively evaluate a delete expression.
8202 if (Info.SpeculativeEvaluationDepth)
8203 return false;
8204
8205 FunctionDecl *OperatorNew = E->getOperatorNew();
8206 if (!OperatorNew->isReplaceableGlobalAllocationFunction()) {
8207 Info.FFDiag(E, diag::note_constexpr_new_non_replaceable)
8208 << isa<CXXMethodDecl>(OperatorNew) << OperatorNew;
8209 return false;
8210 }
8211
8212 bool IsNothrow = false;
8213 if (E->getNumPlacementArgs()) {
8214 // The only new-placement list we support is of the form (std::nothrow).
8215 //
8216 // FIXME: There is no restriction on this, but it's not clear that any
8217 // other form makes any sense. We get here for cases such as:
8218 //
8219 // new (std::align_val_t{N}) X(int)
8220 //
8221 // (which should presumably be valid only if N is a multiple of
8222 // alignof(int), and in any case can't be deallocated unless N is
8223 // alignof(X) and X has new-extended alignment).
8224 if (E->getNumPlacementArgs() != 1 ||
8225 !E->getPlacementArg(0)->getType()->isNothrowT())
8226 return Error(E, diag::note_constexpr_new_placement);
8227
8228 LValue Nothrow;
8229 if (!EvaluateLValue(E->getPlacementArg(0), Nothrow, Info))
8230 return false;
8231 IsNothrow = true;
8232 }
8233
8234 const Expr *Init = E->getInitializer();
8235 const InitListExpr *ResizedArrayILE = nullptr;
8236
8237 QualType AllocType = E->getAllocatedType();
8238 if (Optional<const Expr*> ArraySize = E->getArraySize()) {
8239 const Expr *Stripped = *ArraySize;
8240 for (; auto *ICE = dyn_cast<ImplicitCastExpr>(Stripped);
8241 Stripped = ICE->getSubExpr())
8242 if (ICE->getCastKind() != CK_NoOp &&
8243 ICE->getCastKind() != CK_IntegralCast)
8244 break;
8245
8246 llvm::APSInt ArrayBound;
8247 if (!EvaluateInteger(Stripped, ArrayBound, Info))
8248 return false;
8249
8250 // C++ [expr.new]p9:
8251 // The expression is erroneous if:
8252 // -- [...] its value before converting to size_t [or] applying the
8253 // second standard conversion sequence is less than zero
8254 if (ArrayBound.isSigned() && ArrayBound.isNegative()) {
8255 if (IsNothrow)
8256 return ZeroInitialization(E);
8257
8258 Info.FFDiag(*ArraySize, diag::note_constexpr_new_negative)
8259 << ArrayBound << (*ArraySize)->getSourceRange();
8260 return false;
8261 }
8262
8263 // -- its value is such that the size of the allocated object would
8264 // exceed the implementation-defined limit
8265 if (ConstantArrayType::getNumAddressingBits(Info.Ctx, AllocType,
8266 ArrayBound) >
8267 ConstantArrayType::getMaxSizeBits(Info.Ctx)) {
8268 if (IsNothrow)
8269 return ZeroInitialization(E);
8270
8271 Info.FFDiag(*ArraySize, diag::note_constexpr_new_too_large)
8272 << ArrayBound << (*ArraySize)->getSourceRange();
8273 return false;
8274 }
8275
8276 // -- the new-initializer is a braced-init-list and the number of
8277 // array elements for which initializers are provided [...]
8278 // exceeds the number of elements to initialize
8279 if (Init) {
8280 auto *CAT = Info.Ctx.getAsConstantArrayType(Init->getType());
8281 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8281, __PRETTY_FUNCTION__))
;
8282
8283 unsigned Bits =
8284 std::max(CAT->getSize().getBitWidth(), ArrayBound.getBitWidth());
8285 llvm::APInt InitBound = CAT->getSize().zextOrSelf(Bits);
8286 llvm::APInt AllocBound = ArrayBound.zextOrSelf(Bits);
8287 if (InitBound.ugt(AllocBound)) {
8288 if (IsNothrow)
8289 return ZeroInitialization(E);
8290
8291 Info.FFDiag(*ArraySize, diag::note_constexpr_new_too_small)
8292 << AllocBound.toString(10, /*Signed=*/false)
8293 << InitBound.toString(10, /*Signed=*/false)
8294 << (*ArraySize)->getSourceRange();
8295 return false;
8296 }
8297
8298 // If the sizes differ, we must have an initializer list, and we need
8299 // special handling for this case when we initialize.
8300 if (InitBound != AllocBound)
8301 ResizedArrayILE = cast<InitListExpr>(Init);
8302 }
8303
8304 AllocType = Info.Ctx.getConstantArrayType(AllocType, ArrayBound,
8305 ArrayType::Normal, 0);
8306 } else {
8307 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8308, __PRETTY_FUNCTION__))
8308 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8308, __PRETTY_FUNCTION__))
;
8309 }
8310
8311 // Perform the allocation and obtain a pointer to the resulting object.
8312 APValue *Val = Info.createHeapAlloc(E, AllocType, Result);
8313 if (!Val)
8314 return false;
8315
8316 if (ResizedArrayILE) {
8317 if (!EvaluateArrayNewInitList(Info, Result, *Val, ResizedArrayILE,
8318 AllocType))
8319 return false;
8320 } else if (Init) {
8321 if (!EvaluateInPlace(*Val, Info, Result, Init))
8322 return false;
8323 } else {
8324 *Val = getDefaultInitValue(AllocType);
8325 }
8326
8327 // Array new returns a pointer to the first element, not a pointer to the
8328 // array.
8329 if (auto *AT = AllocType->getAsArrayTypeUnsafe())
8330 Result.addArray(Info, E, cast<ConstantArrayType>(AT));
8331
8332 return true;
8333}
8334//===----------------------------------------------------------------------===//
8335// Member Pointer Evaluation
8336//===----------------------------------------------------------------------===//
8337
8338namespace {
8339class MemberPointerExprEvaluator
8340 : public ExprEvaluatorBase<MemberPointerExprEvaluator> {
8341 MemberPtr &Result;
8342
8343 bool Success(const ValueDecl *D) {
8344 Result = MemberPtr(D);
8345 return true;
8346 }
8347public:
8348
8349 MemberPointerExprEvaluator(EvalInfo &Info, MemberPtr &Result)
8350 : ExprEvaluatorBaseTy(Info), Result(Result) {}
8351
8352 bool Success(const APValue &V, const Expr *E) {
8353 Result.setFrom(V);
8354 return true;
8355 }
8356 bool ZeroInitialization(const Expr *E) {
8357 return Success((const ValueDecl*)nullptr);
8358 }
8359
8360 bool VisitCastExpr(const CastExpr *E);
8361 bool VisitUnaryAddrOf(const UnaryOperator *E);
8362};
8363} // end anonymous namespace
8364
8365static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
8366 EvalInfo &Info) {
8367 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8367, __PRETTY_FUNCTION__))
;
8368 return MemberPointerExprEvaluator(Info, Result).Visit(E);
8369}
8370
8371bool MemberPointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
8372 switch (E->getCastKind()) {
8373 default:
8374 return ExprEvaluatorBaseTy::VisitCastExpr(E);
8375
8376 case CK_NullToMemberPointer:
8377 VisitIgnoredValue(E->getSubExpr());
8378 return ZeroInitialization(E);
8379
8380 case CK_BaseToDerivedMemberPointer: {
8381 if (!Visit(E->getSubExpr()))
8382 return false;
8383 if (E->path_empty())
8384 return true;
8385 // Base-to-derived member pointer casts store the path in derived-to-base
8386 // order, so iterate backwards. The CXXBaseSpecifier also provides us with
8387 // the wrong end of the derived->base arc, so stagger the path by one class.
8388 typedef std::reverse_iterator<CastExpr::path_const_iterator> ReverseIter;
8389 for (ReverseIter PathI(E->path_end() - 1), PathE(E->path_begin());
8390 PathI != PathE; ++PathI) {
8391 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8391, __PRETTY_FUNCTION__))
;
8392 const CXXRecordDecl *Derived = (*PathI)->getType()->getAsCXXRecordDecl();
8393 if (!Result.castToDerived(Derived))
8394 return Error(E);
8395 }
8396 const Type *FinalTy = E->getType()->castAs<MemberPointerType>()->getClass();
8397 if (!Result.castToDerived(FinalTy->getAsCXXRecordDecl()))
8398 return Error(E);
8399 return true;
8400 }
8401
8402 case CK_DerivedToBaseMemberPointer:
8403 if (!Visit(E->getSubExpr()))
8404 return false;
8405 for (CastExpr::path_const_iterator PathI = E->path_begin(),
8406 PathE = E->path_end(); PathI != PathE; ++PathI) {
8407 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8407, __PRETTY_FUNCTION__))
;
8408 const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
8409 if (!Result.castToBase(Base))
8410 return Error(E);
8411 }
8412 return true;
8413 }
8414}
8415
8416bool MemberPointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
8417 // C++11 [expr.unary.op]p3 has very strict rules on how the address of a
8418 // member can be formed.
8419 return Success(cast<DeclRefExpr>(E->getSubExpr())->getDecl());
8420}
8421
8422//===----------------------------------------------------------------------===//
8423// Record Evaluation
8424//===----------------------------------------------------------------------===//
8425
8426namespace {
8427 class RecordExprEvaluator
8428 : public ExprEvaluatorBase<RecordExprEvaluator> {
8429 const LValue &This;
8430 APValue &Result;
8431 public:
8432
8433 RecordExprEvaluator(EvalInfo &info, const LValue &This, APValue &Result)
8434 : ExprEvaluatorBaseTy(info), This(This), Result(Result) {}
8435
8436 bool Success(const APValue &V, const Expr *E) {
8437 Result = V;
8438 return true;
8439 }
8440 bool ZeroInitialization(const Expr *E) {
8441 return ZeroInitialization(E, E->getType());
8442 }
8443 bool ZeroInitialization(const Expr *E, QualType T);
8444
8445 bool VisitCallExpr(const CallExpr *E) {
8446 return handleCallExpr(E, Result, &This);
8447 }
8448 bool VisitCastExpr(const CastExpr *E);
8449 bool VisitInitListExpr(const InitListExpr *E);
8450 bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
8451 return VisitCXXConstructExpr(E, E->getType());
8452 }
8453 bool VisitLambdaExpr(const LambdaExpr *E);
8454 bool VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
8455 bool VisitCXXConstructExpr(const CXXConstructExpr *E, QualType T);
8456 bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E);
8457 bool VisitBinCmp(const BinaryOperator *E);
8458 };
8459}
8460
8461/// Perform zero-initialization on an object of non-union class type.
8462/// C++11 [dcl.init]p5:
8463/// To zero-initialize an object or reference of type T means:
8464/// [...]
8465/// -- if T is a (possibly cv-qualified) non-union class type,
8466/// each non-static data member and each base-class subobject is
8467/// zero-initialized
8468static bool HandleClassZeroInitialization(EvalInfo &Info, const Expr *E,
8469 const RecordDecl *RD,
8470 const LValue &This, APValue &Result) {
8471 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8471, __PRETTY_FUNCTION__))
;
8472 const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
8473 Result = APValue(APValue::UninitStruct(), CD ? CD->getNumBases() : 0,
8474 std::distance(RD->field_begin(), RD->field_end()));
8475
8476 if (RD->isInvalidDecl()) return false;
8477 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
8478
8479 if (CD) {
8480 unsigned Index = 0;
8481 for (CXXRecordDecl::base_class_const_iterator I = CD->bases_begin(),
8482 End = CD->bases_end(); I != End; ++I, ++Index) {
8483 const CXXRecordDecl *Base = I->getType()->getAsCXXRecordDecl();
8484 LValue Subobject = This;
8485 if (!HandleLValueDirectBase(Info, E, Subobject, CD, Base, &Layout))
8486 return false;
8487 if (!HandleClassZeroInitialization(Info, E, Base, Subobject,
8488 Result.getStructBase(Index)))
8489 return false;
8490 }
8491 }
8492
8493 for (const auto *I : RD->fields()) {
8494 // -- if T is a reference type, no initialization is performed.
8495 if (I->getType()->isReferenceType())
8496 continue;
8497
8498 LValue Subobject = This;
8499 if (!HandleLValueMember(Info, E, Subobject, I, &Layout))
8500 return false;
8501
8502 ImplicitValueInitExpr VIE(I->getType());
8503 if (!EvaluateInPlace(
8504 Result.getStructField(I->getFieldIndex()), Info, Subobject, &VIE))
8505 return false;
8506 }
8507
8508 return true;
8509}
8510
8511bool RecordExprEvaluator::ZeroInitialization(const Expr *E, QualType T) {
8512 const RecordDecl *RD = T->castAs<RecordType>()->getDecl();
8513 if (RD->isInvalidDecl()) return false;
8514 if (RD->isUnion()) {
8515 // C++11 [dcl.init]p5: If T is a (possibly cv-qualified) union type, the
8516 // object's first non-static named data member is zero-initialized
8517 RecordDecl::field_iterator I = RD->field_begin();
8518 if (I == RD->field_end()) {
8519 Result = APValue((const FieldDecl*)nullptr);
8520 return true;
8521 }
8522
8523 LValue Subobject = This;
8524 if (!HandleLValueMember(Info, E, Subobject, *I))
8525 return false;
8526 Result = APValue(*I);
8527 ImplicitValueInitExpr VIE(I->getType());
8528 return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, &VIE);
8529 }
8530
8531 if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->getNumVBases()) {
8532 Info.FFDiag(E, diag::note_constexpr_virtual_base) << RD;
8533 return false;
8534 }
8535
8536 return HandleClassZeroInitialization(Info, E, RD, This, Result);
8537}
8538
8539bool RecordExprEvaluator::VisitCastExpr(const CastExpr *E) {
8540 switch (E->getCastKind()) {
8541 default:
8542 return ExprEvaluatorBaseTy::VisitCastExpr(E);
8543
8544 case CK_ConstructorConversion:
8545 return Visit(E->getSubExpr());
8546
8547 case CK_DerivedToBase:
8548 case CK_UncheckedDerivedToBase: {
8549 APValue DerivedObject;
8550 if (!Evaluate(DerivedObject, Info, E->getSubExpr()))
8551 return false;
8552 if (!DerivedObject.isStruct())
8553 return Error(E->getSubExpr());
8554
8555 // Derived-to-base rvalue conversion: just slice off the derived part.
8556 APValue *Value = &DerivedObject;
8557 const CXXRecordDecl *RD = E->getSubExpr()->getType()->getAsCXXRecordDecl();
8558 for (CastExpr::path_const_iterator PathI = E->path_begin(),
8559 PathE = E->path_end(); PathI != PathE; ++PathI) {
8560 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8560, __PRETTY_FUNCTION__))
;
8561 const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
8562 Value = &Value->getStructBase(getBaseIndex(RD, Base));
8563 RD = Base;
8564 }
8565 Result = *Value;
8566 return true;
8567 }
8568 }
8569}
8570
8571bool RecordExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
8572 if (E->isTransparent())
8573 return Visit(E->getInit(0));
8574
8575 const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
8576 if (RD->isInvalidDecl()) return false;
8577 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
8578 auto *CXXRD = dyn_cast<CXXRecordDecl>(RD);
8579
8580 EvalInfo::EvaluatingConstructorRAII EvalObj(
8581 Info,
8582 ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries},
8583 CXXRD && CXXRD->getNumBases());
8584
8585 if (RD->isUnion()) {
8586 const FieldDecl *Field = E->getInitializedFieldInUnion();
8587 Result = APValue(Field);
8588 if (!Field)
8589 return true;
8590
8591 // If the initializer list for a union does not contain any elements, the
8592 // first element of the union is value-initialized.
8593 // FIXME: The element should be initialized from an initializer list.
8594 // Is this difference ever observable for initializer lists which
8595 // we don't build?
8596 ImplicitValueInitExpr VIE(Field->getType());
8597 const Expr *InitExpr = E->getNumInits() ? E->getInit(0) : &VIE;
8598
8599 LValue Subobject = This;
8600 if (!HandleLValueMember(Info, InitExpr, Subobject, Field, &Layout))
8601 return false;
8602
8603 // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
8604 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
8605 isa<CXXDefaultInitExpr>(InitExpr));
8606
8607 return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, InitExpr);
8608 }
8609
8610 if (!Result.hasValue())
8611 Result = APValue(APValue::UninitStruct(), CXXRD ? CXXRD->getNumBases() : 0,
8612 std::distance(RD->field_begin(), RD->field_end()));
8613 unsigned ElementNo = 0;
8614 bool Success = true;
8615
8616 // Initialize base classes.
8617 if (CXXRD && CXXRD->getNumBases()) {
8618 for (const auto &Base : CXXRD->bases()) {
8619 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8619, __PRETTY_FUNCTION__))
;
8620 const Expr *Init = E->getInit(ElementNo);
8621
8622 LValue Subobject = This;
8623 if (!HandleLValueBase(Info, Init, Subobject, CXXRD, &Base))
8624 return false;
8625
8626 APValue &FieldVal = Result.getStructBase(ElementNo);
8627 if (!EvaluateInPlace(FieldVal, Info, Subobject, Init)) {
8628 if (!Info.noteFailure())
8629 return false;
8630 Success = false;
8631 }
8632 ++ElementNo;
8633 }
8634
8635 EvalObj.finishedConstructingBases();
8636 }
8637
8638 // Initialize members.
8639 for (const auto *Field : RD->fields()) {
8640 // Anonymous bit-fields are not considered members of the class for
8641 // purposes of aggregate initialization.
8642 if (Field->isUnnamedBitfield())
8643 continue;
8644
8645 LValue Subobject = This;
8646
8647 bool HaveInit = ElementNo < E->getNumInits();
8648
8649 // FIXME: Diagnostics here should point to the end of the initializer
8650 // list, not the start.
8651 if (!HandleLValueMember(Info, HaveInit ? E->getInit(ElementNo) : E,
8652 Subobject, Field, &Layout))
8653 return false;
8654
8655 // Perform an implicit value-initialization for members beyond the end of
8656 // the initializer list.
8657 ImplicitValueInitExpr VIE(HaveInit ? Info.Ctx.IntTy : Field->getType());
8658 const Expr *Init = HaveInit ? E->getInit(ElementNo++) : &VIE;
8659
8660 // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
8661 ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
8662 isa<CXXDefaultInitExpr>(Init));
8663
8664 APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
8665 if (!EvaluateInPlace(FieldVal, Info, Subobject, Init) ||
8666 (Field->isBitField() && !truncateBitfieldValue(Info, Init,
8667 FieldVal, Field))) {
8668 if (!Info.noteFailure())
8669 return false;
8670 Success = false;
8671 }
8672 }
8673
8674 return Success;
8675}
8676
8677bool RecordExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
8678 QualType T) {
8679 // Note that E's type is not necessarily the type of our class here; we might
8680 // be initializing an array element instead.
8681 const CXXConstructorDecl *FD = E->getConstructor();
8682 if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl()) return false;
8683
8684 bool ZeroInit = E->requiresZeroInitialization();
8685 if (CheckTrivialDefaultConstructor(Info, E->getExprLoc(), FD, ZeroInit)) {
8686 // If we've already performed zero-initialization, we're already done.
8687 if (Result.hasValue())
8688 return true;
8689
8690 if (ZeroInit)
8691 return ZeroInitialization(E, T);
8692
8693 Result = getDefaultInitValue(T);
8694 return true;
8695 }
8696
8697 const FunctionDecl *Definition = nullptr;
8698 auto Body = FD->getBody(Definition);
8699
8700 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
8701 return false;
8702
8703 // Avoid materializing a temporary for an elidable copy/move constructor.
8704 if (E->isElidable() && !ZeroInit)
8705 if (const MaterializeTemporaryExpr *ME
8706 = dyn_cast<MaterializeTemporaryExpr>(E->getArg(0)))
8707 return Visit(ME->GetTemporaryExpr());
8708
8709 if (ZeroInit && !ZeroInitialization(E, T))
8710 return false;
8711
8712 auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
8713 return HandleConstructorCall(E, This, Args,
8714 cast<CXXConstructorDecl>(Definition), Info,
8715 Result);
8716}
8717
8718bool RecordExprEvaluator::VisitCXXInheritedCtorInitExpr(
8719 const CXXInheritedCtorInitExpr *E) {
8720 if (!Info.CurrentCall) {
8721 assert(Info.checkingPotentialConstantExpression())((Info.checkingPotentialConstantExpression()) ? static_cast<
void> (0) : __assert_fail ("Info.checkingPotentialConstantExpression()"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8721, __PRETTY_FUNCTION__))
;
8722 return false;
8723 }
8724
8725 const CXXConstructorDecl *FD = E->getConstructor();
8726 if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl())
8727 return false;
8728
8729 const FunctionDecl *Definition = nullptr;
8730 auto Body = FD->getBody(Definition);
8731
8732 if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
8733 return false;
8734
8735 return HandleConstructorCall(E, This, Info.CurrentCall->Arguments,
8736 cast<CXXConstructorDecl>(Definition), Info,
8737 Result);
8738}
8739
8740bool RecordExprEvaluator::VisitCXXStdInitializerListExpr(
8741 const CXXStdInitializerListExpr *E) {
8742 const ConstantArrayType *ArrayType =
8743 Info.Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
8744
8745 LValue Array;
8746 if (!EvaluateLValue(E->getSubExpr(), Array, Info))
8747 return false;
8748
8749 // Get a pointer to the first element of the array.
8750 Array.addArray(Info, E, ArrayType);
8751
8752 // FIXME: Perform the checks on the field types in SemaInit.
8753 RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
8754 RecordDecl::field_iterator Field = Record->field_begin();
8755 if (Field == Record->field_end())
8756 return Error(E);
8757
8758 // Start pointer.
8759 if (!Field->getType()->isPointerType() ||
8760 !Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
8761 ArrayType->getElementType()))
8762 return Error(E);
8763
8764 // FIXME: What if the initializer_list type has base classes, etc?
8765 Result = APValue(APValue::UninitStruct(), 0, 2);
8766 Array.moveInto(Result.getStructField(0));
8767
8768 if (++Field == Record->field_end())
8769 return Error(E);
8770
8771 if (Field->getType()->isPointerType() &&
8772 Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
8773 ArrayType->getElementType())) {
8774 // End pointer.
8775 if (!HandleLValueArrayAdjustment(Info, E, Array,
8776 ArrayType->getElementType(),
8777 ArrayType->getSize().getZExtValue()))
8778 return false;
8779 Array.moveInto(Result.getStructField(1));
8780 } else if (Info.Ctx.hasSameType(Field->getType(), Info.Ctx.getSizeType()))
8781 // Length.
8782 Result.getStructField(1) = APValue(APSInt(ArrayType->getSize()));
8783 else
8784 return Error(E);
8785
8786 if (++Field != Record->field_end())
8787 return Error(E);
8788
8789 return true;
8790}
8791
8792bool RecordExprEvaluator::VisitLambdaExpr(const LambdaExpr *E) {
8793 const CXXRecordDecl *ClosureClass = E->getLambdaClass();
8794 if (ClosureClass->isInvalidDecl())
8795 return false;
8796
8797 const size_t NumFields =
8798 std::distance(ClosureClass->field_begin(), ClosureClass->field_end());
8799
8800 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8803, __PRETTY_FUNCTION__))
8801 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8803, __PRETTY_FUNCTION__))
8802 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8803, __PRETTY_FUNCTION__))
8803 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8803, __PRETTY_FUNCTION__))
;
8804
8805 Result = APValue(APValue::UninitStruct(), /*NumBases*/0, NumFields);
8806 // Iterate through all the lambda's closure object's fields and initialize
8807 // them.
8808 auto *CaptureInitIt = E->capture_init_begin();
8809 const LambdaCapture *CaptureIt = ClosureClass->captures_begin();
8810 bool Success = true;
8811 for (const auto *Field : ClosureClass->fields()) {
8812 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8812, __PRETTY_FUNCTION__))
;
8813 // Get the initializer for this field
8814 Expr *const CurFieldInit = *CaptureInitIt++;
8815
8816 // If there is no initializer, either this is a VLA or an error has
8817 // occurred.
8818 if (!CurFieldInit)
8819 return Error(E);
8820
8821 APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
8822 if (!EvaluateInPlace(FieldVal, Info, This, CurFieldInit)) {
8823 if (!Info.keepEvaluatingAfterFailure())
8824 return false;
8825 Success = false;
8826 }
8827 ++CaptureIt;
8828 }
8829 return Success;
8830}
8831
8832static bool EvaluateRecord(const Expr *E, const LValue &This,
8833 APValue &Result, EvalInfo &Info) {
8834 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8835, __PRETTY_FUNCTION__))
8835 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8835, __PRETTY_FUNCTION__))
;
8836 return RecordExprEvaluator(Info, This, Result).Visit(E);
8837}
8838
8839//===----------------------------------------------------------------------===//
8840// Temporary Evaluation
8841//
8842// Temporaries are represented in the AST as rvalues, but generally behave like
8843// lvalues. The full-object of which the temporary is a subobject is implicitly
8844// materialized so that a reference can bind to it.
8845//===----------------------------------------------------------------------===//
8846namespace {
8847class TemporaryExprEvaluator
8848 : public LValueExprEvaluatorBase<TemporaryExprEvaluator> {
8849public:
8850 TemporaryExprEvaluator(EvalInfo &Info, LValue &Result) :
8851 LValueExprEvaluatorBaseTy(Info, Result, false) {}
8852
8853 /// Visit an expression which constructs the value of this temporary.
8854 bool VisitConstructExpr(const Expr *E) {
8855 APValue &Value =
8856 Info.CurrentCall->createTemporary(E, E->getType(), false, Result);
8857 return EvaluateInPlace(Value, Info, Result, E);
8858 }
8859
8860 bool VisitCastExpr(const CastExpr *E) {
8861 switch (E->getCastKind()) {
8862 default:
8863 return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
8864
8865 case CK_ConstructorConversion:
8866 return VisitConstructExpr(E->getSubExpr());
8867 }
8868 }
8869 bool VisitInitListExpr(const InitListExpr *E) {
8870 return VisitConstructExpr(E);
8871 }
8872 bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
8873 return VisitConstructExpr(E);
8874 }
8875 bool VisitCallExpr(const CallExpr *E) {
8876 return VisitConstructExpr(E);
8877 }
8878 bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E) {
8879 return VisitConstructExpr(E);
8880 }
8881 bool VisitLambdaExpr(const LambdaExpr *E) {
8882 return VisitConstructExpr(E);
8883 }
8884};
8885} // end anonymous namespace
8886
8887/// Evaluate an expression of record type as a temporary.
8888static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info) {
8889 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8889, __PRETTY_FUNCTION__))
;
8890 return TemporaryExprEvaluator(Info, Result).Visit(E);
8891}
8892
8893//===----------------------------------------------------------------------===//
8894// Vector Evaluation
8895//===----------------------------------------------------------------------===//
8896
8897namespace {
8898 class VectorExprEvaluator
8899 : public ExprEvaluatorBase<VectorExprEvaluator> {
8900 APValue &Result;
8901 public:
8902
8903 VectorExprEvaluator(EvalInfo &info, APValue &Result)
8904 : ExprEvaluatorBaseTy(info), Result(Result) {}
8905
8906 bool Success(ArrayRef<APValue> V, const Expr *E) {
8907 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8907, __PRETTY_FUNCTION__))
;
8908 // FIXME: remove this APValue copy.
8909 Result = APValue(V.data(), V.size());
8910 return true;
8911 }
8912 bool Success(const APValue &V, const Expr *E) {
8913 assert(V.isVector())((V.isVector()) ? static_cast<void> (0) : __assert_fail
("V.isVector()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8913, __PRETTY_FUNCTION__))
;
8914 Result = V;
8915 return true;
8916 }
8917 bool ZeroInitialization(const Expr *E);
8918
8919 bool VisitUnaryReal(const UnaryOperator *E)
8920 { return Visit(E->getSubExpr()); }
8921 bool VisitCastExpr(const CastExpr* E);
8922 bool VisitInitListExpr(const InitListExpr *E);
8923 bool VisitUnaryImag(const UnaryOperator *E);
8924 // FIXME: Missing: unary -, unary ~, binary add/sub/mul/div,
8925 // binary comparisons, binary and/or/xor,
8926 // shufflevector, ExtVectorElementExpr
8927 };
8928} // end anonymous namespace
8929
8930static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) {
8931 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 8931, __PRETTY_FUNCTION__))
;
8932 return VectorExprEvaluator(Info, Result).Visit(E);
8933}
8934
8935bool VectorExprEvaluator::VisitCastExpr(const CastExpr *E) {
8936 const VectorType *VTy = E->getType()->castAs<VectorType>();
8937 unsigned NElts = VTy->getNumElements();
8938
8939 const Expr *SE = E->getSubExpr();
8940 QualType SETy = SE->getType();
8941
8942 switch (E->getCastKind()) {
8943 case CK_VectorSplat: {
8944 APValue Val = APValue();
8945 if (SETy->isIntegerType()) {
8946 APSInt IntResult;
8947 if (!EvaluateInteger(SE, IntResult, Info))
8948 return false;
8949 Val = APValue(std::move(IntResult));
8950 } else if (SETy->isRealFloatingType()) {
8951 APFloat FloatResult(0.0);
8952 if (!EvaluateFloat(SE, FloatResult, Info))
8953 return false;
8954 Val = APValue(std::move(FloatResult));
8955 } else {
8956 return Error(E);
8957 }
8958
8959 // Splat and create vector APValue.
8960 SmallVector<APValue, 4> Elts(NElts, Val);
8961 return Success(Elts, E);
8962 }
8963 case CK_BitCast: {
8964 // Evaluate the operand into an APInt we can extract from.
8965 llvm::APInt SValInt;
8966 if (!EvalAndBitcastToAPInt(Info, SE, SValInt))
8967 return false;
8968 // Extract the elements
8969 QualType EltTy = VTy->getElementType();
8970 unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
8971 bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
8972 SmallVector<APValue, 4> Elts;
8973 if (EltTy->isRealFloatingType()) {
8974 const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(EltTy);
8975 unsigned FloatEltSize = EltSize;
8976 if (&Sem == &APFloat::x87DoubleExtended())
8977 FloatEltSize = 80;
8978 for (unsigned i = 0; i < NElts; i++) {
8979 llvm::APInt Elt;
8980 if (BigEndian)
8981 Elt = SValInt.rotl(i*EltSize+FloatEltSize).trunc(FloatEltSize);
8982 else
8983 Elt = SValInt.rotr(i*EltSize).trunc(FloatEltSize);
8984 Elts.push_back(APValue(APFloat(Sem, Elt)));
8985 }
8986 } else if (EltTy->isIntegerType()) {
8987 for (unsigned i = 0; i < NElts; i++) {
8988 llvm::APInt Elt;
8989 if (BigEndian)
8990 Elt = SValInt.rotl(i*EltSize+EltSize).zextOrTrunc(EltSize);
8991 else
8992 Elt = SValInt.rotr(i*EltSize).zextOrTrunc(EltSize);
8993 Elts.push_back(APValue(APSInt(Elt, EltTy->isSignedIntegerType())));
8994 }
8995 } else {
8996 return Error(E);
8997 }
8998 return Success(Elts, E);
8999 }
9000 default:
9001 return ExprEvaluatorBaseTy::VisitCastExpr(E);
9002 }
9003}
9004
9005bool
9006VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
9007 const VectorType *VT = E->getType()->castAs<VectorType>();
9008 unsigned NumInits = E->getNumInits();
9009 unsigned NumElements = VT->getNumElements();
9010
9011 QualType EltTy = VT->getElementType();
9012 SmallVector<APValue, 4> Elements;
9013
9014 // The number of initializers can be less than the number of
9015 // vector elements. For OpenCL, this can be due to nested vector
9016 // initialization. For GCC compatibility, missing trailing elements
9017 // should be initialized with zeroes.
9018 unsigned CountInits = 0, CountElts = 0;
9019 while (CountElts < NumElements) {
9020 // Handle nested vector initialization.
9021 if (CountInits < NumInits
9022 && E->getInit(CountInits)->getType()->isVectorType()) {
9023 APValue v;
9024 if (!EvaluateVector(E->getInit(CountInits), v, Info))
9025 return Error(E);
9026 unsigned vlen = v.getVectorLength();
9027 for (unsigned j = 0; j < vlen; j++)
9028 Elements.push_back(v.getVectorElt(j));
9029 CountElts += vlen;
9030 } else if (EltTy->isIntegerType()) {
9031 llvm::APSInt sInt(32);
9032 if (CountInits < NumInits) {
9033 if (!EvaluateInteger(E->getInit(CountInits), sInt, Info))
9034 return false;
9035 } else // trailing integer zero.
9036 sInt = Info.Ctx.MakeIntValue(0, EltTy);
9037 Elements.push_back(APValue(sInt));
9038 CountElts++;
9039 } else {
9040 llvm::APFloat f(0.0);
9041 if (CountInits < NumInits) {
9042 if (!EvaluateFloat(E->getInit(CountInits), f, Info))
9043 return false;
9044 } else // trailing float zero.
9045 f = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy));
9046 Elements.push_back(APValue(f));
9047 CountElts++;
9048 }
9049 CountInits++;
9050 }
9051 return Success(Elements, E);
9052}
9053
9054bool
9055VectorExprEvaluator::ZeroInitialization(const Expr *E) {
9056 const VectorType *VT = E->getType()->getAs<VectorType>();
9057 QualType EltTy = VT->getElementType();
9058 APValue ZeroElement;
9059 if (EltTy->isIntegerType())
9060 ZeroElement = APValue(Info.Ctx.MakeIntValue(0, EltTy));
9061 else
9062 ZeroElement =
9063 APValue(APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy)));
9064
9065 SmallVector<APValue, 4> Elements(VT->getNumElements(), ZeroElement);
9066 return Success(Elements, E);
9067}
9068
9069bool VectorExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
9070 VisitIgnoredValue(E->getSubExpr());
9071 return ZeroInitialization(E);
9072}
9073
9074//===----------------------------------------------------------------------===//
9075// Array Evaluation
9076//===----------------------------------------------------------------------===//
9077
9078namespace {
9079 class ArrayExprEvaluator
9080 : public ExprEvaluatorBase<ArrayExprEvaluator> {
9081 const LValue &This;
9082 APValue &Result;
9083 public:
9084
9085 ArrayExprEvaluator(EvalInfo &Info, const LValue &This, APValue &Result)
9086 : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
9087
9088 bool Success(const APValue &V, const Expr *E) {
9089 assert(V.isArray() && "expected array")((V.isArray() && "expected array") ? static_cast<void
> (0) : __assert_fail ("V.isArray() && \"expected array\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9089, __PRETTY_FUNCTION__))
;
9090 Result = V;
9091 return true;
9092 }
9093
9094 bool ZeroInitialization(const Expr *E) {
9095 const ConstantArrayType *CAT =
9096 Info.Ctx.getAsConstantArrayType(E->getType());
9097 if (!CAT)
9098 return Error(E);
9099
9100 Result = APValue(APValue::UninitArray(), 0,
9101 CAT->getSize().getZExtValue());
9102 if (!Result.hasArrayFiller()) return true;
9103
9104 // Zero-initialize all elements.
9105 LValue Subobject = This;
9106 Subobject.addArray(Info, E, CAT);
9107 ImplicitValueInitExpr VIE(CAT->getElementType());
9108 return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject, &VIE);
9109 }
9110
9111 bool VisitCallExpr(const CallExpr *E) {
9112 return handleCallExpr(E, Result, &This);
9113 }
9114 bool VisitInitListExpr(const InitListExpr *E,
9115 QualType AllocType = QualType());
9116 bool VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E);
9117 bool VisitCXXConstructExpr(const CXXConstructExpr *E);
9118 bool VisitCXXConstructExpr(const CXXConstructExpr *E,
9119 const LValue &Subobject,
9120 APValue *Value, QualType Type);
9121 bool VisitStringLiteral(const StringLiteral *E,
9122 QualType AllocType = QualType()) {
9123 expandStringLiteral(Info, E, Result, AllocType);
9124 return true;
9125 }
9126 };
9127} // end anonymous namespace
9128
9129static bool EvaluateArray(const Expr *E, const LValue &This,
9130 APValue &Result, EvalInfo &Info) {
9131 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9131, __PRETTY_FUNCTION__))
;
9132 return ArrayExprEvaluator(Info, This, Result).Visit(E);
9133}
9134
9135static bool EvaluateArrayNewInitList(EvalInfo &Info, LValue &This,
9136 APValue &Result, const InitListExpr *ILE,
9137 QualType AllocType) {
9138 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9139, __PRETTY_FUNCTION__))
9139 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9139, __PRETTY_FUNCTION__))
;
9140 return ArrayExprEvaluator(Info, This, Result)
9141 .VisitInitListExpr(ILE, AllocType);
9142}
9143
9144// Return true iff the given array filler may depend on the element index.
9145static bool MaybeElementDependentArrayFiller(const Expr *FillerExpr) {
9146 // For now, just whitelist non-class value-initialization and initialization
9147 // lists comprised of them.
9148 if (isa<ImplicitValueInitExpr>(FillerExpr))
9149 return false;
9150 if (const InitListExpr *ILE = dyn_cast<InitListExpr>(FillerExpr)) {
9151 for (unsigned I = 0, E = ILE->getNumInits(); I != E; ++I) {
9152 if (MaybeElementDependentArrayFiller(ILE->getInit(I)))
9153 return true;
9154 }
9155 return false;
9156 }
9157 return true;
9158}
9159
9160bool ArrayExprEvaluator::VisitInitListExpr(const InitListExpr *E,
9161 QualType AllocType) {
9162 const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(
9163 AllocType.isNull() ? E->getType() : AllocType);
9164 if (!CAT)
9165 return Error(E);
9166
9167 // C++11 [dcl.init.string]p1: A char array [...] can be initialized by [...]
9168 // an appropriately-typed string literal enclosed in braces.
9169 if (E->isStringLiteralInit()) {
9170 auto *SL = dyn_cast<StringLiteral>(E->getInit(0)->IgnoreParens());
9171 // FIXME: Support ObjCEncodeExpr here once we support it in
9172 // ArrayExprEvaluator generally.
9173 if (!SL)
9174 return Error(E);
9175 return VisitStringLiteral(SL, AllocType);
9176 }
9177
9178 bool Success = true;
9179
9180 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9181, __PRETTY_FUNCTION__))
9181 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9181, __PRETTY_FUNCTION__))
;
9182 APValue Filler;
9183 if (Result.isArray() && Result.hasArrayFiller())
9184 Filler = Result.getArrayFiller();
9185
9186 unsigned NumEltsToInit = E->getNumInits();
9187 unsigned NumElts = CAT->getSize().getZExtValue();
9188 const Expr *FillerExpr = E->hasArrayFiller() ? E->getArrayFiller() : nullptr;
9189
9190 // If the initializer might depend on the array index, run it for each
9191 // array element.
9192 if (NumEltsToInit != NumElts && MaybeElementDependentArrayFiller(FillerExpr))
9193 NumEltsToInit = NumElts;
9194
9195 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)
9196 << NumEltsToInit << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("exprconstant")) { llvm::dbgs() << "The number of elements to initialize: "
<< NumEltsToInit << ".\n"; } } while (false)
;
9197
9198 Result = APValue(APValue::UninitArray(), NumEltsToInit, NumElts);
9199
9200 // If the array was previously zero-initialized, preserve the
9201 // zero-initialized values.
9202 if (Filler.hasValue()) {
9203 for (unsigned I = 0, E = Result.getArrayInitializedElts(); I != E; ++I)
9204 Result.getArrayInitializedElt(I) = Filler;
9205 if (Result.hasArrayFiller())
9206 Result.getArrayFiller() = Filler;
9207 }
9208
9209 LValue Subobject = This;
9210 Subobject.addArray(Info, E, CAT);
9211 for (unsigned Index = 0; Index != NumEltsToInit; ++Index) {
9212 const Expr *Init =
9213 Index < E->getNumInits() ? E->getInit(Index) : FillerExpr;
9214 if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
9215 Info, Subobject, Init) ||
9216 !HandleLValueArrayAdjustment(Info, Init, Subobject,
9217 CAT->getElementType(), 1)) {
9218 if (!Info.noteFailure())
9219 return false;
9220 Success = false;
9221 }
9222 }
9223
9224 if (!Result.hasArrayFiller())
9225 return Success;
9226
9227 // If we get here, we have a trivial filler, which we can just evaluate
9228 // once and splat over the rest of the array elements.
9229 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9229, __PRETTY_FUNCTION__))
;
9230 return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject,
9231 FillerExpr) && Success;
9232}
9233
9234bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
9235 LValue CommonLV;
9236 if (E->getCommonExpr() &&
9237 !Evaluate(Info.CurrentCall->createTemporary(
9238 E->getCommonExpr(),
9239 getStorageType(Info.Ctx, E->getCommonExpr()), false,
9240 CommonLV),
9241 Info, E->getCommonExpr()->getSourceExpr()))
9242 return false;
9243
9244 auto *CAT = cast<ConstantArrayType>(E->getType()->castAsArrayTypeUnsafe());
9245
9246 uint64_t Elements = CAT->getSize().getZExtValue();
9247 Result = APValue(APValue::UninitArray(), Elements, Elements);
9248
9249 LValue Subobject = This;
9250 Subobject.addArray(Info, E, CAT);
9251
9252 bool Success = true;
9253 for (EvalInfo::ArrayInitLoopIndex Index(Info); Index != Elements; ++Index) {
9254 if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
9255 Info, Subobject, E->getSubExpr()) ||
9256 !HandleLValueArrayAdjustment(Info, E, Subobject,
9257 CAT->getElementType(), 1)) {
9258 if (!Info.noteFailure())
9259 return false;
9260 Success = false;
9261 }
9262 }
9263
9264 return Success;
9265}
9266
9267bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
9268 return VisitCXXConstructExpr(E, This, &Result, E->getType());
9269}
9270
9271bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
9272 const LValue &Subobject,
9273 APValue *Value,
9274 QualType Type) {
9275 bool HadZeroInit = Value->hasValue();
9276
9277 if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(Type)) {
9278 unsigned N = CAT->getSize().getZExtValue();
9279
9280 // Preserve the array filler if we had prior zero-initialization.
9281 APValue Filler =
9282 HadZeroInit && Value->hasArrayFiller() ? Value->getArrayFiller()
9283 : APValue();
9284
9285 *Value = APValue(APValue::UninitArray(), N, N);
9286
9287 if (HadZeroInit)
9288 for (unsigned I = 0; I != N; ++I)
9289 Value->getArrayInitializedElt(I) = Filler;
9290
9291 // Initialize the elements.
9292 LValue ArrayElt = Subobject;
9293 ArrayElt.addArray(Info, E, CAT);
9294 for (unsigned I = 0; I != N; ++I)
9295 if (!VisitCXXConstructExpr(E, ArrayElt, &Value->getArrayInitializedElt(I),
9296 CAT->getElementType()) ||
9297 !HandleLValueArrayAdjustment(Info, E, ArrayElt,
9298 CAT->getElementType(), 1))
9299 return false;
9300
9301 return true;
9302 }
9303
9304 if (!Type->isRecordType())
9305 return Error(E);
9306
9307 return RecordExprEvaluator(Info, Subobject, *Value)
9308 .VisitCXXConstructExpr(E, Type);
9309}
9310
9311//===----------------------------------------------------------------------===//
9312// Integer Evaluation
9313//
9314// As a GNU extension, we support casting pointers to sufficiently-wide integer
9315// types and back in constant folding. Integer values are thus represented
9316// either as an integer-valued APValue, or as an lvalue-valued APValue.
9317//===----------------------------------------------------------------------===//
9318
9319namespace {
9320class IntExprEvaluator
9321 : public ExprEvaluatorBase<IntExprEvaluator> {
9322 APValue &Result;
9323public:
9324 IntExprEvaluator(EvalInfo &info, APValue &result)
9325 : ExprEvaluatorBaseTy(info), Result(result) {}
9326
9327 bool Success(const llvm::APSInt &SI, const Expr *E, APValue &Result) {
9328 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9329, __PRETTY_FUNCTION__))
9329 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9329, __PRETTY_FUNCTION__))
;
9330 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9331, __PRETTY_FUNCTION__))
9331 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9331, __PRETTY_FUNCTION__))
;
9332 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9333, __PRETTY_FUNCTION__))
9333 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9333, __PRETTY_FUNCTION__))
;
9334 Result = APValue(SI);
9335 return true;
9336 }
9337 bool Success(const llvm::APSInt &SI, const Expr *E) {
9338 return Success(SI, E, Result);
9339 }
9340
9341 bool Success(const llvm::APInt &I, const Expr *E, APValue &Result) {
9342 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9343, __PRETTY_FUNCTION__))
9343 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9343, __PRETTY_FUNCTION__))
;
9344 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9345, __PRETTY_FUNCTION__))
9345 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9345, __PRETTY_FUNCTION__))
;
9346 Result = APValue(APSInt(I));
9347 Result.getInt().setIsUnsigned(
9348 E->getType()->isUnsignedIntegerOrEnumerationType());
9349 return true;
9350 }
9351 bool Success(const llvm::APInt &I, const Expr *E) {
9352 return Success(I, E, Result);
9353 }
9354
9355 bool Success(uint64_t Value, const Expr *E, APValue &Result) {
9356 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9357, __PRETTY_FUNCTION__))
9357 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9357, __PRETTY_FUNCTION__))
;
9358 Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType()));
9359 return true;
9360 }
9361 bool Success(uint64_t Value, const Expr *E) {
9362 return Success(Value, E, Result);
9363 }
9364
9365 bool Success(CharUnits Size, const Expr *E) {
9366 return Success(Size.getQuantity(), E);
9367 }
9368
9369 bool Success(const APValue &V, const Expr *E) {
9370 if (V.isLValue() || V.isAddrLabelDiff() || V.isIndeterminate()) {
9371 Result = V;
9372 return true;
9373 }
9374 return Success(V.getInt(), E);
9375 }
9376
9377 bool ZeroInitialization(const Expr *E) { return Success(0, E); }
9378
9379 //===--------------------------------------------------------------------===//
9380 // Visitor Methods
9381 //===--------------------------------------------------------------------===//
9382
9383 bool VisitConstantExpr(const ConstantExpr *E);
9384
9385 bool VisitIntegerLiteral(const IntegerLiteral *E) {
9386 return Success(E->getValue(), E);
9387 }
9388 bool VisitCharacterLiteral(const CharacterLiteral *E) {
9389 return Success(E->getValue(), E);
9390 }
9391
9392 bool CheckReferencedDecl(const Expr *E, const Decl *D);
9393 bool VisitDeclRefExpr(const DeclRefExpr *E) {
9394 if (CheckReferencedDecl(E, E->getDecl()))
9395 return true;
9396
9397 return ExprEvaluatorBaseTy::VisitDeclRefExpr(E);
9398 }
9399 bool VisitMemberExpr(const MemberExpr *E) {
9400 if (CheckReferencedDecl(E, E->getMemberDecl())) {
9401 VisitIgnoredBaseExpression(E->getBase());
9402 return true;
9403 }
9404
9405 return ExprEvaluatorBaseTy::VisitMemberExpr(E);
9406 }
9407
9408 bool VisitCallExpr(const CallExpr *E);
9409 bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
9410 bool VisitBinaryOperator(const BinaryOperator *E);
9411 bool VisitOffsetOfExpr(const OffsetOfExpr *E);
9412 bool VisitUnaryOperator(const UnaryOperator *E);
9413
9414 bool VisitCastExpr(const CastExpr* E);
9415 bool VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
9416
9417 bool VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
9418 return Success(E->getValue(), E);
9419 }
9420
9421 bool VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) {
9422 return Success(E->getValue(), E);
9423 }
9424
9425 bool VisitArrayInitIndexExpr(const ArrayInitIndexExpr *E) {
9426 if (Info.ArrayInitIndex == uint64_t(-1)) {
9427 // We were asked to evaluate this subexpression independent of the
9428 // enclosing ArrayInitLoopExpr. We can't do that.
9429 Info.FFDiag(E);
9430 return false;
9431 }
9432 return Success(Info.ArrayInitIndex, E);
9433 }
9434
9435 // Note, GNU defines __null as an integer, not a pointer.
9436 bool VisitGNUNullExpr(const GNUNullExpr *E) {
9437 return ZeroInitialization(E);
9438 }
9439
9440 bool VisitTypeTraitExpr(const TypeTraitExpr *E) {
9441 return Success(E->getValue(), E);
9442 }
9443
9444 bool VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
9445 return Success(E->getValue(), E);
9446 }
9447
9448 bool VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
9449 return Success(E->getValue(), E);
9450 }
9451
9452 bool VisitUnaryReal(const UnaryOperator *E);
9453 bool VisitUnaryImag(const UnaryOperator *E);
9454
9455 bool VisitCXXNoexceptExpr(const CXXNoexceptExpr *E);
9456 bool VisitSizeOfPackExpr(const SizeOfPackExpr *E);
9457 bool VisitSourceLocExpr(const SourceLocExpr *E);
9458 // FIXME: Missing: array subscript of vector, member of vector
9459};
9460
9461class FixedPointExprEvaluator
9462 : public ExprEvaluatorBase<FixedPointExprEvaluator> {
9463 APValue &Result;
9464
9465 public:
9466 FixedPointExprEvaluator(EvalInfo &info, APValue &result)
9467 : ExprEvaluatorBaseTy(info), Result(result) {}
9468
9469 bool Success(const llvm::APInt &I, const Expr *E) {
9470 return Success(
9471 APFixedPoint(I, Info.Ctx.getFixedPointSemantics(E->getType())), E);
9472 }
9473
9474 bool Success(uint64_t Value, const Expr *E) {
9475 return Success(
9476 APFixedPoint(Value, Info.Ctx.getFixedPointSemantics(E->getType())), E);
9477 }
9478
9479 bool Success(const APValue &V, const Expr *E) {
9480 return Success(V.getFixedPoint(), E);
9481 }
9482
9483 bool Success(const APFixedPoint &V, const Expr *E) {
9484 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9484, __PRETTY_FUNCTION__))
;
9485 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9486, __PRETTY_FUNCTION__))
9486 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9486, __PRETTY_FUNCTION__))
;
9487 Result = APValue(V);
9488 return true;
9489 }
9490
9491 //===--------------------------------------------------------------------===//
9492 // Visitor Methods
9493 //===--------------------------------------------------------------------===//
9494
9495 bool VisitFixedPointLiteral(const FixedPointLiteral *E) {
9496 return Success(E->getValue(), E);
9497 }
9498
9499 bool VisitCastExpr(const CastExpr *E);
9500 bool VisitUnaryOperator(const UnaryOperator *E);
9501 bool VisitBinaryOperator(const BinaryOperator *E);
9502};
9503} // end anonymous namespace
9504
9505/// EvaluateIntegerOrLValue - Evaluate an rvalue integral-typed expression, and
9506/// produce either the integer value or a pointer.
9507///
9508/// GCC has a heinous extension which folds casts between pointer types and
9509/// pointer-sized integral types. We support this by allowing the evaluation of
9510/// an integer rvalue to produce a pointer (represented as an lvalue) instead.
9511/// Some simple arithmetic on such values is supported (they are treated much
9512/// like char*).
9513static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
9514 EvalInfo &Info) {
9515 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9515, __PRETTY_FUNCTION__))
;
9516 return IntExprEvaluator(Info, Result).Visit(E);
9517}
9518
9519static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info) {
9520 APValue Val;
9521 if (!EvaluateIntegerOrLValue(E, Val, Info))
9522 return false;
9523 if (!Val.isInt()) {
9524 // FIXME: It would be better to produce the diagnostic for casting
9525 // a pointer to an integer.
9526 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
9527 return false;
9528 }
9529 Result = Val.getInt();
9530 return true;
9531}
9532
9533bool IntExprEvaluator::VisitSourceLocExpr(const SourceLocExpr *E) {
9534 APValue Evaluated = E->EvaluateInContext(
9535 Info.Ctx, Info.CurrentCall->CurSourceLocExprScope.getDefaultExpr());
9536 return Success(Evaluated, E);
9537}
9538
9539static bool EvaluateFixedPoint(const Expr *E, APFixedPoint &Result,
9540 EvalInfo &Info) {
9541 if (E->getType()->isFixedPointType()) {
9542 APValue Val;
9543 if (!FixedPointExprEvaluator(Info, Val).Visit(E))
9544 return false;
9545 if (!Val.isFixedPoint())
9546 return false;
9547
9548 Result = Val.getFixedPoint();
9549 return true;
9550 }
9551 return false;
9552}
9553
9554static bool EvaluateFixedPointOrInteger(const Expr *E, APFixedPoint &Result,
9555 EvalInfo &Info) {
9556 if (E->getType()->isIntegerType()) {
9557 auto FXSema = Info.Ctx.getFixedPointSemantics(E->getType());
9558 APSInt Val;
9559 if (!EvaluateInteger(E, Val, Info))
9560 return false;
9561 Result = APFixedPoint(Val, FXSema);
9562 return true;
9563 } else if (E->getType()->isFixedPointType()) {
9564 return EvaluateFixedPoint(E, Result, Info);
9565 }
9566 return false;
9567}
9568
9569/// Check whether the given declaration can be directly converted to an integral
9570/// rvalue. If not, no diagnostic is produced; there are other things we can
9571/// try.
9572bool IntExprEvaluator::CheckReferencedDecl(const Expr* E, const Decl* D) {
9573 // Enums are integer constant exprs.
9574 if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) {
9575 // Check for signedness/width mismatches between E type and ECD value.
9576 bool SameSign = (ECD->getInitVal().isSigned()
9577 == E->getType()->isSignedIntegerOrEnumerationType());
9578 bool SameWidth = (ECD->getInitVal().getBitWidth()
9579 == Info.Ctx.getIntWidth(E->getType()));
9580 if (SameSign && SameWidth)
9581 return Success(ECD->getInitVal(), E);
9582 else {
9583 // Get rid of mismatch (otherwise Success assertions will fail)
9584 // by computing a new value matching the type of E.
9585 llvm::APSInt Val = ECD->getInitVal();
9586 if (!SameSign)
9587 Val.setIsSigned(!ECD->getInitVal().isSigned());
9588 if (!SameWidth)
9589 Val = Val.extOrTrunc(Info.Ctx.getIntWidth(E->getType()));
9590 return Success(Val, E);
9591 }
9592 }
9593 return false;
9594}
9595
9596/// Values returned by __builtin_classify_type, chosen to match the values
9597/// produced by GCC's builtin.
9598enum class GCCTypeClass {
9599 None = -1,
9600 Void = 0,
9601 Integer = 1,
9602 // GCC reserves 2 for character types, but instead classifies them as
9603 // integers.
9604 Enum = 3,
9605 Bool = 4,
9606 Pointer = 5,
9607 // GCC reserves 6 for references, but appears to never use it (because
9608 // expressions never have reference type, presumably).
9609 PointerToDataMember = 7,
9610 RealFloat = 8,
9611 Complex = 9,
9612 // GCC reserves 10 for functions, but does not use it since GCC version 6 due
9613 // to decay to pointer. (Prior to version 6 it was only used in C++ mode).
9614 // GCC claims to reserve 11 for pointers to member functions, but *actually*
9615 // uses 12 for that purpose, same as for a class or struct. Maybe it
9616 // internally implements a pointer to member as a struct? Who knows.
9617 PointerToMemberFunction = 12, // Not a bug, see above.
9618 ClassOrStruct = 12,
9619 Union = 13,
9620 // GCC reserves 14 for arrays, but does not use it since GCC version 6 due to
9621 // decay to pointer. (Prior to version 6 it was only used in C++ mode).
9622 // GCC reserves 15 for strings, but actually uses 5 (pointer) for string
9623 // literals.
9624};
9625
9626/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
9627/// as GCC.
9628static GCCTypeClass
9629EvaluateBuiltinClassifyType(QualType T, const LangOptions &LangOpts) {
9630 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9630, __PRETTY_FUNCTION__))
;
9631
9632 QualType CanTy = T.getCanonicalType();
9633 const BuiltinType *BT = dyn_cast<BuiltinType>(CanTy);
9634
9635 switch (CanTy->getTypeClass()) {
9636#define TYPE(ID, BASE)
9637#define DEPENDENT_TYPE(ID, BASE) case Type::ID:
9638#define NON_CANONICAL_TYPE(ID, BASE) case Type::ID:
9639#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(ID, BASE) case Type::ID:
9640#include "clang/AST/TypeNodes.inc"
9641 case Type::Auto:
9642 case Type::DeducedTemplateSpecialization:
9643 llvm_unreachable("unexpected non-canonical or dependent type")::llvm::llvm_unreachable_internal("unexpected non-canonical or dependent type"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9643)
;
9644
9645 case Type::Builtin:
9646 switch (BT->getKind()) {
9647#define BUILTIN_TYPE(ID, SINGLETON_ID)
9648#define SIGNED_TYPE(ID, SINGLETON_ID) \
9649 case BuiltinType::ID: return GCCTypeClass::Integer;
9650#define FLOATING_TYPE(ID, SINGLETON_ID) \
9651 case BuiltinType::ID: return GCCTypeClass::RealFloat;
9652#define PLACEHOLDER_TYPE(ID, SINGLETON_ID) \
9653 case BuiltinType::ID: break;
9654#include "clang/AST/BuiltinTypes.def"
9655 case BuiltinType::Void:
9656 return GCCTypeClass::Void;
9657
9658 case BuiltinType::Bool:
9659 return GCCTypeClass::Bool;
9660
9661 case BuiltinType::Char_U:
9662 case BuiltinType::UChar:
9663 case BuiltinType::WChar_U:
9664 case BuiltinType::Char8:
9665 case BuiltinType::Char16:
9666 case BuiltinType::Char32:
9667 case BuiltinType::UShort:
9668 case BuiltinType::UInt:
9669 case BuiltinType::ULong:
9670 case BuiltinType::ULongLong:
9671 case BuiltinType::UInt128:
9672 return GCCTypeClass::Integer;
9673
9674 case BuiltinType::UShortAccum:
9675 case BuiltinType::UAccum:
9676 case BuiltinType::ULongAccum:
9677 case BuiltinType::UShortFract:
9678 case BuiltinType::UFract:
9679 case BuiltinType::ULongFract:
9680 case BuiltinType::SatUShortAccum:
9681 case BuiltinType::SatUAccum:
9682 case BuiltinType::SatULongAccum:
9683 case BuiltinType::SatUShortFract:
9684 case BuiltinType::SatUFract:
9685 case BuiltinType::SatULongFract:
9686 return GCCTypeClass::None;
9687
9688 case BuiltinType::NullPtr:
9689
9690 case BuiltinType::ObjCId:
9691 case BuiltinType::ObjCClass:
9692 case BuiltinType::ObjCSel:
9693#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
9694 case BuiltinType::Id:
9695#include "clang/Basic/OpenCLImageTypes.def"
9696#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
9697 case BuiltinType::Id:
9698#include "clang/Basic/OpenCLExtensionTypes.def"
9699 case BuiltinType::OCLSampler:
9700 case BuiltinType::OCLEvent:
9701 case BuiltinType::OCLClkEvent:
9702 case BuiltinType::OCLQueue:
9703 case BuiltinType::OCLReserveID:
9704#define SVE_TYPE(Name, Id, SingletonId) \
9705 case BuiltinType::Id:
9706#include "clang/Basic/AArch64SVEACLETypes.def"
9707 return GCCTypeClass::None;
9708
9709 case BuiltinType::Dependent:
9710 llvm_unreachable("unexpected dependent type")::llvm::llvm_unreachable_internal("unexpected dependent type"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9710)
;
9711 };
9712 llvm_unreachable("unexpected placeholder type")::llvm::llvm_unreachable_internal("unexpected placeholder type"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9712)
;
9713
9714 case Type::Enum:
9715 return LangOpts.CPlusPlus ? GCCTypeClass::Enum : GCCTypeClass::Integer;
9716
9717 case Type::Pointer:
9718 case Type::ConstantArray:
9719 case Type::VariableArray:
9720 case Type::IncompleteArray:
9721 case Type::FunctionNoProto:
9722 case Type::FunctionProto:
9723 return GCCTypeClass::Pointer;
9724
9725 case Type::MemberPointer:
9726 return CanTy->isMemberDataPointerType()
9727 ? GCCTypeClass::PointerToDataMember
9728 : GCCTypeClass::PointerToMemberFunction;
9729
9730 case Type::Complex:
9731 return GCCTypeClass::Complex;
9732
9733 case Type::Record:
9734 return CanTy->isUnionType() ? GCCTypeClass::Union
9735 : GCCTypeClass::ClassOrStruct;
9736
9737 case Type::Atomic:
9738 // GCC classifies _Atomic T the same as T.
9739 return EvaluateBuiltinClassifyType(
9740 CanTy->castAs<AtomicType>()->getValueType(), LangOpts);
9741
9742 case Type::BlockPointer:
9743 case Type::Vector:
9744 case Type::ExtVector:
9745 case Type::ObjCObject:
9746 case Type::ObjCInterface:
9747 case Type::ObjCObjectPointer:
9748 case Type::Pipe:
9749 // GCC classifies vectors as None. We follow its lead and classify all
9750 // other types that don't fit into the regular classification the same way.
9751 return GCCTypeClass::None;
9752
9753 case Type::LValueReference:
9754 case Type::RValueReference:
9755 llvm_unreachable("invalid type for expression")::llvm::llvm_unreachable_internal("invalid type for expression"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9755)
;
9756 }
9757
9758 llvm_unreachable("unexpected type class")::llvm::llvm_unreachable_internal("unexpected type class", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9758)
;
9759}
9760
9761/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
9762/// as GCC.
9763static GCCTypeClass
9764EvaluateBuiltinClassifyType(const CallExpr *E, const LangOptions &LangOpts) {
9765 // If no argument was supplied, default to None. This isn't
9766 // ideal, however it is what gcc does.
9767 if (E->getNumArgs() == 0)
9768 return GCCTypeClass::None;
9769
9770 // FIXME: Bizarrely, GCC treats a call with more than one argument as not
9771 // being an ICE, but still folds it to a constant using the type of the first
9772 // argument.
9773 return EvaluateBuiltinClassifyType(E->getArg(0)->getType(), LangOpts);
9774}
9775
9776/// EvaluateBuiltinConstantPForLValue - Determine the result of
9777/// __builtin_constant_p when applied to the given pointer.
9778///
9779/// A pointer is only "constant" if it is null (or a pointer cast to integer)
9780/// or it points to the first character of a string literal.
9781static bool EvaluateBuiltinConstantPForLValue(const APValue &LV) {
9782 APValue::LValueBase Base = LV.getLValueBase();
9783 if (Base.isNull()) {
9784 // A null base is acceptable.
9785 return true;
9786 } else if (const Expr *E = Base.dyn_cast<const Expr *>()) {
9787 if (!isa<StringLiteral>(E))
9788 return false;
9789 return LV.getLValueOffset().isZero();
9790 } else if (Base.is<TypeInfoLValue>()) {
9791 // Surprisingly, GCC considers __builtin_constant_p(&typeid(int)) to
9792 // evaluate to true.
9793 return true;
9794 } else {
9795 // Any other base is not constant enough for GCC.
9796 return false;
9797 }
9798}
9799
9800/// EvaluateBuiltinConstantP - Evaluate __builtin_constant_p as similarly to
9801/// GCC as we can manage.
9802static bool EvaluateBuiltinConstantP(EvalInfo &Info, const Expr *Arg) {
9803 // This evaluation is not permitted to have side-effects, so evaluate it in
9804 // a speculative evaluation context.
9805 SpeculativeEvaluationRAII SpeculativeEval(Info);
9806
9807 // Constant-folding is always enabled for the operand of __builtin_constant_p
9808 // (even when the enclosing evaluation context otherwise requires a strict
9809 // language-specific constant expression).
9810 FoldConstant Fold(Info, true);
9811
9812 QualType ArgType = Arg->getType();
9813
9814 // __builtin_constant_p always has one operand. The rules which gcc follows
9815 // are not precisely documented, but are as follows:
9816 //
9817 // - If the operand is of integral, floating, complex or enumeration type,
9818 // and can be folded to a known value of that type, it returns 1.
9819 // - If the operand can be folded to a pointer to the first character
9820 // of a string literal (or such a pointer cast to an integral type)
9821 // or to a null pointer or an integer cast to a pointer, it returns 1.
9822 //
9823 // Otherwise, it returns 0.
9824 //
9825 // FIXME: GCC also intends to return 1 for literals of aggregate types, but
9826 // its support for this did not work prior to GCC 9 and is not yet well
9827 // understood.
9828 if (ArgType->isIntegralOrEnumerationType() || ArgType->isFloatingType() ||
9829 ArgType->isAnyComplexType() || ArgType->isPointerType() ||
9830 ArgType->isNullPtrType()) {
9831 APValue V;
9832 if (!::EvaluateAsRValue(Info, Arg, V)) {
9833 Fold.keepDiagnostics();
9834 return false;
9835 }
9836
9837 // For a pointer (possibly cast to integer), there are special rules.
9838 if (V.getKind() == APValue::LValue)
9839 return EvaluateBuiltinConstantPForLValue(V);
9840
9841 // Otherwise, any constant value is good enough.
9842 return V.hasValue();
9843 }
9844
9845 // Anything else isn't considered to be sufficiently constant.
9846 return false;
9847}
9848
9849/// Retrieves the "underlying object type" of the given expression,
9850/// as used by __builtin_object_size.
9851static QualType getObjectType(APValue::LValueBase B) {
9852 if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
9853 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
9854 return VD->getType();
9855 } else if (const Expr *E = B.get<const Expr*>()) {
9856 if (isa<CompoundLiteralExpr>(E))
9857 return E->getType();
9858 } else if (B.is<TypeInfoLValue>()) {
9859 return B.getTypeInfoType();
9860 } else if (B.is<DynamicAllocLValue>()) {
9861 return B.getDynamicAllocType();
9862 }
9863
9864 return QualType();
9865}
9866
9867/// A more selective version of E->IgnoreParenCasts for
9868/// tryEvaluateBuiltinObjectSize. This ignores some casts/parens that serve only
9869/// to change the type of E.
9870/// Ex. For E = `(short*)((char*)(&foo))`, returns `&foo`
9871///
9872/// Always returns an RValue with a pointer representation.
9873static const Expr *ignorePointerCastsAndParens(const Expr *E) {
9874 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9874, __PRETTY_FUNCTION__))
;
9875
9876 auto *NoParens = E->IgnoreParens();
9877 auto *Cast = dyn_cast<CastExpr>(NoParens);
9878 if (Cast == nullptr)
9879 return NoParens;
9880
9881 // We only conservatively allow a few kinds of casts, because this code is
9882 // inherently a simple solution that seeks to support the common case.
9883 auto CastKind = Cast->getCastKind();
9884 if (CastKind != CK_NoOp && CastKind != CK_BitCast &&
9885 CastKind != CK_AddressSpaceConversion)
9886 return NoParens;
9887
9888 auto *SubExpr = Cast->getSubExpr();
9889 if (!SubExpr->getType()->hasPointerRepresentation() || !SubExpr->isRValue())
9890 return NoParens;
9891 return ignorePointerCastsAndParens(SubExpr);
9892}
9893
9894/// Checks to see if the given LValue's Designator is at the end of the LValue's
9895/// record layout. e.g.
9896/// struct { struct { int a, b; } fst, snd; } obj;
9897/// obj.fst // no
9898/// obj.snd // yes
9899/// obj.fst.a // no
9900/// obj.fst.b // no
9901/// obj.snd.a // no
9902/// obj.snd.b // yes
9903///
9904/// Please note: this function is specialized for how __builtin_object_size
9905/// views "objects".
9906///
9907/// If this encounters an invalid RecordDecl or otherwise cannot determine the
9908/// correct result, it will always return true.
9909static bool isDesignatorAtObjectEnd(const ASTContext &Ctx, const LValue &LVal) {
9910 assert(!LVal.Designator.Invalid)((!LVal.Designator.Invalid) ? static_cast<void> (0) : __assert_fail
("!LVal.Designator.Invalid", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9910, __PRETTY_FUNCTION__))
;
9911
9912 auto IsLastOrInvalidFieldDecl = [&Ctx](const FieldDecl *FD, bool &Invalid) {
9913 const RecordDecl *Parent = FD->getParent();
9914 Invalid = Parent->isInvalidDecl();
9915 if (Invalid || Parent->isUnion())
9916 return true;
9917 const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(Parent);
9918 return FD->getFieldIndex() + 1 == Layout.getFieldCount();
9919 };
9920
9921 auto &Base = LVal.getLValueBase();
9922 if (auto *ME = dyn_cast_or_null<MemberExpr>(Base.dyn_cast<const Expr *>())) {
9923 if (auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
9924 bool Invalid;
9925 if (!IsLastOrInvalidFieldDecl(FD, Invalid))
9926 return Invalid;
9927 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(ME->getMemberDecl())) {
9928 for (auto *FD : IFD->chain()) {
9929 bool Invalid;
9930 if (!IsLastOrInvalidFieldDecl(cast<FieldDecl>(FD), Invalid))
9931 return Invalid;
9932 }
9933 }
9934 }
9935
9936 unsigned I = 0;
9937 QualType BaseType = getType(Base);
9938 if (LVal.Designator.FirstEntryIsAnUnsizedArray) {
9939 // If we don't know the array bound, conservatively assume we're looking at
9940 // the final array element.
9941 ++I;
9942 if (BaseType->isIncompleteArrayType())
9943 BaseType = Ctx.getAsArrayType(BaseType)->getElementType();
9944 else
9945 BaseType = BaseType->castAs<PointerType>()->getPointeeType();
9946 }
9947
9948 for (unsigned E = LVal.Designator.Entries.size(); I != E; ++I) {
9949 const auto &Entry = LVal.Designator.Entries[I];
9950 if (BaseType->isArrayType()) {
9951 // Because __builtin_object_size treats arrays as objects, we can ignore
9952 // the index iff this is the last array in the Designator.
9953 if (I + 1 == E)
9954 return true;
9955 const auto *CAT = cast<ConstantArrayType>(Ctx.getAsArrayType(BaseType));
9956 uint64_t Index = Entry.getAsArrayIndex();
9957 if (Index + 1 != CAT->getSize())
9958 return false;
9959 BaseType = CAT->getElementType();
9960 } else if (BaseType->isAnyComplexType()) {
9961 const auto *CT = BaseType->castAs<ComplexType>();
9962 uint64_t Index = Entry.getAsArrayIndex();
9963 if (Index != 1)
9964 return false;
9965 BaseType = CT->getElementType();
9966 } else if (auto *FD = getAsField(Entry)) {
9967 bool Invalid;
9968 if (!IsLastOrInvalidFieldDecl(FD, Invalid))
9969 return Invalid;
9970 BaseType = FD->getType();
9971 } else {
9972 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 9972, __PRETTY_FUNCTION__))
;
9973 return false;
9974 }
9975 }
9976 return true;
9977}
9978
9979/// Tests to see if the LValue has a user-specified designator (that isn't
9980/// necessarily valid). Note that this always returns 'true' if the LValue has
9981/// an unsized array as its first designator entry, because there's currently no
9982/// way to tell if the user typed *foo or foo[0].
9983static bool refersToCompleteObject(const LValue &LVal) {
9984 if (LVal.Designator.Invalid)
9985 return false;
9986
9987 if (!LVal.Designator.Entries.empty())
9988 return LVal.Designator.isMostDerivedAnUnsizedArray();
9989
9990 if (!LVal.InvalidBase)
9991 return true;
9992
9993 // If `E` is a MemberExpr, then the first part of the designator is hiding in
9994 // the LValueBase.
9995 const auto *E = LVal.Base.dyn_cast<const Expr *>();
9996 return !E || !isa<MemberExpr>(E);
9997}
9998
9999/// Attempts to detect a user writing into a piece of memory that's impossible
10000/// to figure out the size of by just using types.
10001static bool isUserWritingOffTheEnd(const ASTContext &Ctx, const LValue &LVal) {
10002 const SubobjectDesignator &Designator = LVal.Designator;
10003 // Notes:
10004 // - Users can only write off of the end when we have an invalid base. Invalid
10005 // bases imply we don't know where the memory came from.
10006 // - We used to be a bit more aggressive here; we'd only be conservative if
10007 // the array at the end was flexible, or if it had 0 or 1 elements. This
10008 // broke some common standard library extensions (PR30346), but was
10009 // otherwise seemingly fine. It may be useful to reintroduce this behavior
10010 // with some sort of whitelist. OTOH, it seems that GCC is always
10011 // conservative with the last element in structs (if it's an array), so our
10012 // current behavior is more compatible than a whitelisting approach would
10013 // be.
10014 return LVal.InvalidBase &&
10015 Designator.Entries.size() == Designator.MostDerivedPathLength &&
10016 Designator.MostDerivedIsArrayElement &&
10017 isDesignatorAtObjectEnd(Ctx, LVal);
10018}
10019
10020/// Converts the given APInt to CharUnits, assuming the APInt is unsigned.
10021/// Fails if the conversion would cause loss of precision.
10022static bool convertUnsignedAPIntToCharUnits(const llvm::APInt &Int,
10023 CharUnits &Result) {
10024 auto CharUnitsMax = std::numeric_limits<CharUnits::QuantityType>::max();
10025 if (Int.ugt(CharUnitsMax))
10026 return false;
10027 Result = CharUnits::fromQuantity(Int.getZExtValue());
10028 return true;
10029}
10030
10031/// Helper for tryEvaluateBuiltinObjectSize -- Given an LValue, this will
10032/// determine how many bytes exist from the beginning of the object to either
10033/// the end of the current subobject, or the end of the object itself, depending
10034/// on what the LValue looks like + the value of Type.
10035///
10036/// If this returns false, the value of Result is undefined.
10037static bool determineEndOffset(EvalInfo &Info, SourceLocation ExprLoc,
10038 unsigned Type, const LValue &LVal,
10039 CharUnits &EndOffset) {
10040 bool DetermineForCompleteObject = refersToCompleteObject(LVal);
10041
10042 auto CheckedHandleSizeof = [&](QualType Ty, CharUnits &Result) {
10043 if (Ty.isNull() || Ty->isIncompleteType() || Ty->isFunctionType())
10044 return false;
10045 return HandleSizeof(Info, ExprLoc, Ty, Result);
10046 };
10047
10048 // We want to evaluate the size of the entire object. This is a valid fallback
10049 // for when Type=1 and the designator is invalid, because we're asked for an
10050 // upper-bound.
10051 if (!(Type & 1) || LVal.Designator.Invalid || DetermineForCompleteObject) {
10052 // Type=3 wants a lower bound, so we can't fall back to this.
10053 if (Type == 3 && !DetermineForCompleteObject)
10054 return false;
10055
10056 llvm::APInt APEndOffset;
10057 if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
10058 getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
10059 return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
10060
10061 if (LVal.InvalidBase)
10062 return false;
10063
10064 QualType BaseTy = getObjectType(LVal.getLValueBase());
10065 return CheckedHandleSizeof(BaseTy, EndOffset);
10066 }
10067
10068 // We want to evaluate the size of a subobject.
10069 const SubobjectDesignator &Designator = LVal.Designator;
10070
10071 // The following is a moderately common idiom in C:
10072 //
10073 // struct Foo { int a; char c[1]; };
10074 // struct Foo *F = (struct Foo *)malloc(sizeof(struct Foo) + strlen(Bar));
10075 // strcpy(&F->c[0], Bar);
10076 //
10077 // In order to not break too much legacy code, we need to support it.
10078 if (isUserWritingOffTheEnd(Info.Ctx, LVal)) {
10079 // If we can resolve this to an alloc_size call, we can hand that back,
10080 // because we know for certain how many bytes there are to write to.
10081 llvm::APInt APEndOffset;
10082 if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
10083 getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
10084 return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
10085
10086 // If we cannot determine the size of the initial allocation, then we can't
10087 // given an accurate upper-bound. However, we are still able to give
10088 // conservative lower-bounds for Type=3.
10089 if (Type == 1)
10090 return false;
10091 }
10092
10093 CharUnits BytesPerElem;
10094 if (!CheckedHandleSizeof(Designator.MostDerivedType, BytesPerElem))
10095 return false;
10096
10097 // According to the GCC documentation, we want the size of the subobject
10098 // denoted by the pointer. But that's not quite right -- what we actually
10099 // want is the size of the immediately-enclosing array, if there is one.
10100 int64_t ElemsRemaining;
10101 if (Designator.MostDerivedIsArrayElement &&
10102 Designator.Entries.size() == Designator.MostDerivedPathLength) {
10103 uint64_t ArraySize = Designator.getMostDerivedArraySize();
10104 uint64_t ArrayIndex = Designator.Entries.back().getAsArrayIndex();
10105 ElemsRemaining = ArraySize <= ArrayIndex ? 0 : ArraySize - ArrayIndex;
10106 } else {
10107 ElemsRemaining = Designator.isOnePastTheEnd() ? 0 : 1;
10108 }
10109
10110 EndOffset = LVal.getLValueOffset() + BytesPerElem * ElemsRemaining;
10111 return true;
10112}
10113
10114/// Tries to evaluate the __builtin_object_size for @p E. If successful,
10115/// returns true and stores the result in @p Size.
10116///
10117/// If @p WasError is non-null, this will report whether the failure to evaluate
10118/// is to be treated as an Error in IntExprEvaluator.
10119static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
10120 EvalInfo &Info, uint64_t &Size) {
10121 // Determine the denoted object.
10122 LValue LVal;
10123 {
10124 // The operand of __builtin_object_size is never evaluated for side-effects.
10125 // If there are any, but we can determine the pointed-to object anyway, then
10126 // ignore the side-effects.
10127 SpeculativeEvaluationRAII SpeculativeEval(Info);
10128 IgnoreSideEffectsRAII Fold(Info);
10129
10130 if (E->isGLValue()) {
10131 // It's possible for us to be given GLValues if we're called via
10132 // Expr::tryEvaluateObjectSize.
10133 APValue RVal;
10134 if (!EvaluateAsRValue(Info, E, RVal))
10135 return false;
10136 LVal.setFrom(Info.Ctx, RVal);
10137 } else if (!EvaluatePointer(ignorePointerCastsAndParens(E), LVal, Info,
10138 /*InvalidBaseOK=*/true))
10139 return false;
10140 }
10141
10142 // If we point to before the start of the object, there are no accessible
10143 // bytes.
10144 if (LVal.getLValueOffset().isNegative()) {
10145 Size = 0;
10146 return true;
10147 }
10148
10149 CharUnits EndOffset;
10150 if (!determineEndOffset(Info, E->getExprLoc(), Type, LVal, EndOffset))
10151 return false;
10152
10153 // If we've fallen outside of the end offset, just pretend there's nothing to
10154 // write to/read from.
10155 if (EndOffset <= LVal.getLValueOffset())
10156 Size = 0;
10157 else
10158 Size = (EndOffset - LVal.getLValueOffset()).getQuantity();
10159 return true;
10160}
10161
10162bool IntExprEvaluator::VisitConstantExpr(const ConstantExpr *E) {
10163 llvm::SaveAndRestore<bool> InConstantContext(Info.InConstantContext, true);
10164 if (E->getResultAPValueKind() != APValue::None)
10165 return Success(E->getAPValueResult(), E);
10166 return ExprEvaluatorBaseTy::VisitConstantExpr(E);
10167}
10168
10169bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
10170 if (unsigned BuiltinOp = E->getBuiltinCallee())
10171 return VisitBuiltinCallExpr(E, BuiltinOp);
10172
10173 return ExprEvaluatorBaseTy::VisitCallExpr(E);
10174}
10175
10176bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
10177 unsigned BuiltinOp) {
10178 switch (unsigned BuiltinOp = E->getBuiltinCallee()) {
10179 default:
10180 return ExprEvaluatorBaseTy::VisitCallExpr(E);
10181
10182 case Builtin::BI__builtin_dynamic_object_size:
10183 case Builtin::BI__builtin_object_size: {
10184 // The type was checked when we built the expression.
10185 unsigned Type =
10186 E->getArg(1)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
10187 assert(Type <= 3 && "unexpected type")((Type <= 3 && "unexpected type") ? static_cast<
void> (0) : __assert_fail ("Type <= 3 && \"unexpected type\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10187, __PRETTY_FUNCTION__))
;
10188
10189 uint64_t Size;
10190 if (tryEvaluateBuiltinObjectSize(E->getArg(0), Type, Info, Size))
10191 return Success(Size, E);
10192
10193 if (E->getArg(0)->HasSideEffects(Info.Ctx))
10194 return Success((Type & 2) ? 0 : -1, E);
10195
10196 // Expression had no side effects, but we couldn't statically determine the
10197 // size of the referenced object.
10198 switch (Info.EvalMode) {
10199 case EvalInfo::EM_ConstantExpression:
10200 case EvalInfo::EM_ConstantFold:
10201 case EvalInfo::EM_IgnoreSideEffects:
10202 // Leave it to IR generation.
10203 return Error(E);
10204 case EvalInfo::EM_ConstantExpressionUnevaluated:
10205 // Reduce it to a constant now.
10206 return Success((Type & 2) ? 0 : -1, E);
10207 }
10208
10209 llvm_unreachable("unexpected EvalMode")::llvm::llvm_unreachable_internal("unexpected EvalMode", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10209)
;
10210 }
10211
10212 case Builtin::BI__builtin_os_log_format_buffer_size: {
10213 analyze_os_log::OSLogBufferLayout Layout;
10214 analyze_os_log::computeOSLogBufferLayout(Info.Ctx, E, Layout);
10215 return Success(Layout.size().getQuantity(), E);
10216 }
10217
10218 case Builtin::BI__builtin_bswap16:
10219 case Builtin::BI__builtin_bswap32:
10220 case Builtin::BI__builtin_bswap64: {
10221 APSInt Val;
10222 if (!EvaluateInteger(E->getArg(0), Val, Info))
10223 return false;
10224
10225 return Success(Val.byteSwap(), E);
10226 }
10227
10228 case Builtin::BI__builtin_classify_type:
10229 return Success((int)EvaluateBuiltinClassifyType(E, Info.getLangOpts()), E);
10230
10231 case Builtin::BI__builtin_clrsb:
10232 case Builtin::BI__builtin_clrsbl:
10233 case Builtin::BI__builtin_clrsbll: {
10234 APSInt Val;
10235 if (!EvaluateInteger(E->getArg(0), Val, Info))
10236 return false;
10237
10238 return Success(Val.getBitWidth() - Val.getMinSignedBits(), E);
10239 }
10240
10241 case Builtin::BI__builtin_clz:
10242 case Builtin::BI__builtin_clzl:
10243 case Builtin::BI__builtin_clzll:
10244 case Builtin::BI__builtin_clzs: {
10245 APSInt Val;
10246 if (!EvaluateInteger(E->getArg(0), Val, Info))
10247 return false;
10248 if (!Val)
10249 return Error(E);
10250
10251 return Success(Val.countLeadingZeros(), E);
10252 }
10253
10254 case Builtin::BI__builtin_constant_p: {
10255 const Expr *Arg = E->getArg(0);
10256 if (EvaluateBuiltinConstantP(Info, Arg))
10257 return Success(true, E);
10258 if (Info.InConstantContext || Arg->HasSideEffects(Info.Ctx)) {
10259 // Outside a constant context, eagerly evaluate to false in the presence
10260 // of side-effects in order to avoid -Wunsequenced false-positives in
10261 // a branch on __builtin_constant_p(expr).
10262 return Success(false, E);
10263 }
10264 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
10265 return false;
10266 }
10267
10268 case Builtin::BI__builtin_is_constant_evaluated:
10269 return Success(Info.InConstantContext, E);
10270
10271 case Builtin::BI__builtin_ctz:
10272 case Builtin::BI__builtin_ctzl:
10273 case Builtin::BI__builtin_ctzll:
10274 case Builtin::BI__builtin_ctzs: {
10275 APSInt Val;
10276 if (!EvaluateInteger(E->getArg(0), Val, Info))
10277 return false;
10278 if (!Val)
10279 return Error(E);
10280
10281 return Success(Val.countTrailingZeros(), E);
10282 }
10283
10284 case Builtin::BI__builtin_eh_return_data_regno: {
10285 int Operand = E->getArg(0)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
10286 Operand = Info.Ctx.getTargetInfo().getEHDataRegisterNumber(Operand);
10287 return Success(Operand, E);
10288 }
10289
10290 case Builtin::BI__builtin_expect:
10291 return Visit(E->getArg(0));
10292
10293 case Builtin::BI__builtin_ffs:
10294 case Builtin::BI__builtin_ffsl:
10295 case Builtin::BI__builtin_ffsll: {
10296 APSInt Val;
10297 if (!EvaluateInteger(E->getArg(0), Val, Info))
10298 return false;
10299
10300 unsigned N = Val.countTrailingZeros();
10301 return Success(N == Val.getBitWidth() ? 0 : N + 1, E);
10302 }
10303
10304 case Builtin::BI__builtin_fpclassify: {
10305 APFloat Val(0.0);
10306 if (!EvaluateFloat(E->getArg(5), Val, Info))
10307 return false;
10308 unsigned Arg;
10309 switch (Val.getCategory()) {
10310 case APFloat::fcNaN: Arg = 0; break;
10311 case APFloat::fcInfinity: Arg = 1; break;
10312 case APFloat::fcNormal: Arg = Val.isDenormal() ? 3 : 2; break;
10313 case APFloat::fcZero: Arg = 4; break;
10314 }
10315 return Visit(E->getArg(Arg));
10316 }
10317
10318 case Builtin::BI__builtin_isinf_sign: {
10319 APFloat Val(0.0);
10320 return EvaluateFloat(E->getArg(0), Val, Info) &&
10321 Success(Val.isInfinity() ? (Val.isNegative() ? -1 : 1) : 0, E);
10322 }
10323
10324 case Builtin::BI__builtin_isinf: {
10325 APFloat Val(0.0);
10326 return EvaluateFloat(E->getArg(0), Val, Info) &&
10327 Success(Val.isInfinity() ? 1 : 0, E);
10328 }
10329
10330 case Builtin::BI__builtin_isfinite: {
10331 APFloat Val(0.0);
10332 return EvaluateFloat(E->getArg(0), Val, Info) &&
10333 Success(Val.isFinite() ? 1 : 0, E);
10334 }
10335
10336 case Builtin::BI__builtin_isnan: {
10337 APFloat Val(0.0);
10338 return EvaluateFloat(E->getArg(0), Val, Info) &&
10339 Success(Val.isNaN() ? 1 : 0, E);
10340 }
10341
10342 case Builtin::BI__builtin_isnormal: {
10343 APFloat Val(0.0);
10344 return EvaluateFloat(E->getArg(0), Val, Info) &&
10345 Success(Val.isNormal() ? 1 : 0, E);
10346 }
10347
10348 case Builtin::BI__builtin_parity:
10349 case Builtin::BI__builtin_parityl:
10350 case Builtin::BI__builtin_parityll: {
10351 APSInt Val;
10352 if (!EvaluateInteger(E->getArg(0), Val, Info))
10353 return false;
10354
10355 return Success(Val.countPopulation() % 2, E);
10356 }
10357
10358 case Builtin::BI__builtin_popcount:
10359 case Builtin::BI__builtin_popcountl:
10360 case Builtin::BI__builtin_popcountll: {
10361 APSInt Val;
10362 if (!EvaluateInteger(E->getArg(0), Val, Info))
10363 return false;
10364
10365 return Success(Val.countPopulation(), E);
10366 }
10367
10368 case Builtin::BIstrlen:
10369 case Builtin::BIwcslen:
10370 // A call to strlen is not a constant expression.
10371 if (Info.getLangOpts().CPlusPlus11)
10372 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
10373 << /*isConstexpr*/0 << /*isConstructor*/0
10374 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
10375 else
10376 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
10377 LLVM_FALLTHROUGH[[gnu::fallthrough]];
10378 case Builtin::BI__builtin_strlen:
10379 case Builtin::BI__builtin_wcslen: {
10380 // As an extension, we support __builtin_strlen() as a constant expression,
10381 // and support folding strlen() to a constant.
10382 LValue String;
10383 if (!EvaluatePointer(E->getArg(0), String, Info))
10384 return false;
10385
10386 QualType CharTy = E->getArg(0)->getType()->getPointeeType();
10387
10388 // Fast path: if it's a string literal, search the string value.
10389 if (const StringLiteral *S = dyn_cast_or_null<StringLiteral>(
10390 String.getLValueBase().dyn_cast<const Expr *>())) {
10391 // The string literal may have embedded null characters. Find the first
10392 // one and truncate there.
10393 StringRef Str = S->getBytes();
10394 int64_t Off = String.Offset.getQuantity();
10395 if (Off >= 0 && (uint64_t)Off <= (uint64_t)Str.size() &&
10396 S->getCharByteWidth() == 1 &&
10397 // FIXME: Add fast-path for wchar_t too.
10398 Info.Ctx.hasSameUnqualifiedType(CharTy, Info.Ctx.CharTy)) {
10399 Str = Str.substr(Off);
10400
10401 StringRef::size_type Pos = Str.find(0);
10402 if (Pos != StringRef::npos)
10403 Str = Str.substr(0, Pos);
10404
10405 return Success(Str.size(), E);
10406 }
10407
10408 // Fall through to slow path to issue appropriate diagnostic.
10409 }
10410
10411 // Slow path: scan the bytes of the string looking for the terminating 0.
10412 for (uint64_t Strlen = 0; /**/; ++Strlen) {
10413 APValue Char;
10414 if (!handleLValueToRValueConversion(Info, E, CharTy, String, Char) ||
10415 !Char.isInt())
10416 return false;
10417 if (!Char.getInt())
10418 return Success(Strlen, E);
10419 if (!HandleLValueArrayAdjustment(Info, E, String, CharTy, 1))
10420 return false;
10421 }
10422 }
10423
10424 case Builtin::BIstrcmp:
10425 case Builtin::BIwcscmp:
10426 case Builtin::BIstrncmp:
10427 case Builtin::BIwcsncmp:
10428 case Builtin::BImemcmp:
10429 case Builtin::BIbcmp:
10430 case Builtin::BIwmemcmp:
10431 // A call to strlen is not a constant expression.
10432 if (Info.getLangOpts().CPlusPlus11)
10433 Info.CCEDiag(E, diag::note_constexpr_invalid_function)
10434 << /*isConstexpr*/0 << /*isConstructor*/0
10435 << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
10436 else
10437 Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
10438 LLVM_FALLTHROUGH[[gnu::fallthrough]];
10439 case Builtin::BI__builtin_strcmp:
10440 case Builtin::BI__builtin_wcscmp:
10441 case Builtin::BI__builtin_strncmp:
10442 case Builtin::BI__builtin_wcsncmp:
10443 case Builtin::BI__builtin_memcmp:
10444 case Builtin::BI__builtin_bcmp:
10445 case Builtin::BI__builtin_wmemcmp: {
10446 LValue String1, String2;
10447 if (!EvaluatePointer(E->getArg(0), String1, Info) ||
10448 !EvaluatePointer(E->getArg(1), String2, Info))
10449 return false;
10450
10451 uint64_t MaxLength = uint64_t(-1);
10452 if (BuiltinOp != Builtin::BIstrcmp &&
10453 BuiltinOp != Builtin::BIwcscmp &&
10454 BuiltinOp != Builtin::BI__builtin_strcmp &&
10455 BuiltinOp != Builtin::BI__builtin_wcscmp) {
10456 APSInt N;
10457 if (!EvaluateInteger(E->getArg(2), N, Info))
10458 return false;
10459 MaxLength = N.getExtValue();
10460 }
10461
10462 // Empty substrings compare equal by definition.
10463 if (MaxLength == 0u)
10464 return Success(0, E);
10465
10466 if (!String1.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
10467 !String2.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
10468 String1.Designator.Invalid || String2.Designator.Invalid)
10469 return false;
10470
10471 QualType CharTy1 = String1.Designator.getType(Info.Ctx);
10472 QualType CharTy2 = String2.Designator.getType(Info.Ctx);
10473
10474 bool IsRawByte = BuiltinOp == Builtin::BImemcmp ||
10475 BuiltinOp == Builtin::BIbcmp ||
10476 BuiltinOp == Builtin::BI__builtin_memcmp ||
10477 BuiltinOp == Builtin::BI__builtin_bcmp;
10478
10479 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10482, __PRETTY_FUNCTION__))
10480 (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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10482, __PRETTY_FUNCTION__))
10481 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10482, __PRETTY_FUNCTION__))
10482 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10482, __PRETTY_FUNCTION__))
;
10483
10484 const auto &ReadCurElems = [&](APValue &Char1, APValue &Char2) {
10485 return handleLValueToRValueConversion(Info, E, CharTy1, String1, Char1) &&
10486 handleLValueToRValueConversion(Info, E, CharTy2, String2, Char2) &&
10487 Char1.isInt() && Char2.isInt();
10488 };
10489 const auto &AdvanceElems = [&] {
10490 return HandleLValueArrayAdjustment(Info, E, String1, CharTy1, 1) &&
10491 HandleLValueArrayAdjustment(Info, E, String2, CharTy2, 1);
10492 };
10493
10494 if (IsRawByte) {
10495 uint64_t BytesRemaining = MaxLength;
10496 // Pointers to const void may point to objects of incomplete type.
10497 if (CharTy1->isIncompleteType()) {
10498 Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy1;
10499 return false;
10500 }
10501 if (CharTy2->isIncompleteType()) {
10502 Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy2;
10503 return false;
10504 }
10505 uint64_t CharTy1Width{Info.Ctx.getTypeSize(CharTy1)};
10506 CharUnits CharTy1Size = Info.Ctx.toCharUnitsFromBits(CharTy1Width);
10507 // Give up on comparing between elements with disparate widths.
10508 if (CharTy1Size != Info.Ctx.getTypeSizeInChars(CharTy2))
10509 return false;
10510 uint64_t BytesPerElement = CharTy1Size.getQuantity();
10511 assert(BytesRemaining && "BytesRemaining should not be zero: the "((BytesRemaining && "BytesRemaining should not be zero: the "
"following loop considers at least one element") ? static_cast
<void> (0) : __assert_fail ("BytesRemaining && \"BytesRemaining should not be zero: the \" \"following loop considers at least one element\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10512, __PRETTY_FUNCTION__))
10512 "following loop considers at least one element")((BytesRemaining && "BytesRemaining should not be zero: the "
"following loop considers at least one element") ? static_cast
<void> (0) : __assert_fail ("BytesRemaining && \"BytesRemaining should not be zero: the \" \"following loop considers at least one element\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10512, __PRETTY_FUNCTION__))
;
10513 while (true) {
10514 APValue Char1, Char2;
10515 if (!ReadCurElems(Char1, Char2))
10516 return false;
10517 // We have compatible in-memory widths, but a possible type and
10518 // (for `bool`) internal representation mismatch.
10519 // Assuming two's complement representation, including 0 for `false` and
10520 // 1 for `true`, we can check an appropriate number of elements for
10521 // equality even if they are not byte-sized.
10522 APSInt Char1InMem = Char1.getInt().extOrTrunc(CharTy1Width);
10523 APSInt Char2InMem = Char2.getInt().extOrTrunc(CharTy1Width);
10524 if (Char1InMem.ne(Char2InMem)) {
10525 // If the elements are byte-sized, then we can produce a three-way
10526 // comparison result in a straightforward manner.
10527 if (BytesPerElement == 1u) {
10528 // memcmp always compares unsigned chars.
10529 return Success(Char1InMem.ult(Char2InMem) ? -1 : 1, E);
10530 }
10531 // The result is byte-order sensitive, and we have multibyte elements.
10532 // FIXME: We can compare the remaining bytes in the correct order.
10533 return false;
10534 }
10535 if (!AdvanceElems())
10536 return false;
10537 if (BytesRemaining <= BytesPerElement)
10538 break;
10539 BytesRemaining -= BytesPerElement;
10540 }
10541 // Enough elements are equal to account for the memcmp limit.
10542 return Success(0, E);
10543 }
10544
10545 bool StopAtNull =
10546 (BuiltinOp != Builtin::BImemcmp && BuiltinOp != Builtin::BIbcmp &&
10547 BuiltinOp != Builtin::BIwmemcmp &&
10548 BuiltinOp != Builtin::BI__builtin_memcmp &&
10549 BuiltinOp != Builtin::BI__builtin_bcmp &&
10550 BuiltinOp != Builtin::BI__builtin_wmemcmp);
10551 bool IsWide = BuiltinOp == Builtin::BIwcscmp ||
10552 BuiltinOp == Builtin::BIwcsncmp ||
10553 BuiltinOp == Builtin::BIwmemcmp ||
10554 BuiltinOp == Builtin::BI__builtin_wcscmp ||
10555 BuiltinOp == Builtin::BI__builtin_wcsncmp ||
10556 BuiltinOp == Builtin::BI__builtin_wmemcmp;
10557
10558 for (; MaxLength; --MaxLength) {
10559 APValue Char1, Char2;
10560 if (!ReadCurElems(Char1, Char2))
10561 return false;
10562 if (Char1.getInt() != Char2.getInt()) {
10563 if (IsWide) // wmemcmp compares with wchar_t signedness.
10564 return Success(Char1.getInt() < Char2.getInt() ? -1 : 1, E);
10565 // memcmp always compares unsigned chars.
10566 return Success(Char1.getInt().ult(Char2.getInt()) ? -1 : 1, E);
10567 }
10568 if (StopAtNull && !Char1.getInt())
10569 return Success(0, E);
10570 assert(!(StopAtNull && !Char2.getInt()))((!(StopAtNull && !Char2.getInt())) ? static_cast<
void> (0) : __assert_fail ("!(StopAtNull && !Char2.getInt())"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10570, __PRETTY_FUNCTION__))
;
10571 if (!AdvanceElems())
10572 return false;
10573 }
10574 // We hit the strncmp / memcmp limit.
10575 return Success(0, E);
10576 }
10577
10578 case Builtin::BI__atomic_always_lock_free:
10579 case Builtin::BI__atomic_is_lock_free:
10580 case Builtin::BI__c11_atomic_is_lock_free: {
10581 APSInt SizeVal;
10582 if (!EvaluateInteger(E->getArg(0), SizeVal, Info))
10583 return false;
10584
10585 // For __atomic_is_lock_free(sizeof(_Atomic(T))), if the size is a power
10586 // of two less than the maximum inline atomic width, we know it is
10587 // lock-free. If the size isn't a power of two, or greater than the
10588 // maximum alignment where we promote atomics, we know it is not lock-free
10589 // (at least not in the sense of atomic_is_lock_free). Otherwise,
10590 // the answer can only be determined at runtime; for example, 16-byte
10591 // atomics have lock-free implementations on some, but not all,
10592 // x86-64 processors.
10593
10594 // Check power-of-two.
10595 CharUnits Size = CharUnits::fromQuantity(SizeVal.getZExtValue());
10596 if (Size.isPowerOfTwo()) {
10597 // Check against inlining width.
10598 unsigned InlineWidthBits =
10599 Info.Ctx.getTargetInfo().getMaxAtomicInlineWidth();
10600 if (Size <= Info.Ctx.toCharUnitsFromBits(InlineWidthBits)) {
10601 if (BuiltinOp == Builtin::BI__c11_atomic_is_lock_free ||
10602 Size == CharUnits::One() ||
10603 E->getArg(1)->isNullPointerConstant(Info.Ctx,
10604 Expr::NPC_NeverValueDependent))
10605 // OK, we will inline appropriately-aligned operations of this size,
10606 // and _Atomic(T) is appropriately-aligned.
10607 return Success(1, E);
10608
10609 QualType PointeeType = E->getArg(1)->IgnoreImpCasts()->getType()->
10610 castAs<PointerType>()->getPointeeType();
10611 if (!PointeeType->isIncompleteType() &&
10612 Info.Ctx.getTypeAlignInChars(PointeeType) >= Size) {
10613 // OK, we will inline operations on this object.
10614 return Success(1, E);
10615 }
10616 }
10617 }
10618
10619 return BuiltinOp == Builtin::BI__atomic_always_lock_free ?
10620 Success(0, E) : Error(E);
10621 }
10622 case Builtin::BIomp_is_initial_device:
10623 // We can decide statically which value the runtime would return if called.
10624 return Success(Info.getLangOpts().OpenMPIsDevice ? 0 : 1, E);
10625 case Builtin::BI__builtin_add_overflow:
10626 case Builtin::BI__builtin_sub_overflow:
10627 case Builtin::BI__builtin_mul_overflow:
10628 case Builtin::BI__builtin_sadd_overflow:
10629 case Builtin::BI__builtin_uadd_overflow:
10630 case Builtin::BI__builtin_uaddl_overflow:
10631 case Builtin::BI__builtin_uaddll_overflow:
10632 case Builtin::BI__builtin_usub_overflow:
10633 case Builtin::BI__builtin_usubl_overflow:
10634 case Builtin::BI__builtin_usubll_overflow:
10635 case Builtin::BI__builtin_umul_overflow:
10636 case Builtin::BI__builtin_umull_overflow:
10637 case Builtin::BI__builtin_umulll_overflow:
10638 case Builtin::BI__builtin_saddl_overflow:
10639 case Builtin::BI__builtin_saddll_overflow:
10640 case Builtin::BI__builtin_ssub_overflow:
10641 case Builtin::BI__builtin_ssubl_overflow:
10642 case Builtin::BI__builtin_ssubll_overflow:
10643 case Builtin::BI__builtin_smul_overflow:
10644 case Builtin::BI__builtin_smull_overflow:
10645 case Builtin::BI__builtin_smulll_overflow: {
10646 LValue ResultLValue;
10647 APSInt LHS, RHS;
10648
10649 QualType ResultType = E->getArg(2)->getType()->getPointeeType();
10650 if (!EvaluateInteger(E->getArg(0), LHS, Info) ||
10651 !EvaluateInteger(E->getArg(1), RHS, Info) ||
10652 !EvaluatePointer(E->getArg(2), ResultLValue, Info))
10653 return false;
10654
10655 APSInt Result;
10656 bool DidOverflow = false;
10657
10658 // If the types don't have to match, enlarge all 3 to the largest of them.
10659 if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
10660 BuiltinOp == Builtin::BI__builtin_sub_overflow ||
10661 BuiltinOp == Builtin::BI__builtin_mul_overflow) {
10662 bool IsSigned = LHS.isSigned() || RHS.isSigned() ||
10663 ResultType->isSignedIntegerOrEnumerationType();
10664 bool AllSigned = LHS.isSigned() && RHS.isSigned() &&
10665 ResultType->isSignedIntegerOrEnumerationType();
10666 uint64_t LHSSize = LHS.getBitWidth();
10667 uint64_t RHSSize = RHS.getBitWidth();
10668 uint64_t ResultSize = Info.Ctx.getTypeSize(ResultType);
10669 uint64_t MaxBits = std::max(std::max(LHSSize, RHSSize), ResultSize);
10670
10671 // Add an additional bit if the signedness isn't uniformly agreed to. We
10672 // could do this ONLY if there is a signed and an unsigned that both have
10673 // MaxBits, but the code to check that is pretty nasty. The issue will be
10674 // caught in the shrink-to-result later anyway.
10675 if (IsSigned && !AllSigned)
10676 ++MaxBits;
10677
10678 LHS = APSInt(LHS.extOrTrunc(MaxBits), !IsSigned);
10679 RHS = APSInt(RHS.extOrTrunc(MaxBits), !IsSigned);
10680 Result = APSInt(MaxBits, !IsSigned);
10681 }
10682
10683 // Find largest int.
10684 switch (BuiltinOp) {
10685 default:
10686 llvm_unreachable("Invalid value for BuiltinOp")::llvm::llvm_unreachable_internal("Invalid value for BuiltinOp"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10686)
;
10687 case Builtin::BI__builtin_add_overflow:
10688 case Builtin::BI__builtin_sadd_overflow:
10689 case Builtin::BI__builtin_saddl_overflow:
10690 case Builtin::BI__builtin_saddll_overflow:
10691 case Builtin::BI__builtin_uadd_overflow:
10692 case Builtin::BI__builtin_uaddl_overflow:
10693 case Builtin::BI__builtin_uaddll_overflow:
10694 Result = LHS.isSigned() ? LHS.sadd_ov(RHS, DidOverflow)
10695 : LHS.uadd_ov(RHS, DidOverflow);
10696 break;
10697 case Builtin::BI__builtin_sub_overflow:
10698 case Builtin::BI__builtin_ssub_overflow:
10699 case Builtin::BI__builtin_ssubl_overflow:
10700 case Builtin::BI__builtin_ssubll_overflow:
10701 case Builtin::BI__builtin_usub_overflow:
10702 case Builtin::BI__builtin_usubl_overflow:
10703 case Builtin::BI__builtin_usubll_overflow:
10704 Result = LHS.isSigned() ? LHS.ssub_ov(RHS, DidOverflow)
10705 : LHS.usub_ov(RHS, DidOverflow);
10706 break;
10707 case Builtin::BI__builtin_mul_overflow:
10708 case Builtin::BI__builtin_smul_overflow:
10709 case Builtin::BI__builtin_smull_overflow:
10710 case Builtin::BI__builtin_smulll_overflow:
10711 case Builtin::BI__builtin_umul_overflow:
10712 case Builtin::BI__builtin_umull_overflow:
10713 case Builtin::BI__builtin_umulll_overflow:
10714 Result = LHS.isSigned() ? LHS.smul_ov(RHS, DidOverflow)
10715 : LHS.umul_ov(RHS, DidOverflow);
10716 break;
10717 }
10718
10719 // In the case where multiple sizes are allowed, truncate and see if
10720 // the values are the same.
10721 if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
10722 BuiltinOp == Builtin::BI__builtin_sub_overflow ||
10723 BuiltinOp == Builtin::BI__builtin_mul_overflow) {
10724 // APSInt doesn't have a TruncOrSelf, so we use extOrTrunc instead,
10725 // since it will give us the behavior of a TruncOrSelf in the case where
10726 // its parameter <= its size. We previously set Result to be at least the
10727 // type-size of the result, so getTypeSize(ResultType) <= Result.BitWidth
10728 // will work exactly like TruncOrSelf.
10729 APSInt Temp = Result.extOrTrunc(Info.Ctx.getTypeSize(ResultType));
10730 Temp.setIsSigned(ResultType->isSignedIntegerOrEnumerationType());
10731
10732 if (!APSInt::isSameValue(Temp, Result))
10733 DidOverflow = true;
10734 Result = Temp;
10735 }
10736
10737 APValue APV{Result};
10738 if (!handleAssignment(Info, E, ResultLValue, ResultType, APV))
10739 return false;
10740 return Success(DidOverflow, E);
10741 }
10742 }
10743}
10744
10745/// Determine whether this is a pointer past the end of the complete
10746/// object referred to by the lvalue.
10747static bool isOnePastTheEndOfCompleteObject(const ASTContext &Ctx,
10748 const LValue &LV) {
10749 // A null pointer can be viewed as being "past the end" but we don't
10750 // choose to look at it that way here.
10751 if (!LV.getLValueBase())
10752 return false;
10753
10754 // If the designator is valid and refers to a subobject, we're not pointing
10755 // past the end.
10756 if (!LV.getLValueDesignator().Invalid &&
10757 !LV.getLValueDesignator().isOnePastTheEnd())
10758 return false;
10759
10760 // A pointer to an incomplete type might be past-the-end if the type's size is
10761 // zero. We cannot tell because the type is incomplete.
10762 QualType Ty = getType(LV.getLValueBase());
10763 if (Ty->isIncompleteType())
10764 return true;
10765
10766 // We're a past-the-end pointer if we point to the byte after the object,
10767 // no matter what our type or path is.
10768 auto Size = Ctx.getTypeSizeInChars(Ty);
10769 return LV.getLValueOffset() == Size;
10770}
10771
10772namespace {
10773
10774/// Data recursive integer evaluator of certain binary operators.
10775///
10776/// We use a data recursive algorithm for binary operators so that we are able
10777/// to handle extreme cases of chained binary operators without causing stack
10778/// overflow.
10779class DataRecursiveIntBinOpEvaluator {
10780 struct EvalResult {
10781 APValue Val;
10782 bool Failed;
10783
10784 EvalResult() : Failed(false) { }
10785
10786 void swap(EvalResult &RHS) {
10787 Val.swap(RHS.Val);
10788 Failed = RHS.Failed;
10789 RHS.Failed = false;
10790 }
10791 };
10792
10793 struct Job {
10794 const Expr *E;
10795 EvalResult LHSResult; // meaningful only for binary operator expression.
10796 enum { AnyExprKind, BinOpKind, BinOpVisitedLHSKind } Kind;
10797
10798 Job() = default;
10799 Job(Job &&) = default;
10800
10801 void startSpeculativeEval(EvalInfo &Info) {
10802 SpecEvalRAII = SpeculativeEvaluationRAII(Info);
10803 }
10804
10805 private:
10806 SpeculativeEvaluationRAII SpecEvalRAII;
10807 };
10808
10809 SmallVector<Job, 16> Queue;
10810
10811 IntExprEvaluator &IntEval;
10812 EvalInfo &Info;
10813 APValue &FinalResult;
10814
10815public:
10816 DataRecursiveIntBinOpEvaluator(IntExprEvaluator &IntEval, APValue &Result)
10817 : IntEval(IntEval), Info(IntEval.getEvalInfo()), FinalResult(Result) { }
10818
10819 /// True if \param E is a binary operator that we are going to handle
10820 /// data recursively.
10821 /// We handle binary operators that are comma, logical, or that have operands
10822 /// with integral or enumeration type.
10823 static bool shouldEnqueue(const BinaryOperator *E) {
10824 return E->getOpcode() == BO_Comma || E->isLogicalOp() ||
10825 (E->isRValue() && E->getType()->isIntegralOrEnumerationType() &&
10826 E->getLHS()->getType()->isIntegralOrEnumerationType() &&
10827 E->getRHS()->getType()->isIntegralOrEnumerationType());
10828 }
10829
10830 bool Traverse(const BinaryOperator *E) {
10831 enqueue(E);
10832 EvalResult PrevResult;
10833 while (!Queue.empty())
10834 process(PrevResult);
10835
10836 if (PrevResult.Failed) return false;
10837
10838 FinalResult.swap(PrevResult.Val);
10839 return true;
10840 }
10841
10842private:
10843 bool Success(uint64_t Value, const Expr *E, APValue &Result) {
10844 return IntEval.Success(Value, E, Result);
10845 }
10846 bool Success(const APSInt &Value, const Expr *E, APValue &Result) {
10847 return IntEval.Success(Value, E, Result);
10848 }
10849 bool Error(const Expr *E) {
10850 return IntEval.Error(E);
10851 }
10852 bool Error(const Expr *E, diag::kind D) {
10853 return IntEval.Error(E, D);
10854 }
10855
10856 OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
10857 return Info.CCEDiag(E, D);
10858 }
10859
10860 // Returns true if visiting the RHS is necessary, false otherwise.
10861 bool VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
10862 bool &SuppressRHSDiags);
10863
10864 bool VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
10865 const BinaryOperator *E, APValue &Result);
10866
10867 void EvaluateExpr(const Expr *E, EvalResult &Result) {
10868 Result.Failed = !Evaluate(Result.Val, Info, E);
10869 if (Result.Failed)
10870 Result.Val = APValue();
10871 }
10872
10873 void process(EvalResult &Result);
10874
10875 void enqueue(const Expr *E) {
10876 E = E->IgnoreParens();
10877 Queue.resize(Queue.size()+1);
10878 Queue.back().E = E;
10879 Queue.back().Kind = Job::AnyExprKind;
10880 }
10881};
10882
10883}
10884
10885bool DataRecursiveIntBinOpEvaluator::
10886 VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
10887 bool &SuppressRHSDiags) {
10888 if (E->getOpcode() == BO_Comma) {
10889 // Ignore LHS but note if we could not evaluate it.
10890 if (LHSResult.Failed)
10891 return Info.noteSideEffect();
10892 return true;
10893 }
10894
10895 if (E->isLogicalOp()) {
10896 bool LHSAsBool;
10897 if (!LHSResult.Failed && HandleConversionToBool(LHSResult.Val, LHSAsBool)) {
10898 // We were able to evaluate the LHS, see if we can get away with not
10899 // evaluating the RHS: 0 && X -> 0, 1 || X -> 1
10900 if (LHSAsBool == (E->getOpcode() == BO_LOr)) {
10901 Success(LHSAsBool, E, LHSResult.Val);
10902 return false; // Ignore RHS
10903 }
10904 } else {
10905 LHSResult.Failed = true;
10906
10907 // Since we weren't able to evaluate the left hand side, it
10908 // might have had side effects.
10909 if (!Info.noteSideEffect())
10910 return false;
10911
10912 // We can't evaluate the LHS; however, sometimes the result
10913 // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
10914 // Don't ignore RHS and suppress diagnostics from this arm.
10915 SuppressRHSDiags = true;
10916 }
10917
10918 return true;
10919 }
10920
10921 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10922, __PRETTY_FUNCTION__))
10922 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10922, __PRETTY_FUNCTION__))
;
10923
10924 if (LHSResult.Failed && !Info.noteFailure())
10925 return false; // Ignore RHS;
10926
10927 return true;
10928}
10929
10930static void addOrSubLValueAsInteger(APValue &LVal, const APSInt &Index,
10931 bool IsSub) {
10932 // Compute the new offset in the appropriate width, wrapping at 64 bits.
10933 // FIXME: When compiling for a 32-bit target, we should use 32-bit
10934 // offsets.
10935 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10935, __PRETTY_FUNCTION__))
;
10936 CharUnits &Offset = LVal.getLValueOffset();
10937 uint64_t Offset64 = Offset.getQuantity();
10938 uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
10939 Offset = CharUnits::fromQuantity(IsSub ? Offset64 - Index64
10940 : Offset64 + Index64);
10941}
10942
10943bool DataRecursiveIntBinOpEvaluator::
10944 VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
10945 const BinaryOperator *E, APValue &Result) {
10946 if (E->getOpcode() == BO_Comma) {
10947 if (RHSResult.Failed)
10948 return false;
10949 Result = RHSResult.Val;
10950 return true;
10951 }
10952
10953 if (E->isLogicalOp()) {
10954 bool lhsResult, rhsResult;
10955 bool LHSIsOK = HandleConversionToBool(LHSResult.Val, lhsResult);
10956 bool RHSIsOK = HandleConversionToBool(RHSResult.Val, rhsResult);
10957
10958 if (LHSIsOK) {
10959 if (RHSIsOK) {
10960 if (E->getOpcode() == BO_LOr)
10961 return Success(lhsResult || rhsResult, E, Result);
10962 else
10963 return Success(lhsResult && rhsResult, E, Result);
10964 }
10965 } else {
10966 if (RHSIsOK) {
10967 // We can't evaluate the LHS; however, sometimes the result
10968 // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
10969 if (rhsResult == (E->getOpcode() == BO_LOr))
10970 return Success(rhsResult, E, Result);
10971 }
10972 }
10973
10974 return false;
10975 }
10976
10977 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10978, __PRETTY_FUNCTION__))
10978 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 10978, __PRETTY_FUNCTION__))
;
10979
10980 if (LHSResult.Failed || RHSResult.Failed)
10981 return false;
10982
10983 const APValue &LHSVal = LHSResult.Val;
10984 const APValue &RHSVal = RHSResult.Val;
10985
10986 // Handle cases like (unsigned long)&a + 4.
10987 if (E->isAdditiveOp() && LHSVal.isLValue() && RHSVal.isInt()) {
10988 Result = LHSVal;
10989 addOrSubLValueAsInteger(Result, RHSVal.getInt(), E->getOpcode() == BO_Sub);
10990 return true;
10991 }
10992
10993 // Handle cases like 4 + (unsigned long)&a
10994 if (E->getOpcode() == BO_Add &&
10995 RHSVal.isLValue() && LHSVal.isInt()) {
10996 Result = RHSVal;
10997 addOrSubLValueAsInteger(Result, LHSVal.getInt(), /*IsSub*/false);
10998 return true;
10999 }
11000
11001 if (E->getOpcode() == BO_Sub && LHSVal.isLValue() && RHSVal.isLValue()) {
11002 // Handle (intptr_t)&&A - (intptr_t)&&B.
11003 if (!LHSVal.getLValueOffset().isZero() ||
11004 !RHSVal.getLValueOffset().isZero())
11005 return false;
11006 const Expr *LHSExpr = LHSVal.getLValueBase().dyn_cast<const Expr*>();
11007 const Expr *RHSExpr = RHSVal.getLValueBase().dyn_cast<const Expr*>();
11008 if (!LHSExpr || !RHSExpr)
11009 return false;
11010 const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
11011 const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
11012 if (!LHSAddrExpr || !RHSAddrExpr)
11013 return false;
11014 // Make sure both labels come from the same function.
11015 if (LHSAddrExpr->getLabel()->getDeclContext() !=
11016 RHSAddrExpr->getLabel()->getDeclContext())
11017 return false;
11018 Result = APValue(LHSAddrExpr, RHSAddrExpr);
11019 return true;
11020 }
11021
11022 // All the remaining cases expect both operands to be an integer
11023 if (!LHSVal.isInt() || !RHSVal.isInt())
11024 return Error(E);
11025
11026 // Set up the width and signedness manually, in case it can't be deduced
11027 // from the operation we're performing.
11028 // FIXME: Don't do this in the cases where we can deduce it.
11029 APSInt Value(Info.Ctx.getIntWidth(E->getType()),
11030 E->getType()->isUnsignedIntegerOrEnumerationType());
11031 if (!handleIntIntBinOp(Info, E, LHSVal.getInt(), E->getOpcode(),
11032 RHSVal.getInt(), Value))
11033 return false;
11034 return Success(Value, E, Result);
11035}
11036
11037void DataRecursiveIntBinOpEvaluator::process(EvalResult &Result) {
11038 Job &job = Queue.back();
11039
11040 switch (job.Kind) {
11041 case Job::AnyExprKind: {
11042 if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(job.E)) {
11043 if (shouldEnqueue(Bop)) {
11044 job.Kind = Job::BinOpKind;
11045 enqueue(Bop->getLHS());
11046 return;
11047 }
11048 }
11049
11050 EvaluateExpr(job.E, Result);
11051 Queue.pop_back();
11052 return;
11053 }
11054
11055 case Job::BinOpKind: {
11056 const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
11057 bool SuppressRHSDiags = false;
11058 if (!VisitBinOpLHSOnly(Result, Bop, SuppressRHSDiags)) {
11059 Queue.pop_back();
11060 return;
11061 }
11062 if (SuppressRHSDiags)
11063 job.startSpeculativeEval(Info);
11064 job.LHSResult.swap(Result);
11065 job.Kind = Job::BinOpVisitedLHSKind;
11066 enqueue(Bop->getRHS());
11067 return;
11068 }
11069
11070 case Job::BinOpVisitedLHSKind: {
11071 const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
11072 EvalResult RHS;
11073 RHS.swap(Result);
11074 Result.Failed = !VisitBinOp(job.LHSResult, RHS, Bop, Result.Val);
11075 Queue.pop_back();
11076 return;
11077 }
11078 }
11079
11080 llvm_unreachable("Invalid Job::Kind!")::llvm::llvm_unreachable_internal("Invalid Job::Kind!", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11080)
;
11081}
11082
11083namespace {
11084/// Used when we determine that we should fail, but can keep evaluating prior to
11085/// noting that we had a failure.
11086class DelayedNoteFailureRAII {
11087 EvalInfo &Info;
11088 bool NoteFailure;
11089
11090public:
11091 DelayedNoteFailureRAII(EvalInfo &Info, bool NoteFailure = true)
11092 : Info(Info), NoteFailure(NoteFailure) {}
11093 ~DelayedNoteFailureRAII() {
11094 if (NoteFailure) {
11095 bool ContinueAfterFailure = Info.noteFailure();
11096 (void)ContinueAfterFailure;
11097 assert(ContinueAfterFailure &&((ContinueAfterFailure && "Shouldn't have kept evaluating on failure."
) ? static_cast<void> (0) : __assert_fail ("ContinueAfterFailure && \"Shouldn't have kept evaluating on failure.\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11098, __PRETTY_FUNCTION__))
11098 "Shouldn't have kept evaluating on failure.")((ContinueAfterFailure && "Shouldn't have kept evaluating on failure."
) ? static_cast<void> (0) : __assert_fail ("ContinueAfterFailure && \"Shouldn't have kept evaluating on failure.\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11098, __PRETTY_FUNCTION__))
;
11099 }
11100 }
11101};
11102}
11103
11104template <class SuccessCB, class AfterCB>
11105static bool
11106EvaluateComparisonBinaryOperator(EvalInfo &Info, const BinaryOperator *E,
11107 SuccessCB &&Success, AfterCB &&DoAfter) {
11108 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11108, __PRETTY_FUNCTION__))
;
11109 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11111, __PRETTY_FUNCTION__))
11110 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11111, __PRETTY_FUNCTION__))
11111 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11111, __PRETTY_FUNCTION__))
;
11112 auto Error = [&](const Expr *E) {
11113 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
11114 return false;
11115 };
11116
11117 using CCR = ComparisonCategoryResult;
11118 bool IsRelational = E->isRelationalOp();
11119 bool IsEquality = E->isEqualityOp();
11120 if (E->getOpcode() == BO_Cmp) {
11121 const ComparisonCategoryInfo &CmpInfo =
11122 Info.Ctx.CompCategories.getInfoForType(E->getType());
11123 IsRelational = CmpInfo.isOrdered();
11124 IsEquality = CmpInfo.isEquality();
11125 }
11126
11127 QualType LHSTy = E->getLHS()->getType();
11128 QualType RHSTy = E->getRHS()->getType();
11129
11130 if (LHSTy->isIntegralOrEnumerationType() &&
11131 RHSTy->isIntegralOrEnumerationType()) {
11132 APSInt LHS, RHS;
11133 bool LHSOK = EvaluateInteger(E->getLHS(), LHS, Info);
11134 if (!LHSOK && !Info.noteFailure())
11135 return false;
11136 if (!EvaluateInteger(E->getRHS(), RHS, Info) || !LHSOK)
11137 return false;
11138 if (LHS < RHS)
11139 return Success(CCR::Less, E);
11140 if (LHS > RHS)
11141 return Success(CCR::Greater, E);
11142 return Success(CCR::Equal, E);
11143 }
11144
11145 if (LHSTy->isFixedPointType() || RHSTy->isFixedPointType()) {
11146 APFixedPoint LHSFX(Info.Ctx.getFixedPointSemantics(LHSTy));
11147 APFixedPoint RHSFX(Info.Ctx.getFixedPointSemantics(RHSTy));
11148
11149 bool LHSOK = EvaluateFixedPointOrInteger(E->getLHS(), LHSFX, Info);
11150 if (!LHSOK && !Info.noteFailure())
11151 return false;
11152 if (!EvaluateFixedPointOrInteger(E->getRHS(), RHSFX, Info) || !LHSOK)
11153 return false;
11154 if (LHSFX < RHSFX)
11155 return Success(CCR::Less, E);
11156 if (LHSFX > RHSFX)
11157 return Success(CCR::Greater, E);
11158 return Success(CCR::Equal, E);
11159 }
11160
11161 if (LHSTy->isAnyComplexType() || RHSTy->isAnyComplexType()) {
11162 ComplexValue LHS, RHS;
11163 bool LHSOK;
11164 if (E->isAssignmentOp()) {
11165 LValue LV;
11166 EvaluateLValue(E->getLHS(), LV, Info);
11167 LHSOK = false;
11168 } else if (LHSTy->isRealFloatingType()) {
11169 LHSOK = EvaluateFloat(E->getLHS(), LHS.FloatReal, Info);
11170 if (LHSOK) {
11171 LHS.makeComplexFloat();
11172 LHS.FloatImag = APFloat(LHS.FloatReal.getSemantics());
11173 }
11174 } else {
11175 LHSOK = EvaluateComplex(E->getLHS(), LHS, Info);
11176 }
11177 if (!LHSOK && !Info.noteFailure())
11178 return false;
11179
11180 if (E->getRHS()->getType()->isRealFloatingType()) {
11181 if (!EvaluateFloat(E->getRHS(), RHS.FloatReal, Info) || !LHSOK)
11182 return false;
11183 RHS.makeComplexFloat();
11184 RHS.FloatImag = APFloat(RHS.FloatReal.getSemantics());
11185 } else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
11186 return false;
11187
11188 if (LHS.isComplexFloat()) {
11189 APFloat::cmpResult CR_r =
11190 LHS.getComplexFloatReal().compare(RHS.getComplexFloatReal());
11191 APFloat::cmpResult CR_i =
11192 LHS.getComplexFloatImag().compare(RHS.getComplexFloatImag());
11193 bool IsEqual = CR_r == APFloat::cmpEqual && CR_i == APFloat::cmpEqual;
11194 return Success(IsEqual ? CCR::Equal : CCR::Nonequal, E);
11195 } else {
11196 assert(IsEquality && "invalid complex comparison")((IsEquality && "invalid complex comparison") ? static_cast
<void> (0) : __assert_fail ("IsEquality && \"invalid complex comparison\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11196, __PRETTY_FUNCTION__))
;
11197 bool IsEqual = LHS.getComplexIntReal() == RHS.getComplexIntReal() &&
11198 LHS.getComplexIntImag() == RHS.getComplexIntImag();
11199 return Success(IsEqual ? CCR::Equal : CCR::Nonequal, E);
11200 }
11201 }
11202
11203 if (LHSTy->isRealFloatingType() &&
11204 RHSTy->isRealFloatingType()) {
11205 APFloat RHS(0.0), LHS(0.0);
11206
11207 bool LHSOK = EvaluateFloat(E->getRHS(), RHS, Info);
11208 if (!LHSOK && !Info.noteFailure())
11209 return false;
11210
11211 if (!EvaluateFloat(E->getLHS(), LHS, Info) || !LHSOK)
11212 return false;
11213
11214 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11214, __PRETTY_FUNCTION__))
;
11215 auto GetCmpRes = [&]() {
11216 switch (LHS.compare(RHS)) {
11217 case APFloat::cmpEqual:
11218 return CCR::Equal;
11219 case APFloat::cmpLessThan:
11220 return CCR::Less;
11221 case APFloat::cmpGreaterThan:
11222 return CCR::Greater;
11223 case APFloat::cmpUnordered:
11224 return CCR::Unordered;
11225 }
11226 llvm_unreachable("Unrecognised APFloat::cmpResult enum")::llvm::llvm_unreachable_internal("Unrecognised APFloat::cmpResult enum"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11226)
;
11227 };
11228 return Success(GetCmpRes(), E);
11229 }
11230
11231 if (LHSTy->isPointerType() && RHSTy->isPointerType()) {
11232 LValue LHSValue, RHSValue;
11233
11234 bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
11235 if (!LHSOK && !Info.noteFailure())
11236 return false;
11237
11238 if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
11239 return false;
11240
11241 // Reject differing bases from the normal codepath; we special-case
11242 // comparisons to null.
11243 if (!HasSameBase(LHSValue, RHSValue)) {
11244 // Inequalities and subtractions between unrelated pointers have
11245 // unspecified or undefined behavior.
11246 if (!IsEquality)
11247 return Error(E);
11248 // A constant address may compare equal to the address of a symbol.
11249 // The one exception is that address of an object cannot compare equal
11250 // to a null pointer constant.
11251 if ((!LHSValue.Base && !LHSValue.Offset.isZero()) ||
11252 (!RHSValue.Base && !RHSValue.Offset.isZero()))
11253 return Error(E);
11254 // It's implementation-defined whether distinct literals will have
11255 // distinct addresses. In clang, the result of such a comparison is
11256 // unspecified, so it is not a constant expression. However, we do know
11257 // that the address of a literal will be non-null.
11258 if ((IsLiteralLValue(LHSValue) || IsLiteralLValue(RHSValue)) &&
11259 LHSValue.Base && RHSValue.Base)
11260 return Error(E);
11261 // We can't tell whether weak symbols will end up pointing to the same
11262 // object.
11263 if (IsWeakLValue(LHSValue) || IsWeakLValue(RHSValue))
11264 return Error(E);
11265 // We can't compare the address of the start of one object with the
11266 // past-the-end address of another object, per C++ DR1652.
11267 if ((LHSValue.Base && LHSValue.Offset.isZero() &&
11268 isOnePastTheEndOfCompleteObject(Info.Ctx, RHSValue)) ||
11269 (RHSValue.Base && RHSValue.Offset.isZero() &&
11270 isOnePastTheEndOfCompleteObject(Info.Ctx, LHSValue)))
11271 return Error(E);
11272 // We can't tell whether an object is at the same address as another
11273 // zero sized object.
11274 if ((RHSValue.Base && isZeroSized(LHSValue)) ||
11275 (LHSValue.Base && isZeroSized(RHSValue)))
11276 return Error(E);
11277 return Success(CCR::Nonequal, E);
11278 }
11279
11280 const CharUnits &LHSOffset = LHSValue.getLValueOffset();
11281 const CharUnits &RHSOffset = RHSValue.getLValueOffset();
11282
11283 SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
11284 SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
11285
11286 // C++11 [expr.rel]p3:
11287 // Pointers to void (after pointer conversions) can be compared, with a
11288 // result defined as follows: If both pointers represent the same
11289 // address or are both the null pointer value, the result is true if the
11290 // operator is <= or >= and false otherwise; otherwise the result is
11291 // unspecified.
11292 // We interpret this as applying to pointers to *cv* void.
11293 if (LHSTy->isVoidPointerType() && LHSOffset != RHSOffset && IsRelational)
11294 Info.CCEDiag(E, diag::note_constexpr_void_comparison);
11295
11296 // C++11 [expr.rel]p2:
11297 // - If two pointers point to non-static data members of the same object,
11298 // or to subobjects or array elements fo such members, recursively, the
11299 // pointer to the later declared member compares greater provided the
11300 // two members have the same access control and provided their class is
11301 // not a union.
11302 // [...]
11303 // - Otherwise pointer comparisons are unspecified.
11304 if (!LHSDesignator.Invalid && !RHSDesignator.Invalid && IsRelational) {
11305 bool WasArrayIndex;
11306 unsigned Mismatch = FindDesignatorMismatch(
11307 getType(LHSValue.Base), LHSDesignator, RHSDesignator, WasArrayIndex);
11308 // At the point where the designators diverge, the comparison has a
11309 // specified value if:
11310 // - we are comparing array indices
11311 // - we are comparing fields of a union, or fields with the same access
11312 // Otherwise, the result is unspecified and thus the comparison is not a
11313 // constant expression.
11314 if (!WasArrayIndex && Mismatch < LHSDesignator.Entries.size() &&
11315 Mismatch < RHSDesignator.Entries.size()) {
11316 const FieldDecl *LF = getAsField(LHSDesignator.Entries[Mismatch]);
11317 const FieldDecl *RF = getAsField(RHSDesignator.Entries[Mismatch]);
11318 if (!LF && !RF)
11319 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_classes);
11320 else if (!LF)
11321 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
11322 << getAsBaseClass(LHSDesignator.Entries[Mismatch])
11323 << RF->getParent() << RF;
11324 else if (!RF)
11325 Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
11326 << getAsBaseClass(RHSDesignator.Entries[Mismatch])
11327 << LF->getParent() << LF;
11328 else if (!LF->getParent()->isUnion() &&
11329 LF->getAccess() != RF->getAccess())
11330 Info.CCEDiag(E,
11331 diag::note_constexpr_pointer_comparison_differing_access)
11332 << LF << LF->getAccess() << RF << RF->getAccess()
11333 << LF->getParent();
11334 }
11335 }
11336
11337 // The comparison here must be unsigned, and performed with the same
11338 // width as the pointer.
11339 unsigned PtrSize = Info.Ctx.getTypeSize(LHSTy);
11340 uint64_t CompareLHS = LHSOffset.getQuantity();
11341 uint64_t CompareRHS = RHSOffset.getQuantity();
11342 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11342, __PRETTY_FUNCTION__))
;
11343 uint64_t Mask = ~0ULL >> (64 - PtrSize);
11344 CompareLHS &= Mask;
11345 CompareRHS &= Mask;
11346
11347 // If there is a base and this is a relational operator, we can only
11348 // compare pointers within the object in question; otherwise, the result
11349 // depends on where the object is located in memory.
11350 if (!LHSValue.Base.isNull() && IsRelational) {
11351 QualType BaseTy = getType(LHSValue.Base);
11352 if (BaseTy->isIncompleteType())
11353 return Error(E);
11354 CharUnits Size = Info.Ctx.getTypeSizeInChars(BaseTy);
11355 uint64_t OffsetLimit = Size.getQuantity();
11356 if (CompareLHS > OffsetLimit || CompareRHS > OffsetLimit)
11357 return Error(E);
11358 }
11359
11360 if (CompareLHS < CompareRHS)
11361 return Success(CCR::Less, E);
11362 if (CompareLHS > CompareRHS)
11363 return Success(CCR::Greater, E);
11364 return Success(CCR::Equal, E);
11365 }
11366
11367 if (LHSTy->isMemberPointerType()) {
11368 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11368, __PRETTY_FUNCTION__))
;
11369 assert(RHSTy->isMemberPointerType() && "invalid comparison")((RHSTy->isMemberPointerType() && "invalid comparison"
) ? static_cast<void> (0) : __assert_fail ("RHSTy->isMemberPointerType() && \"invalid comparison\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11369, __PRETTY_FUNCTION__))
;
11370
11371 MemberPtr LHSValue, RHSValue;
11372
11373 bool LHSOK = EvaluateMemberPointer(E->getLHS(), LHSValue, Info);
11374 if (!LHSOK && !Info.noteFailure())
11375 return false;
11376
11377 if (!EvaluateMemberPointer(E->getRHS(), RHSValue, Info) || !LHSOK)
11378 return false;
11379
11380 // C++11 [expr.eq]p2:
11381 // If both operands are null, they compare equal. Otherwise if only one is
11382 // null, they compare unequal.
11383 if (!LHSValue.getDecl() || !RHSValue.getDecl()) {
11384 bool Equal = !LHSValue.getDecl() && !RHSValue.getDecl();
11385 return Success(Equal ? CCR::Equal : CCR::Nonequal, E);
11386 }
11387
11388 // Otherwise if either is a pointer to a virtual member function, the
11389 // result is unspecified.
11390 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(LHSValue.getDecl()))
11391 if (MD->isVirtual())
11392 Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
11393 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(RHSValue.getDecl()))
11394 if (MD->isVirtual())
11395 Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
11396
11397 // Otherwise they compare equal if and only if they would refer to the
11398 // same member of the same most derived object or the same subobject if
11399 // they were dereferenced with a hypothetical object of the associated
11400 // class type.
11401 bool Equal = LHSValue == RHSValue;
11402 return Success(Equal ? CCR::Equal : CCR::Nonequal, E);
11403 }
11404
11405 if (LHSTy->isNullPtrType()) {
11406 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11406, __PRETTY_FUNCTION__))
;
11407 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11407, __PRETTY_FUNCTION__))
;
11408 // C++11 [expr.rel]p4, [expr.eq]p3: If two operands of type std::nullptr_t
11409 // are compared, the result is true of the operator is <=, >= or ==, and
11410 // false otherwise.
11411 return Success(CCR::Equal, E);
11412 }
11413
11414 return DoAfter();
11415}
11416
11417bool RecordExprEvaluator::VisitBinCmp(const BinaryOperator *E) {
11418 if (!CheckLiteralType(Info, E))
11419 return false;
11420
11421 auto OnSuccess = [&](ComparisonCategoryResult ResKind,
11422 const BinaryOperator *E) {
11423 // Evaluation succeeded. Lookup the information for the comparison category
11424 // type and fetch the VarDecl for the result.
11425 const ComparisonCategoryInfo &CmpInfo =
11426 Info.Ctx.CompCategories.getInfoForType(E->getType());
11427 const VarDecl *VD =
11428 CmpInfo.getValueInfo(CmpInfo.makeWeakResult(ResKind))->VD;
11429 // Check and evaluate the result as a constant expression.
11430 LValue LV;
11431 LV.set(VD);
11432 if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
11433 return false;
11434 return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result);
11435 };
11436 return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
11437 return ExprEvaluatorBaseTy::VisitBinCmp(E);
11438 });
11439}
11440
11441bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
11442 // We don't call noteFailure immediately because the assignment happens after
11443 // we evaluate LHS and RHS.
11444 if (!Info.keepEvaluatingAfterFailure() && E->isAssignmentOp())
11445 return Error(E);
11446
11447 DelayedNoteFailureRAII MaybeNoteFailureLater(Info, E->isAssignmentOp());
11448 if (DataRecursiveIntBinOpEvaluator::shouldEnqueue(E))
11449 return DataRecursiveIntBinOpEvaluator(*this, Result).Traverse(E);
11450
11451 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11453, __PRETTY_FUNCTION__))
11452 !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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11453, __PRETTY_FUNCTION__))
11453 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11453, __PRETTY_FUNCTION__))
;
11454
11455 if (E->isComparisonOp()) {
11456 // Evaluate builtin binary comparisons by evaluating them as C++2a three-way
11457 // comparisons and then translating the result.
11458 auto OnSuccess = [&](ComparisonCategoryResult ResKind,
11459 const BinaryOperator *E) {
11460 using CCR = ComparisonCategoryResult;
11461 bool IsEqual = ResKind == CCR::Equal,
11462 IsLess = ResKind == CCR::Less,
11463 IsGreater = ResKind == CCR::Greater;
11464 auto Op = E->getOpcode();
11465 switch (Op) {
11466 default:
11467 llvm_unreachable("unsupported binary operator")::llvm::llvm_unreachable_internal("unsupported binary operator"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11467)
;
11468 case BO_EQ:
11469 case BO_NE:
11470 return Success(IsEqual == (Op == BO_EQ), E);
11471 case BO_LT: return Success(IsLess, E);
11472 case BO_GT: return Success(IsGreater, E);
11473 case BO_LE: return Success(IsEqual || IsLess, E);
11474 case BO_GE: return Success(IsEqual || IsGreater, E);
11475 }
11476 };
11477 return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
11478 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
11479 });
11480 }
11481
11482 QualType LHSTy = E->getLHS()->getType();
11483 QualType RHSTy = E->getRHS()->getType();
11484
11485 if (LHSTy->isPointerType() && RHSTy->isPointerType() &&
11486 E->getOpcode() == BO_Sub) {
11487 LValue LHSValue, RHSValue;
11488
11489 bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
11490 if (!LHSOK && !Info.noteFailure())
11491 return false;
11492
11493 if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
11494 return false;
11495
11496 // Reject differing bases from the normal codepath; we special-case
11497 // comparisons to null.
11498 if (!HasSameBase(LHSValue, RHSValue)) {
11499 // Handle &&A - &&B.
11500 if (!LHSValue.Offset.isZero() || !RHSValue.Offset.isZero())
11501 return Error(E);
11502 const Expr *LHSExpr = LHSValue.Base.dyn_cast<const Expr *>();
11503 const Expr *RHSExpr = RHSValue.Base.dyn_cast<const Expr *>();
11504 if (!LHSExpr || !RHSExpr)
11505 return Error(E);
11506 const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
11507 const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
11508 if (!LHSAddrExpr || !RHSAddrExpr)
11509 return Error(E);
11510 // Make sure both labels come from the same function.
11511 if (LHSAddrExpr->getLabel()->getDeclContext() !=
11512 RHSAddrExpr->getLabel()->getDeclContext())
11513 return Error(E);
11514 return Success(APValue(LHSAddrExpr, RHSAddrExpr), E);
11515 }
11516 const CharUnits &LHSOffset = LHSValue.getLValueOffset();
11517 const CharUnits &RHSOffset = RHSValue.getLValueOffset();
11518
11519 SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
11520 SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
11521
11522 // C++11 [expr.add]p6:
11523 // Unless both pointers point to elements of the same array object, or
11524 // one past the last element of the array object, the behavior is
11525 // undefined.
11526 if (!LHSDesignator.Invalid && !RHSDesignator.Invalid &&
11527 !AreElementsOfSameArray(getType(LHSValue.Base), LHSDesignator,
11528 RHSDesignator))
11529 Info.CCEDiag(E, diag::note_constexpr_pointer_subtraction_not_same_array);
11530
11531 QualType Type = E->getLHS()->getType();
11532 QualType ElementType = Type->getAs<PointerType>()->getPointeeType();
11533
11534 CharUnits ElementSize;
11535 if (!HandleSizeof(Info, E->getExprLoc(), ElementType, ElementSize))
11536 return false;
11537
11538 // As an extension, a type may have zero size (empty struct or union in
11539 // C, array of zero length). Pointer subtraction in such cases has
11540 // undefined behavior, so is not constant.
11541 if (ElementSize.isZero()) {
11542 Info.FFDiag(E, diag::note_constexpr_pointer_subtraction_zero_size)
11543 << ElementType;
11544 return false;
11545 }
11546
11547 // FIXME: LLVM and GCC both compute LHSOffset - RHSOffset at runtime,
11548 // and produce incorrect results when it overflows. Such behavior
11549 // appears to be non-conforming, but is common, so perhaps we should
11550 // assume the standard intended for such cases to be undefined behavior
11551 // and check for them.
11552
11553 // Compute (LHSOffset - RHSOffset) / Size carefully, checking for
11554 // overflow in the final conversion to ptrdiff_t.
11555 APSInt LHS(llvm::APInt(65, (int64_t)LHSOffset.getQuantity(), true), false);
11556 APSInt RHS(llvm::APInt(65, (int64_t)RHSOffset.getQuantity(), true), false);
11557 APSInt ElemSize(llvm::APInt(65, (int64_t)ElementSize.getQuantity(), true),
11558 false);
11559 APSInt TrueResult = (LHS - RHS) / ElemSize;
11560 APSInt Result = TrueResult.trunc(Info.Ctx.getIntWidth(E->getType()));
11561
11562 if (Result.extend(65) != TrueResult &&
11563 !HandleOverflow(Info, E, TrueResult, E->getType()))
11564 return false;
11565 return Success(Result, E);
11566 }
11567
11568 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
11569}
11570
11571/// VisitUnaryExprOrTypeTraitExpr - Evaluate a sizeof, alignof or vec_step with
11572/// a result as the expression's type.
11573bool IntExprEvaluator::VisitUnaryExprOrTypeTraitExpr(
11574 const UnaryExprOrTypeTraitExpr *E) {
11575 switch(E->getKind()) {
11576 case UETT_PreferredAlignOf:
11577 case UETT_AlignOf: {
11578 if (E->isArgumentType())
11579 return Success(GetAlignOfType(Info, E->getArgumentType(), E->getKind()),
11580 E);
11581 else
11582 return Success(GetAlignOfExpr(Info, E->getArgumentExpr(), E->getKind()),
11583 E);
11584 }
11585
11586 case UETT_VecStep: {
11587 QualType Ty = E->getTypeOfArgument();
11588
11589 if (Ty->isVectorType()) {
11590 unsigned n = Ty->castAs<VectorType>()->getNumElements();
11591
11592 // The vec_step built-in functions that take a 3-component
11593 // vector return 4. (OpenCL 1.1 spec 6.11.12)
11594 if (n == 3)
11595 n = 4;
11596
11597 return Success(n, E);
11598 } else
11599 return Success(1, E);
11600 }
11601
11602 case UETT_SizeOf: {
11603 QualType SrcTy = E->getTypeOfArgument();
11604 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
11605 // the result is the size of the referenced type."
11606 if (const ReferenceType *Ref = SrcTy->getAs<ReferenceType>())
11607 SrcTy = Ref->getPointeeType();
11608
11609 CharUnits Sizeof;
11610 if (!HandleSizeof(Info, E->getExprLoc(), SrcTy, Sizeof))
11611 return false;
11612 return Success(Sizeof, E);
11613 }
11614 case UETT_OpenMPRequiredSimdAlign:
11615 assert(E->isArgumentType())((E->isArgumentType()) ? static_cast<void> (0) : __assert_fail
("E->isArgumentType()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11615, __PRETTY_FUNCTION__))
;
11616 return Success(
11617 Info.Ctx.toCharUnitsFromBits(
11618 Info.Ctx.getOpenMPDefaultSimdAlign(E->getArgumentType()))
11619 .getQuantity(),
11620 E);
11621 }
11622
11623 llvm_unreachable("unknown expr/type trait")::llvm::llvm_unreachable_internal("unknown expr/type trait", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11623)
;
11624}
11625
11626bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *OOE) {
11627 CharUnits Result;
11628 unsigned n = OOE->getNumComponents();
11629 if (n == 0)
11630 return Error(OOE);
11631 QualType CurrentType = OOE->getTypeSourceInfo()->getType();
11632 for (unsigned i = 0; i != n; ++i) {
11633 OffsetOfNode ON = OOE->getComponent(i);
11634 switch (ON.getKind()) {
11635 case OffsetOfNode::Array: {
11636 const Expr *Idx = OOE->getIndexExpr(ON.getArrayExprIndex());
11637 APSInt IdxResult;
11638 if (!EvaluateInteger(Idx, IdxResult, Info))
11639 return false;
11640 const ArrayType *AT = Info.Ctx.getAsArrayType(CurrentType);
11641 if (!AT)
11642 return Error(OOE);
11643 CurrentType = AT->getElementType();
11644 CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(CurrentType);
11645 Result += IdxResult.getSExtValue() * ElementSize;
11646 break;
11647 }
11648
11649 case OffsetOfNode::Field: {
11650 FieldDecl *MemberDecl = ON.getField();
11651 const RecordType *RT = CurrentType->getAs<RecordType>();
11652 if (!RT)
11653 return Error(OOE);
11654 RecordDecl *RD = RT->getDecl();
11655 if (RD->isInvalidDecl()) return false;
11656 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
11657 unsigned i = MemberDecl->getFieldIndex();
11658 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11658, __PRETTY_FUNCTION__))
;
11659 Result += Info.Ctx.toCharUnitsFromBits(RL.getFieldOffset(i));
11660 CurrentType = MemberDecl->getType().getNonReferenceType();
11661 break;
11662 }
11663
11664 case OffsetOfNode::Identifier:
11665 llvm_unreachable("dependent __builtin_offsetof")::llvm::llvm_unreachable_internal("dependent __builtin_offsetof"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11665)
;
11666
11667 case OffsetOfNode::Base: {
11668 CXXBaseSpecifier *BaseSpec = ON.getBase();
11669 if (BaseSpec->isVirtual())
11670 return Error(OOE);
11671
11672 // Find the layout of the class whose base we are looking into.
11673 const RecordType *RT = CurrentType->getAs<RecordType>();
11674 if (!RT)
11675 return Error(OOE);
11676 RecordDecl *RD = RT->getDecl();
11677 if (RD->isInvalidDecl()) return false;
11678 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
11679
11680 // Find the base class itself.
11681 CurrentType = BaseSpec->getType();
11682 const RecordType *BaseRT = CurrentType->getAs<RecordType>();
11683 if (!BaseRT)
11684 return Error(OOE);
11685
11686 // Add the offset to the base.
11687 Result += RL.getBaseClassOffset(cast<CXXRecordDecl>(BaseRT->getDecl()));
11688 break;
11689 }
11690 }
11691 }
11692 return Success(Result, OOE);
11693}
11694
11695bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
11696 switch (E->getOpcode()) {
11697 default:
11698 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
11699 // See C99 6.6p3.
11700 return Error(E);
11701 case UO_Extension:
11702 // FIXME: Should extension allow i-c-e extension expressions in its scope?
11703 // If so, we could clear the diagnostic ID.
11704 return Visit(E->getSubExpr());
11705 case UO_Plus:
11706 // The result is just the value.
11707 return Visit(E->getSubExpr());
11708 case UO_Minus: {
11709 if (!Visit(E->getSubExpr()))
11710 return false;
11711 if (!Result.isInt()) return Error(E);
11712 const APSInt &Value = Result.getInt();
11713 if (Value.isSigned() && Value.isMinSignedValue() && E->canOverflow() &&
11714 !HandleOverflow(Info, E, -Value.extend(Value.getBitWidth() + 1),
11715 E->getType()))
11716 return false;
11717 return Success(-Value, E);
11718 }
11719 case UO_Not: {
11720 if (!Visit(E->getSubExpr()))
11721 return false;
11722 if (!Result.isInt()) return Error(E);
11723 return Success(~Result.getInt(), E);
11724 }
11725 case UO_LNot: {
11726 bool bres;
11727 if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
11728 return false;
11729 return Success(!bres, E);
11730 }
11731 }
11732}
11733
11734/// HandleCast - This is used to evaluate implicit or explicit casts where the
11735/// result type is integer.
11736bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
11737 const Expr *SubExpr = E->getSubExpr();
11738 QualType DestType = E->getType();
11739 QualType SrcType = SubExpr->getType();
11740
11741 switch (E->getCastKind()) {
11742 case CK_BaseToDerived:
11743 case CK_DerivedToBase:
11744 case CK_UncheckedDerivedToBase:
11745 case CK_Dynamic:
11746 case CK_ToUnion:
11747 case CK_ArrayToPointerDecay:
11748 case CK_FunctionToPointerDecay:
11749 case CK_NullToPointer:
11750 case CK_NullToMemberPointer:
11751 case CK_BaseToDerivedMemberPointer:
11752 case CK_DerivedToBaseMemberPointer:
11753 case CK_ReinterpretMemberPointer:
11754 case CK_ConstructorConversion:
11755 case CK_IntegralToPointer:
11756 case CK_ToVoid:
11757 case CK_VectorSplat:
11758 case CK_IntegralToFloating:
11759 case CK_FloatingCast:
11760 case CK_CPointerToObjCPointerCast:
11761 case CK_BlockPointerToObjCPointerCast:
11762 case CK_AnyPointerToBlockPointerCast:
11763 case CK_ObjCObjectLValueCast:
11764 case CK_FloatingRealToComplex:
11765 case CK_FloatingComplexToReal:
11766 case CK_FloatingComplexCast:
11767 case CK_FloatingComplexToIntegralComplex:
11768 case CK_IntegralRealToComplex:
11769 case CK_IntegralComplexCast:
11770 case CK_IntegralComplexToFloatingComplex:
11771 case CK_BuiltinFnToFnPtr:
11772 case CK_ZeroToOCLOpaqueType:
11773 case CK_NonAtomicToAtomic:
11774 case CK_AddressSpaceConversion:
11775 case CK_IntToOCLSampler:
11776 case CK_FixedPointCast:
11777 case CK_IntegralToFixedPoint:
11778 llvm_unreachable("invalid cast kind for integral value")::llvm::llvm_unreachable_internal("invalid cast kind for integral value"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11778)
;
11779
11780 case CK_BitCast:
11781 case CK_Dependent:
11782 case CK_LValueBitCast:
11783 case CK_ARCProduceObject:
11784 case CK_ARCConsumeObject:
11785 case CK_ARCReclaimReturnedObject:
11786 case CK_ARCExtendBlockObject:
11787 case CK_CopyAndAutoreleaseBlockObject:
11788 return Error(E);
11789
11790 case CK_UserDefinedConversion:
11791 case CK_LValueToRValue:
11792 case CK_AtomicToNonAtomic:
11793 case CK_NoOp:
11794 case CK_LValueToRValueBitCast:
11795 return ExprEvaluatorBaseTy::VisitCastExpr(E);
11796
11797 case CK_MemberPointerToBoolean:
11798 case CK_PointerToBoolean:
11799 case CK_IntegralToBoolean:
11800 case CK_FloatingToBoolean:
11801 case CK_BooleanToSignedIntegral:
11802 case CK_FloatingComplexToBoolean:
11803 case CK_IntegralComplexToBoolean: {
11804 bool BoolResult;
11805 if (!EvaluateAsBooleanCondition(SubExpr, BoolResult, Info))
11806 return false;
11807 uint64_t IntResult = BoolResult;
11808 if (BoolResult && E->getCastKind() == CK_BooleanToSignedIntegral)
11809 IntResult = (uint64_t)-1;
11810 return Success(IntResult, E);
11811 }
11812
11813 case CK_FixedPointToIntegral: {
11814 APFixedPoint Src(Info.Ctx.getFixedPointSemantics(SrcType));
11815 if (!EvaluateFixedPoint(SubExpr, Src, Info))
11816 return false;
11817 bool Overflowed;
11818 llvm::APSInt Result = Src.convertToInt(
11819 Info.Ctx.getIntWidth(DestType),
11820 DestType->isSignedIntegerOrEnumerationType(), &Overflowed);
11821 if (Overflowed && !HandleOverflow(Info, E, Result, DestType))
11822 return false;
11823 return Success(Result, E);
11824 }
11825
11826 case CK_FixedPointToBoolean: {
11827 // Unsigned padding does not affect this.
11828 APValue Val;
11829 if (!Evaluate(Val, Info, SubExpr))
11830 return false;
11831 return Success(Val.getFixedPoint().getBoolValue(), E);
11832 }
11833
11834 case CK_IntegralCast: {
11835 if (!Visit(SubExpr))
11836 return false;
11837
11838 if (!Result.isInt()) {
11839 // Allow casts of address-of-label differences if they are no-ops
11840 // or narrowing. (The narrowing case isn't actually guaranteed to
11841 // be constant-evaluatable except in some narrow cases which are hard
11842 // to detect here. We let it through on the assumption the user knows
11843 // what they are doing.)
11844 if (Result.isAddrLabelDiff())
11845 return Info.Ctx.getTypeSize(DestType) <= Info.Ctx.getTypeSize(SrcType);
11846 // Only allow casts of lvalues if they are lossless.
11847 return Info.Ctx.getTypeSize(DestType) == Info.Ctx.getTypeSize(SrcType);
11848 }
11849
11850 return Success(HandleIntToIntCast(Info, E, DestType, SrcType,
11851 Result.getInt()), E);
11852 }
11853
11854 case CK_PointerToIntegral: {
11855 CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
11856
11857 LValue LV;
11858 if (!EvaluatePointer(SubExpr, LV, Info))
11859 return false;
11860
11861 if (LV.getLValueBase()) {
11862 // Only allow based lvalue casts if they are lossless.
11863 // FIXME: Allow a larger integer size than the pointer size, and allow
11864 // narrowing back down to pointer width in subsequent integral casts.
11865 // FIXME: Check integer type's active bits, not its type size.
11866 if (Info.Ctx.getTypeSize(DestType) != Info.Ctx.getTypeSize(SrcType))
11867 return Error(E);
11868
11869 LV.Designator.setInvalid();
11870 LV.moveInto(Result);
11871 return true;
11872 }
11873
11874 APSInt AsInt;
11875 APValue V;
11876 LV.moveInto(V);
11877 if (!V.toIntegralConstant(AsInt, SrcType, Info.Ctx))
11878 llvm_unreachable("Can't cast this!")::llvm::llvm_unreachable_internal("Can't cast this!", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11878)
;
11879
11880 return Success(HandleIntToIntCast(Info, E, DestType, SrcType, AsInt), E);
11881 }
11882
11883 case CK_IntegralComplexToReal: {
11884 ComplexValue C;
11885 if (!EvaluateComplex(SubExpr, C, Info))
11886 return false;
11887 return Success(C.getComplexIntReal(), E);
11888 }
11889
11890 case CK_FloatingToIntegral: {
11891 APFloat F(0.0);
11892 if (!EvaluateFloat(SubExpr, F, Info))
11893 return false;
11894
11895 APSInt Value;
11896 if (!HandleFloatToIntCast(Info, E, SrcType, F, DestType, Value))
11897 return false;
11898 return Success(Value, E);
11899 }
11900 }
11901
11902 llvm_unreachable("unknown cast resulting in integral value")::llvm::llvm_unreachable_internal("unknown cast resulting in integral value"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11902)
;
11903}
11904
11905bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
11906 if (E->getSubExpr()->getType()->isAnyComplexType()) {
11907 ComplexValue LV;
11908 if (!EvaluateComplex(E->getSubExpr(), LV, Info))
11909 return false;
11910 if (!LV.isComplexInt())
11911 return Error(E);
11912 return Success(LV.getComplexIntReal(), E);
11913 }
11914
11915 return Visit(E->getSubExpr());
11916}
11917
11918bool IntExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
11919 if (E->getSubExpr()->getType()->isComplexIntegerType()) {
11920 ComplexValue LV;
11921 if (!EvaluateComplex(E->getSubExpr(), LV, Info))
11922 return false;
11923 if (!LV.isComplexInt())
11924 return Error(E);
11925 return Success(LV.getComplexIntImag(), E);
11926 }
11927
11928 VisitIgnoredValue(E->getSubExpr());
11929 return Success(0, E);
11930}
11931
11932bool IntExprEvaluator::VisitSizeOfPackExpr(const SizeOfPackExpr *E) {
11933 return Success(E->getPackLength(), E);
11934}
11935
11936bool IntExprEvaluator::VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
11937 return Success(E->getValue(), E);
11938}
11939
11940bool FixedPointExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
11941 switch (E->getOpcode()) {
11942 default:
11943 // Invalid unary operators
11944 return Error(E);
11945 case UO_Plus:
11946 // The result is just the value.
11947 return Visit(E->getSubExpr());
11948 case UO_Minus: {
11949 if (!Visit(E->getSubExpr())) return false;
11950 if (!Result.isFixedPoint())
11951 return Error(E);
11952 bool Overflowed;
11953 APFixedPoint Negated = Result.getFixedPoint().negate(&Overflowed);
11954 if (Overflowed && !HandleOverflow(Info, E, Negated, E->getType()))
11955 return false;
11956 return Success(Negated, E);
11957 }
11958 case UO_LNot: {
11959 bool bres;
11960 if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
11961 return false;
11962 return Success(!bres, E);
11963 }
11964 }
11965}
11966
11967bool FixedPointExprEvaluator::VisitCastExpr(const CastExpr *E) {
11968 const Expr *SubExpr = E->getSubExpr();
11969 QualType DestType = E->getType();
11970 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11971, __PRETTY_FUNCTION__))
11971 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 11971, __PRETTY_FUNCTION__))
;
11972 auto DestFXSema = Info.Ctx.getFixedPointSemantics(DestType);
11973
11974 switch (E->getCastKind()) {
11975 case CK_FixedPointCast: {
11976 APFixedPoint Src(Info.Ctx.getFixedPointSemantics(SubExpr->getType()));
11977 if (!EvaluateFixedPoint(SubExpr, Src, Info))
11978 return false;
11979 bool Overflowed;
11980 APFixedPoint Result = Src.convert(DestFXSema, &Overflowed);
11981 if (Overflowed && !HandleOverflow(Info, E, Result, DestType))
11982 return false;
11983 return Success(Result, E);
11984 }
11985 case CK_IntegralToFixedPoint: {
11986 APSInt Src;
11987 if (!EvaluateInteger(SubExpr, Src, Info))
11988 return false;
11989
11990 bool Overflowed;
11991 APFixedPoint IntResult = APFixedPoint::getFromIntValue(
11992 Src, Info.Ctx.getFixedPointSemantics(DestType), &Overflowed);
11993
11994 if (Overflowed && !HandleOverflow(Info, E, IntResult, DestType))
11995 return false;
11996
11997 return Success(IntResult, E);
11998 }
11999 case CK_NoOp:
12000 case CK_LValueToRValue:
12001 return ExprEvaluatorBaseTy::VisitCastExpr(E);
12002 default:
12003 return Error(E);
12004 }
12005}
12006
12007bool FixedPointExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
12008 const Expr *LHS = E->getLHS();
12009 const Expr *RHS = E->getRHS();
12010 FixedPointSemantics ResultFXSema =
12011 Info.Ctx.getFixedPointSemantics(E->getType());
12012
12013 APFixedPoint LHSFX(Info.Ctx.getFixedPointSemantics(LHS->getType()));
12014 if (!EvaluateFixedPointOrInteger(LHS, LHSFX, Info))
12015 return false;
12016 APFixedPoint RHSFX(Info.Ctx.getFixedPointSemantics(RHS->getType()));
12017 if (!EvaluateFixedPointOrInteger(RHS, RHSFX, Info))
12018 return false;
12019
12020 switch (E->getOpcode()) {
12021 case BO_Add: {
12022 bool AddOverflow, ConversionOverflow;
12023 APFixedPoint Result = LHSFX.add(RHSFX, &AddOverflow)
12024 .convert(ResultFXSema, &ConversionOverflow);
12025 if ((AddOverflow || ConversionOverflow) &&
12026 !HandleOverflow(Info, E, Result, E->getType()))
12027 return false;
12028 return Success(Result, E);
12029 }
12030 default:
12031 return false;
12032 }
12033 llvm_unreachable("Should've exited before this")::llvm::llvm_unreachable_internal("Should've exited before this"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12033)
;
12034}
12035
12036//===----------------------------------------------------------------------===//
12037// Float Evaluation
12038//===----------------------------------------------------------------------===//
12039
12040namespace {
12041class FloatExprEvaluator
12042 : public ExprEvaluatorBase<FloatExprEvaluator> {
12043 APFloat &Result;
12044public:
12045 FloatExprEvaluator(EvalInfo &info, APFloat &result)
12046 : ExprEvaluatorBaseTy(info), Result(result) {}
12047
12048 bool Success(const APValue &V, const Expr *e) {
12049 Result = V.getFloat();
12050 return true;
12051 }
12052
12053 bool ZeroInitialization(const Expr *E) {
12054 Result = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(E->getType()));
12055 return true;
12056 }
12057
12058 bool VisitCallExpr(const CallExpr *E);
12059
12060 bool VisitUnaryOperator(const UnaryOperator *E);
12061 bool VisitBinaryOperator(const BinaryOperator *E);
12062 bool VisitFloatingLiteral(const FloatingLiteral *E);
12063 bool VisitCastExpr(const CastExpr *E);
12064
12065 bool VisitUnaryReal(const UnaryOperator *E);
12066 bool VisitUnaryImag(const UnaryOperator *E);
12067
12068 // FIXME: Missing: array subscript of vector, member of vector
12069};
12070} // end anonymous namespace
12071
12072static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) {
12073 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12073, __PRETTY_FUNCTION__))
;
12074 return FloatExprEvaluator(Info, Result).Visit(E);
12075}
12076
12077static bool TryEvaluateBuiltinNaN(const ASTContext &Context,
12078 QualType ResultTy,
12079 const Expr *Arg,
12080 bool SNaN,
12081 llvm::APFloat &Result) {
12082 const StringLiteral *S = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts());
12083 if (!S) return false;
12084
12085 const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(ResultTy);
12086
12087 llvm::APInt fill;
12088
12089 // Treat empty strings as if they were zero.
12090 if (S->getString().empty())
12091 fill = llvm::APInt(32, 0);
12092 else if (S->getString().getAsInteger(0, fill))
12093 return false;
12094
12095 if (Context.getTargetInfo().isNan2008()) {
12096 if (SNaN)
12097 Result = llvm::APFloat::getSNaN(Sem, false, &fill);
12098 else
12099 Result = llvm::APFloat::getQNaN(Sem, false, &fill);
12100 } else {
12101 // Prior to IEEE 754-2008, architectures were allowed to choose whether
12102 // the first bit of their significand was set for qNaN or sNaN. MIPS chose
12103 // a different encoding to what became a standard in 2008, and for pre-
12104 // 2008 revisions, MIPS interpreted sNaN-2008 as qNan and qNaN-2008 as
12105 // sNaN. This is now known as "legacy NaN" encoding.
12106 if (SNaN)
12107 Result = llvm::APFloat::getQNaN(Sem, false, &fill);
12108 else
12109 Result = llvm::APFloat::getSNaN(Sem, false, &fill);
12110 }
12111
12112 return true;
12113}
12114
12115bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
12116 switch (E->getBuiltinCallee()) {
12117 default:
12118 return ExprEvaluatorBaseTy::VisitCallExpr(E);
12119
12120 case Builtin::BI__builtin_huge_val:
12121 case Builtin::BI__builtin_huge_valf:
12122 case Builtin::BI__builtin_huge_vall:
12123 case Builtin::BI__builtin_huge_valf128:
12124 case Builtin::BI__builtin_inf:
12125 case Builtin::BI__builtin_inff:
12126 case Builtin::BI__builtin_infl:
12127 case Builtin::BI__builtin_inff128: {
12128 const llvm::fltSemantics &Sem =
12129 Info.Ctx.getFloatTypeSemantics(E->getType());
12130 Result = llvm::APFloat::getInf(Sem);
12131 return true;
12132 }
12133
12134 case Builtin::BI__builtin_nans:
12135 case Builtin::BI__builtin_nansf:
12136 case Builtin::BI__builtin_nansl:
12137 case Builtin::BI__builtin_nansf128:
12138 if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
12139 true, Result))
12140 return Error(E);
12141 return true;
12142
12143 case Builtin::BI__builtin_nan:
12144 case Builtin::BI__builtin_nanf:
12145 case Builtin::BI__builtin_nanl:
12146 case Builtin::BI__builtin_nanf128:
12147 // If this is __builtin_nan() turn this into a nan, otherwise we
12148 // can't constant fold it.
12149 if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
12150 false, Result))
12151 return Error(E);
12152 return true;
12153
12154 case Builtin::BI__builtin_fabs:
12155 case Builtin::BI__builtin_fabsf:
12156 case Builtin::BI__builtin_fabsl:
12157 case Builtin::BI__builtin_fabsf128:
12158 if (!EvaluateFloat(E->getArg(0), Result, Info))
12159 return false;
12160
12161 if (Result.isNegative())
12162 Result.changeSign();
12163 return true;
12164
12165 // FIXME: Builtin::BI__builtin_powi
12166 // FIXME: Builtin::BI__builtin_powif
12167 // FIXME: Builtin::BI__builtin_powil
12168
12169 case Builtin::BI__builtin_copysign:
12170 case Builtin::BI__builtin_copysignf:
12171 case Builtin::BI__builtin_copysignl:
12172 case Builtin::BI__builtin_copysignf128: {
12173 APFloat RHS(0.);
12174 if (!EvaluateFloat(E->getArg(0), Result, Info) ||
12175 !EvaluateFloat(E->getArg(1), RHS, Info))
12176 return false;
12177 Result.copySign(RHS);
12178 return true;
12179 }
12180 }
12181}
12182
12183bool FloatExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
12184 if (E->getSubExpr()->getType()->isAnyComplexType()) {
12185 ComplexValue CV;
12186 if (!EvaluateComplex(E->getSubExpr(), CV, Info))
12187 return false;
12188 Result = CV.FloatReal;
12189 return true;
12190 }
12191
12192 return Visit(E->getSubExpr());
12193}
12194
12195bool FloatExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
12196 if (E->getSubExpr()->getType()->isAnyComplexType()) {
12197 ComplexValue CV;
12198 if (!EvaluateComplex(E->getSubExpr(), CV, Info))
12199 return false;
12200 Result = CV.FloatImag;
12201 return true;
12202 }
12203
12204 VisitIgnoredValue(E->getSubExpr());
12205 const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(E->getType());
12206 Result = llvm::APFloat::getZero(Sem);
12207 return true;
12208}
12209
12210bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
12211 switch (E->getOpcode()) {
12212 default: return Error(E);
12213 case UO_Plus:
12214 return EvaluateFloat(E->getSubExpr(), Result, Info);
12215 case UO_Minus:
12216 if (!EvaluateFloat(E->getSubExpr(), Result, Info))
12217 return false;
12218 Result.changeSign();
12219 return true;
12220 }
12221}
12222
12223bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
12224 if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
12225 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
12226
12227 APFloat RHS(0.0);
12228 bool LHSOK = EvaluateFloat(E->getLHS(), Result, Info);
12229 if (!LHSOK && !Info.noteFailure())
12230 return false;
12231 return EvaluateFloat(E->getRHS(), RHS, Info) && LHSOK &&
12232 handleFloatFloatBinOp(Info, E, Result, E->getOpcode(), RHS);
12233}
12234
12235bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) {
12236 Result = E->getValue();
12237 return true;
12238}
12239
12240bool FloatExprEvaluator::VisitCastExpr(const CastExpr *E) {
12241 const Expr* SubExpr = E->getSubExpr();
12242
12243 switch (E->getCastKind()) {
12244 default:
12245 return ExprEvaluatorBaseTy::VisitCastExpr(E);
12246
12247 case CK_IntegralToFloating: {
12248 APSInt IntResult;
12249 return EvaluateInteger(SubExpr, IntResult, Info) &&
12250 HandleIntToFloatCast(Info, E, SubExpr->getType(), IntResult,
12251 E->getType(), Result);
12252 }
12253
12254 case CK_FloatingCast: {
12255 if (!Visit(SubExpr))
12256 return false;
12257 return HandleFloatToFloatCast(Info, E, SubExpr->getType(), E->getType(),
12258 Result);
12259 }
12260
12261 case CK_FloatingComplexToReal: {
12262 ComplexValue V;
12263 if (!EvaluateComplex(SubExpr, V, Info))
12264 return false;
12265 Result = V.getComplexFloatReal();
12266 return true;
12267 }
12268 }
12269}
12270
12271//===----------------------------------------------------------------------===//
12272// Complex Evaluation (for float and integer)
12273//===----------------------------------------------------------------------===//
12274
12275namespace {
12276class ComplexExprEvaluator
12277 : public ExprEvaluatorBase<ComplexExprEvaluator> {
12278 ComplexValue &Result;
12279
12280public:
12281 ComplexExprEvaluator(EvalInfo &info, ComplexValue &Result)
12282 : ExprEvaluatorBaseTy(info), Result(Result) {}
12283
12284 bool Success(const APValue &V, const Expr *e) {
12285 Result.setFrom(V);
12286 return true;
12287 }
12288
12289 bool ZeroInitialization(const Expr *E);
12290
12291 //===--------------------------------------------------------------------===//
12292 // Visitor Methods
12293 //===--------------------------------------------------------------------===//
12294
12295 bool VisitImaginaryLiteral(const ImaginaryLiteral *E);
12296 bool VisitCastExpr(const CastExpr *E);
12297 bool VisitBinaryOperator(const BinaryOperator *E);
12298 bool VisitUnaryOperator(const UnaryOperator *E);
12299 bool VisitInitListExpr(const InitListExpr *E);
12300};
12301} // end anonymous namespace
12302
12303static bool EvaluateComplex(const Expr *E, ComplexValue &Result,
12304 EvalInfo &Info) {
12305 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12305, __PRETTY_FUNCTION__))
;
12306 return ComplexExprEvaluator(Info, Result).Visit(E);
12307}
12308
12309bool ComplexExprEvaluator::ZeroInitialization(const Expr *E) {
12310 QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
12311 if (ElemTy->isRealFloatingType()) {
12312 Result.makeComplexFloat();
12313 APFloat Zero = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(ElemTy));
12314 Result.FloatReal = Zero;
12315 Result.FloatImag = Zero;
12316 } else {
12317 Result.makeComplexInt();
12318 APSInt Zero = Info.Ctx.MakeIntValue(0, ElemTy);
12319 Result.IntReal = Zero;
12320 Result.IntImag = Zero;
12321 }
12322 return true;
12323}
12324
12325bool ComplexExprEvaluator::VisitImaginaryLiteral(const ImaginaryLiteral *E) {
12326 const Expr* SubExpr = E->getSubExpr();
12327
12328 if (SubExpr->getType()->isRealFloatingType()) {
12329 Result.makeComplexFloat();
12330 APFloat &Imag = Result.FloatImag;
12331 if (!EvaluateFloat(SubExpr, Imag, Info))
12332 return false;
12333
12334 Result.FloatReal = APFloat(Imag.getSemantics());
12335 return true;
12336 } else {
12337 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12338, __PRETTY_FUNCTION__))
12338 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12338, __PRETTY_FUNCTION__))
;
12339
12340 Result.makeComplexInt();
12341 APSInt &Imag = Result.IntImag;
12342 if (!EvaluateInteger(SubExpr, Imag, Info))
12343 return false;
12344
12345 Result.IntReal = APSInt(Imag.getBitWidth(), !Imag.isSigned());
12346 return true;
12347 }
12348}
12349
12350bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
12351
12352 switch (E->getCastKind()) {
2
Control jumps to 'case CK_IntegralComplexCast:' at line 12461
12353 case CK_BitCast:
12354 case CK_BaseToDerived:
12355 case CK_DerivedToBase:
12356 case CK_UncheckedDerivedToBase:
12357 case CK_Dynamic:
12358 case CK_ToUnion:
12359 case CK_ArrayToPointerDecay:
12360 case CK_FunctionToPointerDecay:
12361 case CK_NullToPointer:
12362 case CK_NullToMemberPointer:
12363 case CK_BaseToDerivedMemberPointer:
12364 case CK_DerivedToBaseMemberPointer:
12365 case CK_MemberPointerToBoolean:
12366 case CK_ReinterpretMemberPointer:
12367 case CK_ConstructorConversion:
12368 case CK_IntegralToPointer:
12369 case CK_PointerToIntegral:
12370 case CK_PointerToBoolean:
12371 case CK_ToVoid:
12372 case CK_VectorSplat:
12373 case CK_IntegralCast:
12374 case CK_BooleanToSignedIntegral:
12375 case CK_IntegralToBoolean:
12376 case CK_IntegralToFloating:
12377 case CK_FloatingToIntegral:
12378 case CK_FloatingToBoolean:
12379 case CK_FloatingCast:
12380 case CK_CPointerToObjCPointerCast:
12381 case CK_BlockPointerToObjCPointerCast:
12382 case CK_AnyPointerToBlockPointerCast:
12383 case CK_ObjCObjectLValueCast:
12384 case CK_FloatingComplexToReal:
12385 case CK_FloatingComplexToBoolean:
12386 case CK_IntegralComplexToReal:
12387 case CK_IntegralComplexToBoolean:
12388 case CK_ARCProduceObject:
12389 case CK_ARCConsumeObject:
12390 case CK_ARCReclaimReturnedObject:
12391 case CK_ARCExtendBlockObject:
12392 case CK_CopyAndAutoreleaseBlockObject:
12393 case CK_BuiltinFnToFnPtr:
12394 case CK_ZeroToOCLOpaqueType:
12395 case CK_NonAtomicToAtomic:
12396 case CK_AddressSpaceConversion:
12397 case CK_IntToOCLSampler:
12398 case CK_FixedPointCast:
12399 case CK_FixedPointToBoolean:
12400 case CK_FixedPointToIntegral:
12401 case CK_IntegralToFixedPoint:
12402 llvm_unreachable("invalid cast kind for complex value")::llvm::llvm_unreachable_internal("invalid cast kind for complex value"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12402)
;
12403
12404 case CK_LValueToRValue:
12405 case CK_AtomicToNonAtomic:
12406 case CK_NoOp:
12407 case CK_LValueToRValueBitCast:
12408 return ExprEvaluatorBaseTy::VisitCastExpr(E);
12409
12410 case CK_Dependent:
12411 case CK_LValueBitCast:
12412 case CK_UserDefinedConversion:
12413 return Error(E);
12414
12415 case CK_FloatingRealToComplex: {
12416 APFloat &Real = Result.FloatReal;
12417 if (!EvaluateFloat(E->getSubExpr(), Real, Info))
12418 return false;
12419
12420 Result.makeComplexFloat();
12421 Result.FloatImag = APFloat(Real.getSemantics());
12422 return true;
12423 }
12424
12425 case CK_FloatingComplexCast: {
12426 if (!Visit(E->getSubExpr()))
12427 return false;
12428
12429 QualType To = E->getType()->getAs<ComplexType>()->getElementType();
12430 QualType From
12431 = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
12432
12433 return HandleFloatToFloatCast(Info, E, From, To, Result.FloatReal) &&
12434 HandleFloatToFloatCast(Info, E, From, To, Result.FloatImag);
12435 }
12436
12437 case CK_FloatingComplexToIntegralComplex: {
12438 if (!Visit(E->getSubExpr()))
12439 return false;
12440
12441 QualType To = E->getType()->getAs<ComplexType>()->getElementType();
12442 QualType From
12443 = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
12444 Result.makeComplexInt();
12445 return HandleFloatToIntCast(Info, E, From, Result.FloatReal,
12446 To, Result.IntReal) &&
12447 HandleFloatToIntCast(Info, E, From, Result.FloatImag,
12448 To, Result.IntImag);
12449 }
12450
12451 case CK_IntegralRealToComplex: {
12452 APSInt &Real = Result.IntReal;
12453 if (!EvaluateInteger(E->getSubExpr(), Real, Info))
12454 return false;
12455
12456 Result.makeComplexInt();
12457 Result.IntImag = APSInt(Real.getBitWidth(), !Real.isSigned());
12458 return true;
12459 }
12460
12461 case CK_IntegralComplexCast: {
12462 if (!Visit(E->getSubExpr()))
3
Assuming the condition is false
4
Taking false branch
12463 return false;
12464
12465 QualType To = E->getType()->getAs<ComplexType>()->getElementType();
5
Assuming the object is a 'ComplexType'
12466 QualType From
12467 = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
6
Assuming the object is not a 'ComplexType'
7
Called C++ object pointer is null
12468
12469 Result.IntReal = HandleIntToIntCast(Info, E, To, From, Result.IntReal);
12470 Result.IntImag = HandleIntToIntCast(Info, E, To, From, Result.IntImag);
12471 return true;
12472 }
12473
12474 case CK_IntegralComplexToFloatingComplex: {
12475 if (!Visit(E->getSubExpr()))
12476 return false;
12477
12478 QualType To = E->getType()->castAs<ComplexType>()->getElementType();
12479 QualType From
12480 = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
12481 Result.makeComplexFloat();
12482 return HandleIntToFloatCast(Info, E, From, Result.IntReal,
12483 To, Result.FloatReal) &&
12484 HandleIntToFloatCast(Info, E, From, Result.IntImag,
12485 To, Result.FloatImag);
12486 }
12487 }
12488
12489 llvm_unreachable("unknown cast resulting in complex value")::llvm::llvm_unreachable_internal("unknown cast resulting in complex value"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12489)
;
12490}
12491
12492bool ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
12493 if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
12494 return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
12495
12496 // Track whether the LHS or RHS is real at the type system level. When this is
12497 // the case we can simplify our evaluation strategy.
12498 bool LHSReal = false, RHSReal = false;
12499
12500 bool LHSOK;
12501 if (E->getLHS()->getType()->isRealFloatingType()) {
12502 LHSReal = true;
12503 APFloat &Real = Result.FloatReal;
12504 LHSOK = EvaluateFloat(E->getLHS(), Real, Info);
12505 if (LHSOK) {
12506 Result.makeComplexFloat();
12507 Result.FloatImag = APFloat(Real.getSemantics());
12508 }
12509 } else {
12510 LHSOK = Visit(E->getLHS());
12511 }
12512 if (!LHSOK && !Info.noteFailure())
12513 return false;
12514
12515 ComplexValue RHS;
12516 if (E->getRHS()->getType()->isRealFloatingType()) {
12517 RHSReal = true;
12518 APFloat &Real = RHS.FloatReal;
12519 if (!EvaluateFloat(E->getRHS(), Real, Info) || !LHSOK)
12520 return false;
12521 RHS.makeComplexFloat();
12522 RHS.FloatImag = APFloat(Real.getSemantics());
12523 } else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
12524 return false;
12525
12526 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12527, __PRETTY_FUNCTION__))
12527 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12527, __PRETTY_FUNCTION__))
;
12528 switch (E->getOpcode()) {
12529 default: return Error(E);
12530 case BO_Add:
12531 if (Result.isComplexFloat()) {
12532 Result.getComplexFloatReal().add(RHS.getComplexFloatReal(),
12533 APFloat::rmNearestTiesToEven);
12534 if (LHSReal)
12535 Result.getComplexFloatImag() = RHS.getComplexFloatImag();
12536 else if (!RHSReal)
12537 Result.getComplexFloatImag().add(RHS.getComplexFloatImag(),
12538 APFloat::rmNearestTiesToEven);
12539 } else {
12540 Result.getComplexIntReal() += RHS.getComplexIntReal();
12541 Result.getComplexIntImag() += RHS.getComplexIntImag();
12542 }
12543 break;
12544 case BO_Sub:
12545 if (Result.isComplexFloat()) {
12546 Result.getComplexFloatReal().subtract(RHS.getComplexFloatReal(),
12547 APFloat::rmNearestTiesToEven);
12548 if (LHSReal) {
12549 Result.getComplexFloatImag() = RHS.getComplexFloatImag();
12550 Result.getComplexFloatImag().changeSign();
12551 } else if (!RHSReal) {
12552 Result.getComplexFloatImag().subtract(RHS.getComplexFloatImag(),
12553 APFloat::rmNearestTiesToEven);
12554 }
12555 } else {
12556 Result.getComplexIntReal() -= RHS.getComplexIntReal();
12557 Result.getComplexIntImag() -= RHS.getComplexIntImag();
12558 }
12559 break;
12560 case BO_Mul:
12561 if (Result.isComplexFloat()) {
12562 // This is an implementation of complex multiplication according to the
12563 // constraints laid out in C11 Annex G. The implementation uses the
12564 // following naming scheme:
12565 // (a + ib) * (c + id)
12566 ComplexValue LHS = Result;
12567 APFloat &A = LHS.getComplexFloatReal();
12568 APFloat &B = LHS.getComplexFloatImag();
12569 APFloat &C = RHS.getComplexFloatReal();
12570 APFloat &D = RHS.getComplexFloatImag();
12571 APFloat &ResR = Result.getComplexFloatReal();
12572 APFloat &ResI = Result.getComplexFloatImag();
12573 if (LHSReal) {
12574 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12574, __PRETTY_FUNCTION__))
;
12575 ResR = A * C;
12576 ResI = A * D;
12577 } else if (RHSReal) {
12578 ResR = C * A;
12579 ResI = C * B;
12580 } else {
12581 // In the fully general case, we need to handle NaNs and infinities
12582 // robustly.
12583 APFloat AC = A * C;
12584 APFloat BD = B * D;
12585 APFloat AD = A * D;
12586 APFloat BC = B * C;
12587 ResR = AC - BD;
12588 ResI = AD + BC;
12589 if (ResR.isNaN() && ResI.isNaN()) {
12590 bool Recalc = false;
12591 if (A.isInfinity() || B.isInfinity()) {
12592 A = APFloat::copySign(
12593 APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
12594 B = APFloat::copySign(
12595 APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
12596 if (C.isNaN())
12597 C = APFloat::copySign(APFloat(C.getSemantics()), C);
12598 if (D.isNaN())
12599 D = APFloat::copySign(APFloat(D.getSemantics()), D);
12600 Recalc = true;
12601 }
12602 if (C.isInfinity() || D.isInfinity()) {
12603 C = APFloat::copySign(
12604 APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
12605 D = APFloat::copySign(
12606 APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
12607 if (A.isNaN())
12608 A = APFloat::copySign(APFloat(A.getSemantics()), A);
12609 if (B.isNaN())
12610 B = APFloat::copySign(APFloat(B.getSemantics()), B);
12611 Recalc = true;
12612 }
12613 if (!Recalc && (AC.isInfinity() || BD.isInfinity() ||
12614 AD.isInfinity() || BC.isInfinity())) {
12615 if (A.isNaN())
12616 A = APFloat::copySign(APFloat(A.getSemantics()), A);
12617 if (B.isNaN())
12618 B = APFloat::copySign(APFloat(B.getSemantics()), B);
12619 if (C.isNaN())
12620 C = APFloat::copySign(APFloat(C.getSemantics()), C);
12621 if (D.isNaN())
12622 D = APFloat::copySign(APFloat(D.getSemantics()), D);
12623 Recalc = true;
12624 }
12625 if (Recalc) {
12626 ResR = APFloat::getInf(A.getSemantics()) * (A * C - B * D);
12627 ResI = APFloat::getInf(A.getSemantics()) * (A * D + B * C);
12628 }
12629 }
12630 }
12631 } else {
12632 ComplexValue LHS = Result;
12633 Result.getComplexIntReal() =
12634 (LHS.getComplexIntReal() * RHS.getComplexIntReal() -
12635 LHS.getComplexIntImag() * RHS.getComplexIntImag());
12636 Result.getComplexIntImag() =
12637 (LHS.getComplexIntReal() * RHS.getComplexIntImag() +
12638 LHS.getComplexIntImag() * RHS.getComplexIntReal());
12639 }
12640 break;
12641 case BO_Div:
12642 if (Result.isComplexFloat()) {
12643 // This is an implementation of complex division according to the
12644 // constraints laid out in C11 Annex G. The implementation uses the
12645 // following naming scheme:
12646 // (a + ib) / (c + id)
12647 ComplexValue LHS = Result;
12648 APFloat &A = LHS.getComplexFloatReal();
12649 APFloat &B = LHS.getComplexFloatImag();
12650 APFloat &C = RHS.getComplexFloatReal();
12651 APFloat &D = RHS.getComplexFloatImag();
12652 APFloat &ResR = Result.getComplexFloatReal();
12653 APFloat &ResI = Result.getComplexFloatImag();
12654 if (RHSReal) {
12655 ResR = A / C;
12656 ResI = B / C;
12657 } else {
12658 if (LHSReal) {
12659 // No real optimizations we can do here, stub out with zero.
12660 B = APFloat::getZero(A.getSemantics());
12661 }
12662 int DenomLogB = 0;
12663 APFloat MaxCD = maxnum(abs(C), abs(D));
12664 if (MaxCD.isFinite()) {
12665 DenomLogB = ilogb(MaxCD);
12666 C = scalbn(C, -DenomLogB, APFloat::rmNearestTiesToEven);
12667 D = scalbn(D, -DenomLogB, APFloat::rmNearestTiesToEven);
12668 }
12669 APFloat Denom = C * C + D * D;
12670 ResR = scalbn((A * C + B * D) / Denom, -DenomLogB,
12671 APFloat::rmNearestTiesToEven);
12672 ResI = scalbn((B * C - A * D) / Denom, -DenomLogB,
12673 APFloat::rmNearestTiesToEven);
12674 if (ResR.isNaN() && ResI.isNaN()) {
12675 if (Denom.isPosZero() && (!A.isNaN() || !B.isNaN())) {
12676 ResR = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * A;
12677 ResI = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * B;
12678 } else if ((A.isInfinity() || B.isInfinity()) && C.isFinite() &&
12679 D.isFinite()) {
12680 A = APFloat::copySign(
12681 APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
12682 B = APFloat::copySign(
12683 APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
12684 ResR = APFloat::getInf(ResR.getSemantics()) * (A * C + B * D);
12685 ResI = APFloat::getInf(ResI.getSemantics()) * (B * C - A * D);
12686 } else if (MaxCD.isInfinity() && A.isFinite() && B.isFinite()) {
12687 C = APFloat::copySign(
12688 APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
12689 D = APFloat::copySign(
12690 APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
12691 ResR = APFloat::getZero(ResR.getSemantics()) * (A * C + B * D);
12692 ResI = APFloat::getZero(ResI.getSemantics()) * (B * C - A * D);
12693 }
12694 }
12695 }
12696 } else {
12697 if (RHS.getComplexIntReal() == 0 && RHS.getComplexIntImag() == 0)
12698 return Error(E, diag::note_expr_divide_by_zero);
12699
12700 ComplexValue LHS = Result;
12701 APSInt Den = RHS.getComplexIntReal() * RHS.getComplexIntReal() +
12702 RHS.getComplexIntImag() * RHS.getComplexIntImag();
12703 Result.getComplexIntReal() =
12704 (LHS.getComplexIntReal() * RHS.getComplexIntReal() +
12705 LHS.getComplexIntImag() * RHS.getComplexIntImag()) / Den;
12706 Result.getComplexIntImag() =
12707 (LHS.getComplexIntImag() * RHS.getComplexIntReal() -
12708 LHS.getComplexIntReal() * RHS.getComplexIntImag()) / Den;
12709 }
12710 break;
12711 }
12712
12713 return true;
12714}
12715
12716bool ComplexExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
12717 // Get the operand value into 'Result'.
12718 if (!Visit(E->getSubExpr()))
12719 return false;
12720
12721 switch (E->getOpcode()) {
12722 default:
12723 return Error(E);
12724 case UO_Extension:
12725 return true;
12726 case UO_Plus:
12727 // The result is always just the subexpr.
12728 return true;
12729 case UO_Minus:
12730 if (Result.isComplexFloat()) {
12731 Result.getComplexFloatReal().changeSign();
12732 Result.getComplexFloatImag().changeSign();
12733 }
12734 else {
12735 Result.getComplexIntReal() = -Result.getComplexIntReal();
12736 Result.getComplexIntImag() = -Result.getComplexIntImag();
12737 }
12738 return true;
12739 case UO_Not:
12740 if (Result.isComplexFloat())
12741 Result.getComplexFloatImag().changeSign();
12742 else
12743 Result.getComplexIntImag() = -Result.getComplexIntImag();
12744 return true;
12745 }
12746}
12747
12748bool ComplexExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
12749 if (E->getNumInits() == 2) {
12750 if (E->getType()->isComplexType()) {
12751 Result.makeComplexFloat();
12752 if (!EvaluateFloat(E->getInit(0), Result.FloatReal, Info))
12753 return false;
12754 if (!EvaluateFloat(E->getInit(1), Result.FloatImag, Info))
12755 return false;
12756 } else {
12757 Result.makeComplexInt();
12758 if (!EvaluateInteger(E->getInit(0), Result.IntReal, Info))
12759 return false;
12760 if (!EvaluateInteger(E->getInit(1), Result.IntImag, Info))
12761 return false;
12762 }
12763 return true;
12764 }
12765 return ExprEvaluatorBaseTy::VisitInitListExpr(E);
12766}
12767
12768//===----------------------------------------------------------------------===//
12769// Atomic expression evaluation, essentially just handling the NonAtomicToAtomic
12770// implicit conversion.
12771//===----------------------------------------------------------------------===//
12772
12773namespace {
12774class AtomicExprEvaluator :
12775 public ExprEvaluatorBase<AtomicExprEvaluator> {
12776 const LValue *This;
12777 APValue &Result;
12778public:
12779 AtomicExprEvaluator(EvalInfo &Info, const LValue *This, APValue &Result)
12780 : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
12781
12782 bool Success(const APValue &V, const Expr *E) {
12783 Result = V;
12784 return true;
12785 }
12786
12787 bool ZeroInitialization(const Expr *E) {
12788 ImplicitValueInitExpr VIE(
12789 E->getType()->castAs<AtomicType>()->getValueType());
12790 // For atomic-qualified class (and array) types in C++, initialize the
12791 // _Atomic-wrapped subobject directly, in-place.
12792 return This ? EvaluateInPlace(Result, Info, *This, &VIE)
12793 : Evaluate(Result, Info, &VIE);
12794 }
12795
12796 bool VisitCastExpr(const CastExpr *E) {
12797 switch (E->getCastKind()) {
12798 default:
12799 return ExprEvaluatorBaseTy::VisitCastExpr(E);
12800 case CK_NonAtomicToAtomic:
12801 return This ? EvaluateInPlace(Result, Info, *This, E->getSubExpr())
12802 : Evaluate(Result, Info, E->getSubExpr());
12803 }
12804 }
12805};
12806} // end anonymous namespace
12807
12808static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
12809 EvalInfo &Info) {
12810 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12810, __PRETTY_FUNCTION__))
;
12811 return AtomicExprEvaluator(Info, This, Result).Visit(E);
12812}
12813
12814//===----------------------------------------------------------------------===//
12815// Void expression evaluation, primarily for a cast to void on the LHS of a
12816// comma operator
12817//===----------------------------------------------------------------------===//
12818
12819namespace {
12820class VoidExprEvaluator
12821 : public ExprEvaluatorBase<VoidExprEvaluator> {
12822public:
12823 VoidExprEvaluator(EvalInfo &Info) : ExprEvaluatorBaseTy(Info) {}
12824
12825 bool Success(const APValue &V, const Expr *e) { return true; }
12826
12827 bool ZeroInitialization(const Expr *E) { return true; }
12828
12829 bool VisitCastExpr(const CastExpr *E) {
12830 switch (E->getCastKind()) {
12831 default:
12832 return ExprEvaluatorBaseTy::VisitCastExpr(E);
12833 case CK_ToVoid:
12834 VisitIgnoredValue(E->getSubExpr());
12835 return true;
12836 }
12837 }
12838
12839 bool VisitCallExpr(const CallExpr *E) {
12840 switch (E->getBuiltinCallee()) {
12841 default:
12842 return ExprEvaluatorBaseTy::VisitCallExpr(E);
12843 case Builtin::BI__assume:
12844 case Builtin::BI__builtin_assume:
12845 // The argument is not evaluated!
12846 return true;
12847 }
12848 }
12849
12850 bool VisitCXXDeleteExpr(const CXXDeleteExpr *E);
12851};
12852} // end anonymous namespace
12853
12854static bool hasVirtualDestructor(QualType T) {
12855 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
12856 if (CXXDestructorDecl *DD = RD->getDestructor())
12857 return DD->isVirtual();
12858 return false;
12859}
12860
12861bool VoidExprEvaluator::VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
12862 // We cannot speculatively evaluate a delete expression.
12863 if (Info.SpeculativeEvaluationDepth)
12864 return false;
12865
12866 FunctionDecl *OperatorDelete = E->getOperatorDelete();
12867 if (!OperatorDelete->isReplaceableGlobalAllocationFunction()) {
12868 Info.FFDiag(E, diag::note_constexpr_new_non_replaceable)
12869 << isa<CXXMethodDecl>(OperatorDelete) << OperatorDelete;
12870 return false;
12871 }
12872
12873 const Expr *Arg = E->getArgument();
12874
12875 LValue Pointer;
12876 if (!EvaluatePointer(Arg, Pointer, Info))
12877 return false;
12878 if (Pointer.Designator.Invalid)
12879 return false;
12880
12881 // Deleting a null pointer has no effect.
12882 if (Pointer.isNullPointer()) {
12883 // This is the only case where we need to produce an extension warning:
12884 // the only other way we can succeed is if we find a dynamic allocation,
12885 // and we will have warned when we allocated it in that case.
12886 if (!Info.getLangOpts().CPlusPlus2a)
12887 Info.CCEDiag(E, diag::note_constexpr_new);
12888 return true;
12889 }
12890
12891 auto PointerAsString = [&] {
12892 APValue Printable;
12893 Pointer.moveInto(Printable);
12894 return Printable.getAsString(Info.Ctx, Arg->getType());
12895 };
12896
12897 DynamicAllocLValue DA = Pointer.Base.dyn_cast<DynamicAllocLValue>();
12898 if (!DA) {
12899 Info.FFDiag(E, diag::note_constexpr_delete_not_heap_alloc)
12900 << PointerAsString();
12901 if (Pointer.Base)
12902 NoteLValueLocation(Info, Pointer.Base);
12903 return false;
12904 }
12905 QualType AllocType = Pointer.Base.getDynamicAllocType();
12906
12907 Optional<EvalInfo::DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA);
12908 if (!Alloc) {
12909 Info.FFDiag(E, diag::note_constexpr_double_delete);
12910 return false;
12911 }
12912
12913 if (E->isArrayForm() != AllocType->isConstantArrayType()) {
12914 Info.FFDiag(E, diag::note_constexpr_new_delete_mismatch)
12915 << E->isArrayForm() << AllocType;
12916 NoteLValueLocation(Info, Pointer.Base);
12917 return false;
12918 }
12919
12920 bool Subobject = false;
12921 if (E->isArrayForm()) {
12922 Subobject = Pointer.Designator.Entries.size() != 1 ||
12923 Pointer.Designator.Entries[0].getAsArrayIndex() != 0;
12924 } else {
12925 Subobject = Pointer.Designator.MostDerivedPathLength != 0 ||
12926 Pointer.Designator.isOnePastTheEnd();
12927 }
12928 if (Subobject) {
12929 Info.FFDiag(E, diag::note_constexpr_delete_subobject)
12930 << PointerAsString() << Pointer.Designator.isOnePastTheEnd();
12931 return false;
12932 }
12933
12934 // For the non-array case, the designator must be empty if the static type
12935 // does not have a virtual destructor.
12936 if (!E->isArrayForm() && Pointer.Designator.Entries.size() != 0 &&
12937 !hasVirtualDestructor(Arg->getType()->getPointeeType())) {
12938 Info.FFDiag(E, diag::note_constexpr_delete_base_nonvirt_dtor)
12939 << Arg->getType()->getPointeeType() << AllocType;
12940 return false;
12941 }
12942
12943 if (!HandleDestruction(Info, E->getExprLoc(), Pointer.getLValueBase(),
12944 (*Alloc)->Value, AllocType))
12945 return false;
12946
12947 if (!Info.HeapAllocs.erase(DA)) {
12948 // The element was already erased. This means the destructor call also
12949 // deleted the object.
12950 // FIXME: This probably results in undefined behavior before we get this
12951 // far, and should be diagnosed elsewhere first.
12952 Info.FFDiag(E, diag::note_constexpr_double_delete);
12953 return false;
12954 }
12955
12956 return true;
12957}
12958
12959static bool EvaluateVoid(const Expr *E, EvalInfo &Info) {
12960 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 12960, __PRETTY_FUNCTION__))
;
12961 return VoidExprEvaluator(Info).Visit(E);
12962}
12963
12964//===----------------------------------------------------------------------===//
12965// Top level Expr::EvaluateAsRValue method.
12966//===----------------------------------------------------------------------===//
12967
12968static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) {
12969 // In C, function designators are not lvalues, but we evaluate them as if they
12970 // are.
12971 QualType T = E->getType();
12972 if (E->isGLValue() || T->isFunctionType()) {
12973 LValue LV;
12974 if (!EvaluateLValue(E, LV, Info))
12975 return false;
12976 LV.moveInto(Result);
12977 } else if (T->isVectorType()) {
12978 if (!EvaluateVector(E, Result, Info))
12979 return false;
12980 } else if (T->isIntegralOrEnumerationType()) {
12981 if (!IntExprEvaluator(Info, Result).Visit(E))
12982 return false;
12983 } else if (T->hasPointerRepresentation()) {
12984 LValue LV;
12985 if (!EvaluatePointer(E, LV, Info))
12986 return false;
12987 LV.moveInto(Result);
12988 } else if (T->isRealFloatingType()) {
12989 llvm::APFloat F(0.0);
12990 if (!EvaluateFloat(E, F, Info))
12991 return false;
12992 Result = APValue(F);
12993 } else if (T->isAnyComplexType()) {
12994 ComplexValue C;
12995 if (!EvaluateComplex(E, C, Info))
12996 return false;
12997 C.moveInto(Result);
12998 } else if (T->isFixedPointType()) {
12999 if (!FixedPointExprEvaluator(Info, Result).Visit(E)) return false;
13000 } else if (T->isMemberPointerType()) {
13001 MemberPtr P;
13002 if (!EvaluateMemberPointer(E, P, Info))
13003 return false;
13004 P.moveInto(Result);
13005 return true;
13006 } else if (T->isArrayType()) {
13007 LValue LV;
13008 APValue &Value =
13009 Info.CurrentCall->createTemporary(E, T, false, LV);
13010 if (!EvaluateArray(E, LV, Value, Info))
13011 return false;
13012 Result = Value;
13013 } else if (T->isRecordType()) {
13014 LValue LV;
13015 APValue &Value = Info.CurrentCall->createTemporary(E, T, false, LV);
13016 if (!EvaluateRecord(E, LV, Value, Info))
13017 return false;
13018 Result = Value;
13019 } else if (T->isVoidType()) {
13020 if (!Info.getLangOpts().CPlusPlus11)
13021 Info.CCEDiag(E, diag::note_constexpr_nonliteral)
13022 << E->getType();
13023 if (!EvaluateVoid(E, Info))
13024 return false;
13025 } else if (T->isAtomicType()) {
13026 QualType Unqual = T.getAtomicUnqualifiedType();
13027 if (Unqual->isArrayType() || Unqual->isRecordType()) {
13028 LValue LV;
13029 APValue &Value = Info.CurrentCall->createTemporary(E, Unqual, false, LV);
13030 if (!EvaluateAtomic(E, &LV, Value, Info))
13031 return false;
13032 } else {
13033 if (!EvaluateAtomic(E, nullptr, Result, Info))
13034 return false;
13035 }
13036 } else if (Info.getLangOpts().CPlusPlus11) {
13037 Info.FFDiag(E, diag::note_constexpr_nonliteral) << E->getType();
13038 return false;
13039 } else {
13040 Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
13041 return false;
13042 }
13043
13044 return true;
13045}
13046
13047/// EvaluateInPlace - Evaluate an expression in-place in an APValue. In some
13048/// cases, the in-place evaluation is essential, since later initializers for
13049/// an object can indirectly refer to subobjects which were initialized earlier.
13050static bool EvaluateInPlace(APValue &Result, EvalInfo &Info, const LValue &This,
13051 const Expr *E, bool AllowNonLiteralTypes) {
13052 assert(!E->isValueDependent())((!E->isValueDependent()) ? static_cast<void> (0) : __assert_fail
("!E->isValueDependent()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13052, __PRETTY_FUNCTION__))
;
13053
13054 if (!AllowNonLiteralTypes && !CheckLiteralType(Info, E, &This))
13055 return false;
13056
13057 if (E->isRValue()) {
13058 // Evaluate arrays and record types in-place, so that later initializers can
13059 // refer to earlier-initialized members of the object.
13060 QualType T = E->getType();
13061 if (T->isArrayType())
13062 return EvaluateArray(E, This, Result, Info);
13063 else if (T->isRecordType())
13064 return EvaluateRecord(E, This, Result, Info);
13065 else if (T->isAtomicType()) {
13066 QualType Unqual = T.getAtomicUnqualifiedType();
13067 if (Unqual->isArrayType() || Unqual->isRecordType())
13068 return EvaluateAtomic(E, &This, Result, Info);
13069 }
13070 }
13071
13072 // For any other type, in-place evaluation is unimportant.
13073 return Evaluate(Result, Info, E);
13074}
13075
13076/// EvaluateAsRValue - Try to evaluate this expression, performing an implicit
13077/// lvalue-to-rvalue cast if it is an lvalue.
13078static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result) {
13079 if (Info.EnableNewConstInterp) {
13080 auto &InterpCtx = Info.Ctx.getInterpContext();
13081 switch (InterpCtx.evaluateAsRValue(Info, E, Result)) {
13082 case interp::InterpResult::Success:
13083 return true;
13084 case interp::InterpResult::Fail:
13085 return false;
13086 case interp::InterpResult::Bail:
13087 break;
13088 }
13089 }
13090
13091 if (E->getType().isNull())
13092 return false;
13093
13094 if (!CheckLiteralType(Info, E))
13095 return false;
13096
13097 if (!::Evaluate(Result, Info, E))
13098 return false;
13099
13100 if (E->isGLValue()) {
13101 LValue LV;
13102 LV.setFrom(Info.Ctx, Result);
13103 if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
13104 return false;
13105 }
13106
13107 // Check this core constant expression is a constant expression.
13108 return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result) &&
13109 CheckMemoryLeaks(Info);
13110}
13111
13112static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
13113 const ASTContext &Ctx, bool &IsConst) {
13114 // Fast-path evaluations of integer literals, since we sometimes see files
13115 // containing vast quantities of these.
13116 if (const IntegerLiteral *L = dyn_cast<IntegerLiteral>(Exp)) {
13117 Result.Val = APValue(APSInt(L->getValue(),
13118 L->getType()->isUnsignedIntegerType()));
13119 IsConst = true;
13120 return true;
13121 }
13122
13123 // This case should be rare, but we need to check it before we check on
13124 // the type below.
13125 if (Exp->getType().isNull()) {
13126 IsConst = false;
13127 return true;
13128 }
13129
13130 // FIXME: Evaluating values of large array and record types can cause
13131 // performance problems. Only do so in C++11 for now.
13132 if (Exp->isRValue() && (Exp->getType()->isArrayType() ||
13133 Exp->getType()->isRecordType()) &&
13134 !Ctx.getLangOpts().CPlusPlus11) {
13135 IsConst = false;
13136 return true;
13137 }
13138 return false;
13139}
13140
13141static bool hasUnacceptableSideEffect(Expr::EvalStatus &Result,
13142 Expr::SideEffectsKind SEK) {
13143 return (SEK < Expr::SE_AllowSideEffects && Result.HasSideEffects) ||
13144 (SEK < Expr::SE_AllowUndefinedBehavior && Result.HasUndefinedBehavior);
13145}
13146
13147static bool EvaluateAsRValue(const Expr *E, Expr::EvalResult &Result,
13148 const ASTContext &Ctx, EvalInfo &Info) {
13149 bool IsConst;
13150 if (FastEvaluateAsRValue(E, Result, Ctx, IsConst))
13151 return IsConst;
13152
13153 return EvaluateAsRValue(Info, E, Result.Val);
13154}
13155
13156static bool EvaluateAsInt(const Expr *E, Expr::EvalResult &ExprResult,
13157 const ASTContext &Ctx,
13158 Expr::SideEffectsKind AllowSideEffects,
13159 EvalInfo &Info) {
13160 if (!E->getType()->isIntegralOrEnumerationType())
13161 return false;
13162
13163 if (!::EvaluateAsRValue(E, ExprResult, Ctx, Info) ||
13164 !ExprResult.Val.isInt() ||
13165 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
13166 return false;
13167
13168 return true;
13169}
13170
13171static bool EvaluateAsFixedPoint(const Expr *E, Expr::EvalResult &ExprResult,
13172 const ASTContext &Ctx,
13173 Expr::SideEffectsKind AllowSideEffects,
13174 EvalInfo &Info) {
13175 if (!E->getType()->isFixedPointType())
13176 return false;
13177
13178 if (!::EvaluateAsRValue(E, ExprResult, Ctx, Info))
13179 return false;
13180
13181 if (!ExprResult.Val.isFixedPoint() ||
13182 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
13183 return false;
13184
13185 return true;
13186}
13187
13188/// EvaluateAsRValue - Return true if this is a constant which we can fold using
13189/// any crazy technique (that has nothing to do with language standards) that
13190/// we want to. If this function returns true, it returns the folded constant
13191/// in Result. If this expression is a glvalue, an lvalue-to-rvalue conversion
13192/// will be applied to the result.
13193bool Expr::EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx,
13194 bool InConstantContext) const {
13195 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13196, __PRETTY_FUNCTION__))
13196 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13196, __PRETTY_FUNCTION__))
;
13197 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
13198 Info.InConstantContext = InConstantContext;
13199 return ::EvaluateAsRValue(this, Result, Ctx, Info);
13200}
13201
13202bool Expr::EvaluateAsBooleanCondition(bool &Result, const ASTContext &Ctx,
13203 bool InConstantContext) const {
13204 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13205, __PRETTY_FUNCTION__))
13205 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13205, __PRETTY_FUNCTION__))
;
13206 EvalResult Scratch;
13207 return EvaluateAsRValue(Scratch, Ctx, InConstantContext) &&
13208 HandleConversionToBool(Scratch.Val, Result);
13209}
13210
13211bool Expr::EvaluateAsInt(EvalResult &Result, const ASTContext &Ctx,
13212 SideEffectsKind AllowSideEffects,
13213 bool InConstantContext) const {
13214 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13215, __PRETTY_FUNCTION__))
13215 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13215, __PRETTY_FUNCTION__))
;
13216 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
13217 Info.InConstantContext = InConstantContext;
13218 return ::EvaluateAsInt(this, Result, Ctx, AllowSideEffects, Info);
13219}
13220
13221bool Expr::EvaluateAsFixedPoint(EvalResult &Result, const ASTContext &Ctx,
13222 SideEffectsKind AllowSideEffects,
13223 bool InConstantContext) const {
13224 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13225, __PRETTY_FUNCTION__))
13225 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13225, __PRETTY_FUNCTION__))
;
13226 EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
13227 Info.InConstantContext = InConstantContext;
13228 return ::EvaluateAsFixedPoint(this, Result, Ctx, AllowSideEffects, Info);
13229}
13230
13231bool Expr::EvaluateAsFloat(APFloat &Result, const ASTContext &Ctx,
13232 SideEffectsKind AllowSideEffects,
13233 bool InConstantContext) const {
13234 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13235, __PRETTY_FUNCTION__))
13235 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13235, __PRETTY_FUNCTION__))
;
13236
13237 if (!getType()->isRealFloatingType())
13238 return false;
13239
13240 EvalResult ExprResult;
13241 if (!EvaluateAsRValue(ExprResult, Ctx, InConstantContext) ||
13242 !ExprResult.Val.isFloat() ||
13243 hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
13244 return false;
13245
13246 Result = ExprResult.Val.getFloat();
13247 return true;
13248}
13249
13250bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx,
13251 bool InConstantContext) const {
13252 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13253, __PRETTY_FUNCTION__))
13253 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13253, __PRETTY_FUNCTION__))
;
13254
13255 EvalInfo Info(Ctx, Result, EvalInfo::EM_ConstantFold);
13256 Info.InConstantContext = InConstantContext;
13257 LValue LV;
13258 CheckedTemporaries CheckedTemps;
13259 if (!EvaluateLValue(this, LV, Info) || !Info.discardCleanups() ||
13260 Result.HasSideEffects ||
13261 !CheckLValueConstantExpression(Info, getExprLoc(),
13262 Ctx.getLValueReferenceType(getType()), LV,
13263 Expr::EvaluateForCodeGen, CheckedTemps))
13264 return false;
13265
13266 LV.moveInto(Result.Val);
13267 return true;
13268}
13269
13270bool Expr::EvaluateAsConstantExpr(EvalResult &Result, ConstExprUsage Usage,
13271 const ASTContext &Ctx) const {
13272 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13273, __PRETTY_FUNCTION__))
13273 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13273, __PRETTY_FUNCTION__))
;
13274
13275 EvalInfo::EvaluationMode EM = EvalInfo::EM_ConstantExpression;
13276 EvalInfo Info(Ctx, Result, EM);
13277 Info.InConstantContext = true;
13278
13279 if (!::Evaluate(Result.Val, Info, this) || Result.HasSideEffects)
13280 return false;
13281
13282 if (!Info.discardCleanups())
13283 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13283)
;
13284
13285 return CheckConstantExpression(Info, getExprLoc(), getType(), Result.Val,
13286 Usage) &&
13287 CheckMemoryLeaks(Info);
13288}
13289
13290bool Expr::EvaluateAsInitializer(APValue &Value, const ASTContext &Ctx,
13291 const VarDecl *VD,
13292 SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
13293 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13294, __PRETTY_FUNCTION__))
13294 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13294, __PRETTY_FUNCTION__))
;
13295
13296 // FIXME: Evaluating initializers for large array and record types can cause
13297 // performance problems. Only do so in C++11 for now.
13298 if (isRValue() && (getType()->isArrayType() || getType()->isRecordType()) &&
13299 !Ctx.getLangOpts().CPlusPlus11)
13300 return false;
13301
13302 Expr::EvalStatus EStatus;
13303 EStatus.Diag = &Notes;
13304
13305 EvalInfo Info(Ctx, EStatus, VD->isConstexpr()
13306 ? EvalInfo::EM_ConstantExpression
13307 : EvalInfo::EM_ConstantFold);
13308 Info.setEvaluatingDecl(VD, Value);
13309 Info.InConstantContext = true;
13310
13311 SourceLocation DeclLoc = VD->getLocation();
13312 QualType DeclTy = VD->getType();
13313
13314 if (Info.EnableNewConstInterp) {
13315 auto &InterpCtx = const_cast<ASTContext &>(Ctx).getInterpContext();
13316 switch (InterpCtx.evaluateAsInitializer(Info, VD, Value)) {
13317 case interp::InterpResult::Fail:
13318 // Bail out if an error was encountered.
13319 return false;
13320 case interp::InterpResult::Success:
13321 // Evaluation succeeded and value was set.
13322 return CheckConstantExpression(Info, DeclLoc, DeclTy, Value);
13323 case interp::InterpResult::Bail:
13324 // Evaluate the value again for the tree evaluator to use.
13325 break;
13326 }
13327 }
13328
13329 LValue LVal;
13330 LVal.set(VD);
13331
13332 // C++11 [basic.start.init]p2:
13333 // Variables with static storage duration or thread storage duration shall be
13334 // zero-initialized before any other initialization takes place.
13335 // This behavior is not present in C.
13336 if (Ctx.getLangOpts().CPlusPlus && !VD->hasLocalStorage() &&
13337 !DeclTy->isReferenceType()) {
13338 ImplicitValueInitExpr VIE(DeclTy);
13339 if (!EvaluateInPlace(Value, Info, LVal, &VIE,
13340 /*AllowNonLiteralTypes=*/true))
13341 return false;
13342 }
13343
13344 if (!EvaluateInPlace(Value, Info, LVal, this,
13345 /*AllowNonLiteralTypes=*/true) ||
13346 EStatus.HasSideEffects)
13347 return false;
13348
13349 // At this point, any lifetime-extended temporaries are completely
13350 // initialized.
13351 Info.performLifetimeExtension();
13352
13353 if (!Info.discardCleanups())
13354 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13354)
;
13355
13356 return CheckConstantExpression(Info, DeclLoc, DeclTy, Value) &&
13357 CheckMemoryLeaks(Info);
13358}
13359
13360bool VarDecl::evaluateDestruction(
13361 SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
13362 assert(getEvaluatedValue() && !getEvaluatedValue()->isAbsent() &&((getEvaluatedValue() && !getEvaluatedValue()->isAbsent
() && "cannot evaluate destruction of non-constant-initialized variable"
) ? static_cast<void> (0) : __assert_fail ("getEvaluatedValue() && !getEvaluatedValue()->isAbsent() && \"cannot evaluate destruction of non-constant-initialized variable\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13363, __PRETTY_FUNCTION__))
13363 "cannot evaluate destruction of non-constant-initialized variable")((getEvaluatedValue() && !getEvaluatedValue()->isAbsent
() && "cannot evaluate destruction of non-constant-initialized variable"
) ? static_cast<void> (0) : __assert_fail ("getEvaluatedValue() && !getEvaluatedValue()->isAbsent() && \"cannot evaluate destruction of non-constant-initialized variable\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13363, __PRETTY_FUNCTION__))
;
13364
13365 Expr::EvalStatus EStatus;
13366 EStatus.Diag = &Notes;
13367
13368 // Make a copy of the value for the destructor to mutate.
13369 APValue DestroyedValue = *getEvaluatedValue();
13370
13371 EvalInfo Info(getASTContext(), EStatus, EvalInfo::EM_ConstantExpression);
13372 Info.setEvaluatingDecl(this, DestroyedValue,
13373 EvalInfo::EvaluatingDeclKind::Dtor);
13374 Info.InConstantContext = true;
13375
13376 SourceLocation DeclLoc = getLocation();
13377 QualType DeclTy = getType();
13378
13379 LValue LVal;
13380 LVal.set(this);
13381
13382 // FIXME: Consider storing whether this variable has constant destruction in
13383 // the EvaluatedStmt so that CodeGen can query it.
13384 if (!HandleDestruction(Info, DeclLoc, LVal.Base, DestroyedValue, DeclTy) ||
13385 EStatus.HasSideEffects)
13386 return false;
13387
13388 if (!Info.discardCleanups())
13389 llvm_unreachable("Unhandled cleanup; missing full expression marker?")::llvm::llvm_unreachable_internal("Unhandled cleanup; missing full expression marker?"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13389)
;
13390
13391 ensureEvaluatedStmt()->HasConstantDestruction = true;
13392 return true;
13393}
13394
13395/// isEvaluatable - Call EvaluateAsRValue to see if this expression can be
13396/// constant folded, but discard the result.
13397bool Expr::isEvaluatable(const ASTContext &Ctx, SideEffectsKind SEK) const {
13398 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13399, __PRETTY_FUNCTION__))
13399 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13399, __PRETTY_FUNCTION__))
;
13400
13401 EvalResult Result;
13402 return EvaluateAsRValue(Result, Ctx, /* in constant context */ true) &&
13403 !hasUnacceptableSideEffect(Result, SEK);
13404}
13405
13406APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx,
13407 SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
13408 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13409, __PRETTY_FUNCTION__))
13409 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13409, __PRETTY_FUNCTION__))
;
13410
13411 EvalResult EVResult;
13412 EVResult.Diag = Diag;
13413 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
13414 Info.InConstantContext = true;
13415
13416 bool Result = ::EvaluateAsRValue(this, EVResult, Ctx, Info);
13417 (void)Result;
13418 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13418, __PRETTY_FUNCTION__))
;
13419 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13419, __PRETTY_FUNCTION__))
;
13420
13421 return EVResult.Val.getInt();
13422}
13423
13424APSInt Expr::EvaluateKnownConstIntCheckOverflow(
13425 const ASTContext &Ctx, SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
13426 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13427, __PRETTY_FUNCTION__))
13427 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13427, __PRETTY_FUNCTION__))
;
13428
13429 EvalResult EVResult;
13430 EVResult.Diag = Diag;
13431 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
13432 Info.InConstantContext = true;
13433 Info.CheckingForUndefinedBehavior = true;
13434
13435 bool Result = ::EvaluateAsRValue(Info, this, EVResult.Val);
13436 (void)Result;
13437 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13437, __PRETTY_FUNCTION__))
;
13438 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13438, __PRETTY_FUNCTION__))
;
13439
13440 return EVResult.Val.getInt();
13441}
13442
13443void Expr::EvaluateForOverflow(const ASTContext &Ctx) const {
13444 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13445, __PRETTY_FUNCTION__))
13445 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13445, __PRETTY_FUNCTION__))
;
13446
13447 bool IsConst;
13448 EvalResult EVResult;
13449 if (!FastEvaluateAsRValue(this, EVResult, Ctx, IsConst)) {
13450 EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
13451 Info.CheckingForUndefinedBehavior = true;
13452 (void)::EvaluateAsRValue(Info, this, EVResult.Val);
13453 }
13454}
13455
13456bool Expr::EvalResult::isGlobalLValue() const {
13457 assert(Val.isLValue())((Val.isLValue()) ? static_cast<void> (0) : __assert_fail
("Val.isLValue()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13457, __PRETTY_FUNCTION__))
;
13458 return IsGlobalLValue(Val.getLValueBase());
13459}
13460
13461
13462/// isIntegerConstantExpr - this recursive routine will test if an expression is
13463/// an integer constant expression.
13464
13465/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
13466/// comma, etc
13467
13468// CheckICE - This function does the fundamental ICE checking: the returned
13469// ICEDiag contains an ICEKind indicating whether the expression is an ICE,
13470// and a (possibly null) SourceLocation indicating the location of the problem.
13471//
13472// Note that to reduce code duplication, this helper does no evaluation
13473// itself; the caller checks whether the expression is evaluatable, and
13474// in the rare cases where CheckICE actually cares about the evaluated
13475// value, it calls into Evaluate.
13476
13477namespace {
13478
13479enum ICEKind {
13480 /// This expression is an ICE.
13481 IK_ICE,
13482 /// This expression is not an ICE, but if it isn't evaluated, it's
13483 /// a legal subexpression for an ICE. This return value is used to handle
13484 /// the comma operator in C99 mode, and non-constant subexpressions.
13485 IK_ICEIfUnevaluated,
13486 /// This expression is not an ICE, and is not a legal subexpression for one.
13487 IK_NotICE
13488};
13489
13490struct ICEDiag {
13491 ICEKind Kind;
13492 SourceLocation Loc;
13493
13494 ICEDiag(ICEKind IK, SourceLocation l) : Kind(IK), Loc(l) {}
13495};
13496
13497}
13498
13499static ICEDiag NoDiag() { return ICEDiag(IK_ICE, SourceLocation()); }
13500
13501static ICEDiag Worst(ICEDiag A, ICEDiag B) { return A.Kind >= B.Kind ? A : B; }
13502
13503static ICEDiag CheckEvalInICE(const Expr* E, const ASTContext &Ctx) {
13504 Expr::EvalResult EVResult;
13505 Expr::EvalStatus Status;
13506 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
13507
13508 Info.InConstantContext = true;
13509 if (!::EvaluateAsRValue(E, EVResult, Ctx, Info) || EVResult.HasSideEffects ||
13510 !EVResult.Val.isInt())
13511 return ICEDiag(IK_NotICE, E->getBeginLoc());
13512
13513 return NoDiag();
13514}
13515
13516static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
13517 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13517, __PRETTY_FUNCTION__))
;
13518 if (!E->getType()->isIntegralOrEnumerationType())
13519 return ICEDiag(IK_NotICE, E->getBeginLoc());
13520
13521 switch (E->getStmtClass()) {
13522#define ABSTRACT_STMT(Node)
13523#define STMT(Node, Base) case Expr::Node##Class:
13524#define EXPR(Node, Base)
13525#include "clang/AST/StmtNodes.inc"
13526 case Expr::PredefinedExprClass:
13527 case Expr::FloatingLiteralClass:
13528 case Expr::ImaginaryLiteralClass:
13529 case Expr::StringLiteralClass:
13530 case Expr::ArraySubscriptExprClass:
13531 case Expr::OMPArraySectionExprClass:
13532 case Expr::MemberExprClass:
13533 case Expr::CompoundAssignOperatorClass:
13534 case Expr::CompoundLiteralExprClass:
13535 case Expr::ExtVectorElementExprClass:
13536 case Expr::DesignatedInitExprClass:
13537 case Expr::ArrayInitLoopExprClass:
13538 case Expr::ArrayInitIndexExprClass:
13539 case Expr::NoInitExprClass:
13540 case Expr::DesignatedInitUpdateExprClass:
13541 case Expr::ImplicitValueInitExprClass:
13542 case Expr::ParenListExprClass:
13543 case Expr::VAArgExprClass:
13544 case Expr::AddrLabelExprClass:
13545 case Expr::StmtExprClass:
13546 case Expr::CXXMemberCallExprClass:
13547 case Expr::CUDAKernelCallExprClass:
13548 case Expr::CXXDynamicCastExprClass:
13549 case Expr::CXXTypeidExprClass:
13550 case Expr::CXXUuidofExprClass:
13551 case Expr::MSPropertyRefExprClass:
13552 case Expr::MSPropertySubscriptExprClass:
13553 case Expr::CXXNullPtrLiteralExprClass:
13554 case Expr::UserDefinedLiteralClass:
13555 case Expr::CXXThisExprClass:
13556 case Expr::CXXThrowExprClass:
13557 case Expr::CXXNewExprClass:
13558 case Expr::CXXDeleteExprClass:
13559 case Expr::CXXPseudoDestructorExprClass:
13560 case Expr::UnresolvedLookupExprClass:
13561 case Expr::TypoExprClass:
13562 case Expr::DependentScopeDeclRefExprClass:
13563 case Expr::CXXConstructExprClass:
13564 case Expr::CXXInheritedCtorInitExprClass:
13565 case Expr::CXXStdInitializerListExprClass:
13566 case Expr::CXXBindTemporaryExprClass:
13567 case Expr::ExprWithCleanupsClass:
13568 case Expr::CXXTemporaryObjectExprClass:
13569 case Expr::CXXUnresolvedConstructExprClass:
13570 case Expr::CXXDependentScopeMemberExprClass:
13571 case Expr::UnresolvedMemberExprClass:
13572 case Expr::ObjCStringLiteralClass:
13573 case Expr::ObjCBoxedExprClass:
13574 case Expr::ObjCArrayLiteralClass:
13575 case Expr::ObjCDictionaryLiteralClass:
13576 case Expr::ObjCEncodeExprClass:
13577 case Expr::ObjCMessageExprClass:
13578 case Expr::ObjCSelectorExprClass:
13579 case Expr::ObjCProtocolExprClass:
13580 case Expr::ObjCIvarRefExprClass:
13581 case Expr::ObjCPropertyRefExprClass:
13582 case Expr::ObjCSubscriptRefExprClass:
13583 case Expr::ObjCIsaExprClass:
13584 case Expr::ObjCAvailabilityCheckExprClass:
13585 case Expr::ShuffleVectorExprClass:
13586 case Expr::ConvertVectorExprClass:
13587 case Expr::BlockExprClass:
13588 case Expr::NoStmtClass:
13589 case Expr::OpaqueValueExprClass:
13590 case Expr::PackExpansionExprClass:
13591 case Expr::SubstNonTypeTemplateParmPackExprClass:
13592 case Expr::FunctionParmPackExprClass:
13593 case Expr::AsTypeExprClass:
13594 case Expr::ObjCIndirectCopyRestoreExprClass:
13595 case Expr::MaterializeTemporaryExprClass:
13596 case Expr::PseudoObjectExprClass:
13597 case Expr::AtomicExprClass:
13598 case Expr::LambdaExprClass:
13599 case Expr::CXXFoldExprClass:
13600 case Expr::CoawaitExprClass:
13601 case Expr::DependentCoawaitExprClass:
13602 case Expr::CoyieldExprClass:
13603 return ICEDiag(IK_NotICE, E->getBeginLoc());
13604
13605 case Expr::InitListExprClass: {
13606 // C++03 [dcl.init]p13: If T is a scalar type, then a declaration of the
13607 // form "T x = { a };" is equivalent to "T x = a;".
13608 // Unless we're initializing a reference, T is a scalar as it is known to be
13609 // of integral or enumeration type.
13610 if (E->isRValue())
13611 if (cast<InitListExpr>(E)->getNumInits() == 1)
13612 return CheckICE(cast<InitListExpr>(E)->getInit(0), Ctx);
13613 return ICEDiag(IK_NotICE, E->getBeginLoc());
13614 }
13615
13616 case Expr::SizeOfPackExprClass:
13617 case Expr::GNUNullExprClass:
13618 case Expr::SourceLocExprClass:
13619 return NoDiag();
13620
13621 case Expr::SubstNonTypeTemplateParmExprClass:
13622 return
13623 CheckICE(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(), Ctx);
13624
13625 case Expr::ConstantExprClass:
13626 return CheckICE(cast<ConstantExpr>(E)->getSubExpr(), Ctx);
13627
13628 case Expr::ParenExprClass:
13629 return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
13630 case Expr::GenericSelectionExprClass:
13631 return CheckICE(cast<GenericSelectionExpr>(E)->getResultExpr(), Ctx);
13632 case Expr::IntegerLiteralClass:
13633 case Expr::FixedPointLiteralClass:
13634 case Expr::CharacterLiteralClass:
13635 case Expr::ObjCBoolLiteralExprClass:
13636 case Expr::CXXBoolLiteralExprClass:
13637 case Expr::CXXScalarValueInitExprClass:
13638 case Expr::TypeTraitExprClass:
13639 case Expr::ArrayTypeTraitExprClass:
13640 case Expr::ExpressionTraitExprClass:
13641 case Expr::CXXNoexceptExprClass:
13642 return NoDiag();
13643 case Expr::CallExprClass:
13644 case Expr::CXXOperatorCallExprClass: {
13645 // C99 6.6/3 allows function calls within unevaluated subexpressions of
13646 // constant expressions, but they can never be ICEs because an ICE cannot
13647 // contain an operand of (pointer to) function type.
13648 const CallExpr *CE = cast<CallExpr>(E);
13649 if (CE->getBuiltinCallee())
13650 return CheckEvalInICE(E, Ctx);
13651 return ICEDiag(IK_NotICE, E->getBeginLoc());
13652 }
13653 case Expr::DeclRefExprClass: {
13654 if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
13655 return NoDiag();
13656 const ValueDecl *D = cast<DeclRefExpr>(E)->getDecl();
13657 if (Ctx.getLangOpts().CPlusPlus &&
13658 D && IsConstNonVolatile(D->getType())) {
13659 // Parameter variables are never constants. Without this check,
13660 // getAnyInitializer() can find a default argument, which leads
13661 // to chaos.
13662 if (isa<ParmVarDecl>(D))
13663 return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
13664
13665 // C++ 7.1.5.1p2
13666 // A variable of non-volatile const-qualified integral or enumeration
13667 // type initialized by an ICE can be used in ICEs.
13668 if (const VarDecl *Dcl = dyn_cast<VarDecl>(D)) {
13669 if (!Dcl->getType()->isIntegralOrEnumerationType())
13670 return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
13671
13672 const VarDecl *VD;
13673 // Look for a declaration of this variable that has an initializer, and
13674 // check whether it is an ICE.
13675 if (Dcl->getAnyInitializer(VD) && VD->checkInitIsICE())
13676 return NoDiag();
13677 else
13678 return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
13679 }
13680 }
13681 return ICEDiag(IK_NotICE, E->getBeginLoc());
13682 }
13683 case Expr::UnaryOperatorClass: {
13684 const UnaryOperator *Exp = cast<UnaryOperator>(E);
13685 switch (Exp->getOpcode()) {
13686 case UO_PostInc:
13687 case UO_PostDec:
13688 case UO_PreInc:
13689 case UO_PreDec:
13690 case UO_AddrOf:
13691 case UO_Deref:
13692 case UO_Coawait:
13693 // C99 6.6/3 allows increment and decrement within unevaluated
13694 // subexpressions of constant expressions, but they can never be ICEs
13695 // because an ICE cannot contain an lvalue operand.
13696 return ICEDiag(IK_NotICE, E->getBeginLoc());
13697 case UO_Extension:
13698 case UO_LNot:
13699 case UO_Plus:
13700 case UO_Minus:
13701 case UO_Not:
13702 case UO_Real:
13703 case UO_Imag:
13704 return CheckICE(Exp->getSubExpr(), Ctx);
13705 }
13706 llvm_unreachable("invalid unary operator class")::llvm::llvm_unreachable_internal("invalid unary operator class"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13706)
;
13707 }
13708 case Expr::OffsetOfExprClass: {
13709 // Note that per C99, offsetof must be an ICE. And AFAIK, using
13710 // EvaluateAsRValue matches the proposed gcc behavior for cases like
13711 // "offsetof(struct s{int x[4];}, x[1.0])". This doesn't affect
13712 // compliance: we should warn earlier for offsetof expressions with
13713 // array subscripts that aren't ICEs, and if the array subscripts
13714 // are ICEs, the value of the offsetof must be an integer constant.
13715 return CheckEvalInICE(E, Ctx);
13716 }
13717 case Expr::UnaryExprOrTypeTraitExprClass: {
13718 const UnaryExprOrTypeTraitExpr *Exp = cast<UnaryExprOrTypeTraitExpr>(E);
13719 if ((Exp->getKind() == UETT_SizeOf) &&
13720 Exp->getTypeOfArgument()->isVariableArrayType())
13721 return ICEDiag(IK_NotICE, E->getBeginLoc());
13722 return NoDiag();
13723 }
13724 case Expr::BinaryOperatorClass: {
13725 const BinaryOperator *Exp = cast<BinaryOperator>(E);
13726 switch (Exp->getOpcode()) {
13727 case BO_PtrMemD:
13728 case BO_PtrMemI:
13729 case BO_Assign:
13730 case BO_MulAssign:
13731 case BO_DivAssign:
13732 case BO_RemAssign:
13733 case BO_AddAssign:
13734 case BO_SubAssign:
13735 case BO_ShlAssign:
13736 case BO_ShrAssign:
13737 case BO_AndAssign:
13738 case BO_XorAssign:
13739 case BO_OrAssign:
13740 // C99 6.6/3 allows assignments within unevaluated subexpressions of
13741 // constant expressions, but they can never be ICEs because an ICE cannot
13742 // contain an lvalue operand.
13743 return ICEDiag(IK_NotICE, E->getBeginLoc());
13744
13745 case BO_Mul:
13746 case BO_Div:
13747 case BO_Rem:
13748 case BO_Add:
13749 case BO_Sub:
13750 case BO_Shl:
13751 case BO_Shr:
13752 case BO_LT:
13753 case BO_GT:
13754 case BO_LE:
13755 case BO_GE:
13756 case BO_EQ:
13757 case BO_NE:
13758 case BO_And:
13759 case BO_Xor:
13760 case BO_Or:
13761 case BO_Comma:
13762 case BO_Cmp: {
13763 ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
13764 ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
13765 if (Exp->getOpcode() == BO_Div ||
13766 Exp->getOpcode() == BO_Rem) {
13767 // EvaluateAsRValue gives an error for undefined Div/Rem, so make sure
13768 // we don't evaluate one.
13769 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE) {
13770 llvm::APSInt REval = Exp->getRHS()->EvaluateKnownConstInt(Ctx);
13771 if (REval == 0)
13772 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
13773 if (REval.isSigned() && REval.isAllOnesValue()) {
13774 llvm::APSInt LEval = Exp->getLHS()->EvaluateKnownConstInt(Ctx);
13775 if (LEval.isMinSignedValue())
13776 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
13777 }
13778 }
13779 }
13780 if (Exp->getOpcode() == BO_Comma) {
13781 if (Ctx.getLangOpts().C99) {
13782 // C99 6.6p3 introduces a strange edge case: comma can be in an ICE
13783 // if it isn't evaluated.
13784 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE)
13785 return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
13786 } else {
13787 // In both C89 and C++, commas in ICEs are illegal.
13788 return ICEDiag(IK_NotICE, E->getBeginLoc());
13789 }
13790 }
13791 return Worst(LHSResult, RHSResult);
13792 }
13793 case BO_LAnd:
13794 case BO_LOr: {
13795 ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
13796 ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
13797 if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICEIfUnevaluated) {
13798 // Rare case where the RHS has a comma "side-effect"; we need
13799 // to actually check the condition to see whether the side
13800 // with the comma is evaluated.
13801 if ((Exp->getOpcode() == BO_LAnd) !=
13802 (Exp->getLHS()->EvaluateKnownConstInt(Ctx) == 0))
13803 return RHSResult;
13804 return NoDiag();
13805 }
13806
13807 return Worst(LHSResult, RHSResult);
13808 }
13809 }
13810 llvm_unreachable("invalid binary operator kind")::llvm::llvm_unreachable_internal("invalid binary operator kind"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13810)
;
13811 }
13812 case Expr::ImplicitCastExprClass:
13813 case Expr::CStyleCastExprClass:
13814 case Expr::CXXFunctionalCastExprClass:
13815 case Expr::CXXStaticCastExprClass:
13816 case Expr::CXXReinterpretCastExprClass:
13817 case Expr::CXXConstCastExprClass:
13818 case Expr::ObjCBridgedCastExprClass: {
13819 const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr();
13820 if (isa<ExplicitCastExpr>(E)) {
13821 if (const FloatingLiteral *FL
13822 = dyn_cast<FloatingLiteral>(SubExpr->IgnoreParenImpCasts())) {
13823 unsigned DestWidth = Ctx.getIntWidth(E->getType());
13824 bool DestSigned = E->getType()->isSignedIntegerOrEnumerationType();
13825 APSInt IgnoredVal(DestWidth, !DestSigned);
13826 bool Ignored;
13827 // If the value does not fit in the destination type, the behavior is
13828 // undefined, so we are not required to treat it as a constant
13829 // expression.
13830 if (FL->getValue().convertToInteger(IgnoredVal,
13831 llvm::APFloat::rmTowardZero,
13832 &Ignored) & APFloat::opInvalidOp)
13833 return ICEDiag(IK_NotICE, E->getBeginLoc());
13834 return NoDiag();
13835 }
13836 }
13837 switch (cast<CastExpr>(E)->getCastKind()) {
13838 case CK_LValueToRValue:
13839 case CK_AtomicToNonAtomic:
13840 case CK_NonAtomicToAtomic:
13841 case CK_NoOp:
13842 case CK_IntegralToBoolean:
13843 case CK_IntegralCast:
13844 return CheckICE(SubExpr, Ctx);
13845 default:
13846 return ICEDiag(IK_NotICE, E->getBeginLoc());
13847 }
13848 }
13849 case Expr::BinaryConditionalOperatorClass: {
13850 const BinaryConditionalOperator *Exp = cast<BinaryConditionalOperator>(E);
13851 ICEDiag CommonResult = CheckICE(Exp->getCommon(), Ctx);
13852 if (CommonResult.Kind == IK_NotICE) return CommonResult;
13853 ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
13854 if (FalseResult.Kind == IK_NotICE) return FalseResult;
13855 if (CommonResult.Kind == IK_ICEIfUnevaluated) return CommonResult;
13856 if (FalseResult.Kind == IK_ICEIfUnevaluated &&
13857 Exp->getCommon()->EvaluateKnownConstInt(Ctx) != 0) return NoDiag();
13858 return FalseResult;
13859 }
13860 case Expr::ConditionalOperatorClass: {
13861 const ConditionalOperator *Exp = cast<ConditionalOperator>(E);
13862 // If the condition (ignoring parens) is a __builtin_constant_p call,
13863 // then only the true side is actually considered in an integer constant
13864 // expression, and it is fully evaluated. This is an important GNU
13865 // extension. See GCC PR38377 for discussion.
13866 if (const CallExpr *CallCE
13867 = dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts()))
13868 if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
13869 return CheckEvalInICE(E, Ctx);
13870 ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
13871 if (CondResult.Kind == IK_NotICE)
13872 return CondResult;
13873
13874 ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
13875 ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
13876
13877 if (TrueResult.Kind == IK_NotICE)
13878 return TrueResult;
13879 if (FalseResult.Kind == IK_NotICE)
13880 return FalseResult;
13881 if (CondResult.Kind == IK_ICEIfUnevaluated)
13882 return CondResult;
13883 if (TrueResult.Kind == IK_ICE && FalseResult.Kind == IK_ICE)
13884 return NoDiag();
13885 // Rare case where the diagnostics depend on which side is evaluated
13886 // Note that if we get here, CondResult is 0, and at least one of
13887 // TrueResult and FalseResult is non-zero.
13888 if (Exp->getCond()->EvaluateKnownConstInt(Ctx) == 0)
13889 return FalseResult;
13890 return TrueResult;
13891 }
13892 case Expr::CXXDefaultArgExprClass:
13893 return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx);
13894 case Expr::CXXDefaultInitExprClass:
13895 return CheckICE(cast<CXXDefaultInitExpr>(E)->getExpr(), Ctx);
13896 case Expr::ChooseExprClass: {
13897 return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(), Ctx);
13898 }
13899 case Expr::BuiltinBitCastExprClass: {
13900 if (!checkBitCastConstexprEligibility(nullptr, Ctx, cast<CastExpr>(E)))
13901 return ICEDiag(IK_NotICE, E->getBeginLoc());
13902 return CheckICE(cast<CastExpr>(E)->getSubExpr(), Ctx);
13903 }
13904 }
13905
13906 llvm_unreachable("Invalid StmtClass!")::llvm::llvm_unreachable_internal("Invalid StmtClass!", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13906)
;
13907}
13908
13909/// Evaluate an expression as a C++11 integral constant expression.
13910static bool EvaluateCPlusPlus11IntegralConstantExpr(const ASTContext &Ctx,
13911 const Expr *E,
13912 llvm::APSInt *Value,
13913 SourceLocation *Loc) {
13914 if (!E->getType()->isIntegralOrUnscopedEnumerationType()) {
13915 if (Loc) *Loc = E->getExprLoc();
13916 return false;
13917 }
13918
13919 APValue Result;
13920 if (!E->isCXX11ConstantExpr(Ctx, &Result, Loc))
13921 return false;
13922
13923 if (!Result.isInt()) {
13924 if (Loc) *Loc = E->getExprLoc();
13925 return false;
13926 }
13927
13928 if (Value) *Value = Result.getInt();
13929 return true;
13930}
13931
13932bool Expr::isIntegerConstantExpr(const ASTContext &Ctx,
13933 SourceLocation *Loc) const {
13934 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13935, __PRETTY_FUNCTION__))
13935 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13935, __PRETTY_FUNCTION__))
;
13936
13937 if (Ctx.getLangOpts().CPlusPlus11)
13938 return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, nullptr, Loc);
13939
13940 ICEDiag D = CheckICE(this, Ctx);
13941 if (D.Kind != IK_ICE) {
13942 if (Loc) *Loc = D.Loc;
13943 return false;
13944 }
13945 return true;
13946}
13947
13948bool Expr::isIntegerConstantExpr(llvm::APSInt &Value, const ASTContext &Ctx,
13949 SourceLocation *Loc, bool isEvaluated) const {
13950 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13951, __PRETTY_FUNCTION__))
13951 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13951, __PRETTY_FUNCTION__))
;
13952
13953 if (Ctx.getLangOpts().CPlusPlus11)
13954 return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, &Value, Loc);
13955
13956 if (!isIntegerConstantExpr(Ctx, Loc))
13957 return false;
13958
13959 // The only possible side-effects here are due to UB discovered in the
13960 // evaluation (for instance, INT_MAX + 1). In such a case, we are still
13961 // required to treat the expression as an ICE, so we produce the folded
13962 // value.
13963 EvalResult ExprResult;
13964 Expr::EvalStatus Status;
13965 EvalInfo Info(Ctx, Status, EvalInfo::EM_IgnoreSideEffects);
13966 Info.InConstantContext = true;
13967
13968 if (!::EvaluateAsInt(this, ExprResult, Ctx, SE_AllowSideEffects, Info))
13969 llvm_unreachable("ICE cannot be evaluated!")::llvm::llvm_unreachable_internal("ICE cannot be evaluated!",
"/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13969)
;
13970
13971 Value = ExprResult.Val.getInt();
13972 return true;
13973}
13974
13975bool Expr::isCXX98IntegralConstantExpr(const ASTContext &Ctx) const {
13976 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13977, __PRETTY_FUNCTION__))
13977 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13977, __PRETTY_FUNCTION__))
;
13978
13979 return CheckICE(this, Ctx).Kind == IK_ICE;
13980}
13981
13982bool Expr::isCXX11ConstantExpr(const ASTContext &Ctx, APValue *Result,
13983 SourceLocation *Loc) const {
13984 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13985, __PRETTY_FUNCTION__))
13985 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13985, __PRETTY_FUNCTION__))
;
13986
13987 // We support this checking in C++98 mode in order to diagnose compatibility
13988 // issues.
13989 assert(Ctx.getLangOpts().CPlusPlus)((Ctx.getLangOpts().CPlusPlus) ? static_cast<void> (0) :
__assert_fail ("Ctx.getLangOpts().CPlusPlus", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 13989, __PRETTY_FUNCTION__))
;
13990
13991 // Build evaluation settings.
13992 Expr::EvalStatus Status;
13993 SmallVector<PartialDiagnosticAt, 8> Diags;
13994 Status.Diag = &Diags;
13995 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
13996
13997 APValue Scratch;
13998 bool IsConstExpr =
13999 ::EvaluateAsRValue(Info, this, Result ? *Result : Scratch) &&
14000 // FIXME: We don't produce a diagnostic for this, but the callers that
14001 // call us on arbitrary full-expressions should generally not care.
14002 Info.discardCleanups() && !Status.HasSideEffects;
14003
14004 if (!Diags.empty()) {
14005 IsConstExpr = false;
14006 if (Loc) *Loc = Diags[0].first;
14007 } else if (!IsConstExpr) {
14008 // FIXME: This shouldn't happen.
14009 if (Loc) *Loc = getExprLoc();
14010 }
14011
14012 return IsConstExpr;
14013}
14014
14015bool Expr::EvaluateWithSubstitution(APValue &Value, ASTContext &Ctx,
14016 const FunctionDecl *Callee,
14017 ArrayRef<const Expr*> Args,
14018 const Expr *This) const {
14019 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 14020, __PRETTY_FUNCTION__))
14020 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 14020, __PRETTY_FUNCTION__))
;
14021
14022 Expr::EvalStatus Status;
14023 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpressionUnevaluated);
14024 Info.InConstantContext = true;
14025
14026 LValue ThisVal;
14027 const LValue *ThisPtr = nullptr;
14028 if (This) {
14029#ifndef NDEBUG
14030 auto *MD = dyn_cast<CXXMethodDecl>(Callee);
14031 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 14031, __PRETTY_FUNCTION__))
;
14032 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 14032, __PRETTY_FUNCTION__))
;
14033#endif
14034 if (EvaluateObjectArgument(Info, This, ThisVal))
14035 ThisPtr = &ThisVal;
14036 if (Info.EvalStatus.HasSideEffects)
14037 return false;
14038 }
14039
14040 ArgVector ArgValues(Args.size());
14041 for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
14042 I != E; ++I) {
14043 if ((*I)->isValueDependent() ||
14044 !Evaluate(ArgValues[I - Args.begin()], Info, *I))
14045 // If evaluation fails, throw away the argument entirely.
14046 ArgValues[I - Args.begin()] = APValue();
14047 if (Info.EvalStatus.HasSideEffects)
14048 return false;
14049 }
14050
14051 // Build fake call to Callee.
14052 CallStackFrame Frame(Info, Callee->getLocation(), Callee, ThisPtr,
14053 ArgValues.data());
14054 return Evaluate(Value, Info, this) && Info.discardCleanups() &&
14055 !Info.EvalStatus.HasSideEffects;
14056}
14057
14058bool Expr::isPotentialConstantExpr(const FunctionDecl *FD,
14059 SmallVectorImpl<
14060 PartialDiagnosticAt> &Diags) {
14061 // FIXME: It would be useful to check constexpr function templates, but at the
14062 // moment the constant expression evaluator cannot cope with the non-rigorous
14063 // ASTs which we build for dependent expressions.
14064 if (FD->isDependentContext())
14065 return true;
14066
14067 Expr::EvalStatus Status;
14068 Status.Diag = &Diags;
14069
14070 EvalInfo Info(FD->getASTContext(), Status, EvalInfo::EM_ConstantExpression);
14071 Info.InConstantContext = true;
14072 Info.CheckingPotentialConstantExpression = true;
14073
14074 // The constexpr VM attempts to compile all methods to bytecode here.
14075 if (Info.EnableNewConstInterp) {
14076 auto &InterpCtx = Info.Ctx.getInterpContext();
14077 switch (InterpCtx.isPotentialConstantExpr(Info, FD)) {
14078 case interp::InterpResult::Success:
14079 case interp::InterpResult::Fail:
14080 return Diags.empty();
14081 case interp::InterpResult::Bail:
14082 break;
14083 }
14084 }
14085
14086 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
14087 const CXXRecordDecl *RD = MD ? MD->getParent()->getCanonicalDecl() : nullptr;
14088
14089 // Fabricate an arbitrary expression on the stack and pretend that it
14090 // is a temporary being used as the 'this' pointer.
14091 LValue This;
14092 ImplicitValueInitExpr VIE(RD ? Info.Ctx.getRecordType(RD) : Info.Ctx.IntTy);
14093 This.set({&VIE, Info.CurrentCall->Index});
14094
14095 ArrayRef<const Expr*> Args;
14096
14097 APValue Scratch;
14098 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) {
14099 // Evaluate the call as a constant initializer, to allow the construction
14100 // of objects of non-literal types.
14101 Info.setEvaluatingDecl(This.getLValueBase(), Scratch);
14102 HandleConstructorCall(&VIE, This, Args, CD, Info, Scratch);
14103 } else {
14104 SourceLocation Loc = FD->getLocation();
14105 HandleFunctionCall(Loc, FD, (MD && MD->isInstance()) ? &This : nullptr,
14106 Args, FD->getBody(), Info, Scratch, nullptr);
14107 }
14108
14109 return Diags.empty();
14110}
14111
14112bool Expr::isPotentialConstantExprUnevaluated(Expr *E,
14113 const FunctionDecl *FD,
14114 SmallVectorImpl<
14115 PartialDiagnosticAt> &Diags) {
14116 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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 14117, __PRETTY_FUNCTION__))
14117 "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-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 14117, __PRETTY_FUNCTION__))
;
14118
14119 Expr::EvalStatus Status;
14120 Status.Diag = &Diags;
14121
14122 EvalInfo Info(FD->getASTContext(), Status,
14123 EvalInfo::EM_ConstantExpressionUnevaluated);
14124 Info.InConstantContext = true;
14125 Info.CheckingPotentialConstantExpression = true;
14126
14127 // Fabricate a call stack frame to give the arguments a plausible cover story.
14128 ArrayRef<const Expr*> Args;
14129 ArgVector ArgValues(0);
14130 bool Success = EvaluateArgs(Args, ArgValues, Info, FD);
14131 (void)Success;
14132 assert(Success &&((Success && "Failed to set up arguments for potential constant evaluation"
) ? static_cast<void> (0) : __assert_fail ("Success && \"Failed to set up arguments for potential constant evaluation\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 14133, __PRETTY_FUNCTION__))
14133 "Failed to set up arguments for potential constant evaluation")((Success && "Failed to set up arguments for potential constant evaluation"
) ? static_cast<void> (0) : __assert_fail ("Success && \"Failed to set up arguments for potential constant evaluation\""
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/AST/ExprConstant.cpp"
, 14133, __PRETTY_FUNCTION__))
;
14134 CallStackFrame Frame(Info, SourceLocation(), FD, nullptr, ArgValues.data());
14135
14136 APValue ResultScratch;
14137 Evaluate(ResultScratch, Info, E);
14138 return Diags.empty();
14139}
14140
14141bool Expr::tryEvaluateObjectSize(uint64_t &Result, ASTContext &Ctx,
14142 unsigned Type) const {
14143 if (!getType()->isPointerType())
14144 return false;
14145
14146 Expr::EvalStatus Status;
14147 EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
14148 return tryEvaluateBuiltinObjectSize(this, Type, Info, Result);
14149}