}
namespace {
+ /// A dynamically-allocated heap object.
+ struct DynAlloc {
+ /// The value of this heap-allocated object.
+ APValue Value;
+ /// The allocating expression; used for diagnostics. Either a CXXNewExpr
+ /// or a CallExpr (the latter is for direct calls to operator new inside
+ /// std::allocator<T>::allocate).
+ const Expr *AllocExpr = nullptr;
+
+ enum Kind {
+ New,
+ ArrayNew,
+ StdAllocator
+ };
+
+ /// Get the kind of the allocation. This must match between allocation
+ /// and deallocation.
+ Kind getKind() const {
+ if (auto *NE = dyn_cast<CXXNewExpr>(AllocExpr))
+ return NE->isArray() ? ArrayNew : New;
+ assert(isa<CallExpr>(AllocExpr));
+ return StdAllocator;
+ }
+ };
+
+ struct DynAllocOrder {
+ bool operator()(DynamicAllocLValue L, DynamicAllocLValue R) const {
+ return L.getIndex() < R.getIndex();
+ }
+ };
+
/// EvalInfo - This is a private struct used by the evaluator to capture
/// information about a subexpression as it is folded. It retains information
/// about the AST context, but also maintains information about the folded
llvm::DenseMap<ObjectUnderConstruction, ConstructionPhase>
ObjectsUnderConstruction;
- /// A dynamically-allocated heap object.
- struct DynAlloc {
- /// The value of this heap-allocated object.
- APValue Value;
- /// The allocating expression; used for diagnostics.
- const Expr *AllocExpr = nullptr;
- };
-
- struct DynAllocOrder {
- bool operator()(DynamicAllocLValue L, DynamicAllocLValue R) const {
- return L.getIndex() < R.getIndex();
- }
- };
-
/// Current heap allocations, along with the location where each was
/// allocated. We use std::map here because we need stable addresses
/// for the stored APValues.
return Result;
}
+ /// Information about a stack frame for std::allocator<T>::[de]allocate.
+ struct StdAllocatorCaller {
+ unsigned FrameIndex;
+ QualType ElemType;
+ explicit operator bool() const { return FrameIndex != 0; };
+ };
+
+ StdAllocatorCaller getStdAllocatorCaller(StringRef FnName) const {
+ for (const CallStackFrame *Call = CurrentCall; Call != &BottomFrame;
+ Call = Call->Caller) {
+ const auto *MD = dyn_cast_or_null<CXXMethodDecl>(Call->Callee);
+ if (!MD)
+ continue;
+ const IdentifierInfo *FnII = MD->getIdentifier();
+ if (!FnII || !FnII->isStr(FnName))
+ continue;
+
+ const auto *CTSD =
+ dyn_cast<ClassTemplateSpecializationDecl>(MD->getParent());
+ if (!CTSD)
+ continue;
+
+ const IdentifierInfo *ClassII = CTSD->getIdentifier();
+ const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
+ if (CTSD->isInStdNamespace() && ClassII &&
+ ClassII->isStr("allocator") && TAL.size() >= 1 &&
+ TAL[0].getKind() == TemplateArgument::Type)
+ return {Call->Index, TAL[0].getAsType()};
+ }
+
+ return {};
+ }
+
void performLifetimeExtension() {
// Disable the cleanups for lifetime-extended temporaries.
CleanupStack.erase(
IsNullPtr = false;
}
- void setNull(QualType PointerTy, uint64_t TargetVal) {
+ void setNull(ASTContext &Ctx, QualType PointerTy) {
Base = (Expr *)nullptr;
- Offset = CharUnits::fromQuantity(TargetVal);
+ Offset =
+ CharUnits::fromQuantity(Ctx.getTargetNullPointerValue(PointerTy));
InvalidBase = false;
Designator = SubobjectDesignator(PointerTy->getPointeeType());
IsNullPtr = true;
set(B, true);
}
+ std::string toString(ASTContext &Ctx, QualType T) const {
+ APValue Printable;
+ moveInto(Printable);
+ return Printable.getAsString(Ctx, T);
+ }
+
private:
// Check that this LValue is not based on a null pointer. If it is, produce
// a diagnostic and mark the designator as invalid.
Info.Note(E->getExprLoc(), diag::note_constexpr_temporary_here);
else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
// FIXME: Produce a note for dangling pointers too.
- if (Optional<EvalInfo::DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA))
+ if (Optional<DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA))
Info.Note((*Alloc)->AllocExpr->getExprLoc(),
diag::note_constexpr_dynamic_alloc_here);
}
if (!evaluateVarDeclInit(Info, E, VD, Frame, BaseVal, &LVal))
return CompleteObject();
} else if (DynamicAllocLValue DA = LVal.Base.dyn_cast<DynamicAllocLValue>()) {
- Optional<EvalInfo::DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA);
+ Optional<DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA);
if (!Alloc) {
Info.FFDiag(E, diag::note_constexpr_access_deleted_object) << AK;
return CompleteObject();
if (!E->isGLValue()) {
// The value of a failed cast to pointer type is the null pointer value
// of the required result type.
- auto TargetVal = Info.Ctx.getTargetNullPointerValue(E->getType());
- Ptr.setNull(E->getType(), TargetVal);
+ Ptr.setNull(Info.Ctx, E->getType());
return true;
}
return HandleDestructionImpl(Info, Loc, LV, Value, T);
}
+/// Perform a call to 'perator new' or to `__builtin_operator_new'.
+static bool HandleOperatorNewCall(EvalInfo &Info, const CallExpr *E,
+ LValue &Result) {
+ if (Info.checkingPotentialConstantExpression() ||
+ Info.SpeculativeEvaluationDepth)
+ return false;
+
+ // This is permitted only within a call to std::allocator<T>::allocate.
+ auto Caller = Info.getStdAllocatorCaller("allocate");
+ if (!Caller) {
+ Info.FFDiag(E->getExprLoc(), Info.getLangOpts().CPlusPlus2a
+ ? diag::note_constexpr_new_untyped
+ : diag::note_constexpr_new);
+ return false;
+ }
+
+ QualType ElemType = Caller.ElemType;
+ if (ElemType->isIncompleteType() || ElemType->isFunctionType()) {
+ Info.FFDiag(E->getExprLoc(),
+ diag::note_constexpr_new_not_complete_object_type)
+ << (ElemType->isIncompleteType() ? 0 : 1) << ElemType;
+ return false;
+ }
+
+ APSInt ByteSize;
+ if (!EvaluateInteger(E->getArg(0), ByteSize, Info))
+ return false;
+ bool IsNothrow = false;
+ for (unsigned I = 1, N = E->getNumArgs(); I != N; ++I) {
+ EvaluateIgnoredValue(Info, E->getArg(I));
+ IsNothrow |= E->getType()->isNothrowT();
+ }
+
+ CharUnits ElemSize;
+ if (!HandleSizeof(Info, E->getExprLoc(), ElemType, ElemSize))
+ return false;
+ APInt Size, Remainder;
+ APInt ElemSizeAP(ByteSize.getBitWidth(), ElemSize.getQuantity());
+ APInt::udivrem(ByteSize, ElemSizeAP, Size, Remainder);
+ if (Remainder != 0) {
+ // This likely indicates a bug in the implementation of 'std::allocator'.
+ Info.FFDiag(E->getExprLoc(), diag::note_constexpr_operator_new_bad_size)
+ << ByteSize << APSInt(ElemSizeAP, true) << ElemType;
+ return false;
+ }
+
+ if (ByteSize.getActiveBits() > ConstantArrayType::getMaxSizeBits(Info.Ctx)) {
+ if (IsNothrow) {
+ Result.setNull(Info.Ctx, E->getType());
+ return true;
+ }
+
+ Info.FFDiag(E, diag::note_constexpr_new_too_large) << APSInt(Size, true);
+ return false;
+ }
+
+ QualType AllocType =
+ Info.Ctx.getConstantArrayType(ElemType, Size, ArrayType::Normal, 0);
+ APValue *Val = Info.createHeapAlloc(E, AllocType, Result);
+ *Val = APValue(APValue::UninitArray(), 0, Size.getZExtValue());
+ Result.addArray(Info, E, cast<ConstantArrayType>(AllocType));
+ return true;
+}
+
+static bool hasVirtualDestructor(QualType T) {
+ if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
+ if (CXXDestructorDecl *DD = RD->getDestructor())
+ return DD->isVirtual();
+ return false;
+}
+
+/// Check that the given object is a suitable pointer to a heap allocation that
+/// still exists and is of the right kind for the purpose of a deletion.
+///
+/// On success, returns the heap allocation to deallocate. On failure, produces
+/// a diagnostic and returns None.
+static Optional<DynAlloc *> CheckDeleteKind(EvalInfo &Info, const Expr *E,
+ const LValue &Pointer,
+ DynAlloc::Kind DeallocKind) {
+ auto PointerAsString = [&] {
+ return Pointer.toString(Info.Ctx, Info.Ctx.VoidPtrTy);
+ };
+
+ DynamicAllocLValue DA = Pointer.Base.dyn_cast<DynamicAllocLValue>();
+ if (!DA) {
+ Info.FFDiag(E, diag::note_constexpr_delete_not_heap_alloc)
+ << PointerAsString();
+ if (Pointer.Base)
+ NoteLValueLocation(Info, Pointer.Base);
+ return None;
+ }
+
+ Optional<DynAlloc *> Alloc = Info.lookupDynamicAlloc(DA);
+ if (!Alloc) {
+ Info.FFDiag(E, diag::note_constexpr_double_delete);
+ return None;
+ }
+
+ QualType AllocType = Pointer.Base.getDynamicAllocType();
+ if (DeallocKind != (*Alloc)->getKind()) {
+ Info.FFDiag(E, diag::note_constexpr_new_delete_mismatch)
+ << DeallocKind << (*Alloc)->getKind() << AllocType;
+ NoteLValueLocation(Info, Pointer.Base);
+ return None;
+ }
+
+ bool Subobject = false;
+ if (DeallocKind == DynAlloc::New) {
+ Subobject = Pointer.Designator.MostDerivedPathLength != 0 ||
+ Pointer.Designator.isOnePastTheEnd();
+ } else {
+ Subobject = Pointer.Designator.Entries.size() != 1 ||
+ Pointer.Designator.Entries[0].getAsArrayIndex() != 0;
+ }
+ if (Subobject) {
+ Info.FFDiag(E, diag::note_constexpr_delete_subobject)
+ << PointerAsString() << Pointer.Designator.isOnePastTheEnd();
+ return None;
+ }
+
+ return Alloc;
+}
+
+// Perform a call to 'operator delete' or '__builtin_operator_delete'.
+bool HandleOperatorDeleteCall(EvalInfo &Info, const CallExpr *E) {
+ if (Info.checkingPotentialConstantExpression() ||
+ Info.SpeculativeEvaluationDepth)
+ return false;
+
+ // This is permitted only within a call to std::allocator<T>::deallocate.
+ if (!Info.getStdAllocatorCaller("deallocate")) {
+ Info.FFDiag(E->getExprLoc());
+ return true;
+ }
+
+ LValue Pointer;
+ if (!EvaluatePointer(E->getArg(0), Pointer, Info))
+ return false;
+ for (unsigned I = 1, N = E->getNumArgs(); I != N; ++I)
+ EvaluateIgnoredValue(Info, E->getArg(I));
+
+ if (Pointer.Designator.Invalid)
+ return false;
+
+ // Deleting a null pointer has no effect.
+ if (Pointer.isNullPointer())
+ return true;
+
+ if (!CheckDeleteKind(Info, E, Pointer, DynAlloc::StdAllocator))
+ return false;
+
+ Info.HeapAllocs.erase(Pointer.Base.get<DynamicAllocLValue>());
+ return true;
+}
+
//===----------------------------------------------------------------------===//
// Generic Evaluation
//===----------------------------------------------------------------------===//
FD = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
} else
FD = LambdaCallOp;
+ } else if (FD->isReplaceableGlobalAllocationFunction()) {
+ if (FD->getDeclName().getCXXOverloadedOperator() == OO_New ||
+ FD->getDeclName().getCXXOverloadedOperator() == OO_Array_New) {
+ LValue Ptr;
+ if (!HandleOperatorNewCall(Info, E, Ptr))
+ return false;
+ Ptr.moveInto(Result);
+ return true;
+ } else {
+ return HandleOperatorDeleteCall(Info, E);
+ }
}
} else
return Error(E);
return true;
}
bool ZeroInitialization(const Expr *E) {
- auto TargetVal = Info.Ctx.getTargetNullPointerValue(E->getType());
- Result.setNull(E->getType(), TargetVal);
+ Result.setNull(Info.Ctx, E->getType());
return true;
}
// permitted in constant expressions in C++11. Bitcasts from cv void* are
// also static_casts, but we disallow them as a resolution to DR1312.
if (!E->getType()->isVoidPointerType()) {
- Result.Designator.setInvalid();
- if (SubExpr->getType()->isVoidPointerType())
- CCEDiag(E, diag::note_constexpr_invalid_cast)
- << 3 << SubExpr->getType();
- else
- CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
+ if (!Result.InvalidBase && !Result.Designator.Invalid &&
+ !Result.IsNullPtr &&
+ Info.Ctx.hasSameUnqualifiedType(Result.Designator.getType(Info.Ctx),
+ E->getType()->getPointeeType()) &&
+ Info.getStdAllocatorCaller("allocate")) {
+ // Inside a call to std::allocator::allocate and friends, we permit
+ // casting from void* back to cv1 T* for a pointer that points to a
+ // cv2 T.
+ } else {
+ Result.Designator.setInvalid();
+ if (SubExpr->getType()->isVoidPointerType())
+ CCEDiag(E, diag::note_constexpr_invalid_cast)
+ << 3 << SubExpr->getType();
+ else
+ CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
+ }
}
if (E->getCastKind() == CK_AddressSpaceConversion && Result.IsNullPtr)
ZeroInitialization(E);
return true;
}
+ case Builtin::BI__builtin_operator_new:
+ return HandleOperatorNewCall(Info, E, Result);
case Builtin::BI__builtin_launder:
return evaluatePointer(E->getArg(0), Result);
case Builtin::BIstrchr:
}
default:
- return visitNonBuiltinCallExpr(E);
+ break;
}
+
+ return visitNonBuiltinCallExpr(E);
}
static bool EvaluateArrayNewInitList(EvalInfo &Info, LValue &This,
bool VisitCallExpr(const CallExpr *E) {
switch (E->getBuiltinCallee()) {
- default:
- return ExprEvaluatorBaseTy::VisitCallExpr(E);
case Builtin::BI__assume:
case Builtin::BI__builtin_assume:
// The argument is not evaluated!
return true;
+
+ case Builtin::BI__builtin_operator_delete:
+ return HandleOperatorDeleteCall(Info, E);
+
+ default:
+ break;
}
+
+ return ExprEvaluatorBaseTy::VisitCallExpr(E);
}
bool VisitCXXDeleteExpr(const CXXDeleteExpr *E);
};
} // end anonymous namespace
-static bool hasVirtualDestructor(QualType T) {
- if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
- if (CXXDestructorDecl *DD = RD->getDestructor())
- return DD->isVirtual();
- return false;
-}
-
bool VoidExprEvaluator::VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
// We cannot speculatively evaluate a delete expression.
if (Info.SpeculativeEvaluationDepth)
return true;
}
- auto PointerAsString = [&] {
- APValue Printable;
- Pointer.moveInto(Printable);
- return Printable.getAsString(Info.Ctx, Arg->getType());
- };
-
- DynamicAllocLValue DA = Pointer.Base.dyn_cast<DynamicAllocLValue>();
- if (!DA) {
- Info.FFDiag(E, diag::note_constexpr_delete_not_heap_alloc)
- << PointerAsString();
- if (Pointer.Base)
- NoteLValueLocation(Info, Pointer.Base);
+ Optional<DynAlloc *> Alloc = CheckDeleteKind(
+ Info, E, Pointer, E->isArrayForm() ? DynAlloc::ArrayNew : DynAlloc::New);
+ if (!Alloc)
return false;
- }
QualType AllocType = Pointer.Base.getDynamicAllocType();
- Optional<EvalInfo::DynAlloc*> Alloc = Info.lookupDynamicAlloc(DA);
- if (!Alloc) {
- Info.FFDiag(E, diag::note_constexpr_double_delete);
- return false;
- }
-
- if (E->isArrayForm() != AllocType->isConstantArrayType()) {
- Info.FFDiag(E, diag::note_constexpr_new_delete_mismatch)
- << E->isArrayForm() << AllocType;
- NoteLValueLocation(Info, Pointer.Base);
- return false;
- }
-
- bool Subobject = false;
- if (E->isArrayForm()) {
- Subobject = Pointer.Designator.Entries.size() != 1 ||
- Pointer.Designator.Entries[0].getAsArrayIndex() != 0;
- } else {
- Subobject = Pointer.Designator.MostDerivedPathLength != 0 ||
- Pointer.Designator.isOnePastTheEnd();
- }
- if (Subobject) {
- Info.FFDiag(E, diag::note_constexpr_delete_subobject)
- << PointerAsString() << Pointer.Designator.isOnePastTheEnd();
- return false;
- }
-
// For the non-array case, the designator must be empty if the static type
// does not have a virtual destructor.
if (!E->isArrayForm() && Pointer.Designator.Entries.size() != 0 &&
(*Alloc)->Value, AllocType))
return false;
- if (!Info.HeapAllocs.erase(DA)) {
+ if (!Info.HeapAllocs.erase(Pointer.Base.dyn_cast<DynamicAllocLValue>())) {
// The element was already erased. This means the destructor call also
// deleted the object.
// FIXME: This probably results in undefined behavior before we get this
projects / clang / commitdiff