diff options
Diffstat (limited to 'clang/lib/AST/ExprConstant.cpp')
| -rw-r--r-- | clang/lib/AST/ExprConstant.cpp | 549 |
1 files changed, 448 insertions, 101 deletions
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp index 4e371d7ca95..fbec3ae582b 100644 --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -134,6 +134,14 @@ namespace { return E.getAsBaseOrMember().getInt(); } + /// Given an expression, determine the type used to store the result of + /// evaluating that expression. + static QualType getStorageType(ASTContext &Ctx, Expr *E) { + if (E->isRValue()) + return E->getType(); + return Ctx.getLValueReferenceType(E->getType()); + } + /// Given a CallExpr, try to get the alloc_size attribute. May return null. static const AllocSizeAttr *getAllocSizeAttr(const CallExpr *CE) { const FunctionDecl *Callee = CE->getDirectCallee(); @@ -572,7 +580,13 @@ namespace { return 0; } - APValue &createTemporary(const void *Key, bool IsLifetimeExtended); + /// Allocate storage for an object of type T in this stack frame. + /// Populates LV with a handle to the created object. Key identifies + /// the temporary within the stack frame, and must not be reused without + /// bumping the temporary version number. + template<typename KeyT> + APValue &createTemporary(const KeyT *Key, QualType T, + bool IsLifetimeExtended, LValue &LV); void describe(llvm::raw_ostream &OS) override; @@ -596,18 +610,33 @@ namespace { CallStackFrame &Frame; const LValue *OldThis; }; +} + +static bool HandleDestructorCall(EvalInfo &Info, APValue::LValueBase LVBase, + APValue &Value, QualType T); +namespace { /// A cleanup, and a flag indicating whether it is lifetime-extended. class Cleanup { llvm::PointerIntPair<APValue*, 1, bool> Value; + APValue::LValueBase Base; + QualType T; public: - Cleanup(APValue *Val, bool IsLifetimeExtended) - : Value(Val, IsLifetimeExtended) {} + Cleanup(APValue *Val, APValue::LValueBase Base, QualType T, + bool IsLifetimeExtended) + : Value(Val, IsLifetimeExtended), Base(Base), T(T) {} bool isLifetimeExtended() const { return Value.getInt(); } - void endLifetime() { + bool endLifetime(EvalInfo &Info, bool RunDestructors) { + if (RunDestructors && T.isDestructedType()) + return HandleDestructorCall(Info, Base, *Value.getPointer(), T); *Value.getPointer() = APValue(); + return true; + } + + bool hasSideEffect() { + return T.isDestructedType(); } }; @@ -623,7 +652,13 @@ namespace { return llvm::hash_combine(Obj.Base, Obj.Path); } }; - enum class ConstructionPhase { None, Bases, AfterBases }; + enum class ConstructionPhase { + None, + Bases, + AfterBases, + Destroying, + DestroyingBases + }; } namespace llvm { @@ -728,9 +763,29 @@ namespace { } }; + struct EvaluatingDestructorRAII { + EvalInfo &EI; + ObjectUnderConstruction Object; + EvaluatingDestructorRAII(EvalInfo &EI, ObjectUnderConstruction Object) + : EI(EI), Object(Object) { + bool DidInsert = EI.ObjectsUnderConstruction + .insert({Object, ConstructionPhase::Destroying}) + .second; + (void)DidInsert; + assert(DidInsert && "destroyed object multiple times"); + } + void startedDestroyingBases() { + EI.ObjectsUnderConstruction[Object] = + ConstructionPhase::DestroyingBases; + } + ~EvaluatingDestructorRAII() { + EI.ObjectsUnderConstruction.erase(Object); + } + }; + ConstructionPhase - isEvaluatingConstructor(APValue::LValueBase Base, - ArrayRef<APValue::LValuePathEntry> Path) { + isEvaluatingCtorDtor(APValue::LValueBase Base, + ArrayRef<APValue::LValuePathEntry> Path) { return ObjectsUnderConstruction.lookup({Base, Path}); } @@ -811,6 +866,10 @@ namespace { HasFoldFailureDiagnostic(false), InConstantContext(false), EvalMode(Mode) {} + ~EvalInfo() { + discardCleanups(); + } + void setEvaluatingDecl(APValue::LValueBase Base, APValue &Value) { EvaluatingDecl = Base; EvaluatingDeclValue = &Value; @@ -858,6 +917,25 @@ namespace { return true; } + void performLifetimeExtension() { + // Disable the cleanups for lifetime-extended temporaries. + CleanupStack.erase( + std::remove_if(CleanupStack.begin(), CleanupStack.end(), + [](Cleanup &C) { return C.isLifetimeExtended(); }), + CleanupStack.end()); + } + + /// Throw away any remaining cleanups at the end of evaluation. If any + /// cleanups would have had a side-effect, note that as an unmodeled + /// side-effect and return false. Otherwise, return true. + bool discardCleanups() { + for (Cleanup &C : CleanupStack) + if (C.hasSideEffect()) + if (!noteSideEffect()) + return false; + return true; + } + private: interp::Frame *getCurrentFrame() override { return CurrentCall; } const interp::Frame *getBottomFrame() const override { return &BottomFrame; } @@ -1101,29 +1179,37 @@ namespace { // temporaries created in different iterations of a loop. Info.CurrentCall->pushTempVersion(); } + bool destroy(bool RunDestructors = true) { + bool OK = cleanup(Info, RunDestructors, OldStackSize); + OldStackSize = -1U; + return OK; + } ~ScopeRAII() { + if (OldStackSize != -1U) + destroy(false); // Body moved to a static method to encourage the compiler to inline away // instances of this class. - cleanup(Info, OldStackSize); Info.CurrentCall->popTempVersion(); } private: - static void cleanup(EvalInfo &Info, unsigned OldStackSize) { - unsigned NewEnd = OldStackSize; - for (unsigned I = OldStackSize, N = Info.CleanupStack.size(); - I != N; ++I) { - if (IsFullExpression && Info.CleanupStack[I].isLifetimeExtended()) { - // Full-expression cleanup of a lifetime-extended temporary: nothing - // to do, just move this cleanup to the right place in the stack. - std::swap(Info.CleanupStack[I], Info.CleanupStack[NewEnd]); - ++NewEnd; - } else { - // End the lifetime of the object. - Info.CleanupStack[I].endLifetime(); + static bool cleanup(EvalInfo &Info, bool RunDestructors, unsigned OldStackSize) { + // Run all cleanups for a block scope, and non-lifetime-extended cleanups + // for a full-expression scope. + for (unsigned I = Info.CleanupStack.size(); I > OldStackSize; --I) { + if (!(IsFullExpression && Info.CleanupStack[I-1].isLifetimeExtended())) { + if (!Info.CleanupStack[I-1].endLifetime(Info, RunDestructors)) + return false; } } - Info.CleanupStack.erase(Info.CleanupStack.begin() + NewEnd, - Info.CleanupStack.end()); + + // Compact lifetime-extended cleanups. + auto NewEnd = Info.CleanupStack.begin() + OldStackSize; + if (IsFullExpression) + NewEnd = + std::remove_if(NewEnd, Info.CleanupStack.end(), + [](Cleanup &C) { return !C.isLifetimeExtended(); }); + Info.CleanupStack.erase(NewEnd, Info.CleanupStack.end()); + return true; } }; typedef ScopeRAII<false> BlockScopeRAII; @@ -1183,15 +1269,6 @@ CallStackFrame::~CallStackFrame() { Info.CurrentCall = Caller; } -APValue &CallStackFrame::createTemporary(const void *Key, - bool IsLifetimeExtended) { - unsigned Version = Info.CurrentCall->getTempVersion(); - APValue &Result = Temporaries[MapKeyTy(Key, Version)]; - assert(Result.isAbsent() && "temporary created multiple times"); - Info.CleanupStack.push_back(Cleanup(&Result, IsLifetimeExtended)); - return Result; -} - static bool isRead(AccessKinds AK) { return AK == AK_Read || AK == AK_ReadObjectRepresentation; } @@ -1544,15 +1621,6 @@ static bool EvaluateFixedPoint(const Expr *E, APFixedPoint &Result, // Misc utilities //===----------------------------------------------------------------------===// -/// A helper function to create a temporary and set an LValue. -template <class KeyTy> -static APValue &createTemporary(const KeyTy *Key, bool IsLifetimeExtended, - LValue &LV, CallStackFrame &Frame) { - LV.set({Key, Frame.Info.CurrentCall->Index, - Frame.Info.CurrentCall->getTempVersion()}); - return Frame.createTemporary(Key, IsLifetimeExtended); -} - /// Negate an APSInt in place, converting it to a signed form if necessary, and /// preserving its value (by extending by up to one bit as needed). static void negateAsSigned(APSInt &Int) { @@ -1563,6 +1631,18 @@ static void negateAsSigned(APSInt &Int) { Int = -Int; } +template<typename KeyT> +APValue &CallStackFrame::createTemporary(const KeyT *Key, QualType T, + bool IsLifetimeExtended, LValue &LV) { + unsigned Version = Info.CurrentCall->getTempVersion(); + APValue::LValueBase Base(Key, Index, Version); + LV.set(Base); + APValue &Result = Temporaries[MapKeyTy(Key, Version)]; + assert(Result.isAbsent() && "temporary created multiple times"); + Info.CleanupStack.push_back(Cleanup(&Result, Base, T, IsLifetimeExtended)); + return Result; +} + /// Produce a string describing the given constexpr call. void CallStackFrame::describe(raw_ostream &Out) { unsigned ArgIndex = 0; @@ -2858,12 +2938,12 @@ findSubobject(EvalInfo &Info, const Expr *E, const CompleteObject &Obj, return handler.failed(); } - // C++ [class.ctor]p5: + // C++ [class.ctor]p5, C++ [class.dtor]p5: // const and volatile semantics are not applied on an object under - // construction. + // {con,de}struction. if ((ObjType.isConstQualified() || ObjType.isVolatileQualified()) && ObjType->isRecordType() && - Info.isEvaluatingConstructor( + Info.isEvaluatingCtorDtor( Obj.Base, llvm::makeArrayRef(Sub.Entries.begin(), Sub.Entries.begin() + I)) != ConstructionPhase::None) { @@ -3938,7 +4018,8 @@ static bool EvaluateVarDecl(EvalInfo &Info, const VarDecl *VD) { return true; LValue Result; - APValue &Val = createTemporary(VD, true, Result, *Info.CurrentCall); + APValue &Val = + Info.CurrentCall->createTemporary(VD, VD->getType(), true, Result); const Expr *InitE = VD->getInit(); if (!InitE) { @@ -3980,7 +4061,9 @@ static bool EvaluateCond(EvalInfo &Info, const VarDecl *CondDecl, FullExpressionRAII Scope(Info); if (CondDecl && !EvaluateDecl(Info, CondDecl)) return false; - return EvaluateAsBooleanCondition(Cond, Result, Info); + if (!EvaluateAsBooleanCondition(Cond, Result, Info)) + return false; + return Scope.destroy(); } namespace { @@ -4016,7 +4099,12 @@ static EvalStmtResult EvaluateLoopBody(StmtResult &Result, EvalInfo &Info, const Stmt *Body, const SwitchCase *Case = nullptr) { BlockScopeRAII Scope(Info); - switch (EvalStmtResult ESR = EvaluateStmt(Result, Info, Body, Case)) { + + EvalStmtResult ESR = EvaluateStmt(Result, Info, Body, Case); + if (ESR != ESR_Failed && ESR != ESR_CaseNotFound && !Scope.destroy()) + ESR = ESR_Failed; + + switch (ESR) { case ESR_Break: return ESR_Succeeded; case ESR_Succeeded: @@ -4038,17 +4126,23 @@ static EvalStmtResult EvaluateSwitch(StmtResult &Result, EvalInfo &Info, // Evaluate the switch condition. APSInt Value; { - FullExpressionRAII Scope(Info); if (const Stmt *Init = SS->getInit()) { EvalStmtResult ESR = EvaluateStmt(Result, Info, Init); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && !Scope.destroy()) + ESR = ESR_Failed; return ESR; + } } + + FullExpressionRAII CondScope(Info); if (SS->getConditionVariable() && !EvaluateDecl(Info, SS->getConditionVariable())) return ESR_Failed; if (!EvaluateInteger(SS->getCond(), Value, Info)) return ESR_Failed; + if (!CondScope.destroy()) + return ESR_Failed; } // Find the switch case corresponding to the value of the condition. @@ -4072,10 +4166,14 @@ static EvalStmtResult EvaluateSwitch(StmtResult &Result, EvalInfo &Info, } if (!Found) - return ESR_Succeeded; + return Scope.destroy() ? ESR_Failed : ESR_Succeeded; // Search the switch body for the switch case and evaluate it from there. - switch (EvalStmtResult ESR = EvaluateStmt(Result, Info, SS->getBody(), Found)) { + EvalStmtResult ESR = EvaluateStmt(Result, Info, SS->getBody(), Found); + if (ESR != ESR_Failed && ESR != ESR_CaseNotFound && !Scope.destroy()) + return ESR_Failed; + + switch (ESR) { case ESR_Break: return ESR_Succeeded; case ESR_Succeeded: @@ -4143,9 +4241,19 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, // (The same is true for 'for' statements.) EvalStmtResult ESR = EvaluateStmt(Result, Info, IS->getThen(), Case); - if (ESR != ESR_CaseNotFound || !IS->getElse()) + if (ESR == ESR_Failed) + return ESR; + if (ESR != ESR_CaseNotFound) + return Scope.destroy() ? ESR : ESR_Failed; + if (!IS->getElse()) + return ESR_CaseNotFound; + + ESR = EvaluateStmt(Result, Info, IS->getElse(), Case); + if (ESR == ESR_Failed) return ESR; - return EvaluateStmt(Result, Info, IS->getElse(), Case); + if (ESR != ESR_CaseNotFound) + return Scope.destroy() ? ESR : ESR_Failed; + return ESR_CaseNotFound; } case Stmt::WhileStmtClass: { @@ -4176,7 +4284,7 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, return ESR; if (FS->getInc()) { FullExpressionRAII IncScope(Info); - if (!EvaluateIgnoredValue(Info, FS->getInc())) + if (!EvaluateIgnoredValue(Info, FS->getInc()) || !IncScope.destroy()) return ESR_Failed; } break; @@ -4209,8 +4317,10 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, if (const Expr *E = dyn_cast<Expr>(S)) { // Don't bother evaluating beyond an expression-statement which couldn't // be evaluated. + // FIXME: Do we need the FullExpressionRAII object here? + // VisitExprWithCleanups should create one when necessary. FullExpressionRAII Scope(Info); - if (!EvaluateIgnoredValue(Info, E)) + if (!EvaluateIgnoredValue(Info, E) || !Scope.destroy()) return ESR_Failed; return ESR_Succeeded; } @@ -4228,6 +4338,8 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, FullExpressionRAII Scope(Info); if (!EvaluateDecl(Info, D) && !Info.noteFailure()) return ESR_Failed; + if (!Scope.destroy()) + return ESR_Failed; } return ESR_Succeeded; } @@ -4240,7 +4352,7 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, ? EvaluateInPlace(Result.Value, Info, *Result.Slot, RetExpr) : Evaluate(Result.Value, Info, RetExpr))) return ESR_Failed; - return ESR_Returned; + return Scope.destroy() ? ESR_Returned : ESR_Failed; } case Stmt::CompoundStmtClass: { @@ -4251,10 +4363,15 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, EvalStmtResult ESR = EvaluateStmt(Result, Info, BI, Case); if (ESR == ESR_Succeeded) Case = nullptr; - else if (ESR != ESR_CaseNotFound) + else if (ESR != ESR_CaseNotFound) { + if (ESR != ESR_Failed && !Scope.destroy()) + return ESR_Failed; return ESR; + } } - return Case ? ESR_CaseNotFound : ESR_Succeeded; + if (Case) + return ESR_CaseNotFound; + return Scope.destroy() ? ESR_Succeeded : ESR_Failed; } case Stmt::IfStmtClass: { @@ -4264,8 +4381,11 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, BlockScopeRAII Scope(Info); if (const Stmt *Init = IS->getInit()) { EvalStmtResult ESR = EvaluateStmt(Result, Info, Init); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && !Scope.destroy()) + return ESR_Failed; return ESR; + } } bool Cond; if (!EvaluateCond(Info, IS->getConditionVariable(), IS->getCond(), Cond)) @@ -4273,10 +4393,13 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, if (const Stmt *SubStmt = Cond ? IS->getThen() : IS->getElse()) { EvalStmtResult ESR = EvaluateStmt(Result, Info, SubStmt); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && !Scope.destroy()) + return ESR_Failed; return ESR; + } } - return ESR_Succeeded; + return Scope.destroy() ? ESR_Succeeded : ESR_Failed; } case Stmt::WhileStmtClass: { @@ -4291,8 +4414,13 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, break; EvalStmtResult ESR = EvaluateLoopBody(Result, Info, WS->getBody()); - if (ESR != ESR_Continue) + if (ESR != ESR_Continue) { + if (ESR != ESR_Failed && !Scope.destroy()) + return ESR_Failed; return ESR; + } + if (!Scope.destroy()) + return ESR_Failed; } return ESR_Succeeded; } @@ -4307,7 +4435,8 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, Case = nullptr; FullExpressionRAII CondScope(Info); - if (!EvaluateAsBooleanCondition(DS->getCond(), Continue, Info)) + if (!EvaluateAsBooleanCondition(DS->getCond(), Continue, Info) || + !CondScope.destroy()) return ESR_Failed; } while (Continue); return ESR_Succeeded; @@ -4315,14 +4444,17 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, case Stmt::ForStmtClass: { const ForStmt *FS = cast<ForStmt>(S); - BlockScopeRAII Scope(Info); + BlockScopeRAII ForScope(Info); if (FS->getInit()) { EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit()); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && !ForScope.destroy()) + return ESR_Failed; return ESR; + } } while (true) { - BlockScopeRAII Scope(Info); + BlockScopeRAII IterScope(Info); bool Continue = true; if (FS->getCond() && !EvaluateCond(Info, FS->getConditionVariable(), FS->getCond(), Continue)) @@ -4331,16 +4463,22 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, break; EvalStmtResult ESR = EvaluateLoopBody(Result, Info, FS->getBody()); - if (ESR != ESR_Continue) + if (ESR != ESR_Continue) { + if (ESR != ESR_Failed && (!IterScope.destroy() || !ForScope.destroy())) + return ESR_Failed; return ESR; + } if (FS->getInc()) { FullExpressionRAII IncScope(Info); - if (!EvaluateIgnoredValue(Info, FS->getInc())) + if (!EvaluateIgnoredValue(Info, FS->getInc()) || !IncScope.destroy()) return ESR_Failed; } + + if (!IterScope.destroy()) + return ESR_Failed; } - return ESR_Succeeded; + return ForScope.destroy() ? ESR_Succeeded : ESR_Failed; } case Stmt::CXXForRangeStmtClass: { @@ -4350,22 +4488,34 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, // Evaluate the init-statement if present. if (FS->getInit()) { EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit()); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && !Scope.destroy()) + return ESR_Failed; return ESR; + } } // Initialize the __range variable. EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getRangeStmt()); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && !Scope.destroy()) + return ESR_Failed; return ESR; + } // Create the __begin and __end iterators. ESR = EvaluateStmt(Result, Info, FS->getBeginStmt()); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && !Scope.destroy()) + return ESR_Failed; return ESR; + } ESR = EvaluateStmt(Result, Info, FS->getEndStmt()); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && !Scope.destroy()) + return ESR_Failed; return ESR; + } while (true) { // Condition: __begin != __end. @@ -4381,20 +4531,29 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, // User's variable declaration, initialized by *__begin. BlockScopeRAII InnerScope(Info); ESR = EvaluateStmt(Result, Info, FS->getLoopVarStmt()); - if (ESR != ESR_Succeeded) + if (ESR != ESR_Succeeded) { + if (ESR != ESR_Failed && (!InnerScope.destroy() || !Scope.destroy())) + return ESR_Failed; return ESR; + } // Loop body. ESR = EvaluateLoopBody(Result, Info, FS->getBody()); - if (ESR != ESR_Continue) + if (ESR != ESR_Continue) { + if (ESR != ESR_Failed && (!InnerScope.destroy() || !Scope.destroy())) + return ESR_Failed; return ESR; + } // Increment: ++__begin if (!EvaluateIgnoredValue(Info, FS->getInc())) return ESR_Failed; + + if (!InnerScope.destroy()) + return ESR_Failed; } - return ESR_Succeeded; + return Scope.destroy() ? ESR_Succeeded : ESR_Failed; } case Stmt::SwitchStmtClass: @@ -4619,16 +4778,19 @@ static Optional<DynamicType> ComputeDynamicType(EvalInfo &Info, const Expr *E, ArrayRef<APValue::LValuePathEntry> Path = This.Designator.Entries; for (unsigned PathLength = This.Designator.MostDerivedPathLength; PathLength <= Path.size(); ++PathLength) { - switch (Info.isEvaluatingConstructor(This.getLValueBase(), - Path.slice(0, PathLength))) { + switch (Info.isEvaluatingCtorDtor(This.getLValueBase(), + Path.slice(0, PathLength))) { case ConstructionPhase::Bases: - // We're constructing a base class. This is not the dynamic type. + case ConstructionPhase::DestroyingBases: + // We're constructing or destroying a base class. This is not the dynamic + // type. break; case ConstructionPhase::None: case ConstructionPhase::AfterBases: - // We've finished constructing the base classes, so this is the dynamic - // type. + case ConstructionPhase::Destroying: + // We've finished constructing the base classes and not yet started + // destroying them again, so this is the dynamic type. return DynamicType{getBaseClassType(This.Designator, PathLength), PathLength}; } @@ -5117,7 +5279,8 @@ static bool HandleConstructorCall(const Expr *E, const LValue &This, CXXConstructorDecl::init_const_iterator I = Definition->init_begin(); { FullExpressionRAII InitScope(Info); - if (!EvaluateInPlace(Result, Info, This, (*I)->getInit())) + if (!EvaluateInPlace(Result, Info, This, (*I)->getInit()) || + !InitScope.destroy()) return false; } return EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed; @@ -5280,7 +5443,8 @@ static bool HandleConstructorCall(const Expr *E, const LValue &This, } return Success && - EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed; + EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed && + LifetimeExtendedScope.destroy(); } static bool HandleConstructorCall(const Expr *E, const LValue &This, @@ -5295,6 +5459,158 @@ static bool HandleConstructorCall(const Expr *E, const LValue &This, Info, Result); } +static bool HandleDestructorCallImpl(EvalInfo &Info, SourceLocation CallLoc, + const LValue &This, APValue &Value, + QualType T) { + // Invent an expression for location purposes. + // FIXME: We shouldn't need to do this. + OpaqueValueExpr LocE(CallLoc, Info.Ctx.IntTy, VK_RValue); + + // For arrays, destroy elements right-to-left. + if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(T)) { + uint64_t Size = CAT->getSize().getZExtValue(); + QualType ElemT = CAT->getElementType(); + + LValue ElemLV = This; + ElemLV.addArray(Info, &LocE, CAT); + if (!HandleLValueArrayAdjustment(Info, &LocE, ElemLV, ElemT, Size)) + return false; + + for (; Size != 0; --Size) { + APValue &Elem = Value.getArrayInitializedElt(Size - 1); + if (!HandleDestructorCallImpl(Info, CallLoc, ElemLV, Elem, ElemT) || + !HandleLValueArrayAdjustment(Info, &LocE, ElemLV, ElemT, -1)) + return false; + } + + // End the lifetime of this array now. + Value = APValue(); + return true; + } + + const CXXRecordDecl *RD = T->getAsCXXRecordDecl(); + if (!RD) { + if (T.isDestructedType()) { + Info.FFDiag(CallLoc, diag::note_constexpr_unsupported_destruction) << T; + return false; + } + + Value = APValue(); + return true; + } + + if (RD->getNumVBases()) { + Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD; + return false; + } + + const CXXDestructorDecl *DD = RD->getDestructor(); + if (!DD) { + // FIXME: Can we get here for a type with an irrelevant destructor? + Info.FFDiag(CallLoc); + return false; + } + + const FunctionDecl *Definition = nullptr; + const Stmt *Body = DD->getBody(Definition); + + if ((DD && DD->isTrivial()) || + (RD->isAnonymousStructOrUnion() && RD->isUnion())) { + // A trivial destructor just ends the lifetime of the object. Check for + // this case before checking for a body, because we might not bother + // building a body for a trivial destructor. Note that it doesn't matter + // whether the destructor is constexpr in this case; all trivial + // destructors are constexpr. + // + // If an anonymous union would be destroyed, some enclosing destructor must + // have been explicitly defined, and the anonymous union destruction should + // have no effect. + Value = APValue(); + return true; + } + + if (!Info.CheckCallLimit(CallLoc)) + return false; + + if (!CheckConstexprFunction(Info, CallLoc, DD, Definition, Body)) + return false; + + CallStackFrame Frame(Info, CallLoc, Definition, &This, nullptr); + + // We're now in the period of destruction of this object. + unsigned BasesLeft = RD->getNumBases(); + EvalInfo::EvaluatingDestructorRAII EvalObj( + Info, + ObjectUnderConstruction{This.getLValueBase(), This.Designator.Entries}); + + // FIXME: Creating an APValue just to hold a nonexistent return value is + // wasteful. + APValue RetVal; + StmtResult Ret = {RetVal, nullptr}; + if (EvaluateStmt(Ret, Info, Definition->getBody()) == ESR_Failed) + return false; + + // A union destructor does not implicitly destroy its members. + if (RD->isUnion()) + return true; + + const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD); + + // We don't have a good way to iterate fields in reverse, so collect all the + // fields first and then walk them backwards. + SmallVector<FieldDecl*, 16> Fields(RD->field_begin(), RD->field_end()); + for (const FieldDecl *FD : llvm::reverse(Fields)) { + if (FD->isUnnamedBitfield()) + continue; + + LValue Subobject = This; + if (!HandleLValueMember(Info, &LocE, Subobject, FD, &Layout)) + return false; + + APValue *SubobjectValue = &Value.getStructField(FD->getFieldIndex()); + if (!HandleDestructorCallImpl(Info, CallLoc, Subobject, *SubobjectValue, + FD->getType())) + return false; + } + + if (BasesLeft != 0) + EvalObj.startedDestroyingBases(); + + // Destroy base classes in reverse order. + for (const CXXBaseSpecifier &Base : llvm::reverse(RD->bases())) { + --BasesLeft; + + QualType BaseType = Base.getType(); + LValue Subobject = This; + if (!HandleLValueDirectBase(Info, &LocE, Subobject, RD, + BaseType->getAsCXXRecordDecl(), &Layout)) + return false; + + APValue *SubobjectValue = &Value.getStructBase(BasesLeft); + if (!HandleDestructorCallImpl(Info, CallLoc, Subobject, *SubobjectValue, + BaseType)) + return false; + } + assert(BasesLeft == 0 && "NumBases was wrong?"); + + // The period of destruction ends now. The object is gone. + Value = APValue(); + return true; +} + +static bool HandleDestructorCall(EvalInfo &Info, APValue::LValueBase LVBase, + APValue &Value, QualType T) { + SourceLocation Loc; + if (const ValueDecl *VD = LVBase.dyn_cast<const ValueDecl*>()) + Loc = VD->getLocation(); + else if (const Expr *E = LVBase.dyn_cast<const Expr*>()) + Loc = E->getExprLoc(); + + LValue LV; + LV.set({LVBase}); + return HandleDestructorCallImpl(Info, Loc, LV, Value, T); +} + //===----------------------------------------------------------------------===// // Generic Evaluation //===----------------------------------------------------------------------===// @@ -5905,10 +6221,10 @@ public: return StmtVisitorTy::Visit(E->getExpr()); } - // We cannot create any objects for which cleanups are required, so there is - // nothing to do here; all cleanups must come from unevaluated subexpressions. - bool VisitExprWithCleanups(const ExprWithCleanups *E) - { return StmtVisitorTy::Visit(E->getSubExpr()); } + bool VisitExprWithCleanups(const ExprWithCleanups *E) { + FullExpressionRAII Scope(Info); + return StmtVisitorTy::Visit(E->getSubExpr()) && Scope.destroy(); + } bool VisitCXXReinterpretCastExpr(const CXXReinterpretCastExpr *E) { CCEDiag(E, diag::note_constexpr_invalid_cast) << 0; @@ -5948,7 +6264,10 @@ public: bool VisitBinaryConditionalOperator(const BinaryConditionalOperator *E) { // Evaluate and cache the common expression. We treat it as a temporary, // even though it's not quite the same thing. - if (!Evaluate(Info.CurrentCall->createTemporary(E->getOpaqueValue(), false), + LValue CommonLV; + if (!Evaluate(Info.CurrentCall->createTemporary( + E->getOpaqueValue(), getStorageType(Info.Ctx, E->getOpaqueValue()), + false, CommonLV), Info, E->getCommon())) return false; @@ -6255,11 +6574,11 @@ public: if (Info.checkingForUndefinedBehavior()) return Error(E); - BlockScopeRAII Scope(Info); const CompoundStmt *CS = E->getSubStmt(); if (CS->body_empty()) return true; + BlockScopeRAII Scope(Info); for (CompoundStmt::const_body_iterator BI = CS->body_begin(), BE = CS->body_end(); /**/; ++BI) { @@ -6270,7 +6589,7 @@ public: diag::note_constexpr_stmt_expr_unsupported); return false; } - return this->Visit(FinalExpr); + return this->Visit(FinalExpr) && Scope.destroy(); } APValue ReturnValue; @@ -6619,8 +6938,8 @@ bool LValueExprEvaluator::VisitMaterializeTemporaryExpr( *Value = APValue(); Result.set(E); } else { - Value = &createTemporary(E, E->getStorageDuration() == SD_Automatic, Result, - *Info.CurrentCall); + Value = &Info.CurrentCall->createTemporary( + E, E->getType(), E->getStorageDuration() == SD_Automatic, Result); } QualType Type = Inner->getType(); @@ -7152,8 +7471,8 @@ bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) { if (!evaluateLValue(SubExpr, Result)) return false; } else { - APValue &Value = createTemporary(SubExpr, false, Result, - *Info.CurrentCall); + APValue &Value = Info.CurrentCall->createTemporary( + SubExpr, SubExpr->getType(), false, Result); if (!EvaluateInPlace(Value, Info, Result, SubExpr)) return false; } @@ -7705,6 +8024,12 @@ namespace { bool VisitCXXConstructExpr(const CXXConstructExpr *E, QualType T); bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E); + // Temporaries are registered when created, so we don't care about + // CXXBindTemporaryExpr. + bool VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *E) { + return Visit(E->getSubExpr()); + } + bool VisitBinCmp(const BinaryOperator *E); }; } @@ -8104,7 +8429,8 @@ public: /// Visit an expression which constructs the value of this temporary. bool VisitConstructExpr(const Expr *E) { - APValue &Value = createTemporary(E, false, Result, *Info.CurrentCall); + APValue &Value = + Info.CurrentCall->createTemporary(E, E->getType(), false, Result); return EvaluateInPlace(Value, Info, Result, E); } @@ -8464,8 +8790,12 @@ bool ArrayExprEvaluator::VisitInitListExpr(const InitListExpr *E) { } bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) { + LValue CommonLV; if (E->getCommonExpr() && - !Evaluate(Info.CurrentCall->createTemporary(E->getCommonExpr(), false), + !Evaluate(Info.CurrentCall->createTemporary( + E->getCommonExpr(), + getStorageType(Info.Ctx, E->getCommonExpr()), false, + CommonLV), Info, E->getCommonExpr()->getSourceExpr())) return false; @@ -12124,13 +12454,14 @@ static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) { return true; } else if (T->isArrayType()) { LValue LV; - APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall); + APValue &Value = + Info.CurrentCall->createTemporary(E, T, false, LV); if (!EvaluateArray(E, LV, Value, Info)) return false; Result = Value; } else if (T->isRecordType()) { LValue LV; - APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall); + APValue &Value = Info.CurrentCall->createTemporary(E, T, false, LV); if (!EvaluateRecord(E, LV, Value, Info)) return false; Result = Value; @@ -12144,7 +12475,7 @@ static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) { QualType Unqual = T.getAtomicUnqualifiedType(); if (Unqual->isArrayType() || Unqual->isRecordType()) { LValue LV; - APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall); + APValue &Value = Info.CurrentCall->createTemporary(E, Unqual, false, LV); if (!EvaluateAtomic(E, &LV, Value, Info)) return false; } else { @@ -12372,7 +12703,8 @@ bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx, EvalInfo Info(Ctx, Result, EvalInfo::EM_ConstantFold); Info.InConstantContext = InConstantContext; LValue LV; - if (!EvaluateLValue(this, LV, Info) || Result.HasSideEffects || + if (!EvaluateLValue(this, LV, Info) || !Info.discardCleanups() || + Result.HasSideEffects || !CheckLValueConstantExpression(Info, getExprLoc(), Ctx.getLValueReferenceType(getType()), LV, Expr::EvaluateForCodeGen)) @@ -12394,6 +12726,9 @@ bool Expr::EvaluateAsConstantExpr(EvalResult &Result, ConstExprUsage Usage, if (!::Evaluate(Result.Val, Info, this)) return false; + if (!Info.discardCleanups()) + llvm_unreachable("Unhandled cleanup; missing full expression marker?"); + return CheckConstantExpression(Info, getExprLoc(), getType(), Result.Val, Usage); } @@ -12457,6 +12792,13 @@ bool Expr::EvaluateAsInitializer(APValue &Value, const ASTContext &Ctx, EStatus.HasSideEffects) return false; + // At this point, any lifetime-extended temporaries are completely + // initialized. + Info.performLifetimeExtension(); + + if (!Info.discardCleanups()) + llvm_unreachable("Unhandled cleanup; missing full expression marker?"); + return CheckConstantExpression(Info, DeclLoc, DeclTy, Value); } @@ -13063,7 +13405,11 @@ bool Expr::isCXX11ConstantExpr(const ASTContext &Ctx, APValue *Result, EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression); APValue Scratch; - bool IsConstExpr = ::EvaluateAsRValue(Info, this, Result ? *Result : Scratch); + bool IsConstExpr = + ::EvaluateAsRValue(Info, this, Result ? *Result : Scratch) && + // FIXME: We don't produce a diagnostic for this, but the callers that + // call us on arbitrary full-expressions should generally not care. + Info.discardCleanups(); if (!Diags.empty()) { IsConstExpr = false; @@ -13115,7 +13461,8 @@ bool Expr::EvaluateWithSubstitution(APValue &Value, ASTContext &Ctx, // Build fake call to Callee. CallStackFrame Frame(Info, Callee->getLocation(), Callee, ThisPtr, ArgValues.data()); - return Evaluate(Value, Info, this) && !Info.EvalStatus.HasSideEffects; + return Evaluate(Value, Info, this) && Info.discardCleanups() && + !Info.EvalStatus.HasSideEffects; } bool Expr::isPotentialConstantExpr(const FunctionDecl *FD, |
