From 41bd0122fae3556ef3d9d90ba6ae910d40d68b6b Mon Sep 17 00:00:00 2001 From: Richard Smith Date: Mon, 27 Apr 2015 21:27:54 +0000 Subject: [PATCH] PR23334: Perform semantic checking of lambda capture initialization in the right context. Previously we'd try to perform checks on the captures from the middle of parsing the lambda's body, at the point where we detected that a variable needed to be captured. This was wrong in a number of subtle ways. In PR23334, we couldn't correctly handle the list of potential odr-uses resulting from the capture, and our attempt to recover from that resulted in a use-after-free. We now defer building the initialization expression until we leave the lambda body and return to the enclosing context, where the initialization does the right thing. This patch only covers lambda-expressions, but we should apply the same change to blocks and captured statements too. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@235921 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/clang/Sema/Sema.h | 8 +- lib/Analysis/UninitializedValues.cpp | 2 +- lib/Sema/SemaDecl.cpp | 17 ++ lib/Sema/SemaExpr.cpp | 153 +++----------- lib/Sema/SemaLambda.cpp | 187 ++++++++++++------ lib/Sema/SemaTemplateInstantiate.cpp | 36 ++-- lib/Sema/TreeTransform.h | 80 ++++---- .../expr/expr.prim/expr.prim.lambda/p2.cpp | 7 +- .../expr.prim/expr.prim.lambda/templates.cpp | 5 +- test/SemaCXX/PR23334.cpp | 10 + test/SemaCXX/cxx1y-generic-lambdas.cpp | 6 +- test/SemaCXX/uninitialized.cpp | 9 + 12 files changed, 255 insertions(+), 265 deletions(-) create mode 100644 test/SemaCXX/PR23334.cpp diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h index 41b6025f5d..c38226abc6 100644 --- a/include/clang/Sema/Sema.h +++ b/include/clang/Sema/Sema.h @@ -4794,8 +4794,12 @@ public: /// ActOnLambdaExpr - This is called when the body of a lambda expression /// was successfully completed. ExprResult ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, - Scope *CurScope, - bool IsInstantiation = false); + Scope *CurScope); + + /// \brief Complete a lambda-expression having processed and attached the + /// lambda body. + ExprResult BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc, + sema::LambdaScopeInfo *LSI); /// \brief Define the "body" of the conversion from a lambda object to a /// function pointer. diff --git a/lib/Analysis/UninitializedValues.cpp b/lib/Analysis/UninitializedValues.cpp index 3c7bc4ea29..f2f791957a 100644 --- a/lib/Analysis/UninitializedValues.cpp +++ b/lib/Analysis/UninitializedValues.cpp @@ -36,7 +36,7 @@ using namespace clang; static bool isTrackedVar(const VarDecl *vd, const DeclContext *dc) { if (vd->isLocalVarDecl() && !vd->hasGlobalStorage() && !vd->isExceptionVariable() && !vd->isInitCapture() && - vd->getDeclContext() == dc) { + !vd->isImplicit() && vd->getDeclContext() == dc) { QualType ty = vd->getType(); return ty->isScalarType() || ty->isVectorType() || ty->isRecordType(); } diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp index 58e78387fd..e11b4e14c5 100644 --- a/lib/Sema/SemaDecl.cpp +++ b/lib/Sema/SemaDecl.cpp @@ -10587,6 +10587,23 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body, Context.adjustDeducedFunctionResultType( FD, SubstAutoType(ResultType.getType(), Context.VoidTy)); } + } else if (getLangOpts().CPlusPlus11 && isLambdaCallOperator(FD)) { + auto *LSI = getCurLambda(); + if (LSI->HasImplicitReturnType) { + deduceClosureReturnType(*LSI); + + // C++11 [expr.prim.lambda]p4: + // [...] if there are no return statements in the compound-statement + // [the deduced type is] the type void + QualType RetType = + LSI->ReturnType.isNull() ? Context.VoidTy : LSI->ReturnType; + + // Update the return type to the deduced type. + const FunctionProtoType *Proto = + FD->getType()->getAs(); + FD->setType(Context.getFunctionType(RetType, Proto->getParamTypes(), + Proto->getExtProtoInfo())); + } } // The only way to be included in UndefinedButUsed is if there is an diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp index d18aeab57a..493ebe7826 100644 --- a/lib/Sema/SemaExpr.cpp +++ b/lib/Sema/SemaExpr.cpp @@ -12534,13 +12534,11 @@ static bool captureInCapturedRegion(CapturedRegionScopeInfo *RSI, } /// \brief Create a field within the lambda class for the variable -/// being captured. Handle Array captures. -static ExprResult addAsFieldToClosureType(Sema &S, - LambdaScopeInfo *LSI, - VarDecl *Var, QualType FieldType, - QualType DeclRefType, - SourceLocation Loc, - bool RefersToCapturedVariable) { +/// being captured. +static void addAsFieldToClosureType(Sema &S, LambdaScopeInfo *LSI, VarDecl *Var, + QualType FieldType, QualType DeclRefType, + SourceLocation Loc, + bool RefersToCapturedVariable) { CXXRecordDecl *Lambda = LSI->Lambda; // Build the non-static data member. @@ -12551,111 +12549,8 @@ static ExprResult addAsFieldToClosureType(Sema &S, Field->setImplicit(true); Field->setAccess(AS_private); Lambda->addDecl(Field); - - // C++11 [expr.prim.lambda]p21: - // When the lambda-expression is evaluated, the entities that - // are captured by copy are used to direct-initialize each - // corresponding non-static data member of the resulting closure - // object. (For array members, the array elements are - // direct-initialized in increasing subscript order.) These - // initializations are performed in the (unspecified) order in - // which the non-static data members are declared. - - // Introduce a new evaluation context for the initialization, so - // that temporaries introduced as part of the capture are retained - // to be re-"exported" from the lambda expression itself. - EnterExpressionEvaluationContext scope(S, Sema::PotentiallyEvaluated); - - // C++ [expr.prim.labda]p12: - // An entity captured by a lambda-expression is odr-used (3.2) in - // the scope containing the lambda-expression. - Expr *Ref = new (S.Context) DeclRefExpr(Var, RefersToCapturedVariable, - DeclRefType, VK_LValue, Loc); - Var->setReferenced(true); - Var->markUsed(S.Context); - - // When the field has array type, create index variables for each - // dimension of the array. We use these index variables to subscript - // the source array, and other clients (e.g., CodeGen) will perform - // the necessary iteration with these index variables. - SmallVector IndexVariables; - QualType BaseType = FieldType; - QualType SizeType = S.Context.getSizeType(); - LSI->ArrayIndexStarts.push_back(LSI->ArrayIndexVars.size()); - while (const ConstantArrayType *Array - = S.Context.getAsConstantArrayType(BaseType)) { - // Create the iteration variable for this array index. - IdentifierInfo *IterationVarName = nullptr; - { - SmallString<8> Str; - llvm::raw_svector_ostream OS(Str); - OS << "__i" << IndexVariables.size(); - IterationVarName = &S.Context.Idents.get(OS.str()); - } - VarDecl *IterationVar - = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, - IterationVarName, SizeType, - S.Context.getTrivialTypeSourceInfo(SizeType, Loc), - SC_None); - IndexVariables.push_back(IterationVar); - LSI->ArrayIndexVars.push_back(IterationVar); - - // Create a reference to the iteration variable. - ExprResult IterationVarRef - = S.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc); - assert(!IterationVarRef.isInvalid() && - "Reference to invented variable cannot fail!"); - IterationVarRef = S.DefaultLvalueConversion(IterationVarRef.get()); - assert(!IterationVarRef.isInvalid() && - "Conversion of invented variable cannot fail!"); - - // Subscript the array with this iteration variable. - ExprResult Subscript = S.CreateBuiltinArraySubscriptExpr( - Ref, Loc, IterationVarRef.get(), Loc); - if (Subscript.isInvalid()) { - S.CleanupVarDeclMarking(); - S.DiscardCleanupsInEvaluationContext(); - return ExprError(); - } - - Ref = Subscript.get(); - BaseType = Array->getElementType(); - } - - // Construct the entity that we will be initializing. For an array, this - // will be first element in the array, which may require several levels - // of array-subscript entities. - SmallVector Entities; - Entities.reserve(1 + IndexVariables.size()); - Entities.push_back( - InitializedEntity::InitializeLambdaCapture(Var->getIdentifier(), - Field->getType(), Loc)); - for (unsigned I = 0, N = IndexVariables.size(); I != N; ++I) - Entities.push_back(InitializedEntity::InitializeElement(S.Context, - 0, - Entities.back())); - - InitializationKind InitKind - = InitializationKind::CreateDirect(Loc, Loc, Loc); - InitializationSequence Init(S, Entities.back(), InitKind, Ref); - ExprResult Result(true); - if (!Init.Diagnose(S, Entities.back(), InitKind, Ref)) - Result = Init.Perform(S, Entities.back(), InitKind, Ref); - - // If this initialization requires any cleanups (e.g., due to a - // default argument to a copy constructor), note that for the - // lambda. - if (S.ExprNeedsCleanups) - LSI->ExprNeedsCleanups = true; - - // Exit the expression evaluation context used for the capture. - S.CleanupVarDeclMarking(); - S.DiscardCleanupsInEvaluationContext(); - return Result; } - - /// \brief Capture the given variable in the lambda. static bool captureInLambda(LambdaScopeInfo *LSI, VarDecl *Var, @@ -12733,14 +12628,9 @@ static bool captureInLambda(LambdaScopeInfo *LSI, } // Capture this variable in the lambda. - Expr *CopyExpr = nullptr; - if (BuildAndDiagnose) { - ExprResult Result = addAsFieldToClosureType(S, LSI, Var, - CaptureType, DeclRefType, Loc, - RefersToCapturedVariable); - if (!Result.isInvalid()) - CopyExpr = Result.get(); - } + if (BuildAndDiagnose) + addAsFieldToClosureType(S, LSI, Var, CaptureType, DeclRefType, Loc, + RefersToCapturedVariable); // Compute the type of a reference to this captured variable. if (ByRef) @@ -12759,18 +12649,20 @@ static bool captureInLambda(LambdaScopeInfo *LSI, // Add the capture. if (BuildAndDiagnose) LSI->addCapture(Var, /*IsBlock=*/false, ByRef, RefersToCapturedVariable, - Loc, EllipsisLoc, CaptureType, CopyExpr); + Loc, EllipsisLoc, CaptureType, /*CopyExpr=*/nullptr); return true; } -bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc, - TryCaptureKind Kind, SourceLocation EllipsisLoc, - bool BuildAndDiagnose, - QualType &CaptureType, - QualType &DeclRefType, - const unsigned *const FunctionScopeIndexToStopAt) { - bool Nested = Var->isInitCapture(); +bool Sema::tryCaptureVariable( + VarDecl *Var, SourceLocation ExprLoc, TryCaptureKind Kind, + SourceLocation EllipsisLoc, bool BuildAndDiagnose, QualType &CaptureType, + QualType &DeclRefType, const unsigned *const FunctionScopeIndexToStopAt) { + // An init-capture is notionally from the context surrounding its + // declaration, but its parent DC is the lambda class. + DeclContext *VarDC = Var->getDeclContext(); + if (Var->isInitCapture()) + VarDC = VarDC->getParent(); DeclContext *DC = CurContext; const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt @@ -12786,9 +12678,9 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc, } - // If the variable is declared in the current context (and is not an - // init-capture), there is no need to capture it. - if (!Nested && Var->getDeclContext() == DC) return true; + // If the variable is declared in the current context, there is no need to + // capture it. + if (VarDC == DC) return true; // Capture global variables if it is required to use private copy of this // variable. @@ -12806,6 +12698,7 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc, // the variable. CaptureType = Var->getType(); DeclRefType = CaptureType.getNonReferenceType(); + bool Nested = false; bool Explicit = (Kind != TryCapture_Implicit); unsigned FunctionScopesIndex = MaxFunctionScopesIndex; do { @@ -13006,7 +12899,7 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc, FunctionScopesIndex--; DC = ParentDC; Explicit = false; - } while (!Var->getDeclContext()->Equals(DC)); + } while (!VarDC->Equals(DC)); // Walk back down the scope stack, (e.g. from outer lambda to inner lambda) // computing the type of the capture at each step, checking type-specific diff --git a/lib/Sema/SemaLambda.cpp b/lib/Sema/SemaLambda.cpp index 147dd7ef21..80c6df0dd5 100644 --- a/lib/Sema/SemaLambda.cpp +++ b/lib/Sema/SemaLambda.cpp @@ -837,7 +837,8 @@ FieldDecl *Sema::buildInitCaptureField(LambdaScopeInfo *LSI, VarDecl *Var) { } void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro, - Declarator &ParamInfo, Scope *CurScope) { + Declarator &ParamInfo, + Scope *CurScope) { // Determine if we're within a context where we know that the lambda will // be dependent, because there are template parameters in scope. bool KnownDependent = false; @@ -930,12 +931,8 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro, PushDeclContext(CurScope, Method); // Build the lambda scope. - buildLambdaScope(LSI, Method, - Intro.Range, - Intro.Default, Intro.DefaultLoc, - ExplicitParams, - ExplicitResultType, - !Method->isConst()); + buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc, + ExplicitParams, ExplicitResultType, !Method->isConst()); // C++11 [expr.prim.lambda]p9: // A lambda-expression whose smallest enclosing scope is a block scope is a @@ -1137,7 +1134,7 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro, void Sema::ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope, bool IsInstantiation) { - LambdaScopeInfo *LSI = getCurLambda(); + LambdaScopeInfo *LSI = cast(FunctionScopes.back()); // Leave the expression-evaluation context. DiscardCleanupsInEvaluationContext(); @@ -1379,10 +1376,109 @@ static void addBlockPointerConversion(Sema &S, Conversion->setImplicit(true); Class->addDecl(Conversion); } + +static ExprResult performLambdaVarCaptureInitialization( + Sema &S, LambdaScopeInfo::Capture &Capture, + FieldDecl *Field, + SmallVectorImpl &ArrayIndexVars, + SmallVectorImpl &ArrayIndexStarts) { + assert(Capture.isVariableCapture() && "not a variable capture"); + + auto *Var = Capture.getVariable(); + SourceLocation Loc = Capture.getLocation(); + + // C++11 [expr.prim.lambda]p21: + // When the lambda-expression is evaluated, the entities that + // are captured by copy are used to direct-initialize each + // corresponding non-static data member of the resulting closure + // object. (For array members, the array elements are + // direct-initialized in increasing subscript order.) These + // initializations are performed in the (unspecified) order in + // which the non-static data members are declared. + + // C++ [expr.prim.lambda]p12: + // An entity captured by a lambda-expression is odr-used (3.2) in + // the scope containing the lambda-expression. + ExprResult RefResult = S.BuildDeclarationNameExpr( + CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var); + if (RefResult.isInvalid()) + return ExprError(); + Expr *Ref = RefResult.get(); + + QualType FieldType = Field->getType(); + + // When the variable has array type, create index variables for each + // dimension of the array. We use these index variables to subscript + // the source array, and other clients (e.g., CodeGen) will perform + // the necessary iteration with these index variables. + // + // FIXME: This is dumb. Add a proper AST representation for array + // copy-construction and use it here. + SmallVector IndexVariables; + QualType BaseType = FieldType; + QualType SizeType = S.Context.getSizeType(); + ArrayIndexStarts.push_back(ArrayIndexVars.size()); + while (const ConstantArrayType *Array + = S.Context.getAsConstantArrayType(BaseType)) { + // Create the iteration variable for this array index. + IdentifierInfo *IterationVarName = nullptr; + { + SmallString<8> Str; + llvm::raw_svector_ostream OS(Str); + OS << "__i" << IndexVariables.size(); + IterationVarName = &S.Context.Idents.get(OS.str()); + } + VarDecl *IterationVar = VarDecl::Create( + S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType, + S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None); + IterationVar->setImplicit(); + IndexVariables.push_back(IterationVar); + ArrayIndexVars.push_back(IterationVar); + + // Create a reference to the iteration variable. + ExprResult IterationVarRef = + S.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc); + assert(!IterationVarRef.isInvalid() && + "Reference to invented variable cannot fail!"); + IterationVarRef = S.DefaultLvalueConversion(IterationVarRef.get()); + assert(!IterationVarRef.isInvalid() && + "Conversion of invented variable cannot fail!"); + + // Subscript the array with this iteration variable. + ExprResult Subscript = + S.CreateBuiltinArraySubscriptExpr(Ref, Loc, IterationVarRef.get(), Loc); + if (Subscript.isInvalid()) + return ExprError(); + + Ref = Subscript.get(); + BaseType = Array->getElementType(); + } + + // Construct the entity that we will be initializing. For an array, this + // will be first element in the array, which may require several levels + // of array-subscript entities. + SmallVector Entities; + Entities.reserve(1 + IndexVariables.size()); + Entities.push_back(InitializedEntity::InitializeLambdaCapture( + Var->getIdentifier(), FieldType, Loc)); + for (unsigned I = 0, N = IndexVariables.size(); I != N; ++I) + Entities.push_back( + InitializedEntity::InitializeElement(S.Context, 0, Entities.back())); + + InitializationKind InitKind = InitializationKind::CreateDirect(Loc, Loc, Loc); + InitializationSequence Init(S, Entities.back(), InitKind, Ref); + return Init.Perform(S, Entities.back(), InitKind, Ref); +} ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, - Scope *CurScope, - bool IsInstantiation) { + Scope *CurScope) { + LambdaScopeInfo LSI = *cast(FunctionScopes.back()); + ActOnFinishFunctionBody(LSI.CallOperator, Body); + return BuildLambdaExpr(StartLoc, Body->getLocEnd(), &LSI); +} + +ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc, + LambdaScopeInfo *LSI) { // Collect information from the lambda scope. SmallVector Captures; SmallVector CaptureInits; @@ -1398,7 +1494,6 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, SmallVector ArrayIndexVars; SmallVector ArrayIndexStarts; { - LambdaScopeInfo *LSI = getCurLambda(); CallOperator = LSI->CallOperator; Class = LSI->Lambda; IntroducerRange = LSI->IntroducerRange; @@ -1409,8 +1504,20 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, ArrayIndexVars.swap(LSI->ArrayIndexVars); ArrayIndexStarts.swap(LSI->ArrayIndexStarts); + CallOperator->setLexicalDeclContext(Class); + Decl *TemplateOrNonTemplateCallOperatorDecl = + CallOperator->getDescribedFunctionTemplate() + ? CallOperator->getDescribedFunctionTemplate() + : cast(CallOperator); + + TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class); + Class->addDecl(TemplateOrNonTemplateCallOperatorDecl); + + PopExpressionEvaluationContext(); + // Translate captures. - for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I) { + auto CurField = Class->field_begin(); + for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I, ++CurField) { LambdaScopeInfo::Capture From = LSI->Captures[I]; assert(!From.isBlockCapture() && "Cannot capture __block variables"); bool IsImplicit = I >= LSI->NumExplicitCaptures; @@ -1432,10 +1539,18 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, } VarDecl *Var = From.getVariable(); - LambdaCaptureKind Kind = From.isCopyCapture()? LCK_ByCopy : LCK_ByRef; + LambdaCaptureKind Kind = From.isCopyCapture() ? LCK_ByCopy : LCK_ByRef; Captures.push_back(LambdaCapture(From.getLocation(), IsImplicit, Kind, Var, From.getEllipsisLoc())); - CaptureInits.push_back(From.getInitExpr()); + Expr *Init = From.getInitExpr(); + if (!Init) { + auto InitResult = performLambdaVarCaptureInitialization( + *this, From, *CurField, ArrayIndexVars, ArrayIndexStarts); + if (InitResult.isInvalid()) + return ExprError(); + Init = InitResult.get(); + } + CaptureInits.push_back(Init); } switch (LSI->ImpCaptureStyle) { @@ -1458,48 +1573,6 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, } CaptureDefaultLoc = LSI->CaptureDefaultLoc; - // C++11 [expr.prim.lambda]p4: - // If a lambda-expression does not include a - // trailing-return-type, it is as if the trailing-return-type - // denotes the following type: - // - // Skip for C++1y return type deduction semantics which uses - // different machinery. - // FIXME: Refactor and Merge the return type deduction machinery. - // FIXME: Assumes current resolution to core issue 975. - if (LSI->HasImplicitReturnType && !getLangOpts().CPlusPlus14) { - deduceClosureReturnType(*LSI); - - // - if there are no return statements in the - // compound-statement, or all return statements return - // either an expression of type void or no expression or - // braced-init-list, the type void; - if (LSI->ReturnType.isNull()) { - LSI->ReturnType = Context.VoidTy; - } - - // Create a function type with the inferred return type. - const FunctionProtoType *Proto - = CallOperator->getType()->getAs(); - QualType FunctionTy = Context.getFunctionType( - LSI->ReturnType, Proto->getParamTypes(), Proto->getExtProtoInfo()); - CallOperator->setType(FunctionTy); - } - // C++ [expr.prim.lambda]p7: - // The lambda-expression's compound-statement yields the - // function-body (8.4) of the function call operator [...]. - ActOnFinishFunctionBody(CallOperator, Body, IsInstantiation); - CallOperator->setLexicalDeclContext(Class); - Decl *TemplateOrNonTemplateCallOperatorDecl = - CallOperator->getDescribedFunctionTemplate() - ? CallOperator->getDescribedFunctionTemplate() - : cast(CallOperator); - - TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class); - Class->addDecl(TemplateOrNonTemplateCallOperatorDecl); - - PopExpressionEvaluationContext(); - // C++11 [expr.prim.lambda]p6: // The closure type for a lambda-expression with no lambda-capture // has a public non-virtual non-explicit const conversion function @@ -1534,7 +1607,7 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, Captures, ExplicitParams, ExplicitResultType, CaptureInits, ArrayIndexVars, - ArrayIndexStarts, Body->getLocEnd(), + ArrayIndexStarts, EndLoc, ContainsUnexpandedParameterPack); if (!CurContext->isDependentContext()) { diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp index f93a848b74..eec13c581d 100644 --- a/lib/Sema/SemaTemplateInstantiate.cpp +++ b/lib/Sema/SemaTemplateInstantiate.cpp @@ -714,6 +714,20 @@ namespace { } void transformedLocalDecl(Decl *Old, Decl *New) { + // If we've instantiated the call operator of a lambda or the call + // operator template of a generic lambda, update the "instantiation of" + // information. + auto *NewMD = dyn_cast(New); + if (NewMD && isLambdaCallOperator(NewMD)) { + auto *OldMD = dyn_cast(Old); + if (auto *NewTD = NewMD->getDescribedFunctionTemplate()) + NewTD->setInstantiatedFromMemberTemplate( + OldMD->getDescribedFunctionTemplate()); + else + NewMD->setInstantiationOfMemberFunction(OldMD, + TSK_ImplicitInstantiation); + } + SemaRef.CurrentInstantiationScope->InstantiatedLocal(Old, New); } @@ -816,28 +830,6 @@ namespace { return TreeTransform::TransformLambdaExpr(E); } - ExprResult TransformLambdaScope(LambdaExpr *E, - CXXMethodDecl *NewCallOperator, - ArrayRef InitCaptureExprsAndTypes) { - CXXMethodDecl *const OldCallOperator = E->getCallOperator(); - // In the generic lambda case, we set the NewTemplate to be considered - // an "instantiation" of the OldTemplate. - if (FunctionTemplateDecl *const NewCallOperatorTemplate = - NewCallOperator->getDescribedFunctionTemplate()) { - - FunctionTemplateDecl *const OldCallOperatorTemplate = - OldCallOperator->getDescribedFunctionTemplate(); - NewCallOperatorTemplate->setInstantiatedFromMemberTemplate( - OldCallOperatorTemplate); - } else - // For a non-generic lambda we set the NewCallOperator to - // be an instantiation of the OldCallOperator. - NewCallOperator->setInstantiationOfMemberFunction(OldCallOperator, - TSK_ImplicitInstantiation); - - return inherited::TransformLambdaScope(E, NewCallOperator, - InitCaptureExprsAndTypes); - } TemplateParameterList *TransformTemplateParameterList( TemplateParameterList *OrigTPL) { if (!OrigTPL || !OrigTPL->size()) return OrigTPL; diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h index df0e4b316d..704cef36d4 100644 --- a/lib/Sema/TreeTransform.h +++ b/lib/Sema/TreeTransform.h @@ -619,11 +619,6 @@ public: StmtResult TransformCompoundStmt(CompoundStmt *S, bool IsStmtExpr); ExprResult TransformCXXNamedCastExpr(CXXNamedCastExpr *E); - - typedef std::pair InitCaptureInfoTy; - /// \brief Transform the captures and body of a lambda expression. - ExprResult TransformLambdaScope(LambdaExpr *E, CXXMethodDecl *CallOperator, - ArrayRef InitCaptureExprsAndTypes); TemplateParameterList *TransformTemplateParameterList( TemplateParameterList *TPL) { @@ -9131,9 +9126,10 @@ ExprResult TreeTransform::TransformLambdaExpr(LambdaExpr *E) { // Transform any init-capture expressions before entering the scope of the // lambda body, because they are not semantically within that scope. + typedef std::pair InitCaptureInfoTy; SmallVector InitCaptureExprsAndTypes; InitCaptureExprsAndTypes.resize(E->explicit_capture_end() - - E->explicit_capture_begin()); + E->explicit_capture_begin()); for (LambdaExpr::capture_iterator C = E->capture_begin(), CEnd = E->capture_end(); C != CEnd; ++C) { @@ -9159,12 +9155,9 @@ TreeTransform::TransformLambdaExpr(LambdaExpr *E) { std::make_pair(NewExprInitResult, NewInitCaptureType); } - LambdaScopeInfo *LSI = getSema().PushLambdaScope(); - Sema::FunctionScopeRAII FuncScopeCleanup(getSema()); - // Transform the template parameters, and add them to the current // instantiation scope. The null case is handled correctly. - LSI->GLTemplateParameterList = getDerived().TransformTemplateParameterList( + auto TPL = getDerived().TransformTemplateParameterList( E->getTemplateParameterList()); // Transform the type of the original lambda's call operator. @@ -9192,6 +9185,10 @@ TreeTransform::TransformLambdaExpr(LambdaExpr *E) { NewCallOpType); } + LambdaScopeInfo *LSI = getSema().PushLambdaScope(); + Sema::FunctionScopeRAII FuncScopeCleanup(getSema()); + LSI->GLTemplateParameterList = TPL; + // Create the local class that will describe the lambda. CXXRecordDecl *Class = getSema().createLambdaClosureType(E->getIntroducerRange(), @@ -9208,34 +9205,22 @@ TreeTransform::TransformLambdaExpr(LambdaExpr *E) { LSI->CallOperator = NewCallOperator; getDerived().transformAttrs(E->getCallOperator(), NewCallOperator); - - // TransformLambdaScope will manage the function scope, so we can disable the - // cleanup. - FuncScopeCleanup.disable(); - - return getDerived().TransformLambdaScope(E, NewCallOperator, - InitCaptureExprsAndTypes); -} - -template -ExprResult -TreeTransform::TransformLambdaScope(LambdaExpr *E, - CXXMethodDecl *CallOperator, - ArrayRef InitCaptureExprsAndTypes) { - bool Invalid = false; + getDerived().transformedLocalDecl(E->getCallOperator(), NewCallOperator); // Introduce the context of the call operator. - Sema::ContextRAII SavedContext(getSema(), CallOperator, + Sema::ContextRAII SavedContext(getSema(), NewCallOperator, /*NewThisContext*/false); - LambdaScopeInfo *const LSI = getSema().getCurLambda(); // Enter the scope of the lambda. - getSema().buildLambdaScope(LSI, CallOperator, E->getIntroducerRange(), - E->getCaptureDefault(), - E->getCaptureDefaultLoc(), - E->hasExplicitParameters(), - E->hasExplicitResultType(), - E->isMutable()); + getSema().buildLambdaScope(LSI, NewCallOperator, + E->getIntroducerRange(), + E->getCaptureDefault(), + E->getCaptureDefaultLoc(), + E->hasExplicitParameters(), + E->hasExplicitResultType(), + E->isMutable()); + + bool Invalid = false; // Transform captures. bool FinishedExplicitCaptures = false; @@ -9261,7 +9246,6 @@ TreeTransform::TransformLambdaScope(LambdaExpr *E, // Rebuild init-captures, including the implied field declaration. if (C->isInitCapture()) { - InitCaptureInfoTy InitExprTypePair = InitCaptureExprsAndTypes[C - E->capture_begin()]; ExprResult Init = InitExprTypePair.first; @@ -9348,28 +9332,34 @@ TreeTransform::TransformLambdaScope(LambdaExpr *E, if (!FinishedExplicitCaptures) getSema().finishLambdaExplicitCaptures(LSI); - // Enter a new evaluation context to insulate the lambda from any // cleanups from the enclosing full-expression. getSema().PushExpressionEvaluationContext(Sema::PotentiallyEvaluated); - if (Invalid) { - getSema().ActOnLambdaError(E->getLocStart(), /*CurScope=*/nullptr, - /*IsInstantiation=*/true); - return ExprError(); - } - // Instantiate the body of the lambda expression. - StmtResult Body = getDerived().TransformStmt(E->getBody()); + StmtResult Body = + Invalid ? StmtError() : getDerived().TransformStmt(E->getBody()); + + // ActOnLambda* will pop the function scope for us. + FuncScopeCleanup.disable(); + if (Body.isInvalid()) { + SavedContext.pop(); getSema().ActOnLambdaError(E->getLocStart(), /*CurScope=*/nullptr, /*IsInstantiation=*/true); return ExprError(); } - return getSema().ActOnLambdaExpr(E->getLocStart(), Body.get(), - /*CurScope=*/nullptr, - /*IsInstantiation=*/true); + // Copy the LSI before ActOnFinishFunctionBody removes it. + // FIXME: This is dumb. Store the lambda information somewhere that outlives + // the call operator. + auto LSICopy = *LSI; + getSema().ActOnFinishFunctionBody(NewCallOperator, Body.get(), + /*IsInstantiation*/ true); + SavedContext.pop(); + + return getSema().BuildLambdaExpr(E->getLocStart(), Body.get()->getLocEnd(), + &LSICopy); } template diff --git a/test/CXX/expr/expr.prim/expr.prim.lambda/p2.cpp b/test/CXX/expr/expr.prim/expr.prim.lambda/p2.cpp index 647c76d604..872248e77e 100644 --- a/test/CXX/expr/expr.prim/expr.prim.lambda/p2.cpp +++ b/test/CXX/expr/expr.prim/expr.prim.lambda/p2.cpp @@ -24,7 +24,6 @@ template struct Boom { Boom(const Boom&) { T* x = 1; // expected-error{{cannot initialize a variable of type 'int *' with an rvalue of type 'int'}} \ - // expected-error{{cannot initialize a variable of type 'float *' with an rvalue of type 'int'}} \ // expected-error{{cannot initialize a variable of type 'double *' with an rvalue of type 'int'}} } void tickle() const; @@ -34,9 +33,11 @@ void odr_used(P &p, Boom boom_int, Boom boom_float, Boom boom_double) { const std::type_info &ti1 = typeid([=,&p]() -> P& { boom_int.tickle(); return p; }()); // expected-note{{in instantiation of member function 'Boom::Boom' requested here}} + // This does not cause the instantiation of the Boom copy constructor, + // because the copy-initialization of the capture of boom_float occurs in an + // unevaluated operand. const std::type_info &ti2 - = typeid([=]() -> int { boom_float.tickle(); return 0; }()); // expected-error{{lambda expression in an unevaluated operand}} \ - // expected-note{{in instantiation of member function 'Boom::Boom' requested here}} + = typeid([=]() -> int { boom_float.tickle(); return 0; }()); // expected-error{{lambda expression in an unevaluated operand}} auto foo = [=]() -> int { boom_double.tickle(); return 0; }; // expected-note{{in instantiation of member function 'Boom::Boom' requested here}} } diff --git a/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp b/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp index 90cbf02b2a..c18bb7d192 100644 --- a/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp +++ b/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp @@ -69,8 +69,7 @@ namespace p2 { template struct Boom { Boom(const Boom&) { - T* x = 1; // expected-error{{cannot initialize a variable of type 'int *' with an rvalue of type 'int'}} \ - // expected-error{{cannot initialize a variable of type 'float *' with an rvalue of type 'int'}} + T* x = 1; // expected-error{{cannot initialize a variable of type 'float *' with an rvalue of type 'int'}} } void tickle() const; }; @@ -79,7 +78,7 @@ namespace p2 { void odr_used(R &r, Boom boom) { const std::type_info &ti = typeid([=,&r] () -> R& { // expected-error{{lambda expression in an unevaluated operand}} - boom.tickle(); // expected-note{{in instantiation of member function}} + boom.tickle(); return r; }()); } diff --git a/test/SemaCXX/PR23334.cpp b/test/SemaCXX/PR23334.cpp new file mode 100644 index 0000000000..cd6b4f4551 --- /dev/null +++ b/test/SemaCXX/PR23334.cpp @@ -0,0 +1,10 @@ +// RUN: %clang_cc1 -std=c++11 -verify %s -Wno-unused + +// This must be at the start of the file (the failure depends on a SmallPtrSet +// not having been reallocated yet). +void fn1() { + // expected-no-diagnostics + constexpr int kIsolationClass = 0; + const int kBytesPerConnection = 0; + [=] { kIsolationClass, kBytesPerConnection, kBytesPerConnection; }; +} diff --git a/test/SemaCXX/cxx1y-generic-lambdas.cpp b/test/SemaCXX/cxx1y-generic-lambdas.cpp index 90ecf6904e..f4c67fbba0 100644 --- a/test/SemaCXX/cxx1y-generic-lambdas.cpp +++ b/test/SemaCXX/cxx1y-generic-lambdas.cpp @@ -899,8 +899,10 @@ struct X1 { int L2 = ([](auto i) { return i; })(2); void fooG(T i = ([] (auto i) { return i; })(2)) { } int BG : ([](auto i) { return i; })(3); //expected-error{{not an integral constant}}\ - //expected-note{{non-literal type}} - int arrG[([](auto i) { return i; })(3)]; //expected-error{{must have a constant size}} + //expected-note{{non-literal type}}\ + //expected-error{{inside of a constant expression}} + int arrG[([](auto i) { return i; })(3)]; //expected-error{{must have a constant size}} \ + //expected-error{{inside of a constant expression}} int (*fpG)(T) = [](auto i) { return i; }; void fooptrG(T (*fp)(char) = [](auto c) { return 0; }) { } template int fooG2(T (*fp)(U) = [](auto a) { return 0; }) { return 0; } diff --git a/test/SemaCXX/uninitialized.cpp b/test/SemaCXX/uninitialized.cpp index f02357419f..5769a0c028 100644 --- a/test/SemaCXX/uninitialized.cpp +++ b/test/SemaCXX/uninitialized.cpp @@ -1428,3 +1428,12 @@ class A { A(int (*) [7]) : a(rvalueref::notmove(a)) {} }; } + +void array_capture(bool b) { + const char fname[] = "array_capture"; + if (b) { + int unused; // expected-warning {{unused variable}} + } else { + [fname]{}; + } +} -- 2.40.0