| //===--- CGClass.cpp - Emit LLVM Code for C++ classes ---------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code dealing with C++ code generation of classes |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CGBlocks.h" |
| #include "CGCXXABI.h" |
| #include "CGDebugInfo.h" |
| #include "CGRecordLayout.h" |
| #include "CodeGenFunction.h" |
| #include "clang/AST/CXXInheritance.h" |
| #include "clang/AST/DeclTemplate.h" |
| #include "clang/AST/EvaluatedExprVisitor.h" |
| #include "clang/AST/RecordLayout.h" |
| #include "clang/AST/StmtCXX.h" |
| #include "clang/Basic/TargetBuiltins.h" |
| #include "clang/CodeGen/CGFunctionInfo.h" |
| #include "clang/Frontend/CodeGenOptions.h" |
| #include "llvm/IR/Intrinsics.h" |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| static CharUnits |
| ComputeNonVirtualBaseClassOffset(ASTContext &Context, |
| const CXXRecordDecl *DerivedClass, |
| CastExpr::path_const_iterator Start, |
| CastExpr::path_const_iterator End) { |
| CharUnits Offset = CharUnits::Zero(); |
| |
| const CXXRecordDecl *RD = DerivedClass; |
| |
| for (CastExpr::path_const_iterator I = Start; I != End; ++I) { |
| const CXXBaseSpecifier *Base = *I; |
| assert(!Base->isVirtual() && "Should not see virtual bases here!"); |
| |
| // Get the layout. |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl()); |
| |
| // Add the offset. |
| Offset += Layout.getBaseClassOffset(BaseDecl); |
| |
| RD = BaseDecl; |
| } |
| |
| return Offset; |
| } |
| |
| llvm::Constant * |
| CodeGenModule::GetNonVirtualBaseClassOffset(const CXXRecordDecl *ClassDecl, |
| CastExpr::path_const_iterator PathBegin, |
| CastExpr::path_const_iterator PathEnd) { |
| assert(PathBegin != PathEnd && "Base path should not be empty!"); |
| |
| CharUnits Offset = |
| ComputeNonVirtualBaseClassOffset(getContext(), ClassDecl, |
| PathBegin, PathEnd); |
| if (Offset.isZero()) |
| return nullptr; |
| |
| llvm::Type *PtrDiffTy = |
| Types.ConvertType(getContext().getPointerDiffType()); |
| |
| return llvm::ConstantInt::get(PtrDiffTy, Offset.getQuantity()); |
| } |
| |
| /// Gets the address of a direct base class within a complete object. |
| /// This should only be used for (1) non-virtual bases or (2) virtual bases |
| /// when the type is known to be complete (e.g. in complete destructors). |
| /// |
| /// The object pointed to by 'This' is assumed to be non-null. |
| llvm::Value * |
| CodeGenFunction::GetAddressOfDirectBaseInCompleteClass(llvm::Value *This, |
| const CXXRecordDecl *Derived, |
| const CXXRecordDecl *Base, |
| bool BaseIsVirtual) { |
| // 'this' must be a pointer (in some address space) to Derived. |
| assert(This->getType()->isPointerTy() && |
| cast<llvm::PointerType>(This->getType())->getElementType() |
| == ConvertType(Derived)); |
| |
| // Compute the offset of the virtual base. |
| CharUnits Offset; |
| const ASTRecordLayout &Layout = getContext().getASTRecordLayout(Derived); |
| if (BaseIsVirtual) |
| Offset = Layout.getVBaseClassOffset(Base); |
| else |
| Offset = Layout.getBaseClassOffset(Base); |
| |
| // Shift and cast down to the base type. |
| // TODO: for complete types, this should be possible with a GEP. |
| llvm::Value *V = This; |
| if (Offset.isPositive()) { |
| V = Builder.CreateBitCast(V, Int8PtrTy); |
| V = Builder.CreateConstInBoundsGEP1_64(V, Offset.getQuantity()); |
| } |
| V = Builder.CreateBitCast(V, ConvertType(Base)->getPointerTo()); |
| |
| return V; |
| } |
| |
| static llvm::Value * |
| ApplyNonVirtualAndVirtualOffset(CodeGenFunction &CGF, llvm::Value *ptr, |
| CharUnits nonVirtualOffset, |
| llvm::Value *virtualOffset) { |
| // Assert that we have something to do. |
| assert(!nonVirtualOffset.isZero() || virtualOffset != nullptr); |
| |
| // Compute the offset from the static and dynamic components. |
| llvm::Value *baseOffset; |
| if (!nonVirtualOffset.isZero()) { |
| baseOffset = llvm::ConstantInt::get(CGF.PtrDiffTy, |
| nonVirtualOffset.getQuantity()); |
| if (virtualOffset) { |
| baseOffset = CGF.Builder.CreateAdd(virtualOffset, baseOffset); |
| } |
| } else { |
| baseOffset = virtualOffset; |
| } |
| |
| // Apply the base offset. |
| ptr = CGF.Builder.CreateBitCast(ptr, CGF.Int8PtrTy); |
| ptr = CGF.Builder.CreateInBoundsGEP(ptr, baseOffset, "add.ptr"); |
| return ptr; |
| } |
| |
| llvm::Value *CodeGenFunction::GetAddressOfBaseClass( |
| llvm::Value *Value, const CXXRecordDecl *Derived, |
| CastExpr::path_const_iterator PathBegin, |
| CastExpr::path_const_iterator PathEnd, bool NullCheckValue, |
| SourceLocation Loc) { |
| assert(PathBegin != PathEnd && "Base path should not be empty!"); |
| |
| CastExpr::path_const_iterator Start = PathBegin; |
| const CXXRecordDecl *VBase = nullptr; |
| |
| // Sema has done some convenient canonicalization here: if the |
| // access path involved any virtual steps, the conversion path will |
| // *start* with a step down to the correct virtual base subobject, |
| // and hence will not require any further steps. |
| if ((*Start)->isVirtual()) { |
| VBase = |
| cast<CXXRecordDecl>((*Start)->getType()->getAs<RecordType>()->getDecl()); |
| ++Start; |
| } |
| |
| // Compute the static offset of the ultimate destination within its |
| // allocating subobject (the virtual base, if there is one, or else |
| // the "complete" object that we see). |
| CharUnits NonVirtualOffset = |
| ComputeNonVirtualBaseClassOffset(getContext(), VBase ? VBase : Derived, |
| Start, PathEnd); |
| |
| // If there's a virtual step, we can sometimes "devirtualize" it. |
| // For now, that's limited to when the derived type is final. |
| // TODO: "devirtualize" this for accesses to known-complete objects. |
| if (VBase && Derived->hasAttr<FinalAttr>()) { |
| const ASTRecordLayout &layout = getContext().getASTRecordLayout(Derived); |
| CharUnits vBaseOffset = layout.getVBaseClassOffset(VBase); |
| NonVirtualOffset += vBaseOffset; |
| VBase = nullptr; // we no longer have a virtual step |
| } |
| |
| // Get the base pointer type. |
| llvm::Type *BasePtrTy = |
| ConvertType((PathEnd[-1])->getType())->getPointerTo(); |
| |
| QualType DerivedTy = getContext().getRecordType(Derived); |
| CharUnits DerivedAlign = getContext().getTypeAlignInChars(DerivedTy); |
| |
| // If the static offset is zero and we don't have a virtual step, |
| // just do a bitcast; null checks are unnecessary. |
| if (NonVirtualOffset.isZero() && !VBase) { |
| if (sanitizePerformTypeCheck()) { |
| EmitTypeCheck(TCK_Upcast, Loc, Value, DerivedTy, DerivedAlign, |
| !NullCheckValue); |
| } |
| return Builder.CreateBitCast(Value, BasePtrTy); |
| } |
| |
| llvm::BasicBlock *origBB = nullptr; |
| llvm::BasicBlock *endBB = nullptr; |
| |
| // Skip over the offset (and the vtable load) if we're supposed to |
| // null-check the pointer. |
| if (NullCheckValue) { |
| origBB = Builder.GetInsertBlock(); |
| llvm::BasicBlock *notNullBB = createBasicBlock("cast.notnull"); |
| endBB = createBasicBlock("cast.end"); |
| |
| llvm::Value *isNull = Builder.CreateIsNull(Value); |
| Builder.CreateCondBr(isNull, endBB, notNullBB); |
| EmitBlock(notNullBB); |
| } |
| |
| if (sanitizePerformTypeCheck()) { |
| EmitTypeCheck(VBase ? TCK_UpcastToVirtualBase : TCK_Upcast, Loc, Value, |
| DerivedTy, DerivedAlign, true); |
| } |
| |
| // Compute the virtual offset. |
| llvm::Value *VirtualOffset = nullptr; |
| if (VBase) { |
| VirtualOffset = |
| CGM.getCXXABI().GetVirtualBaseClassOffset(*this, Value, Derived, VBase); |
| } |
| |
| // Apply both offsets. |
| Value = ApplyNonVirtualAndVirtualOffset(*this, Value, |
| NonVirtualOffset, |
| VirtualOffset); |
| |
| // Cast to the destination type. |
| Value = Builder.CreateBitCast(Value, BasePtrTy); |
| |
| // Build a phi if we needed a null check. |
| if (NullCheckValue) { |
| llvm::BasicBlock *notNullBB = Builder.GetInsertBlock(); |
| Builder.CreateBr(endBB); |
| EmitBlock(endBB); |
| |
| llvm::PHINode *PHI = Builder.CreatePHI(BasePtrTy, 2, "cast.result"); |
| PHI->addIncoming(Value, notNullBB); |
| PHI->addIncoming(llvm::Constant::getNullValue(BasePtrTy), origBB); |
| Value = PHI; |
| } |
| |
| return Value; |
| } |
| |
| llvm::Value * |
| CodeGenFunction::GetAddressOfDerivedClass(llvm::Value *Value, |
| const CXXRecordDecl *Derived, |
| CastExpr::path_const_iterator PathBegin, |
| CastExpr::path_const_iterator PathEnd, |
| bool NullCheckValue) { |
| assert(PathBegin != PathEnd && "Base path should not be empty!"); |
| |
| QualType DerivedTy = |
| getContext().getCanonicalType(getContext().getTagDeclType(Derived)); |
| llvm::Type *DerivedPtrTy = ConvertType(DerivedTy)->getPointerTo(); |
| |
| llvm::Value *NonVirtualOffset = |
| CGM.GetNonVirtualBaseClassOffset(Derived, PathBegin, PathEnd); |
| |
| if (!NonVirtualOffset) { |
| // No offset, we can just cast back. |
| return Builder.CreateBitCast(Value, DerivedPtrTy); |
| } |
| |
| llvm::BasicBlock *CastNull = nullptr; |
| llvm::BasicBlock *CastNotNull = nullptr; |
| llvm::BasicBlock *CastEnd = nullptr; |
| |
| if (NullCheckValue) { |
| CastNull = createBasicBlock("cast.null"); |
| CastNotNull = createBasicBlock("cast.notnull"); |
| CastEnd = createBasicBlock("cast.end"); |
| |
| llvm::Value *IsNull = Builder.CreateIsNull(Value); |
| Builder.CreateCondBr(IsNull, CastNull, CastNotNull); |
| EmitBlock(CastNotNull); |
| } |
| |
| // Apply the offset. |
| Value = Builder.CreateBitCast(Value, Int8PtrTy); |
| Value = Builder.CreateGEP(Value, Builder.CreateNeg(NonVirtualOffset), |
| "sub.ptr"); |
| |
| // Just cast. |
| Value = Builder.CreateBitCast(Value, DerivedPtrTy); |
| |
| if (NullCheckValue) { |
| Builder.CreateBr(CastEnd); |
| EmitBlock(CastNull); |
| Builder.CreateBr(CastEnd); |
| EmitBlock(CastEnd); |
| |
| llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2); |
| PHI->addIncoming(Value, CastNotNull); |
| PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), |
| CastNull); |
| Value = PHI; |
| } |
| |
| return Value; |
| } |
| |
| llvm::Value *CodeGenFunction::GetVTTParameter(GlobalDecl GD, |
| bool ForVirtualBase, |
| bool Delegating) { |
| if (!CGM.getCXXABI().NeedsVTTParameter(GD)) { |
| // This constructor/destructor does not need a VTT parameter. |
| return nullptr; |
| } |
| |
| const CXXRecordDecl *RD = cast<CXXMethodDecl>(CurCodeDecl)->getParent(); |
| const CXXRecordDecl *Base = cast<CXXMethodDecl>(GD.getDecl())->getParent(); |
| |
| llvm::Value *VTT; |
| |
| uint64_t SubVTTIndex; |
| |
| if (Delegating) { |
| // If this is a delegating constructor call, just load the VTT. |
| return LoadCXXVTT(); |
| } else if (RD == Base) { |
| // If the record matches the base, this is the complete ctor/dtor |
| // variant calling the base variant in a class with virtual bases. |
| assert(!CGM.getCXXABI().NeedsVTTParameter(CurGD) && |
| "doing no-op VTT offset in base dtor/ctor?"); |
| assert(!ForVirtualBase && "Can't have same class as virtual base!"); |
| SubVTTIndex = 0; |
| } else { |
| const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD); |
| CharUnits BaseOffset = ForVirtualBase ? |
| Layout.getVBaseClassOffset(Base) : |
| Layout.getBaseClassOffset(Base); |
| |
| SubVTTIndex = |
| CGM.getVTables().getSubVTTIndex(RD, BaseSubobject(Base, BaseOffset)); |
| assert(SubVTTIndex != 0 && "Sub-VTT index must be greater than zero!"); |
| } |
| |
| if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) { |
| // A VTT parameter was passed to the constructor, use it. |
| VTT = LoadCXXVTT(); |
| VTT = Builder.CreateConstInBoundsGEP1_64(VTT, SubVTTIndex); |
| } else { |
| // We're the complete constructor, so get the VTT by name. |
| VTT = CGM.getVTables().GetAddrOfVTT(RD); |
| VTT = Builder.CreateConstInBoundsGEP2_64(VTT, 0, SubVTTIndex); |
| } |
| |
| return VTT; |
| } |
| |
| namespace { |
| /// Call the destructor for a direct base class. |
| struct CallBaseDtor : EHScopeStack::Cleanup { |
| const CXXRecordDecl *BaseClass; |
| bool BaseIsVirtual; |
| CallBaseDtor(const CXXRecordDecl *Base, bool BaseIsVirtual) |
| : BaseClass(Base), BaseIsVirtual(BaseIsVirtual) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| const CXXRecordDecl *DerivedClass = |
| cast<CXXMethodDecl>(CGF.CurCodeDecl)->getParent(); |
| |
| const CXXDestructorDecl *D = BaseClass->getDestructor(); |
| llvm::Value *Addr = |
| CGF.GetAddressOfDirectBaseInCompleteClass(CGF.LoadCXXThis(), |
| DerivedClass, BaseClass, |
| BaseIsVirtual); |
| CGF.EmitCXXDestructorCall(D, Dtor_Base, BaseIsVirtual, |
| /*Delegating=*/false, Addr); |
| } |
| }; |
| |
| /// A visitor which checks whether an initializer uses 'this' in a |
| /// way which requires the vtable to be properly set. |
| struct DynamicThisUseChecker : EvaluatedExprVisitor<DynamicThisUseChecker> { |
| typedef EvaluatedExprVisitor<DynamicThisUseChecker> super; |
| |
| bool UsesThis; |
| |
| DynamicThisUseChecker(ASTContext &C) : super(C), UsesThis(false) {} |
| |
| // Black-list all explicit and implicit references to 'this'. |
| // |
| // Do we need to worry about external references to 'this' derived |
| // from arbitrary code? If so, then anything which runs arbitrary |
| // external code might potentially access the vtable. |
| void VisitCXXThisExpr(CXXThisExpr *E) { UsesThis = true; } |
| }; |
| } |
| |
| static bool BaseInitializerUsesThis(ASTContext &C, const Expr *Init) { |
| DynamicThisUseChecker Checker(C); |
| Checker.Visit(const_cast<Expr*>(Init)); |
| return Checker.UsesThis; |
| } |
| |
| static void EmitBaseInitializer(CodeGenFunction &CGF, |
| const CXXRecordDecl *ClassDecl, |
| CXXCtorInitializer *BaseInit, |
| CXXCtorType CtorType) { |
| assert(BaseInit->isBaseInitializer() && |
| "Must have base initializer!"); |
| |
| llvm::Value *ThisPtr = CGF.LoadCXXThis(); |
| |
| const Type *BaseType = BaseInit->getBaseClass(); |
| CXXRecordDecl *BaseClassDecl = |
| cast<CXXRecordDecl>(BaseType->getAs<RecordType>()->getDecl()); |
| |
| bool isBaseVirtual = BaseInit->isBaseVirtual(); |
| |
| // The base constructor doesn't construct virtual bases. |
| if (CtorType == Ctor_Base && isBaseVirtual) |
| return; |
| |
| // If the initializer for the base (other than the constructor |
| // itself) accesses 'this' in any way, we need to initialize the |
| // vtables. |
| if (BaseInitializerUsesThis(CGF.getContext(), BaseInit->getInit())) |
| CGF.InitializeVTablePointers(ClassDecl); |
| |
| // We can pretend to be a complete class because it only matters for |
| // virtual bases, and we only do virtual bases for complete ctors. |
| llvm::Value *V = |
| CGF.GetAddressOfDirectBaseInCompleteClass(ThisPtr, ClassDecl, |
| BaseClassDecl, |
| isBaseVirtual); |
| CharUnits Alignment = CGF.getContext().getTypeAlignInChars(BaseType); |
| AggValueSlot AggSlot = |
| AggValueSlot::forAddr(V, Alignment, Qualifiers(), |
| AggValueSlot::IsDestructed, |
| AggValueSlot::DoesNotNeedGCBarriers, |
| AggValueSlot::IsNotAliased); |
| |
| CGF.EmitAggExpr(BaseInit->getInit(), AggSlot); |
| |
| if (CGF.CGM.getLangOpts().Exceptions && |
| !BaseClassDecl->hasTrivialDestructor()) |
| CGF.EHStack.pushCleanup<CallBaseDtor>(EHCleanup, BaseClassDecl, |
| isBaseVirtual); |
| } |
| |
| static void EmitAggMemberInitializer(CodeGenFunction &CGF, |
| LValue LHS, |
| Expr *Init, |
| llvm::Value *ArrayIndexVar, |
| QualType T, |
| ArrayRef<VarDecl *> ArrayIndexes, |
| unsigned Index) { |
| if (Index == ArrayIndexes.size()) { |
| LValue LV = LHS; |
| |
| if (ArrayIndexVar) { |
| // If we have an array index variable, load it and use it as an offset. |
| // Then, increment the value. |
| llvm::Value *Dest = LHS.getAddress(); |
| llvm::Value *ArrayIndex = CGF.Builder.CreateLoad(ArrayIndexVar); |
| Dest = CGF.Builder.CreateInBoundsGEP(Dest, ArrayIndex, "destaddress"); |
| llvm::Value *Next = llvm::ConstantInt::get(ArrayIndex->getType(), 1); |
| Next = CGF.Builder.CreateAdd(ArrayIndex, Next, "inc"); |
| CGF.Builder.CreateStore(Next, ArrayIndexVar); |
| |
| // Update the LValue. |
| LV.setAddress(Dest); |
| CharUnits Align = CGF.getContext().getTypeAlignInChars(T); |
| LV.setAlignment(std::min(Align, LV.getAlignment())); |
| } |
| |
| switch (CGF.getEvaluationKind(T)) { |
| case TEK_Scalar: |
| CGF.EmitScalarInit(Init, /*decl*/ nullptr, LV, false); |
| break; |
| case TEK_Complex: |
| CGF.EmitComplexExprIntoLValue(Init, LV, /*isInit*/ true); |
| break; |
| case TEK_Aggregate: { |
| AggValueSlot Slot = |
| AggValueSlot::forLValue(LV, |
| AggValueSlot::IsDestructed, |
| AggValueSlot::DoesNotNeedGCBarriers, |
| AggValueSlot::IsNotAliased); |
| |
| CGF.EmitAggExpr(Init, Slot); |
| break; |
| } |
| } |
| |
| return; |
| } |
| |
| const ConstantArrayType *Array = CGF.getContext().getAsConstantArrayType(T); |
| assert(Array && "Array initialization without the array type?"); |
| llvm::Value *IndexVar |
| = CGF.GetAddrOfLocalVar(ArrayIndexes[Index]); |
| assert(IndexVar && "Array index variable not loaded"); |
| |
| // Initialize this index variable to zero. |
| llvm::Value* Zero |
| = llvm::Constant::getNullValue( |
| CGF.ConvertType(CGF.getContext().getSizeType())); |
| CGF.Builder.CreateStore(Zero, IndexVar); |
| |
| // Start the loop with a block that tests the condition. |
| llvm::BasicBlock *CondBlock = CGF.createBasicBlock("for.cond"); |
| llvm::BasicBlock *AfterFor = CGF.createBasicBlock("for.end"); |
| |
| CGF.EmitBlock(CondBlock); |
| |
| llvm::BasicBlock *ForBody = CGF.createBasicBlock("for.body"); |
| // Generate: if (loop-index < number-of-elements) fall to the loop body, |
| // otherwise, go to the block after the for-loop. |
| uint64_t NumElements = Array->getSize().getZExtValue(); |
| llvm::Value *Counter = CGF.Builder.CreateLoad(IndexVar); |
| llvm::Value *NumElementsPtr = |
| llvm::ConstantInt::get(Counter->getType(), NumElements); |
| llvm::Value *IsLess = CGF.Builder.CreateICmpULT(Counter, NumElementsPtr, |
| "isless"); |
| |
| // If the condition is true, execute the body. |
| CGF.Builder.CreateCondBr(IsLess, ForBody, AfterFor); |
| |
| CGF.EmitBlock(ForBody); |
| llvm::BasicBlock *ContinueBlock = CGF.createBasicBlock("for.inc"); |
| |
| // Inside the loop body recurse to emit the inner loop or, eventually, the |
| // constructor call. |
| EmitAggMemberInitializer(CGF, LHS, Init, ArrayIndexVar, |
| Array->getElementType(), ArrayIndexes, Index + 1); |
| |
| CGF.EmitBlock(ContinueBlock); |
| |
| // Emit the increment of the loop counter. |
| llvm::Value *NextVal = llvm::ConstantInt::get(Counter->getType(), 1); |
| Counter = CGF.Builder.CreateLoad(IndexVar); |
| NextVal = CGF.Builder.CreateAdd(Counter, NextVal, "inc"); |
| CGF.Builder.CreateStore(NextVal, IndexVar); |
| |
| // Finally, branch back up to the condition for the next iteration. |
| CGF.EmitBranch(CondBlock); |
| |
| // Emit the fall-through block. |
| CGF.EmitBlock(AfterFor, true); |
| } |
| |
| static void EmitMemberInitializer(CodeGenFunction &CGF, |
| const CXXRecordDecl *ClassDecl, |
| CXXCtorInitializer *MemberInit, |
| const CXXConstructorDecl *Constructor, |
| FunctionArgList &Args) { |
| ApplyDebugLocation Loc(CGF, MemberInit->getSourceLocation()); |
| assert(MemberInit->isAnyMemberInitializer() && |
| "Must have member initializer!"); |
| assert(MemberInit->getInit() && "Must have initializer!"); |
| |
| // non-static data member initializers. |
| FieldDecl *Field = MemberInit->getAnyMember(); |
| QualType FieldType = Field->getType(); |
| |
| llvm::Value *ThisPtr = CGF.LoadCXXThis(); |
| QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl); |
| LValue LHS = CGF.MakeNaturalAlignAddrLValue(ThisPtr, RecordTy); |
| |
| if (MemberInit->isIndirectMemberInitializer()) { |
| // If we are initializing an anonymous union field, drill down to |
| // the field. |
| IndirectFieldDecl *IndirectField = MemberInit->getIndirectMember(); |
| for (const auto *I : IndirectField->chain()) |
| LHS = CGF.EmitLValueForFieldInitialization(LHS, cast<FieldDecl>(I)); |
| FieldType = MemberInit->getIndirectMember()->getAnonField()->getType(); |
| } else { |
| LHS = CGF.EmitLValueForFieldInitialization(LHS, Field); |
| } |
| |
| // Special case: if we are in a copy or move constructor, and we are copying |
| // an array of PODs or classes with trivial copy constructors, ignore the |
| // AST and perform the copy we know is equivalent. |
| // FIXME: This is hacky at best... if we had a bit more explicit information |
| // in the AST, we could generalize it more easily. |
| const ConstantArrayType *Array |
| = CGF.getContext().getAsConstantArrayType(FieldType); |
| if (Array && Constructor->isDefaulted() && |
| Constructor->isCopyOrMoveConstructor()) { |
| QualType BaseElementTy = CGF.getContext().getBaseElementType(Array); |
| CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(MemberInit->getInit()); |
| if (BaseElementTy.isPODType(CGF.getContext()) || |
| (CE && CE->getConstructor()->isTrivial())) { |
| unsigned SrcArgIndex = |
| CGF.CGM.getCXXABI().getSrcArgforCopyCtor(Constructor, Args); |
| llvm::Value *SrcPtr |
| = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(Args[SrcArgIndex])); |
| LValue ThisRHSLV = CGF.MakeNaturalAlignAddrLValue(SrcPtr, RecordTy); |
| LValue Src = CGF.EmitLValueForFieldInitialization(ThisRHSLV, Field); |
| |
| // Copy the aggregate. |
| CGF.EmitAggregateCopy(LHS.getAddress(), Src.getAddress(), FieldType, |
| LHS.isVolatileQualified()); |
| return; |
| } |
| } |
| |
| ArrayRef<VarDecl *> ArrayIndexes; |
| if (MemberInit->getNumArrayIndices()) |
| ArrayIndexes = MemberInit->getArrayIndexes(); |
| CGF.EmitInitializerForField(Field, LHS, MemberInit->getInit(), ArrayIndexes); |
| } |
| |
| void CodeGenFunction::EmitInitializerForField( |
| FieldDecl *Field, LValue LHS, Expr *Init, |
| ArrayRef<VarDecl *> ArrayIndexes) { |
| QualType FieldType = Field->getType(); |
| switch (getEvaluationKind(FieldType)) { |
| case TEK_Scalar: |
| if (LHS.isSimple()) { |
| EmitExprAsInit(Init, Field, LHS, false); |
| } else { |
| RValue RHS = RValue::get(EmitScalarExpr(Init)); |
| EmitStoreThroughLValue(RHS, LHS); |
| } |
| break; |
| case TEK_Complex: |
| EmitComplexExprIntoLValue(Init, LHS, /*isInit*/ true); |
| break; |
| case TEK_Aggregate: { |
| llvm::Value *ArrayIndexVar = nullptr; |
| if (ArrayIndexes.size()) { |
| llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); |
| |
| // The LHS is a pointer to the first object we'll be constructing, as |
| // a flat array. |
| QualType BaseElementTy = getContext().getBaseElementType(FieldType); |
| llvm::Type *BasePtr = ConvertType(BaseElementTy); |
| BasePtr = llvm::PointerType::getUnqual(BasePtr); |
| llvm::Value *BaseAddrPtr = Builder.CreateBitCast(LHS.getAddress(), |
| BasePtr); |
| LHS = MakeAddrLValue(BaseAddrPtr, BaseElementTy); |
| |
| // Create an array index that will be used to walk over all of the |
| // objects we're constructing. |
| ArrayIndexVar = CreateTempAlloca(SizeTy, "object.index"); |
| llvm::Value *Zero = llvm::Constant::getNullValue(SizeTy); |
| Builder.CreateStore(Zero, ArrayIndexVar); |
| |
| |
| // Emit the block variables for the array indices, if any. |
| for (unsigned I = 0, N = ArrayIndexes.size(); I != N; ++I) |
| EmitAutoVarDecl(*ArrayIndexes[I]); |
| } |
| |
| EmitAggMemberInitializer(*this, LHS, Init, ArrayIndexVar, FieldType, |
| ArrayIndexes, 0); |
| } |
| } |
| |
| // Ensure that we destroy this object if an exception is thrown |
| // later in the constructor. |
| QualType::DestructionKind dtorKind = FieldType.isDestructedType(); |
| if (needsEHCleanup(dtorKind)) |
| pushEHDestroy(dtorKind, LHS.getAddress(), FieldType); |
| } |
| |
| /// Checks whether the given constructor is a valid subject for the |
| /// complete-to-base constructor delegation optimization, i.e. |
| /// emitting the complete constructor as a simple call to the base |
| /// constructor. |
| static bool IsConstructorDelegationValid(const CXXConstructorDecl *Ctor) { |
| |
| // Currently we disable the optimization for classes with virtual |
| // bases because (1) the addresses of parameter variables need to be |
| // consistent across all initializers but (2) the delegate function |
| // call necessarily creates a second copy of the parameter variable. |
| // |
| // The limiting example (purely theoretical AFAIK): |
| // struct A { A(int &c) { c++; } }; |
| // struct B : virtual A { |
| // B(int count) : A(count) { printf("%d\n", count); } |
| // }; |
| // ...although even this example could in principle be emitted as a |
| // delegation since the address of the parameter doesn't escape. |
| if (Ctor->getParent()->getNumVBases()) { |
| // TODO: white-list trivial vbase initializers. This case wouldn't |
| // be subject to the restrictions below. |
| |
| // TODO: white-list cases where: |
| // - there are no non-reference parameters to the constructor |
| // - the initializers don't access any non-reference parameters |
| // - the initializers don't take the address of non-reference |
| // parameters |
| // - etc. |
| // If we ever add any of the above cases, remember that: |
| // - function-try-blocks will always blacklist this optimization |
| // - we need to perform the constructor prologue and cleanup in |
| // EmitConstructorBody. |
| |
| return false; |
| } |
| |
| // We also disable the optimization for variadic functions because |
| // it's impossible to "re-pass" varargs. |
| if (Ctor->getType()->getAs<FunctionProtoType>()->isVariadic()) |
| return false; |
| |
| // FIXME: Decide if we can do a delegation of a delegating constructor. |
| if (Ctor->isDelegatingConstructor()) |
| return false; |
| |
| return true; |
| } |
| |
| // Emit code in ctor (Prologue==true) or dtor (Prologue==false) |
| // to poison the extra field paddings inserted under |
| // -fsanitize-address-field-padding=1|2. |
| void CodeGenFunction::EmitAsanPrologueOrEpilogue(bool Prologue) { |
| ASTContext &Context = getContext(); |
| const CXXRecordDecl *ClassDecl = |
| Prologue ? cast<CXXConstructorDecl>(CurGD.getDecl())->getParent() |
| : cast<CXXDestructorDecl>(CurGD.getDecl())->getParent(); |
| if (!ClassDecl->mayInsertExtraPadding()) return; |
| |
| struct SizeAndOffset { |
| uint64_t Size; |
| uint64_t Offset; |
| }; |
| |
| unsigned PtrSize = CGM.getDataLayout().getPointerSizeInBits(); |
| const ASTRecordLayout &Info = Context.getASTRecordLayout(ClassDecl); |
| |
| // Populate sizes and offsets of fields. |
| SmallVector<SizeAndOffset, 16> SSV(Info.getFieldCount()); |
| for (unsigned i = 0, e = Info.getFieldCount(); i != e; ++i) |
| SSV[i].Offset = |
| Context.toCharUnitsFromBits(Info.getFieldOffset(i)).getQuantity(); |
| |
| size_t NumFields = 0; |
| for (const auto *Field : ClassDecl->fields()) { |
| const FieldDecl *D = Field; |
| std::pair<CharUnits, CharUnits> FieldInfo = |
| Context.getTypeInfoInChars(D->getType()); |
| CharUnits FieldSize = FieldInfo.first; |
| assert(NumFields < SSV.size()); |
| SSV[NumFields].Size = D->isBitField() ? 0 : FieldSize.getQuantity(); |
| NumFields++; |
| } |
| assert(NumFields == SSV.size()); |
| if (SSV.size() <= 1) return; |
| |
| // We will insert calls to __asan_* run-time functions. |
| // LLVM AddressSanitizer pass may decide to inline them later. |
| llvm::Type *Args[2] = {IntPtrTy, IntPtrTy}; |
| llvm::FunctionType *FTy = |
| llvm::FunctionType::get(CGM.VoidTy, Args, false); |
| llvm::Constant *F = CGM.CreateRuntimeFunction( |
| FTy, Prologue ? "__asan_poison_intra_object_redzone" |
| : "__asan_unpoison_intra_object_redzone"); |
| |
| llvm::Value *ThisPtr = LoadCXXThis(); |
| ThisPtr = Builder.CreatePtrToInt(ThisPtr, IntPtrTy); |
| uint64_t TypeSize = Info.getNonVirtualSize().getQuantity(); |
| // For each field check if it has sufficient padding, |
| // if so (un)poison it with a call. |
| for (size_t i = 0; i < SSV.size(); i++) { |
| uint64_t AsanAlignment = 8; |
| uint64_t NextField = i == SSV.size() - 1 ? TypeSize : SSV[i + 1].Offset; |
| uint64_t PoisonSize = NextField - SSV[i].Offset - SSV[i].Size; |
| uint64_t EndOffset = SSV[i].Offset + SSV[i].Size; |
| if (PoisonSize < AsanAlignment || !SSV[i].Size || |
| (NextField % AsanAlignment) != 0) |
| continue; |
| Builder.CreateCall2( |
| F, Builder.CreateAdd(ThisPtr, Builder.getIntN(PtrSize, EndOffset)), |
| Builder.getIntN(PtrSize, PoisonSize)); |
| } |
| } |
| |
| /// EmitConstructorBody - Emits the body of the current constructor. |
| void CodeGenFunction::EmitConstructorBody(FunctionArgList &Args) { |
| EmitAsanPrologueOrEpilogue(true); |
| const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(CurGD.getDecl()); |
| CXXCtorType CtorType = CurGD.getCtorType(); |
| |
| assert((CGM.getTarget().getCXXABI().hasConstructorVariants() || |
| CtorType == Ctor_Complete) && |
| "can only generate complete ctor for this ABI"); |
| |
| // Before we go any further, try the complete->base constructor |
| // delegation optimization. |
| if (CtorType == Ctor_Complete && IsConstructorDelegationValid(Ctor) && |
| CGM.getTarget().getCXXABI().hasConstructorVariants()) { |
| EmitDelegateCXXConstructorCall(Ctor, Ctor_Base, Args, Ctor->getLocEnd()); |
| return; |
| } |
| |
| const FunctionDecl *Definition = 0; |
| Stmt *Body = Ctor->getBody(Definition); |
| assert(Definition == Ctor && "emitting wrong constructor body"); |
| |
| // Enter the function-try-block before the constructor prologue if |
| // applicable. |
| bool IsTryBody = (Body && isa<CXXTryStmt>(Body)); |
| if (IsTryBody) |
| EnterCXXTryStmt(*cast<CXXTryStmt>(Body), true); |
| |
| RegionCounter Cnt = getPGORegionCounter(Body); |
| Cnt.beginRegion(Builder); |
| |
| RunCleanupsScope RunCleanups(*this); |
| |
| // TODO: in restricted cases, we can emit the vbase initializers of |
| // a complete ctor and then delegate to the base ctor. |
| |
| // Emit the constructor prologue, i.e. the base and member |
| // initializers. |
| EmitCtorPrologue(Ctor, CtorType, Args); |
| |
| // Emit the body of the statement. |
| if (IsTryBody) |
| EmitStmt(cast<CXXTryStmt>(Body)->getTryBlock()); |
| else if (Body) |
| EmitStmt(Body); |
| |
| // Emit any cleanup blocks associated with the member or base |
| // initializers, which includes (along the exceptional path) the |
| // destructors for those members and bases that were fully |
| // constructed. |
| RunCleanups.ForceCleanup(); |
| |
| if (IsTryBody) |
| ExitCXXTryStmt(*cast<CXXTryStmt>(Body), true); |
| } |
| |
| namespace { |
| /// RAII object to indicate that codegen is copying the value representation |
| /// instead of the object representation. Useful when copying a struct or |
| /// class which has uninitialized members and we're only performing |
| /// lvalue-to-rvalue conversion on the object but not its members. |
| class CopyingValueRepresentation { |
| public: |
| explicit CopyingValueRepresentation(CodeGenFunction &CGF) |
| : CGF(CGF), OldSanOpts(CGF.SanOpts) { |
| CGF.SanOpts.set(SanitizerKind::Bool, false); |
| CGF.SanOpts.set(SanitizerKind::Enum, false); |
| } |
| ~CopyingValueRepresentation() { |
| CGF.SanOpts = OldSanOpts; |
| } |
| private: |
| CodeGenFunction &CGF; |
| SanitizerSet OldSanOpts; |
| }; |
| } |
| |
| namespace { |
| class FieldMemcpyizer { |
| public: |
| FieldMemcpyizer(CodeGenFunction &CGF, const CXXRecordDecl *ClassDecl, |
| const VarDecl *SrcRec) |
| : CGF(CGF), ClassDecl(ClassDecl), SrcRec(SrcRec), |
| RecLayout(CGF.getContext().getASTRecordLayout(ClassDecl)), |
| FirstField(nullptr), LastField(nullptr), FirstFieldOffset(0), |
| LastFieldOffset(0), LastAddedFieldIndex(0) {} |
| |
| bool isMemcpyableField(FieldDecl *F) const { |
| // Never memcpy fields when we are adding poisoned paddings. |
| if (CGF.getContext().getLangOpts().SanitizeAddressFieldPadding) |
| return false; |
| Qualifiers Qual = F->getType().getQualifiers(); |
| if (Qual.hasVolatile() || Qual.hasObjCLifetime()) |
| return false; |
| return true; |
| } |
| |
| void addMemcpyableField(FieldDecl *F) { |
| if (!FirstField) |
| addInitialField(F); |
| else |
| addNextField(F); |
| } |
| |
| CharUnits getMemcpySize(uint64_t FirstByteOffset) const { |
| unsigned LastFieldSize = |
| LastField->isBitField() ? |
| LastField->getBitWidthValue(CGF.getContext()) : |
| CGF.getContext().getTypeSize(LastField->getType()); |
| uint64_t MemcpySizeBits = |
| LastFieldOffset + LastFieldSize - FirstByteOffset + |
| CGF.getContext().getCharWidth() - 1; |
| CharUnits MemcpySize = |
| CGF.getContext().toCharUnitsFromBits(MemcpySizeBits); |
| return MemcpySize; |
| } |
| |
| void emitMemcpy() { |
| // Give the subclass a chance to bail out if it feels the memcpy isn't |
| // worth it (e.g. Hasn't aggregated enough data). |
| if (!FirstField) { |
| return; |
| } |
| |
| CharUnits Alignment; |
| |
| uint64_t FirstByteOffset; |
| if (FirstField->isBitField()) { |
| const CGRecordLayout &RL = |
| CGF.getTypes().getCGRecordLayout(FirstField->getParent()); |
| const CGBitFieldInfo &BFInfo = RL.getBitFieldInfo(FirstField); |
| Alignment = CharUnits::fromQuantity(BFInfo.StorageAlignment); |
| // FirstFieldOffset is not appropriate for bitfields, |
| // it won't tell us what the storage offset should be and thus might not |
| // be properly aligned. |
| // |
| // Instead calculate the storage offset using the offset of the field in |
| // the struct type. |
| const llvm::DataLayout &DL = CGF.CGM.getDataLayout(); |
| FirstByteOffset = |
| DL.getStructLayout(RL.getLLVMType()) |
| ->getElementOffsetInBits(RL.getLLVMFieldNo(FirstField)); |
| } else { |
| Alignment = CGF.getContext().getDeclAlign(FirstField); |
| FirstByteOffset = FirstFieldOffset; |
| } |
| |
| assert((CGF.getContext().toCharUnitsFromBits(FirstByteOffset) % |
| Alignment) == 0 && "Bad field alignment."); |
| |
| CharUnits MemcpySize = getMemcpySize(FirstByteOffset); |
| QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl); |
| llvm::Value *ThisPtr = CGF.LoadCXXThis(); |
| LValue DestLV = CGF.MakeNaturalAlignAddrLValue(ThisPtr, RecordTy); |
| LValue Dest = CGF.EmitLValueForFieldInitialization(DestLV, FirstField); |
| llvm::Value *SrcPtr = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(SrcRec)); |
| LValue SrcLV = CGF.MakeNaturalAlignAddrLValue(SrcPtr, RecordTy); |
| LValue Src = CGF.EmitLValueForFieldInitialization(SrcLV, FirstField); |
| |
| emitMemcpyIR(Dest.isBitField() ? Dest.getBitFieldAddr() : Dest.getAddress(), |
| Src.isBitField() ? Src.getBitFieldAddr() : Src.getAddress(), |
| MemcpySize, Alignment); |
| reset(); |
| } |
| |
| void reset() { |
| FirstField = nullptr; |
| } |
| |
| protected: |
| CodeGenFunction &CGF; |
| const CXXRecordDecl *ClassDecl; |
| |
| private: |
| |
| void emitMemcpyIR(llvm::Value *DestPtr, llvm::Value *SrcPtr, |
| CharUnits Size, CharUnits Alignment) { |
| llvm::PointerType *DPT = cast<llvm::PointerType>(DestPtr->getType()); |
| llvm::Type *DBP = |
| llvm::Type::getInt8PtrTy(CGF.getLLVMContext(), DPT->getAddressSpace()); |
| DestPtr = CGF.Builder.CreateBitCast(DestPtr, DBP); |
| |
| llvm::PointerType *SPT = cast<llvm::PointerType>(SrcPtr->getType()); |
| llvm::Type *SBP = |
| llvm::Type::getInt8PtrTy(CGF.getLLVMContext(), SPT->getAddressSpace()); |
| SrcPtr = CGF.Builder.CreateBitCast(SrcPtr, SBP); |
| |
| CGF.Builder.CreateMemCpy(DestPtr, SrcPtr, Size.getQuantity(), |
| Alignment.getQuantity()); |
| } |
| |
| void addInitialField(FieldDecl *F) { |
| FirstField = F; |
| LastField = F; |
| FirstFieldOffset = RecLayout.getFieldOffset(F->getFieldIndex()); |
| LastFieldOffset = FirstFieldOffset; |
| LastAddedFieldIndex = F->getFieldIndex(); |
| return; |
| } |
| |
| void addNextField(FieldDecl *F) { |
| // For the most part, the following invariant will hold: |
| // F->getFieldIndex() == LastAddedFieldIndex + 1 |
| // The one exception is that Sema won't add a copy-initializer for an |
| // unnamed bitfield, which will show up here as a gap in the sequence. |
| assert(F->getFieldIndex() >= LastAddedFieldIndex + 1 && |
| "Cannot aggregate fields out of order."); |
| LastAddedFieldIndex = F->getFieldIndex(); |
| |
| // The 'first' and 'last' fields are chosen by offset, rather than field |
| // index. This allows the code to support bitfields, as well as regular |
| // fields. |
| uint64_t FOffset = RecLayout.getFieldOffset(F->getFieldIndex()); |
| if (FOffset < FirstFieldOffset) { |
| FirstField = F; |
| FirstFieldOffset = FOffset; |
| } else if (FOffset > LastFieldOffset) { |
| LastField = F; |
| LastFieldOffset = FOffset; |
| } |
| } |
| |
| const VarDecl *SrcRec; |
| const ASTRecordLayout &RecLayout; |
| FieldDecl *FirstField; |
| FieldDecl *LastField; |
| uint64_t FirstFieldOffset, LastFieldOffset; |
| unsigned LastAddedFieldIndex; |
| }; |
| |
| class ConstructorMemcpyizer : public FieldMemcpyizer { |
| private: |
| |
| /// Get source argument for copy constructor. Returns null if not a copy |
| /// constructor. |
| static const VarDecl *getTrivialCopySource(CodeGenFunction &CGF, |
| const CXXConstructorDecl *CD, |
| FunctionArgList &Args) { |
| if (CD->isCopyOrMoveConstructor() && CD->isDefaulted()) |
| return Args[CGF.CGM.getCXXABI().getSrcArgforCopyCtor(CD, Args)]; |
| return nullptr; |
| } |
| |
| // Returns true if a CXXCtorInitializer represents a member initialization |
| // that can be rolled into a memcpy. |
| bool isMemberInitMemcpyable(CXXCtorInitializer *MemberInit) const { |
| if (!MemcpyableCtor) |
| return false; |
| FieldDecl *Field = MemberInit->getMember(); |
| assert(Field && "No field for member init."); |
| QualType FieldType = Field->getType(); |
| CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(MemberInit->getInit()); |
| |
| // Bail out on non-POD, not-trivially-constructable members. |
| if (!(CE && CE->getConstructor()->isTrivial()) && |
| !(FieldType.isTriviallyCopyableType(CGF.getContext()) || |
| FieldType->isReferenceType())) |
| return false; |
| |
| // Bail out on volatile fields. |
| if (!isMemcpyableField(Field)) |
| return false; |
| |
| // Otherwise we're good. |
| return true; |
| } |
| |
| public: |
| ConstructorMemcpyizer(CodeGenFunction &CGF, const CXXConstructorDecl *CD, |
| FunctionArgList &Args) |
| : FieldMemcpyizer(CGF, CD->getParent(), getTrivialCopySource(CGF, CD, Args)), |
| ConstructorDecl(CD), |
| MemcpyableCtor(CD->isDefaulted() && |
| CD->isCopyOrMoveConstructor() && |
| CGF.getLangOpts().getGC() == LangOptions::NonGC), |
| Args(Args) { } |
| |
| void addMemberInitializer(CXXCtorInitializer *MemberInit) { |
| if (isMemberInitMemcpyable(MemberInit)) { |
| AggregatedInits.push_back(MemberInit); |
| addMemcpyableField(MemberInit->getMember()); |
| } else { |
| emitAggregatedInits(); |
| EmitMemberInitializer(CGF, ConstructorDecl->getParent(), MemberInit, |
| ConstructorDecl, Args); |
| } |
| } |
| |
| void emitAggregatedInits() { |
| if (AggregatedInits.size() <= 1) { |
| // This memcpy is too small to be worthwhile. Fall back on default |
| // codegen. |
| if (!AggregatedInits.empty()) { |
| CopyingValueRepresentation CVR(CGF); |
| EmitMemberInitializer(CGF, ConstructorDecl->getParent(), |
| AggregatedInits[0], ConstructorDecl, Args); |
| } |
| reset(); |
| return; |
| } |
| |
| pushEHDestructors(); |
| emitMemcpy(); |
| AggregatedInits.clear(); |
| } |
| |
| void pushEHDestructors() { |
| llvm::Value *ThisPtr = CGF.LoadCXXThis(); |
| QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl); |
| LValue LHS = CGF.MakeNaturalAlignAddrLValue(ThisPtr, RecordTy); |
| |
| for (unsigned i = 0; i < AggregatedInits.size(); ++i) { |
| QualType FieldType = AggregatedInits[i]->getMember()->getType(); |
| QualType::DestructionKind dtorKind = FieldType.isDestructedType(); |
| if (CGF.needsEHCleanup(dtorKind)) |
| CGF.pushEHDestroy(dtorKind, LHS.getAddress(), FieldType); |
| } |
| } |
| |
| void finish() { |
| emitAggregatedInits(); |
| } |
| |
| private: |
| const CXXConstructorDecl *ConstructorDecl; |
| bool MemcpyableCtor; |
| FunctionArgList &Args; |
| SmallVector<CXXCtorInitializer*, 16> AggregatedInits; |
| }; |
| |
| class AssignmentMemcpyizer : public FieldMemcpyizer { |
| private: |
| |
| // Returns the memcpyable field copied by the given statement, if one |
| // exists. Otherwise returns null. |
| FieldDecl *getMemcpyableField(Stmt *S) { |
| if (!AssignmentsMemcpyable) |
| return nullptr; |
| if (BinaryOperator *BO = dyn_cast<BinaryOperator>(S)) { |
| // Recognise trivial assignments. |
| if (BO->getOpcode() != BO_Assign) |
| return nullptr; |
| MemberExpr *ME = dyn_cast<MemberExpr>(BO->getLHS()); |
| if (!ME) |
| return nullptr; |
| FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl()); |
| if (!Field || !isMemcpyableField(Field)) |
| return nullptr; |
| Stmt *RHS = BO->getRHS(); |
| if (ImplicitCastExpr *EC = dyn_cast<ImplicitCastExpr>(RHS)) |
| RHS = EC->getSubExpr(); |
| if (!RHS) |
| return nullptr; |
| MemberExpr *ME2 = dyn_cast<MemberExpr>(RHS); |
| if (dyn_cast<FieldDecl>(ME2->getMemberDecl()) != Field) |
| return nullptr; |
| return Field; |
| } else if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(S)) { |
| CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MCE->getCalleeDecl()); |
| if (!(MD && (MD->isCopyAssignmentOperator() || |
| MD->isMoveAssignmentOperator()) && |
| MD->isTrivial())) |
| return nullptr; |
| MemberExpr *IOA = dyn_cast<MemberExpr>(MCE->getImplicitObjectArgument()); |
| if (!IOA) |
| return nullptr; |
| FieldDecl *Field = dyn_cast<FieldDecl>(IOA->getMemberDecl()); |
| if (!Field || !isMemcpyableField(Field)) |
| return nullptr; |
| MemberExpr *Arg0 = dyn_cast<MemberExpr>(MCE->getArg(0)); |
| if (!Arg0 || Field != dyn_cast<FieldDecl>(Arg0->getMemberDecl())) |
| return nullptr; |
| return Field; |
| } else if (CallExpr *CE = dyn_cast<CallExpr>(S)) { |
| FunctionDecl *FD = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); |
| if (!FD || FD->getBuiltinID() != Builtin::BI__builtin_memcpy) |
| return nullptr; |
| Expr *DstPtr = CE->getArg(0); |
| if (ImplicitCastExpr *DC = dyn_cast<ImplicitCastExpr>(DstPtr)) |
| DstPtr = DC->getSubExpr(); |
| UnaryOperator *DUO = dyn_cast<UnaryOperator>(DstPtr); |
| if (!DUO || DUO->getOpcode() != UO_AddrOf) |
| return nullptr; |
| MemberExpr *ME = dyn_cast<MemberExpr>(DUO->getSubExpr()); |
| if (!ME) |
| return nullptr; |
| FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl()); |
| if (!Field || !isMemcpyableField(Field)) |
| return nullptr; |
| Expr *SrcPtr = CE->getArg(1); |
| if (ImplicitCastExpr *SC = dyn_cast<ImplicitCastExpr>(SrcPtr)) |
| SrcPtr = SC->getSubExpr(); |
| UnaryOperator *SUO = dyn_cast<UnaryOperator>(SrcPtr); |
| if (!SUO || SUO->getOpcode() != UO_AddrOf) |
| return nullptr; |
| MemberExpr *ME2 = dyn_cast<MemberExpr>(SUO->getSubExpr()); |
| if (!ME2 || Field != dyn_cast<FieldDecl>(ME2->getMemberDecl())) |
| return nullptr; |
| return Field; |
| } |
| |
| return nullptr; |
| } |
| |
| bool AssignmentsMemcpyable; |
| SmallVector<Stmt*, 16> AggregatedStmts; |
| |
| public: |
| |
| AssignmentMemcpyizer(CodeGenFunction &CGF, const CXXMethodDecl *AD, |
| FunctionArgList &Args) |
| : FieldMemcpyizer(CGF, AD->getParent(), Args[Args.size() - 1]), |
| AssignmentsMemcpyable(CGF.getLangOpts().getGC() == LangOptions::NonGC) { |
| assert(Args.size() == 2); |
| } |
| |
| void emitAssignment(Stmt *S) { |
| FieldDecl *F = getMemcpyableField(S); |
| if (F) { |
| addMemcpyableField(F); |
| AggregatedStmts.push_back(S); |
| } else { |
| emitAggregatedStmts(); |
| CGF.EmitStmt(S); |
| } |
| } |
| |
| void emitAggregatedStmts() { |
| if (AggregatedStmts.size() <= 1) { |
| if (!AggregatedStmts.empty()) { |
| CopyingValueRepresentation CVR(CGF); |
| CGF.EmitStmt(AggregatedStmts[0]); |
| } |
| reset(); |
| } |
| |
| emitMemcpy(); |
| AggregatedStmts.clear(); |
| } |
| |
| void finish() { |
| emitAggregatedStmts(); |
| } |
| }; |
| |
| } |
| |
| /// EmitCtorPrologue - This routine generates necessary code to initialize |
| /// base classes and non-static data members belonging to this constructor. |
| void CodeGenFunction::EmitCtorPrologue(const CXXConstructorDecl *CD, |
| CXXCtorType CtorType, |
| FunctionArgList &Args) { |
| if (CD->isDelegatingConstructor()) |
| return EmitDelegatingCXXConstructorCall(CD, Args); |
| |
| const CXXRecordDecl *ClassDecl = CD->getParent(); |
| |
| CXXConstructorDecl::init_const_iterator B = CD->init_begin(), |
| E = CD->init_end(); |
| |
| llvm::BasicBlock *BaseCtorContinueBB = nullptr; |
| if (ClassDecl->getNumVBases() && |
| !CGM.getTarget().getCXXABI().hasConstructorVariants()) { |
| // The ABIs that don't have constructor variants need to put a branch |
| // before the virtual base initialization code. |
| BaseCtorContinueBB = |
| CGM.getCXXABI().EmitCtorCompleteObjectHandler(*this, ClassDecl); |
| assert(BaseCtorContinueBB); |
| } |
| |
| // Virtual base initializers first. |
| for (; B != E && (*B)->isBaseInitializer() && (*B)->isBaseVirtual(); B++) { |
| EmitBaseInitializer(*this, ClassDecl, *B, CtorType); |
| } |
| |
| if (BaseCtorContinueBB) { |
| // Complete object handler should continue to the remaining initializers. |
| Builder.CreateBr(BaseCtorContinueBB); |
| EmitBlock(BaseCtorContinueBB); |
| } |
| |
| // Then, non-virtual base initializers. |
| for (; B != E && (*B)->isBaseInitializer(); B++) { |
| assert(!(*B)->isBaseVirtual()); |
| EmitBaseInitializer(*this, ClassDecl, *B, CtorType); |
| } |
| |
| InitializeVTablePointers(ClassDecl); |
| |
| // And finally, initialize class members. |
| FieldConstructionScope FCS(*this, CXXThisValue); |
| ConstructorMemcpyizer CM(*this, CD, Args); |
| for (; B != E; B++) { |
| CXXCtorInitializer *Member = (*B); |
| assert(!Member->isBaseInitializer()); |
| assert(Member->isAnyMemberInitializer() && |
| "Delegating initializer on non-delegating constructor"); |
| CM.addMemberInitializer(Member); |
| } |
| CM.finish(); |
| } |
| |
| static bool |
| FieldHasTrivialDestructorBody(ASTContext &Context, const FieldDecl *Field); |
| |
| static bool |
| HasTrivialDestructorBody(ASTContext &Context, |
| const CXXRecordDecl *BaseClassDecl, |
| const CXXRecordDecl *MostDerivedClassDecl) |
| { |
| // If the destructor is trivial we don't have to check anything else. |
| if (BaseClassDecl->hasTrivialDestructor()) |
| return true; |
| |
| if (!BaseClassDecl->getDestructor()->hasTrivialBody()) |
| return false; |
| |
| // Check fields. |
| for (const auto *Field : BaseClassDecl->fields()) |
| if (!FieldHasTrivialDestructorBody(Context, Field)) |
| return false; |
| |
| // Check non-virtual bases. |
| for (const auto &I : BaseClassDecl->bases()) { |
| if (I.isVirtual()) |
| continue; |
| |
| const CXXRecordDecl *NonVirtualBase = |
| cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl()); |
| if (!HasTrivialDestructorBody(Context, NonVirtualBase, |
| MostDerivedClassDecl)) |
| return false; |
| } |
| |
| if (BaseClassDecl == MostDerivedClassDecl) { |
| // Check virtual bases. |
| for (const auto &I : BaseClassDecl->vbases()) { |
| const CXXRecordDecl *VirtualBase = |
| cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl()); |
| if (!HasTrivialDestructorBody(Context, VirtualBase, |
| MostDerivedClassDecl)) |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| static bool |
| FieldHasTrivialDestructorBody(ASTContext &Context, |
| const FieldDecl *Field) |
| { |
| QualType FieldBaseElementType = Context.getBaseElementType(Field->getType()); |
| |
| const RecordType *RT = FieldBaseElementType->getAs<RecordType>(); |
| if (!RT) |
| return true; |
| |
| CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl()); |
| return HasTrivialDestructorBody(Context, FieldClassDecl, FieldClassDecl); |
| } |
| |
| /// CanSkipVTablePointerInitialization - Check whether we need to initialize |
| /// any vtable pointers before calling this destructor. |
| static bool CanSkipVTablePointerInitialization(ASTContext &Context, |
| const CXXDestructorDecl *Dtor) { |
| if (!Dtor->hasTrivialBody()) |
| return false; |
| |
| // Check the fields. |
| const CXXRecordDecl *ClassDecl = Dtor->getParent(); |
| for (const auto *Field : ClassDecl->fields()) |
| if (!FieldHasTrivialDestructorBody(Context, Field)) |
| return false; |
| |
| return true; |
| } |
| |
| /// EmitDestructorBody - Emits the body of the current destructor. |
| void CodeGenFunction::EmitDestructorBody(FunctionArgList &Args) { |
| const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CurGD.getDecl()); |
| CXXDtorType DtorType = CurGD.getDtorType(); |
| |
| // The call to operator delete in a deleting destructor happens |
| // outside of the function-try-block, which means it's always |
| // possible to delegate the destructor body to the complete |
| // destructor. Do so. |
| if (DtorType == Dtor_Deleting) { |
| EnterDtorCleanups(Dtor, Dtor_Deleting); |
| EmitCXXDestructorCall(Dtor, Dtor_Complete, /*ForVirtualBase=*/false, |
| /*Delegating=*/false, LoadCXXThis()); |
| PopCleanupBlock(); |
| return; |
| } |
| |
| Stmt *Body = Dtor->getBody(); |
| |
| // If the body is a function-try-block, enter the try before |
| // anything else. |
| bool isTryBody = (Body && isa<CXXTryStmt>(Body)); |
| if (isTryBody) |
| EnterCXXTryStmt(*cast<CXXTryStmt>(Body), true); |
| EmitAsanPrologueOrEpilogue(false); |
| |
| // Enter the epilogue cleanups. |
| RunCleanupsScope DtorEpilogue(*this); |
| |
| // If this is the complete variant, just invoke the base variant; |
| // the epilogue will destruct the virtual bases. But we can't do |
| // this optimization if the body is a function-try-block, because |
| // we'd introduce *two* handler blocks. In the Microsoft ABI, we |
| // always delegate because we might not have a definition in this TU. |
| switch (DtorType) { |
| case Dtor_Comdat: |
| llvm_unreachable("not expecting a COMDAT"); |
| |
| case Dtor_Deleting: llvm_unreachable("already handled deleting case"); |
| |
| case Dtor_Complete: |
| assert((Body || getTarget().getCXXABI().isMicrosoft()) && |
| "can't emit a dtor without a body for non-Microsoft ABIs"); |
| |
| // Enter the cleanup scopes for virtual bases. |
| EnterDtorCleanups(Dtor, Dtor_Complete); |
| |
| if (!isTryBody) { |
| EmitCXXDestructorCall(Dtor, Dtor_Base, /*ForVirtualBase=*/false, |
| /*Delegating=*/false, LoadCXXThis()); |
| break; |
| } |
| // Fallthrough: act like we're in the base variant. |
| |
| case Dtor_Base: |
| assert(Body); |
| |
| RegionCounter Cnt = getPGORegionCounter(Body); |
| Cnt.beginRegion(Builder); |
| |
| // Enter the cleanup scopes for fields and non-virtual bases. |
| EnterDtorCleanups(Dtor, Dtor_Base); |
| |
| // Initialize the vtable pointers before entering the body. |
| if (!CanSkipVTablePointerInitialization(getContext(), Dtor)) |
| InitializeVTablePointers(Dtor->getParent()); |
| |
| if (isTryBody) |
| EmitStmt(cast<CXXTryStmt>(Body)->getTryBlock()); |
| else if (Body) |
| EmitStmt(Body); |
| else { |
| assert(Dtor->isImplicit() && "bodyless dtor not implicit"); |
| // nothing to do besides what's in the epilogue |
| } |
| // -fapple-kext must inline any call to this dtor into |
| // the caller's body. |
| if (getLangOpts().AppleKext) |
| CurFn->addFnAttr(llvm::Attribute::AlwaysInline); |
| break; |
| } |
| |
| // Jump out through the epilogue cleanups. |
| DtorEpilogue.ForceCleanup(); |
| |
| // Exit the try if applicable. |
| if (isTryBody) |
| ExitCXXTryStmt(*cast<CXXTryStmt>(Body), true); |
| } |
| |
| void CodeGenFunction::emitImplicitAssignmentOperatorBody(FunctionArgList &Args) { |
| const CXXMethodDecl *AssignOp = cast<CXXMethodDecl>(CurGD.getDecl()); |
| const Stmt *RootS = AssignOp->getBody(); |
| assert(isa<CompoundStmt>(RootS) && |
| "Body of an implicit assignment operator should be compound stmt."); |
| const CompoundStmt *RootCS = cast<CompoundStmt>(RootS); |
| |
| LexicalScope Scope(*this, RootCS->getSourceRange()); |
| |
| AssignmentMemcpyizer AM(*this, AssignOp, Args); |
| for (auto *I : RootCS->body()) |
| AM.emitAssignment(I); |
| AM.finish(); |
| } |
| |
| namespace { |
| /// Call the operator delete associated with the current destructor. |
| struct CallDtorDelete : EHScopeStack::Cleanup { |
| CallDtorDelete() {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CGF.CurCodeDecl); |
| const CXXRecordDecl *ClassDecl = Dtor->getParent(); |
| CGF.EmitDeleteCall(Dtor->getOperatorDelete(), CGF.LoadCXXThis(), |
| CGF.getContext().getTagDeclType(ClassDecl)); |
| } |
| }; |
| |
| struct CallDtorDeleteConditional : EHScopeStack::Cleanup { |
| llvm::Value *ShouldDeleteCondition; |
| public: |
| CallDtorDeleteConditional(llvm::Value *ShouldDeleteCondition) |
| : ShouldDeleteCondition(ShouldDeleteCondition) { |
| assert(ShouldDeleteCondition != nullptr); |
| } |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| llvm::BasicBlock *callDeleteBB = CGF.createBasicBlock("dtor.call_delete"); |
| llvm::BasicBlock *continueBB = CGF.createBasicBlock("dtor.continue"); |
| llvm::Value *ShouldCallDelete |
| = CGF.Builder.CreateIsNull(ShouldDeleteCondition); |
| CGF.Builder.CreateCondBr(ShouldCallDelete, continueBB, callDeleteBB); |
| |
| CGF.EmitBlock(callDeleteBB); |
| const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CGF.CurCodeDecl); |
| const CXXRecordDecl *ClassDecl = Dtor->getParent(); |
| CGF.EmitDeleteCall(Dtor->getOperatorDelete(), CGF.LoadCXXThis(), |
| CGF.getContext().getTagDeclType(ClassDecl)); |
| CGF.Builder.CreateBr(continueBB); |
| |
| CGF.EmitBlock(continueBB); |
| } |
| }; |
| |
| class DestroyField : public EHScopeStack::Cleanup { |
| const FieldDecl *field; |
| CodeGenFunction::Destroyer *destroyer; |
| bool useEHCleanupForArray; |
| |
| public: |
| DestroyField(const FieldDecl *field, CodeGenFunction::Destroyer *destroyer, |
| bool useEHCleanupForArray) |
| : field(field), destroyer(destroyer), |
| useEHCleanupForArray(useEHCleanupForArray) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| // Find the address of the field. |
| llvm::Value *thisValue = CGF.LoadCXXThis(); |
| QualType RecordTy = CGF.getContext().getTagDeclType(field->getParent()); |
| LValue ThisLV = CGF.MakeAddrLValue(thisValue, RecordTy); |
| LValue LV = CGF.EmitLValueForField(ThisLV, field); |
| assert(LV.isSimple()); |
| |
| CGF.emitDestroy(LV.getAddress(), field->getType(), destroyer, |
| flags.isForNormalCleanup() && useEHCleanupForArray); |
| } |
| }; |
| } |
| |
| /// \brief Emit all code that comes at the end of class's |
| /// destructor. This is to call destructors on members and base classes |
| /// in reverse order of their construction. |
| void CodeGenFunction::EnterDtorCleanups(const CXXDestructorDecl *DD, |
| CXXDtorType DtorType) { |
| assert((!DD->isTrivial() || DD->hasAttr<DLLExportAttr>()) && |
| "Should not emit dtor epilogue for non-exported trivial dtor!"); |
| |
| // The deleting-destructor phase just needs to call the appropriate |
| // operator delete that Sema picked up. |
| if (DtorType == Dtor_Deleting) { |
| assert(DD->getOperatorDelete() && |
| "operator delete missing - EnterDtorCleanups"); |
| if (CXXStructorImplicitParamValue) { |
| // If there is an implicit param to the deleting dtor, it's a boolean |
| // telling whether we should call delete at the end of the dtor. |
| EHStack.pushCleanup<CallDtorDeleteConditional>( |
| NormalAndEHCleanup, CXXStructorImplicitParamValue); |
| } else { |
| EHStack.pushCleanup<CallDtorDelete>(NormalAndEHCleanup); |
| } |
| return; |
| } |
| |
| const CXXRecordDecl *ClassDecl = DD->getParent(); |
| |
| // Unions have no bases and do not call field destructors. |
| if (ClassDecl->isUnion()) |
| return; |
| |
| // The complete-destructor phase just destructs all the virtual bases. |
| if (DtorType == Dtor_Complete) { |
| |
| // We push them in the forward order so that they'll be popped in |
| // the reverse order. |
| for (const auto &Base : ClassDecl->vbases()) { |
| CXXRecordDecl *BaseClassDecl |
| = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl()); |
| |
| // Ignore trivial destructors. |
| if (BaseClassDecl->hasTrivialDestructor()) |
| continue; |
| |
| EHStack.pushCleanup<CallBaseDtor>(NormalAndEHCleanup, |
| BaseClassDecl, |
| /*BaseIsVirtual*/ true); |
| } |
| |
| return; |
| } |
| |
| assert(DtorType == Dtor_Base); |
| |
| // Destroy non-virtual bases. |
| for (const auto &Base : ClassDecl->bases()) { |
| // Ignore virtual bases. |
| if (Base.isVirtual()) |
| continue; |
| |
| CXXRecordDecl *BaseClassDecl = Base.getType()->getAsCXXRecordDecl(); |
| |
| // Ignore trivial destructors. |
| if (BaseClassDecl->hasTrivialDestructor()) |
| continue; |
| |
| EHStack.pushCleanup<CallBaseDtor>(NormalAndEHCleanup, |
| BaseClassDecl, |
| /*BaseIsVirtual*/ false); |
| } |
| |
| // Destroy direct fields. |
| for (const auto *Field : ClassDecl->fields()) { |
| QualType type = Field->getType(); |
| QualType::DestructionKind dtorKind = type.isDestructedType(); |
| if (!dtorKind) continue; |
| |
| // Anonymous union members do not have their destructors called. |
| const RecordType *RT = type->getAsUnionType(); |
| if (RT && RT->getDecl()->isAnonymousStructOrUnion()) continue; |
| |
| CleanupKind cleanupKind = getCleanupKind(dtorKind); |
| EHStack.pushCleanup<DestroyField>(cleanupKind, Field, |
| getDestroyer(dtorKind), |
| cleanupKind & EHCleanup); |
| } |
| } |
| |
| /// EmitCXXAggrConstructorCall - Emit a loop to call a particular |
| /// constructor for each of several members of an array. |
| /// |
| /// \param ctor the constructor to call for each element |
| /// \param arrayType the type of the array to initialize |
| /// \param arrayBegin an arrayType* |
| /// \param zeroInitialize true if each element should be |
| /// zero-initialized before it is constructed |
| void CodeGenFunction::EmitCXXAggrConstructorCall( |
| const CXXConstructorDecl *ctor, const ConstantArrayType *arrayType, |
| llvm::Value *arrayBegin, const CXXConstructExpr *E, bool zeroInitialize) { |
| QualType elementType; |
| llvm::Value *numElements = |
| emitArrayLength(arrayType, elementType, arrayBegin); |
| |
| EmitCXXAggrConstructorCall(ctor, numElements, arrayBegin, E, zeroInitialize); |
| } |
| |
| /// EmitCXXAggrConstructorCall - Emit a loop to call a particular |
| /// constructor for each of several members of an array. |
| /// |
| /// \param ctor the constructor to call for each element |
| /// \param numElements the number of elements in the array; |
| /// may be zero |
| /// \param arrayBegin a T*, where T is the type constructed by ctor |
| /// \param zeroInitialize true if each element should be |
| /// zero-initialized before it is constructed |
| void CodeGenFunction::EmitCXXAggrConstructorCall(const CXXConstructorDecl *ctor, |
| llvm::Value *numElements, |
| llvm::Value *arrayBegin, |
| const CXXConstructExpr *E, |
| bool zeroInitialize) { |
| |
| // It's legal for numElements to be zero. This can happen both |
| // dynamically, because x can be zero in 'new A[x]', and statically, |
| // because of GCC extensions that permit zero-length arrays. There |
| // are probably legitimate places where we could assume that this |
| // doesn't happen, but it's not clear that it's worth it. |
| llvm::BranchInst *zeroCheckBranch = nullptr; |
| |
| // Optimize for a constant count. |
| llvm::ConstantInt *constantCount |
| = dyn_cast<llvm::ConstantInt>(numElements); |
| if (constantCount) { |
| // Just skip out if the constant count is zero. |
| if (constantCount->isZero()) return; |
| |
| // Otherwise, emit the check. |
| } else { |
| llvm::BasicBlock *loopBB = createBasicBlock("new.ctorloop"); |
| llvm::Value *iszero = Builder.CreateIsNull(numElements, "isempty"); |
| zeroCheckBranch = Builder.CreateCondBr(iszero, loopBB, loopBB); |
| EmitBlock(loopBB); |
| } |
| |
| // Find the end of the array. |
| llvm::Value *arrayEnd = Builder.CreateInBoundsGEP(arrayBegin, numElements, |
| "arrayctor.end"); |
| |
| // Enter the loop, setting up a phi for the current location to initialize. |
| llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); |
| llvm::BasicBlock *loopBB = createBasicBlock("arrayctor.loop"); |
| EmitBlock(loopBB); |
| llvm::PHINode *cur = Builder.CreatePHI(arrayBegin->getType(), 2, |
| "arrayctor.cur"); |
| cur->addIncoming(arrayBegin, entryBB); |
| |
| // Inside the loop body, emit the constructor call on the array element. |
| |
| QualType type = getContext().getTypeDeclType(ctor->getParent()); |
| |
| // Zero initialize the storage, if requested. |
| if (zeroInitialize) |
| EmitNullInitialization(cur, type); |
| |
| // C++ [class.temporary]p4: |
| // There are two contexts in which temporaries are destroyed at a different |
| // point than the end of the full-expression. The first context is when a |
| // default constructor is called to initialize an element of an array. |
| // If the constructor has one or more default arguments, the destruction of |
| // every temporary created in a default argument expression is sequenced |
| // before the construction of the next array element, if any. |
| |
| { |
| RunCleanupsScope Scope(*this); |
| |
| // Evaluate the constructor and its arguments in a regular |
| // partial-destroy cleanup. |
| if (getLangOpts().Exceptions && |
| !ctor->getParent()->hasTrivialDestructor()) { |
| Destroyer *destroyer = destroyCXXObject; |
| pushRegularPartialArrayCleanup(arrayBegin, cur, type, *destroyer); |
| } |
| |
| EmitCXXConstructorCall(ctor, Ctor_Complete, /*ForVirtualBase=*/false, |
| /*Delegating=*/false, cur, E); |
| } |
| |
| // Go to the next element. |
| llvm::Value *next = |
| Builder.CreateInBoundsGEP(cur, llvm::ConstantInt::get(SizeTy, 1), |
| "arrayctor.next"); |
| cur->addIncoming(next, Builder.GetInsertBlock()); |
| |
| // Check whether that's the end of the loop. |
| llvm::Value *done = Builder.CreateICmpEQ(next, arrayEnd, "arrayctor.done"); |
| llvm::BasicBlock *contBB = createBasicBlock("arrayctor.cont"); |
| Builder.CreateCondBr(done, contBB, loopBB); |
| |
| // Patch the earlier check to skip over the loop. |
| if (zeroCheckBranch) zeroCheckBranch->setSuccessor(0, contBB); |
| |
| EmitBlock(contBB); |
| } |
| |
| void CodeGenFunction::destroyCXXObject(CodeGenFunction &CGF, |
| llvm::Value *addr, |
| QualType type) { |
| const RecordType *rtype = type->castAs<RecordType>(); |
| const CXXRecordDecl *record = cast<CXXRecordDecl>(rtype->getDecl()); |
| const CXXDestructorDecl *dtor = record->getDestructor(); |
| assert(!dtor->isTrivial()); |
| CGF.EmitCXXDestructorCall(dtor, Dtor_Complete, /*for vbase*/ false, |
| /*Delegating=*/false, addr); |
| } |
| |
| void CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D, |
| CXXCtorType Type, |
| bool ForVirtualBase, |
| bool Delegating, llvm::Value *This, |
| const CXXConstructExpr *E) { |
| // If this is a trivial constructor, just emit what's needed. |
| if (D->isTrivial() && !D->getParent()->mayInsertExtraPadding()) { |
| if (E->getNumArgs() == 0) { |
| // Trivial default constructor, no codegen required. |
| assert(D->isDefaultConstructor() && |
| "trivial 0-arg ctor not a default ctor"); |
| return; |
| } |
| |
| assert(E->getNumArgs() == 1 && "unexpected argcount for trivial ctor"); |
| assert(D->isCopyOrMoveConstructor() && |
| "trivial 1-arg ctor not a copy/move ctor"); |
| |
| const Expr *Arg = E->getArg(0); |
| QualType SrcTy = Arg->getType(); |
| llvm::Value *Src = EmitLValue(Arg).getAddress(); |
| QualType DestTy = getContext().getTypeDeclType(D->getParent()); |
| EmitAggregateCopyCtor(This, Src, DestTy, SrcTy); |
| return; |
| } |
| |
| // C++11 [class.mfct.non-static]p2: |
| // If a non-static member function of a class X is called for an object that |
| // is not of type X, or of a type derived from X, the behavior is undefined. |
| // FIXME: Provide a source location here. |
| EmitTypeCheck(CodeGenFunction::TCK_ConstructorCall, SourceLocation(), This, |
| getContext().getRecordType(D->getParent())); |
| |
| CallArgList Args; |
| |
| // Push the this ptr. |
| Args.add(RValue::get(This), D->getThisType(getContext())); |
| |
| // Add the rest of the user-supplied arguments. |
| const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>(); |
| EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end(), E->getConstructor()); |
| |
| // Insert any ABI-specific implicit constructor arguments. |
| unsigned ExtraArgs = CGM.getCXXABI().addImplicitConstructorArgs( |
| *this, D, Type, ForVirtualBase, Delegating, Args); |
| |
| // Emit the call. |
| llvm::Value *Callee = CGM.getAddrOfCXXStructor(D, getFromCtorType(Type)); |
| const CGFunctionInfo &Info = |
| CGM.getTypes().arrangeCXXConstructorCall(Args, D, Type, ExtraArgs); |
| EmitCall(Info, Callee, ReturnValueSlot(), Args, D); |
| } |
| |
| void |
| CodeGenFunction::EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D, |
| llvm::Value *This, llvm::Value *Src, |
| const CXXConstructExpr *E) { |
| if (D->isTrivial() && |
| !D->getParent()->mayInsertExtraPadding()) { |
| assert(E->getNumArgs() == 1 && "unexpected argcount for trivial ctor"); |
| assert(D->isCopyOrMoveConstructor() && |
| "trivial 1-arg ctor not a copy/move ctor"); |
| EmitAggregateCopyCtor(This, Src, |
| getContext().getTypeDeclType(D->getParent()), |
| E->arg_begin()->getType()); |
| return; |
| } |
| llvm::Value *Callee = CGM.getAddrOfCXXStructor(D, StructorType::Complete); |
| assert(D->isInstance() && |
| "Trying to emit a member call expr on a static method!"); |
| |
| const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>(); |
| |
| CallArgList Args; |
| |
| // Push the this ptr. |
| Args.add(RValue::get(This), D->getThisType(getContext())); |
| |
| // Push the src ptr. |
| QualType QT = *(FPT->param_type_begin()); |
| llvm::Type *t = CGM.getTypes().ConvertType(QT); |
| Src = Builder.CreateBitCast(Src, t); |
| Args.add(RValue::get(Src), QT); |
| |
| // Skip over first argument (Src). |
| EmitCallArgs(Args, FPT, E->arg_begin() + 1, E->arg_end(), E->getConstructor(), |
| /*ParamsToSkip*/ 1); |
| |
| EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, RequiredArgs::All), |
| Callee, ReturnValueSlot(), Args, D); |
| } |
| |
| void |
| CodeGenFunction::EmitDelegateCXXConstructorCall(const CXXConstructorDecl *Ctor, |
| CXXCtorType CtorType, |
| const FunctionArgList &Args, |
| SourceLocation Loc) { |
| CallArgList DelegateArgs; |
| |
| FunctionArgList::const_iterator I = Args.begin(), E = Args.end(); |
| assert(I != E && "no parameters to constructor"); |
| |
| // this |
| DelegateArgs.add(RValue::get(LoadCXXThis()), (*I)->getType()); |
| ++I; |
| |
| // vtt |
| if (llvm::Value *VTT = GetVTTParameter(GlobalDecl(Ctor, CtorType), |
| /*ForVirtualBase=*/false, |
| /*Delegating=*/true)) { |
| QualType VoidPP = getContext().getPointerType(getContext().VoidPtrTy); |
| DelegateArgs.add(RValue::get(VTT), VoidPP); |
| |
| if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) { |
| assert(I != E && "cannot skip vtt parameter, already done with args"); |
| assert((*I)->getType() == VoidPP && "skipping parameter not of vtt type"); |
| ++I; |
| } |
| } |
| |
| // Explicit arguments. |
| for (; I != E; ++I) { |
| const VarDecl *param = *I; |
| // FIXME: per-argument source location |
| EmitDelegateCallArg(DelegateArgs, param, Loc); |
| } |
| |
| llvm::Value *Callee = |
| CGM.getAddrOfCXXStructor(Ctor, getFromCtorType(CtorType)); |
| EmitCall(CGM.getTypes() |
| .arrangeCXXStructorDeclaration(Ctor, getFromCtorType(CtorType)), |
| Callee, ReturnValueSlot(), DelegateArgs, Ctor); |
| } |
| |
| namespace { |
| struct CallDelegatingCtorDtor : EHScopeStack::Cleanup { |
| const CXXDestructorDecl *Dtor; |
| llvm::Value *Addr; |
| CXXDtorType Type; |
| |
| CallDelegatingCtorDtor(const CXXDestructorDecl *D, llvm::Value *Addr, |
| CXXDtorType Type) |
| : Dtor(D), Addr(Addr), Type(Type) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| CGF.EmitCXXDestructorCall(Dtor, Type, /*ForVirtualBase=*/false, |
| /*Delegating=*/true, Addr); |
| } |
| }; |
| } |
| |
| void |
| CodeGenFunction::EmitDelegatingCXXConstructorCall(const CXXConstructorDecl *Ctor, |
| const FunctionArgList &Args) { |
| assert(Ctor->isDelegatingConstructor()); |
| |
| llvm::Value *ThisPtr = LoadCXXThis(); |
| |
| QualType Ty = getContext().getTagDeclType(Ctor->getParent()); |
| CharUnits Alignment = getContext().getTypeAlignInChars(Ty); |
| AggValueSlot AggSlot = |
| AggValueSlot::forAddr(ThisPtr, Alignment, Qualifiers(), |
| AggValueSlot::IsDestructed, |
| AggValueSlot::DoesNotNeedGCBarriers, |
| AggValueSlot::IsNotAliased); |
| |
| EmitAggExpr(Ctor->init_begin()[0]->getInit(), AggSlot); |
| |
| const CXXRecordDecl *ClassDecl = Ctor->getParent(); |
| if (CGM.getLangOpts().Exceptions && !ClassDecl->hasTrivialDestructor()) { |
| CXXDtorType Type = |
| CurGD.getCtorType() == Ctor_Complete ? Dtor_Complete : Dtor_Base; |
| |
| EHStack.pushCleanup<CallDelegatingCtorDtor>(EHCleanup, |
| ClassDecl->getDestructor(), |
| ThisPtr, Type); |
| } |
| } |
| |
| void CodeGenFunction::EmitCXXDestructorCall(const CXXDestructorDecl *DD, |
| CXXDtorType Type, |
| bool ForVirtualBase, |
| bool Delegating, |
| llvm::Value *This) { |
| CGM.getCXXABI().EmitDestructorCall(*this, DD, Type, ForVirtualBase, |
| Delegating, This); |
| } |
| |
| namespace { |
| struct CallLocalDtor : EHScopeStack::Cleanup { |
| const CXXDestructorDecl *Dtor; |
| llvm::Value *Addr; |
| |
| CallLocalDtor(const CXXDestructorDecl *D, llvm::Value *Addr) |
| : Dtor(D), Addr(Addr) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, |
| /*ForVirtualBase=*/false, |
| /*Delegating=*/false, Addr); |
| } |
| }; |
| } |
| |
| void CodeGenFunction::PushDestructorCleanup(const CXXDestructorDecl *D, |
| llvm::Value *Addr) { |
| EHStack.pushCleanup<CallLocalDtor>(NormalAndEHCleanup, D, Addr); |
| } |
| |
| void CodeGenFunction::PushDestructorCleanup(QualType T, llvm::Value *Addr) { |
| CXXRecordDecl *ClassDecl = T->getAsCXXRecordDecl(); |
| if (!ClassDecl) return; |
| if (ClassDecl->hasTrivialDestructor()) return; |
| |
| const CXXDestructorDecl *D = ClassDecl->getDestructor(); |
| assert(D && D->isUsed() && "destructor not marked as used!"); |
| PushDestructorCleanup(D, Addr); |
| } |
| |
| void |
| CodeGenFunction::InitializeVTablePointer(BaseSubobject Base, |
| const CXXRecordDecl *NearestVBase, |
| CharUnits OffsetFromNearestVBase, |
| const CXXRecordDecl *VTableClass) { |
| const CXXRecordDecl *RD = Base.getBase(); |
| |
| // Don't initialize the vtable pointer if the class is marked with the |
| // 'novtable' attribute. |
| if ((RD == VTableClass || RD == NearestVBase) && |
| VTableClass->hasAttr<MSNoVTableAttr>()) |
| return; |
| |
| // Compute the address point. |
| bool NeedsVirtualOffset; |
| llvm::Value *VTableAddressPoint = |
| CGM.getCXXABI().getVTableAddressPointInStructor( |
| *this, VTableClass, Base, NearestVBase, NeedsVirtualOffset); |
| if (!VTableAddressPoint) |
| return; |
| |
| // Compute where to store the address point. |
| llvm::Value *VirtualOffset = nullptr; |
| CharUnits NonVirtualOffset = CharUnits::Zero(); |
| |
| if (NeedsVirtualOffset) { |
| // We need to use the virtual base offset offset because the virtual base |
| // might have a different offset in the most derived class. |
| VirtualOffset = CGM.getCXXABI().GetVirtualBaseClassOffset(*this, |
| LoadCXXThis(), |
| VTableClass, |
| NearestVBase); |
| NonVirtualOffset = OffsetFromNearestVBase; |
| } else { |
| // We can just use the base offset in the complete class. |
| NonVirtualOffset = Base.getBaseOffset(); |
| } |
| |
| // Apply the offsets. |
| llvm::Value *VTableField = LoadCXXThis(); |
| |
| if (!NonVirtualOffset.isZero() || VirtualOffset) |
| VTableField = ApplyNonVirtualAndVirtualOffset(*this, VTableField, |
| NonVirtualOffset, |
| VirtualOffset); |
| |
| // Finally, store the address point. Use the same LLVM types as the field to |
| // support optimization. |
| llvm::Type *VTablePtrTy = |
| llvm::FunctionType::get(CGM.Int32Ty, /*isVarArg=*/true) |
| ->getPointerTo() |
| ->getPointerTo(); |
| VTableField = Builder.CreateBitCast(VTableField, VTablePtrTy->getPointerTo()); |
| VTableAddressPoint = Builder.CreateBitCast(VTableAddressPoint, VTablePtrTy); |
| llvm::StoreInst *Store = Builder.CreateStore(VTableAddressPoint, VTableField); |
| CGM.DecorateInstruction(Store, CGM.getTBAAInfoForVTablePtr()); |
| } |
| |
| void |
| CodeGenFunction::InitializeVTablePointers(BaseSubobject Base, |
| const CXXRecordDecl *NearestVBase, |
| CharUnits OffsetFromNearestVBase, |
| bool BaseIsNonVirtualPrimaryBase, |
| const CXXRecordDecl *VTableClass, |
| VisitedVirtualBasesSetTy& VBases) { |
| // If this base is a non-virtual primary base the address point has already |
| // been set. |
| if (!BaseIsNonVirtualPrimaryBase) { |
| // Initialize the vtable pointer for this base. |
| InitializeVTablePointer(Base, NearestVBase, OffsetFromNearestVBase, |
| VTableClass); |
| } |
| |
| const CXXRecordDecl *RD = Base.getBase(); |
| |
| // Traverse bases. |
| for (const auto &I : RD->bases()) { |
| CXXRecordDecl *BaseDecl |
| = cast<CXXRecordDecl>(I.getType()->getAs<RecordType>()->getDecl()); |
| |
| // Ignore classes without a vtable. |
| if (!BaseDecl->isDynamicClass()) |
| continue; |
| |
| CharUnits BaseOffset; |
| CharUnits BaseOffsetFromNearestVBase; |
| bool BaseDeclIsNonVirtualPrimaryBase; |
| |
| if (I.isVirtual()) { |
| // Check if we've visited this virtual base before. |
| if (!VBases.insert(BaseDecl).second) |
| continue; |
| |
| const ASTRecordLayout &Layout = |
| getContext().getASTRecordLayout(VTableClass); |
| |
| BaseOffset = Layout.getVBaseClassOffset(BaseDecl); |
| BaseOffsetFromNearestVBase = CharUnits::Zero(); |
| BaseDeclIsNonVirtualPrimaryBase = false; |
| } else { |
| const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD); |
| |
| BaseOffset = Base.getBaseOffset() + Layout.getBaseClassOffset(BaseDecl); |
| BaseOffsetFromNearestVBase = |
| OffsetFromNearestVBase + Layout.getBaseClassOffset(BaseDecl); |
| BaseDeclIsNonVirtualPrimaryBase = Layout.getPrimaryBase() == BaseDecl; |
| } |
| |
| InitializeVTablePointers(BaseSubobject(BaseDecl, BaseOffset), |
| I.isVirtual() ? BaseDecl : NearestVBase, |
| BaseOffsetFromNearestVBase, |
| BaseDeclIsNonVirtualPrimaryBase, |
| VTableClass, VBases); |
| } |
| } |
| |
| void CodeGenFunction::InitializeVTablePointers(const CXXRecordDecl *RD) { |
| // Ignore classes without a vtable. |
| if (!RD->isDynamicClass()) |
| return; |
| |
| // Initialize the vtable pointers for this class and all of its bases. |
| VisitedVirtualBasesSetTy VBases; |
| InitializeVTablePointers(BaseSubobject(RD, CharUnits::Zero()), |
| /*NearestVBase=*/nullptr, |
| /*OffsetFromNearestVBase=*/CharUnits::Zero(), |
| /*BaseIsNonVirtualPrimaryBase=*/false, RD, VBases); |
| |
| if (RD->getNumVBases()) |
| CGM.getCXXABI().initializeHiddenVirtualInheritanceMembers(*this, RD); |
| } |
| |
| llvm::Value *CodeGenFunction::GetVTablePtr(llvm::Value *This, |
| llvm::Type *Ty) { |
| llvm::Value *VTablePtrSrc = Builder.CreateBitCast(This, Ty->getPointerTo()); |
| llvm::Instruction *VTable = Builder.CreateLoad(VTablePtrSrc, "vtable"); |
| CGM.DecorateInstruction(VTable, CGM.getTBAAInfoForVTablePtr()); |
| return VTable; |
| } |
| |
| // If a class has a single non-virtual base and does not introduce or override |
| // virtual member functions or fields, it will have the same layout as its base. |
| // This function returns the least derived such class. |
| // |
| // Casting an instance of a base class to such a derived class is technically |
| // undefined behavior, but it is a relatively common hack for introducing member |
| // functions on class instances with specific properties (e.g. llvm::Operator) |
| // that works under most compilers and should not have security implications, so |
| // we allow it by default. It can be disabled with -fsanitize=cfi-cast-strict. |
| static const CXXRecordDecl * |
| LeastDerivedClassWithSameLayout(const CXXRecordDecl *RD) { |
| if (!RD->field_empty()) |
| return RD; |
| |
| if (RD->getNumVBases() != 0) |
| return RD; |
| |
| if (RD->getNumBases() != 1) |
| return RD; |
| |
| for (const CXXMethodDecl *MD : RD->methods()) { |
| if (MD->isVirtual()) { |
| // Virtual member functions are only ok if they are implicit destructors |
| // because the implicit destructor will have the same semantics as the |
| // base class's destructor if no fields are added. |
| if (isa<CXXDestructorDecl>(MD) && MD->isImplicit()) |
| continue; |
| return RD; |
| } |
| } |
| |
| return LeastDerivedClassWithSameLayout( |
| RD->bases_begin()->getType()->getAsCXXRecordDecl()); |
| } |
| |
| void CodeGenFunction::EmitVTablePtrCheckForCall(const CXXMethodDecl *MD, |
| llvm::Value *VTable) { |
| const CXXRecordDecl *ClassDecl = MD->getParent(); |
| if (!SanOpts.has(SanitizerKind::CFICastStrict)) |
| ClassDecl = LeastDerivedClassWithSameLayout(ClassDecl); |
| |
| EmitVTablePtrCheck(ClassDecl, VTable); |
| } |
| |
| void CodeGenFunction::EmitVTablePtrCheckForCast(QualType T, |
| llvm::Value *Derived, |
| bool MayBeNull) { |
| if (!getLangOpts().CPlusPlus) |
| return; |
| |
| auto *ClassTy = T->getAs<RecordType>(); |
| if (!ClassTy) |
| return; |
| |
| const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassTy->getDecl()); |
| |
| if (!ClassDecl->isCompleteDefinition() || !ClassDecl->isDynamicClass()) |
| return; |
| |
| SmallString<64> MangledName; |
| llvm::raw_svector_ostream Out(MangledName); |
| CGM.getCXXABI().getMangleContext().mangleCXXRTTI(T.getUnqualifiedType(), |
| Out); |
| |
| // Blacklist based on the mangled type. |
| if (CGM.getContext().getSanitizerBlacklist().isBlacklistedType(Out.str())) |
| return; |
| |
| if (!SanOpts.has(SanitizerKind::CFICastStrict)) |
| ClassDecl = LeastDerivedClassWithSameLayout(ClassDecl); |
| |
| llvm::BasicBlock *ContBlock = 0; |
| |
| if (MayBeNull) { |
| llvm::Value *DerivedNotNull = |
| Builder.CreateIsNotNull(Derived, "cast.nonnull"); |
| |
| llvm::BasicBlock *CheckBlock = createBasicBlock("cast.check"); |
| ContBlock = createBasicBlock("cast.cont"); |
| |
| Builder.CreateCondBr(DerivedNotNull, CheckBlock, ContBlock); |
| |
| EmitBlock(CheckBlock); |
| } |
| |
| llvm::Value *VTable = GetVTablePtr(Derived, Int8PtrTy); |
| EmitVTablePtrCheck(ClassDecl, VTable); |
| |
| if (MayBeNull) { |
| Builder.CreateBr(ContBlock); |
| EmitBlock(ContBlock); |
| } |
| } |
| |
| void CodeGenFunction::EmitVTablePtrCheck(const CXXRecordDecl *RD, |
| llvm::Value *VTable) { |
| // FIXME: Add blacklisting scheme. |
| if (RD->isInStdNamespace()) |
| return; |
| |
| std::string OutName; |
| llvm::raw_string_ostream Out(OutName); |
| CGM.getCXXABI().getMangleContext().mangleCXXVTableBitSet(RD, Out); |
| |
| llvm::Value *BitSetName = llvm::MetadataAsValue::get( |
| getLLVMContext(), llvm::MDString::get(getLLVMContext(), Out.str())); |
| |
| llvm::Value *BitSetTest = Builder.CreateCall2( |
| CGM.getIntrinsic(llvm::Intrinsic::bitset_test), |
| Builder.CreateBitCast(VTable, CGM.Int8PtrTy), BitSetName); |
| |
| llvm::BasicBlock *ContBlock = createBasicBlock("vtable.check.cont"); |
| llvm::BasicBlock *TrapBlock = createBasicBlock("vtable.check.trap"); |
| |
| Builder.CreateCondBr(BitSetTest, ContBlock, TrapBlock); |
| |
| EmitBlock(TrapBlock); |
| Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::trap)); |
| Builder.CreateUnreachable(); |
| |
| EmitBlock(ContBlock); |
| } |
| |
| // FIXME: Ideally Expr::IgnoreParenNoopCasts should do this, but it doesn't do |
| // quite what we want. |
| static const Expr *skipNoOpCastsAndParens(const Expr *E) { |
| while (true) { |
| if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) { |
| E = PE->getSubExpr(); |
| continue; |
| } |
| |
| if (const CastExpr *CE = dyn_cast<CastExpr>(E)) { |
| if (CE->getCastKind() == CK_NoOp) { |
| E = CE->getSubExpr(); |
| continue; |
| } |
| } |
| if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { |
| if (UO->getOpcode() == UO_Extension) { |
| E = UO->getSubExpr(); |
| continue; |
| } |
| } |
| return E; |
| } |
| } |
| |
| bool |
| CodeGenFunction::CanDevirtualizeMemberFunctionCall(const Expr *Base, |
| const CXXMethodDecl *MD) { |
| // When building with -fapple-kext, all calls must go through the vtable since |
| // the kernel linker can do runtime patching of vtables. |
| if (getLangOpts().AppleKext) |
| return false; |
| |
| // If the most derived class is marked final, we know that no subclass can |
| // override this member function and so we can devirtualize it. For example: |
| // |
| // struct A { virtual void f(); } |
| // struct B final : A { }; |
| // |
| // void f(B *b) { |
| // b->f(); |
| // } |
| // |
| const CXXRecordDecl *MostDerivedClassDecl = Base->getBestDynamicClassType(); |
| if (MostDerivedClassDecl->hasAttr<FinalAttr>()) |
| return true; |
| |
| // If the member function is marked 'final', we know that it can't be |
| // overridden and can therefore devirtualize it. |
| if (MD->hasAttr<FinalAttr>()) |
| return true; |
| |
| // Similarly, if the class itself is marked 'final' it can't be overridden |
| // and we can therefore devirtualize the member function call. |
| if (MD->getParent()->hasAttr<FinalAttr>()) |
| return true; |
| |
| Base = skipNoOpCastsAndParens(Base); |
| if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) { |
| if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) { |
| // This is a record decl. We know the type and can devirtualize it. |
| return VD->getType()->isRecordType(); |
| } |
| |
| return false; |
| } |
| |
| // We can devirtualize calls on an object accessed by a class member access |
| // expression, since by C++11 [basic.life]p6 we know that it can't refer to |
| // a derived class object constructed in the same location. |
| if (const MemberExpr *ME = dyn_cast<MemberExpr>(Base)) |
| if (const ValueDecl *VD = dyn_cast<ValueDecl>(ME->getMemberDecl())) |
| return VD->getType()->isRecordType(); |
| |
| // We can always devirtualize calls on temporary object expressions. |
| if (isa<CXXConstructExpr>(Base)) |
| return true; |
| |
| // And calls on bound temporaries. |
| if (isa<CXXBindTemporaryExpr>(Base)) |
| return true; |
| |
| // Check if this is a call expr that returns a record type. |
| if (const CallExpr *CE = dyn_cast<CallExpr>(Base)) |
| return CE->getCallReturnType(getContext())->isRecordType(); |
| |
| // We can't devirtualize the call. |
| return false; |
| } |
| |
| void CodeGenFunction::EmitForwardingCallToLambda( |
| const CXXMethodDecl *callOperator, |
| CallArgList &callArgs) { |
| // Get the address of the call operator. |
| const CGFunctionInfo &calleeFnInfo = |
| CGM.getTypes().arrangeCXXMethodDeclaration(callOperator); |
| llvm::Value *callee = |
| CGM.GetAddrOfFunction(GlobalDecl(callOperator), |
| CGM.getTypes().GetFunctionType(calleeFnInfo)); |
| |
| // Prepare the return slot. |
| const FunctionProtoType *FPT = |
| callOperator->getType()->castAs<FunctionProtoType>(); |
| QualType resultType = FPT->getReturnType(); |
| ReturnValueSlot returnSlot; |
| if (!resultType->isVoidType() && |
| calleeFnInfo.getReturnInfo().getKind() == ABIArgInfo::Indirect && |
| !hasScalarEvaluationKind(calleeFnInfo.getReturnType())) |
| returnSlot = ReturnValueSlot(ReturnValue, resultType.isVolatileQualified()); |
| |
| // We don't need to separately arrange the call arguments because |
| // the call can't be variadic anyway --- it's impossible to forward |
| // variadic arguments. |
| |
| // Now emit our call. |
| RValue RV = EmitCall(calleeFnInfo, callee, returnSlot, |
| callArgs, callOperator); |
| |
| // If necessary, copy the returned value into the slot. |
| if (!resultType->isVoidType() && returnSlot.isNull()) |
| EmitReturnOfRValue(RV, resultType); |
| else |
| EmitBranchThroughCleanup(ReturnBlock); |
| } |
| |
| void CodeGenFunction::EmitLambdaBlockInvokeBody() { |
| const BlockDecl *BD = BlockInfo->getBlockDecl(); |
| const VarDecl *variable = BD->capture_begin()->getVariable(); |
| const CXXRecordDecl *Lambda = variable->getType()->getAsCXXRecordDecl(); |
| |
| // Start building arguments for forwarding call |
| CallArgList CallArgs; |
| |
| QualType ThisType = getContext().getPointerType(getContext().getRecordType(Lambda)); |
| llvm::Value *ThisPtr = GetAddrOfBlockDecl(variable, false); |
| CallArgs.add(RValue::get(ThisPtr), ThisType); |
| |
| // Add the rest of the parameters. |
| for (auto param : BD->params()) |
| EmitDelegateCallArg(CallArgs, param, param->getLocStart()); |
| |
| assert(!Lambda->isGenericLambda() && |
| "generic lambda interconversion to block not implemented"); |
| EmitForwardingCallToLambda(Lambda->getLambdaCallOperator(), CallArgs); |
| } |
| |
| void CodeGenFunction::EmitLambdaToBlockPointerBody(FunctionArgList &Args) { |
| if (cast<CXXMethodDecl>(CurCodeDecl)->isVariadic()) { |
| // FIXME: Making this work correctly is nasty because it requires either |
| // cloning the body of the call operator or making the call operator forward. |
| CGM.ErrorUnsupported(CurCodeDecl, "lambda conversion to variadic function"); |
| return; |
| } |
| |
| EmitFunctionBody(Args, cast<FunctionDecl>(CurGD.getDecl())->getBody()); |
| } |
| |
| void CodeGenFunction::EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD) { |
| const CXXRecordDecl *Lambda = MD->getParent(); |
| |
| // Start building arguments for forwarding call |
| CallArgList CallArgs; |
| |
| QualType ThisType = getContext().getPointerType(getContext().getRecordType(Lambda)); |
| llvm::Value *ThisPtr = llvm::UndefValue::get(getTypes().ConvertType(ThisType)); |
| CallArgs.add(RValue::get(ThisPtr), ThisType); |
| |
| // Add the rest of the parameters. |
| for (auto Param : MD->params()) |
| EmitDelegateCallArg(CallArgs, Param, Param->getLocStart()); |
| |
| const CXXMethodDecl *CallOp = Lambda->getLambdaCallOperator(); |
| // For a generic lambda, find the corresponding call operator specialization |
| // to which the call to the static-invoker shall be forwarded. |
| if (Lambda->isGenericLambda()) { |
| assert(MD->isFunctionTemplateSpecialization()); |
| const TemplateArgumentList *TAL = MD->getTemplateSpecializationArgs(); |
| FunctionTemplateDecl *CallOpTemplate = CallOp->getDescribedFunctionTemplate(); |
| void *InsertPos = nullptr; |
| FunctionDecl *CorrespondingCallOpSpecialization = |
| CallOpTemplate->findSpecialization(TAL->asArray(), InsertPos); |
| assert(CorrespondingCallOpSpecialization); |
| CallOp = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization); |
| } |
| EmitForwardingCallToLambda(CallOp, CallArgs); |
| } |
| |
| void CodeGenFunction::EmitLambdaStaticInvokeFunction(const CXXMethodDecl *MD) { |
| if (MD->isVariadic()) { |
| // FIXME: Making this work correctly is nasty because it requires either |
| // cloning the body of the call operator or making the call operator forward. |
| CGM.ErrorUnsupported(MD, "lambda conversion to variadic function"); |
| return; |
| } |
| |
| EmitLambdaDelegatingInvokeBody(MD); |
| } |