| //===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code to emit Decl nodes as LLVM code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CGBlocks.h" |
| #include "CGCXXABI.h" |
| #include "CGCleanup.h" |
| #include "CGDebugInfo.h" |
| #include "CGOpenCLRuntime.h" |
| #include "CGOpenMPRuntime.h" |
| #include "CodeGenFunction.h" |
| #include "CodeGenModule.h" |
| #include "ConstantEmitter.h" |
| #include "PatternInit.h" |
| #include "TargetInfo.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Attr.h" |
| #include "clang/AST/CharUnits.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclObjC.h" |
| #include "clang/AST/DeclOpenMP.h" |
| #include "clang/Basic/CodeGenOptions.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/CodeGen/CGFunctionInfo.h" |
| #include "clang/Sema/Sema.h" |
| #include "llvm/Analysis/ValueTracking.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/GlobalVariable.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/IR/Type.h" |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| static_assert(clang::Sema::MaximumAlignment <= llvm::Value::MaximumAlignment, |
| "Clang max alignment greater than what LLVM supports?"); |
| |
| void CodeGenFunction::EmitDecl(const Decl &D) { |
| switch (D.getKind()) { |
| case Decl::BuiltinTemplate: |
| case Decl::TranslationUnit: |
| case Decl::ExternCContext: |
| case Decl::Namespace: |
| case Decl::UnresolvedUsingTypename: |
| case Decl::ClassTemplateSpecialization: |
| case Decl::ClassTemplatePartialSpecialization: |
| case Decl::VarTemplateSpecialization: |
| case Decl::VarTemplatePartialSpecialization: |
| case Decl::TemplateTypeParm: |
| case Decl::UnresolvedUsingValue: |
| case Decl::NonTypeTemplateParm: |
| case Decl::CXXDeductionGuide: |
| case Decl::CXXMethod: |
| case Decl::CXXConstructor: |
| case Decl::CXXDestructor: |
| case Decl::CXXConversion: |
| case Decl::Field: |
| case Decl::MSProperty: |
| case Decl::IndirectField: |
| case Decl::ObjCIvar: |
| case Decl::ObjCAtDefsField: |
| case Decl::ParmVar: |
| case Decl::ImplicitParam: |
| case Decl::ClassTemplate: |
| case Decl::VarTemplate: |
| case Decl::FunctionTemplate: |
| case Decl::TypeAliasTemplate: |
| case Decl::TemplateTemplateParm: |
| case Decl::ObjCMethod: |
| case Decl::ObjCCategory: |
| case Decl::ObjCProtocol: |
| case Decl::ObjCInterface: |
| case Decl::ObjCCategoryImpl: |
| case Decl::ObjCImplementation: |
| case Decl::ObjCProperty: |
| case Decl::ObjCCompatibleAlias: |
| case Decl::PragmaComment: |
| case Decl::PragmaDetectMismatch: |
| case Decl::AccessSpec: |
| case Decl::LinkageSpec: |
| case Decl::Export: |
| case Decl::ObjCPropertyImpl: |
| case Decl::FileScopeAsm: |
| case Decl::Friend: |
| case Decl::FriendTemplate: |
| case Decl::Block: |
| case Decl::Captured: |
| case Decl::ClassScopeFunctionSpecialization: |
| case Decl::UsingShadow: |
| case Decl::ConstructorUsingShadow: |
| case Decl::ObjCTypeParam: |
| case Decl::Binding: |
| case Decl::UnresolvedUsingIfExists: |
| llvm_unreachable("Declaration should not be in declstmts!"); |
| case Decl::Record: // struct/union/class X; |
| case Decl::CXXRecord: // struct/union/class X; [C++] |
| if (CGDebugInfo *DI = getDebugInfo()) |
| if (cast<RecordDecl>(D).getDefinition()) |
| DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(&D))); |
| return; |
| case Decl::Enum: // enum X; |
| if (CGDebugInfo *DI = getDebugInfo()) |
| if (cast<EnumDecl>(D).getDefinition()) |
| DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(&D))); |
| return; |
| case Decl::Function: // void X(); |
| case Decl::EnumConstant: // enum ? { X = ? } |
| case Decl::StaticAssert: // static_assert(X, ""); [C++0x] |
| case Decl::Label: // __label__ x; |
| case Decl::Import: |
| case Decl::MSGuid: // __declspec(uuid("...")) |
| case Decl::TemplateParamObject: |
| case Decl::OMPThreadPrivate: |
| case Decl::OMPAllocate: |
| case Decl::OMPCapturedExpr: |
| case Decl::OMPRequires: |
| case Decl::Empty: |
| case Decl::Concept: |
| case Decl::LifetimeExtendedTemporary: |
| case Decl::RequiresExprBody: |
| // None of these decls require codegen support. |
| return; |
| |
| case Decl::NamespaceAlias: |
| if (CGDebugInfo *DI = getDebugInfo()) |
| DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(D)); |
| return; |
| case Decl::Using: // using X; [C++] |
| if (CGDebugInfo *DI = getDebugInfo()) |
| DI->EmitUsingDecl(cast<UsingDecl>(D)); |
| return; |
| case Decl::UsingEnum: // using enum X; [C++] |
| if (CGDebugInfo *DI = getDebugInfo()) |
| DI->EmitUsingEnumDecl(cast<UsingEnumDecl>(D)); |
| return; |
| case Decl::UsingPack: |
| for (auto *Using : cast<UsingPackDecl>(D).expansions()) |
| EmitDecl(*Using); |
| return; |
| case Decl::UsingDirective: // using namespace X; [C++] |
| if (CGDebugInfo *DI = getDebugInfo()) |
| DI->EmitUsingDirective(cast<UsingDirectiveDecl>(D)); |
| return; |
| case Decl::Var: |
| case Decl::Decomposition: { |
| const VarDecl &VD = cast<VarDecl>(D); |
| assert(VD.isLocalVarDecl() && |
| "Should not see file-scope variables inside a function!"); |
| EmitVarDecl(VD); |
| if (auto *DD = dyn_cast<DecompositionDecl>(&VD)) |
| for (auto *B : DD->bindings()) |
| if (auto *HD = B->getHoldingVar()) |
| EmitVarDecl(*HD); |
| return; |
| } |
| |
| case Decl::OMPDeclareReduction: |
| return CGM.EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(&D), this); |
| |
| case Decl::OMPDeclareMapper: |
| return CGM.EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(&D), this); |
| |
| case Decl::Typedef: // typedef int X; |
| case Decl::TypeAlias: { // using X = int; [C++0x] |
| QualType Ty = cast<TypedefNameDecl>(D).getUnderlyingType(); |
| if (CGDebugInfo *DI = getDebugInfo()) |
| DI->EmitAndRetainType(Ty); |
| if (Ty->isVariablyModifiedType()) |
| EmitVariablyModifiedType(Ty); |
| return; |
| } |
| } |
| } |
| |
| /// EmitVarDecl - This method handles emission of any variable declaration |
| /// inside a function, including static vars etc. |
| void CodeGenFunction::EmitVarDecl(const VarDecl &D) { |
| if (D.hasExternalStorage()) |
| // Don't emit it now, allow it to be emitted lazily on its first use. |
| return; |
| |
| // Some function-scope variable does not have static storage but still |
| // needs to be emitted like a static variable, e.g. a function-scope |
| // variable in constant address space in OpenCL. |
| if (D.getStorageDuration() != SD_Automatic) { |
| // Static sampler variables translated to function calls. |
| if (D.getType()->isSamplerT()) |
| return; |
| |
| llvm::GlobalValue::LinkageTypes Linkage = |
| CGM.getLLVMLinkageVarDefinition(&D, /*IsConstant=*/false); |
| |
| // FIXME: We need to force the emission/use of a guard variable for |
| // some variables even if we can constant-evaluate them because |
| // we can't guarantee every translation unit will constant-evaluate them. |
| |
| return EmitStaticVarDecl(D, Linkage); |
| } |
| |
| if (D.getType().getAddressSpace() == LangAS::opencl_local) |
| return CGM.getOpenCLRuntime().EmitWorkGroupLocalVarDecl(*this, D); |
| |
| assert(D.hasLocalStorage()); |
| return EmitAutoVarDecl(D); |
| } |
| |
| static std::string getStaticDeclName(CodeGenModule &CGM, const VarDecl &D) { |
| if (CGM.getLangOpts().CPlusPlus) |
| return CGM.getMangledName(&D).str(); |
| |
| // If this isn't C++, we don't need a mangled name, just a pretty one. |
| assert(!D.isExternallyVisible() && "name shouldn't matter"); |
| std::string ContextName; |
| const DeclContext *DC = D.getDeclContext(); |
| if (auto *CD = dyn_cast<CapturedDecl>(DC)) |
| DC = cast<DeclContext>(CD->getNonClosureContext()); |
| if (const auto *FD = dyn_cast<FunctionDecl>(DC)) |
| ContextName = std::string(CGM.getMangledName(FD)); |
| else if (const auto *BD = dyn_cast<BlockDecl>(DC)) |
| ContextName = std::string(CGM.getBlockMangledName(GlobalDecl(), BD)); |
| else if (const auto *OMD = dyn_cast<ObjCMethodDecl>(DC)) |
| ContextName = OMD->getSelector().getAsString(); |
| else |
| llvm_unreachable("Unknown context for static var decl"); |
| |
| ContextName += "." + D.getNameAsString(); |
| return ContextName; |
| } |
| |
| llvm::Constant *CodeGenModule::getOrCreateStaticVarDecl( |
| const VarDecl &D, llvm::GlobalValue::LinkageTypes Linkage) { |
| // In general, we don't always emit static var decls once before we reference |
| // them. It is possible to reference them before emitting the function that |
| // contains them, and it is possible to emit the containing function multiple |
| // times. |
| if (llvm::Constant *ExistingGV = StaticLocalDeclMap[&D]) |
| return ExistingGV; |
| |
| QualType Ty = D.getType(); |
| assert(Ty->isConstantSizeType() && "VLAs can't be static"); |
| |
| // Use the label if the variable is renamed with the asm-label extension. |
| std::string Name; |
| if (D.hasAttr<AsmLabelAttr>()) |
| Name = std::string(getMangledName(&D)); |
| else |
| Name = getStaticDeclName(*this, D); |
| |
| llvm::Type *LTy = getTypes().ConvertTypeForMem(Ty); |
| LangAS AS = GetGlobalVarAddressSpace(&D); |
| unsigned TargetAS = getContext().getTargetAddressSpace(AS); |
| |
| // OpenCL variables in local address space and CUDA shared |
| // variables cannot have an initializer. |
| llvm::Constant *Init = nullptr; |
| if (Ty.getAddressSpace() == LangAS::opencl_local || |
| D.hasAttr<CUDASharedAttr>() || D.hasAttr<LoaderUninitializedAttr>()) |
| Init = llvm::UndefValue::get(LTy); |
| else |
| Init = EmitNullConstant(Ty); |
| |
| llvm::GlobalVariable *GV = new llvm::GlobalVariable( |
| getModule(), LTy, Ty.isConstant(getContext()), Linkage, Init, Name, |
| nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS); |
| GV->setAlignment(getContext().getDeclAlign(&D).getAsAlign()); |
| |
| if (supportsCOMDAT() && GV->isWeakForLinker()) |
| GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); |
| |
| if (D.getTLSKind()) |
| setTLSMode(GV, D); |
| |
| setGVProperties(GV, &D); |
| |
| // Make sure the result is of the correct type. |
| LangAS ExpectedAS = Ty.getAddressSpace(); |
| llvm::Constant *Addr = GV; |
| if (AS != ExpectedAS) { |
| Addr = getTargetCodeGenInfo().performAddrSpaceCast( |
| *this, GV, AS, ExpectedAS, |
| LTy->getPointerTo(getContext().getTargetAddressSpace(ExpectedAS))); |
| } |
| |
| setStaticLocalDeclAddress(&D, Addr); |
| |
| // Ensure that the static local gets initialized by making sure the parent |
| // function gets emitted eventually. |
| const Decl *DC = cast<Decl>(D.getDeclContext()); |
| |
| // We can't name blocks or captured statements directly, so try to emit their |
| // parents. |
| if (isa<BlockDecl>(DC) || isa<CapturedDecl>(DC)) { |
| DC = DC->getNonClosureContext(); |
| // FIXME: Ensure that global blocks get emitted. |
| if (!DC) |
| return Addr; |
| } |
| |
| GlobalDecl GD; |
| if (const auto *CD = dyn_cast<CXXConstructorDecl>(DC)) |
| GD = GlobalDecl(CD, Ctor_Base); |
| else if (const auto *DD = dyn_cast<CXXDestructorDecl>(DC)) |
| GD = GlobalDecl(DD, Dtor_Base); |
| else if (const auto *FD = dyn_cast<FunctionDecl>(DC)) |
| GD = GlobalDecl(FD); |
| else { |
| // Don't do anything for Obj-C method decls or global closures. We should |
| // never defer them. |
| assert(isa<ObjCMethodDecl>(DC) && "unexpected parent code decl"); |
| } |
| if (GD.getDecl()) { |
| // Disable emission of the parent function for the OpenMP device codegen. |
| CGOpenMPRuntime::DisableAutoDeclareTargetRAII NoDeclTarget(*this); |
| (void)GetAddrOfGlobal(GD); |
| } |
| |
| return Addr; |
| } |
| |
| /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the |
| /// global variable that has already been created for it. If the initializer |
| /// has a different type than GV does, this may free GV and return a different |
| /// one. Otherwise it just returns GV. |
| llvm::GlobalVariable * |
| CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D, |
| llvm::GlobalVariable *GV) { |
| ConstantEmitter emitter(*this); |
| llvm::Constant *Init = emitter.tryEmitForInitializer(D); |
| |
| // If constant emission failed, then this should be a C++ static |
| // initializer. |
| if (!Init) { |
| if (!getLangOpts().CPlusPlus) |
| CGM.ErrorUnsupported(D.getInit(), "constant l-value expression"); |
| else if (HaveInsertPoint()) { |
| // Since we have a static initializer, this global variable can't |
| // be constant. |
| GV->setConstant(false); |
| |
| EmitCXXGuardedInit(D, GV, /*PerformInit*/true); |
| } |
| return GV; |
| } |
| |
| // The initializer may differ in type from the global. Rewrite |
| // the global to match the initializer. (We have to do this |
| // because some types, like unions, can't be completely represented |
| // in the LLVM type system.) |
| if (GV->getValueType() != Init->getType()) { |
| llvm::GlobalVariable *OldGV = GV; |
| |
| GV = new llvm::GlobalVariable( |
| CGM.getModule(), Init->getType(), OldGV->isConstant(), |
| OldGV->getLinkage(), Init, "", |
| /*InsertBefore*/ OldGV, OldGV->getThreadLocalMode(), |
| OldGV->getType()->getPointerAddressSpace()); |
| GV->setVisibility(OldGV->getVisibility()); |
| GV->setDSOLocal(OldGV->isDSOLocal()); |
| GV->setComdat(OldGV->getComdat()); |
| |
| // Steal the name of the old global |
| GV->takeName(OldGV); |
| |
| // Replace all uses of the old global with the new global |
| llvm::Constant *NewPtrForOldDecl = |
| llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); |
| OldGV->replaceAllUsesWith(NewPtrForOldDecl); |
| |
| // Erase the old global, since it is no longer used. |
| OldGV->eraseFromParent(); |
| } |
| |
| GV->setConstant(CGM.isTypeConstant(D.getType(), true)); |
| GV->setInitializer(Init); |
| |
| emitter.finalize(GV); |
| |
| if (D.needsDestruction(getContext()) == QualType::DK_cxx_destructor && |
| HaveInsertPoint()) { |
| // We have a constant initializer, but a nontrivial destructor. We still |
| // need to perform a guarded "initialization" in order to register the |
| // destructor. |
| EmitCXXGuardedInit(D, GV, /*PerformInit*/false); |
| } |
| |
| return GV; |
| } |
| |
| void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D, |
| llvm::GlobalValue::LinkageTypes Linkage) { |
| // Check to see if we already have a global variable for this |
| // declaration. This can happen when double-emitting function |
| // bodies, e.g. with complete and base constructors. |
| llvm::Constant *addr = CGM.getOrCreateStaticVarDecl(D, Linkage); |
| CharUnits alignment = getContext().getDeclAlign(&D); |
| |
| // Store into LocalDeclMap before generating initializer to handle |
| // circular references. |
| setAddrOfLocalVar(&D, Address(addr, alignment)); |
| |
| // We can't have a VLA here, but we can have a pointer to a VLA, |
| // even though that doesn't really make any sense. |
| // Make sure to evaluate VLA bounds now so that we have them for later. |
| if (D.getType()->isVariablyModifiedType()) |
| EmitVariablyModifiedType(D.getType()); |
| |
| // Save the type in case adding the initializer forces a type change. |
| llvm::Type *expectedType = addr->getType(); |
| |
| llvm::GlobalVariable *var = |
| cast<llvm::GlobalVariable>(addr->stripPointerCasts()); |
| |
| // CUDA's local and local static __shared__ variables should not |
| // have any non-empty initializers. This is ensured by Sema. |
| // Whatever initializer such variable may have when it gets here is |
| // a no-op and should not be emitted. |
| bool isCudaSharedVar = getLangOpts().CUDA && getLangOpts().CUDAIsDevice && |
| D.hasAttr<CUDASharedAttr>(); |
| // If this value has an initializer, emit it. |
| if (D.getInit() && !isCudaSharedVar) |
| var = AddInitializerToStaticVarDecl(D, var); |
| |
| var->setAlignment(alignment.getAsAlign()); |
| |
| if (D.hasAttr<AnnotateAttr>()) |
| CGM.AddGlobalAnnotations(&D, var); |
| |
| if (auto *SA = D.getAttr<PragmaClangBSSSectionAttr>()) |
| var->addAttribute("bss-section", SA->getName()); |
| if (auto *SA = D.getAttr<PragmaClangDataSectionAttr>()) |
| var->addAttribute("data-section", SA->getName()); |
| if (auto *SA = D.getAttr<PragmaClangRodataSectionAttr>()) |
| var->addAttribute("rodata-section", SA->getName()); |
| if (auto *SA = D.getAttr<PragmaClangRelroSectionAttr>()) |
| var->addAttribute("relro-section", SA->getName()); |
| |
| if (const SectionAttr *SA = D.getAttr<SectionAttr>()) |
| var->setSection(SA->getName()); |
| |
| if (D.hasAttr<RetainAttr>()) |
| CGM.addUsedGlobal(var); |
| else if (D.hasAttr<UsedAttr>()) |
| CGM.addUsedOrCompilerUsedGlobal(var); |
| |
| // We may have to cast the constant because of the initializer |
| // mismatch above. |
| // |
| // FIXME: It is really dangerous to store this in the map; if anyone |
| // RAUW's the GV uses of this constant will be invalid. |
| llvm::Constant *castedAddr = |
| llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(var, expectedType); |
| if (var != castedAddr) |
| LocalDeclMap.find(&D)->second = Address(castedAddr, alignment); |
| CGM.setStaticLocalDeclAddress(&D, castedAddr); |
| |
| CGM.getSanitizerMetadata()->reportGlobalToASan(var, D); |
| |
| // Emit global variable debug descriptor for static vars. |
| CGDebugInfo *DI = getDebugInfo(); |
| if (DI && CGM.getCodeGenOpts().hasReducedDebugInfo()) { |
| DI->setLocation(D.getLocation()); |
| DI->EmitGlobalVariable(var, &D); |
| } |
| } |
| |
| namespace { |
| struct DestroyObject final : EHScopeStack::Cleanup { |
| DestroyObject(Address addr, QualType type, |
| CodeGenFunction::Destroyer *destroyer, |
| bool useEHCleanupForArray) |
| : addr(addr), type(type), destroyer(destroyer), |
| useEHCleanupForArray(useEHCleanupForArray) {} |
| |
| Address addr; |
| QualType type; |
| CodeGenFunction::Destroyer *destroyer; |
| bool useEHCleanupForArray; |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| // Don't use an EH cleanup recursively from an EH cleanup. |
| bool useEHCleanupForArray = |
| flags.isForNormalCleanup() && this->useEHCleanupForArray; |
| |
| CGF.emitDestroy(addr, type, destroyer, useEHCleanupForArray); |
| } |
| }; |
| |
| template <class Derived> |
| struct DestroyNRVOVariable : EHScopeStack::Cleanup { |
| DestroyNRVOVariable(Address addr, QualType type, llvm::Value *NRVOFlag) |
| : NRVOFlag(NRVOFlag), Loc(addr), Ty(type) {} |
| |
| llvm::Value *NRVOFlag; |
| Address Loc; |
| QualType Ty; |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| // Along the exceptions path we always execute the dtor. |
| bool NRVO = flags.isForNormalCleanup() && NRVOFlag; |
| |
| llvm::BasicBlock *SkipDtorBB = nullptr; |
| if (NRVO) { |
| // If we exited via NRVO, we skip the destructor call. |
| llvm::BasicBlock *RunDtorBB = CGF.createBasicBlock("nrvo.unused"); |
| SkipDtorBB = CGF.createBasicBlock("nrvo.skipdtor"); |
| llvm::Value *DidNRVO = |
| CGF.Builder.CreateFlagLoad(NRVOFlag, "nrvo.val"); |
| CGF.Builder.CreateCondBr(DidNRVO, SkipDtorBB, RunDtorBB); |
| CGF.EmitBlock(RunDtorBB); |
| } |
| |
| static_cast<Derived *>(this)->emitDestructorCall(CGF); |
| |
| if (NRVO) CGF.EmitBlock(SkipDtorBB); |
| } |
| |
| virtual ~DestroyNRVOVariable() = default; |
| }; |
| |
| struct DestroyNRVOVariableCXX final |
| : DestroyNRVOVariable<DestroyNRVOVariableCXX> { |
| DestroyNRVOVariableCXX(Address addr, QualType type, |
| const CXXDestructorDecl *Dtor, llvm::Value *NRVOFlag) |
| : DestroyNRVOVariable<DestroyNRVOVariableCXX>(addr, type, NRVOFlag), |
| Dtor(Dtor) {} |
| |
| const CXXDestructorDecl *Dtor; |
| |
| void emitDestructorCall(CodeGenFunction &CGF) { |
| CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, |
| /*ForVirtualBase=*/false, |
| /*Delegating=*/false, Loc, Ty); |
| } |
| }; |
| |
| struct DestroyNRVOVariableC final |
| : DestroyNRVOVariable<DestroyNRVOVariableC> { |
| DestroyNRVOVariableC(Address addr, llvm::Value *NRVOFlag, QualType Ty) |
| : DestroyNRVOVariable<DestroyNRVOVariableC>(addr, Ty, NRVOFlag) {} |
| |
| void emitDestructorCall(CodeGenFunction &CGF) { |
| CGF.destroyNonTrivialCStruct(CGF, Loc, Ty); |
| } |
| }; |
| |
| struct CallStackRestore final : EHScopeStack::Cleanup { |
| Address Stack; |
| CallStackRestore(Address Stack) : Stack(Stack) {} |
| bool isRedundantBeforeReturn() override { return true; } |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| llvm::Value *V = CGF.Builder.CreateLoad(Stack); |
| llvm::Function *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore); |
| CGF.Builder.CreateCall(F, V); |
| } |
| }; |
| |
| struct ExtendGCLifetime final : EHScopeStack::Cleanup { |
| const VarDecl &Var; |
| ExtendGCLifetime(const VarDecl *var) : Var(*var) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| // Compute the address of the local variable, in case it's a |
| // byref or something. |
| DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(&Var), false, |
| Var.getType(), VK_LValue, SourceLocation()); |
| llvm::Value *value = CGF.EmitLoadOfScalar(CGF.EmitDeclRefLValue(&DRE), |
| SourceLocation()); |
| CGF.EmitExtendGCLifetime(value); |
| } |
| }; |
| |
| struct CallCleanupFunction final : EHScopeStack::Cleanup { |
| llvm::Constant *CleanupFn; |
| const CGFunctionInfo &FnInfo; |
| const VarDecl &Var; |
| |
| CallCleanupFunction(llvm::Constant *CleanupFn, const CGFunctionInfo *Info, |
| const VarDecl *Var) |
| : CleanupFn(CleanupFn), FnInfo(*Info), Var(*Var) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(&Var), false, |
| Var.getType(), VK_LValue, SourceLocation()); |
| // Compute the address of the local variable, in case it's a byref |
| // or something. |
| llvm::Value *Addr = CGF.EmitDeclRefLValue(&DRE).getPointer(CGF); |
| |
| // In some cases, the type of the function argument will be different from |
| // the type of the pointer. An example of this is |
| // void f(void* arg); |
| // __attribute__((cleanup(f))) void *g; |
| // |
| // To fix this we insert a bitcast here. |
| QualType ArgTy = FnInfo.arg_begin()->type; |
| llvm::Value *Arg = |
| CGF.Builder.CreateBitCast(Addr, CGF.ConvertType(ArgTy)); |
| |
| CallArgList Args; |
| Args.add(RValue::get(Arg), |
| CGF.getContext().getPointerType(Var.getType())); |
| auto Callee = CGCallee::forDirect(CleanupFn); |
| CGF.EmitCall(FnInfo, Callee, ReturnValueSlot(), Args); |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// EmitAutoVarWithLifetime - Does the setup required for an automatic |
| /// variable with lifetime. |
| static void EmitAutoVarWithLifetime(CodeGenFunction &CGF, const VarDecl &var, |
| Address addr, |
| Qualifiers::ObjCLifetime lifetime) { |
| switch (lifetime) { |
| case Qualifiers::OCL_None: |
| llvm_unreachable("present but none"); |
| |
| case Qualifiers::OCL_ExplicitNone: |
| // nothing to do |
| break; |
| |
| case Qualifiers::OCL_Strong: { |
| CodeGenFunction::Destroyer *destroyer = |
| (var.hasAttr<ObjCPreciseLifetimeAttr>() |
| ? CodeGenFunction::destroyARCStrongPrecise |
| : CodeGenFunction::destroyARCStrongImprecise); |
| |
| CleanupKind cleanupKind = CGF.getARCCleanupKind(); |
| CGF.pushDestroy(cleanupKind, addr, var.getType(), destroyer, |
| cleanupKind & EHCleanup); |
| break; |
| } |
| case Qualifiers::OCL_Autoreleasing: |
| // nothing to do |
| break; |
| |
| case Qualifiers::OCL_Weak: |
| // __weak objects always get EH cleanups; otherwise, exceptions |
| // could cause really nasty crashes instead of mere leaks. |
| CGF.pushDestroy(NormalAndEHCleanup, addr, var.getType(), |
| CodeGenFunction::destroyARCWeak, |
| /*useEHCleanup*/ true); |
| break; |
| } |
| } |
| |
| static bool isAccessedBy(const VarDecl &var, const Stmt *s) { |
| if (const Expr *e = dyn_cast<Expr>(s)) { |
| // Skip the most common kinds of expressions that make |
| // hierarchy-walking expensive. |
| s = e = e->IgnoreParenCasts(); |
| |
| if (const DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e)) |
| return (ref->getDecl() == &var); |
| if (const BlockExpr *be = dyn_cast<BlockExpr>(e)) { |
| const BlockDecl *block = be->getBlockDecl(); |
| for (const auto &I : block->captures()) { |
| if (I.getVariable() == &var) |
| return true; |
| } |
| } |
| } |
| |
| for (const Stmt *SubStmt : s->children()) |
| // SubStmt might be null; as in missing decl or conditional of an if-stmt. |
| if (SubStmt && isAccessedBy(var, SubStmt)) |
| return true; |
| |
| return false; |
| } |
| |
| static bool isAccessedBy(const ValueDecl *decl, const Expr *e) { |
| if (!decl) return false; |
| if (!isa<VarDecl>(decl)) return false; |
| const VarDecl *var = cast<VarDecl>(decl); |
| return isAccessedBy(*var, e); |
| } |
| |
| static bool tryEmitARCCopyWeakInit(CodeGenFunction &CGF, |
| const LValue &destLV, const Expr *init) { |
| bool needsCast = false; |
| |
| while (auto castExpr = dyn_cast<CastExpr>(init->IgnoreParens())) { |
| switch (castExpr->getCastKind()) { |
| // Look through casts that don't require representation changes. |
| case CK_NoOp: |
| case CK_BitCast: |
| case CK_BlockPointerToObjCPointerCast: |
| needsCast = true; |
| break; |
| |
| // If we find an l-value to r-value cast from a __weak variable, |
| // emit this operation as a copy or move. |
| case CK_LValueToRValue: { |
| const Expr *srcExpr = castExpr->getSubExpr(); |
| if (srcExpr->getType().getObjCLifetime() != Qualifiers::OCL_Weak) |
| return false; |
| |
| // Emit the source l-value. |
| LValue srcLV = CGF.EmitLValue(srcExpr); |
| |
| // Handle a formal type change to avoid asserting. |
| auto srcAddr = srcLV.getAddress(CGF); |
| if (needsCast) { |
| srcAddr = CGF.Builder.CreateElementBitCast( |
| srcAddr, destLV.getAddress(CGF).getElementType()); |
| } |
| |
| // If it was an l-value, use objc_copyWeak. |
| if (srcExpr->isLValue()) { |
| CGF.EmitARCCopyWeak(destLV.getAddress(CGF), srcAddr); |
| } else { |
| assert(srcExpr->isXValue()); |
| CGF.EmitARCMoveWeak(destLV.getAddress(CGF), srcAddr); |
| } |
| return true; |
| } |
| |
| // Stop at anything else. |
| default: |
| return false; |
| } |
| |
| init = castExpr->getSubExpr(); |
| } |
| return false; |
| } |
| |
| static void drillIntoBlockVariable(CodeGenFunction &CGF, |
| LValue &lvalue, |
| const VarDecl *var) { |
| lvalue.setAddress(CGF.emitBlockByrefAddress(lvalue.getAddress(CGF), var)); |
| } |
| |
| void CodeGenFunction::EmitNullabilityCheck(LValue LHS, llvm::Value *RHS, |
| SourceLocation Loc) { |
| if (!SanOpts.has(SanitizerKind::NullabilityAssign)) |
| return; |
| |
| auto Nullability = LHS.getType()->getNullability(getContext()); |
| if (!Nullability || *Nullability != NullabilityKind::NonNull) |
| return; |
| |
| // Check if the right hand side of the assignment is nonnull, if the left |
| // hand side must be nonnull. |
| SanitizerScope SanScope(this); |
| llvm::Value *IsNotNull = Builder.CreateIsNotNull(RHS); |
| llvm::Constant *StaticData[] = { |
| EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(LHS.getType()), |
| llvm::ConstantInt::get(Int8Ty, 0), // The LogAlignment info is unused. |
| llvm::ConstantInt::get(Int8Ty, TCK_NonnullAssign)}; |
| EmitCheck({{IsNotNull, SanitizerKind::NullabilityAssign}}, |
| SanitizerHandler::TypeMismatch, StaticData, RHS); |
| } |
| |
| void CodeGenFunction::EmitScalarInit(const Expr *init, const ValueDecl *D, |
| LValue lvalue, bool capturedByInit) { |
| Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime(); |
| if (!lifetime) { |
| llvm::Value *value = EmitScalarExpr(init); |
| if (capturedByInit) |
| drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); |
| EmitNullabilityCheck(lvalue, value, init->getExprLoc()); |
| EmitStoreThroughLValue(RValue::get(value), lvalue, true); |
| return; |
| } |
| |
| if (const CXXDefaultInitExpr *DIE = dyn_cast<CXXDefaultInitExpr>(init)) |
| init = DIE->getExpr(); |
| |
| // If we're emitting a value with lifetime, we have to do the |
| // initialization *before* we leave the cleanup scopes. |
| if (auto *EWC = dyn_cast<ExprWithCleanups>(init)) { |
| CodeGenFunction::RunCleanupsScope Scope(*this); |
| return EmitScalarInit(EWC->getSubExpr(), D, lvalue, capturedByInit); |
| } |
| |
| // We have to maintain the illusion that the variable is |
| // zero-initialized. If the variable might be accessed in its |
| // initializer, zero-initialize before running the initializer, then |
| // actually perform the initialization with an assign. |
| bool accessedByInit = false; |
| if (lifetime != Qualifiers::OCL_ExplicitNone) |
| accessedByInit = (capturedByInit || isAccessedBy(D, init)); |
| if (accessedByInit) { |
| LValue tempLV = lvalue; |
| // Drill down to the __block object if necessary. |
| if (capturedByInit) { |
| // We can use a simple GEP for this because it can't have been |
| // moved yet. |
| tempLV.setAddress(emitBlockByrefAddress(tempLV.getAddress(*this), |
| cast<VarDecl>(D), |
| /*follow*/ false)); |
| } |
| |
| auto ty = |
| cast<llvm::PointerType>(tempLV.getAddress(*this).getElementType()); |
| llvm::Value *zero = CGM.getNullPointer(ty, tempLV.getType()); |
| |
| // If __weak, we want to use a barrier under certain conditions. |
| if (lifetime == Qualifiers::OCL_Weak) |
| EmitARCInitWeak(tempLV.getAddress(*this), zero); |
| |
| // Otherwise just do a simple store. |
| else |
| EmitStoreOfScalar(zero, tempLV, /* isInitialization */ true); |
| } |
| |
| // Emit the initializer. |
| llvm::Value *value = nullptr; |
| |
| switch (lifetime) { |
| case Qualifiers::OCL_None: |
| llvm_unreachable("present but none"); |
| |
| case Qualifiers::OCL_Strong: { |
| if (!D || !isa<VarDecl>(D) || !cast<VarDecl>(D)->isARCPseudoStrong()) { |
| value = EmitARCRetainScalarExpr(init); |
| break; |
| } |
| // If D is pseudo-strong, treat it like __unsafe_unretained here. This means |
| // that we omit the retain, and causes non-autoreleased return values to be |
| // immediately released. |
| LLVM_FALLTHROUGH; |
| } |
| |
| case Qualifiers::OCL_ExplicitNone: |
| value = EmitARCUnsafeUnretainedScalarExpr(init); |
| break; |
| |
| case Qualifiers::OCL_Weak: { |
| // If it's not accessed by the initializer, try to emit the |
| // initialization with a copy or move. |
| if (!accessedByInit && tryEmitARCCopyWeakInit(*this, lvalue, init)) { |
| return; |
| } |
| |
| // No way to optimize a producing initializer into this. It's not |
| // worth optimizing for, because the value will immediately |
| // disappear in the common case. |
| value = EmitScalarExpr(init); |
| |
| if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); |
| if (accessedByInit) |
| EmitARCStoreWeak(lvalue.getAddress(*this), value, /*ignored*/ true); |
| else |
| EmitARCInitWeak(lvalue.getAddress(*this), value); |
| return; |
| } |
| |
| case Qualifiers::OCL_Autoreleasing: |
| value = EmitARCRetainAutoreleaseScalarExpr(init); |
| break; |
| } |
| |
| if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); |
| |
| EmitNullabilityCheck(lvalue, value, init->getExprLoc()); |
| |
| // If the variable might have been accessed by its initializer, we |
| // might have to initialize with a barrier. We have to do this for |
| // both __weak and __strong, but __weak got filtered out above. |
| if (accessedByInit && lifetime == Qualifiers::OCL_Strong) { |
| llvm::Value *oldValue = EmitLoadOfScalar(lvalue, init->getExprLoc()); |
| EmitStoreOfScalar(value, lvalue, /* isInitialization */ true); |
| EmitARCRelease(oldValue, ARCImpreciseLifetime); |
| return; |
| } |
| |
| EmitStoreOfScalar(value, lvalue, /* isInitialization */ true); |
| } |
| |
| /// Decide whether we can emit the non-zero parts of the specified initializer |
| /// with equal or fewer than NumStores scalar stores. |
| static bool canEmitInitWithFewStoresAfterBZero(llvm::Constant *Init, |
| unsigned &NumStores) { |
| // Zero and Undef never requires any extra stores. |
| if (isa<llvm::ConstantAggregateZero>(Init) || |
| isa<llvm::ConstantPointerNull>(Init) || |
| isa<llvm::UndefValue>(Init)) |
| return true; |
| if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) || |
| isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) || |
| isa<llvm::ConstantExpr>(Init)) |
| return Init->isNullValue() || NumStores--; |
| |
| // See if we can emit each element. |
| if (isa<llvm::ConstantArray>(Init) || isa<llvm::ConstantStruct>(Init)) { |
| for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) { |
| llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i)); |
| if (!canEmitInitWithFewStoresAfterBZero(Elt, NumStores)) |
| return false; |
| } |
| return true; |
| } |
| |
| if (llvm::ConstantDataSequential *CDS = |
| dyn_cast<llvm::ConstantDataSequential>(Init)) { |
| for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { |
| llvm::Constant *Elt = CDS->getElementAsConstant(i); |
| if (!canEmitInitWithFewStoresAfterBZero(Elt, NumStores)) |
| return false; |
| } |
| return true; |
| } |
| |
| // Anything else is hard and scary. |
| return false; |
| } |
| |
| /// For inits that canEmitInitWithFewStoresAfterBZero returned true for, emit |
| /// the scalar stores that would be required. |
| static void emitStoresForInitAfterBZero(CodeGenModule &CGM, |
| llvm::Constant *Init, Address Loc, |
| bool isVolatile, CGBuilderTy &Builder, |
| bool IsAutoInit) { |
| assert(!Init->isNullValue() && !isa<llvm::UndefValue>(Init) && |
| "called emitStoresForInitAfterBZero for zero or undef value."); |
| |
| if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) || |
| isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) || |
| isa<llvm::ConstantExpr>(Init)) { |
| auto *I = Builder.CreateStore(Init, Loc, isVolatile); |
| if (IsAutoInit) |
| I->addAnnotationMetadata("auto-init"); |
| return; |
| } |
| |
| if (llvm::ConstantDataSequential *CDS = |
| dyn_cast<llvm::ConstantDataSequential>(Init)) { |
| for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { |
| llvm::Constant *Elt = CDS->getElementAsConstant(i); |
| |
| // If necessary, get a pointer to the element and emit it. |
| if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Elt)) |
| emitStoresForInitAfterBZero( |
| CGM, Elt, Builder.CreateConstInBoundsGEP2_32(Loc, 0, i), isVolatile, |
| Builder, IsAutoInit); |
| } |
| return; |
| } |
| |
| assert((isa<llvm::ConstantStruct>(Init) || isa<llvm::ConstantArray>(Init)) && |
| "Unknown value type!"); |
| |
| for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) { |
| llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i)); |
| |
| // If necessary, get a pointer to the element and emit it. |
| if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Elt)) |
| emitStoresForInitAfterBZero(CGM, Elt, |
| Builder.CreateConstInBoundsGEP2_32(Loc, 0, i), |
| isVolatile, Builder, IsAutoInit); |
| } |
| } |
| |
| /// Decide whether we should use bzero plus some stores to initialize a local |
| /// variable instead of using a memcpy from a constant global. It is beneficial |
| /// to use bzero if the global is all zeros, or mostly zeros and large. |
| static bool shouldUseBZeroPlusStoresToInitialize(llvm::Constant *Init, |
| uint64_t GlobalSize) { |
| // If a global is all zeros, always use a bzero. |
| if (isa<llvm::ConstantAggregateZero>(Init)) return true; |
| |
| // If a non-zero global is <= 32 bytes, always use a memcpy. If it is large, |
| // do it if it will require 6 or fewer scalar stores. |
| // TODO: Should budget depends on the size? Avoiding a large global warrants |
| // plopping in more stores. |
| unsigned StoreBudget = 6; |
| uint64_t SizeLimit = 32; |
| |
| return GlobalSize > SizeLimit && |
| canEmitInitWithFewStoresAfterBZero(Init, StoreBudget); |
| } |
| |
| /// Decide whether we should use memset to initialize a local variable instead |
| /// of using a memcpy from a constant global. Assumes we've already decided to |
| /// not user bzero. |
| /// FIXME We could be more clever, as we are for bzero above, and generate |
| /// memset followed by stores. It's unclear that's worth the effort. |
| static llvm::Value *shouldUseMemSetToInitialize(llvm::Constant *Init, |
| uint64_t GlobalSize, |
| const llvm::DataLayout &DL) { |
| uint64_t SizeLimit = 32; |
| if (GlobalSize <= SizeLimit) |
| return nullptr; |
| return llvm::isBytewiseValue(Init, DL); |
| } |
| |
| /// Decide whether we want to split a constant structure or array store into a |
| /// sequence of its fields' stores. This may cost us code size and compilation |
| /// speed, but plays better with store optimizations. |
| static bool shouldSplitConstantStore(CodeGenModule &CGM, |
| uint64_t GlobalByteSize) { |
| // Don't break things that occupy more than one cacheline. |
| uint64_t ByteSizeLimit = 64; |
| if (CGM.getCodeGenOpts().OptimizationLevel == 0) |
| return false; |
| if (GlobalByteSize <= ByteSizeLimit) |
| return true; |
| return false; |
| } |
| |
| enum class IsPattern { No, Yes }; |
| |
| /// Generate a constant filled with either a pattern or zeroes. |
| static llvm::Constant *patternOrZeroFor(CodeGenModule &CGM, IsPattern isPattern, |
| llvm::Type *Ty) { |
| if (isPattern == IsPattern::Yes) |
| return initializationPatternFor(CGM, Ty); |
| else |
| return llvm::Constant::getNullValue(Ty); |
| } |
| |
| static llvm::Constant *constWithPadding(CodeGenModule &CGM, IsPattern isPattern, |
| llvm::Constant *constant); |
| |
| /// Helper function for constWithPadding() to deal with padding in structures. |
| static llvm::Constant *constStructWithPadding(CodeGenModule &CGM, |
| IsPattern isPattern, |
| llvm::StructType *STy, |
| llvm::Constant *constant) { |
| const llvm::DataLayout &DL = CGM.getDataLayout(); |
| const llvm::StructLayout *Layout = DL.getStructLayout(STy); |
| llvm::Type *Int8Ty = llvm::IntegerType::getInt8Ty(CGM.getLLVMContext()); |
| unsigned SizeSoFar = 0; |
| SmallVector<llvm::Constant *, 8> Values; |
| bool NestedIntact = true; |
| for (unsigned i = 0, e = STy->getNumElements(); i != e; i++) { |
| unsigned CurOff = Layout->getElementOffset(i); |
| if (SizeSoFar < CurOff) { |
| assert(!STy->isPacked()); |
| auto *PadTy = llvm::ArrayType::get(Int8Ty, CurOff - SizeSoFar); |
| Values.push_back(patternOrZeroFor(CGM, isPattern, PadTy)); |
| } |
| llvm::Constant *CurOp; |
| if (constant->isZeroValue()) |
| CurOp = llvm::Constant::getNullValue(STy->getElementType(i)); |
| else |
| CurOp = cast<llvm::Constant>(constant->getAggregateElement(i)); |
| auto *NewOp = constWithPadding(CGM, isPattern, CurOp); |
| if (CurOp != NewOp) |
| NestedIntact = false; |
| Values.push_back(NewOp); |
| SizeSoFar = CurOff + DL.getTypeAllocSize(CurOp->getType()); |
| } |
| unsigned TotalSize = Layout->getSizeInBytes(); |
| if (SizeSoFar < TotalSize) { |
| auto *PadTy = llvm::ArrayType::get(Int8Ty, TotalSize - SizeSoFar); |
| Values.push_back(patternOrZeroFor(CGM, isPattern, PadTy)); |
| } |
| if (NestedIntact && Values.size() == STy->getNumElements()) |
| return constant; |
| return llvm::ConstantStruct::getAnon(Values, STy->isPacked()); |
| } |
| |
| /// Replace all padding bytes in a given constant with either a pattern byte or |
| /// 0x00. |
| static llvm::Constant *constWithPadding(CodeGenModule &CGM, IsPattern isPattern, |
| llvm::Constant *constant) { |
| llvm::Type *OrigTy = constant->getType(); |
| if (const auto STy = dyn_cast<llvm::StructType>(OrigTy)) |
| return constStructWithPadding(CGM, isPattern, STy, constant); |
| if (auto *ArrayTy = dyn_cast<llvm::ArrayType>(OrigTy)) { |
| llvm::SmallVector<llvm::Constant *, 8> Values; |
| uint64_t Size = ArrayTy->getNumElements(); |
| if (!Size) |
| return constant; |
| llvm::Type *ElemTy = ArrayTy->getElementType(); |
| bool ZeroInitializer = constant->isNullValue(); |
| llvm::Constant *OpValue, *PaddedOp; |
| if (ZeroInitializer) { |
| OpValue = llvm::Constant::getNullValue(ElemTy); |
| PaddedOp = constWithPadding(CGM, isPattern, OpValue); |
| } |
| for (unsigned Op = 0; Op != Size; ++Op) { |
| if (!ZeroInitializer) { |
| OpValue = constant->getAggregateElement(Op); |
| PaddedOp = constWithPadding(CGM, isPattern, OpValue); |
| } |
| Values.push_back(PaddedOp); |
| } |
| auto *NewElemTy = Values[0]->getType(); |
| if (NewElemTy == ElemTy) |
| return constant; |
| auto *NewArrayTy = llvm::ArrayType::get(NewElemTy, Size); |
| return llvm::ConstantArray::get(NewArrayTy, Values); |
| } |
| // FIXME: Add handling for tail padding in vectors. Vectors don't |
| // have padding between or inside elements, but the total amount of |
| // data can be less than the allocated size. |
| return constant; |
| } |
| |
| Address CodeGenModule::createUnnamedGlobalFrom(const VarDecl &D, |
| llvm::Constant *Constant, |
| CharUnits Align) { |
| auto FunctionName = [&](const DeclContext *DC) -> std::string { |
| if (const auto *FD = dyn_cast<FunctionDecl>(DC)) { |
| if (const auto *CC = dyn_cast<CXXConstructorDecl>(FD)) |
| return CC->getNameAsString(); |
| if (const auto *CD = dyn_cast<CXXDestructorDecl>(FD)) |
| return CD->getNameAsString(); |
| return std::string(getMangledName(FD)); |
| } else if (const auto *OM = dyn_cast<ObjCMethodDecl>(DC)) { |
| return OM->getNameAsString(); |
| } else if (isa<BlockDecl>(DC)) { |
| return "<block>"; |
| } else if (isa<CapturedDecl>(DC)) { |
| return "<captured>"; |
| } else { |
| llvm_unreachable("expected a function or method"); |
| } |
| }; |
| |
| // Form a simple per-variable cache of these values in case we find we |
| // want to reuse them. |
| llvm::GlobalVariable *&CacheEntry = InitializerConstants[&D]; |
| if (!CacheEntry || CacheEntry->getInitializer() != Constant) { |
| auto *Ty = Constant->getType(); |
| bool isConstant = true; |
| llvm::GlobalVariable *InsertBefore = nullptr; |
| unsigned AS = |
| getContext().getTargetAddressSpace(GetGlobalConstantAddressSpace()); |
| std::string Name; |
| if (D.hasGlobalStorage()) |
| Name = getMangledName(&D).str() + ".const"; |
| else if (const DeclContext *DC = D.getParentFunctionOrMethod()) |
| Name = ("__const." + FunctionName(DC) + "." + D.getName()).str(); |
| else |
| llvm_unreachable("local variable has no parent function or method"); |
| llvm::GlobalVariable *GV = new llvm::GlobalVariable( |
| getModule(), Ty, isConstant, llvm::GlobalValue::PrivateLinkage, |
| Constant, Name, InsertBefore, llvm::GlobalValue::NotThreadLocal, AS); |
| GV->setAlignment(Align.getAsAlign()); |
| GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); |
| CacheEntry = GV; |
| } else if (CacheEntry->getAlignment() < uint64_t(Align.getQuantity())) { |
| CacheEntry->setAlignment(Align.getAsAlign()); |
| } |
| |
| return Address(CacheEntry, Align); |
| } |
| |
| static Address createUnnamedGlobalForMemcpyFrom(CodeGenModule &CGM, |
| const VarDecl &D, |
| CGBuilderTy &Builder, |
| llvm::Constant *Constant, |
| CharUnits Align) { |
| Address SrcPtr = CGM.createUnnamedGlobalFrom(D, Constant, Align); |
| llvm::Type *BP = llvm::PointerType::getInt8PtrTy(CGM.getLLVMContext(), |
| SrcPtr.getAddressSpace()); |
| if (SrcPtr.getType() != BP) |
| SrcPtr = Builder.CreateBitCast(SrcPtr, BP); |
| return SrcPtr; |
| } |
| |
| static void emitStoresForConstant(CodeGenModule &CGM, const VarDecl &D, |
| Address Loc, bool isVolatile, |
| CGBuilderTy &Builder, |
| llvm::Constant *constant, bool IsAutoInit) { |
| auto *Ty = constant->getType(); |
| uint64_t ConstantSize = CGM.getDataLayout().getTypeAllocSize(Ty); |
| if (!ConstantSize) |
| return; |
| |
| bool canDoSingleStore = Ty->isIntOrIntVectorTy() || |
| Ty->isPtrOrPtrVectorTy() || Ty->isFPOrFPVectorTy(); |
| if (canDoSingleStore) { |
| auto *I = Builder.CreateStore(constant, Loc, isVolatile); |
| if (IsAutoInit) |
| I->addAnnotationMetadata("auto-init"); |
| return; |
| } |
| |
| auto *SizeVal = llvm::ConstantInt::get(CGM.IntPtrTy, ConstantSize); |
| |
| // If the initializer is all or mostly the same, codegen with bzero / memset |
| // then do a few stores afterward. |
| if (shouldUseBZeroPlusStoresToInitialize(constant, ConstantSize)) { |
| auto *I = Builder.CreateMemSet(Loc, llvm::ConstantInt::get(CGM.Int8Ty, 0), |
| SizeVal, isVolatile); |
| if (IsAutoInit) |
| I->addAnnotationMetadata("auto-init"); |
| |
| bool valueAlreadyCorrect = |
| constant->isNullValue() || isa<llvm::UndefValue>(constant); |
| if (!valueAlreadyCorrect) { |
| Loc = Builder.CreateBitCast(Loc, Ty->getPointerTo(Loc.getAddressSpace())); |
| emitStoresForInitAfterBZero(CGM, constant, Loc, isVolatile, Builder, |
| IsAutoInit); |
| } |
| return; |
| } |
| |
| // If the initializer is a repeated byte pattern, use memset. |
| llvm::Value *Pattern = |
| shouldUseMemSetToInitialize(constant, ConstantSize, CGM.getDataLayout()); |
| if (Pattern) { |
| uint64_t Value = 0x00; |
| if (!isa<llvm::UndefValue>(Pattern)) { |
| const llvm::APInt &AP = cast<llvm::ConstantInt>(Pattern)->getValue(); |
| assert(AP.getBitWidth() <= 8); |
| Value = AP.getLimitedValue(); |
| } |
| auto *I = Builder.CreateMemSet( |
| Loc, llvm::ConstantInt::get(CGM.Int8Ty, Value), SizeVal, isVolatile); |
| if (IsAutoInit) |
| I->addAnnotationMetadata("auto-init"); |
| return; |
| } |
| |
| // If the initializer is small, use a handful of stores. |
| if (shouldSplitConstantStore(CGM, ConstantSize)) { |
| if (auto *STy = dyn_cast<llvm::StructType>(Ty)) { |
| // FIXME: handle the case when STy != Loc.getElementType(). |
| if (STy == Loc.getElementType()) { |
| for (unsigned i = 0; i != constant->getNumOperands(); i++) { |
| Address EltPtr = Builder.CreateStructGEP(Loc, i); |
| emitStoresForConstant( |
| CGM, D, EltPtr, isVolatile, Builder, |
| cast<llvm::Constant>(Builder.CreateExtractValue(constant, i)), |
| IsAutoInit); |
| } |
| return; |
| } |
| } else if (auto *ATy = dyn_cast<llvm::ArrayType>(Ty)) { |
| // FIXME: handle the case when ATy != Loc.getElementType(). |
| if (ATy == Loc.getElementType()) { |
| for (unsigned i = 0; i != ATy->getNumElements(); i++) { |
| Address EltPtr = Builder.CreateConstArrayGEP(Loc, i); |
| emitStoresForConstant( |
| CGM, D, EltPtr, isVolatile, Builder, |
| cast<llvm::Constant>(Builder.CreateExtractValue(constant, i)), |
| IsAutoInit); |
| } |
| return; |
| } |
| } |
| } |
| |
| // Copy from a global. |
| auto *I = |
| Builder.CreateMemCpy(Loc, |
| createUnnamedGlobalForMemcpyFrom( |
| CGM, D, Builder, constant, Loc.getAlignment()), |
| SizeVal, isVolatile); |
| if (IsAutoInit) |
| I->addAnnotationMetadata("auto-init"); |
| } |
| |
| static void emitStoresForZeroInit(CodeGenModule &CGM, const VarDecl &D, |
| Address Loc, bool isVolatile, |
| CGBuilderTy &Builder) { |
| llvm::Type *ElTy = Loc.getElementType(); |
| llvm::Constant *constant = |
| constWithPadding(CGM, IsPattern::No, llvm::Constant::getNullValue(ElTy)); |
| emitStoresForConstant(CGM, D, Loc, isVolatile, Builder, constant, |
| /*IsAutoInit=*/true); |
| } |
| |
| static void emitStoresForPatternInit(CodeGenModule &CGM, const VarDecl &D, |
| Address Loc, bool isVolatile, |
| CGBuilderTy &Builder) { |
| llvm::Type *ElTy = Loc.getElementType(); |
| llvm::Constant *constant = constWithPadding( |
| CGM, IsPattern::Yes, initializationPatternFor(CGM, ElTy)); |
| assert(!isa<llvm::UndefValue>(constant)); |
| emitStoresForConstant(CGM, D, Loc, isVolatile, Builder, constant, |
| /*IsAutoInit=*/true); |
| } |
| |
| static bool containsUndef(llvm::Constant *constant) { |
| auto *Ty = constant->getType(); |
| if (isa<llvm::UndefValue>(constant)) |
| return true; |
| if (Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()) |
| for (llvm::Use &Op : constant->operands()) |
| if (containsUndef(cast<llvm::Constant>(Op))) |
| return true; |
| return false; |
| } |
| |
| static llvm::Constant *replaceUndef(CodeGenModule &CGM, IsPattern isPattern, |
| llvm::Constant *constant) { |
| auto *Ty = constant->getType(); |
| if (isa<llvm::UndefValue>(constant)) |
| return patternOrZeroFor(CGM, isPattern, Ty); |
| if (!(Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy())) |
| return constant; |
| if (!containsUndef(constant)) |
| return constant; |
| llvm::SmallVector<llvm::Constant *, 8> Values(constant->getNumOperands()); |
| for (unsigned Op = 0, NumOp = constant->getNumOperands(); Op != NumOp; ++Op) { |
| auto *OpValue = cast<llvm::Constant>(constant->getOperand(Op)); |
| Values[Op] = replaceUndef(CGM, isPattern, OpValue); |
| } |
| if (Ty->isStructTy()) |
| return llvm::ConstantStruct::get(cast<llvm::StructType>(Ty), Values); |
| if (Ty->isArrayTy()) |
| return llvm::ConstantArray::get(cast<llvm::ArrayType>(Ty), Values); |
| assert(Ty->isVectorTy()); |
| return llvm::ConstantVector::get(Values); |
| } |
| |
| /// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a |
| /// variable declaration with auto, register, or no storage class specifier. |
| /// These turn into simple stack objects, or GlobalValues depending on target. |
| void CodeGenFunction::EmitAutoVarDecl(const VarDecl &D) { |
| AutoVarEmission emission = EmitAutoVarAlloca(D); |
| EmitAutoVarInit(emission); |
| EmitAutoVarCleanups(emission); |
| } |
| |
| /// Emit a lifetime.begin marker if some criteria are satisfied. |
| /// \return a pointer to the temporary size Value if a marker was emitted, null |
| /// otherwise |
| llvm::Value *CodeGenFunction::EmitLifetimeStart(llvm::TypeSize Size, |
| llvm::Value *Addr) { |
| if (!ShouldEmitLifetimeMarkers) |
| return nullptr; |
| |
| assert(Addr->getType()->getPointerAddressSpace() == |
| CGM.getDataLayout().getAllocaAddrSpace() && |
| "Pointer should be in alloca address space"); |
| llvm::Value *SizeV = llvm::ConstantInt::get( |
| Int64Ty, Size.isScalable() ? -1 : Size.getFixedValue()); |
| Addr = Builder.CreateBitCast(Addr, AllocaInt8PtrTy); |
| llvm::CallInst *C = |
| Builder.CreateCall(CGM.getLLVMLifetimeStartFn(), {SizeV, Addr}); |
| C->setDoesNotThrow(); |
| return SizeV; |
| } |
| |
| void CodeGenFunction::EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr) { |
| assert(Addr->getType()->getPointerAddressSpace() == |
| CGM.getDataLayout().getAllocaAddrSpace() && |
| "Pointer should be in alloca address space"); |
| Addr = Builder.CreateBitCast(Addr, AllocaInt8PtrTy); |
| llvm::CallInst *C = |
| Builder.CreateCall(CGM.getLLVMLifetimeEndFn(), {Size, Addr}); |
| C->setDoesNotThrow(); |
| } |
| |
| void CodeGenFunction::EmitAndRegisterVariableArrayDimensions( |
| CGDebugInfo *DI, const VarDecl &D, bool EmitDebugInfo) { |
| // For each dimension stores its QualType and corresponding |
| // size-expression Value. |
| SmallVector<CodeGenFunction::VlaSizePair, 4> Dimensions; |
| SmallVector<IdentifierInfo *, 4> VLAExprNames; |
| |
| // Break down the array into individual dimensions. |
| QualType Type1D = D.getType(); |
| while (getContext().getAsVariableArrayType(Type1D)) { |
| auto VlaSize = getVLAElements1D(Type1D); |
| if (auto *C = dyn_cast<llvm::ConstantInt>(VlaSize.NumElts)) |
| Dimensions.emplace_back(C, Type1D.getUnqualifiedType()); |
| else { |
| // Generate a locally unique name for the size expression. |
| Twine Name = Twine("__vla_expr") + Twine(VLAExprCounter++); |
| SmallString<12> Buffer; |
| StringRef NameRef = Name.toStringRef(Buffer); |
| auto &Ident = getContext().Idents.getOwn(NameRef); |
| VLAExprNames.push_back(&Ident); |
| auto SizeExprAddr = |
| CreateDefaultAlignTempAlloca(VlaSize.NumElts->getType(), NameRef); |
| Builder.CreateStore(VlaSize.NumElts, SizeExprAddr); |
| Dimensions.emplace_back(SizeExprAddr.getPointer(), |
| Type1D.getUnqualifiedType()); |
| } |
| Type1D = VlaSize.Type; |
| } |
| |
| if (!EmitDebugInfo) |
| return; |
| |
| // Register each dimension's size-expression with a DILocalVariable, |
| // so that it can be used by CGDebugInfo when instantiating a DISubrange |
| // to describe this array. |
| unsigned NameIdx = 0; |
| for (auto &VlaSize : Dimensions) { |
| llvm::Metadata *MD; |
| if (auto *C = dyn_cast<llvm::ConstantInt>(VlaSize.NumElts)) |
| MD = llvm::ConstantAsMetadata::get(C); |
| else { |
| // Create an artificial VarDecl to generate debug info for. |
| IdentifierInfo *NameIdent = VLAExprNames[NameIdx++]; |
| auto VlaExprTy = VlaSize.NumElts->getType()->getPointerElementType(); |
| auto QT = getContext().getIntTypeForBitwidth( |
| VlaExprTy->getScalarSizeInBits(), false); |
| auto *ArtificialDecl = VarDecl::Create( |
| getContext(), const_cast<DeclContext *>(D.getDeclContext()), |
| D.getLocation(), D.getLocation(), NameIdent, QT, |
| getContext().CreateTypeSourceInfo(QT), SC_Auto); |
| ArtificialDecl->setImplicit(); |
| |
| MD = DI->EmitDeclareOfAutoVariable(ArtificialDecl, VlaSize.NumElts, |
| Builder); |
| } |
| assert(MD && "No Size expression debug node created"); |
| DI->registerVLASizeExpression(VlaSize.Type, MD); |
| } |
| } |
| |
| /// EmitAutoVarAlloca - Emit the alloca and debug information for a |
| /// local variable. Does not emit initialization or destruction. |
| CodeGenFunction::AutoVarEmission |
| CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) { |
| QualType Ty = D.getType(); |
| assert( |
| Ty.getAddressSpace() == LangAS::Default || |
| (Ty.getAddressSpace() == LangAS::opencl_private && getLangOpts().OpenCL)); |
| |
| AutoVarEmission emission(D); |
| |
| bool isEscapingByRef = D.isEscapingByref(); |
| emission.IsEscapingByRef = isEscapingByRef; |
| |
| CharUnits alignment = getContext().getDeclAlign(&D); |
| |
| // If the type is variably-modified, emit all the VLA sizes for it. |
| if (Ty->isVariablyModifiedType()) |
| EmitVariablyModifiedType(Ty); |
| |
| auto *DI = getDebugInfo(); |
| bool EmitDebugInfo = DI && CGM.getCodeGenOpts().hasReducedDebugInfo(); |
| |
| Address address = Address::invalid(); |
| Address AllocaAddr = Address::invalid(); |
| Address OpenMPLocalAddr = Address::invalid(); |
| if (CGM.getLangOpts().OpenMPIRBuilder) |
| OpenMPLocalAddr = OMPBuilderCBHelpers::getAddressOfLocalVariable(*this, &D); |
| else |
| OpenMPLocalAddr = |
| getLangOpts().OpenMP |
| ? CGM.getOpenMPRuntime().getAddressOfLocalVariable(*this, &D) |
| : Address::invalid(); |
| |
| bool NRVO = getLangOpts().ElideConstructors && D.isNRVOVariable(); |
| |
| if (getLangOpts().OpenMP && OpenMPLocalAddr.isValid()) { |
| address = OpenMPLocalAddr; |
| AllocaAddr = OpenMPLocalAddr; |
| } else if (Ty->isConstantSizeType()) { |
| // If this value is an array or struct with a statically determinable |
| // constant initializer, there are optimizations we can do. |
| // |
| // TODO: We should constant-evaluate the initializer of any variable, |
| // as long as it is initialized by a constant expression. Currently, |
| // isConstantInitializer produces wrong answers for structs with |
| // reference or bitfield members, and a few other cases, and checking |
| // for POD-ness protects us from some of these. |
| if (D.getInit() && (Ty->isArrayType() || Ty->isRecordType()) && |
| (D.isConstexpr() || |
| ((Ty.isPODType(getContext()) || |
| getContext().getBaseElementType(Ty)->isObjCObjectPointerType()) && |
| D.getInit()->isConstantInitializer(getContext(), false)))) { |
| |
| // If the variable's a const type, and it's neither an NRVO |
| // candidate nor a __block variable and has no mutable members, |
| // emit it as a global instead. |
| // Exception is if a variable is located in non-constant address space |
| // in OpenCL. |
| if ((!getLangOpts().OpenCL || |
| Ty.getAddressSpace() == LangAS::opencl_constant) && |
| (CGM.getCodeGenOpts().MergeAllConstants && !NRVO && |
| !isEscapingByRef && CGM.isTypeConstant(Ty, true))) { |
| EmitStaticVarDecl(D, llvm::GlobalValue::InternalLinkage); |
| |
| // Signal this condition to later callbacks. |
| emission.Addr = Address::invalid(); |
| assert(emission.wasEmittedAsGlobal()); |
| return emission; |
| } |
| |
| // Otherwise, tell the initialization code that we're in this case. |
| emission.IsConstantAggregate = true; |
| } |
| |
| // A normal fixed sized variable becomes an alloca in the entry block, |
| // unless: |
| // - it's an NRVO variable. |
| // - we are compiling OpenMP and it's an OpenMP local variable. |
| if (NRVO) { |
| // The named return value optimization: allocate this variable in the |
| // return slot, so that we can elide the copy when returning this |
| // variable (C++0x [class.copy]p34). |
| address = ReturnValue; |
| AllocaAddr = ReturnValue; |
| |
| if (const RecordType *RecordTy = Ty->getAs<RecordType>()) { |
| const auto *RD = RecordTy->getDecl(); |
| const auto *CXXRD = dyn_cast<CXXRecordDecl>(RD); |
| if ((CXXRD && !CXXRD->hasTrivialDestructor()) || |
| RD->isNonTrivialToPrimitiveDestroy()) { |
| // Create a flag that is used to indicate when the NRVO was applied |
| // to this variable. Set it to zero to indicate that NRVO was not |
| // applied. |
| llvm::Value *Zero = Builder.getFalse(); |
| Address NRVOFlag = |
| CreateTempAlloca(Zero->getType(), CharUnits::One(), "nrvo", |
| /*ArraySize=*/nullptr, &AllocaAddr); |
| EnsureInsertPoint(); |
| Builder.CreateStore(Zero, NRVOFlag); |
| |
| // Record the NRVO flag for this variable. |
| NRVOFlags[&D] = NRVOFlag.getPointer(); |
| emission.NRVOFlag = NRVOFlag.getPointer(); |
| } |
| } |
| } else { |
| CharUnits allocaAlignment; |
| llvm::Type *allocaTy; |
| if (isEscapingByRef) { |
| auto &byrefInfo = getBlockByrefInfo(&D); |
| allocaTy = byrefInfo.Type; |
| allocaAlignment = byrefInfo.ByrefAlignment; |
| } else { |
| allocaTy = ConvertTypeForMem(Ty); |
| allocaAlignment = alignment; |
| } |
| |
| // Create the alloca. Note that we set the name separately from |
| // building the instruction so that it's there even in no-asserts |
| // builds. |
| address = CreateTempAlloca(allocaTy, allocaAlignment, D.getName(), |
| /*ArraySize=*/nullptr, &AllocaAddr); |
| |
| // Don't emit lifetime markers for MSVC catch parameters. The lifetime of |
| // the catch parameter starts in the catchpad instruction, and we can't |
| // insert code in those basic blocks. |
| bool IsMSCatchParam = |
| D.isExceptionVariable() && getTarget().getCXXABI().isMicrosoft(); |
| |
| // Emit a lifetime intrinsic if meaningful. There's no point in doing this |
| // if we don't have a valid insertion point (?). |
| if (HaveInsertPoint() && !IsMSCatchParam) { |
| // If there's a jump into the lifetime of this variable, its lifetime |
| // gets broken up into several regions in IR, which requires more work |
| // to handle correctly. For now, just omit the intrinsics; this is a |
| // rare case, and it's better to just be conservatively correct. |
| // PR28267. |
| // |
| // We have to do this in all language modes if there's a jump past the |
| // declaration. We also have to do it in C if there's a jump to an |
| // earlier point in the current block because non-VLA lifetimes begin as |
| // soon as the containing block is entered, not when its variables |
| // actually come into scope; suppressing the lifetime annotations |
| // completely in this case is unnecessarily pessimistic, but again, this |
| // is rare. |
| if (!Bypasses.IsBypassed(&D) && |
| !(!getLangOpts().CPlusPlus && hasLabelBeenSeenInCurrentScope())) { |
| llvm::TypeSize Size = CGM.getDataLayout().getTypeAllocSize(allocaTy); |
| emission.SizeForLifetimeMarkers = |
| EmitLifetimeStart(Size, AllocaAddr.getPointer()); |
| } |
| } else { |
| assert(!emission.useLifetimeMarkers()); |
| } |
| } |
| } else { |
| EnsureInsertPoint(); |
| |
| if (!DidCallStackSave) { |
| // Save the stack. |
| Address Stack = |
| CreateTempAlloca(Int8PtrTy, getPointerAlign(), "saved_stack"); |
| |
| llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave); |
| llvm::Value *V = Builder.CreateCall(F); |
| Builder.CreateStore(V, Stack); |
| |
| DidCallStackSave = true; |
| |
| // Push a cleanup block and restore the stack there. |
| // FIXME: in general circumstances, this should be an EH cleanup. |
| pushStackRestore(NormalCleanup, Stack); |
| } |
| |
| auto VlaSize = getVLASize(Ty); |
| llvm::Type *llvmTy = ConvertTypeForMem(VlaSize.Type); |
| |
| // Allocate memory for the array. |
| address = CreateTempAlloca(llvmTy, alignment, "vla", VlaSize.NumElts, |
| &AllocaAddr); |
| |
| // If we have debug info enabled, properly describe the VLA dimensions for |
| // this type by registering the vla size expression for each of the |
| // dimensions. |
| EmitAndRegisterVariableArrayDimensions(DI, D, EmitDebugInfo); |
| } |
| |
| setAddrOfLocalVar(&D, address); |
| emission.Addr = address; |
| emission.AllocaAddr = AllocaAddr; |
| |
| // Emit debug info for local var declaration. |
| if (EmitDebugInfo && HaveInsertPoint()) { |
| Address DebugAddr = address; |
| bool UsePointerValue = NRVO && ReturnValuePointer.isValid(); |
| DI->setLocation(D.getLocation()); |
| |
| // If NRVO, use a pointer to the return address. |
| if (UsePointerValue) { |
| DebugAddr = ReturnValuePointer; |
| AllocaAddr = ReturnValuePointer; |
| } |
| (void)DI->EmitDeclareOfAutoVariable(&D, AllocaAddr.getPointer(), Builder, |
| UsePointerValue); |
| } |
| |
| if (D.hasAttr<AnnotateAttr>() && HaveInsertPoint()) |
| EmitVarAnnotations(&D, address.getPointer()); |
| |
| // Make sure we call @llvm.lifetime.end. |
| if (emission.useLifetimeMarkers()) |
| EHStack.pushCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, |
| emission.getOriginalAllocatedAddress(), |
| emission.getSizeForLifetimeMarkers()); |
| |
| return emission; |
| } |
| |
| static bool isCapturedBy(const VarDecl &, const Expr *); |
| |
| /// Determines whether the given __block variable is potentially |
| /// captured by the given statement. |
| static bool isCapturedBy(const VarDecl &Var, const Stmt *S) { |
| if (const Expr *E = dyn_cast<Expr>(S)) |
| return isCapturedBy(Var, E); |
| for (const Stmt *SubStmt : S->children()) |
| if (isCapturedBy(Var, SubStmt)) |
| return true; |
| return false; |
| } |
| |
| /// Determines whether the given __block variable is potentially |
| /// captured by the given expression. |
| static bool isCapturedBy(const VarDecl &Var, const Expr *E) { |
| // Skip the most common kinds of expressions that make |
| // hierarchy-walking expensive. |
| E = E->IgnoreParenCasts(); |
| |
| if (const BlockExpr *BE = dyn_cast<BlockExpr>(E)) { |
| const BlockDecl *Block = BE->getBlockDecl(); |
| for (const auto &I : Block->captures()) { |
| if (I.getVariable() == &Var) |
| return true; |
| } |
| |
| // No need to walk into the subexpressions. |
| return false; |
| } |
| |
| if (const StmtExpr *SE = dyn_cast<StmtExpr>(E)) { |
| const CompoundStmt *CS = SE->getSubStmt(); |
| for (const auto *BI : CS->body()) |
| if (const auto *BIE = dyn_cast<Expr>(BI)) { |
| if (isCapturedBy(Var, BIE)) |
| return true; |
| } |
| else if (const auto *DS = dyn_cast<DeclStmt>(BI)) { |
| // special case declarations |
| for (const auto *I : DS->decls()) { |
| if (const auto *VD = dyn_cast<VarDecl>((I))) { |
| const Expr *Init = VD->getInit(); |
| if (Init && isCapturedBy(Var, Init)) |
| return true; |
| } |
| } |
| } |
| else |
| // FIXME. Make safe assumption assuming arbitrary statements cause capturing. |
| // Later, provide code to poke into statements for capture analysis. |
| return true; |
| return false; |
| } |
| |
| for (const Stmt *SubStmt : E->children()) |
| if (isCapturedBy(Var, SubStmt)) |
| return true; |
| |
| return false; |
| } |
| |
| /// Determine whether the given initializer is trivial in the sense |
| /// that it requires no code to be generated. |
| bool CodeGenFunction::isTrivialInitializer(const Expr *Init) { |
| if (!Init) |
| return true; |
| |
| if (const CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) |
| if (CXXConstructorDecl *Constructor = Construct->getConstructor()) |
| if (Constructor->isTrivial() && |
| Constructor->isDefaultConstructor() && |
| !Construct->requiresZeroInitialization()) |
| return true; |
| |
| return false; |
| } |
| |
| void CodeGenFunction::emitZeroOrPatternForAutoVarInit(QualType type, |
| const VarDecl &D, |
| Address Loc) { |
| auto trivialAutoVarInit = getContext().getLangOpts().getTrivialAutoVarInit(); |
| CharUnits Size = getContext().getTypeSizeInChars(type); |
| bool isVolatile = type.isVolatileQualified(); |
| if (!Size.isZero()) { |
| switch (trivialAutoVarInit) { |
| case LangOptions::TrivialAutoVarInitKind::Uninitialized: |
| llvm_unreachable("Uninitialized handled by caller"); |
| case LangOptions::TrivialAutoVarInitKind::Zero: |
| if (CGM.stopAutoInit()) |
| return; |
| emitStoresForZeroInit(CGM, D, Loc, isVolatile, Builder); |
| break; |
| case LangOptions::TrivialAutoVarInitKind::Pattern: |
| if (CGM.stopAutoInit()) |
| return; |
| emitStoresForPatternInit(CGM, D, Loc, isVolatile, Builder); |
| break; |
| } |
| return; |
| } |
| |
| // VLAs look zero-sized to getTypeInfo. We can't emit constant stores to |
| // them, so emit a memcpy with the VLA size to initialize each element. |
| // Technically zero-sized or negative-sized VLAs are undefined, and UBSan |
| // will catch that code, but there exists code which generates zero-sized |
| // VLAs. Be nice and initialize whatever they requested. |
| const auto *VlaType = getContext().getAsVariableArrayType(type); |
| if (!VlaType) |
| return; |
| auto VlaSize = getVLASize(VlaType); |
| auto SizeVal = VlaSize.NumElts; |
| CharUnits EltSize = getContext().getTypeSizeInChars(VlaSize.Type); |
| switch (trivialAutoVarInit) { |
| case LangOptions::TrivialAutoVarInitKind::Uninitialized: |
| llvm_unreachable("Uninitialized handled by caller"); |
| |
| case LangOptions::TrivialAutoVarInitKind::Zero: { |
| if (CGM.stopAutoInit()) |
| return; |
| if (!EltSize.isOne()) |
| SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(EltSize)); |
| auto *I = Builder.CreateMemSet(Loc, llvm::ConstantInt::get(Int8Ty, 0), |
| SizeVal, isVolatile); |
| I->addAnnotationMetadata("auto-init"); |
| break; |
| } |
| |
| case LangOptions::TrivialAutoVarInitKind::Pattern: { |
| if (CGM.stopAutoInit()) |
| return; |
| llvm::Type *ElTy = Loc.getElementType(); |
| llvm::Constant *Constant = constWithPadding( |
| CGM, IsPattern::Yes, initializationPatternFor(CGM, ElTy)); |
| CharUnits ConstantAlign = getContext().getTypeAlignInChars(VlaSize.Type); |
| llvm::BasicBlock *SetupBB = createBasicBlock("vla-setup.loop"); |
| llvm::BasicBlock *LoopBB = createBasicBlock("vla-init.loop"); |
| llvm::BasicBlock *ContBB = createBasicBlock("vla-init.cont"); |
| llvm::Value *IsZeroSizedVLA = Builder.CreateICmpEQ( |
| SizeVal, llvm::ConstantInt::get(SizeVal->getType(), 0), |
| "vla.iszerosized"); |
| Builder.CreateCondBr(IsZeroSizedVLA, ContBB, SetupBB); |
| EmitBlock(SetupBB); |
| if (!EltSize.isOne()) |
| SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(EltSize)); |
| llvm::Value *BaseSizeInChars = |
| llvm::ConstantInt::get(IntPtrTy, EltSize.getQuantity()); |
| Address Begin = Builder.CreateElementBitCast(Loc, Int8Ty, "vla.begin"); |
| llvm::Value *End = Builder.CreateInBoundsGEP( |
| Begin.getElementType(), Begin.getPointer(), SizeVal, "vla.end"); |
| llvm::BasicBlock *OriginBB = Builder.GetInsertBlock(); |
| EmitBlock(LoopBB); |
| llvm::PHINode *Cur = Builder.CreatePHI(Begin.getType(), 2, "vla.cur"); |
| Cur->addIncoming(Begin.getPointer(), OriginBB); |
| CharUnits CurAlign = Loc.getAlignment().alignmentOfArrayElement(EltSize); |
| auto *I = |
| Builder.CreateMemCpy(Address(Cur, CurAlign), |
| createUnnamedGlobalForMemcpyFrom( |
| CGM, D, Builder, Constant, ConstantAlign), |
| BaseSizeInChars, isVolatile); |
| I->addAnnotationMetadata("auto-init"); |
| llvm::Value *Next = |
| Builder.CreateInBoundsGEP(Int8Ty, Cur, BaseSizeInChars, "vla.next"); |
| llvm::Value *Done = Builder.CreateICmpEQ(Next, End, "vla-init.isdone"); |
| Builder.CreateCondBr(Done, ContBB, LoopBB); |
| Cur->addIncoming(Next, LoopBB); |
| EmitBlock(ContBB); |
| } break; |
| } |
| } |
| |
| void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) { |
| assert(emission.Variable && "emission was not valid!"); |
| |
| // If this was emitted as a global constant, we're done. |
| if (emission.wasEmittedAsGlobal()) return; |
| |
| const VarDecl &D = *emission.Variable; |
| auto DL = ApplyDebugLocation::CreateDefaultArtificial(*this, D.getLocation()); |
| QualType type = D.getType(); |
| |
| // If this local has an initializer, emit it now. |
| const Expr *Init = D.getInit(); |
| |
| // If we are at an unreachable point, we don't need to emit the initializer |
| // unless it contains a label. |
| if (!HaveInsertPoint()) { |
| if (!Init || !ContainsLabel(Init)) return; |
| EnsureInsertPoint(); |
| } |
| |
| // Initialize the structure of a __block variable. |
| if (emission.IsEscapingByRef) |
| emitByrefStructureInit(emission); |
| |
| // Initialize the variable here if it doesn't have a initializer and it is a |
| // C struct that is non-trivial to initialize or an array containing such a |
| // struct. |
| if (!Init && |
| type.isNonTrivialToPrimitiveDefaultInitialize() == |
| QualType::PDIK_Struct) { |
| LValue Dst = MakeAddrLValue(emission.getAllocatedAddress(), type); |
| if (emission.IsEscapingByRef) |
| drillIntoBlockVariable(*this, Dst, &D); |
| defaultInitNonTrivialCStructVar(Dst); |
| return; |
| } |
| |
| // Check whether this is a byref variable that's potentially |
| // captured and moved by its own initializer. If so, we'll need to |
| // emit the initializer first, then copy into the variable. |
| bool capturedByInit = |
| Init && emission.IsEscapingByRef && isCapturedBy(D, Init); |
| |
| bool locIsByrefHeader = !capturedByInit; |
| const Address Loc = |
| locIsByrefHeader ? emission.getObjectAddress(*this) : emission.Addr; |
| |
| // Note: constexpr already initializes everything correctly. |
| LangOptions::TrivialAutoVarInitKind trivialAutoVarInit = |
| (D.isConstexpr() |
| ? LangOptions::TrivialAutoVarInitKind::Uninitialized |
| : (D.getAttr<UninitializedAttr>() |
| ? LangOptions::TrivialAutoVarInitKind::Uninitialized |
| : getContext().getLangOpts().getTrivialAutoVarInit())); |
| |
| auto initializeWhatIsTechnicallyUninitialized = [&](Address Loc) { |
| if (trivialAutoVarInit == |
| LangOptions::TrivialAutoVarInitKind::Uninitialized) |
| return; |
| |
| // Only initialize a __block's storage: we always initialize the header. |
| if (emission.IsEscapingByRef && !locIsByrefHeader) |
| Loc = emitBlockByrefAddress(Loc, &D, /*follow=*/false); |
| |
| return emitZeroOrPatternForAutoVarInit(type, D, Loc); |
| }; |
| |
| if (isTrivialInitializer(Init)) |
| return initializeWhatIsTechnicallyUninitialized(Loc); |
| |
| llvm::Constant *constant = nullptr; |
| if (emission.IsConstantAggregate || |
| D.mightBeUsableInConstantExpressions(getContext())) { |
| assert(!capturedByInit && "constant init contains a capturing block?"); |
| constant = ConstantEmitter(*this).tryEmitAbstractForInitializer(D); |
| if (constant && !constant->isZeroValue() && |
| (trivialAutoVarInit != |
| LangOptions::TrivialAutoVarInitKind::Uninitialized)) { |
| IsPattern isPattern = |
| (trivialAutoVarInit == LangOptions::TrivialAutoVarInitKind::Pattern) |
| ? IsPattern::Yes |
| : IsPattern::No; |
| // C guarantees that brace-init with fewer initializers than members in |
| // the aggregate will initialize the rest of the aggregate as-if it were |
| // static initialization. In turn static initialization guarantees that |
| // padding is initialized to zero bits. We could instead pattern-init if D |
| // has any ImplicitValueInitExpr, but that seems to be unintuitive |
| // behavior. |
| constant = constWithPadding(CGM, IsPattern::No, |
| replaceUndef(CGM, isPattern, constant)); |
| } |
| } |
| |
| if (!constant) { |
| initializeWhatIsTechnicallyUninitialized(Loc); |
| LValue lv = MakeAddrLValue(Loc, type); |
| lv.setNonGC(true); |
| return EmitExprAsInit(Init, &D, lv, capturedByInit); |
| } |
| |
| if (!emission.IsConstantAggregate) { |
| // For simple scalar/complex initialization, store the value directly. |
| LValue lv = MakeAddrLValue(Loc, type); |
| lv.setNonGC(true); |
| return EmitStoreThroughLValue(RValue::get(constant), lv, true); |
| } |
| |
| llvm::Type *BP = CGM.Int8Ty->getPointerTo(Loc.getAddressSpace()); |
| emitStoresForConstant( |
| CGM, D, (Loc.getType() == BP) ? Loc : Builder.CreateBitCast(Loc, BP), |
| type.isVolatileQualified(), Builder, constant, /*IsAutoInit=*/false); |
| } |
| |
| /// Emit an expression as an initializer for an object (variable, field, etc.) |
| /// at the given location. The expression is not necessarily the normal |
| /// initializer for the object, and the address is not necessarily |
| /// its normal location. |
| /// |
| /// \param init the initializing expression |
| /// \param D the object to act as if we're initializing |
| /// \param lvalue the lvalue to initialize |
| /// \param capturedByInit true if \p D is a __block variable |
| /// whose address is potentially changed by the initializer |
| void CodeGenFunction::EmitExprAsInit(const Expr *init, const ValueDecl *D, |
| LValue lvalue, bool capturedByInit) { |
| QualType type = D->getType(); |
| |
| if (type->isReferenceType()) { |
| RValue rvalue = EmitReferenceBindingToExpr(init); |
| if (capturedByInit) |
| drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); |
| EmitStoreThroughLValue(rvalue, lvalue, true); |
| return; |
| } |
| switch (getEvaluationKind(type)) { |
| case TEK_Scalar: |
| EmitScalarInit(init, D, lvalue, capturedByInit); |
| return; |
| case TEK_Complex: { |
| ComplexPairTy complex = EmitComplexExpr(init); |
| if (capturedByInit) |
| drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); |
| EmitStoreOfComplex(complex, lvalue, /*init*/ true); |
| return; |
| } |
| case TEK_Aggregate: |
| if (type->isAtomicType()) { |
| EmitAtomicInit(const_cast<Expr*>(init), lvalue); |
| } else { |
| AggValueSlot::Overlap_t Overlap = AggValueSlot::MayOverlap; |
| if (isa<VarDecl>(D)) |
| Overlap = AggValueSlot::DoesNotOverlap; |
| else if (auto *FD = dyn_cast<FieldDecl>(D)) |
| Overlap = getOverlapForFieldInit(FD); |
| // TODO: how can we delay here if D is captured by its initializer? |
| EmitAggExpr(init, AggValueSlot::forLValue( |
| lvalue, *this, AggValueSlot::IsDestructed, |
| AggValueSlot::DoesNotNeedGCBarriers, |
| AggValueSlot::IsNotAliased, Overlap)); |
| } |
| return; |
| } |
| llvm_unreachable("bad evaluation kind"); |
| } |
| |
| /// Enter a destroy cleanup for the given local variable. |
| void CodeGenFunction::emitAutoVarTypeCleanup( |
| const CodeGenFunction::AutoVarEmission &emission, |
| QualType::DestructionKind dtorKind) { |
| assert(dtorKind != QualType::DK_none); |
| |
| // Note that for __block variables, we want to destroy the |
| // original stack object, not the possibly forwarded object. |
| Address addr = emission.getObjectAddress(*this); |
| |
| const VarDecl *var = emission.Variable; |
| QualType type = var->getType(); |
| |
| CleanupKind cleanupKind = NormalAndEHCleanup; |
| CodeGenFunction::Destroyer *destroyer = nullptr; |
| |
| switch (dtorKind) { |
| case QualType::DK_none: |
| llvm_unreachable("no cleanup for trivially-destructible variable"); |
| |
| case QualType::DK_cxx_destructor: |
| // If there's an NRVO flag on the emission, we need a different |
| // cleanup. |
| if (emission.NRVOFlag) { |
| assert(!type->isArrayType()); |
| CXXDestructorDecl *dtor = type->getAsCXXRecordDecl()->getDestructor(); |
| EHStack.pushCleanup<DestroyNRVOVariableCXX>(cleanupKind, addr, type, dtor, |
| emission.NRVOFlag); |
| return; |
| } |
| break; |
| |
| case QualType::DK_objc_strong_lifetime: |
| // Suppress cleanups for pseudo-strong variables. |
| if (var->isARCPseudoStrong()) return; |
| |
| // Otherwise, consider whether to use an EH cleanup or not. |
| cleanupKind = getARCCleanupKind(); |
| |
| // Use the imprecise destroyer by default. |
| if (!var->hasAttr<ObjCPreciseLifetimeAttr>()) |
| destroyer = CodeGenFunction::destroyARCStrongImprecise; |
| break; |
| |
| case QualType::DK_objc_weak_lifetime: |
| break; |
| |
| case QualType::DK_nontrivial_c_struct: |
| destroyer = CodeGenFunction::destroyNonTrivialCStruct; |
| if (emission.NRVOFlag) { |
| assert(!type->isArrayType()); |
| EHStack.pushCleanup<DestroyNRVOVariableC>(cleanupKind, addr, |
| emission.NRVOFlag, type); |
| return; |
| } |
| break; |
| } |
| |
| // If we haven't chosen a more specific destroyer, use the default. |
| if (!destroyer) destroyer = getDestroyer(dtorKind); |
| |
| // Use an EH cleanup in array destructors iff the destructor itself |
| // is being pushed as an EH cleanup. |
| bool useEHCleanup = (cleanupKind & EHCleanup); |
| EHStack.pushCleanup<DestroyObject>(cleanupKind, addr, type, destroyer, |
| useEHCleanup); |
| } |
| |
| void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) { |
| assert(emission.Variable && "emission was not valid!"); |
| |
| // If this was emitted as a global constant, we're done. |
| if (emission.wasEmittedAsGlobal()) return; |
| |
| // If we don't have an insertion point, we're done. Sema prevents |
| // us from jumping into any of these scopes anyway. |
| if (!HaveInsertPoint()) return; |
| |
| const VarDecl &D = *emission.Variable; |
| |
| // Check the type for a cleanup. |
| if (QualType::DestructionKind dtorKind = D.needsDestruction(getContext())) |
| emitAutoVarTypeCleanup(emission, dtorKind); |
| |
| // In GC mode, honor objc_precise_lifetime. |
| if (getLangOpts().getGC() != LangOptions::NonGC && |
| D.hasAttr<ObjCPreciseLifetimeAttr>()) { |
| EHStack.pushCleanup<ExtendGCLifetime>(NormalCleanup, &D); |
| } |
| |
| // Handle the cleanup attribute. |
| if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) { |
| const FunctionDecl *FD = CA->getFunctionDecl(); |
| |
| llvm::Constant *F = CGM.GetAddrOfFunction(FD); |
| assert(F && "Could not find function!"); |
| |
| const CGFunctionInfo &Info = CGM.getTypes().arrangeFunctionDeclaration(FD); |
| EHStack.pushCleanup<CallCleanupFunction>(NormalAndEHCleanup, F, &Info, &D); |
| } |
| |
| // If this is a block variable, call _Block_object_destroy |
| // (on the unforwarded address). Don't enter this cleanup if we're in pure-GC |
| // mode. |
| if (emission.IsEscapingByRef && |
| CGM.getLangOpts().getGC() != LangOptions::GCOnly) { |
| BlockFieldFlags Flags = BLOCK_FIELD_IS_BYREF; |
| if (emission.Variable->getType().isObjCGCWeak()) |
| Flags |= BLOCK_FIELD_IS_WEAK; |
| enterByrefCleanup(NormalAndEHCleanup, emission.Addr, Flags, |
| /*LoadBlockVarAddr*/ false, |
| cxxDestructorCanThrow(emission.Variable->getType())); |
| } |
| } |
| |
| CodeGenFunction::Destroyer * |
| CodeGenFunction::getDestroyer(QualType::DestructionKind kind) { |
| switch (kind) { |
| case QualType::DK_none: llvm_unreachable("no destroyer for trivial dtor"); |
| case QualType::DK_cxx_destructor: |
| return destroyCXXObject; |
| case QualType::DK_objc_strong_lifetime: |
| return destroyARCStrongPrecise; |
| case QualType::DK_objc_weak_lifetime: |
| return destroyARCWeak; |
| case QualType::DK_nontrivial_c_struct: |
| return destroyNonTrivialCStruct; |
| } |
| llvm_unreachable("Unknown DestructionKind"); |
| } |
| |
| /// pushEHDestroy - Push the standard destructor for the given type as |
| /// an EH-only cleanup. |
| void CodeGenFunction::pushEHDestroy(QualType::DestructionKind dtorKind, |
| Address addr, QualType type) { |
| assert(dtorKind && "cannot push destructor for trivial type"); |
| assert(needsEHCleanup(dtorKind)); |
| |
| pushDestroy(EHCleanup, addr, type, getDestroyer(dtorKind), true); |
| } |
| |
| /// pushDestroy - Push the standard destructor for the given type as |
| /// at least a normal cleanup. |
| void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind, |
| Address addr, QualType type) { |
| assert(dtorKind && "cannot push destructor for trivial type"); |
| |
| CleanupKind cleanupKind = getCleanupKind(dtorKind); |
| pushDestroy(cleanupKind, addr, type, getDestroyer(dtorKind), |
| cleanupKind & EHCleanup); |
| } |
| |
| void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, Address addr, |
| QualType type, Destroyer *destroyer, |
| bool useEHCleanupForArray) { |
| pushFullExprCleanup<DestroyObject>(cleanupKind, addr, type, |
| destroyer, useEHCleanupForArray); |
| } |
| |
| void CodeGenFunction::pushStackRestore(CleanupKind Kind, Address SPMem) { |
| EHStack.pushCleanup<CallStackRestore>(Kind, SPMem); |
| } |
| |
| void CodeGenFunction::pushLifetimeExtendedDestroy(CleanupKind cleanupKind, |
| Address addr, QualType type, |
| Destroyer *destroyer, |
| bool useEHCleanupForArray) { |
| // If we're not in a conditional branch, we don't need to bother generating a |
| // conditional cleanup. |
| if (!isInConditionalBranch()) { |
| // Push an EH-only cleanup for the object now. |
| // FIXME: When popping normal cleanups, we need to keep this EH cleanup |
| // around in case a temporary's destructor throws an exception. |
| if (cleanupKind & EHCleanup) |
| EHStack.pushCleanup<DestroyObject>( |
| static_cast<CleanupKind>(cleanupKind & ~NormalCleanup), addr, type, |
| destroyer, useEHCleanupForArray); |
| |
| return pushCleanupAfterFullExprWithActiveFlag<DestroyObject>( |
| cleanupKind, Address::invalid(), addr, type, destroyer, useEHCleanupForArray); |
| } |
| |
| // Otherwise, we should only destroy the object if it's been initialized. |
| // Re-use the active flag and saved address across both the EH and end of |
| // scope cleanups. |
| |
| using SavedType = typename DominatingValue<Address>::saved_type; |
| using ConditionalCleanupType = |
| EHScopeStack::ConditionalCleanup<DestroyObject, Address, QualType, |
| Destroyer *, bool>; |
| |
| Address ActiveFlag = createCleanupActiveFlag(); |
| SavedType SavedAddr = saveValueInCond(addr); |
| |
| if (cleanupKind & EHCleanup) { |
| EHStack.pushCleanup<ConditionalCleanupType>( |
| static_cast<CleanupKind>(cleanupKind & ~NormalCleanup), SavedAddr, type, |
| destroyer, useEHCleanupForArray); |
| initFullExprCleanupWithFlag(ActiveFlag); |
| } |
| |
| pushCleanupAfterFullExprWithActiveFlag<ConditionalCleanupType>( |
| cleanupKind, ActiveFlag, SavedAddr, type, destroyer, |
| useEHCleanupForArray); |
| } |
| |
| /// emitDestroy - Immediately perform the destruction of the given |
| /// object. |
| /// |
| /// \param addr - the address of the object; a type* |
| /// \param type - the type of the object; if an array type, all |
| /// objects are destroyed in reverse order |
| /// \param destroyer - the function to call to destroy individual |
| /// elements |
| /// \param useEHCleanupForArray - whether an EH cleanup should be |
| /// used when destroying array elements, in case one of the |
| /// destructions throws an exception |
| void CodeGenFunction::emitDestroy(Address addr, QualType type, |
| Destroyer *destroyer, |
| bool useEHCleanupForArray) { |
| const ArrayType *arrayType = getContext().getAsArrayType(type); |
| if (!arrayType) |
| return destroyer(*this, addr, type); |
| |
| llvm::Value *length = emitArrayLength(arrayType, type, addr); |
| |
| CharUnits elementAlign = |
| addr.getAlignment() |
| .alignmentOfArrayElement(getContext().getTypeSizeInChars(type)); |
| |
| // Normally we have to check whether the array is zero-length. |
| bool checkZeroLength = true; |
| |
| // But if the array length is constant, we can suppress that. |
| if (llvm::ConstantInt *constLength = dyn_cast<llvm::ConstantInt>(length)) { |
| // ...and if it's constant zero, we can just skip the entire thing. |
| if (constLength->isZero()) return; |
| checkZeroLength = false; |
| } |
| |
| llvm::Value *begin = addr.getPointer(); |
| llvm::Value *end = |
| Builder.CreateInBoundsGEP(addr.getElementType(), begin, length); |
| emitArrayDestroy(begin, end, type, elementAlign, destroyer, |
| checkZeroLength, useEHCleanupForArray); |
| } |
| |
| /// emitArrayDestroy - Destroys all the elements of the given array, |
| /// beginning from last to first. The array cannot be zero-length. |
| /// |
| /// \param begin - a type* denoting the first element of the array |
| /// \param end - a type* denoting one past the end of the array |
| /// \param elementType - the element type of the array |
| /// \param destroyer - the function to call to destroy elements |
| /// \param useEHCleanup - whether to push an EH cleanup to destroy |
| /// the remaining elements in case the destruction of a single |
| /// element throws |
| void CodeGenFunction::emitArrayDestroy(llvm::Value *begin, |
| llvm::Value *end, |
| QualType elementType, |
| CharUnits elementAlign, |
| Destroyer *destroyer, |
| bool checkZeroLength, |
| bool useEHCleanup) { |
| assert(!elementType->isArrayType()); |
| |
| // The basic structure here is a do-while loop, because we don't |
| // need to check for the zero-element case. |
| llvm::BasicBlock *bodyBB = createBasicBlock("arraydestroy.body"); |
| llvm::BasicBlock *doneBB = createBasicBlock("arraydestroy.done"); |
| |
| if (checkZeroLength) { |
| llvm::Value *isEmpty = Builder.CreateICmpEQ(begin, end, |
| "arraydestroy.isempty"); |
| Builder.CreateCondBr(isEmpty, doneBB, bodyBB); |
| } |
| |
| // Enter the loop body, making that address the current address. |
| llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); |
| EmitBlock(bodyBB); |
| llvm::PHINode *elementPast = |
| Builder.CreatePHI(begin->getType(), 2, "arraydestroy.elementPast"); |
| elementPast->addIncoming(end, entryBB); |
| |
| // Shift the address back by one element. |
| llvm::Value *negativeOne = llvm::ConstantInt::get(SizeTy, -1, true); |
| llvm::Value *element = Builder.CreateInBoundsGEP( |
| elementPast->getType()->getPointerElementType(), elementPast, negativeOne, |
| "arraydestroy.element"); |
| |
| if (useEHCleanup) |
| pushRegularPartialArrayCleanup(begin, element, elementType, elementAlign, |
| destroyer); |
| |
| // Perform the actual destruction there. |
| destroyer(*this, Address(element, elementAlign), elementType); |
| |
| if (useEHCleanup) |
| PopCleanupBlock(); |
| |
| // Check whether we've reached the end. |
| llvm::Value *done = Builder.CreateICmpEQ(element, begin, "arraydestroy.done"); |
| Builder.CreateCondBr(done, doneBB, bodyBB); |
| elementPast->addIncoming(element, Builder.GetInsertBlock()); |
| |
| // Done. |
| EmitBlock(doneBB); |
| } |
| |
| /// Perform partial array destruction as if in an EH cleanup. Unlike |
| /// emitArrayDestroy, the element type here may still be an array type. |
| static void emitPartialArrayDestroy(CodeGenFunction &CGF, |
| llvm::Value *begin, llvm::Value *end, |
| QualType type, CharUnits elementAlign, |
| CodeGenFunction::Destroyer *destroyer) { |
| // If the element type is itself an array, drill down. |
| unsigned arrayDepth = 0; |
| while (const ArrayType *arrayType = CGF.getContext().getAsArrayType(type)) { |
| // VLAs don't require a GEP index to walk into. |
| if (!isa<VariableArrayType>(arrayType)) |
| arrayDepth++; |
| type = arrayType->getElementType(); |
| } |
| |
| if (arrayDepth) { |
| llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0); |
| |
| SmallVector<llvm::Value*,4> gepIndices(arrayDepth+1, zero); |
| llvm::Type *elemTy = begin->getType()->getPointerElementType(); |
| begin = CGF.Builder.CreateInBoundsGEP( |
| elemTy, begin, gepIndices, "pad.arraybegin"); |
| end = CGF.Builder.CreateInBoundsGEP( |
| elemTy, end, gepIndices, "pad.arrayend"); |
| } |
| |
| // Destroy the array. We don't ever need an EH cleanup because we |
| // assume that we're in an EH cleanup ourselves, so a throwing |
| // destructor causes an immediate terminate. |
| CGF.emitArrayDestroy(begin, end, type, elementAlign, destroyer, |
| /*checkZeroLength*/ true, /*useEHCleanup*/ false); |
| } |
| |
| namespace { |
| /// RegularPartialArrayDestroy - a cleanup which performs a partial |
| /// array destroy where the end pointer is regularly determined and |
| /// does not need to be loaded from a local. |
| class RegularPartialArrayDestroy final : public EHScopeStack::Cleanup { |
| llvm::Value *ArrayBegin; |
| llvm::Value *ArrayEnd; |
| QualType ElementType; |
| CodeGenFunction::Destroyer *Destroyer; |
| CharUnits ElementAlign; |
| public: |
| RegularPartialArrayDestroy(llvm::Value *arrayBegin, llvm::Value *arrayEnd, |
| QualType elementType, CharUnits elementAlign, |
| CodeGenFunction::Destroyer *destroyer) |
| : ArrayBegin(arrayBegin), ArrayEnd(arrayEnd), |
| ElementType(elementType), Destroyer(destroyer), |
| ElementAlign(elementAlign) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| emitPartialArrayDestroy(CGF, ArrayBegin, ArrayEnd, |
| ElementType, ElementAlign, Destroyer); |
| } |
| }; |
| |
| /// IrregularPartialArrayDestroy - a cleanup which performs a |
| /// partial array destroy where the end pointer is irregularly |
| /// determined and must be loaded from a local. |
| class IrregularPartialArrayDestroy final : public EHScopeStack::Cleanup { |
| llvm::Value *ArrayBegin; |
| Address ArrayEndPointer; |
| QualType ElementType; |
| CodeGenFunction::Destroyer *Destroyer; |
| CharUnits ElementAlign; |
| public: |
| IrregularPartialArrayDestroy(llvm::Value *arrayBegin, |
| Address arrayEndPointer, |
| QualType elementType, |
| CharUnits elementAlign, |
| CodeGenFunction::Destroyer *destroyer) |
| : ArrayBegin(arrayBegin), ArrayEndPointer(arrayEndPointer), |
| ElementType(elementType), Destroyer(destroyer), |
| ElementAlign(elementAlign) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| llvm::Value *arrayEnd = CGF.Builder.CreateLoad(ArrayEndPointer); |
| emitPartialArrayDestroy(CGF, ArrayBegin, arrayEnd, |
| ElementType, ElementAlign, Destroyer); |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// pushIrregularPartialArrayCleanup - Push an EH cleanup to destroy |
| /// already-constructed elements of the given array. The cleanup |
| /// may be popped with DeactivateCleanupBlock or PopCleanupBlock. |
| /// |
| /// \param elementType - the immediate element type of the array; |
| /// possibly still an array type |
| void CodeGenFunction::pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin, |
| Address arrayEndPointer, |
| QualType elementType, |
| CharUnits elementAlign, |
| Destroyer *destroyer) { |
| pushFullExprCleanup<IrregularPartialArrayDestroy>(EHCleanup, |
| arrayBegin, arrayEndPointer, |
| elementType, elementAlign, |
| destroyer); |
| } |
| |
| /// pushRegularPartialArrayCleanup - Push an EH cleanup to destroy |
| /// already-constructed elements of the given array. The cleanup |
| /// may be popped with DeactivateCleanupBlock or PopCleanupBlock. |
| /// |
| /// \param elementType - the immediate element type of the array; |
| /// possibly still an array type |
| void CodeGenFunction::pushRegularPartialArrayCleanup(llvm::Value *arrayBegin, |
| llvm::Value *arrayEnd, |
| QualType elementType, |
| CharUnits elementAlign, |
| Destroyer *destroyer) { |
| pushFullExprCleanup<RegularPartialArrayDestroy>(EHCleanup, |
| arrayBegin, arrayEnd, |
| elementType, elementAlign, |
| destroyer); |
| } |
| |
| /// Lazily declare the @llvm.lifetime.start intrinsic. |
| llvm::Function *CodeGenModule::getLLVMLifetimeStartFn() { |
| if (LifetimeStartFn) |
| return LifetimeStartFn; |
| LifetimeStartFn = llvm::Intrinsic::getDeclaration(&getModule(), |
| llvm::Intrinsic::lifetime_start, AllocaInt8PtrTy); |
| return LifetimeStartFn; |
| } |
| |
| /// Lazily declare the @llvm.lifetime.end intrinsic. |
| llvm::Function *CodeGenModule::getLLVMLifetimeEndFn() { |
| if (LifetimeEndFn) |
| return LifetimeEndFn; |
| LifetimeEndFn = llvm::Intrinsic::getDeclaration(&getModule(), |
| llvm::Intrinsic::lifetime_end, AllocaInt8PtrTy); |
| return LifetimeEndFn; |
| } |
| |
| namespace { |
| /// A cleanup to perform a release of an object at the end of a |
| /// function. This is used to balance out the incoming +1 of a |
| /// ns_consumed argument when we can't reasonably do that just by |
| /// not doing the initial retain for a __block argument. |
| struct ConsumeARCParameter final : EHScopeStack::Cleanup { |
| ConsumeARCParameter(llvm::Value *param, |
| ARCPreciseLifetime_t precise) |
| : Param(param), Precise(precise) {} |
| |
| llvm::Value *Param; |
| ARCPreciseLifetime_t Precise; |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| CGF.EmitARCRelease(Param, Precise); |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// Emit an alloca (or GlobalValue depending on target) |
| /// for the specified parameter and set up LocalDeclMap. |
| void CodeGenFunction::EmitParmDecl(const VarDecl &D, ParamValue Arg, |
| unsigned ArgNo) { |
| // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl? |
| assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) && |
| "Invalid argument to EmitParmDecl"); |
| |
| Arg.getAnyValue()->setName(D.getName()); |
| |
| QualType Ty = D.getType(); |
| |
| // Use better IR generation for certain implicit parameters. |
| if (auto IPD = dyn_cast<ImplicitParamDecl>(&D)) { |
| // The only implicit argument a block has is its literal. |
| // This may be passed as an inalloca'ed value on Windows x86. |
| if (BlockInfo) { |
| llvm::Value *V = Arg.isIndirect() |
| ? Builder.CreateLoad(Arg.getIndirectAddress()) |
| : Arg.getDirectValue(); |
| setBlockContextParameter(IPD, ArgNo, V); |
| return; |
| } |
| } |
| |
| Address DeclPtr = Address::invalid(); |
| Address AllocaPtr = Address::invalid(); |
| bool DoStore = false; |
| bool IsScalar = hasScalarEvaluationKind(Ty); |
| // If we already have a pointer to the argument, reuse the input pointer. |
| if (Arg.isIndirect()) { |
| DeclPtr = Arg.getIndirectAddress(); |
| // If we have a prettier pointer type at this point, bitcast to that. |
| unsigned AS = DeclPtr.getType()->getAddressSpace(); |
| llvm::Type *IRTy = ConvertTypeForMem(Ty)->getPointerTo(AS); |
| if (DeclPtr.getType() != IRTy) |
| DeclPtr = Builder.CreateBitCast(DeclPtr, IRTy, D.getName()); |
| // Indirect argument is in alloca address space, which may be different |
| // from the default address space. |
| auto AllocaAS = CGM.getASTAllocaAddressSpace(); |
| auto *V = DeclPtr.getPointer(); |
| AllocaPtr = DeclPtr; |
| auto SrcLangAS = getLangOpts().OpenCL ? LangAS::opencl_private : AllocaAS; |
| auto DestLangAS = |
| getLangOpts().OpenCL ? LangAS::opencl_private : LangAS::Default; |
| if (SrcLangAS != DestLangAS) { |
| assert(getContext().getTargetAddressSpace(SrcLangAS) == |
| CGM.getDataLayout().getAllocaAddrSpace()); |
| auto DestAS = getContext().getTargetAddressSpace(DestLangAS); |
| auto *T = V->getType()->getPointerElementType()->getPointerTo(DestAS); |
| DeclPtr = Address(getTargetHooks().performAddrSpaceCast( |
| *this, V, SrcLangAS, DestLangAS, T, true), |
| DeclPtr.getAlignment()); |
| } |
| |
| // Push a destructor cleanup for this parameter if the ABI requires it. |
| // Don't push a cleanup in a thunk for a method that will also emit a |
| // cleanup. |
| if (Ty->isRecordType() && !CurFuncIsThunk && |
| Ty->castAs<RecordType>()->getDecl()->isParamDestroyedInCallee()) { |
| if (QualType::DestructionKind DtorKind = |
| D.needsDestruction(getContext())) { |
| assert((DtorKind == QualType::DK_cxx_destructor || |
| DtorKind == QualType::DK_nontrivial_c_struct) && |
| "unexpected destructor type"); |
| pushDestroy(DtorKind, DeclPtr, Ty); |
| CalleeDestructedParamCleanups[cast<ParmVarDecl>(&D)] = |
| EHStack.stable_begin(); |
| } |
| } |
| } else { |
| // Check if the parameter address is controlled by OpenMP runtime. |
| Address OpenMPLocalAddr = |
| getLangOpts().OpenMP |
| ? CGM.getOpenMPRuntime().getAddressOfLocalVariable(*this, &D) |
| : Address::invalid(); |
| if (getLangOpts().OpenMP && OpenMPLocalAddr.isValid()) { |
| DeclPtr = OpenMPLocalAddr; |
| AllocaPtr = DeclPtr; |
| } else { |
| // Otherwise, create a temporary to hold the value. |
| DeclPtr = CreateMemTemp(Ty, getContext().getDeclAlign(&D), |
| D.getName() + ".addr", &AllocaPtr); |
| } |
| DoStore = true; |
| } |
| |
| llvm::Value *ArgVal = (DoStore ? Arg.getDirectValue() : nullptr); |
| |
| LValue lv = MakeAddrLValue(DeclPtr, Ty); |
| if (IsScalar) { |
| Qualifiers qs = Ty.getQualifiers(); |
| if (Qualifiers::ObjCLifetime lt = qs.getObjCLifetime()) { |
| // We honor __attribute__((ns_consumed)) for types with lifetime. |
| // For __strong, it's handled by just skipping the initial retain; |
| // otherwise we have to balance out the initial +1 with an extra |
| // cleanup to do the release at the end of the function. |
| bool isConsumed = D.hasAttr<NSConsumedAttr>(); |
| |
| // If a parameter is pseudo-strong then we can omit the implicit retain. |
| if (D.isARCPseudoStrong()) { |
| assert(lt == Qualifiers::OCL_Strong && |
| "pseudo-strong variable isn't strong?"); |
| assert(qs.hasConst() && "pseudo-strong variable should be const!"); |
| lt = Qualifiers::OCL_ExplicitNone; |
| } |
| |
| // Load objects passed indirectly. |
| if (Arg.isIndirect() && !ArgVal) |
| ArgVal = Builder.CreateLoad(DeclPtr); |
| |
| if (lt == Qualifiers::OCL_Strong) { |
| if (!isConsumed) { |
| if (CGM.getCodeGenOpts().OptimizationLevel == 0) { |
| // use objc_storeStrong(&dest, value) for retaining the |
| // object. But first, store a null into 'dest' because |
| // objc_storeStrong attempts to release its old value. |
| llvm::Value *Null = CGM.EmitNullConstant(D.getType()); |
| EmitStoreOfScalar(Null, lv, /* isInitialization */ true); |
| EmitARCStoreStrongCall(lv.getAddress(*this), ArgVal, true); |
| DoStore = false; |
| } |
| else |
| // Don't use objc_retainBlock for block pointers, because we |
| // don't want to Block_copy something just because we got it |
| // as a parameter. |
| ArgVal = EmitARCRetainNonBlock(ArgVal); |
| } |
| } else { |
| // Push the cleanup for a consumed parameter. |
| if (isConsumed) { |
| ARCPreciseLifetime_t precise = (D.hasAttr<ObjCPreciseLifetimeAttr>() |
| ? ARCPreciseLifetime : ARCImpreciseLifetime); |
| EHStack.pushCleanup<ConsumeARCParameter>(getARCCleanupKind(), ArgVal, |
| precise); |
| } |
| |
| if (lt == Qualifiers::OCL_Weak) { |
| EmitARCInitWeak(DeclPtr, ArgVal); |
| DoStore = false; // The weak init is a store, no need to do two. |
| } |
| } |
| |
| // Enter the cleanup scope. |
| EmitAutoVarWithLifetime(*this, D, DeclPtr, lt); |
| } |
| } |
| |
| // Store the initial value into the alloca. |
| if (DoStore) |
| EmitStoreOfScalar(ArgVal, lv, /* isInitialization */ true); |
| |
| setAddrOfLocalVar(&D, DeclPtr); |
| |
| // Emit debug info for param declarations in non-thunk functions. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| if (CGM.getCodeGenOpts().hasReducedDebugInfo() && !CurFuncIsThunk) { |
| llvm::DILocalVariable *DILocalVar = DI->EmitDeclareOfArgVariable( |
| &D, AllocaPtr.getPointer(), ArgNo, Builder); |
| if (const auto *Var = dyn_cast_or_null<ParmVarDecl>(&D)) |
| DI->getParamDbgMappings().insert({Var, DILocalVar}); |
| } |
| } |
| |
| if (D.hasAttr<AnnotateAttr>()) |
| EmitVarAnnotations(&D, DeclPtr.getPointer()); |
| |
| // We can only check return value nullability if all arguments to the |
| // function satisfy their nullability preconditions. This makes it necessary |
| // to emit null checks for args in the function body itself. |
| if (requiresReturnValueNullabilityCheck()) { |
| auto Nullability = Ty->getNullability(getContext()); |
| if (Nullability && *Nullability == NullabilityKind::NonNull) { |
| SanitizerScope SanScope(this); |
| RetValNullabilityPrecondition = |
| Builder.CreateAnd(RetValNullabilityPrecondition, |
| Builder.CreateIsNotNull(Arg.getAnyValue())); |
| } |
| } |
| } |
| |
| void CodeGenModule::EmitOMPDeclareReduction(const OMPDeclareReductionDecl *D, |
| CodeGenFunction *CGF) { |
| if (!LangOpts.OpenMP || (!LangOpts.EmitAllDecls && !D->isUsed())) |
| return; |
| getOpenMPRuntime().emitUserDefinedReduction(CGF, D); |
| } |
| |
| void CodeGenModule::EmitOMPDeclareMapper(const OMPDeclareMapperDecl *D, |
| CodeGenFunction *CGF) { |
| if (!LangOpts.OpenMP || LangOpts.OpenMPSimd || |
| (!LangOpts.EmitAllDecls && !D->isUsed())) |
| return; |
| getOpenMPRuntime().emitUserDefinedMapper(D, CGF); |
| } |
| |
| void CodeGenModule::EmitOMPRequiresDecl(const OMPRequiresDecl *D) { |
| getOpenMPRuntime().processRequiresDirective(D); |
| } |
| |
| void CodeGenModule::EmitOMPAllocateDecl(const OMPAllocateDecl *D) { |
| for (const Expr *E : D->varlists()) { |
| const auto *DE = cast<DeclRefExpr>(E); |
| const auto *VD = cast<VarDecl>(DE->getDecl()); |
| |
| // Skip all but globals. |
| if (!VD->hasGlobalStorage()) |
| continue; |
| |
| // Check if the global has been materialized yet or not. If not, we are done |
| // as any later generation will utilize the OMPAllocateDeclAttr. However, if |
| // we already emitted the global we might have done so before the |
| // OMPAllocateDeclAttr was attached, leading to the wrong address space |
| // (potentially). While not pretty, common practise is to remove the old IR |
| // global and generate a new one, so we do that here too. Uses are replaced |
| // properly. |
| StringRef MangledName = getMangledName(VD); |
| llvm::GlobalValue *Entry = GetGlobalValue(MangledName); |
| if (!Entry) |
| continue; |
| |
| // We can also keep the existing global if the address space is what we |
| // expect it to be, if not, it is replaced. |
| QualType ASTTy = VD->getType(); |
| clang::LangAS GVAS = GetGlobalVarAddressSpace(VD); |
| auto TargetAS = getContext().getTargetAddressSpace(GVAS); |
| if (Entry->getType()->getAddressSpace() == TargetAS) |
| continue; |
| |
| // Make a new global with the correct type / address space. |
| llvm::Type *Ty = getTypes(). |