| //===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code to emit Decl nodes as LLVM code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CodeGenFunction.h" |
| #include "CGBlocks.h" |
| #include "CGCleanup.h" |
| #include "CGDebugInfo.h" |
| #include "CGOpenCLRuntime.h" |
| #include "CGOpenMPRuntime.h" |
| #include "CodeGenModule.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/CharUnits.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclObjC.h" |
| #include "clang/AST/DeclOpenMP.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/CodeGen/CGFunctionInfo.h" |
| #include "clang/Frontend/CodeGenOptions.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; |
| |
| 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::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::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: |
| llvm_unreachable("Declaration should not be in declstmts!"); |
| case Decl::Function: // void X(); |
| case Decl::Record: // struct/union/class X; |
| case Decl::Enum: // enum X; |
| case Decl::EnumConstant: // enum ? { X = ? } |
| case Decl::CXXRecord: // struct/union/class X; [C++] |
| case Decl::StaticAssert: // static_assert(X, ""); [C++0x] |
| case Decl::Label: // __label__ x; |
| case Decl::Import: |
| case Decl::OMPThreadPrivate: |
| case Decl::OMPCapturedExpr: |
| case Decl::Empty: |
| // 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::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::Typedef: // typedef int X; |
| case Decl::TypeAlias: { // using X = int; [C++0x] |
| const TypedefNameDecl &TD = cast<TypedefNameDecl>(D); |
| QualType Ty = TD.getUnderlyingType(); |
| |
| if (Ty->isVariablyModifiedType()) |
| EmitVariablyModifiedType(Ty); |
| } |
| } |
| } |
| |
| /// EmitVarDecl - This method handles emission of any variable declaration |
| /// inside a function, including static vars etc. |
| void CodeGenFunction::EmitVarDecl(const VarDecl &D) { |
| if (D.isStaticLocal()) { |
| 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.hasExternalStorage()) |
| // Don't emit it now, allow it to be emitted lazily on its first use. |
| return; |
| |
| 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 = CGM.getMangledName(FD); |
| else if (const auto *BD = dyn_cast<BlockDecl>(DC)) |
| ContextName = 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 = getMangledName(&D); |
| else |
| Name = getStaticDeclName(*this, D); |
| |
| llvm::Type *LTy = getTypes().ConvertTypeForMem(Ty); |
| unsigned AddrSpace = |
| GetGlobalVarAddressSpace(&D, getContext().getTargetAddressSpace(Ty)); |
| |
| // Local address space cannot have an initializer. |
| llvm::Constant *Init = nullptr; |
| if (Ty.getAddressSpace() != LangAS::opencl_local) |
| Init = EmitNullConstant(Ty); |
| else |
| Init = llvm::UndefValue::get(LTy); |
| |
| llvm::GlobalVariable *GV = |
| new llvm::GlobalVariable(getModule(), LTy, |
| Ty.isConstant(getContext()), Linkage, |
| Init, Name, nullptr, |
| llvm::GlobalVariable::NotThreadLocal, |
| AddrSpace); |
| GV->setAlignment(getContext().getDeclAlign(&D).getQuantity()); |
| setGlobalVisibility(GV, &D); |
| |
| if (supportsCOMDAT() && GV->isWeakForLinker()) |
| GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); |
| |
| if (D.getTLSKind()) |
| setTLSMode(GV, D); |
| |
| if (D.isExternallyVisible()) { |
| if (D.hasAttr<DLLImportAttr>()) |
| GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass); |
| else if (D.hasAttr<DLLExportAttr>()) |
| GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass); |
| } |
| |
| // Make sure the result is of the correct type. |
| unsigned ExpectedAddrSpace = getContext().getTargetAddressSpace(Ty); |
| llvm::Constant *Addr = GV; |
| if (AddrSpace != ExpectedAddrSpace) { |
| llvm::PointerType *PTy = llvm::PointerType::get(LTy, ExpectedAddrSpace); |
| Addr = llvm::ConstantExpr::getAddrSpaceCast(GV, PTy); |
| } |
| |
| 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()) |
| (void)GetAddrOfGlobal(GD); |
| |
| return Addr; |
| } |
| |
| /// hasNontrivialDestruction - Determine whether a type's destruction is |
| /// non-trivial. If so, and the variable uses static initialization, we must |
| /// register its destructor to run on exit. |
| static bool hasNontrivialDestruction(QualType T) { |
| CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); |
| return RD && !RD->hasTrivialDestructor(); |
| } |
| |
| /// 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) { |
| llvm::Constant *Init = CGM.EmitConstantInit(D, this); |
| |
| // 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 (Builder.GetInsertBlock()) { |
| // 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->getType()->getElementType() != Init->getType()) { |
| llvm::GlobalVariable *OldGV = GV; |
| |
| GV = new llvm::GlobalVariable(CGM.getModule(), Init->getType(), |
| OldGV->isConstant(), |
| OldGV->getLinkage(), Init, "", |
| /*InsertBefore*/ OldGV, |
| OldGV->getThreadLocalMode(), |
| CGM.getContext().getTargetAddressSpace(D.getType())); |
| GV->setVisibility(OldGV->getVisibility()); |
| 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); |
| |
| if (hasNontrivialDestruction(D.getType())) { |
| // 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.getQuantity()); |
| |
| if (D.hasAttr<AnnotateAttr>()) |
| CGM.AddGlobalAnnotations(&D, var); |
| |
| if (const SectionAttr *SA = D.getAttr<SectionAttr>()) |
| var->setSection(SA->getName()); |
| |
| if (D.hasAttr<UsedAttr>()) |
| CGM.addUsedGlobal(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().getDebugInfo() >= codegenoptions::LimitedDebugInfo) { |
| 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); |
| } |
| }; |
| |
| struct DestroyNRVOVariable final : EHScopeStack::Cleanup { |
| DestroyNRVOVariable(Address addr, |
| const CXXDestructorDecl *Dtor, |
| llvm::Value *NRVOFlag) |
| : Dtor(Dtor), NRVOFlag(NRVOFlag), Loc(addr) {} |
| |
| const CXXDestructorDecl *Dtor; |
| llvm::Value *NRVOFlag; |
| Address Loc; |
| |
| 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); |
| } |
| |
| CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, |
| /*ForVirtualBase=*/false, |
| /*Delegating=*/false, |
| Loc); |
| |
| if (NRVO) CGF.EmitBlock(SkipDtorBB); |
| } |
| }; |
| |
| struct CallStackRestore final : EHScopeStack::Cleanup { |
| Address Stack; |
| CallStackRestore(Address Stack) : Stack(Stack) {} |
| void Emit(CodeGenFunction &CGF, Flags flags) override { |
| llvm::Value *V = CGF.Builder.CreateLoad(Stack); |
| llvm::Value *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(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(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(); |
| |
| // 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())); |
| CGF.EmitCall(FnInfo, CleanupFn, 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(); |
| if (needsCast) { |
| srcAddr = CGF.Builder.CreateElementBitCast(srcAddr, |
| destLV.getAddress().getElementType()); |
| } |
| |
| // If it was an l-value, use objc_copyWeak. |
| if (srcExpr->getValueKind() == VK_LValue) { |
| CGF.EmitARCCopyWeak(destLV.getAddress(), srcAddr); |
| } else { |
| assert(srcExpr->getValueKind() == VK_XValue); |
| CGF.EmitARCMoveWeak(destLV.getAddress(), 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(), var)); |
| } |
| |
| 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)); |
| 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 (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(init)) { |
| enterFullExpression(ewc); |
| init = ewc->getSubExpr(); |
| } |
| CodeGenFunction::RunCleanupsScope Scope(*this); |
| |
| // 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(), |
| cast<VarDecl>(D), |
| /*follow*/ false)); |
| } |
| |
| auto ty = cast<llvm::PointerType>(tempLV.getAddress().getElementType()); |
| llvm::Value *zero = llvm::ConstantPointerNull::get(ty); |
| |
| // If __weak, we want to use a barrier under certain conditions. |
| if (lifetime == Qualifiers::OCL_Weak) |
| EmitARCInitWeak(tempLV.getAddress(), 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_ExplicitNone: |
| value = EmitARCUnsafeUnretainedScalarExpr(init); |
| break; |
| |
| case Qualifiers::OCL_Strong: { |
| value = EmitARCRetainScalarExpr(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(), value, /*ignored*/ true); |
| else |
| EmitARCInitWeak(lvalue.getAddress(), value); |
| return; |
| } |
| |
| case Qualifiers::OCL_Autoreleasing: |
| value = EmitARCRetainAutoreleaseScalarExpr(init); |
| break; |
| } |
| |
| if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); |
| |
| // 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); |
| } |
| |
| /// EmitScalarInit - Initialize the given lvalue with the given object. |
| void CodeGenFunction::EmitScalarInit(llvm::Value *init, LValue lvalue) { |
| Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime(); |
| if (!lifetime) |
| return EmitStoreThroughLValue(RValue::get(init), lvalue, true); |
| |
| switch (lifetime) { |
| case Qualifiers::OCL_None: |
| llvm_unreachable("present but none"); |
| |
| case Qualifiers::OCL_ExplicitNone: |
| // nothing to do |
| break; |
| |
| case Qualifiers::OCL_Strong: |
| init = EmitARCRetain(lvalue.getType(), init); |
| break; |
| |
| case Qualifiers::OCL_Weak: |
| // Initialize and then skip the primitive store. |
| EmitARCInitWeak(lvalue.getAddress(), init); |
| return; |
| |
| case Qualifiers::OCL_Autoreleasing: |
| init = EmitARCRetainAutorelease(lvalue.getType(), init); |
| break; |
| } |
| |
| EmitStoreOfScalar(init, lvalue, /* isInitialization */ true); |
| } |
| |
| /// canEmitInitWithFewStoresAfterMemset - Decide whether we can emit the |
| /// non-zero parts of the specified initializer with equal or fewer than |
| /// NumStores scalar stores. |
| static bool canEmitInitWithFewStoresAfterMemset(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 (!canEmitInitWithFewStoresAfterMemset(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 (!canEmitInitWithFewStoresAfterMemset(Elt, NumStores)) |
| return false; |
| } |
| return true; |
| } |
| |
| // Anything else is hard and scary. |
| return false; |
| } |
| |
| /// emitStoresForInitAfterMemset - For inits that |
| /// canEmitInitWithFewStoresAfterMemset returned true for, emit the scalar |
| /// stores that would be required. |
| static void emitStoresForInitAfterMemset(llvm::Constant *Init, llvm::Value *Loc, |
| bool isVolatile, CGBuilderTy &Builder) { |
| assert(!Init->isNullValue() && !isa<llvm::UndefValue>(Init) && |
| "called emitStoresForInitAfterMemset 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)) { |
| Builder.CreateDefaultAlignedStore(Init, Loc, isVolatile); |
| 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)) |
| emitStoresForInitAfterMemset( |
| Elt, Builder.CreateConstGEP2_32(Init->getType(), Loc, 0, i), |
| isVolatile, Builder); |
| } |
| 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)) |
| emitStoresForInitAfterMemset( |
| Elt, Builder.CreateConstGEP2_32(Init->getType(), Loc, 0, i), |
| isVolatile, Builder); |
| } |
| } |
| |
| /// shouldUseMemSetPlusStoresToInitialize - Decide whether we should use memset |
| /// plus some stores to initialize a local variable instead of using a memcpy |
| /// from a constant global. It is beneficial to use memset if the global is all |
| /// zeros, or mostly zeros and large. |
| static bool shouldUseMemSetPlusStoresToInitialize(llvm::Constant *Init, |
| uint64_t GlobalSize) { |
| // If a global is all zeros, always use a memset. |
| 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 && |
| canEmitInitWithFewStoresAfterMemset(Init, StoreBudget); |
| } |
| |
| /// 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); |
| } |
| |
| /// shouldEmitLifetimeMarkers - Decide whether we need emit the life-time |
| /// markers. |
| static bool shouldEmitLifetimeMarkers(const CodeGenOptions &CGOpts, |
| const LangOptions &LangOpts) { |
| // Asan uses markers for use-after-scope checks. |
| if (CGOpts.SanitizeAddressUseAfterScope) |
| return true; |
| |
| // Disable lifetime markers in msan builds. |
| // FIXME: Remove this when msan works with lifetime markers. |
| if (LangOpts.Sanitize.has(SanitizerKind::Memory)) |
| return false; |
| |
| // For now, only in optimized builds. |
| return CGOpts.OptimizationLevel != 0; |
| } |
| |
| /// 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(uint64_t Size, |
| llvm::Value *Addr) { |
| if (!shouldEmitLifetimeMarkers(CGM.getCodeGenOpts(), getLangOpts())) |
| return nullptr; |
| |
| llvm::Value *SizeV = llvm::ConstantInt::get(Int64Ty, Size); |
| Addr = Builder.CreateBitCast(Addr, Int8PtrTy); |
| llvm::CallInst *C = |
| Builder.CreateCall(CGM.getLLVMLifetimeStartFn(), {SizeV, Addr}); |
| C->setDoesNotThrow(); |
| return SizeV; |
| } |
| |
| void CodeGenFunction::EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr) { |
| Addr = Builder.CreateBitCast(Addr, Int8PtrTy); |
| llvm::CallInst *C = |
| Builder.CreateCall(CGM.getLLVMLifetimeEndFn(), {Size, Addr}); |
| C->setDoesNotThrow(); |
| } |
| |
| /// 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(); |
| |
| AutoVarEmission emission(D); |
| |
| bool isByRef = D.hasAttr<BlocksAttr>(); |
| emission.IsByRef = isByRef; |
| |
| CharUnits alignment = getContext().getDeclAlign(&D); |
| |
| // If the type is variably-modified, emit all the VLA sizes for it. |
| if (Ty->isVariablyModifiedType()) |
| EmitVariablyModifiedType(Ty); |
| |
| Address address = Address::invalid(); |
| if (Ty->isConstantSizeType()) { |
| bool NRVO = getLangOpts().ElideConstructors && |
| D.isNRVOVariable(); |
| |
| // 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. |
| if (CGM.getCodeGenOpts().MergeAllConstants && !NRVO && !isByRef && |
| 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. |
| |
| 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; |
| |
| if (const RecordType *RecordTy = Ty->getAs<RecordType>()) { |
| if (!cast<CXXRecordDecl>(RecordTy->getDecl())->hasTrivialDestructor()) { |
| // 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"); |
| 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 (isByRef) { |
| 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); |
| address.getPointer()->setName(D.getName()); |
| |
| // 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) { |
| uint64_t size = CGM.getDataLayout().getTypeAllocSize(allocaTy); |
| emission.SizeForLifetimeMarkers = |
| EmitLifetimeStart(size, address.getPointer()); |
| } else { |
| assert(!emission.useLifetimeMarkers()); |
| } |
| } |
| } else { |
| EnsureInsertPoint(); |
| |
| if (!DidCallStackSave) { |
| // Save the stack. |
| Address Stack = |
| CreateTempAlloca(Int8PtrTy, getPointerAlign(), "saved_stack"); |
| |
| llvm::Value *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); |
| } |
| |
| llvm::Value *elementCount; |
| QualType elementType; |
| std::tie(elementCount, elementType) = getVLASize(Ty); |
| |
| llvm::Type *llvmTy = ConvertTypeForMem(elementType); |
| |
| // Allocate memory for the array. |
| llvm::AllocaInst *vla = Builder.CreateAlloca(llvmTy, elementCount, "vla"); |
| vla->setAlignment(alignment.getQuantity()); |
| |
| address = Address(vla, alignment); |
| } |
| |
| setAddrOfLocalVar(&D, address); |
| emission.Addr = address; |
| |
| // Emit debug info for local var declaration. |
| if (HaveInsertPoint()) |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| if (CGM.getCodeGenOpts().getDebugInfo() >= |
| codegenoptions::LimitedDebugInfo) { |
| DI->setLocation(D.getLocation()); |
| DI->EmitDeclareOfAutoVariable(&D, address.getPointer(), Builder); |
| } |
| } |
| |
| if (D.hasAttr<AnnotateAttr>()) |
| EmitVarAnnotations(&D, address.getPointer()); |
| |
| return emission; |
| } |
| |
| /// 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 *E = dyn_cast<Expr>(BI)) { |
| if (isCapturedBy(var, E)) |
| 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, cast<Expr>(SubStmt))) |
| return true; |
| |
| return false; |
| } |
| |
| /// \brief 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::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.IsByRef) |
| emitByrefStructureInit(emission); |
| |
| if (isTrivialInitializer(Init)) |
| 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 = emission.IsByRef && isCapturedBy(D, Init); |
| |
| Address Loc = |
| capturedByInit ? emission.Addr : emission.getObjectAddress(*this); |
| |
| llvm::Constant *constant = nullptr; |
| if (emission.IsConstantAggregate || D.isConstexpr()) { |
| assert(!capturedByInit && "constant init contains a capturing block?"); |
| constant = CGM.EmitConstantInit(D, this); |
| } |
| |
| if (!constant) { |
| 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); |
| } |
| |
| // If this is a simple aggregate initialization, we can optimize it |
| // in various ways. |
| bool isVolatile = type.isVolatileQualified(); |
| |
| llvm::Value *SizeVal = |
| llvm::ConstantInt::get(IntPtrTy, |
| getContext().getTypeSizeInChars(type).getQuantity()); |
| |
| llvm::Type *BP = Int8PtrTy; |
| if (Loc.getType() != BP) |
| Loc = Builder.CreateBitCast(Loc, BP); |
| |
| // If the initializer is all or mostly zeros, codegen with memset then do |
| // a few stores afterward. |
| if (shouldUseMemSetPlusStoresToInitialize(constant, |
| CGM.getDataLayout().getTypeAllocSize(constant->getType()))) { |
| Builder.CreateMemSet(Loc, llvm::ConstantInt::get(Int8Ty, 0), SizeVal, |
| isVolatile); |
| // Zero and undef don't require a stores. |
| if (!constant->isNullValue() && !isa<llvm::UndefValue>(constant)) { |
| Loc = Builder.CreateBitCast(Loc, constant->getType()->getPointerTo()); |
| emitStoresForInitAfterMemset(constant, Loc.getPointer(), |
| isVolatile, Builder); |
| } |
| } else { |
| // Otherwise, create a temporary global with the initializer then |
| // memcpy from the global to the alloca. |
| std::string Name = getStaticDeclName(CGM, D); |
| llvm::GlobalVariable *GV = |
| new llvm::GlobalVariable(CGM.getModule(), constant->getType(), true, |
| llvm::GlobalValue::PrivateLinkage, |
| constant, Name); |
| GV->setAlignment(Loc.getAlignment().getQuantity()); |
| GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); |
| |
| Address SrcPtr = Address(GV, Loc.getAlignment()); |
| if (SrcPtr.getType() != BP) |
| SrcPtr = Builder.CreateBitCast(SrcPtr, BP); |
| |
| Builder.CreateMemCpy(Loc, SrcPtr, SizeVal, isVolatile); |
| } |
| } |
| |
| /// Emit an expression as an initializer for a variable at the given |
| /// location. The expression is not necessarily the normal |
| /// initializer for the variable, and the address is not necessarily |
| /// its normal location. |
| /// |
| /// \param init the initializing expression |
| /// \param var the variable to act as if we're initializing |
| /// \param loc the address to initialize; its type is a pointer |
| /// to the LLVM mapping of the variable's type |
| /// \param alignment the alignment of the address |
| /// \param capturedByInit true if the variable 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 { |
| // TODO: how can we delay here if D is captured by its initializer? |
| EmitAggExpr(init, AggValueSlot::forLValue(lvalue, |
| AggValueSlot::IsDestructed, |
| AggValueSlot::DoesNotNeedGCBarriers, |
| AggValueSlot::IsNotAliased)); |
| } |
| 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<DestroyNRVOVariable>(cleanupKind, addr, |
| 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; |
| } |
| |
| // 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; |
| |
| // Make sure we call @llvm.lifetime.end. This needs to happen |
| // *last*, so the cleanup needs to be pushed *first*. |
| if (emission.useLifetimeMarkers()) |
| EHStack.pushCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, |
| emission.getAllocatedAddress(), |
| emission.getSizeForLifetimeMarkers()); |
| |
| // Check the type for a cleanup. |
| if (QualType::DestructionKind dtorKind = D.getType().isDestructedType()) |
| 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). |
| if (emission.IsByRef) |
| enterByrefCleanup(emission); |
| } |
| |
| 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; |
| } |
| 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) { |
| assert(!isInConditionalBranch() && |
| "performing lifetime extension from within conditional"); |
| |
| // 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); |
| |
| // Remember that we need to push a full cleanup for the object at the |
| // end of the full-expression. |
| pushCleanupAfterFullExpr<DestroyObject>( |
| cleanupKind, addr, 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(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, 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); |
| begin = CGF.Builder.CreateInBoundsGEP(begin, gepIndices, "pad.arraybegin"); |
| end = CGF.Builder.CreateInBoundsGEP(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::Constant *CodeGenModule::getLLVMLifetimeStartFn() { |
| if (LifetimeStartFn) return LifetimeStartFn; |
| LifetimeStartFn = llvm::Intrinsic::getDeclaration(&getModule(), |
| llvm::Intrinsic::lifetime_start); |
| return LifetimeStartFn; |
| } |
| |
| /// Lazily declare the @llvm.lifetime.end intrinsic. |
| llvm::Constant *CodeGenModule::getLLVMLifetimeEndFn() { |
| if (LifetimeEndFn) return LifetimeEndFn; |
| LifetimeEndFn = llvm::Intrinsic::getDeclaration(&getModule(), |
| llvm::Intrinsic::lifetime_end); |
| 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. |
| // We assume this is always passed directly. |
| if (BlockInfo) { |
| setBlockContextParameter(IPD, ArgNo, Arg.getDirectValue()); |
| return; |
| } |
| } |
| |
| Address DeclPtr = 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()); |
| |
| // 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 (!IsScalar && !CurFuncIsThunk && |
| getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) { |
| const CXXRecordDecl *RD = Ty->getAsCXXRecordDecl(); |
| if (RD && RD->hasNonTrivialDestructor()) |
| pushDestroy(QualType::DK_cxx_destructor, DeclPtr, Ty); |
| } |
| } else { |
| // Otherwise, create a temporary to hold the value. |
| DeclPtr = CreateMemTemp(Ty, getContext().getDeclAlign(&D), |
| D.getName() + ".addr"); |
| 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>(); |
| |
| // 'self' is always formally __strong, but if this is not an |
| // init method then we don't want to retain it. |
| if (D.isARCPseudoStrong()) { |
| const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CurCodeDecl); |
| assert(&D == method->getSelfDecl()); |
| assert(lt == Qualifiers::OCL_Strong); |
| assert(qs.hasConst()); |
| assert(method->getMethodFamily() != OMF_init); |
| (void) method; |
| lt = Qualifiers::OCL_ExplicitNone; |
| } |
| |
| 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(), 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 declaration. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| if (CGM.getCodeGenOpts().getDebugInfo() >= |
| codegenoptions::LimitedDebugInfo) { |
| DI->EmitDeclareOfArgVariable(&D, DeclPtr.getPointer(), ArgNo, Builder); |
| } |
| } |
| |
| if (D.hasAttr<AnnotateAttr>()) |
| EmitVarAnnotations(&D, DeclPtr.getPointer()); |
| } |
| |
| void CodeGenModule::EmitOMPDeclareReduction(const OMPDeclareReductionDecl *D, |
| CodeGenFunction *CGF) { |
| if (!LangOpts.OpenMP || (!LangOpts.EmitAllDecls && !D->isUsed())) |
| return; |
| getOpenMPRuntime().emitUserDefinedReduction(CGF, D); |
| } |