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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGDecl.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGDecl.cpp | 1931 | 
1 files changed, 1931 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGDecl.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGDecl.cpp new file mode 100644 index 000000000000..0fa8eeb1c3e1 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGDecl.cpp @@ -0,0 +1,1931 @@ +//===--- 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 "CGCXXABI.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::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: +    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::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::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.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) { +    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 = 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 (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->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()) && 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.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())); +      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(); +      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::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 (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 = CGM.getNullPointer(ty, tempLV.getType()); + +    // 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)); + +  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); +} + +/// 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); +} + +/// 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) +    return nullptr; + +  llvm::Value *SizeV = llvm::ConstantInt::get(Int64Ty, Size); +  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) { +  Addr = Builder.CreateBitCast(Addr, AllocaInt8PtrTy); +  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. +      // 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 && !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) { +        // 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())) { +          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()); + +  // Make sure we call @llvm.lifetime.end. +  if (emission.useLifetimeMarkers()) +    EHStack.pushCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, +                                         emission.getAllocatedAddress(), +                                         emission.getSizeForLifetimeMarkers()); + +  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); +    unsigned AS = 0; +    if (getLangOpts().OpenCL) { +      AS = CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant); +      BP = llvm::PointerType::getInt8PtrTy(getLLVMContext(), AS); +    } +    llvm::GlobalVariable *GV = +      new llvm::GlobalVariable(CGM.getModule(), constant->getType(), true, +                               llvm::GlobalValue::PrivateLinkage, +                               constant, Name, nullptr, +                               llvm::GlobalValue::NotThreadLocal, AS); +    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; + +  // 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, AllocaInt8PtrTy); +  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, 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. +    // We assume this is always passed directly. +    if (BlockInfo) { +      setBlockContextParameter(IPD, ArgNo, Arg.getDirectValue()); +      return; +    } + +    // Apply any prologue 'this' adjustments required by the ABI. Be careful to +    // handle the case where 'this' is passed indirectly as part of an inalloca +    // struct. +    if (const CXXMethodDecl *MD = +            dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl)) { +      if (MD->isVirtual() && IPD == CXXABIThisDecl) { +        llvm::Value *This = Arg.isIndirect() +                                ? Builder.CreateLoad(Arg.getIndirectAddress()) +                                : Arg.getDirectValue(); +        This = CGM.getCXXABI().adjustThisParameterInVirtualFunctionPrologue( +            *this, CurGD, This); +        if (Arg.isIndirect()) +          Builder.CreateStore(This, Arg.getIndirectAddress()); +        else +          Arg = ParamValue::forDirect(This); +      } +    } +  } + +  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()); + +  // 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); +}  | 
