--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/lib/CodeGen/CGDeclCXX.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,782 @@
+//===--- CGDeclCXX.cpp - Emit LLVM Code for C++ declarations --------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code dealing with code generation of C++ declarations
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGCXXABI.h"
+#include "CGObjCRuntime.h"
+#include "CGOpenMPRuntime.h"
+#include "CodeGenFunction.h"
+#include "TargetInfo.h"
+#include "clang/AST/Attr.h"
+#include "clang/Basic/CodeGenOptions.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/MDBuilder.h"
+#include "llvm/Support/Path.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D,
+                         ConstantAddress DeclPtr) {
+  assert(
+      (D.hasGlobalStorage() ||
+       (D.hasLocalStorage() && CGF.getContext().getLangOpts().OpenCLCPlusPlus)) &&
+      "VarDecl must have global or local (in the case of OpenCL) storage!");
+  assert(!D.getType()->isReferenceType() &&
+         "Should not call EmitDeclInit on a reference!");
+
+  QualType type = D.getType();
+  LValue lv = CGF.MakeAddrLValue(DeclPtr, type);
+
+  const Expr *Init = D.getInit();
+  switch (CGF.getEvaluationKind(type)) {
+  case TEK_Scalar: {
+    CodeGenModule &CGM = CGF.CGM;
+    if (lv.isObjCStrong())
+      CGM.getObjCRuntime().EmitObjCGlobalAssign(CGF, CGF.EmitScalarExpr(Init),
+                                                DeclPtr, D.getTLSKind());
+    else if (lv.isObjCWeak())
+      CGM.getObjCRuntime().EmitObjCWeakAssign(CGF, CGF.EmitScalarExpr(Init),
+                                              DeclPtr);
+    else
+      CGF.EmitScalarInit(Init, &D, lv, false);
+    return;
+  }
+  case TEK_Complex:
+    CGF.EmitComplexExprIntoLValue(Init, lv, /*isInit*/ true);
+    return;
+  case TEK_Aggregate:
+    CGF.EmitAggExpr(Init,
+                    AggValueSlot::forLValue(lv, CGF, AggValueSlot::IsDestructed,
+                                            AggValueSlot::DoesNotNeedGCBarriers,
+                                            AggValueSlot::IsNotAliased,
+                                            AggValueSlot::DoesNotOverlap));
+    return;
+  }
+  llvm_unreachable("bad evaluation kind");
+}
+
+/// Emit code to cause the destruction of the given variable with
+/// static storage duration.
+static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D,
+                            ConstantAddress Addr) {
+  // Honor __attribute__((no_destroy)) and bail instead of attempting
+  // to emit a reference to a possibly nonexistent destructor, which
+  // in turn can cause a crash. This will result in a global constructor
+  // that isn't balanced out by a destructor call as intended by the
+  // attribute. This also checks for -fno-c++-static-destructors and
+  // bails even if the attribute is not present.
+  QualType::DestructionKind DtorKind = D.needsDestruction(CGF.getContext());
+
+  // FIXME:  __attribute__((cleanup)) ?
+
+  switch (DtorKind) {
+  case QualType::DK_none:
+    return;
+
+  case QualType::DK_cxx_destructor:
+    break;
+
+  case QualType::DK_objc_strong_lifetime:
+  case QualType::DK_objc_weak_lifetime:
+  case QualType::DK_nontrivial_c_struct:
+    // We don't care about releasing objects during process teardown.
+    assert(!D.getTLSKind() && "should have rejected this");
+    return;
+  }
+
+  llvm::FunctionCallee Func;
+  llvm::Constant *Argument;
+
+  CodeGenModule &CGM = CGF.CGM;
+  QualType Type = D.getType();
+
+  // Special-case non-array C++ destructors, if they have the right signature.
+  // Under some ABIs, destructors return this instead of void, and cannot be
+  // passed directly to __cxa_atexit if the target does not allow this
+  // mismatch.
+  const CXXRecordDecl *Record = Type->getAsCXXRecordDecl();
+  bool CanRegisterDestructor =
+      Record && (!CGM.getCXXABI().HasThisReturn(
+                     GlobalDecl(Record->getDestructor(), Dtor_Complete)) ||
+                 CGM.getCXXABI().canCallMismatchedFunctionType());
+  // If __cxa_atexit is disabled via a flag, a different helper function is
+  // generated elsewhere which uses atexit instead, and it takes the destructor
+  // directly.
+  bool UsingExternalHelper = !CGM.getCodeGenOpts().CXAAtExit;
+  if (Record && (CanRegisterDestructor || UsingExternalHelper)) {
+    assert(!Record->hasTrivialDestructor());
+    CXXDestructorDecl *Dtor = Record->getDestructor();
+
+    Func = CGM.getAddrAndTypeOfCXXStructor(GlobalDecl(Dtor, Dtor_Complete));
+    if (CGF.getContext().getLangOpts().OpenCL) {
+      auto DestAS =
+          CGM.getTargetCodeGenInfo().getAddrSpaceOfCxaAtexitPtrParam();
+      auto DestTy = CGF.getTypes().ConvertType(Type)->getPointerTo(
+          CGM.getContext().getTargetAddressSpace(DestAS));
+      auto SrcAS = D.getType().getQualifiers().getAddressSpace();
+      if (DestAS == SrcAS)
+        Argument = llvm::ConstantExpr::getBitCast(Addr.getPointer(), DestTy);
+      else
+        // FIXME: On addr space mismatch we are passing NULL. The generation
+        // of the global destructor function should be adjusted accordingly.
+        Argument = llvm::ConstantPointerNull::get(DestTy);
+    } else {
+      Argument = llvm::ConstantExpr::getBitCast(
+          Addr.getPointer(), CGF.getTypes().ConvertType(Type)->getPointerTo());
+    }
+  // Otherwise, the standard logic requires a helper function.
+  } else {
+    Func = CodeGenFunction(CGM)
+           .generateDestroyHelper(Addr, Type, CGF.getDestroyer(DtorKind),
+                                  CGF.needsEHCleanup(DtorKind), &D);
+    Argument = llvm::Constant::getNullValue(CGF.Int8PtrTy);
+  }
+
+  CGM.getCXXABI().registerGlobalDtor(CGF, D, Func, Argument);
+}
+
+/// Emit code to cause the variable at the given address to be considered as
+/// constant from this point onwards.
+static void EmitDeclInvariant(CodeGenFunction &CGF, const VarDecl &D,
+                              llvm::Constant *Addr) {
+  return CGF.EmitInvariantStart(
+      Addr, CGF.getContext().getTypeSizeInChars(D.getType()));
+}
+
+void CodeGenFunction::EmitInvariantStart(llvm::Constant *Addr, CharUnits Size) {
+  // Do not emit the intrinsic if we're not optimizing.
+  if (!CGM.getCodeGenOpts().OptimizationLevel)
+    return;
+
+  // Grab the llvm.invariant.start intrinsic.
+  llvm::Intrinsic::ID InvStartID = llvm::Intrinsic::invariant_start;
+  // Overloaded address space type.
+  llvm::Type *ObjectPtr[1] = {Int8PtrTy};
+  llvm::Function *InvariantStart = CGM.getIntrinsic(InvStartID, ObjectPtr);
+
+  // Emit a call with the size in bytes of the object.
+  uint64_t Width = Size.getQuantity();
+  llvm::Value *Args[2] = { llvm::ConstantInt::getSigned(Int64Ty, Width),
+                           llvm::ConstantExpr::getBitCast(Addr, Int8PtrTy)};
+  Builder.CreateCall(InvariantStart, Args);
+}
+
+void CodeGenFunction::EmitCXXGlobalVarDeclInit(const VarDecl &D,
+                                               llvm::Constant *DeclPtr,
+                                               bool PerformInit) {
+
+  const Expr *Init = D.getInit();
+  QualType T = D.getType();
+
+  // The address space of a static local variable (DeclPtr) may be different
+  // from the address space of the "this" argument of the constructor. In that
+  // case, we need an addrspacecast before calling the constructor.
+  //
+  // struct StructWithCtor {
+  //   __device__ StructWithCtor() {...}
+  // };
+  // __device__ void foo() {
+  //   __shared__ StructWithCtor s;
+  //   ...
+  // }
+  //
+  // For example, in the above CUDA code, the static local variable s has a
+  // "shared" address space qualifier, but the constructor of StructWithCtor
+  // expects "this" in the "generic" address space.
+  unsigned ExpectedAddrSpace = getContext().getTargetAddressSpace(T);
+  unsigned ActualAddrSpace = DeclPtr->getType()->getPointerAddressSpace();
+  if (ActualAddrSpace != ExpectedAddrSpace) {
+    llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(T);
+    llvm::PointerType *PTy = llvm::PointerType::get(LTy, ExpectedAddrSpace);
+    DeclPtr = llvm::ConstantExpr::getAddrSpaceCast(DeclPtr, PTy);
+  }
+
+  ConstantAddress DeclAddr(DeclPtr, getContext().getDeclAlign(&D));
+
+  if (!T->isReferenceType()) {
+    if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
+        D.hasAttr<OMPThreadPrivateDeclAttr>()) {
+      (void)CGM.getOpenMPRuntime().emitThreadPrivateVarDefinition(
+          &D, DeclAddr, D.getAttr<OMPThreadPrivateDeclAttr>()->getLocation(),
+          PerformInit, this);
+    }
+    if (PerformInit)
+      EmitDeclInit(*this, D, DeclAddr);
+    if (CGM.isTypeConstant(D.getType(), true))
+      EmitDeclInvariant(*this, D, DeclPtr);
+    else
+      EmitDeclDestroy(*this, D, DeclAddr);
+    return;
+  }
+
+  assert(PerformInit && "cannot have constant initializer which needs "
+         "destruction for reference");
+  RValue RV = EmitReferenceBindingToExpr(Init);
+  EmitStoreOfScalar(RV.getScalarVal(), DeclAddr, false, T);
+}
+
+/// Create a stub function, suitable for being passed to atexit,
+/// which passes the given address to the given destructor function.
+llvm::Function *CodeGenFunction::createAtExitStub(const VarDecl &VD,
+                                                  llvm::FunctionCallee dtor,
+                                                  llvm::Constant *addr) {
+  // Get the destructor function type, void(*)(void).
+  llvm::FunctionType *ty = llvm::FunctionType::get(CGM.VoidTy, false);
+  SmallString<256> FnName;
+  {
+    llvm::raw_svector_ostream Out(FnName);
+    CGM.getCXXABI().getMangleContext().mangleDynamicAtExitDestructor(&VD, Out);
+  }
+
+  const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
+  llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(
+      ty, FnName.str(), FI, VD.getLocation());
+
+  CodeGenFunction CGF(CGM);
+
+  CGF.StartFunction(GlobalDecl(&VD, DynamicInitKind::AtExit),
+                    CGM.getContext().VoidTy, fn, FI, FunctionArgList());
+
+  llvm::CallInst *call = CGF.Builder.CreateCall(dtor, addr);
+
+ // Make sure the call and the callee agree on calling convention.
+  if (auto *dtorFn = dyn_cast<llvm::Function>(
+          dtor.getCallee()->stripPointerCastsAndAliases()))
+    call->setCallingConv(dtorFn->getCallingConv());
+
+  CGF.FinishFunction();
+
+  return fn;
+}
+
+/// Register a global destructor using the C atexit runtime function.
+void CodeGenFunction::registerGlobalDtorWithAtExit(const VarDecl &VD,
+                                                   llvm::FunctionCallee dtor,
+                                                   llvm::Constant *addr) {
+  // Create a function which calls the destructor.
+  llvm::Constant *dtorStub = createAtExitStub(VD, dtor, addr);
+  registerGlobalDtorWithAtExit(dtorStub);
+}
+
+void CodeGenFunction::registerGlobalDtorWithAtExit(llvm::Constant *dtorStub) {
+  // extern "C" int atexit(void (*f)(void));
+  llvm::FunctionType *atexitTy =
+    llvm::FunctionType::get(IntTy, dtorStub->getType(), false);
+
+  llvm::FunctionCallee atexit =
+      CGM.CreateRuntimeFunction(atexitTy, "atexit", llvm::AttributeList(),
+                                /*Local=*/true);
+  if (llvm::Function *atexitFn = dyn_cast<llvm::Function>(atexit.getCallee()))
+    atexitFn->setDoesNotThrow();
+
+  EmitNounwindRuntimeCall(atexit, dtorStub);
+}
+
+void CodeGenFunction::EmitCXXGuardedInit(const VarDecl &D,
+                                         llvm::GlobalVariable *DeclPtr,
+                                         bool PerformInit) {
+  // If we've been asked to forbid guard variables, emit an error now.
+  // This diagnostic is hard-coded for Darwin's use case;  we can find
+  // better phrasing if someone else needs it.
+  if (CGM.getCodeGenOpts().ForbidGuardVariables)
+    CGM.Error(D.getLocation(),
+              "this initialization requires a guard variable, which "
+              "the kernel does not support");
+
+  CGM.getCXXABI().EmitGuardedInit(*this, D, DeclPtr, PerformInit);
+}
+
+void CodeGenFunction::EmitCXXGuardedInitBranch(llvm::Value *NeedsInit,
+                                               llvm::BasicBlock *InitBlock,
+                                               llvm::BasicBlock *NoInitBlock,
+                                               GuardKind Kind,
+                                               const VarDecl *D) {
+  assert((Kind == GuardKind::TlsGuard || D) && "no guarded variable");
+
+  // A guess at how many times we will enter the initialization of a
+  // variable, depending on the kind of variable.
+  static const uint64_t InitsPerTLSVar = 1024;
+  static const uint64_t InitsPerLocalVar = 1024 * 1024;
+
+  llvm::MDNode *Weights;
+  if (Kind == GuardKind::VariableGuard && !D->isLocalVarDecl()) {
+    // For non-local variables, don't apply any weighting for now. Due to our
+    // use of COMDATs, we expect there to be at most one initialization of the
+    // variable per DSO, but we have no way to know how many DSOs will try to
+    // initialize the variable.
+    Weights = nullptr;
+  } else {
+    uint64_t NumInits;
+    // FIXME: For the TLS case, collect and use profiling information to
+    // determine a more accurate brach weight.
+    if (Kind == GuardKind::TlsGuard || D->getTLSKind())
+      NumInits = InitsPerTLSVar;
+    else
+      NumInits = InitsPerLocalVar;
+
+    // The probability of us entering the initializer is
+    //   1 / (total number of times we attempt to initialize the variable).
+    llvm::MDBuilder MDHelper(CGM.getLLVMContext());
+    Weights = MDHelper.createBranchWeights(1, NumInits - 1);
+  }
+
+  Builder.CreateCondBr(NeedsInit, InitBlock, NoInitBlock, Weights);
+}
+
+llvm::Function *CodeGenModule::CreateGlobalInitOrDestructFunction(
+    llvm::FunctionType *FTy, const Twine &Name, const CGFunctionInfo &FI,
+    SourceLocation Loc, bool TLS) {
+  llvm::Function *Fn =
+    llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage,
+                           Name, &getModule());
+  if (!getLangOpts().AppleKext && !TLS) {
+    // Set the section if needed.
+    if (const char *Section = getTarget().getStaticInitSectionSpecifier())
+      Fn->setSection(Section);
+  }
+
+  SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
+
+  Fn->setCallingConv(getRuntimeCC());
+
+  if (!getLangOpts().Exceptions)
+    Fn->setDoesNotThrow();
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::Address) &&
+      !isInSanitizerBlacklist(SanitizerKind::Address, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::KernelAddress) &&
+      !isInSanitizerBlacklist(SanitizerKind::KernelAddress, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::HWAddress) &&
+      !isInSanitizerBlacklist(SanitizerKind::HWAddress, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::KernelHWAddress) &&
+      !isInSanitizerBlacklist(SanitizerKind::KernelHWAddress, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::MemTag) &&
+      !isInSanitizerBlacklist(SanitizerKind::MemTag, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeMemTag);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::Thread) &&
+      !isInSanitizerBlacklist(SanitizerKind::Thread, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeThread);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::Memory) &&
+      !isInSanitizerBlacklist(SanitizerKind::Memory, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::KernelMemory) &&
+      !isInSanitizerBlacklist(SanitizerKind::KernelMemory, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::SafeStack) &&
+      !isInSanitizerBlacklist(SanitizerKind::SafeStack, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SafeStack);
+
+  if (getLangOpts().Sanitize.has(SanitizerKind::ShadowCallStack) &&
+      !isInSanitizerBlacklist(SanitizerKind::ShadowCallStack, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::ShadowCallStack);
+
+  auto RASignKind = getCodeGenOpts().getSignReturnAddress();
+  if (RASignKind != CodeGenOptions::SignReturnAddressScope::None) {
+    Fn->addFnAttr("sign-return-address",
+                  RASignKind == CodeGenOptions::SignReturnAddressScope::All
+                      ? "all"
+                      : "non-leaf");
+    auto RASignKey = getCodeGenOpts().getSignReturnAddressKey();
+    Fn->addFnAttr("sign-return-address-key",
+                  RASignKey == CodeGenOptions::SignReturnAddressKeyValue::AKey
+                      ? "a_key"
+                      : "b_key");
+  }
+
+  if (getCodeGenOpts().BranchTargetEnforcement)
+    Fn->addFnAttr("branch-target-enforcement");
+
+  return Fn;
+}
+
+/// Create a global pointer to a function that will initialize a global
+/// variable.  The user has requested that this pointer be emitted in a specific
+/// section.
+void CodeGenModule::EmitPointerToInitFunc(const VarDecl *D,
+                                          llvm::GlobalVariable *GV,
+                                          llvm::Function *InitFunc,
+                                          InitSegAttr *ISA) {
+  llvm::GlobalVariable *PtrArray = new llvm::GlobalVariable(
+      TheModule, InitFunc->getType(), /*isConstant=*/true,
+      llvm::GlobalValue::PrivateLinkage, InitFunc, "__cxx_init_fn_ptr");
+  PtrArray->setSection(ISA->getSection());
+  addUsedGlobal(PtrArray);
+
+  // If the GV is already in a comdat group, then we have to join it.
+  if (llvm::Comdat *C = GV->getComdat())
+    PtrArray->setComdat(C);
+}
+
+void
+CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
+                                            llvm::GlobalVariable *Addr,
+                                            bool PerformInit) {
+
+  // According to E.2.3.1 in CUDA-7.5 Programming guide: __device__,
+  // __constant__ and __shared__ variables defined in namespace scope,
+  // that are of class type, cannot have a non-empty constructor. All
+  // the checks have been done in Sema by now. Whatever initializers
+  // are allowed are empty and we just need to ignore them here.
+  if (getLangOpts().CUDAIsDevice && !getLangOpts().GPUAllowDeviceInit &&
+      (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
+       D->hasAttr<CUDASharedAttr>()))
+    return;
+
+  if (getLangOpts().OpenMP &&
+      getOpenMPRuntime().emitDeclareTargetVarDefinition(D, Addr, PerformInit))
+    return;
+
+  // Check if we've already initialized this decl.
+  auto I = DelayedCXXInitPosition.find(D);
+  if (I != DelayedCXXInitPosition.end() && I->second == ~0U)
+    return;
+
+  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
+  SmallString<256> FnName;
+  {
+    llvm::raw_svector_ostream Out(FnName);
+    getCXXABI().getMangleContext().mangleDynamicInitializer(D, Out);
+  }
+
+  // Create a variable initialization function.
+  llvm::Function *Fn =
+      CreateGlobalInitOrDestructFunction(FTy, FnName.str(),
+                                         getTypes().arrangeNullaryFunction(),
+                                         D->getLocation());
+
+  auto *ISA = D->getAttr<InitSegAttr>();
+  CodeGenFunction(*this).GenerateCXXGlobalVarDeclInitFunc(Fn, D, Addr,
+                                                          PerformInit);
+
+  llvm::GlobalVariable *COMDATKey =
+      supportsCOMDAT() && D->isExternallyVisible() ? Addr : nullptr;
+
+  if (D->getTLSKind()) {
+    // FIXME: Should we support init_priority for thread_local?
+    // FIXME: We only need to register one __cxa_thread_atexit function for the
+    // entire TU.
+    CXXThreadLocalInits.push_back(Fn);
+    CXXThreadLocalInitVars.push_back(D);
+  } else if (PerformInit && ISA) {
+    EmitPointerToInitFunc(D, Addr, Fn, ISA);
+  } else if (auto *IPA = D->getAttr<InitPriorityAttr>()) {
+    OrderGlobalInits Key(IPA->getPriority(), PrioritizedCXXGlobalInits.size());
+    PrioritizedCXXGlobalInits.push_back(std::make_pair(Key, Fn));
+  } else if (isTemplateInstantiation(D->getTemplateSpecializationKind()) ||
+             getContext().GetGVALinkageForVariable(D) == GVA_DiscardableODR) {
+    // C++ [basic.start.init]p2:
+    //   Definitions of explicitly specialized class template static data
+    //   members have ordered initialization. Other class template static data
+    //   members (i.e., implicitly or explicitly instantiated specializations)
+    //   have unordered initialization.
+    //
+    // As a consequence, we can put them into their own llvm.global_ctors entry.
+    //
+    // If the global is externally visible, put the initializer into a COMDAT
+    // group with the global being initialized.  On most platforms, this is a
+    // minor startup time optimization.  In the MS C++ ABI, there are no guard
+    // variables, so this COMDAT key is required for correctness.
+    AddGlobalCtor(Fn, 65535, COMDATKey);
+    if (getTarget().getCXXABI().isMicrosoft() && COMDATKey) {
+      // In The MS C++, MS add template static data member in the linker
+      // drective.
+      addUsedGlobal(COMDATKey);
+    }
+  } else if (D->hasAttr<SelectAnyAttr>()) {
+    // SelectAny globals will be comdat-folded. Put the initializer into a
+    // COMDAT group associated with the global, so the initializers get folded
+    // too.
+    AddGlobalCtor(Fn, 65535, COMDATKey);
+  } else {
+    I = DelayedCXXInitPosition.find(D); // Re-do lookup in case of re-hash.
+    if (I == DelayedCXXInitPosition.end()) {
+      CXXGlobalInits.push_back(Fn);
+    } else if (I->second != ~0U) {
+      assert(I->second < CXXGlobalInits.size() &&
+             CXXGlobalInits[I->second] == nullptr);
+      CXXGlobalInits[I->second] = Fn;
+    }
+  }
+
+  // Remember that we already emitted the initializer for this global.
+  DelayedCXXInitPosition[D] = ~0U;
+}
+
+void CodeGenModule::EmitCXXThreadLocalInitFunc() {
+  getCXXABI().EmitThreadLocalInitFuncs(
+      *this, CXXThreadLocals, CXXThreadLocalInits, CXXThreadLocalInitVars);
+
+  CXXThreadLocalInits.clear();
+  CXXThreadLocalInitVars.clear();
+  CXXThreadLocals.clear();
+}
+
+void
+CodeGenModule::EmitCXXGlobalInitFunc() {
+  while (!CXXGlobalInits.empty() && !CXXGlobalInits.back())
+    CXXGlobalInits.pop_back();
+
+  if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty())
+    return;
+
+  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
+  const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
+
+  // Create our global initialization function.
+  if (!PrioritizedCXXGlobalInits.empty()) {
+    SmallVector<llvm::Function *, 8> LocalCXXGlobalInits;
+    llvm::array_pod_sort(PrioritizedCXXGlobalInits.begin(),
+                         PrioritizedCXXGlobalInits.end());
+    // Iterate over "chunks" of ctors with same priority and emit each chunk
+    // into separate function. Note - everything is sorted first by priority,
+    // second - by lex order, so we emit ctor functions in proper order.
+    for (SmallVectorImpl<GlobalInitData >::iterator
+           I = PrioritizedCXXGlobalInits.begin(),
+           E = PrioritizedCXXGlobalInits.end(); I != E; ) {
+      SmallVectorImpl<GlobalInitData >::iterator
+        PrioE = std::upper_bound(I + 1, E, *I, GlobalInitPriorityCmp());
+
+      LocalCXXGlobalInits.clear();
+      unsigned Priority = I->first.priority;
+      // Compute the function suffix from priority. Prepend with zeroes to make
+      // sure the function names are also ordered as priorities.
+      std::string PrioritySuffix = llvm::utostr(Priority);
+      // Priority is always <= 65535 (enforced by sema).
+      PrioritySuffix = std::string(6-PrioritySuffix.size(), '0')+PrioritySuffix;
+      llvm::Function *Fn = CreateGlobalInitOrDestructFunction(
+          FTy, "_GLOBAL__I_" + PrioritySuffix, FI);
+
+      for (; I < PrioE; ++I)
+        LocalCXXGlobalInits.push_back(I->second);
+
+      CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, LocalCXXGlobalInits);
+      AddGlobalCtor(Fn, Priority);
+    }
+    PrioritizedCXXGlobalInits.clear();
+  }
+
+  // Include the filename in the symbol name. Including "sub_" matches gcc and
+  // makes sure these symbols appear lexicographically behind the symbols with
+  // priority emitted above.
+  SmallString<128> FileName = llvm::sys::path::filename(getModule().getName());
+  if (FileName.empty())
+    FileName = "<null>";
+
+  for (size_t i = 0; i < FileName.size(); ++i) {
+    // Replace everything that's not [a-zA-Z0-9._] with a _. This set happens
+    // to be the set of C preprocessing numbers.
+    if (!isPreprocessingNumberBody(FileName[i]))
+      FileName[i] = '_';
+  }
+
+  llvm::Function *Fn = CreateGlobalInitOrDestructFunction(
+      FTy, llvm::Twine("_GLOBAL__sub_I_", FileName), FI);
+
+  CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, CXXGlobalInits);
+  AddGlobalCtor(Fn);
+
+  // In OpenCL global init functions must be converted to kernels in order to
+  // be able to launch them from the host.
+  // FIXME: Some more work might be needed to handle destructors correctly.
+  // Current initialization function makes use of function pointers callbacks.
+  // We can't support function pointers especially between host and device.
+  // However it seems global destruction has little meaning without any
+  // dynamic resource allocation on the device and program scope variables are
+  // destroyed by the runtime when program is released.
+  if (getLangOpts().OpenCL) {
+    GenOpenCLArgMetadata(Fn);
+    Fn->setCallingConv(llvm::CallingConv::SPIR_KERNEL);
+  }
+
+  if (getLangOpts().HIP) {
+    Fn->setCallingConv(llvm::CallingConv::AMDGPU_KERNEL);
+    Fn->addFnAttr("device-init");
+  }
+
+  CXXGlobalInits.clear();
+}
+
+void CodeGenModule::EmitCXXGlobalDtorFunc() {
+  if (CXXGlobalDtors.empty())
+    return;
+
+  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
+
+  // Create our global destructor function.
+  const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
+  llvm::Function *Fn =
+      CreateGlobalInitOrDestructFunction(FTy, "_GLOBAL__D_a", FI);
+
+  CodeGenFunction(*this).GenerateCXXGlobalDtorsFunc(Fn, CXXGlobalDtors);
+  AddGlobalDtor(Fn);
+}
+
+/// Emit the code necessary to initialize the given global variable.
+void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
+                                                       const VarDecl *D,
+                                                 llvm::GlobalVariable *Addr,
+                                                       bool PerformInit) {
+  // Check if we need to emit debug info for variable initializer.
+  if (D->hasAttr<NoDebugAttr>())
+    DebugInfo = nullptr; // disable debug info indefinitely for this function
+
+  CurEHLocation = D->getBeginLoc();
+
+  StartFunction(GlobalDecl(D, DynamicInitKind::Initializer),
+                getContext().VoidTy, Fn, getTypes().arrangeNullaryFunction(),
+                FunctionArgList(), D->getLocation(),
+                D->getInit()->getExprLoc());
+
+  // Use guarded initialization if the global variable is weak. This
+  // occurs for, e.g., instantiated static data members and
+  // definitions explicitly marked weak.
+  //
+  // Also use guarded initialization for a variable with dynamic TLS and
+  // unordered initialization. (If the initialization is ordered, the ABI
+  // layer will guard the whole-TU initialization for us.)
+  if (Addr->hasWeakLinkage() || Addr->hasLinkOnceLinkage() ||
+      (D->getTLSKind() == VarDecl::TLS_Dynamic &&
+       isTemplateInstantiation(D->getTemplateSpecializationKind()))) {
+    EmitCXXGuardedInit(*D, Addr, PerformInit);
+  } else {
+    EmitCXXGlobalVarDeclInit(*D, Addr, PerformInit);
+  }
+
+  FinishFunction();
+}
+
+void
+CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn,
+                                           ArrayRef<llvm::Function *> Decls,
+                                           ConstantAddress Guard) {
+  {
+    auto NL = ApplyDebugLocation::CreateEmpty(*this);
+    StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
+                  getTypes().arrangeNullaryFunction(), FunctionArgList());
+    // Emit an artificial location for this function.
+    auto AL = ApplyDebugLocation::CreateArtificial(*this);
+
+    llvm::BasicBlock *ExitBlock = nullptr;
+    if (Guard.isValid()) {
+      // If we have a guard variable, check whether we've already performed
+      // these initializations. This happens for TLS initialization functions.
+      llvm::Value *GuardVal = Builder.CreateLoad(Guard);
+      llvm::Value *Uninit = Builder.CreateIsNull(GuardVal,
+                                                 "guard.uninitialized");
+      llvm::BasicBlock *InitBlock = createBasicBlock("init");
+      ExitBlock = createBasicBlock("exit");
+      EmitCXXGuardedInitBranch(Uninit, InitBlock, ExitBlock,
+                               GuardKind::TlsGuard, nullptr);
+      EmitBlock(InitBlock);
+      // Mark as initialized before initializing anything else. If the
+      // initializers use previously-initialized thread_local vars, that's
+      // probably supposed to be OK, but the standard doesn't say.
+      Builder.CreateStore(llvm::ConstantInt::get(GuardVal->getType(),1), Guard);
+
+      // The guard variable can't ever change again.
+      EmitInvariantStart(
+          Guard.getPointer(),
+          CharUnits::fromQuantity(
+              CGM.getDataLayout().getTypeAllocSize(GuardVal->getType())));
+    }
+
+    RunCleanupsScope Scope(*this);
+
+    // When building in Objective-C++ ARC mode, create an autorelease pool
+    // around the global initializers.
+    if (getLangOpts().ObjCAutoRefCount && getLangOpts().CPlusPlus) {
+      llvm::Value *token = EmitObjCAutoreleasePoolPush();
+      EmitObjCAutoreleasePoolCleanup(token);
+    }
+
+    for (unsigned i = 0, e = Decls.size(); i != e; ++i)
+      if (Decls[i])
+        EmitRuntimeCall(Decls[i]);
+
+    Scope.ForceCleanup();
+
+    if (ExitBlock) {
+      Builder.CreateBr(ExitBlock);
+      EmitBlock(ExitBlock);
+    }
+  }
+
+  FinishFunction();
+}
+
+void CodeGenFunction::GenerateCXXGlobalDtorsFunc(
+    llvm::Function *Fn,
+    const std::vector<std::tuple<llvm::FunctionType *, llvm::WeakTrackingVH,
+                                 llvm::Constant *>> &DtorsAndObjects) {
+  {
+    auto NL = ApplyDebugLocation::CreateEmpty(*this);
+    StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
+                  getTypes().arrangeNullaryFunction(), FunctionArgList());
+    // Emit an artificial location for this function.
+    auto AL = ApplyDebugLocation::CreateArtificial(*this);
+
+    // Emit the dtors, in reverse order from construction.
+    for (unsigned i = 0, e = DtorsAndObjects.size(); i != e; ++i) {
+      llvm::FunctionType *CalleeTy;
+      llvm::Value *Callee;
+      llvm::Constant *Arg;
+      std::tie(CalleeTy, Callee, Arg) = DtorsAndObjects[e - i - 1];
+      llvm::CallInst *CI = Builder.CreateCall(CalleeTy, Callee, Arg);
+      // Make sure the call and the callee agree on calling convention.
+      if (llvm::Function *F = dyn_cast<llvm::Function>(Callee))
+        CI->setCallingConv(F->getCallingConv());
+    }
+  }
+
+  FinishFunction();
+}
+
+/// generateDestroyHelper - Generates a helper function which, when
+/// invoked, destroys the given object.  The address of the object
+/// should be in global memory.
+llvm::Function *CodeGenFunction::generateDestroyHelper(
+    Address addr, QualType type, Destroyer *destroyer,
+    bool useEHCleanupForArray, const VarDecl *VD) {
+  FunctionArgList args;
+  ImplicitParamDecl Dst(getContext(), getContext().VoidPtrTy,
+                        ImplicitParamDecl::Other);
+  args.push_back(&Dst);
+
+  const CGFunctionInfo &FI =
+    CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, args);
+  llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FI);
+  llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(
+      FTy, "__cxx_global_array_dtor", FI, VD->getLocation());
+
+  CurEHLocation = VD->getBeginLoc();
+
+  StartFunction(VD, getContext().VoidTy, fn, FI, args);
+
+  emitDestroy(addr, type, destroyer, useEHCleanupForArray);
+
+  FinishFunction();
+
+  return fn;
+}