//===--- 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/LangOptions.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 && 
(4.41k
!CGM.getCXXABI().HasThisReturn(

                     GlobalDecl(Record->getDestructor(), Dtor_Complete)) ||

                 
CGM.getCXXABI().canCallMismatchedFunctionType()8
);

  // 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 && 
(4.41k
CanRegisterDestructor4.41k
 || 
UsingExternalHelper1
)) {

    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 {

    Addr = Addr.getElementBitCast(CGF.ConvertTypeForMem(Type));

    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::GlobalVariable *GV,

                                               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 = GV->getAddressSpace();

  llvm::Constant *DeclPtr = GV;

  if (ActualAddrSpace != ExpectedAddrSpace) {

    llvm::PointerType *PTy = llvm::PointerType::getWithSamePointeeType(

        GV->getType(), ExpectedAddrSpace);

    DeclPtr = llvm::ConstantExpr::getAddrSpaceCast(DeclPtr, PTy);

  }

  ConstantAddress DeclAddr(

      DeclPtr, GV->getValueType(), getContext().getDeclAlign(&D));

  if (!T->isReferenceType()) {

    if (getLangOpts().OpenMP && 
!getLangOpts().OpenMPSimd3.88k
 &&

        
D.hasAttr<OMPThreadPrivateDeclAttr>()1.67k
) {

      (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.CreateGlobalInitOrCleanUpFunction(

      ty, FnName.str(), FI, VD.getLocation());

  CodeGenFunction CGF(CGM);

  CGF.StartFunction(GlobalDecl(&VD, DynamicInitKind::AtExit),

                    CGM.getContext().VoidTy, fn, FI, FunctionArgList(),

                    VD.getLocation(), VD.getInit()->getExprLoc());

  // Emit an artificial location for this function.

  auto AL = ApplyDebugLocation::CreateArtificial(CGF);

  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;

}

/// Create a stub function, suitable for being passed to __pt_atexit_np,

/// which passes the given address to the given destructor function.

llvm::Function *CodeGenFunction::createTLSAtExitStub(

    const VarDecl &D, llvm::FunctionCallee Dtor, llvm::Constant *Addr,

    llvm::FunctionCallee &AtExit) {

  SmallString<256> FnName;

  {

    llvm::raw_svector_ostream Out(FnName);

    CGM.getCXXABI().getMangleContext().mangleDynamicAtExitDestructor(&D, Out);

  }

  const CGFunctionInfo &FI = CGM.getTypes().arrangeLLVMFunctionInfo(

      getContext().IntTy, /*instanceMethod=*/false, /*chainCall=*/false,

      {getContext().IntTy}, FunctionType::ExtInfo(), {}, RequiredArgs::All);

  // Get the stub function type, int(*)(int,...).

  llvm::FunctionType *StubTy =

      llvm::FunctionType::get(CGM.IntTy, {CGM.IntTy}, true);

  llvm::Function *DtorStub = CGM.CreateGlobalInitOrCleanUpFunction(

      StubTy, FnName.str(), FI, D.getLocation());

  CodeGenFunction CGF(CGM);

  FunctionArgList Args;

  ImplicitParamDecl IPD(CGM.getContext(), CGM.getContext().IntTy,

                        ImplicitParamDecl::Other);

  Args.push_back(&IPD);

  QualType ResTy = CGM.getContext().IntTy;

  CGF.StartFunction(GlobalDecl(&D, DynamicInitKind::AtExit), ResTy, DtorStub,

                    FI, Args, D.getLocation(), D.getInit()->getExprLoc());

  // Emit an artificial location for this function.

  auto AL = ApplyDebugLocation::CreateArtificial(CGF);

  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());

  // Return 0 from function

  CGF.Builder.CreateStore(llvm::Constant::getNullValue(CGM.IntTy),

                          CGF.ReturnValue);

  CGF.FinishFunction();

  return DtorStub;

}

/// 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));

  assert(dtorStub->getType() ==

             llvm::PointerType::get(

                 llvm::FunctionType::get(CGM.VoidTy, false),

                 dtorStub->getType()->getPointerAddressSpace()) &&

         "Argument to atexit has a wrong type.");

  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);

}

llvm::Value *

CodeGenFunction::unregisterGlobalDtorWithUnAtExit(llvm::Constant *dtorStub) {

  // The unatexit subroutine unregisters __dtor functions that were previously

  // registered by the atexit subroutine. If the referenced function is found,

  // it is removed from the list of functions that are called at normal program

  // termination and the unatexit returns a value of 0, otherwise a non-zero

  // value is returned.

  //

  // extern "C" int unatexit(void (*f)(void));

  assert(dtorStub->getType() ==

             llvm::PointerType::get(

                 llvm::FunctionType::get(CGM.VoidTy, false),

                 dtorStub->getType()->getPointerAddressSpace()) &&

         "Argument to unatexit has a wrong type.");

  llvm::FunctionType *unatexitTy =

      llvm::FunctionType::get(IntTy, {dtorStub->getType()}, /*isVarArg=*/false);

  llvm::FunctionCallee unatexit =

      CGM.CreateRuntimeFunction(unatexitTy, "unatexit", llvm::AttributeList());

  cast<llvm::Function>(unatexit.getCallee())->setDoesNotThrow();

  return EmitNounwindRuntimeCall(unatexit, 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()9.18k
) {

    // 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()8.99k
)

      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::CreateGlobalInitOrCleanUpFunction(

    llvm::FunctionType *FTy, const Twine &Name, const CGFunctionInfo &FI,

    SourceLocation Loc, bool TLS, llvm::GlobalVariable::LinkageTypes Linkage) {

  llvm::Function *Fn = llvm::Function::Create(FTy, Linkage, Name, &getModule());

  if (!getLangOpts().AppleKext && 
!TLS10.7k
) {

    // Set the section if needed.

    if (const char *Section = getTarget().getStaticInitSectionSpecifier())

      Fn->setSection(Section);

  }

  if (Linkage == llvm::GlobalVariable::InternalLinkage)

    SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);

  Fn->setCallingConv(getRuntimeCC());

  if (!getLangOpts().Exceptions)

    Fn->setDoesNotThrow();

  if (getLangOpts().Sanitize.has(SanitizerKind::Address) &&

      
!isInNoSanitizeList(SanitizerKind::Address, Fn, Loc)93
)

    Fn->addFnAttr(llvm::Attribute::SanitizeAddress);

  if (getLangOpts().Sanitize.has(SanitizerKind::KernelAddress) &&

      
!isInNoSanitizeList(SanitizerKind::KernelAddress, Fn, Loc)4
)

    Fn->addFnAttr(llvm::Attribute::SanitizeAddress);

  if (getLangOpts().Sanitize.has(SanitizerKind::HWAddress) &&

      
!isInNoSanitizeList(SanitizerKind::HWAddress, Fn, Loc)0
)

    Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress);

  if (getLangOpts().Sanitize.has(SanitizerKind::KernelHWAddress) &&

      
!isInNoSanitizeList(SanitizerKind::KernelHWAddress, Fn, Loc)0
)

    Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress);

  if (getLangOpts().Sanitize.has(SanitizerKind::MemtagStack) &&

      
!isInNoSanitizeList(SanitizerKind::MemtagStack, Fn, Loc)0
)

    Fn->addFnAttr(llvm::Attribute::SanitizeMemTag);

  if (getLangOpts().Sanitize.has(SanitizerKind::Thread) &&

      
!isInNoSanitizeList(SanitizerKind::Thread, Fn, Loc)6
)

    Fn->addFnAttr(llvm::Attribute::SanitizeThread);

  if (getLangOpts().Sanitize.has(SanitizerKind::Memory) &&

      
!isInNoSanitizeList(SanitizerKind::Memory, Fn, Loc)97
)

    Fn->addFnAttr(llvm::Attribute::SanitizeMemory);

  if (getLangOpts().Sanitize.has(SanitizerKind::KernelMemory) &&

      
!isInNoSanitizeList(SanitizerKind::KernelMemory, Fn, Loc)0
)

    Fn->addFnAttr(llvm::Attribute::SanitizeMemory);

  if (getLangOpts().Sanitize.has(SanitizerKind::SafeStack) &&

      
!isInNoSanitizeList(SanitizerKind::SafeStack, Fn, Loc)0
)

    Fn->addFnAttr(llvm::Attribute::SafeStack);

  if (getLangOpts().Sanitize.has(SanitizerKind::ShadowCallStack) &&

      
!isInNoSanitizeList(SanitizerKind::ShadowCallStack, Fn, Loc)0
)

    Fn->addFnAttr(llvm::Attribute::ShadowCallStack);

  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().GPUAllowDeviceInit1
 &&

      
(0
D->hasAttr<CUDADeviceAttr>()0
 || 
D->hasAttr<CUDAConstantAttr>()0
 ||

       D->hasAttr<CUDASharedAttr>()))

    return;

  if (getLangOpts().OpenMP &&

      
getOpenMPRuntime().emitDeclareTargetVarDefinition(D, Addr, PerformInit)3.90k
)

    return;

  // Check if we've already initialized this decl.

  auto I = DelayedCXXInitPosition.find(D);

  if (I != DelayedCXXInitPosition.end() && 
I->second == ~0U1.63k
)

    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 = CreateGlobalInitOrCleanUpFunction(

      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()4.66k
 ? 
Addr3.93k
 : 
nullptr1.91k
;

  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 && 
ISA5.23k
) {

    EmitPointerToInitFunc(D, Addr, Fn, ISA);

  } else if (auto *IPA = D->getAttr<InitPriorityAttr>()) {

    OrderGlobalInitsOrStermFinalizers Key(IPA->getPriority(),

                                          PrioritizedCXXGlobalInits.size());

    PrioritizedCXXGlobalInits.push_back(std::make_pair(Key, Fn));

  } else if (isTemplateInstantiation(D->getTemplateSpecializationKind()) ||

             
getContext().GetGVALinkageForVariable(D) == GVA_DiscardableODR4.61k
 ||

             
D->hasAttr<SelectAnyAttr>()4.58k
) {

    // 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.

    //

    // 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);

    if (COMDATKey && 
(106
getTriple().isOSBinFormatELF()106
 ||

                      
getTarget().getCXXABI().isMicrosoft()37
)) {

      // When COMDAT is used on ELF or in the MS C++ ABI, the key must be in

      // llvm.used to prevent linker GC.

      addUsedGlobal(COMDATKey);

    }

    // If we used a COMDAT key for the global ctor, the init function can be

    // discarded if the global ctor entry is discarded.

    // FIXME: Do we need to restrict this to ELF and Wasm?

    llvm::Comdat *C = Addr->getComdat();

    if (COMDATKey && 
C106
 &&

        
(106
getTarget().getTriple().isOSBinFormatELF()106
 ||

         
getTarget().getTriple().isOSBinFormatWasm()37
)) {

      Fn->setComdat(C);

    }

  } else {

    I = DelayedCXXInitPosition.find(D); // Re-do lookup in case of re-hash.

    if (I == DelayedCXXInitPosition.end()) {

      CXXGlobalInits.push_back(Fn);

    } else 
if (1.23k
I->second != ~0U1.23k
) {

      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();

}

static SmallString<128> getTransformedFileName(llvm::Module &M) {

  SmallString<128> FileName = llvm::sys::path::filename(M.getName());

  if (FileName.empty())

    FileName = "<null>";

  for (size_t i = 0; i < FileName.size(); 
++i45.0k
) {

    // 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] = '_';

  }

  return FileName;

}

static std::string getPrioritySuffix(unsigned int Priority) {

  assert(Priority <= 65535 && "Priority should always be <= 65535.");

  // 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);

  PrioritySuffix = std::string(6 - PrioritySuffix.size(), '0') + PrioritySuffix;

  return PrioritySuffix;

}

void

CodeGenModule::EmitCXXGlobalInitFunc() {

  while (!CXXGlobalInits.empty() && 
!CXXGlobalInits.back()33.5k
)

    CXXGlobalInits.pop_back();

  if (CXXGlobalInits.empty() && 
PrioritizedCXXGlobalInits.empty()34.5k
)

    return;

  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);

  const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();

  // Create our global prioritized 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 int Priority = I->first.priority;

      llvm::Function *Fn = CreateGlobalInitOrCleanUpFunction(

          FTy, "_GLOBAL__I_" + getPrioritySuffix(Priority), FI);

      for (; I < PrioE; 
++I929
)

        LocalCXXGlobalInits.push_back(I->second);

      CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, LocalCXXGlobalInits);

      AddGlobalCtor(Fn, Priority);

    }

    PrioritizedCXXGlobalInits.clear();

  }

  if (getCXXABI().useSinitAndSterm() && 
CXXGlobalInits.empty()15
)

    return;

  // 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.

  llvm::Function *Fn = CreateGlobalInitOrCleanUpFunction(

      FTy, llvm::Twine("_GLOBAL__sub_I_", getTransformedFileName(getModule())),

      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) {

    GenKernelArgMetadata(Fn);

    Fn->setCallingConv(llvm::CallingConv::SPIR_KERNEL);

  }

  assert(!getLangOpts().CUDA || !getLangOpts().CUDAIsDevice ||

         getLangOpts().GPUAllowDeviceInit);

  if (getLangOpts().HIP && 
getLangOpts().CUDAIsDevice1
) {

    Fn->setCallingConv(llvm::CallingConv::AMDGPU_KERNEL);

    Fn->addFnAttr("device-init");

  }

  CXXGlobalInits.clear();

}

void CodeGenModule::EmitCXXGlobalCleanUpFunc() {

  if (CXXGlobalDtorsOrStermFinalizers.empty() &&

      
PrioritizedCXXStermFinalizers.empty()35.8k
)

    return;

  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);

  const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();

  // Create our global prioritized cleanup function.

  if (!PrioritizedCXXStermFinalizers.empty()) {

    SmallVector<CXXGlobalDtorsOrStermFinalizer_t, 8> LocalCXXStermFinalizers;

    llvm::array_pod_sort(PrioritizedCXXStermFinalizers.begin(),

                         PrioritizedCXXStermFinalizers.end());

    // Iterate over "chunks" of dtors with same priority and emit each chunk

    // into separate function. Note - everything is sorted first by priority,

    // second - by lex order, so we emit dtor functions in proper order.

    for (SmallVectorImpl<StermFinalizerData>::iterator

             I = PrioritizedCXXStermFinalizers.begin(),

             E = PrioritizedCXXStermFinalizers.end();

         I != E;) {

      SmallVectorImpl<StermFinalizerData>::iterator PrioE =

          std::upper_bound(I + 1, E, *I, StermFinalizerPriorityCmp());

      LocalCXXStermFinalizers.clear();

      unsigned int Priority = I->first.priority;

      llvm::Function *Fn = CreateGlobalInitOrCleanUpFunction(

          FTy, "_GLOBAL__a_" + getPrioritySuffix(Priority), FI);

      for (; I < PrioE; 
++I8
) {

        llvm::FunctionCallee DtorFn = I->second;

        LocalCXXStermFinalizers.emplace_back(DtorFn.getFunctionType(),

                                             DtorFn.getCallee(), nullptr);

      }

      CodeGenFunction(*this).GenerateCXXGlobalCleanUpFunc(

          Fn, LocalCXXStermFinalizers);

      AddGlobalDtor(Fn, Priority);

    }

    PrioritizedCXXStermFinalizers.clear();

  }

  if (CXXGlobalDtorsOrStermFinalizers.empty())

    return;

  // Create our global cleanup function.

  llvm::Function *Fn =

      CreateGlobalInitOrCleanUpFunction(FTy, "_GLOBAL__D_a", FI);

  CodeGenFunction(*this).GenerateCXXGlobalCleanUpFunc(

      Fn, CXXGlobalDtorsOrStermFinalizers);

  AddGlobalDtor(Fn);

  CXXGlobalDtorsOrStermFinalizers.clear();

}

/// 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());

  // Emit an artificial location for this function.

  auto AL = ApplyDebugLocation::CreateArtificial(*this);

  // 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()5.77k
 ||

      
(5.61k
D->getTLSKind() == VarDecl::TLS_Dynamic5.61k
 &&

       
isTemplateInstantiation(D->getTemplateSpecializationKind())105
)) {

    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().CPlusPlus4
) {

      llvm::Value *token = EmitObjCAutoreleasePoolPush();

      EmitObjCAutoreleasePoolCleanup(token);

    }

    for (unsigned i = 0, e = Decls.size(); i != e; 
++i8.38k
)

      if (Decls[i])

        EmitRuntimeCall(Decls[i]);

    Scope.ForceCleanup();

    if (ExitBlock) {

      Builder.CreateBr(ExitBlock);

      EmitBlock(ExitBlock);

    }

  }

  FinishFunction();

}

void CodeGenFunction::GenerateCXXGlobalCleanUpFunc(

    llvm::Function *Fn,

    ArrayRef<std::tuple<llvm::FunctionType *, llvm::WeakTrackingVH,

                        llvm::Constant *>>

        DtorsOrStermFinalizers) {

  {

    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 cleanups, in reverse order from construction.

    for (unsigned i = 0, e = DtorsOrStermFinalizers.size(); i != e; 
++i36
) {

      llvm::FunctionType *CalleeTy;

      llvm::Value *Callee;

      llvm::Constant *Arg;

      std::tie(CalleeTy, Callee, Arg) = DtorsOrStermFinalizers[e - i - 1];

      llvm::CallInst *CI = nullptr;

      if (Arg == nullptr) {

        assert(

            CGM.getCXXABI().useSinitAndSterm() &&

            "Arg could not be nullptr unless using sinit and sterm functions.");

        CI = Builder.CreateCall(CalleeTy, Callee);

      } else

        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.CreateGlobalInitOrCleanUpFunction(

      FTy, "__cxx_global_array_dtor", FI, VD->getLocation());

  CurEHLocation = VD->getBeginLoc();

  StartFunction(GlobalDecl(VD, DynamicInitKind::GlobalArrayDestructor),

                getContext().VoidTy, fn, FI, args);

  // Emit an artificial location for this function.

  auto AL = ApplyDebugLocation::CreateArtificial(*this);

  emitDestroy(addr, type, destroyer, useEHCleanupForArray);

  FinishFunction();

  return fn;

}