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llvm-project/clang/lib/CodeGen/CGDecl.cpp
Alexey Bader 7818906ca1 [SYCL] Implement SYCL address space attributes handling 
Default address space (applies when no explicit address space was
specified) maps to generic (4) address space.

Added SYCL named address spaces `sycl_global`, `sycl_local` and
`sycl_private` defined as sub-sets of the default address space.

Static variables without address space now reside in global address
space when compile for SPIR target, unless they have an explicit address
space qualifier in source code.

Differential Revision: https://reviews.llvm.org/D89909
2021-04-26 13:44:10 +03:00

2615 lines
101 KiB
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//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Decl nodes as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CGBlocks.h"
#include "CGCXXABI.h"
#include "CGCleanup.h"
#include "CGDebugInfo.h"
#include "CGOpenCLRuntime.h"
#include "CGOpenMPRuntime.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "ConstantEmitter.h"
#include "PatternInit.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclOpenMP.h"
#include "clang/Basic/CodeGenOptions.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/CodeGen/CGFunctionInfo.h"
#include "clang/Sema/Sema.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Type.h"
using namespace clang;
using namespace CodeGen;
static_assert(clang::Sema::MaximumAlignment <= llvm::Value::MaximumAlignment,
"Clang max alignment greater than what LLVM supports?");
void CodeGenFunction::EmitDecl(const Decl &D) {
switch (D.getKind()) {
case Decl::BuiltinTemplate:
case Decl::TranslationUnit:
case Decl::ExternCContext:
case Decl::Namespace:
case Decl::UnresolvedUsingTypename:
case Decl::ClassTemplateSpecialization:
case Decl::ClassTemplatePartialSpecialization:
case Decl::VarTemplateSpecialization:
case Decl::VarTemplatePartialSpecialization:
case Decl::TemplateTypeParm:
case Decl::UnresolvedUsingValue:
case Decl::NonTypeTemplateParm:
case Decl::CXXDeductionGuide:
case Decl::CXXMethod:
case Decl::CXXConstructor:
case Decl::CXXDestructor:
case Decl::CXXConversion:
case Decl::Field:
case Decl::MSProperty:
case Decl::IndirectField:
case Decl::ObjCIvar:
case Decl::ObjCAtDefsField:
case Decl::ParmVar:
case Decl::ImplicitParam:
case Decl::ClassTemplate:
case Decl::VarTemplate:
case Decl::FunctionTemplate:
case Decl::TypeAliasTemplate:
case Decl::TemplateTemplateParm:
case Decl::ObjCMethod:
case Decl::ObjCCategory:
case Decl::ObjCProtocol:
case Decl::ObjCInterface:
case Decl::ObjCCategoryImpl:
case Decl::ObjCImplementation:
case Decl::ObjCProperty:
case Decl::ObjCCompatibleAlias:
case Decl::PragmaComment:
case Decl::PragmaDetectMismatch:
case Decl::AccessSpec:
case Decl::LinkageSpec:
case Decl::Export:
case Decl::ObjCPropertyImpl:
case Decl::FileScopeAsm:
case Decl::Friend:
case Decl::FriendTemplate:
case Decl::Block:
case Decl::Captured:
case Decl::ClassScopeFunctionSpecialization:
case Decl::UsingShadow:
case Decl::ConstructorUsingShadow:
case Decl::ObjCTypeParam:
case Decl::Binding:
llvm_unreachable("Declaration should not be in declstmts!");
case Decl::Record: // struct/union/class X;
case Decl::CXXRecord: // struct/union/class X; [C++]
if (CGDebugInfo *DI = getDebugInfo())
if (cast<RecordDecl>(D).getDefinition())
DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(&D)));
return;
case Decl::Enum: // enum X;
if (CGDebugInfo *DI = getDebugInfo())
if (cast<EnumDecl>(D).getDefinition())
DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(&D)));
return;
case Decl::Function: // void X();
case Decl::EnumConstant: // enum ? { X = ? }
case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
case Decl::Label: // __label__ x;
case Decl::Import:
case Decl::MSGuid: // __declspec(uuid("..."))
case Decl::TemplateParamObject:
case Decl::OMPThreadPrivate:
case Decl::OMPAllocate:
case Decl::OMPCapturedExpr:
case Decl::OMPRequires:
case Decl::Empty:
case Decl::Concept:
case Decl::LifetimeExtendedTemporary:
case Decl::RequiresExprBody:
// None of these decls require codegen support.
return;
case Decl::NamespaceAlias:
if (CGDebugInfo *DI = getDebugInfo())
DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(D));
return;
case Decl::Using: // using X; [C++]
if (CGDebugInfo *DI = getDebugInfo())
DI->EmitUsingDecl(cast<UsingDecl>(D));
return;
case Decl::UsingPack:
for (auto *Using : cast<UsingPackDecl>(D).expansions())
EmitDecl(*Using);
return;
case Decl::UsingDirective: // using namespace X; [C++]
if (CGDebugInfo *DI = getDebugInfo())
DI->EmitUsingDirective(cast<UsingDirectiveDecl>(D));
return;
case Decl::Var:
case Decl::Decomposition: {
const VarDecl &VD = cast<VarDecl>(D);
assert(VD.isLocalVarDecl() &&
"Should not see file-scope variables inside a function!");
EmitVarDecl(VD);
if (auto *DD = dyn_cast<DecompositionDecl>(&VD))
for (auto *B : DD->bindings())
if (auto *HD = B->getHoldingVar())
EmitVarDecl(*HD);
return;
}
case Decl::OMPDeclareReduction:
return CGM.EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(&D), this);
case Decl::OMPDeclareMapper:
return CGM.EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(&D), this);
case Decl::Typedef: // typedef int X;
case Decl::TypeAlias: { // using X = int; [C++0x]
QualType Ty = cast<TypedefNameDecl>(D).getUnderlyingType();
if (CGDebugInfo *DI = getDebugInfo())
DI->EmitAndRetainType(Ty);
if (Ty->isVariablyModifiedType())
EmitVariablyModifiedType(Ty);
return;
}
}
}
/// EmitVarDecl - This method handles emission of any variable declaration
/// inside a function, including static vars etc.
void CodeGenFunction::EmitVarDecl(const VarDecl &D) {
if (D.hasExternalStorage())
// Don't emit it now, allow it to be emitted lazily on its first use.
return;
// Some function-scope variable does not have static storage but still
// needs to be emitted like a static variable, e.g. a function-scope
// variable in constant address space in OpenCL.
if (D.getStorageDuration() != SD_Automatic) {
// Static sampler variables translated to function calls.
if (D.getType()->isSamplerT())
return;
llvm::GlobalValue::LinkageTypes Linkage =
CGM.getLLVMLinkageVarDefinition(&D, /*IsConstant=*/false);
// FIXME: We need to force the emission/use of a guard variable for
// some variables even if we can constant-evaluate them because
// we can't guarantee every translation unit will constant-evaluate them.
return EmitStaticVarDecl(D, Linkage);
}
if (D.getType().getAddressSpace() == LangAS::opencl_local)
return CGM.getOpenCLRuntime().EmitWorkGroupLocalVarDecl(*this, D);
assert(D.hasLocalStorage());
return EmitAutoVarDecl(D);
}
static std::string getStaticDeclName(CodeGenModule &CGM, const VarDecl &D) {
if (CGM.getLangOpts().CPlusPlus)
return CGM.getMangledName(&D).str();
// If this isn't C++, we don't need a mangled name, just a pretty one.
assert(!D.isExternallyVisible() && "name shouldn't matter");
std::string ContextName;
const DeclContext *DC = D.getDeclContext();
if (auto *CD = dyn_cast<CapturedDecl>(DC))
DC = cast<DeclContext>(CD->getNonClosureContext());
if (const auto *FD = dyn_cast<FunctionDecl>(DC))
ContextName = std::string(CGM.getMangledName(FD));
else if (const auto *BD = dyn_cast<BlockDecl>(DC))
ContextName = std::string(CGM.getBlockMangledName(GlobalDecl(), BD));
else if (const auto *OMD = dyn_cast<ObjCMethodDecl>(DC))
ContextName = OMD->getSelector().getAsString();
else
llvm_unreachable("Unknown context for static var decl");
ContextName += "." + D.getNameAsString();
return ContextName;
}
llvm::Constant *CodeGenModule::getOrCreateStaticVarDecl(
const VarDecl &D, llvm::GlobalValue::LinkageTypes Linkage) {
// In general, we don't always emit static var decls once before we reference
// them. It is possible to reference them before emitting the function that
// contains them, and it is possible to emit the containing function multiple
// times.
if (llvm::Constant *ExistingGV = StaticLocalDeclMap[&D])
return ExistingGV;
QualType Ty = D.getType();
assert(Ty->isConstantSizeType() && "VLAs can't be static");
// Use the label if the variable is renamed with the asm-label extension.
std::string Name;
if (D.hasAttr<AsmLabelAttr>())
Name = std::string(getMangledName(&D));
else
Name = getStaticDeclName(*this, D);
llvm::Type *LTy = getTypes().ConvertTypeForMem(Ty);
LangAS AS = GetGlobalVarAddressSpace(&D);
unsigned TargetAS = getContext().getTargetAddressSpace(AS);
// OpenCL variables in local address space and CUDA shared
// variables cannot have an initializer.
llvm::Constant *Init = nullptr;
if (Ty.getAddressSpace() == LangAS::opencl_local ||
D.hasAttr<CUDASharedAttr>() || D.hasAttr<LoaderUninitializedAttr>())
Init = llvm::UndefValue::get(LTy);
else
Init = EmitNullConstant(Ty);
llvm::GlobalVariable *GV = new llvm::GlobalVariable(
getModule(), LTy, Ty.isConstant(getContext()), Linkage, Init, Name,
nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
GV->setAlignment(getContext().getDeclAlign(&D).getAsAlign());
if (supportsCOMDAT() && GV->isWeakForLinker())
GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
if (D.getTLSKind())
setTLSMode(GV, D);
setGVProperties(GV, &D);
// Make sure the result is of the correct type.
LangAS ExpectedAS = Ty.getAddressSpace();
llvm::Constant *Addr = GV;
if (AS != ExpectedAS) {
Addr = getTargetCodeGenInfo().performAddrSpaceCast(
*this, GV, AS, ExpectedAS,
LTy->getPointerTo(getContext().getTargetAddressSpace(ExpectedAS)));
}
setStaticLocalDeclAddress(&D, Addr);
// Ensure that the static local gets initialized by making sure the parent
// function gets emitted eventually.
const Decl *DC = cast<Decl>(D.getDeclContext());
// We can't name blocks or captured statements directly, so try to emit their
// parents.
if (isa<BlockDecl>(DC) || isa<CapturedDecl>(DC)) {
DC = DC->getNonClosureContext();
// FIXME: Ensure that global blocks get emitted.
if (!DC)
return Addr;
}
GlobalDecl GD;
if (const auto *CD = dyn_cast<CXXConstructorDecl>(DC))
GD = GlobalDecl(CD, Ctor_Base);
else if (const auto *DD = dyn_cast<CXXDestructorDecl>(DC))
GD = GlobalDecl(DD, Dtor_Base);
else if (const auto *FD = dyn_cast<FunctionDecl>(DC))
GD = GlobalDecl(FD);
else {
// Don't do anything for Obj-C method decls or global closures. We should
// never defer them.
assert(isa<ObjCMethodDecl>(DC) && "unexpected parent code decl");
}
if (GD.getDecl()) {
// Disable emission of the parent function for the OpenMP device codegen.
CGOpenMPRuntime::DisableAutoDeclareTargetRAII NoDeclTarget(*this);
(void)GetAddrOfGlobal(GD);
}
return Addr;
}
/// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
/// global variable that has already been created for it. If the initializer
/// has a different type than GV does, this may free GV and return a different
/// one. Otherwise it just returns GV.
llvm::GlobalVariable *
CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
llvm::GlobalVariable *GV) {
ConstantEmitter emitter(*this);
llvm::Constant *Init = emitter.tryEmitForInitializer(D);
// If constant emission failed, then this should be a C++ static
// initializer.
if (!Init) {
if (!getLangOpts().CPlusPlus)
CGM.ErrorUnsupported(D.getInit(), "constant l-value expression");
else if (HaveInsertPoint()) {
// Since we have a static initializer, this global variable can't
// be constant.
GV->setConstant(false);
EmitCXXGuardedInit(D, GV, /*PerformInit*/true);
}
return GV;
}
// The initializer may differ in type from the global. Rewrite
// the global to match the initializer. (We have to do this
// because some types, like unions, can't be completely represented
// in the LLVM type system.)
if (GV->getValueType() != Init->getType()) {
llvm::GlobalVariable *OldGV = GV;
GV = new llvm::GlobalVariable(
CGM.getModule(), Init->getType(), OldGV->isConstant(),
OldGV->getLinkage(), Init, "",
/*InsertBefore*/ OldGV, OldGV->getThreadLocalMode(),
OldGV->getType()->getPointerAddressSpace());
GV->setVisibility(OldGV->getVisibility());
GV->setDSOLocal(OldGV->isDSOLocal());
GV->setComdat(OldGV->getComdat());
// Steal the name of the old global
GV->takeName(OldGV);
// Replace all uses of the old global with the new global
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
OldGV->replaceAllUsesWith(NewPtrForOldDecl);
// Erase the old global, since it is no longer used.
OldGV->eraseFromParent();
}
GV->setConstant(CGM.isTypeConstant(D.getType(), true));
GV->setInitializer(Init);
emitter.finalize(GV);
if (D.needsDestruction(getContext()) == QualType::DK_cxx_destructor &&
HaveInsertPoint()) {
// We have a constant initializer, but a nontrivial destructor. We still
// need to perform a guarded "initialization" in order to register the
// destructor.
EmitCXXGuardedInit(D, GV, /*PerformInit*/false);
}
return GV;
}
void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
llvm::GlobalValue::LinkageTypes Linkage) {
// Check to see if we already have a global variable for this
// declaration. This can happen when double-emitting function
// bodies, e.g. with complete and base constructors.
llvm::Constant *addr = CGM.getOrCreateStaticVarDecl(D, Linkage);
CharUnits alignment = getContext().getDeclAlign(&D);
// Store into LocalDeclMap before generating initializer to handle
// circular references.
setAddrOfLocalVar(&D, Address(addr, alignment));
// We can't have a VLA here, but we can have a pointer to a VLA,
// even though that doesn't really make any sense.
// Make sure to evaluate VLA bounds now so that we have them for later.
if (D.getType()->isVariablyModifiedType())
EmitVariablyModifiedType(D.getType());
// Save the type in case adding the initializer forces a type change.
llvm::Type *expectedType = addr->getType();
llvm::GlobalVariable *var =
cast<llvm::GlobalVariable>(addr->stripPointerCasts());
// CUDA's local and local static __shared__ variables should not
// have any non-empty initializers. This is ensured by Sema.
// Whatever initializer such variable may have when it gets here is
// a no-op and should not be emitted.
bool isCudaSharedVar = getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
D.hasAttr<CUDASharedAttr>();
// If this value has an initializer, emit it.
if (D.getInit() && !isCudaSharedVar)
var = AddInitializerToStaticVarDecl(D, var);
var->setAlignment(alignment.getAsAlign());
if (D.hasAttr<AnnotateAttr>())
CGM.AddGlobalAnnotations(&D, var);
if (auto *SA = D.getAttr<PragmaClangBSSSectionAttr>())
var->addAttribute("bss-section", SA->getName());
if (auto *SA = D.getAttr<PragmaClangDataSectionAttr>())
var->addAttribute("data-section", SA->getName());
if (auto *SA = D.getAttr<PragmaClangRodataSectionAttr>())
var->addAttribute("rodata-section", SA->getName());
if (auto *SA = D.getAttr<PragmaClangRelroSectionAttr>())
var->addAttribute("relro-section", SA->getName());
if (const SectionAttr *SA = D.getAttr<SectionAttr>())
var->setSection(SA->getName());
if (D.hasAttr<RetainAttr>())
CGM.addUsedGlobal(var);
else if (D.hasAttr<UsedAttr>())
CGM.addUsedOrCompilerUsedGlobal(var);
// We may have to cast the constant because of the initializer
// mismatch above.
//
// FIXME: It is really dangerous to store this in the map; if anyone
// RAUW's the GV uses of this constant will be invalid.
llvm::Constant *castedAddr =
llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(var, expectedType);
if (var != castedAddr)
LocalDeclMap.find(&D)->second = Address(castedAddr, alignment);
CGM.setStaticLocalDeclAddress(&D, castedAddr);
CGM.getSanitizerMetadata()->reportGlobalToASan(var, D);
// Emit global variable debug descriptor for static vars.
CGDebugInfo *DI = getDebugInfo();
if (DI && CGM.getCodeGenOpts().hasReducedDebugInfo()) {
DI->setLocation(D.getLocation());
DI->EmitGlobalVariable(var, &D);
}
}
namespace {
struct DestroyObject final : EHScopeStack::Cleanup {
DestroyObject(Address addr, QualType type,
CodeGenFunction::Destroyer *destroyer,
bool useEHCleanupForArray)
: addr(addr), type(type), destroyer(destroyer),
useEHCleanupForArray(useEHCleanupForArray) {}
Address addr;
QualType type;
CodeGenFunction::Destroyer *destroyer;
bool useEHCleanupForArray;
void Emit(CodeGenFunction &CGF, Flags flags) override {
// Don't use an EH cleanup recursively from an EH cleanup.
bool useEHCleanupForArray =
flags.isForNormalCleanup() && this->useEHCleanupForArray;
CGF.emitDestroy(addr, type, destroyer, useEHCleanupForArray);
}
};
template <class Derived>
struct DestroyNRVOVariable : EHScopeStack::Cleanup {
DestroyNRVOVariable(Address addr, QualType type, llvm::Value *NRVOFlag)
: NRVOFlag(NRVOFlag), Loc(addr), Ty(type) {}
llvm::Value *NRVOFlag;
Address Loc;
QualType Ty;
void Emit(CodeGenFunction &CGF, Flags flags) override {
// Along the exceptions path we always execute the dtor.
bool NRVO = flags.isForNormalCleanup() && NRVOFlag;
llvm::BasicBlock *SkipDtorBB = nullptr;
if (NRVO) {
// If we exited via NRVO, we skip the destructor call.
llvm::BasicBlock *RunDtorBB = CGF.createBasicBlock("nrvo.unused");
SkipDtorBB = CGF.createBasicBlock("nrvo.skipdtor");
llvm::Value *DidNRVO =
CGF.Builder.CreateFlagLoad(NRVOFlag, "nrvo.val");
CGF.Builder.CreateCondBr(DidNRVO, SkipDtorBB, RunDtorBB);
CGF.EmitBlock(RunDtorBB);
}
static_cast<Derived *>(this)->emitDestructorCall(CGF);
if (NRVO) CGF.EmitBlock(SkipDtorBB);
}
virtual ~DestroyNRVOVariable() = default;
};
struct DestroyNRVOVariableCXX final
: DestroyNRVOVariable<DestroyNRVOVariableCXX> {
DestroyNRVOVariableCXX(Address addr, QualType type,
const CXXDestructorDecl *Dtor, llvm::Value *NRVOFlag)
: DestroyNRVOVariable<DestroyNRVOVariableCXX>(addr, type, NRVOFlag),
Dtor(Dtor) {}
const CXXDestructorDecl *Dtor;
void emitDestructorCall(CodeGenFunction &CGF) {
CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
/*ForVirtualBase=*/false,
/*Delegating=*/false, Loc, Ty);
}
};
struct DestroyNRVOVariableC final
: DestroyNRVOVariable<DestroyNRVOVariableC> {
DestroyNRVOVariableC(Address addr, llvm::Value *NRVOFlag, QualType Ty)
: DestroyNRVOVariable<DestroyNRVOVariableC>(addr, Ty, NRVOFlag) {}
void emitDestructorCall(CodeGenFunction &CGF) {
CGF.destroyNonTrivialCStruct(CGF, Loc, Ty);
}
};
struct CallStackRestore final : EHScopeStack::Cleanup {
Address Stack;
CallStackRestore(Address Stack) : Stack(Stack) {}
bool isRedundantBeforeReturn() override { return true; }
void Emit(CodeGenFunction &CGF, Flags flags) override {
llvm::Value *V = CGF.Builder.CreateLoad(Stack);
llvm::Function *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
CGF.Builder.CreateCall(F, V);
}
};
struct ExtendGCLifetime final : EHScopeStack::Cleanup {
const VarDecl &Var;
ExtendGCLifetime(const VarDecl *var) : Var(*var) {}
void Emit(CodeGenFunction &CGF, Flags flags) override {
// Compute the address of the local variable, in case it's a
// byref or something.
DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(&Var), false,
Var.getType(), VK_LValue, SourceLocation());
llvm::Value *value = CGF.EmitLoadOfScalar(CGF.EmitDeclRefLValue(&DRE),
SourceLocation());
CGF.EmitExtendGCLifetime(value);
}
};
struct CallCleanupFunction final : EHScopeStack::Cleanup {
llvm::Constant *CleanupFn;
const CGFunctionInfo &FnInfo;
const VarDecl &Var;
CallCleanupFunction(llvm::Constant *CleanupFn, const CGFunctionInfo *Info,
const VarDecl *Var)
: CleanupFn(CleanupFn), FnInfo(*Info), Var(*Var) {}
void Emit(CodeGenFunction &CGF, Flags flags) override {
DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(&Var), false,
Var.getType(), VK_LValue, SourceLocation());
// Compute the address of the local variable, in case it's a byref
// or something.
llvm::Value *Addr = CGF.EmitDeclRefLValue(&DRE).getPointer(CGF);
// In some cases, the type of the function argument will be different from
// the type of the pointer. An example of this is
// void f(void* arg);
// __attribute__((cleanup(f))) void *g;
//
// To fix this we insert a bitcast here.
QualType ArgTy = FnInfo.arg_begin()->type;
llvm::Value *Arg =
CGF.Builder.CreateBitCast(Addr, CGF.ConvertType(ArgTy));
CallArgList Args;
Args.add(RValue::get(Arg),
CGF.getContext().getPointerType(Var.getType()));
auto Callee = CGCallee::forDirect(CleanupFn);
CGF.EmitCall(FnInfo, Callee, ReturnValueSlot(), Args);
}
};
} // end anonymous namespace
/// EmitAutoVarWithLifetime - Does the setup required for an automatic
/// variable with lifetime.
static void EmitAutoVarWithLifetime(CodeGenFunction &CGF, const VarDecl &var,
Address addr,
Qualifiers::ObjCLifetime lifetime) {
switch (lifetime) {
case Qualifiers::OCL_None:
llvm_unreachable("present but none");
case Qualifiers::OCL_ExplicitNone:
// nothing to do
break;
case Qualifiers::OCL_Strong: {
CodeGenFunction::Destroyer *destroyer =
(var.hasAttr<ObjCPreciseLifetimeAttr>()
? CodeGenFunction::destroyARCStrongPrecise
: CodeGenFunction::destroyARCStrongImprecise);
CleanupKind cleanupKind = CGF.getARCCleanupKind();
CGF.pushDestroy(cleanupKind, addr, var.getType(), destroyer,
cleanupKind & EHCleanup);
break;
}
case Qualifiers::OCL_Autoreleasing:
// nothing to do
break;
case Qualifiers::OCL_Weak:
// __weak objects always get EH cleanups; otherwise, exceptions
// could cause really nasty crashes instead of mere leaks.
CGF.pushDestroy(NormalAndEHCleanup, addr, var.getType(),
CodeGenFunction::destroyARCWeak,
/*useEHCleanup*/ true);
break;
}
}
static bool isAccessedBy(const VarDecl &var, const Stmt *s) {
if (const Expr *e = dyn_cast<Expr>(s)) {
// Skip the most common kinds of expressions that make
// hierarchy-walking expensive.
s = e = e->IgnoreParenCasts();
if (const DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e))
return (ref->getDecl() == &var);
if (const BlockExpr *be = dyn_cast<BlockExpr>(e)) {
const BlockDecl *block = be->getBlockDecl();
for (const auto &I : block->captures()) {
if (I.getVariable() == &var)
return true;
}
}
}
for (const Stmt *SubStmt : s->children())
// SubStmt might be null; as in missing decl or conditional of an if-stmt.
if (SubStmt && isAccessedBy(var, SubStmt))
return true;
return false;
}
static bool isAccessedBy(const ValueDecl *decl, const Expr *e) {
if (!decl) return false;
if (!isa<VarDecl>(decl)) return false;
const VarDecl *var = cast<VarDecl>(decl);
return isAccessedBy(*var, e);
}
static bool tryEmitARCCopyWeakInit(CodeGenFunction &CGF,
const LValue &destLV, const Expr *init) {
bool needsCast = false;
while (auto castExpr = dyn_cast<CastExpr>(init->IgnoreParens())) {
switch (castExpr->getCastKind()) {
// Look through casts that don't require representation changes.
case CK_NoOp:
case CK_BitCast:
case CK_BlockPointerToObjCPointerCast:
needsCast = true;
break;
// If we find an l-value to r-value cast from a __weak variable,
// emit this operation as a copy or move.
case CK_LValueToRValue: {
const Expr *srcExpr = castExpr->getSubExpr();
if (srcExpr->getType().getObjCLifetime() != Qualifiers::OCL_Weak)
return false;
// Emit the source l-value.
LValue srcLV = CGF.EmitLValue(srcExpr);
// Handle a formal type change to avoid asserting.
auto srcAddr = srcLV.getAddress(CGF);
if (needsCast) {
srcAddr = CGF.Builder.CreateElementBitCast(
srcAddr, destLV.getAddress(CGF).getElementType());
}
// If it was an l-value, use objc_copyWeak.
if (srcExpr->getValueKind() == VK_LValue) {
CGF.EmitARCCopyWeak(destLV.getAddress(CGF), srcAddr);
} else {
assert(srcExpr->getValueKind() == VK_XValue);
CGF.EmitARCMoveWeak(destLV.getAddress(CGF), srcAddr);
}
return true;
}
// Stop at anything else.
default:
return false;
}
init = castExpr->getSubExpr();
}
return false;
}
static void drillIntoBlockVariable(CodeGenFunction &CGF,
LValue &lvalue,
const VarDecl *var) {
lvalue.setAddress(CGF.emitBlockByrefAddress(lvalue.getAddress(CGF), var));
}
void CodeGenFunction::EmitNullabilityCheck(LValue LHS, llvm::Value *RHS,
SourceLocation Loc) {
if (!SanOpts.has(SanitizerKind::NullabilityAssign))
return;
auto Nullability = LHS.getType()->getNullability(getContext());
if (!Nullability || *Nullability != NullabilityKind::NonNull)
return;
// Check if the right hand side of the assignment is nonnull, if the left
// hand side must be nonnull.
SanitizerScope SanScope(this);
llvm::Value *IsNotNull = Builder.CreateIsNotNull(RHS);
llvm::Constant *StaticData[] = {
EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(LHS.getType()),
llvm::ConstantInt::get(Int8Ty, 0), // The LogAlignment info is unused.
llvm::ConstantInt::get(Int8Ty, TCK_NonnullAssign)};
EmitCheck({{IsNotNull, SanitizerKind::NullabilityAssign}},
SanitizerHandler::TypeMismatch, StaticData, RHS);
}
void CodeGenFunction::EmitScalarInit(const Expr *init, const ValueDecl *D,
LValue lvalue, bool capturedByInit) {
Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
if (!lifetime) {
llvm::Value *value = EmitScalarExpr(init);
if (capturedByInit)
drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
EmitNullabilityCheck(lvalue, value, init->getExprLoc());
EmitStoreThroughLValue(RValue::get(value), lvalue, true);
return;
}
if (const CXXDefaultInitExpr *DIE = dyn_cast<CXXDefaultInitExpr>(init))
init = DIE->getExpr();
// If we're emitting a value with lifetime, we have to do the
// initialization *before* we leave the cleanup scopes.
if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(init))
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(*this),
cast<VarDecl>(D),
/*follow*/ false));
}
auto ty =
cast<llvm::PointerType>(tempLV.getAddress(*this).getElementType());
llvm::Value *zero = CGM.getNullPointer(ty, tempLV.getType());
// If __weak, we want to use a barrier under certain conditions.
if (lifetime == Qualifiers::OCL_Weak)
EmitARCInitWeak(tempLV.getAddress(*this), zero);
// Otherwise just do a simple store.
else
EmitStoreOfScalar(zero, tempLV, /* isInitialization */ true);
}
// Emit the initializer.
llvm::Value *value = nullptr;
switch (lifetime) {
case Qualifiers::OCL_None:
llvm_unreachable("present but none");
case Qualifiers::OCL_Strong: {
if (!D || !isa<VarDecl>(D) || !cast<VarDecl>(D)->isARCPseudoStrong()) {
value = EmitARCRetainScalarExpr(init);
break;
}
// If D is pseudo-strong, treat it like __unsafe_unretained here. This means
// that we omit the retain, and causes non-autoreleased return values to be
// immediately released.
LLVM_FALLTHROUGH;
}
case Qualifiers::OCL_ExplicitNone:
value = EmitARCUnsafeUnretainedScalarExpr(init);
break;
case Qualifiers::OCL_Weak: {
// If it's not accessed by the initializer, try to emit the
// initialization with a copy or move.
if (!accessedByInit && tryEmitARCCopyWeakInit(*this, lvalue, init)) {
return;
}
// No way to optimize a producing initializer into this. It's not
// worth optimizing for, because the value will immediately
// disappear in the common case.
value = EmitScalarExpr(init);
if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
if (accessedByInit)
EmitARCStoreWeak(lvalue.getAddress(*this), value, /*ignored*/ true);
else
EmitARCInitWeak(lvalue.getAddress(*this), value);
return;
}
case Qualifiers::OCL_Autoreleasing:
value = EmitARCRetainAutoreleaseScalarExpr(init);
break;
}
if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
EmitNullabilityCheck(lvalue, value, init->getExprLoc());
// If the variable might have been accessed by its initializer, we
// might have to initialize with a barrier. We have to do this for
// both __weak and __strong, but __weak got filtered out above.
if (accessedByInit && lifetime == Qualifiers::OCL_Strong) {
llvm::Value *oldValue = EmitLoadOfScalar(lvalue, init->getExprLoc());
EmitStoreOfScalar(value, lvalue, /* isInitialization */ true);
EmitARCRelease(oldValue, ARCImpreciseLifetime);
return;
}
EmitStoreOfScalar(value, lvalue, /* isInitialization */ true);
}
/// Decide whether we can emit the non-zero parts of the specified initializer
/// with equal or fewer than NumStores scalar stores.
static bool canEmitInitWithFewStoresAfterBZero(llvm::Constant *Init,
unsigned &NumStores) {
// Zero and Undef never requires any extra stores.
if (isa<llvm::ConstantAggregateZero>(Init) ||
isa<llvm::ConstantPointerNull>(Init) ||
isa<llvm::UndefValue>(Init))
return true;
if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) ||
isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) ||
isa<llvm::ConstantExpr>(Init))
return Init->isNullValue() || NumStores--;
// See if we can emit each element.
if (isa<llvm::ConstantArray>(Init) || isa<llvm::ConstantStruct>(Init)) {
for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i));
if (!canEmitInitWithFewStoresAfterBZero(Elt, NumStores))
return false;
}
return true;
}
if (llvm::ConstantDataSequential *CDS =
dyn_cast<llvm::ConstantDataSequential>(Init)) {
for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
llvm::Constant *Elt = CDS->getElementAsConstant(i);
if (!canEmitInitWithFewStoresAfterBZero(Elt, NumStores))
return false;
}
return true;
}
// Anything else is hard and scary.
return false;
}
/// For inits that canEmitInitWithFewStoresAfterBZero returned true for, emit
/// the scalar stores that would be required.
static void emitStoresForInitAfterBZero(CodeGenModule &CGM,
llvm::Constant *Init, Address Loc,
bool isVolatile, CGBuilderTy &Builder,
bool IsAutoInit) {
assert(!Init->isNullValue() && !isa<llvm::UndefValue>(Init) &&
"called emitStoresForInitAfterBZero for zero or undef value.");
if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) ||
isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) ||
isa<llvm::ConstantExpr>(Init)) {
auto *I = Builder.CreateStore(Init, Loc, isVolatile);
if (IsAutoInit)
I->addAnnotationMetadata("auto-init");
return;
}
if (llvm::ConstantDataSequential *CDS =
dyn_cast<llvm::ConstantDataSequential>(Init)) {
for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
llvm::Constant *Elt = CDS->getElementAsConstant(i);
// If necessary, get a pointer to the element and emit it.
if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Elt))
emitStoresForInitAfterBZero(
CGM, Elt, Builder.CreateConstInBoundsGEP2_32(Loc, 0, i), isVolatile,
Builder, IsAutoInit);
}
return;
}
assert((isa<llvm::ConstantStruct>(Init) || isa<llvm::ConstantArray>(Init)) &&
"Unknown value type!");
for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i));
// If necessary, get a pointer to the element and emit it.
if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Elt))
emitStoresForInitAfterBZero(CGM, Elt,
Builder.CreateConstInBoundsGEP2_32(Loc, 0, i),
isVolatile, Builder, IsAutoInit);
}
}
/// Decide whether we should use bzero plus some stores to initialize a local
/// variable instead of using a memcpy from a constant global. It is beneficial
/// to use bzero if the global is all zeros, or mostly zeros and large.
static bool shouldUseBZeroPlusStoresToInitialize(llvm::Constant *Init,
uint64_t GlobalSize) {
// If a global is all zeros, always use a bzero.
if (isa<llvm::ConstantAggregateZero>(Init)) return true;
// If a non-zero global is <= 32 bytes, always use a memcpy. If it is large,
// do it if it will require 6 or fewer scalar stores.
// TODO: Should budget depends on the size? Avoiding a large global warrants
// plopping in more stores.
unsigned StoreBudget = 6;
uint64_t SizeLimit = 32;
return GlobalSize > SizeLimit &&
canEmitInitWithFewStoresAfterBZero(Init, StoreBudget);
}
/// Decide whether we should use memset to initialize a local variable instead
/// of using a memcpy from a constant global. Assumes we've already decided to
/// not user bzero.
/// FIXME We could be more clever, as we are for bzero above, and generate
/// memset followed by stores. It's unclear that's worth the effort.
static llvm::Value *shouldUseMemSetToInitialize(llvm::Constant *Init,
uint64_t GlobalSize,
const llvm::DataLayout &DL) {
uint64_t SizeLimit = 32;
if (GlobalSize <= SizeLimit)
return nullptr;
return llvm::isBytewiseValue(Init, DL);
}
/// Decide whether we want to split a constant structure or array store into a
/// sequence of its fields' stores. This may cost us code size and compilation
/// speed, but plays better with store optimizations.
static bool shouldSplitConstantStore(CodeGenModule &CGM,
uint64_t GlobalByteSize) {
// Don't break things that occupy more than one cacheline.
uint64_t ByteSizeLimit = 64;
if (CGM.getCodeGenOpts().OptimizationLevel == 0)
return false;
if (GlobalByteSize <= ByteSizeLimit)
return true;
return false;
}
enum class IsPattern { No, Yes };
/// Generate a constant filled with either a pattern or zeroes.
static llvm::Constant *patternOrZeroFor(CodeGenModule &CGM, IsPattern isPattern,
llvm::Type *Ty) {
if (isPattern == IsPattern::Yes)
return initializationPatternFor(CGM, Ty);
else
return llvm::Constant::getNullValue(Ty);
}
static llvm::Constant *constWithPadding(CodeGenModule &CGM, IsPattern isPattern,
llvm::Constant *constant);
/// Helper function for constWithPadding() to deal with padding in structures.
static llvm::Constant *constStructWithPadding(CodeGenModule &CGM,
IsPattern isPattern,
llvm::StructType *STy,
llvm::Constant *constant) {
const llvm::DataLayout &DL = CGM.getDataLayout();
const llvm::StructLayout *Layout = DL.getStructLayout(STy);
llvm::Type *Int8Ty = llvm::IntegerType::getInt8Ty(CGM.getLLVMContext());
unsigned SizeSoFar = 0;
SmallVector<llvm::Constant *, 8> Values;
bool NestedIntact = true;
for (unsigned i = 0, e = STy->getNumElements(); i != e; i++) {
unsigned CurOff = Layout->getElementOffset(i);
if (SizeSoFar < CurOff) {
assert(!STy->isPacked());
auto *PadTy = llvm::ArrayType::get(Int8Ty, CurOff - SizeSoFar);
Values.push_back(patternOrZeroFor(CGM, isPattern, PadTy));
}
llvm::Constant *CurOp;
if (constant->isZeroValue())
CurOp = llvm::Constant::getNullValue(STy->getElementType(i));
else
CurOp = cast<llvm::Constant>(constant->getAggregateElement(i));
auto *NewOp = constWithPadding(CGM, isPattern, CurOp);
if (CurOp != NewOp)
NestedIntact = false;
Values.push_back(NewOp);
SizeSoFar = CurOff + DL.getTypeAllocSize(CurOp->getType());
}
unsigned TotalSize = Layout->getSizeInBytes();
if (SizeSoFar < TotalSize) {
auto *PadTy = llvm::ArrayType::get(Int8Ty, TotalSize - SizeSoFar);
Values.push_back(patternOrZeroFor(CGM, isPattern, PadTy));
}
if (NestedIntact && Values.size() == STy->getNumElements())
return constant;
return llvm::ConstantStruct::getAnon(Values, STy->isPacked());
}
/// Replace all padding bytes in a given constant with either a pattern byte or
/// 0x00.
static llvm::Constant *constWithPadding(CodeGenModule &CGM, IsPattern isPattern,
llvm::Constant *constant) {
llvm::Type *OrigTy = constant->getType();
if (const auto STy = dyn_cast<llvm::StructType>(OrigTy))
return constStructWithPadding(CGM, isPattern, STy, constant);
if (auto *ArrayTy = dyn_cast<llvm::ArrayType>(OrigTy)) {
llvm::SmallVector<llvm::Constant *, 8> Values;
uint64_t Size = ArrayTy->getNumElements();
if (!Size)
return constant;
llvm::Type *ElemTy = ArrayTy->getElementType();
bool ZeroInitializer = constant->isNullValue();
llvm::Constant *OpValue, *PaddedOp;
if (ZeroInitializer) {
OpValue = llvm::Constant::getNullValue(ElemTy);
PaddedOp = constWithPadding(CGM, isPattern, OpValue);
}
for (unsigned Op = 0; Op != Size; ++Op) {
if (!ZeroInitializer) {
OpValue = constant->getAggregateElement(Op);
PaddedOp = constWithPadding(CGM, isPattern, OpValue);
}
Values.push_back(PaddedOp);
}
auto *NewElemTy = Values[0]->getType();
if (NewElemTy == ElemTy)
return constant;
auto *NewArrayTy = llvm::ArrayType::get(NewElemTy, Size);
return llvm::ConstantArray::get(NewArrayTy, Values);
}
// FIXME: Add handling for tail padding in vectors. Vectors don't
// have padding between or inside elements, but the total amount of
// data can be less than the allocated size.
return constant;
}
Address CodeGenModule::createUnnamedGlobalFrom(const VarDecl &D,
llvm::Constant *Constant,
CharUnits Align) {
auto FunctionName = [&](const DeclContext *DC) -> std::string {
if (const auto *FD = dyn_cast<FunctionDecl>(DC)) {
if (const auto *CC = dyn_cast<CXXConstructorDecl>(FD))
return CC->getNameAsString();
if (const auto *CD = dyn_cast<CXXDestructorDecl>(FD))
return CD->getNameAsString();
return std::string(getMangledName(FD));
} else if (const auto *OM = dyn_cast<ObjCMethodDecl>(DC)) {
return OM->getNameAsString();
} else if (isa<BlockDecl>(DC)) {
return "<block>";
} else if (isa<CapturedDecl>(DC)) {
return "<captured>";
} else {
llvm_unreachable("expected a function or method");
}
};
// Form a simple per-variable cache of these values in case we find we
// want to reuse them.
llvm::GlobalVariable *&CacheEntry = InitializerConstants[&D];
if (!CacheEntry || CacheEntry->getInitializer() != Constant) {
auto *Ty = Constant->getType();
bool isConstant = true;
llvm::GlobalVariable *InsertBefore = nullptr;
unsigned AS =
getContext().getTargetAddressSpace(GetGlobalConstantAddressSpace());
std::string Name;
if (D.hasGlobalStorage())
Name = getMangledName(&D).str() + ".const";
else if (const DeclContext *DC = D.getParentFunctionOrMethod())
Name = ("__const." + FunctionName(DC) + "." + D.getName()).str();
else
llvm_unreachable("local variable has no parent function or method");
llvm::GlobalVariable *GV = new llvm::GlobalVariable(
getModule(), Ty, isConstant, llvm::GlobalValue::PrivateLinkage,
Constant, Name, InsertBefore, llvm::GlobalValue::NotThreadLocal, AS);
GV->setAlignment(Align.getAsAlign());
GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
CacheEntry = GV;
} else if (CacheEntry->getAlignment() < Align.getQuantity()) {
CacheEntry->setAlignment(Align.getAsAlign());
}
return Address(CacheEntry, Align);
}
static Address createUnnamedGlobalForMemcpyFrom(CodeGenModule &CGM,
const VarDecl &D,
CGBuilderTy &Builder,
llvm::Constant *Constant,
CharUnits Align) {
Address SrcPtr = CGM.createUnnamedGlobalFrom(D, Constant, Align);
llvm::Type *BP = llvm::PointerType::getInt8PtrTy(CGM.getLLVMContext(),
SrcPtr.getAddressSpace());
if (SrcPtr.getType() != BP)
SrcPtr = Builder.CreateBitCast(SrcPtr, BP);
return SrcPtr;
}
static void emitStoresForConstant(CodeGenModule &CGM, const VarDecl &D,
Address Loc, bool isVolatile,
CGBuilderTy &Builder,
llvm::Constant *constant, bool IsAutoInit) {
auto *Ty = constant->getType();
uint64_t ConstantSize = CGM.getDataLayout().getTypeAllocSize(Ty);
if (!ConstantSize)
return;
bool canDoSingleStore = Ty->isIntOrIntVectorTy() ||
Ty->isPtrOrPtrVectorTy() || Ty->isFPOrFPVectorTy();
if (canDoSingleStore) {
auto *I = Builder.CreateStore(constant, Loc, isVolatile);
if (IsAutoInit)
I->addAnnotationMetadata("auto-init");
return;
}
auto *SizeVal = llvm::ConstantInt::get(CGM.IntPtrTy, ConstantSize);
// If the initializer is all or mostly the same, codegen with bzero / memset
// then do a few stores afterward.
if (shouldUseBZeroPlusStoresToInitialize(constant, ConstantSize)) {
auto *I = Builder.CreateMemSet(Loc, llvm::ConstantInt::get(CGM.Int8Ty, 0),
SizeVal, isVolatile);
if (IsAutoInit)
I->addAnnotationMetadata("auto-init");
bool valueAlreadyCorrect =
constant->isNullValue() || isa<llvm::UndefValue>(constant);
if (!valueAlreadyCorrect) {
Loc = Builder.CreateBitCast(Loc, Ty->getPointerTo(Loc.getAddressSpace()));
emitStoresForInitAfterBZero(CGM, constant, Loc, isVolatile, Builder,
IsAutoInit);
}
return;
}
// If the initializer is a repeated byte pattern, use memset.
llvm::Value *Pattern =
shouldUseMemSetToInitialize(constant, ConstantSize, CGM.getDataLayout());
if (Pattern) {
uint64_t Value = 0x00;
if (!isa<llvm::UndefValue>(Pattern)) {
const llvm::APInt &AP = cast<llvm::ConstantInt>(Pattern)->getValue();
assert(AP.getBitWidth() <= 8);
Value = AP.getLimitedValue();
}
auto *I = Builder.CreateMemSet(
Loc, llvm::ConstantInt::get(CGM.Int8Ty, Value), SizeVal, isVolatile);
if (IsAutoInit)
I->addAnnotationMetadata("auto-init");
return;
}
// If the initializer is small, use a handful of stores.
if (shouldSplitConstantStore(CGM, ConstantSize)) {
if (auto *STy = dyn_cast<llvm::StructType>(Ty)) {
// FIXME: handle the case when STy != Loc.getElementType().
if (STy == Loc.getElementType()) {
for (unsigned i = 0; i != constant->getNumOperands(); i++) {
Address EltPtr = Builder.CreateStructGEP(Loc, i);
emitStoresForConstant(
CGM, D, EltPtr, isVolatile, Builder,
cast<llvm::Constant>(Builder.CreateExtractValue(constant, i)),
IsAutoInit);
}
return;
}
} else if (auto *ATy = dyn_cast<llvm::ArrayType>(Ty)) {
// FIXME: handle the case when ATy != Loc.getElementType().
if (ATy == Loc.getElementType()) {
for (unsigned i = 0; i != ATy->getNumElements(); i++) {
Address EltPtr = Builder.CreateConstArrayGEP(Loc, i);
emitStoresForConstant(
CGM, D, EltPtr, isVolatile, Builder,
cast<llvm::Constant>(Builder.CreateExtractValue(constant, i)),
IsAutoInit);
}
return;
}
}
}
// Copy from a global.
auto *I =
Builder.CreateMemCpy(Loc,
createUnnamedGlobalForMemcpyFrom(
CGM, D, Builder, constant, Loc.getAlignment()),
SizeVal, isVolatile);
if (IsAutoInit)
I->addAnnotationMetadata("auto-init");
}
static void emitStoresForZeroInit(CodeGenModule &CGM, const VarDecl &D,
Address Loc, bool isVolatile,
CGBuilderTy &Builder) {
llvm::Type *ElTy = Loc.getElementType();
llvm::Constant *constant =
constWithPadding(CGM, IsPattern::No, llvm::Constant::getNullValue(ElTy));
emitStoresForConstant(CGM, D, Loc, isVolatile, Builder, constant,
/*IsAutoInit=*/true);
}
static void emitStoresForPatternInit(CodeGenModule &CGM, const VarDecl &D,
Address Loc, bool isVolatile,
CGBuilderTy &Builder) {
llvm::Type *ElTy = Loc.getElementType();
llvm::Constant *constant = constWithPadding(
CGM, IsPattern::Yes, initializationPatternFor(CGM, ElTy));
assert(!isa<llvm::UndefValue>(constant));
emitStoresForConstant(CGM, D, Loc, isVolatile, Builder, constant,
/*IsAutoInit=*/true);
}
static bool containsUndef(llvm::Constant *constant) {
auto *Ty = constant->getType();
if (isa<llvm::UndefValue>(constant))
return true;
if (Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy())
for (llvm::Use &Op : constant->operands())
if (containsUndef(cast<llvm::Constant>(Op)))
return true;
return false;
}
static llvm::Constant *replaceUndef(CodeGenModule &CGM, IsPattern isPattern,
llvm::Constant *constant) {
auto *Ty = constant->getType();
if (isa<llvm::UndefValue>(constant))
return patternOrZeroFor(CGM, isPattern, Ty);
if (!(Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()))
return constant;
if (!containsUndef(constant))
return constant;
llvm::SmallVector<llvm::Constant *, 8> Values(constant->getNumOperands());
for (unsigned Op = 0, NumOp = constant->getNumOperands(); Op != NumOp; ++Op) {
auto *OpValue = cast<llvm::Constant>(constant->getOperand(Op));
Values[Op] = replaceUndef(CGM, isPattern, OpValue);
}
if (Ty->isStructTy())
return llvm::ConstantStruct::get(cast<llvm::StructType>(Ty), Values);
if (Ty->isArrayTy())
return llvm::ConstantArray::get(cast<llvm::ArrayType>(Ty), Values);
assert(Ty->isVectorTy());
return llvm::ConstantVector::get(Values);
}
/// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a
/// variable declaration with auto, register, or no storage class specifier.
/// These turn into simple stack objects, or GlobalValues depending on target.
void CodeGenFunction::EmitAutoVarDecl(const VarDecl &D) {
AutoVarEmission emission = EmitAutoVarAlloca(D);
EmitAutoVarInit(emission);
EmitAutoVarCleanups(emission);
}
/// Emit a lifetime.begin marker if some criteria are satisfied.
/// \return a pointer to the temporary size Value if a marker was emitted, null
/// otherwise
llvm::Value *CodeGenFunction::EmitLifetimeStart(uint64_t Size,
llvm::Value *Addr) {
if (!ShouldEmitLifetimeMarkers)
return nullptr;
assert(Addr->getType()->getPointerAddressSpace() ==
CGM.getDataLayout().getAllocaAddrSpace() &&
"Pointer should be in alloca address space");
llvm::Value *SizeV = llvm::ConstantInt::get(Int64Ty, Size);
Addr = Builder.CreateBitCast(Addr, AllocaInt8PtrTy);
llvm::CallInst *C =
Builder.CreateCall(CGM.getLLVMLifetimeStartFn(), {SizeV, Addr});
C->setDoesNotThrow();
return SizeV;
}
void CodeGenFunction::EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr) {
assert(Addr->getType()->getPointerAddressSpace() ==
CGM.getDataLayout().getAllocaAddrSpace() &&
"Pointer should be in alloca address space");
Addr = Builder.CreateBitCast(Addr, AllocaInt8PtrTy);
llvm::CallInst *C =
Builder.CreateCall(CGM.getLLVMLifetimeEndFn(), {Size, Addr});
C->setDoesNotThrow();
}
void CodeGenFunction::EmitAndRegisterVariableArrayDimensions(
CGDebugInfo *DI, const VarDecl &D, bool EmitDebugInfo) {
// For each dimension stores its QualType and corresponding
// size-expression Value.
SmallVector<CodeGenFunction::VlaSizePair, 4> Dimensions;
SmallVector<IdentifierInfo *, 4> VLAExprNames;
// Break down the array into individual dimensions.
QualType Type1D = D.getType();
while (getContext().getAsVariableArrayType(Type1D)) {
auto VlaSize = getVLAElements1D(Type1D);
if (auto *C = dyn_cast<llvm::ConstantInt>(VlaSize.NumElts))
Dimensions.emplace_back(C, Type1D.getUnqualifiedType());
else {
// Generate a locally unique name for the size expression.
Twine Name = Twine("__vla_expr") + Twine(VLAExprCounter++);
SmallString<12> Buffer;
StringRef NameRef = Name.toStringRef(Buffer);
auto &Ident = getContext().Idents.getOwn(NameRef);
VLAExprNames.push_back(&Ident);
auto SizeExprAddr =
CreateDefaultAlignTempAlloca(VlaSize.NumElts->getType(), NameRef);
Builder.CreateStore(VlaSize.NumElts, SizeExprAddr);
Dimensions.emplace_back(SizeExprAddr.getPointer(),
Type1D.getUnqualifiedType());
}
Type1D = VlaSize.Type;
}
if (!EmitDebugInfo)
return;
// Register each dimension's size-expression with a DILocalVariable,
// so that it can be used by CGDebugInfo when instantiating a DISubrange
// to describe this array.
unsigned NameIdx = 0;
for (auto &VlaSize : Dimensions) {
llvm::Metadata *MD;
if (auto *C = dyn_cast<llvm::ConstantInt>(VlaSize.NumElts))
MD = llvm::ConstantAsMetadata::get(C);
else {
// Create an artificial VarDecl to generate debug info for.
IdentifierInfo *NameIdent = VLAExprNames[NameIdx++];
auto VlaExprTy = VlaSize.NumElts->getType()->getPointerElementType();
auto QT = getContext().getIntTypeForBitwidth(
VlaExprTy->getScalarSizeInBits(), false);
auto *ArtificialDecl = VarDecl::Create(
getContext(), const_cast<DeclContext *>(D.getDeclContext()),
D.getLocation(), D.getLocation(), NameIdent, QT,
getContext().CreateTypeSourceInfo(QT), SC_Auto);
ArtificialDecl->setImplicit();
MD = DI->EmitDeclareOfAutoVariable(ArtificialDecl, VlaSize.NumElts,
Builder);
}
assert(MD && "No Size expression debug node created");
DI->registerVLASizeExpression(VlaSize.Type, MD);
}
}
/// EmitAutoVarAlloca - Emit the alloca and debug information for a
/// local variable. Does not emit initialization or destruction.
CodeGenFunction::AutoVarEmission
CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) {
QualType Ty = D.getType();
assert(
Ty.getAddressSpace() == LangAS::Default ||
(Ty.getAddressSpace() == LangAS::opencl_private && getLangOpts().OpenCL));
AutoVarEmission emission(D);
bool isEscapingByRef = D.isEscapingByref();
emission.IsEscapingByRef = isEscapingByRef;
CharUnits alignment = getContext().getDeclAlign(&D);
// If the type is variably-modified, emit all the VLA sizes for it.
if (Ty->isVariablyModifiedType())
EmitVariablyModifiedType(Ty);
auto *DI = getDebugInfo();
bool EmitDebugInfo = DI && CGM.getCodeGenOpts().hasReducedDebugInfo();
Address address = Address::invalid();
Address AllocaAddr = Address::invalid();
Address OpenMPLocalAddr = Address::invalid();
if (CGM.getLangOpts().OpenMPIRBuilder)
OpenMPLocalAddr = OMPBuilderCBHelpers::getAddressOfLocalVariable(*this, &D);
else
OpenMPLocalAddr =
getLangOpts().OpenMP
? CGM.getOpenMPRuntime().getAddressOfLocalVariable(*this, &D)
: Address::invalid();
bool NRVO = getLangOpts().ElideConstructors && D.isNRVOVariable();
if (getLangOpts().OpenMP && OpenMPLocalAddr.isValid()) {
address = OpenMPLocalAddr;
} else if (Ty->isConstantSizeType()) {
// If this value is an array or struct with a statically determinable
// constant initializer, there are optimizations we can do.
//
// TODO: We should constant-evaluate the initializer of any variable,
// as long as it is initialized by a constant expression. Currently,
// isConstantInitializer produces wrong answers for structs with
// reference or bitfield members, and a few other cases, and checking
// for POD-ness protects us from some of these.
if (D.getInit() && (Ty->isArrayType() || Ty->isRecordType()) &&
(D.isConstexpr() ||
((Ty.isPODType(getContext()) ||
getContext().getBaseElementType(Ty)->isObjCObjectPointerType()) &&
D.getInit()->isConstantInitializer(getContext(), false)))) {
// If the variable's a const type, and it's neither an NRVO
// candidate nor a __block variable and has no mutable members,
// emit it as a global instead.
// Exception is if a variable is located in non-constant address space
// in OpenCL.
if ((!getLangOpts().OpenCL ||
Ty.getAddressSpace() == LangAS::opencl_constant) &&
(CGM.getCodeGenOpts().MergeAllConstants && !NRVO &&
!isEscapingByRef && CGM.isTypeConstant(Ty, true))) {
EmitStaticVarDecl(D, llvm::GlobalValue::InternalLinkage);
// Signal this condition to later callbacks.
emission.Addr = Address::invalid();
assert(emission.wasEmittedAsGlobal());
return emission;
}
// Otherwise, tell the initialization code that we're in this case.
emission.IsConstantAggregate = true;
}
// A normal fixed sized variable becomes an alloca in the entry block,
// unless:
// - it's an NRVO variable.
// - we are compiling OpenMP and it's an OpenMP local variable.
if (NRVO) {
// The named return value optimization: allocate this variable in the
// return slot, so that we can elide the copy when returning this
// variable (C++0x [class.copy]p34).
address = ReturnValue;
if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
const auto *RD = RecordTy->getDecl();
const auto *CXXRD = dyn_cast<CXXRecordDecl>(RD);
if ((CXXRD && !CXXRD->hasTrivialDestructor()) ||
RD->isNonTrivialToPrimitiveDestroy()) {
// Create a flag that is used to indicate when the NRVO was applied
// to this variable. Set it to zero to indicate that NRVO was not
// applied.
llvm::Value *Zero = Builder.getFalse();
Address NRVOFlag =
CreateTempAlloca(Zero->getType(), CharUnits::One(), "nrvo");
EnsureInsertPoint();
Builder.CreateStore(Zero, NRVOFlag);
// Record the NRVO flag for this variable.
NRVOFlags[&D] = NRVOFlag.getPointer();
emission.NRVOFlag = NRVOFlag.getPointer();
}
}
} else {
CharUnits allocaAlignment;
llvm::Type *allocaTy;
if (isEscapingByRef) {
auto &byrefInfo = getBlockByrefInfo(&D);
allocaTy = byrefInfo.Type;
allocaAlignment = byrefInfo.ByrefAlignment;
} else {
allocaTy = ConvertTypeForMem(Ty);
allocaAlignment = alignment;
}
// Create the alloca. Note that we set the name separately from
// building the instruction so that it's there even in no-asserts
// builds.
address = CreateTempAlloca(allocaTy, allocaAlignment, D.getName(),
/*ArraySize=*/nullptr, &AllocaAddr);
// Don't emit lifetime markers for MSVC catch parameters. The lifetime of
// the catch parameter starts in the catchpad instruction, and we can't
// insert code in those basic blocks.
bool IsMSCatchParam =
D.isExceptionVariable() && getTarget().getCXXABI().isMicrosoft();
// Emit a lifetime intrinsic if meaningful. There's no point in doing this
// if we don't have a valid insertion point (?).
if (HaveInsertPoint() && !IsMSCatchParam) {
// If there's a jump into the lifetime of this variable, its lifetime
// gets broken up into several regions in IR, which requires more work
// to handle correctly. For now, just omit the intrinsics; this is a
// rare case, and it's better to just be conservatively correct.
// PR28267.
//
// We have to do this in all language modes if there's a jump past the
// declaration. We also have to do it in C if there's a jump to an
// earlier point in the current block because non-VLA lifetimes begin as
// soon as the containing block is entered, not when its variables
// actually come into scope; suppressing the lifetime annotations
// completely in this case is unnecessarily pessimistic, but again, this
// is rare.
if (!Bypasses.IsBypassed(&D) &&
!(!getLangOpts().CPlusPlus && hasLabelBeenSeenInCurrentScope())) {
llvm::TypeSize size =
CGM.getDataLayout().getTypeAllocSize(allocaTy);
emission.SizeForLifetimeMarkers =
size.isScalable() ? EmitLifetimeStart(-1, AllocaAddr.getPointer())
: EmitLifetimeStart(size.getFixedSize(),
AllocaAddr.getPointer());
}
} else {
assert(!emission.useLifetimeMarkers());
}
}
} else {
EnsureInsertPoint();
if (!DidCallStackSave) {
// Save the stack.
Address Stack =
CreateTempAlloca(Int8PtrTy, getPointerAlign(), "saved_stack");
llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave);
llvm::Value *V = Builder.CreateCall(F);
Builder.CreateStore(V, Stack);
DidCallStackSave = true;
// Push a cleanup block and restore the stack there.
// FIXME: in general circumstances, this should be an EH cleanup.
pushStackRestore(NormalCleanup, Stack);
}
auto VlaSize = getVLASize(Ty);
llvm::Type *llvmTy = ConvertTypeForMem(VlaSize.Type);
// Allocate memory for the array.
address = CreateTempAlloca(llvmTy, alignment, "vla", VlaSize.NumElts,
&AllocaAddr);
// If we have debug info enabled, properly describe the VLA dimensions for
// this type by registering the vla size expression for each of the
// dimensions.
EmitAndRegisterVariableArrayDimensions(DI, D, EmitDebugInfo);
}
setAddrOfLocalVar(&D, address);
emission.Addr = address;
emission.AllocaAddr = AllocaAddr;
// Emit debug info for local var declaration.
if (EmitDebugInfo && HaveInsertPoint()) {
Address DebugAddr = address;
bool UsePointerValue = NRVO && ReturnValuePointer.isValid();
DI->setLocation(D.getLocation());
// If NRVO, use a pointer to the return address.
if (UsePointerValue)
DebugAddr = ReturnValuePointer;
(void)DI->EmitDeclareOfAutoVariable(&D, DebugAddr.getPointer(), Builder,
UsePointerValue);
}
if (D.hasAttr<AnnotateAttr>() && HaveInsertPoint())
EmitVarAnnotations(&D, address.getPointer());
// Make sure we call @llvm.lifetime.end.
if (emission.useLifetimeMarkers())
EHStack.pushCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker,
emission.getOriginalAllocatedAddress(),
emission.getSizeForLifetimeMarkers());
return emission;
}
static bool isCapturedBy(const VarDecl &, const Expr *);
/// Determines whether the given __block variable is potentially
/// captured by the given statement.
static bool isCapturedBy(const VarDecl &Var, const Stmt *S) {
if (const Expr *E = dyn_cast<Expr>(S))
return isCapturedBy(Var, E);
for (const Stmt *SubStmt : S->children())
if (isCapturedBy(Var, SubStmt))
return true;
return false;
}
/// Determines whether the given __block variable is potentially
/// captured by the given expression.
static bool isCapturedBy(const VarDecl &Var, const Expr *E) {
// Skip the most common kinds of expressions that make
// hierarchy-walking expensive.
E = E->IgnoreParenCasts();
if (const BlockExpr *BE = dyn_cast<BlockExpr>(E)) {
const BlockDecl *Block = BE->getBlockDecl();
for (const auto &I : Block->captures()) {
if (I.getVariable() == &Var)
return true;
}
// No need to walk into the subexpressions.
return false;
}
if (const StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
const CompoundStmt *CS = SE->getSubStmt();
for (const auto *BI : CS->body())
if (const auto *BIE = dyn_cast<Expr>(BI)) {
if (isCapturedBy(Var, BIE))
return true;
}
else if (const auto *DS = dyn_cast<DeclStmt>(BI)) {
// special case declarations
for (const auto *I : DS->decls()) {
if (const auto *VD = dyn_cast<VarDecl>((I))) {
const Expr *Init = VD->getInit();
if (Init && isCapturedBy(Var, Init))
return true;
}
}
}
else
// FIXME. Make safe assumption assuming arbitrary statements cause capturing.
// Later, provide code to poke into statements for capture analysis.
return true;
return false;
}
for (const Stmt *SubStmt : E->children())
if (isCapturedBy(Var, SubStmt))
return true;
return false;
}
/// Determine whether the given initializer is trivial in the sense
/// that it requires no code to be generated.
bool CodeGenFunction::isTrivialInitializer(const Expr *Init) {
if (!Init)
return true;
if (const CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init))
if (CXXConstructorDecl *Constructor = Construct->getConstructor())
if (Constructor->isTrivial() &&
Constructor->isDefaultConstructor() &&
!Construct->requiresZeroInitialization())
return true;
return false;
}
void CodeGenFunction::emitZeroOrPatternForAutoVarInit(QualType type,
const VarDecl &D,
Address Loc) {
auto trivialAutoVarInit = getContext().getLangOpts().getTrivialAutoVarInit();
CharUnits Size = getContext().getTypeSizeInChars(type);
bool isVolatile = type.isVolatileQualified();
if (!Size.isZero()) {
switch (trivialAutoVarInit) {
case LangOptions::TrivialAutoVarInitKind::Uninitialized:
llvm_unreachable("Uninitialized handled by caller");
case LangOptions::TrivialAutoVarInitKind::Zero:
if (CGM.stopAutoInit())
return;
emitStoresForZeroInit(CGM, D, Loc, isVolatile, Builder);
break;
case LangOptions::TrivialAutoVarInitKind::Pattern:
if (CGM.stopAutoInit())
return;
emitStoresForPatternInit(CGM, D, Loc, isVolatile, Builder);
break;
}
return;
}
// VLAs look zero-sized to getTypeInfo. We can't emit constant stores to
// them, so emit a memcpy with the VLA size to initialize each element.
// Technically zero-sized or negative-sized VLAs are undefined, and UBSan
// will catch that code, but there exists code which generates zero-sized
// VLAs. Be nice and initialize whatever they requested.
const auto *VlaType = getContext().getAsVariableArrayType(type);
if (!VlaType)
return;
auto VlaSize = getVLASize(VlaType);
auto SizeVal = VlaSize.NumElts;
CharUnits EltSize = getContext().getTypeSizeInChars(VlaSize.Type);
switch (trivialAutoVarInit) {
case LangOptions::TrivialAutoVarInitKind::Uninitialized:
llvm_unreachable("Uninitialized handled by caller");
case LangOptions::TrivialAutoVarInitKind::Zero: {
if (CGM.stopAutoInit())
return;
if (!EltSize.isOne())
SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(EltSize));
auto *I = Builder.CreateMemSet(Loc, llvm::ConstantInt::get(Int8Ty, 0),
SizeVal, isVolatile);
I->addAnnotationMetadata("auto-init");
break;
}
case LangOptions::TrivialAutoVarInitKind::Pattern: {
if (CGM.stopAutoInit())
return;
llvm::Type *ElTy = Loc.getElementType();
llvm::Constant *Constant = constWithPadding(
CGM, IsPattern::Yes, initializationPatternFor(CGM, ElTy));
CharUnits ConstantAlign = getContext().getTypeAlignInChars(VlaSize.Type);
llvm::BasicBlock *SetupBB = createBasicBlock("vla-setup.loop");
llvm::BasicBlock *LoopBB = createBasicBlock("vla-init.loop");
llvm::BasicBlock *ContBB = createBasicBlock("vla-init.cont");
llvm::Value *IsZeroSizedVLA = Builder.CreateICmpEQ(
SizeVal, llvm::ConstantInt::get(SizeVal->getType(), 0),
"vla.iszerosized");
Builder.CreateCondBr(IsZeroSizedVLA, ContBB, SetupBB);
EmitBlock(SetupBB);
if (!EltSize.isOne())
SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(EltSize));
llvm::Value *BaseSizeInChars =
llvm::ConstantInt::get(IntPtrTy, EltSize.getQuantity());
Address Begin = Builder.CreateElementBitCast(Loc, Int8Ty, "vla.begin");
llvm::Value *End = Builder.CreateInBoundsGEP(
Begin.getElementType(), Begin.getPointer(), SizeVal, "vla.end");
llvm::BasicBlock *OriginBB = Builder.GetInsertBlock();
EmitBlock(LoopBB);
llvm::PHINode *Cur = Builder.CreatePHI(Begin.getType(), 2, "vla.cur");
Cur->addIncoming(Begin.getPointer(), OriginBB);
CharUnits CurAlign = Loc.getAlignment().alignmentOfArrayElement(EltSize);
auto *I =
Builder.CreateMemCpy(Address(Cur, CurAlign),
createUnnamedGlobalForMemcpyFrom(
CGM, D, Builder, Constant, ConstantAlign),
BaseSizeInChars, isVolatile);
I->addAnnotationMetadata("auto-init");
llvm::Value *Next =
Builder.CreateInBoundsGEP(Int8Ty, Cur, BaseSizeInChars, "vla.next");
llvm::Value *Done = Builder.CreateICmpEQ(Next, End, "vla-init.isdone");
Builder.CreateCondBr(Done, ContBB, LoopBB);
Cur->addIncoming(Next, LoopBB);
EmitBlock(ContBB);
} break;
}
}
void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
assert(emission.Variable && "emission was not valid!");
// If this was emitted as a global constant, we're done.
if (emission.wasEmittedAsGlobal()) return;
const VarDecl &D = *emission.Variable;
auto DL = ApplyDebugLocation::CreateDefaultArtificial(*this, D.getLocation());
QualType type = D.getType();
// If this local has an initializer, emit it now.
const Expr *Init = D.getInit();
// If we are at an unreachable point, we don't need to emit the initializer
// unless it contains a label.
if (!HaveInsertPoint()) {
if (!Init || !ContainsLabel(Init)) return;
EnsureInsertPoint();
}
// Initialize the structure of a __block variable.
if (emission.IsEscapingByRef)
emitByrefStructureInit(emission);
// Initialize the variable here if it doesn't have a initializer and it is a
// C struct that is non-trivial to initialize or an array containing such a
// struct.
if (!Init &&
type.isNonTrivialToPrimitiveDefaultInitialize() ==
QualType::PDIK_Struct) {
LValue Dst = MakeAddrLValue(emission.getAllocatedAddress(), type);
if (emission.IsEscapingByRef)
drillIntoBlockVariable(*this, Dst, &D);
defaultInitNonTrivialCStructVar(Dst);
return;
}
// Check whether this is a byref variable that's potentially
// captured and moved by its own initializer. If so, we'll need to
// emit the initializer first, then copy into the variable.
bool capturedByInit =
Init && emission.IsEscapingByRef && isCapturedBy(D, Init);
bool locIsByrefHeader = !capturedByInit;
const Address Loc =
locIsByrefHeader ? emission.getObjectAddress(*this) : emission.Addr;
// Note: constexpr already initializes everything correctly.
LangOptions::TrivialAutoVarInitKind trivialAutoVarInit =
(D.isConstexpr()
? LangOptions::TrivialAutoVarInitKind::Uninitialized
: (D.getAttr<UninitializedAttr>()
? LangOptions::TrivialAutoVarInitKind::Uninitialized
: getContext().getLangOpts().getTrivialAutoVarInit()));
auto initializeWhatIsTechnicallyUninitialized = [&](Address Loc) {
if (trivialAutoVarInit ==
LangOptions::TrivialAutoVarInitKind::Uninitialized)
return;
// Only initialize a __block's storage: we always initialize the header.
if (emission.IsEscapingByRef && !locIsByrefHeader)
Loc = emitBlockByrefAddress(Loc, &D, /*follow=*/false);
return emitZeroOrPatternForAutoVarInit(type, D, Loc);
};
if (isTrivialInitializer(Init))
return initializeWhatIsTechnicallyUninitialized(Loc);
llvm::Constant *constant = nullptr;
if (emission.IsConstantAggregate ||
D.mightBeUsableInConstantExpressions(getContext())) {
assert(!capturedByInit && "constant init contains a capturing block?");
constant = ConstantEmitter(*this).tryEmitAbstractForInitializer(D);
if (constant && !constant->isZeroValue() &&
(trivialAutoVarInit !=
LangOptions::TrivialAutoVarInitKind::Uninitialized)) {
IsPattern isPattern =
(trivialAutoVarInit == LangOptions::TrivialAutoVarInitKind::Pattern)
? IsPattern::Yes
: IsPattern::No;
// C guarantees that brace-init with fewer initializers than members in
// the aggregate will initialize the rest of the aggregate as-if it were
// static initialization. In turn static initialization guarantees that
// padding is initialized to zero bits. We could instead pattern-init if D
// has any ImplicitValueInitExpr, but that seems to be unintuitive
// behavior.
constant = constWithPadding(CGM, IsPattern::No,
replaceUndef(CGM, isPattern, constant));
}
}
if (!constant) {
initializeWhatIsTechnicallyUninitialized(Loc);
LValue lv = MakeAddrLValue(Loc, type);
lv.setNonGC(true);
return EmitExprAsInit(Init, &D, lv, capturedByInit);
}
if (!emission.IsConstantAggregate) {
// For simple scalar/complex initialization, store the value directly.
LValue lv = MakeAddrLValue(Loc, type);
lv.setNonGC(true);
return EmitStoreThroughLValue(RValue::get(constant), lv, true);
}
llvm::Type *BP = CGM.Int8Ty->getPointerTo(Loc.getAddressSpace());
emitStoresForConstant(
CGM, D, (Loc.getType() == BP) ? Loc : Builder.CreateBitCast(Loc, BP),
type.isVolatileQualified(), Builder, constant, /*IsAutoInit=*/false);
}
/// Emit an expression as an initializer for an object (variable, field, etc.)
/// at the given location. The expression is not necessarily the normal
/// initializer for the object, and the address is not necessarily
/// its normal location.
///
/// \param init the initializing expression
/// \param D the object to act as if we're initializing
/// \param lvalue the lvalue to initialize
/// \param capturedByInit true if \p D is a __block variable
/// whose address is potentially changed by the initializer
void CodeGenFunction::EmitExprAsInit(const Expr *init, const ValueDecl *D,
LValue lvalue, bool capturedByInit) {
QualType type = D->getType();
if (type->isReferenceType()) {
RValue rvalue = EmitReferenceBindingToExpr(init);
if (capturedByInit)
drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
EmitStoreThroughLValue(rvalue, lvalue, true);
return;
}
switch (getEvaluationKind(type)) {
case TEK_Scalar:
EmitScalarInit(init, D, lvalue, capturedByInit);
return;
case TEK_Complex: {
ComplexPairTy complex = EmitComplexExpr(init);
if (capturedByInit)
drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
EmitStoreOfComplex(complex, lvalue, /*init*/ true);
return;
}
case TEK_Aggregate:
if (type->isAtomicType()) {
EmitAtomicInit(const_cast<Expr*>(init), lvalue);
} else {
AggValueSlot::Overlap_t Overlap = AggValueSlot::MayOverlap;
if (isa<VarDecl>(D))
Overlap = AggValueSlot::DoesNotOverlap;
else if (auto *FD = dyn_cast<FieldDecl>(D))
Overlap = getOverlapForFieldInit(FD);
// TODO: how can we delay here if D is captured by its initializer?
EmitAggExpr(init, AggValueSlot::forLValue(
lvalue, *this, AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased, Overlap));
}
return;
}
llvm_unreachable("bad evaluation kind");
}
/// Enter a destroy cleanup for the given local variable.
void CodeGenFunction::emitAutoVarTypeCleanup(
const CodeGenFunction::AutoVarEmission &emission,
QualType::DestructionKind dtorKind) {
assert(dtorKind != QualType::DK_none);
// Note that for __block variables, we want to destroy the
// original stack object, not the possibly forwarded object.
Address addr = emission.getObjectAddress(*this);
const VarDecl *var = emission.Variable;
QualType type = var->getType();
CleanupKind cleanupKind = NormalAndEHCleanup;
CodeGenFunction::Destroyer *destroyer = nullptr;
switch (dtorKind) {
case QualType::DK_none:
llvm_unreachable("no cleanup for trivially-destructible variable");
case QualType::DK_cxx_destructor:
// If there's an NRVO flag on the emission, we need a different
// cleanup.
if (emission.NRVOFlag) {
assert(!type->isArrayType());
CXXDestructorDecl *dtor = type->getAsCXXRecordDecl()->getDestructor();
EHStack.pushCleanup<DestroyNRVOVariableCXX>(cleanupKind, addr, type, dtor,
emission.NRVOFlag);
return;
}
break;
case QualType::DK_objc_strong_lifetime:
// Suppress cleanups for pseudo-strong variables.
if (var->isARCPseudoStrong()) return;
// Otherwise, consider whether to use an EH cleanup or not.
cleanupKind = getARCCleanupKind();
// Use the imprecise destroyer by default.
if (!var->hasAttr<ObjCPreciseLifetimeAttr>())
destroyer = CodeGenFunction::destroyARCStrongImprecise;
break;
case QualType::DK_objc_weak_lifetime:
break;
case QualType::DK_nontrivial_c_struct:
destroyer = CodeGenFunction::destroyNonTrivialCStruct;
if (emission.NRVOFlag) {
assert(!type->isArrayType());
EHStack.pushCleanup<DestroyNRVOVariableC>(cleanupKind, addr,
emission.NRVOFlag, type);
return;
}
break;
}
// If we haven't chosen a more specific destroyer, use the default.
if (!destroyer) destroyer = getDestroyer(dtorKind);
// Use an EH cleanup in array destructors iff the destructor itself
// is being pushed as an EH cleanup.
bool useEHCleanup = (cleanupKind & EHCleanup);
EHStack.pushCleanup<DestroyObject>(cleanupKind, addr, type, destroyer,
useEHCleanup);
}
void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) {
assert(emission.Variable && "emission was not valid!");
// If this was emitted as a global constant, we're done.
if (emission.wasEmittedAsGlobal()) return;
// If we don't have an insertion point, we're done. Sema prevents
// us from jumping into any of these scopes anyway.
if (!HaveInsertPoint()) return;
const VarDecl &D = *emission.Variable;
// Check the type for a cleanup.
if (QualType::DestructionKind dtorKind = D.needsDestruction(getContext()))
emitAutoVarTypeCleanup(emission, dtorKind);
// In GC mode, honor objc_precise_lifetime.
if (getLangOpts().getGC() != LangOptions::NonGC &&
D.hasAttr<ObjCPreciseLifetimeAttr>()) {
EHStack.pushCleanup<ExtendGCLifetime>(NormalCleanup, &D);
}
// Handle the cleanup attribute.
if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
const FunctionDecl *FD = CA->getFunctionDecl();
llvm::Constant *F = CGM.GetAddrOfFunction(FD);
assert(F && "Could not find function!");
const CGFunctionInfo &Info = CGM.getTypes().arrangeFunctionDeclaration(FD);
EHStack.pushCleanup<CallCleanupFunction>(NormalAndEHCleanup, F, &Info, &D);
}
// If this is a block variable, call _Block_object_destroy
// (on the unforwarded address). Don't enter this cleanup if we're in pure-GC
// mode.
if (emission.IsEscapingByRef &&
CGM.getLangOpts().getGC() != LangOptions::GCOnly) {
BlockFieldFlags Flags = BLOCK_FIELD_IS_BYREF;
if (emission.Variable->getType().isObjCGCWeak())
Flags |= BLOCK_FIELD_IS_WEAK;
enterByrefCleanup(NormalAndEHCleanup, emission.Addr, Flags,
/*LoadBlockVarAddr*/ false,
cxxDestructorCanThrow(emission.Variable->getType()));
}
}
CodeGenFunction::Destroyer *
CodeGenFunction::getDestroyer(QualType::DestructionKind kind) {
switch (kind) {
case QualType::DK_none: llvm_unreachable("no destroyer for trivial dtor");
case QualType::DK_cxx_destructor:
return destroyCXXObject;
case QualType::DK_objc_strong_lifetime:
return destroyARCStrongPrecise;
case QualType::DK_objc_weak_lifetime:
return destroyARCWeak;
case QualType::DK_nontrivial_c_struct:
return destroyNonTrivialCStruct;
}
llvm_unreachable("Unknown DestructionKind");
}
/// pushEHDestroy - Push the standard destructor for the given type as
/// an EH-only cleanup.
void CodeGenFunction::pushEHDestroy(QualType::DestructionKind dtorKind,
Address addr, QualType type) {
assert(dtorKind && "cannot push destructor for trivial type");
assert(needsEHCleanup(dtorKind));
pushDestroy(EHCleanup, addr, type, getDestroyer(dtorKind), true);
}
/// pushDestroy - Push the standard destructor for the given type as
/// at least a normal cleanup.
void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind,
Address addr, QualType type) {
assert(dtorKind && "cannot push destructor for trivial type");
CleanupKind cleanupKind = getCleanupKind(dtorKind);
pushDestroy(cleanupKind, addr, type, getDestroyer(dtorKind),
cleanupKind & EHCleanup);
}
void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, Address addr,
QualType type, Destroyer *destroyer,
bool useEHCleanupForArray) {
pushFullExprCleanup<DestroyObject>(cleanupKind, addr, type,
destroyer, useEHCleanupForArray);
}
void CodeGenFunction::pushStackRestore(CleanupKind Kind, Address SPMem) {
EHStack.pushCleanup<CallStackRestore>(Kind, SPMem);
}
void CodeGenFunction::pushLifetimeExtendedDestroy(CleanupKind cleanupKind,
Address addr, QualType type,
Destroyer *destroyer,
bool useEHCleanupForArray) {
// If we're not in a conditional branch, we don't need to bother generating a
// conditional cleanup.
if (!isInConditionalBranch()) {
// Push an EH-only cleanup for the object now.
// FIXME: When popping normal cleanups, we need to keep this EH cleanup
// around in case a temporary's destructor throws an exception.
if (cleanupKind & EHCleanup)
EHStack.pushCleanup<DestroyObject>(
static_cast<CleanupKind>(cleanupKind & ~NormalCleanup), addr, type,
destroyer, useEHCleanupForArray);
return pushCleanupAfterFullExprWithActiveFlag<DestroyObject>(
cleanupKind, Address::invalid(), addr, type, destroyer, useEHCleanupForArray);
}
// Otherwise, we should only destroy the object if it's been initialized.
// Re-use the active flag and saved address across both the EH and end of
// scope cleanups.
using SavedType = typename DominatingValue<Address>::saved_type;
using ConditionalCleanupType =
EHScopeStack::ConditionalCleanup<DestroyObject, Address, QualType,
Destroyer *, bool>;
Address ActiveFlag = createCleanupActiveFlag();
SavedType SavedAddr = saveValueInCond(addr);
if (cleanupKind & EHCleanup) {
EHStack.pushCleanup<ConditionalCleanupType>(
static_cast<CleanupKind>(cleanupKind & ~NormalCleanup), SavedAddr, type,
destroyer, useEHCleanupForArray);
initFullExprCleanupWithFlag(ActiveFlag);
}
pushCleanupAfterFullExprWithActiveFlag<ConditionalCleanupType>(
cleanupKind, ActiveFlag, SavedAddr, type, destroyer,
useEHCleanupForArray);
}
/// emitDestroy - Immediately perform the destruction of the given
/// object.
///
/// \param addr - the address of the object; a type*
/// \param type - the type of the object; if an array type, all
/// objects are destroyed in reverse order
/// \param destroyer - the function to call to destroy individual
/// elements
/// \param useEHCleanupForArray - whether an EH cleanup should be
/// used when destroying array elements, in case one of the
/// destructions throws an exception
void CodeGenFunction::emitDestroy(Address addr, QualType type,
Destroyer *destroyer,
bool useEHCleanupForArray) {
const ArrayType *arrayType = getContext().getAsArrayType(type);
if (!arrayType)
return destroyer(*this, addr, type);
llvm::Value *length = emitArrayLength(arrayType, type, addr);
CharUnits elementAlign =
addr.getAlignment()
.alignmentOfArrayElement(getContext().getTypeSizeInChars(type));
// Normally we have to check whether the array is zero-length.
bool checkZeroLength = true;
// But if the array length is constant, we can suppress that.
if (llvm::ConstantInt *constLength = dyn_cast<llvm::ConstantInt>(length)) {
// ...and if it's constant zero, we can just skip the entire thing.
if (constLength->isZero()) return;
checkZeroLength = false;
}
llvm::Value *begin = addr.getPointer();
llvm::Value *end =
Builder.CreateInBoundsGEP(addr.getElementType(), begin, length);
emitArrayDestroy(begin, end, type, elementAlign, destroyer,
checkZeroLength, useEHCleanupForArray);
}
/// emitArrayDestroy - Destroys all the elements of the given array,
/// beginning from last to first. The array cannot be zero-length.
///
/// \param begin - a type* denoting the first element of the array
/// \param end - a type* denoting one past the end of the array
/// \param elementType - the element type of the array
/// \param destroyer - the function to call to destroy elements
/// \param useEHCleanup - whether to push an EH cleanup to destroy
/// the remaining elements in case the destruction of a single
/// element throws
void CodeGenFunction::emitArrayDestroy(llvm::Value *begin,
llvm::Value *end,
QualType elementType,
CharUnits elementAlign,
Destroyer *destroyer,
bool checkZeroLength,
bool useEHCleanup) {
assert(!elementType->isArrayType());
// The basic structure here is a do-while loop, because we don't
// need to check for the zero-element case.
llvm::BasicBlock *bodyBB = createBasicBlock("arraydestroy.body");
llvm::BasicBlock *doneBB = createBasicBlock("arraydestroy.done");
if (checkZeroLength) {
llvm::Value *isEmpty = Builder.CreateICmpEQ(begin, end,
"arraydestroy.isempty");
Builder.CreateCondBr(isEmpty, doneBB, bodyBB);
}
// Enter the loop body, making that address the current address.
llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
EmitBlock(bodyBB);
llvm::PHINode *elementPast =
Builder.CreatePHI(begin->getType(), 2, "arraydestroy.elementPast");
elementPast->addIncoming(end, entryBB);
// Shift the address back by one element.
llvm::Value *negativeOne = llvm::ConstantInt::get(SizeTy, -1, true);
llvm::Value *element = Builder.CreateInBoundsGEP(elementPast, 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::Function *CodeGenModule::getLLVMLifetimeStartFn() {
if (LifetimeStartFn)
return LifetimeStartFn;
LifetimeStartFn = llvm::Intrinsic::getDeclaration(&getModule(),
llvm::Intrinsic::lifetime_start, AllocaInt8PtrTy);
return LifetimeStartFn;
}
/// Lazily declare the @llvm.lifetime.end intrinsic.
llvm::Function *CodeGenModule::getLLVMLifetimeEndFn() {
if (LifetimeEndFn)
return LifetimeEndFn;
LifetimeEndFn = llvm::Intrinsic::getDeclaration(&getModule(),
llvm::Intrinsic::lifetime_end, AllocaInt8PtrTy);
return LifetimeEndFn;
}
namespace {
/// A cleanup to perform a release of an object at the end of a
/// function. This is used to balance out the incoming +1 of a
/// ns_consumed argument when we can't reasonably do that just by
/// not doing the initial retain for a __block argument.
struct ConsumeARCParameter final : EHScopeStack::Cleanup {
ConsumeARCParameter(llvm::Value *param,
ARCPreciseLifetime_t precise)
: Param(param), Precise(precise) {}
llvm::Value *Param;
ARCPreciseLifetime_t Precise;
void Emit(CodeGenFunction &CGF, Flags flags) override {
CGF.EmitARCRelease(Param, Precise);
}
};
} // end anonymous namespace
/// Emit an alloca (or GlobalValue depending on target)
/// for the specified parameter and set up LocalDeclMap.
void CodeGenFunction::EmitParmDecl(const VarDecl &D, ParamValue Arg,
unsigned ArgNo) {
// FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) &&
"Invalid argument to EmitParmDecl");
Arg.getAnyValue()->setName(D.getName());
QualType Ty = D.getType();
// Use better IR generation for certain implicit parameters.
if (auto IPD = dyn_cast<ImplicitParamDecl>(&D)) {
// The only implicit argument a block has is its literal.
// This may be passed as an inalloca'ed value on Windows x86.
if (BlockInfo) {
llvm::Value *V = Arg.isIndirect()
? Builder.CreateLoad(Arg.getIndirectAddress())
: Arg.getDirectValue();
setBlockContextParameter(IPD, ArgNo, V);
return;
}
}
Address DeclPtr = Address::invalid();
bool DoStore = false;
bool IsScalar = hasScalarEvaluationKind(Ty);
// If we already have a pointer to the argument, reuse the input pointer.
if (Arg.isIndirect()) {
DeclPtr = Arg.getIndirectAddress();
// If we have a prettier pointer type at this point, bitcast to that.
unsigned AS = DeclPtr.getType()->getAddressSpace();
llvm::Type *IRTy = ConvertTypeForMem(Ty)->getPointerTo(AS);
if (DeclPtr.getType() != IRTy)
DeclPtr = Builder.CreateBitCast(DeclPtr, IRTy, D.getName());
// Indirect argument is in alloca address space, which may be different
// from the default address space.
auto AllocaAS = CGM.getASTAllocaAddressSpace();
auto *V = DeclPtr.getPointer();
auto SrcLangAS = getLangOpts().OpenCL ? LangAS::opencl_private : AllocaAS;
auto DestLangAS =
getLangOpts().OpenCL ? LangAS::opencl_private : LangAS::Default;
if (SrcLangAS != DestLangAS) {
assert(getContext().getTargetAddressSpace(SrcLangAS) ==
CGM.getDataLayout().getAllocaAddrSpace());
auto DestAS = getContext().getTargetAddressSpace(DestLangAS);
auto *T = V->getType()->getPointerElementType()->getPointerTo(DestAS);
DeclPtr = Address(getTargetHooks().performAddrSpaceCast(
*this, V, SrcLangAS, DestLangAS, T, true),
DeclPtr.getAlignment());
}
// Push a destructor cleanup for this parameter if the ABI requires it.
// Don't push a cleanup in a thunk for a method that will also emit a
// cleanup.
if (hasAggregateEvaluationKind(Ty) && !CurFuncIsThunk &&
Ty->castAs<RecordType>()->getDecl()->isParamDestroyedInCallee()) {
if (QualType::DestructionKind DtorKind =
D.needsDestruction(getContext())) {
assert((DtorKind == QualType::DK_cxx_destructor ||
DtorKind == QualType::DK_nontrivial_c_struct) &&
"unexpected destructor type");
pushDestroy(DtorKind, DeclPtr, Ty);
CalleeDestructedParamCleanups[cast<ParmVarDecl>(&D)] =
EHStack.stable_begin();
}
}
} else {
// Check if the parameter address is controlled by OpenMP runtime.
Address OpenMPLocalAddr =
getLangOpts().OpenMP
? CGM.getOpenMPRuntime().getAddressOfLocalVariable(*this, &D)
: Address::invalid();
if (getLangOpts().OpenMP && OpenMPLocalAddr.isValid()) {
DeclPtr = OpenMPLocalAddr;
} 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>();
// If a parameter is pseudo-strong then we can omit the implicit retain.
if (D.isARCPseudoStrong()) {
assert(lt == Qualifiers::OCL_Strong &&
"pseudo-strong variable isn't strong?");
assert(qs.hasConst() && "pseudo-strong variable should be const!");
lt = Qualifiers::OCL_ExplicitNone;
}
// Load objects passed indirectly.
if (Arg.isIndirect() && !ArgVal)
ArgVal = Builder.CreateLoad(DeclPtr);
if (lt == Qualifiers::OCL_Strong) {
if (!isConsumed) {
if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
// use objc_storeStrong(&dest, value) for retaining the
// object. But first, store a null into 'dest' because
// objc_storeStrong attempts to release its old value.
llvm::Value *Null = CGM.EmitNullConstant(D.getType());
EmitStoreOfScalar(Null, lv, /* isInitialization */ true);
EmitARCStoreStrongCall(lv.getAddress(*this), ArgVal, true);
DoStore = false;
}
else
// Don't use objc_retainBlock for block pointers, because we
// don't want to Block_copy something just because we got it
// as a parameter.
ArgVal = EmitARCRetainNonBlock(ArgVal);
}
} else {
// Push the cleanup for a consumed parameter.
if (isConsumed) {
ARCPreciseLifetime_t precise = (D.hasAttr<ObjCPreciseLifetimeAttr>()
? ARCPreciseLifetime : ARCImpreciseLifetime);
EHStack.pushCleanup<ConsumeARCParameter>(getARCCleanupKind(), ArgVal,
precise);
}
if (lt == Qualifiers::OCL_Weak) {
EmitARCInitWeak(DeclPtr, ArgVal);
DoStore = false; // The weak init is a store, no need to do two.
}
}
// Enter the cleanup scope.
EmitAutoVarWithLifetime(*this, D, DeclPtr, lt);
}
}
// Store the initial value into the alloca.
if (DoStore)
EmitStoreOfScalar(ArgVal, lv, /* isInitialization */ true);
setAddrOfLocalVar(&D, DeclPtr);
// Emit debug info for param declarations in non-thunk functions.
if (CGDebugInfo *DI = getDebugInfo()) {
if (CGM.getCodeGenOpts().hasReducedDebugInfo() && !CurFuncIsThunk) {
llvm::DILocalVariable *DILocalVar = DI->EmitDeclareOfArgVariable(
&D, DeclPtr.getPointer(), ArgNo, Builder);
if (const auto *Var = dyn_cast_or_null<ParmVarDecl>(&D))
DI->getParamDbgMappings().insert({Var, DILocalVar});
}
}
if (D.hasAttr<AnnotateAttr>())
EmitVarAnnotations(&D, DeclPtr.getPointer());
// We can only check return value nullability if all arguments to the
// function satisfy their nullability preconditions. This makes it necessary
// to emit null checks for args in the function body itself.
if (requiresReturnValueNullabilityCheck()) {
auto Nullability = Ty->getNullability(getContext());
if (Nullability && *Nullability == NullabilityKind::NonNull) {
SanitizerScope SanScope(this);
RetValNullabilityPrecondition =
Builder.CreateAnd(RetValNullabilityPrecondition,
Builder.CreateIsNotNull(Arg.getAnyValue()));
}
}
}
void CodeGenModule::EmitOMPDeclareReduction(const OMPDeclareReductionDecl *D,
CodeGenFunction *CGF) {
if (!LangOpts.OpenMP || (!LangOpts.EmitAllDecls && !D->isUsed()))
return;
getOpenMPRuntime().emitUserDefinedReduction(CGF, D);
}
void CodeGenModule::EmitOMPDeclareMapper(const OMPDeclareMapperDecl *D,
CodeGenFunction *CGF) {
if (!LangOpts.OpenMP || LangOpts.OpenMPSimd ||
(!LangOpts.EmitAllDecls && !D->isUsed()))
return;
getOpenMPRuntime().emitUserDefinedMapper(D, CGF);
}
void CodeGenModule::EmitOMPRequiresDecl(const OMPRequiresDecl *D) {
getOpenMPRuntime().processRequiresDirective(D);
}
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