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//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This coordinates the per-module state used while generating code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenModule.h"
#include "CGDebugInfo.h"
#include "CGCUDARuntime.h"
#include "CGCXXABI.h"
#include "CGObjCRuntime.h"
#include "CGOpenCLRuntime.h"
#include "TargetInfo.h"
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#include "clang/Frontend/CodeGenOptions.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Mangle.h"
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#include "clang/AST/RecordLayout.h"
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#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Basic/ConvertUTF.h"
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#include "llvm/CallingConv.h"
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#include "llvm/Module.h"
#include "llvm/Intrinsics.h"
#include "llvm/LLVMContext.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Target/Mangler.h"
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#include "llvm/Target/TargetData.h"
#include "llvm/Support/CallSite.h"
using namespace clang;
using namespace CodeGen;
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static const char AnnotationSection[] = "llvm.metadata";
static CGCXXABI &createCXXABI(CodeGenModule &CGM) {
switch (CGM.getContext().getTargetInfo().getCXXABI()) {
case CXXABI_ARM: return *CreateARMCXXABI(CGM);
case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM);
case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM);
}
llvm_unreachable("invalid C++ ABI kind");
}
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CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO,
llvm::Module &M, const llvm::TargetData &TD,
DiagnosticsEngine &diags)
: Context(C), Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M),
TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags),
ABI(createCXXABI(*this)),
Types(C, M, TD, getTargetCodeGenInfo().getABIInfo(), ABI, CGO),
VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0),
DebugInfo(0), ARCData(0), RRData(0), CFConstantStringClassRef(0),
ConstantStringClassRef(0), NSConstantStringType(0),
VMContext(M.getContext()),
NSConcreteGlobalBlock(0), NSConcreteStackBlock(0),
BlockObjectAssign(0), BlockObjectDispose(0),
BlockDescriptorType(0), GenericBlockLiteralType(0) {
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if (Features.ObjC1)
createObjCRuntime();
if (Features.OpenCL)
createOpenCLRuntime();
if (Features.CUDA)
createCUDARuntime();
// Enable TBAA unless it's suppressed.
if (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)
TBAA = new CodeGenTBAA(Context, VMContext, getLangOptions(),
ABI.getMangleContext());
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// If debug info or coverage generation is enabled, create the CGDebugInfo
// object.
if (CodeGenOpts.DebugInfo || CodeGenOpts.EmitGcovArcs ||
CodeGenOpts.EmitGcovNotes)
DebugInfo = new CGDebugInfo(*this);
Block.GlobalUniqueCount = 0;
if (C.getLangOptions().ObjCAutoRefCount)
ARCData = new ARCEntrypoints();
RRData = new RREntrypoints();
// Initialize the type cache.
llvm::LLVMContext &LLVMContext = M.getContext();
VoidTy = llvm::Type::getVoidTy(LLVMContext);
Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits);
Int8PtrTy = Int8Ty->getPointerTo(0);
Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
}
CodeGenModule::~CodeGenModule() {
delete ObjCRuntime;
delete OpenCLRuntime;
delete CUDARuntime;
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delete TheTargetCodeGenInfo;
delete &ABI;
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delete DebugInfo;
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}
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void CodeGenModule::createObjCRuntime() {
if (!Features.NeXTRuntime)
ObjCRuntime = CreateGNUObjCRuntime(*this);
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else
ObjCRuntime = CreateMacObjCRuntime(*this);
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}
void CodeGenModule::createOpenCLRuntime() {
OpenCLRuntime = new CGOpenCLRuntime(*this);
}
void CodeGenModule::createCUDARuntime() {
CUDARuntime = CreateNVCUDARuntime(*this);
}
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void CodeGenModule::Release() {
EmitDeferred();
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EmitCXXGlobalInitFunc();
if (ObjCRuntime)
if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
AddGlobalCtor(ObjCInitFunction);
EmitCtorList(GlobalCtors, "llvm.global_ctors");
EmitCtorList(GlobalDtors, "llvm.global_dtors");
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EmitGlobalAnnotations();
EmitLLVMUsed();
SimplifyPersonality();
if (getCodeGenOpts().EmitDeclMetadata)
EmitDeclMetadata();
if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
EmitCoverageFile();
if (DebugInfo)
DebugInfo->finalize();
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
// Make sure that this type is translated.
Types.UpdateCompletedType(TD);
if (DebugInfo)
DebugInfo->UpdateCompletedType(TD);
}
llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) {
if (!TBAA)
return 0;
return TBAA->getTBAAInfo(QTy);
}
void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
llvm::MDNode *TBAAInfo) {
Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
}
bool CodeGenModule::isTargetDarwin() const {
return getContext().getTargetInfo().getTriple().isOSDarwin();
}
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void CodeGenModule::Error(SourceLocation loc, StringRef error) {
unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error);
getDiags().Report(Context.getFullLoc(loc), diagID);
}
/// ErrorUnsupported - Print out an error that codegen doesn't support the
/// specified stmt yet.
void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type,
bool OmitOnError) {
if (OmitOnError && getDiags().hasErrorOccurred())
return;
unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
"cannot compile this %0 yet");
std::string Msg = Type;
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getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
<< Msg << S->getSourceRange();
/// ErrorUnsupported - Print out an error that codegen doesn't support the
/// specified decl yet.
void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type,
bool OmitOnError) {
if (OmitOnError && getDiags().hasErrorOccurred())
return;
unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
"cannot compile this %0 yet");
std::string Msg = Type;
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getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
return llvm::ConstantInt::get(SizeTy, size.getQuantity());
}
void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
const NamedDecl *D) const {
// Internal definitions always have default visibility.
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if (GV->hasLocalLinkage()) {
GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
// Set visibility for definitions.
NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility();
if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage())
GV->setVisibility(GetLLVMVisibility(LV.visibility()));
/// Set the symbol visibility of type information (vtable and RTTI)
/// associated with the given type.
void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV,
const CXXRecordDecl *RD,
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TypeVisibilityKind TVK) const {
setGlobalVisibility(GV, RD);
if (!CodeGenOpts.HiddenWeakVTables)
return;
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// We never want to drop the visibility for RTTI names.
if (TVK == TVK_ForRTTIName)
return;
// We want to drop the visibility to hidden for weak type symbols.
// This isn't possible if there might be unresolved references
// elsewhere that rely on this symbol being visible.
// This should be kept roughly in sync with setThunkVisibility
// in CGVTables.cpp.
// Preconditions.
if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage ||
GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility)
return;
// Don't override an explicit visibility attribute.
if (RD->getExplicitVisibility())
return;
switch (RD->getTemplateSpecializationKind()) {
// We have to disable the optimization if this is an EI definition
// because there might be EI declarations in other shared objects.
case TSK_ExplicitInstantiationDefinition:
case TSK_ExplicitInstantiationDeclaration:
return;
// Every use of a non-template class's type information has to emit it.
case TSK_Undeclared:
break;
// In theory, implicit instantiations can ignore the possibility of
// an explicit instantiation declaration because there necessarily
// must be an EI definition somewhere with default visibility. In
// practice, it's possible to have an explicit instantiation for
// an arbitrary template class, and linkers aren't necessarily able
// to deal with mixed-visibility symbols.
case TSK_ExplicitSpecialization:
case TSK_ImplicitInstantiation:
if (!CodeGenOpts.HiddenWeakTemplateVTables)
return;
break;
}
// If there's a key function, there may be translation units
// that don't have the key function's definition. But ignore
// this if we're emitting RTTI under -fno-rtti.
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if (!(TVK != TVK_ForRTTI) || Features.RTTI) {
if (Context.getKeyFunction(RD))
return;
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}
// Otherwise, drop the visibility to hidden.
GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
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GV->setUnnamedAddr(true);
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StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
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StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()];
if (!Str.empty())
return Str;
if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) {
IdentifierInfo *II = ND->getIdentifier();
assert(II && "Attempt to mangle unnamed decl.");
Str = II->getName();
return Str;
}
SmallString<256> Buffer;
llvm::raw_svector_ostream Out(Buffer);
if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND))
getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out);
else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND))
getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out);
else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND))
getCXXABI().getMangleContext().mangleBlock(BD, Out);
else
getCXXABI().getMangleContext().mangleName(ND, Out);
// Allocate space for the mangled name.
size_t Length = Buffer.size();
char *Name = MangledNamesAllocator.Allocate<char>(Length);
std::copy(Buffer.begin(), Buffer.end(), Name);
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Str = StringRef(Name, Length);
return Str;
}
void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer,
const BlockDecl *BD) {
MangleContext &MangleCtx = getCXXABI().getMangleContext();
const Decl *D = GD.getDecl();
llvm::raw_svector_ostream Out(Buffer.getBuffer());
if (D == 0)
MangleCtx.mangleGlobalBlock(BD, Out);
else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D))
MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
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llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
return getModule().getNamedValue(Name);
}
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/// AddGlobalCtor - Add a function to the list that will be called before
/// main() runs.
void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) {
// FIXME: Type coercion of void()* types.
GlobalCtors.push_back(std::make_pair(Ctor, Priority));
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}
/// AddGlobalDtor - Add a function to the list that will be called
/// when the module is unloaded.
void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) {
// FIXME: Type coercion of void()* types.
GlobalDtors.push_back(std::make_pair(Dtor, Priority));
}
void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) {
// Ctor function type is void()*.
llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
// Get the type of a ctor entry, { i32, void ()* }.
llvm::StructType *CtorStructTy =
llvm::StructType::get(llvm::Type::getInt32Ty(VMContext),
llvm::PointerType::getUnqual(CtorFTy), NULL);
// Construct the constructor and destructor arrays.
std::vector<llvm::Constant*> Ctors;
for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
std::vector<llvm::Constant*> S;
S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy));
Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S));
}
if (!Ctors.empty()) {
llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size());
new llvm::GlobalVariable(TheModule, AT, false,
llvm::GlobalValue::AppendingLinkage,
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}
}
llvm::GlobalValue::LinkageTypes
CodeGenModule::getFunctionLinkage(const FunctionDecl *D) {
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GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
return llvm::Function::InternalLinkage;
return llvm::Function::DLLExportLinkage;
return llvm::Function::WeakAnyLinkage;
// In C99 mode, 'inline' functions are guaranteed to have a strong
// definition somewhere else, so we can use available_externally linkage.
if (Linkage == GVA_C99Inline)
return llvm::Function::AvailableExternallyLinkage;
// Note that Apple's kernel linker doesn't support symbol
// coalescing, so we need to avoid linkonce and weak linkages there.
// Normally, this means we just map to internal, but for explicit
// instantiations we'll map to external.
// In C++, the compiler has to emit a definition in every translation unit
// that references the function. We should use linkonce_odr because
// a) if all references in this translation unit are optimized away, we
// don't need to codegen it. b) if the function persists, it needs to be
// merged with other definitions. c) C++ has the ODR, so we know the
// definition is dependable.
if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation)
return !Context.getLangOptions().AppleKext
? llvm::Function::LinkOnceODRLinkage
: llvm::Function::InternalLinkage;
// An explicit instantiation of a template has weak linkage, since
// explicit instantiations can occur in multiple translation units
// and must all be equivalent. However, we are not allowed to
// throw away these explicit instantiations.
if (Linkage == GVA_ExplicitTemplateInstantiation)
return !Context.getLangOptions().AppleKext
? llvm::Function::WeakODRLinkage
: llvm::Function::ExternalLinkage;
// Otherwise, we have strong external linkage.
assert(Linkage == GVA_StrongExternal);
return llvm::Function::ExternalLinkage;
}
/// SetFunctionDefinitionAttributes - Set attributes for a global.
///
/// FIXME: This is currently only done for aliases and functions, but not for
/// variables (these details are set in EmitGlobalVarDefinition for variables).
void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D,
llvm::GlobalValue *GV) {
void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
llvm::Function *F) {
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unsigned CallingConv;
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ConstructAttributeList(Info, D, AttributeList, CallingConv);
F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(),
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AttributeList.size()));
F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
}
/// Determines whether the language options require us to model
/// unwind exceptions. We treat -fexceptions as mandating this
/// except under the fragile ObjC ABI with only ObjC exceptions
/// enabled. This means, for example, that C with -fexceptions
/// enables this.
static bool hasUnwindExceptions(const LangOptions &Features) {
// If exceptions are completely disabled, obviously this is false.
if (!Features.Exceptions) return false;
// If C++ exceptions are enabled, this is true.
if (Features.CXXExceptions) return true;
// If ObjC exceptions are enabled, this depends on the ABI.
if (Features.ObjCExceptions) {
if (!Features.ObjCNonFragileABI) return false;
}
return true;
}
void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
llvm::Function *F) {
if (CodeGenOpts.UnwindTables)
F->setHasUWTable();
if (!hasUnwindExceptions(Features))
F->addFnAttr(llvm::Attribute::NoUnwind);
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if (D->hasAttr<NakedAttr>()) {
// Naked implies noinline: we should not be inlining such functions.
F->addFnAttr(llvm::Attribute::Naked);
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F->addFnAttr(llvm::Attribute::NoInline);
}
F->addFnAttr(llvm::Attribute::NoInline);
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// (noinline wins over always_inline, and we can't specify both in IR)
if (D->hasAttr<AlwaysInlineAttr>() &&
!F->hasFnAttr(llvm::Attribute::NoInline))
F->addFnAttr(llvm::Attribute::AlwaysInline);
if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
F->setUnnamedAddr(true);
if (Features.getStackProtector() == LangOptions::SSPOn)
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F->addFnAttr(llvm::Attribute::StackProtect);
else if (Features.getStackProtector() == LangOptions::SSPReq)
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F->addFnAttr(llvm::Attribute::StackProtectReq);
if (Features.AddressSanitizer) {
// When AddressSanitizer is enabled, set AddressSafety attribute
// unless __attribute__((no_address_safety_analysis)) is used.
if (!D->hasAttr<NoAddressSafetyAnalysisAttr>())
F->addFnAttr(llvm::Attribute::AddressSafety);
}
unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
if (alignment)
F->setAlignment(alignment);
// C++ ABI requires 2-byte alignment for member functions.
if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
F->setAlignment(2);
}
void CodeGenModule::SetCommonAttributes(const Decl *D,
if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
setGlobalVisibility(GV, ND);
else
GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
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if (D->hasAttr<UsedAttr>())
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if (const SectionAttr *SA = D->getAttr<SectionAttr>())
GV->setSection(SA->getName());
getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this);
void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
llvm::Function *F,
const CGFunctionInfo &FI) {
SetLLVMFunctionAttributes(D, FI, F);
SetLLVMFunctionAttributesForDefinition(D, F);
F->setLinkage(llvm::Function::InternalLinkage);
SetCommonAttributes(D, F);
}
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void CodeGenModule::SetFunctionAttributes(GlobalDecl GD,
llvm::Function *F,
bool IsIncompleteFunction) {
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if (unsigned IID = F->getIntrinsicID()) {
// If this is an intrinsic function, set the function's attributes
// to the intrinsic's attributes.
F->setAttributes(llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)IID));
return;
}
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const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
if (!IsIncompleteFunction)
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SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(GD), F);
// Only a few attributes are set on declarations; these may later be
// overridden by a definition.
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if (FD->hasAttr<DLLImportAttr>()) {
F->setLinkage(llvm::Function::DLLImportLinkage);
} else if (FD->hasAttr<WeakAttr>() ||
FD->isWeakImported()) {
// "extern_weak" is overloaded in LLVM; we probably should have
F->setLinkage(llvm::Function::ExternalWeakLinkage);
} else {
F->setLinkage(llvm::Function::ExternalLinkage);
NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility();
if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) {
F->setVisibility(GetLLVMVisibility(LV.visibility()));
}
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if (const SectionAttr *SA = FD->getAttr<SectionAttr>())
F->setSection(SA->getName());
}
void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) {
"Only globals with definition can force usage.");
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LLVMUsed.push_back(GV);
}
void CodeGenModule::EmitLLVMUsed() {
// Don't create llvm.used if there is no need.
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if (LLVMUsed.empty())
return;
llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
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// Convert LLVMUsed to what ConstantArray needs.
std::vector<llvm::Constant*> UsedArray;
UsedArray.resize(LLVMUsed.size());
for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) {
UsedArray[i] =
llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]),
i8PTy);
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}
if (UsedArray.empty())
return;
llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size());
llvm::GlobalVariable *GV =
new llvm::GlobalVariable(getModule(), ATy, false,
llvm::GlobalValue::AppendingLinkage,
GV->setSection("llvm.metadata");
}
void CodeGenModule::EmitDeferred() {
// Emit code for any potentially referenced deferred decls. Since a
// previously unused static decl may become used during the generation of code
// for a static function, iterate until no changes are made.
while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) {
if (!DeferredVTables.empty()) {
const CXXRecordDecl *RD = DeferredVTables.back();
DeferredVTables.pop_back();
getVTables().GenerateClassData(getVTableLinkage(RD), RD);
continue;
}
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GlobalDecl D = DeferredDeclsToEmit.back();
DeferredDeclsToEmit.pop_back();
// Check to see if we've already emitted this. This is necessary
// for a couple of reasons: first, decls can end up in the
// deferred-decls queue multiple times, and second, decls can end
// up with definitions in unusual ways (e.g. by an extern inline
// function acquiring a strong function redefinition). Just
// ignore these cases.
//
// TODO: That said, looking this up multiple times is very wasteful.
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StringRef Name = getMangledName(D);
llvm::GlobalValue *CGRef = GetGlobalValue(Name);
assert(CGRef && "Deferred decl wasn't referenced?");
if (!CGRef->isDeclaration())
continue;
// GlobalAlias::isDeclaration() defers to the aliasee, but for our
// purposes an alias counts as a definition.
if (isa<llvm::GlobalAlias>(CGRef))
continue;
// Otherwise, emit the definition and move on to the next one.
EmitGlobalDefinition(D);
}
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void CodeGenModule::EmitGlobalAnnotations() {
if (Annotations.empty())
return;
// Create a new global variable for the ConstantStruct in the Module.
llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
Annotations[0]->getType(), Annotations.size()), Annotations);
llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(),
Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array,
"llvm.global.annotations");
gv->setSection(AnnotationSection);
}
llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) {
llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str);
if (i != AnnotationStrings.end())
return i->second;
// Not found yet, create a new global.
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llvm::Constant *s = llvm::ConstantArray::get(getLLVMContext(), Str, true);
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llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(),
true, llvm::GlobalValue::PrivateLinkage, s, ".str");
gv->setSection(AnnotationSection);
gv->setUnnamedAddr(true);
AnnotationStrings[Str] = gv;
return gv;
}
llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
SourceManager &SM = getContext().getSourceManager();
PresumedLoc PLoc = SM.getPresumedLoc(Loc);
if (PLoc.isValid())
return EmitAnnotationString(PLoc.getFilename());
return EmitAnnotationString(SM.getBufferName(Loc));
}
llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
SourceManager &SM = getContext().getSourceManager();
PresumedLoc PLoc = SM.getPresumedLoc(L);
unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
SM.getExpansionLineNumber(L);
return llvm::ConstantInt::get(Int32Ty, LineNo);
}
llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
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SourceLocation L) {
// Get the globals for file name, annotation, and the line number.
llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
*UnitGV = EmitAnnotationUnit(L),
*LineNoCst = EmitAnnotationLineNo(L);
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llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
LineNoCst
return llvm::ConstantStruct::getAnon(Fields);
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void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
llvm::GlobalValue *GV) {
assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
// Get the struct elements for these annotations.
for (specific_attr_iterator<AnnotateAttr>
ai = D->specific_attr_begin<AnnotateAttr>(),
ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai)
Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation()));
}
bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
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// Never defer when EmitAllDecls is specified.
if (Features.EmitAllDecls)
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return !getContext().DeclMustBeEmitted(Global);
llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
const AliasAttr *AA = VD->getAttr<AliasAttr>();
assert(AA && "No alias?");
llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
// See if there is already something with the target's name in the module.
llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
llvm::Constant *Aliasee;
if (isa<llvm::FunctionType>(DeclTy))
Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(),
/*ForVTable=*/false);
Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
llvm::PointerType::getUnqual(DeclTy), 0);
if (!Entry) {
llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee);
F->setLinkage(llvm::Function::ExternalWeakLinkage);
WeakRefReferences.insert(F);
}
return Aliasee;
}
void CodeGenModule::EmitGlobal(GlobalDecl GD) {
const ValueDecl *Global = cast<ValueDecl>(GD.getDecl());
// Weak references don't produce any output by themselves.
if (Global->hasAttr<WeakRefAttr>())
return;
// If this is an alias definition (which otherwise looks like a declaration)
// emit it now.
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if (Global->hasAttr<AliasAttr>())
return EmitAliasDefinition(GD);
// If this is CUDA, be selective about which declarations we emit.
if (Features.CUDA) {
if (CodeGenOpts.CUDAIsDevice) {
if (!Global->hasAttr<CUDADeviceAttr>() &&
!Global->hasAttr<CUDAGlobalAttr>() &&
!Global->hasAttr<CUDAConstantAttr>() &&
!Global->hasAttr<CUDASharedAttr>())
return;
} else {
if (!Global->hasAttr<CUDAHostAttr>() && (
Global->hasAttr<CUDADeviceAttr>() ||
Global->hasAttr<CUDAConstantAttr>() ||
Global->hasAttr<CUDASharedAttr>()))
return;
}
}
// Ignore declarations, they will be emitted on their first use.
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
// Forward declarations are emitted lazily on first use.
if (!FD->doesThisDeclarationHaveABody()) {
if (!FD->doesDeclarationForceExternallyVisibleDefinition())
return;
const FunctionDecl *InlineDefinition = 0;
FD->getBody(InlineDefinition);
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StringRef MangledName = getMangledName(GD);
llvm::StringMap<GlobalDecl>::iterator DDI =
DeferredDecls.find(MangledName);
if (DDI != DeferredDecls.end())
DeferredDecls.erase(DDI);
EmitGlobalDefinition(InlineDefinition);
}
} else {
const VarDecl *VD = cast<VarDecl>(Global);
assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
if (VD->isThisDeclarationADefinition() != VarDecl::Definition)
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}
// Defer code generation when possible if this is a static definition, inline
// function etc. These we only want to emit if they are used.
if (!MayDeferGeneration(Global)) {
// Emit the definition if it can't be deferred.
EmitGlobalDefinition(GD);
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// If we're deferring emission of a C++ variable with an
// initializer, remember the order in which it appeared in the file.
if (getLangOptions().CPlusPlus && isa<VarDecl>(Global) &&
cast<VarDecl>(Global)->hasInit()) {
DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
CXXGlobalInits.push_back(0);
}
// If the value has already been used, add it directly to the
// DeferredDeclsToEmit list.
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StringRef MangledName = getMangledName(GD);
if (GetGlobalValue(MangledName))
DeferredDeclsToEmit.push_back(GD);
else {
// Otherwise, remember that we saw a deferred decl with this name. The
// first use of the mangled name will cause it to move into
// DeferredDeclsToEmit.
DeferredDecls[MangledName] = GD;
}
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}
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namespace {
struct FunctionIsDirectlyRecursive :
public RecursiveASTVisitor<FunctionIsDirectlyRecursive> {
const StringRef Name;
const Builtin::Context &BI;
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bool Result;
FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) :
Name(N), BI(C), Result(false) {
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}
typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base;
bool TraverseCallExpr(CallExpr *E) {
const FunctionDecl *FD = E->getDirectCallee();
if (!FD)
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return true;
AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
if (Attr && Name == Attr->getLabel()) {
Result = true;
return false;
}
unsigned BuiltinID = FD->getBuiltinID();
if (!BuiltinID)
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return true;
StringRef BuiltinName = BI.GetName(BuiltinID);
if (BuiltinName.startswith("__builtin_") &&
Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
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Result = true;
return false;
}
return true;
}
};
}
// isTriviallyRecursive - Check if this function calls another
// decl that, because of the asm attribute or the other decl being a builtin,
// ends up pointing to itself.
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bool
CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
StringRef Name;
if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
// asm labels are a special kind of mangling we have to support.
AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
if (!Attr)
return false;
Name = Attr->getLabel();
} else {
Name = FD->getName();
}
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FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD));
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return Walker.Result;
}
bool
CodeGenModule::shouldEmitFunction(const FunctionDecl *F) {
if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage)
return true;
if (CodeGenOpts.OptimizationLevel == 0 &&
!F->hasAttr<AlwaysInlineAttr>())
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return false;
// PR9614. Avoid cases where the source code is lying to us. An available
// externally function should have an equivalent function somewhere else,
// but a function that calls itself is clearly not equivalent to the real
// implementation.
// This happens in glibc's btowc and in some configure checks.
return !isTriviallyRecursive(F);
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}
void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {
const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
Context.getSourceManager(),
"Generating code for declaration");
if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
// At -O0, don't generate IR for functions with available_externally
// linkage.
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if (!shouldEmitFunction(Function))
return;
if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
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// Make sure to emit the definition(s) before we emit the thunks.
// This is necessary for the generation of certain thunks.
if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method))
EmitCXXConstructor(CD, GD.getCtorType());
else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method))
EmitCXXDestructor(DD, GD.getDtorType());
else
EmitGlobalFunctionDefinition(GD);
if (Method->isVirtual())
getVTables().EmitThunks(GD);
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return;
}
}
if (const VarDecl *VD = dyn_cast<VarDecl>(D))
return EmitGlobalVarDefinition(VD);
llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
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/// GetOrCreateLLVMFunction - If the specified mangled name is not in the
/// module, create and return an llvm Function with the specified type. If there
/// is something in the module with the specified name, return it potentially
/// bitcasted to the right type.
///
/// If D is non-null, it specifies a decl that correspond to this. This is used
/// to set the attributes on the function when it is first created.
llvm::Constant *
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CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName,
GlobalDecl D, bool ForVTable,
llvm::Attributes ExtraAttrs) {
// Lookup the entry, lazily creating it if necessary.
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (Entry) {
if (WeakRefReferences.count(Entry)) {
const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl());
if (FD && !FD->hasAttr<WeakAttr>())
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Entry->setLinkage(llvm::Function::ExternalLinkage);
if (Entry->getType()->getElementType() == Ty)