Magic-Mirror/llvm-capstone
1
0
Fork 0
mirror of https://github.com/capstone-engine/llvm-capstone.git synced 2025-04-09 09:21:41 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity
llvm-capstone/clang/lib/CodeGen/CodeGenModule.cpp
Rafael Espindola 0d4fb98504 [patch][pr19848] Produce explicit comdats in clang. 
The llvm IR until recently had no support for comdats. This was a problem when
targeting C++ on ELF/COFF as just using weak linkage would cause quite a bit of
dead bits to remain on the executable (unless -ffunction-sections,
-fdata-sections and --gc-sections were used).

To fix the problem, llvm's codegen will just assume that any weak or linkonce
that is not in an explicit comdat should be output in one with the same name as
the global.

This unfortunately breaks cases like pr19848 where a weak symbol is not
xpected to be part of any comdat.

Now that we have explicit comdats in the IR, we can finally get both cases
right.

This first patch just makes clang give explicit comdats to GlobalValues where
t is allowed to.

A followup patch to llvm will then stop implicitly producing comdats.

llvm-svn: 225705
2015-01-12 22:13:53 +00:00

3624 lines
134 KiB
C++
Raw Blame History

//===--- 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 "CGCUDARuntime.h"
#include "CGCXXABI.h"
#include "CGCall.h"
#include "CGDebugInfo.h"
#include "CGObjCRuntime.h"
#include "CGOpenCLRuntime.h"
#include "CGOpenMPRuntime.h"
#include "CodeGenFunction.h"
#include "CodeGenPGO.h"
#include "CoverageMappingGen.h"
#include "CodeGenTBAA.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Mangle.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/Module.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Basic/Version.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "clang/Sema/SemaDiagnostic.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/Triple.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/ProfileData/InstrProfReader.h"
#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/ErrorHandling.h"
using namespace clang;
using namespace CodeGen;
static const char AnnotationSection[] = "llvm.metadata";
static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
switch (CGM.getTarget().getCXXABI().getKind()) {
case TargetCXXABI::GenericAArch64:
case TargetCXXABI::GenericARM:
case TargetCXXABI::iOS:
case TargetCXXABI::iOS64:
case TargetCXXABI::GenericItanium:
return CreateItaniumCXXABI(CGM);
case TargetCXXABI::Microsoft:
return CreateMicrosoftCXXABI(CGM);
}
llvm_unreachable("invalid C++ ABI kind");
}
CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO,
llvm::Module &M, const llvm::DataLayout &TD,
DiagnosticsEngine &diags,
CoverageSourceInfo *CoverageInfo)
: Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TheModule(M),
Diags(diags), TheDataLayout(TD), Target(C.getTargetInfo()),
ABI(createCXXABI(*this)), VMContext(M.getContext()), TBAA(nullptr),
TheTargetCodeGenInfo(nullptr), Types(*this), VTables(*this),
ObjCRuntime(nullptr), OpenCLRuntime(nullptr), OpenMPRuntime(nullptr),
CUDARuntime(nullptr), DebugInfo(nullptr), ARCData(nullptr),
NoObjCARCExceptionsMetadata(nullptr), RRData(nullptr), PGOReader(nullptr),
CFConstantStringClassRef(nullptr), ConstantStringClassRef(nullptr),
NSConstantStringType(nullptr), NSConcreteGlobalBlock(nullptr),
NSConcreteStackBlock(nullptr), BlockObjectAssign(nullptr),
BlockObjectDispose(nullptr), BlockDescriptorType(nullptr),
GenericBlockLiteralType(nullptr), LifetimeStartFn(nullptr),
LifetimeEndFn(nullptr), SanitizerMD(new SanitizerMetadata(*this)) {
// Initialize the type cache.
llvm::LLVMContext &LLVMContext = M.getContext();
VoidTy = llvm::Type::getVoidTy(LLVMContext);
Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
FloatTy = llvm::Type::getFloatTy(LLVMContext);
DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
PointerAlignInBytes =
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);
RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
BuiltinCC = getTargetCodeGenInfo().getABIInfo().getBuiltinCC();
if (LangOpts.ObjC1)
createObjCRuntime();
if (LangOpts.OpenCL)
createOpenCLRuntime();
if (LangOpts.OpenMP)
createOpenMPRuntime();
if (LangOpts.CUDA)
createCUDARuntime();
// Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
(!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
TBAA = new CodeGenTBAA(Context, VMContext, CodeGenOpts, getLangOpts(),
getCXXABI().getMangleContext());
// If debug info or coverage generation is enabled, create the CGDebugInfo
// object.
if (CodeGenOpts.getDebugInfo() != CodeGenOptions::NoDebugInfo ||
CodeGenOpts.EmitGcovArcs ||
CodeGenOpts.EmitGcovNotes)
DebugInfo = new CGDebugInfo(*this);
Block.GlobalUniqueCount = 0;
if (C.getLangOpts().ObjCAutoRefCount)
ARCData = new ARCEntrypoints();
RRData = new RREntrypoints();
if (!CodeGenOpts.InstrProfileInput.empty()) {
if (std::error_code EC = llvm::IndexedInstrProfReader::create(
CodeGenOpts.InstrProfileInput, PGOReader)) {
unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
"Could not read profile: %0");
getDiags().Report(DiagID) << EC.message();
}
}
// If coverage mapping generation is enabled, create the
// CoverageMappingModuleGen object.
if (CodeGenOpts.CoverageMapping)
CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
}
CodeGenModule::~CodeGenModule() {
delete ObjCRuntime;
delete OpenCLRuntime;
delete OpenMPRuntime;
delete CUDARuntime;
delete TheTargetCodeGenInfo;
delete TBAA;
delete DebugInfo;
delete ARCData;
delete RRData;
}
void CodeGenModule::createObjCRuntime() {
// This is just isGNUFamily(), but we want to force implementors of
// new ABIs to decide how best to do this.
switch (LangOpts.ObjCRuntime.getKind()) {
case ObjCRuntime::GNUstep:
case ObjCRuntime::GCC:
case ObjCRuntime::ObjFW:
ObjCRuntime = CreateGNUObjCRuntime(*this);
return;
case ObjCRuntime::FragileMacOSX:
case ObjCRuntime::MacOSX:
case ObjCRuntime::iOS:
ObjCRuntime = CreateMacObjCRuntime(*this);
return;
}
llvm_unreachable("bad runtime kind");
}
void CodeGenModule::createOpenCLRuntime() {
OpenCLRuntime = new CGOpenCLRuntime(*this);
}
void CodeGenModule::createOpenMPRuntime() {
OpenMPRuntime = new CGOpenMPRuntime(*this);
}
void CodeGenModule::createCUDARuntime() {
CUDARuntime = CreateNVCUDARuntime(*this);
}
void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
Replacements[Name] = C;
}
void CodeGenModule::applyReplacements() {
for (ReplacementsTy::iterator I = Replacements.begin(),
E = Replacements.end();
I != E; ++I) {
StringRef MangledName = I->first();
llvm::Constant *Replacement = I->second;
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (!Entry)
continue;
auto *OldF = cast<llvm::Function>(Entry);
auto *NewF = dyn_cast<llvm::Function>(Replacement);
if (!NewF) {
if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
} else {
auto *CE = cast<llvm::ConstantExpr>(Replacement);
assert(CE->getOpcode() == llvm::Instruction::BitCast ||
CE->getOpcode() == llvm::Instruction::GetElementPtr);
NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
}
}
// Replace old with new, but keep the old order.
OldF->replaceAllUsesWith(Replacement);
if (NewF) {
NewF->removeFromParent();
OldF->getParent()->getFunctionList().insertAfter(OldF, NewF);
}
OldF->eraseFromParent();
}
}
// This is only used in aliases that we created and we know they have a
// linear structure.
static const llvm::GlobalObject *getAliasedGlobal(const llvm::GlobalAlias &GA) {
llvm::SmallPtrSet<const llvm::GlobalAlias*, 4> Visited;
const llvm::Constant *C = &GA;
for (;;) {
C = C->stripPointerCasts();
if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
return GO;
// stripPointerCasts will not walk over weak aliases.
auto *GA2 = dyn_cast<llvm::GlobalAlias>(C);
if (!GA2)
return nullptr;
if (!Visited.insert(GA2).second)
return nullptr;
C = GA2->getAliasee();
}
}
void CodeGenModule::checkAliases() {
// Check if the constructed aliases are well formed. It is really unfortunate
// that we have to do this in CodeGen, but we only construct mangled names
// and aliases during codegen.
bool Error = false;
DiagnosticsEngine &Diags = getDiags();
for (std::vector<GlobalDecl>::iterator I = Aliases.begin(),
E = Aliases.end(); I != E; ++I) {
const GlobalDecl &GD = *I;
const auto *D = cast<ValueDecl>(GD.getDecl());
const AliasAttr *AA = D->getAttr<AliasAttr>();
StringRef MangledName = getMangledName(GD);
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
auto *Alias = cast<llvm::GlobalAlias>(Entry);
const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
if (!GV) {
Error = true;
Diags.Report(AA->getLocation(), diag::err_cyclic_alias);
} else if (GV->isDeclaration()) {
Error = true;
Diags.Report(AA->getLocation(), diag::err_alias_to_undefined);
}
llvm::Constant *Aliasee = Alias->getAliasee();
llvm::GlobalValue *AliaseeGV;
if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
else
AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
StringRef AliasSection = SA->getName();
if (AliasSection != AliaseeGV->getSection())
Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
<< AliasSection;
}
// We have to handle alias to weak aliases in here. LLVM itself disallows
// this since the object semantics would not match the IL one. For
// compatibility with gcc we implement it by just pointing the alias
// to its aliasee's aliasee. We also warn, since the user is probably
// expecting the link to be weak.
if (auto GA = dyn_cast<llvm::GlobalAlias>(AliaseeGV)) {
if (GA->mayBeOverridden()) {
Diags.Report(AA->getLocation(), diag::warn_alias_to_weak_alias)
<< GV->getName() << GA->getName();
Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
GA->getAliasee(), Alias->getType());
Alias->setAliasee(Aliasee);
}
}
}
if (!Error)
return;
for (std::vector<GlobalDecl>::iterator I = Aliases.begin(),
E = Aliases.end(); I != E; ++I) {
const GlobalDecl &GD = *I;
StringRef MangledName = getMangledName(GD);
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
auto *Alias = cast<llvm::GlobalAlias>(Entry);
Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
Alias->eraseFromParent();
}
}
void CodeGenModule::clear() {
DeferredDeclsToEmit.clear();
}
void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
StringRef MainFile) {
if (!hasDiagnostics())
return;
if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
if (MainFile.empty())
MainFile = "<stdin>";
Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
} else
Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Missing
<< Mismatched;
}
void CodeGenModule::Release() {
EmitDeferred();
applyReplacements();
checkAliases();
EmitCXXGlobalInitFunc();
EmitCXXGlobalDtorFunc();
EmitCXXThreadLocalInitFunc();
if (ObjCRuntime)
if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
AddGlobalCtor(ObjCInitFunction);
if (PGOReader && PGOStats.hasDiagnostics())
PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
EmitCtorList(GlobalCtors, "llvm.global_ctors");
EmitCtorList(GlobalDtors, "llvm.global_dtors");
EmitGlobalAnnotations();
EmitStaticExternCAliases();
EmitDeferredUnusedCoverageMappings();
if (CoverageMapping)
CoverageMapping->emit();
emitLLVMUsed();
if (CodeGenOpts.Autolink &&
(Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
EmitModuleLinkOptions();
}
if (CodeGenOpts.DwarfVersion)
// We actually want the latest version when there are conflicts.
// We can change from Warning to Latest if such mode is supported.
getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
CodeGenOpts.DwarfVersion);
if (DebugInfo)
// We support a single version in the linked module. The LLVM
// parser will drop debug info with a different version number
// (and warn about it, too).
getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
llvm::DEBUG_METADATA_VERSION);
// We need to record the widths of enums and wchar_t, so that we can generate
// the correct build attributes in the ARM backend.
llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
if ( Arch == llvm::Triple::arm
|| Arch == llvm::Triple::armeb
|| Arch == llvm::Triple::thumb
|| Arch == llvm::Triple::thumbeb) {
// Width of wchar_t in bytes
uint64_t WCharWidth =
Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
// The minimum width of an enum in bytes
uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
}
if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
llvm::PICLevel::Level PL = llvm::PICLevel::Default;
switch (PLevel) {
case 0: break;
case 1: PL = llvm::PICLevel::Small; break;
case 2: PL = llvm::PICLevel::Large; break;
default: llvm_unreachable("Invalid PIC Level");
}
getModule().setPICLevel(PL);
}
SimplifyPersonality();
if (getCodeGenOpts().EmitDeclMetadata)
EmitDeclMetadata();
if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
EmitCoverageFile();
if (DebugInfo)
DebugInfo->finalize();
EmitVersionIdentMetadata();
EmitTargetMetadata();
}
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
// Make sure that this type is translated.
Types.UpdateCompletedType(TD);
}
llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) {
if (!TBAA)
return nullptr;
return TBAA->getTBAAInfo(QTy);
}
llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() {
if (!TBAA)
return nullptr;
return TBAA->getTBAAInfoForVTablePtr();
}
llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
if (!TBAA)
return nullptr;
return TBAA->getTBAAStructInfo(QTy);
}
llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) {
if (!TBAA)
return nullptr;
return TBAA->getTBAAStructTypeInfo(QTy);
}
llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy,
llvm::MDNode *AccessN,
uint64_t O) {
if (!TBAA)
return nullptr;
return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O);
}
/// Decorate the instruction with a TBAA tag. For both scalar TBAA
/// and struct-path aware TBAA, the tag has the same format:
/// base type, access type and offset.
/// When ConvertTypeToTag is true, we create a tag based on the scalar type.
void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
llvm::MDNode *TBAAInfo,
bool ConvertTypeToTag) {
if (ConvertTypeToTag && TBAA)
Inst->setMetadata(llvm::LLVMContext::MD_tbaa,
TBAA->getTBAAScalarTagInfo(TBAAInfo));
else
Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
}
void CodeGenModule::Error(SourceLocation loc, StringRef message) {
unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
getDiags().Report(Context.getFullLoc(loc), diagID) << message;
}
/// ErrorUnsupported - Print out an error that codegen doesn't support the
/// specified stmt yet.
void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
"cannot compile this %0 yet");
std::string Msg = Type;
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) {
unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
"cannot compile this %0 yet");
std::string Msg = Type;
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.
if (GV->hasLocalLinkage()) {
GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
return;
}
// Set visibility for definitions.
LinkageInfo LV = D->getLinkageAndVisibility();
if (LV.isVisibilityExplicit() || !GV->hasAvailableExternallyLinkage())
GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
}
static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
.Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
.Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
.Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
.Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
}
static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(
CodeGenOptions::TLSModel M) {
switch (M) {
case CodeGenOptions::GeneralDynamicTLSModel:
return llvm::GlobalVariable::GeneralDynamicTLSModel;
case CodeGenOptions::LocalDynamicTLSModel:
return llvm::GlobalVariable::LocalDynamicTLSModel;
case CodeGenOptions::InitialExecTLSModel:
return llvm::GlobalVariable::InitialExecTLSModel;
case CodeGenOptions::LocalExecTLSModel:
return llvm::GlobalVariable::LocalExecTLSModel;
}
llvm_unreachable("Invalid TLS model!");
}
void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
llvm::GlobalValue::ThreadLocalMode TLM;
TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel());
// Override the TLS model if it is explicitly specified.
if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
TLM = GetLLVMTLSModel(Attr->getModel());
}
GV->setThreadLocalMode(TLM);
}
StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
StringRef &FoundStr = MangledDeclNames[GD.getCanonicalDecl()];
if (!FoundStr.empty())
return FoundStr;
const auto *ND = cast<NamedDecl>(GD.getDecl());
SmallString<256> Buffer;
StringRef Str;
if (getCXXABI().getMangleContext().shouldMangleDeclName(ND)) {
llvm::raw_svector_ostream Out(Buffer);
if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out);
else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out);
else
getCXXABI().getMangleContext().mangleName(ND, Out);
Str = Out.str();
} else {
IdentifierInfo *II = ND->getIdentifier();
assert(II && "Attempt to mangle unnamed decl.");
Str = II->getName();
}
// Keep the first result in the case of a mangling collision.
auto Result = Manglings.insert(std::make_pair(Str, GD));
return FoundStr = Result.first->first();
}
StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
const BlockDecl *BD) {
MangleContext &MangleCtx = getCXXABI().getMangleContext();
const Decl *D = GD.getDecl();
SmallString<256> Buffer;
llvm::raw_svector_ostream Out(Buffer);
if (!D)
MangleCtx.mangleGlobalBlock(BD,
dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
else
MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
return Result.first->first();
}
llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
return getModule().getNamedValue(Name);
}
/// AddGlobalCtor - Add a function to the list that will be called before
/// main() runs.
void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
llvm::Constant *AssociatedData) {
// FIXME: Type coercion of void()* types.
GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
}
/// 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(Structor(Priority, Dtor, nullptr));
}
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 ()*, i8* }.
llvm::StructType *CtorStructTy = llvm::StructType::get(
Int32Ty, llvm::PointerType::getUnqual(CtorFTy), VoidPtrTy, nullptr);
// Construct the constructor and destructor arrays.
SmallVector<llvm::Constant*, 8> Ctors;
for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
llvm::Constant *S[] = {
llvm::ConstantInt::get(Int32Ty, I->Priority, false),
llvm::ConstantExpr::getBitCast(I->Initializer, CtorPFTy),
(I->AssociatedData
? llvm::ConstantExpr::getBitCast(I->AssociatedData, VoidPtrTy)
: llvm::Constant::getNullValue(VoidPtrTy))
};
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,
llvm::ConstantArray::get(AT, Ctors),
GlobalName);
}
}
llvm::GlobalValue::LinkageTypes
CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
const auto *D = cast<FunctionDecl>(GD.getDecl());
GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
if (isa<CXXDestructorDecl>(D) &&
getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
GD.getDtorType())) {
// Destructor variants in the Microsoft C++ ABI are always internal or
// linkonce_odr thunks emitted on an as-needed basis.
return Linkage == GVA_Internal ? llvm::GlobalValue::InternalLinkage
: llvm::GlobalValue::LinkOnceODRLinkage;
}
return getLLVMLinkageForDeclarator(D, Linkage, /*isConstantVariable=*/false);
}
void CodeGenModule::setFunctionDefinitionAttributes(const FunctionDecl *D,
llvm::Function *F) {
setNonAliasAttributes(D, F);
}
void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
const CGFunctionInfo &Info,
llvm::Function *F) {
unsigned CallingConv;
AttributeListType AttributeList;
ConstructAttributeList(Info, D, AttributeList, CallingConv, false);
F->setAttributes(llvm::AttributeSet::get(getLLVMContext(), AttributeList));
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 &LangOpts) {
// If exceptions are completely disabled, obviously this is false.
if (!LangOpts.Exceptions) return false;
// If C++ exceptions are enabled, this is true.
if (LangOpts.CXXExceptions) return true;
// If ObjC exceptions are enabled, this depends on the ABI.
if (LangOpts.ObjCExceptions) {
return LangOpts.ObjCRuntime.hasUnwindExceptions();
}
return true;
}
void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
llvm::Function *F) {
llvm::AttrBuilder B;
if (CodeGenOpts.UnwindTables)
B.addAttribute(llvm::Attribute::UWTable);
if (!hasUnwindExceptions(LangOpts))
B.addAttribute(llvm::Attribute::NoUnwind);
if (D->hasAttr<NakedAttr>()) {
// Naked implies noinline: we should not be inlining such functions.
B.addAttribute(llvm::Attribute::Naked);
B.addAttribute(llvm::Attribute::NoInline);
} else if (D->hasAttr<NoDuplicateAttr>()) {
B.addAttribute(llvm::Attribute::NoDuplicate);
} else if (D->hasAttr<NoInlineAttr>()) {
B.addAttribute(llvm::Attribute::NoInline);
} else if (D->hasAttr<AlwaysInlineAttr>() &&
!F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex,
llvm::Attribute::NoInline)) {
// (noinline wins over always_inline, and we can't specify both in IR)
B.addAttribute(llvm::Attribute::AlwaysInline);
}
if (D->hasAttr<ColdAttr>()) {
if (!D->hasAttr<OptimizeNoneAttr>())
B.addAttribute(llvm::Attribute::OptimizeForSize);
B.addAttribute(llvm::Attribute::Cold);
}
if (D->hasAttr<MinSizeAttr>())
B.addAttribute(llvm::Attribute::MinSize);
if (LangOpts.getStackProtector() == LangOptions::SSPOn)
B.addAttribute(llvm::Attribute::StackProtect);
else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
B.addAttribute(llvm::Attribute::StackProtectStrong);
else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
B.addAttribute(llvm::Attribute::StackProtectReq);
// Add sanitizer attributes if function is not blacklisted.
if (!isInSanitizerBlacklist(F, D->getLocation())) {
// When AddressSanitizer is enabled, set SanitizeAddress attribute
// unless __attribute__((no_sanitize_address)) is used.
if (LangOpts.Sanitize.has(SanitizerKind::Address) &&
!D->hasAttr<NoSanitizeAddressAttr>())
B.addAttribute(llvm::Attribute::SanitizeAddress);
// Same for ThreadSanitizer and __attribute__((no_sanitize_thread))
if (LangOpts.Sanitize.has(SanitizerKind::Thread) &&
!D->hasAttr<NoSanitizeThreadAttr>())
B.addAttribute(llvm::Attribute::SanitizeThread);
// Same for MemorySanitizer and __attribute__((no_sanitize_memory))
if (LangOpts.Sanitize.has(SanitizerKind::Memory) &&
!D->hasAttr<NoSanitizeMemoryAttr>())
B.addAttribute(llvm::Attribute::SanitizeMemory);
}
F->addAttributes(llvm::AttributeSet::FunctionIndex,
llvm::AttributeSet::get(
F->getContext(), llvm::AttributeSet::FunctionIndex, B));
if (D->hasAttr<OptimizeNoneAttr>()) {
// OptimizeNone implies noinline; we should not be inlining such functions.
F->addFnAttr(llvm::Attribute::OptimizeNone);
F->addFnAttr(llvm::Attribute::NoInline);
// OptimizeNone wins over OptimizeForSize, MinSize, AlwaysInline.
assert(!F->hasFnAttribute(llvm::Attribute::OptimizeForSize) &&
"OptimizeNone and OptimizeForSize on same function!");
assert(!F->hasFnAttribute(llvm::Attribute::MinSize) &&
"OptimizeNone and MinSize on same function!");
assert(!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
"OptimizeNone and AlwaysInline on same function!");
// Attribute 'inlinehint' has no effect on 'optnone' functions.
// Explicitly remove it from the set of function attributes.
F->removeFnAttr(llvm::Attribute::InlineHint);
}
if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
F->setUnnamedAddr(true);
else if (const auto *MD = dyn_cast<CXXMethodDecl>(D))
if (MD->isVirtual())
F->setUnnamedAddr(true);
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,
llvm::GlobalValue *GV) {
if (const auto *ND = dyn_cast<NamedDecl>(D))
setGlobalVisibility(GV, ND);
else
GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
if (D->hasAttr<UsedAttr>())
addUsedGlobal(GV);
}
void CodeGenModule::setAliasAttributes(const Decl *D,
llvm::GlobalValue *GV) {
SetCommonAttributes(D, GV);
// Process the dllexport attribute based on whether the original definition
// (not necessarily the aliasee) was exported.
if (D->hasAttr<DLLExportAttr>())
GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
}
void CodeGenModule::setNonAliasAttributes(const Decl *D,
llvm::GlobalObject *GO) {
SetCommonAttributes(D, GO);
if (const SectionAttr *SA = D->getAttr<SectionAttr>())
GO->setSection(SA->getName());
getTargetCodeGenInfo().SetTargetAttributes(D, GO, *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);
setNonAliasAttributes(D, F);
}
static void setLinkageAndVisibilityForGV(llvm::GlobalValue *GV,
const NamedDecl *ND) {
// Set linkage and visibility in case we never see a definition.
LinkageInfo LV = ND->getLinkageAndVisibility();
if (LV.getLinkage() != ExternalLinkage) {
// Don't set internal linkage on declarations.
} else {
if (ND->hasAttr<DLLImportAttr>()) {
GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
} else if (ND->hasAttr<DLLExportAttr>()) {
GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
} else if (ND->hasAttr<WeakAttr>() || ND->isWeakImported()) {
// "extern_weak" is overloaded in LLVM; we probably should have
// separate linkage types for this.
GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
}
// Set visibility on a declaration only if it's explicit.
if (LV.isVisibilityExplicit())
GV->setVisibility(CodeGenModule::GetLLVMVisibility(LV.getVisibility()));
}
}
void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
bool IsIncompleteFunction,
bool IsThunk) {
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(getLLVMContext(),
(llvm::Intrinsic::ID)IID));
return;
}
const auto *FD = cast<FunctionDecl>(GD.getDecl());
if (!IsIncompleteFunction)
SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F);
// Add the Returned attribute for "this", except for iOS 5 and earlier
// where substantial code, including the libstdc++ dylib, was compiled with
// GCC and does not actually return "this".
if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
!(getTarget().getTriple().isiOS() &&
getTarget().getTriple().isOSVersionLT(6))) {
assert(!F->arg_empty() &&
F->arg_begin()->getType()
->canLosslesslyBitCastTo(F->getReturnType()) &&
"unexpected this return");
F->addAttribute(1, llvm::Attribute::Returned);
}
// Only a few attributes are set on declarations; these may later be
// overridden by a definition.
setLinkageAndVisibilityForGV(F, FD);
if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(FD)) {
if (getCXXABI().useThunkForDtorVariant(Dtor, GD.getDtorType())) {
// Don't dllexport/import destructor thunks.
F->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
}
}
if (const SectionAttr *SA = FD->getAttr<SectionAttr>())
F->setSection(SA->getName());
// A replaceable global allocation function does not act like a builtin by
// default, only if it is invoked by a new-expression or delete-expression.
if (FD->isReplaceableGlobalAllocationFunction())
F->addAttribute(llvm::AttributeSet::FunctionIndex,
llvm::Attribute::NoBuiltin);
}
void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
assert(!GV->isDeclaration() &&
"Only globals with definition can force usage.");
LLVMUsed.push_back(GV);
}
void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
assert(!GV->isDeclaration() &&
"Only globals with definition can force usage.");
LLVMCompilerUsed.push_back(GV);
}
static void emitUsed(CodeGenModule &CGM, StringRef Name,
std::vector<llvm::WeakVH> &List) {
// Don't create llvm.used if there is no need.
if (List.empty())
return;
// Convert List to what ConstantArray needs.
SmallVector<llvm::Constant*, 8> UsedArray;
UsedArray.resize(List.size());
for (unsigned i = 0, e = List.size(); i != e; ++i) {
UsedArray[i] =
llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*List[i]),
CGM.Int8PtrTy);
}
if (UsedArray.empty())
return;
llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
auto *GV = new llvm::GlobalVariable(
CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
llvm::ConstantArray::get(ATy, UsedArray), Name);
GV->setSection("llvm.metadata");
}
void CodeGenModule::emitLLVMUsed() {
emitUsed(*this, "llvm.used", LLVMUsed);
emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
}
void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
}
void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
llvm::SmallString<32> Opt;
getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
}
void CodeGenModule::AddDependentLib(StringRef Lib) {
llvm::SmallString<24> Opt;
getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
}
/// \brief Add link options implied by the given module, including modules
/// it depends on, using a postorder walk.
static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
SmallVectorImpl<llvm::Metadata *> &Metadata,
llvm::SmallPtrSet<Module *, 16> &Visited) {
// Import this module's parent.
if (Mod->Parent && Visited.insert(Mod->Parent).second) {
addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
}
// Import this module's dependencies.
for (unsigned I = Mod->Imports.size(); I > 0; --I) {
if (Visited.insert(Mod->Imports[I - 1]).second)
addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
}
// Add linker options to link against the libraries/frameworks
// described by this module.
llvm::LLVMContext &Context = CGM.getLLVMContext();
for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
// Link against a framework. Frameworks are currently Darwin only, so we
// don't to ask TargetCodeGenInfo for the spelling of the linker option.
if (Mod->LinkLibraries[I-1].IsFramework) {
llvm::Metadata *Args[2] = {
llvm::MDString::get(Context, "-framework"),
llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)};
Metadata.push_back(llvm::MDNode::get(Context, Args));
continue;
}
// Link against a library.
llvm::SmallString<24> Opt;
CGM.getTargetCodeGenInfo().getDependentLibraryOption(
Mod->LinkLibraries[I-1].Library, Opt);
auto *OptString = llvm::MDString::get(Context, Opt);
Metadata.push_back(llvm::MDNode::get(Context, OptString));
}
}
void CodeGenModule::EmitModuleLinkOptions() {
// Collect the set of all of the modules we want to visit to emit link
// options, which is essentially the imported modules and all of their
// non-explicit child modules.
llvm::SetVector<clang::Module *> LinkModules;
llvm::SmallPtrSet<clang::Module *, 16> Visited;
SmallVector<clang::Module *, 16> Stack;
// Seed the stack with imported modules.
for (llvm::SetVector<clang::Module *>::iterator M = ImportedModules.begin(),
MEnd = ImportedModules.end();
M != MEnd; ++M) {
if (Visited.insert(*M).second)
Stack.push_back(*M);
}
// Find all of the modules to import, making a little effort to prune
// non-leaf modules.
while (!Stack.empty()) {
clang::Module *Mod = Stack.pop_back_val();
bool AnyChildren = false;
// Visit the submodules of this module.
for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
SubEnd = Mod->submodule_end();
Sub != SubEnd; ++Sub) {
// Skip explicit children; they need to be explicitly imported to be
// linked against.
if ((*Sub)->IsExplicit)
continue;
if (Visited.insert(*Sub).second) {
Stack.push_back(*Sub);
AnyChildren = true;
}
}
// We didn't find any children, so add this module to the list of
// modules to link against.
if (!AnyChildren) {
LinkModules.insert(Mod);
}
}
// Add link options for all of the imported modules in reverse topological
// order. We don't do anything to try to order import link flags with respect
// to linker options inserted by things like #pragma comment().
SmallVector<llvm::Metadata *, 16> MetadataArgs;
Visited.clear();
for (llvm::SetVector<clang::Module *>::iterator M = LinkModules.begin(),
MEnd = LinkModules.end();
M != MEnd; ++M) {
if (Visited.insert(*M).second)
addLinkOptionsPostorder(*this, *M, MetadataArgs, Visited);
}
std::reverse(MetadataArgs.begin(), MetadataArgs.end());
LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
// Add the linker options metadata flag.
getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options",
llvm::MDNode::get(getLLVMContext(),
LinkerOptionsMetadata));
}
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 (true) {
if (!DeferredVTables.empty()) {
EmitDeferredVTables();
// Emitting a v-table doesn't directly cause more v-tables to
// become deferred, although it can cause functions to be
// emitted that then need those v-tables.
assert(DeferredVTables.empty());
}
// Stop if we're out of both deferred v-tables and deferred declarations.
if (DeferredDeclsToEmit.empty()) break;
DeferredGlobal &G = DeferredDeclsToEmit.back();
GlobalDecl D = G.GD;
llvm::GlobalValue *GV = G.GV;
DeferredDeclsToEmit.pop_back();
assert(!GV || GV == GetGlobalValue(getMangledName(D)));
if (!GV)
GV = GetGlobalValue(getMangledName(D));
// 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.
if (GV && !GV->isDeclaration())
continue;
// Otherwise, emit the definition and move on to the next one.
EmitGlobalDefinition(D, GV);
}
}
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);
auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
llvm::GlobalValue::AppendingLinkage,
Array, "llvm.global.annotations");
gv->setSection(AnnotationSection);
}
llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
llvm::Constant *&AStr = AnnotationStrings[Str];
if (AStr)
return AStr;
// Not found yet, create a new global.
llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
auto *gv =
new llvm::GlobalVariable(getModule(), s->getType(), true,
llvm::GlobalValue::PrivateLinkage, s, ".str");
gv->setSection(AnnotationSection);
gv->setUnnamedAddr(true);
AStr = 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,
const AnnotateAttr *AA,
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);
// Create the ConstantStruct for the global annotation.
llvm::Constant *Fields[4] = {
llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
LineNoCst
};
return llvm::ConstantStruct::getAnon(Fields);
}
void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
llvm::GlobalValue *GV) {
assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
// Get the struct elements for these annotations.
for (const auto *I : D->specific_attrs<AnnotateAttr>())
Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
}
bool CodeGenModule::isInSanitizerBlacklist(llvm::Function *Fn,
SourceLocation Loc) const {
const auto &SanitizerBL = getContext().getSanitizerBlacklist();
// Blacklist by function name.
if (SanitizerBL.isBlacklistedFunction(Fn->getName()))
return true;
// Blacklist by location.
if (!Loc.isInvalid())
return SanitizerBL.isBlacklistedLocation(Loc);
// If location is unknown, this may be a compiler-generated function. Assume
// it's located in the main file.
auto &SM = Context.getSourceManager();
if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
return SanitizerBL.isBlacklistedFile(MainFile->getName());
}
return false;
}
bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
SourceLocation Loc, QualType Ty,
StringRef Category) const {
// For now globals can be blacklisted only in ASan.
if (!LangOpts.Sanitize.has(SanitizerKind::Address))
return false;
const auto &SanitizerBL = getContext().getSanitizerBlacklist();
if (SanitizerBL.isBlacklistedGlobal(GV->getName(), Category))
return true;
if (SanitizerBL.isBlacklistedLocation(Loc, Category))
return true;
// Check global type.
if (!Ty.isNull()) {
// Drill down the array types: if global variable of a fixed type is
// blacklisted, we also don't instrument arrays of them.
while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
Ty = AT->getElementType();
Ty = Ty.getCanonicalType().getUnqualifiedType();
// We allow to blacklist only record types (classes, structs etc.)
if (Ty->isRecordType()) {
std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
if (SanitizerBL.isBlacklistedType(TypeStr, Category))
return true;
}
}
return false;
}
bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
// Never defer when EmitAllDecls is specified.
if (LangOpts.EmitAllDecls)
return true;
return getContext().DeclMustBeEmitted(Global);
}
bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
if (const auto *FD = dyn_cast<FunctionDecl>(Global))
if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
// Implicit template instantiations may change linkage if they are later
// explicitly instantiated, so they should not be emitted eagerly.
return false;
return true;
}
llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor(
const CXXUuidofExpr* E) {
// Sema has verified that IIDSource has a __declspec(uuid()), and that its
// well-formed.
StringRef Uuid = E->getUuidAsStringRef(Context);
std::string Name = "_GUID_" + Uuid.lower();
std::replace(Name.begin(), Name.end(), '-', '_');
// Look for an existing global.
if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
return GV;
llvm::Constant *Init = EmitUuidofInitializer(Uuid);
assert(Init && "failed to initialize as constant");
auto *GV = new llvm::GlobalVariable(
getModule(), Init->getType(),
/*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
return GV;
}
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());
if (Entry) {
unsigned AS = getContext().getTargetAddressSpace(VD->getType());
return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
}
llvm::Constant *Aliasee;
if (isa<llvm::FunctionType>(DeclTy))
Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
GlobalDecl(cast<FunctionDecl>(VD)),
/*ForVTable=*/false);
else
Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
llvm::PointerType::getUnqual(DeclTy),
nullptr);
auto *F = cast<llvm::GlobalValue>(Aliasee);
F->setLinkage(llvm::Function::ExternalWeakLinkage);
WeakRefReferences.insert(F);
return Aliasee;
}
void CodeGenModule::EmitGlobal(GlobalDecl GD) {
const auto *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.
if (Global->hasAttr<AliasAttr>())
return EmitAliasDefinition(GD);
// If this is CUDA, be selective about which declarations we emit.
if (LangOpts.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 auto *FD = dyn_cast<FunctionDecl>(Global)) {
// Forward declarations are emitted lazily on first use.
if (!FD->doesThisDeclarationHaveABody()) {
if (!FD->doesDeclarationForceExternallyVisibleDefinition())
return;
StringRef MangledName = getMangledName(GD);
// Compute the function info and LLVM type.
const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
llvm::Type *Ty = getTypes().GetFunctionType(FI);
GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
/*DontDefer=*/false);
return;
}
} else {
const auto *VD = cast<VarDecl>(Global);
assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
!Context.isMSStaticDataMemberInlineDefinition(VD))
return;
}
// Defer code generation to first use when possible, e.g. if this is an inline
// function. If the global must always be emitted, do it eagerly if possible
// to benefit from cache locality.
if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
// Emit the definition if it can't be deferred.
EmitGlobalDefinition(GD);
return;
}
// If we're deferring emission of a C++ variable with an
// initializer, remember the order in which it appeared in the file.
if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
cast<VarDecl>(Global)->hasInit()) {
DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
CXXGlobalInits.push_back(nullptr);
}
StringRef MangledName = getMangledName(GD);
if (llvm::GlobalValue *GV = GetGlobalValue(MangledName)) {
// The value has already been used and should therefore be emitted.
addDeferredDeclToEmit(GV, GD);
} else if (MustBeEmitted(Global)) {
// The value must be emitted, but cannot be emitted eagerly.
assert(!MayBeEmittedEagerly(Global));
addDeferredDeclToEmit(/*GV=*/nullptr, 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;
}
}
namespace {
struct FunctionIsDirectlyRecursive :
public RecursiveASTVisitor<FunctionIsDirectlyRecursive> {
const StringRef Name;
const Builtin::Context &BI;
bool Result;
FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) :
Name(N), BI(C), Result(false) {
}
typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base;
bool TraverseCallExpr(CallExpr *E) {
const FunctionDecl *FD = E->getDirectCallee();
if (!FD)
return true;
AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
if (Attr && Name == Attr->getLabel()) {
Result = true;
return false;
}
unsigned BuiltinID = FD->getBuiltinID();
if (!BuiltinID)
return true;
StringRef BuiltinName = BI.GetName(BuiltinID);
if (BuiltinName.startswith("__builtin_") &&
Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
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.
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();
}
FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD));
return Walker.Result;
}
bool
CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
return true;
const auto *F = cast<FunctionDecl>(GD.getDecl());
if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
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);
}
/// If the type for the method's class was generated by
/// CGDebugInfo::createContextChain(), the cache contains only a
/// limited DIType without any declarations. Since EmitFunctionStart()
/// needs to find the canonical declaration for each method, we need
/// to construct the complete type prior to emitting the method.
void CodeGenModule::CompleteDIClassType(const CXXMethodDecl* D) {
if (!D->isInstance())
return;
if (CGDebugInfo *DI = getModuleDebugInfo())
if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) {
const auto *ThisPtr = cast<PointerType>(D->getThisType(getContext()));
DI->getOrCreateRecordType(ThisPtr->getPointeeType(), D->getLocation());
}
}
void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
const auto *D = cast<ValueDecl>(GD.getDecl());
PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
Context.getSourceManager(),
"Generating code for declaration");
if (isa<FunctionDecl>(D)) {
// At -O0, don't generate IR for functions with available_externally
// linkage.
if (!shouldEmitFunction(GD))
return;
if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
CompleteDIClassType(Method);
// Make sure to emit the definition(s) before we emit the thunks.
// This is necessary for the generation of certain thunks.
if (const auto *CD = dyn_cast<CXXConstructorDecl>(Method))
ABI->emitCXXStructor(CD, getFromCtorType(GD.getCtorType()));
else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Method))
ABI->emitCXXStructor(DD, getFromDtorType(GD.getDtorType()));
else
EmitGlobalFunctionDefinition(GD, GV);
if (Method->isVirtual())
getVTables().EmitThunks(GD);
return;
}
return EmitGlobalFunctionDefinition(GD, GV);
}
if (const auto *VD = dyn_cast<VarDecl>(D))
return EmitGlobalVarDefinition(VD);
llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
}
/// 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 *
CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName,
llvm::Type *Ty,
GlobalDecl GD, bool ForVTable,
bool DontDefer, bool IsThunk,
llvm::AttributeSet ExtraAttrs) {
const Decl *D = GD.getDecl();
// Lookup the entry, lazily creating it if necessary.
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (Entry) {
if (WeakRefReferences.erase(Entry)) {
const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
if (FD && !FD->hasAttr<WeakAttr>())
Entry->setLinkage(llvm::Function::ExternalLinkage);
}
// Handle dropped DLL attributes.
if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
if (Entry->getType()->getElementType() == Ty)
return Entry;
// Make sure the result is of the correct type.
return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
}
// This function doesn't have a complete type (for example, the return
// type is an incomplete struct). Use a fake type instead, and make
// sure not to try to set attributes.
bool IsIncompleteFunction = false;
llvm::FunctionType *FTy;
if (isa<llvm::FunctionType>(Ty)) {
FTy = cast<llvm::FunctionType>(Ty);
} else {
FTy = llvm::FunctionType::get(VoidTy, false);
IsIncompleteFunction = true;
}
llvm::Function *F = llvm::Function::Create(FTy,
llvm::Function::ExternalLinkage,
MangledName, &getModule());
assert(F->getName() == MangledName && "name was uniqued!");
if (D)
SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
if (ExtraAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) {
llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeSet::FunctionIndex);
F->addAttributes(llvm::AttributeSet::FunctionIndex,
llvm::AttributeSet::get(VMContext,
llvm::AttributeSet::FunctionIndex,
B));
}
if (!DontDefer) {
// All MSVC dtors other than the base dtor are linkonce_odr and delegate to
// each other bottoming out with the base dtor. Therefore we emit non-base
// dtors on usage, even if there is no dtor definition in the TU.
if (D && isa<CXXDestructorDecl>(D) &&
getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
GD.getDtorType()))
addDeferredDeclToEmit(F, GD);
// This is the first use or definition of a mangled name. If there is a
// deferred decl with this name, remember that we need to emit it at the end
// of the file.
auto DDI = DeferredDecls.find(MangledName);
if (DDI != DeferredDecls.end()) {
// Move the potentially referenced deferred decl to the
// DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
// don't need it anymore).
addDeferredDeclToEmit(F, DDI->second);
DeferredDecls.erase(DDI);
// Otherwise, if this is a sized deallocation function, emit a weak
// definition
// for it at the end of the translation unit.
} else if (D && cast<FunctionDecl>(D)
->getCorrespondingUnsizedGlobalDeallocationFunction()) {
addDeferredDeclToEmit(F, GD);
// Otherwise, there are cases we have to worry about where we're
// using a declaration for which we must emit a definition but where
// we might not find a top-level definition:
// - member functions defined inline in their classes
// - friend functions defined inline in some class
// - special member functions with implicit definitions
// If we ever change our AST traversal to walk into class methods,
// this will be unnecessary.
//
// We also don't emit a definition for a function if it's going to be an
// entry in a vtable, unless it's already marked as used.
} else if (getLangOpts().CPlusPlus && D) {
// Look for a declaration that's lexically in a record.
for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
FD = FD->getPreviousDecl()) {
if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
if (FD->doesThisDeclarationHaveABody()) {
addDeferredDeclToEmit(F, GD.getWithDecl(FD));
break;
}
}
}
}
}
// Make sure the result is of the requested type.
if (!IsIncompleteFunction) {
assert(F->getType()->getElementType() == Ty);
return F;
}
llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
return llvm::ConstantExpr::getBitCast(F, PTy);
}
/// GetAddrOfFunction - Return the address of the given function. If Ty is
/// non-null, then this function will use the specified type if it has to
/// create it (this occurs when we see a definition of the function).
llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
llvm::Type *Ty,
bool ForVTable,
bool DontDefer) {
// If there was no specific requested type, just convert it now.
if (!Ty)
Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType());
StringRef MangledName = getMangledName(GD);
return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer);
}
/// CreateRuntimeFunction - Create a new runtime function with the specified
/// type and name.
llvm::Constant *
CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy,
StringRef Name,
llvm::AttributeSet ExtraAttrs) {
llvm::Constant *C =
GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
/*DontDefer=*/false, /*IsThunk=*/false, ExtraAttrs);
if (auto *F = dyn_cast<llvm::Function>(C))
if (F->empty())
F->setCallingConv(getRuntimeCC());
return C;
}
/// CreateBuiltinFunction - Create a new builtin function with the specified
/// type and name.
llvm::Constant *
CodeGenModule::CreateBuiltinFunction(llvm::FunctionType *FTy,
StringRef Name,
llvm::AttributeSet ExtraAttrs) {
llvm::Constant *C =
GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
/*DontDefer=*/false, /*IsThunk=*/false, ExtraAttrs);
if (auto *F = dyn_cast<llvm::Function>(C))
if (F->empty())
F->setCallingConv(getBuiltinCC());
return C;
}
/// isTypeConstant - Determine whether an object of this type can be emitted
/// as a constant.
///
/// If ExcludeCtor is true, the duration when the object's constructor runs
/// will not be considered. The caller will need to verify that the object is
/// not written to during its construction.
bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
if (!Ty.isConstant(Context) && !Ty->isReferenceType())
return false;
if (Context.getLangOpts().CPlusPlus) {
if (const CXXRecordDecl *Record
= Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
return ExcludeCtor && !Record->hasMutableFields() &&
Record->hasTrivialDestructor();
}
return true;
}
/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
/// create and return an llvm GlobalVariable 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 global when it is first created.
llvm::Constant *
CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
llvm::PointerType *Ty,
const VarDecl *D) {
// Lookup the entry, lazily creating it if necessary.
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (Entry) {
if (WeakRefReferences.erase(Entry)) {
if (D && !D->hasAttr<WeakAttr>())
Entry->setLinkage(llvm::Function::ExternalLinkage);
}
// Handle dropped DLL attributes.
if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
if (Entry->getType() == Ty)
return Entry;
// Make sure the result is of the correct type.
if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
return llvm::ConstantExpr::getBitCast(Entry, Ty);
}
unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace());
auto *GV = new llvm::GlobalVariable(
getModule(), Ty->getElementType(), false,
llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
llvm::GlobalVariable::NotThreadLocal, AddrSpace);
// This is the first use or definition of a mangled name. If there is a
// deferred decl with this name, remember that we need to emit it at the end
// of the file.
auto DDI = DeferredDecls.find(MangledName);
if (DDI != DeferredDecls.end()) {
// Move the potentially referenced deferred decl to the DeferredDeclsToEmit
// list, and remove it from DeferredDecls (since we don't need it anymore).
addDeferredDeclToEmit(GV, DDI->second);
DeferredDecls.erase(DDI);
}
// Handle things which are present even on external declarations.
if (D) {
// FIXME: This code is overly simple and should be merged with other global
// handling.
GV->setConstant(isTypeConstant(D->getType(), false));
setLinkageAndVisibilityForGV(GV, D);
if (D->getTLSKind()) {
if (D->getTLSKind() == VarDecl::TLS_Dynamic)
CXXThreadLocals.push_back(std::make_pair(D, GV));
setTLSMode(GV, *D);
}
// If required by the ABI, treat declarations of static data members with
// inline initializers as definitions.
if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
EmitGlobalVarDefinition(D);
}
// Handle XCore specific ABI requirements.
if (getTarget().getTriple().getArch() == llvm::Triple::xcore &&
D->getLanguageLinkage() == CLanguageLinkage &&
D->getType().isConstant(Context) &&
isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
GV->setSection(".cp.rodata");
}
if (AddrSpace != Ty->getAddressSpace())
return llvm::ConstantExpr::getAddrSpaceCast(GV, Ty);
return GV;
}
llvm::GlobalVariable *
CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
llvm::Type *Ty,
llvm::GlobalValue::LinkageTypes Linkage) {
llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
llvm::GlobalVariable *OldGV = nullptr;
if (GV) {
// Check if the variable has the right type.
if (GV->getType()->getElementType() == Ty)
return GV;
// Because C++ name mangling, the only way we can end up with an already
// existing global with the same name is if it has been declared extern "C".
assert(GV->isDeclaration() && "Declaration has wrong type!");
OldGV = GV;
}
// Create a new variable.
GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
Linkage, nullptr, Name);
if (OldGV) {
// Replace occurrences of the old variable if needed.
GV->takeName(OldGV);
if (!OldGV->use_empty()) {
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
OldGV->replaceAllUsesWith(NewPtrForOldDecl);
}
OldGV->eraseFromParent();
}
return GV;
}
/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
/// given global variable. If Ty is non-null and if the global doesn't exist,
/// then it will be created with the specified type instead of whatever the
/// normal requested type would be.
llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
llvm::Type *Ty) {
assert(D->hasGlobalStorage() && "Not a global variable");
QualType ASTTy = D->getType();
if (!Ty)
Ty = getTypes().ConvertTypeForMem(ASTTy);
llvm::PointerType *PTy =
llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
StringRef MangledName = getMangledName(D);
return GetOrCreateLLVMGlobal(MangledName, PTy, D);
}
/// CreateRuntimeVariable - Create a new runtime global variable with the
/// specified type and name.
llvm::Constant *
CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
StringRef Name) {
return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), nullptr);
}
void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
assert(!D->getInit() && "Cannot emit definite definitions here!");
if (!MustBeEmitted(D)) {
// If we have not seen a reference to this variable yet, place it
// into the deferred declarations table to be emitted if needed
// later.
StringRef MangledName = getMangledName(D);
if (!GetGlobalValue(MangledName)) {
DeferredDecls[MangledName] = D;
return;
}
}
// The tentative definition is the only definition.
EmitGlobalVarDefinition(D);
}
CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
return Context.toCharUnitsFromBits(
TheDataLayout.getTypeStoreSizeInBits(Ty));
}
unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D,
unsigned AddrSpace) {
if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) {
if (D->hasAttr<CUDAConstantAttr>())
AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant);
else if (D->hasAttr<CUDASharedAttr>())
AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared);
else
AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device);
}
return AddrSpace;
}
template<typename SomeDecl>
void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
llvm::GlobalValue *GV) {
if (!getLangOpts().CPlusPlus)
return;
// Must have 'used' attribute, or else inline assembly can't rely on
// the name existing.
if (!D->template hasAttr<UsedAttr>())
return;
// Must have internal linkage and an ordinary name.
if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
return;
// Must be in an extern "C" context. Entities declared directly within
// a record are not extern "C" even if the record is in such a context.
const SomeDecl *First = D->getFirstDecl();
if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
return;
// OK, this is an internal linkage entity inside an extern "C" linkage
// specification. Make a note of that so we can give it the "expected"
// mangled name if nothing else is using that name.
std::pair<StaticExternCMap::iterator, bool> R =
StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
// If we have multiple internal linkage entities with the same name
// in extern "C" regions, none of them gets that name.
if (!R.second)
R.first->second = nullptr;
}
static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
if (!CGM.supportsCOMDAT())
return false;
if (D.hasAttr<SelectAnyAttr>())
return true;
GVALinkage Linkage;
if (auto *VD = dyn_cast<VarDecl>(&D))
Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
else
Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
switch (Linkage) {
case GVA_Internal:
case GVA_AvailableExternally:
case GVA_StrongExternal:
return false;
case GVA_DiscardableODR:
case GVA_StrongODR:
return true;
}
llvm_unreachable("No such linkage");
}
void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
llvm::Constant *Init = nullptr;
QualType ASTTy = D->getType();
CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
bool NeedsGlobalCtor = false;
bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
const VarDecl *InitDecl;
const Expr *InitExpr = D->getAnyInitializer(InitDecl);
if (!InitExpr) {
// This is a tentative definition; tentative definitions are
// implicitly initialized with { 0 }.
//
// Note that tentative definitions are only emitted at the end of
// a translation unit, so they should never have incomplete
// type. In addition, EmitTentativeDefinition makes sure that we
// never attempt to emit a tentative definition if a real one
// exists. A use may still exists, however, so we still may need
// to do a RAUW.
assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
Init = EmitNullConstant(D->getType());
} else {
initializedGlobalDecl = GlobalDecl(D);
Init = EmitConstantInit(*InitDecl);
if (!Init) {
QualType T = InitExpr->getType();
if (D->getType()->isReferenceType())
T = D->getType();
if (getLangOpts().CPlusPlus) {
Init = EmitNullConstant(T);
NeedsGlobalCtor = true;
} else {
ErrorUnsupported(D, "static initializer");
Init = llvm::UndefValue::get(getTypes().ConvertType(T));
}
} else {
// We don't need an initializer, so remove the entry for the delayed
// initializer position (just in case this entry was delayed) if we
// also don't need to register a destructor.
if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
DelayedCXXInitPosition.erase(D);
}
}
llvm::Type* InitType = Init->getType();
llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType);
// Strip off a bitcast if we got one back.
if (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
assert(CE->getOpcode() == llvm::Instruction::BitCast ||
CE->getOpcode() == llvm::Instruction::AddrSpaceCast ||
// All zero index gep.
CE->getOpcode() == llvm::Instruction::GetElementPtr);
Entry = CE->getOperand(0);
}
// Entry is now either a Function or GlobalVariable.
auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
// We have a definition after a declaration with the wrong type.
// We must make a new GlobalVariable* and update everything that used OldGV
// (a declaration or tentative definition) with the new GlobalVariable*
// (which will be a definition).
//
// This happens if there is a prototype for a global (e.g.
// "extern int x[];") and then a definition of a different type (e.g.
// "int x[10];"). This also happens when an initializer has a different type
// from the type of the global (this happens with unions).
if (!GV ||
GV->getType()->getElementType() != InitType ||
GV->getType()->getAddressSpace() !=
GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) {
// Move the old entry aside so that we'll create a new one.
Entry->setName(StringRef());
// Make a new global with the correct type, this is now guaranteed to work.
GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType));
// Replace all uses of the old global with the new global
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(GV, Entry->getType());
Entry->replaceAllUsesWith(NewPtrForOldDecl);
// Erase the old global, since it is no longer used.
cast<llvm::GlobalValue>(Entry)->eraseFromParent();
}
MaybeHandleStaticInExternC(D, GV);
if (D->hasAttr<AnnotateAttr>())
AddGlobalAnnotations(D, GV);
GV->setInitializer(Init);
// If it is safe to mark the global 'constant', do so now.
GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
isTypeConstant(D->getType(), true));
// If it is in a read-only section, mark it 'constant'.
if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
GV->setConstant(true);
}
GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
// Set the llvm linkage type as appropriate.
llvm::GlobalValue::LinkageTypes Linkage =
getLLVMLinkageVarDefinition(D, GV->isConstant());
// On Darwin, the backing variable for a C++11 thread_local variable always
// has internal linkage; all accesses should just be calls to the
// Itanium-specified entry point, which has the normal linkage of the
// variable.
if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
Context.getTargetInfo().getTriple().isMacOSX())
Linkage = llvm::GlobalValue::InternalLinkage;
GV->setLinkage(Linkage);
if (D->hasAttr<DLLImportAttr>())
GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
else if (D->hasAttr<DLLExportAttr>())
GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
else
GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
if (Linkage == llvm::GlobalVariable::CommonLinkage)
// common vars aren't constant even if declared const.
GV->setConstant(false);
setNonAliasAttributes(D, GV);
if (D->getTLSKind() && !GV->isThreadLocal()) {
if (D->getTLSKind() == VarDecl::TLS_Dynamic)
CXXThreadLocals.push_back(std::make_pair(D, GV));
setTLSMode(GV, *D);
}
if (shouldBeInCOMDAT(*this, *D))
GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
// Emit the initializer function if necessary.
if (NeedsGlobalCtor || NeedsGlobalDtor)
EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
// Emit global variable debug information.
if (CGDebugInfo *DI = getModuleDebugInfo())
if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo)
DI->EmitGlobalVariable(GV, D);
}
static bool isVarDeclStrongDefinition(const ASTContext &Context,
const VarDecl *D, bool NoCommon) {
// Don't give variables common linkage if -fno-common was specified unless it
// was overridden by a NoCommon attribute.
if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
return true;
// C11 6.9.2/2:
// A declaration of an identifier for an object that has file scope without
// an initializer, and without a storage-class specifier or with the
// storage-class specifier static, constitutes a tentative definition.
if (D->getInit() || D->hasExternalStorage())
return true;
// A variable cannot be both common and exist in a section.
if (D->hasAttr<SectionAttr>())
return true;
// Thread local vars aren't considered common linkage.
if (D->getTLSKind())
return true;
// Tentative definitions marked with WeakImportAttr are true definitions.
if (D->hasAttr<WeakImportAttr>())
return true;
// Declarations with a required alignment do not have common linakge in MSVC
// mode.
if (Context.getLangOpts().MSVCCompat &&
(Context.isAlignmentRequired(D->getType()) || D->hasAttr<AlignedAttr>()))
return true;
return false;
}
llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
if (Linkage == GVA_Internal)
return llvm::Function::InternalLinkage;
if (D->hasAttr<WeakAttr>()) {
if (IsConstantVariable)
return llvm::GlobalVariable::WeakODRLinkage;
else
return llvm::GlobalVariable::WeakAnyLinkage;
}
// We are guaranteed to have a strong definition somewhere else,
// so we can use available_externally linkage.
if (Linkage == GVA_AvailableExternally)
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_DiscardableODR)
return !Context.getLangOpts().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_StrongODR)
return !Context.getLangOpts().AppleKext ? llvm::Function::WeakODRLinkage
: llvm::Function::ExternalLinkage;
// C++ doesn't have tentative definitions and thus cannot have common
// linkage.
if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
!isVarDeclStrongDefinition(Context, cast<VarDecl>(D),
CodeGenOpts.NoCommon))
return llvm::GlobalVariable::CommonLinkage;
// selectany symbols are externally visible, so use weak instead of
// linkonce. MSVC optimizes away references to const selectany globals, so
// all definitions should be the same and ODR linkage should be used.
// http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
if (D->hasAttr<SelectAnyAttr>())
return llvm::GlobalVariable::WeakODRLinkage;
// Otherwise, we have strong external linkage.
assert(Linkage == GVA_StrongExternal);
return llvm::GlobalVariable::ExternalLinkage;
}
llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
const VarDecl *VD, bool IsConstant) {
GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
}
/// Replace the uses of a function that was declared with a non-proto type.
/// We want to silently drop extra arguments from call sites
static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
llvm::Function *newFn) {
// Fast path.
if (old->use_empty()) return;
llvm::Type *newRetTy = newFn->getReturnType();
SmallVector<llvm::Value*, 4> newArgs;
for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
ui != ue; ) {
llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
llvm::User *user = use->getUser();
// Recognize and replace uses of bitcasts. Most calls to
// unprototyped functions will use bitcasts.
if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
if (bitcast->getOpcode() == llvm::Instruction::BitCast)
replaceUsesOfNonProtoConstant(bitcast, newFn);
continue;
}
// Recognize calls to the function.
llvm::CallSite callSite(user);
if (!callSite) continue;
if (!callSite.isCallee(&*use)) continue;
// If the return types don't match exactly, then we can't
// transform this call unless it's dead.
if (callSite->getType() != newRetTy && !callSite->use_empty())
continue;
// Get the call site's attribute list.
SmallVector<llvm::AttributeSet, 8> newAttrs;
llvm::AttributeSet oldAttrs = callSite.getAttributes();
// Collect any return attributes from the call.
if (oldAttrs.hasAttributes(llvm::AttributeSet::ReturnIndex))
newAttrs.push_back(
llvm::AttributeSet::get(newFn->getContext(),
oldAttrs.getRetAttributes()));
// If the function was passed too few arguments, don't transform.
unsigned newNumArgs = newFn->arg_size();
if (callSite.arg_size() < newNumArgs) continue;
// If extra arguments were passed, we silently drop them.
// If any of the types mismatch, we don't transform.
unsigned argNo = 0;
bool dontTransform = false;
for (llvm::Function::arg_iterator ai = newFn->arg_begin(),
ae = newFn->arg_end(); ai != ae; ++ai, ++argNo) {
if (callSite.getArgument(argNo)->getType() != ai->getType()) {
dontTransform = true;
break;
}
// Add any parameter attributes.
if (oldAttrs.hasAttributes(argNo + 1))
newAttrs.
push_back(llvm::
AttributeSet::get(newFn->getContext(),
oldAttrs.getParamAttributes(argNo + 1)));
}
if (dontTransform)
continue;
if (oldAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex))
newAttrs.push_back(llvm::AttributeSet::get(newFn->getContext(),
oldAttrs.getFnAttributes()));
// Okay, we can transform this. Create the new call instruction and copy
// over the required information.
newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo);
llvm::CallSite newCall;
if (callSite.isCall()) {
newCall = llvm::CallInst::Create(newFn, newArgs, "",
callSite.getInstruction());
} else {
auto *oldInvoke = cast<llvm::InvokeInst>(callSite.getInstruction());
newCall = llvm::InvokeInst::Create(newFn,
oldInvoke->getNormalDest(),
oldInvoke->getUnwindDest(),
newArgs, "",
callSite.getInstruction());
}
newArgs.clear(); // for the next iteration
if (!newCall->getType()->isVoidTy())
newCall->takeName(callSite.getInstruction());
newCall.setAttributes(
llvm::AttributeSet::get(newFn->getContext(), newAttrs));
newCall.setCallingConv(callSite.getCallingConv());
// Finally, remove the old call, replacing any uses with the new one.
if (!callSite->use_empty())
callSite->replaceAllUsesWith(newCall.getInstruction());
// Copy debug location attached to CI.
if (!callSite->getDebugLoc().isUnknown())
newCall->setDebugLoc(callSite->getDebugLoc());
callSite->eraseFromParent();
}
}
/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
/// implement a function with no prototype, e.g. "int foo() {}". If there are
/// existing call uses of the old function in the module, this adjusts them to
/// call the new function directly.
///
/// This is not just a cleanup: the always_inline pass requires direct calls to
/// functions to be able to inline them. If there is a bitcast in the way, it
/// won't inline them. Instcombine normally deletes these calls, but it isn't
/// run at -O0.
static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
llvm::Function *NewFn) {
// If we're redefining a global as a function, don't transform it.
if (!isa<llvm::Function>(Old)) return;
replaceUsesOfNonProtoConstant(Old, NewFn);
}
void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
// If we have a definition, this might be a deferred decl. If the
// instantiation is explicit, make sure we emit it at the end.
if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
GetAddrOfGlobalVar(VD);
EmitTopLevelDecl(VD);
}
void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
llvm::GlobalValue *GV) {
const auto *D = cast<FunctionDecl>(GD.getDecl());
// Compute the function info and LLVM type.
const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
// Get or create the prototype for the function.
if (!GV) {
llvm::Constant *C =
GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer*/ true);
// Strip off a bitcast if we got one back.
if (auto *CE = dyn_cast<llvm::ConstantExpr>(C)) {
assert(CE->getOpcode() == llvm::Instruction::BitCast);
GV = cast<llvm::GlobalValue>(CE->getOperand(0));
} else {
GV = cast<llvm::GlobalValue>(C);
}
}
if (!GV->isDeclaration()) {
getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name);
GlobalDecl OldGD = Manglings.lookup(GV->getName());
if (auto *Prev = OldGD.getDecl())
getDiags().Report(Prev->getLocation(), diag::note_previous_definition);
return;
}
if (GV->getType()->getElementType() != Ty) {
// If the types mismatch then we have to rewrite the definition.
assert(GV->isDeclaration() && "Shouldn't replace non-declaration");
// F is the Function* for the one with the wrong type, we must make a new
// Function* and update everything that used F (a declaration) with the new
// Function* (which will be a definition).
//
// This happens if there is a prototype for a function
// (e.g. "int f()") and then a definition of a different type
// (e.g. "int f(int x)"). Move the old function aside so that it
// doesn't interfere with GetAddrOfFunction.
GV->setName(StringRef());
auto *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty));
// This might be an implementation of a function without a
// prototype, in which case, try to do special replacement of
// calls which match the new prototype. The really key thing here
// is that we also potentially drop arguments from the call site
// so as to make a direct call, which makes the inliner happier
// and suppresses a number of optimizer warnings (!) about
// dropping arguments.
if (!GV->use_empty()) {
ReplaceUsesOfNonProtoTypeWithRealFunction(GV, NewFn);
GV->removeDeadConstantUsers();
}
// Replace uses of F with the Function we will endow with a body.
if (!GV->use_empty()) {
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(NewFn, GV->getType());
GV->replaceAllUsesWith(NewPtrForOldDecl);
}
// Ok, delete the old function now, which is dead.
GV->eraseFromParent();
GV = NewFn;
}
// We need to set linkage and visibility on the function before
// generating code for it because various parts of IR generation
// want to propagate this information down (e.g. to local static
// declarations).
auto *Fn = cast<llvm::Function>(GV);
setFunctionLinkage(GD, Fn);
if (D->hasAttr<DLLImportAttr>())
GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
else if (D->hasAttr<DLLExportAttr>())
GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
else
GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
// FIXME: this is redundant with part of setFunctionDefinitionAttributes
setGlobalVisibility(Fn, D);
MaybeHandleStaticInExternC(D, Fn);
if (shouldBeInCOMDAT(*this, *D))
Fn->setComdat(TheModule.getOrInsertComdat(Fn->getName()));
CodeGenFunction(*this).GenerateCode(D, Fn, FI);
setFunctionDefinitionAttributes(D, Fn);
SetLLVMFunctionAttributesForDefinition(D, Fn);
if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
AddGlobalCtor(Fn, CA->getPriority());
if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
AddGlobalDtor(Fn, DA->getPriority());
if (D->hasAttr<AnnotateAttr>())
AddGlobalAnnotations(D, Fn);
}
void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
const auto *D = cast<ValueDecl>(GD.getDecl());
const AliasAttr *AA = D->getAttr<AliasAttr>();
assert(AA && "Not an alias?");
StringRef MangledName = getMangledName(GD);
// If there is a definition in the module, then it wins over the alias.
// This is dubious, but allow it to be safe. Just ignore the alias.
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (Entry && !Entry->isDeclaration())
return;
Aliases.push_back(GD);
llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
// Create a reference to the named value. This ensures that it is emitted
// if a deferred decl.
llvm::Constant *Aliasee;
if (isa<llvm::FunctionType>(DeclTy))
Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
/*ForVTable=*/false);
else
Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
llvm::PointerType::getUnqual(DeclTy),
/*D=*/nullptr);
// Create the new alias itself, but don't set a name yet.
auto *GA = llvm::GlobalAlias::create(
cast<llvm::PointerType>(Aliasee->getType())->getElementType(), 0,
llvm::Function::ExternalLinkage, "", Aliasee, &getModule());
if (Entry) {
if (GA->getAliasee() == Entry) {
Diags.Report(AA->getLocation(), diag::err_cyclic_alias);
return;
}
assert(Entry->isDeclaration());
// If there is a declaration in the module, then we had an extern followed
// by the alias, as in:
// extern int test6();
// ...
// int test6() __attribute__((alias("test7")));
//
// Remove it and replace uses of it with the alias.
GA->takeName(Entry);
Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
Entry->getType()));
Entry->eraseFromParent();
} else {
GA->setName(MangledName);
}
// Set attributes which are particular to an alias; this is a
// specialization of the attributes which may be set on a global
// variable/function.
if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
D->isWeakImported()) {
GA->setLinkage(llvm::Function::WeakAnyLinkage);
}
if (const auto *VD = dyn_cast<VarDecl>(D))
if (VD->getTLSKind())
setTLSMode(GA, *VD);
setAliasAttributes(D, GA);
}
llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
ArrayRef<llvm::Type*> Tys) {
return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
Tys);
}
static llvm::StringMapEntry<llvm::Constant*> &
GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map,
const StringLiteral *Literal,
bool TargetIsLSB,
bool &IsUTF16,
unsigned &StringLength) {
StringRef String = Literal->getString();
unsigned NumBytes = String.size();
// Check for simple case.
if (!Literal->containsNonAsciiOrNull()) {
StringLength = NumBytes;
return *Map.insert(std::make_pair(String, nullptr)).first;
}
// Otherwise, convert the UTF8 literals into a string of shorts.
IsUTF16 = true;
SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
const UTF8 *FromPtr = (const UTF8 *)String.data();
UTF16 *ToPtr = &ToBuf[0];
(void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
&ToPtr, ToPtr + NumBytes,
strictConversion);
// ConvertUTF8toUTF16 returns the length in ToPtr.
StringLength = ToPtr - &ToBuf[0];
// Add an explicit null.
*ToPtr = 0;
return *Map.insert(std::make_pair(
StringRef(reinterpret_cast<const char *>(ToBuf.data()),
(StringLength + 1) * 2),
nullptr)).first;
}
static llvm::StringMapEntry<llvm::Constant*> &
GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map,
const StringLiteral *Literal,
unsigned &StringLength) {
StringRef String = Literal->getString();
StringLength = String.size();
return *Map.insert(std::make_pair(String, nullptr)).first;
}
llvm::Constant *
CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
unsigned StringLength = 0;
bool isUTF16 = false;
llvm::StringMapEntry<llvm::Constant*> &Entry =
GetConstantCFStringEntry(CFConstantStringMap, Literal,
getDataLayout().isLittleEndian(),
isUTF16, StringLength);
if (auto *C = Entry.second)
return C;
llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
llvm::Constant *Zeros[] = { Zero, Zero };
llvm::Value *V;
// If we don't already have it, get __CFConstantStringClassReference.
if (!CFConstantStringClassRef) {
llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
Ty = llvm::ArrayType::get(Ty, 0);
llvm::Constant *GV = CreateRuntimeVariable(Ty,
"__CFConstantStringClassReference");
// Decay array -> ptr
V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
CFConstantStringClassRef = V;
}
else
V = CFConstantStringClassRef;
QualType CFTy = getContext().getCFConstantStringType();
auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
llvm::Constant *Fields[4];
// Class pointer.
Fields[0] = cast<llvm::ConstantExpr>(V);
// Flags.
llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) :
llvm::ConstantInt::get(Ty, 0x07C8);
// String pointer.
llvm::Constant *C = nullptr;
if (isUTF16) {
ArrayRef<uint16_t> Arr = llvm::makeArrayRef<uint16_t>(
reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
Entry.first().size() / 2);
C = llvm::ConstantDataArray::get(VMContext, Arr);
} else {
C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
}
// Note: -fwritable-strings doesn't make the backing store strings of
// CFStrings writable. (See <rdar://problem/10657500>)
auto *GV =
new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
llvm::GlobalValue::PrivateLinkage, C, ".str");
GV->setUnnamedAddr(true);
// Don't enforce the target's minimum global alignment, since the only use
// of the string is via this class initializer.
// FIXME: We set the section explicitly to avoid a bug in ld64 224.1. Without
// it LLVM can merge the string with a non unnamed_addr one during LTO. Doing
// that changes the section it ends in, which surprises ld64.
if (isUTF16) {
CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy);
GV->setAlignment(Align.getQuantity());
GV->setSection("__TEXT,__ustring");
} else {
CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
GV->setAlignment(Align.getQuantity());
GV->setSection("__TEXT,__cstring,cstring_literals");
}
// String.
Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
if (isUTF16)
// Cast the UTF16 string to the correct type.
Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy);
// String length.
Ty = getTypes().ConvertType(getContext().LongTy);
Fields[3] = llvm::ConstantInt::get(Ty, StringLength);
// The struct.
C = llvm::ConstantStruct::get(STy, Fields);
GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
llvm::GlobalVariable::PrivateLinkage, C,
"_unnamed_cfstring_");
GV->setSection("__DATA,__cfstring");
Entry.second = GV;
return GV;
}
llvm::Constant *
CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) {
unsigned StringLength = 0;
llvm::StringMapEntry<llvm::Constant*> &Entry =
GetConstantStringEntry(CFConstantStringMap, Literal, StringLength);
if (auto *C = Entry.second)
return C;
llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
llvm::Constant *Zeros[] = { Zero, Zero };
llvm::Value *V;
// If we don't already have it, get _NSConstantStringClassReference.
if (!ConstantStringClassRef) {
std::string StringClass(getLangOpts().ObjCConstantStringClass);
llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
llvm::Constant *GV;
if (LangOpts.ObjCRuntime.isNonFragile()) {
std::string str =
StringClass.empty() ? "OBJC_CLASS_$_NSConstantString"
: "OBJC_CLASS_$_" + StringClass;
GV = getObjCRuntime().GetClassGlobal(str);
// Make sure the result is of the correct type.
llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
V = llvm::ConstantExpr::getBitCast(GV, PTy);
ConstantStringClassRef = V;
} else {
std::string str =
StringClass.empty() ? "_NSConstantStringClassReference"
: "_" + StringClass + "ClassReference";
llvm::Type *PTy = llvm::ArrayType::get(Ty, 0);
GV = CreateRuntimeVariable(PTy, str);
// Decay array -> ptr
V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
ConstantStringClassRef = V;
}
}
else
V = ConstantStringClassRef;
if (!NSConstantStringType) {
// Construct the type for a constant NSString.
RecordDecl *D = Context.buildImplicitRecord("__builtin_NSString");
D->startDefinition();
QualType FieldTypes[3];
// const int *isa;
FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst());
// const char *str;
FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst());
// unsigned int length;
FieldTypes[2] = Context.UnsignedIntTy;
// Create fields
for (unsigned i = 0; i < 3; ++i) {
FieldDecl *Field = FieldDecl::Create(Context, D,
SourceLocation(),
SourceLocation(), nullptr,
FieldTypes[i], /*TInfo=*/nullptr,
/*BitWidth=*/nullptr,
/*Mutable=*/false,
ICIS_NoInit);
Field->setAccess(AS_public);
D->addDecl(Field);
}
D->completeDefinition();
QualType NSTy = Context.getTagDeclType(D);
NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy));
}
llvm::Constant *Fields[3];
// Class pointer.
Fields[0] = cast<llvm::ConstantExpr>(V);
// String pointer.
llvm::Constant *C =
llvm::ConstantDataArray::getString(VMContext, Entry.first());
llvm::GlobalValue::LinkageTypes Linkage;
bool isConstant;
Linkage = llvm::GlobalValue::PrivateLinkage;
isConstant = !LangOpts.WritableStrings;
auto *GV = new llvm::GlobalVariable(getModule(), C->getType(), isConstant,
Linkage, C, ".str");
GV->setUnnamedAddr(true);
// Don't enforce the target's minimum global alignment, since the only use
// of the string is via this class initializer.
CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
GV->setAlignment(Align.getQuantity());
Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
// String length.
llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
Fields[2] = llvm::ConstantInt::get(Ty, StringLength);
// The struct.
C = llvm::ConstantStruct::get(NSConstantStringType, Fields);
GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
llvm::GlobalVariable::PrivateLinkage, C,
"_unnamed_nsstring_");
const char *NSStringSection = "__OBJC,__cstring_object,regular,no_dead_strip";
const char *NSStringNonFragileABISection =
"__DATA,__objc_stringobj,regular,no_dead_strip";
// FIXME. Fix section.
GV->setSection(LangOpts.ObjCRuntime.isNonFragile()
? NSStringNonFragileABISection
: NSStringSection);
Entry.second = GV;
return GV;
}
QualType CodeGenModule::getObjCFastEnumerationStateType() {
if (ObjCFastEnumerationStateType.isNull()) {
RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
D->startDefinition();
QualType FieldTypes[] = {
Context.UnsignedLongTy,
Context.getPointerType(Context.getObjCIdType()),
Context.getPointerType(Context.UnsignedLongTy),
Context.getConstantArrayType(Context.UnsignedLongTy,
llvm::APInt(32, 5), ArrayType::Normal, 0)
};
for (size_t i = 0; i < 4; ++i) {
FieldDecl *Field = FieldDecl::Create(Context,
D,
SourceLocation(),
SourceLocation(), nullptr,
FieldTypes[i], /*TInfo=*/nullptr,
/*BitWidth=*/nullptr,
/*Mutable=*/false,
ICIS_NoInit);
Field->setAccess(AS_public);
D->addDecl(Field);
}
D->completeDefinition();
ObjCFastEnumerationStateType = Context.getTagDeclType(D);
}
return ObjCFastEnumerationStateType;
}
llvm::Constant *
CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
assert(!E->getType()->isPointerType() && "Strings are always arrays");
// Don't emit it as the address of the string, emit the string data itself
// as an inline array.
if (E->getCharByteWidth() == 1) {
SmallString<64> Str(E->getString());
// Resize the string to the right size, which is indicated by its type.
const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
Str.resize(CAT->getSize().getZExtValue());
return llvm::ConstantDataArray::getString(VMContext, Str, false);
}
auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
llvm::Type *ElemTy = AType->getElementType();
unsigned NumElements = AType->getNumElements();
// Wide strings have either 2-byte or 4-byte elements.
if (ElemTy->getPrimitiveSizeInBits() == 16) {
SmallVector<uint16_t, 32> Elements;
Elements.reserve(NumElements);
for(unsigned i = 0, e = E->getLength(); i != e; ++i)
Elements.push_back(E->getCodeUnit(i));
Elements.resize(NumElements);
return llvm::ConstantDataArray::get(VMContext, Elements);
}
assert(ElemTy->getPrimitiveSizeInBits() == 32);
SmallVector<uint32_t, 32> Elements;
Elements.reserve(NumElements);
for(unsigned i = 0, e = E->getLength(); i != e; ++i)
Elements.push_back(E->getCodeUnit(i));
Elements.resize(NumElements);
return llvm::ConstantDataArray::get(VMContext, Elements);
}
static llvm::GlobalVariable *
GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
CodeGenModule &CGM, StringRef GlobalName,
unsigned Alignment) {
// OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
unsigned AddrSpace = 0;
if (CGM.getLangOpts().OpenCL)
AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant);
// Create a global variable for this string
auto *GV = new llvm::GlobalVariable(
CGM.getModule(), C->getType(), !CGM.getLangOpts().WritableStrings, LT, C,
GlobalName, nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
GV->setAlignment(Alignment);
GV->setUnnamedAddr(true);
return GV;
}
/// GetAddrOfConstantStringFromLiteral - Return a pointer to a
/// constant array for the given string literal.
llvm::GlobalVariable *
CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
StringRef Name) {
auto Alignment =
getContext().getAlignOfGlobalVarInChars(S->getType()).getQuantity();
llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
llvm::GlobalVariable **Entry = nullptr;
if (!LangOpts.WritableStrings) {
Entry = &ConstantStringMap[C];
if (auto GV = *Entry) {
if (Alignment > GV->getAlignment())
GV->setAlignment(Alignment);
return GV;
}
}
SmallString<256> MangledNameBuffer;
StringRef GlobalVariableName;
llvm::GlobalValue::LinkageTypes LT;
// Mangle the string literal if the ABI allows for it. However, we cannot
// do this if we are compiling with ASan or -fwritable-strings because they
// rely on strings having normal linkage.
if (!LangOpts.WritableStrings &&
!LangOpts.Sanitize.has(SanitizerKind::Address) &&
getCXXABI().getMangleContext().shouldMangleStringLiteral(S)) {
llvm::raw_svector_ostream Out(MangledNameBuffer);
getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
Out.flush();
LT = llvm::GlobalValue::LinkOnceODRLinkage;
GlobalVariableName = MangledNameBuffer;
} else {
LT = llvm::GlobalValue::PrivateLinkage;
GlobalVariableName = Name;
}
auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
if (Entry)
*Entry = GV;
SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
QualType());
return GV;
}
/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
/// array for the given ObjCEncodeExpr node.
llvm::GlobalVariable *
CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
std::string Str;
getContext().getObjCEncodingForType(E->getEncodedType(), Str);
return GetAddrOfConstantCString(Str);
}
/// GetAddrOfConstantCString - Returns a pointer to a character array containing
/// the literal and a terminating '\0' character.
/// The result has pointer to array type.
llvm::GlobalVariable *CodeGenModule::GetAddrOfConstantCString(
const std::string &Str, const char *GlobalName, unsigned Alignment) {
StringRef StrWithNull(Str.c_str(), Str.size() + 1);
if (Alignment == 0) {
Alignment = getContext()
.getAlignOfGlobalVarInChars(getContext().CharTy)
.getQuantity();
}
llvm::Constant *C =
llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
// Don't share any string literals if strings aren't constant.
llvm::GlobalVariable **Entry = nullptr;
if (!LangOpts.WritableStrings) {
Entry = &ConstantStringMap[C];
if (auto GV = *Entry) {
if (Alignment > GV->getAlignment())
GV->setAlignment(Alignment);
return GV;
}
}
// Get the default prefix if a name wasn't specified.
if (!GlobalName)
GlobalName = ".str";
// Create a global variable for this.
auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
GlobalName, Alignment);
if (Entry)
*Entry = GV;
return GV;
}
llvm::Constant *CodeGenModule::GetAddrOfGlobalTemporary(
const MaterializeTemporaryExpr *E, const Expr *Init) {
assert((E->getStorageDuration() == SD_Static ||
E->getStorageDuration() == SD_Thread) && "not a global temporary");
const auto *VD = cast<VarDecl>(E->getExtendingDecl());
// If we're not materializing a subobject of the temporary, keep the
// cv-qualifiers from the type of the MaterializeTemporaryExpr.
QualType MaterializedType = Init->getType();
if (Init == E->GetTemporaryExpr())
MaterializedType = E->getType();
llvm::Constant *&Slot = MaterializedGlobalTemporaryMap[E];
if (Slot)
return Slot;
// FIXME: If an externally-visible declaration extends multiple temporaries,
// we need to give each temporary the same name in every translation unit (and
// we also need to make the temporaries externally-visible).
SmallString<256> Name;
llvm::raw_svector_ostream Out(Name);
getCXXABI().getMangleContext().mangleReferenceTemporary(
VD, E->getManglingNumber(), Out);
Out.flush();
APValue *Value = nullptr;
if (E->getStorageDuration() == SD_Static) {
// We might have a cached constant initializer for this temporary. Note
// that this might have a different value from the value computed by
// evaluating the initializer if the surrounding constant expression
// modifies the temporary.
Value = getContext().getMaterializedTemporaryValue(E, false);
if (Value && Value->isUninit())
Value = nullptr;
}
// Try evaluating it now, it might have a constant initializer.
Expr::EvalResult EvalResult;
if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
!EvalResult.hasSideEffects())
Value = &EvalResult.Val;
llvm::Constant *InitialValue = nullptr;
bool Constant = false;
llvm::Type *Type;
if (Value) {
// The temporary has a constant initializer, use it.
InitialValue = EmitConstantValue(*Value, MaterializedType, nullptr);
Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
Type = InitialValue->getType();
} else {
// No initializer, the initialization will be provided when we
// initialize the declaration which performed lifetime extension.
Type = getTypes().ConvertTypeForMem(MaterializedType);
}
// Create a global variable for this lifetime-extended temporary.
llvm::GlobalValue::LinkageTypes Linkage =
getLLVMLinkageVarDefinition(VD, Constant);
// There is no need for this temporary to have global linkage if the global
// variable has external linkage.
if (Linkage == llvm::GlobalVariable::ExternalLinkage)
Linkage = llvm::GlobalVariable::PrivateLinkage;
unsigned AddrSpace = GetGlobalVarAddressSpace(
VD, getContext().getTargetAddressSpace(MaterializedType));
auto *GV = new llvm::GlobalVariable(
getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
/*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal,
AddrSpace);
setGlobalVisibility(GV, VD);
GV->setAlignment(
getContext().getTypeAlignInChars(MaterializedType).getQuantity());
if (VD->getTLSKind())
setTLSMode(GV, *VD);
Slot = GV;
return GV;
}
/// EmitObjCPropertyImplementations - Emit information for synthesized
/// properties for an implementation.
void CodeGenModule::EmitObjCPropertyImplementations(const
ObjCImplementationDecl *D) {
for (const auto *PID : D->property_impls()) {
// Dynamic is just for type-checking.
if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
ObjCPropertyDecl *PD = PID->getPropertyDecl();
// Determine which methods need to be implemented, some may have
// been overridden. Note that ::isPropertyAccessor is not the method
// we want, that just indicates if the decl came from a
// property. What we want to know is if the method is defined in
// this implementation.
if (!D->getInstanceMethod(PD->getGetterName()))
CodeGenFunction(*this).GenerateObjCGetter(
const_cast<ObjCImplementationDecl *>(D), PID);
if (!PD->isReadOnly() &&
!D->getInstanceMethod(PD->getSetterName()))
CodeGenFunction(*this).GenerateObjCSetter(
const_cast<ObjCImplementationDecl *>(D), PID);
}
}
}
static bool needsDestructMethod(ObjCImplementationDecl *impl) {
const ObjCInterfaceDecl *iface = impl->getClassInterface();
for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
ivar; ivar = ivar->getNextIvar())
if (ivar->getType().isDestructedType())
return true;
return false;
}
static bool AllTrivialInitializers(CodeGenModule &CGM,
ObjCImplementationDecl *D) {
CodeGenFunction CGF(CGM);
for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
E = D->init_end(); B != E; ++B) {
CXXCtorInitializer *CtorInitExp = *B;
Expr *Init = CtorInitExp->getInit();
if (!CGF.isTrivialInitializer(Init))
return false;
}
return true;
}
/// EmitObjCIvarInitializations - Emit information for ivar initialization
/// for an implementation.
void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
// We might need a .cxx_destruct even if we don't have any ivar initializers.
if (needsDestructMethod(D)) {
IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
ObjCMethodDecl *DTORMethod =
ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(),
cxxSelector, getContext().VoidTy, nullptr, D,
/*isInstance=*/true, /*isVariadic=*/false,
/*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true,
/*isDefined=*/false, ObjCMethodDecl::Required);
D->addInstanceMethod(DTORMethod);
CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
D->setHasDestructors(true);
}
// If the implementation doesn't have any ivar initializers, we don't need
// a .cxx_construct.
if (D->getNumIvarInitializers() == 0 ||
AllTrivialInitializers(*this, D))
return;
IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
// The constructor returns 'self'.
ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(),
D->getLocation(),
D->getLocation(),
cxxSelector,
getContext().getObjCIdType(),
nullptr, D, /*isInstance=*/true,
/*isVariadic=*/false,
/*isPropertyAccessor=*/true,
/*isImplicitlyDeclared=*/true,
/*isDefined=*/false,
ObjCMethodDecl::Required);
D->addInstanceMethod(CTORMethod);
CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
D->setHasNonZeroConstructors(true);
}
/// EmitNamespace - Emit all declarations in a namespace.
void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) {
for (auto *I : ND->decls()) {
if (const auto *VD = dyn_cast<VarDecl>(I))
if (VD->getTemplateSpecializationKind() != TSK_ExplicitSpecialization &&
VD->getTemplateSpecializationKind() != TSK_Undeclared)
continue;
EmitTopLevelDecl(I);
}
}
// EmitLinkageSpec - Emit all declarations in a linkage spec.
void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
ErrorUnsupported(LSD, "linkage spec");
return;
}
for (auto *I : LSD->decls()) {
// Meta-data for ObjC class includes references to implemented methods.
// Generate class's method definitions first.
if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
for (auto *M : OID->methods())
EmitTopLevelDecl(M);
}
EmitTopLevelDecl(I);
}
}
/// EmitTopLevelDecl - Emit code for a single top level declaration.
void CodeGenModule::EmitTopLevelDecl(Decl *D) {
// Ignore dependent declarations.
if (D->getDeclContext() && D->getDeclContext()->isDependentContext())
return;
switch (D->getKind()) {
case Decl::CXXConversion:
case Decl::CXXMethod:
case Decl::Function:
// Skip function templates
if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
cast<FunctionDecl>(D)->isLateTemplateParsed())
return;
EmitGlobal(cast<FunctionDecl>(D));
// Always provide some coverage mapping
// even for the functions that aren't emitted.
AddDeferredUnusedCoverageMapping(D);
break;
case Decl::Var:
// Skip variable templates
if (cast<VarDecl>(D)->getDescribedVarTemplate())
return;
case Decl::VarTemplateSpecialization:
EmitGlobal(cast<VarDecl>(D));
break;
// Indirect fields from global anonymous structs and unions can be
// ignored; only the actual variable requires IR gen support.
case Decl::IndirectField:
break;
// C++ Decls
case Decl::Namespace:
EmitNamespace(cast<NamespaceDecl>(D));
break;
// No code generation needed.
case Decl::UsingShadow:
case Decl::ClassTemplate:
case Decl::VarTemplate:
case Decl::VarTemplatePartialSpecialization:
case Decl::FunctionTemplate:
case Decl::TypeAliasTemplate:
case Decl::Block:
case Decl::Empty:
break;
case Decl::Using: // using X; [C++]
if (CGDebugInfo *DI = getModuleDebugInfo())
DI->EmitUsingDecl(cast<UsingDecl>(*D));
return;
case Decl::NamespaceAlias:
if (CGDebugInfo *DI = getModuleDebugInfo())
DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
return;
case Decl::UsingDirective: // using namespace X; [C++]
if (CGDebugInfo *DI = getModuleDebugInfo())
DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
return;
case Decl::CXXConstructor:
// Skip function templates
if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
cast<FunctionDecl>(D)->isLateTemplateParsed())
return;
getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
break;
case Decl::CXXDestructor:
if (cast<FunctionDecl>(D)->isLateTemplateParsed())
return;
getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
break;
case Decl::StaticAssert:
// Nothing to do.
break;
// Objective-C Decls
// Forward declarations, no (immediate) code generation.
case Decl::ObjCInterface:
case Decl::ObjCCategory:
break;
case Decl::ObjCProtocol: {
auto *Proto = cast<ObjCProtocolDecl>(D);
if (Proto->isThisDeclarationADefinition())
ObjCRuntime->GenerateProtocol(Proto);
break;
}
case Decl::ObjCCategoryImpl:
// Categories have properties but don't support synthesize so we
// can ignore them here.
ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
break;
case Decl::ObjCImplementation: {
auto *OMD = cast<ObjCImplementationDecl>(D);
EmitObjCPropertyImplementations(OMD);
EmitObjCIvarInitializations(OMD);
ObjCRuntime->GenerateClass(OMD);
// Emit global variable debug information.
if (CGDebugInfo *DI = getModuleDebugInfo())
if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo)
DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
OMD->getClassInterface()), OMD->getLocation());
break;
}
case Decl::ObjCMethod: {
auto *OMD = cast<ObjCMethodDecl>(D);
// If this is not a prototype, emit the body.
if (OMD->getBody())
CodeGenFunction(*this).GenerateObjCMethod(OMD);
break;
}
case Decl::ObjCCompatibleAlias:
ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
break;
case Decl::LinkageSpec:
EmitLinkageSpec(cast<LinkageSpecDecl>(D));
break;
case Decl::FileScopeAsm: {
auto *AD = cast<FileScopeAsmDecl>(D);
StringRef AsmString = AD->getAsmString()->getString();
const std::string &S = getModule().getModuleInlineAsm();
if (S.empty())
getModule().setModuleInlineAsm(AsmString);
else if (S.end()[-1] == '\n')
getModule().setModuleInlineAsm(S + AsmString.str());
else
getModule().setModuleInlineAsm(S + '\n' + AsmString.str());
break;
}
case Decl::Import: {
auto *Import = cast<ImportDecl>(D);
// Ignore import declarations that come from imported modules.
if (clang::Module *Owner = Import->getOwningModule()) {
if (getLangOpts().CurrentModule.empty() ||
Owner->getTopLevelModule()->Name == getLangOpts().CurrentModule)
break;
}
ImportedModules.insert(Import->getImportedModule());
break;
}
case Decl::OMPThreadPrivate:
EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
break;
case Decl::ClassTemplateSpecialization: {
const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
if (DebugInfo &&
Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition &&
Spec->hasDefinition())
DebugInfo->completeTemplateDefinition(*Spec);
break;
}
default:
// Make sure we handled everything we should, every other kind is a
// non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
// function. Need to recode Decl::Kind to do that easily.
assert(isa<TypeDecl>(D) && "Unsupported decl kind");
break;
}
}
void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
// Do we need to generate coverage mapping?
if (!CodeGenOpts.CoverageMapping)
return;
switch (D->getKind()) {
case Decl::CXXConversion:
case Decl::CXXMethod:
case Decl::Function:
case Decl::ObjCMethod:
case Decl::CXXConstructor:
case Decl::CXXDestructor: {
if (!cast<FunctionDecl>(D)->hasBody())
return;
auto I = DeferredEmptyCoverageMappingDecls.find(D);
if (I == DeferredEmptyCoverageMappingDecls.end())
DeferredEmptyCoverageMappingDecls[D] = true;
break;
}
default:
break;
};
}
void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
// Do we need to generate coverage mapping?
if (!CodeGenOpts.CoverageMapping)
return;
if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
if (Fn->isTemplateInstantiation())
ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
}
auto I = DeferredEmptyCoverageMappingDecls.find(D);
if (I == DeferredEmptyCoverageMappingDecls.end())
DeferredEmptyCoverageMappingDecls[D] = false;
else
I->second = false;
}
void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
std::vector<const Decl *> DeferredDecls;
for (const auto I : DeferredEmptyCoverageMappingDecls) {
if (!I.second)
continue;
DeferredDecls.push_back(I.first);
}
// Sort the declarations by their location to make sure that the tests get a
// predictable order for the coverage mapping for the unused declarations.
if (CodeGenOpts.DumpCoverageMapping)
std::sort(DeferredDecls.begin(), DeferredDecls.end(),
[] (const Decl *LHS, const Decl *RHS) {
return LHS->getLocStart() < RHS->getLocStart();
});
for (const auto *D : DeferredDecls) {
switch (D->getKind()) {
case Decl::CXXConversion:
case Decl::CXXMethod:
case Decl::Function:
case Decl::ObjCMethod: {
CodeGenPGO PGO(*this);
GlobalDecl GD(cast<FunctionDecl>(D));
PGO.emitEmptyCounterMapping(D, getMangledName(GD),
getFunctionLinkage(GD));
break;
}
case Decl::CXXConstructor: {
CodeGenPGO PGO(*this);
GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
PGO.emitEmptyCounterMapping(D, getMangledName(GD),
getFunctionLinkage(GD));
break;
}
case Decl::CXXDestructor: {
CodeGenPGO PGO(*this);
GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
PGO.emitEmptyCounterMapping(D, getMangledName(GD),
getFunctionLinkage(GD));
break;
}
default:
break;
};
}
}
/// Turns the given pointer into a constant.
static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
const void *Ptr) {
uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
return llvm::ConstantInt::get(i64, PtrInt);
}
static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
llvm::NamedMDNode *&GlobalMetadata,
GlobalDecl D,
llvm::GlobalValue *Addr) {
if (!GlobalMetadata)
GlobalMetadata =
CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
// TODO: should we report variant information for ctors/dtors?
llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
llvm::ConstantAsMetadata::get(GetPointerConstant(
CGM.getLLVMContext(), D.getDecl()))};
GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
}
/// For each function which is declared within an extern "C" region and marked
/// as 'used', but has internal linkage, create an alias from the unmangled
/// name to the mangled name if possible. People expect to be able to refer
/// to such functions with an unmangled name from inline assembly within the
/// same translation unit.
void CodeGenModule::EmitStaticExternCAliases() {
for (StaticExternCMap::iterator I = StaticExternCValues.begin(),
E = StaticExternCValues.end();
I != E; ++I) {
IdentifierInfo *Name = I->first;
llvm::GlobalValue *Val = I->second;
if (Val && !getModule().getNamedValue(Name->getName()))
addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
}
}
bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
GlobalDecl &Result) const {
auto Res = Manglings.find(MangledName);
if (Res == Manglings.end())
return false;
Result = Res->getValue();
return true;
}
/// Emits metadata nodes associating all the global values in the
/// current module with the Decls they came from. This is useful for
/// projects using IR gen as a subroutine.
///
/// Since there's currently no way to associate an MDNode directly
/// with an llvm::GlobalValue, we create a global named metadata
/// with the name 'clang.global.decl.ptrs'.
void CodeGenModule::EmitDeclMetadata() {
llvm::NamedMDNode *GlobalMetadata = nullptr;
// StaticLocalDeclMap
for (auto &I : MangledDeclNames) {
llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
}
}
/// Emits metadata nodes for all the local variables in the current
/// function.
void CodeGenFunction::EmitDeclMetadata() {
if (LocalDeclMap.empty()) return;
llvm::LLVMContext &Context = getLLVMContext();
// Find the unique metadata ID for this name.
unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
llvm::NamedMDNode *GlobalMetadata = nullptr;
for (auto &I : LocalDeclMap) {
const Decl *D = I.first;
llvm::Value *Addr = I.second;
if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
Alloca->setMetadata(
DeclPtrKind, llvm::MDNode::get(
Context, llvm::ValueAsMetadata::getConstant(DAddr)));
} else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
}
}
}
void CodeGenModule::EmitVersionIdentMetadata() {
llvm::NamedMDNode *IdentMetadata =
TheModule.getOrInsertNamedMetadata("llvm.ident");
std::string Version = getClangFullVersion();
llvm::LLVMContext &Ctx = TheModule.getContext();
llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
}
void CodeGenModule::EmitTargetMetadata() {
// Warning, new MangledDeclNames may be appended within this loop.
// We rely on MapVector insertions adding new elements to the end
// of the container.
// FIXME: Move this loop into the one target that needs it, and only
// loop over those declarations for which we couldn't emit the target
// metadata when we emitted the declaration.
for (unsigned I = 0; I != MangledDeclNames.size(); ++I) {
auto Val = *(MangledDeclNames.begin() + I);
const Decl *D = Val.first.getDecl()->getMostRecentDecl();
llvm::GlobalValue *GV = GetGlobalValue(Val.second);
getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
}
}
void CodeGenModule::EmitCoverageFile() {
if (!getCodeGenOpts().CoverageFile.empty()) {
if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) {
llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
llvm::LLVMContext &Ctx = TheModule.getContext();
llvm::MDString *CoverageFile =
llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile);
for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
llvm::MDNode *CU = CUNode->getOperand(i);
llvm::Metadata *Elts[] = {CoverageFile, CU};
GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
}
}
}
}
llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) {
// Sema has checked that all uuid strings are of the form
// "12345678-1234-1234-1234-1234567890ab".
assert(Uuid.size() == 36);
for (unsigned i = 0; i < 36; ++i) {
if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
else assert(isHexDigit(Uuid[i]));
}
// The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab".
const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
llvm::Constant *Field3[8];
for (unsigned Idx = 0; Idx < 8; ++Idx)
Field3[Idx] = llvm::ConstantInt::get(
Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
llvm::Constant *Fields[4] = {
llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
};
return llvm::ConstantStruct::getAnon(Fields);
}
llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
bool ForEH) {
// Return a bogus pointer if RTTI is disabled, unless it's for EH.
// FIXME: should we even be calling this method if RTTI is disabled
// and it's not for EH?
if (!ForEH && !getLangOpts().RTTI)
return llvm::Constant::getNullValue(Int8PtrTy);
if (ForEH && Ty->isObjCObjectPointerType() &&
LangOpts.ObjCRuntime.isGNUFamily())
return ObjCRuntime->GetEHType(Ty);
return getCXXABI().getAddrOfRTTIDescriptor(Ty);
}
void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
for (auto RefExpr : D->varlists()) {
auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
bool PerformInit =
VD->getAnyInitializer() &&
!VD->getAnyInitializer()->isConstantInitializer(getContext(),
/*ForRef=*/false);
if (auto InitFunction =
getOpenMPRuntime().EmitOMPThreadPrivateVarDefinition(
VD, GetAddrOfGlobalVar(VD), RefExpr->getLocStart(),
PerformInit))
CXXGlobalInits.push_back(InitFunction);
}
}
Reference in New Issue View Git Blame Copy Permalink