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llvm-project/clang/lib/CodeGen/CodeGenModule.cpp
Erich Keane 7ef210d053 Give Multiversion-inline functions linkonce linkage 
Since multiversion variant functions can be inline, in C they become
available-externally linkage.  This ends up causing the variants to not
be emitted, and not available to the linker.

The solution is to make sure that multiversion functions are always
emitted by marking them linkonce.

Change-Id: I897aa37c7cbba0c1eb2c57ee881d5000a2113b75
llvm-svn: 344957
2018-10-22 21:20:45 +00:00

5346 lines
201 KiB
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//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This coordinates the per-module state used while generating code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenModule.h"
#include "CGBlocks.h"
#include "CGCUDARuntime.h"
#include "CGCXXABI.h"
#include "CGCall.h"
#include "CGDebugInfo.h"
#include "CGObjCRuntime.h"
#include "CGOpenCLRuntime.h"
#include "CGOpenMPRuntime.h"
#include "CGOpenMPRuntimeNVPTX.h"
#include "CodeGenFunction.h"
#include "CodeGenPGO.h"
#include "ConstantEmitter.h"
#include "CoverageMappingGen.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/CodeGen/ConstantInitBuilder.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "clang/Sema/SemaDiagnostic.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/TargetLibraryInfo.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/CodeGen.h"
#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MD5.h"
using namespace clang;
using namespace CodeGen;
static llvm::cl::opt<bool> LimitedCoverage(
"limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden,
llvm::cl::desc("Emit limited coverage mapping information (experimental)"),
llvm::cl::init(false));
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::WatchOS:
case TargetCXXABI::GenericMIPS:
case TargetCXXABI::GenericItanium:
case TargetCXXABI::WebAssembly:
return CreateItaniumCXXABI(CGM);
case TargetCXXABI::Microsoft:
return CreateMicrosoftCXXABI(CGM);
}
llvm_unreachable("invalid C++ ABI kind");
}
CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
const PreprocessorOptions &PPO,
const CodeGenOptions &CGO, llvm::Module &M,
DiagnosticsEngine &diags,
CoverageSourceInfo *CoverageInfo)
: Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO),
PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
VMContext(M.getContext()), Types(*this), VTables(*this),
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);
HalfTy = llvm::Type::getHalfTy(LLVMContext);
FloatTy = llvm::Type::getFloatTy(LLVMContext);
DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
PointerAlignInBytes =
C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
SizeSizeInBytes =
C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
IntAlignInBytes =
C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
IntPtrTy = llvm::IntegerType::get(LLVMContext,
C.getTargetInfo().getMaxPointerWidth());
Int8PtrTy = Int8Ty->getPointerTo(0);
Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
AllocaInt8PtrTy = Int8Ty->getPointerTo(
M.getDataLayout().getAllocaAddrSpace());
ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
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.reset(new CodeGenTBAA(Context, TheModule, 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.reset(new CGDebugInfo(*this));
Block.GlobalUniqueCount = 0;
if (C.getLangOpts().ObjC1)
ObjCData.reset(new ObjCEntrypoints());
if (CodeGenOpts.hasProfileClangUse()) {
auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile);
if (auto E = ReaderOrErr.takeError()) {
unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
"Could not read profile %0: %1");
llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
<< EI.message();
});
} else
PGOReader = std::move(ReaderOrErr.get());
}
// If coverage mapping generation is enabled, create the
// CoverageMappingModuleGen object.
if (CodeGenOpts.CoverageMapping)
CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
}
CodeGenModule::~CodeGenModule() {}
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.reset(CreateGNUObjCRuntime(*this));
return;
case ObjCRuntime::FragileMacOSX:
case ObjCRuntime::MacOSX:
case ObjCRuntime::iOS:
case ObjCRuntime::WatchOS:
ObjCRuntime.reset(CreateMacObjCRuntime(*this));
return;
}
llvm_unreachable("bad runtime kind");
}
void CodeGenModule::createOpenCLRuntime() {
OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
}
void CodeGenModule::createOpenMPRuntime() {
// Select a specialized code generation class based on the target, if any.
// If it does not exist use the default implementation.
switch (getTriple().getArch()) {
case llvm::Triple::nvptx:
case llvm::Triple::nvptx64:
assert(getLangOpts().OpenMPIsDevice &&
"OpenMP NVPTX is only prepared to deal with device code.");
OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
break;
default:
if (LangOpts.OpenMPSimd)
OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
else
OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
break;
}
}
void CodeGenModule::createCUDARuntime() {
CUDARuntime.reset(CreateNVCUDARuntime(*this));
}
void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
Replacements[Name] = C;
}
void CodeGenModule::applyReplacements() {
for (auto &I : Replacements) {
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->getIterator(),
NewF);
}
OldF->eraseFromParent();
}
}
void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
GlobalValReplacements.push_back(std::make_pair(GV, C));
}
void CodeGenModule::applyGlobalValReplacements() {
for (auto &I : GlobalValReplacements) {
llvm::GlobalValue *GV = I.first;
llvm::Constant *C = I.second;
GV->replaceAllUsesWith(C);
GV->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::GlobalIndirectSymbol &GIS) {
llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
const llvm::Constant *C = &GIS;
for (;;) {
C = C->stripPointerCasts();
if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
return GO;
// stripPointerCasts will not walk over weak aliases.
auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
if (!GIS2)
return nullptr;
if (!Visited.insert(GIS2).second)
return nullptr;
C = GIS2->getIndirectSymbol();
}
}
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 (const GlobalDecl &GD : Aliases) {
const auto *D = cast<ValueDecl>(GD.getDecl());
SourceLocation Location;
bool IsIFunc = D->hasAttr<IFuncAttr>();
if (const Attr *A = D->getDefiningAttr())
Location = A->getLocation();
else
llvm_unreachable("Not an alias or ifunc?");
StringRef MangledName = getMangledName(GD);
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
if (!GV) {
Error = true;
Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
} else if (GV->isDeclaration()) {
Error = true;
Diags.Report(Location, diag::err_alias_to_undefined)
<< IsIFunc << IsIFunc;
} else if (IsIFunc) {
// Check resolver function type.
llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
GV->getType()->getPointerElementType());
assert(FTy);
if (!FTy->getReturnType()->isPointerTy())
Diags.Report(Location, diag::err_ifunc_resolver_return);
}
llvm::Constant *Aliasee = Alias->getIndirectSymbol();
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 << IsIFunc << IsIFunc;
}
// 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::GlobalIndirectSymbol>(AliaseeGV)) {
if (GA->isInterposable()) {
Diags.Report(Location, diag::warn_alias_to_weak_alias)
<< GV->getName() << GA->getName() << IsIFunc;
Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
GA->getIndirectSymbol(), Alias->getType());
Alias->setIndirectSymbol(Aliasee);
}
}
}
if (!Error)
return;
for (const GlobalDecl &GD : Aliases) {
StringRef MangledName = getMangledName(GD);
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
auto *Alias = dyn_cast<llvm::GlobalIndirectSymbol>(Entry);
Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
Alias->eraseFromParent();
}
}
void CodeGenModule::clear() {
DeferredDeclsToEmit.clear();
if (OpenMPRuntime)
OpenMPRuntime->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 {
if (Mismatched > 0)
Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
if (Missing > 0)
Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
}
}
void CodeGenModule::Release() {
EmitDeferred();
EmitVTablesOpportunistically();
applyGlobalValReplacements();
applyReplacements();
checkAliases();
emitMultiVersionFunctions();
EmitCXXGlobalInitFunc();
EmitCXXGlobalDtorFunc();
registerGlobalDtorsWithAtExit();
EmitCXXThreadLocalInitFunc();
if (ObjCRuntime)
if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
AddGlobalCtor(ObjCInitFunction);
if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice &&
CUDARuntime) {
if (llvm::Function *CudaCtorFunction =
CUDARuntime->makeModuleCtorFunction())
AddGlobalCtor(CudaCtorFunction);
}
if (OpenMPRuntime) {
if (llvm::Function *OpenMPRegistrationFunction =
OpenMPRuntime->emitRegistrationFunction()) {
auto ComdatKey = OpenMPRegistrationFunction->hasComdat() ?
OpenMPRegistrationFunction : nullptr;
AddGlobalCtor(OpenMPRegistrationFunction, 0, ComdatKey);
}
OpenMPRuntime->clear();
}
if (PGOReader) {
getModule().setProfileSummary(PGOReader->getSummary().getMD(VMContext));
if (PGOStats.hasDiagnostics())
PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
}
EmitCtorList(GlobalCtors, "llvm.global_ctors");
EmitCtorList(GlobalDtors, "llvm.global_dtors");
EmitGlobalAnnotations();
EmitStaticExternCAliases();
EmitDeferredUnusedCoverageMappings();
if (CoverageMapping)
CoverageMapping->emit();
if (CodeGenOpts.SanitizeCfiCrossDso) {
CodeGenFunction(*this).EmitCfiCheckFail();
CodeGenFunction(*this).EmitCfiCheckStub();
}
emitAtAvailableLinkGuard();
emitLLVMUsed();
if (SanStats)
SanStats->finish();
if (CodeGenOpts.Autolink &&
(Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
EmitModuleLinkOptions();
}
// Record mregparm value now so it is visible through rest of codegen.
if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
CodeGenOpts.NumRegisterParameters);
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 (CodeGenOpts.EmitCodeView) {
// Indicate that we want CodeView in the metadata.
getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
}
if (CodeGenOpts.ControlFlowGuard) {
// We want function ID tables for Control Flow Guard.
getModule().addModuleFlag(llvm::Module::Warning, "cfguardtable", 1);
}
if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
// We don't support LTO with 2 with different StrictVTablePointers
// FIXME: we could support it by stripping all the information introduced
// by StrictVTablePointers.
getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
llvm::Metadata *Ops[2] = {
llvm::MDString::get(VMContext, "StrictVTablePointers"),
llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
llvm::Type::getInt32Ty(VMContext), 1))};
getModule().addModuleFlag(llvm::Module::Require,
"StrictVTablePointersRequirement",
llvm::MDNode::get(VMContext, Ops));
}
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. wchar_size is also used by
// TargetLibraryInfo.
uint64_t WCharWidth =
Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
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) {
// 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 (CodeGenOpts.SanitizeCfiCrossDso) {
// Indicate that we want cross-DSO control flow integrity checks.
getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
}
if (CodeGenOpts.CFProtectionReturn &&
Target.checkCFProtectionReturnSupported(getDiags())) {
// Indicate that we want to instrument return control flow protection.
getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return",
1);
}
if (CodeGenOpts.CFProtectionBranch &&
Target.checkCFProtectionBranchSupported(getDiags())) {
// Indicate that we want to instrument branch control flow protection.
getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch",
1);
}
if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
// Indicate whether __nvvm_reflect should be configured to flush denormal
// floating point values to 0. (This corresponds to its "__CUDA_FTZ"
// property.)
getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
CodeGenOpts.FlushDenorm ? 1 : 0);
}
// Emit OpenCL specific module metadata: OpenCL/SPIR version.
if (LangOpts.OpenCL) {
EmitOpenCLMetadata();
// Emit SPIR version.
if (getTriple().getArch() == llvm::Triple::spir ||
getTriple().getArch() == llvm::Triple::spir64) {
// SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
// opencl.spir.version named metadata.
llvm::Metadata *SPIRVerElts[] = {
llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
Int32Ty, LangOpts.OpenCLVersion / 100)),
llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
Int32Ty, (LangOpts.OpenCLVersion / 100 > 1) ? 0 : 2))};
llvm::NamedMDNode *SPIRVerMD =
TheModule.getOrInsertNamedMetadata("opencl.spir.version");
llvm::LLVMContext &Ctx = TheModule.getContext();
SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
}
}
if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
assert(PLevel < 3 && "Invalid PIC Level");
getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
if (Context.getLangOpts().PIE)
getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
}
if (getCodeGenOpts().CodeModel.size() > 0) {
unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
.Case("tiny", llvm::CodeModel::Tiny)
.Case("small", llvm::CodeModel::Small)
.Case("kernel", llvm::CodeModel::Kernel)
.Case("medium", llvm::CodeModel::Medium)
.Case("large", llvm::CodeModel::Large)
.Default(~0u);
if (CM != ~0u) {
llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
getModule().setCodeModel(codeModel);
}
}
if (CodeGenOpts.NoPLT)
getModule().setRtLibUseGOT();
SimplifyPersonality();
if (getCodeGenOpts().EmitDeclMetadata)
EmitDeclMetadata();
if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
EmitCoverageFile();
if (DebugInfo)
DebugInfo->finalize();
if (getCodeGenOpts().EmitVersionIdentMetadata)
EmitVersionIdentMetadata();
EmitTargetMetadata();
}
void CodeGenModule::EmitOpenCLMetadata() {
// SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
// opencl.ocl.version named metadata node.
llvm::Metadata *OCLVerElts[] = {
llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
Int32Ty, LangOpts.OpenCLVersion / 100)),
llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
Int32Ty, (LangOpts.OpenCLVersion % 100) / 10))};
llvm::NamedMDNode *OCLVerMD =
TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
llvm::LLVMContext &Ctx = TheModule.getContext();
OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
}
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
// Make sure that this type is translated.
Types.UpdateCompletedType(TD);
}
void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
// Make sure that this type is translated.
Types.RefreshTypeCacheForClass(RD);
}
llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
if (!TBAA)
return nullptr;
return TBAA->getTypeInfo(QTy);
}
TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
if (!TBAA)
return TBAAAccessInfo();
return TBAA->getAccessInfo(AccessType);
}
TBAAAccessInfo
CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
if (!TBAA)
return TBAAAccessInfo();
return TBAA->getVTablePtrAccessInfo(VTablePtrType);
}
llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
if (!TBAA)
return nullptr;
return TBAA->getTBAAStructInfo(QTy);
}
llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
if (!TBAA)
return nullptr;
return TBAA->getBaseTypeInfo(QTy);
}
llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
if (!TBAA)
return nullptr;
return TBAA->getAccessTagInfo(Info);
}
TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
TBAAAccessInfo TargetInfo) {
if (!TBAA)
return TBAAAccessInfo();
return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
}
TBAAAccessInfo
CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
TBAAAccessInfo InfoB) {
if (!TBAA)
return TBAAAccessInfo();
return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
}
TBAAAccessInfo
CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
TBAAAccessInfo SrcInfo) {
if (!TBAA)
return TBAAAccessInfo();
return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
}
void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
TBAAAccessInfo TBAAInfo) {
if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
}
void CodeGenModule::DecorateInstructionWithInvariantGroup(
llvm::Instruction *I, const CXXRecordDecl *RD) {
I->setMetadata(llvm::LLVMContext::MD_invariant_group,
llvm::MDNode::get(getLLVMContext(), {}));
}
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->getBeginLoc()), 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 {
if (GV->hasDLLImportStorageClass())
return;
// Internal definitions always have default visibility.
if (GV->hasLocalLinkage()) {
GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
return;
}
if (!D)
return;
// Set visibility for definitions.
LinkageInfo LV = D->getLinkageAndVisibility();
if (LV.isVisibilityExplicit() || !GV->isDeclarationForLinker())
GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
}
static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
llvm::GlobalValue *GV) {
if (GV->hasLocalLinkage())
return true;
if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
return true;
// DLLImport explicitly marks the GV as external.
if (GV->hasDLLImportStorageClass())
return false;
const llvm::Triple &TT = CGM.getTriple();
if (TT.isWindowsGNUEnvironment()) {
// In MinGW, variables without DLLImport can still be automatically
// imported from a DLL by the linker; don't mark variables that
// potentially could come from another DLL as DSO local.
if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
!GV->isThreadLocal())
return false;
}
// Every other GV is local on COFF.
// Make an exception for windows OS in the triple: Some firmware builds use
// *-win32-macho triples. This (accidentally?) produced windows relocations
// without GOT tables in older clang versions; Keep this behaviour.
// FIXME: even thread local variables?
if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
return true;
// Only handle COFF and ELF for now.
if (!TT.isOSBinFormatELF())
return false;
// If this is not an executable, don't assume anything is local.
const auto &CGOpts = CGM.getCodeGenOpts();
llvm::Reloc::Model RM = CGOpts.RelocationModel;
const auto &LOpts = CGM.getLangOpts();
if (RM != llvm::Reloc::Static && !LOpts.PIE)
return false;
// A definition cannot be preempted from an executable.
if (!GV->isDeclarationForLinker())
return true;
// Most PIC code sequences that assume that a symbol is local cannot produce a
// 0 if it turns out the symbol is undefined. While this is ABI and relocation
// depended, it seems worth it to handle it here.
if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
return false;
// PPC has no copy relocations and cannot use a plt entry as a symbol address.
llvm::Triple::ArchType Arch = TT.getArch();
if (Arch == llvm::Triple::ppc || Arch == llvm::Triple::ppc64 ||
Arch == llvm::Triple::ppc64le)
return false;
// If we can use copy relocations we can assume it is local.
if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
if (!Var->isThreadLocal() &&
(RM == llvm::Reloc::Static || CGOpts.PIECopyRelocations))
return true;
// If we can use a plt entry as the symbol address we can assume it
// is local.
// FIXME: This should work for PIE, but the gold linker doesn't support it.
if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
return true;
// Otherwise don't assue it is local.
return false;
}
void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
}
void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
GlobalDecl GD) const {
const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
// C++ destructors have a few C++ ABI specific special cases.
if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
return;
}
setDLLImportDLLExport(GV, D);
}
void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
const NamedDecl *D) const {
if (D && D->isExternallyVisible()) {
if (D->hasAttr<DLLImportAttr>())
GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker())
GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
}
}
void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
GlobalDecl GD) const {
setDLLImportDLLExport(GV, GD);
setGlobalVisibilityAndLocal(GV, dyn_cast<NamedDecl>(GD.getDecl()));
}
void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
const NamedDecl *D) const {
setDLLImportDLLExport(GV, D);
setGlobalVisibilityAndLocal(GV, D);
}
void CodeGenModule::setGlobalVisibilityAndLocal(llvm::GlobalValue *GV,
const NamedDecl *D) const {
setGlobalVisibility(GV, D);
setDSOLocal(GV);
}
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);
}
static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
StringRef Name) {
const TargetInfo &Target = CGM.getTarget();
return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
}
static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
const CPUSpecificAttr *Attr,
raw_ostream &Out) {
// cpu_specific gets the current name, dispatch gets the resolver.
if (Attr)
Out << getCPUSpecificMangling(CGM, Attr->getCurCPUName()->getName());
else
Out << ".resolver";
}
static void AppendTargetMangling(const CodeGenModule &CGM,
const TargetAttr *Attr, raw_ostream &Out) {
if (Attr->isDefaultVersion())
return;
Out << '.';
const TargetInfo &Target = CGM.getTarget();
TargetAttr::ParsedTargetAttr Info =
Attr->parse([&Target](StringRef LHS, StringRef RHS) {
// Multiversioning doesn't allow "no-${feature}", so we can
// only have "+" prefixes here.
assert(LHS.startswith("+") && RHS.startswith("+") &&
"Features should always have a prefix.");
return Target.multiVersionSortPriority(LHS.substr(1)) >
Target.multiVersionSortPriority(RHS.substr(1));
});
bool IsFirst = true;
if (!Info.Architecture.empty()) {
IsFirst = false;
Out << "arch_" << Info.Architecture;
}
for (StringRef Feat : Info.Features) {
if (!IsFirst)
Out << '_';
IsFirst = false;
Out << Feat.substr(1);
}
}
static std::string getMangledNameImpl(const CodeGenModule &CGM, GlobalDecl GD,
const NamedDecl *ND,
bool OmitMultiVersionMangling = false) {
SmallString<256> Buffer;
llvm::raw_svector_ostream Out(Buffer);
MangleContext &MC = CGM.getCXXABI().getMangleContext();
if (MC.shouldMangleDeclName(ND)) {
llvm::raw_svector_ostream Out(Buffer);
if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
MC.mangleCXXCtor(D, GD.getCtorType(), Out);
else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
MC.mangleCXXDtor(D, GD.getDtorType(), Out);
else
MC.mangleName(ND, Out);
} else {
IdentifierInfo *II = ND->getIdentifier();
assert(II && "Attempt to mangle unnamed decl.");
const auto *FD = dyn_cast<FunctionDecl>(ND);
if (FD &&
FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
llvm::raw_svector_ostream Out(Buffer);
Out << "__regcall3__" << II->getName();
} else {
Out << II->getName();
}
}
if (const auto *FD = dyn_cast<FunctionDecl>(ND))
if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
if (FD->isCPUDispatchMultiVersion() || FD->isCPUSpecificMultiVersion())
AppendCPUSpecificCPUDispatchMangling(
CGM, FD->getAttr<CPUSpecificAttr>(), Out);
else
AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
}
return Out.str();
}
void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
const FunctionDecl *FD) {
if (!FD->isMultiVersion())
return;
// Get the name of what this would be without the 'target' attribute. This
// allows us to lookup the version that was emitted when this wasn't a
// multiversion function.
std::string NonTargetName =
getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
GlobalDecl OtherGD;
if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
assert(OtherGD.getCanonicalDecl()
.getDecl()
->getAsFunction()
->isMultiVersion() &&
"Other GD should now be a multiversioned function");
// OtherFD is the version of this function that was mangled BEFORE
// becoming a MultiVersion function. It potentially needs to be updated.
const FunctionDecl *OtherFD =
OtherGD.getCanonicalDecl().getDecl()->getAsFunction();
std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
// This is so that if the initial version was already the 'default'
// version, we don't try to update it.
if (OtherName != NonTargetName) {
// Remove instead of erase, since others may have stored the StringRef
// to this.
const auto ExistingRecord = Manglings.find(NonTargetName);
if (ExistingRecord != std::end(Manglings))
Manglings.remove(&(*ExistingRecord));
auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
MangledDeclNames[OtherGD.getCanonicalDecl()] = Result.first->first();
if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
Entry->setName(OtherName);
}
}
}
StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
GlobalDecl CanonicalGD = GD.getCanonicalDecl();
// Some ABIs don't have constructor variants. Make sure that base and
// complete constructors get mangled the same.
if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
if (!getTarget().getCXXABI().hasConstructorVariants()) {
CXXCtorType OrigCtorType = GD.getCtorType();
assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
if (OrigCtorType == Ctor_Base)
CanonicalGD = GlobalDecl(CD, Ctor_Complete);
}
}
const auto *FD = dyn_cast<FunctionDecl>(GD.getDecl());
// Since CPUSpecific can require multiple emits per decl, store the manglings
// separately.
if (FD &&
(FD->isCPUDispatchMultiVersion() || FD->isCPUSpecificMultiVersion())) {
const auto *SD = FD->getAttr<CPUSpecificAttr>();
std::pair<GlobalDecl, unsigned> SpecCanonicalGD{
CanonicalGD,
SD ? SD->ActiveArgIndex : std::numeric_limits<unsigned>::max()};
auto FoundName = CPUSpecificMangledDeclNames.find(SpecCanonicalGD);
if (FoundName != CPUSpecificMangledDeclNames.end())
return FoundName->second;
auto Result = CPUSpecificManglings.insert(
std::make_pair(getMangledNameImpl(*this, GD, FD), SpecCanonicalGD));
return CPUSpecificMangledDeclNames[SpecCanonicalGD] = Result.first->first();
}
auto FoundName = MangledDeclNames.find(CanonicalGD);
if (FoundName != MangledDeclNames.end())
return FoundName->second;
// Keep the first result in the case of a mangling collision.
const auto *ND = cast<NamedDecl>(GD.getDecl());
auto Result =
Manglings.insert(std::make_pair(getMangledNameImpl(*this, GD, ND), GD));
return MangledDeclNames[CanonicalGD] = 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) {
if (CodeGenOpts.RegisterGlobalDtorsWithAtExit) {
DtorsUsingAtExit[Priority].push_back(Dtor);
return;
}
// FIXME: Type coercion of void()* types.
GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
}
void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
if (Fns.empty()) return;
// 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);
// Construct the constructor and destructor arrays.
ConstantInitBuilder builder(*this);
auto ctors = builder.beginArray(CtorStructTy);
for (const auto &I : Fns) {
auto ctor = ctors.beginStruct(CtorStructTy);
ctor.addInt(Int32Ty, I.Priority);
ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
if (I.AssociatedData)
ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
else
ctor.addNullPointer(VoidPtrTy);
ctor.finishAndAddTo(ctors);
}
auto list =
ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
/*constant*/ false,
llvm::GlobalValue::AppendingLinkage);
// The LTO linker doesn't seem to like it when we set an alignment
// on appending variables. Take it off as a workaround.
list->setAlignment(0);
Fns.clear();
}
llvm::GlobalValue::LinkageTypes
CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
const auto *D = cast<FunctionDecl>(GD.getDecl());
GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
if (isa<CXXConstructorDecl>(D) &&
cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
Context.getTargetInfo().getCXXABI().isMicrosoft()) {
// Our approach to inheriting constructors is fundamentally different from
// that used by the MS ABI, so keep our inheriting constructor thunks
// internal rather than trying to pick an unambiguous mangling for them.
return llvm::GlobalValue::InternalLinkage;
}
return getLLVMLinkageForDeclarator(D, Linkage, /*isConstantVariable=*/false);
}
llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
if (!MDS) return nullptr;
return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
}
void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
const CGFunctionInfo &Info,
llvm::Function *F) {
unsigned CallingConv;
llvm::AttributeList PAL;
ConstructAttributeList(F->getName(), Info, D, PAL, CallingConv, false);
F->setAttributes(PAL);
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;
}
static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
const CXXMethodDecl *MD) {
// Check that the type metadata can ever actually be used by a call.
if (!CGM.getCodeGenOpts().LTOUnit ||
!CGM.HasHiddenLTOVisibility(MD->getParent()))
return false;
// Only functions whose address can be taken with a member function pointer
// need this sort of type metadata.
return !MD->isStatic() && !MD->isVirtual() && !isa<CXXConstructorDecl>(MD) &&
!isa<CXXDestructorDecl>(MD);
}
std::vector<const CXXRecordDecl *>
CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
llvm::SetVector<const CXXRecordDecl *> MostBases;
std::function<void (const CXXRecordDecl *)> CollectMostBases;
CollectMostBases = [&](const CXXRecordDecl *RD) {
if (RD->getNumBases() == 0)
MostBases.insert(RD);
for (const CXXBaseSpecifier &B : RD->bases())
CollectMostBases(B.getType()->getAsCXXRecordDecl());
};
CollectMostBases(RD);
return MostBases.takeVector();
}
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 || !D->hasAttr<NoStackProtectorAttr>()) {
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);
}
if (!D) {
// If we don't have a declaration to control inlining, the function isn't
// explicitly marked as alwaysinline for semantic reasons, and inlining is
// disabled, mark the function as noinline.
if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
B.addAttribute(llvm::Attribute::NoInline);
F->addAttributes(llvm::AttributeList::FunctionIndex, B);
return;
}
// Track whether we need to add the optnone LLVM attribute,
// starting with the default for this optimization level.
bool ShouldAddOptNone =
!CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
// We can't add optnone in the following cases, it won't pass the verifier.
ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
ShouldAddOptNone &= !F->hasFnAttribute(llvm::Attribute::AlwaysInline);
ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
if (ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) {
B.addAttribute(llvm::Attribute::OptimizeNone);
// OptimizeNone implies noinline; we should not be inlining such functions.
B.addAttribute(llvm::Attribute::NoInline);
assert(!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
"OptimizeNone and AlwaysInline on same function!");
// We still need to handle naked functions even though optnone subsumes
// much of their semantics.
if (D->hasAttr<NakedAttr>())
B.addAttribute(llvm::Attribute::Naked);
// OptimizeNone wins over OptimizeForSize and MinSize.
F->removeFnAttr(llvm::Attribute::OptimizeForSize);
F->removeFnAttr(llvm::Attribute::MinSize);
} else 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->hasFnAttribute(llvm::Attribute::NoInline)) {
// (noinline wins over always_inline, and we can't specify both in IR)
B.addAttribute(llvm::Attribute::AlwaysInline);
} else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
// If we're not inlining, then force everything that isn't always_inline to
// carry an explicit noinline attribute.
if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
B.addAttribute(llvm::Attribute::NoInline);
} else {
// Otherwise, propagate the inline hint attribute and potentially use its
// absence to mark things as noinline.
if (auto *FD = dyn_cast<FunctionDecl>(D)) {
if (any_of(FD->redecls(), [&](const FunctionDecl *Redecl) {
return Redecl->isInlineSpecified();
})) {
B.addAttribute(llvm::Attribute::InlineHint);
} else if (CodeGenOpts.getInlining() ==
CodeGenOptions::OnlyHintInlining &&
!FD->isInlined() &&
!F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
B.addAttribute(llvm::Attribute::NoInline);
}
}
}
// Add other optimization related attributes if we are optimizing this
// function.
if (!D->hasAttr<OptimizeNoneAttr>()) {
if (D->hasAttr<ColdAttr>()) {
if (!ShouldAddOptNone)
B.addAttribute(llvm::Attribute::OptimizeForSize);
B.addAttribute(llvm::Attribute::Cold);
}
if (D->hasAttr<MinSizeAttr>())
B.addAttribute(llvm::Attribute::MinSize);
}
F->addAttributes(llvm::AttributeList::FunctionIndex, B);
unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
if (alignment)
F->setAlignment(alignment);
if (!D->hasAttr<AlignedAttr>())
if (LangOpts.FunctionAlignment)
F->setAlignment(1 << LangOpts.FunctionAlignment);
// Some C++ ABIs require 2-byte alignment for member functions, in order to
// reserve a bit for differentiating between virtual and non-virtual member
// functions. If the current target's C++ ABI requires this and this is a
// member function, set its alignment accordingly.
if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
F->setAlignment(2);
}
// In the cross-dso CFI mode, we want !type attributes on definitions only.
if (CodeGenOpts.SanitizeCfiCrossDso)
if (auto *FD = dyn_cast<FunctionDecl>(D))
CreateFunctionTypeMetadataForIcall(FD, F);
// Emit type metadata on member functions for member function pointer checks.
// These are only ever necessary on definitions; we're guaranteed that the
// definition will be present in the LTO unit as a result of LTO visibility.
auto *MD = dyn_cast<CXXMethodDecl>(D);
if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
llvm::Metadata *Id =
CreateMetadataIdentifierForType(Context.getMemberPointerType(
MD->getType(), Context.getRecordType(Base).getTypePtr()));
F->addTypeMetadata(0, Id);
}
}
}
void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
const Decl *D = GD.getDecl();
if (dyn_cast_or_null<NamedDecl>(D))
setGVProperties(GV, GD);
else
GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
if (D && D->hasAttr<UsedAttr>())
addUsedGlobal(GV);
if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) {
const auto *VD = cast<VarDecl>(D);
if (VD->getType().isConstQualified() && VD->getStorageClass() == SC_Static)
addUsedGlobal(GV);
}
}
bool CodeGenModule::GetCPUAndFeaturesAttributes(const Decl *D,
llvm::AttrBuilder &Attrs) {
// Add target-cpu and target-features attributes to functions. If
// we have a decl for the function and it has a target attribute then
// parse that and add it to the feature set.
StringRef TargetCPU = getTarget().getTargetOpts().CPU;
std::vector<std::string> Features;
const auto *FD = dyn_cast_or_null<FunctionDecl>(D);
FD = FD ? FD->getMostRecentDecl() : FD;
const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
bool AddedAttr = false;
if (TD || SD) {
llvm::StringMap<bool> FeatureMap;
getFunctionFeatureMap(FeatureMap, FD);
// Produce the canonical string for this set of features.
for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
// Now add the target-cpu and target-features to the function.
// While we populated the feature map above, we still need to
// get and parse the target attribute so we can get the cpu for
// the function.
if (TD) {
TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
if (ParsedAttr.Architecture != "" &&
getTarget().isValidCPUName(ParsedAttr.Architecture))
TargetCPU = ParsedAttr.Architecture;
}
} else {
// Otherwise just add the existing target cpu and target features to the
// function.
Features = getTarget().getTargetOpts().Features;
}
if (TargetCPU != "") {
Attrs.addAttribute("target-cpu", TargetCPU);
AddedAttr = true;
}
if (!Features.empty()) {
llvm::sort(Features);
Attrs.addAttribute("target-features", llvm::join(Features, ","));
AddedAttr = true;
}
return AddedAttr;
}
void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
llvm::GlobalObject *GO) {
const Decl *D = GD.getDecl();
SetCommonAttributes(GD, GO);
if (D) {
if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
GV->addAttribute("bss-section", SA->getName());
if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
GV->addAttribute("data-section", SA->getName());
if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
GV->addAttribute("rodata-section", SA->getName());
}
if (auto *F = dyn_cast<llvm::Function>(GO)) {
if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
if (!D->getAttr<SectionAttr>())
F->addFnAttr("implicit-section-name", SA->getName());
llvm::AttrBuilder Attrs;
if (GetCPUAndFeaturesAttributes(D, Attrs)) {
// We know that GetCPUAndFeaturesAttributes will always have the
// newest set, since it has the newest possible FunctionDecl, so the
// new ones should replace the old.
F->removeFnAttr("target-cpu");
F->removeFnAttr("target-features");
F->addAttributes(llvm::AttributeList::FunctionIndex, Attrs);
}
}
if (const auto *CSA = D->getAttr<CodeSegAttr>())
GO->setSection(CSA->getName());
else if (const auto *SA = D->getAttr<SectionAttr>())
GO->setSection(SA->getName());
}
getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
}
void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
llvm::Function *F,
const CGFunctionInfo &FI) {
const Decl *D = GD.getDecl();
SetLLVMFunctionAttributes(D, FI, F);
SetLLVMFunctionAttributesForDefinition(D, F);
F->setLinkage(llvm::Function::InternalLinkage);
setNonAliasAttributes(GD, F);
}
static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
// Set linkage and visibility in case we never see a definition.
LinkageInfo LV = ND->getLinkageAndVisibility();
// Don't set internal linkage on declarations.
// "extern_weak" is overloaded in LLVM; we probably should have
// separate linkage types for this.
if (isExternallyVisible(LV.getLinkage()) &&
(ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
}
void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
llvm::Function *F) {
// Only if we are checking indirect calls.
if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
return;
// Non-static class methods are handled via vtable or member function pointer
// checks elsewhere.
if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
return;
// Additionally, if building with cross-DSO support...
if (CodeGenOpts.SanitizeCfiCrossDso) {
// Skip available_externally functions. They won't be codegen'ed in the
// current module anyway.
if (getContext().GetGVALinkageForFunction(FD) == GVA_AvailableExternally)
return;
}
llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
F->addTypeMetadata(0, MD);
F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
// Emit a hash-based bit set entry for cross-DSO calls.
if (CodeGenOpts.SanitizeCfiCrossDso)
if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
}
void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
bool IsIncompleteFunction,
bool IsThunk) {
if (llvm::Intrinsic::ID 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(), IID));
return;
}
const auto *FD = cast<FunctionDecl>(GD.getDecl());
if (!IsIncompleteFunction) {
SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F);
// Setup target-specific attributes.
if (F->isDeclaration())
getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
}
// 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) &&
!(getTriple().isiOS() && 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.
setLinkageForGV(F, FD);
setGVProperties(F, FD);
if (const auto *CSA = FD->getAttr<CodeSegAttr>())
F->setSection(CSA->getName());
else if (const auto *SA = FD->getAttr<SectionAttr>())
F->setSection(SA->getName());
if (FD->isReplaceableGlobalAllocationFunction()) {
// 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.
F->addAttribute(llvm::AttributeList::FunctionIndex,
llvm::Attribute::NoBuiltin);
// A sane operator new returns a non-aliasing pointer.
// FIXME: Also add NonNull attribute to the return value
// for the non-nothrow forms?
auto Kind = FD->getDeclName().getCXXOverloadedOperator();
if (getCodeGenOpts().AssumeSaneOperatorNew &&
(Kind == OO_New || Kind == OO_Array_New))
F->addAttribute(llvm::AttributeList::ReturnIndex,
llvm::Attribute::NoAlias);
}
if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
if (MD->isVirtual())
F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
// Don't emit entries for function declarations in the cross-DSO mode. This
// is handled with better precision by the receiving DSO.
if (!CodeGenOpts.SanitizeCfiCrossDso)
CreateFunctionTypeMetadataForIcall(FD, F);
if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
}
void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
assert(!GV->isDeclaration() &&
"Only globals with definition can force usage.");
LLVMUsed.emplace_back(GV);
}
void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
assert(!GV->isDeclaration() &&
"Only globals with definition can force usage.");
LLVMCompilerUsed.emplace_back(GV);
}
static void emitUsed(CodeGenModule &CGM, StringRef Name,
std::vector<llvm::WeakTrackingVH> &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::getPointerBitCastOrAddrSpaceCast(
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::AddELFLibDirective(StringRef Lib) {
auto &C = getLLVMContext();
LinkerOptionsMetadata.push_back(llvm::MDNode::get(
C, {llvm::MDString::get(C, "lib"), llvm::MDString::get(C, Lib)}));
}
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));
}
/// 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::MDNode *> &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 modules that use export_as for linking, use that module
// name instead.
if (Mod->UseExportAsModuleLinkName)
return;
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 (Module *M : ImportedModules) {
// Do not add any link flags when an implementation TU of a module imports
// a header of that same module.
if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
!getLangOpts().isCompilingModule())
continue;
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::MDNode *, 16> MetadataArgs;
Visited.clear();
for (Module *M : LinkModules)
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.
auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
for (auto *MD : LinkerOptionsMetadata)
NMD->addOperand(MD);
}
void CodeGenModule::EmitDeferred() {
// Emit deferred declare target declarations.
if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
getOpenMPRuntime().emitDeferredTargetDecls();
// 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.
if (!DeferredVTables.empty()) {
EmitDeferredVTables();
// Emitting a vtable doesn't directly cause more vtables to
// become deferred, although it can cause functions to be
// emitted that then need those vtables.
assert(DeferredVTables.empty());
}
// Stop if we're out of both deferred vtables and deferred declarations.
if (DeferredDeclsToEmit.empty())
return;
// Grab the list of decls to emit. If EmitGlobalDefinition schedules more
// work, it will not interfere with this.
std::vector<GlobalDecl> CurDeclsToEmit;
CurDeclsToEmit.swap(DeferredDeclsToEmit);
for (GlobalDecl &D : CurDeclsToEmit) {
// We should call GetAddrOfGlobal with IsForDefinition set to true in order
// to get GlobalValue with exactly the type we need, not something that
// might had been created for another decl with the same mangled name but
// different type.
llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
GetAddrOfGlobal(D, ForDefinition));
// In case of different address spaces, we may still get a cast, even with
// IsForDefinition equal to true. Query mangled names table to get
// GlobalValue.
if (!GV)
GV = GetGlobalValue(getMangledName(D));
// Make sure GetGlobalValue returned non-null.
assert(GV);
// 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->isDeclaration())
continue;
// Otherwise, emit the definition and move on to the next one.
EmitGlobalDefinition(D, GV);
// If we found out that we need to emit more decls, do that recursively.
// This has the advantage that the decls are emitted in a DFS and related
// ones are close together, which is convenient for testing.
if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
EmitDeferred();
assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
}
}
}
void CodeGenModule::EmitVTablesOpportunistically() {
// Try to emit external vtables as available_externally if they have emitted
// all inlined virtual functions. It runs after EmitDeferred() and therefore
// is not allowed to create new references to things that need to be emitted
// lazily. Note that it also uses fact that we eagerly emitting RTTI.
assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
&& "Only emit opportunistic vtables with optimizations");
for (const CXXRecordDecl *RD : OpportunisticVTables) {
assert(getVTables().isVTableExternal(RD) &&
"This queue should only contain external vtables");
if (getCXXABI().canSpeculativelyEmitVTable(RD))
VTables.GenerateClassData(RD);
}
OpportunisticVTables.clear();
}
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(llvm::GlobalValue::UnnamedAddr::Global);
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(SanitizerMask Kind,
llvm::Function *Fn,
SourceLocation Loc) const {
const auto &SanitizerBL = getContext().getSanitizerBlacklist();
// Blacklist by function name.
if (SanitizerBL.isBlacklistedFunction(Kind, Fn->getName()))
return true;
// Blacklist by location.
if (Loc.isValid())
return SanitizerBL.isBlacklistedLocation(Kind, 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(Kind, 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 and KASan.
const SanitizerMask EnabledAsanMask = LangOpts.Sanitize.Mask &
(SanitizerKind::Address | SanitizerKind::KernelAddress |
SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress);
if (!EnabledAsanMask)
return false;
const auto &SanitizerBL = getContext().getSanitizerBlacklist();
if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category))
return true;
if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, 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(EnabledAsanMask, TypeStr, Category))
return true;
}
}
return false;
}
bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
StringRef Category) const {
const auto &XRayFilter = getContext().getXRayFilter();
using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
auto Attr = ImbueAttr::NONE;
if (Loc.isValid())
Attr = XRayFilter.shouldImbueLocation(Loc, Category);
if (Attr == ImbueAttr::NONE)
Attr = XRayFilter.shouldImbueFunction(Fn->getName());
switch (Attr) {
case ImbueAttr::NONE:
return false;
case ImbueAttr::ALWAYS:
Fn->addFnAttr("function-instrument", "xray-always");
break;
case ImbueAttr::ALWAYS_ARG1:
Fn->addFnAttr("function-instrument", "xray-always");
Fn->addFnAttr("xray-log-args", "1");
break;
case ImbueAttr::NEVER:
Fn->addFnAttr("function-instrument", "xray-never");
break;
}
return true;
}
bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
// Never defer when EmitAllDecls is specified.
if (LangOpts.EmitAllDecls)
return true;
if (CodeGenOpts.KeepStaticConsts) {
const auto *VD = dyn_cast<VarDecl>(Global);
if (VD && VD->getType().isConstQualified() &&
VD->getStorageClass() == SC_Static)
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;
if (const auto *VD = dyn_cast<VarDecl>(Global))
if (Context.getInlineVariableDefinitionKind(VD) ==
ASTContext::InlineVariableDefinitionKind::WeakUnknown)
// A definition of an inline constexpr static data member may change
// linkage later if it's redeclared outside the class.
return false;
// If OpenMP is enabled and threadprivates must be generated like TLS, delay
// codegen for global variables, because they may be marked as threadprivate.
if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
!isTypeConstant(Global->getType(), false) &&
!OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
return false;
return true;
}
ConstantAddress CodeGenModule::GetAddrOfUuidDescriptor(
const CXXUuidofExpr* E) {
// Sema has verified that IIDSource has a __declspec(uuid()), and that its
// well-formed.
StringRef Uuid = E->getUuidStr();
std::string Name = "_GUID_" + Uuid.lower();
std::replace(Name.begin(), Name.end(), '-', '_');
// The UUID descriptor should be pointer aligned.
CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
// Look for an existing global.
if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
return ConstantAddress(GV, Alignment);
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);
if (supportsCOMDAT())
GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
setDSOLocal(GV);
return ConstantAddress(GV, Alignment);
}
ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
const AliasAttr *AA = VD->getAttr<AliasAttr>();
assert(AA && "No alias?");
CharUnits Alignment = getContext().getDeclAlign(VD);
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());
auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
return ConstantAddress(Ptr, Alignment);
}
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 ConstantAddress(Aliasee, Alignment);
}
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);
// IFunc like an alias whose value is resolved at runtime by calling resolver.
if (Global->hasAttr<IFuncAttr>())
return emitIFuncDefinition(GD);
// If this is a cpu_dispatch multiversion function, emit the resolver.
if (Global->hasAttr<CPUDispatchAttr>())
return emitCPUDispatchDefinition(GD);
// If this is CUDA, be selective about which declarations we emit.
if (LangOpts.CUDA) {
if (LangOpts.CUDAIsDevice) {
if (!Global->hasAttr<CUDADeviceAttr>() &&
!Global->hasAttr<CUDAGlobalAttr>() &&
!Global->hasAttr<CUDAConstantAttr>() &&
!Global->hasAttr<CUDASharedAttr>())
return;
} else {
// We need to emit host-side 'shadows' for all global
// device-side variables because the CUDA runtime needs their
// size and host-side address in order to provide access to
// their device-side incarnations.
// So device-only functions are the only things we skip.
if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
Global->hasAttr<CUDADeviceAttr>())
return;
assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
"Expected Variable or Function");
}
}
if (LangOpts.OpenMP) {
// If this is OpenMP device, check if it is legal to emit this global
// normally.
if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
return;
if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
if (MustBeEmitted(Global))
EmitOMPDeclareReduction(DRD);
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.");
// We need to emit device-side global CUDA variables even if a
// variable does not have a definition -- we still need to define
// host-side shadow for it.
bool MustEmitForCuda = LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
!VD->hasDefinition() &&
(VD->hasAttr<CUDAConstantAttr>() ||
VD->hasAttr<CUDADeviceAttr>());
if (!MustEmitForCuda &&
VD->isThisDeclarationADefinition() != VarDecl::Definition &&
!Context.isMSStaticDataMemberInlineDefinition(VD)) {
if (LangOpts.OpenMP) {
// Emit declaration of the must-be-emitted declare target variable.
if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
if (*Res == OMPDeclareTargetDeclAttr::MT_To) {
(void)GetAddrOfGlobalVar(VD);
} else {
assert(*Res == OMPDeclareTargetDeclAttr::MT_Link &&
"link claue expected.");
(void)getOpenMPRuntime().getAddrOfDeclareTargetLink(VD);
}
return;
}
}
// If this declaration may have caused an inline variable definition to
// change linkage, make sure that it's emitted.
if (Context.getInlineVariableDefinitionKind(VD) ==
ASTContext::InlineVariableDefinitionKind::Strong)
GetAddrOfGlobalVar(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 (GetGlobalValue(MangledName) != nullptr) {
// The value has already been used and should therefore be emitted.
addDeferredDeclToEmit(GD);
} else if (MustBeEmitted(Global)) {
// The value must be emitted, but cannot be emitted eagerly.
assert(!MayBeEmittedEagerly(Global));
addDeferredDeclToEmit(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;
}
}
// Check if T is a class type with a destructor that's not dllimport.
static bool HasNonDllImportDtor(QualType T) {
if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
return true;
return false;
}
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 || !BI.isLibFunction(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;
}
};
// Make sure we're not referencing non-imported vars or functions.
struct DLLImportFunctionVisitor
: public RecursiveASTVisitor<DLLImportFunctionVisitor> {
bool SafeToInline = true;
bool shouldVisitImplicitCode() const { return true; }
bool VisitVarDecl(VarDecl *VD) {
if (VD->getTLSKind()) {
// A thread-local variable cannot be imported.
SafeToInline = false;
return SafeToInline;
}
// A variable definition might imply a destructor call.
if (VD->isThisDeclarationADefinition())
SafeToInline = !HasNonDllImportDtor(VD->getType());
return SafeToInline;
}
bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
if (const auto *D = E->getTemporary()->getDestructor())
SafeToInline = D->hasAttr<DLLImportAttr>();
return SafeToInline;
}
bool VisitDeclRefExpr(DeclRefExpr *E) {
ValueDecl *VD = E->getDecl();
if (isa<FunctionDecl>(VD))
SafeToInline = VD->hasAttr<DLLImportAttr>();
else if (VarDecl *V = dyn_cast<VarDecl>(VD))
SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
return SafeToInline;
}
bool VisitCXXConstructExpr(CXXConstructExpr *E) {
SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
return SafeToInline;
}
bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
CXXMethodDecl *M = E->getMethodDecl();
if (!M) {
// Call through a pointer to member function. This is safe to inline.
SafeToInline = true;
} else {
SafeToInline = M->hasAttr<DLLImportAttr>();
}
return SafeToInline;
}
bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
return SafeToInline;
}
bool VisitCXXNewExpr(CXXNewExpr *E) {
SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
return SafeToInline;
}
};
}
// 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;
if (F->hasAttr<DLLImportAttr>()) {
// Check whether it would be safe to inline this dllimport function.
DLLImportFunctionVisitor Visitor;
Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
if (!Visitor.SafeToInline)
return false;
if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
// Implicit destructor invocations aren't captured in the AST, so the
// check above can't see them. Check for them manually here.
for (const Decl *Member : Dtor->getParent()->decls())
if (isa<FieldDecl>(Member))
if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
return false;
for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
if (HasNonDllImportDtor(B.getType()))
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);
}
bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
return CodeGenOpts.OptimizationLevel > 0;
}
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)) {
// 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, !VD->hasDefinition());
llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
}
static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
llvm::Function *NewFn);
static unsigned
TargetMVPriority(const TargetInfo &TI,
const CodeGenFunction::MultiVersionResolverOption &RO) {
unsigned Priority = 0;
for (StringRef Feat : RO.Conditions.Features)
Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
if (!RO.Conditions.Architecture.empty())
Priority = std::max(
Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
return Priority;
}
void CodeGenModule::emitMultiVersionFunctions() {
for (GlobalDecl GD : MultiVersionFuncs) {
SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
getContext().forEachMultiversionedFunctionVersion(
FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
GlobalDecl CurGD{
(CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
StringRef MangledName = getMangledName(CurGD);
llvm::Constant *Func = GetGlobalValue(MangledName);
if (!Func) {
if (CurFD->isDefined()) {
EmitGlobalFunctionDefinition(CurGD, nullptr);
Func = GetGlobalValue(MangledName);
} else {
const CGFunctionInfo &FI =
getTypes().arrangeGlobalDeclaration(GD);
llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
/*DontDefer=*/false, ForDefinition);
}
assert(Func && "This should have just been created");
}
const auto *TA = CurFD->getAttr<TargetAttr>();
llvm::SmallVector<StringRef, 8> Feats;
TA->getAddedFeatures(Feats);
Options.emplace_back(cast<llvm::Function>(Func),
TA->getArchitecture(), Feats);
});
llvm::Function *ResolverFunc = cast<llvm::Function>(
GetGlobalValue((getMangledName(GD) + ".resolver").str()));
if (supportsCOMDAT())
ResolverFunc->setComdat(
getModule().getOrInsertComdat(ResolverFunc->getName()));
const TargetInfo &TI = getTarget();
std::stable_sort(
Options.begin(), Options.end(),
[&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
const CodeGenFunction::MultiVersionResolverOption &RHS) {
return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
});
CodeGenFunction CGF(*this);
CGF.EmitMultiVersionResolver(ResolverFunc, Options);
}
}
void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
const auto *FD = cast<FunctionDecl>(GD.getDecl());
assert(FD && "Not a FunctionDecl?");
const auto *DD = FD->getAttr<CPUDispatchAttr>();
assert(DD && "Not a cpu_dispatch Function?");
llvm::Type *DeclTy = getTypes().ConvertTypeForMem(FD->getType());
StringRef ResolverName = getMangledName(GD);
llvm::Type *ResolverType = llvm::FunctionType::get(
llvm::PointerType::get(DeclTy,
Context.getTargetAddressSpace(FD->getType())),
false);
auto *ResolverFunc = cast<llvm::Function>(
GetOrCreateLLVMFunction(ResolverName, ResolverType, GlobalDecl{},
/*ForVTable=*/false));
SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
const TargetInfo &Target = getTarget();
for (const IdentifierInfo *II : DD->cpus()) {
// Get the name of the target function so we can look it up/create it.
std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
getCPUSpecificMangling(*this, II->getName());
llvm::Constant *Func = GetOrCreateLLVMFunction(
MangledName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/false,
/*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
llvm::SmallVector<StringRef, 32> Features;
Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
llvm::transform(Features, Features.begin(),
[](StringRef Str) { return Str.substr(1); });
Features.erase(std::remove_if(
Features.begin(), Features.end(), [&Target](StringRef Feat) {
return !Target.validateCpuSupports(Feat);
}), Features.end());
Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
}
llvm::sort(
Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
const CodeGenFunction::MultiVersionResolverOption &RHS) {
return CodeGenFunction::GetX86CpuSupportsMask(LHS.Conditions.Features) >
CodeGenFunction::GetX86CpuSupportsMask(RHS.Conditions.Features);
});
CodeGenFunction CGF(*this);
CGF.EmitMultiVersionResolver(ResolverFunc, Options);
}
/// If an ifunc for the specified mangled name is not in the module, create and
/// return an llvm IFunc Function with the specified type.
llvm::Constant *
CodeGenModule::GetOrCreateMultiVersionIFunc(GlobalDecl GD, llvm::Type *DeclTy,
const FunctionDecl *FD) {
std::string MangledName =
getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
std::string IFuncName = MangledName + ".ifunc";
if (llvm::GlobalValue *IFuncGV = GetGlobalValue(IFuncName))
return IFuncGV;
// Since this is the first time we've created this IFunc, make sure
// that we put this multiversioned function into the list to be
// replaced later if necessary (target multiversioning only).
if (!FD->isCPUDispatchMultiVersion() && !FD->isCPUSpecificMultiVersion())
MultiVersionFuncs.push_back(GD);
std::string ResolverName = MangledName + ".resolver";
llvm::Type *ResolverType = llvm::FunctionType::get(
llvm::PointerType::get(DeclTy,
Context.getTargetAddressSpace(FD->getType())),
false);
llvm::Constant *Resolver =
GetOrCreateLLVMFunction(ResolverName, ResolverType, GlobalDecl{},
/*ForVTable=*/false);
llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
DeclTy, 0, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
GIF->setName(IFuncName);
SetCommonAttributes(FD, GIF);
return GIF;
}
/// 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::AttributeList ExtraAttrs,
ForDefinition_t IsForDefinition) {
const Decl *D = GD.getDecl();
// Any attempts to use a MultiVersion function should result in retrieving
// the iFunc instead. Name Mangling will handle the rest of the changes.
if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
// For the device mark the function as one that should be emitted.
if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
!OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
!DontDefer && !IsForDefinition) {
if (const FunctionDecl *FDDef = FD->getDefinition()) {
GlobalDecl GDDef;
if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
GDDef = GlobalDecl(CD, GD.getCtorType());
else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
GDDef = GlobalDecl(DD, GD.getDtorType());
else
GDDef = GlobalDecl(FDDef);
EmitGlobal(GDDef);
}
}
if (FD->isMultiVersion()) {
const auto *TA = FD->getAttr<TargetAttr>();
if (TA && TA->isDefaultVersion())
UpdateMultiVersionNames(GD, FD);
if (!IsForDefinition)
return GetOrCreateMultiVersionIFunc(GD, Ty, FD);
}
}
// 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);
setDSOLocal(Entry);
}
// If there are two attempts to define the same mangled name, issue an
// error.
if (IsForDefinition && !Entry->isDeclaration()) {
GlobalDecl OtherGD;
// Check that GD is not yet in DiagnosedConflictingDefinitions is required
// to make sure that we issue an error only once.
if (lookupRepresentativeDecl(MangledName, OtherGD) &&
(GD.getCanonicalDecl().getDecl() !=
OtherGD.getCanonicalDecl().getDecl()) &&
DiagnosedConflictingDefinitions.insert(GD).second) {
getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
<< MangledName;
getDiags().Report(OtherGD.getDecl()->getLocation(),
diag::note_previous_definition);
}
}
if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
(Entry->getType()->getElementType() == Ty)) {
return Entry;
}
// Make sure the result is of the correct type.
// (If function is requested for a definition, we always need to create a new
// function, not just return a bitcast.)
if (!IsForDefinition)
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,
Entry ? StringRef() : MangledName, &getModule());
// If we already created a function with the same mangled name (but different
// type) before, take its name and add it to the list of functions to be
// replaced with F at the end of CodeGen.
//
// 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)").
if (Entry) {
F->takeName(Entry);
// 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 (!Entry->use_empty()) {
ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
Entry->removeDeadConstantUsers();
}
llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
F, Entry->getType()->getElementType()->getPointerTo());
addGlobalValReplacement(Entry, BC);
}
assert(F->getName() == MangledName && "name was uniqued!");
if (D)
SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
F->addAttributes(llvm::AttributeList::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(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(DDI->second);
DeferredDecls.erase(DDI);
// 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(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,
ForDefinition_t IsForDefinition) {
// If there was no specific requested type, just convert it now.
if (!Ty) {
const auto *FD = cast<FunctionDecl>(GD.getDecl());
auto CanonTy = Context.getCanonicalType(FD->getType());
Ty = getTypes().ConvertFunctionType(CanonTy, FD);
}
// Devirtualized destructor calls may come through here instead of via
// getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
// of the complete destructor when necessary.
if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
if (getTarget().getCXXABI().isMicrosoft() &&
GD.getDtorType() == Dtor_Complete &&
DD->getParent()->getNumVBases() == 0)
GD = GlobalDecl(DD, Dtor_Base);
}
StringRef MangledName = getMangledName(GD);
return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
/*IsThunk=*/false, llvm::AttributeList(),
IsForDefinition);
}
static const FunctionDecl *
GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
IdentifierInfo &CII = C.Idents.get(Name);
for (const auto &Result : DC->lookup(&CII))
if (const auto FD = dyn_cast<FunctionDecl>(Result))
return FD;
if (!C.getLangOpts().CPlusPlus)
return nullptr;
// Demangle the premangled name from getTerminateFn()
IdentifierInfo &CXXII =
(Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
? C.Idents.get("terminate")
: C.Idents.get(Name);
for (const auto &N : {"__cxxabiv1", "std"}) {
IdentifierInfo &NS = C.Idents.get(N);
for (const auto &Result : DC->lookup(&NS)) {
NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
if (auto LSD = dyn_cast<LinkageSpecDecl>(Result))
for (const auto &Result : LSD->lookup(&NS))
if ((ND = dyn_cast<NamespaceDecl>(Result)))
break;
if (ND)
for (const auto &Result : ND->lookup(&CXXII))
if (const auto *FD = dyn_cast<FunctionDecl>(Result))
return FD;
}
}
return nullptr;
}
/// CreateRuntimeFunction - Create a new runtime function with the specified
/// type and name.
llvm::Constant *
CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
llvm::AttributeList ExtraAttrs,
bool Local) {
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());
if (!Local && getTriple().isOSBinFormatCOFF() &&
!getCodeGenOpts().LTOVisibilityPublicStd &&
!getTriple().isWindowsGNUEnvironment()) {
const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
if (!FD || FD->hasAttr<DLLImportAttr>()) {
F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
F->setLinkage(llvm::GlobalValue::ExternalLinkage);
}
}
setDSOLocal(F);
}
}
return C;
}
/// CreateBuiltinFunction - Create a new builtin function with the specified
/// type and name.
llvm::Constant *
CodeGenModule::CreateBuiltinFunction(llvm::FunctionType *FTy, StringRef Name,
llvm::AttributeList ExtraAttrs) {
return CreateRuntimeFunction(FTy, Name, ExtraAttrs, true);
}
/// 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.
///
/// If IsForDefinition is true, it is guaranteed that an actual global with
/// type Ty will be returned, not conversion of a variable with the same
/// mangled name but some other type.
llvm::Constant *
CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
llvm::PointerType *Ty,
const VarDecl *D,
ForDefinition_t IsForDefinition) {
// 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 (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
if (Entry->getType() == Ty)
return Entry;
// If there are two attempts to define the same mangled name, issue an
// error.
if (IsForDefinition && !Entry->isDeclaration()) {
GlobalDecl OtherGD;
const VarDecl *OtherD;
// Check that D is not yet in DiagnosedConflictingDefinitions is required
// to make sure that we issue an error only once.
if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
(D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
(OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
OtherD->hasInit() &&
DiagnosedConflictingDefinitions.insert(D).second) {
getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
<< MangledName;
getDiags().Report(OtherGD.getDecl()->getLocation(),
diag::note_previous_definition);
}
}
// Make sure the result is of the correct type.
if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
// (If global is requested for a definition, we always need to create a new
// global, not just return a bitcast.)
if (!IsForDefinition)
return llvm::ConstantExpr::getBitCast(Entry, Ty);
}
auto AddrSpace = GetGlobalVarAddressSpace(D);
auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace);
auto *GV = new llvm::GlobalVariable(
getModule(), Ty->getElementType(), false,
llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace);
// If we already created a global with the same mangled name (but different
// type) before, take its name and remove it from its parent.
if (Entry) {
GV->takeName(Entry);
if (!Entry->use_empty()) {
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(GV, Entry->getType());
Entry->replaceAllUsesWith(NewPtrForOldDecl);
}
Entry->eraseFromParent();
}
// 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(DDI->second);
DeferredDecls.erase(DDI);
}
// Handle things which are present even on external declarations.
if (D) {
if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
// FIXME: This code is overly simple and should be merged with other global
// handling.
GV->setConstant(isTypeConstant(D->getType(), false));
GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
setLinkageForGV(GV, D);
if (D->getTLSKind()) {
if (D->getTLSKind() == VarDecl::TLS_Dynamic)
CXXThreadLocals.push_back(D);
setTLSMode(GV, *D);
}
setGVProperties(GV, D);
// If required by the ABI, treat declarations of static data members with
// inline initializers as definitions.
if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
EmitGlobalVarDefinition(D);
}
// Emit section information for extern variables.
if (D->hasExternalStorage()) {
if (const SectionAttr *SA = D->getAttr<SectionAttr>())
GV->setSection(SA->getName());
}
// Handle XCore specific ABI requirements.
if (getTriple().getArch() == llvm::Triple::xcore &&
D->getLanguageLinkage() == CLanguageLinkage &&
D->getType().isConstant(Context) &&
isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
GV->setSection(".cp.rodata");
// Check if we a have a const declaration with an initializer, we may be
// able to emit it as available_externally to expose it's value to the
// optimizer.
if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
D->getType().isConstQualified() && !GV->hasInitializer() &&
!D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
const auto *Record =
Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
bool HasMutableFields = Record && Record->hasMutableFields();
if (!HasMutableFields) {
const VarDecl *InitDecl;
const Expr *InitExpr = D->getAnyInitializer(InitDecl);
if (InitExpr) {
ConstantEmitter emitter(*this);
llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
if (Init) {
auto *InitType = Init->getType();
if (GV->getType()->getElementType() != InitType) {
// The type of the initializer does not match the definition.
// This happens when an initializer has a different type from
// the type of the global (because of padding at the end of a
// structure for instance).
GV->setName(StringRef());
// Make a new global with the correct type, this is now guaranteed
// to work.
auto *NewGV = cast<llvm::GlobalVariable>(
GetAddrOfGlobalVar(D, InitType, IsForDefinition));
// Erase the old global, since it is no longer used.
GV->eraseFromParent();
GV = NewGV;
} else {
GV->setInitializer(Init);
GV->setConstant(true);
GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
}
emitter.finalize(GV);
}
}
}
}
}
LangAS ExpectedAS =
D ? D->getType().getAddressSpace()
: (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
assert(getContext().getTargetAddressSpace(ExpectedAS) ==
Ty->getPointerAddressSpace());
if (AddrSpace != ExpectedAS)
return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace,
ExpectedAS, Ty);
return GV;
}
llvm::Constant *
CodeGenModule::GetAddrOfGlobal(GlobalDecl GD,
ForDefinition_t IsForDefinition) {
const Decl *D = GD.getDecl();
if (isa<CXXConstructorDecl>(D))
return getAddrOfCXXStructor(cast<CXXConstructorDecl>(D),
getFromCtorType(GD.getCtorType()),
/*FnInfo=*/nullptr, /*FnType=*/nullptr,
/*DontDefer=*/false, IsForDefinition);
else if (isa<CXXDestructorDecl>(D))
return getAddrOfCXXStructor(cast<CXXDestructorDecl>(D),
getFromDtorType(GD.getDtorType()),
/*FnInfo=*/nullptr, /*FnType=*/nullptr,
/*DontDefer=*/false, IsForDefinition);
else if (isa<CXXMethodDecl>(D)) {
auto FInfo = &getTypes().arrangeCXXMethodDeclaration(
cast<CXXMethodDecl>(D));
auto Ty = getTypes().GetFunctionType(*FInfo);
return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
IsForDefinition);
} else if (isa<FunctionDecl>(D)) {
const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
IsForDefinition);
} else
return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr,
IsForDefinition);
}
llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
unsigned Alignment) {
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();
}
if (supportsCOMDAT() && GV->isWeakForLinker() &&
!GV->hasAvailableExternallyLinkage())
GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
GV->setAlignment(Alignment);
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. If IsForDefinition is true, it is guaranteed
/// that an actual global with type Ty will be returned, not conversion of a
/// variable with the same mangled name but some other type.
llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
llvm::Type *Ty,
ForDefinition_t IsForDefinition) {
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, IsForDefinition);
}
/// CreateRuntimeVariable - Create a new runtime global variable with the
/// specified type and name.
llvm::Constant *
CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
StringRef Name) {
auto *Ret =
GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), nullptr);
setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
return Ret;
}
void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
assert(!D->getInit() && "Cannot emit definite definitions here!");
StringRef MangledName = getMangledName(D);
llvm::GlobalValue *GV = GetGlobalValue(MangledName);
// We already have a definition, not declaration, with the same mangled name.
// Emitting of declaration is not required (and actually overwrites emitted
// definition).
if (GV && !GV->isDeclaration())
return;
// If we have not seen a reference to this variable yet, place it into the
// deferred declarations table to be emitted if needed later.
if (!MustBeEmitted(D) && !GV) {
DeferredDecls[MangledName] = D;
return;
}
// The tentative definition is the only definition.
EmitGlobalVarDefinition(D);
}
CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
return Context.toCharUnitsFromBits(
getDataLayout().getTypeStoreSizeInBits(Ty));
}
LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
LangAS AddrSpace = LangAS::Default;
if (LangOpts.OpenCL) {
AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
assert(AddrSpace == LangAS::opencl_global ||
AddrSpace == LangAS::opencl_constant ||
AddrSpace == LangAS::opencl_local ||
AddrSpace >= LangAS::FirstTargetAddressSpace);
return AddrSpace;
}
if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
if (D && D->hasAttr<CUDAConstantAttr>())
return LangAS::cuda_constant;
else if (D && D->hasAttr<CUDASharedAttr>())
return LangAS::cuda_shared;
else if (D && D->hasAttr<CUDADeviceAttr>())
return LangAS::cuda_device;
else if (D && D->getType().isConstQualified())
return LangAS::cuda_constant;
else
return LangAS::cuda_device;
}
return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
}
LangAS CodeGenModule::getStringLiteralAddressSpace() const {
// OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
if (LangOpts.OpenCL)
return LangAS::opencl_constant;
if (auto AS = getTarget().getConstantAddressSpace())
return AS.getValue();
return LangAS::Default;
}
// In address space agnostic languages, string literals are in default address
// space in AST. However, certain targets (e.g. amdgcn) request them to be
// emitted in constant address space in LLVM IR. To be consistent with other
// parts of AST, string literal global variables in constant address space
// need to be casted to default address space before being put into address
// map and referenced by other part of CodeGen.
// In OpenCL, string literals are in constant address space in AST, therefore
// they should not be casted to default address space.
static llvm::Constant *
castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
llvm::GlobalVariable *GV) {
llvm::Constant *Cast = GV;
if (!CGM.getLangOpts().OpenCL) {
if (auto AS = CGM.getTarget().getConstantAddressSpace()) {
if (AS != LangAS::Default)
Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
CGM, GV, AS.getValue(), LangAS::Default,
GV->getValueType()->getPointerTo(
CGM.getContext().getTargetAddressSpace(LangAS::Default)));
}
}
return Cast;
}
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::maybeSetTrivialComdat(const Decl &D,
llvm::GlobalObject &GO) {
if (!shouldBeInCOMDAT(*this, D))
return;
GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
}
/// Pass IsTentative as true if you want to create a tentative definition.
void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
bool IsTentative) {
// OpenCL global variables of sampler type are translated to function calls,
// therefore no need to be translated.
QualType ASTTy = D->getType();
if (getLangOpts().OpenCL && ASTTy->isSamplerT())
return;
// If this is OpenMP device, check if it is legal to emit this global
// normally.
if (LangOpts.OpenMPIsDevice && OpenMPRuntime &&
OpenMPRuntime->emitTargetGlobalVariable(D))
return;
llvm::Constant *Init = nullptr;
CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
bool NeedsGlobalCtor = false;
bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
const VarDecl *InitDecl;
const Expr *InitExpr = D->getAnyInitializer(InitDecl);
Optional<ConstantEmitter> emitter;
// CUDA E.2.4.1 "__shared__ variables cannot have an initialization
// as part of their declaration." Sema has already checked for
// error cases, so we just need to set Init to UndefValue.
if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
D->hasAttr<CUDASharedAttr>())
Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
else 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);
emitter.emplace(*this);
Init = emitter->tryEmitForInitializer(*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, ForDefinition_t(!IsTentative));
// 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() !=
getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
// 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, ForDefinition_t(!IsTentative)));
// 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);
// Set the llvm linkage type as appropriate.
llvm::GlobalValue::LinkageTypes Linkage =
getLLVMLinkageVarDefinition(D, GV->isConstant());
// CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
// the device. [...]"
// CUDA B.2.2 "The __constant__ qualifier, optionally used together with
// __device__, declares a variable that: [...]
// Is accessible from all the threads within the grid and from the host
// through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
// / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
if (GV && LangOpts.CUDA) {
if (LangOpts.CUDAIsDevice) {
if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>())
GV->setExternallyInitialized(true);
} else {
// Host-side shadows of external declarations of device-side
// global variables become internal definitions. These have to
// be internal in order to prevent name conflicts with global
// host variables with the same name in a different TUs.
if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) {
Linkage = llvm::GlobalValue::InternalLinkage;
// Shadow variables and their properties must be registered
// with CUDA runtime.
unsigned Flags = 0;
if (!D->hasDefinition())
Flags |= CGCUDARuntime::ExternDeviceVar;
if (D->hasAttr<CUDAConstantAttr>())
Flags |= CGCUDARuntime::ConstantDeviceVar;
getCUDARuntime().registerDeviceVar(*GV, Flags);
} else if (D->hasAttr<CUDASharedAttr>())
// __shared__ variables are odd. Shadows do get created, but
// they are not registered with the CUDA runtime, so they
// can't really be used to access their device-side
// counterparts. It's not clear yet whether it's nvcc's bug or
// a feature, but we've got to do the same for compatibility.
Linkage = llvm::GlobalValue::InternalLinkage;
}
}
GV->setInitializer(Init);
if (emitter) emitter->finalize(GV);
// 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());
// On Darwin, if the normal linkage of a C++ thread_local variable is
// LinkOnce or Weak, we keep the normal linkage to prevent multiple
// copies within a linkage unit; otherwise, the backing variable has
// internal linkage and all accesses should just be calls to the
// Itanium-specified entry point, which has the normal linkage of the
// variable. This is to preserve the ability to change the implementation
// behind the scenes.
if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
Context.getTargetInfo().getTriple().isOSDarwin() &&
!llvm::GlobalVariable::isLinkOnceLinkage(Linkage) &&
!llvm::GlobalVariable::isWeakLinkage(Linkage))
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);
// Tentative definition of global variables may be initialized with
// non-zero null pointers. In this case they should have weak linkage
// since common linkage must have zero initializer and must not have
// explicit section therefore cannot have non-zero initial value.
if (!GV->getInitializer()->isNullValue())
GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
}
setNonAliasAttributes(D, GV);
if (D->getTLSKind() && !GV->isThreadLocal()) {
if (D->getTLSKind() == VarDecl::TLS_Dynamic)
CXXThreadLocals.push_back(D);
setTLSMode(GV, *D);
}
maybeSetTrivialComdat(*D, *GV);
// 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,
CodeGenModule &CGM, 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;
// A variable cannot be both common and exist in a section.
// We don't try to determine which is the right section in the front-end.
// If no specialized section name is applicable, it will resort to default.
if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
D->hasAttr<PragmaClangDataSectionAttr>() ||
D->hasAttr<PragmaClangRodataSectionAttr>())
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;
// A variable cannot be both common and exist in a comdat.
if (shouldBeInCOMDAT(CGM, *D))
return true;
// Declarations with a required alignment do not have common linkage in MSVC
// mode.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
if (D->hasAttr<AlignedAttr>())
return true;
QualType VarType = D->getType();
if (Context.isAlignmentRequired(VarType))
return true;
if (const auto *RT = VarType->getAs<RecordType>()) {
const RecordDecl *RD = RT->getDecl();
for (const FieldDecl *FD : RD->fields()) {
if (FD->isBitField())
continue;
if (FD->hasAttr<AlignedAttr>())
return true;
if (Context.isAlignmentRequired(FD->getType()))
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;
}
if (const auto *FD = D->getAsFunction())
if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
return llvm::GlobalVariable::LinkOnceAnyLinkage;
// We are guaranteed to have a strong definition somewhere else,
// so we can use available_externally linkage.
if (Linkage == GVA_AvailableExternally)
return llvm::GlobalValue::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.
//
// We don't currently support CUDA device code spread out across multiple TUs,
// so say that CUDA templates are either external (for kernels) or internal.
// This lets llvm perform aggressive inter-procedural optimizations.
if (Linkage == GVA_StrongODR) {
if (Context.getLangOpts().AppleKext)
return llvm::Function::ExternalLinkage;
if (Context.getLangOpts().CUDA && Context.getLangOpts().CUDAIsDevice)
return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
: llvm::Function::InternalLinkage;
return llvm::Function::WeakODRLinkage;
}
// C++ doesn't have tentative definitions and thus cannot have common
// linkage.
if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
!isVarDeclStrongDefinition(Context, *this, 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;
SmallVector<llvm::OperandBundleDef, 1> newBundles;
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> newArgAttrs;
llvm::AttributeList oldAttrs = callSite.getAttributes();
// 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::Argument &A : newFn->args()) {
if (callSite.getArgument(argNo)->getType() != A.getType()) {
dontTransform = true;
break;
}
// Add any parameter attributes.
newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
argNo++;
}
if (dontTransform)
continue;
// 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);
// Copy over any operand bundles.
callSite.getOperandBundlesAsDefs(newBundles);
llvm::CallSite newCall;
if (callSite.isCall()) {
newCall = llvm::CallInst::Create(newFn, newArgs, newBundles, "",
callSite.getInstruction());
} else {
auto *oldInvoke = cast<llvm::InvokeInst>(callSite.getInstruction());
newCall = llvm::InvokeInst::Create(newFn,
oldInvoke->getNormalDest(),
oldInvoke->getUnwindDest(),
newArgs, newBundles, "",
callSite.getInstruction());
}
newArgs.clear(); // for the next iteration
if (!newCall->getType()->isVoidTy())
newCall->takeName(callSite.getInstruction());
newCall.setAttributes(llvm::AttributeList::get(
newFn->getContext(), oldAttrs.getFnAttributes(),
oldAttrs.getRetAttributes(), newArgAttrs));
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())
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) {
auto DK = VD->isThisDeclarationADefinition();
if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
return;
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 || (GV->getType()->getElementType() != Ty))
GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
/*DontDefer=*/true,
ForDefinition));
// Already emitted.
if (!GV->isDeclaration())
return;
// 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);
// FIXME: this is redundant with part of setFunctionDefinitionAttributes
setGVProperties(Fn, GD);
MaybeHandleStaticInExternC(D, Fn);
maybeSetTrivialComdat(*D, *Fn);
CodeGenFunction(*this).GenerateCode(D, Fn, FI);
setNonAliasAttributes(GD, 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);
if (D->isCPUSpecificMultiVersion()) {
auto *Spec = D->getAttr<CPUSpecificAttr>();
// If there is another specific version we need to emit, do so here.
if (Spec->ActiveArgIndex + 1 < Spec->cpus_size()) {
++Spec->ActiveArgIndex;
EmitGlobalFunctionDefinition(GD, nullptr);
}
}
}
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 (AA->getAliasee() == MangledName) {
Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
return;
}
// 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(
DeclTy, 0, llvm::Function::ExternalLinkage, "", Aliasee, &getModule());
if (Entry) {
if (GA->getAliasee() == Entry) {
Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
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);
SetCommonAttributes(GD, GA);
}
void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
const auto *D = cast<ValueDecl>(GD.getDecl());
const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
assert(IFA && "Not an ifunc?");
StringRef MangledName = getMangledName(GD);
if (IFA->getResolver() == MangledName) {
Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
return;
}
// Report an error if some definition overrides ifunc.
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (Entry && !Entry->isDeclaration()) {
GlobalDecl OtherGD;
if (lookupRepresentativeDecl(MangledName, OtherGD) &&
DiagnosedConflictingDefinitions.insert(GD).second) {
Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
<< MangledName;
Diags.Report(OtherGD.getDecl()->getLocation(),
diag::note_previous_definition);
}
return;
}
Aliases.push_back(GD);
llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
llvm::Constant *Resolver =
GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
/*ForVTable=*/false);
llvm::GlobalIFunc *GIF =
llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
"", Resolver, &getModule());
if (Entry) {
if (GIF->getResolver() == Entry) {
Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
return;
}
assert(Entry->isDeclaration());
// If there is a declaration in the module, then we had an extern followed
// by the ifunc, as in:
// extern int test();
// ...
// int test() __attribute__((ifunc("resolver")));
//
// Remove it and replace uses of it with the ifunc.
GIF->takeName(Entry);
Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
Entry->getType()));
Entry->eraseFromParent();
} else
GIF->setName(MangledName);
SetCommonAttributes(GD, GIF);
}
llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
ArrayRef<llvm::Type*> Tys) {
return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
Tys);
}
static llvm::StringMapEntry<llvm::GlobalVariable *> &
GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &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<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
llvm::UTF16 *ToPtr = &ToBuf[0];
(void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
ToPtr + NumBytes, llvm::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;
}
ConstantAddress
CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
unsigned StringLength = 0;
bool isUTF16 = false;
llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
GetConstantCFStringEntry(CFConstantStringMap, Literal,
getDataLayout().isLittleEndian(), isUTF16,
StringLength);
if (auto *C = Entry.second)
return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
llvm::Constant *Zeros[] = { Zero, Zero };
// 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 *C =
CreateRuntimeVariable(Ty, "__CFConstantStringClassReference");
if (getTriple().isOSBinFormatELF() || getTriple().isOSBinFormatCOFF()) {
llvm::GlobalValue *GV = nullptr;
if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
IdentifierInfo &II = getContext().Idents.get(GV->getName());
TranslationUnitDecl *TUDecl = getContext().getTranslationUnitDecl();
DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
const VarDecl *VD = nullptr;
for (const auto &Result : DC->lookup(&II))
if ((VD = dyn_cast<VarDecl>(Result)))
break;
if (getTriple().isOSBinFormatELF()) {
if (!VD)
GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
}
else {
if (!VD || !VD->hasAttr<DLLExportAttr>()) {
GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
} else {
GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
}
}
setDSOLocal(GV);
}
}
// Decay array -> ptr
CFConstantStringClassRef =
llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
}
QualType CFTy = getContext().getCFConstantStringType();
auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
ConstantInitBuilder Builder(*this);
auto Fields = Builder.beginStruct(STy);
// Class pointer.
Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
// Flags.
Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
// String pointer.
llvm::Constant *C = nullptr;
if (isUTF16) {
auto Arr = llvm::makeArrayRef(
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(llvm::GlobalValue::UnnamedAddr::Global);
// Don't enforce the target's minimum global alignment, since the only use
// of the string is via this class initializer.
CharUnits Align = isUTF16
? getContext().getTypeAlignInChars(getContext().ShortTy)
: getContext().getTypeAlignInChars(getContext().CharTy);
GV->setAlignment(Align.getQuantity());
// 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 (getTriple().isOSBinFormatMachO())
GV->setSection(isUTF16 ? "__TEXT,__ustring"
: "__TEXT,__cstring,cstring_literals");
// Make sure the literal ends up in .rodata to allow for safe ICF and for
// the static linker to adjust permissions to read-only later on.
else if (getTriple().isOSBinFormatELF())
GV->setSection(".rodata");
// String.
llvm::Constant *Str =
llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
if (isUTF16)
// Cast the UTF16 string to the correct type.
Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
Fields.add(Str);
// String length.
auto Ty = getTypes().ConvertType(getContext().LongTy);
Fields.addInt(cast<llvm::IntegerType>(Ty), StringLength);
CharUnits Alignment = getPointerAlign();
// The struct.
GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
/*isConstant=*/false,
llvm::GlobalVariable::PrivateLinkage);
switch (getTriple().getObjectFormat()) {
case llvm::Triple::UnknownObjectFormat:
llvm_unreachable("unknown file format");
case llvm::Triple::COFF:
case llvm::Triple::ELF:
case llvm::Triple::Wasm:
GV->setSection("cfstring");
break;
case llvm::Triple::MachO:
GV->setSection("__DATA,__cfstring");
break;
}
Entry.second = GV;
return ConstantAddress(GV, Alignment);
}
bool CodeGenModule::getExpressionLocationsEnabled() const {
return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
}
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,
CharUnits Alignment) {
unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
CGM.getStringLiteralAddressSpace());
llvm::Module &M = CGM.getModule();
// Create a global variable for this string
auto *GV = new llvm::GlobalVariable(
M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
GV->setAlignment(Alignment.getQuantity());
GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
if (GV->isWeakForLinker()) {
assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
GV->setComdat(M.getOrInsertComdat(GV->getName()));
}
CGM.setDSOLocal(GV);
return GV;
}
/// GetAddrOfConstantStringFromLiteral - Return a pointer to a
/// constant array for the given string literal.
ConstantAddress
CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
StringRef Name) {
CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
llvm::GlobalVariable **Entry = nullptr;
if (!LangOpts.WritableStrings) {
Entry = &ConstantStringMap[C];
if (auto GV = *Entry) {
if (Alignment.getQuantity() > GV->getAlignment())
GV->setAlignment(Alignment.getQuantity());
return ConstantAddress(GV, Alignment);
}
}
SmallString<256> MangledNameBuffer;
StringRef GlobalVariableName;
llvm::GlobalValue::LinkageTypes LT;
// Mangle the string literal if that's how the ABI merges duplicate strings.
// Don't do it if they are writable, since we don't want writes in one TU to
// affect strings in another.
if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
!LangOpts.WritableStrings) {
llvm::raw_svector_ostream Out(MangledNameBuffer);
getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
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 ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
Alignment);
}
/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
/// array for the given ObjCEncodeExpr node.
ConstantAddress
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.
ConstantAddress CodeGenModule::GetAddrOfConstantCString(
const std::string &Str, const char *GlobalName) {
StringRef StrWithNull(Str.c_str(), Str.size() + 1);
CharUnits Alignment =
getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
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.getQuantity() > GV->getAlignment())
GV->setAlignment(Alignment.getQuantity());
return ConstantAddress(GV, Alignment);
}
}
// 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 ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
Alignment);
}
ConstantAddress 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();
CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E])
return ConstantAddress(Slot, Align);
// 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);
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;
LangAS AddrSpace =
VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
Optional<ConstantEmitter> emitter;
llvm::Constant *InitialValue = nullptr;
bool Constant = false;
llvm::Type *Type;
if (Value) {
// The temporary has a constant initializer, use it.
emitter.emplace(*this);
InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
MaterializedType);
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);
if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
const VarDecl *InitVD;
if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
// Temporaries defined inside a class get linkonce_odr linkage because the
// class can be defined in multiple translation units.
Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
} else {
// There is no need for this temporary to have external linkage if the
// VarDecl has external linkage.
Linkage = llvm::GlobalVariable::InternalLinkage;
}
}
auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
auto *GV = new llvm::GlobalVariable(
getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
/*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
if (emitter) emitter->finalize(GV);
setGVProperties(GV, VD);
GV->setAlignment(Align.getQuantity());
if (supportsCOMDAT() && GV->isWeakForLinker())
GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
if (VD->getTLSKind())
setTLSMode(GV, *VD);
llvm::Constant *CV = GV;
if (AddrSpace != LangAS::Default)
CV = getTargetCodeGenInfo().performAddrSpaceCast(
*this, GV, AddrSpace, LangAS::Default,
Type->getPointerTo(
getContext().getTargetAddressSpace(LangAS::Default)));
MaterializedGlobalTemporaryMap[E] = CV;
return ConstantAddress(CV, Align);
}
/// 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);
}
// 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;
}
EmitDeclContext(LSD);
}
void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
for (auto *I : DC->decls()) {
// Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
// are themselves considered "top-level", so EmitTopLevelDecl on an
// ObjCImplDecl does not recursively visit them. We need to do that in
// case they're nested inside another construct (LinkageSpecDecl /
// ExportDecl) that does stop them from being considered "top-level".
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->isTemplated())
return;
switch (D->getKind()) {
case Decl::CXXConversion:
case Decl::CXXMethod:
case Decl::Function:
EmitGlobal(cast<FunctionDecl>(D));
// Always provide some coverage mapping
// even for the functions that aren't emitted.
AddDeferredUnusedCoverageMapping(D);
break;
case Decl::CXXDeductionGuide:
// Function-like, but does not result in code emission.
break;
case Decl::Var:
case Decl::Decomposition:
case Decl::VarTemplateSpecialization:
EmitGlobal(cast<VarDecl>(D));
if (auto *DD = dyn_cast<DecompositionDecl>(D))
for (auto *B : DD->bindings())
if (auto *HD = B->getHoldingVar())
EmitGlobal(HD);
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:
EmitDeclContext(cast<NamespaceDecl>(D));
break;
case Decl::ClassTemplateSpecialization: {
const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
if (DebugInfo &&
Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition &&
Spec->hasDefinition())
DebugInfo->completeTemplateDefinition(*Spec);
} LLVM_FALLTHROUGH;
case Decl::CXXRecord:
if (DebugInfo) {
if (auto *ES = D->getASTContext().getExternalSource())
if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
DebugInfo->completeUnusedClass(cast<CXXRecordDecl>(*D));
}
// Emit any static data members, they may be definitions.
for (auto *I : cast<CXXRecordDecl>(D)->decls())
if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
EmitTopLevelDecl(I);
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:
getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
break;
case Decl::CXXDestructor:
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::PragmaComment: {
const auto *PCD = cast<PragmaCommentDecl>(D);
switch (PCD->getCommentKind()) {
case PCK_Unknown:
llvm_unreachable("unexpected pragma comment kind");
case PCK_Linker:
AppendLinkerOptions(PCD->getArg());
break;
case PCK_Lib:
if (getTarget().getTriple().isOSBinFormatELF() &&
!getTarget().getTriple().isPS4())
AddELFLibDirective(PCD->getArg());
else
AddDependentLib(PCD->getArg());
break;
case PCK_Compiler:
case PCK_ExeStr:
case PCK_User:
break; // We ignore all of these.
}
break;
}
case Decl::PragmaDetectMismatch: {
const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
AddDetectMismatch(PDMD->getName(), PDMD->getValue());
break;
}
case Decl::LinkageSpec:
EmitLinkageSpec(cast<LinkageSpecDecl>(D));
break;
case Decl::FileScopeAsm: {
// File-scope asm is ignored during device-side CUDA compilation.
if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
break;
// File-scope asm is ignored during device-side OpenMP compilation.
if (LangOpts.OpenMPIsDevice)
break;
auto *AD = cast<FileScopeAsmDecl>(D);
getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
break;
}
case Decl::Import: {
auto *Import = cast<ImportDecl>(D);
// If we've already imported this module, we're done.
if (!ImportedModules.insert(Import->getImportedModule()))
break;
// Emit debug information for direct imports.
if (!Import->getImportedOwningModule()) {
if (CGDebugInfo *DI = getModuleDebugInfo())
DI->EmitImportDecl(*Import);
}
// Find all of the submodules and emit the module initializers.
llvm::SmallPtrSet<clang::Module *, 16> Visited;
SmallVector<clang::Module *, 16> Stack;
Visited.insert(Import->getImportedModule());
Stack.push_back(Import->getImportedModule());
while (!Stack.empty()) {
clang::Module *Mod = Stack.pop_back_val();
if (!EmittedModuleInitializers.insert(Mod).second)
continue;
for (auto *D : Context.getModuleInitializers(Mod))
EmitTopLevelDecl(D);
// 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 emit
// the initializers.
if ((*Sub)->IsExplicit)
continue;
if (Visited.insert(*Sub).second)
Stack.push_back(*Sub);
}
}
break;
}
case Decl::Export:
EmitDeclContext(cast<ExportDecl>(D));
break;
case Decl::OMPThreadPrivate:
EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
break;
case Decl::OMPDeclareReduction:
EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
break;
case Decl::OMPRequires:
EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
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)->doesThisDeclarationHaveABody())
return;
SourceManager &SM = getContext().getSourceManager();
if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
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() {
// We call takeVector() here to avoid use-after-free.
// FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
// we deserialize function bodies to emit coverage info for them, and that
// deserializes more declarations. How should we handle that case?
for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
if (!Entry.second)
continue;
const Decl *D = Entry.first;
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() {
if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
return;
for (auto &I : StaticExternCValues) {
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;
for (auto &I : MangledDeclNames) {
llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
// Some mangled names don't necessarily have an associated GlobalValue
// in this module, e.g. if we mangled it for DebugInfo.
if (Addr)
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.getPointer();
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().CoverageDataFile.empty() &&
getCodeGenOpts().CoverageNotesFile.empty())
return;
llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
if (!CUNode)
return;
llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
llvm::LLVMContext &Ctx = TheModule.getContext();
auto *CoverageDataFile =
llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
auto *CoverageNotesFile =
llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
llvm::MDNode *CU = CUNode->getOperand(i);
llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, 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) || getLangOpts().CUDAIsDevice)
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) {
// Do not emit threadprivates in simd-only mode.
if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
return;
for (auto RefExpr : D->varlists()) {
auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
bool PerformInit =
VD->getAnyInitializer() &&
!VD->getAnyInitializer()->isConstantInitializer(getContext(),
/*ForRef=*/false);
Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD));
if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
VD, Addr, RefExpr->getBeginLoc(), PerformInit))
CXXGlobalInits.push_back(InitFunction);
}
}
llvm::Metadata *
CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
StringRef Suffix) {
llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
if (InternalId)
return InternalId;
if (isExternallyVisible(T->getLinkage())) {
std::string OutName;
llvm::raw_string_ostream Out(OutName);
getCXXABI().getMangleContext().mangleTypeName(T, Out);
Out << Suffix;
InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
} else {
InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
llvm::ArrayRef<llvm::Metadata *>());
}
return InternalId;
}
llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
}
llvm::Metadata *
CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
}
// Generalize pointer types to a void pointer with the qualifiers of the
// originally pointed-to type, e.g. 'const char *' and 'char * const *'
// generalize to 'const void *' while 'char *' and 'const char **' generalize to
// 'void *'.
static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
if (!Ty->isPointerType())
return Ty;
return Ctx.getPointerType(
QualType(Ctx.VoidTy).withCVRQualifiers(
Ty->getPointeeType().getCVRQualifiers()));
}
// Apply type generalization to a FunctionType's return and argument types
static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
SmallVector<QualType, 8> GeneralizedParams;
for (auto &Param : FnType->param_types())
GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
return Ctx.getFunctionType(
GeneralizeType(Ctx, FnType->getReturnType()),
GeneralizedParams, FnType->getExtProtoInfo());
}
if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
return Ctx.getFunctionNoProtoType(
GeneralizeType(Ctx, FnType->getReturnType()));
llvm_unreachable("Encountered unknown FunctionType");
}
llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
GeneralizedMetadataIdMap, ".generalized");
}
/// Returns whether this module needs the "all-vtables" type identifier.
bool CodeGenModule::NeedAllVtablesTypeId() const {
// Returns true if at least one of vtable-based CFI checkers is enabled and
// is not in the trapping mode.
return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
!CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
(LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
!CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
(LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
!CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
(LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
!CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
}
void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
CharUnits Offset,
const CXXRecordDecl *RD) {
llvm::Metadata *MD =
CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
VTable->addTypeMetadata(Offset.getQuantity(), MD);
if (CodeGenOpts.SanitizeCfiCrossDso)
if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
VTable->addTypeMetadata(Offset.getQuantity(),
llvm::ConstantAsMetadata::get(CrossDsoTypeId));
if (NeedAllVtablesTypeId()) {
llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
VTable->addTypeMetadata(Offset.getQuantity(), MD);
}
}
TargetAttr::ParsedTargetAttr CodeGenModule::filterFunctionTargetAttrs(const TargetAttr *TD) {
assert(TD != nullptr);
TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
ParsedAttr.Features.erase(
llvm::remove_if(ParsedAttr.Features,
[&](const std::string &Feat) {
return !Target.isValidFeatureName(
StringRef{Feat}.substr(1));
}),
ParsedAttr.Features.end());
return ParsedAttr;
}
// Fills in the supplied string map with the set of target features for the
// passed in function.
void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
const FunctionDecl *FD) {
StringRef TargetCPU = Target.getTargetOpts().CPU;
if (const auto *TD = FD->getAttr<TargetAttr>()) {
TargetAttr::ParsedTargetAttr ParsedAttr = filterFunctionTargetAttrs(TD);
// Make a copy of the features as passed on the command line into the
// beginning of the additional features from the function to override.
ParsedAttr.Features.insert(ParsedAttr.Features.begin(),
Target.getTargetOpts().FeaturesAsWritten.begin(),
Target.getTargetOpts().FeaturesAsWritten.end());
if (ParsedAttr.Architecture != "" &&
Target.isValidCPUName(ParsedAttr.Architecture))
TargetCPU = ParsedAttr.Architecture;
// Now populate the feature map, first with the TargetCPU which is either
// the default or a new one from the target attribute string. Then we'll use
// the passed in features (FeaturesAsWritten) along with the new ones from
// the attribute.
Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU,
ParsedAttr.Features);
} else if (const auto *SD = FD->getAttr<CPUSpecificAttr>()) {
llvm::SmallVector<StringRef, 32> FeaturesTmp;
Target.getCPUSpecificCPUDispatchFeatures(SD->getCurCPUName()->getName(),
FeaturesTmp);
std::vector<std::string> Features(FeaturesTmp.begin(), FeaturesTmp.end());
Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU, Features);
} else {
Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU,
Target.getTargetOpts().Features);
}
}
llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
if (!SanStats)
SanStats = llvm::make_unique<llvm::SanitizerStatReport>(&getModule());
return *SanStats;
}
llvm::Value *
CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
CodeGenFunction &CGF) {
llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
auto SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
auto FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
return CGF.Builder.CreateCall(CreateRuntimeFunction(FTy,
"__translate_sampler_initializer"),
{C});
}
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