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llvm / clang / b15c08d32c072399e59c388bbf6a814831a0bb92 / . / lib / CodeGen / BackendUtil.cpp
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//===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "clang/CodeGen/BackendUtil.h"
#include "clang/Basic/CodeGenOptions.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/TargetOptions.h"
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Frontend/Utils.h"
#include "clang/Lex/HeaderSearchOptions.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/Bitcode/BitcodeWriter.h"
#include "llvm/Bitcode/BitcodeWriterPass.h"
#include "llvm/CodeGen/RegAllocRegistry.h"
#include "llvm/CodeGen/SchedulerRegistry.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/IRPrintingPasses.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ModuleSummaryIndex.h"
#include "llvm/IR/Verifier.h"
#include "llvm/LTO/LTOBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Passes/PassBuilder.h"
#include "llvm/Passes/PassPlugin.h"
#include "llvm/Passes/StandardInstrumentations.h"
#include "llvm/Support/BuryPointer.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Transforms/Coroutines.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/IPO/AlwaysInliner.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
#include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
#include "llvm/Transforms/InstCombine/InstCombine.h"
#include "llvm/Transforms/Instrumentation.h"
#include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
#include "llvm/Transforms/Instrumentation/BoundsChecking.h"
#include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
#include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
#include "llvm/Transforms/Instrumentation/InstrProfiling.h"
#include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
#include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
#include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
#include "llvm/Transforms/ObjCARC.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Scalar/GVN.h"
#include "llvm/Transforms/Utils.h"
#include "llvm/Transforms/Utils/CanonicalizeAliases.h"
#include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
#include "llvm/Transforms/Utils/NameAnonGlobals.h"
#include "llvm/Transforms/Utils/SymbolRewriter.h"
#include <memory>
using namespace clang;
using namespace llvm;
namespace {
// Default filename used for profile generation.
static constexpr StringLiteral DefaultProfileGenName = "default_%m.profraw";
class EmitAssemblyHelper {
DiagnosticsEngine &Diags;
const HeaderSearchOptions &HSOpts;
const CodeGenOptions &CodeGenOpts;
const clang::TargetOptions &TargetOpts;
const LangOptions &LangOpts;
Module *TheModule;
Timer CodeGenerationTime;
std::unique_ptr<raw_pwrite_stream> OS;
TargetIRAnalysis getTargetIRAnalysis() const {
if (TM)
return TM->getTargetIRAnalysis();
return TargetIRAnalysis();
}
void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM);
/// Generates the TargetMachine.
/// Leaves TM unchanged if it is unable to create the target machine.
/// Some of our clang tests specify triples which are not built
/// into clang. This is okay because these tests check the generated
/// IR, and they require DataLayout which depends on the triple.
/// In this case, we allow this method to fail and not report an error.
/// When MustCreateTM is used, we print an error if we are unable to load
/// the requested target.
void CreateTargetMachine(bool MustCreateTM);
/// Add passes necessary to emit assembly or LLVM IR.
///
/// \return True on success.
bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
raw_pwrite_stream &OS, raw_pwrite_stream *DwoOS);
std::unique_ptr<llvm::ToolOutputFile> openOutputFile(StringRef Path) {
std::error_code EC;
auto F = std::make_unique<llvm::ToolOutputFile>(Path, EC,
llvm::sys::fs::OF_None);
if (EC) {
Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
F.reset();
}
return F;
}
public:
EmitAssemblyHelper(DiagnosticsEngine &_Diags,
const HeaderSearchOptions &HeaderSearchOpts,
const CodeGenOptions &CGOpts,
const clang::TargetOptions &TOpts,
const LangOptions &LOpts, Module *M)
: Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
TargetOpts(TOpts), LangOpts(LOpts), TheModule(M),
CodeGenerationTime("codegen", "Code Generation Time") {}
~EmitAssemblyHelper() {
if (CodeGenOpts.DisableFree)
BuryPointer(std::move(TM));
}
std::unique_ptr<TargetMachine> TM;
void EmitAssembly(BackendAction Action,
std::unique_ptr<raw_pwrite_stream> OS);
void EmitAssemblyWithNewPassManager(BackendAction Action,
std::unique_ptr<raw_pwrite_stream> OS);
};
// We need this wrapper to access LangOpts and CGOpts from extension functions
// that we add to the PassManagerBuilder.
class PassManagerBuilderWrapper : public PassManagerBuilder {
public:
PassManagerBuilderWrapper(const Triple &TargetTriple,
const CodeGenOptions &CGOpts,
const LangOptions &LangOpts)
: PassManagerBuilder(), TargetTriple(TargetTriple), CGOpts(CGOpts),
LangOpts(LangOpts) {}
const Triple &getTargetTriple() const { return TargetTriple; }
const CodeGenOptions &getCGOpts() const { return CGOpts; }
const LangOptions &getLangOpts() const { return LangOpts; }
private:
const Triple &TargetTriple;
const CodeGenOptions &CGOpts;
const LangOptions &LangOpts;
};
}
static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
if (Builder.OptLevel > 0)
PM.add(createObjCARCAPElimPass());
}
static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
if (Builder.OptLevel > 0)
PM.add(createObjCARCExpandPass());
}
static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
if (Builder.OptLevel > 0)
PM.add(createObjCARCOptPass());
}
static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
PM.add(createAddDiscriminatorsPass());
}
static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
PM.add(createBoundsCheckingLegacyPass());
}
static SanitizerCoverageOptions
getSancovOptsFromCGOpts(const CodeGenOptions &CGOpts) {
SanitizerCoverageOptions Opts;
Opts.CoverageType =
static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
Opts.Inline8bitCounters = CGOpts.SanitizeCoverageInline8bitCounters;
Opts.PCTable = CGOpts.SanitizeCoveragePCTable;
Opts.StackDepth = CGOpts.SanitizeCoverageStackDepth;
return Opts;
}
static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
const PassManagerBuilderWrapper &BuilderWrapper =
static_cast<const PassManagerBuilderWrapper &>(Builder);
const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
auto Opts = getSancovOptsFromCGOpts(CGOpts);
PM.add(createModuleSanitizerCoverageLegacyPassPass(Opts));
}
// Check if ASan should use GC-friendly instrumentation for globals.
// First of all, there is no point if -fdata-sections is off (expect for MachO,
// where this is not a factor). Also, on ELF this feature requires an assembler
// extension that only works with -integrated-as at the moment.
static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
return false;
switch (T.getObjectFormat()) {
case Triple::MachO:
case Triple::COFF:
return true;
case Triple::ELF:
return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
case Triple::XCOFF:
llvm::report_fatal_error("ASan not implemented for XCOFF.");
case Triple::Wasm:
case Triple::UnknownObjectFormat:
break;
}
return false;
}
static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
const PassManagerBuilderWrapper &BuilderWrapper =
static_cast<const PassManagerBuilderWrapper&>(Builder);
const Triple &T = BuilderWrapper.getTargetTriple();
const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
bool UseOdrIndicator = CGOpts.SanitizeAddressUseOdrIndicator;
bool UseGlobalsGC = asanUseGlobalsGC(T, CGOpts);
PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
UseAfterScope));
PM.add(createModuleAddressSanitizerLegacyPassPass(
/*CompileKernel*/ false, Recover, UseGlobalsGC, UseOdrIndicator));
}
static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
PM.add(createAddressSanitizerFunctionPass(
/*CompileKernel*/ true, /*Recover*/ true, /*UseAfterScope*/ false));
PM.add(createModuleAddressSanitizerLegacyPassPass(
/*CompileKernel*/ true, /*Recover*/ true, /*UseGlobalsGC*/ true,
/*UseOdrIndicator*/ false));
}
static void addHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
const PassManagerBuilderWrapper &BuilderWrapper =
static_cast<const PassManagerBuilderWrapper &>(Builder);
const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
PM.add(
createHWAddressSanitizerLegacyPassPass(/*CompileKernel*/ false, Recover));
}
static void addKernelHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
PM.add(createHWAddressSanitizerLegacyPassPass(
/*CompileKernel*/ true, /*Recover*/ true));
}
static void addGeneralOptsForMemorySanitizer(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM,
bool CompileKernel) {
const PassManagerBuilderWrapper &BuilderWrapper =
static_cast<const PassManagerBuilderWrapper&>(Builder);
const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
PM.add(createMemorySanitizerLegacyPassPass(
MemorySanitizerOptions{TrackOrigins, Recover, CompileKernel}));
// MemorySanitizer inserts complex instrumentation that mostly follows
// the logic of the original code, but operates on "shadow" values.
// It can benefit from re-running some general purpose optimization passes.
if (Builder.OptLevel > 0) {
PM.add(createEarlyCSEPass());
PM.add(createReassociatePass());
PM.add(createLICMPass());
PM.add(createGVNPass());
PM.add(createInstructionCombiningPass());
PM.add(createDeadStoreEliminationPass());
}
}
static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ false);
}
static void addKernelMemorySanitizerPass(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ true);
}
static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
PM.add(createThreadSanitizerLegacyPassPass());
}
static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
legacy::PassManagerBase &PM) {
const PassManagerBuilderWrapper &BuilderWrapper =
static_cast<const PassManagerBuilderWrapper&>(Builder);
const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
}
static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
const CodeGenOptions &CodeGenOpts) {
TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
if (!CodeGenOpts.SimplifyLibCalls)
TLII->disableAllFunctions();
else {
// Disable individual libc/libm calls in TargetLibraryInfo.
LibFunc F;
for (auto &FuncName : CodeGenOpts.getNoBuiltinFuncs())
if (TLII->getLibFunc(FuncName, F))
TLII->setUnavailable(F);
}
switch (CodeGenOpts.getVecLib()) {
case CodeGenOptions::Accelerate:
TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
break;
case CodeGenOptions::MASSV:
TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV);
break;
case CodeGenOptions::SVML:
TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
break;
default:
break;
}
return TLII;
}
static void addSymbolRewriterPass(const CodeGenOptions &Opts,
legacy::PassManager *MPM) {
llvm::SymbolRewriter::RewriteDescriptorList DL;
llvm::SymbolRewriter::RewriteMapParser MapParser;
for (const auto &MapFile : Opts.RewriteMapFiles)
MapParser.parse(MapFile, &DL);
MPM->add(createRewriteSymbolsPass(DL));
}
static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
switch (CodeGenOpts.OptimizationLevel) {
default:
llvm_unreachable("Invalid optimization level!");
case 0:
return CodeGenOpt::None;
case 1:
return CodeGenOpt::Less;
case 2:
return CodeGenOpt::Default; // O2/Os/Oz
case 3:
return CodeGenOpt::Aggressive;
}
}
static Optional<llvm::CodeModel::Model>
getCodeModel(const CodeGenOptions &CodeGenOpts) {
unsigned CodeModel = llvm::StringSwitch<unsigned>(CodeGenOpts.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)
.Case("default", ~1u)
.Default(~0u);
assert(CodeModel != ~0u && "invalid code model!");
if (CodeModel == ~1u)
return None;
return static_cast<llvm::CodeModel::Model>(CodeModel);
}
static TargetMachine::CodeGenFileType getCodeGenFileType(BackendAction Action) {
if (Action == Backend_EmitObj)
return TargetMachine::CGFT_ObjectFile;
else if (Action == Backend_EmitMCNull)
return TargetMachine::CGFT_Null;
else {
assert(Action == Backend_EmitAssembly && "Invalid action!");
return TargetMachine::CGFT_AssemblyFile;
}
}
static void initTargetOptions(llvm::TargetOptions &Options,
const CodeGenOptions &CodeGenOpts,
const clang::TargetOptions &TargetOpts,
const LangOptions &LangOpts,
const HeaderSearchOptions &HSOpts) {
Options.ThreadModel =
llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
.Case("posix", llvm::ThreadModel::POSIX)
.Case("single", llvm::ThreadModel::Single);
// Set float ABI type.
assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
"Invalid Floating Point ABI!");
Options.FloatABIType =
llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
.Case("soft", llvm::FloatABI::Soft)
.Case("softfp", llvm::FloatABI::Soft)
.Case("hard", llvm::FloatABI::Hard)
.Default(llvm::FloatABI::Default);
// Set FP fusion mode.
switch (LangOpts.getDefaultFPContractMode()) {
case LangOptions::FPC_Off:
// Preserve any contraction performed by the front-end. (Strict performs
// splitting of the muladd intrinsic in the backend.)
Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
break;
case LangOptions::FPC_On:
Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
break;
case LangOptions::FPC_Fast:
Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
break;
}
Options.UseInitArray = CodeGenOpts.UseInitArray;
Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
// Set EABI version.
Options.EABIVersion = TargetOpts.EABIVersion;
if (LangOpts.SjLjExceptions)
Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
if (LangOpts.SEHExceptions)
Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
if (LangOpts.DWARFExceptions)
Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
if (LangOpts.WasmExceptions)
Options.ExceptionModel = llvm::ExceptionHandling::Wasm;
Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
Options.FunctionSections = CodeGenOpts.FunctionSections;
Options.DataSections = CodeGenOpts.DataSections;
Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
Options.EmitAddrsig = CodeGenOpts.Addrsig;
Options.EnableDebugEntryValues = CodeGenOpts.EnableDebugEntryValues;
Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
Options.MCOptions.MCIncrementalLinkerCompatible =
CodeGenOpts.IncrementalLinkerCompatible;
Options.MCOptions.MCPIECopyRelocations = CodeGenOpts.PIECopyRelocations;
Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
Options.MCOptions.ABIName = TargetOpts.ABI;
for (const auto &Entry : HSOpts.UserEntries)
if (!Entry.IsFramework &&
(Entry.Group == frontend::IncludeDirGroup::Quoted ||
Entry.Group == frontend::IncludeDirGroup::Angled ||
Entry.Group == frontend::IncludeDirGroup::System))
Options.MCOptions.IASSearchPaths.push_back(
Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
}
static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts) {
if (CodeGenOpts.DisableGCov)
return None;
if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
return None;
// Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
// LLVM's -default-gcov-version flag is set to something invalid.
GCOVOptions Options;
Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
Options.EmitData = CodeGenOpts.EmitGcovArcs;
llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
Options.NoRedZone = CodeGenOpts.DisableRedZone;
Options.FunctionNamesInData = !CodeGenOpts.CoverageNoFunctionNamesInData;
Options.Filter = CodeGenOpts.ProfileFilterFiles;
Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
return Options;
}
static Optional<InstrProfOptions>
getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
const LangOptions &LangOpts) {
if (!CodeGenOpts.hasProfileClangInstr())
return None;
InstrProfOptions Options;
Options.NoRedZone = CodeGenOpts.DisableRedZone;
Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
// TODO: Surface the option to emit atomic profile counter increments at
// the driver level.
Options.Atomic = LangOpts.Sanitize.has(SanitizerKind::Thread);
return Options;
}
void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
legacy::FunctionPassManager &FPM) {
// Handle disabling of all LLVM passes, where we want to preserve the
// internal module before any optimization.
if (CodeGenOpts.DisableLLVMPasses)
return;
// Figure out TargetLibraryInfo. This needs to be added to MPM and FPM
// manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
// are inserted before PMBuilder ones - they'd get the default-constructed
// TLI with an unknown target otherwise.
Triple TargetTriple(TheModule->getTargetTriple());
std::unique_ptr<TargetLibraryInfoImpl> TLII(
createTLII(TargetTriple, CodeGenOpts));
PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
// At O0 and O1 we only run the always inliner which is more efficient. At
// higher optimization levels we run the normal inliner.
if (CodeGenOpts.OptimizationLevel <= 1) {
bool InsertLifetimeIntrinsics = (CodeGenOpts.OptimizationLevel != 0 &&
!CodeGenOpts.DisableLifetimeMarkers);
PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
} else {
// We do not want to inline hot callsites for SamplePGO module-summary build
// because profile annotation will happen again in ThinLTO backend, and we
// want the IR of the hot path to match the profile.
PMBuilder.Inliner = createFunctionInliningPass(
CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
(!CodeGenOpts.SampleProfileFile.empty() &&
CodeGenOpts.PrepareForThinLTO));
}
PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
// Loop interleaving in the loop vectorizer has historically been set to be
// enabled when loop unrolling is enabled.
PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
if (TM)
TM->adjustPassManager(PMBuilder);
if (CodeGenOpts.DebugInfoForProfiling ||
!CodeGenOpts.SampleProfileFile.empty())
PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
addAddDiscriminatorsPass);
// In ObjC ARC mode, add the main ARC optimization passes.
if (LangOpts.ObjCAutoRefCount) {
PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
addObjCARCExpandPass);
PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
addObjCARCAPElimPass);
PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
addObjCARCOptPass);
}
if (LangOpts.Coroutines)
addCoroutinePassesToExtensionPoints(PMBuilder);
if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
addBoundsCheckingPass);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addBoundsCheckingPass);
}
if (CodeGenOpts.SanitizeCoverageType ||
CodeGenOpts.SanitizeCoverageIndirectCalls ||
CodeGenOpts.SanitizeCoverageTraceCmp) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addSanitizerCoveragePass);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addSanitizerCoveragePass);
}
if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addAddressSanitizerPasses);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addAddressSanitizerPasses);
}
if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addKernelAddressSanitizerPasses);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addKernelAddressSanitizerPasses);
}
if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addHWAddressSanitizerPasses);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addHWAddressSanitizerPasses);
}
if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addKernelHWAddressSanitizerPasses);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addKernelHWAddressSanitizerPasses);
}
if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addMemorySanitizerPass);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addMemorySanitizerPass);
}
if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addKernelMemorySanitizerPass);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addKernelMemorySanitizerPass);
}
if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addThreadSanitizerPass);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addThreadSanitizerPass);
}
if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
addDataFlowSanitizerPass);
PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
addDataFlowSanitizerPass);
}
// Set up the per-function pass manager.
FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
if (CodeGenOpts.VerifyModule)
FPM.add(createVerifierPass());
// Set up the per-module pass manager.
if (!CodeGenOpts.RewriteMapFiles.empty())
addSymbolRewriterPass(CodeGenOpts, &MPM);
if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts)) {
MPM.add(createGCOVProfilerPass(*Options));
if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
MPM.add(createStripSymbolsPass(true));
}
if (Optional<InstrProfOptions> Options =
getInstrProfOptions(CodeGenOpts, LangOpts))
MPM.add(createInstrProfilingLegacyPass(*Options, false));
bool hasIRInstr = false;
if (CodeGenOpts.hasProfileIRInstr()) {
PMBuilder.EnablePGOInstrGen = true;
hasIRInstr = true;
}
if (CodeGenOpts.hasProfileCSIRInstr()) {
assert(!CodeGenOpts.hasProfileCSIRUse() &&
"Cannot have both CSProfileUse pass and CSProfileGen pass at the "
"same time");
assert(!hasIRInstr &&
"Cannot have both ProfileGen pass and CSProfileGen pass at the "
"same time");
PMBuilder.EnablePGOCSInstrGen = true;
hasIRInstr = true;
}
if (hasIRInstr) {
if (!CodeGenOpts.InstrProfileOutput.empty())
PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
else
PMBuilder.PGOInstrGen = DefaultProfileGenName;
}
if (CodeGenOpts.hasProfileIRUse()) {
PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
}
if (!CodeGenOpts.SampleProfileFile.empty())
PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
PMBuilder.populateFunctionPassManager(FPM);
PMBuilder.populateModulePassManager(MPM);
}
static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
SmallVector<const char *, 16> BackendArgs;
BackendArgs.push_back("clang"); // Fake program name.
if (!CodeGenOpts.DebugPass.empty()) {
BackendArgs.push_back("-debug-pass");
BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
}
if (!CodeGenOpts.LimitFloatPrecision.empty()) {
BackendArgs.push_back("-limit-float-precision");
BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
}
BackendArgs.push_back(nullptr);
llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
BackendArgs.data());
}
void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
// Create the TargetMachine for generating code.
std::string Error;
std::string Triple = TheModule->getTargetTriple();
const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
if (!TheTarget) {
if (MustCreateTM)
Diags.Report(diag::err_fe_unable_to_create_target) << Error;
return;
}
Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
std::string FeaturesStr =
llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
llvm::TargetOptions Options;
initTargetOptions(Options, CodeGenOpts, TargetOpts, LangOpts, HSOpts);
TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
Options, RM, CM, OptLevel));
}
bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
BackendAction Action,
raw_pwrite_stream &OS,
raw_pwrite_stream *DwoOS) {
// Add LibraryInfo.
llvm::Triple TargetTriple(TheModule->getTargetTriple());
std::unique_ptr<TargetLibraryInfoImpl> TLII(
createTLII(TargetTriple, CodeGenOpts));
CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
// Normal mode, emit a .s or .o file by running the code generator. Note,
// this also adds codegenerator level optimization passes.
TargetMachine::CodeGenFileType CGFT = getCodeGenFileType(Action);
// Add ObjC ARC final-cleanup optimizations. This is done as part of the
// "codegen" passes so that it isn't run multiple times when there is
// inlining happening.
if (CodeGenOpts.OptimizationLevel > 0)
CodeGenPasses.add(createObjCARCContractPass());
if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
/*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
Diags.Report(diag::err_fe_unable_to_interface_with_target);
return false;
}
return true;
}
void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
std::unique_ptr<raw_pwrite_stream> OS) {
TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
setCommandLineOpts(CodeGenOpts);
bool UsesCodeGen = (Action != Backend_EmitNothing &&
Action != Backend_EmitBC &&
Action != Backend_EmitLL);
CreateTargetMachine(UsesCodeGen);
if (UsesCodeGen && !TM)
return;
if (TM)
TheModule->setDataLayout(TM->createDataLayout());
legacy::PassManager PerModulePasses;
PerModulePasses.add(
createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
legacy::FunctionPassManager PerFunctionPasses(TheModule);
PerFunctionPasses.add(
createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
CreatePasses(PerModulePasses, PerFunctionPasses);
legacy::PassManager CodeGenPasses;
CodeGenPasses.add(
createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
switch (Action) {
case Backend_EmitNothing:
break;
case Backend_EmitBC:
if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
if (!ThinLinkOS)
return;
}
TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
CodeGenOpts.EnableSplitLTOUnit);
PerModulePasses.add(createWriteThinLTOBitcodePass(
*OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
} else {
// Emit a module summary by default for Regular LTO except for ld64
// targets
bool EmitLTOSummary =
(CodeGenOpts.PrepareForLTO &&
!CodeGenOpts.DisableLLVMPasses &&
llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
llvm::Triple::Apple);
if (EmitLTOSummary) {
if (!TheModule->getModuleFlag("ThinLTO"))
TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
uint32_t(1));
}
PerModulePasses.add(createBitcodeWriterPass(
*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
}
break;
case Backend_EmitLL:
PerModulePasses.add(
createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
break;
default:
if (!CodeGenOpts.SplitDwarfOutput.empty()) {
DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
if (!DwoOS)
return;
}
if (!AddEmitPasses(CodeGenPasses, Action, *OS,
DwoOS ? &DwoOS->os() : nullptr))
return;
}
// Before executing passes, print the final values of the LLVM options.
cl::PrintOptionValues();
// Run passes. For now we do all passes at once, but eventually we
// would like to have the option of streaming code generation.
{
PrettyStackTraceString CrashInfo("Per-function optimization");
llvm::TimeTraceScope TimeScope("PerFunctionPasses", StringRef(""));
PerFunctionPasses.doInitialization();
for (Function &F : *TheModule)
if (!F.isDeclaration())
PerFunctionPasses.run(F);
PerFunctionPasses.doFinalization();
}
{
PrettyStackTraceString CrashInfo("Per-module optimization passes");
llvm::TimeTraceScope TimeScope("PerModulePasses", StringRef(""));
PerModulePasses.run(*TheModule);
}
{
PrettyStackTraceString CrashInfo("Code generation");
llvm::TimeTraceScope TimeScope("CodeGenPasses", StringRef(""));
CodeGenPasses.run(*TheModule);
}
if (ThinLinkOS)
ThinLinkOS->keep();
if (DwoOS)
DwoOS->keep();
}
static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
switch (Opts.OptimizationLevel) {
default:
llvm_unreachable("Invalid optimization level!");
case 1:
return PassBuilder::O1;
case 2:
switch (Opts.OptimizeSize) {
default:
llvm_unreachable("Invalid optimization level for size!");
case 0:
return PassBuilder::O2;
case 1:
return PassBuilder::Os;
case 2:
return PassBuilder::Oz;
}
case 3:
return PassBuilder::O3;
}
}
static void addSanitizersAtO0(ModulePassManager &MPM,
const Triple &TargetTriple,
const LangOptions &LangOpts,
const CodeGenOptions &CodeGenOpts) {
auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
MPM.addPass(RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
MPM.addPass(createModuleToFunctionPassAdaptor(AddressSanitizerPass(
CompileKernel, Recover, CodeGenOpts.SanitizeAddressUseAfterScope)));
bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
MPM.addPass(
ModuleAddressSanitizerPass(CompileKernel, Recover, ModuleUseAfterScope,
CodeGenOpts.SanitizeAddressUseOdrIndicator));
};
if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
ASanPass(SanitizerKind::Address, /*CompileKernel=*/false);
}
if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
ASanPass(SanitizerKind::KernelAddress, /*CompileKernel=*/true);
}
if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
MPM.addPass(MemorySanitizerPass({}));
MPM.addPass(createModuleToFunctionPassAdaptor(MemorySanitizerPass({})));
}
if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
MPM.addPass(createModuleToFunctionPassAdaptor(
MemorySanitizerPass({0, false, /*Kernel=*/true})));
}
if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
MPM.addPass(ThreadSanitizerPass());
MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
}
}
/// A clean version of `EmitAssembly` that uses the new pass manager.
///
/// Not all features are currently supported in this system, but where
/// necessary it falls back to the legacy pass manager to at least provide
/// basic functionality.
///
/// This API is planned to have its functionality finished and then to replace
/// `EmitAssembly` at some point in the future when the default switches.
void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
setCommandLineOpts(CodeGenOpts);
bool RequiresCodeGen = (Action != Backend_EmitNothing &&
Action != Backend_EmitBC &&
Action != Backend_EmitLL);
CreateTargetMachine(RequiresCodeGen);
if (RequiresCodeGen && !TM)
return;
if (TM)
TheModule->setDataLayout(TM->createDataLayout());
Optional<PGOOptions> PGOOpt;
if (CodeGenOpts.hasProfileIRInstr())
// -fprofile-generate.
PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
? DefaultProfileGenName
: CodeGenOpts.InstrProfileOutput,
"", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
CodeGenOpts.DebugInfoForProfiling);
else if (CodeGenOpts.hasProfileIRUse()) {
// -fprofile-use.
auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
: PGOOptions::NoCSAction;
PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
CSAction, CodeGenOpts.DebugInfoForProfiling);
} else if (!CodeGenOpts.SampleProfileFile.empty())
// -fprofile-sample-use
PGOOpt =
PGOOptions(CodeGenOpts.SampleProfileFile, "",
CodeGenOpts.ProfileRemappingFile, PGOOptions::SampleUse,
PGOOptions::NoCSAction, CodeGenOpts.DebugInfoForProfiling);
else if (CodeGenOpts.DebugInfoForProfiling)
// -fdebug-info-for-profiling
PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
PGOOptions::NoCSAction, true);
// Check to see if we want to generate a CS profile.
if (CodeGenOpts.hasProfileCSIRInstr()) {
assert(!CodeGenOpts.hasProfileCSIRUse() &&
"Cannot have both CSProfileUse pass and CSProfileGen pass at "
"the same time");
if (PGOOpt.hasValue()) {
assert(PGOOpt->Action != PGOOptions::IRInstr &&
PGOOpt->Action != PGOOptions::SampleUse &&
"Cannot run CSProfileGen pass with ProfileGen or SampleUse "
" pass");
PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
? DefaultProfileGenName
: CodeGenOpts.InstrProfileOutput;
PGOOpt->CSAction = PGOOptions::CSIRInstr;
} else
PGOOpt = PGOOptions("",
CodeGenOpts.InstrProfileOutput.empty()
? DefaultProfileGenName
: CodeGenOpts.InstrProfileOutput,
"", PGOOptions::NoAction, PGOOptions::CSIRInstr,
CodeGenOpts.DebugInfoForProfiling);
}
PipelineTuningOptions PTO;
PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
// For historical reasons, loop interleaving is set to mirror setting for loop
// unrolling.
PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
PassInstrumentationCallbacks PIC;
StandardInstrumentations SI;
SI.registerCallbacks(PIC);
PassBuilder PB(TM.get(), PTO, PGOOpt, &PIC);
// Attempt to load pass plugins and register their callbacks with PB.
for (auto &PluginFN : CodeGenOpts.PassPlugins) {
auto PassPlugin = PassPlugin::Load(PluginFN);
if (PassPlugin) {
PassPlugin->registerPassBuilderCallbacks(PB);
} else {
Diags.Report(diag::err_fe_unable_to_load_plugin)
<< PluginFN << toString(PassPlugin.takeError());
}
}
LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
// Register the AA manager first so that our version is the one used.
FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
// Register the target library analysis directly and give it a customized
// preset TLI.
Triple TargetTriple(TheModule->getTargetTriple());
std::unique_ptr<TargetLibraryInfoImpl> TLII(
createTLII(TargetTriple, CodeGenOpts));
FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
// Register all the basic analyses with the managers.
PB.registerModuleAnalyses(MAM);
PB.registerCGSCCAnalyses(CGAM);
PB.registerFunctionAnalyses(FAM);
PB.registerLoopAnalyses(LAM);
PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
ModulePassManager MPM(CodeGenOpts.DebugPassManager);
if (!CodeGenOpts.DisableLLVMPasses) {
bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
bool IsLTO = CodeGenOpts.PrepareForLTO;
if (CodeGenOpts.OptimizationLevel == 0) {
if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts))
MPM.addPass(GCOVProfilerPass(*Options));
if (Optional<InstrProfOptions> Options =
getInstrProfOptions(CodeGenOpts, LangOpts))
MPM.addPass(InstrProfiling(*Options, false));
// Build a minimal pipeline based on the semantics required by Clang,
// which is just that always inlining occurs. Further, disable generating
// lifetime intrinsics to avoid enabling further optimizations during
// code generation.
MPM.addPass(AlwaysInlinerPass(/*InsertLifetimeIntrinsics=*/false));
// At -O0, we can still do PGO. Add all the requested passes for
// instrumentation PGO, if requested.
if (PGOOpt && (PGOOpt->Action == PGOOptions::IRInstr ||
PGOOpt->Action == PGOOptions::IRUse))
PB.addPGOInstrPassesForO0(
MPM, CodeGenOpts.DebugPassManager,
/* RunProfileGen */ (PGOOpt->Action == PGOOptions::IRInstr),
/* IsCS */ false, PGOOpt->ProfileFile,
PGOOpt->ProfileRemappingFile);
// At -O0 we directly run necessary sanitizer passes.
if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
MPM.addPass(createModuleToFunctionPassAdaptor(BoundsCheckingPass()));
// Lastly, add semantically necessary passes for LTO.
if (IsLTO || IsThinLTO) {
MPM.addPass(CanonicalizeAliasesPass());
MPM.addPass(NameAnonGlobalPass());
}
} else {
// Map our optimization levels into one of the distinct levels used to
// configure the pipeline.
PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
PB.registerPipelineStartEPCallback([](ModulePassManager &MPM) {
MPM.addPass(createModuleToFunctionPassAdaptor(
EntryExitInstrumenterPass(/*PostInlining=*/false)));
});
// Register callbacks to schedule sanitizer passes at the appropriate part of
// the pipeline.
// FIXME: either handle asan/the remaining sanitizers or error out
if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
PB.registerScalarOptimizerLateEPCallback(
[](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
FPM.addPass(BoundsCheckingPass());
});
if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
PB.registerPipelineStartEPCallback([](ModulePassManager &MPM) {
MPM.addPass(MemorySanitizerPass({}));
});
PB.registerOptimizerLastEPCallback(
[](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
FPM.addPass(MemorySanitizerPass({}));
});
}
if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
PB.registerPipelineStartEPCallback(
[](ModulePassManager &MPM) { MPM.addPass(ThreadSanitizerPass()); });
PB.registerOptimizerLastEPCallback(
[](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
FPM.addPass(ThreadSanitizerPass());
});
}
if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
PB.registerPipelineStartEPCallback([&](ModulePassManager &MPM) {
MPM.addPass(
RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
});
bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::Address);
bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
PB.registerOptimizerLastEPCallback(
[Recover, UseAfterScope](FunctionPassManager &FPM,
PassBuilder::OptimizationLevel Level) {
FPM.addPass(AddressSanitizerPass(
/*CompileKernel=*/false, Recover, UseAfterScope));
});
bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
PB.registerPipelineStartEPCallback(
[Recover, ModuleUseAfterScope,
UseOdrIndicator](ModulePassManager &MPM) {
MPM.addPass(ModuleAddressSanitizerPass(
/*CompileKernel=*/false, Recover, ModuleUseAfterScope,
UseOdrIndicator));
});
}
if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts))
PB.registerPipelineStartEPCallback([Options](ModulePassManager &MPM) {
MPM.addPass(GCOVProfilerPass(*Options));
});
if (Optional<InstrProfOptions> Options =
getInstrProfOptions(CodeGenOpts, LangOpts))
PB.registerPipelineStartEPCallback([Options](ModulePassManager &MPM) {
MPM.addPass(InstrProfiling(*Options, false));
});
if (IsThinLTO) {
MPM = PB.buildThinLTOPreLinkDefaultPipeline(
Level, CodeGenOpts.DebugPassManager);
MPM.addPass(CanonicalizeAliasesPass());
MPM.addPass(NameAnonGlobalPass());
} else if (IsLTO) {
MPM = PB.buildLTOPreLinkDefaultPipeline(Level,
CodeGenOpts.DebugPassManager);
MPM.addPass(CanonicalizeAliasesPass());
MPM.addPass(NameAnonGlobalPass());
} else {
MPM = PB.buildPerModuleDefaultPipeline(Level,
CodeGenOpts.DebugPassManager);
}
}
if (CodeGenOpts.SanitizeCoverageType ||
CodeGenOpts.SanitizeCoverageIndirectCalls ||
CodeGenOpts.SanitizeCoverageTraceCmp) {
auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
MPM.addPass(ModuleSanitizerCoveragePass(SancovOpts));
}
if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
MPM.addPass(HWAddressSanitizerPass(
/*CompileKernel=*/false, Recover));
}
if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
MPM.addPass(HWAddressSanitizerPass(
/*CompileKernel=*/true, /*Recover=*/true));
}
if (CodeGenOpts.OptimizationLevel == 0) {
addSanitizersAtO0(MPM, TargetTriple, LangOpts, CodeGenOpts);
}
}
// FIXME: We still use the legacy pass manager to do code generation. We
// create that pass manager here and use it as needed below.
legacy::PassManager CodeGenPasses;
bool NeedCodeGen = false;
std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
// Append any output we need to the pass manager.
switch (Action) {
case Backend_EmitNothing:
break;
case Backend_EmitBC:
if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
if (!ThinLinkOS)
return;
}
TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
CodeGenOpts.EnableSplitLTOUnit);
MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
: nullptr));
} else {
// Emit a module summary by default for Regular LTO except for ld64
// targets
bool EmitLTOSummary =
(CodeGenOpts.PrepareForLTO &&
!CodeGenOpts.DisableLLVMPasses &&
llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
llvm::Triple::Apple);
if (EmitLTOSummary) {
if (!TheModule->getModuleFlag("ThinLTO"))
TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
uint32_t(1));
}
MPM.addPass(
BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
}
break;
case Backend_EmitLL:
MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
break;
case Backend_EmitAssembly:
case Backend_EmitMCNull:
case Backend_EmitObj:
NeedCodeGen = true;
CodeGenPasses.add(
createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
if (!CodeGenOpts.SplitDwarfOutput.empty()) {
DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
if (!DwoOS)
return;
}
if (!AddEmitPasses(CodeGenPasses, Action, *OS,
DwoOS ? &DwoOS->os() : nullptr))
// FIXME: Should we handle this error differently?
return;
break;
}
// Before executing passes, print the final values of the LLVM options.
cl::PrintOptionValues();
// Now that we have all of the passes ready, run them.
{
PrettyStackTraceString CrashInfo("Optimizer");
MPM.run(*TheModule, MAM);
}
// Now if needed, run the legacy PM for codegen.
if (NeedCodeGen) {
PrettyStackTraceString CrashInfo("Code generation");
CodeGenPasses.run(*TheModule);
}
if (ThinLinkOS)
ThinLinkOS->keep();
if (DwoOS)
DwoOS->keep();
}
Expected<BitcodeModule> clang::FindThinLTOModule(MemoryBufferRef MBRef) {
Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
if (!BMsOrErr)
return BMsOrErr.takeError();
// The bitcode file may contain multiple modules, we want the one that is
// marked as being the ThinLTO module.
if (const BitcodeModule *Bm = FindThinLTOModule(*BMsOrErr))
return *Bm;
return make_error<StringError>("Could not find module summary",
inconvertibleErrorCode());
}
BitcodeModule *clang::FindThinLTOModule(MutableArrayRef<BitcodeModule> BMs) {
for (BitcodeModule &BM : BMs) {
Expected<BitcodeLTOInfo> LTOInfo = BM.getLTOInfo();
if (LTOInfo && LTOInfo->IsThinLTO)
return &BM;
}
return nullptr;
}
static void runThinLTOBackend(ModuleSummaryIndex *CombinedIndex, Module *M,
const HeaderSearchOptions &HeaderOpts,
const CodeGenOptions &CGOpts,
const clang::TargetOptions &TOpts,
const LangOptions &LOpts,
std::unique_ptr<raw_pwrite_stream> OS,
std::string SampleProfile,
std::string ProfileRemapping,
BackendAction Action) {
StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
ModuleToDefinedGVSummaries;
CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
setCommandLineOpts(CGOpts);
// We can simply import the values mentioned in the combined index, since
// we should only invoke this using the individual indexes written out
// via a WriteIndexesThinBackend.
FunctionImporter::ImportMapTy ImportList;
for (auto &GlobalList : *CombinedIndex) {
// Ignore entries for undefined references.
if (GlobalList.second.SummaryList.empty())
continue;
auto GUID = GlobalList.first;
for (auto &Summary : GlobalList.second.SummaryList) {
// Skip the summaries for the importing module. These are included to
// e.g. record required linkage changes.
if (Summary->modulePath() == M->getModuleIdentifier())
continue;
// Add an entry to provoke importing by thinBackend.
ImportList[Summary->modulePath()].insert(GUID);
}
}
std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
for (auto &I : ImportList) {
ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr =
llvm::MemoryBuffer::getFile(I.first());
if (!MBOrErr) {
errs() << "Error loading imported file '" << I.first()
<< "': " << MBOrErr.getError().message() << "\n";
return;
}
Expected<BitcodeModule> BMOrErr = FindThinLTOModule(**MBOrErr);
if (!BMOrErr) {
handleAllErrors(BMOrErr.takeError(), [&](ErrorInfoBase &EIB) {
errs() << "Error loading imported file '" << I.first()
<< "': " << EIB.message() << '\n';
});
return;
}
ModuleMap.insert({I.first(), *BMOrErr});
OwnedImports.push_back(std::move(*MBOrErr));
}
auto AddStream = [&](size_t Task) {
return std::make_unique<lto::NativeObjectStream>(std::move(OS));
};
lto::Config Conf;
if (CGOpts.SaveTempsFilePrefix != "") {
if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
/* UseInputModulePath */ false)) {
handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
<< '\n';
});
}
}
Conf.CPU = TOpts.CPU;
Conf.CodeModel = getCodeModel(CGOpts);
Conf.MAttrs = TOpts.Features;
Conf.RelocModel = CGOpts.RelocationModel;
Conf.CGOptLevel = getCGOptLevel(CGOpts);
Conf.OptLevel = CGOpts.OptimizationLevel;
initTargetOptions(Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
Conf.SampleProfile = std::move(SampleProfile);
// Context sensitive profile.
if (CGOpts.hasProfileCSIRInstr()) {
Conf.RunCSIRInstr = true;
Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
} else if (CGOpts.hasProfileCSIRUse()) {
Conf.RunCSIRInstr = false;
Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
}
Conf.ProfileRemapping = std::move(ProfileRemapping);
Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
Conf.DebugPassManager = CGOpts.DebugPassManager;
Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
Conf.RemarksFilename = CGOpts.OptRecordFile;
Conf.RemarksPasses = CGOpts.OptRecordPasses;
Conf.RemarksFormat = CGOpts.OptRecordFormat;
Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
switch (Action) {
case Backend_EmitNothing:
Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
return false;
};
break;
case Backend_EmitLL:
Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
return false;
};
break;
case Backend_EmitBC:
Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
return false;
};
break;
default:
Conf.CGFileType = getCodeGenFileType(Action);
break;
}
if (Error E = thinBackend(
Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
ModuleToDefinedGVSummaries[M->getModuleIdentifier()], ModuleMap)) {
handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
});
}
}
void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
const HeaderSearchOptions &HeaderOpts,
const CodeGenOptions &CGOpts,
const clang::TargetOptions &TOpts,
const LangOptions &LOpts,
const llvm::DataLayout &TDesc, Module *M,
BackendAction Action,
std::unique_ptr<raw_pwrite_stream> OS) {
llvm::TimeTraceScope TimeScope("Backend", StringRef(""));
std::unique_ptr<llvm::Module> EmptyModule;
if (!CGOpts.ThinLTOIndexFile.empty()) {
// If we are performing a ThinLTO importing compile, load the function index
// into memory and pass it into runThinLTOBackend, which will run the
// function importer and invoke LTO passes.
Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
/*IgnoreEmptyThinLTOIndexFile*/true);
if (!IndexOrErr) {
logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
"Error loading index file '" +
CGOpts.ThinLTOIndexFile + "': ");
return;
}
std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
// A null CombinedIndex means we should skip ThinLTO compilation
// (LLVM will optionally ignore empty index files, returning null instead
// of an error).
if (CombinedIndex) {
if (!CombinedIndex->skipModuleByDistributedBackend()) {
runThinLTOBackend(CombinedIndex.get(), M, HeaderOpts, CGOpts, TOpts,
LOpts, std::move(OS), CGOpts.SampleProfileFile,
CGOpts.ProfileRemappingFile, Action);
return;
}
// Distributed indexing detected that nothing from the module is needed
// for the final linking. So we can skip the compilation. We sill need to
// output an empty object file to make sure that a linker does not fail
// trying to read it. Also for some features, like CFI, we must skip
// the compilation as CombinedIndex does not contain all required
// information.
EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
EmptyModule->setTargetTriple(M->getTargetTriple());
M = EmptyModule.get();
}
}
EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
if (CGOpts.ExperimentalNewPassManager)
AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
else
AsmHelper.EmitAssembly(Action, std::move(OS));
// Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
// DataLayout.
if (AsmHelper.TM) {
std::string DLDesc = M->getDataLayout().getStringRepresentation();
if (DLDesc != TDesc.getStringRepresentation()) {
unsigned DiagID = Diags.getCustomDiagID(
DiagnosticsEngine::Error, "backend data layout '%0' does not match "
"expected target description '%1'");
Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
}
}
}
static const char* getSectionNameForBitcode(const Triple &T) {
switch (T.getObjectFormat()) {
case Triple::MachO:
return "__LLVM,__bitcode";
case Triple::COFF:
case Triple::ELF:
case Triple::Wasm:
case Triple::UnknownObjectFormat:
return ".llvmbc";
case Triple::XCOFF:
llvm_unreachable("XCOFF is not yet implemented");
break;
}
llvm_unreachable("Unimplemented ObjectFormatType");
}
static const char* getSectionNameForCommandline(const Triple &T) {
switch (T.getObjectFormat()) {
case Triple::MachO:
return "__LLVM,__cmdline";
case Triple::COFF:
case Triple::ELF:
case Triple::Wasm:
case Triple::UnknownObjectFormat:
return ".llvmcmd";
case Triple::XCOFF:
llvm_unreachable("XCOFF is not yet implemented");
break;
}
llvm_unreachable("Unimplemented ObjectFormatType");
}
// With -fembed-bitcode, save a copy of the llvm IR as data in the
// __LLVM,__bitcode section.
void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
llvm::MemoryBufferRef Buf) {
if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
return;
// Save llvm.compiler.used and remote it.
SmallVector<Constant*, 2> UsedArray;
SmallPtrSet<GlobalValue*, 4> UsedGlobals;
Type *UsedElementType = Type::getInt8Ty(M->getContext())->getPointerTo(0);
GlobalVariable *Used = collectUsedGlobalVariables(*M, UsedGlobals, true);
for (auto *GV : UsedGlobals) {
if (GV->getName() != "llvm.embedded.module" &&
GV->getName() != "llvm.cmdline")
UsedArray.push_back(
ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
}
if (Used)
Used->eraseFromParent();
// Embed the bitcode for the llvm module.
std::string Data;
ArrayRef<uint8_t> ModuleData;
Triple T(M->getTargetTriple());
// Create a constant that contains the bitcode.
// In case of embedding a marker, ignore the input Buf and use the empty
// ArrayRef. It is also legal to create a bitcode marker even Buf is empty.
if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker) {
if (!isBitcode((const unsigned char *)Buf.getBufferStart(),
(const unsigned char *)Buf.getBufferEnd())) {
// If the input is LLVM Assembly, bitcode is produced by serializing
// the module. Use-lists order need to be perserved in this case.
llvm::raw_string_ostream OS(Data);
llvm::WriteBitcodeToFile(*M, OS, /* ShouldPreserveUseListOrder */ true);
ModuleData =
ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
} else
// If the input is LLVM bitcode, write the input byte stream directly.
ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
Buf.getBufferSize());
}
llvm::Constant *ModuleConstant =
llvm::ConstantDataArray::get(M->getContext(), ModuleData);
llvm::GlobalVariable *GV = new llvm::GlobalVariable(
*M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
ModuleConstant);
GV->setSection(getSectionNameForBitcode(T));
UsedArray.push_back(
ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
if (llvm::GlobalVariable *Old =
M->getGlobalVariable("llvm.embedded.module", true)) {
assert(Old->hasOneUse() &&
"llvm.embedded.module can only be used once in llvm.compiler.used");
GV->takeName(Old);
Old->eraseFromParent();
} else {
GV->setName("llvm.embedded.module");
}
// Skip if only bitcode needs to be embedded.
if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode) {
// Embed command-line options.
ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CGOpts.CmdArgs.data()),
CGOpts.CmdArgs.size());
llvm::Constant *CmdConstant =
llvm::ConstantDataArray::get(M->getContext(), CmdData);
GV = new llvm::GlobalVariable(*M, CmdConstant->getType(), true,
llvm::GlobalValue::PrivateLinkage,
CmdConstant);
GV->setSection(getSectionNameForCommandline(T));
UsedArray.push_back(
ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
if (llvm::GlobalVariable *Old =
M->getGlobalVariable("llvm.cmdline", true)) {
assert(Old->hasOneUse() &&
"llvm.cmdline can only be used once in llvm.compiler.used");
GV->takeName(Old);
Old->eraseFromParent();
} else {
GV->setName("llvm.cmdline");
}
}
if (UsedArray.empty())
return;
// Recreate llvm.compiler.used.
ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
auto *NewUsed = new GlobalVariable(
*M, ATy, false, llvm::GlobalValue::AppendingLinkage,
llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
NewUsed->setSection("llvm.metadata");
}