1 //===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #include "clang/CodeGen/BackendUtil.h"
10 #include "clang/Basic/CodeGenOptions.h"
11 #include "clang/Basic/Diagnostic.h"
12 #include "clang/Basic/LangOptions.h"
13 #include "clang/Basic/TargetOptions.h"
14 #include "clang/Frontend/FrontendDiagnostic.h"
15 #include "clang/Frontend/Utils.h"
16 #include "clang/Lex/HeaderSearchOptions.h"
17 #include "llvm/ADT/SmallSet.h"
18 #include "llvm/ADT/StringExtras.h"
19 #include "llvm/ADT/StringSwitch.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/Analysis/TargetLibraryInfo.h"
22 #include "llvm/Analysis/TargetTransformInfo.h"
23 #include "llvm/Bitcode/BitcodeReader.h"
24 #include "llvm/Bitcode/BitcodeWriter.h"
25 #include "llvm/Bitcode/BitcodeWriterPass.h"
26 #include "llvm/CodeGen/RegAllocRegistry.h"
27 #include "llvm/CodeGen/SchedulerRegistry.h"
28 #include "llvm/CodeGen/TargetSubtargetInfo.h"
29 #include "llvm/IR/DataLayout.h"
30 #include "llvm/IR/IRPrintingPasses.h"
31 #include "llvm/IR/LegacyPassManager.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/IR/ModuleSummaryIndex.h"
34 #include "llvm/IR/Verifier.h"
35 #include "llvm/LTO/LTOBackend.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/MC/SubtargetFeature.h"
38 #include "llvm/Passes/PassBuilder.h"
39 #include "llvm/Passes/PassPlugin.h"
40 #include "llvm/Support/BuryPointer.h"
41 #include "llvm/Support/CommandLine.h"
42 #include "llvm/Support/MemoryBuffer.h"
43 #include "llvm/Support/PrettyStackTrace.h"
44 #include "llvm/Support/TargetRegistry.h"
45 #include "llvm/Support/TimeProfiler.h"
46 #include "llvm/Support/Timer.h"
47 #include "llvm/Support/raw_ostream.h"
48 #include "llvm/Target/TargetMachine.h"
49 #include "llvm/Target/TargetOptions.h"
50 #include "llvm/Transforms/Coroutines.h"
51 #include "llvm/Transforms/IPO.h"
52 #include "llvm/Transforms/IPO/AlwaysInliner.h"
53 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
54 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
55 #include "llvm/Transforms/InstCombine/InstCombine.h"
56 #include "llvm/Transforms/Instrumentation.h"
57 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
58 #include "llvm/Transforms/Instrumentation/BoundsChecking.h"
59 #include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
60 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
61 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
62 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
63 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
64 #include "llvm/Transforms/ObjCARC.h"
65 #include "llvm/Transforms/Scalar.h"
66 #include "llvm/Transforms/Scalar/GVN.h"
67 #include "llvm/Transforms/Utils.h"
68 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
69 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
70 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
71 #include "llvm/Transforms/Utils/SymbolRewriter.h"
73 using namespace clang;
78 // Default filename used for profile generation.
79 static constexpr StringLiteral DefaultProfileGenName = "default_%m.profraw";
81 class EmitAssemblyHelper {
82 DiagnosticsEngine &Diags;
83 const HeaderSearchOptions &HSOpts;
84 const CodeGenOptions &CodeGenOpts;
85 const clang::TargetOptions &TargetOpts;
86 const LangOptions &LangOpts;
89 Timer CodeGenerationTime;
91 std::unique_ptr<raw_pwrite_stream> OS;
93 TargetIRAnalysis getTargetIRAnalysis() const {
95 return TM->getTargetIRAnalysis();
97 return TargetIRAnalysis();
100 void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM);
102 /// Generates the TargetMachine.
103 /// Leaves TM unchanged if it is unable to create the target machine.
104 /// Some of our clang tests specify triples which are not built
105 /// into clang. This is okay because these tests check the generated
106 /// IR, and they require DataLayout which depends on the triple.
107 /// In this case, we allow this method to fail and not report an error.
108 /// When MustCreateTM is used, we print an error if we are unable to load
109 /// the requested target.
110 void CreateTargetMachine(bool MustCreateTM);
112 /// Add passes necessary to emit assembly or LLVM IR.
114 /// \return True on success.
115 bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
116 raw_pwrite_stream &OS, raw_pwrite_stream *DwoOS);
118 std::unique_ptr<llvm::ToolOutputFile> openOutputFile(StringRef Path) {
120 auto F = llvm::make_unique<llvm::ToolOutputFile>(Path, EC,
121 llvm::sys::fs::F_None);
123 Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
130 EmitAssemblyHelper(DiagnosticsEngine &_Diags,
131 const HeaderSearchOptions &HeaderSearchOpts,
132 const CodeGenOptions &CGOpts,
133 const clang::TargetOptions &TOpts,
134 const LangOptions &LOpts, Module *M)
135 : Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
136 TargetOpts(TOpts), LangOpts(LOpts), TheModule(M),
137 CodeGenerationTime("codegen", "Code Generation Time") {}
139 ~EmitAssemblyHelper() {
140 if (CodeGenOpts.DisableFree)
141 BuryPointer(std::move(TM));
144 std::unique_ptr<TargetMachine> TM;
146 void EmitAssembly(BackendAction Action,
147 std::unique_ptr<raw_pwrite_stream> OS);
149 void EmitAssemblyWithNewPassManager(BackendAction Action,
150 std::unique_ptr<raw_pwrite_stream> OS);
153 // We need this wrapper to access LangOpts and CGOpts from extension functions
154 // that we add to the PassManagerBuilder.
155 class PassManagerBuilderWrapper : public PassManagerBuilder {
157 PassManagerBuilderWrapper(const Triple &TargetTriple,
158 const CodeGenOptions &CGOpts,
159 const LangOptions &LangOpts)
160 : PassManagerBuilder(), TargetTriple(TargetTriple), CGOpts(CGOpts),
161 LangOpts(LangOpts) {}
162 const Triple &getTargetTriple() const { return TargetTriple; }
163 const CodeGenOptions &getCGOpts() const { return CGOpts; }
164 const LangOptions &getLangOpts() const { return LangOpts; }
167 const Triple &TargetTriple;
168 const CodeGenOptions &CGOpts;
169 const LangOptions &LangOpts;
173 static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
174 if (Builder.OptLevel > 0)
175 PM.add(createObjCARCAPElimPass());
178 static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
179 if (Builder.OptLevel > 0)
180 PM.add(createObjCARCExpandPass());
183 static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
184 if (Builder.OptLevel > 0)
185 PM.add(createObjCARCOptPass());
188 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
189 legacy::PassManagerBase &PM) {
190 PM.add(createAddDiscriminatorsPass());
193 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
194 legacy::PassManagerBase &PM) {
195 PM.add(createBoundsCheckingLegacyPass());
198 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
199 legacy::PassManagerBase &PM) {
200 const PassManagerBuilderWrapper &BuilderWrapper =
201 static_cast<const PassManagerBuilderWrapper&>(Builder);
202 const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
203 SanitizerCoverageOptions Opts;
205 static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
206 Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
207 Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
208 Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
209 Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
210 Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
211 Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
212 Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
213 Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
214 Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
215 Opts.Inline8bitCounters = CGOpts.SanitizeCoverageInline8bitCounters;
216 Opts.PCTable = CGOpts.SanitizeCoveragePCTable;
217 Opts.StackDepth = CGOpts.SanitizeCoverageStackDepth;
218 PM.add(createSanitizerCoverageModulePass(Opts));
221 // Check if ASan should use GC-friendly instrumentation for globals.
222 // First of all, there is no point if -fdata-sections is off (expect for MachO,
223 // where this is not a factor). Also, on ELF this feature requires an assembler
224 // extension that only works with -integrated-as at the moment.
225 static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
226 if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
228 switch (T.getObjectFormat()) {
233 return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
239 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
240 legacy::PassManagerBase &PM) {
241 const PassManagerBuilderWrapper &BuilderWrapper =
242 static_cast<const PassManagerBuilderWrapper&>(Builder);
243 const Triple &T = BuilderWrapper.getTargetTriple();
244 const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
245 bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
246 bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
247 bool UseOdrIndicator = CGOpts.SanitizeAddressUseOdrIndicator;
248 bool UseGlobalsGC = asanUseGlobalsGC(T, CGOpts);
249 PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
251 PM.add(createModuleAddressSanitizerLegacyPassPass(
252 /*CompileKernel*/ false, Recover, UseGlobalsGC, UseOdrIndicator));
255 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
256 legacy::PassManagerBase &PM) {
257 PM.add(createAddressSanitizerFunctionPass(
258 /*CompileKernel*/ true, /*Recover*/ true, /*UseAfterScope*/ false));
259 PM.add(createModuleAddressSanitizerLegacyPassPass(
260 /*CompileKernel*/ true, /*Recover*/ true, /*UseGlobalsGC*/ true,
261 /*UseOdrIndicator*/ false));
264 static void addHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
265 legacy::PassManagerBase &PM) {
266 const PassManagerBuilderWrapper &BuilderWrapper =
267 static_cast<const PassManagerBuilderWrapper &>(Builder);
268 const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
269 bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
271 createHWAddressSanitizerLegacyPassPass(/*CompileKernel*/ false, Recover));
274 static void addKernelHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
275 legacy::PassManagerBase &PM) {
276 PM.add(createHWAddressSanitizerLegacyPassPass(
277 /*CompileKernel*/ true, /*Recover*/ true));
280 static void addGeneralOptsForMemorySanitizer(const PassManagerBuilder &Builder,
281 legacy::PassManagerBase &PM,
282 bool CompileKernel) {
283 const PassManagerBuilderWrapper &BuilderWrapper =
284 static_cast<const PassManagerBuilderWrapper&>(Builder);
285 const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
286 int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
287 bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
288 PM.add(createMemorySanitizerLegacyPassPass(
289 MemorySanitizerOptions{TrackOrigins, Recover, CompileKernel}));
291 // MemorySanitizer inserts complex instrumentation that mostly follows
292 // the logic of the original code, but operates on "shadow" values.
293 // It can benefit from re-running some general purpose optimization passes.
294 if (Builder.OptLevel > 0) {
295 PM.add(createEarlyCSEPass());
296 PM.add(createReassociatePass());
297 PM.add(createLICMPass());
298 PM.add(createGVNPass());
299 PM.add(createInstructionCombiningPass());
300 PM.add(createDeadStoreEliminationPass());
304 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
305 legacy::PassManagerBase &PM) {
306 addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ false);
309 static void addKernelMemorySanitizerPass(const PassManagerBuilder &Builder,
310 legacy::PassManagerBase &PM) {
311 addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ true);
314 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
315 legacy::PassManagerBase &PM) {
316 PM.add(createThreadSanitizerLegacyPassPass());
319 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
320 legacy::PassManagerBase &PM) {
321 const PassManagerBuilderWrapper &BuilderWrapper =
322 static_cast<const PassManagerBuilderWrapper&>(Builder);
323 const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
324 PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
327 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
328 const CodeGenOptions &CodeGenOpts) {
329 TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
330 if (!CodeGenOpts.SimplifyLibCalls)
331 TLII->disableAllFunctions();
333 // Disable individual libc/libm calls in TargetLibraryInfo.
335 for (auto &FuncName : CodeGenOpts.getNoBuiltinFuncs())
336 if (TLII->getLibFunc(FuncName, F))
337 TLII->setUnavailable(F);
340 switch (CodeGenOpts.getVecLib()) {
341 case CodeGenOptions::Accelerate:
342 TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
344 case CodeGenOptions::MASSV:
345 TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV);
347 case CodeGenOptions::SVML:
348 TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
356 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
357 legacy::PassManager *MPM) {
358 llvm::SymbolRewriter::RewriteDescriptorList DL;
360 llvm::SymbolRewriter::RewriteMapParser MapParser;
361 for (const auto &MapFile : Opts.RewriteMapFiles)
362 MapParser.parse(MapFile, &DL);
364 MPM->add(createRewriteSymbolsPass(DL));
367 static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
368 switch (CodeGenOpts.OptimizationLevel) {
370 llvm_unreachable("Invalid optimization level!");
372 return CodeGenOpt::None;
374 return CodeGenOpt::Less;
376 return CodeGenOpt::Default; // O2/Os/Oz
378 return CodeGenOpt::Aggressive;
382 static Optional<llvm::CodeModel::Model>
383 getCodeModel(const CodeGenOptions &CodeGenOpts) {
384 unsigned CodeModel = llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
385 .Case("tiny", llvm::CodeModel::Tiny)
386 .Case("small", llvm::CodeModel::Small)
387 .Case("kernel", llvm::CodeModel::Kernel)
388 .Case("medium", llvm::CodeModel::Medium)
389 .Case("large", llvm::CodeModel::Large)
390 .Case("default", ~1u)
392 assert(CodeModel != ~0u && "invalid code model!");
393 if (CodeModel == ~1u)
395 return static_cast<llvm::CodeModel::Model>(CodeModel);
398 static TargetMachine::CodeGenFileType getCodeGenFileType(BackendAction Action) {
399 if (Action == Backend_EmitObj)
400 return TargetMachine::CGFT_ObjectFile;
401 else if (Action == Backend_EmitMCNull)
402 return TargetMachine::CGFT_Null;
404 assert(Action == Backend_EmitAssembly && "Invalid action!");
405 return TargetMachine::CGFT_AssemblyFile;
409 static void initTargetOptions(llvm::TargetOptions &Options,
410 const CodeGenOptions &CodeGenOpts,
411 const clang::TargetOptions &TargetOpts,
412 const LangOptions &LangOpts,
413 const HeaderSearchOptions &HSOpts) {
414 Options.ThreadModel =
415 llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
416 .Case("posix", llvm::ThreadModel::POSIX)
417 .Case("single", llvm::ThreadModel::Single);
419 // Set float ABI type.
420 assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
421 CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
422 "Invalid Floating Point ABI!");
423 Options.FloatABIType =
424 llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
425 .Case("soft", llvm::FloatABI::Soft)
426 .Case("softfp", llvm::FloatABI::Soft)
427 .Case("hard", llvm::FloatABI::Hard)
428 .Default(llvm::FloatABI::Default);
430 // Set FP fusion mode.
431 switch (LangOpts.getDefaultFPContractMode()) {
432 case LangOptions::FPC_Off:
433 // Preserve any contraction performed by the front-end. (Strict performs
434 // splitting of the muladd intrinsic in the backend.)
435 Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
437 case LangOptions::FPC_On:
438 Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
440 case LangOptions::FPC_Fast:
441 Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
445 Options.UseInitArray = CodeGenOpts.UseInitArray;
446 Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
447 Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
448 Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
451 Options.EABIVersion = TargetOpts.EABIVersion;
453 if (LangOpts.SjLjExceptions)
454 Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
455 if (LangOpts.SEHExceptions)
456 Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
457 if (LangOpts.DWARFExceptions)
458 Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
460 Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
461 Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
462 Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
463 Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
464 Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
465 Options.FunctionSections = CodeGenOpts.FunctionSections;
466 Options.DataSections = CodeGenOpts.DataSections;
467 Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
468 Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
469 Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
470 Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
471 Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
472 Options.EmitAddrsig = CodeGenOpts.Addrsig;
473 Options.EnableDebugEntryValues = CodeGenOpts.EnableDebugEntryValues;
475 Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
476 Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
477 Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
478 Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
479 Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
480 Options.MCOptions.MCIncrementalLinkerCompatible =
481 CodeGenOpts.IncrementalLinkerCompatible;
482 Options.MCOptions.MCPIECopyRelocations = CodeGenOpts.PIECopyRelocations;
483 Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
484 Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
485 Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
486 Options.MCOptions.ABIName = TargetOpts.ABI;
487 for (const auto &Entry : HSOpts.UserEntries)
488 if (!Entry.IsFramework &&
489 (Entry.Group == frontend::IncludeDirGroup::Quoted ||
490 Entry.Group == frontend::IncludeDirGroup::Angled ||
491 Entry.Group == frontend::IncludeDirGroup::System))
492 Options.MCOptions.IASSearchPaths.push_back(
493 Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
495 static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts) {
496 if (CodeGenOpts.DisableGCov)
498 if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
500 // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
501 // LLVM's -default-gcov-version flag is set to something invalid.
503 Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
504 Options.EmitData = CodeGenOpts.EmitGcovArcs;
505 llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
506 Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
507 Options.NoRedZone = CodeGenOpts.DisableRedZone;
508 Options.FunctionNamesInData = !CodeGenOpts.CoverageNoFunctionNamesInData;
509 Options.Filter = CodeGenOpts.ProfileFilterFiles;
510 Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
511 Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
515 static Optional<InstrProfOptions>
516 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
517 const LangOptions &LangOpts) {
518 if (!CodeGenOpts.hasProfileClangInstr())
520 InstrProfOptions Options;
521 Options.NoRedZone = CodeGenOpts.DisableRedZone;
522 Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
524 // TODO: Surface the option to emit atomic profile counter increments at
526 Options.Atomic = LangOpts.Sanitize.has(SanitizerKind::Thread);
530 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
531 legacy::FunctionPassManager &FPM) {
532 // Handle disabling of all LLVM passes, where we want to preserve the
533 // internal module before any optimization.
534 if (CodeGenOpts.DisableLLVMPasses)
537 // Figure out TargetLibraryInfo. This needs to be added to MPM and FPM
538 // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
539 // are inserted before PMBuilder ones - they'd get the default-constructed
540 // TLI with an unknown target otherwise.
541 Triple TargetTriple(TheModule->getTargetTriple());
542 std::unique_ptr<TargetLibraryInfoImpl> TLII(
543 createTLII(TargetTriple, CodeGenOpts));
545 PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
547 // At O0 and O1 we only run the always inliner which is more efficient. At
548 // higher optimization levels we run the normal inliner.
549 if (CodeGenOpts.OptimizationLevel <= 1) {
550 bool InsertLifetimeIntrinsics = (CodeGenOpts.OptimizationLevel != 0 &&
551 !CodeGenOpts.DisableLifetimeMarkers);
552 PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
554 // We do not want to inline hot callsites for SamplePGO module-summary build
555 // because profile annotation will happen again in ThinLTO backend, and we
556 // want the IR of the hot path to match the profile.
557 PMBuilder.Inliner = createFunctionInliningPass(
558 CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
559 (!CodeGenOpts.SampleProfileFile.empty() &&
560 CodeGenOpts.PrepareForThinLTO));
563 PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
564 PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
565 PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
566 PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
568 PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
569 // Loop interleaving in the loop vectorizer has historically been set to be
570 // enabled when loop unrolling is enabled.
571 PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
572 PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
573 PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
574 PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
575 PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
577 MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
580 TM->adjustPassManager(PMBuilder);
582 if (CodeGenOpts.DebugInfoForProfiling ||
583 !CodeGenOpts.SampleProfileFile.empty())
584 PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
585 addAddDiscriminatorsPass);
587 // In ObjC ARC mode, add the main ARC optimization passes.
588 if (LangOpts.ObjCAutoRefCount) {
589 PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
590 addObjCARCExpandPass);
591 PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
592 addObjCARCAPElimPass);
593 PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
597 if (LangOpts.Coroutines)
598 addCoroutinePassesToExtensionPoints(PMBuilder);
600 if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
601 PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
602 addBoundsCheckingPass);
603 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
604 addBoundsCheckingPass);
607 if (CodeGenOpts.SanitizeCoverageType ||
608 CodeGenOpts.SanitizeCoverageIndirectCalls ||
609 CodeGenOpts.SanitizeCoverageTraceCmp) {
610 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
611 addSanitizerCoveragePass);
612 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
613 addSanitizerCoveragePass);
616 if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
617 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
618 addAddressSanitizerPasses);
619 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
620 addAddressSanitizerPasses);
623 if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
624 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
625 addKernelAddressSanitizerPasses);
626 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
627 addKernelAddressSanitizerPasses);
630 if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
631 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
632 addHWAddressSanitizerPasses);
633 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
634 addHWAddressSanitizerPasses);
637 if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
638 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
639 addKernelHWAddressSanitizerPasses);
640 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
641 addKernelHWAddressSanitizerPasses);
644 if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
645 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
646 addMemorySanitizerPass);
647 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
648 addMemorySanitizerPass);
651 if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
652 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
653 addKernelMemorySanitizerPass);
654 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
655 addKernelMemorySanitizerPass);
658 if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
659 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
660 addThreadSanitizerPass);
661 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
662 addThreadSanitizerPass);
665 if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
666 PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
667 addDataFlowSanitizerPass);
668 PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
669 addDataFlowSanitizerPass);
672 // Set up the per-function pass manager.
673 FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
674 if (CodeGenOpts.VerifyModule)
675 FPM.add(createVerifierPass());
677 // Set up the per-module pass manager.
678 if (!CodeGenOpts.RewriteMapFiles.empty())
679 addSymbolRewriterPass(CodeGenOpts, &MPM);
681 if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts)) {
682 MPM.add(createGCOVProfilerPass(*Options));
683 if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
684 MPM.add(createStripSymbolsPass(true));
687 if (Optional<InstrProfOptions> Options =
688 getInstrProfOptions(CodeGenOpts, LangOpts))
689 MPM.add(createInstrProfilingLegacyPass(*Options, false));
691 bool hasIRInstr = false;
692 if (CodeGenOpts.hasProfileIRInstr()) {
693 PMBuilder.EnablePGOInstrGen = true;
696 if (CodeGenOpts.hasProfileCSIRInstr()) {
697 assert(!CodeGenOpts.hasProfileCSIRUse() &&
698 "Cannot have both CSProfileUse pass and CSProfileGen pass at the "
700 assert(!hasIRInstr &&
701 "Cannot have both ProfileGen pass and CSProfileGen pass at the "
703 PMBuilder.EnablePGOCSInstrGen = true;
707 if (!CodeGenOpts.InstrProfileOutput.empty())
708 PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
710 PMBuilder.PGOInstrGen = DefaultProfileGenName;
712 if (CodeGenOpts.hasProfileIRUse()) {
713 PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
714 PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
717 if (!CodeGenOpts.SampleProfileFile.empty())
718 PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
720 PMBuilder.populateFunctionPassManager(FPM);
721 PMBuilder.populateModulePassManager(MPM);
724 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
725 SmallVector<const char *, 16> BackendArgs;
726 BackendArgs.push_back("clang"); // Fake program name.
727 if (!CodeGenOpts.DebugPass.empty()) {
728 BackendArgs.push_back("-debug-pass");
729 BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
731 if (!CodeGenOpts.LimitFloatPrecision.empty()) {
732 BackendArgs.push_back("-limit-float-precision");
733 BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
735 BackendArgs.push_back(nullptr);
736 llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
740 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
741 // Create the TargetMachine for generating code.
743 std::string Triple = TheModule->getTargetTriple();
744 const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
747 Diags.Report(diag::err_fe_unable_to_create_target) << Error;
751 Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
752 std::string FeaturesStr =
753 llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
754 llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
755 CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
757 llvm::TargetOptions Options;
758 initTargetOptions(Options, CodeGenOpts, TargetOpts, LangOpts, HSOpts);
759 TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
760 Options, RM, CM, OptLevel));
763 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
764 BackendAction Action,
765 raw_pwrite_stream &OS,
766 raw_pwrite_stream *DwoOS) {
768 llvm::Triple TargetTriple(TheModule->getTargetTriple());
769 std::unique_ptr<TargetLibraryInfoImpl> TLII(
770 createTLII(TargetTriple, CodeGenOpts));
771 CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
773 // Normal mode, emit a .s or .o file by running the code generator. Note,
774 // this also adds codegenerator level optimization passes.
775 TargetMachine::CodeGenFileType CGFT = getCodeGenFileType(Action);
777 // Add ObjC ARC final-cleanup optimizations. This is done as part of the
778 // "codegen" passes so that it isn't run multiple times when there is
779 // inlining happening.
780 if (CodeGenOpts.OptimizationLevel > 0)
781 CodeGenPasses.add(createObjCARCContractPass());
783 if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
784 /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
785 Diags.Report(diag::err_fe_unable_to_interface_with_target);
792 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
793 std::unique_ptr<raw_pwrite_stream> OS) {
794 TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
796 setCommandLineOpts(CodeGenOpts);
798 bool UsesCodeGen = (Action != Backend_EmitNothing &&
799 Action != Backend_EmitBC &&
800 Action != Backend_EmitLL);
801 CreateTargetMachine(UsesCodeGen);
803 if (UsesCodeGen && !TM)
806 TheModule->setDataLayout(TM->createDataLayout());
808 legacy::PassManager PerModulePasses;
810 createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
812 legacy::FunctionPassManager PerFunctionPasses(TheModule);
813 PerFunctionPasses.add(
814 createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
816 CreatePasses(PerModulePasses, PerFunctionPasses);
818 legacy::PassManager CodeGenPasses;
820 createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
822 std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
825 case Backend_EmitNothing:
829 if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
830 if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
831 ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
835 TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
836 CodeGenOpts.EnableSplitLTOUnit);
837 PerModulePasses.add(createWriteThinLTOBitcodePass(
838 *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
840 // Emit a module summary by default for Regular LTO except for ld64
842 bool EmitLTOSummary =
843 (CodeGenOpts.PrepareForLTO &&
844 !CodeGenOpts.DisableLLVMPasses &&
845 llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
846 llvm::Triple::Apple);
847 if (EmitLTOSummary) {
848 if (!TheModule->getModuleFlag("ThinLTO"))
849 TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
850 TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
851 CodeGenOpts.EnableSplitLTOUnit);
854 PerModulePasses.add(createBitcodeWriterPass(
855 *OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
861 createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
865 if (!CodeGenOpts.SplitDwarfOutput.empty()) {
866 DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
870 if (!AddEmitPasses(CodeGenPasses, Action, *OS,
871 DwoOS ? &DwoOS->os() : nullptr))
875 // Before executing passes, print the final values of the LLVM options.
876 cl::PrintOptionValues();
878 // Run passes. For now we do all passes at once, but eventually we
879 // would like to have the option of streaming code generation.
882 PrettyStackTraceString CrashInfo("Per-function optimization");
884 PerFunctionPasses.doInitialization();
885 for (Function &F : *TheModule)
886 if (!F.isDeclaration())
887 PerFunctionPasses.run(F);
888 PerFunctionPasses.doFinalization();
892 PrettyStackTraceString CrashInfo("Per-module optimization passes");
893 PerModulePasses.run(*TheModule);
897 PrettyStackTraceString CrashInfo("Code generation");
898 CodeGenPasses.run(*TheModule);
907 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
908 switch (Opts.OptimizationLevel) {
910 llvm_unreachable("Invalid optimization level!");
913 return PassBuilder::O1;
916 switch (Opts.OptimizeSize) {
918 llvm_unreachable("Invalid optimization level for size!");
921 return PassBuilder::O2;
924 return PassBuilder::Os;
927 return PassBuilder::Oz;
931 return PassBuilder::O3;
935 static void addSanitizersAtO0(ModulePassManager &MPM,
936 const Triple &TargetTriple,
937 const LangOptions &LangOpts,
938 const CodeGenOptions &CodeGenOpts) {
939 auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
940 MPM.addPass(RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
941 bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
942 MPM.addPass(createModuleToFunctionPassAdaptor(AddressSanitizerPass(
943 CompileKernel, Recover, CodeGenOpts.SanitizeAddressUseAfterScope)));
944 bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
946 ModuleAddressSanitizerPass(CompileKernel, Recover, ModuleUseAfterScope,
947 CodeGenOpts.SanitizeAddressUseOdrIndicator));
950 if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
951 ASanPass(SanitizerKind::Address, /*CompileKernel=*/false);
954 if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
955 ASanPass(SanitizerKind::KernelAddress, /*CompileKernel=*/true);
958 if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
959 MPM.addPass(createModuleToFunctionPassAdaptor(MemorySanitizerPass({})));
962 if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
963 MPM.addPass(createModuleToFunctionPassAdaptor(
964 MemorySanitizerPass({0, false, /*Kernel=*/true})));
967 if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
968 MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
972 /// A clean version of `EmitAssembly` that uses the new pass manager.
974 /// Not all features are currently supported in this system, but where
975 /// necessary it falls back to the legacy pass manager to at least provide
976 /// basic functionality.
978 /// This API is planned to have its functionality finished and then to replace
979 /// `EmitAssembly` at some point in the future when the default switches.
980 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
981 BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
982 TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
983 setCommandLineOpts(CodeGenOpts);
985 bool RequiresCodeGen = (Action != Backend_EmitNothing &&
986 Action != Backend_EmitBC &&
987 Action != Backend_EmitLL);
988 CreateTargetMachine(RequiresCodeGen);
990 if (RequiresCodeGen && !TM)
993 TheModule->setDataLayout(TM->createDataLayout());
995 Optional<PGOOptions> PGOOpt;
997 if (CodeGenOpts.hasProfileIRInstr())
998 // -fprofile-generate.
999 PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
1000 ? DefaultProfileGenName
1001 : CodeGenOpts.InstrProfileOutput,
1002 "", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
1003 CodeGenOpts.DebugInfoForProfiling);
1004 else if (CodeGenOpts.hasProfileIRUse()) {
1006 auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
1007 : PGOOptions::NoCSAction;
1008 PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
1009 CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
1010 CSAction, CodeGenOpts.DebugInfoForProfiling);
1011 } else if (!CodeGenOpts.SampleProfileFile.empty())
1012 // -fprofile-sample-use
1014 PGOOptions(CodeGenOpts.SampleProfileFile, "",
1015 CodeGenOpts.ProfileRemappingFile, PGOOptions::SampleUse,
1016 PGOOptions::NoCSAction, CodeGenOpts.DebugInfoForProfiling);
1017 else if (CodeGenOpts.DebugInfoForProfiling)
1018 // -fdebug-info-for-profiling
1019 PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
1020 PGOOptions::NoCSAction, true);
1022 // Check to see if we want to generate a CS profile.
1023 if (CodeGenOpts.hasProfileCSIRInstr()) {
1024 assert(!CodeGenOpts.hasProfileCSIRUse() &&
1025 "Cannot have both CSProfileUse pass and CSProfileGen pass at "
1027 if (PGOOpt.hasValue()) {
1028 assert(PGOOpt->Action != PGOOptions::IRInstr &&
1029 PGOOpt->Action != PGOOptions::SampleUse &&
1030 "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
1032 PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
1033 ? DefaultProfileGenName
1034 : CodeGenOpts.InstrProfileOutput;
1035 PGOOpt->CSAction = PGOOptions::CSIRInstr;
1037 PGOOpt = PGOOptions("",
1038 CodeGenOpts.InstrProfileOutput.empty()
1039 ? DefaultProfileGenName
1040 : CodeGenOpts.InstrProfileOutput,
1041 "", PGOOptions::NoAction, PGOOptions::CSIRInstr,
1042 CodeGenOpts.DebugInfoForProfiling);
1045 PipelineTuningOptions PTO;
1046 PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
1047 // For historical reasons, loop interleaving is set to mirror setting for loop
1049 PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
1050 PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
1051 PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
1053 PassBuilder PB(TM.get(), PTO, PGOOpt);
1055 // Attempt to load pass plugins and register their callbacks with PB.
1056 for (auto &PluginFN : CodeGenOpts.PassPlugins) {
1057 auto PassPlugin = PassPlugin::Load(PluginFN);
1059 PassPlugin->registerPassBuilderCallbacks(PB);
1061 Diags.Report(diag::err_fe_unable_to_load_plugin)
1062 << PluginFN << toString(PassPlugin.takeError());
1066 LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
1067 FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
1068 CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
1069 ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
1071 // Register the AA manager first so that our version is the one used.
1072 FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
1074 // Register the target library analysis directly and give it a customized
1076 Triple TargetTriple(TheModule->getTargetTriple());
1077 std::unique_ptr<TargetLibraryInfoImpl> TLII(
1078 createTLII(TargetTriple, CodeGenOpts));
1079 FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1080 MAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1082 // Register all the basic analyses with the managers.
1083 PB.registerModuleAnalyses(MAM);
1084 PB.registerCGSCCAnalyses(CGAM);
1085 PB.registerFunctionAnalyses(FAM);
1086 PB.registerLoopAnalyses(LAM);
1087 PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
1089 ModulePassManager MPM(CodeGenOpts.DebugPassManager);
1091 if (!CodeGenOpts.DisableLLVMPasses) {
1092 bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
1093 bool IsLTO = CodeGenOpts.PrepareForLTO;
1095 if (CodeGenOpts.OptimizationLevel == 0) {
1096 if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts))
1097 MPM.addPass(GCOVProfilerPass(*Options));
1098 if (Optional<InstrProfOptions> Options =
1099 getInstrProfOptions(CodeGenOpts, LangOpts))
1100 MPM.addPass(InstrProfiling(*Options, false));
1102 // Build a minimal pipeline based on the semantics required by Clang,
1103 // which is just that always inlining occurs. Further, disable generating
1104 // lifetime intrinsics to avoid enabling further optimizations during
1106 MPM.addPass(AlwaysInlinerPass(/*InsertLifetimeIntrinsics=*/false));
1108 // At -O0 we directly run necessary sanitizer passes.
1109 if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1110 MPM.addPass(createModuleToFunctionPassAdaptor(BoundsCheckingPass()));
1112 // Lastly, add semantically necessary passes for LTO.
1113 if (IsLTO || IsThinLTO) {
1114 MPM.addPass(CanonicalizeAliasesPass());
1115 MPM.addPass(NameAnonGlobalPass());
1118 // Map our optimization levels into one of the distinct levels used to
1119 // configure the pipeline.
1120 PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
1122 PB.registerPipelineStartEPCallback([](ModulePassManager &MPM) {
1123 MPM.addPass(createModuleToFunctionPassAdaptor(
1124 EntryExitInstrumenterPass(/*PostInlining=*/false)));
1127 // Register callbacks to schedule sanitizer passes at the appropriate part of
1129 // FIXME: either handle asan/the remaining sanitizers or error out
1130 if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1131 PB.registerScalarOptimizerLateEPCallback(
1132 [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1133 FPM.addPass(BoundsCheckingPass());
1135 if (LangOpts.Sanitize.has(SanitizerKind::Memory))
1136 PB.registerOptimizerLastEPCallback(
1137 [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1138 FPM.addPass(MemorySanitizerPass({}));
1140 if (LangOpts.Sanitize.has(SanitizerKind::Thread))
1141 PB.registerOptimizerLastEPCallback(
1142 [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1143 FPM.addPass(ThreadSanitizerPass());
1145 if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
1146 PB.registerPipelineStartEPCallback([&](ModulePassManager &MPM) {
1148 RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
1150 bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::Address);
1151 bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
1152 PB.registerOptimizerLastEPCallback(
1153 [Recover, UseAfterScope](FunctionPassManager &FPM,
1154 PassBuilder::OptimizationLevel Level) {
1155 FPM.addPass(AddressSanitizerPass(
1156 /*CompileKernel=*/false, Recover, UseAfterScope));
1158 bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
1159 bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
1160 PB.registerPipelineStartEPCallback(
1161 [Recover, ModuleUseAfterScope,
1162 UseOdrIndicator](ModulePassManager &MPM) {
1163 MPM.addPass(ModuleAddressSanitizerPass(
1164 /*CompileKernel=*/false, Recover, ModuleUseAfterScope,
1168 if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts))
1169 PB.registerPipelineStartEPCallback([Options](ModulePassManager &MPM) {
1170 MPM.addPass(GCOVProfilerPass(*Options));
1172 if (Optional<InstrProfOptions> Options =
1173 getInstrProfOptions(CodeGenOpts, LangOpts))
1174 PB.registerPipelineStartEPCallback([Options](ModulePassManager &MPM) {
1175 MPM.addPass(InstrProfiling(*Options, false));
1179 MPM = PB.buildThinLTOPreLinkDefaultPipeline(
1180 Level, CodeGenOpts.DebugPassManager);
1181 MPM.addPass(CanonicalizeAliasesPass());
1182 MPM.addPass(NameAnonGlobalPass());
1184 MPM = PB.buildLTOPreLinkDefaultPipeline(Level,
1185 CodeGenOpts.DebugPassManager);
1186 MPM.addPass(CanonicalizeAliasesPass());
1187 MPM.addPass(NameAnonGlobalPass());
1189 MPM = PB.buildPerModuleDefaultPipeline(Level,
1190 CodeGenOpts.DebugPassManager);
1194 if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
1195 bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
1196 MPM.addPass(HWAddressSanitizerPass(
1197 /*CompileKernel=*/false, Recover));
1199 if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
1200 MPM.addPass(HWAddressSanitizerPass(
1201 /*CompileKernel=*/true, /*Recover=*/true));
1204 if (CodeGenOpts.OptimizationLevel == 0)
1205 addSanitizersAtO0(MPM, TargetTriple, LangOpts, CodeGenOpts);
1208 // FIXME: We still use the legacy pass manager to do code generation. We
1209 // create that pass manager here and use it as needed below.
1210 legacy::PassManager CodeGenPasses;
1211 bool NeedCodeGen = false;
1212 std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1214 // Append any output we need to the pass manager.
1216 case Backend_EmitNothing:
1219 case Backend_EmitBC:
1220 if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1221 if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1222 ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1226 TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1227 CodeGenOpts.EnableSplitLTOUnit);
1228 MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1231 // Emit a module summary by default for Regular LTO except for ld64
1233 bool EmitLTOSummary =
1234 (CodeGenOpts.PrepareForLTO &&
1235 !CodeGenOpts.DisableLLVMPasses &&
1236 llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
1237 llvm::Triple::Apple);
1238 if (EmitLTOSummary) {
1239 if (!TheModule->getModuleFlag("ThinLTO"))
1240 TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1241 TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1242 CodeGenOpts.EnableSplitLTOUnit);
1245 BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
1249 case Backend_EmitLL:
1250 MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1253 case Backend_EmitAssembly:
1254 case Backend_EmitMCNull:
1255 case Backend_EmitObj:
1258 createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1259 if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1260 DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1264 if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1265 DwoOS ? &DwoOS->os() : nullptr))
1266 // FIXME: Should we handle this error differently?
1271 // Before executing passes, print the final values of the LLVM options.
1272 cl::PrintOptionValues();
1274 // Now that we have all of the passes ready, run them.
1276 PrettyStackTraceString CrashInfo("Optimizer");
1277 MPM.run(*TheModule, MAM);
1280 // Now if needed, run the legacy PM for codegen.
1282 PrettyStackTraceString CrashInfo("Code generation");
1283 CodeGenPasses.run(*TheModule);
1292 Expected<BitcodeModule> clang::FindThinLTOModule(MemoryBufferRef MBRef) {
1293 Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
1295 return BMsOrErr.takeError();
1297 // The bitcode file may contain multiple modules, we want the one that is
1298 // marked as being the ThinLTO module.
1299 if (const BitcodeModule *Bm = FindThinLTOModule(*BMsOrErr))
1302 return make_error<StringError>("Could not find module summary",
1303 inconvertibleErrorCode());
1306 BitcodeModule *clang::FindThinLTOModule(MutableArrayRef<BitcodeModule> BMs) {
1307 for (BitcodeModule &BM : BMs) {
1308 Expected<BitcodeLTOInfo> LTOInfo = BM.getLTOInfo();
1309 if (LTOInfo && LTOInfo->IsThinLTO)
1315 static void runThinLTOBackend(ModuleSummaryIndex *CombinedIndex, Module *M,
1316 const HeaderSearchOptions &HeaderOpts,
1317 const CodeGenOptions &CGOpts,
1318 const clang::TargetOptions &TOpts,
1319 const LangOptions &LOpts,
1320 std::unique_ptr<raw_pwrite_stream> OS,
1321 std::string SampleProfile,
1322 std::string ProfileRemapping,
1323 BackendAction Action) {
1324 StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1325 ModuleToDefinedGVSummaries;
1326 CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1328 setCommandLineOpts(CGOpts);
1330 // We can simply import the values mentioned in the combined index, since
1331 // we should only invoke this using the individual indexes written out
1332 // via a WriteIndexesThinBackend.
1333 FunctionImporter::ImportMapTy ImportList;
1334 for (auto &GlobalList : *CombinedIndex) {
1335 // Ignore entries for undefined references.
1336 if (GlobalList.second.SummaryList.empty())
1339 auto GUID = GlobalList.first;
1340 for (auto &Summary : GlobalList.second.SummaryList) {
1341 // Skip the summaries for the importing module. These are included to
1342 // e.g. record required linkage changes.
1343 if (Summary->modulePath() == M->getModuleIdentifier())
1345 // Add an entry to provoke importing by thinBackend.
1346 ImportList[Summary->modulePath()].insert(GUID);
1350 std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1351 MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1353 for (auto &I : ImportList) {
1354 ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr =
1355 llvm::MemoryBuffer::getFile(I.first());
1357 errs() << "Error loading imported file '" << I.first()
1358 << "': " << MBOrErr.getError().message() << "\n";
1362 Expected<BitcodeModule> BMOrErr = FindThinLTOModule(**MBOrErr);
1364 handleAllErrors(BMOrErr.takeError(), [&](ErrorInfoBase &EIB) {
1365 errs() << "Error loading imported file '" << I.first()
1366 << "': " << EIB.message() << '\n';
1370 ModuleMap.insert({I.first(), *BMOrErr});
1372 OwnedImports.push_back(std::move(*MBOrErr));
1374 auto AddStream = [&](size_t Task) {
1375 return llvm::make_unique<lto::NativeObjectStream>(std::move(OS));
1378 if (CGOpts.SaveTempsFilePrefix != "") {
1379 if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1380 /* UseInputModulePath */ false)) {
1381 handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1382 errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1387 Conf.CPU = TOpts.CPU;
1388 Conf.CodeModel = getCodeModel(CGOpts);
1389 Conf.MAttrs = TOpts.Features;
1390 Conf.RelocModel = CGOpts.RelocationModel;
1391 Conf.CGOptLevel = getCGOptLevel(CGOpts);
1392 Conf.OptLevel = CGOpts.OptimizationLevel;
1393 initTargetOptions(Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1394 Conf.SampleProfile = std::move(SampleProfile);
1396 // Context sensitive profile.
1397 if (CGOpts.hasProfileCSIRInstr()) {
1398 Conf.RunCSIRInstr = true;
1399 Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1400 } else if (CGOpts.hasProfileCSIRUse()) {
1401 Conf.RunCSIRInstr = false;
1402 Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1405 Conf.ProfileRemapping = std::move(ProfileRemapping);
1406 Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
1407 Conf.DebugPassManager = CGOpts.DebugPassManager;
1408 Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1409 Conf.RemarksFilename = CGOpts.OptRecordFile;
1410 Conf.RemarksPasses = CGOpts.OptRecordPasses;
1411 Conf.RemarksFormat = CGOpts.OptRecordFormat;
1412 Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1413 Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1415 case Backend_EmitNothing:
1416 Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1420 case Backend_EmitLL:
1421 Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1422 M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1426 case Backend_EmitBC:
1427 Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1428 WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1433 Conf.CGFileType = getCodeGenFileType(Action);
1436 if (Error E = thinBackend(
1437 Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1438 ModuleToDefinedGVSummaries[M->getModuleIdentifier()], ModuleMap)) {
1439 handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1440 errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1445 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1446 const HeaderSearchOptions &HeaderOpts,
1447 const CodeGenOptions &CGOpts,
1448 const clang::TargetOptions &TOpts,
1449 const LangOptions &LOpts,
1450 const llvm::DataLayout &TDesc, Module *M,
1451 BackendAction Action,
1452 std::unique_ptr<raw_pwrite_stream> OS) {
1454 llvm::TimeTraceScope TimeScope("Backend", StringRef(""));
1456 std::unique_ptr<llvm::Module> EmptyModule;
1457 if (!CGOpts.ThinLTOIndexFile.empty()) {
1458 // If we are performing a ThinLTO importing compile, load the function index
1459 // into memory and pass it into runThinLTOBackend, which will run the
1460 // function importer and invoke LTO passes.
1461 Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1462 llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1463 /*IgnoreEmptyThinLTOIndexFile*/true);
1465 logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1466 "Error loading index file '" +
1467 CGOpts.ThinLTOIndexFile + "': ");
1470 std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1471 // A null CombinedIndex means we should skip ThinLTO compilation
1472 // (LLVM will optionally ignore empty index files, returning null instead
1474 if (CombinedIndex) {
1475 if (!CombinedIndex->skipModuleByDistributedBackend()) {
1476 runThinLTOBackend(CombinedIndex.get(), M, HeaderOpts, CGOpts, TOpts,
1477 LOpts, std::move(OS), CGOpts.SampleProfileFile,
1478 CGOpts.ProfileRemappingFile, Action);
1481 // Distributed indexing detected that nothing from the module is needed
1482 // for the final linking. So we can skip the compilation. We sill need to
1483 // output an empty object file to make sure that a linker does not fail
1484 // trying to read it. Also for some features, like CFI, we must skip
1485 // the compilation as CombinedIndex does not contain all required
1487 EmptyModule = llvm::make_unique<llvm::Module>("empty", M->getContext());
1488 EmptyModule->setTargetTriple(M->getTargetTriple());
1489 M = EmptyModule.get();
1493 EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1495 if (CGOpts.ExperimentalNewPassManager)
1496 AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1498 AsmHelper.EmitAssembly(Action, std::move(OS));
1500 // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1503 std::string DLDesc = M->getDataLayout().getStringRepresentation();
1504 if (DLDesc != TDesc.getStringRepresentation()) {
1505 unsigned DiagID = Diags.getCustomDiagID(
1506 DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1507 "expected target description '%1'");
1508 Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1513 static const char* getSectionNameForBitcode(const Triple &T) {
1514 switch (T.getObjectFormat()) {
1516 return "__LLVM,__bitcode";
1520 case Triple::UnknownObjectFormat:
1523 llvm_unreachable("XCOFF is not yet implemented");
1526 llvm_unreachable("Unimplemented ObjectFormatType");
1529 static const char* getSectionNameForCommandline(const Triple &T) {
1530 switch (T.getObjectFormat()) {
1532 return "__LLVM,__cmdline";
1536 case Triple::UnknownObjectFormat:
1539 llvm_unreachable("XCOFF is not yet implemented");
1542 llvm_unreachable("Unimplemented ObjectFormatType");
1545 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1546 // __LLVM,__bitcode section.
1547 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1548 llvm::MemoryBufferRef Buf) {
1549 if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1552 // Save llvm.compiler.used and remote it.
1553 SmallVector<Constant*, 2> UsedArray;
1554 SmallPtrSet<GlobalValue*, 4> UsedGlobals;
1555 Type *UsedElementType = Type::getInt8Ty(M->getContext())->getPointerTo(0);
1556 GlobalVariable *Used = collectUsedGlobalVariables(*M, UsedGlobals, true);
1557 for (auto *GV : UsedGlobals) {
1558 if (GV->getName() != "llvm.embedded.module" &&
1559 GV->getName() != "llvm.cmdline")
1560 UsedArray.push_back(
1561 ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1564 Used->eraseFromParent();
1566 // Embed the bitcode for the llvm module.
1568 ArrayRef<uint8_t> ModuleData;
1569 Triple T(M->getTargetTriple());
1570 // Create a constant that contains the bitcode.
1571 // In case of embedding a marker, ignore the input Buf and use the empty
1572 // ArrayRef. It is also legal to create a bitcode marker even Buf is empty.
1573 if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker) {
1574 if (!isBitcode((const unsigned char *)Buf.getBufferStart(),
1575 (const unsigned char *)Buf.getBufferEnd())) {
1576 // If the input is LLVM Assembly, bitcode is produced by serializing
1577 // the module. Use-lists order need to be perserved in this case.
1578 llvm::raw_string_ostream OS(Data);
1579 llvm::WriteBitcodeToFile(*M, OS, /* ShouldPreserveUseListOrder */ true);
1581 ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
1583 // If the input is LLVM bitcode, write the input byte stream directly.
1584 ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
1585 Buf.getBufferSize());
1587 llvm::Constant *ModuleConstant =
1588 llvm::ConstantDataArray::get(M->getContext(), ModuleData);
1589 llvm::GlobalVariable *GV = new llvm::GlobalVariable(
1590 *M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
1592 GV->setSection(getSectionNameForBitcode(T));
1593 UsedArray.push_back(
1594 ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1595 if (llvm::GlobalVariable *Old =
1596 M->getGlobalVariable("llvm.embedded.module", true)) {
1597 assert(Old->hasOneUse() &&
1598 "llvm.embedded.module can only be used once in llvm.compiler.used");
1600 Old->eraseFromParent();
1602 GV->setName("llvm.embedded.module");
1605 // Skip if only bitcode needs to be embedded.
1606 if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode) {
1607 // Embed command-line options.
1608 ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CGOpts.CmdArgs.data()),
1609 CGOpts.CmdArgs.size());
1610 llvm::Constant *CmdConstant =
1611 llvm::ConstantDataArray::get(M->getContext(), CmdData);
1612 GV = new llvm::GlobalVariable(*M, CmdConstant->getType(), true,
1613 llvm::GlobalValue::PrivateLinkage,
1615 GV->setSection(getSectionNameForCommandline(T));
1616 UsedArray.push_back(
1617 ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1618 if (llvm::GlobalVariable *Old =
1619 M->getGlobalVariable("llvm.cmdline", true)) {
1620 assert(Old->hasOneUse() &&
1621 "llvm.cmdline can only be used once in llvm.compiler.used");
1623 Old->eraseFromParent();
1625 GV->setName("llvm.cmdline");
1629 if (UsedArray.empty())
1632 // Recreate llvm.compiler.used.
1633 ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
1634 auto *NewUsed = new GlobalVariable(
1635 *M, ATy, false, llvm::GlobalValue::AppendingLinkage,
1636 llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
1637 NewUsed->setSection("llvm.metadata");