src/llvm/lib/LTO/LTOCodeGenerator.cpp

   1 //===-LTOCodeGenerator.cpp - LLVM Link Time Optimizer ---------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the Link Time Optimization library. This library is
  11 // intended to be used by linker to optimize code at link time.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/LTO/LTOCodeGenerator.h"
  16 #include "llvm/ADT/StringExtras.h"
  17 #include "llvm/Analysis/Passes.h"
  18 #include "llvm/Bitcode/ReaderWriter.h"
  19 #include "llvm/CodeGen/RuntimeLibcalls.h"
  20 #include "llvm/Config/config.h"
  21 #include "llvm/IR/Constants.h"
  22 #include "llvm/IR/DataLayout.h"
  23 #include "llvm/IR/DerivedTypes.h"
  24 #include "llvm/IR/DiagnosticInfo.h"
  25 #include "llvm/IR/DiagnosticPrinter.h"
  26 #include "llvm/IR/LLVMContext.h"
  27 #include "llvm/IR/Mangler.h"
  28 #include "llvm/IR/Module.h"
  29 #include "llvm/IR/Verifier.h"
  30 #include "llvm/InitializePasses.h"
  31 #include "llvm/LTO/LTOModule.h"
  32 #include "llvm/Linker/Linker.h"
  33 #include "llvm/MC/MCAsmInfo.h"
  34 #include "llvm/MC/MCContext.h"
  35 #include "llvm/MC/SubtargetFeature.h"
  36 #include "llvm/PassManager.h"
  37 #include "llvm/Support/CommandLine.h"
  38 #include "llvm/Support/FileSystem.h"
  39 #include "llvm/Support/FormattedStream.h"
  40 #include "llvm/Support/Host.h"
  41 #include "llvm/Support/MemoryBuffer.h"
  42 #include "llvm/Support/Signals.h"
  43 #include "llvm/Support/TargetRegistry.h"
  44 #include "llvm/Support/TargetSelect.h"
  45 #include "llvm/Support/ToolOutputFile.h"
  46 #include "llvm/Support/raw_ostream.h"
  47 #include "llvm/Target/TargetLibraryInfo.h"
  48 #include "llvm/Target/TargetLowering.h"
  49 #include "llvm/Target/TargetOptions.h"
  50 #include "llvm/Target/TargetRegisterInfo.h"
  51 #include "llvm/Target/TargetSubtargetInfo.h"
  52 #include "llvm/Transforms/IPO.h"
  53 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
  54 #include "llvm/Transforms/ObjCARC.h"
  55 #include <system_error>
  56 using namespace llvm;
  57
  58 const char* LTOCodeGenerator::getVersionString() {
  59 #ifdef LLVM_VERSION_INFO
  60   return PACKAGE_NAME " version " PACKAGE_VERSION ", " LLVM_VERSION_INFO;
  61 #else
  62   return PACKAGE_NAME " version " PACKAGE_VERSION;
  63 #endif
  64 }
  65
  66 LTOCodeGenerator::LTOCodeGenerator()
  67     : Context(getGlobalContext()), IRLinker(new Module("ld-temp.o", Context)) {
  68   initialize();
  69 }
  70
  71 LTOCodeGenerator::LTOCodeGenerator(std::unique_ptr<LLVMContext> Context)
  72     : OwnedContext(std::move(Context)), Context(*OwnedContext),
  73       IRLinker(new Module("ld-temp.o", *OwnedContext)) {
  74   initialize();
  75 }
  76
  77 void LTOCodeGenerator::initialize() {
  78   TargetMach = nullptr;
  79   EmitDwarfDebugInfo = false;
  80   ScopeRestrictionsDone = false;
  81   CodeModel = LTO_CODEGEN_PIC_MODEL_DEFAULT;
  82   DiagHandler = nullptr;
  83   DiagContext = nullptr;
  84
  85   initializeLTOPasses();
  86 }
  87
  88 LTOCodeGenerator::~LTOCodeGenerator() {
  89   delete TargetMach;
  90   TargetMach = nullptr;
  91
  92   IRLinker.deleteModule();
  93
  94   for (std::vector<char *>::iterator I = CodegenOptions.begin(),
  95                                      E = CodegenOptions.end();
  96        I != E; ++I)
  97     free(*I);
  98 }
  99
 100 // Initialize LTO passes. Please keep this funciton in sync with
 101 // PassManagerBuilder::populateLTOPassManager(), and make sure all LTO
 102 // passes are initialized.
 103 void LTOCodeGenerator::initializeLTOPasses() {
 104   PassRegistry &R = *PassRegistry::getPassRegistry();
 105
 106   initializeInternalizePassPass(R);
 107   initializeIPSCCPPass(R);
 108   initializeGlobalOptPass(R);
 109   initializeConstantMergePass(R);
 110   initializeDAHPass(R);
 111   initializeInstCombinerPass(R);
 112   initializeSimpleInlinerPass(R);
 113   initializePruneEHPass(R);
 114   initializeGlobalDCEPass(R);
 115   initializeArgPromotionPass(R);
 116   initializeJumpThreadingPass(R);
 117   initializeSROAPass(R);
 118   initializeSROA_DTPass(R);
 119   initializeSROA_SSAUpPass(R);
 120   initializeFunctionAttrsPass(R);
 121   initializeGlobalsModRefPass(R);
 122   initializeLICMPass(R);
 123   initializeMergedLoadStoreMotionPass(R);
 124   initializeGVNPass(R);
 125   initializeMemCpyOptPass(R);
 126   initializeDCEPass(R);
 127   initializeCFGSimplifyPassPass(R);
 128 }
 129
 130 bool LTOCodeGenerator::addModule(LTOModule *mod) {
 131   assert(&mod->getModule().getContext() == &Context &&
 132          "Expected module in same context");
 133
 134   bool ret = IRLinker.linkInModule(&mod->getModule());
 135
 136   const std::vector<const char*> &undefs = mod->getAsmUndefinedRefs();
 137   for (int i = 0, e = undefs.size(); i != e; ++i)
 138     AsmUndefinedRefs[undefs[i]] = 1;
 139
 140   return !ret;
 141 }
 142
 143 void LTOCodeGenerator::setTargetOptions(TargetOptions options) {
 144   Options = options;
 145 }
 146
 147 void LTOCodeGenerator::setDebugInfo(lto_debug_model debug) {
 148   switch (debug) {
 149   case LTO_DEBUG_MODEL_NONE:
 150     EmitDwarfDebugInfo = false;
 151     return;
 152
 153   case LTO_DEBUG_MODEL_DWARF:
 154     EmitDwarfDebugInfo = true;
 155     return;
 156   }
 157   llvm_unreachable("Unknown debug format!");
 158 }
 159
 160 void LTOCodeGenerator::setCodePICModel(lto_codegen_model model) {
 161   switch (model) {
 162   case LTO_CODEGEN_PIC_MODEL_STATIC:
 163   case LTO_CODEGEN_PIC_MODEL_DYNAMIC:
 164   case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC:
 165   case LTO_CODEGEN_PIC_MODEL_DEFAULT:
 166     CodeModel = model;
 167     return;
 168   }
 169   llvm_unreachable("Unknown PIC model!");
 170 }
 171
 172 bool LTOCodeGenerator::writeMergedModules(const char *path,
 173                                           std::string &errMsg) {
 174   if (!determineTarget(errMsg))
 175     return false;
 176
 177   // mark which symbols can not be internalized
 178   applyScopeRestrictions();
 179
 180   // create output file
 181   std::error_code EC;
 182   tool_output_file Out(path, EC, sys::fs::F_None);
 183   if (EC) {
 184     errMsg = "could not open bitcode file for writing: ";
 185     errMsg += path;
 186     return false;
 187   }
 188
 189   // write bitcode to it
 190   WriteBitcodeToFile(IRLinker.getModule(), Out.os());
 191   Out.os().close();
 192
 193   if (Out.os().has_error()) {
 194     errMsg = "could not write bitcode file: ";
 195     errMsg += path;
 196     Out.os().clear_error();
 197     return false;
 198   }
 199
 200   Out.keep();
 201   return true;
 202 }
 203
 204 bool LTOCodeGenerator::compile_to_file(const char** name,
 205                                        bool disableOpt,
 206                                        bool disableInline,
 207                                        bool disableGVNLoadPRE,
 208                                        bool disableVectorization,
 209                                        std::string& errMsg) {
 210   // make unique temp .o file to put generated object file
 211   SmallString<128> Filename;
 212   int FD;
 213   std::error_code EC =
 214       sys::fs::createTemporaryFile("lto-llvm", "o", FD, Filename);
 215   if (EC) {
 216     errMsg = EC.message();
 217     return false;
 218   }
 219
 220   // generate object file
 221   tool_output_file objFile(Filename.c_str(), FD);
 222
 223   bool genResult =
 224       generateObjectFile(objFile.os(), disableOpt, disableInline,
 225                          disableGVNLoadPRE, disableVectorization, errMsg);
 226   objFile.os().close();
 227   if (objFile.os().has_error()) {
 228     objFile.os().clear_error();
 229     sys::fs::remove(Twine(Filename));
 230     return false;
 231   }
 232
 233   objFile.keep();
 234   if (!genResult) {
 235     sys::fs::remove(Twine(Filename));
 236     return false;
 237   }
 238
 239   NativeObjectPath = Filename.c_str();
 240   *name = NativeObjectPath.c_str();
 241   return true;
 242 }
 243
 244 const void* LTOCodeGenerator::compile(size_t* length,
 245                                       bool disableOpt,
 246                                       bool disableInline,
 247                                       bool disableGVNLoadPRE,
 248                                       bool disableVectorization,
 249                                       std::string& errMsg) {
 250   const char *name;
 251   if (!compile_to_file(&name, disableOpt, disableInline, disableGVNLoadPRE,
 252                        disableVectorization, errMsg))
 253     return nullptr;
 254
 255   // read .o file into memory buffer
 256   ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
 257       MemoryBuffer::getFile(name, -1, false);
 258   if (std::error_code EC = BufferOrErr.getError()) {
 259     errMsg = EC.message();
 260     sys::fs::remove(NativeObjectPath);
 261     return nullptr;
 262   }
 263   NativeObjectFile = std::move(*BufferOrErr);
 264
 265   // remove temp files
 266   sys::fs::remove(NativeObjectPath);
 267
 268   // return buffer, unless error
 269   if (!NativeObjectFile)
 270     return nullptr;
 271   *length = NativeObjectFile->getBufferSize();
 272   return NativeObjectFile->getBufferStart();
 273 }
 274
 275 bool LTOCodeGenerator::determineTarget(std::string &errMsg) {
 276   if (TargetMach)
 277     return true;
 278
 279   std::string TripleStr = IRLinker.getModule()->getTargetTriple();
 280   if (TripleStr.empty())
 281     TripleStr = sys::getDefaultTargetTriple();
 282   llvm::Triple Triple(TripleStr);
 283
 284   // create target machine from info for merged modules
 285   const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
 286   if (!march)
 287     return false;
 288
 289   // The relocation model is actually a static member of TargetMachine and
 290   // needs to be set before the TargetMachine is instantiated.
 291   Reloc::Model RelocModel = Reloc::Default;
 292   switch (CodeModel) {
 293   case LTO_CODEGEN_PIC_MODEL_STATIC:
 294     RelocModel = Reloc::Static;
 295     break;
 296   case LTO_CODEGEN_PIC_MODEL_DYNAMIC:
 297     RelocModel = Reloc::PIC_;
 298     break;
 299   case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC:
 300     RelocModel = Reloc::DynamicNoPIC;
 301     break;
 302   case LTO_CODEGEN_PIC_MODEL_DEFAULT:
 303     // RelocModel is already the default, so leave it that way.
 304     break;
 305   }
 306
 307   // Construct LTOModule, hand over ownership of module and target. Use MAttr as
 308   // the default set of features.
 309   SubtargetFeatures Features(MAttr);
 310   Features.getDefaultSubtargetFeatures(Triple);
 311   std::string FeatureStr = Features.getString();
 312   // Set a default CPU for Darwin triples.
 313   if (MCpu.empty() && Triple.isOSDarwin()) {
 314     if (Triple.getArch() == llvm::Triple::x86_64)
 315       MCpu = "core2";
 316     else if (Triple.getArch() == llvm::Triple::x86)
 317       MCpu = "yonah";
 318     else if (Triple.getArch() == llvm::Triple::aarch64)
 319       MCpu = "cyclone";
 320   }
 321
 322   TargetMach = march->createTargetMachine(TripleStr, MCpu, FeatureStr, Options,
 323                                           RelocModel, CodeModel::Default,
 324                                           CodeGenOpt::Aggressive);
 325   return true;
 326 }
 327
 328 void LTOCodeGenerator::
 329 applyRestriction(GlobalValue &GV,
 330                  ArrayRef<StringRef> Libcalls,
 331                  std::vector<const char*> &MustPreserveList,
 332                  SmallPtrSetImpl<GlobalValue*> &AsmUsed,
 333                  Mangler &Mangler) {
 334   // There are no restrictions to apply to declarations.
 335   if (GV.isDeclaration())
 336     return;
 337
 338   // There is nothing more restrictive than private linkage.
 339   if (GV.hasPrivateLinkage())
 340     return;
 341
 342   SmallString<64> Buffer;
 343   TargetMach->getNameWithPrefix(Buffer, &GV, Mangler);
 344
 345   if (MustPreserveSymbols.count(Buffer))
 346     MustPreserveList.push_back(GV.getName().data());
 347   if (AsmUndefinedRefs.count(Buffer))
 348     AsmUsed.insert(&GV);
 349
 350   // Conservatively append user-supplied runtime library functions to
 351   // llvm.compiler.used.  These could be internalized and deleted by
 352   // optimizations like -globalopt, causing problems when later optimizations
 353   // add new library calls (e.g., llvm.memset => memset and printf => puts).
 354   // Leave it to the linker to remove any dead code (e.g. with -dead_strip).
 355   if (isa<Function>(GV) &&
 356       std::binary_search(Libcalls.begin(), Libcalls.end(), GV.getName()))
 357     AsmUsed.insert(&GV);
 358 }
 359
 360 static void findUsedValues(GlobalVariable *LLVMUsed,
 361                            SmallPtrSetImpl<GlobalValue*> &UsedValues) {
 362   if (!LLVMUsed) return;
 363
 364   ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
 365   for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
 366     if (GlobalValue *GV =
 367         dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
 368       UsedValues.insert(GV);
 369 }
 370
 371 static void accumulateAndSortLibcalls(std::vector<StringRef> &Libcalls,
 372                                       const TargetLibraryInfo& TLI,
 373                                       const TargetLowering *Lowering)
 374 {
 375   // TargetLibraryInfo has info on C runtime library calls on the current
 376   // target.
 377   for (unsigned I = 0, E = static_cast<unsigned>(LibFunc::NumLibFuncs);
 378        I != E; ++I) {
 379     LibFunc::Func F = static_cast<LibFunc::Func>(I);
 380     if (TLI.has(F))
 381       Libcalls.push_back(TLI.getName(F));
 382   }
 383
 384   // TargetLowering has info on library calls that CodeGen expects to be
 385   // available, both from the C runtime and compiler-rt.
 386   if (Lowering)
 387     for (unsigned I = 0, E = static_cast<unsigned>(RTLIB::UNKNOWN_LIBCALL);
 388          I != E; ++I)
 389       if (const char *Name
 390           = Lowering->getLibcallName(static_cast<RTLIB::Libcall>(I)))
 391         Libcalls.push_back(Name);
 392
 393   array_pod_sort(Libcalls.begin(), Libcalls.end());
 394   Libcalls.erase(std::unique(Libcalls.begin(), Libcalls.end()),
 395                  Libcalls.end());
 396 }
 397
 398 void LTOCodeGenerator::applyScopeRestrictions() {
 399   if (ScopeRestrictionsDone)
 400     return;
 401   Module *mergedModule = IRLinker.getModule();
 402
 403   // Start off with a verification pass.
 404   PassManager passes;
 405   passes.add(createVerifierPass());
 406   passes.add(createDebugInfoVerifierPass());
 407
 408   // mark which symbols can not be internalized
 409   Mangler Mangler(TargetMach->getSubtargetImpl()->getDataLayout());
 410   std::vector<const char*> MustPreserveList;
 411   SmallPtrSet<GlobalValue*, 8> AsmUsed;
 412   std::vector<StringRef> Libcalls;
 413   TargetLibraryInfo TLI(Triple(TargetMach->getTargetTriple()));
 414   accumulateAndSortLibcalls(
 415       Libcalls, TLI, TargetMach->getSubtargetImpl()->getTargetLowering());
 416
 417   for (Module::iterator f = mergedModule->begin(),
 418          e = mergedModule->end(); f != e; ++f)
 419     applyRestriction(*f, Libcalls, MustPreserveList, AsmUsed, Mangler);
 420   for (Module::global_iterator v = mergedModule->global_begin(),
 421          e = mergedModule->global_end(); v !=  e; ++v)
 422     applyRestriction(*v, Libcalls, MustPreserveList, AsmUsed, Mangler);
 423   for (Module::alias_iterator a = mergedModule->alias_begin(),
 424          e = mergedModule->alias_end(); a != e; ++a)
 425     applyRestriction(*a, Libcalls, MustPreserveList, AsmUsed, Mangler);
 426
 427   GlobalVariable *LLVMCompilerUsed =
 428     mergedModule->getGlobalVariable("llvm.compiler.used");
 429   findUsedValues(LLVMCompilerUsed, AsmUsed);
 430   if (LLVMCompilerUsed)
 431     LLVMCompilerUsed->eraseFromParent();
 432
 433   if (!AsmUsed.empty()) {
 434     llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(Context);
 435     std::vector<Constant*> asmUsed2;
 436     for (auto *GV : AsmUsed) {
 437       Constant *c = ConstantExpr::getBitCast(GV, i8PTy);
 438       asmUsed2.push_back(c);
 439     }
 440
 441     llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size());
 442     LLVMCompilerUsed =
 443       new llvm::GlobalVariable(*mergedModule, ATy, false,
 444                                llvm::GlobalValue::AppendingLinkage,
 445                                llvm::ConstantArray::get(ATy, asmUsed2),
 446                                "llvm.compiler.used");
 447
 448     LLVMCompilerUsed->setSection("llvm.metadata");
 449   }
 450
 451   passes.add(createInternalizePass(MustPreserveList));
 452
 453   // apply scope restrictions
 454   passes.run(*mergedModule);
 455
 456   ScopeRestrictionsDone = true;
 457 }
 458
 459 /// Optimize merged modules using various IPO passes
 460 bool LTOCodeGenerator::generateObjectFile(raw_ostream &out,
 461                                           bool DisableOpt,
 462                                           bool DisableInline,
 463                                           bool DisableGVNLoadPRE,
 464                                           bool DisableVectorization,
 465                                           std::string &errMsg) {
 466   if (!this->determineTarget(errMsg))
 467     return false;
 468
 469   Module *mergedModule = IRLinker.getModule();
 470
 471   // Mark which symbols can not be internalized
 472   this->applyScopeRestrictions();
 473
 474   // Instantiate the pass manager to organize the passes.
 475   PassManager passes;
 476
 477   // Add an appropriate DataLayout instance for this module...
 478   mergedModule->setDataLayout(TargetMach->getSubtargetImpl()->getDataLayout());
 479
 480   Triple TargetTriple(TargetMach->getTargetTriple());
 481   PassManagerBuilder PMB;
 482   PMB.DisableGVNLoadPRE = DisableGVNLoadPRE;
 483   PMB.LoopVectorize = !DisableVectorization;
 484   PMB.SLPVectorize = !DisableVectorization;
 485   if (!DisableInline)
 486     PMB.Inliner = createFunctionInliningPass();
 487   PMB.LibraryInfo = new TargetLibraryInfo(TargetTriple);
 488   if (DisableOpt)
 489     PMB.OptLevel = 0;
 490   PMB.VerifyInput = true;
 491   PMB.VerifyOutput = true;
 492
 493   PMB.populateLTOPassManager(passes, TargetMach);
 494
 495   PassManager codeGenPasses;
 496
 497   codeGenPasses.add(new DataLayoutPass());
 498
 499   formatted_raw_ostream Out(out);
 500
 501   // If the bitcode files contain ARC code and were compiled with optimization,
 502   // the ObjCARCContractPass must be run, so do it unconditionally here.
 503   codeGenPasses.add(createObjCARCContractPass());
 504
 505   if (TargetMach->addPassesToEmitFile(codeGenPasses, Out,
 506                                       TargetMachine::CGFT_ObjectFile)) {
 507     errMsg = "target file type not supported";
 508     return false;
 509   }
 510
 511   // Run our queue of passes all at once now, efficiently.
 512   passes.run(*mergedModule);
 513
 514   // Run the code generator, and write assembly file
 515   codeGenPasses.run(*mergedModule);
 516
 517   return true;
 518 }
 519
 520 /// setCodeGenDebugOptions - Set codegen debugging options to aid in debugging
 521 /// LTO problems.
 522 void LTOCodeGenerator::setCodeGenDebugOptions(const char *options) {
 523   for (std::pair<StringRef, StringRef> o = getToken(options);
 524        !o.first.empty(); o = getToken(o.second)) {
 525     // ParseCommandLineOptions() expects argv[0] to be program name. Lazily add
 526     // that.
 527     if (CodegenOptions.empty())
 528       CodegenOptions.push_back(strdup("libLLVMLTO"));
 529     CodegenOptions.push_back(strdup(o.first.str().c_str()));
 530   }
 531 }
 532
 533 void LTOCodeGenerator::parseCodeGenDebugOptions() {
 534   // if options were requested, set them
 535   if (!CodegenOptions.empty())
 536     cl::ParseCommandLineOptions(CodegenOptions.size(),
 537                                 const_cast<char **>(&CodegenOptions[0]));
 538 }
 539
 540 void LTOCodeGenerator::DiagnosticHandler(const DiagnosticInfo &DI,
 541                                          void *Context) {
 542   ((LTOCodeGenerator *)Context)->DiagnosticHandler2(DI);
 543 }
 544
 545 void LTOCodeGenerator::DiagnosticHandler2(const DiagnosticInfo &DI) {
 546   // Map the LLVM internal diagnostic severity to the LTO diagnostic severity.
 547   lto_codegen_diagnostic_severity_t Severity;
 548   switch (DI.getSeverity()) {
 549   case DS_Error:
 550     Severity = LTO_DS_ERROR;
 551     break;
 552   case DS_Warning:
 553     Severity = LTO_DS_WARNING;
 554     break;
 555   case DS_Remark:
 556     Severity = LTO_DS_REMARK;
 557     break;
 558   case DS_Note:
 559     Severity = LTO_DS_NOTE;
 560     break;
 561   }
 562   // Create the string that will be reported to the external diagnostic handler.
 563   std::string MsgStorage;
 564   raw_string_ostream Stream(MsgStorage);
 565   DiagnosticPrinterRawOStream DP(Stream);
 566   DI.print(DP);
 567   Stream.flush();
 568
 569   // If this method has been called it means someone has set up an external
 570   // diagnostic handler. Assert on that.
 571   assert(DiagHandler && "Invalid diagnostic handler");
 572   (*DiagHandler)(Severity, MsgStorage.c_str(), DiagContext);
 573 }
 574
 575 void
 576 LTOCodeGenerator::setDiagnosticHandler(lto_diagnostic_handler_t DiagHandler,
 577                                        void *Ctxt) {
 578   this->DiagHandler = DiagHandler;
 579   this->DiagContext = Ctxt;
 580   if (!DiagHandler)
 581     return Context.setDiagnosticHandler(nullptr, nullptr);
 582   // Register the LTOCodeGenerator stub in the LLVMContext to forward the
 583   // diagnostic to the external DiagHandler.
 584   Context.setDiagnosticHandler(LTOCodeGenerator::DiagnosticHandler, this,
 585                                /* RespectFilters */ true);
 586 }