clang/lib/CodeGen/CodeGenAction.cpp

   1 //===--- CodeGenAction.cpp - LLVM Code Generation Frontend Action ---------===//
   2 //
   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
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "clang/CodeGen/CodeGenAction.h"
  10 #include "BackendConsumer.h"
  11 #include "CGCall.h"
  12 #include "CodeGenModule.h"
  13 #include "CoverageMappingGen.h"
  14 #include "MacroPPCallbacks.h"
  15 #include "clang/AST/ASTConsumer.h"
  16 #include "clang/AST/ASTContext.h"
  17 #include "clang/AST/DeclCXX.h"
  18 #include "clang/AST/DeclGroup.h"
  19 #include "clang/Basic/DiagnosticFrontend.h"
  20 #include "clang/Basic/FileManager.h"
  21 #include "clang/Basic/LangStandard.h"
  22 #include "clang/Basic/SourceManager.h"
  23 #include "clang/Basic/TargetInfo.h"
  24 #include "clang/CodeGen/BackendUtil.h"
  25 #include "clang/CodeGen/ModuleBuilder.h"
  26 #include "clang/Driver/DriverDiagnostic.h"
  27 #include "clang/Frontend/CompilerInstance.h"
  28 #include "clang/Frontend/FrontendActions.h"
  29 #include "clang/Frontend/FrontendDiagnostic.h"
  30 #include "clang/Frontend/MultiplexConsumer.h"
  31 #include "clang/Lex/Preprocessor.h"
  32 #include "clang/Serialization/ASTWriter.h"
  33 #include "llvm/ADT/Hashing.h"
  34 #include "llvm/Bitcode/BitcodeReader.h"
  35 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
  36 #include "llvm/Demangle/Demangle.h"
  37 #include "llvm/IR/DebugInfo.h"
  38 #include "llvm/IR/DiagnosticInfo.h"
  39 #include "llvm/IR/DiagnosticPrinter.h"
  40 #include "llvm/IR/GlobalValue.h"
  41 #include "llvm/IR/LLVMContext.h"
  42 #include "llvm/IR/LLVMRemarkStreamer.h"
  43 #include "llvm/IR/Module.h"
  44 #include "llvm/IRReader/IRReader.h"
  45 #include "llvm/LTO/LTOBackend.h"
  46 #include "llvm/Linker/Linker.h"
  47 #include "llvm/Pass.h"
  48 #include "llvm/Support/MemoryBuffer.h"
  49 #include "llvm/Support/SourceMgr.h"
  50 #include "llvm/Support/TimeProfiler.h"
  51 #include "llvm/Support/Timer.h"
  52 #include "llvm/Support/ToolOutputFile.h"
  53 #include "llvm/Support/YAMLTraits.h"
  54 #include "llvm/Transforms/IPO/Internalize.h"
  55 #include "llvm/Transforms/Utils/Cloning.h"
  56
  57 #include <optional>
  58 using namespace clang;
  59 using namespace llvm;
  60
  61 #define DEBUG_TYPE "codegenaction"
  62
  63 namespace clang {
  64 class BackendConsumer;
  65 class ClangDiagnosticHandler final : public DiagnosticHandler {
  66 public:
  67   ClangDiagnosticHandler(const CodeGenOptions &CGOpts, BackendConsumer *BCon)
  68       : CodeGenOpts(CGOpts), BackendCon(BCon) {}
  69
  70   bool handleDiagnostics(const DiagnosticInfo &DI) override;
  71
  72   bool isAnalysisRemarkEnabled(StringRef PassName) const override {
  73     return CodeGenOpts.OptimizationRemarkAnalysis.patternMatches(PassName);
  74   }
  75   bool isMissedOptRemarkEnabled(StringRef PassName) const override {
  76     return CodeGenOpts.OptimizationRemarkMissed.patternMatches(PassName);
  77   }
  78   bool isPassedOptRemarkEnabled(StringRef PassName) const override {
  79     return CodeGenOpts.OptimizationRemark.patternMatches(PassName);
  80   }
  81
  82   bool isAnyRemarkEnabled() const override {
  83     return CodeGenOpts.OptimizationRemarkAnalysis.hasValidPattern() ||
  84            CodeGenOpts.OptimizationRemarkMissed.hasValidPattern() ||
  85            CodeGenOpts.OptimizationRemark.hasValidPattern();
  86   }
  87
  88 private:
  89   const CodeGenOptions &CodeGenOpts;
  90   BackendConsumer *BackendCon;
  91 };
  92
  93 static void reportOptRecordError(Error E, DiagnosticsEngine &Diags,
  94                                  const CodeGenOptions &CodeGenOpts) {
  95   handleAllErrors(
  96       std::move(E),
  97     [&](const LLVMRemarkSetupFileError &E) {
  98         Diags.Report(diag::err_cannot_open_file)
  99             << CodeGenOpts.OptRecordFile << E.message();
 100       },
 101     [&](const LLVMRemarkSetupPatternError &E) {
 102         Diags.Report(diag::err_drv_optimization_remark_pattern)
 103             << E.message() << CodeGenOpts.OptRecordPasses;
 104       },
 105     [&](const LLVMRemarkSetupFormatError &E) {
 106         Diags.Report(diag::err_drv_optimization_remark_format)
 107             << CodeGenOpts.OptRecordFormat;
 108       });
 109 }
 110
 111 BackendConsumer::BackendConsumer(
 112     BackendAction Action, DiagnosticsEngine &Diags,
 113     IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
 114     const HeaderSearchOptions &HeaderSearchOpts,
 115     const PreprocessorOptions &PPOpts, const CodeGenOptions &CodeGenOpts,
 116     const TargetOptions &TargetOpts, const LangOptions &LangOpts,
 117     const std::string &InFile, SmallVector<LinkModule, 4> LinkModules,
 118     std::unique_ptr<raw_pwrite_stream> OS, LLVMContext &C,
 119     CoverageSourceInfo *CoverageInfo)
 120     : Diags(Diags), Action(Action), HeaderSearchOpts(HeaderSearchOpts),
 121       CodeGenOpts(CodeGenOpts), TargetOpts(TargetOpts), LangOpts(LangOpts),
 122       AsmOutStream(std::move(OS)), Context(nullptr), FS(VFS),
 123       LLVMIRGeneration("irgen", "LLVM IR Generation Time"),
 124       LLVMIRGenerationRefCount(0),
 125       Gen(CreateLLVMCodeGen(Diags, InFile, std::move(VFS), HeaderSearchOpts,
 126                             PPOpts, CodeGenOpts, C, CoverageInfo)),
 127       LinkModules(std::move(LinkModules)) {
 128   TimerIsEnabled = CodeGenOpts.TimePasses;
 129   llvm::TimePassesIsEnabled = CodeGenOpts.TimePasses;
 130   llvm::TimePassesPerRun = CodeGenOpts.TimePassesPerRun;
 131 }
 132
 133 // This constructor is used in installing an empty BackendConsumer
 134 // to use the clang diagnostic handler for IR input files. It avoids
 135 // initializing the OS field.
 136 BackendConsumer::BackendConsumer(
 137     BackendAction Action, DiagnosticsEngine &Diags,
 138     IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
 139     const HeaderSearchOptions &HeaderSearchOpts,
 140     const PreprocessorOptions &PPOpts, const CodeGenOptions &CodeGenOpts,
 141     const TargetOptions &TargetOpts, const LangOptions &LangOpts,
 142     llvm::Module *Module, SmallVector<LinkModule, 4> LinkModules,
 143     LLVMContext &C, CoverageSourceInfo *CoverageInfo)
 144     : Diags(Diags), Action(Action), HeaderSearchOpts(HeaderSearchOpts),
 145       CodeGenOpts(CodeGenOpts), TargetOpts(TargetOpts), LangOpts(LangOpts),
 146       Context(nullptr), FS(VFS),
 147       LLVMIRGeneration("irgen", "LLVM IR Generation Time"),
 148       LLVMIRGenerationRefCount(0),
 149       Gen(CreateLLVMCodeGen(Diags, "", std::move(VFS), HeaderSearchOpts, PPOpts,
 150                             CodeGenOpts, C, CoverageInfo)),
 151       LinkModules(std::move(LinkModules)), CurLinkModule(Module) {
 152   TimerIsEnabled = CodeGenOpts.TimePasses;
 153   llvm::TimePassesIsEnabled = CodeGenOpts.TimePasses;
 154   llvm::TimePassesPerRun = CodeGenOpts.TimePassesPerRun;
 155 }
 156
 157 llvm::Module* BackendConsumer::getModule() const {
 158   return Gen->GetModule();
 159 }
 160
 161 std::unique_ptr<llvm::Module> BackendConsumer::takeModule() {
 162   return std::unique_ptr<llvm::Module>(Gen->ReleaseModule());
 163 }
 164
 165 CodeGenerator* BackendConsumer::getCodeGenerator() {
 166   return Gen.get();
 167 }
 168
 169 void BackendConsumer::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
 170   Gen->HandleCXXStaticMemberVarInstantiation(VD);
 171 }
 172
 173 void BackendConsumer::Initialize(ASTContext &Ctx) {
 174   assert(!Context && "initialized multiple times");
 175
 176   Context = &Ctx;
 177
 178   if (TimerIsEnabled)
 179     LLVMIRGeneration.startTimer();
 180
 181   Gen->Initialize(Ctx);
 182
 183   if (TimerIsEnabled)
 184     LLVMIRGeneration.stopTimer();
 185 }
 186
 187 bool BackendConsumer::HandleTopLevelDecl(DeclGroupRef D) {
 188   PrettyStackTraceDecl CrashInfo(*D.begin(), SourceLocation(),
 189                                  Context->getSourceManager(),
 190                                  "LLVM IR generation of declaration");
 191
 192   // Recurse.
 193   if (TimerIsEnabled) {
 194     LLVMIRGenerationRefCount += 1;
 195     if (LLVMIRGenerationRefCount == 1)
 196       LLVMIRGeneration.startTimer();
 197   }
 198
 199   Gen->HandleTopLevelDecl(D);
 200
 201   if (TimerIsEnabled) {
 202     LLVMIRGenerationRefCount -= 1;
 203     if (LLVMIRGenerationRefCount == 0)
 204       LLVMIRGeneration.stopTimer();
 205   }
 206
 207   return true;
 208 }
 209
 210 void BackendConsumer::HandleInlineFunctionDefinition(FunctionDecl *D) {
 211   PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
 212                                  Context->getSourceManager(),
 213                                  "LLVM IR generation of inline function");
 214   if (TimerIsEnabled)
 215     LLVMIRGeneration.startTimer();
 216
 217   Gen->HandleInlineFunctionDefinition(D);
 218
 219   if (TimerIsEnabled)
 220     LLVMIRGeneration.stopTimer();
 221 }
 222
 223 void BackendConsumer::HandleInterestingDecl(DeclGroupRef D) {
 224   // Ignore interesting decls from the AST reader after IRGen is finished.
 225   if (!IRGenFinished)
 226     HandleTopLevelDecl(D);
 227 }
 228
 229 // Links each entry in LinkModules into our module. Returns true on error.
 230 bool BackendConsumer::LinkInModules(llvm::Module *M) {
 231   for (auto &LM : LinkModules) {
 232     assert(LM.Module && "LinkModule does not actually have a module");
 233
 234     if (LM.PropagateAttrs)
 235       for (Function &F : *LM.Module) {
 236         // Skip intrinsics. Keep consistent with how intrinsics are created
 237         // in LLVM IR.
 238         if (F.isIntrinsic())
 239           continue;
 240         CodeGen::mergeDefaultFunctionDefinitionAttributes(
 241           F, CodeGenOpts, LangOpts, TargetOpts, LM.Internalize);
 242       }
 243
 244     CurLinkModule = LM.Module.get();
 245     bool Err;
 246
 247     if (LM.Internalize) {
 248       Err = Linker::linkModules(
 249           *M, std::move(LM.Module), LM.LinkFlags,
 250           [](llvm::Module &M, const llvm::StringSet<> &GVS) {
 251             internalizeModule(M, [&GVS](const llvm::GlobalValue &GV) {
 252               return !GV.hasName() || (GVS.count(GV.getName()) == 0);
 253             });
 254           });
 255     } else
 256       Err = Linker::linkModules(*M, std::move(LM.Module), LM.LinkFlags);
 257
 258     if (Err)
 259       return true;
 260   }
 261
 262   LinkModules.clear();
 263   return false; // success
 264 }
 265
 266 void BackendConsumer::HandleTranslationUnit(ASTContext &C) {
 267   {
 268     llvm::TimeTraceScope TimeScope("Frontend");
 269     PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
 270     if (TimerIsEnabled) {
 271       LLVMIRGenerationRefCount += 1;
 272       if (LLVMIRGenerationRefCount == 1)
 273         LLVMIRGeneration.startTimer();
 274     }
 275
 276     Gen->HandleTranslationUnit(C);
 277
 278     if (TimerIsEnabled) {
 279       LLVMIRGenerationRefCount -= 1;
 280       if (LLVMIRGenerationRefCount == 0)
 281         LLVMIRGeneration.stopTimer();
 282     }
 283
 284     IRGenFinished = true;
 285   }
 286
 287   // Silently ignore if we weren't initialized for some reason.
 288   if (!getModule())
 289     return;
 290
 291   LLVMContext &Ctx = getModule()->getContext();
 292   std::unique_ptr<DiagnosticHandler> OldDiagnosticHandler =
 293     Ctx.getDiagnosticHandler();
 294   Ctx.setDiagnosticHandler(std::make_unique<ClangDiagnosticHandler>(
 295       CodeGenOpts, this));
 296
 297   Ctx.setDefaultTargetCPU(TargetOpts.CPU);
 298   Ctx.setDefaultTargetFeatures(llvm::join(TargetOpts.Features, ","));
 299
 300   Expected<std::unique_ptr<llvm::ToolOutputFile>> OptRecordFileOrErr =
 301     setupLLVMOptimizationRemarks(
 302       Ctx, CodeGenOpts.OptRecordFile, CodeGenOpts.OptRecordPasses,
 303       CodeGenOpts.OptRecordFormat, CodeGenOpts.DiagnosticsWithHotness,
 304       CodeGenOpts.DiagnosticsHotnessThreshold);
 305
 306   if (Error E = OptRecordFileOrErr.takeError()) {
 307     reportOptRecordError(std::move(E), Diags, CodeGenOpts);
 308     return;
 309   }
 310
 311   std::unique_ptr<llvm::ToolOutputFile> OptRecordFile =
 312     std::move(*OptRecordFileOrErr);
 313
 314   if (OptRecordFile &&
 315       CodeGenOpts.getProfileUse() != CodeGenOptions::ProfileNone)
 316     Ctx.setDiagnosticsHotnessRequested(true);
 317
 318   if (CodeGenOpts.MisExpect) {
 319     Ctx.setMisExpectWarningRequested(true);
 320   }
 321
 322   if (CodeGenOpts.DiagnosticsMisExpectTolerance) {
 323     Ctx.setDiagnosticsMisExpectTolerance(
 324       CodeGenOpts.DiagnosticsMisExpectTolerance);
 325   }
 326
 327   // Link each LinkModule into our module.
 328   if (!CodeGenOpts.LinkBitcodePostopt && LinkInModules(getModule()))
 329     return;
 330
 331   for (auto &F : getModule()->functions()) {
 332     if (const Decl *FD = Gen->GetDeclForMangledName(F.getName())) {
 333       auto Loc = FD->getASTContext().getFullLoc(FD->getLocation());
 334       // TODO: use a fast content hash when available.
 335       auto NameHash = llvm::hash_value(F.getName());
 336       ManglingFullSourceLocs.push_back(std::make_pair(NameHash, Loc));
 337     }
 338   }
 339
 340   if (CodeGenOpts.ClearASTBeforeBackend) {
 341     LLVM_DEBUG(llvm::dbgs() << "Clearing AST...\n");
 342     // Access to the AST is no longer available after this.
 343     // Other things that the ASTContext manages are still available, e.g.
 344     // the SourceManager. It'd be nice if we could separate out all the
 345     // things in ASTContext used after this point and null out the
 346     // ASTContext, but too many various parts of the ASTContext are still
 347     // used in various parts.
 348     C.cleanup();
 349     C.getAllocator().Reset();
 350   }
 351
 352   EmbedBitcode(getModule(), CodeGenOpts, llvm::MemoryBufferRef());
 353
 354   EmitBackendOutput(Diags, HeaderSearchOpts, CodeGenOpts, TargetOpts, LangOpts,
 355                     C.getTargetInfo().getDataLayoutString(), getModule(),
 356                     Action, FS, std::move(AsmOutStream), this);
 357
 358   Ctx.setDiagnosticHandler(std::move(OldDiagnosticHandler));
 359
 360   if (OptRecordFile)
 361     OptRecordFile->keep();
 362 }
 363
 364 void BackendConsumer::HandleTagDeclDefinition(TagDecl *D) {
 365   PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
 366                                  Context->getSourceManager(),
 367                                  "LLVM IR generation of declaration");
 368   Gen->HandleTagDeclDefinition(D);
 369 }
 370
 371 void BackendConsumer::HandleTagDeclRequiredDefinition(const TagDecl *D) {
 372   Gen->HandleTagDeclRequiredDefinition(D);
 373 }
 374
 375 void BackendConsumer::CompleteTentativeDefinition(VarDecl *D) {
 376   Gen->CompleteTentativeDefinition(D);
 377 }
 378
 379 void BackendConsumer::CompleteExternalDeclaration(DeclaratorDecl *D) {
 380   Gen->CompleteExternalDeclaration(D);
 381 }
 382
 383 void BackendConsumer::AssignInheritanceModel(CXXRecordDecl *RD) {
 384   Gen->AssignInheritanceModel(RD);
 385 }
 386
 387 void BackendConsumer::HandleVTable(CXXRecordDecl *RD) {
 388   Gen->HandleVTable(RD);
 389 }
 390
 391 void BackendConsumer::anchor() { }
 392
 393 } // namespace clang
 394
 395 bool ClangDiagnosticHandler::handleDiagnostics(const DiagnosticInfo &DI) {
 396   BackendCon->DiagnosticHandlerImpl(DI);
 397   return true;
 398 }
 399
 400 /// ConvertBackendLocation - Convert a location in a temporary llvm::SourceMgr
 401 /// buffer to be a valid FullSourceLoc.
 402 static FullSourceLoc ConvertBackendLocation(const llvm::SMDiagnostic &D,
 403                                             SourceManager &CSM) {
 404   // Get both the clang and llvm source managers.  The location is relative to
 405   // a memory buffer that the LLVM Source Manager is handling, we need to add
 406   // a copy to the Clang source manager.
 407   const llvm::SourceMgr &LSM = *D.getSourceMgr();
 408
 409   // We need to copy the underlying LLVM memory buffer because llvm::SourceMgr
 410   // already owns its one and clang::SourceManager wants to own its one.
 411   const MemoryBuffer *LBuf =
 412   LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
 413
 414   // Create the copy and transfer ownership to clang::SourceManager.
 415   // TODO: Avoid copying files into memory.
 416   std::unique_ptr<llvm::MemoryBuffer> CBuf =
 417       llvm::MemoryBuffer::getMemBufferCopy(LBuf->getBuffer(),
 418                                            LBuf->getBufferIdentifier());
 419   // FIXME: Keep a file ID map instead of creating new IDs for each location.
 420   FileID FID = CSM.createFileID(std::move(CBuf));
 421
 422   // Translate the offset into the file.
 423   unsigned Offset = D.getLoc().getPointer() - LBuf->getBufferStart();
 424   SourceLocation NewLoc =
 425   CSM.getLocForStartOfFile(FID).getLocWithOffset(Offset);
 426   return FullSourceLoc(NewLoc, CSM);
 427 }
 428
 429 #define ComputeDiagID(Severity, GroupName, DiagID)                             \
 430   do {                                                                         \
 431     switch (Severity) {                                                        \
 432     case llvm::DS_Error:                                                       \
 433       DiagID = diag::err_fe_##GroupName;                                       \
 434       break;                                                                   \
 435     case llvm::DS_Warning:                                                     \
 436       DiagID = diag::warn_fe_##GroupName;                                      \
 437       break;                                                                   \
 438     case llvm::DS_Remark:                                                      \
 439       llvm_unreachable("'remark' severity not expected");                      \
 440       break;                                                                   \
 441     case llvm::DS_Note:                                                        \
 442       DiagID = diag::note_fe_##GroupName;                                      \
 443       break;                                                                   \
 444     }                                                                          \
 445   } while (false)
 446
 447 #define ComputeDiagRemarkID(Severity, GroupName, DiagID)                       \
 448   do {                                                                         \
 449     switch (Severity) {                                                        \
 450     case llvm::DS_Error:                                                       \
 451       DiagID = diag::err_fe_##GroupName;                                       \
 452       break;                                                                   \
 453     case llvm::DS_Warning:                                                     \
 454       DiagID = diag::warn_fe_##GroupName;                                      \
 455       break;                                                                   \
 456     case llvm::DS_Remark:                                                      \
 457       DiagID = diag::remark_fe_##GroupName;                                    \
 458       break;                                                                   \
 459     case llvm::DS_Note:                                                        \
 460       DiagID = diag::note_fe_##GroupName;                                      \
 461       break;                                                                   \
 462     }                                                                          \
 463   } while (false)
 464
 465 void BackendConsumer::SrcMgrDiagHandler(const llvm::DiagnosticInfoSrcMgr &DI) {
 466   const llvm::SMDiagnostic &D = DI.getSMDiag();
 467
 468   unsigned DiagID;
 469   if (DI.isInlineAsmDiag())
 470     ComputeDiagID(DI.getSeverity(), inline_asm, DiagID);
 471   else
 472     ComputeDiagID(DI.getSeverity(), source_mgr, DiagID);
 473
 474   // This is for the empty BackendConsumer that uses the clang diagnostic
 475   // handler for IR input files.
 476   if (!Context) {
 477     D.print(nullptr, llvm::errs());
 478     Diags.Report(DiagID).AddString("cannot compile inline asm");
 479     return;
 480   }
 481
 482   // There are a couple of different kinds of errors we could get here.
 483   // First, we re-format the SMDiagnostic in terms of a clang diagnostic.
 484
 485   // Strip "error: " off the start of the message string.
 486   StringRef Message = D.getMessage();
 487   (void)Message.consume_front("error: ");
 488
 489   // If the SMDiagnostic has an inline asm source location, translate it.
 490   FullSourceLoc Loc;
 491   if (D.getLoc() != SMLoc())
 492     Loc = ConvertBackendLocation(D, Context->getSourceManager());
 493
 494   // If this problem has clang-level source location information, report the
 495   // issue in the source with a note showing the instantiated
 496   // code.
 497   if (DI.isInlineAsmDiag()) {
 498     SourceLocation LocCookie =
 499         SourceLocation::getFromRawEncoding(DI.getLocCookie());
 500     if (LocCookie.isValid()) {
 501       Diags.Report(LocCookie, DiagID).AddString(Message);
 502
 503       if (D.getLoc().isValid()) {
 504         DiagnosticBuilder B = Diags.Report(Loc, diag::note_fe_inline_asm_here);
 505         // Convert the SMDiagnostic ranges into SourceRange and attach them
 506         // to the diagnostic.
 507         for (const std::pair<unsigned, unsigned> &Range : D.getRanges()) {
 508           unsigned Column = D.getColumnNo();
 509           B << SourceRange(Loc.getLocWithOffset(Range.first - Column),
 510                            Loc.getLocWithOffset(Range.second - Column));
 511         }
 512       }
 513       return;
 514     }
 515   }
 516
 517   // Otherwise, report the backend issue as occurring in the generated .s file.
 518   // If Loc is invalid, we still need to report the issue, it just gets no
 519   // location info.
 520   Diags.Report(Loc, DiagID).AddString(Message);
 521 }
 522
 523 bool
 524 BackendConsumer::InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D) {
 525   unsigned DiagID;
 526   ComputeDiagID(D.getSeverity(), inline_asm, DiagID);
 527   std::string Message = D.getMsgStr().str();
 528
 529   // If this problem has clang-level source location information, report the
 530   // issue as being a problem in the source with a note showing the instantiated
 531   // code.
 532   SourceLocation LocCookie =
 533       SourceLocation::getFromRawEncoding(D.getLocCookie());
 534   if (LocCookie.isValid())
 535     Diags.Report(LocCookie, DiagID).AddString(Message);
 536   else {
 537     // Otherwise, report the backend diagnostic as occurring in the generated
 538     // .s file.
 539     // If Loc is invalid, we still need to report the diagnostic, it just gets
 540     // no location info.
 541     FullSourceLoc Loc;
 542     Diags.Report(Loc, DiagID).AddString(Message);
 543   }
 544   // We handled all the possible severities.
 545   return true;
 546 }
 547
 548 bool
 549 BackendConsumer::StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D) {
 550   if (D.getSeverity() != llvm::DS_Warning)
 551     // For now, the only support we have for StackSize diagnostic is warning.
 552     // We do not know how to format other severities.
 553     return false;
 554
 555   auto Loc = getFunctionSourceLocation(D.getFunction());
 556   if (!Loc)
 557     return false;
 558
 559   Diags.Report(*Loc, diag::warn_fe_frame_larger_than)
 560       << D.getStackSize() << D.getStackLimit()
 561       << llvm::demangle(D.getFunction().getName());
 562   return true;
 563 }
 564
 565 bool BackendConsumer::ResourceLimitDiagHandler(
 566     const llvm::DiagnosticInfoResourceLimit &D) {
 567   auto Loc = getFunctionSourceLocation(D.getFunction());
 568   if (!Loc)
 569     return false;
 570   unsigned DiagID = diag::err_fe_backend_resource_limit;
 571   ComputeDiagID(D.getSeverity(), backend_resource_limit, DiagID);
 572
 573   Diags.Report(*Loc, DiagID)
 574       << D.getResourceName() << D.getResourceSize() << D.getResourceLimit()
 575       << llvm::demangle(D.getFunction().getName());
 576   return true;
 577 }
 578
 579 const FullSourceLoc BackendConsumer::getBestLocationFromDebugLoc(
 580     const llvm::DiagnosticInfoWithLocationBase &D, bool &BadDebugInfo,
 581     StringRef &Filename, unsigned &Line, unsigned &Column) const {
 582   SourceManager &SourceMgr = Context->getSourceManager();
 583   FileManager &FileMgr = SourceMgr.getFileManager();
 584   SourceLocation DILoc;
 585
 586   if (D.isLocationAvailable()) {
 587     D.getLocation(Filename, Line, Column);
 588     if (Line > 0) {
 589       auto FE = FileMgr.getFile(Filename);
 590       if (!FE)
 591         FE = FileMgr.getFile(D.getAbsolutePath());
 592       if (FE) {
 593         // If -gcolumn-info was not used, Column will be 0. This upsets the
 594         // source manager, so pass 1 if Column is not set.
 595         DILoc = SourceMgr.translateFileLineCol(*FE, Line, Column ? Column : 1);
 596       }
 597     }
 598     BadDebugInfo = DILoc.isInvalid();
 599   }
 600
 601   // If a location isn't available, try to approximate it using the associated
 602   // function definition. We use the definition's right brace to differentiate
 603   // from diagnostics that genuinely relate to the function itself.
 604   FullSourceLoc Loc(DILoc, SourceMgr);
 605   if (Loc.isInvalid()) {
 606     if (auto MaybeLoc = getFunctionSourceLocation(D.getFunction()))
 607       Loc = *MaybeLoc;
 608   }
 609
 610   if (DILoc.isInvalid() && D.isLocationAvailable())
 611     // If we were not able to translate the file:line:col information
 612     // back to a SourceLocation, at least emit a note stating that
 613     // we could not translate this location. This can happen in the
 614     // case of #line directives.
 615     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
 616         << Filename << Line << Column;
 617
 618   return Loc;
 619 }
 620
 621 std::optional<FullSourceLoc>
 622 BackendConsumer::getFunctionSourceLocation(const Function &F) const {
 623   auto Hash = llvm::hash_value(F.getName());
 624   for (const auto &Pair : ManglingFullSourceLocs) {
 625     if (Pair.first == Hash)
 626       return Pair.second;
 627   }
 628   return std::nullopt;
 629 }
 630
 631 void BackendConsumer::UnsupportedDiagHandler(
 632     const llvm::DiagnosticInfoUnsupported &D) {
 633   // We only support warnings or errors.
 634   assert(D.getSeverity() == llvm::DS_Error ||
 635          D.getSeverity() == llvm::DS_Warning);
 636
 637   StringRef Filename;
 638   unsigned Line, Column;
 639   bool BadDebugInfo = false;
 640   FullSourceLoc Loc;
 641   std::string Msg;
 642   raw_string_ostream MsgStream(Msg);
 643
 644   // Context will be nullptr for IR input files, we will construct the diag
 645   // message from llvm::DiagnosticInfoUnsupported.
 646   if (Context != nullptr) {
 647     Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
 648     MsgStream << D.getMessage();
 649   } else {
 650     DiagnosticPrinterRawOStream DP(MsgStream);
 651     D.print(DP);
 652   }
 653
 654   auto DiagType = D.getSeverity() == llvm::DS_Error
 655                       ? diag::err_fe_backend_unsupported
 656                       : diag::warn_fe_backend_unsupported;
 657   Diags.Report(Loc, DiagType) << MsgStream.str();
 658
 659   if (BadDebugInfo)
 660     // If we were not able to translate the file:line:col information
 661     // back to a SourceLocation, at least emit a note stating that
 662     // we could not translate this location. This can happen in the
 663     // case of #line directives.
 664     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
 665         << Filename << Line << Column;
 666 }
 667
 668 void BackendConsumer::EmitOptimizationMessage(
 669     const llvm::DiagnosticInfoOptimizationBase &D, unsigned DiagID) {
 670   // We only support warnings and remarks.
 671   assert(D.getSeverity() == llvm::DS_Remark ||
 672          D.getSeverity() == llvm::DS_Warning);
 673
 674   StringRef Filename;
 675   unsigned Line, Column;
 676   bool BadDebugInfo = false;
 677   FullSourceLoc Loc;
 678   std::string Msg;
 679   raw_string_ostream MsgStream(Msg);
 680
 681   // Context will be nullptr for IR input files, we will construct the remark
 682   // message from llvm::DiagnosticInfoOptimizationBase.
 683   if (Context != nullptr) {
 684     Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
 685     MsgStream << D.getMsg();
 686   } else {
 687     DiagnosticPrinterRawOStream DP(MsgStream);
 688     D.print(DP);
 689   }
 690
 691   if (D.getHotness())
 692     MsgStream << " (hotness: " << *D.getHotness() << ")";
 693
 694   Diags.Report(Loc, DiagID)
 695       << AddFlagValue(D.getPassName())
 696       << MsgStream.str();
 697
 698   if (BadDebugInfo)
 699     // If we were not able to translate the file:line:col information
 700     // back to a SourceLocation, at least emit a note stating that
 701     // we could not translate this location. This can happen in the
 702     // case of #line directives.
 703     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
 704         << Filename << Line << Column;
 705 }
 706
 707 void BackendConsumer::OptimizationRemarkHandler(
 708     const llvm::DiagnosticInfoOptimizationBase &D) {
 709   // Without hotness information, don't show noisy remarks.
 710   if (D.isVerbose() && !D.getHotness())
 711     return;
 712
 713   if (D.isPassed()) {
 714     // Optimization remarks are active only if the -Rpass flag has a regular
 715     // expression that matches the name of the pass name in \p D.
 716     if (CodeGenOpts.OptimizationRemark.patternMatches(D.getPassName()))
 717       EmitOptimizationMessage(D, diag::remark_fe_backend_optimization_remark);
 718   } else if (D.isMissed()) {
 719     // Missed optimization remarks are active only if the -Rpass-missed
 720     // flag has a regular expression that matches the name of the pass
 721     // name in \p D.
 722     if (CodeGenOpts.OptimizationRemarkMissed.patternMatches(D.getPassName()))
 723       EmitOptimizationMessage(
 724           D, diag::remark_fe_backend_optimization_remark_missed);
 725   } else {
 726     assert(D.isAnalysis() && "Unknown remark type");
 727
 728     bool ShouldAlwaysPrint = false;
 729     if (auto *ORA = dyn_cast<llvm::OptimizationRemarkAnalysis>(&D))
 730       ShouldAlwaysPrint = ORA->shouldAlwaysPrint();
 731
 732     if (ShouldAlwaysPrint ||
 733         CodeGenOpts.OptimizationRemarkAnalysis.patternMatches(D.getPassName()))
 734       EmitOptimizationMessage(
 735           D, diag::remark_fe_backend_optimization_remark_analysis);
 736   }
 737 }
 738
 739 void BackendConsumer::OptimizationRemarkHandler(
 740     const llvm::OptimizationRemarkAnalysisFPCommute &D) {
 741   // Optimization analysis remarks are active if the pass name is set to
 742   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
 743   // regular expression that matches the name of the pass name in \p D.
 744
 745   if (D.shouldAlwaysPrint() ||
 746       CodeGenOpts.OptimizationRemarkAnalysis.patternMatches(D.getPassName()))
 747     EmitOptimizationMessage(
 748         D, diag::remark_fe_backend_optimization_remark_analysis_fpcommute);
 749 }
 750
 751 void BackendConsumer::OptimizationRemarkHandler(
 752     const llvm::OptimizationRemarkAnalysisAliasing &D) {
 753   // Optimization analysis remarks are active if the pass name is set to
 754   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
 755   // regular expression that matches the name of the pass name in \p D.
 756
 757   if (D.shouldAlwaysPrint() ||
 758       CodeGenOpts.OptimizationRemarkAnalysis.patternMatches(D.getPassName()))
 759     EmitOptimizationMessage(
 760         D, diag::remark_fe_backend_optimization_remark_analysis_aliasing);
 761 }
 762
 763 void BackendConsumer::OptimizationFailureHandler(
 764     const llvm::DiagnosticInfoOptimizationFailure &D) {
 765   EmitOptimizationMessage(D, diag::warn_fe_backend_optimization_failure);
 766 }
 767
 768 void BackendConsumer::DontCallDiagHandler(const DiagnosticInfoDontCall &D) {
 769   SourceLocation LocCookie =
 770       SourceLocation::getFromRawEncoding(D.getLocCookie());
 771
 772   // FIXME: we can't yet diagnose indirect calls. When/if we can, we
 773   // should instead assert that LocCookie.isValid().
 774   if (!LocCookie.isValid())
 775     return;
 776
 777   Diags.Report(LocCookie, D.getSeverity() == DiagnosticSeverity::DS_Error
 778                               ? diag::err_fe_backend_error_attr
 779                               : diag::warn_fe_backend_warning_attr)
 780       << llvm::demangle(D.getFunctionName()) << D.getNote();
 781 }
 782
 783 void BackendConsumer::MisExpectDiagHandler(
 784     const llvm::DiagnosticInfoMisExpect &D) {
 785   StringRef Filename;
 786   unsigned Line, Column;
 787   bool BadDebugInfo = false;
 788   FullSourceLoc Loc =
 789       getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
 790
 791   Diags.Report(Loc, diag::warn_profile_data_misexpect) << D.getMsg().str();
 792
 793   if (BadDebugInfo)
 794     // If we were not able to translate the file:line:col information
 795     // back to a SourceLocation, at least emit a note stating that
 796     // we could not translate this location. This can happen in the
 797     // case of #line directives.
 798     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
 799         << Filename << Line << Column;
 800 }
 801
 802 /// This function is invoked when the backend needs
 803 /// to report something to the user.
 804 void BackendConsumer::DiagnosticHandlerImpl(const DiagnosticInfo &DI) {
 805   unsigned DiagID = diag::err_fe_inline_asm;
 806   llvm::DiagnosticSeverity Severity = DI.getSeverity();
 807   // Get the diagnostic ID based.
 808   switch (DI.getKind()) {
 809   case llvm::DK_InlineAsm:
 810     if (InlineAsmDiagHandler(cast<DiagnosticInfoInlineAsm>(DI)))
 811       return;
 812     ComputeDiagID(Severity, inline_asm, DiagID);
 813     break;
 814   case llvm::DK_SrcMgr:
 815     SrcMgrDiagHandler(cast<DiagnosticInfoSrcMgr>(DI));
 816     return;
 817   case llvm::DK_StackSize:
 818     if (StackSizeDiagHandler(cast<DiagnosticInfoStackSize>(DI)))
 819       return;
 820     ComputeDiagID(Severity, backend_frame_larger_than, DiagID);
 821     break;
 822   case llvm::DK_ResourceLimit:
 823     if (ResourceLimitDiagHandler(cast<DiagnosticInfoResourceLimit>(DI)))
 824       return;
 825     ComputeDiagID(Severity, backend_resource_limit, DiagID);
 826     break;
 827   case DK_Linker:
 828     ComputeDiagID(Severity, linking_module, DiagID);
 829     break;
 830   case llvm::DK_OptimizationRemark:
 831     // Optimization remarks are always handled completely by this
 832     // handler. There is no generic way of emitting them.
 833     OptimizationRemarkHandler(cast<OptimizationRemark>(DI));
 834     return;
 835   case llvm::DK_OptimizationRemarkMissed:
 836     // Optimization remarks are always handled completely by this
 837     // handler. There is no generic way of emitting them.
 838     OptimizationRemarkHandler(cast<OptimizationRemarkMissed>(DI));
 839     return;
 840   case llvm::DK_OptimizationRemarkAnalysis:
 841     // Optimization remarks are always handled completely by this
 842     // handler. There is no generic way of emitting them.
 843     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysis>(DI));
 844     return;
 845   case llvm::DK_OptimizationRemarkAnalysisFPCommute:
 846     // Optimization remarks are always handled completely by this
 847     // handler. There is no generic way of emitting them.
 848     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysisFPCommute>(DI));
 849     return;
 850   case llvm::DK_OptimizationRemarkAnalysisAliasing:
 851     // Optimization remarks are always handled completely by this
 852     // handler. There is no generic way of emitting them.
 853     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysisAliasing>(DI));
 854     return;
 855   case llvm::DK_MachineOptimizationRemark:
 856     // Optimization remarks are always handled completely by this
 857     // handler. There is no generic way of emitting them.
 858     OptimizationRemarkHandler(cast<MachineOptimizationRemark>(DI));
 859     return;
 860   case llvm::DK_MachineOptimizationRemarkMissed:
 861     // Optimization remarks are always handled completely by this
 862     // handler. There is no generic way of emitting them.
 863     OptimizationRemarkHandler(cast<MachineOptimizationRemarkMissed>(DI));
 864     return;
 865   case llvm::DK_MachineOptimizationRemarkAnalysis:
 866     // Optimization remarks are always handled completely by this
 867     // handler. There is no generic way of emitting them.
 868     OptimizationRemarkHandler(cast<MachineOptimizationRemarkAnalysis>(DI));
 869     return;
 870   case llvm::DK_OptimizationFailure:
 871     // Optimization failures are always handled completely by this
 872     // handler.
 873     OptimizationFailureHandler(cast<DiagnosticInfoOptimizationFailure>(DI));
 874     return;
 875   case llvm::DK_Unsupported:
 876     UnsupportedDiagHandler(cast<DiagnosticInfoUnsupported>(DI));
 877     return;
 878   case llvm::DK_DontCall:
 879     DontCallDiagHandler(cast<DiagnosticInfoDontCall>(DI));
 880     return;
 881   case llvm::DK_MisExpect:
 882     MisExpectDiagHandler(cast<DiagnosticInfoMisExpect>(DI));
 883     return;
 884   default:
 885     // Plugin IDs are not bound to any value as they are set dynamically.
 886     ComputeDiagRemarkID(Severity, backend_plugin, DiagID);
 887     break;
 888   }
 889   std::string MsgStorage;
 890   {
 891     raw_string_ostream Stream(MsgStorage);
 892     DiagnosticPrinterRawOStream DP(Stream);
 893     DI.print(DP);
 894   }
 895
 896   if (DI.getKind() == DK_Linker) {
 897     assert(CurLinkModule && "CurLinkModule must be set for linker diagnostics");
 898     Diags.Report(DiagID) << CurLinkModule->getModuleIdentifier() << MsgStorage;
 899     return;
 900   }
 901
 902   // Report the backend message using the usual diagnostic mechanism.
 903   FullSourceLoc Loc;
 904   Diags.Report(Loc, DiagID).AddString(MsgStorage);
 905 }
 906 #undef ComputeDiagID
 907
 908 CodeGenAction::CodeGenAction(unsigned _Act, LLVMContext *_VMContext)
 909     : Act(_Act), VMContext(_VMContext ? _VMContext : new LLVMContext),
 910       OwnsVMContext(!_VMContext) {}
 911
 912 CodeGenAction::~CodeGenAction() {
 913   TheModule.reset();
 914   if (OwnsVMContext)
 915     delete VMContext;
 916 }
 917
 918 bool CodeGenAction::loadLinkModules(CompilerInstance &CI) {
 919   if (!LinkModules.empty())
 920     return false;
 921
 922   for (const CodeGenOptions::BitcodeFileToLink &F :
 923        CI.getCodeGenOpts().LinkBitcodeFiles) {
 924     auto BCBuf = CI.getFileManager().getBufferForFile(F.Filename);
 925     if (!BCBuf) {
 926       CI.getDiagnostics().Report(diag::err_cannot_open_file)
 927           << F.Filename << BCBuf.getError().message();
 928       LinkModules.clear();
 929       return true;
 930     }
 931
 932     Expected<std::unique_ptr<llvm::Module>> ModuleOrErr =
 933         getOwningLazyBitcodeModule(std::move(*BCBuf), *VMContext);
 934     if (!ModuleOrErr) {
 935       handleAllErrors(ModuleOrErr.takeError(), [&](ErrorInfoBase &EIB) {
 936         CI.getDiagnostics().Report(diag::err_cannot_open_file)
 937             << F.Filename << EIB.message();
 938       });
 939       LinkModules.clear();
 940       return true;
 941     }
 942     LinkModules.push_back({std::move(ModuleOrErr.get()), F.PropagateAttrs,
 943                            F.Internalize, F.LinkFlags});
 944   }
 945   return false;
 946 }
 947
 948 bool CodeGenAction::hasIRSupport() const { return true; }
 949
 950 void CodeGenAction::EndSourceFileAction() {
 951   // If the consumer creation failed, do nothing.
 952   if (!getCompilerInstance().hasASTConsumer())
 953     return;
 954
 955   // Steal the module from the consumer.
 956   TheModule = BEConsumer->takeModule();
 957 }
 958
 959 std::unique_ptr<llvm::Module> CodeGenAction::takeModule() {
 960   return std::move(TheModule);
 961 }
 962
 963 llvm::LLVMContext *CodeGenAction::takeLLVMContext() {
 964   OwnsVMContext = false;
 965   return VMContext;
 966 }
 967
 968 CodeGenerator *CodeGenAction::getCodeGenerator() const {
 969   return BEConsumer->getCodeGenerator();
 970 }
 971
 972 bool CodeGenAction::BeginSourceFileAction(CompilerInstance &CI) {
 973   if (CI.getFrontendOpts().GenReducedBMI)
 974     CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleInterface);
 975   return true;
 976 }
 977
 978 static std::unique_ptr<raw_pwrite_stream>
 979 GetOutputStream(CompilerInstance &CI, StringRef InFile, BackendAction Action) {
 980   switch (Action) {
 981   case Backend_EmitAssembly:
 982     return CI.createDefaultOutputFile(false, InFile, "s");
 983   case Backend_EmitLL:
 984     return CI.createDefaultOutputFile(false, InFile, "ll");
 985   case Backend_EmitBC:
 986     return CI.createDefaultOutputFile(true, InFile, "bc");
 987   case Backend_EmitNothing:
 988     return nullptr;
 989   case Backend_EmitMCNull:
 990     return CI.createNullOutputFile();
 991   case Backend_EmitObj:
 992     return CI.createDefaultOutputFile(true, InFile, "o");
 993   }
 994
 995   llvm_unreachable("Invalid action!");
 996 }
 997
 998 std::unique_ptr<ASTConsumer>
 999 CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
1000   BackendAction BA = static_cast<BackendAction>(Act);
1001   std::unique_ptr<raw_pwrite_stream> OS = CI.takeOutputStream();
1002   if (!OS)
1003     OS = GetOutputStream(CI, InFile, BA);
1004
1005   if (BA != Backend_EmitNothing && !OS)
1006     return nullptr;
1007
1008   // Load bitcode modules to link with, if we need to.
1009   if (loadLinkModules(CI))
1010     return nullptr;
1011
1012   CoverageSourceInfo *CoverageInfo = nullptr;
1013   // Add the preprocessor callback only when the coverage mapping is generated.
1014   if (CI.getCodeGenOpts().CoverageMapping)
1015     CoverageInfo = CodeGen::CoverageMappingModuleGen::setUpCoverageCallbacks(
1016         CI.getPreprocessor());
1017
1018   std::unique_ptr<BackendConsumer> Result(new BackendConsumer(
1019       BA, CI.getDiagnostics(), &CI.getVirtualFileSystem(),
1020       CI.getHeaderSearchOpts(), CI.getPreprocessorOpts(), CI.getCodeGenOpts(),
1021       CI.getTargetOpts(), CI.getLangOpts(), std::string(InFile),
1022       std::move(LinkModules), std::move(OS), *VMContext, CoverageInfo));
1023   BEConsumer = Result.get();
1024
1025   // Enable generating macro debug info only when debug info is not disabled and
1026   // also macro debug info is enabled.
1027   if (CI.getCodeGenOpts().getDebugInfo() != codegenoptions::NoDebugInfo &&
1028       CI.getCodeGenOpts().MacroDebugInfo) {
1029     std::unique_ptr<PPCallbacks> Callbacks =
1030         std::make_unique<MacroPPCallbacks>(BEConsumer->getCodeGenerator(),
1031                                             CI.getPreprocessor());
1032     CI.getPreprocessor().addPPCallbacks(std::move(Callbacks));
1033   }
1034
1035   if (CI.getFrontendOpts().GenReducedBMI &&
1036       !CI.getFrontendOpts().ModuleOutputPath.empty()) {
1037     std::vector<std::unique_ptr<ASTConsumer>> Consumers(2);
1038     Consumers[0] = std::make_unique<ReducedBMIGenerator>(
1039         CI.getPreprocessor(), CI.getModuleCache(),
1040         CI.getFrontendOpts().ModuleOutputPath);
1041     Consumers[1] = std::move(Result);
1042     return std::make_unique<MultiplexConsumer>(std::move(Consumers));
1043   }
1044
1045   return std::move(Result);
1046 }
1047
1048 std::unique_ptr<llvm::Module>
1049 CodeGenAction::loadModule(MemoryBufferRef MBRef) {
1050   CompilerInstance &CI = getCompilerInstance();
1051   SourceManager &SM = CI.getSourceManager();
1052
1053   auto DiagErrors = [&](Error E) -> std::unique_ptr<llvm::Module> {
1054     unsigned DiagID =
1055         CI.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1056     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1057       CI.getDiagnostics().Report(DiagID) << EIB.message();
1058     });
1059     return {};
1060   };
1061
1062   // For ThinLTO backend invocations, ensure that the context
1063   // merges types based on ODR identifiers. We also need to read
1064   // the correct module out of a multi-module bitcode file.
1065   if (!CI.getCodeGenOpts().ThinLTOIndexFile.empty()) {
1066     VMContext->enableDebugTypeODRUniquing();
1067
1068     Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
1069     if (!BMsOrErr)
1070       return DiagErrors(BMsOrErr.takeError());
1071     BitcodeModule *Bm = llvm::lto::findThinLTOModule(*BMsOrErr);
1072     // We have nothing to do if the file contains no ThinLTO module. This is
1073     // possible if ThinLTO compilation was not able to split module. Content of
1074     // the file was already processed by indexing and will be passed to the
1075     // linker using merged object file.
1076     if (!Bm) {
1077       auto M = std::make_unique<llvm::Module>("empty", *VMContext);
1078       M->setTargetTriple(CI.getTargetOpts().Triple);
1079       return M;
1080     }
1081     Expected<std::unique_ptr<llvm::Module>> MOrErr =
1082         Bm->parseModule(*VMContext);
1083     if (!MOrErr)
1084       return DiagErrors(MOrErr.takeError());
1085     return std::move(*MOrErr);
1086   }
1087
1088   // Load bitcode modules to link with, if we need to.
1089   if (loadLinkModules(CI))
1090     return nullptr;
1091
1092   // Handle textual IR and bitcode file with one single module.
1093   llvm::SMDiagnostic Err;
1094   if (std::unique_ptr<llvm::Module> M = parseIR(MBRef, Err, *VMContext))
1095     return M;
1096
1097   // If MBRef is a bitcode with multiple modules (e.g., -fsplit-lto-unit
1098   // output), place the extra modules (actually only one, a regular LTO module)
1099   // into LinkModules as if we are using -mlink-bitcode-file.
1100   Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
1101   if (BMsOrErr && BMsOrErr->size()) {
1102     std::unique_ptr<llvm::Module> FirstM;
1103     for (auto &BM : *BMsOrErr) {
1104       Expected<std::unique_ptr<llvm::Module>> MOrErr =
1105           BM.parseModule(*VMContext);
1106       if (!MOrErr)
1107         return DiagErrors(MOrErr.takeError());
1108       if (FirstM)
1109         LinkModules.push_back({std::move(*MOrErr), /*PropagateAttrs=*/false,
1110                                /*Internalize=*/false, /*LinkFlags=*/{}});
1111       else
1112         FirstM = std::move(*MOrErr);
1113     }
1114     if (FirstM)
1115       return FirstM;
1116   }
1117   // If BMsOrErr fails, consume the error and use the error message from
1118   // parseIR.
1119   consumeError(BMsOrErr.takeError());
1120
1121   // Translate from the diagnostic info to the SourceManager location if
1122   // available.
1123   // TODO: Unify this with ConvertBackendLocation()
1124   SourceLocation Loc;
1125   if (Err.getLineNo() > 0) {
1126     assert(Err.getColumnNo() >= 0);
1127     Loc = SM.translateFileLineCol(SM.getFileEntryForID(SM.getMainFileID()),
1128                                   Err.getLineNo(), Err.getColumnNo() + 1);
1129   }
1130
1131   // Strip off a leading diagnostic code if there is one.
1132   StringRef Msg = Err.getMessage();
1133   Msg.consume_front("error: ");
1134
1135   unsigned DiagID =
1136       CI.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1137
1138   CI.getDiagnostics().Report(Loc, DiagID) << Msg;
1139   return {};
1140 }
1141
1142 void CodeGenAction::ExecuteAction() {
1143   if (getCurrentFileKind().getLanguage() != Language::LLVM_IR) {
1144     this->ASTFrontendAction::ExecuteAction();
1145     return;
1146   }
1147
1148   // If this is an IR file, we have to treat it specially.
1149   BackendAction BA = static_cast<BackendAction>(Act);
1150   CompilerInstance &CI = getCompilerInstance();
1151   auto &CodeGenOpts = CI.getCodeGenOpts();
1152   auto &Diagnostics = CI.getDiagnostics();
1153   std::unique_ptr<raw_pwrite_stream> OS =
1154       GetOutputStream(CI, getCurrentFileOrBufferName(), BA);
1155   if (BA != Backend_EmitNothing && !OS)
1156     return;
1157
1158   SourceManager &SM = CI.getSourceManager();
1159   FileID FID = SM.getMainFileID();
1160   std::optional<MemoryBufferRef> MainFile = SM.getBufferOrNone(FID);
1161   if (!MainFile)
1162     return;
1163
1164   TheModule = loadModule(*MainFile);
1165   if (!TheModule)
1166     return;
1167
1168   const TargetOptions &TargetOpts = CI.getTargetOpts();
1169   if (TheModule->getTargetTriple() != TargetOpts.Triple) {
1170     Diagnostics.Report(SourceLocation(), diag::warn_fe_override_module)
1171         << TargetOpts.Triple;
1172     TheModule->setTargetTriple(TargetOpts.Triple);
1173   }
1174
1175   EmbedObject(TheModule.get(), CodeGenOpts, Diagnostics);
1176   EmbedBitcode(TheModule.get(), CodeGenOpts, *MainFile);
1177
1178   LLVMContext &Ctx = TheModule->getContext();
1179
1180   // Restore any diagnostic handler previously set before returning from this
1181   // function.
1182   struct RAII {
1183     LLVMContext &Ctx;
1184     std::unique_ptr<DiagnosticHandler> PrevHandler = Ctx.getDiagnosticHandler();
1185     ~RAII() { Ctx.setDiagnosticHandler(std::move(PrevHandler)); }
1186   } _{Ctx};
1187
1188   // Set clang diagnostic handler. To do this we need to create a fake
1189   // BackendConsumer.
1190   BackendConsumer Result(BA, CI.getDiagnostics(), &CI.getVirtualFileSystem(),
1191                          CI.getHeaderSearchOpts(), CI.getPreprocessorOpts(),
1192                          CI.getCodeGenOpts(), CI.getTargetOpts(),
1193                          CI.getLangOpts(), TheModule.get(),
1194                          std::move(LinkModules), *VMContext, nullptr);
1195
1196   // Link in each pending link module.
1197   if (!CodeGenOpts.LinkBitcodePostopt && Result.LinkInModules(&*TheModule))
1198     return;
1199
1200   // PR44896: Force DiscardValueNames as false. DiscardValueNames cannot be
1201   // true here because the valued names are needed for reading textual IR.
1202   Ctx.setDiscardValueNames(false);
1203   Ctx.setDiagnosticHandler(
1204       std::make_unique<ClangDiagnosticHandler>(CodeGenOpts, &Result));
1205
1206   Ctx.setDefaultTargetCPU(TargetOpts.CPU);
1207   Ctx.setDefaultTargetFeatures(llvm::join(TargetOpts.Features, ","));
1208
1209   Expected<std::unique_ptr<llvm::ToolOutputFile>> OptRecordFileOrErr =
1210       setupLLVMOptimizationRemarks(
1211           Ctx, CodeGenOpts.OptRecordFile, CodeGenOpts.OptRecordPasses,
1212           CodeGenOpts.OptRecordFormat, CodeGenOpts.DiagnosticsWithHotness,
1213           CodeGenOpts.DiagnosticsHotnessThreshold);
1214
1215   if (Error E = OptRecordFileOrErr.takeError()) {
1216     reportOptRecordError(std::move(E), Diagnostics, CodeGenOpts);
1217     return;
1218   }
1219   std::unique_ptr<llvm::ToolOutputFile> OptRecordFile =
1220       std::move(*OptRecordFileOrErr);
1221
1222   EmitBackendOutput(
1223       Diagnostics, CI.getHeaderSearchOpts(), CodeGenOpts, TargetOpts,
1224       CI.getLangOpts(), CI.getTarget().getDataLayoutString(), TheModule.get(),
1225       BA, CI.getFileManager().getVirtualFileSystemPtr(), std::move(OS));
1226   if (OptRecordFile)
1227     OptRecordFile->keep();
1228 }
1229
1230 //
1231
1232 void EmitAssemblyAction::anchor() { }
1233 EmitAssemblyAction::EmitAssemblyAction(llvm::LLVMContext *_VMContext)
1234   : CodeGenAction(Backend_EmitAssembly, _VMContext) {}
1235
1236 void EmitBCAction::anchor() { }
1237 EmitBCAction::EmitBCAction(llvm::LLVMContext *_VMContext)
1238   : CodeGenAction(Backend_EmitBC, _VMContext) {}
1239
1240 void EmitLLVMAction::anchor() { }
1241 EmitLLVMAction::EmitLLVMAction(llvm::LLVMContext *_VMContext)
1242   : CodeGenAction(Backend_EmitLL, _VMContext) {}
1243
1244 void EmitLLVMOnlyAction::anchor() { }
1245 EmitLLVMOnlyAction::EmitLLVMOnlyAction(llvm::LLVMContext *_VMContext)
1246   : CodeGenAction(Backend_EmitNothing, _VMContext) {}
1247
1248 void EmitCodeGenOnlyAction::anchor() { }
1249 EmitCodeGenOnlyAction::EmitCodeGenOnlyAction(llvm::LLVMContext *_VMContext)
1250   : CodeGenAction(Backend_EmitMCNull, _VMContext) {}
1251
1252 void EmitObjAction::anchor() { }
1253 EmitObjAction::EmitObjAction(llvm::LLVMContext *_VMContext)
1254   : CodeGenAction(Backend_EmitObj, _VMContext) {}