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 "CGCall.h"
  11 #include "CodeGenModule.h"
  12 #include "CoverageMappingGen.h"
  13 #include "MacroPPCallbacks.h"
  14 #include "clang/AST/ASTConsumer.h"
  15 #include "clang/AST/ASTContext.h"
  16 #include "clang/AST/DeclCXX.h"
  17 #include "clang/AST/DeclGroup.h"
  18 #include "clang/Basic/DiagnosticFrontend.h"
  19 #include "clang/Basic/FileManager.h"
  20 #include "clang/Basic/LangStandard.h"
  21 #include "clang/Basic/SourceManager.h"
  22 #include "clang/Basic/TargetInfo.h"
  23 #include "clang/CodeGen/BackendUtil.h"
  24 #include "clang/CodeGen/ModuleBuilder.h"
  25 #include "clang/Driver/DriverDiagnostic.h"
  26 #include "clang/Frontend/CompilerInstance.h"
  27 #include "clang/Frontend/FrontendDiagnostic.h"
  28 #include "clang/Lex/Preprocessor.h"
  29 #include "llvm/ADT/Hashing.h"
  30 #include "llvm/Bitcode/BitcodeReader.h"
  31 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
  32 #include "llvm/Demangle/Demangle.h"
  33 #include "llvm/IR/DebugInfo.h"
  34 #include "llvm/IR/DiagnosticInfo.h"
  35 #include "llvm/IR/DiagnosticPrinter.h"
  36 #include "llvm/IR/GlobalValue.h"
  37 #include "llvm/IR/LLVMContext.h"
  38 #include "llvm/IR/LLVMRemarkStreamer.h"
  39 #include "llvm/IR/Module.h"
  40 #include "llvm/IRReader/IRReader.h"
  41 #include "llvm/LTO/LTOBackend.h"
  42 #include "llvm/Linker/Linker.h"
  43 #include "llvm/Pass.h"
  44 #include "llvm/Support/MemoryBuffer.h"
  45 #include "llvm/Support/SourceMgr.h"
  46 #include "llvm/Support/TimeProfiler.h"
  47 #include "llvm/Support/Timer.h"
  48 #include "llvm/Support/ToolOutputFile.h"
  49 #include "llvm/Support/YAMLTraits.h"
  50 #include "llvm/Transforms/IPO/Internalize.h"
  51
  52 #include <memory>
  53 #include <optional>
  54 using namespace clang;
  55 using namespace llvm;
  56
  57 #define DEBUG_TYPE "codegenaction"
  58
  59 namespace clang {
  60   class BackendConsumer;
  61   class ClangDiagnosticHandler final : public DiagnosticHandler {
  62   public:
  63     ClangDiagnosticHandler(const CodeGenOptions &CGOpts, BackendConsumer *BCon)
  64         : CodeGenOpts(CGOpts), BackendCon(BCon) {}
  65
  66     bool handleDiagnostics(const DiagnosticInfo &DI) override;
  67
  68     bool isAnalysisRemarkEnabled(StringRef PassName) const override {
  69       return CodeGenOpts.OptimizationRemarkAnalysis.patternMatches(PassName);
  70     }
  71     bool isMissedOptRemarkEnabled(StringRef PassName) const override {
  72       return CodeGenOpts.OptimizationRemarkMissed.patternMatches(PassName);
  73     }
  74     bool isPassedOptRemarkEnabled(StringRef PassName) const override {
  75       return CodeGenOpts.OptimizationRemark.patternMatches(PassName);
  76     }
  77
  78     bool isAnyRemarkEnabled() const override {
  79       return CodeGenOpts.OptimizationRemarkAnalysis.hasValidPattern() ||
  80              CodeGenOpts.OptimizationRemarkMissed.hasValidPattern() ||
  81              CodeGenOpts.OptimizationRemark.hasValidPattern();
  82     }
  83
  84   private:
  85     const CodeGenOptions &CodeGenOpts;
  86     BackendConsumer *BackendCon;
  87   };
  88
  89   static void reportOptRecordError(Error E, DiagnosticsEngine &Diags,
  90                                    const CodeGenOptions &CodeGenOpts) {
  91     handleAllErrors(
  92         std::move(E),
  93       [&](const LLVMRemarkSetupFileError &E) {
  94           Diags.Report(diag::err_cannot_open_file)
  95               << CodeGenOpts.OptRecordFile << E.message();
  96         },
  97       [&](const LLVMRemarkSetupPatternError &E) {
  98           Diags.Report(diag::err_drv_optimization_remark_pattern)
  99               << E.message() << CodeGenOpts.OptRecordPasses;
 100         },
 101       [&](const LLVMRemarkSetupFormatError &E) {
 102           Diags.Report(diag::err_drv_optimization_remark_format)
 103               << CodeGenOpts.OptRecordFormat;
 104         });
 105     }
 106
 107   class BackendConsumer : public ASTConsumer {
 108     using LinkModule = CodeGenAction::LinkModule;
 109
 110     virtual void anchor();
 111     DiagnosticsEngine &Diags;
 112     BackendAction Action;
 113     const HeaderSearchOptions &HeaderSearchOpts;
 114     const CodeGenOptions &CodeGenOpts;
 115     const TargetOptions &TargetOpts;
 116     const LangOptions &LangOpts;
 117     std::unique_ptr<raw_pwrite_stream> AsmOutStream;
 118     ASTContext *Context;
 119     IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS;
 120
 121     Timer LLVMIRGeneration;
 122     unsigned LLVMIRGenerationRefCount;
 123
 124     /// True if we've finished generating IR. This prevents us from generating
 125     /// additional LLVM IR after emitting output in HandleTranslationUnit. This
 126     /// can happen when Clang plugins trigger additional AST deserialization.
 127     bool IRGenFinished = false;
 128
 129     bool TimerIsEnabled = false;
 130
 131     std::unique_ptr<CodeGenerator> Gen;
 132
 133     SmallVector<LinkModule, 4> LinkModules;
 134
 135     // A map from mangled names to their function's source location, used for
 136     // backend diagnostics as the Clang AST may be unavailable. We actually use
 137     // the mangled name's hash as the key because mangled names can be very
 138     // long and take up lots of space. Using a hash can cause name collision,
 139     // but that is rare and the consequences are pointing to a wrong source
 140     // location which is not severe. This is a vector instead of an actual map
 141     // because we optimize for time building this map rather than time
 142     // retrieving an entry, as backend diagnostics are uncommon.
 143     std::vector<std::pair<llvm::hash_code, FullSourceLoc>>
 144         ManglingFullSourceLocs;
 145
 146     // This is here so that the diagnostic printer knows the module a diagnostic
 147     // refers to.
 148     llvm::Module *CurLinkModule = nullptr;
 149
 150   public:
 151     BackendConsumer(BackendAction Action, DiagnosticsEngine &Diags,
 152                     IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
 153                     const HeaderSearchOptions &HeaderSearchOpts,
 154                     const PreprocessorOptions &PPOpts,
 155                     const CodeGenOptions &CodeGenOpts,
 156                     const TargetOptions &TargetOpts,
 157                     const LangOptions &LangOpts, const std::string &InFile,
 158                     SmallVector<LinkModule, 4> LinkModules,
 159                     std::unique_ptr<raw_pwrite_stream> OS, LLVMContext &C,
 160                     CoverageSourceInfo *CoverageInfo = nullptr)
 161         : Diags(Diags), Action(Action), HeaderSearchOpts(HeaderSearchOpts),
 162           CodeGenOpts(CodeGenOpts), TargetOpts(TargetOpts), LangOpts(LangOpts),
 163           AsmOutStream(std::move(OS)), Context(nullptr), FS(VFS),
 164           LLVMIRGeneration("irgen", "LLVM IR Generation Time"),
 165           LLVMIRGenerationRefCount(0),
 166           Gen(CreateLLVMCodeGen(Diags, InFile, std::move(VFS), HeaderSearchOpts,
 167                                 PPOpts, CodeGenOpts, C, CoverageInfo)),
 168           LinkModules(std::move(LinkModules)) {
 169       TimerIsEnabled = CodeGenOpts.TimePasses;
 170       llvm::TimePassesIsEnabled = CodeGenOpts.TimePasses;
 171       llvm::TimePassesPerRun = CodeGenOpts.TimePassesPerRun;
 172     }
 173
 174     // This constructor is used in installing an empty BackendConsumer
 175     // to use the clang diagnostic handler for IR input files. It avoids
 176     // initializing the OS field.
 177     BackendConsumer(BackendAction Action, DiagnosticsEngine &Diags,
 178                     IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
 179                     const HeaderSearchOptions &HeaderSearchOpts,
 180                     const PreprocessorOptions &PPOpts,
 181                     const CodeGenOptions &CodeGenOpts,
 182                     const TargetOptions &TargetOpts,
 183                     const LangOptions &LangOpts, llvm::Module *Module,
 184                     SmallVector<LinkModule, 4> LinkModules, LLVMContext &C,
 185                     CoverageSourceInfo *CoverageInfo = nullptr)
 186         : Diags(Diags), Action(Action), HeaderSearchOpts(HeaderSearchOpts),
 187           CodeGenOpts(CodeGenOpts), TargetOpts(TargetOpts), LangOpts(LangOpts),
 188           Context(nullptr), FS(VFS),
 189           LLVMIRGeneration("irgen", "LLVM IR Generation Time"),
 190           LLVMIRGenerationRefCount(0),
 191           Gen(CreateLLVMCodeGen(Diags, "", std::move(VFS), HeaderSearchOpts,
 192                                 PPOpts, CodeGenOpts, C, CoverageInfo)),
 193           LinkModules(std::move(LinkModules)), CurLinkModule(Module) {
 194       TimerIsEnabled = CodeGenOpts.TimePasses;
 195       llvm::TimePassesIsEnabled = CodeGenOpts.TimePasses;
 196       llvm::TimePassesPerRun = CodeGenOpts.TimePassesPerRun;
 197     }
 198     llvm::Module *getModule() const { return Gen->GetModule(); }
 199     std::unique_ptr<llvm::Module> takeModule() {
 200       return std::unique_ptr<llvm::Module>(Gen->ReleaseModule());
 201     }
 202
 203     CodeGenerator *getCodeGenerator() { return Gen.get(); }
 204
 205     void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override {
 206       Gen->HandleCXXStaticMemberVarInstantiation(VD);
 207     }
 208
 209     void Initialize(ASTContext &Ctx) override {
 210       assert(!Context && "initialized multiple times");
 211
 212       Context = &Ctx;
 213
 214       if (TimerIsEnabled)
 215         LLVMIRGeneration.startTimer();
 216
 217       Gen->Initialize(Ctx);
 218
 219       if (TimerIsEnabled)
 220         LLVMIRGeneration.stopTimer();
 221     }
 222
 223     bool HandleTopLevelDecl(DeclGroupRef D) override {
 224       PrettyStackTraceDecl CrashInfo(*D.begin(), SourceLocation(),
 225                                      Context->getSourceManager(),
 226                                      "LLVM IR generation of declaration");
 227
 228       // Recurse.
 229       if (TimerIsEnabled) {
 230         LLVMIRGenerationRefCount += 1;
 231         if (LLVMIRGenerationRefCount == 1)
 232           LLVMIRGeneration.startTimer();
 233       }
 234
 235       Gen->HandleTopLevelDecl(D);
 236
 237       if (TimerIsEnabled) {
 238         LLVMIRGenerationRefCount -= 1;
 239         if (LLVMIRGenerationRefCount == 0)
 240           LLVMIRGeneration.stopTimer();
 241       }
 242
 243       return true;
 244     }
 245
 246     void HandleInlineFunctionDefinition(FunctionDecl *D) override {
 247       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
 248                                      Context->getSourceManager(),
 249                                      "LLVM IR generation of inline function");
 250       if (TimerIsEnabled)
 251         LLVMIRGeneration.startTimer();
 252
 253       Gen->HandleInlineFunctionDefinition(D);
 254
 255       if (TimerIsEnabled)
 256         LLVMIRGeneration.stopTimer();
 257     }
 258
 259     void HandleInterestingDecl(DeclGroupRef D) override {
 260       // Ignore interesting decls from the AST reader after IRGen is finished.
 261       if (!IRGenFinished)
 262         HandleTopLevelDecl(D);
 263     }
 264
 265     // Links each entry in LinkModules into our module.  Returns true on error.
 266     bool LinkInModules(llvm::Module *M) {
 267       for (auto &LM : LinkModules) {
 268         assert(LM.Module && "LinkModule does not actually have a module");
 269         if (LM.PropagateAttrs)
 270           for (Function &F : *LM.Module) {
 271             // Skip intrinsics. Keep consistent with how intrinsics are created
 272             // in LLVM IR.
 273             if (F.isIntrinsic())
 274               continue;
 275             CodeGen::mergeDefaultFunctionDefinitionAttributes(
 276                 F, CodeGenOpts, LangOpts, TargetOpts, LM.Internalize);
 277           }
 278
 279         CurLinkModule = LM.Module.get();
 280
 281         bool Err;
 282         if (LM.Internalize) {
 283           Err = Linker::linkModules(
 284               *M, std::move(LM.Module), LM.LinkFlags,
 285               [](llvm::Module &M, const llvm::StringSet<> &GVS) {
 286                 internalizeModule(M, [&GVS](const llvm::GlobalValue &GV) {
 287                   return !GV.hasName() || (GVS.count(GV.getName()) == 0);
 288                 });
 289               });
 290         } else {
 291           Err = Linker::linkModules(*M, std::move(LM.Module), LM.LinkFlags);
 292         }
 293
 294         if (Err)
 295           return true;
 296       }
 297       LinkModules.clear();
 298       return false; // success
 299     }
 300
 301     void HandleTranslationUnit(ASTContext &C) override {
 302       {
 303         llvm::TimeTraceScope TimeScope("Frontend");
 304         PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
 305         if (TimerIsEnabled) {
 306           LLVMIRGenerationRefCount += 1;
 307           if (LLVMIRGenerationRefCount == 1)
 308             LLVMIRGeneration.startTimer();
 309         }
 310
 311         Gen->HandleTranslationUnit(C);
 312
 313         if (TimerIsEnabled) {
 314           LLVMIRGenerationRefCount -= 1;
 315           if (LLVMIRGenerationRefCount == 0)
 316             LLVMIRGeneration.stopTimer();
 317         }
 318
 319         IRGenFinished = true;
 320       }
 321
 322       // Silently ignore if we weren't initialized for some reason.
 323       if (!getModule())
 324         return;
 325
 326       LLVMContext &Ctx = getModule()->getContext();
 327       std::unique_ptr<DiagnosticHandler> OldDiagnosticHandler =
 328           Ctx.getDiagnosticHandler();
 329       Ctx.setDiagnosticHandler(std::make_unique<ClangDiagnosticHandler>(
 330         CodeGenOpts, this));
 331
 332       Expected<std::unique_ptr<llvm::ToolOutputFile>> OptRecordFileOrErr =
 333           setupLLVMOptimizationRemarks(
 334               Ctx, CodeGenOpts.OptRecordFile, CodeGenOpts.OptRecordPasses,
 335               CodeGenOpts.OptRecordFormat, CodeGenOpts.DiagnosticsWithHotness,
 336               CodeGenOpts.DiagnosticsHotnessThreshold);
 337
 338       if (Error E = OptRecordFileOrErr.takeError()) {
 339         reportOptRecordError(std::move(E), Diags, CodeGenOpts);
 340         return;
 341       }
 342
 343       std::unique_ptr<llvm::ToolOutputFile> OptRecordFile =
 344           std::move(*OptRecordFileOrErr);
 345
 346       if (OptRecordFile &&
 347           CodeGenOpts.getProfileUse() != CodeGenOptions::ProfileNone)
 348         Ctx.setDiagnosticsHotnessRequested(true);
 349
 350       if (CodeGenOpts.MisExpect) {
 351         Ctx.setMisExpectWarningRequested(true);
 352       }
 353
 354       if (CodeGenOpts.DiagnosticsMisExpectTolerance) {
 355         Ctx.setDiagnosticsMisExpectTolerance(
 356             CodeGenOpts.DiagnosticsMisExpectTolerance);
 357       }
 358
 359       // Link each LinkModule into our module.
 360       if (LinkInModules(getModule()))
 361         return;
 362
 363       for (auto &F : getModule()->functions()) {
 364         if (const Decl *FD = Gen->GetDeclForMangledName(F.getName())) {
 365           auto Loc = FD->getASTContext().getFullLoc(FD->getLocation());
 366           // TODO: use a fast content hash when available.
 367           auto NameHash = llvm::hash_value(F.getName());
 368           ManglingFullSourceLocs.push_back(std::make_pair(NameHash, Loc));
 369         }
 370       }
 371
 372       if (CodeGenOpts.ClearASTBeforeBackend) {
 373         LLVM_DEBUG(llvm::dbgs() << "Clearing AST...\n");
 374         // Access to the AST is no longer available after this.
 375         // Other things that the ASTContext manages are still available, e.g.
 376         // the SourceManager. It'd be nice if we could separate out all the
 377         // things in ASTContext used after this point and null out the
 378         // ASTContext, but too many various parts of the ASTContext are still
 379         // used in various parts.
 380         C.cleanup();
 381         C.getAllocator().Reset();
 382       }
 383
 384       EmbedBitcode(getModule(), CodeGenOpts, llvm::MemoryBufferRef());
 385
 386       EmitBackendOutput(Diags, HeaderSearchOpts, CodeGenOpts, TargetOpts,
 387                         LangOpts, C.getTargetInfo().getDataLayoutString(),
 388                         getModule(), Action, FS, std::move(AsmOutStream));
 389
 390       Ctx.setDiagnosticHandler(std::move(OldDiagnosticHandler));
 391
 392       if (OptRecordFile)
 393         OptRecordFile->keep();
 394     }
 395
 396     void HandleTagDeclDefinition(TagDecl *D) override {
 397       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
 398                                      Context->getSourceManager(),
 399                                      "LLVM IR generation of declaration");
 400       Gen->HandleTagDeclDefinition(D);
 401     }
 402
 403     void HandleTagDeclRequiredDefinition(const TagDecl *D) override {
 404       Gen->HandleTagDeclRequiredDefinition(D);
 405     }
 406
 407     void CompleteTentativeDefinition(VarDecl *D) override {
 408       Gen->CompleteTentativeDefinition(D);
 409     }
 410
 411     void CompleteExternalDeclaration(VarDecl *D) override {
 412       Gen->CompleteExternalDeclaration(D);
 413     }
 414
 415     void AssignInheritanceModel(CXXRecordDecl *RD) override {
 416       Gen->AssignInheritanceModel(RD);
 417     }
 418
 419     void HandleVTable(CXXRecordDecl *RD) override {
 420       Gen->HandleVTable(RD);
 421     }
 422
 423     /// Get the best possible source location to represent a diagnostic that
 424     /// may have associated debug info.
 425     const FullSourceLoc
 426     getBestLocationFromDebugLoc(const llvm::DiagnosticInfoWithLocationBase &D,
 427                                 bool &BadDebugInfo, StringRef &Filename,
 428                                 unsigned &Line, unsigned &Column) const;
 429
 430     std::optional<FullSourceLoc>
 431     getFunctionSourceLocation(const Function &F) const;
 432
 433     void DiagnosticHandlerImpl(const llvm::DiagnosticInfo &DI);
 434     /// Specialized handler for InlineAsm diagnostic.
 435     /// \return True if the diagnostic has been successfully reported, false
 436     /// otherwise.
 437     bool InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D);
 438     /// Specialized handler for diagnostics reported using SMDiagnostic.
 439     void SrcMgrDiagHandler(const llvm::DiagnosticInfoSrcMgr &D);
 440     /// Specialized handler for StackSize diagnostic.
 441     /// \return True if the diagnostic has been successfully reported, false
 442     /// otherwise.
 443     bool StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D);
 444     /// Specialized handler for ResourceLimit diagnostic.
 445     /// \return True if the diagnostic has been successfully reported, false
 446     /// otherwise.
 447     bool ResourceLimitDiagHandler(const llvm::DiagnosticInfoResourceLimit &D);
 448
 449     /// Specialized handler for unsupported backend feature diagnostic.
 450     void UnsupportedDiagHandler(const llvm::DiagnosticInfoUnsupported &D);
 451     /// Specialized handlers for optimization remarks.
 452     /// Note that these handlers only accept remarks and they always handle
 453     /// them.
 454     void EmitOptimizationMessage(const llvm::DiagnosticInfoOptimizationBase &D,
 455                                  unsigned DiagID);
 456     void
 457     OptimizationRemarkHandler(const llvm::DiagnosticInfoOptimizationBase &D);
 458     void OptimizationRemarkHandler(
 459         const llvm::OptimizationRemarkAnalysisFPCommute &D);
 460     void OptimizationRemarkHandler(
 461         const llvm::OptimizationRemarkAnalysisAliasing &D);
 462     void OptimizationFailureHandler(
 463         const llvm::DiagnosticInfoOptimizationFailure &D);
 464     void DontCallDiagHandler(const DiagnosticInfoDontCall &D);
 465     /// Specialized handler for misexpect warnings.
 466     /// Note that misexpect remarks are emitted through ORE
 467     void MisExpectDiagHandler(const llvm::DiagnosticInfoMisExpect &D);
 468   };
 469
 470   void BackendConsumer::anchor() {}
 471 }
 472
 473 bool ClangDiagnosticHandler::handleDiagnostics(const DiagnosticInfo &DI) {
 474   BackendCon->DiagnosticHandlerImpl(DI);
 475   return true;
 476 }
 477
 478 /// ConvertBackendLocation - Convert a location in a temporary llvm::SourceMgr
 479 /// buffer to be a valid FullSourceLoc.
 480 static FullSourceLoc ConvertBackendLocation(const llvm::SMDiagnostic &D,
 481                                             SourceManager &CSM) {
 482   // Get both the clang and llvm source managers.  The location is relative to
 483   // a memory buffer that the LLVM Source Manager is handling, we need to add
 484   // a copy to the Clang source manager.
 485   const llvm::SourceMgr &LSM = *D.getSourceMgr();
 486
 487   // We need to copy the underlying LLVM memory buffer because llvm::SourceMgr
 488   // already owns its one and clang::SourceManager wants to own its one.
 489   const MemoryBuffer *LBuf =
 490   LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
 491
 492   // Create the copy and transfer ownership to clang::SourceManager.
 493   // TODO: Avoid copying files into memory.
 494   std::unique_ptr<llvm::MemoryBuffer> CBuf =
 495       llvm::MemoryBuffer::getMemBufferCopy(LBuf->getBuffer(),
 496                                            LBuf->getBufferIdentifier());
 497   // FIXME: Keep a file ID map instead of creating new IDs for each location.
 498   FileID FID = CSM.createFileID(std::move(CBuf));
 499
 500   // Translate the offset into the file.
 501   unsigned Offset = D.getLoc().getPointer() - LBuf->getBufferStart();
 502   SourceLocation NewLoc =
 503   CSM.getLocForStartOfFile(FID).getLocWithOffset(Offset);
 504   return FullSourceLoc(NewLoc, CSM);
 505 }
 506
 507 #define ComputeDiagID(Severity, GroupName, DiagID)                             \
 508   do {                                                                         \
 509     switch (Severity) {                                                        \
 510     case llvm::DS_Error:                                                       \
 511       DiagID = diag::err_fe_##GroupName;                                       \
 512       break;                                                                   \
 513     case llvm::DS_Warning:                                                     \
 514       DiagID = diag::warn_fe_##GroupName;                                      \
 515       break;                                                                   \
 516     case llvm::DS_Remark:                                                      \
 517       llvm_unreachable("'remark' severity not expected");                      \
 518       break;                                                                   \
 519     case llvm::DS_Note:                                                        \
 520       DiagID = diag::note_fe_##GroupName;                                      \
 521       break;                                                                   \
 522     }                                                                          \
 523   } while (false)
 524
 525 #define ComputeDiagRemarkID(Severity, GroupName, DiagID)                       \
 526   do {                                                                         \
 527     switch (Severity) {                                                        \
 528     case llvm::DS_Error:                                                       \
 529       DiagID = diag::err_fe_##GroupName;                                       \
 530       break;                                                                   \
 531     case llvm::DS_Warning:                                                     \
 532       DiagID = diag::warn_fe_##GroupName;                                      \
 533       break;                                                                   \
 534     case llvm::DS_Remark:                                                      \
 535       DiagID = diag::remark_fe_##GroupName;                                    \
 536       break;                                                                   \
 537     case llvm::DS_Note:                                                        \
 538       DiagID = diag::note_fe_##GroupName;                                      \
 539       break;                                                                   \
 540     }                                                                          \
 541   } while (false)
 542
 543 void BackendConsumer::SrcMgrDiagHandler(const llvm::DiagnosticInfoSrcMgr &DI) {
 544   const llvm::SMDiagnostic &D = DI.getSMDiag();
 545
 546   unsigned DiagID;
 547   if (DI.isInlineAsmDiag())
 548     ComputeDiagID(DI.getSeverity(), inline_asm, DiagID);
 549   else
 550     ComputeDiagID(DI.getSeverity(), source_mgr, DiagID);
 551
 552   // This is for the empty BackendConsumer that uses the clang diagnostic
 553   // handler for IR input files.
 554   if (!Context) {
 555     D.print(nullptr, llvm::errs());
 556     Diags.Report(DiagID).AddString("cannot compile inline asm");
 557     return;
 558   }
 559
 560   // There are a couple of different kinds of errors we could get here.
 561   // First, we re-format the SMDiagnostic in terms of a clang diagnostic.
 562
 563   // Strip "error: " off the start of the message string.
 564   StringRef Message = D.getMessage();
 565   (void)Message.consume_front("error: ");
 566
 567   // If the SMDiagnostic has an inline asm source location, translate it.
 568   FullSourceLoc Loc;
 569   if (D.getLoc() != SMLoc())
 570     Loc = ConvertBackendLocation(D, Context->getSourceManager());
 571
 572   // If this problem has clang-level source location information, report the
 573   // issue in the source with a note showing the instantiated
 574   // code.
 575   if (DI.isInlineAsmDiag()) {
 576     SourceLocation LocCookie =
 577         SourceLocation::getFromRawEncoding(DI.getLocCookie());
 578     if (LocCookie.isValid()) {
 579       Diags.Report(LocCookie, DiagID).AddString(Message);
 580
 581       if (D.getLoc().isValid()) {
 582         DiagnosticBuilder B = Diags.Report(Loc, diag::note_fe_inline_asm_here);
 583         // Convert the SMDiagnostic ranges into SourceRange and attach them
 584         // to the diagnostic.
 585         for (const std::pair<unsigned, unsigned> &Range : D.getRanges()) {
 586           unsigned Column = D.getColumnNo();
 587           B << SourceRange(Loc.getLocWithOffset(Range.first - Column),
 588                            Loc.getLocWithOffset(Range.second - Column));
 589         }
 590       }
 591       return;
 592     }
 593   }
 594
 595   // Otherwise, report the backend issue as occurring in the generated .s file.
 596   // If Loc is invalid, we still need to report the issue, it just gets no
 597   // location info.
 598   Diags.Report(Loc, DiagID).AddString(Message);
 599 }
 600
 601 bool
 602 BackendConsumer::InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D) {
 603   unsigned DiagID;
 604   ComputeDiagID(D.getSeverity(), inline_asm, DiagID);
 605   std::string Message = D.getMsgStr().str();
 606
 607   // If this problem has clang-level source location information, report the
 608   // issue as being a problem in the source with a note showing the instantiated
 609   // code.
 610   SourceLocation LocCookie =
 611       SourceLocation::getFromRawEncoding(D.getLocCookie());
 612   if (LocCookie.isValid())
 613     Diags.Report(LocCookie, DiagID).AddString(Message);
 614   else {
 615     // Otherwise, report the backend diagnostic as occurring in the generated
 616     // .s file.
 617     // If Loc is invalid, we still need to report the diagnostic, it just gets
 618     // no location info.
 619     FullSourceLoc Loc;
 620     Diags.Report(Loc, DiagID).AddString(Message);
 621   }
 622   // We handled all the possible severities.
 623   return true;
 624 }
 625
 626 bool
 627 BackendConsumer::StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D) {
 628   if (D.getSeverity() != llvm::DS_Warning)
 629     // For now, the only support we have for StackSize diagnostic is warning.
 630     // We do not know how to format other severities.
 631     return false;
 632
 633   auto Loc = getFunctionSourceLocation(D.getFunction());
 634   if (!Loc)
 635     return false;
 636
 637   Diags.Report(*Loc, diag::warn_fe_frame_larger_than)
 638       << D.getStackSize() << D.getStackLimit()
 639       << llvm::demangle(D.getFunction().getName());
 640   return true;
 641 }
 642
 643 bool BackendConsumer::ResourceLimitDiagHandler(
 644     const llvm::DiagnosticInfoResourceLimit &D) {
 645   auto Loc = getFunctionSourceLocation(D.getFunction());
 646   if (!Loc)
 647     return false;
 648   unsigned DiagID = diag::err_fe_backend_resource_limit;
 649   ComputeDiagID(D.getSeverity(), backend_resource_limit, DiagID);
 650
 651   Diags.Report(*Loc, DiagID)
 652       << D.getResourceName() << D.getResourceSize() << D.getResourceLimit()
 653       << llvm::demangle(D.getFunction().getName());
 654   return true;
 655 }
 656
 657 const FullSourceLoc BackendConsumer::getBestLocationFromDebugLoc(
 658     const llvm::DiagnosticInfoWithLocationBase &D, bool &BadDebugInfo,
 659     StringRef &Filename, unsigned &Line, unsigned &Column) const {
 660   SourceManager &SourceMgr = Context->getSourceManager();
 661   FileManager &FileMgr = SourceMgr.getFileManager();
 662   SourceLocation DILoc;
 663
 664   if (D.isLocationAvailable()) {
 665     D.getLocation(Filename, Line, Column);
 666     if (Line > 0) {
 667       auto FE = FileMgr.getFile(Filename);
 668       if (!FE)
 669         FE = FileMgr.getFile(D.getAbsolutePath());
 670       if (FE) {
 671         // If -gcolumn-info was not used, Column will be 0. This upsets the
 672         // source manager, so pass 1 if Column is not set.
 673         DILoc = SourceMgr.translateFileLineCol(*FE, Line, Column ? Column : 1);
 674       }
 675     }
 676     BadDebugInfo = DILoc.isInvalid();
 677   }
 678
 679   // If a location isn't available, try to approximate it using the associated
 680   // function definition. We use the definition's right brace to differentiate
 681   // from diagnostics that genuinely relate to the function itself.
 682   FullSourceLoc Loc(DILoc, SourceMgr);
 683   if (Loc.isInvalid()) {
 684     if (auto MaybeLoc = getFunctionSourceLocation(D.getFunction()))
 685       Loc = *MaybeLoc;
 686   }
 687
 688   if (DILoc.isInvalid() && D.isLocationAvailable())
 689     // If we were not able to translate the file:line:col information
 690     // back to a SourceLocation, at least emit a note stating that
 691     // we could not translate this location. This can happen in the
 692     // case of #line directives.
 693     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
 694         << Filename << Line << Column;
 695
 696   return Loc;
 697 }
 698
 699 std::optional<FullSourceLoc>
 700 BackendConsumer::getFunctionSourceLocation(const Function &F) const {
 701   auto Hash = llvm::hash_value(F.getName());
 702   for (const auto &Pair : ManglingFullSourceLocs) {
 703     if (Pair.first == Hash)
 704       return Pair.second;
 705   }
 706   return std::nullopt;
 707 }
 708
 709 void BackendConsumer::UnsupportedDiagHandler(
 710     const llvm::DiagnosticInfoUnsupported &D) {
 711   // We only support warnings or errors.
 712   assert(D.getSeverity() == llvm::DS_Error ||
 713          D.getSeverity() == llvm::DS_Warning);
 714
 715   StringRef Filename;
 716   unsigned Line, Column;
 717   bool BadDebugInfo = false;
 718   FullSourceLoc Loc;
 719   std::string Msg;
 720   raw_string_ostream MsgStream(Msg);
 721
 722   // Context will be nullptr for IR input files, we will construct the diag
 723   // message from llvm::DiagnosticInfoUnsupported.
 724   if (Context != nullptr) {
 725     Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
 726     MsgStream << D.getMessage();
 727   } else {
 728     DiagnosticPrinterRawOStream DP(MsgStream);
 729     D.print(DP);
 730   }
 731
 732   auto DiagType = D.getSeverity() == llvm::DS_Error
 733                       ? diag::err_fe_backend_unsupported
 734                       : diag::warn_fe_backend_unsupported;
 735   Diags.Report(Loc, DiagType) << MsgStream.str();
 736
 737   if (BadDebugInfo)
 738     // If we were not able to translate the file:line:col information
 739     // back to a SourceLocation, at least emit a note stating that
 740     // we could not translate this location. This can happen in the
 741     // case of #line directives.
 742     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
 743         << Filename << Line << Column;
 744 }
 745
 746 void BackendConsumer::EmitOptimizationMessage(
 747     const llvm::DiagnosticInfoOptimizationBase &D, unsigned DiagID) {
 748   // We only support warnings and remarks.
 749   assert(D.getSeverity() == llvm::DS_Remark ||
 750          D.getSeverity() == llvm::DS_Warning);
 751
 752   StringRef Filename;
 753   unsigned Line, Column;
 754   bool BadDebugInfo = false;
 755   FullSourceLoc Loc;
 756   std::string Msg;
 757   raw_string_ostream MsgStream(Msg);
 758
 759   // Context will be nullptr for IR input files, we will construct the remark
 760   // message from llvm::DiagnosticInfoOptimizationBase.
 761   if (Context != nullptr) {
 762     Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
 763     MsgStream << D.getMsg();
 764   } else {
 765     DiagnosticPrinterRawOStream DP(MsgStream);
 766     D.print(DP);
 767   }
 768
 769   if (D.getHotness())
 770     MsgStream << " (hotness: " << *D.getHotness() << ")";
 771
 772   Diags.Report(Loc, DiagID)
 773       << AddFlagValue(D.getPassName())
 774       << MsgStream.str();
 775
 776   if (BadDebugInfo)
 777     // If we were not able to translate the file:line:col information
 778     // back to a SourceLocation, at least emit a note stating that
 779     // we could not translate this location. This can happen in the
 780     // case of #line directives.
 781     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
 782         << Filename << Line << Column;
 783 }
 784
 785 void BackendConsumer::OptimizationRemarkHandler(
 786     const llvm::DiagnosticInfoOptimizationBase &D) {
 787   // Without hotness information, don't show noisy remarks.
 788   if (D.isVerbose() && !D.getHotness())
 789     return;
 790
 791   if (D.isPassed()) {
 792     // Optimization remarks are active only if the -Rpass flag has a regular
 793     // expression that matches the name of the pass name in \p D.
 794     if (CodeGenOpts.OptimizationRemark.patternMatches(D.getPassName()))
 795       EmitOptimizationMessage(D, diag::remark_fe_backend_optimization_remark);
 796   } else if (D.isMissed()) {
 797     // Missed optimization remarks are active only if the -Rpass-missed
 798     // flag has a regular expression that matches the name of the pass
 799     // name in \p D.
 800     if (CodeGenOpts.OptimizationRemarkMissed.patternMatches(D.getPassName()))
 801       EmitOptimizationMessage(
 802           D, diag::remark_fe_backend_optimization_remark_missed);
 803   } else {
 804     assert(D.isAnalysis() && "Unknown remark type");
 805
 806     bool ShouldAlwaysPrint = false;
 807     if (auto *ORA = dyn_cast<llvm::OptimizationRemarkAnalysis>(&D))
 808       ShouldAlwaysPrint = ORA->shouldAlwaysPrint();
 809
 810     if (ShouldAlwaysPrint ||
 811         CodeGenOpts.OptimizationRemarkAnalysis.patternMatches(D.getPassName()))
 812       EmitOptimizationMessage(
 813           D, diag::remark_fe_backend_optimization_remark_analysis);
 814   }
 815 }
 816
 817 void BackendConsumer::OptimizationRemarkHandler(
 818     const llvm::OptimizationRemarkAnalysisFPCommute &D) {
 819   // Optimization analysis remarks are active if the pass name is set to
 820   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
 821   // regular expression that matches the name of the pass name in \p D.
 822
 823   if (D.shouldAlwaysPrint() ||
 824       CodeGenOpts.OptimizationRemarkAnalysis.patternMatches(D.getPassName()))
 825     EmitOptimizationMessage(
 826         D, diag::remark_fe_backend_optimization_remark_analysis_fpcommute);
 827 }
 828
 829 void BackendConsumer::OptimizationRemarkHandler(
 830     const llvm::OptimizationRemarkAnalysisAliasing &D) {
 831   // Optimization analysis remarks are active if the pass name is set to
 832   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
 833   // regular expression that matches the name of the pass name in \p D.
 834
 835   if (D.shouldAlwaysPrint() ||
 836       CodeGenOpts.OptimizationRemarkAnalysis.patternMatches(D.getPassName()))
 837     EmitOptimizationMessage(
 838         D, diag::remark_fe_backend_optimization_remark_analysis_aliasing);
 839 }
 840
 841 void BackendConsumer::OptimizationFailureHandler(
 842     const llvm::DiagnosticInfoOptimizationFailure &D) {
 843   EmitOptimizationMessage(D, diag::warn_fe_backend_optimization_failure);
 844 }
 845
 846 void BackendConsumer::DontCallDiagHandler(const DiagnosticInfoDontCall &D) {
 847   SourceLocation LocCookie =
 848       SourceLocation::getFromRawEncoding(D.getLocCookie());
 849
 850   // FIXME: we can't yet diagnose indirect calls. When/if we can, we
 851   // should instead assert that LocCookie.isValid().
 852   if (!LocCookie.isValid())
 853     return;
 854
 855   Diags.Report(LocCookie, D.getSeverity() == DiagnosticSeverity::DS_Error
 856                               ? diag::err_fe_backend_error_attr
 857                               : diag::warn_fe_backend_warning_attr)
 858       << llvm::demangle(D.getFunctionName()) << D.getNote();
 859 }
 860
 861 void BackendConsumer::MisExpectDiagHandler(
 862     const llvm::DiagnosticInfoMisExpect &D) {
 863   StringRef Filename;
 864   unsigned Line, Column;
 865   bool BadDebugInfo = false;
 866   FullSourceLoc Loc =
 867       getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
 868
 869   Diags.Report(Loc, diag::warn_profile_data_misexpect) << D.getMsg().str();
 870
 871   if (BadDebugInfo)
 872     // If we were not able to translate the file:line:col information
 873     // back to a SourceLocation, at least emit a note stating that
 874     // we could not translate this location. This can happen in the
 875     // case of #line directives.
 876     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
 877         << Filename << Line << Column;
 878 }
 879
 880 /// This function is invoked when the backend needs
 881 /// to report something to the user.
 882 void BackendConsumer::DiagnosticHandlerImpl(const DiagnosticInfo &DI) {
 883   unsigned DiagID = diag::err_fe_inline_asm;
 884   llvm::DiagnosticSeverity Severity = DI.getSeverity();
 885   // Get the diagnostic ID based.
 886   switch (DI.getKind()) {
 887   case llvm::DK_InlineAsm:
 888     if (InlineAsmDiagHandler(cast<DiagnosticInfoInlineAsm>(DI)))
 889       return;
 890     ComputeDiagID(Severity, inline_asm, DiagID);
 891     break;
 892   case llvm::DK_SrcMgr:
 893     SrcMgrDiagHandler(cast<DiagnosticInfoSrcMgr>(DI));
 894     return;
 895   case llvm::DK_StackSize:
 896     if (StackSizeDiagHandler(cast<DiagnosticInfoStackSize>(DI)))
 897       return;
 898     ComputeDiagID(Severity, backend_frame_larger_than, DiagID);
 899     break;
 900   case llvm::DK_ResourceLimit:
 901     if (ResourceLimitDiagHandler(cast<DiagnosticInfoResourceLimit>(DI)))
 902       return;
 903     ComputeDiagID(Severity, backend_resource_limit, DiagID);
 904     break;
 905   case DK_Linker:
 906     ComputeDiagID(Severity, linking_module, DiagID);
 907     break;
 908   case llvm::DK_OptimizationRemark:
 909     // Optimization remarks are always handled completely by this
 910     // handler. There is no generic way of emitting them.
 911     OptimizationRemarkHandler(cast<OptimizationRemark>(DI));
 912     return;
 913   case llvm::DK_OptimizationRemarkMissed:
 914     // Optimization remarks are always handled completely by this
 915     // handler. There is no generic way of emitting them.
 916     OptimizationRemarkHandler(cast<OptimizationRemarkMissed>(DI));
 917     return;
 918   case llvm::DK_OptimizationRemarkAnalysis:
 919     // Optimization remarks are always handled completely by this
 920     // handler. There is no generic way of emitting them.
 921     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysis>(DI));
 922     return;
 923   case llvm::DK_OptimizationRemarkAnalysisFPCommute:
 924     // Optimization remarks are always handled completely by this
 925     // handler. There is no generic way of emitting them.
 926     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysisFPCommute>(DI));
 927     return;
 928   case llvm::DK_OptimizationRemarkAnalysisAliasing:
 929     // Optimization remarks are always handled completely by this
 930     // handler. There is no generic way of emitting them.
 931     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysisAliasing>(DI));
 932     return;
 933   case llvm::DK_MachineOptimizationRemark:
 934     // Optimization remarks are always handled completely by this
 935     // handler. There is no generic way of emitting them.
 936     OptimizationRemarkHandler(cast<MachineOptimizationRemark>(DI));
 937     return;
 938   case llvm::DK_MachineOptimizationRemarkMissed:
 939     // Optimization remarks are always handled completely by this
 940     // handler. There is no generic way of emitting them.
 941     OptimizationRemarkHandler(cast<MachineOptimizationRemarkMissed>(DI));
 942     return;
 943   case llvm::DK_MachineOptimizationRemarkAnalysis:
 944     // Optimization remarks are always handled completely by this
 945     // handler. There is no generic way of emitting them.
 946     OptimizationRemarkHandler(cast<MachineOptimizationRemarkAnalysis>(DI));
 947     return;
 948   case llvm::DK_OptimizationFailure:
 949     // Optimization failures are always handled completely by this
 950     // handler.
 951     OptimizationFailureHandler(cast<DiagnosticInfoOptimizationFailure>(DI));
 952     return;
 953   case llvm::DK_Unsupported:
 954     UnsupportedDiagHandler(cast<DiagnosticInfoUnsupported>(DI));
 955     return;
 956   case llvm::DK_DontCall:
 957     DontCallDiagHandler(cast<DiagnosticInfoDontCall>(DI));
 958     return;
 959   case llvm::DK_MisExpect:
 960     MisExpectDiagHandler(cast<DiagnosticInfoMisExpect>(DI));
 961     return;
 962   default:
 963     // Plugin IDs are not bound to any value as they are set dynamically.
 964     ComputeDiagRemarkID(Severity, backend_plugin, DiagID);
 965     break;
 966   }
 967   std::string MsgStorage;
 968   {
 969     raw_string_ostream Stream(MsgStorage);
 970     DiagnosticPrinterRawOStream DP(Stream);
 971     DI.print(DP);
 972   }
 973
 974   if (DI.getKind() == DK_Linker) {
 975     assert(CurLinkModule && "CurLinkModule must be set for linker diagnostics");
 976     Diags.Report(DiagID) << CurLinkModule->getModuleIdentifier() << MsgStorage;
 977     return;
 978   }
 979
 980   // Report the backend message using the usual diagnostic mechanism.
 981   FullSourceLoc Loc;
 982   Diags.Report(Loc, DiagID).AddString(MsgStorage);
 983 }
 984 #undef ComputeDiagID
 985
 986 CodeGenAction::CodeGenAction(unsigned _Act, LLVMContext *_VMContext)
 987     : Act(_Act), VMContext(_VMContext ? _VMContext : new LLVMContext),
 988       OwnsVMContext(!_VMContext) {}
 989
 990 CodeGenAction::~CodeGenAction() {
 991   TheModule.reset();
 992   if (OwnsVMContext)
 993     delete VMContext;
 994 }
 995
 996 bool CodeGenAction::loadLinkModules(CompilerInstance &CI) {
 997   if (!LinkModules.empty())
 998     return false;
 999
1000   for (const CodeGenOptions::BitcodeFileToLink &F :
1001        CI.getCodeGenOpts().LinkBitcodeFiles) {
1002     auto BCBuf = CI.getFileManager().getBufferForFile(F.Filename);
1003     if (!BCBuf) {
1004       CI.getDiagnostics().Report(diag::err_cannot_open_file)
1005           << F.Filename << BCBuf.getError().message();
1006       LinkModules.clear();
1007       return true;
1008     }
1009
1010     Expected<std::unique_ptr<llvm::Module>> ModuleOrErr =
1011         getOwningLazyBitcodeModule(std::move(*BCBuf), *VMContext);
1012     if (!ModuleOrErr) {
1013       handleAllErrors(ModuleOrErr.takeError(), [&](ErrorInfoBase &EIB) {
1014         CI.getDiagnostics().Report(diag::err_cannot_open_file)
1015             << F.Filename << EIB.message();
1016       });
1017       LinkModules.clear();
1018       return true;
1019     }
1020     LinkModules.push_back({std::move(ModuleOrErr.get()), F.PropagateAttrs,
1021                            F.Internalize, F.LinkFlags});
1022   }
1023   return false;
1024 }
1025
1026 bool CodeGenAction::hasIRSupport() const { return true; }
1027
1028 void CodeGenAction::EndSourceFileAction() {
1029   // If the consumer creation failed, do nothing.
1030   if (!getCompilerInstance().hasASTConsumer())
1031     return;
1032
1033   // Steal the module from the consumer.
1034   TheModule = BEConsumer->takeModule();
1035 }
1036
1037 std::unique_ptr<llvm::Module> CodeGenAction::takeModule() {
1038   return std::move(TheModule);
1039 }
1040
1041 llvm::LLVMContext *CodeGenAction::takeLLVMContext() {
1042   OwnsVMContext = false;
1043   return VMContext;
1044 }
1045
1046 CodeGenerator *CodeGenAction::getCodeGenerator() const {
1047   return BEConsumer->getCodeGenerator();
1048 }
1049
1050 static std::unique_ptr<raw_pwrite_stream>
1051 GetOutputStream(CompilerInstance &CI, StringRef InFile, BackendAction Action) {
1052   switch (Action) {
1053   case Backend_EmitAssembly:
1054     return CI.createDefaultOutputFile(false, InFile, "s");
1055   case Backend_EmitLL:
1056     return CI.createDefaultOutputFile(false, InFile, "ll");
1057   case Backend_EmitBC:
1058     return CI.createDefaultOutputFile(true, InFile, "bc");
1059   case Backend_EmitNothing:
1060     return nullptr;
1061   case Backend_EmitMCNull:
1062     return CI.createNullOutputFile();
1063   case Backend_EmitObj:
1064     return CI.createDefaultOutputFile(true, InFile, "o");
1065   }
1066
1067   llvm_unreachable("Invalid action!");
1068 }
1069
1070 std::unique_ptr<ASTConsumer>
1071 CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
1072   BackendAction BA = static_cast<BackendAction>(Act);
1073   std::unique_ptr<raw_pwrite_stream> OS = CI.takeOutputStream();
1074   if (!OS)
1075     OS = GetOutputStream(CI, InFile, BA);
1076
1077   if (BA != Backend_EmitNothing && !OS)
1078     return nullptr;
1079
1080   // Load bitcode modules to link with, if we need to.
1081   if (loadLinkModules(CI))
1082     return nullptr;
1083
1084   CoverageSourceInfo *CoverageInfo = nullptr;
1085   // Add the preprocessor callback only when the coverage mapping is generated.
1086   if (CI.getCodeGenOpts().CoverageMapping)
1087     CoverageInfo = CodeGen::CoverageMappingModuleGen::setUpCoverageCallbacks(
1088         CI.getPreprocessor());
1089
1090   std::unique_ptr<BackendConsumer> Result(new BackendConsumer(
1091       BA, CI.getDiagnostics(), &CI.getVirtualFileSystem(),
1092       CI.getHeaderSearchOpts(), CI.getPreprocessorOpts(), CI.getCodeGenOpts(),
1093       CI.getTargetOpts(), CI.getLangOpts(), std::string(InFile),
1094       std::move(LinkModules), std::move(OS), *VMContext, CoverageInfo));
1095   BEConsumer = Result.get();
1096
1097   // Enable generating macro debug info only when debug info is not disabled and
1098   // also macro debug info is enabled.
1099   if (CI.getCodeGenOpts().getDebugInfo() != codegenoptions::NoDebugInfo &&
1100       CI.getCodeGenOpts().MacroDebugInfo) {
1101     std::unique_ptr<PPCallbacks> Callbacks =
1102         std::make_unique<MacroPPCallbacks>(BEConsumer->getCodeGenerator(),
1103                                             CI.getPreprocessor());
1104     CI.getPreprocessor().addPPCallbacks(std::move(Callbacks));
1105   }
1106
1107   return std::move(Result);
1108 }
1109
1110 std::unique_ptr<llvm::Module>
1111 CodeGenAction::loadModule(MemoryBufferRef MBRef) {
1112   CompilerInstance &CI = getCompilerInstance();
1113   SourceManager &SM = CI.getSourceManager();
1114
1115   auto DiagErrors = [&](Error E) -> std::unique_ptr<llvm::Module> {
1116     unsigned DiagID =
1117         CI.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1118     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1119       CI.getDiagnostics().Report(DiagID) << EIB.message();
1120     });
1121     return {};
1122   };
1123
1124   // For ThinLTO backend invocations, ensure that the context
1125   // merges types based on ODR identifiers. We also need to read
1126   // the correct module out of a multi-module bitcode file.
1127   if (!CI.getCodeGenOpts().ThinLTOIndexFile.empty()) {
1128     VMContext->enableDebugTypeODRUniquing();
1129
1130     Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
1131     if (!BMsOrErr)
1132       return DiagErrors(BMsOrErr.takeError());
1133     BitcodeModule *Bm = llvm::lto::findThinLTOModule(*BMsOrErr);
1134     // We have nothing to do if the file contains no ThinLTO module. This is
1135     // possible if ThinLTO compilation was not able to split module. Content of
1136     // the file was already processed by indexing and will be passed to the
1137     // linker using merged object file.
1138     if (!Bm) {
1139       auto M = std::make_unique<llvm::Module>("empty", *VMContext);
1140       M->setTargetTriple(CI.getTargetOpts().Triple);
1141       return M;
1142     }
1143     Expected<std::unique_ptr<llvm::Module>> MOrErr =
1144         Bm->parseModule(*VMContext);
1145     if (!MOrErr)
1146       return DiagErrors(MOrErr.takeError());
1147     return std::move(*MOrErr);
1148   }
1149
1150   // Load bitcode modules to link with, if we need to.
1151   if (loadLinkModules(CI))
1152     return nullptr;
1153
1154   // Handle textual IR and bitcode file with one single module.
1155   llvm::SMDiagnostic Err;
1156   if (std::unique_ptr<llvm::Module> M = parseIR(MBRef, Err, *VMContext))
1157     return M;
1158
1159   // If MBRef is a bitcode with multiple modules (e.g., -fsplit-lto-unit
1160   // output), place the extra modules (actually only one, a regular LTO module)
1161   // into LinkModules as if we are using -mlink-bitcode-file.
1162   Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
1163   if (BMsOrErr && BMsOrErr->size()) {
1164     std::unique_ptr<llvm::Module> FirstM;
1165     for (auto &BM : *BMsOrErr) {
1166       Expected<std::unique_ptr<llvm::Module>> MOrErr =
1167           BM.parseModule(*VMContext);
1168       if (!MOrErr)
1169         return DiagErrors(MOrErr.takeError());
1170       if (FirstM)
1171         LinkModules.push_back({std::move(*MOrErr), /*PropagateAttrs=*/false,
1172                                /*Internalize=*/false, /*LinkFlags=*/{}});
1173       else
1174         FirstM = std::move(*MOrErr);
1175     }
1176     if (FirstM)
1177       return FirstM;
1178   }
1179   // If BMsOrErr fails, consume the error and use the error message from
1180   // parseIR.
1181   consumeError(BMsOrErr.takeError());
1182
1183   // Translate from the diagnostic info to the SourceManager location if
1184   // available.
1185   // TODO: Unify this with ConvertBackendLocation()
1186   SourceLocation Loc;
1187   if (Err.getLineNo() > 0) {
1188     assert(Err.getColumnNo() >= 0);
1189     Loc = SM.translateFileLineCol(SM.getFileEntryForID(SM.getMainFileID()),
1190                                   Err.getLineNo(), Err.getColumnNo() + 1);
1191   }
1192
1193   // Strip off a leading diagnostic code if there is one.
1194   StringRef Msg = Err.getMessage();
1195   if (Msg.startswith("error: "))
1196     Msg = Msg.substr(7);
1197
1198   unsigned DiagID =
1199       CI.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1200
1201   CI.getDiagnostics().Report(Loc, DiagID) << Msg;
1202   return {};
1203 }
1204
1205 void CodeGenAction::ExecuteAction() {
1206   if (getCurrentFileKind().getLanguage() != Language::LLVM_IR) {
1207     this->ASTFrontendAction::ExecuteAction();
1208     return;
1209   }
1210
1211   // If this is an IR file, we have to treat it specially.
1212   BackendAction BA = static_cast<BackendAction>(Act);
1213   CompilerInstance &CI = getCompilerInstance();
1214   auto &CodeGenOpts = CI.getCodeGenOpts();
1215   auto &Diagnostics = CI.getDiagnostics();
1216   std::unique_ptr<raw_pwrite_stream> OS =
1217       GetOutputStream(CI, getCurrentFileOrBufferName(), BA);
1218   if (BA != Backend_EmitNothing && !OS)
1219     return;
1220
1221   SourceManager &SM = CI.getSourceManager();
1222   FileID FID = SM.getMainFileID();
1223   std::optional<MemoryBufferRef> MainFile = SM.getBufferOrNone(FID);
1224   if (!MainFile)
1225     return;
1226
1227   TheModule = loadModule(*MainFile);
1228   if (!TheModule)
1229     return;
1230
1231   const TargetOptions &TargetOpts = CI.getTargetOpts();
1232   if (TheModule->getTargetTriple() != TargetOpts.Triple) {
1233     Diagnostics.Report(SourceLocation(), diag::warn_fe_override_module)
1234         << TargetOpts.Triple;
1235     TheModule->setTargetTriple(TargetOpts.Triple);
1236   }
1237
1238   EmbedObject(TheModule.get(), CodeGenOpts, Diagnostics);
1239   EmbedBitcode(TheModule.get(), CodeGenOpts, *MainFile);
1240
1241   LLVMContext &Ctx = TheModule->getContext();
1242
1243   // Restore any diagnostic handler previously set before returning from this
1244   // function.
1245   struct RAII {
1246     LLVMContext &Ctx;
1247     std::unique_ptr<DiagnosticHandler> PrevHandler = Ctx.getDiagnosticHandler();
1248     ~RAII() { Ctx.setDiagnosticHandler(std::move(PrevHandler)); }
1249   } _{Ctx};
1250
1251   // Set clang diagnostic handler. To do this we need to create a fake
1252   // BackendConsumer.
1253   BackendConsumer Result(BA, CI.getDiagnostics(), &CI.getVirtualFileSystem(),
1254                          CI.getHeaderSearchOpts(), CI.getPreprocessorOpts(),
1255                          CI.getCodeGenOpts(), CI.getTargetOpts(),
1256                          CI.getLangOpts(), TheModule.get(),
1257                          std::move(LinkModules), *VMContext, nullptr);
1258
1259   // Link in each pending link module.
1260   if (Result.LinkInModules(&*TheModule))
1261     return;
1262
1263   // PR44896: Force DiscardValueNames as false. DiscardValueNames cannot be
1264   // true here because the valued names are needed for reading textual IR.
1265   Ctx.setDiscardValueNames(false);
1266   Ctx.setDiagnosticHandler(
1267       std::make_unique<ClangDiagnosticHandler>(CodeGenOpts, &Result));
1268
1269   Expected<std::unique_ptr<llvm::ToolOutputFile>> OptRecordFileOrErr =
1270       setupLLVMOptimizationRemarks(
1271           Ctx, CodeGenOpts.OptRecordFile, CodeGenOpts.OptRecordPasses,
1272           CodeGenOpts.OptRecordFormat, CodeGenOpts.DiagnosticsWithHotness,
1273           CodeGenOpts.DiagnosticsHotnessThreshold);
1274
1275   if (Error E = OptRecordFileOrErr.takeError()) {
1276     reportOptRecordError(std::move(E), Diagnostics, CodeGenOpts);
1277     return;
1278   }
1279   std::unique_ptr<llvm::ToolOutputFile> OptRecordFile =
1280       std::move(*OptRecordFileOrErr);
1281
1282   EmitBackendOutput(
1283       Diagnostics, CI.getHeaderSearchOpts(), CodeGenOpts, TargetOpts,
1284       CI.getLangOpts(), CI.getTarget().getDataLayoutString(), TheModule.get(),
1285       BA, CI.getFileManager().getVirtualFileSystemPtr(), std::move(OS));
1286   if (OptRecordFile)
1287     OptRecordFile->keep();
1288 }
1289
1290 //
1291
1292 void EmitAssemblyAction::anchor() { }
1293 EmitAssemblyAction::EmitAssemblyAction(llvm::LLVMContext *_VMContext)
1294   : CodeGenAction(Backend_EmitAssembly, _VMContext) {}
1295
1296 void EmitBCAction::anchor() { }
1297 EmitBCAction::EmitBCAction(llvm::LLVMContext *_VMContext)
1298   : CodeGenAction(Backend_EmitBC, _VMContext) {}
1299
1300 void EmitLLVMAction::anchor() { }
1301 EmitLLVMAction::EmitLLVMAction(llvm::LLVMContext *_VMContext)
1302   : CodeGenAction(Backend_EmitLL, _VMContext) {}
1303
1304 void EmitLLVMOnlyAction::anchor() { }
1305 EmitLLVMOnlyAction::EmitLLVMOnlyAction(llvm::LLVMContext *_VMContext)
1306   : CodeGenAction(Backend_EmitNothing, _VMContext) {}
1307
1308 void EmitCodeGenOnlyAction::anchor() { }
1309 EmitCodeGenOnlyAction::EmitCodeGenOnlyAction(llvm::LLVMContext *_VMContext)
1310   : CodeGenAction(Backend_EmitMCNull, _VMContext) {}
1311
1312 void EmitObjAction::anchor() { }
1313 EmitObjAction::EmitObjAction(llvm::LLVMContext *_VMContext)
1314   : CodeGenAction(Backend_EmitObj, _VMContext) {}