xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/CodeGenAction.cpp (revision 85868e8a1daeaae7a0e48effb2ea2310ae3b02c6)
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 "CodeGenModule.h"
11 #include "CoverageMappingGen.h"
12 #include "MacroPPCallbacks.h"
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/DeclCXX.h"
16 #include "clang/AST/DeclGroup.h"
17 #include "clang/Basic/DiagnosticFrontend.h"
18 #include "clang/Basic/FileManager.h"
19 #include "clang/Basic/LangStandard.h"
20 #include "clang/Basic/SourceManager.h"
21 #include "clang/Basic/TargetInfo.h"
22 #include "clang/CodeGen/BackendUtil.h"
23 #include "clang/CodeGen/ModuleBuilder.h"
24 #include "clang/Driver/DriverDiagnostic.h"
25 #include "clang/Frontend/CompilerInstance.h"
26 #include "clang/Frontend/FrontendDiagnostic.h"
27 #include "clang/Lex/Preprocessor.h"
28 #include "llvm/Bitcode/BitcodeReader.h"
29 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
30 #include "llvm/IR/DebugInfo.h"
31 #include "llvm/IR/DiagnosticInfo.h"
32 #include "llvm/IR/DiagnosticPrinter.h"
33 #include "llvm/IR/GlobalValue.h"
34 #include "llvm/IR/LLVMContext.h"
35 #include "llvm/IR/Module.h"
36 #include "llvm/IR/RemarkStreamer.h"
37 #include "llvm/IRReader/IRReader.h"
38 #include "llvm/Linker/Linker.h"
39 #include "llvm/Pass.h"
40 #include "llvm/Support/MemoryBuffer.h"
41 #include "llvm/Support/SourceMgr.h"
42 #include "llvm/Support/TimeProfiler.h"
43 #include "llvm/Support/Timer.h"
44 #include "llvm/Support/ToolOutputFile.h"
45 #include "llvm/Support/YAMLTraits.h"
46 #include "llvm/Transforms/IPO/Internalize.h"
47 
48 #include <memory>
49 using namespace clang;
50 using namespace llvm;
51 
52 namespace clang {
53   class BackendConsumer;
54   class ClangDiagnosticHandler final : public DiagnosticHandler {
55   public:
56     ClangDiagnosticHandler(const CodeGenOptions &CGOpts, BackendConsumer *BCon)
57         : CodeGenOpts(CGOpts), BackendCon(BCon) {}
58 
59     bool handleDiagnostics(const DiagnosticInfo &DI) override;
60 
61     bool isAnalysisRemarkEnabled(StringRef PassName) const override {
62       return (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
63               CodeGenOpts.OptimizationRemarkAnalysisPattern->match(PassName));
64     }
65     bool isMissedOptRemarkEnabled(StringRef PassName) const override {
66       return (CodeGenOpts.OptimizationRemarkMissedPattern &&
67               CodeGenOpts.OptimizationRemarkMissedPattern->match(PassName));
68     }
69     bool isPassedOptRemarkEnabled(StringRef PassName) const override {
70       return (CodeGenOpts.OptimizationRemarkPattern &&
71               CodeGenOpts.OptimizationRemarkPattern->match(PassName));
72     }
73 
74     bool isAnyRemarkEnabled() const override {
75       return (CodeGenOpts.OptimizationRemarkAnalysisPattern ||
76               CodeGenOpts.OptimizationRemarkMissedPattern ||
77               CodeGenOpts.OptimizationRemarkPattern);
78     }
79 
80   private:
81     const CodeGenOptions &CodeGenOpts;
82     BackendConsumer *BackendCon;
83   };
84 
85   class BackendConsumer : public ASTConsumer {
86     using LinkModule = CodeGenAction::LinkModule;
87 
88     virtual void anchor();
89     DiagnosticsEngine &Diags;
90     BackendAction Action;
91     const HeaderSearchOptions &HeaderSearchOpts;
92     const CodeGenOptions &CodeGenOpts;
93     const TargetOptions &TargetOpts;
94     const LangOptions &LangOpts;
95     std::unique_ptr<raw_pwrite_stream> AsmOutStream;
96     ASTContext *Context;
97 
98     Timer LLVMIRGeneration;
99     unsigned LLVMIRGenerationRefCount;
100 
101     /// True if we've finished generating IR. This prevents us from generating
102     /// additional LLVM IR after emitting output in HandleTranslationUnit. This
103     /// can happen when Clang plugins trigger additional AST deserialization.
104     bool IRGenFinished = false;
105 
106     std::unique_ptr<CodeGenerator> Gen;
107 
108     SmallVector<LinkModule, 4> LinkModules;
109 
110     // This is here so that the diagnostic printer knows the module a diagnostic
111     // refers to.
112     llvm::Module *CurLinkModule = nullptr;
113 
114   public:
115     BackendConsumer(BackendAction Action, DiagnosticsEngine &Diags,
116                     const HeaderSearchOptions &HeaderSearchOpts,
117                     const PreprocessorOptions &PPOpts,
118                     const CodeGenOptions &CodeGenOpts,
119                     const TargetOptions &TargetOpts,
120                     const LangOptions &LangOpts, bool TimePasses,
121                     const std::string &InFile,
122                     SmallVector<LinkModule, 4> LinkModules,
123                     std::unique_ptr<raw_pwrite_stream> OS, LLVMContext &C,
124                     CoverageSourceInfo *CoverageInfo = nullptr)
125         : Diags(Diags), Action(Action), HeaderSearchOpts(HeaderSearchOpts),
126           CodeGenOpts(CodeGenOpts), TargetOpts(TargetOpts), LangOpts(LangOpts),
127           AsmOutStream(std::move(OS)), Context(nullptr),
128           LLVMIRGeneration("irgen", "LLVM IR Generation Time"),
129           LLVMIRGenerationRefCount(0),
130           Gen(CreateLLVMCodeGen(Diags, InFile, HeaderSearchOpts, PPOpts,
131                                 CodeGenOpts, C, CoverageInfo)),
132           LinkModules(std::move(LinkModules)) {
133       FrontendTimesIsEnabled = TimePasses;
134       llvm::TimePassesIsEnabled = TimePasses;
135     }
136     llvm::Module *getModule() const { return Gen->GetModule(); }
137     std::unique_ptr<llvm::Module> takeModule() {
138       return std::unique_ptr<llvm::Module>(Gen->ReleaseModule());
139     }
140 
141     CodeGenerator *getCodeGenerator() { return Gen.get(); }
142 
143     void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override {
144       Gen->HandleCXXStaticMemberVarInstantiation(VD);
145     }
146 
147     void Initialize(ASTContext &Ctx) override {
148       assert(!Context && "initialized multiple times");
149 
150       Context = &Ctx;
151 
152       if (FrontendTimesIsEnabled)
153         LLVMIRGeneration.startTimer();
154 
155       Gen->Initialize(Ctx);
156 
157       if (FrontendTimesIsEnabled)
158         LLVMIRGeneration.stopTimer();
159     }
160 
161     bool HandleTopLevelDecl(DeclGroupRef D) override {
162       PrettyStackTraceDecl CrashInfo(*D.begin(), SourceLocation(),
163                                      Context->getSourceManager(),
164                                      "LLVM IR generation of declaration");
165 
166       // Recurse.
167       if (FrontendTimesIsEnabled) {
168         LLVMIRGenerationRefCount += 1;
169         if (LLVMIRGenerationRefCount == 1)
170           LLVMIRGeneration.startTimer();
171       }
172 
173       Gen->HandleTopLevelDecl(D);
174 
175       if (FrontendTimesIsEnabled) {
176         LLVMIRGenerationRefCount -= 1;
177         if (LLVMIRGenerationRefCount == 0)
178           LLVMIRGeneration.stopTimer();
179       }
180 
181       return true;
182     }
183 
184     void HandleInlineFunctionDefinition(FunctionDecl *D) override {
185       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
186                                      Context->getSourceManager(),
187                                      "LLVM IR generation of inline function");
188       if (FrontendTimesIsEnabled)
189         LLVMIRGeneration.startTimer();
190 
191       Gen->HandleInlineFunctionDefinition(D);
192 
193       if (FrontendTimesIsEnabled)
194         LLVMIRGeneration.stopTimer();
195     }
196 
197     void HandleInterestingDecl(DeclGroupRef D) override {
198       // Ignore interesting decls from the AST reader after IRGen is finished.
199       if (!IRGenFinished)
200         HandleTopLevelDecl(D);
201     }
202 
203     // Links each entry in LinkModules into our module.  Returns true on error.
204     bool LinkInModules() {
205       for (auto &LM : LinkModules) {
206         if (LM.PropagateAttrs)
207           for (Function &F : *LM.Module)
208             Gen->CGM().AddDefaultFnAttrs(F);
209 
210         CurLinkModule = LM.Module.get();
211 
212         bool Err;
213         if (LM.Internalize) {
214           Err = Linker::linkModules(
215               *getModule(), std::move(LM.Module), LM.LinkFlags,
216               [](llvm::Module &M, const llvm::StringSet<> &GVS) {
217                 internalizeModule(M, [&GVS](const llvm::GlobalValue &GV) {
218                   return !GV.hasName() || (GVS.count(GV.getName()) == 0);
219                 });
220               });
221         } else {
222           Err = Linker::linkModules(*getModule(), std::move(LM.Module),
223                                     LM.LinkFlags);
224         }
225 
226         if (Err)
227           return true;
228       }
229       return false; // success
230     }
231 
232     void HandleTranslationUnit(ASTContext &C) override {
233       {
234         llvm::TimeTraceScope TimeScope("Frontend", StringRef(""));
235         PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
236         if (FrontendTimesIsEnabled) {
237           LLVMIRGenerationRefCount += 1;
238           if (LLVMIRGenerationRefCount == 1)
239             LLVMIRGeneration.startTimer();
240         }
241 
242         Gen->HandleTranslationUnit(C);
243 
244         if (FrontendTimesIsEnabled) {
245           LLVMIRGenerationRefCount -= 1;
246           if (LLVMIRGenerationRefCount == 0)
247             LLVMIRGeneration.stopTimer();
248         }
249 
250         IRGenFinished = true;
251       }
252 
253       // Silently ignore if we weren't initialized for some reason.
254       if (!getModule())
255         return;
256 
257       // Install an inline asm handler so that diagnostics get printed through
258       // our diagnostics hooks.
259       LLVMContext &Ctx = getModule()->getContext();
260       LLVMContext::InlineAsmDiagHandlerTy OldHandler =
261         Ctx.getInlineAsmDiagnosticHandler();
262       void *OldContext = Ctx.getInlineAsmDiagnosticContext();
263       Ctx.setInlineAsmDiagnosticHandler(InlineAsmDiagHandler, this);
264 
265       std::unique_ptr<DiagnosticHandler> OldDiagnosticHandler =
266           Ctx.getDiagnosticHandler();
267       Ctx.setDiagnosticHandler(std::make_unique<ClangDiagnosticHandler>(
268         CodeGenOpts, this));
269 
270       Expected<std::unique_ptr<llvm::ToolOutputFile>> OptRecordFileOrErr =
271           setupOptimizationRemarks(Ctx, CodeGenOpts.OptRecordFile,
272                                    CodeGenOpts.OptRecordPasses,
273                                    CodeGenOpts.OptRecordFormat,
274                                    CodeGenOpts.DiagnosticsWithHotness,
275                                    CodeGenOpts.DiagnosticsHotnessThreshold);
276 
277       if (Error E = OptRecordFileOrErr.takeError()) {
278         handleAllErrors(
279             std::move(E),
280             [&](const RemarkSetupFileError &E) {
281               Diags.Report(diag::err_cannot_open_file)
282                   << CodeGenOpts.OptRecordFile << E.message();
283             },
284             [&](const RemarkSetupPatternError &E) {
285               Diags.Report(diag::err_drv_optimization_remark_pattern)
286                   << E.message() << CodeGenOpts.OptRecordPasses;
287             },
288             [&](const RemarkSetupFormatError &E) {
289               Diags.Report(diag::err_drv_optimization_remark_format)
290                   << CodeGenOpts.OptRecordFormat;
291             });
292         return;
293       }
294       std::unique_ptr<llvm::ToolOutputFile> OptRecordFile =
295           std::move(*OptRecordFileOrErr);
296 
297       if (OptRecordFile &&
298           CodeGenOpts.getProfileUse() != CodeGenOptions::ProfileNone)
299         Ctx.setDiagnosticsHotnessRequested(true);
300 
301       // Link each LinkModule into our module.
302       if (LinkInModules())
303         return;
304 
305       EmbedBitcode(getModule(), CodeGenOpts, llvm::MemoryBufferRef());
306 
307       EmitBackendOutput(Diags, HeaderSearchOpts, CodeGenOpts, TargetOpts,
308                         LangOpts, C.getTargetInfo().getDataLayout(),
309                         getModule(), Action, std::move(AsmOutStream));
310 
311       Ctx.setInlineAsmDiagnosticHandler(OldHandler, OldContext);
312 
313       Ctx.setDiagnosticHandler(std::move(OldDiagnosticHandler));
314 
315       if (OptRecordFile)
316         OptRecordFile->keep();
317     }
318 
319     void HandleTagDeclDefinition(TagDecl *D) override {
320       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
321                                      Context->getSourceManager(),
322                                      "LLVM IR generation of declaration");
323       Gen->HandleTagDeclDefinition(D);
324     }
325 
326     void HandleTagDeclRequiredDefinition(const TagDecl *D) override {
327       Gen->HandleTagDeclRequiredDefinition(D);
328     }
329 
330     void CompleteTentativeDefinition(VarDecl *D) override {
331       Gen->CompleteTentativeDefinition(D);
332     }
333 
334     void AssignInheritanceModel(CXXRecordDecl *RD) override {
335       Gen->AssignInheritanceModel(RD);
336     }
337 
338     void HandleVTable(CXXRecordDecl *RD) override {
339       Gen->HandleVTable(RD);
340     }
341 
342     static void InlineAsmDiagHandler(const llvm::SMDiagnostic &SM,void *Context,
343                                      unsigned LocCookie) {
344       SourceLocation Loc = SourceLocation::getFromRawEncoding(LocCookie);
345       ((BackendConsumer*)Context)->InlineAsmDiagHandler2(SM, Loc);
346     }
347 
348     /// Get the best possible source location to represent a diagnostic that
349     /// may have associated debug info.
350     const FullSourceLoc
351     getBestLocationFromDebugLoc(const llvm::DiagnosticInfoWithLocationBase &D,
352                                 bool &BadDebugInfo, StringRef &Filename,
353                                 unsigned &Line, unsigned &Column) const;
354 
355     void InlineAsmDiagHandler2(const llvm::SMDiagnostic &,
356                                SourceLocation LocCookie);
357 
358     void DiagnosticHandlerImpl(const llvm::DiagnosticInfo &DI);
359     /// Specialized handler for InlineAsm diagnostic.
360     /// \return True if the diagnostic has been successfully reported, false
361     /// otherwise.
362     bool InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D);
363     /// Specialized handler for StackSize diagnostic.
364     /// \return True if the diagnostic has been successfully reported, false
365     /// otherwise.
366     bool StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D);
367     /// Specialized handler for unsupported backend feature diagnostic.
368     void UnsupportedDiagHandler(const llvm::DiagnosticInfoUnsupported &D);
369     /// Specialized handler for misexpect warnings.
370     /// Note that misexpect remarks are emitted through ORE
371     void MisExpectDiagHandler(const llvm::DiagnosticInfoMisExpect &D);
372     /// Specialized handlers for optimization remarks.
373     /// Note that these handlers only accept remarks and they always handle
374     /// them.
375     void EmitOptimizationMessage(const llvm::DiagnosticInfoOptimizationBase &D,
376                                  unsigned DiagID);
377     void
378     OptimizationRemarkHandler(const llvm::DiagnosticInfoOptimizationBase &D);
379     void OptimizationRemarkHandler(
380         const llvm::OptimizationRemarkAnalysisFPCommute &D);
381     void OptimizationRemarkHandler(
382         const llvm::OptimizationRemarkAnalysisAliasing &D);
383     void OptimizationFailureHandler(
384         const llvm::DiagnosticInfoOptimizationFailure &D);
385   };
386 
387   void BackendConsumer::anchor() {}
388 }
389 
390 bool ClangDiagnosticHandler::handleDiagnostics(const DiagnosticInfo &DI) {
391   BackendCon->DiagnosticHandlerImpl(DI);
392   return true;
393 }
394 
395 /// ConvertBackendLocation - Convert a location in a temporary llvm::SourceMgr
396 /// buffer to be a valid FullSourceLoc.
397 static FullSourceLoc ConvertBackendLocation(const llvm::SMDiagnostic &D,
398                                             SourceManager &CSM) {
399   // Get both the clang and llvm source managers.  The location is relative to
400   // a memory buffer that the LLVM Source Manager is handling, we need to add
401   // a copy to the Clang source manager.
402   const llvm::SourceMgr &LSM = *D.getSourceMgr();
403 
404   // We need to copy the underlying LLVM memory buffer because llvm::SourceMgr
405   // already owns its one and clang::SourceManager wants to own its one.
406   const MemoryBuffer *LBuf =
407   LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
408 
409   // Create the copy and transfer ownership to clang::SourceManager.
410   // TODO: Avoid copying files into memory.
411   std::unique_ptr<llvm::MemoryBuffer> CBuf =
412       llvm::MemoryBuffer::getMemBufferCopy(LBuf->getBuffer(),
413                                            LBuf->getBufferIdentifier());
414   // FIXME: Keep a file ID map instead of creating new IDs for each location.
415   FileID FID = CSM.createFileID(std::move(CBuf));
416 
417   // Translate the offset into the file.
418   unsigned Offset = D.getLoc().getPointer() - LBuf->getBufferStart();
419   SourceLocation NewLoc =
420   CSM.getLocForStartOfFile(FID).getLocWithOffset(Offset);
421   return FullSourceLoc(NewLoc, CSM);
422 }
423 
424 
425 /// InlineAsmDiagHandler2 - This function is invoked when the backend hits an
426 /// error parsing inline asm.  The SMDiagnostic indicates the error relative to
427 /// the temporary memory buffer that the inline asm parser has set up.
428 void BackendConsumer::InlineAsmDiagHandler2(const llvm::SMDiagnostic &D,
429                                             SourceLocation LocCookie) {
430   // There are a couple of different kinds of errors we could get here.  First,
431   // we re-format the SMDiagnostic in terms of a clang diagnostic.
432 
433   // Strip "error: " off the start of the message string.
434   StringRef Message = D.getMessage();
435   if (Message.startswith("error: "))
436     Message = Message.substr(7);
437 
438   // If the SMDiagnostic has an inline asm source location, translate it.
439   FullSourceLoc Loc;
440   if (D.getLoc() != SMLoc())
441     Loc = ConvertBackendLocation(D, Context->getSourceManager());
442 
443   unsigned DiagID;
444   switch (D.getKind()) {
445   case llvm::SourceMgr::DK_Error:
446     DiagID = diag::err_fe_inline_asm;
447     break;
448   case llvm::SourceMgr::DK_Warning:
449     DiagID = diag::warn_fe_inline_asm;
450     break;
451   case llvm::SourceMgr::DK_Note:
452     DiagID = diag::note_fe_inline_asm;
453     break;
454   case llvm::SourceMgr::DK_Remark:
455     llvm_unreachable("remarks unexpected");
456   }
457   // If this problem has clang-level source location information, report the
458   // issue in the source with a note showing the instantiated
459   // code.
460   if (LocCookie.isValid()) {
461     Diags.Report(LocCookie, DiagID).AddString(Message);
462 
463     if (D.getLoc().isValid()) {
464       DiagnosticBuilder B = Diags.Report(Loc, diag::note_fe_inline_asm_here);
465       // Convert the SMDiagnostic ranges into SourceRange and attach them
466       // to the diagnostic.
467       for (const std::pair<unsigned, unsigned> &Range : D.getRanges()) {
468         unsigned Column = D.getColumnNo();
469         B << SourceRange(Loc.getLocWithOffset(Range.first - Column),
470                          Loc.getLocWithOffset(Range.second - Column));
471       }
472     }
473     return;
474   }
475 
476   // Otherwise, report the backend issue as occurring in the generated .s file.
477   // If Loc is invalid, we still need to report the issue, it just gets no
478   // location info.
479   Diags.Report(Loc, DiagID).AddString(Message);
480 }
481 
482 #define ComputeDiagID(Severity, GroupName, DiagID)                             \
483   do {                                                                         \
484     switch (Severity) {                                                        \
485     case llvm::DS_Error:                                                       \
486       DiagID = diag::err_fe_##GroupName;                                       \
487       break;                                                                   \
488     case llvm::DS_Warning:                                                     \
489       DiagID = diag::warn_fe_##GroupName;                                      \
490       break;                                                                   \
491     case llvm::DS_Remark:                                                      \
492       llvm_unreachable("'remark' severity not expected");                      \
493       break;                                                                   \
494     case llvm::DS_Note:                                                        \
495       DiagID = diag::note_fe_##GroupName;                                      \
496       break;                                                                   \
497     }                                                                          \
498   } while (false)
499 
500 #define ComputeDiagRemarkID(Severity, GroupName, DiagID)                       \
501   do {                                                                         \
502     switch (Severity) {                                                        \
503     case llvm::DS_Error:                                                       \
504       DiagID = diag::err_fe_##GroupName;                                       \
505       break;                                                                   \
506     case llvm::DS_Warning:                                                     \
507       DiagID = diag::warn_fe_##GroupName;                                      \
508       break;                                                                   \
509     case llvm::DS_Remark:                                                      \
510       DiagID = diag::remark_fe_##GroupName;                                    \
511       break;                                                                   \
512     case llvm::DS_Note:                                                        \
513       DiagID = diag::note_fe_##GroupName;                                      \
514       break;                                                                   \
515     }                                                                          \
516   } while (false)
517 
518 bool
519 BackendConsumer::InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D) {
520   unsigned DiagID;
521   ComputeDiagID(D.getSeverity(), inline_asm, DiagID);
522   std::string Message = D.getMsgStr().str();
523 
524   // If this problem has clang-level source location information, report the
525   // issue as being a problem in the source with a note showing the instantiated
526   // code.
527   SourceLocation LocCookie =
528       SourceLocation::getFromRawEncoding(D.getLocCookie());
529   if (LocCookie.isValid())
530     Diags.Report(LocCookie, DiagID).AddString(Message);
531   else {
532     // Otherwise, report the backend diagnostic as occurring in the generated
533     // .s file.
534     // If Loc is invalid, we still need to report the diagnostic, it just gets
535     // no location info.
536     FullSourceLoc Loc;
537     Diags.Report(Loc, DiagID).AddString(Message);
538   }
539   // We handled all the possible severities.
540   return true;
541 }
542 
543 bool
544 BackendConsumer::StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D) {
545   if (D.getSeverity() != llvm::DS_Warning)
546     // For now, the only support we have for StackSize diagnostic is warning.
547     // We do not know how to format other severities.
548     return false;
549 
550   if (const Decl *ND = Gen->GetDeclForMangledName(D.getFunction().getName())) {
551     // FIXME: Shouldn't need to truncate to uint32_t
552     Diags.Report(ND->getASTContext().getFullLoc(ND->getLocation()),
553                  diag::warn_fe_frame_larger_than)
554       << static_cast<uint32_t>(D.getStackSize()) << Decl::castToDeclContext(ND);
555     return true;
556   }
557 
558   return false;
559 }
560 
561 const FullSourceLoc BackendConsumer::getBestLocationFromDebugLoc(
562     const llvm::DiagnosticInfoWithLocationBase &D, bool &BadDebugInfo,
563     StringRef &Filename, unsigned &Line, unsigned &Column) const {
564   SourceManager &SourceMgr = Context->getSourceManager();
565   FileManager &FileMgr = SourceMgr.getFileManager();
566   SourceLocation DILoc;
567 
568   if (D.isLocationAvailable()) {
569     D.getLocation(Filename, Line, Column);
570     if (Line > 0) {
571       auto FE = FileMgr.getFile(Filename);
572       if (!FE)
573         FE = FileMgr.getFile(D.getAbsolutePath());
574       if (FE) {
575         // If -gcolumn-info was not used, Column will be 0. This upsets the
576         // source manager, so pass 1 if Column is not set.
577         DILoc = SourceMgr.translateFileLineCol(*FE, Line, Column ? Column : 1);
578       }
579     }
580     BadDebugInfo = DILoc.isInvalid();
581   }
582 
583   // If a location isn't available, try to approximate it using the associated
584   // function definition. We use the definition's right brace to differentiate
585   // from diagnostics that genuinely relate to the function itself.
586   FullSourceLoc Loc(DILoc, SourceMgr);
587   if (Loc.isInvalid())
588     if (const Decl *FD = Gen->GetDeclForMangledName(D.getFunction().getName()))
589       Loc = FD->getASTContext().getFullLoc(FD->getLocation());
590 
591   if (DILoc.isInvalid() && D.isLocationAvailable())
592     // If we were not able to translate the file:line:col information
593     // back to a SourceLocation, at least emit a note stating that
594     // we could not translate this location. This can happen in the
595     // case of #line directives.
596     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
597         << Filename << Line << Column;
598 
599   return Loc;
600 }
601 
602 void BackendConsumer::UnsupportedDiagHandler(
603     const llvm::DiagnosticInfoUnsupported &D) {
604   // We only support errors.
605   assert(D.getSeverity() == llvm::DS_Error);
606 
607   StringRef Filename;
608   unsigned Line, Column;
609   bool BadDebugInfo = false;
610   FullSourceLoc Loc =
611       getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
612 
613   Diags.Report(Loc, diag::err_fe_backend_unsupported) << D.getMessage().str();
614 
615   if (BadDebugInfo)
616     // If we were not able to translate the file:line:col information
617     // back to a SourceLocation, at least emit a note stating that
618     // we could not translate this location. This can happen in the
619     // case of #line directives.
620     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
621         << Filename << Line << Column;
622 }
623 
624 void BackendConsumer::MisExpectDiagHandler(
625     const llvm::DiagnosticInfoMisExpect &D) {
626   StringRef Filename;
627   unsigned Line, Column;
628   bool BadDebugInfo = false;
629   FullSourceLoc Loc =
630       getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
631 
632   Diags.Report(Loc, diag::warn_profile_data_misexpect) << D.getMsg().str();
633 
634   if (BadDebugInfo)
635     // If we were not able to translate the file:line:col information
636     // back to a SourceLocation, at least emit a note stating that
637     // we could not translate this location. This can happen in the
638     // case of #line directives.
639     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
640         << Filename << Line << Column;
641 }
642 
643 void BackendConsumer::EmitOptimizationMessage(
644     const llvm::DiagnosticInfoOptimizationBase &D, unsigned DiagID) {
645   // We only support warnings and remarks.
646   assert(D.getSeverity() == llvm::DS_Remark ||
647          D.getSeverity() == llvm::DS_Warning);
648 
649   StringRef Filename;
650   unsigned Line, Column;
651   bool BadDebugInfo = false;
652   FullSourceLoc Loc =
653       getBestLocationFromDebugLoc(D, BadDebugInfo, Filename, Line, Column);
654 
655   std::string Msg;
656   raw_string_ostream MsgStream(Msg);
657   MsgStream << D.getMsg();
658 
659   if (D.getHotness())
660     MsgStream << " (hotness: " << *D.getHotness() << ")";
661 
662   Diags.Report(Loc, DiagID)
663       << AddFlagValue(D.getPassName())
664       << MsgStream.str();
665 
666   if (BadDebugInfo)
667     // If we were not able to translate the file:line:col information
668     // back to a SourceLocation, at least emit a note stating that
669     // we could not translate this location. This can happen in the
670     // case of #line directives.
671     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
672         << Filename << Line << Column;
673 }
674 
675 void BackendConsumer::OptimizationRemarkHandler(
676     const llvm::DiagnosticInfoOptimizationBase &D) {
677   // Without hotness information, don't show noisy remarks.
678   if (D.isVerbose() && !D.getHotness())
679     return;
680 
681   if (D.isPassed()) {
682     // Optimization remarks are active only if the -Rpass flag has a regular
683     // expression that matches the name of the pass name in \p D.
684     if (CodeGenOpts.OptimizationRemarkPattern &&
685         CodeGenOpts.OptimizationRemarkPattern->match(D.getPassName()))
686       EmitOptimizationMessage(D, diag::remark_fe_backend_optimization_remark);
687   } else if (D.isMissed()) {
688     // Missed optimization remarks are active only if the -Rpass-missed
689     // flag has a regular expression that matches the name of the pass
690     // name in \p D.
691     if (CodeGenOpts.OptimizationRemarkMissedPattern &&
692         CodeGenOpts.OptimizationRemarkMissedPattern->match(D.getPassName()))
693       EmitOptimizationMessage(
694           D, diag::remark_fe_backend_optimization_remark_missed);
695   } else {
696     assert(D.isAnalysis() && "Unknown remark type");
697 
698     bool ShouldAlwaysPrint = false;
699     if (auto *ORA = dyn_cast<llvm::OptimizationRemarkAnalysis>(&D))
700       ShouldAlwaysPrint = ORA->shouldAlwaysPrint();
701 
702     if (ShouldAlwaysPrint ||
703         (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
704          CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
705       EmitOptimizationMessage(
706           D, diag::remark_fe_backend_optimization_remark_analysis);
707   }
708 }
709 
710 void BackendConsumer::OptimizationRemarkHandler(
711     const llvm::OptimizationRemarkAnalysisFPCommute &D) {
712   // Optimization analysis remarks are active if the pass name is set to
713   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
714   // regular expression that matches the name of the pass name in \p D.
715 
716   if (D.shouldAlwaysPrint() ||
717       (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
718        CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
719     EmitOptimizationMessage(
720         D, diag::remark_fe_backend_optimization_remark_analysis_fpcommute);
721 }
722 
723 void BackendConsumer::OptimizationRemarkHandler(
724     const llvm::OptimizationRemarkAnalysisAliasing &D) {
725   // Optimization analysis remarks are active if the pass name is set to
726   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
727   // regular expression that matches the name of the pass name in \p D.
728 
729   if (D.shouldAlwaysPrint() ||
730       (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
731        CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
732     EmitOptimizationMessage(
733         D, diag::remark_fe_backend_optimization_remark_analysis_aliasing);
734 }
735 
736 void BackendConsumer::OptimizationFailureHandler(
737     const llvm::DiagnosticInfoOptimizationFailure &D) {
738   EmitOptimizationMessage(D, diag::warn_fe_backend_optimization_failure);
739 }
740 
741 /// This function is invoked when the backend needs
742 /// to report something to the user.
743 void BackendConsumer::DiagnosticHandlerImpl(const DiagnosticInfo &DI) {
744   unsigned DiagID = diag::err_fe_inline_asm;
745   llvm::DiagnosticSeverity Severity = DI.getSeverity();
746   // Get the diagnostic ID based.
747   switch (DI.getKind()) {
748   case llvm::DK_InlineAsm:
749     if (InlineAsmDiagHandler(cast<DiagnosticInfoInlineAsm>(DI)))
750       return;
751     ComputeDiagID(Severity, inline_asm, DiagID);
752     break;
753   case llvm::DK_StackSize:
754     if (StackSizeDiagHandler(cast<DiagnosticInfoStackSize>(DI)))
755       return;
756     ComputeDiagID(Severity, backend_frame_larger_than, DiagID);
757     break;
758   case DK_Linker:
759     assert(CurLinkModule);
760     // FIXME: stop eating the warnings and notes.
761     if (Severity != DS_Error)
762       return;
763     DiagID = diag::err_fe_cannot_link_module;
764     break;
765   case llvm::DK_OptimizationRemark:
766     // Optimization remarks are always handled completely by this
767     // handler. There is no generic way of emitting them.
768     OptimizationRemarkHandler(cast<OptimizationRemark>(DI));
769     return;
770   case llvm::DK_OptimizationRemarkMissed:
771     // Optimization remarks are always handled completely by this
772     // handler. There is no generic way of emitting them.
773     OptimizationRemarkHandler(cast<OptimizationRemarkMissed>(DI));
774     return;
775   case llvm::DK_OptimizationRemarkAnalysis:
776     // Optimization remarks are always handled completely by this
777     // handler. There is no generic way of emitting them.
778     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysis>(DI));
779     return;
780   case llvm::DK_OptimizationRemarkAnalysisFPCommute:
781     // Optimization remarks are always handled completely by this
782     // handler. There is no generic way of emitting them.
783     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysisFPCommute>(DI));
784     return;
785   case llvm::DK_OptimizationRemarkAnalysisAliasing:
786     // Optimization remarks are always handled completely by this
787     // handler. There is no generic way of emitting them.
788     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysisAliasing>(DI));
789     return;
790   case llvm::DK_MachineOptimizationRemark:
791     // Optimization remarks are always handled completely by this
792     // handler. There is no generic way of emitting them.
793     OptimizationRemarkHandler(cast<MachineOptimizationRemark>(DI));
794     return;
795   case llvm::DK_MachineOptimizationRemarkMissed:
796     // Optimization remarks are always handled completely by this
797     // handler. There is no generic way of emitting them.
798     OptimizationRemarkHandler(cast<MachineOptimizationRemarkMissed>(DI));
799     return;
800   case llvm::DK_MachineOptimizationRemarkAnalysis:
801     // Optimization remarks are always handled completely by this
802     // handler. There is no generic way of emitting them.
803     OptimizationRemarkHandler(cast<MachineOptimizationRemarkAnalysis>(DI));
804     return;
805   case llvm::DK_OptimizationFailure:
806     // Optimization failures are always handled completely by this
807     // handler.
808     OptimizationFailureHandler(cast<DiagnosticInfoOptimizationFailure>(DI));
809     return;
810   case llvm::DK_Unsupported:
811     UnsupportedDiagHandler(cast<DiagnosticInfoUnsupported>(DI));
812     return;
813   case llvm::DK_MisExpect:
814     MisExpectDiagHandler(cast<DiagnosticInfoMisExpect>(DI));
815     return;
816   default:
817     // Plugin IDs are not bound to any value as they are set dynamically.
818     ComputeDiagRemarkID(Severity, backend_plugin, DiagID);
819     break;
820   }
821   std::string MsgStorage;
822   {
823     raw_string_ostream Stream(MsgStorage);
824     DiagnosticPrinterRawOStream DP(Stream);
825     DI.print(DP);
826   }
827 
828   if (DiagID == diag::err_fe_cannot_link_module) {
829     Diags.Report(diag::err_fe_cannot_link_module)
830         << CurLinkModule->getModuleIdentifier() << MsgStorage;
831     return;
832   }
833 
834   // Report the backend message using the usual diagnostic mechanism.
835   FullSourceLoc Loc;
836   Diags.Report(Loc, DiagID).AddString(MsgStorage);
837 }
838 #undef ComputeDiagID
839 
840 CodeGenAction::CodeGenAction(unsigned _Act, LLVMContext *_VMContext)
841     : Act(_Act), VMContext(_VMContext ? _VMContext : new LLVMContext),
842       OwnsVMContext(!_VMContext) {}
843 
844 CodeGenAction::~CodeGenAction() {
845   TheModule.reset();
846   if (OwnsVMContext)
847     delete VMContext;
848 }
849 
850 bool CodeGenAction::hasIRSupport() const { return true; }
851 
852 void CodeGenAction::EndSourceFileAction() {
853   // If the consumer creation failed, do nothing.
854   if (!getCompilerInstance().hasASTConsumer())
855     return;
856 
857   // Steal the module from the consumer.
858   TheModule = BEConsumer->takeModule();
859 }
860 
861 std::unique_ptr<llvm::Module> CodeGenAction::takeModule() {
862   return std::move(TheModule);
863 }
864 
865 llvm::LLVMContext *CodeGenAction::takeLLVMContext() {
866   OwnsVMContext = false;
867   return VMContext;
868 }
869 
870 static std::unique_ptr<raw_pwrite_stream>
871 GetOutputStream(CompilerInstance &CI, StringRef InFile, BackendAction Action) {
872   switch (Action) {
873   case Backend_EmitAssembly:
874     return CI.createDefaultOutputFile(false, InFile, "s");
875   case Backend_EmitLL:
876     return CI.createDefaultOutputFile(false, InFile, "ll");
877   case Backend_EmitBC:
878     return CI.createDefaultOutputFile(true, InFile, "bc");
879   case Backend_EmitNothing:
880     return nullptr;
881   case Backend_EmitMCNull:
882     return CI.createNullOutputFile();
883   case Backend_EmitObj:
884     return CI.createDefaultOutputFile(true, InFile, "o");
885   }
886 
887   llvm_unreachable("Invalid action!");
888 }
889 
890 std::unique_ptr<ASTConsumer>
891 CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
892   BackendAction BA = static_cast<BackendAction>(Act);
893   std::unique_ptr<raw_pwrite_stream> OS = CI.takeOutputStream();
894   if (!OS)
895     OS = GetOutputStream(CI, InFile, BA);
896 
897   if (BA != Backend_EmitNothing && !OS)
898     return nullptr;
899 
900   // Load bitcode modules to link with, if we need to.
901   if (LinkModules.empty())
902     for (const CodeGenOptions::BitcodeFileToLink &F :
903          CI.getCodeGenOpts().LinkBitcodeFiles) {
904       auto BCBuf = CI.getFileManager().getBufferForFile(F.Filename);
905       if (!BCBuf) {
906         CI.getDiagnostics().Report(diag::err_cannot_open_file)
907             << F.Filename << BCBuf.getError().message();
908         LinkModules.clear();
909         return nullptr;
910       }
911 
912       Expected<std::unique_ptr<llvm::Module>> ModuleOrErr =
913           getOwningLazyBitcodeModule(std::move(*BCBuf), *VMContext);
914       if (!ModuleOrErr) {
915         handleAllErrors(ModuleOrErr.takeError(), [&](ErrorInfoBase &EIB) {
916           CI.getDiagnostics().Report(diag::err_cannot_open_file)
917               << F.Filename << EIB.message();
918         });
919         LinkModules.clear();
920         return nullptr;
921       }
922       LinkModules.push_back({std::move(ModuleOrErr.get()), F.PropagateAttrs,
923                              F.Internalize, F.LinkFlags});
924     }
925 
926   CoverageSourceInfo *CoverageInfo = nullptr;
927   // Add the preprocessor callback only when the coverage mapping is generated.
928   if (CI.getCodeGenOpts().CoverageMapping) {
929     CoverageInfo = new CoverageSourceInfo;
930     CI.getPreprocessor().addPPCallbacks(
931                                     std::unique_ptr<PPCallbacks>(CoverageInfo));
932   }
933 
934   std::unique_ptr<BackendConsumer> Result(new BackendConsumer(
935       BA, CI.getDiagnostics(), CI.getHeaderSearchOpts(),
936       CI.getPreprocessorOpts(), CI.getCodeGenOpts(), CI.getTargetOpts(),
937       CI.getLangOpts(), CI.getFrontendOpts().ShowTimers, InFile,
938       std::move(LinkModules), std::move(OS), *VMContext, CoverageInfo));
939   BEConsumer = Result.get();
940 
941   // Enable generating macro debug info only when debug info is not disabled and
942   // also macro debug info is enabled.
943   if (CI.getCodeGenOpts().getDebugInfo() != codegenoptions::NoDebugInfo &&
944       CI.getCodeGenOpts().MacroDebugInfo) {
945     std::unique_ptr<PPCallbacks> Callbacks =
946         std::make_unique<MacroPPCallbacks>(BEConsumer->getCodeGenerator(),
947                                             CI.getPreprocessor());
948     CI.getPreprocessor().addPPCallbacks(std::move(Callbacks));
949   }
950 
951   return std::move(Result);
952 }
953 
954 static void BitcodeInlineAsmDiagHandler(const llvm::SMDiagnostic &SM,
955                                          void *Context,
956                                          unsigned LocCookie) {
957   SM.print(nullptr, llvm::errs());
958 
959   auto Diags = static_cast<DiagnosticsEngine *>(Context);
960   unsigned DiagID;
961   switch (SM.getKind()) {
962   case llvm::SourceMgr::DK_Error:
963     DiagID = diag::err_fe_inline_asm;
964     break;
965   case llvm::SourceMgr::DK_Warning:
966     DiagID = diag::warn_fe_inline_asm;
967     break;
968   case llvm::SourceMgr::DK_Note:
969     DiagID = diag::note_fe_inline_asm;
970     break;
971   case llvm::SourceMgr::DK_Remark:
972     llvm_unreachable("remarks unexpected");
973   }
974 
975   Diags->Report(DiagID).AddString("cannot compile inline asm");
976 }
977 
978 std::unique_ptr<llvm::Module>
979 CodeGenAction::loadModule(MemoryBufferRef MBRef) {
980   CompilerInstance &CI = getCompilerInstance();
981   SourceManager &SM = CI.getSourceManager();
982 
983   // For ThinLTO backend invocations, ensure that the context
984   // merges types based on ODR identifiers. We also need to read
985   // the correct module out of a multi-module bitcode file.
986   if (!CI.getCodeGenOpts().ThinLTOIndexFile.empty()) {
987     VMContext->enableDebugTypeODRUniquing();
988 
989     auto DiagErrors = [&](Error E) -> std::unique_ptr<llvm::Module> {
990       unsigned DiagID =
991           CI.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, "%0");
992       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
993         CI.getDiagnostics().Report(DiagID) << EIB.message();
994       });
995       return {};
996     };
997 
998     Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
999     if (!BMsOrErr)
1000       return DiagErrors(BMsOrErr.takeError());
1001     BitcodeModule *Bm = FindThinLTOModule(*BMsOrErr);
1002     // We have nothing to do if the file contains no ThinLTO module. This is
1003     // possible if ThinLTO compilation was not able to split module. Content of
1004     // the file was already processed by indexing and will be passed to the
1005     // linker using merged object file.
1006     if (!Bm) {
1007       auto M = std::make_unique<llvm::Module>("empty", *VMContext);
1008       M->setTargetTriple(CI.getTargetOpts().Triple);
1009       return M;
1010     }
1011     Expected<std::unique_ptr<llvm::Module>> MOrErr =
1012         Bm->parseModule(*VMContext);
1013     if (!MOrErr)
1014       return DiagErrors(MOrErr.takeError());
1015     return std::move(*MOrErr);
1016   }
1017 
1018   llvm::SMDiagnostic Err;
1019   if (std::unique_ptr<llvm::Module> M = parseIR(MBRef, Err, *VMContext))
1020     return M;
1021 
1022   // Translate from the diagnostic info to the SourceManager location if
1023   // available.
1024   // TODO: Unify this with ConvertBackendLocation()
1025   SourceLocation Loc;
1026   if (Err.getLineNo() > 0) {
1027     assert(Err.getColumnNo() >= 0);
1028     Loc = SM.translateFileLineCol(SM.getFileEntryForID(SM.getMainFileID()),
1029                                   Err.getLineNo(), Err.getColumnNo() + 1);
1030   }
1031 
1032   // Strip off a leading diagnostic code if there is one.
1033   StringRef Msg = Err.getMessage();
1034   if (Msg.startswith("error: "))
1035     Msg = Msg.substr(7);
1036 
1037   unsigned DiagID =
1038       CI.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1039 
1040   CI.getDiagnostics().Report(Loc, DiagID) << Msg;
1041   return {};
1042 }
1043 
1044 void CodeGenAction::ExecuteAction() {
1045   // If this is an IR file, we have to treat it specially.
1046   if (getCurrentFileKind().getLanguage() == Language::LLVM_IR) {
1047     BackendAction BA = static_cast<BackendAction>(Act);
1048     CompilerInstance &CI = getCompilerInstance();
1049     std::unique_ptr<raw_pwrite_stream> OS =
1050         GetOutputStream(CI, getCurrentFile(), BA);
1051     if (BA != Backend_EmitNothing && !OS)
1052       return;
1053 
1054     bool Invalid;
1055     SourceManager &SM = CI.getSourceManager();
1056     FileID FID = SM.getMainFileID();
1057     const llvm::MemoryBuffer *MainFile = SM.getBuffer(FID, &Invalid);
1058     if (Invalid)
1059       return;
1060 
1061     TheModule = loadModule(*MainFile);
1062     if (!TheModule)
1063       return;
1064 
1065     const TargetOptions &TargetOpts = CI.getTargetOpts();
1066     if (TheModule->getTargetTriple() != TargetOpts.Triple) {
1067       CI.getDiagnostics().Report(SourceLocation(),
1068                                  diag::warn_fe_override_module)
1069           << TargetOpts.Triple;
1070       TheModule->setTargetTriple(TargetOpts.Triple);
1071     }
1072 
1073     EmbedBitcode(TheModule.get(), CI.getCodeGenOpts(),
1074                  MainFile->getMemBufferRef());
1075 
1076     LLVMContext &Ctx = TheModule->getContext();
1077     Ctx.setInlineAsmDiagnosticHandler(BitcodeInlineAsmDiagHandler,
1078                                       &CI.getDiagnostics());
1079 
1080     EmitBackendOutput(CI.getDiagnostics(), CI.getHeaderSearchOpts(),
1081                       CI.getCodeGenOpts(), TargetOpts, CI.getLangOpts(),
1082                       CI.getTarget().getDataLayout(), TheModule.get(), BA,
1083                       std::move(OS));
1084     return;
1085   }
1086 
1087   // Otherwise follow the normal AST path.
1088   this->ASTFrontendAction::ExecuteAction();
1089 }
1090 
1091 //
1092 
1093 void EmitAssemblyAction::anchor() { }
1094 EmitAssemblyAction::EmitAssemblyAction(llvm::LLVMContext *_VMContext)
1095   : CodeGenAction(Backend_EmitAssembly, _VMContext) {}
1096 
1097 void EmitBCAction::anchor() { }
1098 EmitBCAction::EmitBCAction(llvm::LLVMContext *_VMContext)
1099   : CodeGenAction(Backend_EmitBC, _VMContext) {}
1100 
1101 void EmitLLVMAction::anchor() { }
1102 EmitLLVMAction::EmitLLVMAction(llvm::LLVMContext *_VMContext)
1103   : CodeGenAction(Backend_EmitLL, _VMContext) {}
1104 
1105 void EmitLLVMOnlyAction::anchor() { }
1106 EmitLLVMOnlyAction::EmitLLVMOnlyAction(llvm::LLVMContext *_VMContext)
1107   : CodeGenAction(Backend_EmitNothing, _VMContext) {}
1108 
1109 void EmitCodeGenOnlyAction::anchor() { }
1110 EmitCodeGenOnlyAction::EmitCodeGenOnlyAction(llvm::LLVMContext *_VMContext)
1111   : CodeGenAction(Backend_EmitMCNull, _VMContext) {}
1112 
1113 void EmitObjAction::anchor() { }
1114 EmitObjAction::EmitObjAction(llvm::LLVMContext *_VMContext)
1115   : CodeGenAction(Backend_EmitObj, _VMContext) {}
1116