xref: /llvm-project/clang/lib/CodeGen/CodeGenAction.cpp (revision 7a964feccbc3b366223a1f0b4c1f51c7e4a1d695)
1 //===--- CodeGenAction.cpp - LLVM Code Generation Frontend Action ---------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "CoverageMappingGen.h"
11 #include "clang/AST/ASTConsumer.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/AST/DeclCXX.h"
14 #include "clang/AST/DeclGroup.h"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Basic/SourceManager.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/CodeGen/BackendUtil.h"
19 #include "clang/CodeGen/CodeGenAction.h"
20 #include "clang/CodeGen/ModuleBuilder.h"
21 #include "clang/Frontend/CompilerInstance.h"
22 #include "clang/Frontend/FrontendDiagnostic.h"
23 #include "clang/Lex/Preprocessor.h"
24 #include "llvm/ADT/SmallString.h"
25 #include "llvm/Bitcode/ReaderWriter.h"
26 #include "llvm/CodeGen/DiagnosticInfoCodeGen.h"
27 #include "llvm/IR/DebugInfo.h"
28 #include "llvm/IR/DiagnosticInfo.h"
29 #include "llvm/IR/DiagnosticPrinter.h"
30 #include "llvm/IR/LLVMContext.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/IRReader/IRReader.h"
33 #include "llvm/Linker/Linker.h"
34 #include "llvm/Pass.h"
35 #include "llvm/Support/MemoryBuffer.h"
36 #include "llvm/Support/SourceMgr.h"
37 #include "llvm/Support/Timer.h"
38 #include <memory>
39 using namespace clang;
40 using namespace llvm;
41 
42 namespace clang {
43   class BackendConsumer : public ASTConsumer {
44     virtual void anchor();
45     DiagnosticsEngine &Diags;
46     BackendAction Action;
47     const CodeGenOptions &CodeGenOpts;
48     const TargetOptions &TargetOpts;
49     const LangOptions &LangOpts;
50     raw_pwrite_stream *AsmOutStream;
51     ASTContext *Context;
52 
53     Timer LLVMIRGeneration;
54 
55     std::unique_ptr<CodeGenerator> Gen;
56 
57     std::unique_ptr<llvm::Module> TheModule;
58     SmallVector<std::pair<unsigned, std::unique_ptr<llvm::Module>>, 4>
59         LinkModules;
60 
61     // This is here so that the diagnostic printer knows the module a diagnostic
62     // refers to.
63     llvm::Module *CurLinkModule = nullptr;
64 
65   public:
66     BackendConsumer(
67         BackendAction Action, DiagnosticsEngine &Diags,
68         const HeaderSearchOptions &HeaderSearchOpts,
69         const PreprocessorOptions &PPOpts, const CodeGenOptions &CodeGenOpts,
70         const TargetOptions &TargetOpts, const LangOptions &LangOpts,
71         bool TimePasses, const std::string &InFile,
72         const SmallVectorImpl<std::pair<unsigned, llvm::Module *>> &LinkModules,
73         raw_pwrite_stream *OS, LLVMContext &C,
74         CoverageSourceInfo *CoverageInfo = nullptr)
75         : Diags(Diags), Action(Action), CodeGenOpts(CodeGenOpts),
76           TargetOpts(TargetOpts), LangOpts(LangOpts), AsmOutStream(OS),
77           Context(nullptr), LLVMIRGeneration("LLVM IR Generation Time"),
78           Gen(CreateLLVMCodeGen(Diags, InFile, HeaderSearchOpts, PPOpts,
79                                 CodeGenOpts, C, CoverageInfo)) {
80       llvm::TimePassesIsEnabled = TimePasses;
81       for (auto &I : LinkModules)
82         this->LinkModules.push_back(
83             std::make_pair(I.first, std::unique_ptr<llvm::Module>(I.second)));
84     }
85     std::unique_ptr<llvm::Module> takeModule() { return std::move(TheModule); }
86     void releaseLinkModules() {
87       for (auto &I : LinkModules)
88         I.second.release();
89     }
90 
91     void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override {
92       Gen->HandleCXXStaticMemberVarInstantiation(VD);
93     }
94 
95     void Initialize(ASTContext &Ctx) override {
96       assert(!Context && "initialized multiple times");
97 
98       Context = &Ctx;
99 
100       if (llvm::TimePassesIsEnabled)
101         LLVMIRGeneration.startTimer();
102 
103       Gen->Initialize(Ctx);
104 
105       TheModule.reset(Gen->GetModule());
106 
107       if (llvm::TimePassesIsEnabled)
108         LLVMIRGeneration.stopTimer();
109     }
110 
111     bool HandleTopLevelDecl(DeclGroupRef D) override {
112       PrettyStackTraceDecl CrashInfo(*D.begin(), SourceLocation(),
113                                      Context->getSourceManager(),
114                                      "LLVM IR generation of declaration");
115 
116       if (llvm::TimePassesIsEnabled)
117         LLVMIRGeneration.startTimer();
118 
119       Gen->HandleTopLevelDecl(D);
120 
121       if (llvm::TimePassesIsEnabled)
122         LLVMIRGeneration.stopTimer();
123 
124       return true;
125     }
126 
127     void HandleInlineMethodDefinition(CXXMethodDecl *D) override {
128       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
129                                      Context->getSourceManager(),
130                                      "LLVM IR generation of inline method");
131       if (llvm::TimePassesIsEnabled)
132         LLVMIRGeneration.startTimer();
133 
134       Gen->HandleInlineMethodDefinition(D);
135 
136       if (llvm::TimePassesIsEnabled)
137         LLVMIRGeneration.stopTimer();
138     }
139 
140     void HandleTranslationUnit(ASTContext &C) override {
141       {
142         PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
143         if (llvm::TimePassesIsEnabled)
144           LLVMIRGeneration.startTimer();
145 
146         Gen->HandleTranslationUnit(C);
147 
148         if (llvm::TimePassesIsEnabled)
149           LLVMIRGeneration.stopTimer();
150       }
151 
152       // Silently ignore if we weren't initialized for some reason.
153       if (!TheModule)
154         return;
155 
156       // Make sure IR generation is happy with the module. This is released by
157       // the module provider.
158       llvm::Module *M = Gen->ReleaseModule();
159       if (!M) {
160         // The module has been released by IR gen on failures, do not double
161         // free.
162         TheModule.release();
163         return;
164       }
165 
166       assert(TheModule.get() == M &&
167              "Unexpected module change during IR generation");
168 
169       // Install an inline asm handler so that diagnostics get printed through
170       // our diagnostics hooks.
171       LLVMContext &Ctx = TheModule->getContext();
172       LLVMContext::InlineAsmDiagHandlerTy OldHandler =
173         Ctx.getInlineAsmDiagnosticHandler();
174       void *OldContext = Ctx.getInlineAsmDiagnosticContext();
175       Ctx.setInlineAsmDiagnosticHandler(InlineAsmDiagHandler, this);
176 
177       LLVMContext::DiagnosticHandlerTy OldDiagnosticHandler =
178           Ctx.getDiagnosticHandler();
179       void *OldDiagnosticContext = Ctx.getDiagnosticContext();
180       Ctx.setDiagnosticHandler(DiagnosticHandler, this);
181 
182       // Link LinkModule into this module if present, preserving its validity.
183       for (auto &I : LinkModules) {
184         unsigned LinkFlags = I.first;
185         CurLinkModule = I.second.get();
186         if (Linker::linkModules(*M, std::move(I.second), LinkFlags))
187           return;
188       }
189 
190       EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
191                         C.getTargetInfo().getDataLayoutString(),
192                         TheModule.get(), Action, AsmOutStream);
193 
194       Ctx.setInlineAsmDiagnosticHandler(OldHandler, OldContext);
195 
196       Ctx.setDiagnosticHandler(OldDiagnosticHandler, OldDiagnosticContext);
197     }
198 
199     void HandleTagDeclDefinition(TagDecl *D) override {
200       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
201                                      Context->getSourceManager(),
202                                      "LLVM IR generation of declaration");
203       Gen->HandleTagDeclDefinition(D);
204     }
205 
206     void HandleTagDeclRequiredDefinition(const TagDecl *D) override {
207       Gen->HandleTagDeclRequiredDefinition(D);
208     }
209 
210     void CompleteTentativeDefinition(VarDecl *D) override {
211       Gen->CompleteTentativeDefinition(D);
212     }
213 
214     void AssignInheritanceModel(CXXRecordDecl *RD) override {
215       Gen->AssignInheritanceModel(RD);
216     }
217 
218     void HandleVTable(CXXRecordDecl *RD) override {
219       Gen->HandleVTable(RD);
220     }
221 
222     void HandleLinkerOption(llvm::StringRef Opts) override {
223       Gen->HandleLinkerOption(Opts);
224     }
225 
226     void HandleDetectMismatch(llvm::StringRef Name,
227                                       llvm::StringRef Value) override {
228       Gen->HandleDetectMismatch(Name, Value);
229     }
230 
231     void HandleDependentLibrary(llvm::StringRef Opts) override {
232       Gen->HandleDependentLibrary(Opts);
233     }
234 
235     static void InlineAsmDiagHandler(const llvm::SMDiagnostic &SM,void *Context,
236                                      unsigned LocCookie) {
237       SourceLocation Loc = SourceLocation::getFromRawEncoding(LocCookie);
238       ((BackendConsumer*)Context)->InlineAsmDiagHandler2(SM, Loc);
239     }
240 
241     static void DiagnosticHandler(const llvm::DiagnosticInfo &DI,
242                                   void *Context) {
243       ((BackendConsumer *)Context)->DiagnosticHandlerImpl(DI);
244     }
245 
246     /// Get the best possible source location to represent a diagnostic that
247     /// may have associated debug info.
248     const FullSourceLoc
249     getBestLocationFromDebugLoc(const llvm::DiagnosticInfoWithDebugLocBase &D,
250                                 bool &BadDebugInfo, StringRef &Filename,
251                                 unsigned &Line, unsigned &Column) const;
252 
253     void InlineAsmDiagHandler2(const llvm::SMDiagnostic &,
254                                SourceLocation LocCookie);
255 
256     void DiagnosticHandlerImpl(const llvm::DiagnosticInfo &DI);
257     /// \brief Specialized handler for InlineAsm diagnostic.
258     /// \return True if the diagnostic has been successfully reported, false
259     /// otherwise.
260     bool InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D);
261     /// \brief Specialized handler for StackSize diagnostic.
262     /// \return True if the diagnostic has been successfully reported, false
263     /// otherwise.
264     bool StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D);
265     /// \brief Specialized handler for unsupported backend feature diagnostic.
266     void UnsupportedDiagHandler(const llvm::DiagnosticInfoUnsupported &D);
267     /// \brief Specialized handlers for optimization remarks.
268     /// Note that these handlers only accept remarks and they always handle
269     /// them.
270     void EmitOptimizationMessage(const llvm::DiagnosticInfoOptimizationBase &D,
271                                  unsigned DiagID);
272     void
273     OptimizationRemarkHandler(const llvm::DiagnosticInfoOptimizationRemark &D);
274     void OptimizationRemarkHandler(
275         const llvm::DiagnosticInfoOptimizationRemarkMissed &D);
276     void OptimizationRemarkHandler(
277         const llvm::DiagnosticInfoOptimizationRemarkAnalysis &D);
278     void OptimizationRemarkHandler(
279         const llvm::DiagnosticInfoOptimizationRemarkAnalysisFPCommute &D);
280     void OptimizationRemarkHandler(
281         const llvm::DiagnosticInfoOptimizationRemarkAnalysisAliasing &D);
282     void OptimizationFailureHandler(
283         const llvm::DiagnosticInfoOptimizationFailure &D);
284   };
285 
286   void BackendConsumer::anchor() {}
287 }
288 
289 /// ConvertBackendLocation - Convert a location in a temporary llvm::SourceMgr
290 /// buffer to be a valid FullSourceLoc.
291 static FullSourceLoc ConvertBackendLocation(const llvm::SMDiagnostic &D,
292                                             SourceManager &CSM) {
293   // Get both the clang and llvm source managers.  The location is relative to
294   // a memory buffer that the LLVM Source Manager is handling, we need to add
295   // a copy to the Clang source manager.
296   const llvm::SourceMgr &LSM = *D.getSourceMgr();
297 
298   // We need to copy the underlying LLVM memory buffer because llvm::SourceMgr
299   // already owns its one and clang::SourceManager wants to own its one.
300   const MemoryBuffer *LBuf =
301   LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
302 
303   // Create the copy and transfer ownership to clang::SourceManager.
304   // TODO: Avoid copying files into memory.
305   std::unique_ptr<llvm::MemoryBuffer> CBuf =
306       llvm::MemoryBuffer::getMemBufferCopy(LBuf->getBuffer(),
307                                            LBuf->getBufferIdentifier());
308   // FIXME: Keep a file ID map instead of creating new IDs for each location.
309   FileID FID = CSM.createFileID(std::move(CBuf));
310 
311   // Translate the offset into the file.
312   unsigned Offset = D.getLoc().getPointer() - LBuf->getBufferStart();
313   SourceLocation NewLoc =
314   CSM.getLocForStartOfFile(FID).getLocWithOffset(Offset);
315   return FullSourceLoc(NewLoc, CSM);
316 }
317 
318 
319 /// InlineAsmDiagHandler2 - This function is invoked when the backend hits an
320 /// error parsing inline asm.  The SMDiagnostic indicates the error relative to
321 /// the temporary memory buffer that the inline asm parser has set up.
322 void BackendConsumer::InlineAsmDiagHandler2(const llvm::SMDiagnostic &D,
323                                             SourceLocation LocCookie) {
324   // There are a couple of different kinds of errors we could get here.  First,
325   // we re-format the SMDiagnostic in terms of a clang diagnostic.
326 
327   // Strip "error: " off the start of the message string.
328   StringRef Message = D.getMessage();
329   if (Message.startswith("error: "))
330     Message = Message.substr(7);
331 
332   // If the SMDiagnostic has an inline asm source location, translate it.
333   FullSourceLoc Loc;
334   if (D.getLoc() != SMLoc())
335     Loc = ConvertBackendLocation(D, Context->getSourceManager());
336 
337   unsigned DiagID;
338   switch (D.getKind()) {
339   case llvm::SourceMgr::DK_Error:
340     DiagID = diag::err_fe_inline_asm;
341     break;
342   case llvm::SourceMgr::DK_Warning:
343     DiagID = diag::warn_fe_inline_asm;
344     break;
345   case llvm::SourceMgr::DK_Note:
346     DiagID = diag::note_fe_inline_asm;
347     break;
348   }
349   // If this problem has clang-level source location information, report the
350   // issue in the source with a note showing the instantiated
351   // code.
352   if (LocCookie.isValid()) {
353     Diags.Report(LocCookie, DiagID).AddString(Message);
354 
355     if (D.getLoc().isValid()) {
356       DiagnosticBuilder B = Diags.Report(Loc, diag::note_fe_inline_asm_here);
357       // Convert the SMDiagnostic ranges into SourceRange and attach them
358       // to the diagnostic.
359       for (const std::pair<unsigned, unsigned> &Range : D.getRanges()) {
360         unsigned Column = D.getColumnNo();
361         B << SourceRange(Loc.getLocWithOffset(Range.first - Column),
362                          Loc.getLocWithOffset(Range.second - Column));
363       }
364     }
365     return;
366   }
367 
368   // Otherwise, report the backend issue as occurring in the generated .s file.
369   // If Loc is invalid, we still need to report the issue, it just gets no
370   // location info.
371   Diags.Report(Loc, DiagID).AddString(Message);
372 }
373 
374 #define ComputeDiagID(Severity, GroupName, DiagID)                             \
375   do {                                                                         \
376     switch (Severity) {                                                        \
377     case llvm::DS_Error:                                                       \
378       DiagID = diag::err_fe_##GroupName;                                       \
379       break;                                                                   \
380     case llvm::DS_Warning:                                                     \
381       DiagID = diag::warn_fe_##GroupName;                                      \
382       break;                                                                   \
383     case llvm::DS_Remark:                                                      \
384       llvm_unreachable("'remark' severity not expected");                      \
385       break;                                                                   \
386     case llvm::DS_Note:                                                        \
387       DiagID = diag::note_fe_##GroupName;                                      \
388       break;                                                                   \
389     }                                                                          \
390   } while (false)
391 
392 #define ComputeDiagRemarkID(Severity, GroupName, DiagID)                       \
393   do {                                                                         \
394     switch (Severity) {                                                        \
395     case llvm::DS_Error:                                                       \
396       DiagID = diag::err_fe_##GroupName;                                       \
397       break;                                                                   \
398     case llvm::DS_Warning:                                                     \
399       DiagID = diag::warn_fe_##GroupName;                                      \
400       break;                                                                   \
401     case llvm::DS_Remark:                                                      \
402       DiagID = diag::remark_fe_##GroupName;                                    \
403       break;                                                                   \
404     case llvm::DS_Note:                                                        \
405       DiagID = diag::note_fe_##GroupName;                                      \
406       break;                                                                   \
407     }                                                                          \
408   } while (false)
409 
410 bool
411 BackendConsumer::InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D) {
412   unsigned DiagID;
413   ComputeDiagID(D.getSeverity(), inline_asm, DiagID);
414   std::string Message = D.getMsgStr().str();
415 
416   // If this problem has clang-level source location information, report the
417   // issue as being a problem in the source with a note showing the instantiated
418   // code.
419   SourceLocation LocCookie =
420       SourceLocation::getFromRawEncoding(D.getLocCookie());
421   if (LocCookie.isValid())
422     Diags.Report(LocCookie, DiagID).AddString(Message);
423   else {
424     // Otherwise, report the backend diagnostic as occurring in the generated
425     // .s file.
426     // If Loc is invalid, we still need to report the diagnostic, it just gets
427     // no location info.
428     FullSourceLoc Loc;
429     Diags.Report(Loc, DiagID).AddString(Message);
430   }
431   // We handled all the possible severities.
432   return true;
433 }
434 
435 bool
436 BackendConsumer::StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D) {
437   if (D.getSeverity() != llvm::DS_Warning)
438     // For now, the only support we have for StackSize diagnostic is warning.
439     // We do not know how to format other severities.
440     return false;
441 
442   if (const Decl *ND = Gen->GetDeclForMangledName(D.getFunction().getName())) {
443     Diags.Report(ND->getASTContext().getFullLoc(ND->getLocation()),
444                  diag::warn_fe_frame_larger_than)
445         << D.getStackSize() << Decl::castToDeclContext(ND);
446     return true;
447   }
448 
449   return false;
450 }
451 
452 const FullSourceLoc BackendConsumer::getBestLocationFromDebugLoc(
453     const llvm::DiagnosticInfoWithDebugLocBase &D, bool &BadDebugInfo, StringRef &Filename,
454                                 unsigned &Line, unsigned &Column) const {
455   SourceManager &SourceMgr = Context->getSourceManager();
456   FileManager &FileMgr = SourceMgr.getFileManager();
457   SourceLocation DILoc;
458 
459   if (D.isLocationAvailable()) {
460     D.getLocation(&Filename, &Line, &Column);
461     const FileEntry *FE = FileMgr.getFile(Filename);
462     if (FE && Line > 0) {
463       // If -gcolumn-info was not used, Column will be 0. This upsets the
464       // source manager, so pass 1 if Column is not set.
465       DILoc = SourceMgr.translateFileLineCol(FE, Line, Column ? Column : 1);
466     }
467     BadDebugInfo = DILoc.isInvalid();
468   }
469 
470   // If a location isn't available, try to approximate it using the associated
471   // function definition. We use the definition's right brace to differentiate
472   // from diagnostics that genuinely relate to the function itself.
473   FullSourceLoc Loc(DILoc, SourceMgr);
474   if (Loc.isInvalid())
475     if (const Decl *FD = Gen->GetDeclForMangledName(D.getFunction().getName()))
476       Loc = FD->getASTContext().getFullLoc(FD->getLocation());
477 
478   if (DILoc.isInvalid() && D.isLocationAvailable())
479     // If we were not able to translate the file:line:col information
480     // back to a SourceLocation, at least emit a note stating that
481     // we could not translate this location. This can happen in the
482     // case of #line directives.
483     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
484         << Filename << Line;
485 
486   return Loc;
487 }
488 
489 void BackendConsumer::UnsupportedDiagHandler(
490     const llvm::DiagnosticInfoUnsupported &D) {
491   // We only support errors.
492   assert(D.getSeverity() == llvm::DS_Error);
493 
494   StringRef Filename;
495   unsigned Line, Column;
496   bool BadDebugInfo;
497   FullSourceLoc Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename,
498       Line, Column);
499 
500   Diags.Report(Loc, diag::err_fe_backend_unsupported) << D.getMessage().str();
501 
502   if (BadDebugInfo)
503     // If we were not able to translate the file:line:col information
504     // back to a SourceLocation, at least emit a note stating that
505     // we could not translate this location. This can happen in the
506     // case of #line directives.
507     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
508         << Filename << Line << Column;
509 }
510 
511 void BackendConsumer::EmitOptimizationMessage(
512     const llvm::DiagnosticInfoOptimizationBase &D, unsigned DiagID) {
513   // We only support warnings and remarks.
514   assert(D.getSeverity() == llvm::DS_Remark ||
515          D.getSeverity() == llvm::DS_Warning);
516 
517   StringRef Filename;
518   unsigned Line, Column;
519   bool BadDebugInfo = false;
520   FullSourceLoc Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename,
521       Line, Column);
522 
523   Diags.Report(Loc, DiagID)
524       << AddFlagValue(D.getPassName() ? D.getPassName() : "")
525       << D.getMsg().str();
526 
527   if (BadDebugInfo)
528     // If we were not able to translate the file:line:col information
529     // back to a SourceLocation, at least emit a note stating that
530     // we could not translate this location. This can happen in the
531     // case of #line directives.
532     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
533         << Filename << Line << Column;
534 }
535 
536 void BackendConsumer::OptimizationRemarkHandler(
537     const llvm::DiagnosticInfoOptimizationRemark &D) {
538   // Optimization remarks are active only if the -Rpass flag has a regular
539   // expression that matches the name of the pass name in \p D.
540   if (CodeGenOpts.OptimizationRemarkPattern &&
541       CodeGenOpts.OptimizationRemarkPattern->match(D.getPassName()))
542     EmitOptimizationMessage(D, diag::remark_fe_backend_optimization_remark);
543 }
544 
545 void BackendConsumer::OptimizationRemarkHandler(
546     const llvm::DiagnosticInfoOptimizationRemarkMissed &D) {
547   // Missed optimization remarks are active only if the -Rpass-missed
548   // flag has a regular expression that matches the name of the pass
549   // name in \p D.
550   if (CodeGenOpts.OptimizationRemarkMissedPattern &&
551       CodeGenOpts.OptimizationRemarkMissedPattern->match(D.getPassName()))
552     EmitOptimizationMessage(D,
553                             diag::remark_fe_backend_optimization_remark_missed);
554 }
555 
556 void BackendConsumer::OptimizationRemarkHandler(
557     const llvm::DiagnosticInfoOptimizationRemarkAnalysis &D) {
558   // Optimization analysis remarks are active if the pass name is set to
559   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
560   // regular expression that matches the name of the pass name in \p D.
561 
562   if (D.getPassName() == llvm::DiagnosticInfo::AlwaysPrint ||
563       (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
564        CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
565     EmitOptimizationMessage(
566         D, diag::remark_fe_backend_optimization_remark_analysis);
567 }
568 
569 void BackendConsumer::OptimizationRemarkHandler(
570     const llvm::DiagnosticInfoOptimizationRemarkAnalysisFPCommute &D) {
571   // Optimization analysis remarks are active if the pass name is set to
572   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
573   // regular expression that matches the name of the pass name in \p D.
574 
575   if (D.getPassName() == llvm::DiagnosticInfo::AlwaysPrint ||
576       (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
577        CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
578     EmitOptimizationMessage(
579         D, diag::remark_fe_backend_optimization_remark_analysis_fpcommute);
580 }
581 
582 void BackendConsumer::OptimizationRemarkHandler(
583     const llvm::DiagnosticInfoOptimizationRemarkAnalysisAliasing &D) {
584   // Optimization analysis remarks are active if the pass name is set to
585   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
586   // regular expression that matches the name of the pass name in \p D.
587 
588   if (D.getPassName() == llvm::DiagnosticInfo::AlwaysPrint ||
589       (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
590        CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
591     EmitOptimizationMessage(
592         D, diag::remark_fe_backend_optimization_remark_analysis_aliasing);
593 }
594 
595 void BackendConsumer::OptimizationFailureHandler(
596     const llvm::DiagnosticInfoOptimizationFailure &D) {
597   EmitOptimizationMessage(D, diag::warn_fe_backend_optimization_failure);
598 }
599 
600 /// \brief This function is invoked when the backend needs
601 /// to report something to the user.
602 void BackendConsumer::DiagnosticHandlerImpl(const DiagnosticInfo &DI) {
603   unsigned DiagID = diag::err_fe_inline_asm;
604   llvm::DiagnosticSeverity Severity = DI.getSeverity();
605   // Get the diagnostic ID based.
606   switch (DI.getKind()) {
607   case llvm::DK_InlineAsm:
608     if (InlineAsmDiagHandler(cast<DiagnosticInfoInlineAsm>(DI)))
609       return;
610     ComputeDiagID(Severity, inline_asm, DiagID);
611     break;
612   case llvm::DK_StackSize:
613     if (StackSizeDiagHandler(cast<DiagnosticInfoStackSize>(DI)))
614       return;
615     ComputeDiagID(Severity, backend_frame_larger_than, DiagID);
616     break;
617   case DK_Linker:
618     assert(CurLinkModule);
619     // FIXME: stop eating the warnings and notes.
620     if (Severity != DS_Error)
621       return;
622     DiagID = diag::err_fe_cannot_link_module;
623     break;
624   case llvm::DK_OptimizationRemark:
625     // Optimization remarks are always handled completely by this
626     // handler. There is no generic way of emitting them.
627     OptimizationRemarkHandler(cast<DiagnosticInfoOptimizationRemark>(DI));
628     return;
629   case llvm::DK_OptimizationRemarkMissed:
630     // Optimization remarks are always handled completely by this
631     // handler. There is no generic way of emitting them.
632     OptimizationRemarkHandler(cast<DiagnosticInfoOptimizationRemarkMissed>(DI));
633     return;
634   case llvm::DK_OptimizationRemarkAnalysis:
635     // Optimization remarks are always handled completely by this
636     // handler. There is no generic way of emitting them.
637     OptimizationRemarkHandler(
638         cast<DiagnosticInfoOptimizationRemarkAnalysis>(DI));
639     return;
640   case llvm::DK_OptimizationRemarkAnalysisFPCommute:
641     // Optimization remarks are always handled completely by this
642     // handler. There is no generic way of emitting them.
643     OptimizationRemarkHandler(
644         cast<DiagnosticInfoOptimizationRemarkAnalysisFPCommute>(DI));
645     return;
646   case llvm::DK_OptimizationRemarkAnalysisAliasing:
647     // Optimization remarks are always handled completely by this
648     // handler. There is no generic way of emitting them.
649     OptimizationRemarkHandler(
650         cast<DiagnosticInfoOptimizationRemarkAnalysisAliasing>(DI));
651     return;
652   case llvm::DK_OptimizationFailure:
653     // Optimization failures are always handled completely by this
654     // handler.
655     OptimizationFailureHandler(cast<DiagnosticInfoOptimizationFailure>(DI));
656     return;
657   case llvm::DK_Unsupported:
658     UnsupportedDiagHandler(cast<DiagnosticInfoUnsupported>(DI));
659     return;
660   default:
661     // Plugin IDs are not bound to any value as they are set dynamically.
662     ComputeDiagRemarkID(Severity, backend_plugin, DiagID);
663     break;
664   }
665   std::string MsgStorage;
666   {
667     raw_string_ostream Stream(MsgStorage);
668     DiagnosticPrinterRawOStream DP(Stream);
669     DI.print(DP);
670   }
671 
672   if (DiagID == diag::err_fe_cannot_link_module) {
673     Diags.Report(diag::err_fe_cannot_link_module)
674         << CurLinkModule->getModuleIdentifier() << MsgStorage;
675     return;
676   }
677 
678   // Report the backend message using the usual diagnostic mechanism.
679   FullSourceLoc Loc;
680   Diags.Report(Loc, DiagID).AddString(MsgStorage);
681 }
682 #undef ComputeDiagID
683 
684 CodeGenAction::CodeGenAction(unsigned _Act, LLVMContext *_VMContext)
685     : Act(_Act), VMContext(_VMContext ? _VMContext : new LLVMContext),
686       OwnsVMContext(!_VMContext) {}
687 
688 CodeGenAction::~CodeGenAction() {
689   TheModule.reset();
690   if (OwnsVMContext)
691     delete VMContext;
692 }
693 
694 bool CodeGenAction::hasIRSupport() const { return true; }
695 
696 void CodeGenAction::EndSourceFileAction() {
697   // If the consumer creation failed, do nothing.
698   if (!getCompilerInstance().hasASTConsumer())
699     return;
700 
701   // Take back ownership of link modules we passed to consumer.
702   if (!LinkModules.empty())
703     BEConsumer->releaseLinkModules();
704 
705   // Steal the module from the consumer.
706   TheModule = BEConsumer->takeModule();
707 }
708 
709 std::unique_ptr<llvm::Module> CodeGenAction::takeModule() {
710   return std::move(TheModule);
711 }
712 
713 llvm::LLVMContext *CodeGenAction::takeLLVMContext() {
714   OwnsVMContext = false;
715   return VMContext;
716 }
717 
718 static raw_pwrite_stream *
719 GetOutputStream(CompilerInstance &CI, StringRef InFile, BackendAction Action) {
720   switch (Action) {
721   case Backend_EmitAssembly:
722     return CI.createDefaultOutputFile(false, InFile, "s");
723   case Backend_EmitLL:
724     return CI.createDefaultOutputFile(false, InFile, "ll");
725   case Backend_EmitBC:
726     return CI.createDefaultOutputFile(true, InFile, "bc");
727   case Backend_EmitNothing:
728     return nullptr;
729   case Backend_EmitMCNull:
730     return CI.createNullOutputFile();
731   case Backend_EmitObj:
732     return CI.createDefaultOutputFile(true, InFile, "o");
733   }
734 
735   llvm_unreachable("Invalid action!");
736 }
737 
738 std::unique_ptr<ASTConsumer>
739 CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
740   BackendAction BA = static_cast<BackendAction>(Act);
741   raw_pwrite_stream *OS = GetOutputStream(CI, InFile, BA);
742   if (BA != Backend_EmitNothing && !OS)
743     return nullptr;
744 
745   // Load bitcode modules to link with, if we need to.
746   if (LinkModules.empty())
747     for (auto &I : CI.getCodeGenOpts().LinkBitcodeFiles) {
748       const std::string &LinkBCFile = I.second;
749 
750       auto BCBuf = CI.getFileManager().getBufferForFile(LinkBCFile);
751       if (!BCBuf) {
752         CI.getDiagnostics().Report(diag::err_cannot_open_file)
753             << LinkBCFile << BCBuf.getError().message();
754         LinkModules.clear();
755         return nullptr;
756       }
757 
758       ErrorOr<std::unique_ptr<llvm::Module>> ModuleOrErr =
759           getLazyBitcodeModule(std::move(*BCBuf), *VMContext);
760       if (std::error_code EC = ModuleOrErr.getError()) {
761         CI.getDiagnostics().Report(diag::err_cannot_open_file) << LinkBCFile
762                                                                << EC.message();
763         LinkModules.clear();
764         return nullptr;
765       }
766       addLinkModule(ModuleOrErr.get().release(), I.first);
767     }
768 
769   CoverageSourceInfo *CoverageInfo = nullptr;
770   // Add the preprocessor callback only when the coverage mapping is generated.
771   if (CI.getCodeGenOpts().CoverageMapping) {
772     CoverageInfo = new CoverageSourceInfo;
773     CI.getPreprocessor().addPPCallbacks(
774                                     std::unique_ptr<PPCallbacks>(CoverageInfo));
775   }
776 
777   std::unique_ptr<BackendConsumer> Result(new BackendConsumer(
778       BA, CI.getDiagnostics(), CI.getHeaderSearchOpts(),
779       CI.getPreprocessorOpts(), CI.getCodeGenOpts(), CI.getTargetOpts(),
780       CI.getLangOpts(), CI.getFrontendOpts().ShowTimers, InFile, LinkModules,
781       OS, *VMContext, CoverageInfo));
782   BEConsumer = Result.get();
783   return std::move(Result);
784 }
785 
786 static void BitcodeInlineAsmDiagHandler(const llvm::SMDiagnostic &SM,
787                                          void *Context,
788                                          unsigned LocCookie) {
789   SM.print(nullptr, llvm::errs());
790 }
791 
792 void CodeGenAction::ExecuteAction() {
793   // If this is an IR file, we have to treat it specially.
794   if (getCurrentFileKind() == IK_LLVM_IR) {
795     BackendAction BA = static_cast<BackendAction>(Act);
796     CompilerInstance &CI = getCompilerInstance();
797     raw_pwrite_stream *OS = GetOutputStream(CI, getCurrentFile(), BA);
798     if (BA != Backend_EmitNothing && !OS)
799       return;
800 
801     bool Invalid;
802     SourceManager &SM = CI.getSourceManager();
803     FileID FID = SM.getMainFileID();
804     llvm::MemoryBuffer *MainFile = SM.getBuffer(FID, &Invalid);
805     if (Invalid)
806       return;
807 
808     llvm::SMDiagnostic Err;
809     TheModule = parseIR(MainFile->getMemBufferRef(), Err, *VMContext);
810     if (!TheModule) {
811       // Translate from the diagnostic info to the SourceManager location if
812       // available.
813       // TODO: Unify this with ConvertBackendLocation()
814       SourceLocation Loc;
815       if (Err.getLineNo() > 0) {
816         assert(Err.getColumnNo() >= 0);
817         Loc = SM.translateFileLineCol(SM.getFileEntryForID(FID),
818                                       Err.getLineNo(), Err.getColumnNo() + 1);
819       }
820 
821       // Strip off a leading diagnostic code if there is one.
822       StringRef Msg = Err.getMessage();
823       if (Msg.startswith("error: "))
824         Msg = Msg.substr(7);
825 
826       unsigned DiagID =
827           CI.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, "%0");
828 
829       CI.getDiagnostics().Report(Loc, DiagID) << Msg;
830       return;
831     }
832     const TargetOptions &TargetOpts = CI.getTargetOpts();
833     if (TheModule->getTargetTriple() != TargetOpts.Triple) {
834       CI.getDiagnostics().Report(SourceLocation(),
835                                  diag::warn_fe_override_module)
836           << TargetOpts.Triple;
837       TheModule->setTargetTriple(TargetOpts.Triple);
838     }
839 
840     LLVMContext &Ctx = TheModule->getContext();
841     Ctx.setInlineAsmDiagnosticHandler(BitcodeInlineAsmDiagHandler);
842     EmitBackendOutput(CI.getDiagnostics(), CI.getCodeGenOpts(), TargetOpts,
843                       CI.getLangOpts(), CI.getTarget().getDataLayoutString(),
844                       TheModule.get(), BA, OS);
845     return;
846   }
847 
848   // Otherwise follow the normal AST path.
849   this->ASTFrontendAction::ExecuteAction();
850 }
851 
852 //
853 
854 void EmitAssemblyAction::anchor() { }
855 EmitAssemblyAction::EmitAssemblyAction(llvm::LLVMContext *_VMContext)
856   : CodeGenAction(Backend_EmitAssembly, _VMContext) {}
857 
858 void EmitBCAction::anchor() { }
859 EmitBCAction::EmitBCAction(llvm::LLVMContext *_VMContext)
860   : CodeGenAction(Backend_EmitBC, _VMContext) {}
861 
862 void EmitLLVMAction::anchor() { }
863 EmitLLVMAction::EmitLLVMAction(llvm::LLVMContext *_VMContext)
864   : CodeGenAction(Backend_EmitLL, _VMContext) {}
865 
866 void EmitLLVMOnlyAction::anchor() { }
867 EmitLLVMOnlyAction::EmitLLVMOnlyAction(llvm::LLVMContext *_VMContext)
868   : CodeGenAction(Backend_EmitNothing, _VMContext) {}
869 
870 void EmitCodeGenOnlyAction::anchor() { }
871 EmitCodeGenOnlyAction::EmitCodeGenOnlyAction(llvm::LLVMContext *_VMContext)
872   : CodeGenAction(Backend_EmitMCNull, _VMContext) {}
873 
874 void EmitObjAction::anchor() { }
875 EmitObjAction::EmitObjAction(llvm::LLVMContext *_VMContext)
876   : CodeGenAction(Backend_EmitObj, _VMContext) {}
877