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/Bitcode/ReaderWriter.h"
25 #include "llvm/IR/DebugInfo.h"
26 #include "llvm/IR/DiagnosticInfo.h"
27 #include "llvm/IR/DiagnosticPrinter.h"
28 #include "llvm/IR/LLVMContext.h"
29 #include "llvm/IR/Module.h"
30 #include "llvm/IRReader/IRReader.h"
31 #include "llvm/Linker/Linker.h"
32 #include "llvm/Pass.h"
33 #include "llvm/Support/MemoryBuffer.h"
34 #include "llvm/Support/SourceMgr.h"
35 #include "llvm/Support/Timer.h"
36 #include "llvm/Support/ToolOutputFile.h"
37 #include "llvm/Support/YAMLTraits.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     std::unique_ptr<raw_pwrite_stream> AsmOutStream;
51     ASTContext *Context;
52 
53     Timer LLVMIRGeneration;
54     unsigned LLVMIRGenerationRefCount;
55 
56     std::unique_ptr<CodeGenerator> Gen;
57 
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         std::unique_ptr<raw_pwrite_stream> OS, LLVMContext &C,
74         CoverageSourceInfo *CoverageInfo = nullptr)
75         : Diags(Diags), Action(Action), CodeGenOpts(CodeGenOpts),
76           TargetOpts(TargetOpts), LangOpts(LangOpts),
77           AsmOutStream(std::move(OS)), Context(nullptr),
78           LLVMIRGeneration("LLVM IR Generation Time"),
79           LLVMIRGenerationRefCount(0),
80           Gen(CreateLLVMCodeGen(Diags, InFile, HeaderSearchOpts, PPOpts,
81                                 CodeGenOpts, C, CoverageInfo)) {
82       llvm::TimePassesIsEnabled = TimePasses;
83       for (auto &I : LinkModules)
84         this->LinkModules.push_back(
85             std::make_pair(I.first, std::unique_ptr<llvm::Module>(I.second)));
86     }
87     llvm::Module *getModule() const { return Gen->GetModule(); }
88     std::unique_ptr<llvm::Module> takeModule() {
89       return std::unique_ptr<llvm::Module>(Gen->ReleaseModule());
90     }
91     void releaseLinkModules() {
92       for (auto &I : LinkModules)
93         I.second.release();
94     }
95 
96     void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override {
97       Gen->HandleCXXStaticMemberVarInstantiation(VD);
98     }
99 
100     void Initialize(ASTContext &Ctx) override {
101       assert(!Context && "initialized multiple times");
102 
103       Context = &Ctx;
104 
105       if (llvm::TimePassesIsEnabled)
106         LLVMIRGeneration.startTimer();
107 
108       Gen->Initialize(Ctx);
109 
110       if (llvm::TimePassesIsEnabled)
111         LLVMIRGeneration.stopTimer();
112     }
113 
114     bool HandleTopLevelDecl(DeclGroupRef D) override {
115       PrettyStackTraceDecl CrashInfo(*D.begin(), SourceLocation(),
116                                      Context->getSourceManager(),
117                                      "LLVM IR generation of declaration");
118 
119       // Recurse.
120       if (llvm::TimePassesIsEnabled) {
121         LLVMIRGenerationRefCount += 1;
122         if (LLVMIRGenerationRefCount == 1)
123           LLVMIRGeneration.startTimer();
124       }
125 
126       Gen->HandleTopLevelDecl(D);
127 
128       if (llvm::TimePassesIsEnabled) {
129         LLVMIRGenerationRefCount -= 1;
130         if (LLVMIRGenerationRefCount == 0)
131           LLVMIRGeneration.stopTimer();
132       }
133 
134       return true;
135     }
136 
137     void HandleInlineFunctionDefinition(FunctionDecl *D) override {
138       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
139                                      Context->getSourceManager(),
140                                      "LLVM IR generation of inline function");
141       if (llvm::TimePassesIsEnabled)
142         LLVMIRGeneration.startTimer();
143 
144       Gen->HandleInlineFunctionDefinition(D);
145 
146       if (llvm::TimePassesIsEnabled)
147         LLVMIRGeneration.stopTimer();
148     }
149 
150     void HandleTranslationUnit(ASTContext &C) override {
151       {
152         PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
153         if (llvm::TimePassesIsEnabled) {
154           LLVMIRGenerationRefCount += 1;
155           if (LLVMIRGenerationRefCount == 1)
156             LLVMIRGeneration.startTimer();
157         }
158 
159         Gen->HandleTranslationUnit(C);
160 
161         if (llvm::TimePassesIsEnabled) {
162           LLVMIRGenerationRefCount -= 1;
163           if (LLVMIRGenerationRefCount == 0)
164             LLVMIRGeneration.stopTimer();
165         }
166       }
167 
168       // Silently ignore if we weren't initialized for some reason.
169       if (!getModule())
170         return;
171 
172       // Install an inline asm handler so that diagnostics get printed through
173       // our diagnostics hooks.
174       LLVMContext &Ctx = getModule()->getContext();
175       LLVMContext::InlineAsmDiagHandlerTy OldHandler =
176         Ctx.getInlineAsmDiagnosticHandler();
177       void *OldContext = Ctx.getInlineAsmDiagnosticContext();
178       Ctx.setInlineAsmDiagnosticHandler(InlineAsmDiagHandler, this);
179 
180       LLVMContext::DiagnosticHandlerTy OldDiagnosticHandler =
181           Ctx.getDiagnosticHandler();
182       void *OldDiagnosticContext = Ctx.getDiagnosticContext();
183       Ctx.setDiagnosticHandler(DiagnosticHandler, this);
184       Ctx.setDiagnosticHotnessRequested(CodeGenOpts.DiagnosticsWithHotness);
185 
186       std::unique_ptr<llvm::tool_output_file> OptRecordFile;
187       if (!CodeGenOpts.OptRecordFile.empty()) {
188         std::error_code EC;
189         OptRecordFile =
190           llvm::make_unique<llvm::tool_output_file>(CodeGenOpts.OptRecordFile,
191                                                     EC, sys::fs::F_None);
192         if (EC) {
193           Diags.Report(diag::err_cannot_open_file) <<
194             CodeGenOpts.OptRecordFile << EC.message();
195           return;
196         }
197 
198         Ctx.setDiagnosticsOutputFile(new yaml::Output(OptRecordFile->os()));
199 
200         if (CodeGenOpts.getProfileUse() != CodeGenOptions::ProfileNone)
201           Ctx.setDiagnosticHotnessRequested(true);
202       }
203 
204       // Link LinkModule into this module if present, preserving its validity.
205       for (auto &I : LinkModules) {
206         unsigned LinkFlags = I.first;
207         CurLinkModule = I.second.get();
208         if (Linker::linkModules(*getModule(), std::move(I.second), LinkFlags))
209           return;
210       }
211 
212       EmbedBitcode(getModule(), CodeGenOpts, llvm::MemoryBufferRef());
213 
214       EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
215                         C.getTargetInfo().getDataLayout(),
216                         getModule(), Action, std::move(AsmOutStream));
217 
218       Ctx.setInlineAsmDiagnosticHandler(OldHandler, OldContext);
219 
220       Ctx.setDiagnosticHandler(OldDiagnosticHandler, OldDiagnosticContext);
221 
222       if (OptRecordFile)
223         OptRecordFile->keep();
224     }
225 
226     void HandleTagDeclDefinition(TagDecl *D) override {
227       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
228                                      Context->getSourceManager(),
229                                      "LLVM IR generation of declaration");
230       Gen->HandleTagDeclDefinition(D);
231     }
232 
233     void HandleTagDeclRequiredDefinition(const TagDecl *D) override {
234       Gen->HandleTagDeclRequiredDefinition(D);
235     }
236 
237     void CompleteTentativeDefinition(VarDecl *D) override {
238       Gen->CompleteTentativeDefinition(D);
239     }
240 
241     void AssignInheritanceModel(CXXRecordDecl *RD) override {
242       Gen->AssignInheritanceModel(RD);
243     }
244 
245     void HandleVTable(CXXRecordDecl *RD) override {
246       Gen->HandleVTable(RD);
247     }
248 
249     static void InlineAsmDiagHandler(const llvm::SMDiagnostic &SM,void *Context,
250                                      unsigned LocCookie) {
251       SourceLocation Loc = SourceLocation::getFromRawEncoding(LocCookie);
252       ((BackendConsumer*)Context)->InlineAsmDiagHandler2(SM, Loc);
253     }
254 
255     static void DiagnosticHandler(const llvm::DiagnosticInfo &DI,
256                                   void *Context) {
257       ((BackendConsumer *)Context)->DiagnosticHandlerImpl(DI);
258     }
259 
260     /// Get the best possible source location to represent a diagnostic that
261     /// may have associated debug info.
262     const FullSourceLoc
263     getBestLocationFromDebugLoc(const llvm::DiagnosticInfoWithDebugLocBase &D,
264                                 bool &BadDebugInfo, StringRef &Filename,
265                                 unsigned &Line, unsigned &Column) const;
266 
267     void InlineAsmDiagHandler2(const llvm::SMDiagnostic &,
268                                SourceLocation LocCookie);
269 
270     void DiagnosticHandlerImpl(const llvm::DiagnosticInfo &DI);
271     /// \brief Specialized handler for InlineAsm diagnostic.
272     /// \return True if the diagnostic has been successfully reported, false
273     /// otherwise.
274     bool InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D);
275     /// \brief Specialized handler for StackSize diagnostic.
276     /// \return True if the diagnostic has been successfully reported, false
277     /// otherwise.
278     bool StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D);
279     /// \brief Specialized handler for unsupported backend feature diagnostic.
280     void UnsupportedDiagHandler(const llvm::DiagnosticInfoUnsupported &D);
281     /// \brief Specialized handlers for optimization remarks.
282     /// Note that these handlers only accept remarks and they always handle
283     /// them.
284     void EmitOptimizationMessage(const llvm::DiagnosticInfoOptimizationBase &D,
285                                  unsigned DiagID);
286     void OptimizationRemarkHandler(const llvm::OptimizationRemark &D);
287     void OptimizationRemarkHandler(const llvm::OptimizationRemarkMissed &D);
288     void OptimizationRemarkHandler(const llvm::OptimizationRemarkAnalysis &D);
289     void OptimizationRemarkHandler(
290         const llvm::OptimizationRemarkAnalysisFPCommute &D);
291     void OptimizationRemarkHandler(
292         const llvm::OptimizationRemarkAnalysisAliasing &D);
293     void OptimizationFailureHandler(
294         const llvm::DiagnosticInfoOptimizationFailure &D);
295   };
296 
297   void BackendConsumer::anchor() {}
298 }
299 
300 /// ConvertBackendLocation - Convert a location in a temporary llvm::SourceMgr
301 /// buffer to be a valid FullSourceLoc.
302 static FullSourceLoc ConvertBackendLocation(const llvm::SMDiagnostic &D,
303                                             SourceManager &CSM) {
304   // Get both the clang and llvm source managers.  The location is relative to
305   // a memory buffer that the LLVM Source Manager is handling, we need to add
306   // a copy to the Clang source manager.
307   const llvm::SourceMgr &LSM = *D.getSourceMgr();
308 
309   // We need to copy the underlying LLVM memory buffer because llvm::SourceMgr
310   // already owns its one and clang::SourceManager wants to own its one.
311   const MemoryBuffer *LBuf =
312   LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
313 
314   // Create the copy and transfer ownership to clang::SourceManager.
315   // TODO: Avoid copying files into memory.
316   std::unique_ptr<llvm::MemoryBuffer> CBuf =
317       llvm::MemoryBuffer::getMemBufferCopy(LBuf->getBuffer(),
318                                            LBuf->getBufferIdentifier());
319   // FIXME: Keep a file ID map instead of creating new IDs for each location.
320   FileID FID = CSM.createFileID(std::move(CBuf));
321 
322   // Translate the offset into the file.
323   unsigned Offset = D.getLoc().getPointer() - LBuf->getBufferStart();
324   SourceLocation NewLoc =
325   CSM.getLocForStartOfFile(FID).getLocWithOffset(Offset);
326   return FullSourceLoc(NewLoc, CSM);
327 }
328 
329 
330 /// InlineAsmDiagHandler2 - This function is invoked when the backend hits an
331 /// error parsing inline asm.  The SMDiagnostic indicates the error relative to
332 /// the temporary memory buffer that the inline asm parser has set up.
333 void BackendConsumer::InlineAsmDiagHandler2(const llvm::SMDiagnostic &D,
334                                             SourceLocation LocCookie) {
335   // There are a couple of different kinds of errors we could get here.  First,
336   // we re-format the SMDiagnostic in terms of a clang diagnostic.
337 
338   // Strip "error: " off the start of the message string.
339   StringRef Message = D.getMessage();
340   if (Message.startswith("error: "))
341     Message = Message.substr(7);
342 
343   // If the SMDiagnostic has an inline asm source location, translate it.
344   FullSourceLoc Loc;
345   if (D.getLoc() != SMLoc())
346     Loc = ConvertBackendLocation(D, Context->getSourceManager());
347 
348   unsigned DiagID;
349   switch (D.getKind()) {
350   case llvm::SourceMgr::DK_Error:
351     DiagID = diag::err_fe_inline_asm;
352     break;
353   case llvm::SourceMgr::DK_Warning:
354     DiagID = diag::warn_fe_inline_asm;
355     break;
356   case llvm::SourceMgr::DK_Note:
357     DiagID = diag::note_fe_inline_asm;
358     break;
359   }
360   // If this problem has clang-level source location information, report the
361   // issue in the source with a note showing the instantiated
362   // code.
363   if (LocCookie.isValid()) {
364     Diags.Report(LocCookie, DiagID).AddString(Message);
365 
366     if (D.getLoc().isValid()) {
367       DiagnosticBuilder B = Diags.Report(Loc, diag::note_fe_inline_asm_here);
368       // Convert the SMDiagnostic ranges into SourceRange and attach them
369       // to the diagnostic.
370       for (const std::pair<unsigned, unsigned> &Range : D.getRanges()) {
371         unsigned Column = D.getColumnNo();
372         B << SourceRange(Loc.getLocWithOffset(Range.first - Column),
373                          Loc.getLocWithOffset(Range.second - Column));
374       }
375     }
376     return;
377   }
378 
379   // Otherwise, report the backend issue as occurring in the generated .s file.
380   // If Loc is invalid, we still need to report the issue, it just gets no
381   // location info.
382   Diags.Report(Loc, DiagID).AddString(Message);
383 }
384 
385 #define ComputeDiagID(Severity, GroupName, DiagID)                             \
386   do {                                                                         \
387     switch (Severity) {                                                        \
388     case llvm::DS_Error:                                                       \
389       DiagID = diag::err_fe_##GroupName;                                       \
390       break;                                                                   \
391     case llvm::DS_Warning:                                                     \
392       DiagID = diag::warn_fe_##GroupName;                                      \
393       break;                                                                   \
394     case llvm::DS_Remark:                                                      \
395       llvm_unreachable("'remark' severity not expected");                      \
396       break;                                                                   \
397     case llvm::DS_Note:                                                        \
398       DiagID = diag::note_fe_##GroupName;                                      \
399       break;                                                                   \
400     }                                                                          \
401   } while (false)
402 
403 #define ComputeDiagRemarkID(Severity, GroupName, DiagID)                       \
404   do {                                                                         \
405     switch (Severity) {                                                        \
406     case llvm::DS_Error:                                                       \
407       DiagID = diag::err_fe_##GroupName;                                       \
408       break;                                                                   \
409     case llvm::DS_Warning:                                                     \
410       DiagID = diag::warn_fe_##GroupName;                                      \
411       break;                                                                   \
412     case llvm::DS_Remark:                                                      \
413       DiagID = diag::remark_fe_##GroupName;                                    \
414       break;                                                                   \
415     case llvm::DS_Note:                                                        \
416       DiagID = diag::note_fe_##GroupName;                                      \
417       break;                                                                   \
418     }                                                                          \
419   } while (false)
420 
421 bool
422 BackendConsumer::InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D) {
423   unsigned DiagID;
424   ComputeDiagID(D.getSeverity(), inline_asm, DiagID);
425   std::string Message = D.getMsgStr().str();
426 
427   // If this problem has clang-level source location information, report the
428   // issue as being a problem in the source with a note showing the instantiated
429   // code.
430   SourceLocation LocCookie =
431       SourceLocation::getFromRawEncoding(D.getLocCookie());
432   if (LocCookie.isValid())
433     Diags.Report(LocCookie, DiagID).AddString(Message);
434   else {
435     // Otherwise, report the backend diagnostic as occurring in the generated
436     // .s file.
437     // If Loc is invalid, we still need to report the diagnostic, it just gets
438     // no location info.
439     FullSourceLoc Loc;
440     Diags.Report(Loc, DiagID).AddString(Message);
441   }
442   // We handled all the possible severities.
443   return true;
444 }
445 
446 bool
447 BackendConsumer::StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D) {
448   if (D.getSeverity() != llvm::DS_Warning)
449     // For now, the only support we have for StackSize diagnostic is warning.
450     // We do not know how to format other severities.
451     return false;
452 
453   if (const Decl *ND = Gen->GetDeclForMangledName(D.getFunction().getName())) {
454     // FIXME: Shouldn't need to truncate to uint32_t
455     Diags.Report(ND->getASTContext().getFullLoc(ND->getLocation()),
456                  diag::warn_fe_frame_larger_than)
457       << static_cast<uint32_t>(D.getStackSize()) << Decl::castToDeclContext(ND);
458     return true;
459   }
460 
461   return false;
462 }
463 
464 const FullSourceLoc BackendConsumer::getBestLocationFromDebugLoc(
465     const llvm::DiagnosticInfoWithDebugLocBase &D, bool &BadDebugInfo, StringRef &Filename,
466                                 unsigned &Line, unsigned &Column) const {
467   SourceManager &SourceMgr = Context->getSourceManager();
468   FileManager &FileMgr = SourceMgr.getFileManager();
469   SourceLocation DILoc;
470 
471   if (D.isLocationAvailable()) {
472     D.getLocation(&Filename, &Line, &Column);
473     const FileEntry *FE = FileMgr.getFile(Filename);
474     if (FE && Line > 0) {
475       // If -gcolumn-info was not used, Column will be 0. This upsets the
476       // source manager, so pass 1 if Column is not set.
477       DILoc = SourceMgr.translateFileLineCol(FE, Line, Column ? Column : 1);
478     }
479     BadDebugInfo = DILoc.isInvalid();
480   }
481 
482   // If a location isn't available, try to approximate it using the associated
483   // function definition. We use the definition's right brace to differentiate
484   // from diagnostics that genuinely relate to the function itself.
485   FullSourceLoc Loc(DILoc, SourceMgr);
486   if (Loc.isInvalid())
487     if (const Decl *FD = Gen->GetDeclForMangledName(D.getFunction().getName()))
488       Loc = FD->getASTContext().getFullLoc(FD->getLocation());
489 
490   if (DILoc.isInvalid() && D.isLocationAvailable())
491     // If we were not able to translate the file:line:col information
492     // back to a SourceLocation, at least emit a note stating that
493     // we could not translate this location. This can happen in the
494     // case of #line directives.
495     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
496         << Filename << Line << Column;
497 
498   return Loc;
499 }
500 
501 void BackendConsumer::UnsupportedDiagHandler(
502     const llvm::DiagnosticInfoUnsupported &D) {
503   // We only support errors.
504   assert(D.getSeverity() == llvm::DS_Error);
505 
506   StringRef Filename;
507   unsigned Line, Column;
508   bool BadDebugInfo;
509   FullSourceLoc Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename,
510       Line, Column);
511 
512   Diags.Report(Loc, diag::err_fe_backend_unsupported) << D.getMessage().str();
513 
514   if (BadDebugInfo)
515     // If we were not able to translate the file:line:col information
516     // back to a SourceLocation, at least emit a note stating that
517     // we could not translate this location. This can happen in the
518     // case of #line directives.
519     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
520         << Filename << Line << Column;
521 }
522 
523 void BackendConsumer::EmitOptimizationMessage(
524     const llvm::DiagnosticInfoOptimizationBase &D, unsigned DiagID) {
525   // We only support warnings and remarks.
526   assert(D.getSeverity() == llvm::DS_Remark ||
527          D.getSeverity() == llvm::DS_Warning);
528 
529   StringRef Filename;
530   unsigned Line, Column;
531   bool BadDebugInfo = false;
532   FullSourceLoc Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename,
533       Line, Column);
534 
535   std::string Msg;
536   raw_string_ostream MsgStream(Msg);
537   MsgStream << D.getMsg();
538 
539   if (D.getHotness())
540     MsgStream << " (hotness: " << *D.getHotness() << ")";
541 
542   Diags.Report(Loc, DiagID)
543       << AddFlagValue(D.getPassName())
544       << MsgStream.str();
545 
546   if (BadDebugInfo)
547     // If we were not able to translate the file:line:col information
548     // back to a SourceLocation, at least emit a note stating that
549     // we could not translate this location. This can happen in the
550     // case of #line directives.
551     Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
552         << Filename << Line << Column;
553 }
554 
555 void BackendConsumer::OptimizationRemarkHandler(
556     const llvm::OptimizationRemark &D) {
557   // Optimization remarks are active only if the -Rpass flag has a regular
558   // expression that matches the name of the pass name in \p D.
559   if (CodeGenOpts.OptimizationRemarkPattern &&
560       CodeGenOpts.OptimizationRemarkPattern->match(D.getPassName()))
561     EmitOptimizationMessage(D, diag::remark_fe_backend_optimization_remark);
562 }
563 
564 void BackendConsumer::OptimizationRemarkHandler(
565     const llvm::OptimizationRemarkMissed &D) {
566   // Missed optimization remarks are active only if the -Rpass-missed
567   // flag has a regular expression that matches the name of the pass
568   // name in \p D.
569   if (CodeGenOpts.OptimizationRemarkMissedPattern &&
570       CodeGenOpts.OptimizationRemarkMissedPattern->match(D.getPassName()))
571     EmitOptimizationMessage(D,
572                             diag::remark_fe_backend_optimization_remark_missed);
573 }
574 
575 void BackendConsumer::OptimizationRemarkHandler(
576     const llvm::OptimizationRemarkAnalysis &D) {
577   // Optimization analysis remarks are active if the pass name is set to
578   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
579   // regular expression that matches the name of the pass name in \p D.
580 
581   if (D.shouldAlwaysPrint() ||
582       (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
583        CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
584     EmitOptimizationMessage(
585         D, diag::remark_fe_backend_optimization_remark_analysis);
586 }
587 
588 void BackendConsumer::OptimizationRemarkHandler(
589     const llvm::OptimizationRemarkAnalysisFPCommute &D) {
590   // Optimization analysis remarks are active if the pass name is set to
591   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
592   // regular expression that matches the name of the pass name in \p D.
593 
594   if (D.shouldAlwaysPrint() ||
595       (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
596        CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
597     EmitOptimizationMessage(
598         D, diag::remark_fe_backend_optimization_remark_analysis_fpcommute);
599 }
600 
601 void BackendConsumer::OptimizationRemarkHandler(
602     const llvm::OptimizationRemarkAnalysisAliasing &D) {
603   // Optimization analysis remarks are active if the pass name is set to
604   // llvm::DiagnosticInfo::AlwasyPrint or if the -Rpass-analysis flag has a
605   // regular expression that matches the name of the pass name in \p D.
606 
607   if (D.shouldAlwaysPrint() ||
608       (CodeGenOpts.OptimizationRemarkAnalysisPattern &&
609        CodeGenOpts.OptimizationRemarkAnalysisPattern->match(D.getPassName())))
610     EmitOptimizationMessage(
611         D, diag::remark_fe_backend_optimization_remark_analysis_aliasing);
612 }
613 
614 void BackendConsumer::OptimizationFailureHandler(
615     const llvm::DiagnosticInfoOptimizationFailure &D) {
616   EmitOptimizationMessage(D, diag::warn_fe_backend_optimization_failure);
617 }
618 
619 /// \brief This function is invoked when the backend needs
620 /// to report something to the user.
621 void BackendConsumer::DiagnosticHandlerImpl(const DiagnosticInfo &DI) {
622   unsigned DiagID = diag::err_fe_inline_asm;
623   llvm::DiagnosticSeverity Severity = DI.getSeverity();
624   // Get the diagnostic ID based.
625   switch (DI.getKind()) {
626   case llvm::DK_InlineAsm:
627     if (InlineAsmDiagHandler(cast<DiagnosticInfoInlineAsm>(DI)))
628       return;
629     ComputeDiagID(Severity, inline_asm, DiagID);
630     break;
631   case llvm::DK_StackSize:
632     if (StackSizeDiagHandler(cast<DiagnosticInfoStackSize>(DI)))
633       return;
634     ComputeDiagID(Severity, backend_frame_larger_than, DiagID);
635     break;
636   case DK_Linker:
637     assert(CurLinkModule);
638     // FIXME: stop eating the warnings and notes.
639     if (Severity != DS_Error)
640       return;
641     DiagID = diag::err_fe_cannot_link_module;
642     break;
643   case llvm::DK_OptimizationRemark:
644     // Optimization remarks are always handled completely by this
645     // handler. There is no generic way of emitting them.
646     OptimizationRemarkHandler(cast<OptimizationRemark>(DI));
647     return;
648   case llvm::DK_OptimizationRemarkMissed:
649     // Optimization remarks are always handled completely by this
650     // handler. There is no generic way of emitting them.
651     OptimizationRemarkHandler(cast<OptimizationRemarkMissed>(DI));
652     return;
653   case llvm::DK_OptimizationRemarkAnalysis:
654     // Optimization remarks are always handled completely by this
655     // handler. There is no generic way of emitting them.
656     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysis>(DI));
657     return;
658   case llvm::DK_OptimizationRemarkAnalysisFPCommute:
659     // Optimization remarks are always handled completely by this
660     // handler. There is no generic way of emitting them.
661     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysisFPCommute>(DI));
662     return;
663   case llvm::DK_OptimizationRemarkAnalysisAliasing:
664     // Optimization remarks are always handled completely by this
665     // handler. There is no generic way of emitting them.
666     OptimizationRemarkHandler(cast<OptimizationRemarkAnalysisAliasing>(DI));
667     return;
668   case llvm::DK_OptimizationFailure:
669     // Optimization failures are always handled completely by this
670     // handler.
671     OptimizationFailureHandler(cast<DiagnosticInfoOptimizationFailure>(DI));
672     return;
673   case llvm::DK_Unsupported:
674     UnsupportedDiagHandler(cast<DiagnosticInfoUnsupported>(DI));
675     return;
676   default:
677     // Plugin IDs are not bound to any value as they are set dynamically.
678     ComputeDiagRemarkID(Severity, backend_plugin, DiagID);
679     break;
680   }
681   std::string MsgStorage;
682   {
683     raw_string_ostream Stream(MsgStorage);
684     DiagnosticPrinterRawOStream DP(Stream);
685     DI.print(DP);
686   }
687 
688   if (DiagID == diag::err_fe_cannot_link_module) {
689     Diags.Report(diag::err_fe_cannot_link_module)
690         << CurLinkModule->getModuleIdentifier() << MsgStorage;
691     return;
692   }
693 
694   // Report the backend message using the usual diagnostic mechanism.
695   FullSourceLoc Loc;
696   Diags.Report(Loc, DiagID).AddString(MsgStorage);
697 }
698 #undef ComputeDiagID
699 
700 CodeGenAction::CodeGenAction(unsigned _Act, LLVMContext *_VMContext)
701     : Act(_Act), VMContext(_VMContext ? _VMContext : new LLVMContext),
702       OwnsVMContext(!_VMContext) {}
703 
704 CodeGenAction::~CodeGenAction() {
705   TheModule.reset();
706   if (OwnsVMContext)
707     delete VMContext;
708 }
709 
710 bool CodeGenAction::hasIRSupport() const { return true; }
711 
712 void CodeGenAction::EndSourceFileAction() {
713   // If the consumer creation failed, do nothing.
714   if (!getCompilerInstance().hasASTConsumer())
715     return;
716 
717   // Take back ownership of link modules we passed to consumer.
718   if (!LinkModules.empty())
719     BEConsumer->releaseLinkModules();
720 
721   // Steal the module from the consumer.
722   TheModule = BEConsumer->takeModule();
723 }
724 
725 std::unique_ptr<llvm::Module> CodeGenAction::takeModule() {
726   return std::move(TheModule);
727 }
728 
729 llvm::LLVMContext *CodeGenAction::takeLLVMContext() {
730   OwnsVMContext = false;
731   return VMContext;
732 }
733 
734 static std::unique_ptr<raw_pwrite_stream>
735 GetOutputStream(CompilerInstance &CI, StringRef InFile, BackendAction Action) {
736   switch (Action) {
737   case Backend_EmitAssembly:
738     return CI.createDefaultOutputFile(false, InFile, "s");
739   case Backend_EmitLL:
740     return CI.createDefaultOutputFile(false, InFile, "ll");
741   case Backend_EmitBC:
742     return CI.createDefaultOutputFile(true, InFile, "bc");
743   case Backend_EmitNothing:
744     return nullptr;
745   case Backend_EmitMCNull:
746     return CI.createNullOutputFile();
747   case Backend_EmitObj:
748     return CI.createDefaultOutputFile(true, InFile, "o");
749   }
750 
751   llvm_unreachable("Invalid action!");
752 }
753 
754 std::unique_ptr<ASTConsumer>
755 CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
756   BackendAction BA = static_cast<BackendAction>(Act);
757   std::unique_ptr<raw_pwrite_stream> OS = GetOutputStream(CI, InFile, BA);
758   if (BA != Backend_EmitNothing && !OS)
759     return nullptr;
760 
761   // Load bitcode modules to link with, if we need to.
762   if (LinkModules.empty())
763     for (auto &I : CI.getCodeGenOpts().LinkBitcodeFiles) {
764       const std::string &LinkBCFile = I.second;
765 
766       auto BCBuf = CI.getFileManager().getBufferForFile(LinkBCFile);
767       if (!BCBuf) {
768         CI.getDiagnostics().Report(diag::err_cannot_open_file)
769             << LinkBCFile << BCBuf.getError().message();
770         LinkModules.clear();
771         return nullptr;
772       }
773 
774       ErrorOr<std::unique_ptr<llvm::Module>> ModuleOrErr =
775           getLazyBitcodeModule(std::move(*BCBuf), *VMContext);
776       if (std::error_code EC = ModuleOrErr.getError()) {
777         CI.getDiagnostics().Report(diag::err_cannot_open_file) << LinkBCFile
778                                                                << EC.message();
779         LinkModules.clear();
780         return nullptr;
781       }
782       addLinkModule(ModuleOrErr.get().release(), I.first);
783     }
784 
785   CoverageSourceInfo *CoverageInfo = nullptr;
786   // Add the preprocessor callback only when the coverage mapping is generated.
787   if (CI.getCodeGenOpts().CoverageMapping) {
788     CoverageInfo = new CoverageSourceInfo;
789     CI.getPreprocessor().addPPCallbacks(
790                                     std::unique_ptr<PPCallbacks>(CoverageInfo));
791   }
792 
793   std::unique_ptr<BackendConsumer> Result(new BackendConsumer(
794       BA, CI.getDiagnostics(), CI.getHeaderSearchOpts(),
795       CI.getPreprocessorOpts(), CI.getCodeGenOpts(), CI.getTargetOpts(),
796       CI.getLangOpts(), CI.getFrontendOpts().ShowTimers, InFile, LinkModules,
797       std::move(OS), *VMContext, CoverageInfo));
798   BEConsumer = Result.get();
799   return std::move(Result);
800 }
801 
802 static void BitcodeInlineAsmDiagHandler(const llvm::SMDiagnostic &SM,
803                                          void *Context,
804                                          unsigned LocCookie) {
805   SM.print(nullptr, llvm::errs());
806 
807   auto Diags = static_cast<DiagnosticsEngine *>(Context);
808   unsigned DiagID;
809   switch (SM.getKind()) {
810   case llvm::SourceMgr::DK_Error:
811     DiagID = diag::err_fe_inline_asm;
812     break;
813   case llvm::SourceMgr::DK_Warning:
814     DiagID = diag::warn_fe_inline_asm;
815     break;
816   case llvm::SourceMgr::DK_Note:
817     DiagID = diag::note_fe_inline_asm;
818     break;
819   }
820 
821   Diags->Report(DiagID).AddString("cannot compile inline asm");
822 }
823 
824 void CodeGenAction::ExecuteAction() {
825   // If this is an IR file, we have to treat it specially.
826   if (getCurrentFileKind() == IK_LLVM_IR) {
827     BackendAction BA = static_cast<BackendAction>(Act);
828     CompilerInstance &CI = getCompilerInstance();
829     std::unique_ptr<raw_pwrite_stream> OS =
830         GetOutputStream(CI, getCurrentFile(), BA);
831     if (BA != Backend_EmitNothing && !OS)
832       return;
833 
834     bool Invalid;
835     SourceManager &SM = CI.getSourceManager();
836     FileID FID = SM.getMainFileID();
837     llvm::MemoryBuffer *MainFile = SM.getBuffer(FID, &Invalid);
838     if (Invalid)
839       return;
840 
841     // For ThinLTO backend invocations, ensure that the context
842     // merges types based on ODR identifiers.
843     if (!CI.getCodeGenOpts().ThinLTOIndexFile.empty())
844       VMContext->enableDebugTypeODRUniquing();
845 
846     llvm::SMDiagnostic Err;
847     TheModule = parseIR(MainFile->getMemBufferRef(), Err, *VMContext);
848     if (!TheModule) {
849       // Translate from the diagnostic info to the SourceManager location if
850       // available.
851       // TODO: Unify this with ConvertBackendLocation()
852       SourceLocation Loc;
853       if (Err.getLineNo() > 0) {
854         assert(Err.getColumnNo() >= 0);
855         Loc = SM.translateFileLineCol(SM.getFileEntryForID(FID),
856                                       Err.getLineNo(), Err.getColumnNo() + 1);
857       }
858 
859       // Strip off a leading diagnostic code if there is one.
860       StringRef Msg = Err.getMessage();
861       if (Msg.startswith("error: "))
862         Msg = Msg.substr(7);
863 
864       unsigned DiagID =
865           CI.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, "%0");
866 
867       CI.getDiagnostics().Report(Loc, DiagID) << Msg;
868       return;
869     }
870     const TargetOptions &TargetOpts = CI.getTargetOpts();
871     if (TheModule->getTargetTriple() != TargetOpts.Triple) {
872       CI.getDiagnostics().Report(SourceLocation(),
873                                  diag::warn_fe_override_module)
874           << TargetOpts.Triple;
875       TheModule->setTargetTriple(TargetOpts.Triple);
876     }
877 
878     EmbedBitcode(TheModule.get(), CI.getCodeGenOpts(),
879                  MainFile->getMemBufferRef());
880 
881     LLVMContext &Ctx = TheModule->getContext();
882     Ctx.setInlineAsmDiagnosticHandler(BitcodeInlineAsmDiagHandler,
883                                       &CI.getDiagnostics());
884 
885     EmitBackendOutput(CI.getDiagnostics(), CI.getCodeGenOpts(), TargetOpts,
886                       CI.getLangOpts(), CI.getTarget().getDataLayout(),
887                       TheModule.get(), BA, std::move(OS));
888     return;
889   }
890 
891   // Otherwise follow the normal AST path.
892   this->ASTFrontendAction::ExecuteAction();
893 }
894 
895 //
896 
897 void EmitAssemblyAction::anchor() { }
898 EmitAssemblyAction::EmitAssemblyAction(llvm::LLVMContext *_VMContext)
899   : CodeGenAction(Backend_EmitAssembly, _VMContext) {}
900 
901 void EmitBCAction::anchor() { }
902 EmitBCAction::EmitBCAction(llvm::LLVMContext *_VMContext)
903   : CodeGenAction(Backend_EmitBC, _VMContext) {}
904 
905 void EmitLLVMAction::anchor() { }
906 EmitLLVMAction::EmitLLVMAction(llvm::LLVMContext *_VMContext)
907   : CodeGenAction(Backend_EmitLL, _VMContext) {}
908 
909 void EmitLLVMOnlyAction::anchor() { }
910 EmitLLVMOnlyAction::EmitLLVMOnlyAction(llvm::LLVMContext *_VMContext)
911   : CodeGenAction(Backend_EmitNothing, _VMContext) {}
912 
913 void EmitCodeGenOnlyAction::anchor() { }
914 EmitCodeGenOnlyAction::EmitCodeGenOnlyAction(llvm::LLVMContext *_VMContext)
915   : CodeGenAction(Backend_EmitMCNull, _VMContext) {}
916 
917 void EmitObjAction::anchor() { }
918 EmitObjAction::EmitObjAction(llvm::LLVMContext *_VMContext)
919   : CodeGenAction(Backend_EmitObj, _VMContext) {}
920