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 "clang/CodeGen/CodeGenAction.h"
11 #include "clang/Basic/FileManager.h"
12 #include "clang/Basic/SourceManager.h"
13 #include "clang/Basic/TargetInfo.h"
14 #include "clang/AST/ASTConsumer.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclGroup.h"
17 #include "clang/CodeGen/BackendUtil.h"
18 #include "clang/CodeGen/ModuleBuilder.h"
19 #include "clang/Frontend/CompilerInstance.h"
20 #include "clang/Frontend/FrontendDiagnostic.h"
21 #include "llvm/LLVMContext.h"
22 #include "llvm/Linker.h"
23 #include "llvm/Module.h"
24 #include "llvm/Pass.h"
25 #include "llvm/ADT/OwningPtr.h"
26 #include "llvm/ADT/SmallString.h"
27 #include "llvm/Bitcode/ReaderWriter.h"
28 #include "llvm/Support/IRReader.h"
29 #include "llvm/Support/MemoryBuffer.h"
30 #include "llvm/Support/SourceMgr.h"
31 #include "llvm/Support/Timer.h"
32 using namespace clang;
33 using namespace llvm;
34
35 namespace clang {
36 class BackendConsumer : public ASTConsumer {
37 virtual void anchor();
38 DiagnosticsEngine &Diags;
39 BackendAction Action;
40 const CodeGenOptions &CodeGenOpts;
41 const TargetOptions &TargetOpts;
42 const LangOptions &LangOpts;
43 raw_ostream *AsmOutStream;
44 ASTContext *Context;
45
46 Timer LLVMIRGeneration;
47
48 OwningPtr<CodeGenerator> Gen;
49
50 OwningPtr<llvm::Module> TheModule, LinkModule;
51
52 public:
BackendConsumer(BackendAction action,DiagnosticsEngine & _Diags,const CodeGenOptions & compopts,const TargetOptions & targetopts,const LangOptions & langopts,bool TimePasses,const std::string & infile,llvm::Module * LinkModule,raw_ostream * OS,LLVMContext & C)53 BackendConsumer(BackendAction action, DiagnosticsEngine &_Diags,
54 const CodeGenOptions &compopts,
55 const TargetOptions &targetopts,
56 const LangOptions &langopts,
57 bool TimePasses,
58 const std::string &infile,
59 llvm::Module *LinkModule,
60 raw_ostream *OS,
61 LLVMContext &C) :
62 Diags(_Diags),
63 Action(action),
64 CodeGenOpts(compopts),
65 TargetOpts(targetopts),
66 LangOpts(langopts),
67 AsmOutStream(OS),
68 LLVMIRGeneration("LLVM IR Generation Time"),
69 Gen(CreateLLVMCodeGen(Diags, infile, compopts, C)),
70 LinkModule(LinkModule) {
71 llvm::TimePassesIsEnabled = TimePasses;
72 }
73
takeModule()74 llvm::Module *takeModule() { return TheModule.take(); }
takeLinkModule()75 llvm::Module *takeLinkModule() { return LinkModule.take(); }
76
HandleCXXStaticMemberVarInstantiation(VarDecl * VD)77 virtual void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
78 Gen->HandleCXXStaticMemberVarInstantiation(VD);
79 }
80
Initialize(ASTContext & Ctx)81 virtual void Initialize(ASTContext &Ctx) {
82 Context = &Ctx;
83
84 if (llvm::TimePassesIsEnabled)
85 LLVMIRGeneration.startTimer();
86
87 Gen->Initialize(Ctx);
88
89 TheModule.reset(Gen->GetModule());
90
91 if (llvm::TimePassesIsEnabled)
92 LLVMIRGeneration.stopTimer();
93 }
94
HandleTopLevelDecl(DeclGroupRef D)95 virtual bool HandleTopLevelDecl(DeclGroupRef D) {
96 PrettyStackTraceDecl CrashInfo(*D.begin(), SourceLocation(),
97 Context->getSourceManager(),
98 "LLVM IR generation of declaration");
99
100 if (llvm::TimePassesIsEnabled)
101 LLVMIRGeneration.startTimer();
102
103 Gen->HandleTopLevelDecl(D);
104
105 if (llvm::TimePassesIsEnabled)
106 LLVMIRGeneration.stopTimer();
107
108 return true;
109 }
110
HandleTranslationUnit(ASTContext & C)111 virtual void HandleTranslationUnit(ASTContext &C) {
112 {
113 PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
114 if (llvm::TimePassesIsEnabled)
115 LLVMIRGeneration.startTimer();
116
117 Gen->HandleTranslationUnit(C);
118
119 if (llvm::TimePassesIsEnabled)
120 LLVMIRGeneration.stopTimer();
121 }
122
123 // Silently ignore if we weren't initialized for some reason.
124 if (!TheModule)
125 return;
126
127 // Make sure IR generation is happy with the module. This is released by
128 // the module provider.
129 llvm::Module *M = Gen->ReleaseModule();
130 if (!M) {
131 // The module has been released by IR gen on failures, do not double
132 // free.
133 TheModule.take();
134 return;
135 }
136
137 assert(TheModule.get() == M &&
138 "Unexpected module change during IR generation");
139
140 // Link LinkModule into this module if present, preserving its validity.
141 if (LinkModule) {
142 std::string ErrorMsg;
143 if (Linker::LinkModules(M, LinkModule.get(), Linker::PreserveSource,
144 &ErrorMsg)) {
145 Diags.Report(diag::err_fe_cannot_link_module)
146 << LinkModule->getModuleIdentifier() << ErrorMsg;
147 return;
148 }
149 }
150
151 // Install an inline asm handler so that diagnostics get printed through
152 // our diagnostics hooks.
153 LLVMContext &Ctx = TheModule->getContext();
154 LLVMContext::InlineAsmDiagHandlerTy OldHandler =
155 Ctx.getInlineAsmDiagnosticHandler();
156 void *OldContext = Ctx.getInlineAsmDiagnosticContext();
157 Ctx.setInlineAsmDiagnosticHandler(InlineAsmDiagHandler, this);
158
159 EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
160 TheModule.get(), Action, AsmOutStream);
161
162 Ctx.setInlineAsmDiagnosticHandler(OldHandler, OldContext);
163 }
164
HandleTagDeclDefinition(TagDecl * D)165 virtual void HandleTagDeclDefinition(TagDecl *D) {
166 PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
167 Context->getSourceManager(),
168 "LLVM IR generation of declaration");
169 Gen->HandleTagDeclDefinition(D);
170 }
171
CompleteTentativeDefinition(VarDecl * D)172 virtual void CompleteTentativeDefinition(VarDecl *D) {
173 Gen->CompleteTentativeDefinition(D);
174 }
175
HandleVTable(CXXRecordDecl * RD,bool DefinitionRequired)176 virtual void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) {
177 Gen->HandleVTable(RD, DefinitionRequired);
178 }
179
InlineAsmDiagHandler(const llvm::SMDiagnostic & SM,void * Context,unsigned LocCookie)180 static void InlineAsmDiagHandler(const llvm::SMDiagnostic &SM,void *Context,
181 unsigned LocCookie) {
182 SourceLocation Loc = SourceLocation::getFromRawEncoding(LocCookie);
183 ((BackendConsumer*)Context)->InlineAsmDiagHandler2(SM, Loc);
184 }
185
186 void InlineAsmDiagHandler2(const llvm::SMDiagnostic &,
187 SourceLocation LocCookie);
188 };
189
anchor()190 void BackendConsumer::anchor() {}
191 }
192
193 /// ConvertBackendLocation - Convert a location in a temporary llvm::SourceMgr
194 /// buffer to be a valid FullSourceLoc.
ConvertBackendLocation(const llvm::SMDiagnostic & D,SourceManager & CSM)195 static FullSourceLoc ConvertBackendLocation(const llvm::SMDiagnostic &D,
196 SourceManager &CSM) {
197 // Get both the clang and llvm source managers. The location is relative to
198 // a memory buffer that the LLVM Source Manager is handling, we need to add
199 // a copy to the Clang source manager.
200 const llvm::SourceMgr &LSM = *D.getSourceMgr();
201
202 // We need to copy the underlying LLVM memory buffer because llvm::SourceMgr
203 // already owns its one and clang::SourceManager wants to own its one.
204 const MemoryBuffer *LBuf =
205 LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
206
207 // Create the copy and transfer ownership to clang::SourceManager.
208 llvm::MemoryBuffer *CBuf =
209 llvm::MemoryBuffer::getMemBufferCopy(LBuf->getBuffer(),
210 LBuf->getBufferIdentifier());
211 FileID FID = CSM.createFileIDForMemBuffer(CBuf);
212
213 // Translate the offset into the file.
214 unsigned Offset = D.getLoc().getPointer() - LBuf->getBufferStart();
215 SourceLocation NewLoc =
216 CSM.getLocForStartOfFile(FID).getLocWithOffset(Offset);
217 return FullSourceLoc(NewLoc, CSM);
218 }
219
220
221 /// InlineAsmDiagHandler2 - This function is invoked when the backend hits an
222 /// error parsing inline asm. The SMDiagnostic indicates the error relative to
223 /// the temporary memory buffer that the inline asm parser has set up.
InlineAsmDiagHandler2(const llvm::SMDiagnostic & D,SourceLocation LocCookie)224 void BackendConsumer::InlineAsmDiagHandler2(const llvm::SMDiagnostic &D,
225 SourceLocation LocCookie) {
226 // There are a couple of different kinds of errors we could get here. First,
227 // we re-format the SMDiagnostic in terms of a clang diagnostic.
228
229 // Strip "error: " off the start of the message string.
230 StringRef Message = D.getMessage();
231 if (Message.startswith("error: "))
232 Message = Message.substr(7);
233
234 // If the SMDiagnostic has an inline asm source location, translate it.
235 FullSourceLoc Loc;
236 if (D.getLoc() != SMLoc())
237 Loc = ConvertBackendLocation(D, Context->getSourceManager());
238
239
240 // If this problem has clang-level source location information, report the
241 // issue as being an error in the source with a note showing the instantiated
242 // code.
243 if (LocCookie.isValid()) {
244 Diags.Report(LocCookie, diag::err_fe_inline_asm).AddString(Message);
245
246 if (D.getLoc().isValid()) {
247 DiagnosticBuilder B = Diags.Report(Loc, diag::note_fe_inline_asm_here);
248 // Convert the SMDiagnostic ranges into SourceRange and attach them
249 // to the diagnostic.
250 for (unsigned i = 0, e = D.getRanges().size(); i != e; ++i) {
251 std::pair<unsigned, unsigned> Range = D.getRanges()[i];
252 unsigned Column = D.getColumnNo();
253 B << SourceRange(Loc.getLocWithOffset(Range.first - Column),
254 Loc.getLocWithOffset(Range.second - Column));
255 }
256 }
257 return;
258 }
259
260 // Otherwise, report the backend error as occurring in the generated .s file.
261 // If Loc is invalid, we still need to report the error, it just gets no
262 // location info.
263 Diags.Report(Loc, diag::err_fe_inline_asm).AddString(Message);
264 }
265
266 //
267
CodeGenAction(unsigned _Act,LLVMContext * _VMContext)268 CodeGenAction::CodeGenAction(unsigned _Act, LLVMContext *_VMContext)
269 : Act(_Act), LinkModule(0),
270 VMContext(_VMContext ? _VMContext : new LLVMContext),
271 OwnsVMContext(!_VMContext) {}
272
~CodeGenAction()273 CodeGenAction::~CodeGenAction() {
274 TheModule.reset();
275 if (OwnsVMContext)
276 delete VMContext;
277 }
278
hasIRSupport() const279 bool CodeGenAction::hasIRSupport() const { return true; }
280
EndSourceFileAction()281 void CodeGenAction::EndSourceFileAction() {
282 // If the consumer creation failed, do nothing.
283 if (!getCompilerInstance().hasASTConsumer())
284 return;
285
286 // If we were given a link module, release consumer's ownership of it.
287 if (LinkModule)
288 BEConsumer->takeLinkModule();
289
290 // Steal the module from the consumer.
291 TheModule.reset(BEConsumer->takeModule());
292 }
293
takeModule()294 llvm::Module *CodeGenAction::takeModule() {
295 return TheModule.take();
296 }
297
takeLLVMContext()298 llvm::LLVMContext *CodeGenAction::takeLLVMContext() {
299 OwnsVMContext = false;
300 return VMContext;
301 }
302
GetOutputStream(CompilerInstance & CI,StringRef InFile,BackendAction Action)303 static raw_ostream *GetOutputStream(CompilerInstance &CI,
304 StringRef InFile,
305 BackendAction Action) {
306 switch (Action) {
307 case Backend_EmitAssembly:
308 return CI.createDefaultOutputFile(false, InFile, "s");
309 case Backend_EmitLL:
310 return CI.createDefaultOutputFile(false, InFile, "ll");
311 case Backend_EmitBC:
312 return CI.createDefaultOutputFile(true, InFile, "bc");
313 case Backend_EmitNothing:
314 return 0;
315 case Backend_EmitMCNull:
316 case Backend_EmitObj:
317 return CI.createDefaultOutputFile(true, InFile, "o");
318 }
319
320 llvm_unreachable("Invalid action!");
321 }
322
CreateASTConsumer(CompilerInstance & CI,StringRef InFile)323 ASTConsumer *CodeGenAction::CreateASTConsumer(CompilerInstance &CI,
324 StringRef InFile) {
325 BackendAction BA = static_cast<BackendAction>(Act);
326 OwningPtr<raw_ostream> OS(GetOutputStream(CI, InFile, BA));
327 if (BA != Backend_EmitNothing && !OS)
328 return 0;
329
330 llvm::Module *LinkModuleToUse = LinkModule;
331
332 // If we were not given a link module, and the user requested that one be
333 // loaded from bitcode, do so now.
334 const std::string &LinkBCFile = CI.getCodeGenOpts().LinkBitcodeFile;
335 if (!LinkModuleToUse && !LinkBCFile.empty()) {
336 std::string ErrorStr;
337
338 llvm::MemoryBuffer *BCBuf =
339 CI.getFileManager().getBufferForFile(LinkBCFile, &ErrorStr);
340 if (!BCBuf) {
341 CI.getDiagnostics().Report(diag::err_cannot_open_file)
342 << LinkBCFile << ErrorStr;
343 return 0;
344 }
345
346 LinkModuleToUse = getLazyBitcodeModule(BCBuf, *VMContext, &ErrorStr);
347 if (!LinkModuleToUse) {
348 CI.getDiagnostics().Report(diag::err_cannot_open_file)
349 << LinkBCFile << ErrorStr;
350 return 0;
351 }
352 }
353
354 BEConsumer =
355 new BackendConsumer(BA, CI.getDiagnostics(),
356 CI.getCodeGenOpts(), CI.getTargetOpts(),
357 CI.getLangOpts(),
358 CI.getFrontendOpts().ShowTimers, InFile,
359 LinkModuleToUse, OS.take(), *VMContext);
360 return BEConsumer;
361 }
362
ExecuteAction()363 void CodeGenAction::ExecuteAction() {
364 // If this is an IR file, we have to treat it specially.
365 if (getCurrentFileKind() == IK_LLVM_IR) {
366 BackendAction BA = static_cast<BackendAction>(Act);
367 CompilerInstance &CI = getCompilerInstance();
368 raw_ostream *OS = GetOutputStream(CI, getCurrentFile(), BA);
369 if (BA != Backend_EmitNothing && !OS)
370 return;
371
372 bool Invalid;
373 SourceManager &SM = CI.getSourceManager();
374 const llvm::MemoryBuffer *MainFile = SM.getBuffer(SM.getMainFileID(),
375 &Invalid);
376 if (Invalid)
377 return;
378
379 // FIXME: This is stupid, IRReader shouldn't take ownership.
380 llvm::MemoryBuffer *MainFileCopy =
381 llvm::MemoryBuffer::getMemBufferCopy(MainFile->getBuffer(),
382 getCurrentFile().c_str());
383
384 llvm::SMDiagnostic Err;
385 TheModule.reset(ParseIR(MainFileCopy, Err, *VMContext));
386 if (!TheModule) {
387 // Translate from the diagnostic info to the SourceManager location.
388 SourceLocation Loc = SM.translateFileLineCol(
389 SM.getFileEntryForID(SM.getMainFileID()), Err.getLineNo(),
390 Err.getColumnNo() + 1);
391
392 // Get a custom diagnostic for the error. We strip off a leading
393 // diagnostic code if there is one.
394 StringRef Msg = Err.getMessage();
395 if (Msg.startswith("error: "))
396 Msg = Msg.substr(7);
397
398 // Escape '%', which is interpreted as a format character.
399 llvm::SmallString<128> EscapedMessage;
400 for (unsigned i = 0, e = Msg.size(); i != e; ++i) {
401 if (Msg[i] == '%')
402 EscapedMessage += '%';
403 EscapedMessage += Msg[i];
404 }
405
406 unsigned DiagID = CI.getDiagnostics().getCustomDiagID(
407 DiagnosticsEngine::Error, EscapedMessage);
408
409 CI.getDiagnostics().Report(Loc, DiagID);
410 return;
411 }
412
413 EmitBackendOutput(CI.getDiagnostics(), CI.getCodeGenOpts(),
414 CI.getTargetOpts(), CI.getLangOpts(),
415 TheModule.get(),
416 BA, OS);
417 return;
418 }
419
420 // Otherwise follow the normal AST path.
421 this->ASTFrontendAction::ExecuteAction();
422 }
423
424 //
425
anchor()426 void EmitAssemblyAction::anchor() { }
EmitAssemblyAction(llvm::LLVMContext * _VMContext)427 EmitAssemblyAction::EmitAssemblyAction(llvm::LLVMContext *_VMContext)
428 : CodeGenAction(Backend_EmitAssembly, _VMContext) {}
429
anchor()430 void EmitBCAction::anchor() { }
EmitBCAction(llvm::LLVMContext * _VMContext)431 EmitBCAction::EmitBCAction(llvm::LLVMContext *_VMContext)
432 : CodeGenAction(Backend_EmitBC, _VMContext) {}
433
anchor()434 void EmitLLVMAction::anchor() { }
EmitLLVMAction(llvm::LLVMContext * _VMContext)435 EmitLLVMAction::EmitLLVMAction(llvm::LLVMContext *_VMContext)
436 : CodeGenAction(Backend_EmitLL, _VMContext) {}
437
anchor()438 void EmitLLVMOnlyAction::anchor() { }
EmitLLVMOnlyAction(llvm::LLVMContext * _VMContext)439 EmitLLVMOnlyAction::EmitLLVMOnlyAction(llvm::LLVMContext *_VMContext)
440 : CodeGenAction(Backend_EmitNothing, _VMContext) {}
441
anchor()442 void EmitCodeGenOnlyAction::anchor() { }
EmitCodeGenOnlyAction(llvm::LLVMContext * _VMContext)443 EmitCodeGenOnlyAction::EmitCodeGenOnlyAction(llvm::LLVMContext *_VMContext)
444 : CodeGenAction(Backend_EmitMCNull, _VMContext) {}
445
anchor()446 void EmitObjAction::anchor() { }
EmitObjAction(llvm::LLVMContext * _VMContext)447 EmitObjAction::EmitObjAction(llvm::LLVMContext *_VMContext)
448 : CodeGenAction(Backend_EmitObj, _VMContext) {}
449