1 //===--- FrontendActions.cpp ----------------------------------------------===//
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/Frontend/FrontendActions.h"
11 #include "clang/AST/ASTConsumer.h"
12 #include "clang/Lex/HeaderSearch.h"
13 #include "clang/Lex/Pragma.h"
14 #include "clang/Lex/Preprocessor.h"
15 #include "clang/Parse/Parser.h"
16 #include "clang/Basic/FileManager.h"
17 #include "clang/Frontend/ASTConsumers.h"
18 #include "clang/Frontend/ASTUnit.h"
19 #include "clang/Frontend/CompilerInstance.h"
20 #include "clang/Frontend/FrontendDiagnostic.h"
21 #include "clang/Frontend/Utils.h"
22 #include "clang/Serialization/ASTWriter.h"
23 #include "llvm/ADT/OwningPtr.h"
24 #include "llvm/Support/MemoryBuffer.h"
25 #include "llvm/Support/raw_ostream.h"
26 #include "llvm/Support/system_error.h"
27 
28 using namespace clang;
29 
30 //===----------------------------------------------------------------------===//
31 // Custom Actions
32 //===----------------------------------------------------------------------===//
33 
34 ASTConsumer *InitOnlyAction::CreateASTConsumer(CompilerInstance &CI,
35                                                StringRef InFile) {
36   return new ASTConsumer();
37 }
38 
39 void InitOnlyAction::ExecuteAction() {
40 }
41 
42 //===----------------------------------------------------------------------===//
43 // AST Consumer Actions
44 //===----------------------------------------------------------------------===//
45 
46 ASTConsumer *ASTPrintAction::CreateASTConsumer(CompilerInstance &CI,
47                                                StringRef InFile) {
48   if (raw_ostream *OS = CI.createDefaultOutputFile(false, InFile))
49     return CreateASTPrinter(OS);
50   return 0;
51 }
52 
53 ASTConsumer *ASTDumpAction::CreateASTConsumer(CompilerInstance &CI,
54                                               StringRef InFile) {
55   return CreateASTDumper();
56 }
57 
58 ASTConsumer *ASTDumpXMLAction::CreateASTConsumer(CompilerInstance &CI,
59                                                  StringRef InFile) {
60   raw_ostream *OS;
61   if (CI.getFrontendOpts().OutputFile.empty())
62     OS = &llvm::outs();
63   else
64     OS = CI.createDefaultOutputFile(false, InFile);
65   if (!OS) return 0;
66   return CreateASTDumperXML(*OS);
67 }
68 
69 ASTConsumer *ASTViewAction::CreateASTConsumer(CompilerInstance &CI,
70                                               StringRef InFile) {
71   return CreateASTViewer();
72 }
73 
74 ASTConsumer *DeclContextPrintAction::CreateASTConsumer(CompilerInstance &CI,
75                                                        StringRef InFile) {
76   return CreateDeclContextPrinter();
77 }
78 
79 ASTConsumer *GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI,
80                                                   StringRef InFile) {
81   std::string Sysroot;
82   std::string OutputFile;
83   raw_ostream *OS = 0;
84   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
85     return 0;
86 
87   if (!CI.getFrontendOpts().RelocatablePCH)
88     Sysroot.clear();
89   return new PCHGenerator(CI.getPreprocessor(), OutputFile, MakeModule,
90                           Sysroot, OS);
91 }
92 
93 bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
94                                                     StringRef InFile,
95                                                     std::string &Sysroot,
96                                                     std::string &OutputFile,
97                                                     raw_ostream *&OS) {
98   Sysroot = CI.getHeaderSearchOpts().Sysroot;
99   if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
100     CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
101     return true;
102   }
103 
104   // We use createOutputFile here because this is exposed via libclang, and we
105   // must disable the RemoveFileOnSignal behavior.
106   // We use a temporary to avoid race conditions.
107   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
108                            /*RemoveFileOnSignal=*/false, InFile,
109                            /*Extension=*/"", /*useTemporary=*/true);
110   if (!OS)
111     return true;
112 
113   OutputFile = CI.getFrontendOpts().OutputFile;
114   return false;
115 }
116 
117 ASTConsumer *GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
118                                                      StringRef InFile) {
119   std::string Sysroot;
120   std::string OutputFile;
121   raw_ostream *OS = 0;
122   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
123     return 0;
124 
125   return new PCHGenerator(CI.getPreprocessor(), OutputFile, /*MakeModule=*/true,
126                           Sysroot, OS);
127 }
128 
129 /// \brief Collect the set of header includes needed to construct the given
130 /// module.
131 ///
132 /// \param Module The module we're collecting includes from.
133 /// \param ExplicitOnly Whether we should only add headers from explicit
134 static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
135                                         ModuleMap::Module *Module,
136                                         bool ExplicitOnly,
137                                         llvm::SmallString<256> &Includes) {
138   if (!ExplicitOnly || Module->IsExplicit) {
139     // Add includes for each of these headers.
140     for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
141       if (LangOpts.ObjC1)
142         Includes += "#import \"";
143       else
144         Includes += "#include \"";
145       Includes += Module->Headers[I]->getName();
146       Includes += "\"\n";
147     }
148   }
149 
150   // Recurse into submodules.
151   for (llvm::StringMap<ModuleMap::Module *>::iterator
152             Sub = Module->SubModules.begin(),
153          SubEnd = Module->SubModules.end();
154        Sub != SubEnd; ++Sub) {
155     collectModuleHeaderIncludes(LangOpts, Sub->getValue(),
156                                 ExplicitOnly && !Module->IsExplicit,
157                                 Includes);
158   }
159 }
160 
161 bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
162                                                  StringRef Filename) {
163   // Find the module map file.
164   const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
165   if (!ModuleMap)  {
166     CI.getDiagnostics().Report(diag::err_module_map_not_found)
167       << Filename;
168     return false;
169   }
170 
171   // Parse the module map file.
172   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
173   if (HS.loadModuleMapFile(ModuleMap))
174     return false;
175 
176   if (CI.getLangOpts().CurrentModule.empty()) {
177     CI.getDiagnostics().Report(diag::err_missing_module_name);
178 
179     // FIXME: Eventually, we could consider asking whether there was just
180     // a single module described in the module map, and use that as a
181     // default. Then it would be fairly trivial to just "compile" a module
182     // map with a single module (the common case).
183     return false;
184   }
185 
186   // Dig out the module definition.
187   ModuleMap::Module *Module = HS.getModule(CI.getLangOpts().CurrentModule,
188                                            /*AllowSearch=*/false);
189   if (!Module) {
190     CI.getDiagnostics().Report(diag::err_missing_module)
191       << CI.getLangOpts().CurrentModule << Filename;
192 
193     return false;
194   }
195 
196   // Collect the set of #includes we need to build the module.
197   llvm::SmallString<256> HeaderContents;
198   collectModuleHeaderIncludes(CI.getLangOpts(), Module,
199                               Module->UmbrellaHeader != 0, HeaderContents);
200   if (Module->UmbrellaHeader && HeaderContents.empty()) {
201     // Simple case: we have an umbrella header and there are no additional
202     // includes, we can just parse the umbrella header directly.
203     setCurrentFile(Module->UmbrellaHeader->getName(), getCurrentFileKind());
204     return true;
205   }
206 
207   FileManager &FileMgr = CI.getFileManager();
208   llvm::SmallString<128> HeaderName;
209   time_t ModTime;
210   if (Module->UmbrellaHeader) {
211     // Read in the umbrella header.
212     // FIXME: Go through the source manager; the umbrella header may have
213     // been overridden.
214     std::string ErrorStr;
215     llvm::MemoryBuffer *UmbrellaContents
216       = FileMgr.getBufferForFile(Module->UmbrellaHeader, &ErrorStr);
217     if (!UmbrellaContents) {
218       CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
219         << Module->UmbrellaHeader->getName() << ErrorStr;
220       return false;
221     }
222 
223     // Combine the contents of the umbrella header with the automatically-
224     // generated includes.
225     llvm::SmallString<256> OldContents = HeaderContents;
226     HeaderContents = UmbrellaContents->getBuffer();
227     HeaderContents += "\n\n";
228     HeaderContents += "/* Module includes */\n";
229     HeaderContents += OldContents;
230 
231     // Pretend that we're parsing the umbrella header.
232     HeaderName = Module->UmbrellaHeader->getName();
233     ModTime = Module->UmbrellaHeader->getModificationTime();
234 
235     delete UmbrellaContents;
236   } else {
237     // Pick an innocuous-sounding name for the umbrella header.
238     HeaderName = Module->Name + ".h";
239     if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
240                         /*CacheFailure=*/false)) {
241       // Try again!
242       HeaderName = Module->Name + "-module.h";
243       if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
244                           /*CacheFailure=*/false)) {
245         // Pick something ridiculous and go with it.
246         HeaderName = Module->Name + "-module.hmod";
247       }
248     }
249     ModTime = time(0);
250   }
251 
252   // Remap the contents of the header name we're using to our synthesized
253   // buffer.
254   const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName,
255                                                        HeaderContents.size(),
256                                                        ModTime);
257   llvm::MemoryBuffer *HeaderContentsBuf
258     = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
259   CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);
260 
261   setCurrentFile(HeaderName, getCurrentFileKind());
262   return true;
263 }
264 
265 bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
266                                                        StringRef InFile,
267                                                        std::string &Sysroot,
268                                                        std::string &OutputFile,
269                                                        raw_ostream *&OS) {
270   // If no output file was provided, figure out where this module would go
271   // in the module cache.
272   if (CI.getFrontendOpts().OutputFile.empty()) {
273     HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
274     llvm::SmallString<256> ModuleFileName(HS.getModuleCachePath());
275     llvm::sys::path::append(ModuleFileName,
276                             CI.getLangOpts().CurrentModule + ".pcm");
277     CI.getFrontendOpts().OutputFile = ModuleFileName.str();
278   }
279 
280   // We use createOutputFile here because this is exposed via libclang, and we
281   // must disable the RemoveFileOnSignal behavior.
282   // We use a temporary to avoid race conditions.
283   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
284                            /*RemoveFileOnSignal=*/false, InFile,
285                            /*Extension=*/"", /*useTemporary=*/true);
286   if (!OS)
287     return true;
288 
289   OutputFile = CI.getFrontendOpts().OutputFile;
290   return false;
291 }
292 
293 ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
294                                                  StringRef InFile) {
295   return new ASTConsumer();
296 }
297 
298 //===----------------------------------------------------------------------===//
299 // Preprocessor Actions
300 //===----------------------------------------------------------------------===//
301 
302 void DumpRawTokensAction::ExecuteAction() {
303   Preprocessor &PP = getCompilerInstance().getPreprocessor();
304   SourceManager &SM = PP.getSourceManager();
305 
306   // Start lexing the specified input file.
307   const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
308   Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOptions());
309   RawLex.SetKeepWhitespaceMode(true);
310 
311   Token RawTok;
312   RawLex.LexFromRawLexer(RawTok);
313   while (RawTok.isNot(tok::eof)) {
314     PP.DumpToken(RawTok, true);
315     llvm::errs() << "\n";
316     RawLex.LexFromRawLexer(RawTok);
317   }
318 }
319 
320 void DumpTokensAction::ExecuteAction() {
321   Preprocessor &PP = getCompilerInstance().getPreprocessor();
322   // Start preprocessing the specified input file.
323   Token Tok;
324   PP.EnterMainSourceFile();
325   do {
326     PP.Lex(Tok);
327     PP.DumpToken(Tok, true);
328     llvm::errs() << "\n";
329   } while (Tok.isNot(tok::eof));
330 }
331 
332 void GeneratePTHAction::ExecuteAction() {
333   CompilerInstance &CI = getCompilerInstance();
334   if (CI.getFrontendOpts().OutputFile.empty() ||
335       CI.getFrontendOpts().OutputFile == "-") {
336     // FIXME: Don't fail this way.
337     // FIXME: Verify that we can actually seek in the given file.
338     llvm::report_fatal_error("PTH requires a seekable file for output!");
339   }
340   llvm::raw_fd_ostream *OS =
341     CI.createDefaultOutputFile(true, getCurrentFile());
342   if (!OS) return;
343 
344   CacheTokens(CI.getPreprocessor(), OS);
345 }
346 
347 void PreprocessOnlyAction::ExecuteAction() {
348   Preprocessor &PP = getCompilerInstance().getPreprocessor();
349 
350   // Ignore unknown pragmas.
351   PP.AddPragmaHandler(new EmptyPragmaHandler());
352 
353   Token Tok;
354   // Start parsing the specified input file.
355   PP.EnterMainSourceFile();
356   do {
357     PP.Lex(Tok);
358   } while (Tok.isNot(tok::eof));
359 }
360 
361 void PrintPreprocessedAction::ExecuteAction() {
362   CompilerInstance &CI = getCompilerInstance();
363   // Output file may need to be set to 'Binary', to avoid converting Unix style
364   // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
365   //
366   // Look to see what type of line endings the file uses. If there's a
367   // CRLF, then we won't open the file up in binary mode. If there is
368   // just an LF or CR, then we will open the file up in binary mode.
369   // In this fashion, the output format should match the input format, unless
370   // the input format has inconsistent line endings.
371   //
372   // This should be a relatively fast operation since most files won't have
373   // all of their source code on a single line. However, that is still a
374   // concern, so if we scan for too long, we'll just assume the file should
375   // be opened in binary mode.
376   bool BinaryMode = true;
377   bool InvalidFile = false;
378   const SourceManager& SM = CI.getSourceManager();
379   const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
380                                                      &InvalidFile);
381   if (!InvalidFile) {
382     const char *cur = Buffer->getBufferStart();
383     const char *end = Buffer->getBufferEnd();
384     const char *next = (cur != end) ? cur + 1 : end;
385 
386     // Limit ourselves to only scanning 256 characters into the source
387     // file.  This is mostly a sanity check in case the file has no
388     // newlines whatsoever.
389     if (end - cur > 256) end = cur + 256;
390 
391     while (next < end) {
392       if (*cur == 0x0D) {  // CR
393         if (*next == 0x0A)  // CRLF
394           BinaryMode = false;
395 
396         break;
397       } else if (*cur == 0x0A)  // LF
398         break;
399 
400       ++cur, ++next;
401     }
402   }
403 
404   raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
405   if (!OS) return;
406 
407   DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
408                            CI.getPreprocessorOutputOpts());
409 }
410 
411 void PrintPreambleAction::ExecuteAction() {
412   switch (getCurrentFileKind()) {
413   case IK_C:
414   case IK_CXX:
415   case IK_ObjC:
416   case IK_ObjCXX:
417   case IK_OpenCL:
418   case IK_CUDA:
419     break;
420 
421   case IK_None:
422   case IK_Asm:
423   case IK_PreprocessedC:
424   case IK_PreprocessedCXX:
425   case IK_PreprocessedObjC:
426   case IK_PreprocessedObjCXX:
427   case IK_AST:
428   case IK_LLVM_IR:
429     // We can't do anything with these.
430     return;
431   }
432 
433   CompilerInstance &CI = getCompilerInstance();
434   llvm::MemoryBuffer *Buffer
435       = CI.getFileManager().getBufferForFile(getCurrentFile());
436   if (Buffer) {
437     unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
438     llvm::outs().write(Buffer->getBufferStart(), Preamble);
439     delete Buffer;
440   }
441 }
442