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, 0, Sysroot, OS);
90 }
91 
92 bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
93                                                     StringRef InFile,
94                                                     std::string &Sysroot,
95                                                     std::string &OutputFile,
96                                                     raw_ostream *&OS) {
97   Sysroot = CI.getHeaderSearchOpts().Sysroot;
98   if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
99     CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
100     return true;
101   }
102 
103   // We use createOutputFile here because this is exposed via libclang, and we
104   // must disable the RemoveFileOnSignal behavior.
105   // We use a temporary to avoid race conditions.
106   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
107                            /*RemoveFileOnSignal=*/false, InFile,
108                            /*Extension=*/"", /*useTemporary=*/true);
109   if (!OS)
110     return true;
111 
112   OutputFile = CI.getFrontendOpts().OutputFile;
113   return false;
114 }
115 
116 ASTConsumer *GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
117                                                      StringRef InFile) {
118   std::string Sysroot;
119   std::string OutputFile;
120   raw_ostream *OS = 0;
121   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
122     return 0;
123 
124   return new PCHGenerator(CI.getPreprocessor(), OutputFile, Module,
125                           Sysroot, OS);
126 }
127 
128 /// \brief Collect the set of header includes needed to construct the given
129 /// module.
130 ///
131 /// \param Module The module we're collecting includes from.
132 ///
133 /// \param Includes Will be augmented with the set of #includes or #imports
134 /// needed to load all of the named headers.
135 static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
136                                         clang::Module *Module,
137                                         llvm::SmallString<256> &Includes) {
138   // Add includes for each of these headers.
139   for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
140     if (LangOpts.ObjC1)
141       Includes += "#import \"";
142     else
143       Includes += "#include \"";
144     Includes += Module->Headers[I]->getName();
145     Includes += "\"\n";
146   }
147 
148   if (Module->UmbrellaHeader && Module->Parent) {
149     // Include the umbrella header for submodules.
150     if (LangOpts.ObjC1)
151       Includes += "#import \"";
152     else
153       Includes += "#include \"";
154     Includes += Module->UmbrellaHeader->getName();
155     Includes += "\"\n";
156   }
157 
158   // Recurse into submodules.
159   for (llvm::StringMap<clang::Module *>::iterator
160             Sub = Module->SubModules.begin(),
161          SubEnd = Module->SubModules.end();
162        Sub != SubEnd; ++Sub)
163     collectModuleHeaderIncludes(LangOpts, Sub->getValue(), Includes);
164 }
165 
166 bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
167                                                  StringRef Filename) {
168   // Find the module map file.
169   const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
170   if (!ModuleMap)  {
171     CI.getDiagnostics().Report(diag::err_module_map_not_found)
172       << Filename;
173     return false;
174   }
175 
176   // Parse the module map file.
177   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
178   if (HS.loadModuleMapFile(ModuleMap))
179     return false;
180 
181   if (CI.getLangOpts().CurrentModule.empty()) {
182     CI.getDiagnostics().Report(diag::err_missing_module_name);
183 
184     // FIXME: Eventually, we could consider asking whether there was just
185     // a single module described in the module map, and use that as a
186     // default. Then it would be fairly trivial to just "compile" a module
187     // map with a single module (the common case).
188     return false;
189   }
190 
191   // Dig out the module definition.
192   Module = HS.getModule(CI.getLangOpts().CurrentModule, /*AllowSearch=*/false);
193   if (!Module) {
194     CI.getDiagnostics().Report(diag::err_missing_module)
195       << CI.getLangOpts().CurrentModule << Filename;
196 
197     return false;
198   }
199 
200   // Collect the set of #includes we need to build the module.
201   llvm::SmallString<256> HeaderContents;
202   collectModuleHeaderIncludes(CI.getLangOpts(), Module, HeaderContents);
203   if (Module->UmbrellaHeader && HeaderContents.empty()) {
204     // Simple case: we have an umbrella header and there are no additional
205     // includes, we can just parse the umbrella header directly.
206     setCurrentFile(Module->UmbrellaHeader->getName(), getCurrentFileKind());
207     return true;
208   }
209 
210   FileManager &FileMgr = CI.getFileManager();
211   llvm::SmallString<128> HeaderName;
212   time_t ModTime;
213   if (Module->UmbrellaHeader) {
214     // Read in the umbrella header.
215     // FIXME: Go through the source manager; the umbrella header may have
216     // been overridden.
217     std::string ErrorStr;
218     llvm::MemoryBuffer *UmbrellaContents
219       = FileMgr.getBufferForFile(Module->UmbrellaHeader, &ErrorStr);
220     if (!UmbrellaContents) {
221       CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
222         << Module->UmbrellaHeader->getName() << ErrorStr;
223       return false;
224     }
225 
226     // Combine the contents of the umbrella header with the automatically-
227     // generated includes.
228     llvm::SmallString<256> OldContents = HeaderContents;
229     HeaderContents = UmbrellaContents->getBuffer();
230     HeaderContents += "\n\n";
231     HeaderContents += "/* Module includes */\n";
232     HeaderContents += OldContents;
233 
234     // Pretend that we're parsing the umbrella header.
235     HeaderName = Module->UmbrellaHeader->getName();
236     ModTime = Module->UmbrellaHeader->getModificationTime();
237 
238     delete UmbrellaContents;
239   } else {
240     // Pick an innocuous-sounding name for the umbrella header.
241     HeaderName = Module->Name + ".h";
242     if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
243                         /*CacheFailure=*/false)) {
244       // Try again!
245       HeaderName = Module->Name + "-module.h";
246       if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
247                           /*CacheFailure=*/false)) {
248         // Pick something ridiculous and go with it.
249         HeaderName = Module->Name + "-module.hmod";
250       }
251     }
252     ModTime = time(0);
253   }
254 
255   // Remap the contents of the header name we're using to our synthesized
256   // buffer.
257   const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName,
258                                                        HeaderContents.size(),
259                                                        ModTime);
260   llvm::MemoryBuffer *HeaderContentsBuf
261     = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
262   CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);
263 
264   setCurrentFile(HeaderName, getCurrentFileKind());
265   return true;
266 }
267 
268 bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
269                                                        StringRef InFile,
270                                                        std::string &Sysroot,
271                                                        std::string &OutputFile,
272                                                        raw_ostream *&OS) {
273   // If no output file was provided, figure out where this module would go
274   // in the module cache.
275   if (CI.getFrontendOpts().OutputFile.empty()) {
276     HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
277     llvm::SmallString<256> ModuleFileName(HS.getModuleCachePath());
278     llvm::sys::path::append(ModuleFileName,
279                             CI.getLangOpts().CurrentModule + ".pcm");
280     CI.getFrontendOpts().OutputFile = ModuleFileName.str();
281   }
282 
283   // We use createOutputFile here because this is exposed via libclang, and we
284   // must disable the RemoveFileOnSignal behavior.
285   // We use a temporary to avoid race conditions.
286   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
287                            /*RemoveFileOnSignal=*/false, InFile,
288                            /*Extension=*/"", /*useTemporary=*/true);
289   if (!OS)
290     return true;
291 
292   OutputFile = CI.getFrontendOpts().OutputFile;
293   return false;
294 }
295 
296 ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
297                                                  StringRef InFile) {
298   return new ASTConsumer();
299 }
300 
301 //===----------------------------------------------------------------------===//
302 // Preprocessor Actions
303 //===----------------------------------------------------------------------===//
304 
305 void DumpRawTokensAction::ExecuteAction() {
306   Preprocessor &PP = getCompilerInstance().getPreprocessor();
307   SourceManager &SM = PP.getSourceManager();
308 
309   // Start lexing the specified input file.
310   const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
311   Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOptions());
312   RawLex.SetKeepWhitespaceMode(true);
313 
314   Token RawTok;
315   RawLex.LexFromRawLexer(RawTok);
316   while (RawTok.isNot(tok::eof)) {
317     PP.DumpToken(RawTok, true);
318     llvm::errs() << "\n";
319     RawLex.LexFromRawLexer(RawTok);
320   }
321 }
322 
323 void DumpTokensAction::ExecuteAction() {
324   Preprocessor &PP = getCompilerInstance().getPreprocessor();
325   // Start preprocessing the specified input file.
326   Token Tok;
327   PP.EnterMainSourceFile();
328   do {
329     PP.Lex(Tok);
330     PP.DumpToken(Tok, true);
331     llvm::errs() << "\n";
332   } while (Tok.isNot(tok::eof));
333 }
334 
335 void GeneratePTHAction::ExecuteAction() {
336   CompilerInstance &CI = getCompilerInstance();
337   if (CI.getFrontendOpts().OutputFile.empty() ||
338       CI.getFrontendOpts().OutputFile == "-") {
339     // FIXME: Don't fail this way.
340     // FIXME: Verify that we can actually seek in the given file.
341     llvm::report_fatal_error("PTH requires a seekable file for output!");
342   }
343   llvm::raw_fd_ostream *OS =
344     CI.createDefaultOutputFile(true, getCurrentFile());
345   if (!OS) return;
346 
347   CacheTokens(CI.getPreprocessor(), OS);
348 }
349 
350 void PreprocessOnlyAction::ExecuteAction() {
351   Preprocessor &PP = getCompilerInstance().getPreprocessor();
352 
353   // Ignore unknown pragmas.
354   PP.AddPragmaHandler(new EmptyPragmaHandler());
355 
356   Token Tok;
357   // Start parsing the specified input file.
358   PP.EnterMainSourceFile();
359   do {
360     PP.Lex(Tok);
361   } while (Tok.isNot(tok::eof));
362 }
363 
364 void PrintPreprocessedAction::ExecuteAction() {
365   CompilerInstance &CI = getCompilerInstance();
366   // Output file may need to be set to 'Binary', to avoid converting Unix style
367   // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
368   //
369   // Look to see what type of line endings the file uses. If there's a
370   // CRLF, then we won't open the file up in binary mode. If there is
371   // just an LF or CR, then we will open the file up in binary mode.
372   // In this fashion, the output format should match the input format, unless
373   // the input format has inconsistent line endings.
374   //
375   // This should be a relatively fast operation since most files won't have
376   // all of their source code on a single line. However, that is still a
377   // concern, so if we scan for too long, we'll just assume the file should
378   // be opened in binary mode.
379   bool BinaryMode = true;
380   bool InvalidFile = false;
381   const SourceManager& SM = CI.getSourceManager();
382   const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
383                                                      &InvalidFile);
384   if (!InvalidFile) {
385     const char *cur = Buffer->getBufferStart();
386     const char *end = Buffer->getBufferEnd();
387     const char *next = (cur != end) ? cur + 1 : end;
388 
389     // Limit ourselves to only scanning 256 characters into the source
390     // file.  This is mostly a sanity check in case the file has no
391     // newlines whatsoever.
392     if (end - cur > 256) end = cur + 256;
393 
394     while (next < end) {
395       if (*cur == 0x0D) {  // CR
396         if (*next == 0x0A)  // CRLF
397           BinaryMode = false;
398 
399         break;
400       } else if (*cur == 0x0A)  // LF
401         break;
402 
403       ++cur, ++next;
404     }
405   }
406 
407   raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
408   if (!OS) return;
409 
410   DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
411                            CI.getPreprocessorOutputOpts());
412 }
413 
414 void PrintPreambleAction::ExecuteAction() {
415   switch (getCurrentFileKind()) {
416   case IK_C:
417   case IK_CXX:
418   case IK_ObjC:
419   case IK_ObjCXX:
420   case IK_OpenCL:
421   case IK_CUDA:
422     break;
423 
424   case IK_None:
425   case IK_Asm:
426   case IK_PreprocessedC:
427   case IK_PreprocessedCXX:
428   case IK_PreprocessedObjC:
429   case IK_PreprocessedObjCXX:
430   case IK_AST:
431   case IK_LLVM_IR:
432     // We can't do anything with these.
433     return;
434   }
435 
436   CompilerInstance &CI = getCompilerInstance();
437   llvm::MemoryBuffer *Buffer
438       = CI.getFileManager().getBufferForFile(getCurrentFile());
439   if (Buffer) {
440     unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
441     llvm::outs().write(Buffer->getBufferStart(), Preamble);
442     delete Buffer;
443   }
444 }
445