FrontendActions.cpp revision b7a7819473709c01ea024a2dc15e99d38f0f8760 
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/FileSystem.h"
25#include "llvm/Support/MemoryBuffer.h"
26#include "llvm/Support/raw_ostream.h"
27#include "llvm/Support/system_error.h"
28
29using namespace clang;
30
31//===----------------------------------------------------------------------===//
32// Custom Actions
33//===----------------------------------------------------------------------===//
34
35ASTConsumer *InitOnlyAction::CreateASTConsumer(CompilerInstance &CI,
36                                               StringRef InFile) {
37  return new ASTConsumer();
38}
39
40void InitOnlyAction::ExecuteAction() {
41}
42
43//===----------------------------------------------------------------------===//
44// AST Consumer Actions
45//===----------------------------------------------------------------------===//
46
47ASTConsumer *ASTPrintAction::CreateASTConsumer(CompilerInstance &CI,
48                                               StringRef InFile) {
49  if (raw_ostream *OS = CI.createDefaultOutputFile(false, InFile))
50    return CreateASTPrinter(OS);
51  return 0;
52}
53
54ASTConsumer *ASTDumpAction::CreateASTConsumer(CompilerInstance &CI,
55                                              StringRef InFile) {
56  return CreateASTDumper();
57}
58
59ASTConsumer *ASTDumpXMLAction::CreateASTConsumer(CompilerInstance &CI,
60                                                 StringRef InFile) {
61  raw_ostream *OS;
62  if (CI.getFrontendOpts().OutputFile.empty())
63    OS = &llvm::outs();
64  else
65    OS = CI.createDefaultOutputFile(false, InFile);
66  if (!OS) return 0;
67  return CreateASTDumperXML(*OS);
68}
69
70ASTConsumer *ASTViewAction::CreateASTConsumer(CompilerInstance &CI,
71                                              StringRef InFile) {
72  return CreateASTViewer();
73}
74
75ASTConsumer *DeclContextPrintAction::CreateASTConsumer(CompilerInstance &CI,
76                                                       StringRef InFile) {
77  return CreateDeclContextPrinter();
78}
79
80ASTConsumer *GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI,
81                                                  StringRef InFile) {
82  std::string Sysroot;
83  std::string OutputFile;
84  raw_ostream *OS = 0;
85  if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
86    return 0;
87
88  if (!CI.getFrontendOpts().RelocatablePCH)
89    Sysroot.clear();
90  return new PCHGenerator(CI.getPreprocessor(), OutputFile, 0, Sysroot, OS);
91}
92
93bool 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
117ASTConsumer *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, Module,
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///
134/// \param Includes Will be augmented with the set of #includes or #imports
135/// needed to load all of the named headers.
136static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
137                                        clang::Module *Module,
138                                        llvm::SmallString<256> &Includes) {
139  // Don't collect any headers for unavailable modules.
140  if (!Module->isAvailable())
141    return;
142
143  // Add includes for each of these headers.
144  for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
145    if (LangOpts.ObjC1)
146      Includes += "#import \"";
147    else
148      Includes += "#include \"";
149    Includes += Module->Headers[I]->getName();
150    Includes += "\"\n";
151  }
152
153  if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
154    if (Module->Parent) {
155      // Include the umbrella header for submodules.
156      if (LangOpts.ObjC1)
157        Includes += "#import \"";
158      else
159        Includes += "#include \"";
160      Includes += UmbrellaHeader->getName();
161      Includes += "\"\n";
162    }
163  } else if (const DirectoryEntry *UmbrellaDir = Module->getUmbrellaDir()) {
164    // Add all of the headers we find in this subdirectory (FIXME: recursively!).
165    llvm::error_code EC;
166    llvm::SmallString<128> DirNative;
167    llvm::sys::path::native(UmbrellaDir->getName(), DirNative);
168    for (llvm::sys::fs::recursive_directory_iterator Dir(DirNative.str(), EC),
169                                                     DirEnd;
170         Dir != DirEnd && !EC; Dir.increment(EC)) {
171      // Check whether this entry has an extension typically associated with
172      // headers.
173      if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
174          .Cases(".h", ".H", ".hh", ".hpp", true)
175          .Default(false))
176        continue;
177
178      // Include this header umbrella header for submodules.
179      if (LangOpts.ObjC1)
180        Includes += "#import \"";
181      else
182        Includes += "#include \"";
183      Includes += Dir->path();
184      Includes += "\"\n";
185    }
186  }
187
188  // Recurse into submodules.
189  for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
190                                      SubEnd = Module->submodule_end();
191       Sub != SubEnd; ++Sub)
192    collectModuleHeaderIncludes(LangOpts, *Sub, Includes);
193}
194
195bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
196                                                 StringRef Filename) {
197  // Find the module map file.
198  const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
199  if (!ModuleMap)  {
200    CI.getDiagnostics().Report(diag::err_module_map_not_found)
201      << Filename;
202    return false;
203  }
204
205  // Parse the module map file.
206  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
207  if (HS.loadModuleMapFile(ModuleMap))
208    return false;
209
210  if (CI.getLangOpts().CurrentModule.empty()) {
211    CI.getDiagnostics().Report(diag::err_missing_module_name);
212
213    // FIXME: Eventually, we could consider asking whether there was just
214    // a single module described in the module map, and use that as a
215    // default. Then it would be fairly trivial to just "compile" a module
216    // map with a single module (the common case).
217    return false;
218  }
219
220  // Dig out the module definition.
221  Module = HS.getModule(CI.getLangOpts().CurrentModule, /*AllowSearch=*/false);
222  if (!Module) {
223    CI.getDiagnostics().Report(diag::err_missing_module)
224      << CI.getLangOpts().CurrentModule << Filename;
225
226    return false;
227  }
228
229  // Check whether we can build this module at all.
230  StringRef Feature;
231  if (!Module->isAvailable(CI.getLangOpts(), Feature)) {
232    CI.getDiagnostics().Report(diag::err_module_unavailable)
233      << Module->getFullModuleName()
234      << Feature;
235
236    return false;
237  }
238
239  // Do we have an umbrella header for this module?
240  const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader();
241
242  // Collect the set of #includes we need to build the module.
243  llvm::SmallString<256> HeaderContents;
244  collectModuleHeaderIncludes(CI.getLangOpts(), Module, HeaderContents);
245  if (UmbrellaHeader && HeaderContents.empty()) {
246    // Simple case: we have an umbrella header and there are no additional
247    // includes, we can just parse the umbrella header directly.
248    setCurrentFile(UmbrellaHeader->getName(), getCurrentFileKind());
249    return true;
250  }
251
252  FileManager &FileMgr = CI.getFileManager();
253  llvm::SmallString<128> HeaderName;
254  time_t ModTime;
255  if (UmbrellaHeader) {
256    // Read in the umbrella header.
257    // FIXME: Go through the source manager; the umbrella header may have
258    // been overridden.
259    std::string ErrorStr;
260    llvm::MemoryBuffer *UmbrellaContents
261      = FileMgr.getBufferForFile(UmbrellaHeader, &ErrorStr);
262    if (!UmbrellaContents) {
263      CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
264        << UmbrellaHeader->getName() << ErrorStr;
265      return false;
266    }
267
268    // Combine the contents of the umbrella header with the automatically-
269    // generated includes.
270    llvm::SmallString<256> OldContents = HeaderContents;
271    HeaderContents = UmbrellaContents->getBuffer();
272    HeaderContents += "\n\n";
273    HeaderContents += "/* Module includes */\n";
274    HeaderContents += OldContents;
275
276    // Pretend that we're parsing the umbrella header.
277    HeaderName = UmbrellaHeader->getName();
278    ModTime = UmbrellaHeader->getModificationTime();
279
280    delete UmbrellaContents;
281  } else {
282    // Pick an innocuous-sounding name for the umbrella header.
283    HeaderName = Module->Name + ".h";
284    if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
285                        /*CacheFailure=*/false)) {
286      // Try again!
287      HeaderName = Module->Name + "-module.h";
288      if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
289                          /*CacheFailure=*/false)) {
290        // Pick something ridiculous and go with it.
291        HeaderName = Module->Name + "-module.hmod";
292      }
293    }
294    ModTime = time(0);
295  }
296
297  // Remap the contents of the header name we're using to our synthesized
298  // buffer.
299  const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName,
300                                                       HeaderContents.size(),
301                                                       ModTime);
302  llvm::MemoryBuffer *HeaderContentsBuf
303    = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
304  CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);
305
306  setCurrentFile(HeaderName, getCurrentFileKind());
307  return true;
308}
309
310bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
311                                                       StringRef InFile,
312                                                       std::string &Sysroot,
313                                                       std::string &OutputFile,
314                                                       raw_ostream *&OS) {
315  // If no output file was provided, figure out where this module would go
316  // in the module cache.
317  if (CI.getFrontendOpts().OutputFile.empty()) {
318    HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
319    llvm::SmallString<256> ModuleFileName(HS.getModuleCachePath());
320    llvm::sys::path::append(ModuleFileName,
321                            CI.getLangOpts().CurrentModule + ".pcm");
322    CI.getFrontendOpts().OutputFile = ModuleFileName.str();
323  }
324
325  // We use createOutputFile here because this is exposed via libclang, and we
326  // must disable the RemoveFileOnSignal behavior.
327  // We use a temporary to avoid race conditions.
328  OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
329                           /*RemoveFileOnSignal=*/false, InFile,
330                           /*Extension=*/"", /*useTemporary=*/true);
331  if (!OS)
332    return true;
333
334  OutputFile = CI.getFrontendOpts().OutputFile;
335  return false;
336}
337
338ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
339                                                 StringRef InFile) {
340  return new ASTConsumer();
341}
342
343//===----------------------------------------------------------------------===//
344// Preprocessor Actions
345//===----------------------------------------------------------------------===//
346
347void DumpRawTokensAction::ExecuteAction() {
348  Preprocessor &PP = getCompilerInstance().getPreprocessor();
349  SourceManager &SM = PP.getSourceManager();
350
351  // Start lexing the specified input file.
352  const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
353  Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOptions());
354  RawLex.SetKeepWhitespaceMode(true);
355
356  Token RawTok;
357  RawLex.LexFromRawLexer(RawTok);
358  while (RawTok.isNot(tok::eof)) {
359    PP.DumpToken(RawTok, true);
360    llvm::errs() << "\n";
361    RawLex.LexFromRawLexer(RawTok);
362  }
363}
364
365void DumpTokensAction::ExecuteAction() {
366  Preprocessor &PP = getCompilerInstance().getPreprocessor();
367  // Start preprocessing the specified input file.
368  Token Tok;
369  PP.EnterMainSourceFile();
370  do {
371    PP.Lex(Tok);
372    PP.DumpToken(Tok, true);
373    llvm::errs() << "\n";
374  } while (Tok.isNot(tok::eof));
375}
376
377void GeneratePTHAction::ExecuteAction() {
378  CompilerInstance &CI = getCompilerInstance();
379  if (CI.getFrontendOpts().OutputFile.empty() ||
380      CI.getFrontendOpts().OutputFile == "-") {
381    // FIXME: Don't fail this way.
382    // FIXME: Verify that we can actually seek in the given file.
383    llvm::report_fatal_error("PTH requires a seekable file for output!");
384  }
385  llvm::raw_fd_ostream *OS =
386    CI.createDefaultOutputFile(true, getCurrentFile());
387  if (!OS) return;
388
389  CacheTokens(CI.getPreprocessor(), OS);
390}
391
392void PreprocessOnlyAction::ExecuteAction() {
393  Preprocessor &PP = getCompilerInstance().getPreprocessor();
394
395  // Ignore unknown pragmas.
396  PP.AddPragmaHandler(new EmptyPragmaHandler());
397
398  Token Tok;
399  // Start parsing the specified input file.
400  PP.EnterMainSourceFile();
401  do {
402    PP.Lex(Tok);
403  } while (Tok.isNot(tok::eof));
404}
405
406void PrintPreprocessedAction::ExecuteAction() {
407  CompilerInstance &CI = getCompilerInstance();
408  // Output file may need to be set to 'Binary', to avoid converting Unix style
409  // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
410  //
411  // Look to see what type of line endings the file uses. If there's a
412  // CRLF, then we won't open the file up in binary mode. If there is
413  // just an LF or CR, then we will open the file up in binary mode.
414  // In this fashion, the output format should match the input format, unless
415  // the input format has inconsistent line endings.
416  //
417  // This should be a relatively fast operation since most files won't have
418  // all of their source code on a single line. However, that is still a
419  // concern, so if we scan for too long, we'll just assume the file should
420  // be opened in binary mode.
421  bool BinaryMode = true;
422  bool InvalidFile = false;
423  const SourceManager& SM = CI.getSourceManager();
424  const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
425                                                     &InvalidFile);
426  if (!InvalidFile) {
427    const char *cur = Buffer->getBufferStart();
428    const char *end = Buffer->getBufferEnd();
429    const char *next = (cur != end) ? cur + 1 : end;
430
431    // Limit ourselves to only scanning 256 characters into the source
432    // file.  This is mostly a sanity check in case the file has no
433    // newlines whatsoever.
434    if (end - cur > 256) end = cur + 256;
435
436    while (next < end) {
437      if (*cur == 0x0D) {  // CR
438        if (*next == 0x0A)  // CRLF
439          BinaryMode = false;
440
441        break;
442      } else if (*cur == 0x0A)  // LF
443        break;
444
445      ++cur, ++next;
446    }
447  }
448
449  raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
450  if (!OS) return;
451
452  DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
453                           CI.getPreprocessorOutputOpts());
454}
455
456void PrintPreambleAction::ExecuteAction() {
457  switch (getCurrentFileKind()) {
458  case IK_C:
459  case IK_CXX:
460  case IK_ObjC:
461  case IK_ObjCXX:
462  case IK_OpenCL:
463  case IK_CUDA:
464    break;
465
466  case IK_None:
467  case IK_Asm:
468  case IK_PreprocessedC:
469  case IK_PreprocessedCXX:
470  case IK_PreprocessedObjC:
471  case IK_PreprocessedObjCXX:
472  case IK_AST:
473  case IK_LLVM_IR:
474    // We can't do anything with these.
475    return;
476  }
477
478  CompilerInstance &CI = getCompilerInstance();
479  llvm::MemoryBuffer *Buffer
480      = CI.getFileManager().getBufferForFile(getCurrentFile());
481  if (Buffer) {
482    unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
483    llvm::outs().write(Buffer->getBufferStart(), Preamble);
484    delete Buffer;
485  }
486}
487