FrontendActions.cpp revision f7ccbad5d9949e7ddd1cbef43d482553b811e026 
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                                        FileManager &FileMgr,
138                                        ModuleMap &ModMap,
139                                        clang::Module *Module,
140                                        SmallString<256> &Includes) {
141  // Don't collect any headers for unavailable modules.
142  if (!Module->isAvailable())
143    return;
144
145  // Add includes for each of these headers.
146  for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
147    if (LangOpts.ObjC1)
148      Includes += "#import \"";
149    else
150      Includes += "#include \"";
151    Includes += Module->Headers[I]->getName();
152    Includes += "\"\n";
153  }
154
155  if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
156    if (Module->Parent) {
157      // Include the umbrella header for submodules.
158      if (LangOpts.ObjC1)
159        Includes += "#import \"";
160      else
161        Includes += "#include \"";
162      Includes += UmbrellaHeader->getName();
163      Includes += "\"\n";
164    }
165  } else if (const DirectoryEntry *UmbrellaDir = Module->getUmbrellaDir()) {
166    // Add all of the headers we find in this subdirectory.
167    llvm::error_code EC;
168    SmallString<128> DirNative;
169    llvm::sys::path::native(UmbrellaDir->getName(), DirNative);
170    for (llvm::sys::fs::recursive_directory_iterator Dir(DirNative.str(), EC),
171                                                     DirEnd;
172         Dir != DirEnd && !EC; Dir.increment(EC)) {
173      // Check whether this entry has an extension typically associated with
174      // headers.
175      if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
176          .Cases(".h", ".H", ".hh", ".hpp", true)
177          .Default(false))
178        continue;
179
180      // If this header is marked 'unavailable' in this module, don't include
181      // it.
182      if (const FileEntry *Header = FileMgr.getFile(Dir->path()))
183        if (ModMap.isHeaderInUnavailableModule(Header))
184          continue;
185
186      // Include this header umbrella header for submodules.
187      if (LangOpts.ObjC1)
188        Includes += "#import \"";
189      else
190        Includes += "#include \"";
191      Includes += Dir->path();
192      Includes += "\"\n";
193    }
194  }
195
196  // Recurse into submodules.
197  for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
198                                      SubEnd = Module->submodule_end();
199       Sub != SubEnd; ++Sub)
200    collectModuleHeaderIncludes(LangOpts, FileMgr, ModMap, *Sub, Includes);
201}
202
203bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
204                                                 StringRef Filename) {
205  // Find the module map file.
206  const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
207  if (!ModuleMap)  {
208    CI.getDiagnostics().Report(diag::err_module_map_not_found)
209      << Filename;
210    return false;
211  }
212
213  // Parse the module map file.
214  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
215  if (HS.loadModuleMapFile(ModuleMap))
216    return false;
217
218  if (CI.getLangOpts().CurrentModule.empty()) {
219    CI.getDiagnostics().Report(diag::err_missing_module_name);
220
221    // FIXME: Eventually, we could consider asking whether there was just
222    // a single module described in the module map, and use that as a
223    // default. Then it would be fairly trivial to just "compile" a module
224    // map with a single module (the common case).
225    return false;
226  }
227
228  // Dig out the module definition.
229  Module = HS.lookupModule(CI.getLangOpts().CurrentModule,
230                           /*AllowSearch=*/false);
231  if (!Module) {
232    CI.getDiagnostics().Report(diag::err_missing_module)
233      << CI.getLangOpts().CurrentModule << Filename;
234
235    return false;
236  }
237
238  // Check whether we can build this module at all.
239  StringRef Feature;
240  if (!Module->isAvailable(CI.getLangOpts(), CI.getTarget(), Feature)) {
241    CI.getDiagnostics().Report(diag::err_module_unavailable)
242      << Module->getFullModuleName()
243      << Feature;
244
245    return false;
246  }
247
248  // Do we have an umbrella header for this module?
249  const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader();
250
251  // Collect the set of #includes we need to build the module.
252  SmallString<256> HeaderContents;
253  collectModuleHeaderIncludes(CI.getLangOpts(), CI.getFileManager(),
254    CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(),
255    Module, HeaderContents);
256  if (UmbrellaHeader && HeaderContents.empty()) {
257    // Simple case: we have an umbrella header and there are no additional
258    // includes, we can just parse the umbrella header directly.
259    setCurrentInput(FrontendInputFile(UmbrellaHeader->getName(),
260                                      getCurrentFileKind(),
261                                      Module->IsSystem));
262    return true;
263  }
264
265  FileManager &FileMgr = CI.getFileManager();
266  SmallString<128> HeaderName;
267  time_t ModTime;
268  if (UmbrellaHeader) {
269    // Read in the umbrella header.
270    // FIXME: Go through the source manager; the umbrella header may have
271    // been overridden.
272    std::string ErrorStr;
273    llvm::MemoryBuffer *UmbrellaContents
274      = FileMgr.getBufferForFile(UmbrellaHeader, &ErrorStr);
275    if (!UmbrellaContents) {
276      CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
277        << UmbrellaHeader->getName() << ErrorStr;
278      return false;
279    }
280
281    // Combine the contents of the umbrella header with the automatically-
282    // generated includes.
283    SmallString<256> OldContents = HeaderContents;
284    HeaderContents = UmbrellaContents->getBuffer();
285    HeaderContents += "\n\n";
286    HeaderContents += "/* Module includes */\n";
287    HeaderContents += OldContents;
288
289    // Pretend that we're parsing the umbrella header.
290    HeaderName = UmbrellaHeader->getName();
291    ModTime = UmbrellaHeader->getModificationTime();
292
293    delete UmbrellaContents;
294  } else {
295    // Pick an innocuous-sounding name for the umbrella header.
296    HeaderName = Module->Name + ".h";
297    if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
298                        /*CacheFailure=*/false)) {
299      // Try again!
300      HeaderName = Module->Name + "-module.h";
301      if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
302                          /*CacheFailure=*/false)) {
303        // Pick something ridiculous and go with it.
304        HeaderName = Module->Name + "-module.hmod";
305      }
306    }
307    ModTime = time(0);
308  }
309
310  // Remap the contents of the header name we're using to our synthesized
311  // buffer.
312  const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName,
313                                                       HeaderContents.size(),
314                                                       ModTime);
315  llvm::MemoryBuffer *HeaderContentsBuf
316    = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
317  CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);
318  setCurrentInput(FrontendInputFile(HeaderName, getCurrentFileKind(),
319                                    Module->IsSystem));
320  return true;
321}
322
323bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
324                                                       StringRef InFile,
325                                                       std::string &Sysroot,
326                                                       std::string &OutputFile,
327                                                       raw_ostream *&OS) {
328  // If no output file was provided, figure out where this module would go
329  // in the module cache.
330  if (CI.getFrontendOpts().OutputFile.empty()) {
331    HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
332    SmallString<256> ModuleFileName(HS.getModuleCachePath());
333    llvm::sys::path::append(ModuleFileName,
334                            CI.getLangOpts().CurrentModule + ".pcm");
335    CI.getFrontendOpts().OutputFile = ModuleFileName.str();
336  }
337
338  // We use createOutputFile here because this is exposed via libclang, and we
339  // must disable the RemoveFileOnSignal behavior.
340  // We use a temporary to avoid race conditions.
341  OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
342                           /*RemoveFileOnSignal=*/false, InFile,
343                           /*Extension=*/"", /*useTemporary=*/true);
344  if (!OS)
345    return true;
346
347  OutputFile = CI.getFrontendOpts().OutputFile;
348  return false;
349}
350
351ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
352                                                 StringRef InFile) {
353  return new ASTConsumer();
354}
355
356//===----------------------------------------------------------------------===//
357// Preprocessor Actions
358//===----------------------------------------------------------------------===//
359
360void DumpRawTokensAction::ExecuteAction() {
361  Preprocessor &PP = getCompilerInstance().getPreprocessor();
362  SourceManager &SM = PP.getSourceManager();
363
364  // Start lexing the specified input file.
365  const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
366  Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOptions());
367  RawLex.SetKeepWhitespaceMode(true);
368
369  Token RawTok;
370  RawLex.LexFromRawLexer(RawTok);
371  while (RawTok.isNot(tok::eof)) {
372    PP.DumpToken(RawTok, true);
373    llvm::errs() << "\n";
374    RawLex.LexFromRawLexer(RawTok);
375  }
376}
377
378void DumpTokensAction::ExecuteAction() {
379  Preprocessor &PP = getCompilerInstance().getPreprocessor();
380  // Start preprocessing the specified input file.
381  Token Tok;
382  PP.EnterMainSourceFile();
383  do {
384    PP.Lex(Tok);
385    PP.DumpToken(Tok, true);
386    llvm::errs() << "\n";
387  } while (Tok.isNot(tok::eof));
388}
389
390void GeneratePTHAction::ExecuteAction() {
391  CompilerInstance &CI = getCompilerInstance();
392  if (CI.getFrontendOpts().OutputFile.empty() ||
393      CI.getFrontendOpts().OutputFile == "-") {
394    // FIXME: Don't fail this way.
395    // FIXME: Verify that we can actually seek in the given file.
396    llvm::report_fatal_error("PTH requires a seekable file for output!");
397  }
398  llvm::raw_fd_ostream *OS =
399    CI.createDefaultOutputFile(true, getCurrentFile());
400  if (!OS) return;
401
402  CacheTokens(CI.getPreprocessor(), OS);
403}
404
405void PreprocessOnlyAction::ExecuteAction() {
406  Preprocessor &PP = getCompilerInstance().getPreprocessor();
407
408  // Ignore unknown pragmas.
409  PP.AddPragmaHandler(new EmptyPragmaHandler());
410
411  Token Tok;
412  // Start parsing the specified input file.
413  PP.EnterMainSourceFile();
414  do {
415    PP.Lex(Tok);
416  } while (Tok.isNot(tok::eof));
417}
418
419void PrintPreprocessedAction::ExecuteAction() {
420  CompilerInstance &CI = getCompilerInstance();
421  // Output file may need to be set to 'Binary', to avoid converting Unix style
422  // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
423  //
424  // Look to see what type of line endings the file uses. If there's a
425  // CRLF, then we won't open the file up in binary mode. If there is
426  // just an LF or CR, then we will open the file up in binary mode.
427  // In this fashion, the output format should match the input format, unless
428  // the input format has inconsistent line endings.
429  //
430  // This should be a relatively fast operation since most files won't have
431  // all of their source code on a single line. However, that is still a
432  // concern, so if we scan for too long, we'll just assume the file should
433  // be opened in binary mode.
434  bool BinaryMode = true;
435  bool InvalidFile = false;
436  const SourceManager& SM = CI.getSourceManager();
437  const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
438                                                     &InvalidFile);
439  if (!InvalidFile) {
440    const char *cur = Buffer->getBufferStart();
441    const char *end = Buffer->getBufferEnd();
442    const char *next = (cur != end) ? cur + 1 : end;
443
444    // Limit ourselves to only scanning 256 characters into the source
445    // file.  This is mostly a sanity check in case the file has no
446    // newlines whatsoever.
447    if (end - cur > 256) end = cur + 256;
448
449    while (next < end) {
450      if (*cur == 0x0D) {  // CR
451        if (*next == 0x0A)  // CRLF
452          BinaryMode = false;
453
454        break;
455      } else if (*cur == 0x0A)  // LF
456        break;
457
458      ++cur, ++next;
459    }
460  }
461
462  raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
463  if (!OS) return;
464
465  DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
466                           CI.getPreprocessorOutputOpts());
467}
468
469void PrintPreambleAction::ExecuteAction() {
470  switch (getCurrentFileKind()) {
471  case IK_C:
472  case IK_CXX:
473  case IK_ObjC:
474  case IK_ObjCXX:
475  case IK_OpenCL:
476  case IK_CUDA:
477    break;
478
479  case IK_None:
480  case IK_Asm:
481  case IK_PreprocessedC:
482  case IK_PreprocessedCXX:
483  case IK_PreprocessedObjC:
484  case IK_PreprocessedObjCXX:
485  case IK_AST:
486  case IK_LLVM_IR:
487    // We can't do anything with these.
488    return;
489  }
490
491  CompilerInstance &CI = getCompilerInstance();
492  llvm::MemoryBuffer *Buffer
493      = CI.getFileManager().getBufferForFile(getCurrentFile());
494  if (Buffer) {
495    unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
496    llvm::outs().write(Buffer->getBufferStart(), Preamble);
497    delete Buffer;
498  }
499}
500