FrontendActions.cpp revision 2a857180050fb78b356c17931e311eef7f2daf3e 
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, CI.getFrontendOpts().ASTDumpFilter);
51  return 0;
52}
53
54ASTConsumer *ASTDumpAction::CreateASTConsumer(CompilerInstance &CI,
55                                              StringRef InFile) {
56  return CreateASTDumper(CI.getFrontendOpts().ASTDumpFilter);
57}
58
59ASTConsumer *ASTDeclListAction::CreateASTConsumer(CompilerInstance &CI,
60                                                  StringRef InFile) {
61  return CreateASTDeclNodeLister();
62}
63
64ASTConsumer *ASTDumpXMLAction::CreateASTConsumer(CompilerInstance &CI,
65                                                 StringRef InFile) {
66  raw_ostream *OS;
67  if (CI.getFrontendOpts().OutputFile.empty())
68    OS = &llvm::outs();
69  else
70    OS = CI.createDefaultOutputFile(false, InFile);
71  if (!OS) return 0;
72  return CreateASTDumperXML(*OS);
73}
74
75ASTConsumer *ASTViewAction::CreateASTConsumer(CompilerInstance &CI,
76                                              StringRef InFile) {
77  return CreateASTViewer();
78}
79
80ASTConsumer *DeclContextPrintAction::CreateASTConsumer(CompilerInstance &CI,
81                                                       StringRef InFile) {
82  return CreateDeclContextPrinter();
83}
84
85ASTConsumer *GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI,
86                                                  StringRef InFile) {
87  std::string Sysroot;
88  std::string OutputFile;
89  raw_ostream *OS = 0;
90  if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
91    return 0;
92
93  if (!CI.getFrontendOpts().RelocatablePCH)
94    Sysroot.clear();
95  return new PCHGenerator(CI.getPreprocessor(), OutputFile, 0, Sysroot, OS);
96}
97
98bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
99                                                    StringRef InFile,
100                                                    std::string &Sysroot,
101                                                    std::string &OutputFile,
102                                                    raw_ostream *&OS) {
103  Sysroot = CI.getHeaderSearchOpts().Sysroot;
104  if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
105    CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
106    return true;
107  }
108
109  // We use createOutputFile here because this is exposed via libclang, and we
110  // must disable the RemoveFileOnSignal behavior.
111  // We use a temporary to avoid race conditions.
112  OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
113                           /*RemoveFileOnSignal=*/false, InFile,
114                           /*Extension=*/"", /*useTemporary=*/true);
115  if (!OS)
116    return true;
117
118  OutputFile = CI.getFrontendOpts().OutputFile;
119  return false;
120}
121
122ASTConsumer *GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
123                                                     StringRef InFile) {
124  std::string Sysroot;
125  std::string OutputFile;
126  raw_ostream *OS = 0;
127  if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
128    return 0;
129
130  return new PCHGenerator(CI.getPreprocessor(), OutputFile, Module,
131                          Sysroot, OS);
132}
133
134static SmallVectorImpl<char> &
135operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
136  Includes.append(RHS.begin(), RHS.end());
137  return Includes;
138}
139
140static void addHeaderInclude(StringRef HeaderName,
141                             SmallVectorImpl<char> &Includes,
142                             const LangOptions &LangOpts) {
143  if (LangOpts.ObjC1)
144    Includes += "#import \"";
145  else
146    Includes += "#include \"";
147  Includes += HeaderName;
148  Includes += "\"\n";
149}
150
151static void addHeaderInclude(const FileEntry *Header,
152                             SmallVectorImpl<char> &Includes,
153                             const LangOptions &LangOpts) {
154  addHeaderInclude(Header->getName(), Includes, LangOpts);
155}
156
157/// \brief Collect the set of header includes needed to construct the given
158/// module and update the TopHeaders file set of the module.
159///
160/// \param Module The module we're collecting includes from.
161///
162/// \param Includes Will be augmented with the set of \#includes or \#imports
163/// needed to load all of the named headers.
164static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
165                                        FileManager &FileMgr,
166                                        ModuleMap &ModMap,
167                                        clang::Module *Module,
168                                        SmallVectorImpl<char> &Includes) {
169  // Don't collect any headers for unavailable modules.
170  if (!Module->isAvailable())
171    return;
172
173  // Add includes for each of these headers.
174  for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
175    const FileEntry *Header = Module->Headers[I];
176    Module->TopHeaders.insert(Header);
177    addHeaderInclude(Header, Includes, LangOpts);
178  }
179
180  if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
181    Module->TopHeaders.insert(UmbrellaHeader);
182    if (Module->Parent) {
183      // Include the umbrella header for submodules.
184      addHeaderInclude(UmbrellaHeader, Includes, LangOpts);
185    }
186  } else if (const DirectoryEntry *UmbrellaDir = Module->getUmbrellaDir()) {
187    // Add all of the headers we find in this subdirectory.
188    llvm::error_code EC;
189    SmallString<128> DirNative;
190    llvm::sys::path::native(UmbrellaDir->getName(), DirNative);
191    for (llvm::sys::fs::recursive_directory_iterator Dir(DirNative.str(), EC),
192                                                     DirEnd;
193         Dir != DirEnd && !EC; Dir.increment(EC)) {
194      // Check whether this entry has an extension typically associated with
195      // headers.
196      if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
197          .Cases(".h", ".H", ".hh", ".hpp", true)
198          .Default(false))
199        continue;
200
201      // If this header is marked 'unavailable' in this module, don't include
202      // it.
203      if (const FileEntry *Header = FileMgr.getFile(Dir->path())) {
204        if (ModMap.isHeaderInUnavailableModule(Header))
205          continue;
206        Module->TopHeaders.insert(Header);
207      }
208
209      // Include this header umbrella header for submodules.
210      addHeaderInclude(Dir->path(), Includes, LangOpts);
211    }
212  }
213
214  // Recurse into submodules.
215  for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
216                                      SubEnd = Module->submodule_end();
217       Sub != SubEnd; ++Sub)
218    collectModuleHeaderIncludes(LangOpts, FileMgr, ModMap, *Sub, Includes);
219}
220
221bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
222                                                 StringRef Filename) {
223  // Find the module map file.
224  const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
225  if (!ModuleMap)  {
226    CI.getDiagnostics().Report(diag::err_module_map_not_found)
227      << Filename;
228    return false;
229  }
230
231  // Parse the module map file.
232  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
233  if (HS.loadModuleMapFile(ModuleMap))
234    return false;
235
236  if (CI.getLangOpts().CurrentModule.empty()) {
237    CI.getDiagnostics().Report(diag::err_missing_module_name);
238
239    // FIXME: Eventually, we could consider asking whether there was just
240    // a single module described in the module map, and use that as a
241    // default. Then it would be fairly trivial to just "compile" a module
242    // map with a single module (the common case).
243    return false;
244  }
245
246  // Dig out the module definition.
247  Module = HS.lookupModule(CI.getLangOpts().CurrentModule,
248                           /*AllowSearch=*/false);
249  if (!Module) {
250    CI.getDiagnostics().Report(diag::err_missing_module)
251      << CI.getLangOpts().CurrentModule << Filename;
252
253    return false;
254  }
255
256  // Check whether we can build this module at all.
257  StringRef Feature;
258  if (!Module->isAvailable(CI.getLangOpts(), CI.getTarget(), Feature)) {
259    CI.getDiagnostics().Report(diag::err_module_unavailable)
260      << Module->getFullModuleName()
261      << Feature;
262
263    return false;
264  }
265
266  FileManager &FileMgr = CI.getFileManager();
267
268  // Collect the set of #includes we need to build the module.
269  SmallString<256> HeaderContents;
270  if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader())
271    addHeaderInclude(UmbrellaHeader, HeaderContents, CI.getLangOpts());
272  collectModuleHeaderIncludes(CI.getLangOpts(), FileMgr,
273    CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(),
274    Module, HeaderContents);
275
276  StringRef InputName = Module::getModuleInputBufferName();
277
278  // We consistently construct a buffer as input to build the module.
279  // This means the main file for modules will always be a virtual one.
280  // FIXME: Maybe allow using a memory buffer as input directly instead of
281  // messing with virtual files.
282  const FileEntry *HeaderFile = FileMgr.getVirtualFile(InputName,
283                                                       HeaderContents.size(),
284                                                       time(0));
285  llvm::MemoryBuffer *HeaderContentsBuf
286    = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
287  CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);
288  setCurrentInput(FrontendInputFile(InputName, getCurrentFileKind(),
289                                    Module->IsSystem));
290  return true;
291}
292
293bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
294                                                       StringRef InFile,
295                                                       std::string &Sysroot,
296                                                       std::string &OutputFile,
297                                                       raw_ostream *&OS) {
298  // If no output file was provided, figure out where this module would go
299  // in the module cache.
300  if (CI.getFrontendOpts().OutputFile.empty()) {
301    HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
302    SmallString<256> ModuleFileName(HS.getModuleCachePath());
303    llvm::sys::path::append(ModuleFileName,
304                            CI.getLangOpts().CurrentModule + ".pcm");
305    CI.getFrontendOpts().OutputFile = ModuleFileName.str();
306  }
307
308  // We use createOutputFile here because this is exposed via libclang, and we
309  // must disable the RemoveFileOnSignal behavior.
310  // We use a temporary to avoid race conditions.
311  OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
312                           /*RemoveFileOnSignal=*/false, InFile,
313                           /*Extension=*/"", /*useTemporary=*/true,
314                           /*CreateMissingDirectories=*/true);
315  if (!OS)
316    return true;
317
318  OutputFile = CI.getFrontendOpts().OutputFile;
319  return false;
320}
321
322ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
323                                                 StringRef InFile) {
324  return new ASTConsumer();
325}
326
327//===----------------------------------------------------------------------===//
328// Preprocessor Actions
329//===----------------------------------------------------------------------===//
330
331void DumpRawTokensAction::ExecuteAction() {
332  Preprocessor &PP = getCompilerInstance().getPreprocessor();
333  SourceManager &SM = PP.getSourceManager();
334
335  // Start lexing the specified input file.
336  const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
337  Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts());
338  RawLex.SetKeepWhitespaceMode(true);
339
340  Token RawTok;
341  RawLex.LexFromRawLexer(RawTok);
342  while (RawTok.isNot(tok::eof)) {
343    PP.DumpToken(RawTok, true);
344    llvm::errs() << "\n";
345    RawLex.LexFromRawLexer(RawTok);
346  }
347}
348
349void DumpTokensAction::ExecuteAction() {
350  Preprocessor &PP = getCompilerInstance().getPreprocessor();
351  // Start preprocessing the specified input file.
352  Token Tok;
353  PP.EnterMainSourceFile();
354  do {
355    PP.Lex(Tok);
356    PP.DumpToken(Tok, true);
357    llvm::errs() << "\n";
358  } while (Tok.isNot(tok::eof));
359}
360
361void GeneratePTHAction::ExecuteAction() {
362  CompilerInstance &CI = getCompilerInstance();
363  if (CI.getFrontendOpts().OutputFile.empty() ||
364      CI.getFrontendOpts().OutputFile == "-") {
365    // FIXME: Don't fail this way.
366    // FIXME: Verify that we can actually seek in the given file.
367    llvm::report_fatal_error("PTH requires a seekable file for output!");
368  }
369  llvm::raw_fd_ostream *OS =
370    CI.createDefaultOutputFile(true, getCurrentFile());
371  if (!OS) return;
372
373  CacheTokens(CI.getPreprocessor(), OS);
374}
375
376void PreprocessOnlyAction::ExecuteAction() {
377  Preprocessor &PP = getCompilerInstance().getPreprocessor();
378
379  // Ignore unknown pragmas.
380  PP.AddPragmaHandler(new EmptyPragmaHandler());
381
382  Token Tok;
383  // Start parsing the specified input file.
384  PP.EnterMainSourceFile();
385  do {
386    PP.Lex(Tok);
387  } while (Tok.isNot(tok::eof));
388}
389
390void PrintPreprocessedAction::ExecuteAction() {
391  CompilerInstance &CI = getCompilerInstance();
392  // Output file may need to be set to 'Binary', to avoid converting Unix style
393  // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
394  //
395  // Look to see what type of line endings the file uses. If there's a
396  // CRLF, then we won't open the file up in binary mode. If there is
397  // just an LF or CR, then we will open the file up in binary mode.
398  // In this fashion, the output format should match the input format, unless
399  // the input format has inconsistent line endings.
400  //
401  // This should be a relatively fast operation since most files won't have
402  // all of their source code on a single line. However, that is still a
403  // concern, so if we scan for too long, we'll just assume the file should
404  // be opened in binary mode.
405  bool BinaryMode = true;
406  bool InvalidFile = false;
407  const SourceManager& SM = CI.getSourceManager();
408  const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
409                                                     &InvalidFile);
410  if (!InvalidFile) {
411    const char *cur = Buffer->getBufferStart();
412    const char *end = Buffer->getBufferEnd();
413    const char *next = (cur != end) ? cur + 1 : end;
414
415    // Limit ourselves to only scanning 256 characters into the source
416    // file.  This is mostly a sanity check in case the file has no
417    // newlines whatsoever.
418    if (end - cur > 256) end = cur + 256;
419
420    while (next < end) {
421      if (*cur == 0x0D) {  // CR
422        if (*next == 0x0A)  // CRLF
423          BinaryMode = false;
424
425        break;
426      } else if (*cur == 0x0A)  // LF
427        break;
428
429      ++cur, ++next;
430    }
431  }
432
433  raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
434  if (!OS) return;
435
436  DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
437                           CI.getPreprocessorOutputOpts());
438}
439
440void PrintPreambleAction::ExecuteAction() {
441  switch (getCurrentFileKind()) {
442  case IK_C:
443  case IK_CXX:
444  case IK_ObjC:
445  case IK_ObjCXX:
446  case IK_OpenCL:
447  case IK_CUDA:
448    break;
449
450  case IK_None:
451  case IK_Asm:
452  case IK_PreprocessedC:
453  case IK_PreprocessedCXX:
454  case IK_PreprocessedObjC:
455  case IK_PreprocessedObjCXX:
456  case IK_AST:
457  case IK_LLVM_IR:
458    // We can't do anything with these.
459    return;
460  }
461
462  CompilerInstance &CI = getCompilerInstance();
463  llvm::MemoryBuffer *Buffer
464      = CI.getFileManager().getBufferForFile(getCurrentFile());
465  if (Buffer) {
466    unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
467    llvm::outs().write(Buffer->getBufferStart(), Preamble);
468    delete Buffer;
469  }
470}
471