FrontendActions.cpp revision 8075ce62f7860224d7f3f9ddba38201ad89e2cbc 
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
28using namespace clang;
29
30//===----------------------------------------------------------------------===//
31// Custom Actions
32//===----------------------------------------------------------------------===//
33
34ASTConsumer *InitOnlyAction::CreateASTConsumer(CompilerInstance &CI,
35                                               StringRef InFile) {
36  return new ASTConsumer();
37}
38
39void InitOnlyAction::ExecuteAction() {
40}
41
42//===----------------------------------------------------------------------===//
43// AST Consumer Actions
44//===----------------------------------------------------------------------===//
45
46ASTConsumer *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
53ASTConsumer *ASTDumpAction::CreateASTConsumer(CompilerInstance &CI,
54                                              StringRef InFile) {
55  return CreateASTDumper();
56}
57
58ASTConsumer *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
69ASTConsumer *ASTViewAction::CreateASTConsumer(CompilerInstance &CI,
70                                              StringRef InFile) {
71  return CreateASTViewer();
72}
73
74ASTConsumer *DeclContextPrintAction::CreateASTConsumer(CompilerInstance &CI,
75                                                       StringRef InFile) {
76  return CreateDeclContextPrinter();
77}
78
79ASTConsumer *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
92bool 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
116ASTConsumer *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.
135static 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
166bool 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
268bool 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
296ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
297                                                 StringRef InFile) {
298  return new ASTConsumer();
299}
300
301//===----------------------------------------------------------------------===//
302// Preprocessor Actions
303//===----------------------------------------------------------------------===//
304
305void 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
323void 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
335void 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
350void 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
364void 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
414void 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