FrontendActions.cpp revision 261e75bd10198c336aded42f0398a13f7bf88889 
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, MakeModule,
90                          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, /*MakeModule=*/true,
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/// \param ExplicitOnly Whether we should only add headers from explicit
134static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
135                                        ModuleMap::Module *Module,
136                                        bool ExplicitOnly,
137                                        llvm::SmallString<256> &Includes) {
138  if (!ExplicitOnly || Module->IsExplicit) {
139    // Add includes for each of these headers.
140    for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
141      if (LangOpts.ObjC1)
142        Includes += "#import \"";
143      else
144        Includes += "#include \"";
145      Includes += Module->Headers[I]->getName();
146      Includes += "\"\n";
147    }
148  }
149
150  // Recurse into submodules.
151  for (llvm::StringMap<ModuleMap::Module *>::iterator
152            Sub = Module->SubModules.begin(),
153         SubEnd = Module->SubModules.end();
154       Sub != SubEnd; ++Sub) {
155    collectModuleHeaderIncludes(LangOpts, Sub->getValue(),
156                                ExplicitOnly && !Module->IsExplicit,
157                                Includes);
158  }
159}
160
161bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
162                                                 StringRef Filename) {
163  // Find the module map file.
164  const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
165  if (!ModuleMap)  {
166    CI.getDiagnostics().Report(diag::err_module_map_not_found)
167      << Filename;
168    return false;
169  }
170
171  // Parse the module map file.
172  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
173  if (HS.loadModuleMapFile(ModuleMap))
174    return false;
175
176  if (CI.getLangOpts().CurrentModule.empty()) {
177    CI.getDiagnostics().Report(diag::err_missing_module_name);
178
179    // FIXME: Eventually, we could consider asking whether there was just
180    // a single module described in the module map, and use that as a
181    // default. Then it would be fairly trivial to just "compile" a module
182    // map with a single module (the common case).
183    return false;
184  }
185
186  // Dig out the module definition.
187  ModuleMap::Module *Module = HS.getModule(CI.getLangOpts().CurrentModule,
188                                           /*AllowSearch=*/false);
189  if (!Module) {
190    CI.getDiagnostics().Report(diag::err_missing_module)
191      << CI.getLangOpts().CurrentModule << Filename;
192
193    return false;
194  }
195
196  // Collect the set of #includes we need to build the module.
197  llvm::SmallString<256> HeaderContents;
198  collectModuleHeaderIncludes(CI.getLangOpts(), Module,
199                              Module->UmbrellaHeader != 0, HeaderContents);
200  if (Module->UmbrellaHeader && HeaderContents.empty()) {
201    // Simple case: we have an umbrella header and there are no additional
202    // includes, we can just parse the umbrella header directly.
203    setCurrentFile(Module->UmbrellaHeader->getName(), getCurrentFileKind());
204    return true;
205  }
206
207  FileManager &FileMgr = CI.getFileManager();
208  llvm::SmallString<128> HeaderName;
209  time_t ModTime;
210  if (Module->UmbrellaHeader) {
211    // Read in the umbrella header.
212    // FIXME: Go through the source manager; the umbrella header may have
213    // been overridden.
214    std::string ErrorStr;
215    llvm::MemoryBuffer *UmbrellaContents
216      = FileMgr.getBufferForFile(Module->UmbrellaHeader, &ErrorStr);
217    if (!UmbrellaContents) {
218      CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
219        << Module->UmbrellaHeader->getName() << ErrorStr;
220      return false;
221    }
222
223    // Combine the contents of the umbrella header with the automatically-
224    // generated includes.
225    llvm::SmallString<256> OldContents = HeaderContents;
226    HeaderContents = UmbrellaContents->getBuffer();
227    HeaderContents += "\n\n";
228    HeaderContents += "/* Module includes */\n";
229    HeaderContents += OldContents;
230
231    // Pretend that we're parsing the umbrella header.
232    HeaderName = Module->UmbrellaHeader->getName();
233    ModTime = Module->UmbrellaHeader->getModificationTime();
234
235    delete UmbrellaContents;
236  } else {
237    // Pick an innocuous-sounding name for the umbrella header.
238    HeaderName = Module->Name + ".h";
239    if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
240                        /*CacheFailure=*/false)) {
241      // Try again!
242      HeaderName = Module->Name + "-module.h";
243      if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
244                          /*CacheFailure=*/false)) {
245        // Pick something ridiculous and go with it.
246        HeaderName = Module->Name + "-module.hmod";
247      }
248    }
249    ModTime = time(0);
250  }
251
252  // Remap the contents of the header name we're using to our synthesized
253  // buffer.
254  const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName,
255                                                       HeaderContents.size(),
256                                                       ModTime);
257  llvm::MemoryBuffer *HeaderContentsBuf
258    = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
259  CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);
260
261  setCurrentFile(HeaderName, getCurrentFileKind());
262  return true;
263}
264
265bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
266                                                       StringRef InFile,
267                                                       std::string &Sysroot,
268                                                       std::string &OutputFile,
269                                                       raw_ostream *&OS) {
270  // If no output file was provided, figure out where this module would go
271  // in the module cache.
272  if (CI.getFrontendOpts().OutputFile.empty()) {
273    HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
274    llvm::SmallString<256> ModuleFileName(HS.getModuleCachePath());
275    llvm::sys::path::append(ModuleFileName,
276                            CI.getLangOpts().CurrentModule + ".pcm");
277    CI.getFrontendOpts().OutputFile = ModuleFileName.str();
278  }
279
280  // We use createOutputFile here because this is exposed via libclang, and we
281  // must disable the RemoveFileOnSignal behavior.
282  // We use a temporary to avoid race conditions.
283  OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
284                           /*RemoveFileOnSignal=*/false, InFile,
285                           /*Extension=*/"", /*useTemporary=*/true);
286  if (!OS)
287    return true;
288
289  OutputFile = CI.getFrontendOpts().OutputFile;
290  return false;
291}
292
293ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
294                                                 StringRef InFile) {
295  return new ASTConsumer();
296}
297
298//===----------------------------------------------------------------------===//
299// Preprocessor Actions
300//===----------------------------------------------------------------------===//
301
302void DumpRawTokensAction::ExecuteAction() {
303  Preprocessor &PP = getCompilerInstance().getPreprocessor();
304  SourceManager &SM = PP.getSourceManager();
305
306  // Start lexing the specified input file.
307  const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
308  Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOptions());
309  RawLex.SetKeepWhitespaceMode(true);
310
311  Token RawTok;
312  RawLex.LexFromRawLexer(RawTok);
313  while (RawTok.isNot(tok::eof)) {
314    PP.DumpToken(RawTok, true);
315    llvm::errs() << "\n";
316    RawLex.LexFromRawLexer(RawTok);
317  }
318}
319
320void DumpTokensAction::ExecuteAction() {
321  Preprocessor &PP = getCompilerInstance().getPreprocessor();
322  // Start preprocessing the specified input file.
323  Token Tok;
324  PP.EnterMainSourceFile();
325  do {
326    PP.Lex(Tok);
327    PP.DumpToken(Tok, true);
328    llvm::errs() << "\n";
329  } while (Tok.isNot(tok::eof));
330}
331
332void GeneratePTHAction::ExecuteAction() {
333  CompilerInstance &CI = getCompilerInstance();
334  if (CI.getFrontendOpts().OutputFile.empty() ||
335      CI.getFrontendOpts().OutputFile == "-") {
336    // FIXME: Don't fail this way.
337    // FIXME: Verify that we can actually seek in the given file.
338    llvm::report_fatal_error("PTH requires a seekable file for output!");
339  }
340  llvm::raw_fd_ostream *OS =
341    CI.createDefaultOutputFile(true, getCurrentFile());
342  if (!OS) return;
343
344  CacheTokens(CI.getPreprocessor(), OS);
345}
346
347void PreprocessOnlyAction::ExecuteAction() {
348  Preprocessor &PP = getCompilerInstance().getPreprocessor();
349
350  // Ignore unknown pragmas.
351  PP.AddPragmaHandler(new EmptyPragmaHandler());
352
353  Token Tok;
354  // Start parsing the specified input file.
355  PP.EnterMainSourceFile();
356  do {
357    PP.Lex(Tok);
358  } while (Tok.isNot(tok::eof));
359}
360
361void PrintPreprocessedAction::ExecuteAction() {
362  CompilerInstance &CI = getCompilerInstance();
363  // Output file may need to be set to 'Binary', to avoid converting Unix style
364  // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
365  //
366  // Look to see what type of line endings the file uses. If there's a
367  // CRLF, then we won't open the file up in binary mode. If there is
368  // just an LF or CR, then we will open the file up in binary mode.
369  // In this fashion, the output format should match the input format, unless
370  // the input format has inconsistent line endings.
371  //
372  // This should be a relatively fast operation since most files won't have
373  // all of their source code on a single line. However, that is still a
374  // concern, so if we scan for too long, we'll just assume the file should
375  // be opened in binary mode.
376  bool BinaryMode = true;
377  bool InvalidFile = false;
378  const SourceManager& SM = CI.getSourceManager();
379  const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
380                                                     &InvalidFile);
381  if (!InvalidFile) {
382    const char *cur = Buffer->getBufferStart();
383    const char *end = Buffer->getBufferEnd();
384    const char *next = (cur != end) ? cur + 1 : end;
385
386    // Limit ourselves to only scanning 256 characters into the source
387    // file.  This is mostly a sanity check in case the file has no
388    // newlines whatsoever.
389    if (end - cur > 256) end = cur + 256;
390
391    while (next < end) {
392      if (*cur == 0x0D) {  // CR
393        if (*next == 0x0A)  // CRLF
394          BinaryMode = false;
395
396        break;
397      } else if (*cur == 0x0A)  // LF
398        break;
399
400      ++cur, ++next;
401    }
402  }
403
404  raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
405  if (!OS) return;
406
407  DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
408                           CI.getPreprocessorOutputOpts());
409}
410
411void PrintPreambleAction::ExecuteAction() {
412  switch (getCurrentFileKind()) {
413  case IK_C:
414  case IK_CXX:
415  case IK_ObjC:
416  case IK_ObjCXX:
417  case IK_OpenCL:
418  case IK_CUDA:
419    break;
420
421  case IK_None:
422  case IK_Asm:
423  case IK_PreprocessedC:
424  case IK_PreprocessedCXX:
425  case IK_PreprocessedObjC:
426  case IK_PreprocessedObjCXX:
427  case IK_AST:
428  case IK_LLVM_IR:
429    // We can't do anything with these.
430    return;
431  }
432
433  CompilerInstance &CI = getCompilerInstance();
434  llvm::MemoryBuffer *Buffer
435      = CI.getFileManager().getBufferForFile(getCurrentFile());
436  if (Buffer) {
437    unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
438    llvm::outs().write(Buffer->getBufferStart(), Preamble);
439    delete Buffer;
440  }
441}
442