FrontendActions.cpp revision 10694cee2588442bee1e717f5042c58ffee25279 
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 (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
149    if (Module->Parent) {
150      // Include the umbrella header for submodules.
151      if (LangOpts.ObjC1)
152        Includes += "#import \"";
153      else
154        Includes += "#include \"";
155      Includes += UmbrellaHeader->getName();
156      Includes += "\"\n";
157    }
158  }
159
160  // Recurse into submodules.
161  for (llvm::StringMap<clang::Module *>::iterator
162            Sub = Module->SubModules.begin(),
163         SubEnd = Module->SubModules.end();
164       Sub != SubEnd; ++Sub)
165    collectModuleHeaderIncludes(LangOpts, Sub->getValue(), Includes);
166}
167
168bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
169                                                 StringRef Filename) {
170  // Find the module map file.
171  const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
172  if (!ModuleMap)  {
173    CI.getDiagnostics().Report(diag::err_module_map_not_found)
174      << Filename;
175    return false;
176  }
177
178  // Parse the module map file.
179  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
180  if (HS.loadModuleMapFile(ModuleMap))
181    return false;
182
183  if (CI.getLangOpts().CurrentModule.empty()) {
184    CI.getDiagnostics().Report(diag::err_missing_module_name);
185
186    // FIXME: Eventually, we could consider asking whether there was just
187    // a single module described in the module map, and use that as a
188    // default. Then it would be fairly trivial to just "compile" a module
189    // map with a single module (the common case).
190    return false;
191  }
192
193  // Dig out the module definition.
194  Module = HS.getModule(CI.getLangOpts().CurrentModule, /*AllowSearch=*/false);
195  if (!Module) {
196    CI.getDiagnostics().Report(diag::err_missing_module)
197      << CI.getLangOpts().CurrentModule << Filename;
198
199    return false;
200  }
201
202  // Do we have an umbrella header for this module?
203  const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader();
204
205  // Collect the set of #includes we need to build the module.
206  llvm::SmallString<256> HeaderContents;
207  collectModuleHeaderIncludes(CI.getLangOpts(), Module, HeaderContents);
208  if (UmbrellaHeader && HeaderContents.empty()) {
209    // Simple case: we have an umbrella header and there are no additional
210    // includes, we can just parse the umbrella header directly.
211    setCurrentFile(UmbrellaHeader->getName(), getCurrentFileKind());
212    return true;
213  }
214
215  FileManager &FileMgr = CI.getFileManager();
216  llvm::SmallString<128> HeaderName;
217  time_t ModTime;
218  if (UmbrellaHeader) {
219    // Read in the umbrella header.
220    // FIXME: Go through the source manager; the umbrella header may have
221    // been overridden.
222    std::string ErrorStr;
223    llvm::MemoryBuffer *UmbrellaContents
224      = FileMgr.getBufferForFile(UmbrellaHeader, &ErrorStr);
225    if (!UmbrellaContents) {
226      CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
227        << UmbrellaHeader->getName() << ErrorStr;
228      return false;
229    }
230
231    // Combine the contents of the umbrella header with the automatically-
232    // generated includes.
233    llvm::SmallString<256> OldContents = HeaderContents;
234    HeaderContents = UmbrellaContents->getBuffer();
235    HeaderContents += "\n\n";
236    HeaderContents += "/* Module includes */\n";
237    HeaderContents += OldContents;
238
239    // Pretend that we're parsing the umbrella header.
240    HeaderName = UmbrellaHeader->getName();
241    ModTime = UmbrellaHeader->getModificationTime();
242
243    delete UmbrellaContents;
244  } else {
245    // Pick an innocuous-sounding name for the umbrella header.
246    HeaderName = Module->Name + ".h";
247    if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
248                        /*CacheFailure=*/false)) {
249      // Try again!
250      HeaderName = Module->Name + "-module.h";
251      if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
252                          /*CacheFailure=*/false)) {
253        // Pick something ridiculous and go with it.
254        HeaderName = Module->Name + "-module.hmod";
255      }
256    }
257    ModTime = time(0);
258  }
259
260  // Remap the contents of the header name we're using to our synthesized
261  // buffer.
262  const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName,
263                                                       HeaderContents.size(),
264                                                       ModTime);
265  llvm::MemoryBuffer *HeaderContentsBuf
266    = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
267  CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);
268
269  setCurrentFile(HeaderName, getCurrentFileKind());
270  return true;
271}
272
273bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
274                                                       StringRef InFile,
275                                                       std::string &Sysroot,
276                                                       std::string &OutputFile,
277                                                       raw_ostream *&OS) {
278  // If no output file was provided, figure out where this module would go
279  // in the module cache.
280  if (CI.getFrontendOpts().OutputFile.empty()) {
281    HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
282    llvm::SmallString<256> ModuleFileName(HS.getModuleCachePath());
283    llvm::sys::path::append(ModuleFileName,
284                            CI.getLangOpts().CurrentModule + ".pcm");
285    CI.getFrontendOpts().OutputFile = ModuleFileName.str();
286  }
287
288  // We use createOutputFile here because this is exposed via libclang, and we
289  // must disable the RemoveFileOnSignal behavior.
290  // We use a temporary to avoid race conditions.
291  OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
292                           /*RemoveFileOnSignal=*/false, InFile,
293                           /*Extension=*/"", /*useTemporary=*/true);
294  if (!OS)
295    return true;
296
297  OutputFile = CI.getFrontendOpts().OutputFile;
298  return false;
299}
300
301ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
302                                                 StringRef InFile) {
303  return new ASTConsumer();
304}
305
306//===----------------------------------------------------------------------===//
307// Preprocessor Actions
308//===----------------------------------------------------------------------===//
309
310void DumpRawTokensAction::ExecuteAction() {
311  Preprocessor &PP = getCompilerInstance().getPreprocessor();
312  SourceManager &SM = PP.getSourceManager();
313
314  // Start lexing the specified input file.
315  const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
316  Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOptions());
317  RawLex.SetKeepWhitespaceMode(true);
318
319  Token RawTok;
320  RawLex.LexFromRawLexer(RawTok);
321  while (RawTok.isNot(tok::eof)) {
322    PP.DumpToken(RawTok, true);
323    llvm::errs() << "\n";
324    RawLex.LexFromRawLexer(RawTok);
325  }
326}
327
328void DumpTokensAction::ExecuteAction() {
329  Preprocessor &PP = getCompilerInstance().getPreprocessor();
330  // Start preprocessing the specified input file.
331  Token Tok;
332  PP.EnterMainSourceFile();
333  do {
334    PP.Lex(Tok);
335    PP.DumpToken(Tok, true);
336    llvm::errs() << "\n";
337  } while (Tok.isNot(tok::eof));
338}
339
340void GeneratePTHAction::ExecuteAction() {
341  CompilerInstance &CI = getCompilerInstance();
342  if (CI.getFrontendOpts().OutputFile.empty() ||
343      CI.getFrontendOpts().OutputFile == "-") {
344    // FIXME: Don't fail this way.
345    // FIXME: Verify that we can actually seek in the given file.
346    llvm::report_fatal_error("PTH requires a seekable file for output!");
347  }
348  llvm::raw_fd_ostream *OS =
349    CI.createDefaultOutputFile(true, getCurrentFile());
350  if (!OS) return;
351
352  CacheTokens(CI.getPreprocessor(), OS);
353}
354
355void PreprocessOnlyAction::ExecuteAction() {
356  Preprocessor &PP = getCompilerInstance().getPreprocessor();
357
358  // Ignore unknown pragmas.
359  PP.AddPragmaHandler(new EmptyPragmaHandler());
360
361  Token Tok;
362  // Start parsing the specified input file.
363  PP.EnterMainSourceFile();
364  do {
365    PP.Lex(Tok);
366  } while (Tok.isNot(tok::eof));
367}
368
369void PrintPreprocessedAction::ExecuteAction() {
370  CompilerInstance &CI = getCompilerInstance();
371  // Output file may need to be set to 'Binary', to avoid converting Unix style
372  // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
373  //
374  // Look to see what type of line endings the file uses. If there's a
375  // CRLF, then we won't open the file up in binary mode. If there is
376  // just an LF or CR, then we will open the file up in binary mode.
377  // In this fashion, the output format should match the input format, unless
378  // the input format has inconsistent line endings.
379  //
380  // This should be a relatively fast operation since most files won't have
381  // all of their source code on a single line. However, that is still a
382  // concern, so if we scan for too long, we'll just assume the file should
383  // be opened in binary mode.
384  bool BinaryMode = true;
385  bool InvalidFile = false;
386  const SourceManager& SM = CI.getSourceManager();
387  const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
388                                                     &InvalidFile);
389  if (!InvalidFile) {
390    const char *cur = Buffer->getBufferStart();
391    const char *end = Buffer->getBufferEnd();
392    const char *next = (cur != end) ? cur + 1 : end;
393
394    // Limit ourselves to only scanning 256 characters into the source
395    // file.  This is mostly a sanity check in case the file has no
396    // newlines whatsoever.
397    if (end - cur > 256) end = cur + 256;
398
399    while (next < end) {
400      if (*cur == 0x0D) {  // CR
401        if (*next == 0x0A)  // CRLF
402          BinaryMode = false;
403
404        break;
405      } else if (*cur == 0x0A)  // LF
406        break;
407
408      ++cur, ++next;
409    }
410  }
411
412  raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
413  if (!OS) return;
414
415  DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
416                           CI.getPreprocessorOutputOpts());
417}
418
419void PrintPreambleAction::ExecuteAction() {
420  switch (getCurrentFileKind()) {
421  case IK_C:
422  case IK_CXX:
423  case IK_ObjC:
424  case IK_ObjCXX:
425  case IK_OpenCL:
426  case IK_CUDA:
427    break;
428
429  case IK_None:
430  case IK_Asm:
431  case IK_PreprocessedC:
432  case IK_PreprocessedCXX:
433  case IK_PreprocessedObjC:
434  case IK_PreprocessedObjCXX:
435  case IK_AST:
436  case IK_LLVM_IR:
437    // We can't do anything with these.
438    return;
439  }
440
441  CompilerInstance &CI = getCompilerInstance();
442  llvm::MemoryBuffer *Buffer
443      = CI.getFileManager().getBufferForFile(getCurrentFile());
444  if (Buffer) {
445    unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
446    llvm::outs().write(Buffer->getBufferStart(), Preamble);
447    delete Buffer;
448  }
449}
450