Preprocessor.cpp revision e434ec71fccfe078906403affd641f709702d598 
1//===--- Preprocess.cpp - C Language Family Preprocessor Implementation ---===//
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//  This file implements the Preprocessor interface.
11//
12//===----------------------------------------------------------------------===//
13//
14// Options to support:
15//   -H       - Print the name of each header file used.
16//   -d[DNI] - Dump various things.
17//   -fworking-directory - #line's with preprocessor's working dir.
18//   -fpreprocessed
19//   -dependency-file,-M,-MM,-MF,-MG,-MP,-MT,-MQ,-MD,-MMD
20//   -W*
21//   -w
22//
23// Messages to emit:
24//   "Multiple include guards may be useful for:\n"
25//
26//===----------------------------------------------------------------------===//
27
28#include "clang/Lex/Preprocessor.h"
29#include "MacroArgs.h"
30#include "clang/Lex/ExternalPreprocessorSource.h"
31#include "clang/Lex/HeaderSearch.h"
32#include "clang/Lex/MacroInfo.h"
33#include "clang/Lex/Pragma.h"
34#include "clang/Lex/PreprocessingRecord.h"
35#include "clang/Lex/ScratchBuffer.h"
36#include "clang/Lex/LexDiagnostic.h"
37#include "clang/Lex/CodeCompletionHandler.h"
38#include "clang/Lex/ModuleLoader.h"
39#include "clang/Basic/SourceManager.h"
40#include "clang/Basic/FileManager.h"
41#include "clang/Basic/TargetInfo.h"
42#include "llvm/ADT/APFloat.h"
43#include "llvm/ADT/SmallVector.h"
44#include "llvm/Support/MemoryBuffer.h"
45#include "llvm/Support/raw_ostream.h"
46#include "llvm/Support/Capacity.h"
47using namespace clang;
48
49//===----------------------------------------------------------------------===//
50ExternalPreprocessorSource::~ExternalPreprocessorSource() { }
51
52Preprocessor::Preprocessor(DiagnosticsEngine &diags, LangOptions &opts,
53                           const TargetInfo *target, SourceManager &SM,
54                           HeaderSearch &Headers, ModuleLoader &TheModuleLoader,
55                           IdentifierInfoLookup* IILookup,
56                           bool OwnsHeaders,
57                           bool DelayInitialization)
58  : Diags(&diags), Features(opts), Target(target),FileMgr(Headers.getFileMgr()),
59    SourceMgr(SM), HeaderInfo(Headers), TheModuleLoader(TheModuleLoader),
60    ExternalSource(0),
61    Identifiers(opts, IILookup), CodeComplete(0),
62    CodeCompletionFile(0), CodeCompletionOffset(0), CodeCompletionReached(0),
63    SkipMainFilePreamble(0, true), CurPPLexer(0),
64    CurDirLookup(0), CurLexerKind(CLK_Lexer), Callbacks(0), MacroArgCache(0),
65    Record(0), MIChainHead(0), MICache(0)
66{
67  OwnsHeaderSearch = OwnsHeaders;
68
69  if (!DelayInitialization) {
70    assert(Target && "Must provide target information for PP initialization");
71    Initialize(*Target);
72  }
73}
74
75Preprocessor::~Preprocessor() {
76  assert(BacktrackPositions.empty() && "EnableBacktrack/Backtrack imbalance!");
77
78  while (!IncludeMacroStack.empty()) {
79    delete IncludeMacroStack.back().TheLexer;
80    delete IncludeMacroStack.back().TheTokenLexer;
81    IncludeMacroStack.pop_back();
82  }
83
84  // Free any macro definitions.
85  for (MacroInfoChain *I = MIChainHead ; I ; I = I->Next)
86    I->MI.Destroy();
87
88  // Free any cached macro expanders.
89  for (unsigned i = 0, e = NumCachedTokenLexers; i != e; ++i)
90    delete TokenLexerCache[i];
91
92  // Free any cached MacroArgs.
93  for (MacroArgs *ArgList = MacroArgCache; ArgList; )
94    ArgList = ArgList->deallocate();
95
96  // Release pragma information.
97  delete PragmaHandlers;
98
99  // Delete the scratch buffer info.
100  delete ScratchBuf;
101
102  // Delete the header search info, if we own it.
103  if (OwnsHeaderSearch)
104    delete &HeaderInfo;
105
106  delete Callbacks;
107}
108
109void Preprocessor::Initialize(const TargetInfo &Target) {
110  assert((!this->Target || this->Target == &Target) &&
111         "Invalid override of target information");
112  this->Target = &Target;
113
114  // Initialize information about built-ins.
115  BuiltinInfo.InitializeTarget(Target);
116
117  ScratchBuf = new ScratchBuffer(SourceMgr);
118  CounterValue = 0; // __COUNTER__ starts at 0.
119
120  // Clear stats.
121  NumDirectives = NumDefined = NumUndefined = NumPragma = 0;
122  NumIf = NumElse = NumEndif = 0;
123  NumEnteredSourceFiles = 0;
124  NumMacroExpanded = NumFnMacroExpanded = NumBuiltinMacroExpanded = 0;
125  NumFastMacroExpanded = NumTokenPaste = NumFastTokenPaste = 0;
126  MaxIncludeStackDepth = 0;
127  NumSkipped = 0;
128
129  // Default to discarding comments.
130  KeepComments = false;
131  KeepMacroComments = false;
132  SuppressIncludeNotFoundError = false;
133
134  // Macro expansion is enabled.
135  DisableMacroExpansion = false;
136  InMacroArgs = false;
137  NumCachedTokenLexers = 0;
138
139  CachedLexPos = 0;
140
141  // We haven't read anything from the external source.
142  ReadMacrosFromExternalSource = false;
143
144  // "Poison" __VA_ARGS__, which can only appear in the expansion of a macro.
145  // This gets unpoisoned where it is allowed.
146  (Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned();
147  SetPoisonReason(Ident__VA_ARGS__,diag::ext_pp_bad_vaargs_use);
148
149  // Initialize the pragma handlers.
150  PragmaHandlers = new PragmaNamespace(StringRef());
151  RegisterBuiltinPragmas();
152
153  // Initialize builtin macros like __LINE__ and friends.
154  RegisterBuiltinMacros();
155
156  if(Features.Borland) {
157    Ident__exception_info        = getIdentifierInfo("_exception_info");
158    Ident___exception_info       = getIdentifierInfo("__exception_info");
159    Ident_GetExceptionInfo       = getIdentifierInfo("GetExceptionInformation");
160    Ident__exception_code        = getIdentifierInfo("_exception_code");
161    Ident___exception_code       = getIdentifierInfo("__exception_code");
162    Ident_GetExceptionCode       = getIdentifierInfo("GetExceptionCode");
163    Ident__abnormal_termination  = getIdentifierInfo("_abnormal_termination");
164    Ident___abnormal_termination = getIdentifierInfo("__abnormal_termination");
165    Ident_AbnormalTermination    = getIdentifierInfo("AbnormalTermination");
166  } else {
167    Ident__exception_info = Ident__exception_code = Ident__abnormal_termination = 0;
168    Ident___exception_info = Ident___exception_code = Ident___abnormal_termination = 0;
169    Ident_GetExceptionInfo = Ident_GetExceptionCode = Ident_AbnormalTermination = 0;
170  }
171}
172
173void Preprocessor::setPTHManager(PTHManager* pm) {
174  PTH.reset(pm);
175  FileMgr.addStatCache(PTH->createStatCache());
176}
177
178void Preprocessor::DumpToken(const Token &Tok, bool DumpFlags) const {
179  llvm::errs() << tok::getTokenName(Tok.getKind()) << " '"
180               << getSpelling(Tok) << "'";
181
182  if (!DumpFlags) return;
183
184  llvm::errs() << "\t";
185  if (Tok.isAtStartOfLine())
186    llvm::errs() << " [StartOfLine]";
187  if (Tok.hasLeadingSpace())
188    llvm::errs() << " [LeadingSpace]";
189  if (Tok.isExpandDisabled())
190    llvm::errs() << " [ExpandDisabled]";
191  if (Tok.needsCleaning()) {
192    const char *Start = SourceMgr.getCharacterData(Tok.getLocation());
193    llvm::errs() << " [UnClean='" << StringRef(Start, Tok.getLength())
194                 << "']";
195  }
196
197  llvm::errs() << "\tLoc=<";
198  DumpLocation(Tok.getLocation());
199  llvm::errs() << ">";
200}
201
202void Preprocessor::DumpLocation(SourceLocation Loc) const {
203  Loc.dump(SourceMgr);
204}
205
206void Preprocessor::DumpMacro(const MacroInfo &MI) const {
207  llvm::errs() << "MACRO: ";
208  for (unsigned i = 0, e = MI.getNumTokens(); i != e; ++i) {
209    DumpToken(MI.getReplacementToken(i));
210    llvm::errs() << "  ";
211  }
212  llvm::errs() << "\n";
213}
214
215void Preprocessor::PrintStats() {
216  llvm::errs() << "\n*** Preprocessor Stats:\n";
217  llvm::errs() << NumDirectives << " directives found:\n";
218  llvm::errs() << "  " << NumDefined << " #define.\n";
219  llvm::errs() << "  " << NumUndefined << " #undef.\n";
220  llvm::errs() << "  #include/#include_next/#import:\n";
221  llvm::errs() << "    " << NumEnteredSourceFiles << " source files entered.\n";
222  llvm::errs() << "    " << MaxIncludeStackDepth << " max include stack depth\n";
223  llvm::errs() << "  " << NumIf << " #if/#ifndef/#ifdef.\n";
224  llvm::errs() << "  " << NumElse << " #else/#elif.\n";
225  llvm::errs() << "  " << NumEndif << " #endif.\n";
226  llvm::errs() << "  " << NumPragma << " #pragma.\n";
227  llvm::errs() << NumSkipped << " #if/#ifndef#ifdef regions skipped\n";
228
229  llvm::errs() << NumMacroExpanded << "/" << NumFnMacroExpanded << "/"
230             << NumBuiltinMacroExpanded << " obj/fn/builtin macros expanded, "
231             << NumFastMacroExpanded << " on the fast path.\n";
232  llvm::errs() << (NumFastTokenPaste+NumTokenPaste)
233             << " token paste (##) operations performed, "
234             << NumFastTokenPaste << " on the fast path.\n";
235}
236
237Preprocessor::macro_iterator
238Preprocessor::macro_begin(bool IncludeExternalMacros) const {
239  if (IncludeExternalMacros && ExternalSource &&
240      !ReadMacrosFromExternalSource) {
241    ReadMacrosFromExternalSource = true;
242    ExternalSource->ReadDefinedMacros();
243  }
244
245  return Macros.begin();
246}
247
248size_t Preprocessor::getTotalMemory() const {
249  return BP.getTotalMemory()
250    + llvm::capacity_in_bytes(MacroExpandedTokens)
251    + Predefines.capacity() /* Predefines buffer. */
252    + llvm::capacity_in_bytes(Macros)
253    + llvm::capacity_in_bytes(PragmaPushMacroInfo)
254    + llvm::capacity_in_bytes(PoisonReasons)
255    + llvm::capacity_in_bytes(CommentHandlers);
256}
257
258Preprocessor::macro_iterator
259Preprocessor::macro_end(bool IncludeExternalMacros) const {
260  if (IncludeExternalMacros && ExternalSource &&
261      !ReadMacrosFromExternalSource) {
262    ReadMacrosFromExternalSource = true;
263    ExternalSource->ReadDefinedMacros();
264  }
265
266  return Macros.end();
267}
268
269void Preprocessor::recomputeCurLexerKind() {
270  if (CurLexer)
271    CurLexerKind = CLK_Lexer;
272  else if (CurPTHLexer)
273    CurLexerKind = CLK_PTHLexer;
274  else if (CurTokenLexer)
275    CurLexerKind = CLK_TokenLexer;
276  else
277    CurLexerKind = CLK_CachingLexer;
278}
279
280bool Preprocessor::SetCodeCompletionPoint(const FileEntry *File,
281                                          unsigned CompleteLine,
282                                          unsigned CompleteColumn) {
283  assert(File);
284  assert(CompleteLine && CompleteColumn && "Starts from 1:1");
285  assert(!CodeCompletionFile && "Already set");
286
287  using llvm::MemoryBuffer;
288
289  // Load the actual file's contents.
290  bool Invalid = false;
291  const MemoryBuffer *Buffer = SourceMgr.getMemoryBufferForFile(File, &Invalid);
292  if (Invalid)
293    return true;
294
295  // Find the byte position of the truncation point.
296  const char *Position = Buffer->getBufferStart();
297  for (unsigned Line = 1; Line < CompleteLine; ++Line) {
298    for (; *Position; ++Position) {
299      if (*Position != '\r' && *Position != '\n')
300        continue;
301
302      // Eat \r\n or \n\r as a single line.
303      if ((Position[1] == '\r' || Position[1] == '\n') &&
304          Position[0] != Position[1])
305        ++Position;
306      ++Position;
307      break;
308    }
309  }
310
311  Position += CompleteColumn - 1;
312
313  // Insert '\0' at the code-completion point.
314  if (Position < Buffer->getBufferEnd()) {
315    CodeCompletionFile = File;
316    CodeCompletionOffset = Position - Buffer->getBufferStart();
317
318    MemoryBuffer *NewBuffer =
319        MemoryBuffer::getNewUninitMemBuffer(Buffer->getBufferSize() + 1,
320                                            Buffer->getBufferIdentifier());
321    char *NewBuf = const_cast<char*>(NewBuffer->getBufferStart());
322    char *NewPos = std::copy(Buffer->getBufferStart(), Position, NewBuf);
323    *NewPos = '\0';
324    std::copy(Position, Buffer->getBufferEnd(), NewPos+1);
325    SourceMgr.overrideFileContents(File, NewBuffer);
326  }
327
328  return false;
329}
330
331void Preprocessor::CodeCompleteNaturalLanguage() {
332  if (CodeComplete)
333    CodeComplete->CodeCompleteNaturalLanguage();
334  setCodeCompletionReached();
335}
336
337/// getSpelling - This method is used to get the spelling of a token into a
338/// SmallVector. Note that the returned StringRef may not point to the
339/// supplied buffer if a copy can be avoided.
340StringRef Preprocessor::getSpelling(const Token &Tok,
341                                          SmallVectorImpl<char> &Buffer,
342                                          bool *Invalid) const {
343  // NOTE: this has to be checked *before* testing for an IdentifierInfo.
344  if (Tok.isNot(tok::raw_identifier)) {
345    // Try the fast path.
346    if (const IdentifierInfo *II = Tok.getIdentifierInfo())
347      return II->getName();
348  }
349
350  // Resize the buffer if we need to copy into it.
351  if (Tok.needsCleaning())
352    Buffer.resize(Tok.getLength());
353
354  const char *Ptr = Buffer.data();
355  unsigned Len = getSpelling(Tok, Ptr, Invalid);
356  return StringRef(Ptr, Len);
357}
358
359/// CreateString - Plop the specified string into a scratch buffer and return a
360/// location for it.  If specified, the source location provides a source
361/// location for the token.
362void Preprocessor::CreateString(const char *Buf, unsigned Len, Token &Tok,
363                                SourceLocation ExpansionLocStart,
364                                SourceLocation ExpansionLocEnd) {
365  Tok.setLength(Len);
366
367  const char *DestPtr;
368  SourceLocation Loc = ScratchBuf->getToken(Buf, Len, DestPtr);
369
370  if (ExpansionLocStart.isValid())
371    Loc = SourceMgr.createExpansionLoc(Loc, ExpansionLocStart,
372                                       ExpansionLocEnd, Len);
373  Tok.setLocation(Loc);
374
375  // If this is a raw identifier or a literal token, set the pointer data.
376  if (Tok.is(tok::raw_identifier))
377    Tok.setRawIdentifierData(DestPtr);
378  else if (Tok.isLiteral())
379    Tok.setLiteralData(DestPtr);
380}
381
382Module *Preprocessor::getCurrentModule() {
383  if (getLangOptions().CurrentModule.empty())
384    return 0;
385
386  return getHeaderSearchInfo().lookupModule(getLangOptions().CurrentModule);
387}
388
389//===----------------------------------------------------------------------===//
390// Preprocessor Initialization Methods
391//===----------------------------------------------------------------------===//
392
393
394/// EnterMainSourceFile - Enter the specified FileID as the main source file,
395/// which implicitly adds the builtin defines etc.
396void Preprocessor::EnterMainSourceFile() {
397  // We do not allow the preprocessor to reenter the main file.  Doing so will
398  // cause FileID's to accumulate information from both runs (e.g. #line
399  // information) and predefined macros aren't guaranteed to be set properly.
400  assert(NumEnteredSourceFiles == 0 && "Cannot reenter the main file!");
401  FileID MainFileID = SourceMgr.getMainFileID();
402
403  // If MainFileID is loaded it means we loaded an AST file, no need to enter
404  // a main file.
405  if (!SourceMgr.isLoadedFileID(MainFileID)) {
406    // Enter the main file source buffer.
407    EnterSourceFile(MainFileID, 0, SourceLocation());
408
409    // If we've been asked to skip bytes in the main file (e.g., as part of a
410    // precompiled preamble), do so now.
411    if (SkipMainFilePreamble.first > 0)
412      CurLexer->SkipBytes(SkipMainFilePreamble.first,
413                          SkipMainFilePreamble.second);
414
415    // Tell the header info that the main file was entered.  If the file is later
416    // #imported, it won't be re-entered.
417    if (const FileEntry *FE = SourceMgr.getFileEntryForID(MainFileID))
418      HeaderInfo.IncrementIncludeCount(FE);
419  }
420
421  // Preprocess Predefines to populate the initial preprocessor state.
422  llvm::MemoryBuffer *SB =
423    llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
424  assert(SB && "Cannot create predefined source buffer");
425  FileID FID = SourceMgr.createFileIDForMemBuffer(SB);
426  assert(!FID.isInvalid() && "Could not create FileID for predefines?");
427
428  // Start parsing the predefines.
429  EnterSourceFile(FID, 0, SourceLocation());
430}
431
432void Preprocessor::EndSourceFile() {
433  // Notify the client that we reached the end of the source file.
434  if (Callbacks)
435    Callbacks->EndOfMainFile();
436}
437
438//===----------------------------------------------------------------------===//
439// Lexer Event Handling.
440//===----------------------------------------------------------------------===//
441
442/// LookUpIdentifierInfo - Given a tok::raw_identifier token, look up the
443/// identifier information for the token and install it into the token,
444/// updating the token kind accordingly.
445IdentifierInfo *Preprocessor::LookUpIdentifierInfo(Token &Identifier) const {
446  assert(Identifier.getRawIdentifierData() != 0 && "No raw identifier data!");
447
448  // Look up this token, see if it is a macro, or if it is a language keyword.
449  IdentifierInfo *II;
450  if (!Identifier.needsCleaning()) {
451    // No cleaning needed, just use the characters from the lexed buffer.
452    II = getIdentifierInfo(StringRef(Identifier.getRawIdentifierData(),
453                                           Identifier.getLength()));
454  } else {
455    // Cleaning needed, alloca a buffer, clean into it, then use the buffer.
456    llvm::SmallString<64> IdentifierBuffer;
457    StringRef CleanedStr = getSpelling(Identifier, IdentifierBuffer);
458    II = getIdentifierInfo(CleanedStr);
459  }
460
461  // Update the token info (identifier info and appropriate token kind).
462  Identifier.setIdentifierInfo(II);
463  Identifier.setKind(II->getTokenID());
464
465  return II;
466}
467
468void Preprocessor::SetPoisonReason(IdentifierInfo *II, unsigned DiagID) {
469  PoisonReasons[II] = DiagID;
470}
471
472void Preprocessor::PoisonSEHIdentifiers(bool Poison) {
473  assert(Ident__exception_code && Ident__exception_info);
474  assert(Ident___exception_code && Ident___exception_info);
475  Ident__exception_code->setIsPoisoned(Poison);
476  Ident___exception_code->setIsPoisoned(Poison);
477  Ident_GetExceptionCode->setIsPoisoned(Poison);
478  Ident__exception_info->setIsPoisoned(Poison);
479  Ident___exception_info->setIsPoisoned(Poison);
480  Ident_GetExceptionInfo->setIsPoisoned(Poison);
481  Ident__abnormal_termination->setIsPoisoned(Poison);
482  Ident___abnormal_termination->setIsPoisoned(Poison);
483  Ident_AbnormalTermination->setIsPoisoned(Poison);
484}
485
486void Preprocessor::HandlePoisonedIdentifier(Token & Identifier) {
487  assert(Identifier.getIdentifierInfo() &&
488         "Can't handle identifiers without identifier info!");
489  llvm::DenseMap<IdentifierInfo*,unsigned>::const_iterator it =
490    PoisonReasons.find(Identifier.getIdentifierInfo());
491  if(it == PoisonReasons.end())
492    Diag(Identifier, diag::err_pp_used_poisoned_id);
493  else
494    Diag(Identifier,it->second) << Identifier.getIdentifierInfo();
495}
496
497/// HandleIdentifier - This callback is invoked when the lexer reads an
498/// identifier.  This callback looks up the identifier in the map and/or
499/// potentially macro expands it or turns it into a named token (like 'for').
500///
501/// Note that callers of this method are guarded by checking the
502/// IdentifierInfo's 'isHandleIdentifierCase' bit.  If this method changes, the
503/// IdentifierInfo methods that compute these properties will need to change to
504/// match.
505void Preprocessor::HandleIdentifier(Token &Identifier) {
506  assert(Identifier.getIdentifierInfo() &&
507         "Can't handle identifiers without identifier info!");
508
509  IdentifierInfo &II = *Identifier.getIdentifierInfo();
510
511  // If the information about this identifier is out of date, update it from
512  // the external source.
513  if (II.isOutOfDate()) {
514    ExternalSource->updateOutOfDateIdentifier(II);
515    Identifier.setKind(II.getTokenID());
516  }
517
518  // If this identifier was poisoned, and if it was not produced from a macro
519  // expansion, emit an error.
520  if (II.isPoisoned() && CurPPLexer) {
521    HandlePoisonedIdentifier(Identifier);
522  }
523
524  // If this is a macro to be expanded, do it.
525  if (MacroInfo *MI = getMacroInfo(&II)) {
526    if (!DisableMacroExpansion) {
527      if (Identifier.isExpandDisabled()) {
528        Diag(Identifier, diag::pp_disabled_macro_expansion);
529      } else if (MI->isEnabled()) {
530        if (!HandleMacroExpandedIdentifier(Identifier, MI))
531          return;
532      } else {
533        // C99 6.10.3.4p2 says that a disabled macro may never again be
534        // expanded, even if it's in a context where it could be expanded in the
535        // future.
536        Identifier.setFlag(Token::DisableExpand);
537        Diag(Identifier, diag::pp_disabled_macro_expansion);
538      }
539    }
540  }
541
542  // If this identifier is a keyword in C++11, produce a warning. Don't warn if
543  // we're not considering macro expansion, since this identifier might be the
544  // name of a macro.
545  // FIXME: This warning is disabled in cases where it shouldn't be, like
546  //   "#define constexpr constexpr", "int constexpr;"
547  if (II.isCXX11CompatKeyword() & !DisableMacroExpansion) {
548    Diag(Identifier, diag::warn_cxx11_keyword) << II.getName();
549    // Don't diagnose this keyword again in this translation unit.
550    II.setIsCXX11CompatKeyword(false);
551  }
552
553  // C++ 2.11p2: If this is an alternative representation of a C++ operator,
554  // then we act as if it is the actual operator and not the textual
555  // representation of it.
556  if (II.isCPlusPlusOperatorKeyword())
557    Identifier.setIdentifierInfo(0);
558
559  // If this is an extension token, diagnose its use.
560  // We avoid diagnosing tokens that originate from macro definitions.
561  // FIXME: This warning is disabled in cases where it shouldn't be,
562  // like "#define TY typeof", "TY(1) x".
563  if (II.isExtensionToken() && !DisableMacroExpansion)
564    Diag(Identifier, diag::ext_token_used);
565
566  // If this is the 'import' contextual keyword, note that the next token
567  // indicates a module name.
568  //
569  // Note that we do not treat 'import' as a contextual keyword when we're
570  // in a caching lexer, because caching lexers only get used in contexts where
571  // import declarations are disallowed.
572  if (II.isImport() && !InMacroArgs && !DisableMacroExpansion &&
573      getLangOptions().Modules && CurLexerKind != CLK_CachingLexer) {
574    ModuleImportLoc = Identifier.getLocation();
575    ModuleImportPath.clear();
576    ModuleImportExpectsIdentifier = true;
577    CurLexerKind = CLK_LexAfterModuleImport;
578  }
579}
580
581/// \brief Lex a token following the 'import' contextual keyword.
582///
583void Preprocessor::LexAfterModuleImport(Token &Result) {
584  // Figure out what kind of lexer we actually have.
585  recomputeCurLexerKind();
586
587  // Lex the next token.
588  Lex(Result);
589
590  // The token sequence
591  //
592  //   import identifier (. identifier)*
593  //
594  // indicates a module import directive. We already saw the 'import'
595  // contextual keyword, so now we're looking for the identifiers.
596  if (ModuleImportExpectsIdentifier && Result.getKind() == tok::identifier) {
597    // We expected to see an identifier here, and we did; continue handling
598    // identifiers.
599    ModuleImportPath.push_back(std::make_pair(Result.getIdentifierInfo(),
600                                              Result.getLocation()));
601    ModuleImportExpectsIdentifier = false;
602    CurLexerKind = CLK_LexAfterModuleImport;
603    return;
604  }
605
606  // If we're expecting a '.' or a ';', and we got a '.', then wait until we
607  // see the next identifier.
608  if (!ModuleImportExpectsIdentifier && Result.getKind() == tok::period) {
609    ModuleImportExpectsIdentifier = true;
610    CurLexerKind = CLK_LexAfterModuleImport;
611    return;
612  }
613
614  // If we have a non-empty module path, load the named module.
615  if (!ModuleImportPath.empty())
616    (void)TheModuleLoader.loadModule(ModuleImportLoc, ModuleImportPath,
617                                     Module::MacrosVisible,
618                                     /*IsIncludeDirective=*/false);
619}
620
621void Preprocessor::AddCommentHandler(CommentHandler *Handler) {
622  assert(Handler && "NULL comment handler");
623  assert(std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler) ==
624         CommentHandlers.end() && "Comment handler already registered");
625  CommentHandlers.push_back(Handler);
626}
627
628void Preprocessor::RemoveCommentHandler(CommentHandler *Handler) {
629  std::vector<CommentHandler *>::iterator Pos
630  = std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler);
631  assert(Pos != CommentHandlers.end() && "Comment handler not registered");
632  CommentHandlers.erase(Pos);
633}
634
635bool Preprocessor::HandleComment(Token &result, SourceRange Comment) {
636  bool AnyPendingTokens = false;
637  for (std::vector<CommentHandler *>::iterator H = CommentHandlers.begin(),
638       HEnd = CommentHandlers.end();
639       H != HEnd; ++H) {
640    if ((*H)->HandleComment(*this, Comment))
641      AnyPendingTokens = true;
642  }
643  if (!AnyPendingTokens || getCommentRetentionState())
644    return false;
645  Lex(result);
646  return true;
647}
648
649ModuleLoader::~ModuleLoader() { }
650
651CommentHandler::~CommentHandler() { }
652
653CodeCompletionHandler::~CodeCompletionHandler() { }
654
655void Preprocessor::createPreprocessingRecord(
656                                      bool IncludeNestedMacroExpansions) {
657  if (Record)
658    return;
659
660  Record = new PreprocessingRecord(getSourceManager(),
661                                   IncludeNestedMacroExpansions);
662  addPPCallbacks(Record);
663}
664