Preprocessor.cpp revision e1d4330adaaa7faf093e725c9c993207eb2d778a 
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/SmallString.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  HeaderInfo.setTarget(Target);
173}
174
175void Preprocessor::setPTHManager(PTHManager* pm) {
176  PTH.reset(pm);
177  FileMgr.addStatCache(PTH->createStatCache());
178}
179
180void Preprocessor::DumpToken(const Token &Tok, bool DumpFlags) const {
181  llvm::errs() << tok::getTokenName(Tok.getKind()) << " '"
182               << getSpelling(Tok) << "'";
183
184  if (!DumpFlags) return;
185
186  llvm::errs() << "\t";
187  if (Tok.isAtStartOfLine())
188    llvm::errs() << " [StartOfLine]";
189  if (Tok.hasLeadingSpace())
190    llvm::errs() << " [LeadingSpace]";
191  if (Tok.isExpandDisabled())
192    llvm::errs() << " [ExpandDisabled]";
193  if (Tok.needsCleaning()) {
194    const char *Start = SourceMgr.getCharacterData(Tok.getLocation());
195    llvm::errs() << " [UnClean='" << StringRef(Start, Tok.getLength())
196                 << "']";
197  }
198
199  llvm::errs() << "\tLoc=<";
200  DumpLocation(Tok.getLocation());
201  llvm::errs() << ">";
202}
203
204void Preprocessor::DumpLocation(SourceLocation Loc) const {
205  Loc.dump(SourceMgr);
206}
207
208void Preprocessor::DumpMacro(const MacroInfo &MI) const {
209  llvm::errs() << "MACRO: ";
210  for (unsigned i = 0, e = MI.getNumTokens(); i != e; ++i) {
211    DumpToken(MI.getReplacementToken(i));
212    llvm::errs() << "  ";
213  }
214  llvm::errs() << "\n";
215}
216
217void Preprocessor::PrintStats() {
218  llvm::errs() << "\n*** Preprocessor Stats:\n";
219  llvm::errs() << NumDirectives << " directives found:\n";
220  llvm::errs() << "  " << NumDefined << " #define.\n";
221  llvm::errs() << "  " << NumUndefined << " #undef.\n";
222  llvm::errs() << "  #include/#include_next/#import:\n";
223  llvm::errs() << "    " << NumEnteredSourceFiles << " source files entered.\n";
224  llvm::errs() << "    " << MaxIncludeStackDepth << " max include stack depth\n";
225  llvm::errs() << "  " << NumIf << " #if/#ifndef/#ifdef.\n";
226  llvm::errs() << "  " << NumElse << " #else/#elif.\n";
227  llvm::errs() << "  " << NumEndif << " #endif.\n";
228  llvm::errs() << "  " << NumPragma << " #pragma.\n";
229  llvm::errs() << NumSkipped << " #if/#ifndef#ifdef regions skipped\n";
230
231  llvm::errs() << NumMacroExpanded << "/" << NumFnMacroExpanded << "/"
232             << NumBuiltinMacroExpanded << " obj/fn/builtin macros expanded, "
233             << NumFastMacroExpanded << " on the fast path.\n";
234  llvm::errs() << (NumFastTokenPaste+NumTokenPaste)
235             << " token paste (##) operations performed, "
236             << NumFastTokenPaste << " on the fast path.\n";
237}
238
239Preprocessor::macro_iterator
240Preprocessor::macro_begin(bool IncludeExternalMacros) const {
241  if (IncludeExternalMacros && ExternalSource &&
242      !ReadMacrosFromExternalSource) {
243    ReadMacrosFromExternalSource = true;
244    ExternalSource->ReadDefinedMacros();
245  }
246
247  return Macros.begin();
248}
249
250size_t Preprocessor::getTotalMemory() const {
251  return BP.getTotalMemory()
252    + llvm::capacity_in_bytes(MacroExpandedTokens)
253    + Predefines.capacity() /* Predefines buffer. */
254    + llvm::capacity_in_bytes(Macros)
255    + llvm::capacity_in_bytes(PragmaPushMacroInfo)
256    + llvm::capacity_in_bytes(PoisonReasons)
257    + llvm::capacity_in_bytes(CommentHandlers);
258}
259
260Preprocessor::macro_iterator
261Preprocessor::macro_end(bool IncludeExternalMacros) const {
262  if (IncludeExternalMacros && ExternalSource &&
263      !ReadMacrosFromExternalSource) {
264    ReadMacrosFromExternalSource = true;
265    ExternalSource->ReadDefinedMacros();
266  }
267
268  return Macros.end();
269}
270
271void Preprocessor::recomputeCurLexerKind() {
272  if (CurLexer)
273    CurLexerKind = CLK_Lexer;
274  else if (CurPTHLexer)
275    CurLexerKind = CLK_PTHLexer;
276  else if (CurTokenLexer)
277    CurLexerKind = CLK_TokenLexer;
278  else
279    CurLexerKind = CLK_CachingLexer;
280}
281
282bool Preprocessor::SetCodeCompletionPoint(const FileEntry *File,
283                                          unsigned CompleteLine,
284                                          unsigned CompleteColumn) {
285  assert(File);
286  assert(CompleteLine && CompleteColumn && "Starts from 1:1");
287  assert(!CodeCompletionFile && "Already set");
288
289  using llvm::MemoryBuffer;
290
291  // Load the actual file's contents.
292  bool Invalid = false;
293  const MemoryBuffer *Buffer = SourceMgr.getMemoryBufferForFile(File, &Invalid);
294  if (Invalid)
295    return true;
296
297  // Find the byte position of the truncation point.
298  const char *Position = Buffer->getBufferStart();
299  for (unsigned Line = 1; Line < CompleteLine; ++Line) {
300    for (; *Position; ++Position) {
301      if (*Position != '\r' && *Position != '\n')
302        continue;
303
304      // Eat \r\n or \n\r as a single line.
305      if ((Position[1] == '\r' || Position[1] == '\n') &&
306          Position[0] != Position[1])
307        ++Position;
308      ++Position;
309      break;
310    }
311  }
312
313  Position += CompleteColumn - 1;
314
315  // Insert '\0' at the code-completion point.
316  if (Position < Buffer->getBufferEnd()) {
317    CodeCompletionFile = File;
318    CodeCompletionOffset = Position - Buffer->getBufferStart();
319
320    MemoryBuffer *NewBuffer =
321        MemoryBuffer::getNewUninitMemBuffer(Buffer->getBufferSize() + 1,
322                                            Buffer->getBufferIdentifier());
323    char *NewBuf = const_cast<char*>(NewBuffer->getBufferStart());
324    char *NewPos = std::copy(Buffer->getBufferStart(), Position, NewBuf);
325    *NewPos = '\0';
326    std::copy(Position, Buffer->getBufferEnd(), NewPos+1);
327    SourceMgr.overrideFileContents(File, NewBuffer);
328  }
329
330  return false;
331}
332
333void Preprocessor::CodeCompleteNaturalLanguage() {
334  if (CodeComplete)
335    CodeComplete->CodeCompleteNaturalLanguage();
336  setCodeCompletionReached();
337}
338
339/// getSpelling - This method is used to get the spelling of a token into a
340/// SmallVector. Note that the returned StringRef may not point to the
341/// supplied buffer if a copy can be avoided.
342StringRef Preprocessor::getSpelling(const Token &Tok,
343                                          SmallVectorImpl<char> &Buffer,
344                                          bool *Invalid) const {
345  // NOTE: this has to be checked *before* testing for an IdentifierInfo.
346  if (Tok.isNot(tok::raw_identifier)) {
347    // Try the fast path.
348    if (const IdentifierInfo *II = Tok.getIdentifierInfo())
349      return II->getName();
350  }
351
352  // Resize the buffer if we need to copy into it.
353  if (Tok.needsCleaning())
354    Buffer.resize(Tok.getLength());
355
356  const char *Ptr = Buffer.data();
357  unsigned Len = getSpelling(Tok, Ptr, Invalid);
358  return StringRef(Ptr, Len);
359}
360
361/// CreateString - Plop the specified string into a scratch buffer and return a
362/// location for it.  If specified, the source location provides a source
363/// location for the token.
364void Preprocessor::CreateString(const char *Buf, unsigned Len, Token &Tok,
365                                SourceLocation ExpansionLocStart,
366                                SourceLocation ExpansionLocEnd) {
367  Tok.setLength(Len);
368
369  const char *DestPtr;
370  SourceLocation Loc = ScratchBuf->getToken(Buf, Len, DestPtr);
371
372  if (ExpansionLocStart.isValid())
373    Loc = SourceMgr.createExpansionLoc(Loc, ExpansionLocStart,
374                                       ExpansionLocEnd, Len);
375  Tok.setLocation(Loc);
376
377  // If this is a raw identifier or a literal token, set the pointer data.
378  if (Tok.is(tok::raw_identifier))
379    Tok.setRawIdentifierData(DestPtr);
380  else if (Tok.isLiteral())
381    Tok.setLiteralData(DestPtr);
382}
383
384Module *Preprocessor::getCurrentModule() {
385  if (getLangOptions().CurrentModule.empty())
386    return 0;
387
388  return getHeaderSearchInfo().lookupModule(getLangOptions().CurrentModule);
389}
390
391//===----------------------------------------------------------------------===//
392// Preprocessor Initialization Methods
393//===----------------------------------------------------------------------===//
394
395
396/// EnterMainSourceFile - Enter the specified FileID as the main source file,
397/// which implicitly adds the builtin defines etc.
398void Preprocessor::EnterMainSourceFile() {
399  // We do not allow the preprocessor to reenter the main file.  Doing so will
400  // cause FileID's to accumulate information from both runs (e.g. #line
401  // information) and predefined macros aren't guaranteed to be set properly.
402  assert(NumEnteredSourceFiles == 0 && "Cannot reenter the main file!");
403  FileID MainFileID = SourceMgr.getMainFileID();
404
405  // If MainFileID is loaded it means we loaded an AST file, no need to enter
406  // a main file.
407  if (!SourceMgr.isLoadedFileID(MainFileID)) {
408    // Enter the main file source buffer.
409    EnterSourceFile(MainFileID, 0, SourceLocation());
410
411    // If we've been asked to skip bytes in the main file (e.g., as part of a
412    // precompiled preamble), do so now.
413    if (SkipMainFilePreamble.first > 0)
414      CurLexer->SkipBytes(SkipMainFilePreamble.first,
415                          SkipMainFilePreamble.second);
416
417    // Tell the header info that the main file was entered.  If the file is later
418    // #imported, it won't be re-entered.
419    if (const FileEntry *FE = SourceMgr.getFileEntryForID(MainFileID))
420      HeaderInfo.IncrementIncludeCount(FE);
421  }
422
423  // Preprocess Predefines to populate the initial preprocessor state.
424  llvm::MemoryBuffer *SB =
425    llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
426  assert(SB && "Cannot create predefined source buffer");
427  FileID FID = SourceMgr.createFileIDForMemBuffer(SB);
428  assert(!FID.isInvalid() && "Could not create FileID for predefines?");
429
430  // Start parsing the predefines.
431  EnterSourceFile(FID, 0, SourceLocation());
432}
433
434void Preprocessor::EndSourceFile() {
435  // Notify the client that we reached the end of the source file.
436  if (Callbacks)
437    Callbacks->EndOfMainFile();
438}
439
440//===----------------------------------------------------------------------===//
441// Lexer Event Handling.
442//===----------------------------------------------------------------------===//
443
444/// LookUpIdentifierInfo - Given a tok::raw_identifier token, look up the
445/// identifier information for the token and install it into the token,
446/// updating the token kind accordingly.
447IdentifierInfo *Preprocessor::LookUpIdentifierInfo(Token &Identifier) const {
448  assert(Identifier.getRawIdentifierData() != 0 && "No raw identifier data!");
449
450  // Look up this token, see if it is a macro, or if it is a language keyword.
451  IdentifierInfo *II;
452  if (!Identifier.needsCleaning()) {
453    // No cleaning needed, just use the characters from the lexed buffer.
454    II = getIdentifierInfo(StringRef(Identifier.getRawIdentifierData(),
455                                           Identifier.getLength()));
456  } else {
457    // Cleaning needed, alloca a buffer, clean into it, then use the buffer.
458    SmallString<64> IdentifierBuffer;
459    StringRef CleanedStr = getSpelling(Identifier, IdentifierBuffer);
460    II = getIdentifierInfo(CleanedStr);
461  }
462
463  // Update the token info (identifier info and appropriate token kind).
464  Identifier.setIdentifierInfo(II);
465  Identifier.setKind(II->getTokenID());
466
467  return II;
468}
469
470void Preprocessor::SetPoisonReason(IdentifierInfo *II, unsigned DiagID) {
471  PoisonReasons[II] = DiagID;
472}
473
474void Preprocessor::PoisonSEHIdentifiers(bool Poison) {
475  assert(Ident__exception_code && Ident__exception_info);
476  assert(Ident___exception_code && Ident___exception_info);
477  Ident__exception_code->setIsPoisoned(Poison);
478  Ident___exception_code->setIsPoisoned(Poison);
479  Ident_GetExceptionCode->setIsPoisoned(Poison);
480  Ident__exception_info->setIsPoisoned(Poison);
481  Ident___exception_info->setIsPoisoned(Poison);
482  Ident_GetExceptionInfo->setIsPoisoned(Poison);
483  Ident__abnormal_termination->setIsPoisoned(Poison);
484  Ident___abnormal_termination->setIsPoisoned(Poison);
485  Ident_AbnormalTermination->setIsPoisoned(Poison);
486}
487
488void Preprocessor::HandlePoisonedIdentifier(Token & Identifier) {
489  assert(Identifier.getIdentifierInfo() &&
490         "Can't handle identifiers without identifier info!");
491  llvm::DenseMap<IdentifierInfo*,unsigned>::const_iterator it =
492    PoisonReasons.find(Identifier.getIdentifierInfo());
493  if(it == PoisonReasons.end())
494    Diag(Identifier, diag::err_pp_used_poisoned_id);
495  else
496    Diag(Identifier,it->second) << Identifier.getIdentifierInfo();
497}
498
499/// HandleIdentifier - This callback is invoked when the lexer reads an
500/// identifier.  This callback looks up the identifier in the map and/or
501/// potentially macro expands it or turns it into a named token (like 'for').
502///
503/// Note that callers of this method are guarded by checking the
504/// IdentifierInfo's 'isHandleIdentifierCase' bit.  If this method changes, the
505/// IdentifierInfo methods that compute these properties will need to change to
506/// match.
507void Preprocessor::HandleIdentifier(Token &Identifier) {
508  assert(Identifier.getIdentifierInfo() &&
509         "Can't handle identifiers without identifier info!");
510
511  IdentifierInfo &II = *Identifier.getIdentifierInfo();
512
513  // If the information about this identifier is out of date, update it from
514  // the external source.
515  if (II.isOutOfDate()) {
516    ExternalSource->updateOutOfDateIdentifier(II);
517    Identifier.setKind(II.getTokenID());
518  }
519
520  // If this identifier was poisoned, and if it was not produced from a macro
521  // expansion, emit an error.
522  if (II.isPoisoned() && CurPPLexer) {
523    HandlePoisonedIdentifier(Identifier);
524  }
525
526  // If this is a macro to be expanded, do it.
527  if (MacroInfo *MI = getMacroInfo(&II)) {
528    if (!DisableMacroExpansion) {
529      if (Identifier.isExpandDisabled()) {
530        Diag(Identifier, diag::pp_disabled_macro_expansion);
531      } else if (MI->isEnabled()) {
532        if (!HandleMacroExpandedIdentifier(Identifier, MI))
533          return;
534      } else {
535        // C99 6.10.3.4p2 says that a disabled macro may never again be
536        // expanded, even if it's in a context where it could be expanded in the
537        // future.
538        Identifier.setFlag(Token::DisableExpand);
539        Diag(Identifier, diag::pp_disabled_macro_expansion);
540      }
541    }
542  }
543
544  // If this identifier is a keyword in C++11, produce a warning. Don't warn if
545  // we're not considering macro expansion, since this identifier might be the
546  // name of a macro.
547  // FIXME: This warning is disabled in cases where it shouldn't be, like
548  //   "#define constexpr constexpr", "int constexpr;"
549  if (II.isCXX11CompatKeyword() & !DisableMacroExpansion) {
550    Diag(Identifier, diag::warn_cxx11_keyword) << II.getName();
551    // Don't diagnose this keyword again in this translation unit.
552    II.setIsCXX11CompatKeyword(false);
553  }
554
555  // C++ 2.11p2: If this is an alternative representation of a C++ operator,
556  // then we act as if it is the actual operator and not the textual
557  // representation of it.
558  if (II.isCPlusPlusOperatorKeyword())
559    Identifier.setIdentifierInfo(0);
560
561  // If this is an extension token, diagnose its use.
562  // We avoid diagnosing tokens that originate from macro definitions.
563  // FIXME: This warning is disabled in cases where it shouldn't be,
564  // like "#define TY typeof", "TY(1) x".
565  if (II.isExtensionToken() && !DisableMacroExpansion)
566    Diag(Identifier, diag::ext_token_used);
567
568  // If this is the 'import' contextual keyword, note that the next token
569  // indicates a module name.
570  //
571  // Note that we do not treat 'import' as a contextual keyword when we're
572  // in a caching lexer, because caching lexers only get used in contexts where
573  // import declarations are disallowed.
574  if (II.isImport() && !InMacroArgs && !DisableMacroExpansion &&
575      getLangOptions().Modules && CurLexerKind != CLK_CachingLexer) {
576    ModuleImportLoc = Identifier.getLocation();
577    ModuleImportPath.clear();
578    ModuleImportExpectsIdentifier = true;
579    CurLexerKind = CLK_LexAfterModuleImport;
580  }
581}
582
583/// \brief Lex a token following the 'import' contextual keyword.
584///
585void Preprocessor::LexAfterModuleImport(Token &Result) {
586  // Figure out what kind of lexer we actually have.
587  recomputeCurLexerKind();
588
589  // Lex the next token.
590  Lex(Result);
591
592  // The token sequence
593  //
594  //   import identifier (. identifier)*
595  //
596  // indicates a module import directive. We already saw the 'import'
597  // contextual keyword, so now we're looking for the identifiers.
598  if (ModuleImportExpectsIdentifier && Result.getKind() == tok::identifier) {
599    // We expected to see an identifier here, and we did; continue handling
600    // identifiers.
601    ModuleImportPath.push_back(std::make_pair(Result.getIdentifierInfo(),
602                                              Result.getLocation()));
603    ModuleImportExpectsIdentifier = false;
604    CurLexerKind = CLK_LexAfterModuleImport;
605    return;
606  }
607
608  // If we're expecting a '.' or a ';', and we got a '.', then wait until we
609  // see the next identifier.
610  if (!ModuleImportExpectsIdentifier && Result.getKind() == tok::period) {
611    ModuleImportExpectsIdentifier = true;
612    CurLexerKind = CLK_LexAfterModuleImport;
613    return;
614  }
615
616  // If we have a non-empty module path, load the named module.
617  if (!ModuleImportPath.empty())
618    (void)TheModuleLoader.loadModule(ModuleImportLoc, ModuleImportPath,
619                                     Module::MacrosVisible,
620                                     /*IsIncludeDirective=*/false);
621}
622
623void Preprocessor::AddCommentHandler(CommentHandler *Handler) {
624  assert(Handler && "NULL comment handler");
625  assert(std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler) ==
626         CommentHandlers.end() && "Comment handler already registered");
627  CommentHandlers.push_back(Handler);
628}
629
630void Preprocessor::RemoveCommentHandler(CommentHandler *Handler) {
631  std::vector<CommentHandler *>::iterator Pos
632  = std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler);
633  assert(Pos != CommentHandlers.end() && "Comment handler not registered");
634  CommentHandlers.erase(Pos);
635}
636
637bool Preprocessor::HandleComment(Token &result, SourceRange Comment) {
638  bool AnyPendingTokens = false;
639  for (std::vector<CommentHandler *>::iterator H = CommentHandlers.begin(),
640       HEnd = CommentHandlers.end();
641       H != HEnd; ++H) {
642    if ((*H)->HandleComment(*this, Comment))
643      AnyPendingTokens = true;
644  }
645  if (!AnyPendingTokens || getCommentRetentionState())
646    return false;
647  Lex(result);
648  return true;
649}
650
651ModuleLoader::~ModuleLoader() { }
652
653CommentHandler::~CommentHandler() { }
654
655CodeCompletionHandler::~CodeCompletionHandler() { }
656
657void Preprocessor::createPreprocessingRecord() {
658  if (Record)
659    return;
660
661  Record = new PreprocessingRecord(getSourceManager());
662  addPPCallbacks(Record);
663}
664