Preprocessor.cpp revision 1952354bd376062c3ab3d328c0fc6c36530c9309 
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                           bool IncrProcessing)
59  : Diags(&diags), LangOpts(opts), Target(target),FileMgr(Headers.getFileMgr()),
60    SourceMgr(SM), HeaderInfo(Headers), TheModuleLoader(TheModuleLoader),
61    ExternalSource(0), Identifiers(opts, IILookup),
62    IncrementalProcessing(IncrProcessing), CodeComplete(0),
63    CodeCompletionFile(0), CodeCompletionOffset(0), CodeCompletionReached(0),
64    SkipMainFilePreamble(0, true), CurPPLexer(0),
65    CurDirLookup(0), CurLexerKind(CLK_Lexer), Callbacks(0), MacroArgCache(0),
66    Record(0), MIChainHead(0), MICache(0)
67{
68  OwnsHeaderSearch = OwnsHeaders;
69
70  ScratchBuf = new ScratchBuffer(SourceMgr);
71  CounterValue = 0; // __COUNTER__ starts at 0.
72
73  // Clear stats.
74  NumDirectives = NumDefined = NumUndefined = NumPragma = 0;
75  NumIf = NumElse = NumEndif = 0;
76  NumEnteredSourceFiles = 0;
77  NumMacroExpanded = NumFnMacroExpanded = NumBuiltinMacroExpanded = 0;
78  NumFastMacroExpanded = NumTokenPaste = NumFastTokenPaste = 0;
79  MaxIncludeStackDepth = 0;
80  NumSkipped = 0;
81
82  // Default to discarding comments.
83  KeepComments = false;
84  KeepMacroComments = false;
85  SuppressIncludeNotFoundError = false;
86
87  // Macro expansion is enabled.
88  DisableMacroExpansion = false;
89  MacroExpansionInDirectivesOverride = false;
90  InMacroArgs = false;
91  InMacroArgPreExpansion = false;
92  NumCachedTokenLexers = 0;
93  PragmasEnabled = true;
94
95  CachedLexPos = 0;
96
97  // We haven't read anything from the external source.
98  ReadMacrosFromExternalSource = false;
99
100  // "Poison" __VA_ARGS__, which can only appear in the expansion of a macro.
101  // This gets unpoisoned where it is allowed.
102  (Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned();
103  SetPoisonReason(Ident__VA_ARGS__,diag::ext_pp_bad_vaargs_use);
104
105  // Initialize the pragma handlers.
106  PragmaHandlers = new PragmaNamespace(StringRef());
107  RegisterBuiltinPragmas();
108
109  // Initialize builtin macros like __LINE__ and friends.
110  RegisterBuiltinMacros();
111
112  if(LangOpts.Borland) {
113    Ident__exception_info        = getIdentifierInfo("_exception_info");
114    Ident___exception_info       = getIdentifierInfo("__exception_info");
115    Ident_GetExceptionInfo       = getIdentifierInfo("GetExceptionInformation");
116    Ident__exception_code        = getIdentifierInfo("_exception_code");
117    Ident___exception_code       = getIdentifierInfo("__exception_code");
118    Ident_GetExceptionCode       = getIdentifierInfo("GetExceptionCode");
119    Ident__abnormal_termination  = getIdentifierInfo("_abnormal_termination");
120    Ident___abnormal_termination = getIdentifierInfo("__abnormal_termination");
121    Ident_AbnormalTermination    = getIdentifierInfo("AbnormalTermination");
122  } else {
123    Ident__exception_info = Ident__exception_code = Ident__abnormal_termination = 0;
124    Ident___exception_info = Ident___exception_code = Ident___abnormal_termination = 0;
125    Ident_GetExceptionInfo = Ident_GetExceptionCode = Ident_AbnormalTermination = 0;
126  }
127
128  if (!DelayInitialization) {
129    assert(Target && "Must provide target information for PP initialization");
130    Initialize(*Target);
131  }
132}
133
134Preprocessor::~Preprocessor() {
135  assert(BacktrackPositions.empty() && "EnableBacktrack/Backtrack imbalance!");
136
137  while (!IncludeMacroStack.empty()) {
138    delete IncludeMacroStack.back().TheLexer;
139    delete IncludeMacroStack.back().TheTokenLexer;
140    IncludeMacroStack.pop_back();
141  }
142
143  // Free any macro definitions.
144  for (MacroInfoChain *I = MIChainHead ; I ; I = I->Next)
145    I->MI.Destroy();
146
147  // Free any cached macro expanders.
148  for (unsigned i = 0, e = NumCachedTokenLexers; i != e; ++i)
149    delete TokenLexerCache[i];
150
151  // Free any cached MacroArgs.
152  for (MacroArgs *ArgList = MacroArgCache; ArgList; )
153    ArgList = ArgList->deallocate();
154
155  // Release pragma information.
156  delete PragmaHandlers;
157
158  // Delete the scratch buffer info.
159  delete ScratchBuf;
160
161  // Delete the header search info, if we own it.
162  if (OwnsHeaderSearch)
163    delete &HeaderInfo;
164
165  delete Callbacks;
166}
167
168void Preprocessor::Initialize(const TargetInfo &Target) {
169  assert((!this->Target || this->Target == &Target) &&
170         "Invalid override of target information");
171  this->Target = &Target;
172
173  // Initialize information about built-ins.
174  BuiltinInfo.InitializeTarget(Target);
175  HeaderInfo.setTarget(Target);
176}
177
178void Preprocessor::setPTHManager(PTHManager* pm) {
179  PTH.reset(pm);
180  FileMgr.addStatCache(PTH->createStatCache());
181}
182
183void Preprocessor::DumpToken(const Token &Tok, bool DumpFlags) const {
184  llvm::errs() << tok::getTokenName(Tok.getKind()) << " '"
185               << getSpelling(Tok) << "'";
186
187  if (!DumpFlags) return;
188
189  llvm::errs() << "\t";
190  if (Tok.isAtStartOfLine())
191    llvm::errs() << " [StartOfLine]";
192  if (Tok.hasLeadingSpace())
193    llvm::errs() << " [LeadingSpace]";
194  if (Tok.isExpandDisabled())
195    llvm::errs() << " [ExpandDisabled]";
196  if (Tok.needsCleaning()) {
197    const char *Start = SourceMgr.getCharacterData(Tok.getLocation());
198    llvm::errs() << " [UnClean='" << StringRef(Start, Tok.getLength())
199                 << "']";
200  }
201
202  llvm::errs() << "\tLoc=<";
203  DumpLocation(Tok.getLocation());
204  llvm::errs() << ">";
205}
206
207void Preprocessor::DumpLocation(SourceLocation Loc) const {
208  Loc.dump(SourceMgr);
209}
210
211void Preprocessor::DumpMacro(const MacroInfo &MI) const {
212  llvm::errs() << "MACRO: ";
213  for (unsigned i = 0, e = MI.getNumTokens(); i != e; ++i) {
214    DumpToken(MI.getReplacementToken(i));
215    llvm::errs() << "  ";
216  }
217  llvm::errs() << "\n";
218}
219
220void Preprocessor::PrintStats() {
221  llvm::errs() << "\n*** Preprocessor Stats:\n";
222  llvm::errs() << NumDirectives << " directives found:\n";
223  llvm::errs() << "  " << NumDefined << " #define.\n";
224  llvm::errs() << "  " << NumUndefined << " #undef.\n";
225  llvm::errs() << "  #include/#include_next/#import:\n";
226  llvm::errs() << "    " << NumEnteredSourceFiles << " source files entered.\n";
227  llvm::errs() << "    " << MaxIncludeStackDepth << " max include stack depth\n";
228  llvm::errs() << "  " << NumIf << " #if/#ifndef/#ifdef.\n";
229  llvm::errs() << "  " << NumElse << " #else/#elif.\n";
230  llvm::errs() << "  " << NumEndif << " #endif.\n";
231  llvm::errs() << "  " << NumPragma << " #pragma.\n";
232  llvm::errs() << NumSkipped << " #if/#ifndef#ifdef regions skipped\n";
233
234  llvm::errs() << NumMacroExpanded << "/" << NumFnMacroExpanded << "/"
235             << NumBuiltinMacroExpanded << " obj/fn/builtin macros expanded, "
236             << NumFastMacroExpanded << " on the fast path.\n";
237  llvm::errs() << (NumFastTokenPaste+NumTokenPaste)
238             << " token paste (##) operations performed, "
239             << NumFastTokenPaste << " on the fast path.\n";
240
241  llvm::errs() << "\nPreprocessor Memory: " << getTotalMemory() << "B total";
242
243  llvm::errs() << "\n  BumpPtr: " << BP.getTotalMemory();
244  llvm::errs() << "\n  Macro Expanded Tokens: "
245               << llvm::capacity_in_bytes(MacroExpandedTokens);
246  llvm::errs() << "\n  Predefines Buffer: " << Predefines.capacity();
247  llvm::errs() << "\n  Macros: " << llvm::capacity_in_bytes(Macros);
248  llvm::errs() << "\n  #pragma push_macro Info: "
249               << llvm::capacity_in_bytes(PragmaPushMacroInfo);
250  llvm::errs() << "\n  Poison Reasons: "
251               << llvm::capacity_in_bytes(PoisonReasons);
252  llvm::errs() << "\n  Comment Handlers: "
253               << llvm::capacity_in_bytes(CommentHandlers) << "\n";
254}
255
256Preprocessor::macro_iterator
257Preprocessor::macro_begin(bool IncludeExternalMacros) const {
258  if (IncludeExternalMacros && ExternalSource &&
259      !ReadMacrosFromExternalSource) {
260    ReadMacrosFromExternalSource = true;
261    ExternalSource->ReadDefinedMacros();
262  }
263
264  return Macros.begin();
265}
266
267size_t Preprocessor::getTotalMemory() const {
268  return BP.getTotalMemory()
269    + llvm::capacity_in_bytes(MacroExpandedTokens)
270    + Predefines.capacity() /* Predefines buffer. */
271    + llvm::capacity_in_bytes(Macros)
272    + llvm::capacity_in_bytes(PragmaPushMacroInfo)
273    + llvm::capacity_in_bytes(PoisonReasons)
274    + llvm::capacity_in_bytes(CommentHandlers);
275}
276
277Preprocessor::macro_iterator
278Preprocessor::macro_end(bool IncludeExternalMacros) const {
279  if (IncludeExternalMacros && ExternalSource &&
280      !ReadMacrosFromExternalSource) {
281    ReadMacrosFromExternalSource = true;
282    ExternalSource->ReadDefinedMacros();
283  }
284
285  return Macros.end();
286}
287
288/// \brief Compares macro tokens with a specified token value sequence.
289static bool MacroDefinitionEquals(const MacroInfo *MI,
290                                  llvm::ArrayRef<TokenValue> Tokens) {
291  return Tokens.size() == MI->getNumTokens() &&
292      std::equal(Tokens.begin(), Tokens.end(), MI->tokens_begin());
293}
294
295StringRef Preprocessor::getLastMacroWithSpelling(
296                                    SourceLocation Loc,
297                                    ArrayRef<TokenValue> Tokens) const {
298  SourceLocation BestLocation;
299  StringRef BestSpelling;
300  for (Preprocessor::macro_iterator I = macro_begin(), E = macro_end();
301       I != E; ++I) {
302    if (!I->second->isObjectLike())
303      continue;
304    const MacroInfo *MI = I->second->findDefinitionAtLoc(Loc, SourceMgr);
305    if (!MI)
306      continue;
307    if (!MacroDefinitionEquals(MI, Tokens))
308      continue;
309    SourceLocation Location = I->second->getDefinitionLoc();
310    // Choose the macro defined latest.
311    if (BestLocation.isInvalid() ||
312        (Location.isValid() &&
313         SourceMgr.isBeforeInTranslationUnit(BestLocation, Location))) {
314      BestLocation = Location;
315      BestSpelling = I->first->getName();
316    }
317  }
318  return BestSpelling;
319}
320
321void Preprocessor::recomputeCurLexerKind() {
322  if (CurLexer)
323    CurLexerKind = CLK_Lexer;
324  else if (CurPTHLexer)
325    CurLexerKind = CLK_PTHLexer;
326  else if (CurTokenLexer)
327    CurLexerKind = CLK_TokenLexer;
328  else
329    CurLexerKind = CLK_CachingLexer;
330}
331
332bool Preprocessor::SetCodeCompletionPoint(const FileEntry *File,
333                                          unsigned CompleteLine,
334                                          unsigned CompleteColumn) {
335  assert(File);
336  assert(CompleteLine && CompleteColumn && "Starts from 1:1");
337  assert(!CodeCompletionFile && "Already set");
338
339  using llvm::MemoryBuffer;
340
341  // Load the actual file's contents.
342  bool Invalid = false;
343  const MemoryBuffer *Buffer = SourceMgr.getMemoryBufferForFile(File, &Invalid);
344  if (Invalid)
345    return true;
346
347  // Find the byte position of the truncation point.
348  const char *Position = Buffer->getBufferStart();
349  for (unsigned Line = 1; Line < CompleteLine; ++Line) {
350    for (; *Position; ++Position) {
351      if (*Position != '\r' && *Position != '\n')
352        continue;
353
354      // Eat \r\n or \n\r as a single line.
355      if ((Position[1] == '\r' || Position[1] == '\n') &&
356          Position[0] != Position[1])
357        ++Position;
358      ++Position;
359      break;
360    }
361  }
362
363  Position += CompleteColumn - 1;
364
365  // Insert '\0' at the code-completion point.
366  if (Position < Buffer->getBufferEnd()) {
367    CodeCompletionFile = File;
368    CodeCompletionOffset = Position - Buffer->getBufferStart();
369
370    MemoryBuffer *NewBuffer =
371        MemoryBuffer::getNewUninitMemBuffer(Buffer->getBufferSize() + 1,
372                                            Buffer->getBufferIdentifier());
373    char *NewBuf = const_cast<char*>(NewBuffer->getBufferStart());
374    char *NewPos = std::copy(Buffer->getBufferStart(), Position, NewBuf);
375    *NewPos = '\0';
376    std::copy(Position, Buffer->getBufferEnd(), NewPos+1);
377    SourceMgr.overrideFileContents(File, NewBuffer);
378  }
379
380  return false;
381}
382
383void Preprocessor::CodeCompleteNaturalLanguage() {
384  if (CodeComplete)
385    CodeComplete->CodeCompleteNaturalLanguage();
386  setCodeCompletionReached();
387}
388
389/// getSpelling - This method is used to get the spelling of a token into a
390/// SmallVector. Note that the returned StringRef may not point to the
391/// supplied buffer if a copy can be avoided.
392StringRef Preprocessor::getSpelling(const Token &Tok,
393                                          SmallVectorImpl<char> &Buffer,
394                                          bool *Invalid) const {
395  // NOTE: this has to be checked *before* testing for an IdentifierInfo.
396  if (Tok.isNot(tok::raw_identifier)) {
397    // Try the fast path.
398    if (const IdentifierInfo *II = Tok.getIdentifierInfo())
399      return II->getName();
400  }
401
402  // Resize the buffer if we need to copy into it.
403  if (Tok.needsCleaning())
404    Buffer.resize(Tok.getLength());
405
406  const char *Ptr = Buffer.data();
407  unsigned Len = getSpelling(Tok, Ptr, Invalid);
408  return StringRef(Ptr, Len);
409}
410
411/// CreateString - Plop the specified string into a scratch buffer and return a
412/// location for it.  If specified, the source location provides a source
413/// location for the token.
414void Preprocessor::CreateString(StringRef Str, Token &Tok,
415                                SourceLocation ExpansionLocStart,
416                                SourceLocation ExpansionLocEnd) {
417  Tok.setLength(Str.size());
418
419  const char *DestPtr;
420  SourceLocation Loc = ScratchBuf->getToken(Str.data(), Str.size(), DestPtr);
421
422  if (ExpansionLocStart.isValid())
423    Loc = SourceMgr.createExpansionLoc(Loc, ExpansionLocStart,
424                                       ExpansionLocEnd, Str.size());
425  Tok.setLocation(Loc);
426
427  // If this is a raw identifier or a literal token, set the pointer data.
428  if (Tok.is(tok::raw_identifier))
429    Tok.setRawIdentifierData(DestPtr);
430  else if (Tok.isLiteral())
431    Tok.setLiteralData(DestPtr);
432}
433
434Module *Preprocessor::getCurrentModule() {
435  if (getLangOpts().CurrentModule.empty())
436    return 0;
437
438  return getHeaderSearchInfo().lookupModule(getLangOpts().CurrentModule);
439}
440
441//===----------------------------------------------------------------------===//
442// Preprocessor Initialization Methods
443//===----------------------------------------------------------------------===//
444
445
446/// EnterMainSourceFile - Enter the specified FileID as the main source file,
447/// which implicitly adds the builtin defines etc.
448void Preprocessor::EnterMainSourceFile() {
449  // We do not allow the preprocessor to reenter the main file.  Doing so will
450  // cause FileID's to accumulate information from both runs (e.g. #line
451  // information) and predefined macros aren't guaranteed to be set properly.
452  assert(NumEnteredSourceFiles == 0 && "Cannot reenter the main file!");
453  FileID MainFileID = SourceMgr.getMainFileID();
454
455  // If MainFileID is loaded it means we loaded an AST file, no need to enter
456  // a main file.
457  if (!SourceMgr.isLoadedFileID(MainFileID)) {
458    // Enter the main file source buffer.
459    EnterSourceFile(MainFileID, 0, SourceLocation());
460
461    // If we've been asked to skip bytes in the main file (e.g., as part of a
462    // precompiled preamble), do so now.
463    if (SkipMainFilePreamble.first > 0)
464      CurLexer->SkipBytes(SkipMainFilePreamble.first,
465                          SkipMainFilePreamble.second);
466
467    // Tell the header info that the main file was entered.  If the file is later
468    // #imported, it won't be re-entered.
469    if (const FileEntry *FE = SourceMgr.getFileEntryForID(MainFileID))
470      HeaderInfo.IncrementIncludeCount(FE);
471  }
472
473  // Preprocess Predefines to populate the initial preprocessor state.
474  llvm::MemoryBuffer *SB =
475    llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
476  assert(SB && "Cannot create predefined source buffer");
477  FileID FID = SourceMgr.createFileIDForMemBuffer(SB);
478  assert(!FID.isInvalid() && "Could not create FileID for predefines?");
479
480  // Start parsing the predefines.
481  EnterSourceFile(FID, 0, SourceLocation());
482}
483
484void Preprocessor::EndSourceFile() {
485  // Notify the client that we reached the end of the source file.
486  if (Callbacks)
487    Callbacks->EndOfMainFile();
488}
489
490//===----------------------------------------------------------------------===//
491// Lexer Event Handling.
492//===----------------------------------------------------------------------===//
493
494/// LookUpIdentifierInfo - Given a tok::raw_identifier token, look up the
495/// identifier information for the token and install it into the token,
496/// updating the token kind accordingly.
497IdentifierInfo *Preprocessor::LookUpIdentifierInfo(Token &Identifier) const {
498  assert(Identifier.getRawIdentifierData() != 0 && "No raw identifier data!");
499
500  // Look up this token, see if it is a macro, or if it is a language keyword.
501  IdentifierInfo *II;
502  if (!Identifier.needsCleaning()) {
503    // No cleaning needed, just use the characters from the lexed buffer.
504    II = getIdentifierInfo(StringRef(Identifier.getRawIdentifierData(),
505                                           Identifier.getLength()));
506  } else {
507    // Cleaning needed, alloca a buffer, clean into it, then use the buffer.
508    SmallString<64> IdentifierBuffer;
509    StringRef CleanedStr = getSpelling(Identifier, IdentifierBuffer);
510    II = getIdentifierInfo(CleanedStr);
511  }
512
513  // Update the token info (identifier info and appropriate token kind).
514  Identifier.setIdentifierInfo(II);
515  Identifier.setKind(II->getTokenID());
516
517  return II;
518}
519
520void Preprocessor::SetPoisonReason(IdentifierInfo *II, unsigned DiagID) {
521  PoisonReasons[II] = DiagID;
522}
523
524void Preprocessor::PoisonSEHIdentifiers(bool Poison) {
525  assert(Ident__exception_code && Ident__exception_info);
526  assert(Ident___exception_code && Ident___exception_info);
527  Ident__exception_code->setIsPoisoned(Poison);
528  Ident___exception_code->setIsPoisoned(Poison);
529  Ident_GetExceptionCode->setIsPoisoned(Poison);
530  Ident__exception_info->setIsPoisoned(Poison);
531  Ident___exception_info->setIsPoisoned(Poison);
532  Ident_GetExceptionInfo->setIsPoisoned(Poison);
533  Ident__abnormal_termination->setIsPoisoned(Poison);
534  Ident___abnormal_termination->setIsPoisoned(Poison);
535  Ident_AbnormalTermination->setIsPoisoned(Poison);
536}
537
538void Preprocessor::HandlePoisonedIdentifier(Token & Identifier) {
539  assert(Identifier.getIdentifierInfo() &&
540         "Can't handle identifiers without identifier info!");
541  llvm::DenseMap<IdentifierInfo*,unsigned>::const_iterator it =
542    PoisonReasons.find(Identifier.getIdentifierInfo());
543  if(it == PoisonReasons.end())
544    Diag(Identifier, diag::err_pp_used_poisoned_id);
545  else
546    Diag(Identifier,it->second) << Identifier.getIdentifierInfo();
547}
548
549/// HandleIdentifier - This callback is invoked when the lexer reads an
550/// identifier.  This callback looks up the identifier in the map and/or
551/// potentially macro expands it or turns it into a named token (like 'for').
552///
553/// Note that callers of this method are guarded by checking the
554/// IdentifierInfo's 'isHandleIdentifierCase' bit.  If this method changes, the
555/// IdentifierInfo methods that compute these properties will need to change to
556/// match.
557void Preprocessor::HandleIdentifier(Token &Identifier) {
558  assert(Identifier.getIdentifierInfo() &&
559         "Can't handle identifiers without identifier info!");
560
561  IdentifierInfo &II = *Identifier.getIdentifierInfo();
562
563  // If the information about this identifier is out of date, update it from
564  // the external source.
565  // We have to treat __VA_ARGS__ in a special way, since it gets
566  // serialized with isPoisoned = true, but our preprocessor may have
567  // unpoisoned it if we're defining a C99 macro.
568  if (II.isOutOfDate()) {
569    bool CurrentIsPoisoned = false;
570    if (&II == Ident__VA_ARGS__)
571      CurrentIsPoisoned = Ident__VA_ARGS__->isPoisoned();
572
573    ExternalSource->updateOutOfDateIdentifier(II);
574    Identifier.setKind(II.getTokenID());
575
576    if (&II == Ident__VA_ARGS__)
577      II.setIsPoisoned(CurrentIsPoisoned);
578  }
579
580  // If this identifier was poisoned, and if it was not produced from a macro
581  // expansion, emit an error.
582  if (II.isPoisoned() && CurPPLexer) {
583    HandlePoisonedIdentifier(Identifier);
584  }
585
586  // If this is a macro to be expanded, do it.
587  if (MacroInfo *MI = getMacroInfo(&II)) {
588    if (!DisableMacroExpansion) {
589      if (Identifier.isExpandDisabled()) {
590        Diag(Identifier, diag::pp_disabled_macro_expansion);
591      } else if (MI->isEnabled()) {
592        if (!HandleMacroExpandedIdentifier(Identifier, MI))
593          return;
594      } else {
595        // C99 6.10.3.4p2 says that a disabled macro may never again be
596        // expanded, even if it's in a context where it could be expanded in the
597        // future.
598        Identifier.setFlag(Token::DisableExpand);
599        Diag(Identifier, diag::pp_disabled_macro_expansion);
600      }
601    }
602  }
603
604  // If this identifier is a keyword in C++11, produce a warning. Don't warn if
605  // we're not considering macro expansion, since this identifier might be the
606  // name of a macro.
607  // FIXME: This warning is disabled in cases where it shouldn't be, like
608  //   "#define constexpr constexpr", "int constexpr;"
609  if (II.isCXX11CompatKeyword() & !DisableMacroExpansion) {
610    Diag(Identifier, diag::warn_cxx11_keyword) << II.getName();
611    // Don't diagnose this keyword again in this translation unit.
612    II.setIsCXX11CompatKeyword(false);
613  }
614
615  // C++ 2.11p2: If this is an alternative representation of a C++ operator,
616  // then we act as if it is the actual operator and not the textual
617  // representation of it.
618  if (II.isCPlusPlusOperatorKeyword())
619    Identifier.setIdentifierInfo(0);
620
621  // If this is an extension token, diagnose its use.
622  // We avoid diagnosing tokens that originate from macro definitions.
623  // FIXME: This warning is disabled in cases where it shouldn't be,
624  // like "#define TY typeof", "TY(1) x".
625  if (II.isExtensionToken() && !DisableMacroExpansion)
626    Diag(Identifier, diag::ext_token_used);
627
628  // If this is the '__experimental_modules_import' contextual keyword, note
629  // that the next token indicates a module name.
630  //
631  // Note that we do not treat '__experimental_modules_import' as a contextual
632  // keyword when we're in a caching lexer, because caching lexers only get
633  // used in contexts where import declarations are disallowed.
634  if (II.isModulesImport() && !InMacroArgs && !DisableMacroExpansion &&
635      getLangOpts().Modules && CurLexerKind != CLK_CachingLexer) {
636    ModuleImportLoc = Identifier.getLocation();
637    ModuleImportPath.clear();
638    ModuleImportExpectsIdentifier = true;
639    CurLexerKind = CLK_LexAfterModuleImport;
640  }
641}
642
643/// \brief Lex a token following the 'import' contextual keyword.
644///
645void Preprocessor::LexAfterModuleImport(Token &Result) {
646  // Figure out what kind of lexer we actually have.
647  recomputeCurLexerKind();
648
649  // Lex the next token.
650  Lex(Result);
651
652  // The token sequence
653  //
654  //   import identifier (. identifier)*
655  //
656  // indicates a module import directive. We already saw the 'import'
657  // contextual keyword, so now we're looking for the identifiers.
658  if (ModuleImportExpectsIdentifier && Result.getKind() == tok::identifier) {
659    // We expected to see an identifier here, and we did; continue handling
660    // identifiers.
661    ModuleImportPath.push_back(std::make_pair(Result.getIdentifierInfo(),
662                                              Result.getLocation()));
663    ModuleImportExpectsIdentifier = false;
664    CurLexerKind = CLK_LexAfterModuleImport;
665    return;
666  }
667
668  // If we're expecting a '.' or a ';', and we got a '.', then wait until we
669  // see the next identifier.
670  if (!ModuleImportExpectsIdentifier && Result.getKind() == tok::period) {
671    ModuleImportExpectsIdentifier = true;
672    CurLexerKind = CLK_LexAfterModuleImport;
673    return;
674  }
675
676  // If we have a non-empty module path, load the named module.
677  if (!ModuleImportPath.empty()) {
678    Module *Imported = TheModuleLoader.loadModule(ModuleImportLoc,
679                                                  ModuleImportPath,
680                                                  Module::MacrosVisible,
681                                                  /*IsIncludeDirective=*/false);
682    if (Callbacks)
683      Callbacks->moduleImport(ModuleImportLoc, ModuleImportPath, Imported);
684  }
685}
686
687void Preprocessor::addCommentHandler(CommentHandler *Handler) {
688  assert(Handler && "NULL comment handler");
689  assert(std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler) ==
690         CommentHandlers.end() && "Comment handler already registered");
691  CommentHandlers.push_back(Handler);
692}
693
694void Preprocessor::removeCommentHandler(CommentHandler *Handler) {
695  std::vector<CommentHandler *>::iterator Pos
696  = std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler);
697  assert(Pos != CommentHandlers.end() && "Comment handler not registered");
698  CommentHandlers.erase(Pos);
699}
700
701bool Preprocessor::HandleComment(Token &result, SourceRange Comment) {
702  bool AnyPendingTokens = false;
703  for (std::vector<CommentHandler *>::iterator H = CommentHandlers.begin(),
704       HEnd = CommentHandlers.end();
705       H != HEnd; ++H) {
706    if ((*H)->HandleComment(*this, Comment))
707      AnyPendingTokens = true;
708  }
709  if (!AnyPendingTokens || getCommentRetentionState())
710    return false;
711  Lex(result);
712  return true;
713}
714
715ModuleLoader::~ModuleLoader() { }
716
717CommentHandler::~CommentHandler() { }
718
719CodeCompletionHandler::~CodeCompletionHandler() { }
720
721void Preprocessor::createPreprocessingRecord(bool RecordConditionalDirectives) {
722  if (Record)
723    return;
724
725  Record = new PreprocessingRecord(getSourceManager(),
726                                   RecordConditionalDirectives);
727  addPPCallbacks(Record);
728}
729