Preprocessor.cpp revision cfa88f893915ceb8ae4ce2f17c46c24a4d67502f 
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/Basic/FileManager.h"
31#include "clang/Basic/SourceManager.h"
32#include "clang/Basic/TargetInfo.h"
33#include "clang/Lex/CodeCompletionHandler.h"
34#include "clang/Lex/ExternalPreprocessorSource.h"
35#include "clang/Lex/HeaderSearch.h"
36#include "clang/Lex/LexDiagnostic.h"
37#include "clang/Lex/LiteralSupport.h"
38#include "clang/Lex/MacroInfo.h"
39#include "clang/Lex/ModuleLoader.h"
40#include "clang/Lex/Pragma.h"
41#include "clang/Lex/PreprocessingRecord.h"
42#include "clang/Lex/PreprocessorOptions.h"
43#include "clang/Lex/ScratchBuffer.h"
44#include "llvm/ADT/APFloat.h"
45#include "llvm/ADT/SmallString.h"
46#include "llvm/Support/Capacity.h"
47#include "llvm/Support/MemoryBuffer.h"
48#include "llvm/Support/raw_ostream.h"
49using namespace clang;
50
51//===----------------------------------------------------------------------===//
52ExternalPreprocessorSource::~ExternalPreprocessorSource() { }
53
54PPMutationListener::~PPMutationListener() { }
55
56Preprocessor::Preprocessor(IntrusiveRefCntPtr<PreprocessorOptions> PPOpts,
57                           DiagnosticsEngine &diags, LangOptions &opts,
58                           const TargetInfo *target, SourceManager &SM,
59                           HeaderSearch &Headers, ModuleLoader &TheModuleLoader,
60                           IdentifierInfoLookup* IILookup,
61                           bool OwnsHeaders,
62                           bool DelayInitialization,
63                           bool IncrProcessing)
64  : PPOpts(PPOpts), Diags(&diags), LangOpts(opts), Target(target),
65    FileMgr(Headers.getFileMgr()),
66    SourceMgr(SM), HeaderInfo(Headers), TheModuleLoader(TheModuleLoader),
67    ExternalSource(0), Identifiers(opts, IILookup),
68    IncrementalProcessing(IncrProcessing), CodeComplete(0),
69    CodeCompletionFile(0), CodeCompletionOffset(0), CodeCompletionReached(0),
70    SkipMainFilePreamble(0, true), CurPPLexer(0),
71    CurDirLookup(0), CurLexerKind(CLK_Lexer), Callbacks(0), Listener(0),
72    MacroArgCache(0), Record(0), MIChainHead(0), MICache(0)
73{
74  OwnsHeaderSearch = OwnsHeaders;
75
76  ScratchBuf = new ScratchBuffer(SourceMgr);
77  CounterValue = 0; // __COUNTER__ starts at 0.
78
79  // Clear stats.
80  NumDirectives = NumDefined = NumUndefined = NumPragma = 0;
81  NumIf = NumElse = NumEndif = 0;
82  NumEnteredSourceFiles = 0;
83  NumMacroExpanded = NumFnMacroExpanded = NumBuiltinMacroExpanded = 0;
84  NumFastMacroExpanded = NumTokenPaste = NumFastTokenPaste = 0;
85  MaxIncludeStackDepth = 0;
86  NumSkipped = 0;
87
88  // Default to discarding comments.
89  KeepComments = false;
90  KeepMacroComments = false;
91  SuppressIncludeNotFoundError = false;
92
93  // Macro expansion is enabled.
94  DisableMacroExpansion = false;
95  MacroExpansionInDirectivesOverride = false;
96  InMacroArgs = false;
97  InMacroArgPreExpansion = false;
98  NumCachedTokenLexers = 0;
99  PragmasEnabled = true;
100
101  CachedLexPos = 0;
102
103  // We haven't read anything from the external source.
104  ReadMacrosFromExternalSource = false;
105
106  // "Poison" __VA_ARGS__, which can only appear in the expansion of a macro.
107  // This gets unpoisoned where it is allowed.
108  (Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned();
109  SetPoisonReason(Ident__VA_ARGS__,diag::ext_pp_bad_vaargs_use);
110
111  // Initialize the pragma handlers.
112  PragmaHandlers = new PragmaNamespace(StringRef());
113  RegisterBuiltinPragmas();
114
115  // Initialize builtin macros like __LINE__ and friends.
116  RegisterBuiltinMacros();
117
118  if(LangOpts.Borland) {
119    Ident__exception_info        = getIdentifierInfo("_exception_info");
120    Ident___exception_info       = getIdentifierInfo("__exception_info");
121    Ident_GetExceptionInfo       = getIdentifierInfo("GetExceptionInformation");
122    Ident__exception_code        = getIdentifierInfo("_exception_code");
123    Ident___exception_code       = getIdentifierInfo("__exception_code");
124    Ident_GetExceptionCode       = getIdentifierInfo("GetExceptionCode");
125    Ident__abnormal_termination  = getIdentifierInfo("_abnormal_termination");
126    Ident___abnormal_termination = getIdentifierInfo("__abnormal_termination");
127    Ident_AbnormalTermination    = getIdentifierInfo("AbnormalTermination");
128  } else {
129    Ident__exception_info = Ident__exception_code = Ident__abnormal_termination = 0;
130    Ident___exception_info = Ident___exception_code = Ident___abnormal_termination = 0;
131    Ident_GetExceptionInfo = Ident_GetExceptionCode = Ident_AbnormalTermination = 0;
132  }
133
134  if (!DelayInitialization) {
135    assert(Target && "Must provide target information for PP initialization");
136    Initialize(*Target);
137  }
138}
139
140Preprocessor::~Preprocessor() {
141  assert(BacktrackPositions.empty() && "EnableBacktrack/Backtrack imbalance!");
142
143  while (!IncludeMacroStack.empty()) {
144    delete IncludeMacroStack.back().TheLexer;
145    delete IncludeMacroStack.back().TheTokenLexer;
146    IncludeMacroStack.pop_back();
147  }
148
149  // Free any macro definitions.
150  for (MacroInfoChain *I = MIChainHead ; I ; I = I->Next)
151    I->MI.Destroy();
152
153  // Free any cached macro expanders.
154  for (unsigned i = 0, e = NumCachedTokenLexers; i != e; ++i)
155    delete TokenLexerCache[i];
156
157  // Free any cached MacroArgs.
158  for (MacroArgs *ArgList = MacroArgCache; ArgList; )
159    ArgList = ArgList->deallocate();
160
161  // Release pragma information.
162  delete PragmaHandlers;
163
164  // Delete the scratch buffer info.
165  delete ScratchBuf;
166
167  // Delete the header search info, if we own it.
168  if (OwnsHeaderSearch)
169    delete &HeaderInfo;
170
171  delete Callbacks;
172}
173
174void Preprocessor::Initialize(const TargetInfo &Target) {
175  assert((!this->Target || this->Target == &Target) &&
176         "Invalid override of target information");
177  this->Target = &Target;
178
179  // Initialize information about built-ins.
180  BuiltinInfo.InitializeTarget(Target);
181  HeaderInfo.setTarget(Target);
182}
183
184void Preprocessor::setPTHManager(PTHManager* pm) {
185  PTH.reset(pm);
186  FileMgr.addStatCache(PTH->createStatCache());
187}
188
189void Preprocessor::DumpToken(const Token &Tok, bool DumpFlags) const {
190  llvm::errs() << tok::getTokenName(Tok.getKind()) << " '"
191               << getSpelling(Tok) << "'";
192
193  if (!DumpFlags) return;
194
195  llvm::errs() << "\t";
196  if (Tok.isAtStartOfLine())
197    llvm::errs() << " [StartOfLine]";
198  if (Tok.hasLeadingSpace())
199    llvm::errs() << " [LeadingSpace]";
200  if (Tok.isExpandDisabled())
201    llvm::errs() << " [ExpandDisabled]";
202  if (Tok.needsCleaning()) {
203    const char *Start = SourceMgr.getCharacterData(Tok.getLocation());
204    llvm::errs() << " [UnClean='" << StringRef(Start, Tok.getLength())
205                 << "']";
206  }
207
208  llvm::errs() << "\tLoc=<";
209  DumpLocation(Tok.getLocation());
210  llvm::errs() << ">";
211}
212
213void Preprocessor::DumpLocation(SourceLocation Loc) const {
214  Loc.dump(SourceMgr);
215}
216
217void Preprocessor::DumpMacro(const MacroInfo &MI) const {
218  llvm::errs() << "MACRO: ";
219  for (unsigned i = 0, e = MI.getNumTokens(); i != e; ++i) {
220    DumpToken(MI.getReplacementToken(i));
221    llvm::errs() << "  ";
222  }
223  llvm::errs() << "\n";
224}
225
226void Preprocessor::PrintStats() {
227  llvm::errs() << "\n*** Preprocessor Stats:\n";
228  llvm::errs() << NumDirectives << " directives found:\n";
229  llvm::errs() << "  " << NumDefined << " #define.\n";
230  llvm::errs() << "  " << NumUndefined << " #undef.\n";
231  llvm::errs() << "  #include/#include_next/#import:\n";
232  llvm::errs() << "    " << NumEnteredSourceFiles << " source files entered.\n";
233  llvm::errs() << "    " << MaxIncludeStackDepth << " max include stack depth\n";
234  llvm::errs() << "  " << NumIf << " #if/#ifndef/#ifdef.\n";
235  llvm::errs() << "  " << NumElse << " #else/#elif.\n";
236  llvm::errs() << "  " << NumEndif << " #endif.\n";
237  llvm::errs() << "  " << NumPragma << " #pragma.\n";
238  llvm::errs() << NumSkipped << " #if/#ifndef#ifdef regions skipped\n";
239
240  llvm::errs() << NumMacroExpanded << "/" << NumFnMacroExpanded << "/"
241             << NumBuiltinMacroExpanded << " obj/fn/builtin macros expanded, "
242             << NumFastMacroExpanded << " on the fast path.\n";
243  llvm::errs() << (NumFastTokenPaste+NumTokenPaste)
244             << " token paste (##) operations performed, "
245             << NumFastTokenPaste << " on the fast path.\n";
246
247  llvm::errs() << "\nPreprocessor Memory: " << getTotalMemory() << "B total";
248
249  llvm::errs() << "\n  BumpPtr: " << BP.getTotalMemory();
250  llvm::errs() << "\n  Macro Expanded Tokens: "
251               << llvm::capacity_in_bytes(MacroExpandedTokens);
252  llvm::errs() << "\n  Predefines Buffer: " << Predefines.capacity();
253  llvm::errs() << "\n  Macros: " << llvm::capacity_in_bytes(Macros);
254  llvm::errs() << "\n  #pragma push_macro Info: "
255               << llvm::capacity_in_bytes(PragmaPushMacroInfo);
256  llvm::errs() << "\n  Poison Reasons: "
257               << llvm::capacity_in_bytes(PoisonReasons);
258  llvm::errs() << "\n  Comment Handlers: "
259               << llvm::capacity_in_bytes(CommentHandlers) << "\n";
260}
261
262Preprocessor::macro_iterator
263Preprocessor::macro_begin(bool IncludeExternalMacros) const {
264  if (IncludeExternalMacros && ExternalSource &&
265      !ReadMacrosFromExternalSource) {
266    ReadMacrosFromExternalSource = true;
267    ExternalSource->ReadDefinedMacros();
268  }
269
270  return Macros.begin();
271}
272
273size_t Preprocessor::getTotalMemory() const {
274  return BP.getTotalMemory()
275    + llvm::capacity_in_bytes(MacroExpandedTokens)
276    + Predefines.capacity() /* Predefines buffer. */
277    + llvm::capacity_in_bytes(Macros)
278    + llvm::capacity_in_bytes(PragmaPushMacroInfo)
279    + llvm::capacity_in_bytes(PoisonReasons)
280    + llvm::capacity_in_bytes(CommentHandlers);
281}
282
283Preprocessor::macro_iterator
284Preprocessor::macro_end(bool IncludeExternalMacros) const {
285  if (IncludeExternalMacros && ExternalSource &&
286      !ReadMacrosFromExternalSource) {
287    ReadMacrosFromExternalSource = true;
288    ExternalSource->ReadDefinedMacros();
289  }
290
291  return Macros.end();
292}
293
294/// \brief Compares macro tokens with a specified token value sequence.
295static bool MacroDefinitionEquals(const MacroInfo *MI,
296                                  ArrayRef<TokenValue> Tokens) {
297  return Tokens.size() == MI->getNumTokens() &&
298      std::equal(Tokens.begin(), Tokens.end(), MI->tokens_begin());
299}
300
301StringRef Preprocessor::getLastMacroWithSpelling(
302                                    SourceLocation Loc,
303                                    ArrayRef<TokenValue> Tokens) const {
304  SourceLocation BestLocation;
305  StringRef BestSpelling;
306  for (Preprocessor::macro_iterator I = macro_begin(), E = macro_end();
307       I != E; ++I) {
308    if (!I->second->isObjectLike())
309      continue;
310    const MacroInfo *MI = I->second->findDefinitionAtLoc(Loc, SourceMgr);
311    if (!MI)
312      continue;
313    if (!MacroDefinitionEquals(MI, Tokens))
314      continue;
315    SourceLocation Location = I->second->getDefinitionLoc();
316    // Choose the macro defined latest.
317    if (BestLocation.isInvalid() ||
318        (Location.isValid() &&
319         SourceMgr.isBeforeInTranslationUnit(BestLocation, Location))) {
320      BestLocation = Location;
321      BestSpelling = I->first->getName();
322    }
323  }
324  return BestSpelling;
325}
326
327void Preprocessor::recomputeCurLexerKind() {
328  if (CurLexer)
329    CurLexerKind = CLK_Lexer;
330  else if (CurPTHLexer)
331    CurLexerKind = CLK_PTHLexer;
332  else if (CurTokenLexer)
333    CurLexerKind = CLK_TokenLexer;
334  else
335    CurLexerKind = CLK_CachingLexer;
336}
337
338bool Preprocessor::SetCodeCompletionPoint(const FileEntry *File,
339                                          unsigned CompleteLine,
340                                          unsigned CompleteColumn) {
341  assert(File);
342  assert(CompleteLine && CompleteColumn && "Starts from 1:1");
343  assert(!CodeCompletionFile && "Already set");
344
345  using llvm::MemoryBuffer;
346
347  // Load the actual file's contents.
348  bool Invalid = false;
349  const MemoryBuffer *Buffer = SourceMgr.getMemoryBufferForFile(File, &Invalid);
350  if (Invalid)
351    return true;
352
353  // Find the byte position of the truncation point.
354  const char *Position = Buffer->getBufferStart();
355  for (unsigned Line = 1; Line < CompleteLine; ++Line) {
356    for (; *Position; ++Position) {
357      if (*Position != '\r' && *Position != '\n')
358        continue;
359
360      // Eat \r\n or \n\r as a single line.
361      if ((Position[1] == '\r' || Position[1] == '\n') &&
362          Position[0] != Position[1])
363        ++Position;
364      ++Position;
365      break;
366    }
367  }
368
369  Position += CompleteColumn - 1;
370
371  // Insert '\0' at the code-completion point.
372  if (Position < Buffer->getBufferEnd()) {
373    CodeCompletionFile = File;
374    CodeCompletionOffset = Position - Buffer->getBufferStart();
375
376    MemoryBuffer *NewBuffer =
377        MemoryBuffer::getNewUninitMemBuffer(Buffer->getBufferSize() + 1,
378                                            Buffer->getBufferIdentifier());
379    char *NewBuf = const_cast<char*>(NewBuffer->getBufferStart());
380    char *NewPos = std::copy(Buffer->getBufferStart(), Position, NewBuf);
381    *NewPos = '\0';
382    std::copy(Position, Buffer->getBufferEnd(), NewPos+1);
383    SourceMgr.overrideFileContents(File, NewBuffer);
384  }
385
386  return false;
387}
388
389void Preprocessor::CodeCompleteNaturalLanguage() {
390  if (CodeComplete)
391    CodeComplete->CodeCompleteNaturalLanguage();
392  setCodeCompletionReached();
393}
394
395/// getSpelling - This method is used to get the spelling of a token into a
396/// SmallVector. Note that the returned StringRef may not point to the
397/// supplied buffer if a copy can be avoided.
398StringRef Preprocessor::getSpelling(const Token &Tok,
399                                          SmallVectorImpl<char> &Buffer,
400                                          bool *Invalid) const {
401  // NOTE: this has to be checked *before* testing for an IdentifierInfo.
402  if (Tok.isNot(tok::raw_identifier)) {
403    // Try the fast path.
404    if (const IdentifierInfo *II = Tok.getIdentifierInfo())
405      return II->getName();
406  }
407
408  // Resize the buffer if we need to copy into it.
409  if (Tok.needsCleaning())
410    Buffer.resize(Tok.getLength());
411
412  const char *Ptr = Buffer.data();
413  unsigned Len = getSpelling(Tok, Ptr, Invalid);
414  return StringRef(Ptr, Len);
415}
416
417/// CreateString - Plop the specified string into a scratch buffer and return a
418/// location for it.  If specified, the source location provides a source
419/// location for the token.
420void Preprocessor::CreateString(StringRef Str, Token &Tok,
421                                SourceLocation ExpansionLocStart,
422                                SourceLocation ExpansionLocEnd) {
423  Tok.setLength(Str.size());
424
425  const char *DestPtr;
426  SourceLocation Loc = ScratchBuf->getToken(Str.data(), Str.size(), DestPtr);
427
428  if (ExpansionLocStart.isValid())
429    Loc = SourceMgr.createExpansionLoc(Loc, ExpansionLocStart,
430                                       ExpansionLocEnd, Str.size());
431  Tok.setLocation(Loc);
432
433  // If this is a raw identifier or a literal token, set the pointer data.
434  if (Tok.is(tok::raw_identifier))
435    Tok.setRawIdentifierData(DestPtr);
436  else if (Tok.isLiteral())
437    Tok.setLiteralData(DestPtr);
438}
439
440Module *Preprocessor::getCurrentModule() {
441  if (getLangOpts().CurrentModule.empty())
442    return 0;
443
444  return getHeaderSearchInfo().lookupModule(getLangOpts().CurrentModule);
445}
446
447//===----------------------------------------------------------------------===//
448// Preprocessor Initialization Methods
449//===----------------------------------------------------------------------===//
450
451
452/// EnterMainSourceFile - Enter the specified FileID as the main source file,
453/// which implicitly adds the builtin defines etc.
454void Preprocessor::EnterMainSourceFile() {
455  // We do not allow the preprocessor to reenter the main file.  Doing so will
456  // cause FileID's to accumulate information from both runs (e.g. #line
457  // information) and predefined macros aren't guaranteed to be set properly.
458  assert(NumEnteredSourceFiles == 0 && "Cannot reenter the main file!");
459  FileID MainFileID = SourceMgr.getMainFileID();
460
461  // If MainFileID is loaded it means we loaded an AST file, no need to enter
462  // a main file.
463  if (!SourceMgr.isLoadedFileID(MainFileID)) {
464    // Enter the main file source buffer.
465    EnterSourceFile(MainFileID, 0, SourceLocation());
466
467    // If we've been asked to skip bytes in the main file (e.g., as part of a
468    // precompiled preamble), do so now.
469    if (SkipMainFilePreamble.first > 0)
470      CurLexer->SkipBytes(SkipMainFilePreamble.first,
471                          SkipMainFilePreamble.second);
472
473    // Tell the header info that the main file was entered.  If the file is later
474    // #imported, it won't be re-entered.
475    if (const FileEntry *FE = SourceMgr.getFileEntryForID(MainFileID))
476      HeaderInfo.IncrementIncludeCount(FE);
477  }
478
479  // Preprocess Predefines to populate the initial preprocessor state.
480  llvm::MemoryBuffer *SB =
481    llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
482  assert(SB && "Cannot create predefined source buffer");
483  FileID FID = SourceMgr.createFileIDForMemBuffer(SB);
484  assert(!FID.isInvalid() && "Could not create FileID for predefines?");
485
486  // Start parsing the predefines.
487  EnterSourceFile(FID, 0, SourceLocation());
488}
489
490void Preprocessor::EndSourceFile() {
491  // Notify the client that we reached the end of the source file.
492  if (Callbacks)
493    Callbacks->EndOfMainFile();
494}
495
496//===----------------------------------------------------------------------===//
497// Lexer Event Handling.
498//===----------------------------------------------------------------------===//
499
500/// LookUpIdentifierInfo - Given a tok::raw_identifier token, look up the
501/// identifier information for the token and install it into the token,
502/// updating the token kind accordingly.
503IdentifierInfo *Preprocessor::LookUpIdentifierInfo(Token &Identifier) const {
504  assert(Identifier.getRawIdentifierData() != 0 && "No raw identifier data!");
505
506  // Look up this token, see if it is a macro, or if it is a language keyword.
507  IdentifierInfo *II;
508  if (!Identifier.needsCleaning()) {
509    // No cleaning needed, just use the characters from the lexed buffer.
510    II = getIdentifierInfo(StringRef(Identifier.getRawIdentifierData(),
511                                           Identifier.getLength()));
512  } else {
513    // Cleaning needed, alloca a buffer, clean into it, then use the buffer.
514    SmallString<64> IdentifierBuffer;
515    StringRef CleanedStr = getSpelling(Identifier, IdentifierBuffer);
516    II = getIdentifierInfo(CleanedStr);
517  }
518
519  // Update the token info (identifier info and appropriate token kind).
520  Identifier.setIdentifierInfo(II);
521  Identifier.setKind(II->getTokenID());
522
523  return II;
524}
525
526void Preprocessor::SetPoisonReason(IdentifierInfo *II, unsigned DiagID) {
527  PoisonReasons[II] = DiagID;
528}
529
530void Preprocessor::PoisonSEHIdentifiers(bool Poison) {
531  assert(Ident__exception_code && Ident__exception_info);
532  assert(Ident___exception_code && Ident___exception_info);
533  Ident__exception_code->setIsPoisoned(Poison);
534  Ident___exception_code->setIsPoisoned(Poison);
535  Ident_GetExceptionCode->setIsPoisoned(Poison);
536  Ident__exception_info->setIsPoisoned(Poison);
537  Ident___exception_info->setIsPoisoned(Poison);
538  Ident_GetExceptionInfo->setIsPoisoned(Poison);
539  Ident__abnormal_termination->setIsPoisoned(Poison);
540  Ident___abnormal_termination->setIsPoisoned(Poison);
541  Ident_AbnormalTermination->setIsPoisoned(Poison);
542}
543
544void Preprocessor::HandlePoisonedIdentifier(Token & Identifier) {
545  assert(Identifier.getIdentifierInfo() &&
546         "Can't handle identifiers without identifier info!");
547  llvm::DenseMap<IdentifierInfo*,unsigned>::const_iterator it =
548    PoisonReasons.find(Identifier.getIdentifierInfo());
549  if(it == PoisonReasons.end())
550    Diag(Identifier, diag::err_pp_used_poisoned_id);
551  else
552    Diag(Identifier,it->second) << Identifier.getIdentifierInfo();
553}
554
555/// HandleIdentifier - This callback is invoked when the lexer reads an
556/// identifier.  This callback looks up the identifier in the map and/or
557/// potentially macro expands it or turns it into a named token (like 'for').
558///
559/// Note that callers of this method are guarded by checking the
560/// IdentifierInfo's 'isHandleIdentifierCase' bit.  If this method changes, the
561/// IdentifierInfo methods that compute these properties will need to change to
562/// match.
563void Preprocessor::HandleIdentifier(Token &Identifier) {
564  assert(Identifier.getIdentifierInfo() &&
565         "Can't handle identifiers without identifier info!");
566
567  IdentifierInfo &II = *Identifier.getIdentifierInfo();
568
569  // If the information about this identifier is out of date, update it from
570  // the external source.
571  // We have to treat __VA_ARGS__ in a special way, since it gets
572  // serialized with isPoisoned = true, but our preprocessor may have
573  // unpoisoned it if we're defining a C99 macro.
574  if (II.isOutOfDate()) {
575    bool CurrentIsPoisoned = false;
576    if (&II == Ident__VA_ARGS__)
577      CurrentIsPoisoned = Ident__VA_ARGS__->isPoisoned();
578
579    ExternalSource->updateOutOfDateIdentifier(II);
580    Identifier.setKind(II.getTokenID());
581
582    if (&II == Ident__VA_ARGS__)
583      II.setIsPoisoned(CurrentIsPoisoned);
584  }
585
586  // If this identifier was poisoned, and if it was not produced from a macro
587  // expansion, emit an error.
588  if (II.isPoisoned() && CurPPLexer) {
589    HandlePoisonedIdentifier(Identifier);
590  }
591
592  // If this is a macro to be expanded, do it.
593  if (MacroInfo *MI = getMacroInfo(&II)) {
594    if (!DisableMacroExpansion) {
595      if (!Identifier.isExpandDisabled() && MI->isEnabled()) {
596        if (!HandleMacroExpandedIdentifier(Identifier, MI))
597          return;
598      } else {
599        // C99 6.10.3.4p2 says that a disabled macro may never again be
600        // expanded, even if it's in a context where it could be expanded in the
601        // future.
602        Identifier.setFlag(Token::DisableExpand);
603        if (MI->isObjectLike() || isNextPPTokenLParen())
604          Diag(Identifier, diag::pp_disabled_macro_expansion);
605      }
606    }
607  }
608
609  // If this identifier is a keyword in C++11, produce a warning. Don't warn if
610  // we're not considering macro expansion, since this identifier might be the
611  // name of a macro.
612  // FIXME: This warning is disabled in cases where it shouldn't be, like
613  //   "#define constexpr constexpr", "int constexpr;"
614  if (II.isCXX11CompatKeyword() & !DisableMacroExpansion) {
615    Diag(Identifier, diag::warn_cxx11_keyword) << II.getName();
616    // Don't diagnose this keyword again in this translation unit.
617    II.setIsCXX11CompatKeyword(false);
618  }
619
620  // C++ 2.11p2: If this is an alternative representation of a C++ operator,
621  // then we act as if it is the actual operator and not the textual
622  // representation of it.
623  if (II.isCPlusPlusOperatorKeyword())
624    Identifier.setIdentifierInfo(0);
625
626  // If this is an extension token, diagnose its use.
627  // We avoid diagnosing tokens that originate from macro definitions.
628  // FIXME: This warning is disabled in cases where it shouldn't be,
629  // like "#define TY typeof", "TY(1) x".
630  if (II.isExtensionToken() && !DisableMacroExpansion)
631    Diag(Identifier, diag::ext_token_used);
632
633  // If this is the 'import' contextual keyword, note
634  // that the next token indicates a module name.
635  //
636  // Note that we do not treat 'import' as a contextual
637  // keyword when we're in a caching lexer, because caching lexers only get
638  // used in contexts where import declarations are disallowed.
639  if (II.isModulesImport() && !InMacroArgs && !DisableMacroExpansion &&
640      getLangOpts().Modules && CurLexerKind != CLK_CachingLexer) {
641    ModuleImportLoc = Identifier.getLocation();
642    ModuleImportPath.clear();
643    ModuleImportExpectsIdentifier = true;
644    CurLexerKind = CLK_LexAfterModuleImport;
645  }
646}
647
648/// \brief Lex a token following the 'import' contextual keyword.
649///
650void Preprocessor::LexAfterModuleImport(Token &Result) {
651  // Figure out what kind of lexer we actually have.
652  recomputeCurLexerKind();
653
654  // Lex the next token.
655  Lex(Result);
656
657  // The token sequence
658  //
659  //   import identifier (. identifier)*
660  //
661  // indicates a module import directive. We already saw the 'import'
662  // contextual keyword, so now we're looking for the identifiers.
663  if (ModuleImportExpectsIdentifier && Result.getKind() == tok::identifier) {
664    // We expected to see an identifier here, and we did; continue handling
665    // identifiers.
666    ModuleImportPath.push_back(std::make_pair(Result.getIdentifierInfo(),
667                                              Result.getLocation()));
668    ModuleImportExpectsIdentifier = false;
669    CurLexerKind = CLK_LexAfterModuleImport;
670    return;
671  }
672
673  // If we're expecting a '.' or a ';', and we got a '.', then wait until we
674  // see the next identifier.
675  if (!ModuleImportExpectsIdentifier && Result.getKind() == tok::period) {
676    ModuleImportExpectsIdentifier = true;
677    CurLexerKind = CLK_LexAfterModuleImport;
678    return;
679  }
680
681  // If we have a non-empty module path, load the named module.
682  if (!ModuleImportPath.empty()) {
683    Module *Imported = TheModuleLoader.loadModule(ModuleImportLoc,
684                                                  ModuleImportPath,
685                                                  Module::MacrosVisible,
686                                                  /*IsIncludeDirective=*/false);
687    if (Callbacks)
688      Callbacks->moduleImport(ModuleImportLoc, ModuleImportPath, Imported);
689  }
690}
691
692bool Preprocessor::FinishLexStringLiteral(Token &Result, std::string &String,
693                                          const char *DiagnosticTag,
694                                          bool AllowMacroExpansion) {
695  // We need at least one string literal.
696  if (Result.isNot(tok::string_literal)) {
697    Diag(Result, diag::err_expected_string_literal)
698      << /*Source='in...'*/0 << DiagnosticTag;
699    return false;
700  }
701
702  // Lex string literal tokens, optionally with macro expansion.
703  SmallVector<Token, 4> StrToks;
704  do {
705    StrToks.push_back(Result);
706
707    if (Result.hasUDSuffix())
708      Diag(Result, diag::err_invalid_string_udl);
709
710    if (AllowMacroExpansion)
711      Lex(Result);
712    else
713      LexUnexpandedToken(Result);
714  } while (Result.is(tok::string_literal));
715
716  // Concatenate and parse the strings.
717  StringLiteralParser Literal(&StrToks[0], StrToks.size(), *this);
718  assert(Literal.isAscii() && "Didn't allow wide strings in");
719
720  if (Literal.hadError)
721    return false;
722
723  if (Literal.Pascal) {
724    Diag(StrToks[0].getLocation(), diag::err_expected_string_literal)
725      << /*Source='in...'*/0 << DiagnosticTag;
726    return false;
727  }
728
729  String = Literal.GetString();
730  return true;
731}
732
733void Preprocessor::addCommentHandler(CommentHandler *Handler) {
734  assert(Handler && "NULL comment handler");
735  assert(std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler) ==
736         CommentHandlers.end() && "Comment handler already registered");
737  CommentHandlers.push_back(Handler);
738}
739
740void Preprocessor::removeCommentHandler(CommentHandler *Handler) {
741  std::vector<CommentHandler *>::iterator Pos
742  = std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler);
743  assert(Pos != CommentHandlers.end() && "Comment handler not registered");
744  CommentHandlers.erase(Pos);
745}
746
747bool Preprocessor::HandleComment(Token &result, SourceRange Comment) {
748  bool AnyPendingTokens = false;
749  for (std::vector<CommentHandler *>::iterator H = CommentHandlers.begin(),
750       HEnd = CommentHandlers.end();
751       H != HEnd; ++H) {
752    if ((*H)->HandleComment(*this, Comment))
753      AnyPendingTokens = true;
754  }
755  if (!AnyPendingTokens || getCommentRetentionState())
756    return false;
757  Lex(result);
758  return true;
759}
760
761ModuleLoader::~ModuleLoader() { }
762
763CommentHandler::~CommentHandler() { }
764
765CodeCompletionHandler::~CodeCompletionHandler() { }
766
767void Preprocessor::createPreprocessingRecord() {
768  if (Record)
769    return;
770
771  Record = new PreprocessingRecord(getSourceManager());
772  addPPCallbacks(Record);
773}
774