PrintPreprocessedOutput.cpp revision 243830 
1//===--- PrintPreprocessedOutput.cpp - Implement the -E mode --------------===//
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 code simply runs the preprocessor on the input file and prints out the
11// result.  This is the traditional behavior of the -E option.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Frontend/Utils.h"
16#include "clang/Basic/Diagnostic.h"
17#include "clang/Basic/SourceManager.h"
18#include "clang/Frontend/PreprocessorOutputOptions.h"
19#include "clang/Lex/MacroInfo.h"
20#include "clang/Lex/PPCallbacks.h"
21#include "clang/Lex/Pragma.h"
22#include "clang/Lex/Preprocessor.h"
23#include "clang/Lex/TokenConcatenation.h"
24#include "llvm/ADT/SmallString.h"
25#include "llvm/ADT/STLExtras.h"
26#include "llvm/ADT/StringRef.h"
27#include "llvm/Support/raw_ostream.h"
28#include "llvm/Support/ErrorHandling.h"
29#include <cctype>
30#include <cstdio>
31using namespace clang;
32
33/// PrintMacroDefinition - Print a macro definition in a form that will be
34/// properly accepted back as a definition.
35static void PrintMacroDefinition(const IdentifierInfo &II, const MacroInfo &MI,
36                                 Preprocessor &PP, raw_ostream &OS) {
37  OS << "#define " << II.getName();
38
39  if (MI.isFunctionLike()) {
40    OS << '(';
41    if (!MI.arg_empty()) {
42      MacroInfo::arg_iterator AI = MI.arg_begin(), E = MI.arg_end();
43      for (; AI+1 != E; ++AI) {
44        OS << (*AI)->getName();
45        OS << ',';
46      }
47
48      // Last argument.
49      if ((*AI)->getName() == "__VA_ARGS__")
50        OS << "...";
51      else
52        OS << (*AI)->getName();
53    }
54
55    if (MI.isGNUVarargs())
56      OS << "...";  // #define foo(x...)
57
58    OS << ')';
59  }
60
61  // GCC always emits a space, even if the macro body is empty.  However, do not
62  // want to emit two spaces if the first token has a leading space.
63  if (MI.tokens_empty() || !MI.tokens_begin()->hasLeadingSpace())
64    OS << ' ';
65
66  SmallString<128> SpellingBuffer;
67  for (MacroInfo::tokens_iterator I = MI.tokens_begin(), E = MI.tokens_end();
68       I != E; ++I) {
69    if (I->hasLeadingSpace())
70      OS << ' ';
71
72    OS << PP.getSpelling(*I, SpellingBuffer);
73  }
74}
75
76//===----------------------------------------------------------------------===//
77// Preprocessed token printer
78//===----------------------------------------------------------------------===//
79
80namespace {
81class PrintPPOutputPPCallbacks : public PPCallbacks {
82  Preprocessor &PP;
83  SourceManager &SM;
84  TokenConcatenation ConcatInfo;
85public:
86  raw_ostream &OS;
87private:
88  unsigned CurLine;
89
90  bool EmittedTokensOnThisLine;
91  bool EmittedDirectiveOnThisLine;
92  SrcMgr::CharacteristicKind FileType;
93  SmallString<512> CurFilename;
94  bool Initialized;
95  bool DisableLineMarkers;
96  bool DumpDefines;
97  bool UseLineDirective;
98public:
99  PrintPPOutputPPCallbacks(Preprocessor &pp, raw_ostream &os,
100                           bool lineMarkers, bool defines)
101     : PP(pp), SM(PP.getSourceManager()),
102       ConcatInfo(PP), OS(os), DisableLineMarkers(lineMarkers),
103       DumpDefines(defines) {
104    CurLine = 0;
105    CurFilename += "<uninit>";
106    EmittedTokensOnThisLine = false;
107    EmittedDirectiveOnThisLine = false;
108    FileType = SrcMgr::C_User;
109    Initialized = false;
110
111    // If we're in microsoft mode, use normal #line instead of line markers.
112    UseLineDirective = PP.getLangOpts().MicrosoftExt;
113  }
114
115  void setEmittedTokensOnThisLine() { EmittedTokensOnThisLine = true; }
116  bool hasEmittedTokensOnThisLine() const { return EmittedTokensOnThisLine; }
117
118  void setEmittedDirectiveOnThisLine() { EmittedDirectiveOnThisLine = true; }
119  bool hasEmittedDirectiveOnThisLine() const {
120    return EmittedDirectiveOnThisLine;
121  }
122
123  bool startNewLineIfNeeded(bool ShouldUpdateCurrentLine = true);
124
125  virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
126                           SrcMgr::CharacteristicKind FileType,
127                           FileID PrevFID);
128  virtual void Ident(SourceLocation Loc, const std::string &str);
129  virtual void PragmaComment(SourceLocation Loc, const IdentifierInfo *Kind,
130                             const std::string &Str);
131  virtual void PragmaMessage(SourceLocation Loc, StringRef Str);
132  virtual void PragmaDiagnosticPush(SourceLocation Loc,
133                                    StringRef Namespace);
134  virtual void PragmaDiagnosticPop(SourceLocation Loc,
135                                   StringRef Namespace);
136  virtual void PragmaDiagnostic(SourceLocation Loc, StringRef Namespace,
137                                diag::Mapping Map, StringRef Str);
138
139  bool HandleFirstTokOnLine(Token &Tok);
140  bool MoveToLine(SourceLocation Loc) {
141    PresumedLoc PLoc = SM.getPresumedLoc(Loc);
142    if (PLoc.isInvalid())
143      return false;
144    return MoveToLine(PLoc.getLine());
145  }
146  bool MoveToLine(unsigned LineNo);
147
148  bool AvoidConcat(const Token &PrevPrevTok, const Token &PrevTok,
149                   const Token &Tok) {
150    return ConcatInfo.AvoidConcat(PrevPrevTok, PrevTok, Tok);
151  }
152  void WriteLineInfo(unsigned LineNo, const char *Extra=0, unsigned ExtraLen=0);
153  bool LineMarkersAreDisabled() const { return DisableLineMarkers; }
154  void HandleNewlinesInToken(const char *TokStr, unsigned Len);
155
156  /// MacroDefined - This hook is called whenever a macro definition is seen.
157  void MacroDefined(const Token &MacroNameTok, const MacroInfo *MI);
158
159  /// MacroUndefined - This hook is called whenever a macro #undef is seen.
160  void MacroUndefined(const Token &MacroNameTok, const MacroInfo *MI);
161};
162}  // end anonymous namespace
163
164void PrintPPOutputPPCallbacks::WriteLineInfo(unsigned LineNo,
165                                             const char *Extra,
166                                             unsigned ExtraLen) {
167  startNewLineIfNeeded(/*ShouldUpdateCurrentLine=*/false);
168
169  // Emit #line directives or GNU line markers depending on what mode we're in.
170  if (UseLineDirective) {
171    OS << "#line" << ' ' << LineNo << ' ' << '"';
172    OS.write(CurFilename.data(), CurFilename.size());
173    OS << '"';
174  } else {
175    OS << '#' << ' ' << LineNo << ' ' << '"';
176    OS.write(CurFilename.data(), CurFilename.size());
177    OS << '"';
178
179    if (ExtraLen)
180      OS.write(Extra, ExtraLen);
181
182    if (FileType == SrcMgr::C_System)
183      OS.write(" 3", 2);
184    else if (FileType == SrcMgr::C_ExternCSystem)
185      OS.write(" 3 4", 4);
186  }
187  OS << '\n';
188}
189
190/// MoveToLine - Move the output to the source line specified by the location
191/// object.  We can do this by emitting some number of \n's, or be emitting a
192/// #line directive.  This returns false if already at the specified line, true
193/// if some newlines were emitted.
194bool PrintPPOutputPPCallbacks::MoveToLine(unsigned LineNo) {
195  // If this line is "close enough" to the original line, just print newlines,
196  // otherwise print a #line directive.
197  if (LineNo-CurLine <= 8) {
198    if (LineNo-CurLine == 1)
199      OS << '\n';
200    else if (LineNo == CurLine)
201      return false;    // Spelling line moved, but expansion line didn't.
202    else {
203      const char *NewLines = "\n\n\n\n\n\n\n\n";
204      OS.write(NewLines, LineNo-CurLine);
205    }
206  } else if (!DisableLineMarkers) {
207    // Emit a #line or line marker.
208    WriteLineInfo(LineNo, 0, 0);
209  } else {
210    // Okay, we're in -P mode, which turns off line markers.  However, we still
211    // need to emit a newline between tokens on different lines.
212    startNewLineIfNeeded(/*ShouldUpdateCurrentLine=*/false);
213  }
214
215  CurLine = LineNo;
216  return true;
217}
218
219bool
220PrintPPOutputPPCallbacks::startNewLineIfNeeded(bool ShouldUpdateCurrentLine) {
221  if (EmittedTokensOnThisLine || EmittedDirectiveOnThisLine) {
222    OS << '\n';
223    EmittedTokensOnThisLine = false;
224    EmittedDirectiveOnThisLine = false;
225    if (ShouldUpdateCurrentLine)
226      ++CurLine;
227    return true;
228  }
229
230  return false;
231}
232
233/// FileChanged - Whenever the preprocessor enters or exits a #include file
234/// it invokes this handler.  Update our conception of the current source
235/// position.
236void PrintPPOutputPPCallbacks::FileChanged(SourceLocation Loc,
237                                           FileChangeReason Reason,
238                                       SrcMgr::CharacteristicKind NewFileType,
239                                       FileID PrevFID) {
240  // Unless we are exiting a #include, make sure to skip ahead to the line the
241  // #include directive was at.
242  SourceManager &SourceMgr = SM;
243
244  PresumedLoc UserLoc = SourceMgr.getPresumedLoc(Loc);
245  if (UserLoc.isInvalid())
246    return;
247
248  unsigned NewLine = UserLoc.getLine();
249
250  if (Reason == PPCallbacks::EnterFile) {
251    SourceLocation IncludeLoc = UserLoc.getIncludeLoc();
252    if (IncludeLoc.isValid())
253      MoveToLine(IncludeLoc);
254  } else if (Reason == PPCallbacks::SystemHeaderPragma) {
255    MoveToLine(NewLine);
256
257    // TODO GCC emits the # directive for this directive on the line AFTER the
258    // directive and emits a bunch of spaces that aren't needed.  Emulate this
259    // strange behavior.
260  }
261
262  CurLine = NewLine;
263
264  CurFilename.clear();
265  CurFilename += UserLoc.getFilename();
266  Lexer::Stringify(CurFilename);
267  FileType = NewFileType;
268
269  if (DisableLineMarkers) return;
270
271  if (!Initialized) {
272    WriteLineInfo(CurLine);
273    Initialized = true;
274  }
275
276  switch (Reason) {
277  case PPCallbacks::EnterFile:
278    WriteLineInfo(CurLine, " 1", 2);
279    break;
280  case PPCallbacks::ExitFile:
281    WriteLineInfo(CurLine, " 2", 2);
282    break;
283  case PPCallbacks::SystemHeaderPragma:
284  case PPCallbacks::RenameFile:
285    WriteLineInfo(CurLine);
286    break;
287  }
288}
289
290/// Ident - Handle #ident directives when read by the preprocessor.
291///
292void PrintPPOutputPPCallbacks::Ident(SourceLocation Loc, const std::string &S) {
293  MoveToLine(Loc);
294
295  OS.write("#ident ", strlen("#ident "));
296  OS.write(&S[0], S.size());
297  EmittedTokensOnThisLine = true;
298}
299
300/// MacroDefined - This hook is called whenever a macro definition is seen.
301void PrintPPOutputPPCallbacks::MacroDefined(const Token &MacroNameTok,
302                                            const MacroInfo *MI) {
303  // Only print out macro definitions in -dD mode.
304  if (!DumpDefines ||
305      // Ignore __FILE__ etc.
306      MI->isBuiltinMacro()) return;
307
308  MoveToLine(MI->getDefinitionLoc());
309  PrintMacroDefinition(*MacroNameTok.getIdentifierInfo(), *MI, PP, OS);
310  setEmittedDirectiveOnThisLine();
311}
312
313void PrintPPOutputPPCallbacks::MacroUndefined(const Token &MacroNameTok,
314                                              const MacroInfo *MI) {
315  // Only print out macro definitions in -dD mode.
316  if (!DumpDefines) return;
317
318  MoveToLine(MacroNameTok.getLocation());
319  OS << "#undef " << MacroNameTok.getIdentifierInfo()->getName();
320  setEmittedDirectiveOnThisLine();
321}
322
323void PrintPPOutputPPCallbacks::PragmaComment(SourceLocation Loc,
324                                             const IdentifierInfo *Kind,
325                                             const std::string &Str) {
326  startNewLineIfNeeded();
327  MoveToLine(Loc);
328  OS << "#pragma comment(" << Kind->getName();
329
330  if (!Str.empty()) {
331    OS << ", \"";
332
333    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
334      unsigned char Char = Str[i];
335      if (isprint(Char) && Char != '\\' && Char != '"')
336        OS << (char)Char;
337      else  // Output anything hard as an octal escape.
338        OS << '\\'
339           << (char)('0'+ ((Char >> 6) & 7))
340           << (char)('0'+ ((Char >> 3) & 7))
341           << (char)('0'+ ((Char >> 0) & 7));
342    }
343    OS << '"';
344  }
345
346  OS << ')';
347  setEmittedDirectiveOnThisLine();
348}
349
350void PrintPPOutputPPCallbacks::PragmaMessage(SourceLocation Loc,
351                                             StringRef Str) {
352  startNewLineIfNeeded();
353  MoveToLine(Loc);
354  OS << "#pragma message(";
355
356  OS << '"';
357
358  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
359    unsigned char Char = Str[i];
360    if (isprint(Char) && Char != '\\' && Char != '"')
361      OS << (char)Char;
362    else  // Output anything hard as an octal escape.
363      OS << '\\'
364         << (char)('0'+ ((Char >> 6) & 7))
365         << (char)('0'+ ((Char >> 3) & 7))
366         << (char)('0'+ ((Char >> 0) & 7));
367  }
368  OS << '"';
369
370  OS << ')';
371  setEmittedDirectiveOnThisLine();
372}
373
374void PrintPPOutputPPCallbacks::
375PragmaDiagnosticPush(SourceLocation Loc, StringRef Namespace) {
376  startNewLineIfNeeded();
377  MoveToLine(Loc);
378  OS << "#pragma " << Namespace << " diagnostic push";
379  setEmittedDirectiveOnThisLine();
380}
381
382void PrintPPOutputPPCallbacks::
383PragmaDiagnosticPop(SourceLocation Loc, StringRef Namespace) {
384  startNewLineIfNeeded();
385  MoveToLine(Loc);
386  OS << "#pragma " << Namespace << " diagnostic pop";
387  setEmittedDirectiveOnThisLine();
388}
389
390void PrintPPOutputPPCallbacks::
391PragmaDiagnostic(SourceLocation Loc, StringRef Namespace,
392                 diag::Mapping Map, StringRef Str) {
393  startNewLineIfNeeded();
394  MoveToLine(Loc);
395  OS << "#pragma " << Namespace << " diagnostic ";
396  switch (Map) {
397  case diag::MAP_WARNING:
398    OS << "warning";
399    break;
400  case diag::MAP_ERROR:
401    OS << "error";
402    break;
403  case diag::MAP_IGNORE:
404    OS << "ignored";
405    break;
406  case diag::MAP_FATAL:
407    OS << "fatal";
408    break;
409  }
410  OS << " \"" << Str << '"';
411  setEmittedDirectiveOnThisLine();
412}
413
414/// HandleFirstTokOnLine - When emitting a preprocessed file in -E mode, this
415/// is called for the first token on each new line.  If this really is the start
416/// of a new logical line, handle it and return true, otherwise return false.
417/// This may not be the start of a logical line because the "start of line"
418/// marker is set for spelling lines, not expansion ones.
419bool PrintPPOutputPPCallbacks::HandleFirstTokOnLine(Token &Tok) {
420  // Figure out what line we went to and insert the appropriate number of
421  // newline characters.
422  if (!MoveToLine(Tok.getLocation()))
423    return false;
424
425  // Print out space characters so that the first token on a line is
426  // indented for easy reading.
427  unsigned ColNo = SM.getExpansionColumnNumber(Tok.getLocation());
428
429  // This hack prevents stuff like:
430  // #define HASH #
431  // HASH define foo bar
432  // From having the # character end up at column 1, which makes it so it
433  // is not handled as a #define next time through the preprocessor if in
434  // -fpreprocessed mode.
435  if (ColNo <= 1 && Tok.is(tok::hash))
436    OS << ' ';
437
438  // Otherwise, indent the appropriate number of spaces.
439  for (; ColNo > 1; --ColNo)
440    OS << ' ';
441
442  return true;
443}
444
445void PrintPPOutputPPCallbacks::HandleNewlinesInToken(const char *TokStr,
446                                                     unsigned Len) {
447  unsigned NumNewlines = 0;
448  for (; Len; --Len, ++TokStr) {
449    if (*TokStr != '\n' &&
450        *TokStr != '\r')
451      continue;
452
453    ++NumNewlines;
454
455    // If we have \n\r or \r\n, skip both and count as one line.
456    if (Len != 1 &&
457        (TokStr[1] == '\n' || TokStr[1] == '\r') &&
458        TokStr[0] != TokStr[1])
459      ++TokStr, --Len;
460  }
461
462  if (NumNewlines == 0) return;
463
464  CurLine += NumNewlines;
465}
466
467
468namespace {
469struct UnknownPragmaHandler : public PragmaHandler {
470  const char *Prefix;
471  PrintPPOutputPPCallbacks *Callbacks;
472
473  UnknownPragmaHandler(const char *prefix, PrintPPOutputPPCallbacks *callbacks)
474    : Prefix(prefix), Callbacks(callbacks) {}
475  virtual void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
476                            Token &PragmaTok) {
477    // Figure out what line we went to and insert the appropriate number of
478    // newline characters.
479    Callbacks->startNewLineIfNeeded();
480    Callbacks->MoveToLine(PragmaTok.getLocation());
481    Callbacks->OS.write(Prefix, strlen(Prefix));
482    // Read and print all of the pragma tokens.
483    while (PragmaTok.isNot(tok::eod)) {
484      if (PragmaTok.hasLeadingSpace())
485        Callbacks->OS << ' ';
486      std::string TokSpell = PP.getSpelling(PragmaTok);
487      Callbacks->OS.write(&TokSpell[0], TokSpell.size());
488      PP.LexUnexpandedToken(PragmaTok);
489    }
490    Callbacks->setEmittedDirectiveOnThisLine();
491  }
492};
493} // end anonymous namespace
494
495
496static void PrintPreprocessedTokens(Preprocessor &PP, Token &Tok,
497                                    PrintPPOutputPPCallbacks *Callbacks,
498                                    raw_ostream &OS) {
499  char Buffer[256];
500  Token PrevPrevTok, PrevTok;
501  PrevPrevTok.startToken();
502  PrevTok.startToken();
503  while (1) {
504    if (Callbacks->hasEmittedDirectiveOnThisLine()) {
505      Callbacks->startNewLineIfNeeded();
506      Callbacks->MoveToLine(Tok.getLocation());
507    }
508
509    // If this token is at the start of a line, emit newlines if needed.
510    if (Tok.isAtStartOfLine() && Callbacks->HandleFirstTokOnLine(Tok)) {
511      // done.
512    } else if (Tok.hasLeadingSpace() ||
513               // If we haven't emitted a token on this line yet, PrevTok isn't
514               // useful to look at and no concatenation could happen anyway.
515               (Callbacks->hasEmittedTokensOnThisLine() &&
516                // Don't print "-" next to "-", it would form "--".
517                Callbacks->AvoidConcat(PrevPrevTok, PrevTok, Tok))) {
518      OS << ' ';
519    }
520
521    if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
522      OS << II->getName();
523    } else if (Tok.isLiteral() && !Tok.needsCleaning() &&
524               Tok.getLiteralData()) {
525      OS.write(Tok.getLiteralData(), Tok.getLength());
526    } else if (Tok.getLength() < 256) {
527      const char *TokPtr = Buffer;
528      unsigned Len = PP.getSpelling(Tok, TokPtr);
529      OS.write(TokPtr, Len);
530
531      // Tokens that can contain embedded newlines need to adjust our current
532      // line number.
533      if (Tok.getKind() == tok::comment)
534        Callbacks->HandleNewlinesInToken(TokPtr, Len);
535    } else {
536      std::string S = PP.getSpelling(Tok);
537      OS.write(&S[0], S.size());
538
539      // Tokens that can contain embedded newlines need to adjust our current
540      // line number.
541      if (Tok.getKind() == tok::comment)
542        Callbacks->HandleNewlinesInToken(&S[0], S.size());
543    }
544    Callbacks->setEmittedTokensOnThisLine();
545
546    if (Tok.is(tok::eof)) break;
547
548    PrevPrevTok = PrevTok;
549    PrevTok = Tok;
550    PP.Lex(Tok);
551  }
552}
553
554typedef std::pair<IdentifierInfo*, MacroInfo*> id_macro_pair;
555static int MacroIDCompare(const void* a, const void* b) {
556  const id_macro_pair *LHS = static_cast<const id_macro_pair*>(a);
557  const id_macro_pair *RHS = static_cast<const id_macro_pair*>(b);
558  return LHS->first->getName().compare(RHS->first->getName());
559}
560
561static void DoPrintMacros(Preprocessor &PP, raw_ostream *OS) {
562  // Ignore unknown pragmas.
563  PP.AddPragmaHandler(new EmptyPragmaHandler());
564
565  // -dM mode just scans and ignores all tokens in the files, then dumps out
566  // the macro table at the end.
567  PP.EnterMainSourceFile();
568
569  Token Tok;
570  do PP.Lex(Tok);
571  while (Tok.isNot(tok::eof));
572
573  SmallVector<id_macro_pair, 128> MacrosByID;
574  for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();
575       I != E; ++I) {
576    if (I->first->hasMacroDefinition())
577      MacrosByID.push_back(id_macro_pair(I->first, I->second));
578  }
579  llvm::array_pod_sort(MacrosByID.begin(), MacrosByID.end(), MacroIDCompare);
580
581  for (unsigned i = 0, e = MacrosByID.size(); i != e; ++i) {
582    MacroInfo &MI = *MacrosByID[i].second;
583    // Ignore computed macros like __LINE__ and friends.
584    if (MI.isBuiltinMacro()) continue;
585
586    PrintMacroDefinition(*MacrosByID[i].first, MI, PP, *OS);
587    *OS << '\n';
588  }
589}
590
591/// DoPrintPreprocessedInput - This implements -E mode.
592///
593void clang::DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
594                                     const PreprocessorOutputOptions &Opts) {
595  // Show macros with no output is handled specially.
596  if (!Opts.ShowCPP) {
597    assert(Opts.ShowMacros && "Not yet implemented!");
598    DoPrintMacros(PP, OS);
599    return;
600  }
601
602  // Inform the preprocessor whether we want it to retain comments or not, due
603  // to -C or -CC.
604  PP.SetCommentRetentionState(Opts.ShowComments, Opts.ShowMacroComments);
605
606  PrintPPOutputPPCallbacks *Callbacks =
607      new PrintPPOutputPPCallbacks(PP, *OS, !Opts.ShowLineMarkers,
608                                   Opts.ShowMacros);
609  PP.AddPragmaHandler(new UnknownPragmaHandler("#pragma", Callbacks));
610  PP.AddPragmaHandler("GCC", new UnknownPragmaHandler("#pragma GCC",Callbacks));
611  PP.AddPragmaHandler("clang",
612                      new UnknownPragmaHandler("#pragma clang", Callbacks));
613
614  PP.addPPCallbacks(Callbacks);
615
616  // After we have configured the preprocessor, enter the main file.
617  PP.EnterMainSourceFile();
618
619  // Consume all of the tokens that come from the predefines buffer.  Those
620  // should not be emitted into the output and are guaranteed to be at the
621  // start.
622  const SourceManager &SourceMgr = PP.getSourceManager();
623  Token Tok;
624  do {
625    PP.Lex(Tok);
626    if (Tok.is(tok::eof) || !Tok.getLocation().isFileID())
627      break;
628
629    PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());
630    if (PLoc.isInvalid())
631      break;
632
633    if (strcmp(PLoc.getFilename(), "<built-in>"))
634      break;
635  } while (true);
636
637  // Read all the preprocessed tokens, printing them out to the stream.
638  PrintPreprocessedTokens(PP, Tok, Callbacks, *OS);
639  *OS << '\n';
640}
641