clang  3.8.0
TokenLexer.cpp
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1 //===--- TokenLexer.cpp - Lex from a token stream -------------------------===//
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 TokenLexer interface.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Lex/TokenLexer.h"
17 #include "clang/Lex/MacroArgs.h"
18 #include "clang/Lex/MacroInfo.h"
19 #include "clang/Lex/Preprocessor.h"
20 #include "llvm/ADT/SmallString.h"
21 using namespace clang;
22 
23 
24 /// Create a TokenLexer for the specified macro with the specified actual
25 /// arguments. Note that this ctor takes ownership of the ActualArgs pointer.
27  MacroArgs *Actuals) {
28  // If the client is reusing a TokenLexer, make sure to free any memory
29  // associated with it.
30  destroy();
31 
32  Macro = MI;
33  ActualArgs = Actuals;
34  CurToken = 0;
35 
36  ExpandLocStart = Tok.getLocation();
37  ExpandLocEnd = ELEnd;
38  AtStartOfLine = Tok.isAtStartOfLine();
39  HasLeadingSpace = Tok.hasLeadingSpace();
40  NextTokGetsSpace = false;
41  Tokens = &*Macro->tokens_begin();
42  OwnsTokens = false;
43  DisableMacroExpansion = false;
44  NumTokens = Macro->tokens_end()-Macro->tokens_begin();
45  MacroExpansionStart = SourceLocation();
46 
48  MacroStartSLocOffset = SM.getNextLocalOffset();
49 
50  if (NumTokens > 0) {
51  assert(Tokens[0].getLocation().isValid());
52  assert((Tokens[0].getLocation().isFileID() || Tokens[0].is(tok::comment)) &&
53  "Macro defined in macro?");
54  assert(ExpandLocStart.isValid());
55 
56  // Reserve a source location entry chunk for the length of the macro
57  // definition. Tokens that get lexed directly from the definition will
58  // have their locations pointing inside this chunk. This is to avoid
59  // creating separate source location entries for each token.
60  MacroDefStart = SM.getExpansionLoc(Tokens[0].getLocation());
61  MacroDefLength = Macro->getDefinitionLength(SM);
62  MacroExpansionStart = SM.createExpansionLoc(MacroDefStart,
63  ExpandLocStart,
64  ExpandLocEnd,
65  MacroDefLength);
66  }
67 
68  // If this is a function-like macro, expand the arguments and change
69  // Tokens to point to the expanded tokens.
70  if (Macro->isFunctionLike() && Macro->getNumArgs())
71  ExpandFunctionArguments();
72 
73  // Mark the macro as currently disabled, so that it is not recursively
74  // expanded. The macro must be disabled only after argument pre-expansion of
75  // function-like macro arguments occurs.
76  Macro->DisableMacro();
77 }
78 
79 
80 
81 /// Create a TokenLexer for the specified token stream. This does not
82 /// take ownership of the specified token vector.
83 void TokenLexer::Init(const Token *TokArray, unsigned NumToks,
84  bool disableMacroExpansion, bool ownsTokens) {
85  // If the client is reusing a TokenLexer, make sure to free any memory
86  // associated with it.
87  destroy();
88 
89  Macro = nullptr;
90  ActualArgs = nullptr;
91  Tokens = TokArray;
92  OwnsTokens = ownsTokens;
93  DisableMacroExpansion = disableMacroExpansion;
94  NumTokens = NumToks;
95  CurToken = 0;
96  ExpandLocStart = ExpandLocEnd = SourceLocation();
97  AtStartOfLine = false;
98  HasLeadingSpace = false;
99  NextTokGetsSpace = false;
100  MacroExpansionStart = SourceLocation();
101 
102  // Set HasLeadingSpace/AtStartOfLine so that the first token will be
103  // returned unmodified.
104  if (NumToks != 0) {
105  AtStartOfLine = TokArray[0].isAtStartOfLine();
106  HasLeadingSpace = TokArray[0].hasLeadingSpace();
107  }
108 }
109 
110 
111 void TokenLexer::destroy() {
112  // If this was a function-like macro that actually uses its arguments, delete
113  // the expanded tokens.
114  if (OwnsTokens) {
115  delete [] Tokens;
116  Tokens = nullptr;
117  OwnsTokens = false;
118  }
119 
120  // TokenLexer owns its formal arguments.
121  if (ActualArgs) ActualArgs->destroy(PP);
122 }
123 
124 bool TokenLexer::MaybeRemoveCommaBeforeVaArgs(
125  SmallVectorImpl<Token> &ResultToks, bool HasPasteOperator, MacroInfo *Macro,
126  unsigned MacroArgNo, Preprocessor &PP) {
127  // Is the macro argument __VA_ARGS__?
128  if (!Macro->isVariadic() || MacroArgNo != Macro->getNumArgs()-1)
129  return false;
130 
131  // In Microsoft-compatibility mode, a comma is removed in the expansion
132  // of " ... , __VA_ARGS__ " if __VA_ARGS__ is empty. This extension is
133  // not supported by gcc.
134  if (!HasPasteOperator && !PP.getLangOpts().MSVCCompat)
135  return false;
136 
137  // GCC removes the comma in the expansion of " ... , ## __VA_ARGS__ " if
138  // __VA_ARGS__ is empty, but not in strict C99 mode where there are no
139  // named arguments, where it remains. In all other modes, including C99
140  // with GNU extensions, it is removed regardless of named arguments.
141  // Microsoft also appears to support this extension, unofficially.
142  if (PP.getLangOpts().C99 && !PP.getLangOpts().GNUMode
143  && Macro->getNumArgs() < 2)
144  return false;
145 
146  // Is a comma available to be removed?
147  if (ResultToks.empty() || !ResultToks.back().is(tok::comma))
148  return false;
149 
150  // Issue an extension diagnostic for the paste operator.
151  if (HasPasteOperator)
152  PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma);
153 
154  // Remove the comma.
155  ResultToks.pop_back();
156 
157  // If the comma was right after another paste (e.g. "X##,##__VA_ARGS__"),
158  // then removal of the comma should produce a placemarker token (in C99
159  // terms) which we model by popping off the previous ##, giving us a plain
160  // "X" when __VA_ARGS__ is empty.
161  if (!ResultToks.empty() && ResultToks.back().is(tok::hashhash))
162  ResultToks.pop_back();
163 
164  // Never add a space, even if the comma, ##, or arg had a space.
165  NextTokGetsSpace = false;
166  return true;
167 }
168 
169 /// Expand the arguments of a function-like macro so that we can quickly
170 /// return preexpanded tokens from Tokens.
171 void TokenLexer::ExpandFunctionArguments() {
172 
173  SmallVector<Token, 128> ResultToks;
174 
175  // Loop through 'Tokens', expanding them into ResultToks. Keep
176  // track of whether we change anything. If not, no need to keep them. If so,
177  // we install the newly expanded sequence as the new 'Tokens' list.
178  bool MadeChange = false;
179 
180  for (unsigned i = 0, e = NumTokens; i != e; ++i) {
181  // If we found the stringify operator, get the argument stringified. The
182  // preprocessor already verified that the following token is a macro name
183  // when the #define was parsed.
184  const Token &CurTok = Tokens[i];
185  if (i != 0 && !Tokens[i-1].is(tok::hashhash) && CurTok.hasLeadingSpace())
186  NextTokGetsSpace = true;
187 
188  if (CurTok.isOneOf(tok::hash, tok::hashat)) {
189  int ArgNo = Macro->getArgumentNum(Tokens[i+1].getIdentifierInfo());
190  assert(ArgNo != -1 && "Token following # is not an argument?");
191 
192  SourceLocation ExpansionLocStart =
193  getExpansionLocForMacroDefLoc(CurTok.getLocation());
194  SourceLocation ExpansionLocEnd =
195  getExpansionLocForMacroDefLoc(Tokens[i+1].getLocation());
196 
197  Token Res;
198  if (CurTok.is(tok::hash)) // Stringify
199  Res = ActualArgs->getStringifiedArgument(ArgNo, PP,
200  ExpansionLocStart,
201  ExpansionLocEnd);
202  else {
203  // 'charify': don't bother caching these.
204  Res = MacroArgs::StringifyArgument(ActualArgs->getUnexpArgument(ArgNo),
205  PP, true,
206  ExpansionLocStart,
207  ExpansionLocEnd);
208  }
210 
211  // The stringified/charified string leading space flag gets set to match
212  // the #/#@ operator.
213  if (NextTokGetsSpace)
215 
216  ResultToks.push_back(Res);
217  MadeChange = true;
218  ++i; // Skip arg name.
219  NextTokGetsSpace = false;
220  continue;
221  }
222 
223  // Find out if there is a paste (##) operator before or after the token.
224  bool NonEmptyPasteBefore =
225  !ResultToks.empty() && ResultToks.back().is(tok::hashhash);
226  bool PasteBefore = i != 0 && Tokens[i-1].is(tok::hashhash);
227  bool PasteAfter = i+1 != e && Tokens[i+1].is(tok::hashhash);
228  assert(!NonEmptyPasteBefore || PasteBefore);
229 
230  // Otherwise, if this is not an argument token, just add the token to the
231  // output buffer.
232  IdentifierInfo *II = CurTok.getIdentifierInfo();
233  int ArgNo = II ? Macro->getArgumentNum(II) : -1;
234  if (ArgNo == -1) {
235  // This isn't an argument, just add it.
236  ResultToks.push_back(CurTok);
237 
238  if (NextTokGetsSpace) {
239  ResultToks.back().setFlag(Token::LeadingSpace);
240  NextTokGetsSpace = false;
241  } else if (PasteBefore && !NonEmptyPasteBefore)
242  ResultToks.back().clearFlag(Token::LeadingSpace);
243 
244  continue;
245  }
246 
247  // An argument is expanded somehow, the result is different than the
248  // input.
249  MadeChange = true;
250 
251  // Otherwise, this is a use of the argument.
252 
253  // In Microsoft mode, remove the comma before __VA_ARGS__ to ensure there
254  // are no trailing commas if __VA_ARGS__ is empty.
255  if (!PasteBefore && ActualArgs->isVarargsElidedUse() &&
256  MaybeRemoveCommaBeforeVaArgs(ResultToks,
257  /*HasPasteOperator=*/false,
258  Macro, ArgNo, PP))
259  continue;
260 
261  // If it is not the LHS/RHS of a ## operator, we must pre-expand the
262  // argument and substitute the expanded tokens into the result. This is
263  // C99 6.10.3.1p1.
264  if (!PasteBefore && !PasteAfter) {
265  const Token *ResultArgToks;
266 
267  // Only preexpand the argument if it could possibly need it. This
268  // avoids some work in common cases.
269  const Token *ArgTok = ActualArgs->getUnexpArgument(ArgNo);
270  if (ActualArgs->ArgNeedsPreexpansion(ArgTok, PP))
271  ResultArgToks = &ActualArgs->getPreExpArgument(ArgNo, Macro, PP)[0];
272  else
273  ResultArgToks = ArgTok; // Use non-preexpanded tokens.
274 
275  // If the arg token expanded into anything, append it.
276  if (ResultArgToks->isNot(tok::eof)) {
277  unsigned FirstResult = ResultToks.size();
278  unsigned NumToks = MacroArgs::getArgLength(ResultArgToks);
279  ResultToks.append(ResultArgToks, ResultArgToks+NumToks);
280 
281  // In Microsoft-compatibility mode, we follow MSVC's preprocessing
282  // behavior by not considering single commas from nested macro
283  // expansions as argument separators. Set a flag on the token so we can
284  // test for this later when the macro expansion is processed.
285  if (PP.getLangOpts().MSVCCompat && NumToks == 1 &&
286  ResultToks.back().is(tok::comma))
287  ResultToks.back().setFlag(Token::IgnoredComma);
288 
289  // If the '##' came from expanding an argument, turn it into 'unknown'
290  // to avoid pasting.
291  for (unsigned i = FirstResult, e = ResultToks.size(); i != e; ++i) {
292  Token &Tok = ResultToks[i];
293  if (Tok.is(tok::hashhash))
294  Tok.setKind(tok::unknown);
295  }
296 
297  if(ExpandLocStart.isValid()) {
298  updateLocForMacroArgTokens(CurTok.getLocation(),
299  ResultToks.begin()+FirstResult,
300  ResultToks.end());
301  }
302 
303  // If any tokens were substituted from the argument, the whitespace
304  // before the first token should match the whitespace of the arg
305  // identifier.
306  ResultToks[FirstResult].setFlagValue(Token::LeadingSpace,
307  NextTokGetsSpace);
308  NextTokGetsSpace = false;
309  }
310  continue;
311  }
312 
313  // Okay, we have a token that is either the LHS or RHS of a paste (##)
314  // argument. It gets substituted as its non-pre-expanded tokens.
315  const Token *ArgToks = ActualArgs->getUnexpArgument(ArgNo);
316  unsigned NumToks = MacroArgs::getArgLength(ArgToks);
317  if (NumToks) { // Not an empty argument?
318  // If this is the GNU ", ## __VA_ARGS__" extension, and we just learned
319  // that __VA_ARGS__ expands to multiple tokens, avoid a pasting error when
320  // the expander trys to paste ',' with the first token of the __VA_ARGS__
321  // expansion.
322  if (NonEmptyPasteBefore && ResultToks.size() >= 2 &&
323  ResultToks[ResultToks.size()-2].is(tok::comma) &&
324  (unsigned)ArgNo == Macro->getNumArgs()-1 &&
325  Macro->isVariadic()) {
326  // Remove the paste operator, report use of the extension.
327  PP.Diag(ResultToks.pop_back_val().getLocation(), diag::ext_paste_comma);
328  }
329 
330  ResultToks.append(ArgToks, ArgToks+NumToks);
331 
332  // If the '##' came from expanding an argument, turn it into 'unknown'
333  // to avoid pasting.
334  for (unsigned i = ResultToks.size() - NumToks, e = ResultToks.size();
335  i != e; ++i) {
336  Token &Tok = ResultToks[i];
337  if (Tok.is(tok::hashhash))
338  Tok.setKind(tok::unknown);
339  }
340 
341  if (ExpandLocStart.isValid()) {
342  updateLocForMacroArgTokens(CurTok.getLocation(),
343  ResultToks.end()-NumToks, ResultToks.end());
344  }
345 
346  // If this token (the macro argument) was supposed to get leading
347  // whitespace, transfer this information onto the first token of the
348  // expansion.
349  //
350  // Do not do this if the paste operator occurs before the macro argument,
351  // as in "A ## MACROARG". In valid code, the first token will get
352  // smooshed onto the preceding one anyway (forming AMACROARG). In
353  // assembler-with-cpp mode, invalid pastes are allowed through: in this
354  // case, we do not want the extra whitespace to be added. For example,
355  // we want ". ## foo" -> ".foo" not ". foo".
356  if (NextTokGetsSpace)
357  ResultToks[ResultToks.size()-NumToks].setFlag(Token::LeadingSpace);
358 
359  NextTokGetsSpace = false;
360  continue;
361  }
362 
363  // If an empty argument is on the LHS or RHS of a paste, the standard (C99
364  // 6.10.3.3p2,3) calls for a bunch of placemarker stuff to occur. We
365  // implement this by eating ## operators when a LHS or RHS expands to
366  // empty.
367  if (PasteAfter) {
368  // Discard the argument token and skip (don't copy to the expansion
369  // buffer) the paste operator after it.
370  ++i;
371  continue;
372  }
373 
374  // If this is on the RHS of a paste operator, we've already copied the
375  // paste operator to the ResultToks list, unless the LHS was empty too.
376  // Remove it.
377  assert(PasteBefore);
378  if (NonEmptyPasteBefore) {
379  assert(ResultToks.back().is(tok::hashhash));
380  ResultToks.pop_back();
381  }
382 
383  // If this is the __VA_ARGS__ token, and if the argument wasn't provided,
384  // and if the macro had at least one real argument, and if the token before
385  // the ## was a comma, remove the comma. This is a GCC extension which is
386  // disabled when using -std=c99.
387  if (ActualArgs->isVarargsElidedUse())
388  MaybeRemoveCommaBeforeVaArgs(ResultToks,
389  /*HasPasteOperator=*/true,
390  Macro, ArgNo, PP);
391 
392  continue;
393  }
394 
395  // If anything changed, install this as the new Tokens list.
396  if (MadeChange) {
397  assert(!OwnsTokens && "This would leak if we already own the token list");
398  // This is deleted in the dtor.
399  NumTokens = ResultToks.size();
400  // The tokens will be added to Preprocessor's cache and will be removed
401  // when this TokenLexer finishes lexing them.
402  Tokens = PP.cacheMacroExpandedTokens(this, ResultToks);
403 
404  // The preprocessor cache of macro expanded tokens owns these tokens,not us.
405  OwnsTokens = false;
406  }
407 }
408 
409 /// \brief Checks if two tokens form wide string literal.
410 static bool isWideStringLiteralFromMacro(const Token &FirstTok,
411  const Token &SecondTok) {
412  return FirstTok.is(tok::identifier) &&
413  FirstTok.getIdentifierInfo()->isStr("L") && SecondTok.isLiteral() &&
414  SecondTok.stringifiedInMacro();
415 }
416 
417 /// Lex - Lex and return a token from this macro stream.
418 ///
419 bool TokenLexer::Lex(Token &Tok) {
420  // Lexing off the end of the macro, pop this macro off the expansion stack.
421  if (isAtEnd()) {
422  // If this is a macro (not a token stream), mark the macro enabled now
423  // that it is no longer being expanded.
424  if (Macro) Macro->EnableMacro();
425 
426  Tok.startToken();
427  Tok.setFlagValue(Token::StartOfLine , AtStartOfLine);
428  Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace || NextTokGetsSpace);
429  if (CurToken == 0)
431  return PP.HandleEndOfTokenLexer(Tok);
432  }
433 
435 
436  // If this is the first token of the expanded result, we inherit spacing
437  // properties later.
438  bool isFirstToken = CurToken == 0;
439 
440  // Get the next token to return.
441  Tok = Tokens[CurToken++];
442 
443  bool TokenIsFromPaste = false;
444 
445  // If this token is followed by a token paste (##) operator, paste the tokens!
446  // Note that ## is a normal token when not expanding a macro.
447  if (!isAtEnd() && Macro &&
448  (Tokens[CurToken].is(tok::hashhash) ||
449  // Special processing of L#x macros in -fms-compatibility mode.
450  // Microsoft compiler is able to form a wide string literal from
451  // 'L#macro_arg' construct in a function-like macro.
452  (PP.getLangOpts().MSVCCompat &&
453  isWideStringLiteralFromMacro(Tok, Tokens[CurToken])))) {
454  // When handling the microsoft /##/ extension, the final token is
455  // returned by PasteTokens, not the pasted token.
456  if (PasteTokens(Tok))
457  return true;
458 
459  TokenIsFromPaste = true;
460  }
461 
462  // The token's current location indicate where the token was lexed from. We
463  // need this information to compute the spelling of the token, but any
464  // diagnostics for the expanded token should appear as if they came from
465  // ExpansionLoc. Pull this information together into a new SourceLocation
466  // that captures all of this.
467  if (ExpandLocStart.isValid() && // Don't do this for token streams.
468  // Check that the token's location was not already set properly.
469  SM.isBeforeInSLocAddrSpace(Tok.getLocation(), MacroStartSLocOffset)) {
470  SourceLocation instLoc;
471  if (Tok.is(tok::comment)) {
472  instLoc = SM.createExpansionLoc(Tok.getLocation(),
473  ExpandLocStart,
474  ExpandLocEnd,
475  Tok.getLength());
476  } else {
477  instLoc = getExpansionLocForMacroDefLoc(Tok.getLocation());
478  }
479 
480  Tok.setLocation(instLoc);
481  }
482 
483  // If this is the first token, set the lexical properties of the token to
484  // match the lexical properties of the macro identifier.
485  if (isFirstToken) {
486  Tok.setFlagValue(Token::StartOfLine , AtStartOfLine);
487  Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace);
488  } else {
489  // If this is not the first token, we may still need to pass through
490  // leading whitespace if we've expanded a macro.
491  if (AtStartOfLine) Tok.setFlag(Token::StartOfLine);
492  if (HasLeadingSpace) Tok.setFlag(Token::LeadingSpace);
493  }
494  AtStartOfLine = false;
495  HasLeadingSpace = false;
496 
497  // Handle recursive expansion!
498  if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != nullptr) {
499  // Change the kind of this identifier to the appropriate token kind, e.g.
500  // turning "for" into a keyword.
501  IdentifierInfo *II = Tok.getIdentifierInfo();
502  Tok.setKind(II->getTokenID());
503 
504  // If this identifier was poisoned and from a paste, emit an error. This
505  // won't be handled by Preprocessor::HandleIdentifier because this is coming
506  // from a macro expansion.
507  if (II->isPoisoned() && TokenIsFromPaste) {
508  PP.HandlePoisonedIdentifier(Tok);
509  }
510 
511  if (!DisableMacroExpansion && II->isHandleIdentifierCase())
512  return PP.HandleIdentifier(Tok);
513  }
514 
515  // Otherwise, return a normal token.
516  return true;
517 }
518 
519 /// PasteTokens - Tok is the LHS of a ## operator, and CurToken is the ##
520 /// operator. Read the ## and RHS, and paste the LHS/RHS together. If there
521 /// are more ## after it, chomp them iteratively. Return the result as Tok.
522 /// If this returns true, the caller should immediately return the token.
523 bool TokenLexer::PasteTokens(Token &Tok) {
524  // MSVC: If previous token was pasted, this must be a recovery from an invalid
525  // paste operation. Ignore spaces before this token to mimic MSVC output.
526  // Required for generating valid UUID strings in some MS headers.
527  if (PP.getLangOpts().MicrosoftExt && (CurToken >= 2) &&
528  Tokens[CurToken - 2].is(tok::hashhash))
530 
532  const char *ResultTokStrPtr = nullptr;
533  SourceLocation StartLoc = Tok.getLocation();
534  SourceLocation PasteOpLoc;
535  do {
536  // Consume the ## operator if any.
537  PasteOpLoc = Tokens[CurToken].getLocation();
538  if (Tokens[CurToken].is(tok::hashhash))
539  ++CurToken;
540  assert(!isAtEnd() && "No token on the RHS of a paste operator!");
541 
542  // Get the RHS token.
543  const Token &RHS = Tokens[CurToken];
544 
545  // Allocate space for the result token. This is guaranteed to be enough for
546  // the two tokens.
547  Buffer.resize(Tok.getLength() + RHS.getLength());
548 
549  // Get the spelling of the LHS token in Buffer.
550  const char *BufPtr = &Buffer[0];
551  bool Invalid = false;
552  unsigned LHSLen = PP.getSpelling(Tok, BufPtr, &Invalid);
553  if (BufPtr != &Buffer[0]) // Really, we want the chars in Buffer!
554  memcpy(&Buffer[0], BufPtr, LHSLen);
555  if (Invalid)
556  return true;
557 
558  BufPtr = Buffer.data() + LHSLen;
559  unsigned RHSLen = PP.getSpelling(RHS, BufPtr, &Invalid);
560  if (Invalid)
561  return true;
562  if (RHSLen && BufPtr != &Buffer[LHSLen])
563  // Really, we want the chars in Buffer!
564  memcpy(&Buffer[LHSLen], BufPtr, RHSLen);
565 
566  // Trim excess space.
567  Buffer.resize(LHSLen+RHSLen);
568 
569  // Plop the pasted result (including the trailing newline and null) into a
570  // scratch buffer where we can lex it.
571  Token ResultTokTmp;
572  ResultTokTmp.startToken();
573 
574  // Claim that the tmp token is a string_literal so that we can get the
575  // character pointer back from CreateString in getLiteralData().
576  ResultTokTmp.setKind(tok::string_literal);
577  PP.CreateString(Buffer, ResultTokTmp);
578  SourceLocation ResultTokLoc = ResultTokTmp.getLocation();
579  ResultTokStrPtr = ResultTokTmp.getLiteralData();
580 
581  // Lex the resultant pasted token into Result.
582  Token Result;
583 
584  if (Tok.isAnyIdentifier() && RHS.isAnyIdentifier()) {
585  // Common paste case: identifier+identifier = identifier. Avoid creating
586  // a lexer and other overhead.
587  PP.IncrementPasteCounter(true);
588  Result.startToken();
589  Result.setKind(tok::raw_identifier);
590  Result.setRawIdentifierData(ResultTokStrPtr);
591  Result.setLocation(ResultTokLoc);
592  Result.setLength(LHSLen+RHSLen);
593  } else {
594  PP.IncrementPasteCounter(false);
595 
596  assert(ResultTokLoc.isFileID() &&
597  "Should be a raw location into scratch buffer");
599  FileID LocFileID = SourceMgr.getFileID(ResultTokLoc);
600 
601  bool Invalid = false;
602  const char *ScratchBufStart
603  = SourceMgr.getBufferData(LocFileID, &Invalid).data();
604  if (Invalid)
605  return false;
606 
607  // Make a lexer to lex this string from. Lex just this one token.
608  // Make a lexer object so that we lex and expand the paste result.
609  Lexer TL(SourceMgr.getLocForStartOfFile(LocFileID),
610  PP.getLangOpts(), ScratchBufStart,
611  ResultTokStrPtr, ResultTokStrPtr+LHSLen+RHSLen);
612 
613  // Lex a token in raw mode. This way it won't look up identifiers
614  // automatically, lexing off the end will return an eof token, and
615  // warnings are disabled. This returns true if the result token is the
616  // entire buffer.
617  bool isInvalid = !TL.LexFromRawLexer(Result);
618 
619  // If we got an EOF token, we didn't form even ONE token. For example, we
620  // did "/ ## /" to get "//".
621  isInvalid |= Result.is(tok::eof);
622 
623  // If pasting the two tokens didn't form a full new token, this is an
624  // error. This occurs with "x ## +" and other stuff. Return with Tok
625  // unmodified and with RHS as the next token to lex.
626  if (isInvalid) {
627  // Explicitly convert the token location to have proper expansion
628  // information so that the user knows where it came from.
630  SourceLocation Loc =
631  SM.createExpansionLoc(PasteOpLoc, ExpandLocStart, ExpandLocEnd, 2);
632 
633  // Test for the Microsoft extension of /##/ turning into // here on the
634  // error path.
635  if (PP.getLangOpts().MicrosoftExt && Tok.is(tok::slash) &&
636  RHS.is(tok::slash)) {
637  HandleMicrosoftCommentPaste(Tok, Loc);
638  return true;
639  }
640 
641  // Do not emit the error when preprocessing assembler code.
642  if (!PP.getLangOpts().AsmPreprocessor) {
643  // If we're in microsoft extensions mode, downgrade this from a hard
644  // error to an extension that defaults to an error. This allows
645  // disabling it.
646  PP.Diag(Loc, PP.getLangOpts().MicrosoftExt ? diag::ext_pp_bad_paste_ms
647  : diag::err_pp_bad_paste)
648  << Buffer;
649  }
650 
651  // An error has occurred so exit loop.
652  break;
653  }
654 
655  // Turn ## into 'unknown' to avoid # ## # from looking like a paste
656  // operator.
657  if (Result.is(tok::hashhash))
658  Result.setKind(tok::unknown);
659  }
660 
661  // Transfer properties of the LHS over the Result.
664 
665  // Finally, replace LHS with the result, consume the RHS, and iterate.
666  ++CurToken;
667  Tok = Result;
668  } while (!isAtEnd() && Tokens[CurToken].is(tok::hashhash));
669 
670  SourceLocation EndLoc = Tokens[CurToken - 1].getLocation();
671 
672  // The token's current location indicate where the token was lexed from. We
673  // need this information to compute the spelling of the token, but any
674  // diagnostics for the expanded token should appear as if the token was
675  // expanded from the full ## expression. Pull this information together into
676  // a new SourceLocation that captures all of this.
677  SourceManager &SM = PP.getSourceManager();
678  if (StartLoc.isFileID())
679  StartLoc = getExpansionLocForMacroDefLoc(StartLoc);
680  if (EndLoc.isFileID())
681  EndLoc = getExpansionLocForMacroDefLoc(EndLoc);
682  FileID MacroFID = SM.getFileID(MacroExpansionStart);
683  while (SM.getFileID(StartLoc) != MacroFID)
684  StartLoc = SM.getImmediateExpansionRange(StartLoc).first;
685  while (SM.getFileID(EndLoc) != MacroFID)
686  EndLoc = SM.getImmediateExpansionRange(EndLoc).second;
687 
688  Tok.setLocation(SM.createExpansionLoc(Tok.getLocation(), StartLoc, EndLoc,
689  Tok.getLength()));
690 
691  // Now that we got the result token, it will be subject to expansion. Since
692  // token pasting re-lexes the result token in raw mode, identifier information
693  // isn't looked up. As such, if the result is an identifier, look up id info.
694  if (Tok.is(tok::raw_identifier)) {
695  // Look up the identifier info for the token. We disabled identifier lookup
696  // by saying we're skipping contents, so we need to do this manually.
697  PP.LookUpIdentifierInfo(Tok);
698  }
699  return false;
700 }
701 
702 /// isNextTokenLParen - If the next token lexed will pop this macro off the
703 /// expansion stack, return 2. If the next unexpanded token is a '(', return
704 /// 1, otherwise return 0.
706  // Out of tokens?
707  if (isAtEnd())
708  return 2;
709  return Tokens[CurToken].is(tok::l_paren);
710 }
711 
712 /// isParsingPreprocessorDirective - Return true if we are in the middle of a
713 /// preprocessor directive.
715  return Tokens[NumTokens-1].is(tok::eod) && !isAtEnd();
716 }
717 
718 /// HandleMicrosoftCommentPaste - In microsoft compatibility mode, /##/ pastes
719 /// together to form a comment that comments out everything in the current
720 /// macro, other active macros, and anything left on the current physical
721 /// source line of the expanded buffer. Handle this by returning the
722 /// first token on the next line.
723 void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok, SourceLocation OpLoc) {
724  PP.Diag(OpLoc, diag::ext_comment_paste_microsoft);
725 
726  // We 'comment out' the rest of this macro by just ignoring the rest of the
727  // tokens that have not been lexed yet, if any.
728 
729  // Since this must be a macro, mark the macro enabled now that it is no longer
730  // being expanded.
731  assert(Macro && "Token streams can't paste comments");
732  Macro->EnableMacro();
733 
735 }
736 
737 /// \brief If \arg loc is a file ID and points inside the current macro
738 /// definition, returns the appropriate source location pointing at the
739 /// macro expansion source location entry, otherwise it returns an invalid
740 /// SourceLocation.
742 TokenLexer::getExpansionLocForMacroDefLoc(SourceLocation loc) const {
743  assert(ExpandLocStart.isValid() && MacroExpansionStart.isValid() &&
744  "Not appropriate for token streams");
745  assert(loc.isValid() && loc.isFileID());
746 
747  SourceManager &SM = PP.getSourceManager();
748  assert(SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength) &&
749  "Expected loc to come from the macro definition");
750 
751  unsigned relativeOffset = 0;
752  SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength, &relativeOffset);
753  return MacroExpansionStart.getLocWithOffset(relativeOffset);
754 }
755 
756 /// \brief Finds the tokens that are consecutive (from the same FileID)
757 /// creates a single SLocEntry, and assigns SourceLocations to each token that
758 /// point to that SLocEntry. e.g for
759 /// assert(foo == bar);
760 /// There will be a single SLocEntry for the "foo == bar" chunk and locations
761 /// for the 'foo', '==', 'bar' tokens will point inside that chunk.
762 ///
763 /// \arg begin_tokens will be updated to a position past all the found
764 /// consecutive tokens.
766  SourceLocation InstLoc,
767  Token *&begin_tokens,
768  Token * end_tokens) {
769  assert(begin_tokens < end_tokens);
770 
771  SourceLocation FirstLoc = begin_tokens->getLocation();
772  SourceLocation CurLoc = FirstLoc;
773 
774  // Compare the source location offset of tokens and group together tokens that
775  // are close, even if their locations point to different FileIDs. e.g.
776  //
777  // |bar | foo | cake | (3 tokens from 3 consecutive FileIDs)
778  // ^ ^
779  // |bar foo cake| (one SLocEntry chunk for all tokens)
780  //
781  // we can perform this "merge" since the token's spelling location depends
782  // on the relative offset.
783 
784  Token *NextTok = begin_tokens + 1;
785  for (; NextTok < end_tokens; ++NextTok) {
786  SourceLocation NextLoc = NextTok->getLocation();
787  if (CurLoc.isFileID() != NextLoc.isFileID())
788  break; // Token from different kind of FileID.
789 
790  int RelOffs;
791  if (!SM.isInSameSLocAddrSpace(CurLoc, NextLoc, &RelOffs))
792  break; // Token from different local/loaded location.
793  // Check that token is not before the previous token or more than 50
794  // "characters" away.
795  if (RelOffs < 0 || RelOffs > 50)
796  break;
797  CurLoc = NextLoc;
798  }
799 
800  // For the consecutive tokens, find the length of the SLocEntry to contain
801  // all of them.
802  Token &LastConsecutiveTok = *(NextTok-1);
803  int LastRelOffs = 0;
804  SM.isInSameSLocAddrSpace(FirstLoc, LastConsecutiveTok.getLocation(),
805  &LastRelOffs);
806  unsigned FullLength = LastRelOffs + LastConsecutiveTok.getLength();
807 
808  // Create a macro expansion SLocEntry that will "contain" all of the tokens.
809  SourceLocation Expansion =
810  SM.createMacroArgExpansionLoc(FirstLoc, InstLoc,FullLength);
811 
812  // Change the location of the tokens from the spelling location to the new
813  // expanded location.
814  for (; begin_tokens < NextTok; ++begin_tokens) {
815  Token &Tok = *begin_tokens;
816  int RelOffs = 0;
817  SM.isInSameSLocAddrSpace(FirstLoc, Tok.getLocation(), &RelOffs);
818  Tok.setLocation(Expansion.getLocWithOffset(RelOffs));
819  }
820 }
821 
822 /// \brief Creates SLocEntries and updates the locations of macro argument
823 /// tokens to their new expanded locations.
824 ///
825 /// \param ArgIdDefLoc the location of the macro argument id inside the macro
826 /// definition.
827 /// \param Tokens the macro argument tokens to update.
828 void TokenLexer::updateLocForMacroArgTokens(SourceLocation ArgIdSpellLoc,
829  Token *begin_tokens,
830  Token *end_tokens) {
831  SourceManager &SM = PP.getSourceManager();
832 
833  SourceLocation InstLoc =
834  getExpansionLocForMacroDefLoc(ArgIdSpellLoc);
835 
836  while (begin_tokens < end_tokens) {
837  // If there's only one token just create a SLocEntry for it.
838  if (end_tokens - begin_tokens == 1) {
839  Token &Tok = *begin_tokens;
841  InstLoc,
842  Tok.getLength()));
843  return;
844  }
845 
846  updateConsecutiveMacroArgTokens(SM, InstLoc, begin_tokens, end_tokens);
847  }
848 }
849 
850 void TokenLexer::PropagateLineStartLeadingSpaceInfo(Token &Result) {
851  AtStartOfLine = Result.isAtStartOfLine();
852  HasLeadingSpace = Result.hasLeadingSpace();
853 }
bool isAtStartOfLine() const
isAtStartOfLine - Return true if this token is at the start of a line.
Definition: Token.h:261
SourceManager & getSourceManager() const
Definition: Preprocessor.h:687
bool isPoisoned() const
Return true if this token has been poisoned.
Lexer - This provides a simple interface that turns a text buffer into a stream of tokens...
Definition: Lexer.h:46
void DisableMacro()
Definition: MacroInfo.h:262
void Init(Token &Tok, SourceLocation ILEnd, MacroInfo *MI, MacroArgs *ActualArgs)
Init - Initialize this TokenLexer to expand from the specified macro with the specified argument info...
Definition: TokenLexer.cpp:26
void setFlagValue(TokenFlags Flag, bool Val)
Set a flag to either true or false.
Definition: Token.h:252
unsigned isNextTokenLParen() const
isNextTokenLParen - If the next token lexed will pop this macro off the expansion stack...
Definition: TokenLexer.cpp:705
Defines the SourceManager interface.
unsigned getNextLocalOffset() const
static void updateConsecutiveMacroArgTokens(SourceManager &SM, SourceLocation InstLoc, Token *&begin_tokens, Token *end_tokens)
Finds the tokens that are consecutive (from the same FileID) creates a single SLocEntry, and assigns SourceLocations to each token that point to that SLocEntry.
Definition: TokenLexer.cpp:765
bool isParsingPreprocessorDirective() const
isParsingPreprocessorDirective - Return true if we are in the middle of a preprocessor directive...
Definition: TokenLexer.cpp:714
Defines the clang::MacroInfo and clang::MacroDirective classes.
bool hasLeadingSpace() const
Return true if this token has whitespace before it.
Definition: Token.h:265
std::unique_ptr< llvm::MemoryBuffer > Buffer
void setFlag(TokenFlags Flag)
Set the specified flag.
Definition: Token.h:234
bool isVarargsElidedUse() const
isVarargsElidedUse - Return true if this is a C99 style varargs macro invocation and there was no arg...
Definition: MacroArgs.h:107
bool isAnyIdentifier() const
Return true if this is a raw identifier (when lexing in raw mode) or a non-keyword identifier (when l...
Definition: Token.h:107
StringRef getSpelling(SourceLocation loc, SmallVectorImpl< char > &buffer, bool *invalid=nullptr) const
Return the 'spelling' of the token at the given location; does not go up to the spelling location or ...
bool HandleEndOfTokenLexer(Token &Result)
Callback invoked when the current TokenLexer hits the end of its token stream.
One of these records is kept for each identifier that is lexed.
bool stringifiedInMacro() const
Returns true if this token is formed by macro by stringizing or charizing operator.
Definition: Token.h:297
void setRawIdentifierData(const char *Ptr)
Definition: Token.h:207
bool isFileID() const
const LangOptions & getLangOpts() const
Definition: Preprocessor.h:683
Token - This structure provides full information about a lexed token.
Definition: Token.h:37
void setKind(tok::TokenKind K)
Definition: Token.h:91
bool Lex(Token &Tok)
Lex - Lex and return a token from this macro stream.
Definition: TokenLexer.cpp:419
SourceLocation getLocWithOffset(int Offset) const
Return a source location with the specified offset from this SourceLocation.
tok::TokenKind getTokenID() const
If this is a source-language token (e.g.
const std::vector< Token > & getPreExpArgument(unsigned Arg, const MacroInfo *MI, Preprocessor &PP)
getPreExpArgument - Return the pre-expanded form of the specified argument.
Definition: MacroArgs.cpp:147
void destroy(Preprocessor &PP)
destroy - Destroy and deallocate the memory for this object.
Definition: MacroArgs.cpp:73
const Token * getUnexpArgument(unsigned Arg) const
getUnexpArgument - Return a pointer to the first token of the unexpanded token list for the specified...
Definition: MacroArgs.cpp:113
tokens_iterator tokens_begin() const
Definition: MacroInfo.h:239
bool isVariadic() const
Definition: MacroInfo.h:204
DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) const
Forwarding function for diagnostics.
const Token & getStringifiedArgument(unsigned ArgNo, Preprocessor &PP, SourceLocation ExpansionLocStart, SourceLocation ExpansionLocEnd)
getStringifiedArgument - Compute, cache, and return the specified argument that has been 'stringified...
Definition: MacroArgs.cpp:297
static bool isWideStringLiteralFromMacro(const Token &FirstTok, const Token &SecondTok)
Checks if two tokens form wide string literal.
Definition: TokenLexer.cpp:410
FileID getFileID(SourceLocation SpellingLoc) const
Return the FileID for a SourceLocation.
static Token StringifyArgument(const Token *ArgToks, Preprocessor &PP, bool Charify, SourceLocation ExpansionLocStart, SourceLocation ExpansionLocEnd)
StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of tokens into the literal string...
Definition: MacroArgs.cpp:194
SourceManager & SM
MacroArgs - An instance of this class captures information about the formal arguments specified to a ...
Definition: MacroArgs.h:29
SourceManager & SourceMgr
Definition: Format.cpp:1352
unsigned getNumArgs() const
Definition: MacroInfo.h:179
SourceLocation createMacroArgExpansionLoc(SourceLocation Loc, SourceLocation ExpansionLoc, unsigned TokLength)
Return a new SourceLocation that encodes the fact that a token from SpellingLoc should actually be re...
Defines the clang::Preprocessor interface.
int getArgumentNum(const IdentifierInfo *Arg) const
Return the argument number of the specified identifier, or -1 if the identifier is not a formal argum...
Definition: MacroInfo.h:186
void HandleMicrosoftCommentPaste(Token &Tok)
When the macro expander pastes together a comment (/##/) in Microsoft mode, this method handles updat...
void IncrementPasteCounter(bool isFast)
Increment the counters for the number of token paste operations performed.
SourceLocation getLocation() const
Return a source location identifier for the specified offset in the current file. ...
Definition: Token.h:124
unsigned getDefinitionLength(SourceManager &SM) const
Get length in characters of the macro definition.
Definition: MacroInfo.h:129
bool isNot(tok::TokenKind K) const
Definition: Token.h:96
SourceLocation createExpansionLoc(SourceLocation Loc, SourceLocation ExpansionLocStart, SourceLocation ExpansionLocEnd, unsigned TokLength, int LoadedID=0, unsigned LoadedOffset=0)
Return a new SourceLocation that encodes the fact that a token from SpellingLoc should actually be re...
The result type of a method or function.
bool isBeforeInSLocAddrSpace(SourceLocation LHS, SourceLocation RHS) const
Determines the order of 2 source locations in the "source location address space".
const char * getLiteralData() const
getLiteralData - For a literal token (numeric constant, string, etc), this returns a pointer to the s...
Definition: Token.h:215
bool isHandleIdentifierCase() const
Return true if the Preprocessor::HandleIdentifier must be called on a token of this identifier...
Encodes a location in the source.
void setLength(unsigned Len)
Definition: Token.h:133
bool isValid() const
Return true if this is a valid SourceLocation object.
bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const
ArgNeedsPreexpansion - If we can prove that the argument won't be affected by pre-expansion, return false.
Definition: MacroArgs.cpp:131
bool is(tok::TokenKind K) const
is/isNot - Predicates to check if this token is a specific kind, as in "if (Tok.is(tok::l_brace)) {...
Definition: Token.h:95
bool isStr(const char(&Str)[StrLen]) const
Return true if this is the identifier for the specified string.
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
bool isInSLocAddrSpace(SourceLocation Loc, SourceLocation Start, unsigned Length, unsigned *RelativeOffset=nullptr) const
Returns true if Loc is inside the [Start, +Length) chunk of the source location address space...
std::pair< SourceLocation, SourceLocation > getImmediateExpansionRange(SourceLocation Loc) const
Return the start/end of the expansion information for an expansion location.
static unsigned getArgLength(const Token *ArgPtr)
getArgLength - Given a pointer to an expanded or unexpanded argument, return the number of tokens...
Definition: MacroArgs.cpp:103
bool isLiteral() const
Return true if this is a "literal", like a numeric constant, string, etc.
Definition: Token.h:113
bool isFunctionLike() const
Definition: MacroInfo.h:196
Encapsulates the data about a macro definition (e.g.
Definition: MacroInfo.h:34
bool isOneOf(tok::TokenKind K1, tok::TokenKind K2) const
Definition: Token.h:97
bool isInSameSLocAddrSpace(SourceLocation LHS, SourceLocation RHS, int *RelativeOffset) const
Return true if both LHS and RHS are in the local source location address space or the loaded one...
bool HandleIdentifier(Token &Identifier)
Callback invoked when the lexer reads an identifier and has filled in the tokens IdentifierInfo membe...
void CreateString(StringRef Str, Token &Tok, SourceLocation ExpansionLocStart=SourceLocation(), SourceLocation ExpansionLocEnd=SourceLocation())
Plop the specified string into a scratch buffer and set the specified token's location and length to ...
tokens_iterator tokens_end() const
Definition: MacroInfo.h:240
static bool isInvalid(SourceLocation Loc, bool *Invalid)
void HandlePoisonedIdentifier(Token &Tok)
Display reason for poisoned identifier.
IdentifierInfo * LookUpIdentifierInfo(Token &Identifier) const
Given a tok::raw_identifier token, look up the identifier information for the token and install it in...
unsigned getLength() const
Definition: Token.h:127
void setLocation(SourceLocation L)
Definition: Token.h:132
void EnableMacro()
Definition: MacroInfo.h:257
void clearFlag(TokenFlags Flag)
Unset the specified flag.
Definition: Token.h:239
SourceLocation getExpansionLoc(SourceLocation Loc) const
Given a SourceLocation object Loc, return the expansion location referenced by the ID...
bool isAnnotation() const
Return true if this is any of tok::annot_* kind tokens.
Definition: Token.h:118
This class handles loading and caching of source files into memory.
void startToken()
Reset all flags to cleared.
Definition: Token.h:169
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:96
IdentifierInfo * getIdentifierInfo() const
Definition: Token.h:177