1 //===--- TokenLexer.cpp - Lex from a token stream -------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the TokenLexer interface.
12 //===----------------------------------------------------------------------===//
14 #include "clang/Lex/TokenLexer.h"
15 #include "clang/Basic/SourceManager.h"
16 #include "clang/Lex/LexDiagnostic.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;
24 /// Create a TokenLexer for the specified macro with the specified actual
25 /// arguments. Note that this ctor takes ownership of the ActualArgs pointer.
26 void TokenLexer::Init(Token &Tok, SourceLocation ELEnd, MacroInfo *MI,
28 // If the client is reusing a TokenLexer, make sure to free any memory
29 // associated with it.
36 ExpandLocStart = Tok.getLocation();
38 AtStartOfLine = Tok.isAtStartOfLine();
39 HasLeadingSpace = Tok.hasLeadingSpace();
40 NextTokGetsSpace = false;
41 Tokens = &*Macro->tokens_begin();
43 DisableMacroExpansion = false;
44 NumTokens = Macro->tokens_end()-Macro->tokens_begin();
45 MacroExpansionStart = SourceLocation();
47 SourceManager &SM = PP.getSourceManager();
48 MacroStartSLocOffset = SM.getNextLocalOffset();
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());
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,
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();
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();
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.
92 OwnsTokens = ownsTokens;
93 DisableMacroExpansion = disableMacroExpansion;
96 ExpandLocStart = ExpandLocEnd = SourceLocation();
97 AtStartOfLine = false;
98 HasLeadingSpace = false;
99 NextTokGetsSpace = false;
100 MacroExpansionStart = SourceLocation();
102 // Set HasLeadingSpace/AtStartOfLine so that the first token will be
103 // returned unmodified.
105 AtStartOfLine = TokArray[0].isAtStartOfLine();
106 HasLeadingSpace = TokArray[0].hasLeadingSpace();
111 void TokenLexer::destroy() {
112 // If this was a function-like macro that actually uses its arguments, delete
113 // the expanded tokens.
120 // TokenLexer owns its formal arguments.
121 if (ActualArgs) ActualArgs->destroy(PP);
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)
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)
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)
146 // Is a comma available to be removed?
147 if (ResultToks.empty() || !ResultToks.back().is(tok::comma))
150 // Issue an extension diagnostic for the paste operator.
151 if (HasPasteOperator)
152 PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma);
155 ResultToks.pop_back();
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();
164 // Never add a space, even if the comma, ##, or arg had a space.
165 NextTokGetsSpace = false;
169 /// Expand the arguments of a function-like macro so that we can quickly
170 /// return preexpanded tokens from Tokens.
171 void TokenLexer::ExpandFunctionArguments() {
173 SmallVector<Token, 128> ResultToks;
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;
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;
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?");
192 SourceLocation ExpansionLocStart =
193 getExpansionLocForMacroDefLoc(CurTok.getLocation());
194 SourceLocation ExpansionLocEnd =
195 getExpansionLocForMacroDefLoc(Tokens[i+1].getLocation());
198 if (CurTok.is(tok::hash)) // Stringify
199 Res = ActualArgs->getStringifiedArgument(ArgNo, PP,
203 // 'charify': don't bother caching these.
204 Res = MacroArgs::StringifyArgument(ActualArgs->getUnexpArgument(ArgNo),
209 Res.setFlag(Token::StringifiedInMacro);
211 // The stringified/charified string leading space flag gets set to match
212 // the #/#@ operator.
213 if (NextTokGetsSpace)
214 Res.setFlag(Token::LeadingSpace);
216 ResultToks.push_back(Res);
218 ++i; // Skip arg name.
219 NextTokGetsSpace = false;
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);
230 // Otherwise, if this is not an argument token, just add the token to the
232 IdentifierInfo *II = CurTok.getIdentifierInfo();
233 int ArgNo = II ? Macro->getArgumentNum(II) : -1;
235 // This isn't an argument, just add it.
236 ResultToks.push_back(CurTok);
238 if (NextTokGetsSpace) {
239 ResultToks.back().setFlag(Token::LeadingSpace);
240 NextTokGetsSpace = false;
241 } else if (PasteBefore && !NonEmptyPasteBefore)
242 ResultToks.back().clearFlag(Token::LeadingSpace);
247 // An argument is expanded somehow, the result is different than the
251 // Otherwise, this is a use of the argument.
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,
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
264 if (!PasteBefore && !PasteAfter) {
265 const Token *ResultArgToks;
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];
273 ResultArgToks = ArgTok; // Use non-preexpanded tokens.
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);
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);
289 // If the '##' came from expanding an argument, turn it into 'unknown'
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);
297 if(ExpandLocStart.isValid()) {
298 updateLocForMacroArgTokens(CurTok.getLocation(),
299 ResultToks.begin()+FirstResult,
303 // If any tokens were substituted from the argument, the whitespace
304 // before the first token should match the whitespace of the arg
306 ResultToks[FirstResult].setFlagValue(Token::LeadingSpace,
308 NextTokGetsSpace = false;
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__
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);
330 ResultToks.append(ArgToks, ArgToks+NumToks);
332 // If the '##' came from expanding an argument, turn it into 'unknown'
334 for (unsigned i = ResultToks.size() - NumToks, e = ResultToks.size();
336 Token &Tok = ResultToks[i];
337 if (Tok.is(tok::hashhash))
338 Tok.setKind(tok::unknown);
341 if (ExpandLocStart.isValid()) {
342 updateLocForMacroArgTokens(CurTok.getLocation(),
343 ResultToks.end()-NumToks, ResultToks.end());
346 // If this token (the macro argument) was supposed to get leading
347 // whitespace, transfer this information onto the first token of the
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);
359 NextTokGetsSpace = false;
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
368 // Discard the argument token and skip (don't copy to the expansion
369 // buffer) the paste operator after it.
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.
378 if (NonEmptyPasteBefore) {
379 assert(ResultToks.back().is(tok::hashhash));
380 ResultToks.pop_back();
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,
395 // If anything changed, install this as the new Tokens list.
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);
404 // The preprocessor cache of macro expanded tokens owns these tokens,not us.
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();
417 /// Lex - Lex and return a token from this macro stream.
419 bool TokenLexer::Lex(Token &Tok) {
420 // Lexing off the end of the macro, pop this macro off the expansion stack.
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();
427 Tok.setFlagValue(Token::StartOfLine , AtStartOfLine);
428 Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace || NextTokGetsSpace);
430 Tok.setFlag(Token::LeadingEmptyMacro);
431 return PP.HandleEndOfTokenLexer(Tok);
434 SourceManager &SM = PP.getSourceManager();
436 // If this is the first token of the expanded result, we inherit spacing
438 bool isFirstToken = CurToken == 0;
440 // Get the next token to return.
441 Tok = Tokens[CurToken++];
443 bool TokenIsFromPaste = false;
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))
459 TokenIsFromPaste = true;
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(),
477 instLoc = getExpansionLocForMacroDefLoc(Tok.getLocation());
480 Tok.setLocation(instLoc);
483 // If this is the first token, set the lexical properties of the token to
484 // match the lexical properties of the macro identifier.
486 Tok.setFlagValue(Token::StartOfLine , AtStartOfLine);
487 Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace);
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);
494 AtStartOfLine = false;
495 HasLeadingSpace = false;
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());
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);
511 if (!DisableMacroExpansion && II->isHandleIdentifierCase())
512 return PP.HandleIdentifier(Tok);
515 // Otherwise, return a normal token.
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))
529 Tok.clearFlag(Token::LeadingSpace);
531 SmallString<128> Buffer;
532 const char *ResultTokStrPtr = nullptr;
533 SourceLocation StartLoc = Tok.getLocation();
534 SourceLocation PasteOpLoc;
536 // Consume the ## operator if any.
537 PasteOpLoc = Tokens[CurToken].getLocation();
538 if (Tokens[CurToken].is(tok::hashhash))
540 assert(!isAtEnd() && "No token on the RHS of a paste operator!");
542 // Get the RHS token.
543 const Token &RHS = Tokens[CurToken];
545 // Allocate space for the result token. This is guaranteed to be enough for
547 Buffer.resize(Tok.getLength() + RHS.getLength());
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);
558 BufPtr = Buffer.data() + LHSLen;
559 unsigned RHSLen = PP.getSpelling(RHS, BufPtr, &Invalid);
562 if (RHSLen && BufPtr != &Buffer[LHSLen])
563 // Really, we want the chars in Buffer!
564 memcpy(&Buffer[LHSLen], BufPtr, RHSLen);
566 // Trim excess space.
567 Buffer.resize(LHSLen+RHSLen);
569 // Plop the pasted result (including the trailing newline and null) into a
570 // scratch buffer where we can lex it.
572 ResultTokTmp.startToken();
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();
581 // Lex the resultant pasted token into Result.
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);
589 Result.setKind(tok::raw_identifier);
590 Result.setRawIdentifierData(ResultTokStrPtr);
591 Result.setLocation(ResultTokLoc);
592 Result.setLength(LHSLen+RHSLen);
594 PP.IncrementPasteCounter(false);
596 assert(ResultTokLoc.isFileID() &&
597 "Should be a raw location into scratch buffer");
598 SourceManager &SourceMgr = PP.getSourceManager();
599 FileID LocFileID = SourceMgr.getFileID(ResultTokLoc);
601 bool Invalid = false;
602 const char *ScratchBufStart
603 = SourceMgr.getBufferData(LocFileID, &Invalid).data();
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);
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
617 bool isInvalid = !TL.LexFromRawLexer(Result);
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);
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.
627 // Test for the Microsoft extension of /##/ turning into // here on the
629 if (PP.getLangOpts().MicrosoftExt && Tok.is(tok::slash) &&
630 RHS.is(tok::slash)) {
631 HandleMicrosoftCommentPaste(Tok);
635 // Do not emit the error when preprocessing assembler code.
636 if (!PP.getLangOpts().AsmPreprocessor) {
637 // Explicitly convert the token location to have proper expansion
638 // information so that the user knows where it came from.
639 SourceManager &SM = PP.getSourceManager();
641 SM.createExpansionLoc(PasteOpLoc, ExpandLocStart, ExpandLocEnd, 2);
642 // If we're in microsoft extensions mode, downgrade this from a hard
643 // error to an extension that defaults to an error. This allows
645 PP.Diag(Loc, PP.getLangOpts().MicrosoftExt ? diag::ext_pp_bad_paste_ms
646 : diag::err_pp_bad_paste)
650 // An error has occurred so exit loop.
654 // Turn ## into 'unknown' to avoid # ## # from looking like a paste
656 if (Result.is(tok::hashhash))
657 Result.setKind(tok::unknown);
660 // Transfer properties of the LHS over the Result.
661 Result.setFlagValue(Token::StartOfLine , Tok.isAtStartOfLine());
662 Result.setFlagValue(Token::LeadingSpace, Tok.hasLeadingSpace());
664 // Finally, replace LHS with the result, consume the RHS, and iterate.
667 } while (!isAtEnd() && Tokens[CurToken].is(tok::hashhash));
669 SourceLocation EndLoc = Tokens[CurToken - 1].getLocation();
671 // The token's current location indicate where the token was lexed from. We
672 // need this information to compute the spelling of the token, but any
673 // diagnostics for the expanded token should appear as if the token was
674 // expanded from the full ## expression. Pull this information together into
675 // a new SourceLocation that captures all of this.
676 SourceManager &SM = PP.getSourceManager();
677 if (StartLoc.isFileID())
678 StartLoc = getExpansionLocForMacroDefLoc(StartLoc);
679 if (EndLoc.isFileID())
680 EndLoc = getExpansionLocForMacroDefLoc(EndLoc);
681 FileID MacroFID = SM.getFileID(MacroExpansionStart);
682 while (SM.getFileID(StartLoc) != MacroFID)
683 StartLoc = SM.getImmediateExpansionRange(StartLoc).first;
684 while (SM.getFileID(EndLoc) != MacroFID)
685 EndLoc = SM.getImmediateExpansionRange(EndLoc).second;
687 Tok.setLocation(SM.createExpansionLoc(Tok.getLocation(), StartLoc, EndLoc,
690 // Now that we got the result token, it will be subject to expansion. Since
691 // token pasting re-lexes the result token in raw mode, identifier information
692 // isn't looked up. As such, if the result is an identifier, look up id info.
693 if (Tok.is(tok::raw_identifier)) {
694 // Look up the identifier info for the token. We disabled identifier lookup
695 // by saying we're skipping contents, so we need to do this manually.
696 PP.LookUpIdentifierInfo(Tok);
701 /// isNextTokenLParen - If the next token lexed will pop this macro off the
702 /// expansion stack, return 2. If the next unexpanded token is a '(', return
703 /// 1, otherwise return 0.
704 unsigned TokenLexer::isNextTokenLParen() const {
708 return Tokens[CurToken].is(tok::l_paren);
711 /// isParsingPreprocessorDirective - Return true if we are in the middle of a
712 /// preprocessor directive.
713 bool TokenLexer::isParsingPreprocessorDirective() const {
714 return Tokens[NumTokens-1].is(tok::eod) && !isAtEnd();
717 /// HandleMicrosoftCommentPaste - In microsoft compatibility mode, /##/ pastes
718 /// together to form a comment that comments out everything in the current
719 /// macro, other active macros, and anything left on the current physical
720 /// source line of the expanded buffer. Handle this by returning the
721 /// first token on the next line.
722 void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok) {
723 // We 'comment out' the rest of this macro by just ignoring the rest of the
724 // tokens that have not been lexed yet, if any.
726 // Since this must be a macro, mark the macro enabled now that it is no longer
728 assert(Macro && "Token streams can't paste comments");
729 Macro->EnableMacro();
731 PP.HandleMicrosoftCommentPaste(Tok);
734 /// \brief If \arg loc is a file ID and points inside the current macro
735 /// definition, returns the appropriate source location pointing at the
736 /// macro expansion source location entry, otherwise it returns an invalid
739 TokenLexer::getExpansionLocForMacroDefLoc(SourceLocation loc) const {
740 assert(ExpandLocStart.isValid() && MacroExpansionStart.isValid() &&
741 "Not appropriate for token streams");
742 assert(loc.isValid() && loc.isFileID());
744 SourceManager &SM = PP.getSourceManager();
745 assert(SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength) &&
746 "Expected loc to come from the macro definition");
748 unsigned relativeOffset = 0;
749 SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength, &relativeOffset);
750 return MacroExpansionStart.getLocWithOffset(relativeOffset);
753 /// \brief Finds the tokens that are consecutive (from the same FileID)
754 /// creates a single SLocEntry, and assigns SourceLocations to each token that
755 /// point to that SLocEntry. e.g for
756 /// assert(foo == bar);
757 /// There will be a single SLocEntry for the "foo == bar" chunk and locations
758 /// for the 'foo', '==', 'bar' tokens will point inside that chunk.
760 /// \arg begin_tokens will be updated to a position past all the found
761 /// consecutive tokens.
762 static void updateConsecutiveMacroArgTokens(SourceManager &SM,
763 SourceLocation InstLoc,
764 Token *&begin_tokens,
765 Token * end_tokens) {
766 assert(begin_tokens < end_tokens);
768 SourceLocation FirstLoc = begin_tokens->getLocation();
769 SourceLocation CurLoc = FirstLoc;
771 // Compare the source location offset of tokens and group together tokens that
772 // are close, even if their locations point to different FileIDs. e.g.
774 // |bar | foo | cake | (3 tokens from 3 consecutive FileIDs)
776 // |bar foo cake| (one SLocEntry chunk for all tokens)
778 // we can perform this "merge" since the token's spelling location depends
779 // on the relative offset.
781 Token *NextTok = begin_tokens + 1;
782 for (; NextTok < end_tokens; ++NextTok) {
783 SourceLocation NextLoc = NextTok->getLocation();
784 if (CurLoc.isFileID() != NextLoc.isFileID())
785 break; // Token from different kind of FileID.
788 if (!SM.isInSameSLocAddrSpace(CurLoc, NextLoc, &RelOffs))
789 break; // Token from different local/loaded location.
790 // Check that token is not before the previous token or more than 50
791 // "characters" away.
792 if (RelOffs < 0 || RelOffs > 50)
797 // For the consecutive tokens, find the length of the SLocEntry to contain
799 Token &LastConsecutiveTok = *(NextTok-1);
801 SM.isInSameSLocAddrSpace(FirstLoc, LastConsecutiveTok.getLocation(),
803 unsigned FullLength = LastRelOffs + LastConsecutiveTok.getLength();
805 // Create a macro expansion SLocEntry that will "contain" all of the tokens.
806 SourceLocation Expansion =
807 SM.createMacroArgExpansionLoc(FirstLoc, InstLoc,FullLength);
809 // Change the location of the tokens from the spelling location to the new
810 // expanded location.
811 for (; begin_tokens < NextTok; ++begin_tokens) {
812 Token &Tok = *begin_tokens;
814 SM.isInSameSLocAddrSpace(FirstLoc, Tok.getLocation(), &RelOffs);
815 Tok.setLocation(Expansion.getLocWithOffset(RelOffs));
819 /// \brief Creates SLocEntries and updates the locations of macro argument
820 /// tokens to their new expanded locations.
822 /// \param ArgIdDefLoc the location of the macro argument id inside the macro
824 /// \param Tokens the macro argument tokens to update.
825 void TokenLexer::updateLocForMacroArgTokens(SourceLocation ArgIdSpellLoc,
828 SourceManager &SM = PP.getSourceManager();
830 SourceLocation InstLoc =
831 getExpansionLocForMacroDefLoc(ArgIdSpellLoc);
833 while (begin_tokens < end_tokens) {
834 // If there's only one token just create a SLocEntry for it.
835 if (end_tokens - begin_tokens == 1) {
836 Token &Tok = *begin_tokens;
837 Tok.setLocation(SM.createMacroArgExpansionLoc(Tok.getLocation(),
843 updateConsecutiveMacroArgTokens(SM, InstLoc, begin_tokens, end_tokens);
847 void TokenLexer::PropagateLineStartLeadingSpaceInfo(Token &Result) {
848 AtStartOfLine = Result.isAtStartOfLine();
849 HasLeadingSpace = Result.hasLeadingSpace();