//===- TokenLexer.cpp - Lex from a token stream ---------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements the TokenLexer interface. // //===----------------------------------------------------------------------===// #include "clang/Lex/TokenLexer.h" #include "clang/Basic/Diagnostic.h" #include "clang/Basic/IdentifierTable.h" #include "clang/Basic/LangOptions.h" #include "clang/Basic/SourceLocation.h" #include "clang/Basic/SourceManager.h" #include "clang/Basic/TokenKinds.h" #include "clang/Lex/LexDiagnostic.h" #include "clang/Lex/Lexer.h" #include "clang/Lex/MacroArgs.h" #include "clang/Lex/MacroInfo.h" #include "clang/Lex/Preprocessor.h" #include "clang/Lex/Token.h" #include "clang/Lex/VariadicMacroSupport.h" #include "llvm/ADT/ArrayRef.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/iterator_range.h" #include #include using namespace clang; /// Create a TokenLexer for the specified macro with the specified actual /// arguments. Note that this ctor takes ownership of the ActualArgs pointer. void TokenLexer::Init(Token &Tok, SourceLocation ELEnd, MacroInfo *MI, MacroArgs *Actuals) { // If the client is reusing a TokenLexer, make sure to free any memory // associated with it. destroy(); Macro = MI; ActualArgs = Actuals; CurTokenIdx = 0; ExpandLocStart = Tok.getLocation(); ExpandLocEnd = ELEnd; AtStartOfLine = Tok.isAtStartOfLine(); HasLeadingSpace = Tok.hasLeadingSpace(); NextTokGetsSpace = false; Tokens = &*Macro->tokens_begin(); OwnsTokens = false; DisableMacroExpansion = false; NumTokens = Macro->tokens_end()-Macro->tokens_begin(); MacroExpansionStart = SourceLocation(); SourceManager &SM = PP.getSourceManager(); MacroStartSLocOffset = SM.getNextLocalOffset(); if (NumTokens > 0) { assert(Tokens[0].getLocation().isValid()); assert((Tokens[0].getLocation().isFileID() || Tokens[0].is(tok::comment)) && "Macro defined in macro?"); assert(ExpandLocStart.isValid()); // Reserve a source location entry chunk for the length of the macro // definition. Tokens that get lexed directly from the definition will // have their locations pointing inside this chunk. This is to avoid // creating separate source location entries for each token. MacroDefStart = SM.getExpansionLoc(Tokens[0].getLocation()); MacroDefLength = Macro->getDefinitionLength(SM); MacroExpansionStart = SM.createExpansionLoc(MacroDefStart, ExpandLocStart, ExpandLocEnd, MacroDefLength); } // If this is a function-like macro, expand the arguments and change // Tokens to point to the expanded tokens. if (Macro->isFunctionLike() && Macro->getNumParams()) ExpandFunctionArguments(); // Mark the macro as currently disabled, so that it is not recursively // expanded. The macro must be disabled only after argument pre-expansion of // function-like macro arguments occurs. Macro->DisableMacro(); } /// Create a TokenLexer for the specified token stream. This does not /// take ownership of the specified token vector. void TokenLexer::Init(const Token *TokArray, unsigned NumToks, bool disableMacroExpansion, bool ownsTokens) { // If the client is reusing a TokenLexer, make sure to free any memory // associated with it. destroy(); Macro = nullptr; ActualArgs = nullptr; Tokens = TokArray; OwnsTokens = ownsTokens; DisableMacroExpansion = disableMacroExpansion; NumTokens = NumToks; CurTokenIdx = 0; ExpandLocStart = ExpandLocEnd = SourceLocation(); AtStartOfLine = false; HasLeadingSpace = false; NextTokGetsSpace = false; MacroExpansionStart = SourceLocation(); // Set HasLeadingSpace/AtStartOfLine so that the first token will be // returned unmodified. if (NumToks != 0) { AtStartOfLine = TokArray[0].isAtStartOfLine(); HasLeadingSpace = TokArray[0].hasLeadingSpace(); } } void TokenLexer::destroy() { // If this was a function-like macro that actually uses its arguments, delete // the expanded tokens. if (OwnsTokens) { delete [] Tokens; Tokens = nullptr; OwnsTokens = false; } // TokenLexer owns its formal arguments. if (ActualArgs) ActualArgs->destroy(PP); } bool TokenLexer::MaybeRemoveCommaBeforeVaArgs( SmallVectorImpl &ResultToks, bool HasPasteOperator, MacroInfo *Macro, unsigned MacroArgNo, Preprocessor &PP) { // Is the macro argument __VA_ARGS__? if (!Macro->isVariadic() || MacroArgNo != Macro->getNumParams()-1) return false; // In Microsoft-compatibility mode, a comma is removed in the expansion // of " ... , __VA_ARGS__ " if __VA_ARGS__ is empty. This extension is // not supported by gcc. if (!HasPasteOperator && !PP.getLangOpts().MSVCCompat) return false; // GCC removes the comma in the expansion of " ... , ## __VA_ARGS__ " if // __VA_ARGS__ is empty, but not in strict C99 mode where there are no // named arguments, where it remains. In all other modes, including C99 // with GNU extensions, it is removed regardless of named arguments. // Microsoft also appears to support this extension, unofficially. if (PP.getLangOpts().C99 && !PP.getLangOpts().GNUMode && Macro->getNumParams() < 2) return false; // Is a comma available to be removed? if (ResultToks.empty() || !ResultToks.back().is(tok::comma)) return false; // Issue an extension diagnostic for the paste operator. if (HasPasteOperator) PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma); // Remove the comma. ResultToks.pop_back(); if (!ResultToks.empty()) { // If the comma was right after another paste (e.g. "X##,##__VA_ARGS__"), // then removal of the comma should produce a placemarker token (in C99 // terms) which we model by popping off the previous ##, giving us a plain // "X" when __VA_ARGS__ is empty. if (ResultToks.back().is(tok::hashhash)) ResultToks.pop_back(); // Remember that this comma was elided. ResultToks.back().setFlag(Token::CommaAfterElided); } // Never add a space, even if the comma, ##, or arg had a space. NextTokGetsSpace = false; return true; } void TokenLexer::stringifyVAOPTContents( SmallVectorImpl &ResultToks, const VAOptExpansionContext &VCtx, const SourceLocation VAOPTClosingParenLoc) { const int NumToksPriorToVAOpt = VCtx.getNumberOfTokensPriorToVAOpt(); const unsigned int NumVAOptTokens = ResultToks.size() - NumToksPriorToVAOpt; Token *const VAOPTTokens = NumVAOptTokens ? &ResultToks[NumToksPriorToVAOpt] : nullptr; SmallVector ConcatenatedVAOPTResultToks; // FIXME: Should we keep track within VCtx that we did or didnot // encounter pasting - and only then perform this loop. // Perform token pasting (concatenation) prior to stringization. for (unsigned int CurTokenIdx = 0; CurTokenIdx != NumVAOptTokens; ++CurTokenIdx) { if (VAOPTTokens[CurTokenIdx].is(tok::hashhash)) { assert(CurTokenIdx != 0 && "Can not have __VAOPT__ contents begin with a ##"); Token &LHS = VAOPTTokens[CurTokenIdx - 1]; pasteTokens(LHS, llvm::makeArrayRef(VAOPTTokens, NumVAOptTokens), CurTokenIdx); // Replace the token prior to the first ## in this iteration. ConcatenatedVAOPTResultToks.back() = LHS; if (CurTokenIdx == NumVAOptTokens) break; } ConcatenatedVAOPTResultToks.push_back(VAOPTTokens[CurTokenIdx]); } ConcatenatedVAOPTResultToks.push_back(VCtx.getEOFTok()); // Get the SourceLocation that represents the start location within // the macro definition that marks where this string is substituted // into: i.e. the __VA_OPT__ and the ')' within the spelling of the // macro definition, and use it to indicate that the stringified token // was generated from that location. const SourceLocation ExpansionLocStartWithinMacro = getExpansionLocForMacroDefLoc(VCtx.getVAOptLoc()); const SourceLocation ExpansionLocEndWithinMacro = getExpansionLocForMacroDefLoc(VAOPTClosingParenLoc); Token StringifiedVAOPT = MacroArgs::StringifyArgument( &ConcatenatedVAOPTResultToks[0], PP, VCtx.hasCharifyBefore() /*Charify*/, ExpansionLocStartWithinMacro, ExpansionLocEndWithinMacro); if (VCtx.getLeadingSpaceForStringifiedToken()) StringifiedVAOPT.setFlag(Token::LeadingSpace); StringifiedVAOPT.setFlag(Token::StringifiedInMacro); // Resize (shrink) the token stream to just capture this stringified token. ResultToks.resize(NumToksPriorToVAOpt + 1); ResultToks.back() = StringifiedVAOPT; } /// Expand the arguments of a function-like macro so that we can quickly /// return preexpanded tokens from Tokens. void TokenLexer::ExpandFunctionArguments() { SmallVector ResultToks; // Loop through 'Tokens', expanding them into ResultToks. Keep // track of whether we change anything. If not, no need to keep them. If so, // we install the newly expanded sequence as the new 'Tokens' list. bool MadeChange = false; const bool CalledWithVariadicArguments = ActualArgs->invokedWithVariadicArgument(Macro); VAOptExpansionContext VCtx(PP); for (unsigned I = 0, E = NumTokens; I != E; ++I) { const Token &CurTok = Tokens[I]; // We don't want a space for the next token after a paste // operator. In valid code, the token will get smooshed onto the // preceding one anyway. In assembler-with-cpp mode, invalid // pastes are allowed through: in this case, we do not want the // extra whitespace to be added. For example, we want ". ## foo" // -> ".foo" not ". foo". if (I != 0 && !Tokens[I-1].is(tok::hashhash) && CurTok.hasLeadingSpace()) NextTokGetsSpace = true; if (VCtx.isVAOptToken(CurTok)) { MadeChange = true; assert(Tokens[I + 1].is(tok::l_paren) && "__VA_OPT__ must be followed by '('"); ++I; // Skip the l_paren VCtx.sawVAOptFollowedByOpeningParens(CurTok.getLocation(), ResultToks.size()); continue; } // We have entered into the __VA_OPT__ context, so handle tokens // appropriately. if (VCtx.isInVAOpt()) { // If we are about to process a token that is either an argument to // __VA_OPT__ or its closing rparen, then: // 1) If the token is the closing rparen that exits us out of __VA_OPT__, // perform any necessary stringification or placemarker processing, // and/or skip to the next token. // 2) else if macro was invoked without variadic arguments skip this // token. // 3) else (macro was invoked with variadic arguments) process the token // normally. if (Tokens[I].is(tok::l_paren)) VCtx.sawOpeningParen(Tokens[I].getLocation()); // Continue skipping tokens within __VA_OPT__ if the macro was not // called with variadic arguments, else let the rest of the loop handle // this token. Note sawClosingParen() returns true only if the r_paren matches // the closing r_paren of the __VA_OPT__. if (!Tokens[I].is(tok::r_paren) || !VCtx.sawClosingParen()) { if (!CalledWithVariadicArguments) { // Skip this token. continue; } // ... else the macro was called with variadic arguments, and we do not // have a closing rparen - so process this token normally. } else { // Current token is the closing r_paren which marks the end of the // __VA_OPT__ invocation, so handle any place-marker pasting (if // empty) by removing hashhash either before (if exists) or after. And // also stringify the entire contents if VAOPT was preceded by a hash, // but do so only after any token concatenation that needs to occur // within the contents of VAOPT. if (VCtx.hasStringifyOrCharifyBefore()) { // Replace all the tokens just added from within VAOPT into a single // stringified token. This requires token-pasting to eagerly occur // within these tokens. If either the contents of VAOPT were empty // or the macro wasn't called with any variadic arguments, the result // is a token that represents an empty string. stringifyVAOPTContents(ResultToks, VCtx, /*ClosingParenLoc*/ Tokens[I].getLocation()); } else if (/*No tokens within VAOPT*/ !( ResultToks.size() - VCtx.getNumberOfTokensPriorToVAOpt())) { // Treat VAOPT as a placemarker token. Eat either the '##' before the // RHS/VAOPT (if one exists, suggesting that the LHS (if any) to that // hashhash was not a placemarker) or the '##' // after VAOPT, but not both. if (ResultToks.size() && ResultToks.back().is(tok::hashhash)) { ResultToks.pop_back(); } else if ((I + 1 != E) && Tokens[I + 1].is(tok::hashhash)) { ++I; // Skip the following hashhash. } } VCtx.reset(); // We processed __VA_OPT__'s closing paren (and the exit out of // __VA_OPT__), so skip to the next token. continue; } } // If we found the stringify operator, get the argument stringified. The // preprocessor already verified that the following token is a macro // parameter or __VA_OPT__ when the #define was lexed. if (CurTok.isOneOf(tok::hash, tok::hashat)) { int ArgNo = Macro->getParameterNum(Tokens[I+1].getIdentifierInfo()); assert((ArgNo != -1 || VCtx.isVAOptToken(Tokens[I + 1])) && "Token following # is not an argument or __VA_OPT__!"); if (ArgNo == -1) { // Handle the __VA_OPT__ case. VCtx.sawHashOrHashAtBefore(NextTokGetsSpace, CurTok.is(tok::hashat)); continue; } // Else handle the simple argument case. SourceLocation ExpansionLocStart = getExpansionLocForMacroDefLoc(CurTok.getLocation()); SourceLocation ExpansionLocEnd = getExpansionLocForMacroDefLoc(Tokens[I+1].getLocation()); Token Res; if (CurTok.is(tok::hash)) // Stringify Res = ActualArgs->getStringifiedArgument(ArgNo, PP, ExpansionLocStart, ExpansionLocEnd); else { // 'charify': don't bother caching these. Res = MacroArgs::StringifyArgument(ActualArgs->getUnexpArgument(ArgNo), PP, true, ExpansionLocStart, ExpansionLocEnd); } Res.setFlag(Token::StringifiedInMacro); // The stringified/charified string leading space flag gets set to match // the #/#@ operator. if (NextTokGetsSpace) Res.setFlag(Token::LeadingSpace); ResultToks.push_back(Res); MadeChange = true; ++I; // Skip arg name. NextTokGetsSpace = false; continue; } // Find out if there is a paste (##) operator before or after the token. bool NonEmptyPasteBefore = !ResultToks.empty() && ResultToks.back().is(tok::hashhash); bool PasteBefore = I != 0 && Tokens[I-1].is(tok::hashhash); bool PasteAfter = I+1 != E && Tokens[I+1].is(tok::hashhash); assert((!NonEmptyPasteBefore || PasteBefore || VCtx.isInVAOpt()) && "unexpected ## in ResultToks"); // Otherwise, if this is not an argument token, just add the token to the // output buffer. IdentifierInfo *II = CurTok.getIdentifierInfo(); int ArgNo = II ? Macro->getParameterNum(II) : -1; if (ArgNo == -1) { // This isn't an argument, just add it. ResultToks.push_back(CurTok); if (NextTokGetsSpace) { ResultToks.back().setFlag(Token::LeadingSpace); NextTokGetsSpace = false; } else if (PasteBefore && !NonEmptyPasteBefore) ResultToks.back().clearFlag(Token::LeadingSpace); continue; } // An argument is expanded somehow, the result is different than the // input. MadeChange = true; // Otherwise, this is a use of the argument. // In Microsoft mode, remove the comma before __VA_ARGS__ to ensure there // are no trailing commas if __VA_ARGS__ is empty. if (!PasteBefore && ActualArgs->isVarargsElidedUse() && MaybeRemoveCommaBeforeVaArgs(ResultToks, /*HasPasteOperator=*/false, Macro, ArgNo, PP)) continue; // If it is not the LHS/RHS of a ## operator, we must pre-expand the // argument and substitute the expanded tokens into the result. This is // C99 6.10.3.1p1. if (!PasteBefore && !PasteAfter) { const Token *ResultArgToks; // Only preexpand the argument if it could possibly need it. This // avoids some work in common cases. const Token *ArgTok = ActualArgs->getUnexpArgument(ArgNo); if (ActualArgs->ArgNeedsPreexpansion(ArgTok, PP)) ResultArgToks = &ActualArgs->getPreExpArgument(ArgNo, PP)[0]; else ResultArgToks = ArgTok; // Use non-preexpanded tokens. // If the arg token expanded into anything, append it. if (ResultArgToks->isNot(tok::eof)) { size_t FirstResult = ResultToks.size(); unsigned NumToks = MacroArgs::getArgLength(ResultArgToks); ResultToks.append(ResultArgToks, ResultArgToks+NumToks); // In Microsoft-compatibility mode, we follow MSVC's preprocessing // behavior by not considering single commas from nested macro // expansions as argument separators. Set a flag on the token so we can // test for this later when the macro expansion is processed. if (PP.getLangOpts().MSVCCompat && NumToks == 1 && ResultToks.back().is(tok::comma)) ResultToks.back().setFlag(Token::IgnoredComma); // If the '##' came from expanding an argument, turn it into 'unknown' // to avoid pasting. for (Token &Tok : llvm::make_range(ResultToks.begin() + FirstResult, ResultToks.end())) { if (Tok.is(tok::hashhash)) Tok.setKind(tok::unknown); } if(ExpandLocStart.isValid()) { updateLocForMacroArgTokens(CurTok.getLocation(), ResultToks.begin()+FirstResult, ResultToks.end()); } // If any tokens were substituted from the argument, the whitespace // before the first token should match the whitespace of the arg // identifier. ResultToks[FirstResult].setFlagValue(Token::LeadingSpace, NextTokGetsSpace); ResultToks[FirstResult].setFlagValue(Token::StartOfLine, false); NextTokGetsSpace = false; } continue; } // Okay, we have a token that is either the LHS or RHS of a paste (##) // argument. It gets substituted as its non-pre-expanded tokens. const Token *ArgToks = ActualArgs->getUnexpArgument(ArgNo); unsigned NumToks = MacroArgs::getArgLength(ArgToks); if (NumToks) { // Not an empty argument? bool VaArgsPseudoPaste = false; // If this is the GNU ", ## __VA_ARGS__" extension, and we just learned // that __VA_ARGS__ expands to multiple tokens, avoid a pasting error when // the expander tries to paste ',' with the first token of the __VA_ARGS__ // expansion. if (NonEmptyPasteBefore && ResultToks.size() >= 2 && ResultToks[ResultToks.size()-2].is(tok::comma) && (unsigned)ArgNo == Macro->getNumParams()-1 && Macro->isVariadic()) { VaArgsPseudoPaste = true; // Remove the paste operator, report use of the extension. PP.Diag(ResultToks.pop_back_val().getLocation(), diag::ext_paste_comma); } ResultToks.append(ArgToks, ArgToks+NumToks); // If the '##' came from expanding an argument, turn it into 'unknown' // to avoid pasting. for (Token &Tok : llvm::make_range(ResultToks.end() - NumToks, ResultToks.end())) { if (Tok.is(tok::hashhash)) Tok.setKind(tok::unknown); } if (ExpandLocStart.isValid()) { updateLocForMacroArgTokens(CurTok.getLocation(), ResultToks.end()-NumToks, ResultToks.end()); } // Transfer the leading whitespace information from the token // (the macro argument) onto the first token of the // expansion. Note that we don't do this for the GNU // pseudo-paste extension ", ## __VA_ARGS__". if (!VaArgsPseudoPaste) { ResultToks[ResultToks.size() - NumToks].setFlagValue(Token::StartOfLine, false); ResultToks[ResultToks.size() - NumToks].setFlagValue( Token::LeadingSpace, NextTokGetsSpace); } NextTokGetsSpace = false; continue; } // If an empty argument is on the LHS or RHS of a paste, the standard (C99 // 6.10.3.3p2,3) calls for a bunch of placemarker stuff to occur. We // implement this by eating ## operators when a LHS or RHS expands to // empty. if (PasteAfter) { // Discard the argument token and skip (don't copy to the expansion // buffer) the paste operator after it. ++I; continue; } // If this is on the RHS of a paste operator, we've already copied the // paste operator to the ResultToks list, unless the LHS was empty too. // Remove it. assert(PasteBefore); if (NonEmptyPasteBefore) { assert(ResultToks.back().is(tok::hashhash)); // Do not remove the paste operator if it is the one before __VA_OPT__ // (and we are still processing tokens within VA_OPT). We handle the case // of removing the paste operator if __VA_OPT__ reduces to the notional // placemarker above when we encounter the closing paren of VA_OPT. if (!VCtx.isInVAOpt() || ResultToks.size() > VCtx.getNumberOfTokensPriorToVAOpt()) ResultToks.pop_back(); } // If this is the __VA_ARGS__ token, and if the argument wasn't provided, // and if the macro had at least one real argument, and if the token before // the ## was a comma, remove the comma. This is a GCC extension which is // disabled when using -std=c99. if (ActualArgs->isVarargsElidedUse()) MaybeRemoveCommaBeforeVaArgs(ResultToks, /*HasPasteOperator=*/true, Macro, ArgNo, PP); } // If anything changed, install this as the new Tokens list. if (MadeChange) { assert(!OwnsTokens && "This would leak if we already own the token list"); // This is deleted in the dtor. NumTokens = ResultToks.size(); // The tokens will be added to Preprocessor's cache and will be removed // when this TokenLexer finishes lexing them. Tokens = PP.cacheMacroExpandedTokens(this, ResultToks); // The preprocessor cache of macro expanded tokens owns these tokens,not us. OwnsTokens = false; } } /// Checks if two tokens form wide string literal. static bool isWideStringLiteralFromMacro(const Token &FirstTok, const Token &SecondTok) { return FirstTok.is(tok::identifier) && FirstTok.getIdentifierInfo()->isStr("L") && SecondTok.isLiteral() && SecondTok.stringifiedInMacro(); } /// Lex - Lex and return a token from this macro stream. bool TokenLexer::Lex(Token &Tok) { // Lexing off the end of the macro, pop this macro off the expansion stack. if (isAtEnd()) { // If this is a macro (not a token stream), mark the macro enabled now // that it is no longer being expanded. if (Macro) Macro->EnableMacro(); Tok.startToken(); Tok.setFlagValue(Token::StartOfLine , AtStartOfLine); Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace || NextTokGetsSpace); if (CurTokenIdx == 0) Tok.setFlag(Token::LeadingEmptyMacro); return PP.HandleEndOfTokenLexer(Tok); } SourceManager &SM = PP.getSourceManager(); // If this is the first token of the expanded result, we inherit spacing // properties later. bool isFirstToken = CurTokenIdx == 0; // Get the next token to return. Tok = Tokens[CurTokenIdx++]; bool TokenIsFromPaste = false; // If this token is followed by a token paste (##) operator, paste the tokens! // Note that ## is a normal token when not expanding a macro. if (!isAtEnd() && Macro && (Tokens[CurTokenIdx].is(tok::hashhash) || // Special processing of L#x macros in -fms-compatibility mode. // Microsoft compiler is able to form a wide string literal from // 'L#macro_arg' construct in a function-like macro. (PP.getLangOpts().MSVCCompat && isWideStringLiteralFromMacro(Tok, Tokens[CurTokenIdx])))) { // When handling the microsoft /##/ extension, the final token is // returned by pasteTokens, not the pasted token. if (pasteTokens(Tok)) return true; TokenIsFromPaste = true; } // The token's current location indicate where the token was lexed from. We // need this information to compute the spelling of the token, but any // diagnostics for the expanded token should appear as if they came from // ExpansionLoc. Pull this information together into a new SourceLocation // that captures all of this. if (ExpandLocStart.isValid() && // Don't do this for token streams. // Check that the token's location was not already set properly. SM.isBeforeInSLocAddrSpace(Tok.getLocation(), MacroStartSLocOffset)) { SourceLocation instLoc; if (Tok.is(tok::comment)) { instLoc = SM.createExpansionLoc(Tok.getLocation(), ExpandLocStart, ExpandLocEnd, Tok.getLength()); } else { instLoc = getExpansionLocForMacroDefLoc(Tok.getLocation()); } Tok.setLocation(instLoc); } // If this is the first token, set the lexical properties of the token to // match the lexical properties of the macro identifier. if (isFirstToken) { Tok.setFlagValue(Token::StartOfLine , AtStartOfLine); Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace); } else { // If this is not the first token, we may still need to pass through // leading whitespace if we've expanded a macro. if (AtStartOfLine) Tok.setFlag(Token::StartOfLine); if (HasLeadingSpace) Tok.setFlag(Token::LeadingSpace); } AtStartOfLine = false; HasLeadingSpace = false; // Handle recursive expansion! if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != nullptr) { // Change the kind of this identifier to the appropriate token kind, e.g. // turning "for" into a keyword. IdentifierInfo *II = Tok.getIdentifierInfo(); Tok.setKind(II->getTokenID()); // If this identifier was poisoned and from a paste, emit an error. This // won't be handled by Preprocessor::HandleIdentifier because this is coming // from a macro expansion. if (II->isPoisoned() && TokenIsFromPaste) { PP.HandlePoisonedIdentifier(Tok); } if (!DisableMacroExpansion && II->isHandleIdentifierCase()) return PP.HandleIdentifier(Tok); } // Otherwise, return a normal token. return true; } bool TokenLexer::pasteTokens(Token &Tok) { return pasteTokens(Tok, llvm::makeArrayRef(Tokens, NumTokens), CurTokenIdx); } /// LHSTok is the LHS of a ## operator, and CurTokenIdx is the ## /// operator. Read the ## and RHS, and paste the LHS/RHS together. If there /// are more ## after it, chomp them iteratively. Return the result as LHSTok. /// If this returns true, the caller should immediately return the token. bool TokenLexer::pasteTokens(Token &LHSTok, ArrayRef TokenStream, unsigned int &CurIdx) { assert(CurIdx > 0 && "## can not be the first token within tokens"); assert((TokenStream[CurIdx].is(tok::hashhash) || (PP.getLangOpts().MSVCCompat && isWideStringLiteralFromMacro(LHSTok, TokenStream[CurIdx]))) && "Token at this Index must be ## or part of the MSVC 'L " "#macro-arg' pasting pair"); // MSVC: If previous token was pasted, this must be a recovery from an invalid // paste operation. Ignore spaces before this token to mimic MSVC output. // Required for generating valid UUID strings in some MS headers. if (PP.getLangOpts().MicrosoftExt && (CurIdx >= 2) && TokenStream[CurIdx - 2].is(tok::hashhash)) LHSTok.clearFlag(Token::LeadingSpace); SmallString<128> Buffer; const char *ResultTokStrPtr = nullptr; SourceLocation StartLoc = LHSTok.getLocation(); SourceLocation PasteOpLoc; auto IsAtEnd = [&TokenStream, &CurIdx] { return TokenStream.size() == CurIdx; }; do { // Consume the ## operator if any. PasteOpLoc = TokenStream[CurIdx].getLocation(); if (TokenStream[CurIdx].is(tok::hashhash)) ++CurIdx; assert(!IsAtEnd() && "No token on the RHS of a paste operator!"); // Get the RHS token. const Token &RHS = TokenStream[CurIdx]; // Allocate space for the result token. This is guaranteed to be enough for // the two tokens. Buffer.resize(LHSTok.getLength() + RHS.getLength()); // Get the spelling of the LHS token in Buffer. const char *BufPtr = &Buffer[0]; bool Invalid = false; unsigned LHSLen = PP.getSpelling(LHSTok, BufPtr, &Invalid); if (BufPtr != &Buffer[0]) // Really, we want the chars in Buffer! memcpy(&Buffer[0], BufPtr, LHSLen); if (Invalid) return true; BufPtr = Buffer.data() + LHSLen; unsigned RHSLen = PP.getSpelling(RHS, BufPtr, &Invalid); if (Invalid) return true; if (RHSLen && BufPtr != &Buffer[LHSLen]) // Really, we want the chars in Buffer! memcpy(&Buffer[LHSLen], BufPtr, RHSLen); // Trim excess space. Buffer.resize(LHSLen+RHSLen); // Plop the pasted result (including the trailing newline and null) into a // scratch buffer where we can lex it. Token ResultTokTmp; ResultTokTmp.startToken(); // Claim that the tmp token is a string_literal so that we can get the // character pointer back from CreateString in getLiteralData(). ResultTokTmp.setKind(tok::string_literal); PP.CreateString(Buffer, ResultTokTmp); SourceLocation ResultTokLoc = ResultTokTmp.getLocation(); ResultTokStrPtr = ResultTokTmp.getLiteralData(); // Lex the resultant pasted token into Result. Token Result; if (LHSTok.isAnyIdentifier() && RHS.isAnyIdentifier()) { // Common paste case: identifier+identifier = identifier. Avoid creating // a lexer and other overhead. PP.IncrementPasteCounter(true); Result.startToken(); Result.setKind(tok::raw_identifier); Result.setRawIdentifierData(ResultTokStrPtr); Result.setLocation(ResultTokLoc); Result.setLength(LHSLen+RHSLen); } else { PP.IncrementPasteCounter(false); assert(ResultTokLoc.isFileID() && "Should be a raw location into scratch buffer"); SourceManager &SourceMgr = PP.getSourceManager(); FileID LocFileID = SourceMgr.getFileID(ResultTokLoc); bool Invalid = false; const char *ScratchBufStart = SourceMgr.getBufferData(LocFileID, &Invalid).data(); if (Invalid) return false; // Make a lexer to lex this string from. Lex just this one token. // Make a lexer object so that we lex and expand the paste result. Lexer TL(SourceMgr.getLocForStartOfFile(LocFileID), PP.getLangOpts(), ScratchBufStart, ResultTokStrPtr, ResultTokStrPtr+LHSLen+RHSLen); // Lex a token in raw mode. This way it won't look up identifiers // automatically, lexing off the end will return an eof token, and // warnings are disabled. This returns true if the result token is the // entire buffer. bool isInvalid = !TL.LexFromRawLexer(Result); // If we got an EOF token, we didn't form even ONE token. For example, we // did "/ ## /" to get "//". isInvalid |= Result.is(tok::eof); // If pasting the two tokens didn't form a full new token, this is an // error. This occurs with "x ## +" and other stuff. Return with LHSTok // unmodified and with RHS as the next token to lex. if (isInvalid) { // Explicitly convert the token location to have proper expansion // information so that the user knows where it came from. SourceManager &SM = PP.getSourceManager(); SourceLocation Loc = SM.createExpansionLoc(PasteOpLoc, ExpandLocStart, ExpandLocEnd, 2); // Test for the Microsoft extension of /##/ turning into // here on the // error path. if (PP.getLangOpts().MicrosoftExt && LHSTok.is(tok::slash) && RHS.is(tok::slash)) { HandleMicrosoftCommentPaste(LHSTok, Loc); return true; } // Do not emit the error when preprocessing assembler code. if (!PP.getLangOpts().AsmPreprocessor) { // If we're in microsoft extensions mode, downgrade this from a hard // error to an extension that defaults to an error. This allows // disabling it. PP.Diag(Loc, PP.getLangOpts().MicrosoftExt ? diag::ext_pp_bad_paste_ms : diag::err_pp_bad_paste) << Buffer; } // An error has occurred so exit loop. break; } // Turn ## into 'unknown' to avoid # ## # from looking like a paste // operator. if (Result.is(tok::hashhash)) Result.setKind(tok::unknown); } // Transfer properties of the LHS over the Result. Result.setFlagValue(Token::StartOfLine , LHSTok.isAtStartOfLine()); Result.setFlagValue(Token::LeadingSpace, LHSTok.hasLeadingSpace()); // Finally, replace LHS with the result, consume the RHS, and iterate. ++CurIdx; LHSTok = Result; } while (!IsAtEnd() && TokenStream[CurIdx].is(tok::hashhash)); SourceLocation EndLoc = TokenStream[CurIdx - 1].getLocation(); // The token's current location indicate where the token was lexed from. We // need this information to compute the spelling of the token, but any // diagnostics for the expanded token should appear as if the token was // expanded from the full ## expression. Pull this information together into // a new SourceLocation that captures all of this. SourceManager &SM = PP.getSourceManager(); if (StartLoc.isFileID()) StartLoc = getExpansionLocForMacroDefLoc(StartLoc); if (EndLoc.isFileID()) EndLoc = getExpansionLocForMacroDefLoc(EndLoc); FileID MacroFID = SM.getFileID(MacroExpansionStart); while (SM.getFileID(StartLoc) != MacroFID) StartLoc = SM.getImmediateExpansionRange(StartLoc).getBegin(); while (SM.getFileID(EndLoc) != MacroFID) EndLoc = SM.getImmediateExpansionRange(EndLoc).getEnd(); LHSTok.setLocation(SM.createExpansionLoc(LHSTok.getLocation(), StartLoc, EndLoc, LHSTok.getLength())); // Now that we got the result token, it will be subject to expansion. Since // token pasting re-lexes the result token in raw mode, identifier information // isn't looked up. As such, if the result is an identifier, look up id info. if (LHSTok.is(tok::raw_identifier)) { // Look up the identifier info for the token. We disabled identifier lookup // by saying we're skipping contents, so we need to do this manually. PP.LookUpIdentifierInfo(LHSTok); } return false; } /// isNextTokenLParen - If the next token lexed will pop this macro off the /// expansion stack, return 2. If the next unexpanded token is a '(', return /// 1, otherwise return 0. unsigned TokenLexer::isNextTokenLParen() const { // Out of tokens? if (isAtEnd()) return 2; return Tokens[CurTokenIdx].is(tok::l_paren); } /// isParsingPreprocessorDirective - Return true if we are in the middle of a /// preprocessor directive. bool TokenLexer::isParsingPreprocessorDirective() const { return Tokens[NumTokens-1].is(tok::eod) && !isAtEnd(); } /// HandleMicrosoftCommentPaste - In microsoft compatibility mode, /##/ pastes /// together to form a comment that comments out everything in the current /// macro, other active macros, and anything left on the current physical /// source line of the expanded buffer. Handle this by returning the /// first token on the next line. void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok, SourceLocation OpLoc) { PP.Diag(OpLoc, diag::ext_comment_paste_microsoft); // We 'comment out' the rest of this macro by just ignoring the rest of the // tokens that have not been lexed yet, if any. // Since this must be a macro, mark the macro enabled now that it is no longer // being expanded. assert(Macro && "Token streams can't paste comments"); Macro->EnableMacro(); PP.HandleMicrosoftCommentPaste(Tok); } /// If \arg loc is a file ID and points inside the current macro /// definition, returns the appropriate source location pointing at the /// macro expansion source location entry, otherwise it returns an invalid /// SourceLocation. SourceLocation TokenLexer::getExpansionLocForMacroDefLoc(SourceLocation loc) const { assert(ExpandLocStart.isValid() && MacroExpansionStart.isValid() && "Not appropriate for token streams"); assert(loc.isValid() && loc.isFileID()); SourceManager &SM = PP.getSourceManager(); assert(SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength) && "Expected loc to come from the macro definition"); unsigned relativeOffset = 0; SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength, &relativeOffset); return MacroExpansionStart.getLocWithOffset(relativeOffset); } /// 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. e.g for /// assert(foo == bar); /// There will be a single SLocEntry for the "foo == bar" chunk and locations /// for the 'foo', '==', 'bar' tokens will point inside that chunk. /// /// \arg begin_tokens will be updated to a position past all the found /// consecutive tokens. static void updateConsecutiveMacroArgTokens(SourceManager &SM, SourceLocation InstLoc, Token *&begin_tokens, Token * end_tokens) { assert(begin_tokens < end_tokens); SourceLocation FirstLoc = begin_tokens->getLocation(); SourceLocation CurLoc = FirstLoc; // Compare the source location offset of tokens and group together tokens that // are close, even if their locations point to different FileIDs. e.g. // // |bar | foo | cake | (3 tokens from 3 consecutive FileIDs) // ^ ^ // |bar foo cake| (one SLocEntry chunk for all tokens) // // we can perform this "merge" since the token's spelling location depends // on the relative offset. Token *NextTok = begin_tokens + 1; for (; NextTok < end_tokens; ++NextTok) { SourceLocation NextLoc = NextTok->getLocation(); if (CurLoc.isFileID() != NextLoc.isFileID()) break; // Token from different kind of FileID. int RelOffs; if (!SM.isInSameSLocAddrSpace(CurLoc, NextLoc, &RelOffs)) break; // Token from different local/loaded location. // Check that token is not before the previous token or more than 50 // "characters" away. if (RelOffs < 0 || RelOffs > 50) break; if (CurLoc.isMacroID() && !SM.isWrittenInSameFile(CurLoc, NextLoc)) break; // Token from a different macro. CurLoc = NextLoc; } // For the consecutive tokens, find the length of the SLocEntry to contain // all of them. Token &LastConsecutiveTok = *(NextTok-1); int LastRelOffs = 0; SM.isInSameSLocAddrSpace(FirstLoc, LastConsecutiveTok.getLocation(), &LastRelOffs); unsigned FullLength = LastRelOffs + LastConsecutiveTok.getLength(); // Create a macro expansion SLocEntry that will "contain" all of the tokens. SourceLocation Expansion = SM.createMacroArgExpansionLoc(FirstLoc, InstLoc,FullLength); // Change the location of the tokens from the spelling location to the new // expanded location. for (; begin_tokens < NextTok; ++begin_tokens) { Token &Tok = *begin_tokens; int RelOffs = 0; SM.isInSameSLocAddrSpace(FirstLoc, Tok.getLocation(), &RelOffs); Tok.setLocation(Expansion.getLocWithOffset(RelOffs)); } } /// Creates SLocEntries and updates the locations of macro argument /// tokens to their new expanded locations. /// /// \param ArgIdSpellLoc the location of the macro argument id inside the macro /// definition. void TokenLexer::updateLocForMacroArgTokens(SourceLocation ArgIdSpellLoc, Token *begin_tokens, Token *end_tokens) { SourceManager &SM = PP.getSourceManager(); SourceLocation InstLoc = getExpansionLocForMacroDefLoc(ArgIdSpellLoc); while (begin_tokens < end_tokens) { // If there's only one token just create a SLocEntry for it. if (end_tokens - begin_tokens == 1) { Token &Tok = *begin_tokens; Tok.setLocation(SM.createMacroArgExpansionLoc(Tok.getLocation(), InstLoc, Tok.getLength())); return; } updateConsecutiveMacroArgTokens(SM, InstLoc, begin_tokens, end_tokens); } } void TokenLexer::PropagateLineStartLeadingSpaceInfo(Token &Result) { AtStartOfLine = Result.isAtStartOfLine(); HasLeadingSpace = Result.hasLeadingSpace(); }