| //===- TokenLexer.cpp - Lex from a token stream ---------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // 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 <cassert> |
| #include <cstring> |
| |
| 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<Token> &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<Token> &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<Token, 64> 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<Token, 128> 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<Token> 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(); |
| } |