| //===--- TokenConcatenation.cpp - Token Concatenation Avoidance -----------===// |
| // |
| // 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 TokenConcatenation class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Lex/TokenConcatenation.h" |
| #include "clang/Lex/Preprocessor.h" |
| using namespace clang; |
| |
| |
| /// StartsWithL - Return true if the spelling of this token starts with 'L'. |
| bool TokenConcatenation::StartsWithL(const Token &Tok) const { |
| if (!Tok.needsCleaning()) { |
| SourceManager &SM = PP.getSourceManager(); |
| return *SM.getCharacterData(SM.getSpellingLoc(Tok.getLocation())) == 'L'; |
| } |
| |
| if (Tok.getLength() < 256) { |
| char Buffer[256]; |
| const char *TokPtr = Buffer; |
| PP.getSpelling(Tok, TokPtr); |
| return TokPtr[0] == 'L'; |
| } |
| |
| return PP.getSpelling(Tok)[0] == 'L'; |
| } |
| |
| /// IsIdentifierL - Return true if the spelling of this token is literally |
| /// 'L'. |
| bool TokenConcatenation::IsIdentifierL(const Token &Tok) const { |
| if (!Tok.needsCleaning()) { |
| if (Tok.getLength() != 1) |
| return false; |
| SourceManager &SM = PP.getSourceManager(); |
| return *SM.getCharacterData(SM.getSpellingLoc(Tok.getLocation())) == 'L'; |
| } |
| |
| if (Tok.getLength() < 256) { |
| char Buffer[256]; |
| const char *TokPtr = Buffer; |
| if (PP.getSpelling(Tok, TokPtr) != 1) |
| return false; |
| return TokPtr[0] == 'L'; |
| } |
| |
| return PP.getSpelling(Tok) == "L"; |
| } |
| |
| TokenConcatenation::TokenConcatenation(Preprocessor &pp) : PP(pp) { |
| memset(TokenInfo, 0, sizeof(TokenInfo)); |
| |
| // These tokens have custom code in AvoidConcat. |
| TokenInfo[tok::identifier ] |= aci_custom; |
| TokenInfo[tok::numeric_constant] |= aci_custom_firstchar; |
| TokenInfo[tok::period ] |= aci_custom_firstchar; |
| TokenInfo[tok::amp ] |= aci_custom_firstchar; |
| TokenInfo[tok::plus ] |= aci_custom_firstchar; |
| TokenInfo[tok::minus ] |= aci_custom_firstchar; |
| TokenInfo[tok::slash ] |= aci_custom_firstchar; |
| TokenInfo[tok::less ] |= aci_custom_firstchar; |
| TokenInfo[tok::greater ] |= aci_custom_firstchar; |
| TokenInfo[tok::pipe ] |= aci_custom_firstchar; |
| TokenInfo[tok::percent ] |= aci_custom_firstchar; |
| TokenInfo[tok::colon ] |= aci_custom_firstchar; |
| TokenInfo[tok::hash ] |= aci_custom_firstchar; |
| TokenInfo[tok::arrow ] |= aci_custom_firstchar; |
| |
| // These tokens change behavior if followed by an '='. |
| TokenInfo[tok::amp ] |= aci_avoid_equal; // &= |
| TokenInfo[tok::plus ] |= aci_avoid_equal; // += |
| TokenInfo[tok::minus ] |= aci_avoid_equal; // -= |
| TokenInfo[tok::slash ] |= aci_avoid_equal; // /= |
| TokenInfo[tok::less ] |= aci_avoid_equal; // <= |
| TokenInfo[tok::greater ] |= aci_avoid_equal; // >= |
| TokenInfo[tok::pipe ] |= aci_avoid_equal; // |= |
| TokenInfo[tok::percent ] |= aci_avoid_equal; // %= |
| TokenInfo[tok::star ] |= aci_avoid_equal; // *= |
| TokenInfo[tok::exclaim ] |= aci_avoid_equal; // != |
| TokenInfo[tok::lessless ] |= aci_avoid_equal; // <<= |
| TokenInfo[tok::greaterequal] |= aci_avoid_equal; // >>= |
| TokenInfo[tok::caret ] |= aci_avoid_equal; // ^= |
| TokenInfo[tok::equal ] |= aci_avoid_equal; // == |
| } |
| |
| /// GetFirstChar - Get the first character of the token \arg Tok, |
| /// avoiding calls to getSpelling where possible. |
| static char GetFirstChar(Preprocessor &PP, const Token &Tok) { |
| if (IdentifierInfo *II = Tok.getIdentifierInfo()) { |
| // Avoid spelling identifiers, the most common form of token. |
| return II->getName()[0]; |
| } else if (!Tok.needsCleaning()) { |
| if (Tok.isLiteral() && Tok.getLiteralData()) { |
| return *Tok.getLiteralData(); |
| } else { |
| SourceManager &SM = PP.getSourceManager(); |
| return *SM.getCharacterData(SM.getSpellingLoc(Tok.getLocation())); |
| } |
| } else if (Tok.getLength() < 256) { |
| char Buffer[256]; |
| const char *TokPtr = Buffer; |
| PP.getSpelling(Tok, TokPtr); |
| return TokPtr[0]; |
| } else { |
| return PP.getSpelling(Tok)[0]; |
| } |
| } |
| |
| /// AvoidConcat - If printing PrevTok immediately followed by Tok would cause |
| /// the two individual tokens to be lexed as a single token, return true |
| /// (which causes a space to be printed between them). This allows the output |
| /// of -E mode to be lexed to the same token stream as lexing the input |
| /// directly would. |
| /// |
| /// This code must conservatively return true if it doesn't want to be 100% |
| /// accurate. This will cause the output to include extra space characters, |
| /// but the resulting output won't have incorrect concatenations going on. |
| /// Examples include "..", which we print with a space between, because we |
| /// don't want to track enough to tell "x.." from "...". |
| bool TokenConcatenation::AvoidConcat(const Token &PrevTok, |
| const Token &Tok) const { |
| // First, check to see if the tokens were directly adjacent in the original |
| // source. If they were, it must be okay to stick them together: if there |
| // were an issue, the tokens would have been lexed differently. |
| if (PrevTok.getLocation().isFileID() && Tok.getLocation().isFileID() && |
| PrevTok.getLocation().getFileLocWithOffset(PrevTok.getLength()) == |
| Tok.getLocation()) |
| return false; |
| |
| tok::TokenKind PrevKind = PrevTok.getKind(); |
| if (PrevTok.getIdentifierInfo()) // Language keyword or named operator. |
| PrevKind = tok::identifier; |
| |
| // Look up information on when we should avoid concatenation with prevtok. |
| unsigned ConcatInfo = TokenInfo[PrevKind]; |
| |
| // If prevtok never causes a problem for anything after it, return quickly. |
| if (ConcatInfo == 0) return false; |
| |
| if (ConcatInfo & aci_avoid_equal) { |
| // If the next token is '=' or '==', avoid concatenation. |
| if (Tok.is(tok::equal) || Tok.is(tok::equalequal)) |
| return true; |
| ConcatInfo &= ~aci_avoid_equal; |
| } |
| |
| if (ConcatInfo == 0) return false; |
| |
| // Basic algorithm: we look at the first character of the second token, and |
| // determine whether it, if appended to the first token, would form (or |
| // would contribute) to a larger token if concatenated. |
| char FirstChar = 0; |
| if (ConcatInfo & aci_custom) { |
| // If the token does not need to know the first character, don't get it. |
| } else { |
| FirstChar = GetFirstChar(PP, Tok); |
| } |
| |
| switch (PrevKind) { |
| default: assert(0 && "InitAvoidConcatTokenInfo built wrong"); |
| case tok::identifier: // id+id or id+number or id+L"foo". |
| // id+'.'... will not append. |
| if (Tok.is(tok::numeric_constant)) |
| return GetFirstChar(PP, Tok) != '.'; |
| |
| if (Tok.getIdentifierInfo() || Tok.is(tok::wide_string_literal) /* || |
| Tok.is(tok::wide_char_literal)*/) |
| return true; |
| |
| // If this isn't identifier + string, we're done. |
| if (Tok.isNot(tok::char_constant) && Tok.isNot(tok::string_literal)) |
| return false; |
| |
| // FIXME: need a wide_char_constant! |
| |
| // If the string was a wide string L"foo" or wide char L'f', it would |
| // concat with the previous identifier into fooL"bar". Avoid this. |
| if (StartsWithL(Tok)) |
| return true; |
| |
| // Otherwise, this is a narrow character or string. If the *identifier* |
| // is a literal 'L', avoid pasting L "foo" -> L"foo". |
| return IsIdentifierL(PrevTok); |
| case tok::numeric_constant: |
| return isalnum(FirstChar) || Tok.is(tok::numeric_constant) || |
| FirstChar == '+' || FirstChar == '-' || FirstChar == '.'; |
| case tok::period: // ..., .*, .1234 |
| return FirstChar == '.' || isdigit(FirstChar) || |
| (PP.getLangOptions().CPlusPlus && FirstChar == '*'); |
| case tok::amp: // && |
| return FirstChar == '&'; |
| case tok::plus: // ++ |
| return FirstChar == '+'; |
| case tok::minus: // --, ->, ->* |
| return FirstChar == '-' || FirstChar == '>'; |
| case tok::slash: //, /*, // |
| return FirstChar == '*' || FirstChar == '/'; |
| case tok::less: // <<, <<=, <:, <% |
| return FirstChar == '<' || FirstChar == ':' || FirstChar == '%'; |
| case tok::greater: // >>, >>= |
| return FirstChar == '>'; |
| case tok::pipe: // || |
| return FirstChar == '|'; |
| case tok::percent: // %>, %: |
| return FirstChar == '>' || FirstChar == ':'; |
| case tok::colon: // ::, :> |
| return FirstChar == '>' || |
| (PP.getLangOptions().CPlusPlus && FirstChar == ':'); |
| case tok::hash: // ##, #@, %:%: |
| return FirstChar == '#' || FirstChar == '@' || FirstChar == '%'; |
| case tok::arrow: // ->* |
| return PP.getLangOptions().CPlusPlus && FirstChar == '*'; |
| } |
| } |
