1 //===--- TokenLexer.h - Lex from a token buffer -----------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines the TokenLexer interface. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_CLANG_TOKENLEXER_H 15 #define LLVM_CLANG_TOKENLEXER_H 16 17 #include "clang/Basic/SourceLocation.h" 18 19 namespace clang { 20 class MacroInfo; 21 class Preprocessor; 22 class Token; 23 class MacroArgs; 24 25 /// TokenLexer - This implements a lexer that returns tokens from a macro body 26 /// or token stream instead of lexing from a character buffer. This is used for 27 /// macro expansion and _Pragma handling, for example. 28 /// 29 class TokenLexer { 30 /// Macro - The macro we are expanding from. This is null if expanding a 31 /// token stream. 32 /// 33 MacroInfo *Macro; 34 35 /// ActualArgs - The actual arguments specified for a function-like macro, or 36 /// null. The TokenLexer owns the pointed-to object. 37 MacroArgs *ActualArgs; 38 39 /// PP - The current preprocessor object we are expanding for. 40 /// 41 Preprocessor &PP; 42 43 /// Tokens - This is the pointer to an array of tokens that the macro is 44 /// defined to, with arguments expanded for function-like macros. If this is 45 /// a token stream, these are the tokens we are returning. This points into 46 /// the macro definition we are lexing from, a cache buffer that is owned by 47 /// the preprocessor, or some other buffer that we may or may not own 48 /// (depending on OwnsTokens). 49 /// Note that if it points into Preprocessor's cache buffer, the Preprocessor 50 /// may update the pointer as needed. 51 const Token *Tokens; 52 friend class Preprocessor; 53 54 /// NumTokens - This is the length of the Tokens array. 55 /// 56 unsigned NumTokens; 57 58 /// CurToken - This is the next token that Lex will return. 59 /// 60 unsigned CurToken; 61 62 /// ExpandLocStart/End - The source location range where this macro was 63 /// expanded. 64 SourceLocation ExpandLocStart, ExpandLocEnd; 65 66 /// \brief Source location pointing at the source location entry chunk that 67 /// was reserved for the current macro expansion. 68 SourceLocation MacroExpansionStart; 69 70 /// \brief The offset of the macro expansion in the 71 /// "source location address space". 72 unsigned MacroStartSLocOffset; 73 74 /// \brief Location of the macro definition. 75 SourceLocation MacroDefStart; 76 /// \brief Length of the macro definition. 77 unsigned MacroDefLength; 78 79 /// Lexical information about the expansion point of the macro: the identifier 80 /// that the macro expanded from had these properties. 81 bool AtStartOfLine : 1; 82 bool HasLeadingSpace : 1; 83 84 /// OwnsTokens - This is true if this TokenLexer allocated the Tokens 85 /// array, and thus needs to free it when destroyed. For simple object-like 86 /// macros (for example) we just point into the token buffer of the macro 87 /// definition, we don't make a copy of it. 88 bool OwnsTokens : 1; 89 90 /// DisableMacroExpansion - This is true when tokens lexed from the TokenLexer 91 /// should not be subject to further macro expansion. 92 bool DisableMacroExpansion : 1; 93 94 TokenLexer(const TokenLexer &) LLVM_DELETED_FUNCTION; 95 void operator=(const TokenLexer &) LLVM_DELETED_FUNCTION; 96 public: 97 /// Create a TokenLexer for the specified macro with the specified actual 98 /// arguments. Note that this ctor takes ownership of the ActualArgs pointer. 99 /// ILEnd specifies the location of the ')' for a function-like macro or the 100 /// identifier for an object-like macro. 101 TokenLexer(Token &Tok, SourceLocation ILEnd, MacroInfo *MI, 102 MacroArgs *ActualArgs, Preprocessor &pp) 103 : Macro(0), ActualArgs(0), PP(pp), OwnsTokens(false) { 104 Init(Tok, ILEnd, MI, ActualArgs); 105 } 106 107 /// Init - Initialize this TokenLexer to expand from the specified macro 108 /// with the specified argument information. Note that this ctor takes 109 /// ownership of the ActualArgs pointer. ILEnd specifies the location of the 110 /// ')' for a function-like macro or the identifier for an object-like macro. 111 void Init(Token &Tok, SourceLocation ILEnd, MacroInfo *MI, 112 MacroArgs *ActualArgs); 113 114 /// Create a TokenLexer for the specified token stream. If 'OwnsTokens' is 115 /// specified, this takes ownership of the tokens and delete[]'s them when 116 /// the token lexer is empty. 117 TokenLexer(const Token *TokArray, unsigned NumToks, bool DisableExpansion, 118 bool ownsTokens, Preprocessor &pp) 119 : Macro(0), ActualArgs(0), PP(pp), OwnsTokens(false) { 120 Init(TokArray, NumToks, DisableExpansion, ownsTokens); 121 } 122 123 /// Init - Initialize this TokenLexer with the specified token stream. 124 /// This does not take ownership of the specified token vector. 125 /// 126 /// DisableExpansion is true when macro expansion of tokens lexed from this 127 /// stream should be disabled. 128 void Init(const Token *TokArray, unsigned NumToks, 129 bool DisableMacroExpansion, bool OwnsTokens); 130 131 ~TokenLexer() { destroy(); } 132 133 /// isNextTokenLParen - If the next token lexed will pop this macro off the 134 /// expansion stack, return 2. If the next unexpanded token is a '(', return 135 /// 1, otherwise return 0. 136 unsigned isNextTokenLParen() const; 137 138 /// Lex - Lex and return a token from this macro stream. 139 void Lex(Token &Tok); 140 141 /// isParsingPreprocessorDirective - Return true if we are in the middle of a 142 /// preprocessor directive. 143 bool isParsingPreprocessorDirective() const; 144 145 private: 146 void destroy(); 147 148 /// isAtEnd - Return true if the next lex call will pop this macro off the 149 /// include stack. 150 bool isAtEnd() const { 151 return CurToken == NumTokens; 152 } 153 154 /// PasteTokens - Tok is the LHS of a ## operator, and CurToken is the ## 155 /// operator. Read the ## and RHS, and paste the LHS/RHS together. If there 156 /// are is another ## after it, chomp it iteratively. Return the result as 157 /// Tok. If this returns true, the caller should immediately return the 158 /// token. 159 bool PasteTokens(Token &Tok); 160 161 /// Expand the arguments of a function-like macro so that we can quickly 162 /// return preexpanded tokens from Tokens. 163 void ExpandFunctionArguments(); 164 165 /// HandleMicrosoftCommentPaste - In microsoft compatibility mode, /##/ pastes 166 /// together to form a comment that comments out everything in the current 167 /// macro, other active macros, and anything left on the current physical 168 /// source line of the expanded buffer. Handle this by returning the 169 /// first token on the next line. 170 void HandleMicrosoftCommentPaste(Token &Tok); 171 172 /// \brief If \p loc is a FileID and points inside the current macro 173 /// definition, returns the appropriate source location pointing at the 174 /// macro expansion source location entry. 175 SourceLocation getExpansionLocForMacroDefLoc(SourceLocation loc) const; 176 177 /// \brief Creates SLocEntries and updates the locations of macro argument 178 /// tokens to their new expanded locations. 179 /// 180 /// \param ArgIdSpellLoc the location of the macro argument id inside the 181 /// macro definition. 182 void updateLocForMacroArgTokens(SourceLocation ArgIdSpellLoc, 183 Token *begin_tokens, Token *end_tokens); 184 }; 185 186 } // end namespace clang 187 188 #endif 189
