MacroArgs.cpp revision 208954
1//===--- TokenLexer.cpp - Lex from a token stream -------------------------===// 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 implements the TokenLexer interface. 11// 12//===----------------------------------------------------------------------===// 13 14#include "MacroArgs.h" 15#include "clang/Lex/MacroInfo.h" 16#include "clang/Lex/Preprocessor.h" 17#include "clang/Lex/LexDiagnostic.h" 18using namespace clang; 19 20/// MacroArgs ctor function - This destroys the vector passed in. 21MacroArgs *MacroArgs::create(const MacroInfo *MI, 22 const Token *UnexpArgTokens, 23 unsigned NumToks, bool VarargsElided, 24 Preprocessor &PP) { 25 assert(MI->isFunctionLike() && 26 "Can't have args for an object-like macro!"); 27 MacroArgs **ResultEnt = 0; 28 unsigned ClosestMatch = ~0U; 29 30 // See if we have an entry with a big enough argument list to reuse on the 31 // free list. If so, reuse it. 32 for (MacroArgs **Entry = &PP.MacroArgCache; *Entry; 33 Entry = &(*Entry)->ArgCache) 34 if ((*Entry)->NumUnexpArgTokens >= NumToks && 35 (*Entry)->NumUnexpArgTokens < ClosestMatch) { 36 ResultEnt = Entry; 37 38 // If we have an exact match, use it. 39 if ((*Entry)->NumUnexpArgTokens == NumToks) 40 break; 41 // Otherwise, use the best fit. 42 ClosestMatch = (*Entry)->NumUnexpArgTokens; 43 } 44 45 MacroArgs *Result; 46 if (ResultEnt == 0) { 47 // Allocate memory for a MacroArgs object with the lexer tokens at the end. 48 Result = (MacroArgs*)malloc(sizeof(MacroArgs) + NumToks*sizeof(Token)); 49 // Construct the MacroArgs object. 50 new (Result) MacroArgs(NumToks, VarargsElided); 51 } else { 52 Result = *ResultEnt; 53 // Unlink this node from the preprocessors singly linked list. 54 *ResultEnt = Result->ArgCache; 55 Result->NumUnexpArgTokens = NumToks; 56 Result->VarargsElided = VarargsElided; 57 } 58 59 // Copy the actual unexpanded tokens to immediately after the result ptr. 60 if (NumToks) 61 memcpy(const_cast<Token*>(Result->getUnexpArgument(0)), 62 UnexpArgTokens, NumToks*sizeof(Token)); 63 64 return Result; 65} 66 67/// destroy - Destroy and deallocate the memory for this object. 68/// 69void MacroArgs::destroy(Preprocessor &PP) { 70 StringifiedArgs.clear(); 71 72 // Don't clear PreExpArgTokens, just clear the entries. Clearing the entries 73 // would deallocate the element vectors. 74 for (unsigned i = 0, e = PreExpArgTokens.size(); i != e; ++i) 75 PreExpArgTokens[i].clear(); 76 77 // Add this to the preprocessor's free list. 78 ArgCache = PP.MacroArgCache; 79 PP.MacroArgCache = this; 80} 81 82/// deallocate - This should only be called by the Preprocessor when managing 83/// its freelist. 84MacroArgs *MacroArgs::deallocate() { 85 MacroArgs *Next = ArgCache; 86 87 // Run the dtor to deallocate the vectors. 88 this->~MacroArgs(); 89 // Release the memory for the object. 90 free(this); 91 92 return Next; 93} 94 95 96/// getArgLength - Given a pointer to an expanded or unexpanded argument, 97/// return the number of tokens, not counting the EOF, that make up the 98/// argument. 99unsigned MacroArgs::getArgLength(const Token *ArgPtr) { 100 unsigned NumArgTokens = 0; 101 for (; ArgPtr->isNot(tok::eof); ++ArgPtr) 102 ++NumArgTokens; 103 return NumArgTokens; 104} 105 106 107/// getUnexpArgument - Return the unexpanded tokens for the specified formal. 108/// 109const Token *MacroArgs::getUnexpArgument(unsigned Arg) const { 110 // The unexpanded argument tokens start immediately after the MacroArgs object 111 // in memory. 112 const Token *Start = (const Token *)(this+1); 113 const Token *Result = Start; 114 // Scan to find Arg. 115 for (; Arg; ++Result) { 116 assert(Result < Start+NumUnexpArgTokens && "Invalid arg #"); 117 if (Result->is(tok::eof)) 118 --Arg; 119 } 120 assert(Result < Start+NumUnexpArgTokens && "Invalid arg #"); 121 return Result; 122} 123 124 125/// ArgNeedsPreexpansion - If we can prove that the argument won't be affected 126/// by pre-expansion, return false. Otherwise, conservatively return true. 127bool MacroArgs::ArgNeedsPreexpansion(const Token *ArgTok, 128 Preprocessor &PP) const { 129 // If there are no identifiers in the argument list, or if the identifiers are 130 // known to not be macros, pre-expansion won't modify it. 131 for (; ArgTok->isNot(tok::eof); ++ArgTok) 132 if (IdentifierInfo *II = ArgTok->getIdentifierInfo()) { 133 if (II->hasMacroDefinition() && PP.getMacroInfo(II)->isEnabled()) 134 // Return true even though the macro could be a function-like macro 135 // without a following '(' token. 136 return true; 137 } 138 return false; 139} 140 141/// getPreExpArgument - Return the pre-expanded form of the specified 142/// argument. 143const std::vector<Token> & 144MacroArgs::getPreExpArgument(unsigned Arg, const MacroInfo *MI, 145 Preprocessor &PP) { 146 assert(Arg < MI->getNumArgs() && "Invalid argument number!"); 147 148 // If we have already computed this, return it. 149 if (PreExpArgTokens.size() < MI->getNumArgs()) 150 PreExpArgTokens.resize(MI->getNumArgs()); 151 152 std::vector<Token> &Result = PreExpArgTokens[Arg]; 153 if (!Result.empty()) return Result; 154 155 const Token *AT = getUnexpArgument(Arg); 156 unsigned NumToks = getArgLength(AT)+1; // Include the EOF. 157 158 // Otherwise, we have to pre-expand this argument, populating Result. To do 159 // this, we set up a fake TokenLexer to lex from the unexpanded argument 160 // list. With this installed, we lex expanded tokens until we hit the EOF 161 // token at the end of the unexp list. 162 PP.EnterTokenStream(AT, NumToks, false /*disable expand*/, 163 false /*owns tokens*/); 164 165 // Lex all of the macro-expanded tokens into Result. 166 do { 167 Result.push_back(Token()); 168 Token &Tok = Result.back(); 169 PP.Lex(Tok); 170 } while (Result.back().isNot(tok::eof)); 171 172 // Pop the token stream off the top of the stack. We know that the internal 173 // pointer inside of it is to the "end" of the token stream, but the stack 174 // will not otherwise be popped until the next token is lexed. The problem is 175 // that the token may be lexed sometime after the vector of tokens itself is 176 // destroyed, which would be badness. 177 PP.RemoveTopOfLexerStack(); 178 return Result; 179} 180 181 182/// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of 183/// tokens into the literal string token that should be produced by the C # 184/// preprocessor operator. If Charify is true, then it should be turned into 185/// a character literal for the Microsoft charize (#@) extension. 186/// 187Token MacroArgs::StringifyArgument(const Token *ArgToks, 188 Preprocessor &PP, bool Charify) { 189 Token Tok; 190 Tok.startToken(); 191 Tok.setKind(Charify ? tok::char_constant : tok::string_literal); 192 193 const Token *ArgTokStart = ArgToks; 194 195 // Stringify all the tokens. 196 llvm::SmallString<128> Result; 197 Result += "\""; 198 199 bool isFirst = true; 200 for (; ArgToks->isNot(tok::eof); ++ArgToks) { 201 const Token &Tok = *ArgToks; 202 if (!isFirst && (Tok.hasLeadingSpace() || Tok.isAtStartOfLine())) 203 Result += ' '; 204 isFirst = false; 205 206 // If this is a string or character constant, escape the token as specified 207 // by 6.10.3.2p2. 208 if (Tok.is(tok::string_literal) || // "foo" 209 Tok.is(tok::wide_string_literal) || // L"foo" 210 Tok.is(tok::char_constant)) { // 'x' and L'x'. 211 bool Invalid = false; 212 std::string TokStr = PP.getSpelling(Tok, &Invalid); 213 if (!Invalid) { 214 std::string Str = Lexer::Stringify(TokStr); 215 Result.append(Str.begin(), Str.end()); 216 } 217 } else { 218 // Otherwise, just append the token. Do some gymnastics to get the token 219 // in place and avoid copies where possible. 220 unsigned CurStrLen = Result.size(); 221 Result.resize(CurStrLen+Tok.getLength()); 222 const char *BufPtr = &Result[CurStrLen]; 223 bool Invalid = false; 224 unsigned ActualTokLen = PP.getSpelling(Tok, BufPtr, &Invalid); 225 226 if (!Invalid) { 227 // If getSpelling returned a pointer to an already uniqued version of 228 // the string instead of filling in BufPtr, memcpy it onto our string. 229 if (BufPtr != &Result[CurStrLen]) 230 memcpy(&Result[CurStrLen], BufPtr, ActualTokLen); 231 232 // If the token was dirty, the spelling may be shorter than the token. 233 if (ActualTokLen != Tok.getLength()) 234 Result.resize(CurStrLen+ActualTokLen); 235 } 236 } 237 } 238 239 // If the last character of the string is a \, and if it isn't escaped, this 240 // is an invalid string literal, diagnose it as specified in C99. 241 if (Result.back() == '\\') { 242 // Count the number of consequtive \ characters. If even, then they are 243 // just escaped backslashes, otherwise it's an error. 244 unsigned FirstNonSlash = Result.size()-2; 245 // Guaranteed to find the starting " if nothing else. 246 while (Result[FirstNonSlash] == '\\') 247 --FirstNonSlash; 248 if ((Result.size()-1-FirstNonSlash) & 1) { 249 // Diagnose errors for things like: #define F(X) #X / F(\) 250 PP.Diag(ArgToks[-1], diag::pp_invalid_string_literal); 251 Result.pop_back(); // remove one of the \'s. 252 } 253 } 254 Result += '"'; 255 256 // If this is the charify operation and the result is not a legal character 257 // constant, diagnose it. 258 if (Charify) { 259 // First step, turn double quotes into single quotes: 260 Result[0] = '\''; 261 Result[Result.size()-1] = '\''; 262 263 // Check for bogus character. 264 bool isBad = false; 265 if (Result.size() == 3) 266 isBad = Result[1] == '\''; // ''' is not legal. '\' already fixed above. 267 else 268 isBad = (Result.size() != 4 || Result[1] != '\\'); // Not '\x' 269 270 if (isBad) { 271 PP.Diag(ArgTokStart[0], diag::err_invalid_character_to_charify); 272 Result = "' '"; // Use something arbitrary, but legal. 273 } 274 } 275 276 PP.CreateString(&Result[0], Result.size(), Tok); 277 return Tok; 278} 279 280/// getStringifiedArgument - Compute, cache, and return the specified argument 281/// that has been 'stringified' as required by the # operator. 282const Token &MacroArgs::getStringifiedArgument(unsigned ArgNo, 283 Preprocessor &PP) { 284 assert(ArgNo < NumUnexpArgTokens && "Invalid argument number!"); 285 if (StringifiedArgs.empty()) { 286 StringifiedArgs.resize(getNumArguments()); 287 memset(&StringifiedArgs[0], 0, 288 sizeof(StringifiedArgs[0])*getNumArguments()); 289 } 290 if (StringifiedArgs[ArgNo].isNot(tok::string_literal)) 291 StringifiedArgs[ArgNo] = StringifyArgument(getUnexpArgument(ArgNo), PP); 292 return StringifiedArgs[ArgNo]; 293} 294