MacroArgs.cpp revision 280031
1233414Sgonzo//===--- MacroArgs.cpp - Formal argument info for Macros ------------------===// 2233414Sgonzo// 3233414Sgonzo// The LLVM Compiler Infrastructure 4233414Sgonzo// 5233414Sgonzo// This file is distributed under the University of Illinois Open Source 6233414Sgonzo// License. See LICENSE.TXT for details. 7233414Sgonzo// 8233414Sgonzo//===----------------------------------------------------------------------===// 9233414Sgonzo// 10233414Sgonzo// This file implements the MacroArgs interface. 11233414Sgonzo// 12233414Sgonzo//===----------------------------------------------------------------------===// 13233414Sgonzo 14233414Sgonzo#include "clang/Lex/MacroArgs.h" 15233414Sgonzo#include "clang/Lex/LexDiagnostic.h" 16233414Sgonzo#include "clang/Lex/MacroInfo.h" 17233414Sgonzo#include "clang/Lex/Preprocessor.h" 18233414Sgonzo#include "llvm/ADT/SmallString.h" 19233414Sgonzo#include "llvm/Support/SaveAndRestore.h" 20233414Sgonzo#include <algorithm> 21233414Sgonzo 22233414Sgonzousing namespace clang; 23233414Sgonzo 24233414Sgonzo/// MacroArgs ctor function - This destroys the vector passed in. 25233414SgonzoMacroArgs *MacroArgs::create(const MacroInfo *MI, 26233414Sgonzo ArrayRef<Token> UnexpArgTokens, 27233414Sgonzo bool VarargsElided, Preprocessor &PP) { 28233414Sgonzo assert(MI->isFunctionLike() && 29233414Sgonzo "Can't have args for an object-like macro!"); 30233414Sgonzo MacroArgs **ResultEnt = nullptr; 31233414Sgonzo unsigned ClosestMatch = ~0U; 32233414Sgonzo 33233414Sgonzo // See if we have an entry with a big enough argument list to reuse on the 34233414Sgonzo // free list. If so, reuse it. 35233414Sgonzo for (MacroArgs **Entry = &PP.MacroArgCache; *Entry; 36233414Sgonzo Entry = &(*Entry)->ArgCache) 37233414Sgonzo if ((*Entry)->NumUnexpArgTokens >= UnexpArgTokens.size() && 38233414Sgonzo (*Entry)->NumUnexpArgTokens < ClosestMatch) { 39233414Sgonzo ResultEnt = Entry; 40233414Sgonzo 41233414Sgonzo // If we have an exact match, use it. 42233414Sgonzo if ((*Entry)->NumUnexpArgTokens == UnexpArgTokens.size()) 43233414Sgonzo break; 44233414Sgonzo // Otherwise, use the best fit. 45233414Sgonzo ClosestMatch = (*Entry)->NumUnexpArgTokens; 46233414Sgonzo } 47233414Sgonzo 48233414Sgonzo MacroArgs *Result; 49233414Sgonzo if (!ResultEnt) { 50233414Sgonzo // Allocate memory for a MacroArgs object with the lexer tokens at the end. 51233414Sgonzo Result = (MacroArgs*)malloc(sizeof(MacroArgs) + 52233414Sgonzo UnexpArgTokens.size() * sizeof(Token)); 53233414Sgonzo // Construct the MacroArgs object. 54233414Sgonzo new (Result) MacroArgs(UnexpArgTokens.size(), VarargsElided); 55233414Sgonzo } else { 56233414Sgonzo Result = *ResultEnt; 57233414Sgonzo // Unlink this node from the preprocessors singly linked list. 58233414Sgonzo *ResultEnt = Result->ArgCache; 59233414Sgonzo Result->NumUnexpArgTokens = UnexpArgTokens.size(); 60233414Sgonzo Result->VarargsElided = VarargsElided; 61233414Sgonzo } 62233414Sgonzo 63233414Sgonzo // Copy the actual unexpanded tokens to immediately after the result ptr. 64233414Sgonzo if (!UnexpArgTokens.empty()) 65233414Sgonzo std::copy(UnexpArgTokens.begin(), UnexpArgTokens.end(), 66233414Sgonzo const_cast<Token*>(Result->getUnexpArgument(0))); 67233414Sgonzo 68233414Sgonzo return Result; 69233414Sgonzo} 70233414Sgonzo 71233414Sgonzo/// destroy - Destroy and deallocate the memory for this object. 72233414Sgonzo/// 73233414Sgonzovoid MacroArgs::destroy(Preprocessor &PP) { 74233414Sgonzo StringifiedArgs.clear(); 75233414Sgonzo 76 // Don't clear PreExpArgTokens, just clear the entries. Clearing the entries 77 // would deallocate the element vectors. 78 for (unsigned i = 0, e = PreExpArgTokens.size(); i != e; ++i) 79 PreExpArgTokens[i].clear(); 80 81 // Add this to the preprocessor's free list. 82 ArgCache = PP.MacroArgCache; 83 PP.MacroArgCache = this; 84} 85 86/// deallocate - This should only be called by the Preprocessor when managing 87/// its freelist. 88MacroArgs *MacroArgs::deallocate() { 89 MacroArgs *Next = ArgCache; 90 91 // Run the dtor to deallocate the vectors. 92 this->~MacroArgs(); 93 // Release the memory for the object. 94 free(this); 95 96 return Next; 97} 98 99 100/// getArgLength - Given a pointer to an expanded or unexpanded argument, 101/// return the number of tokens, not counting the EOF, that make up the 102/// argument. 103unsigned MacroArgs::getArgLength(const Token *ArgPtr) { 104 unsigned NumArgTokens = 0; 105 for (; ArgPtr->isNot(tok::eof); ++ArgPtr) 106 ++NumArgTokens; 107 return NumArgTokens; 108} 109 110 111/// getUnexpArgument - Return the unexpanded tokens for the specified formal. 112/// 113const Token *MacroArgs::getUnexpArgument(unsigned Arg) const { 114 // The unexpanded argument tokens start immediately after the MacroArgs object 115 // in memory. 116 const Token *Start = (const Token *)(this+1); 117 const Token *Result = Start; 118 // Scan to find Arg. 119 for (; Arg; ++Result) { 120 assert(Result < Start+NumUnexpArgTokens && "Invalid arg #"); 121 if (Result->is(tok::eof)) 122 --Arg; 123 } 124 assert(Result < Start+NumUnexpArgTokens && "Invalid arg #"); 125 return Result; 126} 127 128 129/// ArgNeedsPreexpansion - If we can prove that the argument won't be affected 130/// by pre-expansion, return false. Otherwise, conservatively return true. 131bool MacroArgs::ArgNeedsPreexpansion(const Token *ArgTok, 132 Preprocessor &PP) const { 133 // If there are no identifiers in the argument list, or if the identifiers are 134 // known to not be macros, pre-expansion won't modify it. 135 for (; ArgTok->isNot(tok::eof); ++ArgTok) 136 if (IdentifierInfo *II = ArgTok->getIdentifierInfo()) { 137 if (II->hasMacroDefinition() && PP.getMacroInfo(II)->isEnabled()) 138 // Return true even though the macro could be a function-like macro 139 // without a following '(' token. 140 return true; 141 } 142 return false; 143} 144 145/// getPreExpArgument - Return the pre-expanded form of the specified 146/// argument. 147const std::vector<Token> & 148MacroArgs::getPreExpArgument(unsigned Arg, const MacroInfo *MI, 149 Preprocessor &PP) { 150 assert(Arg < MI->getNumArgs() && "Invalid argument number!"); 151 152 // If we have already computed this, return it. 153 if (PreExpArgTokens.size() < MI->getNumArgs()) 154 PreExpArgTokens.resize(MI->getNumArgs()); 155 156 std::vector<Token> &Result = PreExpArgTokens[Arg]; 157 if (!Result.empty()) return Result; 158 159 SaveAndRestore<bool> PreExpandingMacroArgs(PP.InMacroArgPreExpansion, true); 160 161 const Token *AT = getUnexpArgument(Arg); 162 unsigned NumToks = getArgLength(AT)+1; // Include the EOF. 163 164 // Otherwise, we have to pre-expand this argument, populating Result. To do 165 // this, we set up a fake TokenLexer to lex from the unexpanded argument 166 // list. With this installed, we lex expanded tokens until we hit the EOF 167 // token at the end of the unexp list. 168 PP.EnterTokenStream(AT, NumToks, false /*disable expand*/, 169 false /*owns tokens*/); 170 171 // Lex all of the macro-expanded tokens into Result. 172 do { 173 Result.push_back(Token()); 174 Token &Tok = Result.back(); 175 PP.Lex(Tok); 176 } while (Result.back().isNot(tok::eof)); 177 178 // Pop the token stream off the top of the stack. We know that the internal 179 // pointer inside of it is to the "end" of the token stream, but the stack 180 // will not otherwise be popped until the next token is lexed. The problem is 181 // that the token may be lexed sometime after the vector of tokens itself is 182 // destroyed, which would be badness. 183 if (PP.InCachingLexMode()) 184 PP.ExitCachingLexMode(); 185 PP.RemoveTopOfLexerStack(); 186 return Result; 187} 188 189 190/// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of 191/// tokens into the literal string token that should be produced by the C # 192/// preprocessor operator. If Charify is true, then it should be turned into 193/// a character literal for the Microsoft charize (#@) extension. 194/// 195Token MacroArgs::StringifyArgument(const Token *ArgToks, 196 Preprocessor &PP, bool Charify, 197 SourceLocation ExpansionLocStart, 198 SourceLocation ExpansionLocEnd) { 199 Token Tok; 200 Tok.startToken(); 201 Tok.setKind(Charify ? tok::char_constant : tok::string_literal); 202 203 const Token *ArgTokStart = ArgToks; 204 205 // Stringify all the tokens. 206 SmallString<128> Result; 207 Result += "\""; 208 209 bool isFirst = true; 210 for (; ArgToks->isNot(tok::eof); ++ArgToks) { 211 const Token &Tok = *ArgToks; 212 if (!isFirst && (Tok.hasLeadingSpace() || Tok.isAtStartOfLine())) 213 Result += ' '; 214 isFirst = false; 215 216 // If this is a string or character constant, escape the token as specified 217 // by 6.10.3.2p2. 218 if (tok::isStringLiteral(Tok.getKind()) || // "foo", u8R"x(foo)x"_bar, etc. 219 Tok.is(tok::char_constant) || // 'x' 220 Tok.is(tok::wide_char_constant) || // L'x'. 221 Tok.is(tok::utf8_char_constant) || // u8'x'. 222 Tok.is(tok::utf16_char_constant) || // u'x'. 223 Tok.is(tok::utf32_char_constant)) { // U'x'. 224 bool Invalid = false; 225 std::string TokStr = PP.getSpelling(Tok, &Invalid); 226 if (!Invalid) { 227 std::string Str = Lexer::Stringify(TokStr); 228 Result.append(Str.begin(), Str.end()); 229 } 230 } else if (Tok.is(tok::code_completion)) { 231 PP.CodeCompleteNaturalLanguage(); 232 } else { 233 // Otherwise, just append the token. Do some gymnastics to get the token 234 // in place and avoid copies where possible. 235 unsigned CurStrLen = Result.size(); 236 Result.resize(CurStrLen+Tok.getLength()); 237 const char *BufPtr = Result.data() + CurStrLen; 238 bool Invalid = false; 239 unsigned ActualTokLen = PP.getSpelling(Tok, BufPtr, &Invalid); 240 241 if (!Invalid) { 242 // If getSpelling returned a pointer to an already uniqued version of 243 // the string instead of filling in BufPtr, memcpy it onto our string. 244 if (ActualTokLen && BufPtr != &Result[CurStrLen]) 245 memcpy(&Result[CurStrLen], BufPtr, ActualTokLen); 246 247 // If the token was dirty, the spelling may be shorter than the token. 248 if (ActualTokLen != Tok.getLength()) 249 Result.resize(CurStrLen+ActualTokLen); 250 } 251 } 252 } 253 254 // If the last character of the string is a \, and if it isn't escaped, this 255 // is an invalid string literal, diagnose it as specified in C99. 256 if (Result.back() == '\\') { 257 // Count the number of consequtive \ characters. If even, then they are 258 // just escaped backslashes, otherwise it's an error. 259 unsigned FirstNonSlash = Result.size()-2; 260 // Guaranteed to find the starting " if nothing else. 261 while (Result[FirstNonSlash] == '\\') 262 --FirstNonSlash; 263 if ((Result.size()-1-FirstNonSlash) & 1) { 264 // Diagnose errors for things like: #define F(X) #X / F(\) 265 PP.Diag(ArgToks[-1], diag::pp_invalid_string_literal); 266 Result.pop_back(); // remove one of the \'s. 267 } 268 } 269 Result += '"'; 270 271 // If this is the charify operation and the result is not a legal character 272 // constant, diagnose it. 273 if (Charify) { 274 // First step, turn double quotes into single quotes: 275 Result[0] = '\''; 276 Result[Result.size()-1] = '\''; 277 278 // Check for bogus character. 279 bool isBad = false; 280 if (Result.size() == 3) 281 isBad = Result[1] == '\''; // ''' is not legal. '\' already fixed above. 282 else 283 isBad = (Result.size() != 4 || Result[1] != '\\'); // Not '\x' 284 285 if (isBad) { 286 PP.Diag(ArgTokStart[0], diag::err_invalid_character_to_charify); 287 Result = "' '"; // Use something arbitrary, but legal. 288 } 289 } 290 291 PP.CreateString(Result, Tok, 292 ExpansionLocStart, ExpansionLocEnd); 293 return Tok; 294} 295 296/// getStringifiedArgument - Compute, cache, and return the specified argument 297/// that has been 'stringified' as required by the # operator. 298const Token &MacroArgs::getStringifiedArgument(unsigned ArgNo, 299 Preprocessor &PP, 300 SourceLocation ExpansionLocStart, 301 SourceLocation ExpansionLocEnd) { 302 assert(ArgNo < NumUnexpArgTokens && "Invalid argument number!"); 303 if (StringifiedArgs.empty()) { 304 StringifiedArgs.resize(getNumArguments()); 305 memset((void*)&StringifiedArgs[0], 0, 306 sizeof(StringifiedArgs[0])*getNumArguments()); 307 } 308 if (StringifiedArgs[ArgNo].isNot(tok::string_literal)) 309 StringifiedArgs[ArgNo] = StringifyArgument(getUnexpArgument(ArgNo), PP, 310 /*Charify=*/false, 311 ExpansionLocStart, 312 ExpansionLocEnd); 313 return StringifiedArgs[ArgNo]; 314} 315