1 //===--- RewriteMacros.cpp - Rewrite macros into their expansions ---------===// 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 code rewrites macro invocations into their expansions. This gives you 11 // a macro expanded file that retains comments and #includes. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "clang/Rewrite/Frontend/Rewriters.h" 16 #include "clang/Basic/SourceManager.h" 17 #include "clang/Lex/Preprocessor.h" 18 #include "clang/Rewrite/Core/Rewriter.h" 19 #include "llvm/Support/Path.h" 20 #include "llvm/Support/raw_ostream.h" 21 #include <cstdio> 22 #include <memory> 23 24 using namespace clang; 25 26 /// isSameToken - Return true if the two specified tokens start have the same 27 /// content. 28 static bool isSameToken(Token &RawTok, Token &PPTok) { 29 // If two tokens have the same kind and the same identifier info, they are 30 // obviously the same. 31 if (PPTok.getKind() == RawTok.getKind() && 32 PPTok.getIdentifierInfo() == RawTok.getIdentifierInfo()) 33 return true; 34 35 // Otherwise, if they are different but have the same identifier info, they 36 // are also considered to be the same. This allows keywords and raw lexed 37 // identifiers with the same name to be treated the same. 38 if (PPTok.getIdentifierInfo() && 39 PPTok.getIdentifierInfo() == RawTok.getIdentifierInfo()) 40 return true; 41 42 return false; 43 } 44 45 46 /// GetNextRawTok - Return the next raw token in the stream, skipping over 47 /// comments if ReturnComment is false. 48 static const Token &GetNextRawTok(const std::vector<Token> &RawTokens, 49 unsigned &CurTok, bool ReturnComment) { 50 assert(CurTok < RawTokens.size() && "Overran eof!"); 51 52 // If the client doesn't want comments and we have one, skip it. 53 if (!ReturnComment && RawTokens[CurTok].is(tok::comment)) 54 ++CurTok; 55 56 return RawTokens[CurTok++]; 57 } 58 59 60 /// LexRawTokensFromMainFile - Lets all the raw tokens from the main file into 61 /// the specified vector. 62 static void LexRawTokensFromMainFile(Preprocessor &PP, 63 std::vector<Token> &RawTokens) { 64 SourceManager &SM = PP.getSourceManager(); 65 66 // Create a lexer to lex all the tokens of the main file in raw mode. Even 67 // though it is in raw mode, it will not return comments. 68 const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID()); 69 Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts()); 70 71 // Switch on comment lexing because we really do want them. 72 RawLex.SetCommentRetentionState(true); 73 74 Token RawTok; 75 do { 76 RawLex.LexFromRawLexer(RawTok); 77 78 // If we have an identifier with no identifier info for our raw token, look 79 // up the indentifier info. This is important for equality comparison of 80 // identifier tokens. 81 if (RawTok.is(tok::raw_identifier)) 82 PP.LookUpIdentifierInfo(RawTok); 83 84 RawTokens.push_back(RawTok); 85 } while (RawTok.isNot(tok::eof)); 86 } 87 88 89 /// RewriteMacrosInInput - Implement -rewrite-macros mode. 90 void clang::RewriteMacrosInInput(Preprocessor &PP, raw_ostream *OS) { 91 SourceManager &SM = PP.getSourceManager(); 92 93 Rewriter Rewrite; 94 Rewrite.setSourceMgr(SM, PP.getLangOpts()); 95 RewriteBuffer &RB = Rewrite.getEditBuffer(SM.getMainFileID()); 96 97 std::vector<Token> RawTokens; 98 LexRawTokensFromMainFile(PP, RawTokens); 99 unsigned CurRawTok = 0; 100 Token RawTok = GetNextRawTok(RawTokens, CurRawTok, false); 101 102 103 // Get the first preprocessing token. 104 PP.EnterMainSourceFile(); 105 Token PPTok; 106 PP.Lex(PPTok); 107 108 // Preprocess the input file in parallel with raw lexing the main file. Ignore 109 // all tokens that are preprocessed from a file other than the main file (e.g. 110 // a header). If we see tokens that are in the preprocessed file but not the 111 // lexed file, we have a macro expansion. If we see tokens in the lexed file 112 // that aren't in the preprocessed view, we have macros that expand to no 113 // tokens, or macro arguments etc. 114 while (RawTok.isNot(tok::eof) || PPTok.isNot(tok::eof)) { 115 SourceLocation PPLoc = SM.getExpansionLoc(PPTok.getLocation()); 116 117 // If PPTok is from a different source file, ignore it. 118 if (!SM.isWrittenInMainFile(PPLoc)) { 119 PP.Lex(PPTok); 120 continue; 121 } 122 123 // If the raw file hits a preprocessor directive, they will be extra tokens 124 // in the raw file that don't exist in the preprocsesed file. However, we 125 // choose to preserve them in the output file and otherwise handle them 126 // specially. 127 if (RawTok.is(tok::hash) && RawTok.isAtStartOfLine()) { 128 // If this is a #warning directive or #pragma mark (GNU extensions), 129 // comment the line out. 130 if (RawTokens[CurRawTok].is(tok::identifier)) { 131 const IdentifierInfo *II = RawTokens[CurRawTok].getIdentifierInfo(); 132 if (II->getName() == "warning") { 133 // Comment out #warning. 134 RB.InsertTextAfter(SM.getFileOffset(RawTok.getLocation()), "//"); 135 } else if (II->getName() == "pragma" && 136 RawTokens[CurRawTok+1].is(tok::identifier) && 137 (RawTokens[CurRawTok+1].getIdentifierInfo()->getName() == 138 "mark")) { 139 // Comment out #pragma mark. 140 RB.InsertTextAfter(SM.getFileOffset(RawTok.getLocation()), "//"); 141 } 142 } 143 144 // Otherwise, if this is a #include or some other directive, just leave it 145 // in the file by skipping over the line. 146 RawTok = GetNextRawTok(RawTokens, CurRawTok, false); 147 while (!RawTok.isAtStartOfLine() && RawTok.isNot(tok::eof)) 148 RawTok = GetNextRawTok(RawTokens, CurRawTok, false); 149 continue; 150 } 151 152 // Okay, both tokens are from the same file. Get their offsets from the 153 // start of the file. 154 unsigned PPOffs = SM.getFileOffset(PPLoc); 155 unsigned RawOffs = SM.getFileOffset(RawTok.getLocation()); 156 157 // If the offsets are the same and the token kind is the same, ignore them. 158 if (PPOffs == RawOffs && isSameToken(RawTok, PPTok)) { 159 RawTok = GetNextRawTok(RawTokens, CurRawTok, false); 160 PP.Lex(PPTok); 161 continue; 162 } 163 164 // If the PP token is farther along than the raw token, something was 165 // deleted. Comment out the raw token. 166 if (RawOffs <= PPOffs) { 167 // Comment out a whole run of tokens instead of bracketing each one with 168 // comments. Add a leading space if RawTok didn't have one. 169 bool HasSpace = RawTok.hasLeadingSpace(); 170 RB.InsertTextAfter(RawOffs, &" /*"[HasSpace]); 171 unsigned EndPos; 172 173 do { 174 EndPos = RawOffs+RawTok.getLength(); 175 176 RawTok = GetNextRawTok(RawTokens, CurRawTok, true); 177 RawOffs = SM.getFileOffset(RawTok.getLocation()); 178 179 if (RawTok.is(tok::comment)) { 180 // Skip past the comment. 181 RawTok = GetNextRawTok(RawTokens, CurRawTok, false); 182 break; 183 } 184 185 } while (RawOffs <= PPOffs && !RawTok.isAtStartOfLine() && 186 (PPOffs != RawOffs || !isSameToken(RawTok, PPTok))); 187 188 RB.InsertTextBefore(EndPos, "*/"); 189 continue; 190 } 191 192 // Otherwise, there was a replacement an expansion. Insert the new token 193 // in the output buffer. Insert the whole run of new tokens at once to get 194 // them in the right order. 195 unsigned InsertPos = PPOffs; 196 std::string Expansion; 197 while (PPOffs < RawOffs) { 198 Expansion += ' ' + PP.getSpelling(PPTok); 199 PP.Lex(PPTok); 200 PPLoc = SM.getExpansionLoc(PPTok.getLocation()); 201 PPOffs = SM.getFileOffset(PPLoc); 202 } 203 Expansion += ' '; 204 RB.InsertTextBefore(InsertPos, Expansion); 205 } 206 207 // Get the buffer corresponding to MainFileID. If we haven't changed it, then 208 // we are done. 209 if (const RewriteBuffer *RewriteBuf = 210 Rewrite.getRewriteBufferFor(SM.getMainFileID())) { 211 //printf("Changed:\n"); 212 *OS << std::string(RewriteBuf->begin(), RewriteBuf->end()); 213 } else { 214 fprintf(stderr, "No changes\n"); 215 } 216 OS->flush(); 217 } 218
