1 /* 2 * Javassist, a Java-bytecode translator toolkit. 3 * Copyright (C) 1999-2007 Shigeru Chiba. All Rights Reserved. 4 * 5 * The contents of this file are subject to the Mozilla Public License Version 6 * 1.1 (the "License"); you may not use this file except in compliance with 7 * the License. Alternatively, the contents of this file may be used under 8 * the terms of the GNU Lesser General Public License Version 2.1 or later. 9 * 10 * Software distributed under the License is distributed on an "AS IS" basis, 11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 12 * for the specific language governing rights and limitations under the 13 * License. 14 */ 15 16 package javassist.compiler; 17 18 class Token { 19 public Token next = null; 20 public int tokenId; 21 22 public long longValue; 23 public double doubleValue; 24 public String textValue; 25 } 26 27 public class Lex implements TokenId { 28 private int lastChar; 29 private StringBuffer textBuffer; 30 private Token currentToken; 31 private Token lookAheadTokens; 32 33 private String input; 34 private int position, maxlen, lineNumber; 35 36 /** 37 * Constructs a lexical analyzer. 38 */ 39 public Lex(String s) { 40 lastChar = -1; 41 textBuffer = new StringBuffer(); 42 currentToken = new Token(); 43 lookAheadTokens = null; 44 45 input = s; 46 position = 0; 47 maxlen = s.length(); 48 lineNumber = 0; 49 } 50 51 public int get() { 52 if (lookAheadTokens == null) 53 return get(currentToken); 54 else { 55 Token t; 56 currentToken = t = lookAheadTokens; 57 lookAheadTokens = lookAheadTokens.next; 58 return t.tokenId; 59 } 60 } 61 62 /** 63 * Looks at the next token. 64 */ 65 public int lookAhead() { 66 return lookAhead(0); 67 } 68 69 public int lookAhead(int i) { 70 Token tk = lookAheadTokens; 71 if (tk == null) { 72 lookAheadTokens = tk = currentToken; // reuse an object! 73 tk.next = null; 74 get(tk); 75 } 76 77 for (; i-- > 0; tk = tk.next) 78 if (tk.next == null) { 79 Token tk2; 80 tk.next = tk2 = new Token(); 81 get(tk2); 82 } 83 84 currentToken = tk; 85 return tk.tokenId; 86 } 87 88 public String getString() { 89 return currentToken.textValue; 90 } 91 92 public long getLong() { 93 return currentToken.longValue; 94 } 95 96 public double getDouble() { 97 return currentToken.doubleValue; 98 } 99 100 private int get(Token token) { 101 int t; 102 do { 103 t = readLine(token); 104 } while (t == '\n'); 105 token.tokenId = t; 106 return t; 107 } 108 109 private int readLine(Token token) { 110 int c = getNextNonWhiteChar(); 111 if(c < 0) 112 return c; 113 else if(c == '\n') { 114 ++lineNumber; 115 return '\n'; 116 } 117 else if (c == '\'') 118 return readCharConst(token); 119 else if (c == '"') 120 return readStringL(token); 121 else if ('0' <= c && c <= '9') 122 return readNumber(c, token); 123 else if(c == '.'){ 124 c = getc(); 125 if ('0' <= c && c <= '9') { 126 StringBuffer tbuf = textBuffer; 127 tbuf.setLength(0); 128 tbuf.append('.'); 129 return readDouble(tbuf, c, token); 130 } 131 else{ 132 ungetc(c); 133 return readSeparator('.'); 134 } 135 } 136 else if (Character.isJavaIdentifierStart((char)c)) 137 return readIdentifier(c, token); 138 else 139 return readSeparator(c); 140 } 141 142 private int getNextNonWhiteChar() { 143 int c; 144 do { 145 c = getc(); 146 if (c == '/') { 147 c = getc(); 148 if (c == '/') 149 do { 150 c = getc(); 151 } while (c != '\n' && c != '\r' && c != -1); 152 else if (c == '*') 153 while (true) { 154 c = getc(); 155 if (c == -1) 156 break; 157 else if (c == '*') 158 if ((c = getc()) == '/') { 159 c = ' '; 160 break; 161 } 162 else 163 ungetc(c); 164 } 165 else { 166 ungetc(c); 167 c = '/'; 168 } 169 } 170 } while(isBlank(c)); 171 return c; 172 } 173 174 private int readCharConst(Token token) { 175 int c; 176 int value = 0; 177 while ((c = getc()) != '\'') 178 if (c == '\\') 179 value = readEscapeChar(); 180 else if (c < 0x20) { 181 if (c == '\n') 182 ++lineNumber; 183 184 return BadToken; 185 } 186 else 187 value = c; 188 189 token.longValue = value; 190 return CharConstant; 191 } 192 193 private int readEscapeChar() { 194 int c = getc(); 195 if (c == 'n') 196 c = '\n'; 197 else if (c == 't') 198 c = '\t'; 199 else if (c == 'r') 200 c = '\r'; 201 else if (c == 'f') 202 c = '\f'; 203 else if (c == '\n') 204 ++lineNumber; 205 206 return c; 207 } 208 209 private int readStringL(Token token) { 210 int c; 211 StringBuffer tbuf = textBuffer; 212 tbuf.setLength(0); 213 for (;;) { 214 while ((c = getc()) != '"') { 215 if (c == '\\') 216 c = readEscapeChar(); 217 else if (c == '\n' || c < 0) { 218 ++lineNumber; 219 return BadToken; 220 } 221 222 tbuf.append((char)c); 223 } 224 225 for (;;) { 226 c = getc(); 227 if (c == '\n') 228 ++lineNumber; 229 else if (!isBlank(c)) 230 break; 231 } 232 233 if (c != '"') { 234 ungetc(c); 235 break; 236 } 237 } 238 239 token.textValue = tbuf.toString(); 240 return StringL; 241 } 242 243 private int readNumber(int c, Token token) { 244 long value = 0; 245 int c2 = getc(); 246 if (c == '0') 247 if (c2 == 'X' || c2 == 'x') 248 for (;;) { 249 c = getc(); 250 if ('0' <= c && c <= '9') 251 value = value * 16 + (long)(c - '0'); 252 else if ('A' <= c && c <= 'F') 253 value = value * 16 + (long)(c - 'A' + 10); 254 else if ('a' <= c && c <= 'f') 255 value = value * 16 + (long)(c - 'a' + 10); 256 else { 257 token.longValue = value; 258 if (c == 'L' || c == 'l') 259 return LongConstant; 260 else { 261 ungetc(c); 262 return IntConstant; 263 } 264 } 265 } 266 else if ('0' <= c2 && c2 <= '7') { 267 value = c2 - '0'; 268 for (;;) { 269 c = getc(); 270 if ('0' <= c && c <= '7') 271 value = value * 8 + (long)(c - '0'); 272 else { 273 token.longValue = value; 274 if (c == 'L' || c == 'l') 275 return LongConstant; 276 else { 277 ungetc(c); 278 return IntConstant; 279 } 280 } 281 } 282 } 283 284 value = c - '0'; 285 while ('0' <= c2 && c2 <= '9') { 286 value = value * 10 + c2 - '0'; 287 c2 = getc(); 288 } 289 290 token.longValue = value; 291 if (c2 == 'F' || c2 == 'f') { 292 token.doubleValue = (double)value; 293 return FloatConstant; 294 } 295 else if (c2 == 'E' || c2 == 'e' 296 || c2 == 'D' || c2 == 'd' || c2 == '.') { 297 StringBuffer tbuf = textBuffer; 298 tbuf.setLength(0); 299 tbuf.append(value); 300 return readDouble(tbuf, c2, token); 301 } 302 else if (c2 == 'L' || c2 == 'l') 303 return LongConstant; 304 else { 305 ungetc(c2); 306 return IntConstant; 307 } 308 } 309 310 private int readDouble(StringBuffer sbuf, int c, Token token) { 311 if (c != 'E' && c != 'e' && c != 'D' && c != 'd') { 312 sbuf.append((char)c); 313 for (;;) { 314 c = getc(); 315 if ('0' <= c && c <= '9') 316 sbuf.append((char)c); 317 else 318 break; 319 } 320 } 321 322 if (c == 'E' || c == 'e') { 323 sbuf.append((char)c); 324 c = getc(); 325 if (c == '+' || c == '-') { 326 sbuf.append((char)c); 327 c = getc(); 328 } 329 330 while ('0' <= c && c <= '9') { 331 sbuf.append((char)c); 332 c = getc(); 333 } 334 } 335 336 try { 337 token.doubleValue = Double.parseDouble(sbuf.toString()); 338 } 339 catch (NumberFormatException e) { 340 return BadToken; 341 } 342 343 if (c == 'F' || c == 'f') 344 return FloatConstant; 345 else { 346 if (c != 'D' && c != 'd') 347 ungetc(c); 348 349 return DoubleConstant; 350 } 351 } 352 353 // !"#$%&'( )*+,-./0 12345678 9:;<=>? 354 private static final int[] equalOps 355 = { NEQ, 0, 0, 0, MOD_E, AND_E, 0, 0, 356 0, MUL_E, PLUS_E, 0, MINUS_E, 0, DIV_E, 0, 357 0, 0, 0, 0, 0, 0, 0, 0, 358 0, 0, 0, LE, EQ, GE, 0 }; 359 360 private int readSeparator(int c) { 361 int c2, c3; 362 if ('!' <= c && c <= '?') { 363 int t = equalOps[c - '!']; 364 if (t == 0) 365 return c; 366 else { 367 c2 = getc(); 368 if (c == c2) 369 switch (c) { 370 case '=' : 371 return EQ; 372 case '+' : 373 return PLUSPLUS; 374 case '-' : 375 return MINUSMINUS; 376 case '&' : 377 return ANDAND; 378 case '<' : 379 c3 = getc(); 380 if (c3 == '=') 381 return LSHIFT_E; 382 else { 383 ungetc(c3); 384 return LSHIFT; 385 } 386 case '>' : 387 c3 = getc(); 388 if (c3 == '=') 389 return RSHIFT_E; 390 else if (c3 == '>') { 391 c3 = getc(); 392 if (c3 == '=') 393 return ARSHIFT_E; 394 else { 395 ungetc(c3); 396 return ARSHIFT; 397 } 398 } 399 else { 400 ungetc(c3); 401 return RSHIFT; 402 } 403 default : 404 break; 405 } 406 else if (c2 == '=') 407 return t; 408 } 409 } 410 else if (c == '^') { 411 c2 = getc(); 412 if (c2 == '=') 413 return EXOR_E; 414 } 415 else if (c == '|') { 416 c2 = getc(); 417 if (c2 == '=') 418 return OR_E; 419 else if (c2 == '|') 420 return OROR; 421 } 422 else 423 return c; 424 425 ungetc(c2); 426 return c; 427 } 428 429 private int readIdentifier(int c, Token token) { 430 StringBuffer tbuf = textBuffer; 431 tbuf.setLength(0); 432 433 do { 434 tbuf.append((char)c); 435 c = getc(); 436 } while (Character.isJavaIdentifierPart((char)c)); 437 438 ungetc(c); 439 440 String name = tbuf.toString(); 441 int t = ktable.lookup(name); 442 if (t >= 0) 443 return t; 444 else { 445 /* tbuf.toString() is executed quickly since it does not 446 * need memory copy. Using a hand-written extensible 447 * byte-array class instead of StringBuffer is not a good idea 448 * for execution speed. Converting a byte array to a String 449 * object is very slow. Using an extensible char array 450 * might be OK. 451 */ 452 token.textValue = name; 453 return Identifier; 454 } 455 } 456 457 private static final KeywordTable ktable = new KeywordTable(); 458 459 static { 460 ktable.append("abstract", ABSTRACT); 461 ktable.append("boolean", BOOLEAN); 462 ktable.append("break", BREAK); 463 ktable.append("byte", BYTE); 464 ktable.append("case", CASE); 465 ktable.append("catch", CATCH); 466 ktable.append("char", CHAR); 467 ktable.append("class", CLASS); 468 ktable.append("const", CONST); 469 ktable.append("continue", CONTINUE); 470 ktable.append("default", DEFAULT); 471 ktable.append("do", DO); 472 ktable.append("double", DOUBLE); 473 ktable.append("else", ELSE); 474 ktable.append("extends", EXTENDS); 475 ktable.append("false", FALSE); 476 ktable.append("final", FINAL); 477 ktable.append("finally", FINALLY); 478 ktable.append("float", FLOAT); 479 ktable.append("for", FOR); 480 ktable.append("goto", GOTO); 481 ktable.append("if", IF); 482 ktable.append("implements", IMPLEMENTS); 483 ktable.append("import", IMPORT); 484 ktable.append("instanceof", INSTANCEOF); 485 ktable.append("int", INT); 486 ktable.append("interface", INTERFACE); 487 ktable.append("long", LONG); 488 ktable.append("native", NATIVE); 489 ktable.append("new", NEW); 490 ktable.append("null", NULL); 491 ktable.append("package", PACKAGE); 492 ktable.append("private", PRIVATE); 493 ktable.append("protected", PROTECTED); 494 ktable.append("public", PUBLIC); 495 ktable.append("return", RETURN); 496 ktable.append("short", SHORT); 497 ktable.append("static", STATIC); 498 ktable.append("strictfp", STRICT); 499 ktable.append("super", SUPER); 500 ktable.append("switch", SWITCH); 501 ktable.append("synchronized", SYNCHRONIZED); 502 ktable.append("this", THIS); 503 ktable.append("throw", THROW); 504 ktable.append("throws", THROWS); 505 ktable.append("transient", TRANSIENT); 506 ktable.append("true", TRUE); 507 ktable.append("try", TRY); 508 ktable.append("void", VOID); 509 ktable.append("volatile", VOLATILE); 510 ktable.append("while", WHILE); 511 } 512 513 private static boolean isBlank(int c) { 514 return c == ' ' || c == '\t' || c == '\f' || c == '\r' 515 || c == '\n'; 516 } 517 518 private static boolean isDigit(int c) { 519 return '0' <= c && c <= '9'; 520 } 521 522 private void ungetc(int c) { 523 lastChar = c; 524 } 525 526 public String getTextAround() { 527 int begin = position - 10; 528 if (begin < 0) 529 begin = 0; 530 531 int end = position + 10; 532 if (end > maxlen) 533 end = maxlen; 534 535 return input.substring(begin, end); 536 } 537 538 private int getc() { 539 if (lastChar < 0) 540 if (position < maxlen) 541 return input.charAt(position++); 542 else 543 return -1; 544 else { 545 int c = lastChar; 546 lastChar = -1; 547 return c; 548 } 549 } 550 } 551
