| 1 | /* Copyright (c) 1982 Regents of the University of California */ |
| 2 | |
| 3 | static char sccsid[] = "@(#)scanner.c 1.3 %G%"; |
| 4 | |
| 5 | /* |
| 6 | * Debugger scanner. |
| 7 | */ |
| 8 | |
| 9 | #include "defs.h" |
| 10 | #include "scanner.h" |
| 11 | #include "main.h" |
| 12 | #include "keywords.h" |
| 13 | #include "tree.h" |
| 14 | #include "symbols.h" |
| 15 | #include "names.h" |
| 16 | #include "y.tab.h" |
| 17 | |
| 18 | #ifndef public |
| 19 | typedef int Token; |
| 20 | #endif |
| 21 | |
| 22 | public String initfile = ".dbxinit"; |
| 23 | |
| 24 | typedef enum { WHITE, ALPHA, NUM, OTHER } Charclass; |
| 25 | |
| 26 | private Charclass class[256 + 1]; |
| 27 | private Charclass *lexclass = class + 1; |
| 28 | |
| 29 | #define isdigit(c) (lexclass[c] == NUM) |
| 30 | #define isalnum(c) (lexclass[c] == ALPHA or lexclass[c] == NUM) |
| 31 | #define ishexdigit(c) ( \ |
| 32 | isdigit(c) or (c >= 'a' and c <= 'f') or (c >= 'A' and c <= 'F') \ |
| 33 | ) |
| 34 | |
| 35 | #define MAXLINESIZE 1024 |
| 36 | |
| 37 | private File in; |
| 38 | private Char linebuf[MAXLINESIZE]; |
| 39 | private Char *curchar; |
| 40 | |
| 41 | #define MAXINCLDEPTH 10 |
| 42 | |
| 43 | private struct { |
| 44 | File savefile; |
| 45 | Filename savefn; |
| 46 | int savelineno; |
| 47 | } inclinfo[MAXINCLDEPTH]; |
| 48 | |
| 49 | private unsigned int curinclindex; |
| 50 | |
| 51 | private Boolean firsttoken = true; |
| 52 | private Boolean firstinit = true; |
| 53 | |
| 54 | private Token getident(); |
| 55 | private Token getnum(); |
| 56 | private Token getstring(); |
| 57 | private Boolean eofinput(); |
| 58 | private Char charcon(); |
| 59 | private Char charlookup(); |
| 60 | |
| 61 | private enterlexclass(class, s) |
| 62 | Charclass class; |
| 63 | String s; |
| 64 | { |
| 65 | register char *p; |
| 66 | |
| 67 | for (p = s; *p != '\0'; p++) { |
| 68 | lexclass[*p] = class; |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | public scanner_init() |
| 73 | { |
| 74 | register Integer i; |
| 75 | |
| 76 | for (i = 0; i < 257; i++) { |
| 77 | class[i] = OTHER; |
| 78 | } |
| 79 | enterlexclass(WHITE, " \t"); |
| 80 | enterlexclass(ALPHA, "abcdefghijklmnopqrstuvwxyz"); |
| 81 | enterlexclass(ALPHA, "ABCDEFGHIJKLMNOPQRSTUVWXYZ_$"); |
| 82 | enterlexclass(NUM, "0123456789"); |
| 83 | in = stdin; |
| 84 | errfilename = nil; |
| 85 | errlineno = 0; |
| 86 | curchar = linebuf; |
| 87 | linebuf[0] = '\0'; |
| 88 | if (runfirst) { |
| 89 | firstinit = false; |
| 90 | firsttoken = false; |
| 91 | } else if (firstinit and isterm(in)) { |
| 92 | firstinit = false; |
| 93 | printf("> "); |
| 94 | fflush(stdout); |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * Read a single token. |
| 100 | * |
| 101 | * Input is line buffered. |
| 102 | * |
| 103 | * There are two "modes" of operation: one as in a compiler, |
| 104 | * and one for reading shell-like syntax. |
| 105 | */ |
| 106 | |
| 107 | private Boolean shellmode; |
| 108 | |
| 109 | public Token yylex() |
| 110 | { |
| 111 | register int c; |
| 112 | register char *p; |
| 113 | register Token t; |
| 114 | String line; |
| 115 | |
| 116 | p = curchar; |
| 117 | if (*p == '\0') { |
| 118 | do { |
| 119 | if (isterm(in)) { |
| 120 | if (firsttoken) { |
| 121 | firsttoken = false; |
| 122 | } else { |
| 123 | printf("> "); |
| 124 | fflush(stdout); |
| 125 | } |
| 126 | } |
| 127 | line = fgets(linebuf, MAXLINESIZE, in); |
| 128 | } while (line == nil and not eofinput()); |
| 129 | if (line == nil) { |
| 130 | c = EOF; |
| 131 | } else { |
| 132 | p = linebuf; |
| 133 | while (lexclass[*p] == WHITE) { |
| 134 | p++; |
| 135 | } |
| 136 | shellmode = false; |
| 137 | } |
| 138 | } else { |
| 139 | while (lexclass[*p] == WHITE) { |
| 140 | p++; |
| 141 | } |
| 142 | } |
| 143 | curchar = p; |
| 144 | c = *p; |
| 145 | if (lexclass[c] == ALPHA) { |
| 146 | t = getident(); |
| 147 | } else if (lexclass[c] == NUM) { |
| 148 | t = getnum(); |
| 149 | } else { |
| 150 | ++curchar; |
| 151 | switch (c) { |
| 152 | case '\n': |
| 153 | t = '\n'; |
| 154 | if (errlineno != 0) { |
| 155 | errlineno++; |
| 156 | } |
| 157 | break; |
| 158 | |
| 159 | case '"': |
| 160 | case '\'': |
| 161 | t = getstring(); |
| 162 | break; |
| 163 | |
| 164 | case '.': |
| 165 | if (shellmode) { |
| 166 | --curchar; |
| 167 | t = getident(); |
| 168 | } else if (isdigit(*curchar)) { |
| 169 | --curchar; |
| 170 | t = getnum(); |
| 171 | } else { |
| 172 | t = '.'; |
| 173 | } |
| 174 | break; |
| 175 | |
| 176 | case '<': |
| 177 | if (not shellmode and *curchar == '<') { |
| 178 | ++curchar; |
| 179 | t = LFORMER; |
| 180 | } else { |
| 181 | t = '<'; |
| 182 | } |
| 183 | break; |
| 184 | |
| 185 | case '>': |
| 186 | if (not shellmode and *curchar == '>') { |
| 187 | ++curchar; |
| 188 | t = RFORMER; |
| 189 | } else { |
| 190 | t = '>'; |
| 191 | } |
| 192 | break; |
| 193 | |
| 194 | case '#': |
| 195 | if (*curchar == '^') { |
| 196 | ++curchar; |
| 197 | t = ABSTRACTION; |
| 198 | } else { |
| 199 | t = '#'; |
| 200 | } |
| 201 | break; |
| 202 | |
| 203 | case '-': |
| 204 | if (shellmode) { |
| 205 | --curchar; |
| 206 | t = getident(); |
| 207 | } else if (*curchar == '>') { |
| 208 | ++curchar; |
| 209 | t = ARROW; |
| 210 | } else { |
| 211 | t = '-'; |
| 212 | } |
| 213 | break; |
| 214 | |
| 215 | case EOF: |
| 216 | t = 0; |
| 217 | break; |
| 218 | |
| 219 | default: |
| 220 | if (shellmode and index("!&*()[]", c) == nil) { |
| 221 | --curchar; |
| 222 | t = getident(); |
| 223 | } else { |
| 224 | t = c; |
| 225 | } |
| 226 | break; |
| 227 | } |
| 228 | } |
| 229 | # ifdef LEXDEBUG |
| 230 | if (lexdebug) { |
| 231 | fprintf(stderr, "yylex returns "); |
| 232 | print_token(stderr, t); |
| 233 | fprintf(stderr, "\n"); |
| 234 | } |
| 235 | # endif |
| 236 | return t; |
| 237 | } |
| 238 | |
| 239 | /* |
| 240 | * Parser error handling. |
| 241 | */ |
| 242 | |
| 243 | public yyerror(s) |
| 244 | String s; |
| 245 | { |
| 246 | register Char *p, *tokenbegin, *tokenend; |
| 247 | register Integer len; |
| 248 | |
| 249 | if (streq(s, "syntax error")) { |
| 250 | beginerrmsg(); |
| 251 | tokenend = curchar - 1; |
| 252 | tokenbegin = tokenend; |
| 253 | while (lexclass[*tokenbegin] != WHITE and tokenbegin > &linebuf[0]) { |
| 254 | --tokenbegin; |
| 255 | } |
| 256 | len = tokenend - tokenbegin + 1; |
| 257 | p = tokenbegin; |
| 258 | if (p > &linebuf[0]) { |
| 259 | while (lexclass[*p] == WHITE and p > &linebuf[0]) { |
| 260 | --p; |
| 261 | } |
| 262 | } |
| 263 | if (p == &linebuf[0]) { |
| 264 | fprintf(stderr, "unrecognized command \"%.*s\"", len, tokenbegin); |
| 265 | } else { |
| 266 | fprintf(stderr, "syntax error"); |
| 267 | if (len != 0) { |
| 268 | fprintf(stderr, " on \"%.*s\"", len, tokenbegin); |
| 269 | } |
| 270 | } |
| 271 | enderrmsg(); |
| 272 | } else { |
| 273 | error(s); |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | /* |
| 278 | * Eat the current line. |
| 279 | */ |
| 280 | |
| 281 | public gobble() |
| 282 | { |
| 283 | curchar = linebuf; |
| 284 | linebuf[0] = '\0'; |
| 285 | } |
| 286 | |
| 287 | /* |
| 288 | * Scan an identifier and check to see if it's a keyword. |
| 289 | */ |
| 290 | |
| 291 | private Token getident() |
| 292 | { |
| 293 | char buf[256]; |
| 294 | register Char *p, *q; |
| 295 | register Token t; |
| 296 | |
| 297 | p = curchar; |
| 298 | q = buf; |
| 299 | if (shellmode) { |
| 300 | do { |
| 301 | *q++ = *p++; |
| 302 | } while (index(" \t\n!&<>*[]()", *p) == nil); |
| 303 | } else { |
| 304 | do { |
| 305 | *q++ = *p++; |
| 306 | } while (isalnum(*p)); |
| 307 | } |
| 308 | curchar = p; |
| 309 | *q = '\0'; |
| 310 | yylval.y_name = identname(buf, false); |
| 311 | if (not shellmode) { |
| 312 | t = findkeyword(yylval.y_name); |
| 313 | if (t == nil) { |
| 314 | t = NAME; |
| 315 | } |
| 316 | } else { |
| 317 | t = NAME; |
| 318 | } |
| 319 | return t; |
| 320 | } |
| 321 | |
| 322 | /* |
| 323 | * Scan a number. |
| 324 | */ |
| 325 | |
| 326 | private Token getnum() |
| 327 | { |
| 328 | char buf[256]; |
| 329 | register Char *p, *q; |
| 330 | register Token t; |
| 331 | Integer base; |
| 332 | |
| 333 | p = curchar; |
| 334 | q = buf; |
| 335 | if (*p == '0') { |
| 336 | if (*(p+1) == 'x') { |
| 337 | p += 2; |
| 338 | base = 16; |
| 339 | } else { |
| 340 | base = 8; |
| 341 | } |
| 342 | } else { |
| 343 | base = 10; |
| 344 | } |
| 345 | if (base == 16) { |
| 346 | do { |
| 347 | *q++ = *p++; |
| 348 | } while (ishexdigit(*p)); |
| 349 | } else { |
| 350 | do { |
| 351 | *q++ = *p++; |
| 352 | } while (isdigit(*p)); |
| 353 | } |
| 354 | if (*p == '.') { |
| 355 | do { |
| 356 | *q++ = *p++; |
| 357 | } while (isdigit(*p)); |
| 358 | if (*p == 'e' or *p == 'E') { |
| 359 | p++; |
| 360 | if (*p == '+' or *p == '-' or isdigit(*p)) { |
| 361 | *q++ = 'e'; |
| 362 | do { |
| 363 | *q++ = *p++; |
| 364 | } while (isdigit(*p)); |
| 365 | } |
| 366 | } |
| 367 | *q = '\0'; |
| 368 | yylval.y_real = atof(buf); |
| 369 | t = REAL; |
| 370 | } else { |
| 371 | *q = '\0'; |
| 372 | switch (base) { |
| 373 | case 10: |
| 374 | yylval.y_int = atol(buf); |
| 375 | break; |
| 376 | |
| 377 | case 8: |
| 378 | yylval.y_int = octal(buf); |
| 379 | break; |
| 380 | |
| 381 | case 16: |
| 382 | yylval.y_int = hex(buf); |
| 383 | break; |
| 384 | |
| 385 | default: |
| 386 | badcaseval(base); |
| 387 | } |
| 388 | t = INT; |
| 389 | } |
| 390 | curchar = p; |
| 391 | return t; |
| 392 | } |
| 393 | |
| 394 | /* |
| 395 | * Convert a string of octal digits to an integer. |
| 396 | */ |
| 397 | |
| 398 | private int octal(s) |
| 399 | String s; |
| 400 | { |
| 401 | register Char *p; |
| 402 | register Integer n; |
| 403 | |
| 404 | n = 0; |
| 405 | for (p = s; *p != '\0'; p++) { |
| 406 | n = 8*n + (*p - '0'); |
| 407 | } |
| 408 | return n; |
| 409 | } |
| 410 | |
| 411 | /* |
| 412 | * Convert a string of hexadecimal digits to an integer. |
| 413 | */ |
| 414 | |
| 415 | private int hex(s) |
| 416 | String s; |
| 417 | { |
| 418 | register Char *p; |
| 419 | register Integer n; |
| 420 | |
| 421 | n = 0; |
| 422 | for (p = s; *p != '\0'; p++) { |
| 423 | n *= 16; |
| 424 | if (*p >= 'a' and *p <= 'f') { |
| 425 | n += (*p - 'a' + 10); |
| 426 | } else if (*p >= 'A' and *p <= 'F') { |
| 427 | n += (*p - 'A' + 10); |
| 428 | } else { |
| 429 | n += (*p - '0'); |
| 430 | } |
| 431 | } |
| 432 | return n; |
| 433 | } |
| 434 | |
| 435 | /* |
| 436 | * Scan a string. |
| 437 | */ |
| 438 | |
| 439 | private Token getstring() |
| 440 | { |
| 441 | char buf[256]; |
| 442 | register Char *p, *q; |
| 443 | Boolean endofstring; |
| 444 | |
| 445 | p = curchar; |
| 446 | q = buf; |
| 447 | endofstring = false; |
| 448 | while (not endofstring) { |
| 449 | if (*p == '\n' or *p == '\0') { |
| 450 | error("non-terminated string"); |
| 451 | endofstring = true; |
| 452 | } else if (*p == '"' or *p == '\'') { |
| 453 | if (*(p+1) != *p) { |
| 454 | endofstring = true; |
| 455 | } else { |
| 456 | *q++ = *p; |
| 457 | } |
| 458 | } else { |
| 459 | *q++ = charcon(*p); |
| 460 | } |
| 461 | p++; |
| 462 | } |
| 463 | curchar = p; |
| 464 | *q = '\0'; |
| 465 | yylval.y_string = strdup(buf); |
| 466 | return STRING; |
| 467 | } |
| 468 | |
| 469 | /* |
| 470 | * Process a character constant. |
| 471 | * Watch out for backslashes. |
| 472 | */ |
| 473 | |
| 474 | private Char charcon(ch) |
| 475 | Char ch; |
| 476 | { |
| 477 | Char c, buf[10], *p, *q; |
| 478 | |
| 479 | p = curchar; |
| 480 | if (ch == '\\') { |
| 481 | if (*p != '\\') { |
| 482 | q = buf; |
| 483 | do { |
| 484 | *q++ = *p++; |
| 485 | } while (*p != '\\' and *p != '\n' and *p != '\0'); |
| 486 | if (*p != '\\') { |
| 487 | ungetc(*p, in); |
| 488 | error("non-terminated character constant"); |
| 489 | } |
| 490 | *q = '\0'; |
| 491 | if (isdigit(buf[0])) { |
| 492 | c = (Char) octal(buf); |
| 493 | } else { |
| 494 | c = charlookup(buf); |
| 495 | } |
| 496 | curchar = p; |
| 497 | } else { |
| 498 | c = '\\'; |
| 499 | } |
| 500 | } else { |
| 501 | c = ch; |
| 502 | } |
| 503 | return c; |
| 504 | } |
| 505 | |
| 506 | /* |
| 507 | * Do a lookup for a ASCII character name. |
| 508 | */ |
| 509 | |
| 510 | private String ascii[] = { |
| 511 | "NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL", |
| 512 | "BS", "HT", "NL", "VT", "NP", "CR", "SO", "SI", |
| 513 | "DLE", "DC1", "DC2", "DC3", "DC4", "NAK", "SYN", "ETB", |
| 514 | "CAN", "EM", "SUB", "ESC", "FS", "GS", "RS", "US", |
| 515 | "SP", nil |
| 516 | }; |
| 517 | |
| 518 | private char charlookup(s) |
| 519 | String s; |
| 520 | { |
| 521 | register int i; |
| 522 | |
| 523 | for (i = 0; ascii[i] != NULL; i++) { |
| 524 | if (streq(s, ascii[i])) { |
| 525 | return i; |
| 526 | } |
| 527 | } |
| 528 | if (streq(s, "DEL")) { |
| 529 | return 0177; |
| 530 | } |
| 531 | error("unknown ascii name \"%s\"", s); |
| 532 | return '?'; |
| 533 | } |
| 534 | |
| 535 | /* |
| 536 | * Input file management routines. |
| 537 | */ |
| 538 | |
| 539 | public setinput(filename) |
| 540 | Filename filename; |
| 541 | { |
| 542 | File f; |
| 543 | |
| 544 | f = fopen(filename, "r"); |
| 545 | if (f == nil) { |
| 546 | error("can't open %s", filename); |
| 547 | } else { |
| 548 | if (curinclindex >= MAXINCLDEPTH) { |
| 549 | error("unreasonable input nesting on \"%s\"", filename); |
| 550 | } |
| 551 | inclinfo[curinclindex].savefile = in; |
| 552 | inclinfo[curinclindex].savefn = errfilename; |
| 553 | inclinfo[curinclindex].savelineno = errlineno; |
| 554 | curinclindex++; |
| 555 | in = f; |
| 556 | errfilename = filename; |
| 557 | errlineno = 1; |
| 558 | } |
| 559 | } |
| 560 | |
| 561 | private Boolean eofinput() |
| 562 | { |
| 563 | register Boolean b; |
| 564 | |
| 565 | if (curinclindex == 0) { |
| 566 | if (isterm(in)) { |
| 567 | putchar('\n'); |
| 568 | b = false; |
| 569 | } else { |
| 570 | b = true; |
| 571 | } |
| 572 | } else { |
| 573 | fclose(in); |
| 574 | --curinclindex; |
| 575 | in = inclinfo[curinclindex].savefile; |
| 576 | errfilename = inclinfo[curinclindex].savefn; |
| 577 | errlineno = inclinfo[curinclindex].savelineno; |
| 578 | b = false; |
| 579 | } |
| 580 | return b; |
| 581 | } |
| 582 | |
| 583 | /* |
| 584 | * Pop the current input. Return whether successful. |
| 585 | */ |
| 586 | |
| 587 | public Boolean popinput() |
| 588 | { |
| 589 | Boolean b; |
| 590 | |
| 591 | if (curinclindex == 0) { |
| 592 | b = false; |
| 593 | } else { |
| 594 | b = (Boolean) (not eofinput()); |
| 595 | } |
| 596 | return b; |
| 597 | } |
| 598 | |
| 599 | /* |
| 600 | * Return whether we are currently reading from standard input. |
| 601 | */ |
| 602 | |
| 603 | public Boolean isstdin() |
| 604 | { |
| 605 | return (Boolean) (in == stdin); |
| 606 | } |
| 607 | |
| 608 | /* |
| 609 | * Send the current line to the shell. |
| 610 | */ |
| 611 | |
| 612 | public shellline() |
| 613 | { |
| 614 | register char *p; |
| 615 | |
| 616 | p = curchar; |
| 617 | while (*p != '\0' and (*p == '\n' or lexclass[*p] == WHITE)) { |
| 618 | ++p; |
| 619 | } |
| 620 | shell(p); |
| 621 | if (*p == '\0' and isterm(in)) { |
| 622 | putchar('\n'); |
| 623 | } |
| 624 | erecover(); |
| 625 | } |
| 626 | |
| 627 | /* |
| 628 | * Read the rest of the current line in "shell mode". |
| 629 | */ |
| 630 | |
| 631 | public beginshellmode() |
| 632 | { |
| 633 | shellmode = true; |
| 634 | } |
| 635 | |
| 636 | /* |
| 637 | * Print out a token for debugging. |
| 638 | */ |
| 639 | |
| 640 | public print_token(f, t) |
| 641 | File f; |
| 642 | Token t; |
| 643 | { |
| 644 | if (t == '\n') { |
| 645 | fprintf(f, "char '\\n'"); |
| 646 | } else if (t == EOF) { |
| 647 | fprintf(f, "EOF"); |
| 648 | } else if (t < 256) { |
| 649 | fprintf(f, "char '%c'", t); |
| 650 | } else { |
| 651 | fprintf(f, "\"%s\"", keywdstring(t)); |
| 652 | } |
| 653 | } |