1 /*- 2 * Copyright (c) 1992 Diomidis Spinellis. 3 * Copyright (c) 1992, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Diomidis Spinellis of Imperial College, University of London. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38 #ifndef lint 39 /* from: static char sccsid[] = "@(#)compile.c 8.1 (Berkeley) 6/6/93"; */ 40 static char *rcsid = "$Id: compile.c,v 1.12 1994/11/09 19:30:32 mycroft Exp $"; 41 #endif /* not lint */ 42 43 #include <sys/types.h> 44 #include <sys/stat.h> 45 46 #include <ctype.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <limits.h> 50 #include <regex.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 55 #include "defs.h" 56 #include "extern.h" 57 58 #define LHSZ 128 59 #define LHMASK (LHSZ - 1) 60 static struct labhash { 61 struct labhash *lh_next; 62 u_int lh_hash; 63 struct s_command *lh_cmd; 64 int lh_ref; 65 } *labels[LHSZ]; 66 67 static char *compile_addr __P((char *, struct s_addr *)); 68 static char *compile_ccl __P((char **, char *)); 69 static char *compile_delimited __P((char *, char *)); 70 static char *compile_flags __P((char *, struct s_subst *)); 71 static char *compile_re __P((char *, regex_t **)); 72 static char *compile_subst __P((char *, struct s_subst *)); 73 static char *compile_text __P((void)); 74 static char *compile_tr __P((char *, char **)); 75 static struct s_command 76 **compile_stream __P((char *, struct s_command **, char *)); 77 static char *duptoeol __P((char *, char *)); 78 static void enterlabel __P((struct s_command *)); 79 static struct s_command 80 *findlabel __P((char *)); 81 static void fixuplabel __P((struct s_command *, struct s_command *)); 82 static void uselabel __P((void)); 83 84 /* 85 * Command specification. This is used to drive the command parser. 86 */ 87 struct s_format { 88 char code; /* Command code */ 89 int naddr; /* Number of address args */ 90 enum e_args args; /* Argument type */ 91 }; 92 93 static struct s_format cmd_fmts[] = { 94 {'{', 2, GROUP}, 95 {'a', 1, TEXT}, 96 {'b', 2, BRANCH}, 97 {'c', 2, TEXT}, 98 {'d', 2, EMPTY}, 99 {'D', 2, EMPTY}, 100 {'g', 2, EMPTY}, 101 {'G', 2, EMPTY}, 102 {'h', 2, EMPTY}, 103 {'H', 2, EMPTY}, 104 {'i', 1, TEXT}, 105 {'l', 2, EMPTY}, 106 {'n', 2, EMPTY}, 107 {'N', 2, EMPTY}, 108 {'p', 2, EMPTY}, 109 {'P', 2, EMPTY}, 110 {'q', 1, EMPTY}, 111 {'r', 1, RFILE}, 112 {'s', 2, SUBST}, 113 {'t', 2, BRANCH}, 114 {'w', 2, WFILE}, 115 {'x', 2, EMPTY}, 116 {'y', 2, TR}, 117 {'!', 2, NONSEL}, 118 {':', 0, LABEL}, 119 {'#', 0, COMMENT}, 120 {'=', 1, EMPTY}, 121 {'\0', 0, COMMENT}, 122 }; 123 124 /* The compiled program. */ 125 struct s_command *prog; 126 127 /* 128 * Compile the program into prog. 129 * Initialise appends. 130 */ 131 void 132 compile() 133 { 134 *compile_stream(NULL, &prog, NULL) = NULL; 135 fixuplabel(prog, NULL); 136 uselabel(); 137 appends = xmalloc(sizeof(struct s_appends) * appendnum); 138 match = xmalloc((maxnsub + 1) * sizeof(regmatch_t)); 139 } 140 141 #define EATSPACE() do { \ 142 if (p) \ 143 while (*p && isascii(*p) && isspace(*p)) \ 144 p++; \ 145 } while (0) 146 147 static struct s_command ** 148 compile_stream(terminator, link, p) 149 char *terminator; 150 struct s_command **link; 151 register char *p; 152 { 153 static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */ 154 struct s_command *cmd, *cmd2; 155 struct s_format *fp; 156 int naddr; /* Number of addresses */ 157 158 if (p != NULL) 159 goto semicolon; 160 for (;;) { 161 if ((p = cu_fgets(lbuf, sizeof(lbuf))) == NULL) { 162 if (terminator != NULL) 163 err(COMPILE, "unexpected EOF (pending }'s)"); 164 return (link); 165 } 166 167 semicolon: EATSPACE(); 168 if (p && (*p == '#' || *p == '\0')) 169 continue; 170 if (*p == '}') { 171 if (terminator == NULL) 172 err(COMPILE, "unexpected }"); 173 return (link); 174 } 175 *link = cmd = xmalloc(sizeof(struct s_command)); 176 link = &cmd->next; 177 cmd->nonsel = cmd->inrange = 0; 178 /* First parse the addresses */ 179 naddr = 0; 180 181 /* Valid characters to start an address */ 182 #define addrchar(c) (strchr("0123456789/\\$", (c))) 183 if (addrchar(*p)) { 184 naddr++; 185 cmd->a1 = xmalloc(sizeof(struct s_addr)); 186 p = compile_addr(p, cmd->a1); 187 EATSPACE(); /* EXTENSION */ 188 if (*p == ',') { 189 naddr++; 190 p++; 191 EATSPACE(); /* EXTENSION */ 192 cmd->a2 = xmalloc(sizeof(struct s_addr)); 193 p = compile_addr(p, cmd->a2); 194 } else 195 cmd->a2 = 0; 196 } else 197 cmd->a1 = 0; 198 199 nonsel: /* Now parse the command */ 200 EATSPACE(); 201 if (!*p) 202 err(COMPILE, "command expected"); 203 cmd->code = *p; 204 for (fp = cmd_fmts; fp->code; fp++) 205 if (fp->code == *p) 206 break; 207 if (!fp->code) 208 err(COMPILE, "invalid command code %c", *p); 209 if (naddr > fp->naddr) 210 err(COMPILE, 211 "command %c expects up to %d address(es), found %d", *p, fp->naddr, naddr); 212 switch (fp->args) { 213 case NONSEL: /* ! */ 214 cmd->nonsel = ! cmd->nonsel; 215 p++; 216 goto nonsel; 217 case GROUP: /* { */ 218 p++; 219 EATSPACE(); 220 if (!*p) 221 p = NULL; 222 cmd2 = xmalloc(sizeof(struct s_command)); 223 cmd2->code = '}'; 224 *compile_stream("}", &cmd->u.c, p) = cmd2; 225 cmd->next = cmd2; 226 link = &cmd2->next; 227 /* 228 * Short-circuit command processing, since end of 229 * group is really just a noop. 230 */ 231 cmd2->nonsel = 1; 232 cmd2->a1 = cmd2->a2 = 0; 233 break; 234 case EMPTY: /* d D g G h H l n N p P q x = \0 */ 235 p++; 236 EATSPACE(); 237 if (*p == ';') { 238 p++; 239 link = &cmd->next; 240 goto semicolon; 241 } 242 if (*p) 243 err(COMPILE, 244 "extra characters at the end of %c command", cmd->code); 245 break; 246 case TEXT: /* a c i */ 247 p++; 248 EATSPACE(); 249 if (*p != '\\') 250 err(COMPILE, 251 "command %c expects \\ followed by text", cmd->code); 252 p++; 253 EATSPACE(); 254 if (*p) 255 err(COMPILE, 256 "extra characters after \\ at the end of %c command", cmd->code); 257 cmd->t = compile_text(); 258 break; 259 case COMMENT: /* \0 # */ 260 break; 261 case WFILE: /* w */ 262 p++; 263 EATSPACE(); 264 if (*p == '\0') 265 err(COMPILE, "filename expected"); 266 cmd->t = duptoeol(p, "w command"); 267 if (aflag) 268 cmd->u.fd = -1; 269 else if ((cmd->u.fd = open(p, 270 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 271 DEFFILEMODE)) == -1) 272 err(FATAL, "%s: %s\n", p, strerror(errno)); 273 break; 274 case RFILE: /* r */ 275 p++; 276 EATSPACE(); 277 if (*p == '\0') 278 err(COMPILE, "filename expected"); 279 else 280 cmd->t = duptoeol(p, "read command"); 281 break; 282 case BRANCH: /* b t */ 283 p++; 284 EATSPACE(); 285 if (*p == '\0') 286 cmd->t = NULL; 287 else 288 cmd->t = duptoeol(p, "branch"); 289 break; 290 case LABEL: /* : */ 291 p++; 292 EATSPACE(); 293 cmd->t = duptoeol(p, "label"); 294 if (strlen(p) == 0) 295 err(COMPILE, "empty label"); 296 enterlabel(cmd); 297 break; 298 case SUBST: /* s */ 299 p++; 300 if (*p == '\0' || *p == '\\') 301 err(COMPILE, 302 "substitute pattern can not be delimited by newline or backslash"); 303 cmd->u.s = xmalloc(sizeof(struct s_subst)); 304 p = compile_re(p, &cmd->u.s->re); 305 if (p == NULL) 306 err(COMPILE, "unterminated substitute pattern"); 307 --p; 308 p = compile_subst(p, cmd->u.s); 309 p = compile_flags(p, cmd->u.s); 310 EATSPACE(); 311 if (*p == ';') { 312 p++; 313 link = &cmd->next; 314 goto semicolon; 315 } 316 break; 317 case TR: /* y */ 318 p++; 319 p = compile_tr(p, (char **)&cmd->u.y); 320 EATSPACE(); 321 if (*p == ';') { 322 p++; 323 link = &cmd->next; 324 goto semicolon; 325 } 326 if (*p) 327 err(COMPILE, 328 "extra text at the end of a transform command"); 329 break; 330 } 331 } 332 } 333 334 /* 335 * Get a delimited string. P points to the delimeter of the string; d points 336 * to a buffer area. Newline and delimiter escapes are processed; other 337 * escapes are ignored. 338 * 339 * Returns a pointer to the first character after the final delimiter or NULL 340 * in the case of a non-terminated string. The character array d is filled 341 * with the processed string. 342 */ 343 static char * 344 compile_delimited(p, d) 345 char *p, *d; 346 { 347 char c; 348 349 c = *p++; 350 if (c == '\0') 351 return (NULL); 352 else if (c == '\\') 353 err(COMPILE, "\\ can not be used as a string delimiter"); 354 else if (c == '\n') 355 err(COMPILE, "newline can not be used as a string delimiter"); 356 while (*p) { 357 if (*p == '[') { 358 if ((d = compile_ccl(&p, d)) == NULL) 359 err(COMPILE, "unbalanced brackets ([])"); 360 continue; 361 } else if (*p == '\\' && p[1] == '[') { 362 *d++ = *p++; 363 } else if (*p == '\\' && p[1] == c) 364 p++; 365 else if (*p == '\\' && p[1] == 'n') { 366 *d++ = '\n'; 367 p += 2; 368 continue; 369 } else if (*p == '\\' && p[1] == '\\') 370 *d++ = *p++; 371 else if (*p == c) { 372 *d = '\0'; 373 return (p + 1); 374 } 375 *d++ = *p++; 376 } 377 return (NULL); 378 } 379 380 381 /* compile_ccl: expand a POSIX character class */ 382 static char * 383 compile_ccl(sp, t) 384 char **sp; 385 char *t; 386 { 387 int c, d; 388 char *s = *sp; 389 390 *t++ = *s++; 391 if (*s == '^') 392 *t++ = *s++; 393 if (*s == ']') 394 *t++ = *s++; 395 for (; *s && (*t = *s) != ']'; s++, t++) 396 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) { 397 *++t = *++s, t++, s++; 398 for (c = *s; (*t = *s) != ']' || c != d; s++, t++) 399 if ((c = *s) == '\0') 400 return NULL; 401 } else if (*s == '\\' && s[1] == 'n') 402 *t = '\n', s++; 403 return (*s == ']') ? *sp = ++s, ++t : NULL; 404 } 405 406 /* 407 * Get a regular expression. P points to the delimiter of the regular 408 * expression; repp points to the address of a regexp pointer. Newline 409 * and delimiter escapes are processed; other escapes are ignored. 410 * Returns a pointer to the first character after the final delimiter 411 * or NULL in the case of a non terminated regular expression. The regexp 412 * pointer is set to the compiled regular expression. 413 * Cflags are passed to regcomp. 414 */ 415 static char * 416 compile_re(p, repp) 417 char *p; 418 regex_t **repp; 419 { 420 int eval; 421 char re[_POSIX2_LINE_MAX + 1]; 422 423 p = compile_delimited(p, re); 424 if (p && strlen(re) == 0) { 425 *repp = NULL; 426 return (p); 427 } 428 *repp = xmalloc(sizeof(regex_t)); 429 if (p && (eval = regcomp(*repp, re, 0)) != 0) 430 err(COMPILE, "RE error: %s", strregerror(eval, *repp)); 431 if (maxnsub < (*repp)->re_nsub) 432 maxnsub = (*repp)->re_nsub; 433 return (p); 434 } 435 436 /* 437 * Compile the substitution string of a regular expression and set res to 438 * point to a saved copy of it. Nsub is the number of parenthesized regular 439 * expressions. 440 */ 441 static char * 442 compile_subst(p, s) 443 char *p; 444 struct s_subst *s; 445 { 446 static char lbuf[_POSIX2_LINE_MAX + 1]; 447 int asize, ref, size; 448 char c, *text, *op, *sp; 449 450 c = *p++; /* Terminator character */ 451 if (c == '\0') 452 return (NULL); 453 454 s->maxbref = 0; 455 s->linenum = linenum; 456 asize = 2 * _POSIX2_LINE_MAX + 1; 457 text = xmalloc(asize); 458 size = 0; 459 do { 460 op = sp = text + size; 461 for (; *p; p++) { 462 if (*p == '\\') { 463 p++; 464 if (strchr("123456789", *p) != NULL) { 465 *sp++ = '\\'; 466 ref = *p - '0'; 467 if (s->re != NULL && 468 ref > s->re->re_nsub) 469 err(COMPILE, 470 "\\%c not defined in the RE", *p); 471 if (s->maxbref < ref) 472 s->maxbref = ref; 473 } else if (*p == '&' || *p == '\\') 474 *sp++ = '\\'; 475 } else if (*p == c) { 476 p++; 477 *sp++ = '\0'; 478 size += sp - op; 479 s->new = xrealloc(text, size); 480 return (p); 481 } else if (*p == '\n') { 482 err(COMPILE, 483 "unescaped newline inside substitute pattern"); 484 /* NOTREACHED */ 485 } 486 *sp++ = *p; 487 } 488 size += sp - op; 489 if (asize - size < _POSIX2_LINE_MAX + 1) { 490 asize *= 2; 491 text = xmalloc(asize); 492 } 493 } while (cu_fgets(p = lbuf, sizeof(lbuf))); 494 err(COMPILE, "unterminated substitute in regular expression"); 495 /* NOTREACHED */ 496 } 497 498 /* 499 * Compile the flags of the s command 500 */ 501 static char * 502 compile_flags(p, s) 503 char *p; 504 struct s_subst *s; 505 { 506 int gn; /* True if we have seen g or n */ 507 char wfile[_POSIX2_LINE_MAX + 1], *q; 508 509 s->n = 1; /* Default */ 510 s->p = 0; 511 s->wfile = NULL; 512 s->wfd = -1; 513 for (gn = 0;;) { 514 EATSPACE(); /* EXTENSION */ 515 switch (*p) { 516 case 'g': 517 if (gn) 518 err(COMPILE, 519 "more than one number or 'g' in substitute flags"); 520 gn = 1; 521 s->n = 0; 522 break; 523 case '\0': 524 case '\n': 525 case ';': 526 return (p); 527 case 'p': 528 s->p = 1; 529 break; 530 case '1': case '2': case '3': 531 case '4': case '5': case '6': 532 case '7': case '8': case '9': 533 if (gn) 534 err(COMPILE, 535 "more than one number or 'g' in substitute flags"); 536 gn = 1; 537 /* XXX Check for overflow */ 538 s->n = (int)strtol(p, &p, 10); 539 break; 540 case 'w': 541 p++; 542 #ifdef HISTORIC_PRACTICE 543 if (*p != ' ') { 544 err(WARNING, "space missing before w wfile"); 545 return (p); 546 } 547 #endif 548 EATSPACE(); 549 q = wfile; 550 while (*p) { 551 if (*p == '\n') 552 break; 553 *q++ = *p++; 554 } 555 *q = '\0'; 556 if (q == wfile) 557 err(COMPILE, "no wfile specified"); 558 s->wfile = strdup(wfile); 559 if (!aflag && (s->wfd = open(wfile, 560 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 561 DEFFILEMODE)) == -1) 562 err(FATAL, "%s: %s\n", wfile, strerror(errno)); 563 return (p); 564 default: 565 err(COMPILE, 566 "bad flag in substitute command: '%c'", *p); 567 break; 568 } 569 p++; 570 } 571 } 572 573 /* 574 * Compile a translation set of strings into a lookup table. 575 */ 576 static char * 577 compile_tr(p, transtab) 578 char *p; 579 char **transtab; 580 { 581 int i; 582 char *lt, *op, *np; 583 char old[_POSIX2_LINE_MAX + 1]; 584 char new[_POSIX2_LINE_MAX + 1]; 585 586 if (*p == '\0' || *p == '\\') 587 err(COMPILE, 588 "transform pattern can not be delimited by newline or backslash"); 589 p = compile_delimited(p, old); 590 if (p == NULL) { 591 err(COMPILE, "unterminated transform source string"); 592 return (NULL); 593 } 594 p = compile_delimited(--p, new); 595 if (p == NULL) { 596 err(COMPILE, "unterminated transform target string"); 597 return (NULL); 598 } 599 EATSPACE(); 600 if (strlen(new) != strlen(old)) { 601 err(COMPILE, "transform strings are not the same length"); 602 return (NULL); 603 } 604 /* We assume characters are 8 bits */ 605 lt = xmalloc(UCHAR_MAX); 606 for (i = 0; i <= UCHAR_MAX; i++) 607 lt[i] = (char)i; 608 for (op = old, np = new; *op; op++, np++) 609 lt[(u_char)*op] = *np; 610 *transtab = lt; 611 return (p); 612 } 613 614 /* 615 * Compile the text following an a or i command. 616 */ 617 static char * 618 compile_text() 619 { 620 int asize, size; 621 char *text, *p, *op, *s; 622 char lbuf[_POSIX2_LINE_MAX + 1]; 623 624 asize = 2 * _POSIX2_LINE_MAX + 1; 625 text = xmalloc(asize); 626 size = 0; 627 while (cu_fgets(lbuf, sizeof(lbuf))) { 628 op = s = text + size; 629 p = lbuf; 630 EATSPACE(); 631 for (; *p; p++) { 632 if (*p == '\\') 633 p++; 634 *s++ = *p; 635 } 636 size += s - op; 637 if (p[-2] != '\\') { 638 *s = '\0'; 639 break; 640 } 641 if (asize - size < _POSIX2_LINE_MAX + 1) { 642 asize *= 2; 643 text = xmalloc(asize); 644 } 645 } 646 return (xrealloc(text, size + 1)); 647 } 648 649 /* 650 * Get an address and return a pointer to the first character after 651 * it. Fill the structure pointed to according to the address. 652 */ 653 static char * 654 compile_addr(p, a) 655 char *p; 656 struct s_addr *a; 657 { 658 char *end; 659 660 switch (*p) { 661 case '\\': /* Context address */ 662 ++p; 663 /* FALLTHROUGH */ 664 case '/': /* Context address */ 665 p = compile_re(p, &a->u.r); 666 if (p == NULL) 667 err(COMPILE, "unterminated regular expression"); 668 a->type = AT_RE; 669 return (p); 670 671 case '$': /* Last line */ 672 a->type = AT_LAST; 673 return (p + 1); 674 /* Line number */ 675 case '0': case '1': case '2': case '3': case '4': 676 case '5': case '6': case '7': case '8': case '9': 677 a->type = AT_LINE; 678 a->u.l = strtol(p, &end, 10); 679 return (end); 680 default: 681 err(COMPILE, "expected context address"); 682 return (NULL); 683 } 684 } 685 686 /* 687 * duptoeol -- 688 * Return a copy of all the characters up to \n or \0. 689 */ 690 static char * 691 duptoeol(s, ctype) 692 register char *s; 693 char *ctype; 694 { 695 size_t len; 696 int ws; 697 char *start; 698 699 ws = 0; 700 for (start = s; *s != '\0' && *s != '\n'; ++s) 701 ws = isspace(*s); 702 *s = '\0'; 703 if (ws) 704 err(WARNING, "whitespace after %s", ctype); 705 len = s - start + 1; 706 return (memmove(xmalloc(len), start, len)); 707 } 708 709 /* 710 * Convert goto label names to addresses, and count a and r commands, in 711 * the given subset of the script. Free the memory used by labels in b 712 * and t commands (but not by :). 713 * 714 * TODO: Remove } nodes 715 */ 716 static void 717 fixuplabel(cp, end) 718 struct s_command *cp, *end; 719 { 720 721 for (; cp != end; cp = cp->next) 722 switch (cp->code) { 723 case 'a': 724 case 'r': 725 appendnum++; 726 break; 727 case 'b': 728 case 't': 729 /* Resolve branch target. */ 730 if (cp->t == NULL) { 731 cp->u.c = NULL; 732 break; 733 } 734 if ((cp->u.c = findlabel(cp->t)) == NULL) 735 err(COMPILE2, "undefined label '%s'", cp->t); 736 free(cp->t); 737 break; 738 case '{': 739 /* Do interior commands. */ 740 fixuplabel(cp->u.c, cp->next); 741 break; 742 } 743 } 744 745 /* 746 * Associate the given command label for later lookup. 747 */ 748 static void 749 enterlabel(cp) 750 struct s_command *cp; 751 { 752 register struct labhash **lhp, *lh; 753 register u_char *p; 754 register u_int h, c; 755 756 for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++) 757 h = (h << 5) + h + c; 758 lhp = &labels[h & LHMASK]; 759 for (lh = *lhp; lh != NULL; lh = lh->lh_next) 760 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0) 761 err(COMPILE2, "duplicate label '%s'", cp->t); 762 lh = xmalloc(sizeof *lh); 763 lh->lh_next = *lhp; 764 lh->lh_hash = h; 765 lh->lh_cmd = cp; 766 lh->lh_ref = 0; 767 *lhp = lh; 768 } 769 770 /* 771 * Find the label contained in the command l in the command linked 772 * list cp. L is excluded from the search. Return NULL if not found. 773 */ 774 static struct s_command * 775 findlabel(name) 776 char *name; 777 { 778 register struct labhash *lh; 779 register u_char *p; 780 register u_int h, c; 781 782 for (h = 0, p = (u_char *)name; (c = *p) != 0; p++) 783 h = (h << 5) + h + c; 784 for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) { 785 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) { 786 lh->lh_ref = 1; 787 return (lh->lh_cmd); 788 } 789 } 790 return (NULL); 791 } 792 793 /* 794 * Warn about any unused labels. As a side effect, release the label hash 795 * table space. 796 */ 797 static void 798 uselabel() 799 { 800 register struct labhash *lh, *next; 801 register int i; 802 803 for (i = 0; i < LHSZ; i++) { 804 for (lh = labels[i]; lh != NULL; lh = next) { 805 next = lh->lh_next; 806 if (!lh->lh_ref) 807 err(WARNING, "unused label '%s'", 808 lh->lh_cmd->t); 809 free(lh); 810 } 811 } 812 } 813