1 /* $NetBSD: compile.c,v 1.22 2002/02/26 02:37:30 wiz Exp $ */ 2 3 /*- 4 * Copyright (c) 1992 Diomidis Spinellis. 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Diomidis Spinellis of Imperial College, University of London. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 #ifndef lint 42 #if 0 43 static char sccsid[] = "@(#)compile.c 8.2 (Berkeley) 4/28/95"; 44 #else 45 __RCSID("$NetBSD: compile.c,v 1.22 2002/02/26 02:37:30 wiz Exp $"); 46 #endif 47 #endif /* not lint */ 48 49 #include <sys/types.h> 50 #include <sys/stat.h> 51 52 #include <ctype.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <limits.h> 56 #include <regex.h> 57 #include <stdio.h> 58 #include <stdlib.h> 59 #include <string.h> 60 61 #include "defs.h" 62 #include "extern.h" 63 64 #define LHSZ 128 65 #define LHMASK (LHSZ - 1) 66 static struct labhash { 67 struct labhash *lh_next; 68 u_int lh_hash; 69 struct s_command *lh_cmd; 70 int lh_ref; 71 } *labels[LHSZ]; 72 73 static char *compile_addr __P((char *, struct s_addr *)); 74 static char *compile_ccl __P((char **, char *)); 75 static char *compile_delimited __P((char *, char *)); 76 static char *compile_flags __P((char *, struct s_subst *)); 77 static char *compile_re __P((char *, regex_t **)); 78 static char *compile_subst __P((char *, struct s_subst *)); 79 static char *compile_text __P((void)); 80 static char *compile_tr __P((char *, char **)); 81 static struct s_command 82 **compile_stream __P((struct s_command **)); 83 static char *duptoeol __P((char *, char *)); 84 static void enterlabel __P((struct s_command *)); 85 static struct s_command 86 *findlabel __P((char *)); 87 static void fixuplabel __P((struct s_command *, struct s_command *)); 88 static void uselabel __P((void)); 89 90 /* 91 * Command specification. This is used to drive the command parser. 92 */ 93 struct s_format { 94 char code; /* Command code */ 95 int naddr; /* Number of address args */ 96 enum e_args args; /* Argument type */ 97 }; 98 99 static struct s_format cmd_fmts[] = { 100 {'{', 2, GROUP}, 101 {'}', 0, ENDGROUP}, 102 {'a', 1, TEXT}, 103 {'b', 2, BRANCH}, 104 {'c', 2, TEXT}, 105 {'d', 2, EMPTY}, 106 {'D', 2, EMPTY}, 107 {'g', 2, EMPTY}, 108 {'G', 2, EMPTY}, 109 {'h', 2, EMPTY}, 110 {'H', 2, EMPTY}, 111 {'i', 1, TEXT}, 112 {'l', 2, EMPTY}, 113 {'n', 2, EMPTY}, 114 {'N', 2, EMPTY}, 115 {'p', 2, EMPTY}, 116 {'P', 2, EMPTY}, 117 {'q', 1, EMPTY}, 118 {'r', 1, RFILE}, 119 {'s', 2, SUBST}, 120 {'t', 2, BRANCH}, 121 {'w', 2, WFILE}, 122 {'x', 2, EMPTY}, 123 {'y', 2, TR}, 124 {'!', 2, NONSEL}, 125 {':', 0, LABEL}, 126 {'#', 0, COMMENT}, 127 {'=', 1, EMPTY}, 128 {'\0', 0, COMMENT}, 129 }; 130 131 /* The compiled program. */ 132 struct s_command *prog; 133 134 /* 135 * Compile the program into prog. 136 * Initialise appends. 137 */ 138 void 139 compile() 140 { 141 *compile_stream(&prog) = NULL; 142 fixuplabel(prog, NULL); 143 uselabel(); 144 if (appendnum > 0) 145 appends = xmalloc(sizeof(struct s_appends) * appendnum); 146 match = xmalloc((maxnsub + 1) * sizeof(regmatch_t)); 147 } 148 149 #define EATSPACE() do { \ 150 if (p) \ 151 while (*p && isascii((unsigned char)*p) && \ 152 isspace((unsigned char)*p)) \ 153 p++; \ 154 } while (0) 155 156 static struct s_command ** 157 compile_stream(link) 158 struct s_command **link; 159 { 160 char *p; 161 static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */ 162 struct s_command *cmd, *cmd2, *stack; 163 struct s_format *fp; 164 int naddr; /* Number of addresses */ 165 166 stack = 0; 167 for (;;) { 168 if ((p = cu_fgets(lbuf, sizeof(lbuf))) == NULL) { 169 if (stack != 0) 170 err(COMPILE, "unexpected EOF (pending }'s)"); 171 return (link); 172 } 173 174 semicolon: EATSPACE(); 175 if (p) { 176 if (*p == '#' || *p == '\0') 177 continue; 178 else if (*p == ';') { 179 p++; 180 goto semicolon; 181 } 182 } 183 *link = cmd = xmalloc(sizeof(struct s_command)); 184 link = &cmd->next; 185 cmd->nonsel = cmd->inrange = 0; 186 /* First parse the addresses */ 187 naddr = 0; 188 189 /* Valid characters to start an address */ 190 #define addrchar(c) (strchr("0123456789/\\$", (c))) 191 if (addrchar(*p)) { 192 naddr++; 193 cmd->a1 = xmalloc(sizeof(struct s_addr)); 194 p = compile_addr(p, cmd->a1); 195 EATSPACE(); /* EXTENSION */ 196 if (*p == ',') { 197 p++; 198 EATSPACE(); /* EXTENSION */ 199 naddr++; 200 cmd->a2 = xmalloc(sizeof(struct s_addr)); 201 p = compile_addr(p, cmd->a2); 202 EATSPACE(); 203 } else 204 cmd->a2 = 0; 205 } else 206 cmd->a1 = cmd->a2 = 0; 207 208 nonsel: /* Now parse the command */ 209 if (!*p) 210 err(COMPILE, "command expected"); 211 cmd->code = *p; 212 for (fp = cmd_fmts; fp->code; fp++) 213 if (fp->code == *p) 214 break; 215 if (!fp->code) 216 err(COMPILE, "invalid command code %c", *p); 217 if (naddr > fp->naddr) 218 err(COMPILE, 219 "command %c expects up to %d address(es), found %d", *p, fp->naddr, naddr); 220 switch (fp->args) { 221 case NONSEL: /* ! */ 222 p++; 223 EATSPACE(); 224 cmd->nonsel = ! cmd->nonsel; 225 goto nonsel; 226 case GROUP: /* { */ 227 p++; 228 EATSPACE(); 229 cmd->next = stack; 230 stack = cmd; 231 link = &cmd->u.c; 232 if (*p) 233 goto semicolon; 234 break; 235 case ENDGROUP: 236 /* 237 * Short-circuit command processing, since end of 238 * group is really just a noop. 239 */ 240 cmd->nonsel = 1; 241 if (stack == 0) 242 err(COMPILE, "unexpected }"); 243 cmd2 = stack; 244 stack = cmd2->next; 245 cmd2->next = cmd; 246 /*FALLTHROUGH*/ 247 case EMPTY: /* d D g G h H l n N p P q x = \0 */ 248 p++; 249 EATSPACE(); 250 if (*p == ';') { 251 p++; 252 link = &cmd->next; 253 goto semicolon; 254 } 255 if (*p) 256 err(COMPILE, 257 "extra characters at the end of %c command", cmd->code); 258 break; 259 case TEXT: /* a c i */ 260 p++; 261 EATSPACE(); 262 if (*p != '\\') 263 err(COMPILE, 264 "command %c expects \\ followed by text", cmd->code); 265 p++; 266 EATSPACE(); 267 if (*p) 268 err(COMPILE, 269 "extra characters after \\ at the end of %c command", cmd->code); 270 cmd->t = compile_text(); 271 break; 272 case COMMENT: /* \0 # */ 273 break; 274 case WFILE: /* w */ 275 p++; 276 EATSPACE(); 277 if (*p == '\0') 278 err(COMPILE, "filename expected"); 279 cmd->t = duptoeol(p, "w command"); 280 if (aflag) 281 cmd->u.fd = -1; 282 else if ((cmd->u.fd = open(p, 283 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 284 DEFFILEMODE)) == -1) 285 err(FATAL, "%s: %s\n", p, strerror(errno)); 286 break; 287 case RFILE: /* r */ 288 p++; 289 EATSPACE(); 290 if (*p == '\0') 291 err(COMPILE, "filename expected"); 292 else 293 cmd->t = duptoeol(p, "read command"); 294 break; 295 case BRANCH: /* b t */ 296 p++; 297 EATSPACE(); 298 if (*p == '\0') 299 cmd->t = NULL; 300 else 301 cmd->t = duptoeol(p, "branch"); 302 break; 303 case LABEL: /* : */ 304 p++; 305 EATSPACE(); 306 cmd->t = duptoeol(p, "label"); 307 if (strlen(p) == 0) 308 err(COMPILE, "empty label"); 309 enterlabel(cmd); 310 break; 311 case SUBST: /* s */ 312 p++; 313 if (*p == '\0' || *p == '\\') 314 err(COMPILE, 315 "substitute pattern can not be delimited by newline or backslash"); 316 cmd->u.s = xmalloc(sizeof(struct s_subst)); 317 p = compile_re(p, &cmd->u.s->re); 318 if (p == NULL) 319 err(COMPILE, "unterminated substitute pattern"); 320 --p; 321 p = compile_subst(p, cmd->u.s); 322 p = compile_flags(p, cmd->u.s); 323 EATSPACE(); 324 if (*p == ';') { 325 p++; 326 link = &cmd->next; 327 goto semicolon; 328 } 329 break; 330 case TR: /* y */ 331 p++; 332 p = compile_tr(p, (char **)&cmd->u.y); 333 EATSPACE(); 334 if (*p == ';') { 335 p++; 336 link = &cmd->next; 337 goto semicolon; 338 } 339 if (*p) 340 err(COMPILE, 341 "extra text at the end of a transform command"); 342 break; 343 } 344 } 345 } 346 347 /* 348 * Get a delimited string. P points to the delimiter of the string; d points 349 * to a buffer area. Newline and delimiter escapes are processed; other 350 * escapes are ignored. 351 * 352 * Returns a pointer to the first character after the final delimiter or NULL 353 * in the case of a non-terminated string. The character array d is filled 354 * with the processed string. 355 */ 356 static char * 357 compile_delimited(p, d) 358 char *p, *d; 359 { 360 char c; 361 362 c = *p++; 363 if (c == '\0') 364 return (NULL); 365 else if (c == '\\') 366 err(COMPILE, "\\ can not be used as a string delimiter"); 367 else if (c == '\n') 368 err(COMPILE, "newline can not be used as a string delimiter"); 369 while (*p) { 370 if (*p == '[') { 371 if ((d = compile_ccl(&p, d)) == NULL) 372 err(COMPILE, "unbalanced brackets ([])"); 373 continue; 374 } else if (*p == '\\' && p[1] == '[') { 375 *d++ = *p++; 376 } else if (*p == '\\' && p[1] == c) 377 p++; 378 else if (*p == '\\' && p[1] == 'n') { 379 *d++ = '\n'; 380 p += 2; 381 continue; 382 } else if (*p == '\\' && p[1] == '\\') 383 *d++ = *p++; 384 else if (*p == c) { 385 *d = '\0'; 386 return (p + 1); 387 } 388 *d++ = *p++; 389 } 390 return (NULL); 391 } 392 393 394 /* compile_ccl: expand a POSIX character class */ 395 static char * 396 compile_ccl(sp, t) 397 char **sp; 398 char *t; 399 { 400 int c, d; 401 char *s = *sp; 402 403 *t++ = *s++; 404 if (*s == '^') 405 *t++ = *s++; 406 if (*s == ']') 407 *t++ = *s++; 408 for (; *s && (*t = *s) != ']'; s++, t++) 409 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) { 410 *++t = *++s, t++, s++; 411 for (c = *s; (*t = *s) != ']' || c != d; s++, t++) 412 if ((c = *s) == '\0') 413 return NULL; 414 } else if (*s == '\\' && s[1] == 'n') 415 *t = '\n', s++; 416 return (*s == ']') ? *sp = ++s, ++t : NULL; 417 } 418 419 /* 420 * Get a regular expression. P points to the delimiter of the regular 421 * expression; repp points to the address of a regexp pointer. Newline 422 * and delimiter escapes are processed; other escapes are ignored. 423 * Returns a pointer to the first character after the final delimiter 424 * or NULL in the case of a non terminated regular expression. The regexp 425 * pointer is set to the compiled regular expression. 426 * Cflags are passed to regcomp. 427 */ 428 static char * 429 compile_re(p, repp) 430 char *p; 431 regex_t **repp; 432 { 433 int eval; 434 char re[_POSIX2_LINE_MAX + 1]; 435 436 p = compile_delimited(p, re); 437 if (p && strlen(re) == 0) { 438 *repp = NULL; 439 return (p); 440 } 441 *repp = xmalloc(sizeof(regex_t)); 442 if (p && (eval = regcomp(*repp, re, ere)) != 0) 443 err(COMPILE, "RE error: %s", strregerror(eval, *repp)); 444 if (maxnsub < (*repp)->re_nsub) 445 maxnsub = (*repp)->re_nsub; 446 return (p); 447 } 448 449 /* 450 * Compile the substitution string of a regular expression and set res to 451 * point to a saved copy of it. Nsub is the number of parenthesized regular 452 * expressions. 453 */ 454 static char * 455 compile_subst(p, s) 456 char *p; 457 struct s_subst *s; 458 { 459 static char lbuf[_POSIX2_LINE_MAX + 1]; 460 int asize, ref, size; 461 char c, *text, *op, *sp; 462 463 c = *p++; /* Terminator character */ 464 if (c == '\0') 465 return (NULL); 466 467 s->maxbref = 0; 468 s->linenum = linenum; 469 asize = 2 * _POSIX2_LINE_MAX + 1; 470 text = xmalloc(asize); 471 size = 0; 472 do { 473 op = sp = text + size; 474 for (; *p; p++) { 475 if (*p == '\\') { 476 p++; 477 if (strchr("123456789", *p) != NULL) { 478 *sp++ = '\\'; 479 ref = *p - '0'; 480 if (s->re != NULL && 481 ref > s->re->re_nsub) 482 err(COMPILE, 483 "\\%c not defined in the RE", *p); 484 if (s->maxbref < ref) 485 s->maxbref = ref; 486 } else if (*p == '&' || *p == '\\') 487 *sp++ = '\\'; 488 } else if (*p == c) { 489 p++; 490 *sp++ = '\0'; 491 size += sp - op; 492 s->new = xrealloc(text, size); 493 return (p); 494 } else if (*p == '\n') { 495 err(COMPILE, 496 "unescaped newline inside substitute pattern"); 497 /* NOTREACHED */ 498 } 499 *sp++ = *p; 500 } 501 size += sp - op; 502 if (asize - size < _POSIX2_LINE_MAX + 1) { 503 asize *= 2; 504 text = xmalloc(asize); 505 } 506 } while (cu_fgets(p = lbuf, sizeof(lbuf))); 507 err(COMPILE, "unterminated substitute in regular expression"); 508 /* NOTREACHED */ 509 return (NULL); 510 } 511 512 /* 513 * Compile the flags of the s command 514 */ 515 static char * 516 compile_flags(p, s) 517 char *p; 518 struct s_subst *s; 519 { 520 int gn; /* True if we have seen g or n */ 521 char wfile[_POSIX2_LINE_MAX + 1], *q; 522 523 s->n = 1; /* Default */ 524 s->p = 0; 525 s->wfile = NULL; 526 s->wfd = -1; 527 for (gn = 0;;) { 528 EATSPACE(); /* EXTENSION */ 529 switch (*p) { 530 case 'g': 531 if (gn) 532 err(COMPILE, 533 "more than one number or 'g' in substitute flags"); 534 gn = 1; 535 s->n = 0; 536 break; 537 case '\0': 538 case '\n': 539 case ';': 540 return (p); 541 case 'p': 542 s->p = 1; 543 break; 544 case '1': case '2': case '3': 545 case '4': case '5': case '6': 546 case '7': case '8': case '9': 547 if (gn) 548 err(COMPILE, 549 "more than one number or 'g' in substitute flags"); 550 gn = 1; 551 /* XXX Check for overflow */ 552 s->n = (int)strtol(p, &p, 10); 553 break; 554 case 'w': 555 p++; 556 #ifdef HISTORIC_PRACTICE 557 if (*p != ' ') { 558 err(WARNING, "space missing before w wfile"); 559 return (p); 560 } 561 #endif 562 EATSPACE(); 563 q = wfile; 564 while (*p) { 565 if (*p == '\n') 566 break; 567 *q++ = *p++; 568 } 569 *q = '\0'; 570 if (q == wfile) 571 err(COMPILE, "no wfile specified"); 572 s->wfile = strdup(wfile); 573 if (!aflag && (s->wfd = open(wfile, 574 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 575 DEFFILEMODE)) == -1) 576 err(FATAL, "%s: %s\n", wfile, strerror(errno)); 577 return (p); 578 default: 579 err(COMPILE, 580 "bad flag in substitute command: '%c'", *p); 581 break; 582 } 583 p++; 584 } 585 } 586 587 /* 588 * Compile a translation set of strings into a lookup table. 589 */ 590 static char * 591 compile_tr(p, transtab) 592 char *p; 593 char **transtab; 594 { 595 int i; 596 char *lt, *op, *np; 597 char old[_POSIX2_LINE_MAX + 1]; 598 char new[_POSIX2_LINE_MAX + 1]; 599 600 if (*p == '\0' || *p == '\\') 601 err(COMPILE, 602 "transform pattern can not be delimited by newline or backslash"); 603 p = compile_delimited(p, old); 604 if (p == NULL) { 605 err(COMPILE, "unterminated transform source string"); 606 return (NULL); 607 } 608 p = compile_delimited(--p, new); 609 if (p == NULL) { 610 err(COMPILE, "unterminated transform target string"); 611 return (NULL); 612 } 613 EATSPACE(); 614 if (strlen(new) != strlen(old)) { 615 err(COMPILE, "transform strings are not the same length"); 616 return (NULL); 617 } 618 /* We assume characters are 8 bits */ 619 lt = xmalloc(UCHAR_MAX); 620 for (i = 0; i <= UCHAR_MAX; i++) 621 lt[i] = (char)i; 622 for (op = old, np = new; *op; op++, np++) 623 lt[(u_char)*op] = *np; 624 *transtab = lt; 625 return (p); 626 } 627 628 /* 629 * Compile the text following an a or i command. 630 */ 631 static char * 632 compile_text() 633 { 634 int asize, size; 635 char *text, *p, *op, *s; 636 char lbuf[_POSIX2_LINE_MAX + 1]; 637 638 asize = 2 * _POSIX2_LINE_MAX + 1; 639 text = xmalloc(asize); 640 size = 0; 641 while (cu_fgets(lbuf, sizeof(lbuf))) { 642 op = s = text + size; 643 p = lbuf; 644 EATSPACE(); 645 for (; *p; p++) { 646 if (*p == '\\') 647 p++; 648 *s++ = *p; 649 } 650 size += s - op; 651 if (p[-2] != '\\') { 652 *s = '\0'; 653 break; 654 } 655 if (asize - size < _POSIX2_LINE_MAX + 1) { 656 asize *= 2; 657 text = xmalloc(asize); 658 } 659 } 660 return (xrealloc(text, size + 1)); 661 } 662 663 /* 664 * Get an address and return a pointer to the first character after 665 * it. Fill the structure pointed to according to the address. 666 */ 667 static char * 668 compile_addr(p, a) 669 char *p; 670 struct s_addr *a; 671 { 672 char *end; 673 674 switch (*p) { 675 case '\\': /* Context address */ 676 ++p; 677 /* FALLTHROUGH */ 678 case '/': /* Context address */ 679 p = compile_re(p, &a->u.r); 680 if (p == NULL) 681 err(COMPILE, "unterminated regular expression"); 682 a->type = AT_RE; 683 return (p); 684 685 case '$': /* Last line */ 686 a->type = AT_LAST; 687 return (p + 1); 688 /* Line number */ 689 case '0': case '1': case '2': case '3': case '4': 690 case '5': case '6': case '7': case '8': case '9': 691 a->type = AT_LINE; 692 a->u.l = strtol(p, &end, 10); 693 return (end); 694 default: 695 err(COMPILE, "expected context address"); 696 return (NULL); 697 } 698 } 699 700 /* 701 * duptoeol -- 702 * Return a copy of all the characters up to \n or \0. 703 */ 704 static char * 705 duptoeol(s, ctype) 706 char *s; 707 char *ctype; 708 { 709 size_t len; 710 int ws; 711 char *start; 712 713 ws = 0; 714 for (start = s; *s != '\0' && *s != '\n'; ++s) 715 ws = isspace((unsigned char)*s); 716 *s = '\0'; 717 if (ws) 718 err(WARNING, "whitespace after %s", ctype); 719 len = s - start + 1; 720 return (memmove(xmalloc(len), start, len)); 721 } 722 723 /* 724 * Convert goto label names to addresses, and count a and r commands, in 725 * the given subset of the script. Free the memory used by labels in b 726 * and t commands (but not by :). 727 * 728 * TODO: Remove } nodes 729 */ 730 static void 731 fixuplabel(cp, end) 732 struct s_command *cp, *end; 733 { 734 735 for (; cp != end; cp = cp->next) 736 switch (cp->code) { 737 case 'a': 738 case 'r': 739 appendnum++; 740 break; 741 case 'b': 742 case 't': 743 /* Resolve branch target. */ 744 if (cp->t == NULL) { 745 cp->u.c = NULL; 746 break; 747 } 748 if ((cp->u.c = findlabel(cp->t)) == NULL) 749 err(COMPILE2, "undefined label '%s'", cp->t); 750 free(cp->t); 751 break; 752 case '{': 753 /* Do interior commands. */ 754 fixuplabel(cp->u.c, cp->next); 755 break; 756 } 757 } 758 759 /* 760 * Associate the given command label for later lookup. 761 */ 762 static void 763 enterlabel(cp) 764 struct s_command *cp; 765 { 766 struct labhash **lhp, *lh; 767 u_char *p; 768 u_int h, c; 769 770 for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++) 771 h = (h << 5) + h + c; 772 lhp = &labels[h & LHMASK]; 773 for (lh = *lhp; lh != NULL; lh = lh->lh_next) 774 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0) 775 err(COMPILE2, "duplicate label '%s'", cp->t); 776 lh = xmalloc(sizeof *lh); 777 lh->lh_next = *lhp; 778 lh->lh_hash = h; 779 lh->lh_cmd = cp; 780 lh->lh_ref = 0; 781 *lhp = lh; 782 } 783 784 /* 785 * Find the label contained in the command l in the command linked 786 * list cp. L is excluded from the search. Return NULL if not found. 787 */ 788 static struct s_command * 789 findlabel(name) 790 char *name; 791 { 792 struct labhash *lh; 793 u_char *p; 794 u_int h, c; 795 796 for (h = 0, p = (u_char *)name; (c = *p) != 0; p++) 797 h = (h << 5) + h + c; 798 for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) { 799 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) { 800 lh->lh_ref = 1; 801 return (lh->lh_cmd); 802 } 803 } 804 return (NULL); 805 } 806 807 /* 808 * Warn about any unused labels. As a side effect, release the label hash 809 * table space. 810 */ 811 static void 812 uselabel() 813 { 814 struct labhash *lh, *next; 815 int i; 816 817 for (i = 0; i < LHSZ; i++) { 818 for (lh = labels[i]; lh != NULL; lh = next) { 819 next = lh->lh_next; 820 if (!lh->lh_ref) 821 err(WARNING, "unused label '%s'", 822 lh->lh_cmd->t); 823 free(lh); 824 } 825 } 826 } 827