1 /* $OpenBSD: compile.c,v 1.32 2010/07/01 17:02:02 naddy 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. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/types.h> 37 #include <sys/stat.h> 38 39 #include <ctype.h> 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <limits.h> 43 #include <regex.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 48 #include "defs.h" 49 #include "extern.h" 50 51 #define LHSZ 128 52 #define LHMASK (LHSZ - 1) 53 static struct labhash { 54 struct labhash *lh_next; 55 u_int lh_hash; 56 struct s_command *lh_cmd; 57 int lh_ref; 58 } *labels[LHSZ]; 59 60 static char *compile_addr(char *, struct s_addr *); 61 static char *compile_ccl(char **, char *); 62 static char *compile_delimited(char *, char *); 63 static char *compile_flags(char *, struct s_subst *); 64 static char *compile_re(char *, regex_t **); 65 static char *compile_subst(char *, struct s_subst *); 66 static char *compile_text(void); 67 static char *compile_tr(char *, char **); 68 static struct s_command 69 **compile_stream(struct s_command **); 70 static char *duptoeol(char *, char *, char **); 71 static void enterlabel(struct s_command *); 72 static struct s_command 73 *findlabel(char *); 74 static void fixuplabel(struct s_command *, struct s_command *); 75 static void uselabel(void); 76 77 /* 78 * Command specification. This is used to drive the command parser. 79 */ 80 struct s_format { 81 char code; /* Command code */ 82 int naddr; /* Number of address args */ 83 enum e_args args; /* Argument type */ 84 }; 85 86 static struct s_format cmd_fmts[] = { 87 {'{', 2, GROUP}, 88 {'}', 0, ENDGROUP}, 89 {'a', 1, TEXT}, 90 {'b', 2, BRANCH}, 91 {'c', 2, TEXT}, 92 {'d', 2, EMPTY}, 93 {'D', 2, EMPTY}, 94 {'g', 2, EMPTY}, 95 {'G', 2, EMPTY}, 96 {'h', 2, EMPTY}, 97 {'H', 2, EMPTY}, 98 {'i', 1, TEXT}, 99 {'l', 2, EMPTY}, 100 {'n', 2, EMPTY}, 101 {'N', 2, EMPTY}, 102 {'p', 2, EMPTY}, 103 {'P', 2, EMPTY}, 104 {'q', 1, EMPTY}, 105 {'r', 1, RFILE}, 106 {'s', 2, SUBST}, 107 {'t', 2, BRANCH}, 108 {'w', 2, WFILE}, 109 {'x', 2, EMPTY}, 110 {'y', 2, TR}, 111 {'!', 2, NONSEL}, 112 {':', 0, LABEL}, 113 {'#', 0, COMMENT}, 114 {'=', 1, EMPTY}, 115 {'\0', 0, COMMENT}, 116 }; 117 118 /* The compiled program. */ 119 struct s_command *prog; 120 121 /* 122 * Compile the program into prog. 123 * Initialise appends. 124 */ 125 void 126 compile(void) 127 { 128 *compile_stream(&prog) = NULL; 129 fixuplabel(prog, NULL); 130 uselabel(); 131 appends = xmalloc(sizeof(struct s_appends) * appendnum); 132 match = xmalloc((maxnsub + 1) * sizeof(regmatch_t)); 133 } 134 135 #define EATSPACE() do { \ 136 if (p) \ 137 while (isascii(*p) && isspace(*p)) \ 138 p++; \ 139 } while (0) 140 141 static struct s_command ** 142 compile_stream(struct s_command **link) 143 { 144 char *p; 145 static char *lbuf; /* To avoid excessive malloc calls */ 146 static size_t bufsize; 147 struct s_command *cmd, *cmd2, *stack; 148 struct s_format *fp; 149 int naddr; /* Number of addresses */ 150 151 stack = 0; 152 for (;;) { 153 if ((p = cu_fgets(&lbuf, &bufsize)) == NULL) { 154 if (stack != 0) 155 err(COMPILE, "unexpected EOF (pending }'s)"); 156 return (link); 157 } 158 159 semicolon: EATSPACE(); 160 if (*p == '#' || *p == '\0') 161 continue; 162 if (*p == ';') { 163 p++; 164 goto semicolon; 165 } 166 *link = cmd = xmalloc(sizeof(struct s_command)); 167 link = &cmd->next; 168 cmd->nonsel = cmd->inrange = 0; 169 /* First parse the addresses */ 170 naddr = 0; 171 172 /* Valid characters to start an address */ 173 #define addrchar(c) (strchr("0123456789/\\$", (c))) 174 if (addrchar(*p)) { 175 naddr++; 176 cmd->a1 = xmalloc(sizeof(struct s_addr)); 177 p = compile_addr(p, cmd->a1); 178 EATSPACE(); /* EXTENSION */ 179 if (*p == ',') { 180 p++; 181 EATSPACE(); /* EXTENSION */ 182 naddr++; 183 cmd->a2 = xmalloc(sizeof(struct s_addr)); 184 p = compile_addr(p, cmd->a2); 185 EATSPACE(); 186 } else { 187 cmd->a2 = 0; 188 } 189 } else { 190 cmd->a1 = cmd->a2 = 0; 191 } 192 193 nonsel: /* Now parse the command */ 194 if (!*p) 195 err(COMPILE, "command expected"); 196 cmd->code = *p; 197 for (fp = cmd_fmts; fp->code; fp++) 198 if (fp->code == *p) 199 break; 200 if (!fp->code) 201 err(COMPILE, "invalid command code %c", *p); 202 if (naddr > fp->naddr) 203 err(COMPILE, 204 "command %c expects up to %d address(es), found %d", 205 *p, fp->naddr, naddr); 206 switch (fp->args) { 207 case NONSEL: /* ! */ 208 p++; 209 EATSPACE(); 210 cmd->nonsel = ! cmd->nonsel; 211 goto nonsel; 212 case GROUP: /* { */ 213 p++; 214 EATSPACE(); 215 cmd->next = stack; 216 stack = cmd; 217 link = &cmd->u.c; 218 if (*p) 219 goto semicolon; 220 break; 221 case ENDGROUP: 222 /* 223 * Short-circuit command processing, since end of 224 * group is really just a noop. 225 */ 226 cmd->nonsel = 1; 227 if (stack == 0) 228 err(COMPILE, "unexpected }"); 229 cmd2 = stack; 230 stack = cmd2->next; 231 cmd2->next = cmd; 232 /*FALLTHROUGH*/ 233 case EMPTY: /* d D g G h H l n N p P q x = \0 */ 234 p++; 235 EATSPACE(); 236 if (*p == ';') { 237 p++; 238 link = &cmd->next; 239 goto semicolon; 240 } 241 if (*p) 242 err(COMPILE, 243 "extra characters at the end of %c command", cmd->code); 244 break; 245 case TEXT: /* a c i */ 246 p++; 247 EATSPACE(); 248 if (*p != '\\') 249 err(COMPILE, "command %c expects \\ followed by" 250 " text", cmd->code); 251 p++; 252 EATSPACE(); 253 if (*p) 254 err(COMPILE, "extra characters after \\ at the" 255 " end of %c command", cmd->code); 256 cmd->t = compile_text(); 257 break; 258 case COMMENT: /* \0 # */ 259 break; 260 case WFILE: /* w */ 261 p++; 262 EATSPACE(); 263 if (*p == '\0') 264 err(COMPILE, "filename expected"); 265 cmd->t = duptoeol(p, "w command", NULL); 266 if (aflag) 267 cmd->u.fd = -1; 268 else if ((cmd->u.fd = open(p, 269 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 270 DEFFILEMODE)) == -1) 271 err(FATAL, "%s: %s", p, strerror(errno)); 272 break; 273 case RFILE: /* r */ 274 p++; 275 EATSPACE(); 276 cmd->t = duptoeol(p, "read command", NULL); 277 break; 278 case BRANCH: /* b t */ 279 p++; 280 EATSPACE(); 281 if (*p == '\0') 282 cmd->t = NULL; 283 else 284 cmd->t = duptoeol(p, "branch", &p); 285 if (*p == ';') { 286 p++; 287 goto semicolon; 288 } 289 break; 290 case LABEL: /* : */ 291 p++; 292 EATSPACE(); 293 cmd->t = duptoeol(p, "label", &p); 294 if (strlen(cmd->t) == 0) 295 err(COMPILE, "empty label"); 296 enterlabel(cmd); 297 if (*p == ';') { 298 p++; 299 goto semicolon; 300 } 301 break; 302 case SUBST: /* s */ 303 p++; 304 if (*p == '\0' || *p == '\\') 305 err(COMPILE, "substitute pattern can not be" 306 " delimited by newline or backslash"); 307 cmd->u.s = xmalloc(sizeof(struct s_subst)); 308 p = compile_re(p, &cmd->u.s->re); 309 if (p == NULL) 310 err(COMPILE, "unterminated substitute pattern"); 311 --p; 312 p = compile_subst(p, cmd->u.s); 313 p = compile_flags(p, cmd->u.s); 314 EATSPACE(); 315 if (*p == ';') { 316 p++; 317 link = &cmd->next; 318 goto semicolon; 319 } 320 break; 321 case TR: /* y */ 322 p++; 323 p = compile_tr(p, (char **)&cmd->u.y); 324 EATSPACE(); 325 if (*p == ';') { 326 p++; 327 link = &cmd->next; 328 goto semicolon; 329 } 330 if (*p) 331 err(COMPILE, "extra text at the end of a" 332 " transform command"); 333 break; 334 } 335 } 336 } 337 338 /* 339 * Get a delimited string. P points to the delimeter of the string; d points 340 * to a buffer area. Newline and delimiter escapes are processed; other 341 * escapes are ignored. 342 * 343 * Returns a pointer to the first character after the final delimiter or NULL 344 * in the case of a non-terminated string. The character array d is filled 345 * with the processed string. 346 */ 347 static char * 348 compile_delimited(char *p, char *d) 349 { 350 char c; 351 352 c = *p++; 353 if (c == '\0') 354 return (NULL); 355 else if (c == '\\') 356 err(COMPILE, "\\ can not be used as a string delimiter"); 357 else if (c == '\n') 358 err(COMPILE, "newline can not be used as a string delimiter"); 359 while (*p) { 360 if (*p == '[' && *p != c) { 361 if ((d = compile_ccl(&p, d)) == NULL) 362 err(COMPILE, "unbalanced brackets ([])"); 363 continue; 364 } else if (*p == '\\' && p[1] == '[') { 365 *d++ = *p++; 366 } else if (*p == '\\' && p[1] == c) { 367 p++; 368 } else if (*p == '\\' && p[1] == 'n') { 369 *d++ = '\n'; 370 p += 2; 371 continue; 372 } else if (*p == '\\' && p[1] == '\\') { 373 *d++ = *p++; 374 } else if (*p == c) { 375 *d = '\0'; 376 return (p + 1); 377 } 378 *d++ = *p++; 379 } 380 return (NULL); 381 } 382 383 384 /* compile_ccl: expand a POSIX character class */ 385 static char * 386 compile_ccl(char **sp, char *t) 387 { 388 int c, d; 389 char *s = *sp; 390 391 *t++ = *s++; 392 if (*s == '^') 393 *t++ = *s++; 394 if (*s == ']') 395 *t++ = *s++; 396 for (; *s && (*t = *s) != ']'; s++, t++) 397 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) { 398 *++t = *++s, t++, s++; 399 for (c = *s; (*t = *s) != ']' || c != d; s++, t++) 400 if ((c = *s) == '\0') 401 return NULL; 402 } else if (*s == '\\' && s[1] == 'n') { 403 *t = '\n'; 404 s++; 405 } 406 if (*s == ']') { 407 *sp = ++s; 408 return (++t); 409 } else { 410 return (NULL); 411 } 412 } 413 414 /* 415 * Get a regular expression. P points to the delimiter of the regular 416 * expression; repp points to the address of a regexp pointer. Newline 417 * and delimiter escapes are processed; other escapes are ignored. 418 * Returns a pointer to the first character after the final delimiter 419 * or NULL in the case of a non terminated regular expression. The regexp 420 * pointer is set to the compiled regular expression. 421 * Cflags are passed to regcomp. 422 */ 423 static char * 424 compile_re(char *p, regex_t **repp) 425 { 426 int eval; 427 char *re; 428 429 re = xmalloc(strlen(p) + 1); /* strlen(re) <= strlen(p) */ 430 p = compile_delimited(p, re); 431 if (p && strlen(re) == 0) { 432 *repp = NULL; 433 free(re); 434 return (p); 435 } 436 *repp = xmalloc(sizeof(regex_t)); 437 if (p && (eval = regcomp(*repp, re, Eflag ? REG_EXTENDED : 0)) != 0) 438 err(COMPILE, "RE error: %s", strregerror(eval, *repp)); 439 if (maxnsub < (*repp)->re_nsub) 440 maxnsub = (*repp)->re_nsub; 441 free(re); 442 return (p); 443 } 444 445 /* 446 * Compile the substitution string of a regular expression and set res to 447 * point to a saved copy of it. Nsub is the number of parenthesized regular 448 * expressions. 449 */ 450 static char * 451 compile_subst(char *p, struct s_subst *s) 452 { 453 static char *lbuf; 454 static size_t bufsize; 455 int asize, ref, size; 456 char c, *text, *op, *sp; 457 int sawesc = 0; 458 459 c = *p++; /* Terminator character */ 460 if (c == '\0') 461 return (NULL); 462 463 s->maxbref = 0; 464 s->linenum = linenum; 465 text = NULL; 466 asize = size = 0; 467 do { 468 size_t len = ROUNDLEN(strlen(p) + 1); 469 if (asize - size < len) { 470 do { 471 asize += len; 472 } while (asize - size < len); 473 text = xrealloc(text, asize); 474 } 475 op = sp = text + size; 476 for (; *p; p++) { 477 if (*p == '\\' || sawesc) { 478 /* 479 * If this is a continuation from the last 480 * buffer, we won't have a character to 481 * skip over. 482 */ 483 if (sawesc) 484 sawesc = 0; 485 else 486 p++; 487 488 if (*p == '\0') { 489 /* 490 * This escaped character is continued 491 * in the next part of the line. Note 492 * this fact, then cause the loop to 493 * exit w/ normal EOL case and reenter 494 * above with the new buffer. 495 */ 496 sawesc = 1; 497 p--; 498 continue; 499 } else if (strchr("123456789", *p) != NULL) { 500 *sp++ = '\\'; 501 ref = *p - '0'; 502 if (s->re != NULL && 503 ref > s->re->re_nsub) 504 err(COMPILE, 505 "\\%c not defined in the RE", *p); 506 if (s->maxbref < ref) 507 s->maxbref = ref; 508 } else if (*p == '&' || *p == '\\') 509 *sp++ = '\\'; 510 } else if (*p == c) { 511 p++; 512 *sp++ = '\0'; 513 size += sp - op; 514 s->new = xrealloc(text, size); 515 return (p); 516 } else if (*p == '\n') { 517 err(COMPILE, 518 "unescaped newline inside substitute pattern"); 519 /* NOTREACHED */ 520 } 521 *sp++ = *p; 522 } 523 size += sp - op; 524 } while ((p = cu_fgets(&lbuf, &bufsize))); 525 err(COMPILE, "unterminated substitute in regular expression"); 526 /* NOTREACHED */ 527 } 528 529 /* 530 * Compile the flags of the s command 531 */ 532 static char * 533 compile_flags(char *p, struct s_subst *s) 534 { 535 int gn; /* True if we have seen g or n */ 536 long l; 537 char wfile[PATH_MAX], *q; 538 539 s->n = 1; /* Default */ 540 s->p = 0; 541 s->wfile = NULL; 542 s->wfd = -1; 543 for (gn = 0;;) { 544 EATSPACE(); /* EXTENSION */ 545 switch (*p) { 546 case 'g': 547 if (gn) 548 err(COMPILE, "more than one number or 'g' in" 549 " substitute flags"); 550 gn = 1; 551 s->n = 0; 552 break; 553 case '\0': 554 case '\n': 555 case ';': 556 return (p); 557 case 'p': 558 s->p = 1; 559 break; 560 case '1': case '2': case '3': 561 case '4': case '5': case '6': 562 case '7': case '8': case '9': 563 if (gn) 564 err(COMPILE, "more than one number or 'g' in" 565 " substitute flags"); 566 gn = 1; 567 l = strtol(p, &p, 10); 568 if (l <= 0 || l >= INT_MAX) 569 err(COMPILE, 570 "number in substitute flags out of range"); 571 s->n = (int)l; 572 continue; 573 case 'w': 574 p++; 575 #ifdef HISTORIC_PRACTICE 576 if (*p != ' ') { 577 err(WARNING, "space missing before w wfile"); 578 return (p); 579 } 580 #endif 581 EATSPACE(); 582 q = wfile; 583 while (*p) { 584 if (*p == '\n') 585 break; 586 *q++ = *p++; 587 } 588 *q = '\0'; 589 if (q == wfile) 590 err(COMPILE, "no wfile specified"); 591 s->wfile = strdup(wfile); 592 if (!aflag && (s->wfd = open(wfile, 593 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 594 DEFFILEMODE)) == -1) 595 err(FATAL, "%s: %s", wfile, strerror(errno)); 596 return (p); 597 default: 598 err(COMPILE, 599 "bad flag in substitute command: '%c'", *p); 600 break; 601 } 602 p++; 603 } 604 } 605 606 /* 607 * Compile a translation set of strings into a lookup table. 608 */ 609 static char * 610 compile_tr(char *p, char **transtab) 611 { 612 int i; 613 char *lt, *op, *np; 614 char *old = NULL, *new = NULL; 615 616 if (*p == '\0' || *p == '\\') 617 err(COMPILE, 618 "transform pattern can not be delimited by newline or backslash"); 619 old = xmalloc(strlen(p) + 1); 620 p = compile_delimited(p, old); 621 if (p == NULL) { 622 err(COMPILE, "unterminated transform source string"); 623 goto bad; 624 } 625 new = xmalloc(strlen(p) + 1); 626 p = compile_delimited(--p, new); 627 if (p == NULL) { 628 err(COMPILE, "unterminated transform target string"); 629 goto bad; 630 } 631 EATSPACE(); 632 if (strlen(new) != strlen(old)) { 633 err(COMPILE, "transform strings are not the same length"); 634 goto bad; 635 } 636 /* We assume characters are 8 bits */ 637 lt = xmalloc(UCHAR_MAX + 1); 638 for (i = 0; i <= UCHAR_MAX; i++) 639 lt[i] = (char)i; 640 for (op = old, np = new; *op; op++, np++) 641 lt[(u_char)*op] = *np; 642 *transtab = lt; 643 free(old); 644 free(new); 645 return (p); 646 bad: 647 free(old); 648 free(new); 649 return (NULL); 650 } 651 652 /* 653 * Compile the text following an a, c, or i command. 654 */ 655 static char * 656 compile_text(void) 657 { 658 int asize, esc_nl, size; 659 char *lbuf, *text, *p, *op, *s; 660 size_t bufsize; 661 662 lbuf = text = NULL; 663 asize = size = 0; 664 while ((p = cu_fgets(&lbuf, &bufsize))) { 665 size_t len = ROUNDLEN(strlen(p) + 1); 666 if (asize - size < len) { 667 do { 668 asize += len; 669 } while (asize - size < len); 670 text = xrealloc(text, asize); 671 } 672 op = s = text + size; 673 for (esc_nl = 0; *p != '\0'; p++) { 674 if (*p == '\\' && p[1] != '\0' && *++p == '\n') 675 esc_nl = 1; 676 *s++ = *p; 677 } 678 size += s - op; 679 if (!esc_nl) { 680 *s = '\0'; 681 break; 682 } 683 } 684 free(lbuf); 685 text[size] = '\0'; 686 return (xrealloc(text, size + 1)); 687 } 688 689 /* 690 * Get an address and return a pointer to the first character after 691 * it. Fill the structure pointed to according to the address. 692 */ 693 static char * 694 compile_addr(char *p, struct s_addr *a) 695 { 696 char *end; 697 698 switch (*p) { 699 case '\\': /* Context address */ 700 ++p; 701 /* FALLTHROUGH */ 702 case '/': /* Context address */ 703 p = compile_re(p, &a->u.r); 704 if (p == NULL) 705 err(COMPILE, "unterminated regular expression"); 706 a->type = AT_RE; 707 return (p); 708 709 case '$': /* Last line */ 710 a->type = AT_LAST; 711 return (p + 1); 712 /* Line number */ 713 case '0': case '1': case '2': case '3': case '4': 714 case '5': case '6': case '7': case '8': case '9': 715 a->type = AT_LINE; 716 a->u.l = strtoul(p, &end, 10); 717 return (end); 718 default: 719 err(COMPILE, "expected context address"); 720 return (NULL); 721 } 722 } 723 724 /* 725 * duptoeol -- 726 * Return a copy of all the characters up to \n or \0. 727 */ 728 static char * 729 duptoeol(char *s, char *ctype, char **semi) 730 { 731 size_t len; 732 int ws; 733 char *start; 734 735 ws = 0; 736 if (semi) { 737 for (start = s; *s != '\0' && *s != '\n' && *s != ';'; ++s) 738 ws = isspace(*s); 739 } else { 740 for (start = s; *s != '\0' && *s != '\n'; ++s) 741 ws = isspace(*s); 742 *s = '\0'; 743 } 744 if (ws) 745 err(WARNING, "whitespace after %s", ctype); 746 len = s - start + 1; 747 if (semi) 748 *semi = s; 749 s = xmalloc(len); 750 strlcpy(s, start, len); 751 return (s); 752 } 753 754 /* 755 * Convert goto label names to addresses, and count a and r commands, in 756 * the given subset of the script. Free the memory used by labels in b 757 * and t commands (but not by :). 758 * 759 * TODO: Remove } nodes 760 */ 761 static void 762 fixuplabel(struct s_command *cp, struct s_command *end) 763 { 764 765 for (; cp != end; cp = cp->next) 766 switch (cp->code) { 767 case 'a': 768 case 'r': 769 appendnum++; 770 break; 771 case 'b': 772 case 't': 773 /* Resolve branch target. */ 774 if (cp->t == NULL) { 775 cp->u.c = NULL; 776 break; 777 } 778 if ((cp->u.c = findlabel(cp->t)) == NULL) 779 err(COMPILE2, "undefined label '%s'", cp->t); 780 free(cp->t); 781 break; 782 case '{': 783 /* Do interior commands. */ 784 fixuplabel(cp->u.c, cp->next); 785 break; 786 } 787 } 788 789 /* 790 * Associate the given command label for later lookup. 791 */ 792 static void 793 enterlabel(struct s_command *cp) 794 { 795 struct labhash **lhp, *lh; 796 u_char *p; 797 u_int h, c; 798 799 for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++) 800 h = (h << 5) + h + c; 801 lhp = &labels[h & LHMASK]; 802 for (lh = *lhp; lh != NULL; lh = lh->lh_next) 803 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0) 804 err(COMPILE2, "duplicate label '%s'", cp->t); 805 lh = xmalloc(sizeof *lh); 806 lh->lh_next = *lhp; 807 lh->lh_hash = h; 808 lh->lh_cmd = cp; 809 lh->lh_ref = 0; 810 *lhp = lh; 811 } 812 813 /* 814 * Find the label contained in the command l in the command linked 815 * list cp. L is excluded from the search. Return NULL if not found. 816 */ 817 static struct s_command * 818 findlabel(char *name) 819 { 820 struct labhash *lh; 821 u_char *p; 822 u_int h, c; 823 824 for (h = 0, p = (u_char *)name; (c = *p) != 0; p++) 825 h = (h << 5) + h + c; 826 for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) { 827 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) { 828 lh->lh_ref = 1; 829 return (lh->lh_cmd); 830 } 831 } 832 return (NULL); 833 } 834 835 /* 836 * Warn about any unused labels. As a side effect, release the label hash 837 * table space. 838 */ 839 static void 840 uselabel(void) 841 { 842 struct labhash *lh, *next; 843 int i; 844 845 for (i = 0; i < LHSZ; i++) { 846 for (lh = labels[i]; lh != NULL; lh = next) { 847 next = lh->lh_next; 848 if (!lh->lh_ref) 849 err(WARNING, "unused label '%s'", 850 lh->lh_cmd->t); 851 free(lh); 852 } 853 } 854 } 855