1 /* $OpenBSD: compile.c,v 1.43 2017/12/08 18:41:59 martijn 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 *, int); 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 = xreallocarray(NULL, appendnum, sizeof(struct s_appends)); 132 match = xreallocarray(NULL, maxnsub + 1, sizeof(regmatch_t)); 133 } 134 135 #define EATSPACE() do { \ 136 if (p) \ 137 while (isascii((unsigned char)*p) && \ 138 isspace((unsigned char)*p)) \ 139 p++; \ 140 } while (0) 141 142 static struct s_command ** 143 compile_stream(struct s_command **link) 144 { 145 char *p; 146 static char *lbuf; /* To avoid excessive malloc calls */ 147 static size_t bufsize; 148 struct s_command *cmd, *cmd2, *stack; 149 struct s_format *fp; 150 int naddr; /* Number of addresses */ 151 152 stack = 0; 153 for (;;) { 154 if ((p = cu_fgets(&lbuf, &bufsize)) == NULL) { 155 if (stack != 0) 156 error(COMPILE, "unexpected EOF (pending }'s)"); 157 return (link); 158 } 159 160 semicolon: EATSPACE(); 161 if (*p == '#' || *p == '\0') 162 continue; 163 if (*p == ';') { 164 p++; 165 goto semicolon; 166 } 167 *link = cmd = xmalloc(sizeof(struct s_command)); 168 link = &cmd->next; 169 cmd->nonsel = cmd->inrange = 0; 170 /* First parse the addresses */ 171 naddr = 0; 172 173 /* Valid characters to start an address */ 174 #define addrchar(c) (strchr("0123456789/\\$", (c))) 175 if (addrchar(*p)) { 176 naddr++; 177 cmd->a1 = xmalloc(sizeof(struct s_addr)); 178 p = compile_addr(p, cmd->a1); 179 EATSPACE(); /* EXTENSION */ 180 if (*p == ',') { 181 p++; 182 EATSPACE(); /* EXTENSION */ 183 naddr++; 184 cmd->a2 = xmalloc(sizeof(struct s_addr)); 185 p = compile_addr(p, cmd->a2); 186 EATSPACE(); 187 } else { 188 cmd->a2 = 0; 189 } 190 } else { 191 cmd->a1 = cmd->a2 = 0; 192 } 193 194 nonsel: /* Now parse the command */ 195 if (!*p) 196 error(COMPILE, "command expected"); 197 cmd->code = *p; 198 for (fp = cmd_fmts; fp->code; fp++) 199 if (fp->code == *p) 200 break; 201 if (!fp->code) 202 error(COMPILE, "invalid command code %c", *p); 203 if (naddr > fp->naddr) 204 error(COMPILE, 205 "command %c expects up to %d address(es), found %d", 206 *p, fp->naddr, naddr); 207 switch (fp->args) { 208 case NONSEL: /* ! */ 209 p++; 210 EATSPACE(); 211 cmd->nonsel = 1; 212 goto nonsel; 213 case GROUP: /* { */ 214 p++; 215 EATSPACE(); 216 cmd->next = stack; 217 stack = cmd; 218 link = &cmd->u.c; 219 if (*p) 220 goto semicolon; 221 break; 222 case ENDGROUP: 223 /* 224 * Short-circuit command processing, since end of 225 * group is really just a noop. 226 */ 227 cmd->nonsel = 1; 228 if (stack == 0) 229 error(COMPILE, "unexpected }"); 230 cmd2 = stack; 231 stack = cmd2->next; 232 cmd2->next = cmd; 233 /*FALLTHROUGH*/ 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 error(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 error(COMPILE, "command %c expects \\ followed by" 251 " text", cmd->code); 252 p++; 253 EATSPACE(); 254 if (*p) 255 error(COMPILE, "extra characters after \\ at the" 256 " 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 error(COMPILE, "filename expected"); 266 cmd->t = duptoeol(p, "w command", NULL); 267 if (aflag) { 268 cmd->u.fd = -1; 269 pledge_wpath = 1; 270 } 271 else if ((cmd->u.fd = open(p, 272 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 273 DEFFILEMODE)) == -1) 274 error(FATAL, "%s: %s", p, strerror(errno)); 275 break; 276 case RFILE: /* r */ 277 pledge_rpath = 1; 278 p++; 279 EATSPACE(); 280 if (*p == '\0') 281 error(COMPILE, "filename expected"); 282 cmd->t = duptoeol(p, "read command", NULL); 283 break; 284 case BRANCH: /* b t */ 285 p++; 286 EATSPACE(); 287 if (*p == '\0') 288 cmd->t = NULL; 289 else 290 cmd->t = duptoeol(p, "branch", &p); 291 if (*p == ';') { 292 p++; 293 goto semicolon; 294 } 295 break; 296 case LABEL: /* : */ 297 p++; 298 EATSPACE(); 299 cmd->t = duptoeol(p, "label", &p); 300 if (strlen(cmd->t) == 0) 301 error(COMPILE, "empty label"); 302 enterlabel(cmd); 303 if (*p == ';') { 304 p++; 305 goto semicolon; 306 } 307 break; 308 case SUBST: /* s */ 309 p++; 310 if (*p == '\0' || *p == '\\') 311 error(COMPILE, "substitute pattern can not be" 312 " delimited by newline or backslash"); 313 cmd->u.s = xmalloc(sizeof(struct s_subst)); 314 p = compile_re(p, &cmd->u.s->re); 315 if (p == NULL) 316 error(COMPILE, "unterminated substitute pattern"); 317 --p; 318 p = compile_subst(p, cmd->u.s); 319 p = compile_flags(p, cmd->u.s); 320 EATSPACE(); 321 if (*p == ';') { 322 p++; 323 link = &cmd->next; 324 goto semicolon; 325 } 326 break; 327 case TR: /* y */ 328 p++; 329 p = compile_tr(p, (char **)&cmd->u.y); 330 EATSPACE(); 331 if (*p == ';') { 332 p++; 333 link = &cmd->next; 334 goto semicolon; 335 } 336 if (*p) 337 error(COMPILE, "extra text at the end of a" 338 " transform command"); 339 break; 340 } 341 } 342 } 343 344 /* 345 * Get a delimited string. P points to the delimeter of the string; d points 346 * to a buffer area. Newline and delimiter escapes are processed; other 347 * escapes are ignored. 348 * 349 * Returns a pointer to the first character after the final delimiter or NULL 350 * in the case of a non-terminated string. The character array d is filled 351 * with the processed string. 352 */ 353 static char * 354 compile_delimited(char *p, char *d, int is_tr) 355 { 356 char c; 357 358 c = *p++; 359 if (c == '\0') 360 return (NULL); 361 else if (c == '\\') 362 error(COMPILE, "\\ can not be used as a string delimiter"); 363 else if (c == '\n') 364 error(COMPILE, "newline can not be used as a string delimiter"); 365 while (*p) { 366 if (*p == '[' && *p != c) { 367 if ((d = compile_ccl(&p, d)) == NULL) 368 error(COMPILE, "unbalanced brackets ([])"); 369 continue; 370 } else if (*p == '\\' && p[1] == '[') { 371 *d++ = *p++; 372 } else if (*p == '\\' && p[1] == c) { 373 p++; 374 } else if (*p == '\\' && p[1] == 'n') { 375 *d++ = '\n'; 376 p += 2; 377 continue; 378 } else if (*p == '\\' && p[1] == '\\') { 379 if (is_tr) 380 p++; 381 else 382 *d++ = *p++; 383 } else if (*p == c) { 384 *d = '\0'; 385 return (p + 1); 386 } 387 *d++ = *p++; 388 } 389 return (NULL); 390 } 391 392 393 /* compile_ccl: expand a POSIX character class */ 394 static char * 395 compile_ccl(char **sp, char *t) 396 { 397 int c, d; 398 char *s = *sp; 399 400 *t++ = *s++; 401 if (*s == '^') 402 *t++ = *s++; 403 if (*s == ']') 404 *t++ = *s++; 405 for (; *s && (*t = *s) != ']'; s++, t++) 406 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) { 407 *++t = *++s, t++, s++; 408 for (c = *s; (*t = *s) != ']' || c != d; s++, t++) 409 if ((c = *s) == '\0') 410 return NULL; 411 } else if (*s == '\\' && s[1] == 'n') { 412 *t = '\n'; 413 s++; 414 } 415 if (*s == ']') { 416 *sp = ++s; 417 return (++t); 418 } else { 419 return (NULL); 420 } 421 } 422 423 /* 424 * Get a regular expression. P points to the delimiter of the regular 425 * expression; repp points to the address of a regexp pointer. Newline 426 * and delimiter escapes are processed; other escapes are ignored. 427 * Returns a pointer to the first character after the final delimiter 428 * or NULL in the case of a non terminated regular expression. The regexp 429 * pointer is set to the compiled regular expression. 430 * Cflags are passed to regcomp. 431 */ 432 static char * 433 compile_re(char *p, regex_t **repp) 434 { 435 int eval; 436 char *re; 437 438 re = xmalloc(strlen(p) + 1); /* strlen(re) <= strlen(p) */ 439 p = compile_delimited(p, re, 0); 440 if (p && strlen(re) == 0) { 441 *repp = NULL; 442 free(re); 443 return (p); 444 } 445 *repp = xmalloc(sizeof(regex_t)); 446 if (p && (eval = regcomp(*repp, re, Eflag ? REG_EXTENDED : 0)) != 0) 447 error(COMPILE, "RE error: %s", strregerror(eval, *repp)); 448 if (maxnsub < (*repp)->re_nsub) 449 maxnsub = (*repp)->re_nsub; 450 free(re); 451 return (p); 452 } 453 454 /* 455 * Compile the substitution string of a regular expression and set res to 456 * point to a saved copy of it. Nsub is the number of parenthesized regular 457 * expressions. 458 */ 459 static char * 460 compile_subst(char *p, struct s_subst *s) 461 { 462 static char *lbuf; 463 static size_t bufsize; 464 int asize, ref, size; 465 char c, *text, *op, *sp; 466 int sawesc = 0; 467 468 c = *p++; /* Terminator character */ 469 if (c == '\0') 470 return (NULL); 471 472 s->maxbref = 0; 473 s->linenum = linenum; 474 text = NULL; 475 asize = size = 0; 476 do { 477 size_t len = ROUNDLEN(strlen(p) + 1); 478 if (asize - size < len) { 479 do { 480 asize += len; 481 } while (asize - size < len); 482 text = xrealloc(text, asize); 483 } 484 op = sp = text + size; 485 for (; *p; p++) { 486 if (*p == '\\' || sawesc) { 487 /* 488 * If this is a continuation from the last 489 * buffer, we won't have a character to 490 * skip over. 491 */ 492 if (sawesc) 493 sawesc = 0; 494 else 495 p++; 496 497 if (*p == '\0') { 498 /* 499 * This escaped character is continued 500 * in the next part of the line. Note 501 * this fact, then cause the loop to 502 * exit w/ normal EOL case and reenter 503 * above with the new buffer. 504 */ 505 sawesc = 1; 506 p--; 507 continue; 508 } else if (strchr("123456789", *p) != NULL) { 509 *sp++ = '\\'; 510 ref = *p - '0'; 511 if (s->re != NULL && 512 ref > s->re->re_nsub) 513 error(COMPILE, 514 "\\%c not defined in the RE", *p); 515 if (s->maxbref < ref) 516 s->maxbref = ref; 517 } else if (*p == '&' || *p == '\\') 518 *sp++ = '\\'; 519 } else if (*p == c) { 520 p++; 521 *sp++ = '\0'; 522 size += sp - op; 523 s->new = xrealloc(text, size); 524 return (p); 525 } else if (*p == '\n') { 526 error(COMPILE, 527 "unescaped newline inside substitute pattern"); 528 } 529 *sp++ = *p; 530 } 531 size += sp - op; 532 } while ((p = cu_fgets(&lbuf, &bufsize))); 533 error(COMPILE, "unterminated substitute in regular expression"); 534 } 535 536 /* 537 * Compile the flags of the s command 538 */ 539 static char * 540 compile_flags(char *p, struct s_subst *s) 541 { 542 int gn; /* True if we have seen g or n */ 543 long l; 544 545 s->n = 1; /* Default */ 546 s->p = 0; 547 s->wfile = NULL; 548 s->wfd = -1; 549 for (gn = 0;;) { 550 EATSPACE(); /* EXTENSION */ 551 switch (*p) { 552 case 'g': 553 if (gn) 554 error(COMPILE, "more than one number or 'g' in" 555 " substitute flags"); 556 gn = 1; 557 s->n = 0; 558 break; 559 case '\0': 560 case '\n': 561 case ';': 562 return (p); 563 case 'p': 564 s->p = 1; 565 break; 566 case '1': case '2': case '3': 567 case '4': case '5': case '6': 568 case '7': case '8': case '9': 569 if (gn) 570 error(COMPILE, "more than one number or 'g' in" 571 " substitute flags"); 572 gn = 1; 573 l = strtol(p, &p, 10); 574 if (l <= 0 || l >= INT_MAX) 575 error(COMPILE, 576 "number in substitute flags out of range"); 577 s->n = (int)l; 578 continue; 579 case 'w': 580 p++; 581 EATSPACE(); 582 if (*p == '\0') 583 error(COMPILE, "filename expected"); 584 s->wfile = duptoeol(p, "s command w flag", NULL); 585 *p = '\0'; 586 if (aflag) 587 pledge_wpath = 1; 588 else if ((s->wfd = open(s->wfile, 589 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 590 DEFFILEMODE)) == -1) 591 error(FATAL, "%s: %s", s->wfile, strerror(errno)); 592 return (p); 593 default: 594 error(COMPILE, 595 "bad flag in substitute command: '%c'", *p); 596 break; 597 } 598 p++; 599 } 600 } 601 602 /* 603 * Compile a translation set of strings into a lookup table. 604 */ 605 static char * 606 compile_tr(char *p, char **transtab) 607 { 608 int i; 609 char *lt, *op, *np; 610 char *old = NULL, *new = NULL; 611 612 if (*p == '\0' || *p == '\\') 613 error(COMPILE, 614 "transform pattern can not be delimited by newline or backslash"); 615 old = xmalloc(strlen(p) + 1); 616 p = compile_delimited(p, old, 1); 617 if (p == NULL) { 618 error(COMPILE, "unterminated transform source string"); 619 goto bad; 620 } 621 new = xmalloc(strlen(p) + 1); 622 p = compile_delimited(--p, new, 1); 623 if (p == NULL) { 624 error(COMPILE, "unterminated transform target string"); 625 goto bad; 626 } 627 EATSPACE(); 628 if (strlen(new) != strlen(old)) { 629 error(COMPILE, "transform strings are not the same length"); 630 goto bad; 631 } 632 /* We assume characters are 8 bits */ 633 lt = xmalloc(UCHAR_MAX + 1); 634 for (i = 0; i <= UCHAR_MAX; i++) 635 lt[i] = (char)i; 636 for (op = old, np = new; *op; op++, np++) 637 lt[(u_char)*op] = *np; 638 *transtab = lt; 639 free(old); 640 free(new); 641 return (p); 642 bad: 643 free(old); 644 free(new); 645 return (NULL); 646 } 647 648 /* 649 * Compile the text following an a, c, or i command. 650 */ 651 static char * 652 compile_text(void) 653 { 654 int asize, esc_nl, size; 655 char *lbuf, *text, *p, *op, *s; 656 size_t bufsize; 657 658 lbuf = text = NULL; 659 asize = size = 0; 660 while ((p = cu_fgets(&lbuf, &bufsize))) { 661 size_t len = ROUNDLEN(strlen(p) + 1); 662 if (asize - size < len) { 663 do { 664 asize += len; 665 } while (asize - size < len); 666 text = xrealloc(text, asize); 667 } 668 op = s = text + size; 669 for (esc_nl = 0; *p != '\0'; p++) { 670 if (*p == '\\' && p[1] != '\0' && *++p == '\n') 671 esc_nl = 1; 672 *s++ = *p; 673 } 674 size += s - op; 675 if (!esc_nl) { 676 *s = '\0'; 677 break; 678 } 679 } 680 free(lbuf); 681 text = xrealloc(text, size + 1); 682 text[size] = '\0'; 683 return (text); 684 } 685 686 /* 687 * Get an address and return a pointer to the first character after 688 * it. Fill the structure pointed to according to the address. 689 */ 690 static char * 691 compile_addr(char *p, struct s_addr *a) 692 { 693 char *end; 694 695 switch (*p) { 696 case '\\': /* Context address */ 697 ++p; 698 /* FALLTHROUGH */ 699 case '/': /* Context address */ 700 p = compile_re(p, &a->u.r); 701 if (p == NULL) 702 error(COMPILE, "unterminated regular expression"); 703 a->type = AT_RE; 704 return (p); 705 706 case '$': /* Last line */ 707 a->type = AT_LAST; 708 return (p + 1); 709 /* Line number */ 710 case '0': case '1': case '2': case '3': case '4': 711 case '5': case '6': case '7': case '8': case '9': 712 a->type = AT_LINE; 713 a->u.l = strtoul(p, &end, 10); 714 return (end); 715 default: 716 error(COMPILE, "expected context address"); 717 return (NULL); 718 } 719 } 720 721 /* 722 * duptoeol -- 723 * Return a copy of all the characters up to \n or \0. 724 */ 725 static char * 726 duptoeol(char *s, char *ctype, char **semi) 727 { 728 size_t len; 729 int ws; 730 char *start; 731 732 ws = 0; 733 if (semi) { 734 for (start = s; *s != '\0' && *s != '\n' && *s != ';'; ++s) 735 ws = isspace((unsigned char)*s); 736 } else { 737 for (start = s; *s != '\0' && *s != '\n'; ++s) 738 ws = isspace((unsigned char)*s); 739 *s = '\0'; 740 } 741 if (ws) 742 warning("whitespace after %s", ctype); 743 len = s - start + 1; 744 if (semi) 745 *semi = s; 746 s = xmalloc(len); 747 strlcpy(s, start, len); 748 return (s); 749 } 750 751 /* 752 * Convert goto label names to addresses, and count a and r commands, in 753 * the given subset of the script. Free the memory used by labels in b 754 * and t commands (but not by :). 755 * 756 * TODO: Remove } nodes 757 */ 758 static void 759 fixuplabel(struct s_command *cp, struct s_command *end) 760 { 761 762 for (; cp != end; cp = cp->next) 763 switch (cp->code) { 764 case 'a': 765 case 'r': 766 appendnum++; 767 break; 768 case 'b': 769 case 't': 770 /* Resolve branch target. */ 771 if (cp->t == NULL) { 772 cp->u.c = NULL; 773 break; 774 } 775 if ((cp->u.c = findlabel(cp->t)) == NULL) 776 error(COMPILE, "undefined label '%s'", cp->t); 777 free(cp->t); 778 break; 779 case '{': 780 /* Do interior commands. */ 781 fixuplabel(cp->u.c, cp->next); 782 break; 783 } 784 } 785 786 /* 787 * Associate the given command label for later lookup. 788 */ 789 static void 790 enterlabel(struct s_command *cp) 791 { 792 struct labhash **lhp, *lh; 793 u_char *p; 794 u_int h, c; 795 796 for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++) 797 h = (h << 5) + h + c; 798 lhp = &labels[h & LHMASK]; 799 for (lh = *lhp; lh != NULL; lh = lh->lh_next) 800 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0) 801 error(COMPILE, "duplicate label '%s'", cp->t); 802 lh = xmalloc(sizeof *lh); 803 lh->lh_next = *lhp; 804 lh->lh_hash = h; 805 lh->lh_cmd = cp; 806 lh->lh_ref = 0; 807 *lhp = lh; 808 } 809 810 /* 811 * Find the label contained in the command l in the command linked 812 * list cp. L is excluded from the search. Return NULL if not found. 813 */ 814 static struct s_command * 815 findlabel(char *name) 816 { 817 struct labhash *lh; 818 u_char *p; 819 u_int h, c; 820 821 for (h = 0, p = (u_char *)name; (c = *p) != 0; p++) 822 h = (h << 5) + h + c; 823 for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) { 824 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) { 825 lh->lh_ref = 1; 826 return (lh->lh_cmd); 827 } 828 } 829 return (NULL); 830 } 831 832 /* 833 * Warn about any unused labels. As a side effect, release the label hash 834 * table space. 835 */ 836 static void 837 uselabel(void) 838 { 839 struct labhash *lh, *next; 840 int i; 841 842 for (i = 0; i < LHSZ; i++) { 843 for (lh = labels[i]; lh != NULL; lh = next) { 844 next = lh->lh_next; 845 if (!lh->lh_ref) 846 warning("unused label '%s'", 847 lh->lh_cmd->t); 848 free(lh); 849 } 850 } 851 } 852