1 /* $OpenBSD: compile.c,v 1.50 2018/12/07 14:45:40 schwarze 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 = 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' || *p == ';') 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) 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"); 365 366 while (p[0]) { 367 /* Unescaped delimiter: We are done. */ 368 if (p[0] == c) { 369 *d = '\0'; 370 return p + 1; 371 } 372 if (p[0] == '\\') { 373 /* Escaped delimiter: Skip the backslash. */ 374 if (p[1] == c) { 375 p++; 376 } else { 377 /* Backslash-n: Match linefeed. */ 378 if (p[1] == 'n') { 379 *d++ = '\n'; 380 p += 2; 381 /* Other escapes remain unchanged. */ 382 } else { 383 *d++ = *p++; 384 *d++ = *p++; 385 } 386 continue; 387 } 388 } 389 if (p[0] != '[') 390 *d++ = *p++; 391 /* 392 * Bracket expression: 393 * It may contain the delimiter without escaping. 394 */ 395 else if ((d = compile_ccl(&p, d)) == NULL) 396 error(COMPILE, "unbalanced brackets ([])"); 397 } 398 return NULL; 399 } 400 401 402 /* compile_ccl: expand a POSIX character class */ 403 static char * 404 compile_ccl(char **sp, char *t) 405 { 406 int c, d; 407 char *s = *sp; 408 409 *t++ = *s++; 410 if (*s == '^') 411 *t++ = *s++; 412 if (*s == ']') 413 *t++ = *s++; 414 for (; *s && (*t = *s) != ']'; s++, t++) 415 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) { 416 *++t = *++s, t++, s++; 417 for (c = *s; (*t = *s) != ']' || c != d; s++, t++) 418 if ((c = *s) == '\0') 419 return NULL; 420 } else if (*s == '\\' && s[1] == 'n') { 421 *t = '\n'; 422 s++; 423 } 424 if (*s == ']') { 425 *sp = ++s; 426 return (++t); 427 } else { 428 return (NULL); 429 } 430 } 431 432 /* 433 * Get a regular expression. P points to the delimiter of the regular 434 * expression; repp points to the address of a regexp pointer. Newline 435 * and delimiter escapes are processed; other escapes are ignored. 436 * Returns a pointer to the first character after the final delimiter 437 * or NULL in the case of a non terminated regular expression. The regexp 438 * pointer is set to the compiled regular expression. 439 * Cflags are passed to regcomp. 440 */ 441 static char * 442 compile_re(char *p, regex_t **repp) 443 { 444 int eval; 445 char *re; 446 447 re = xmalloc(strlen(p) + 1); /* strlen(re) <= strlen(p) */ 448 p = compile_delimited(p, re); 449 if (p && strlen(re) == 0) { 450 *repp = NULL; 451 free(re); 452 return (p); 453 } 454 *repp = xmalloc(sizeof(regex_t)); 455 if (p && (eval = regcomp(*repp, re, Eflag ? REG_EXTENDED : 0)) != 0) 456 error(COMPILE, "RE error: %s", strregerror(eval, *repp)); 457 if (maxnsub < (*repp)->re_nsub) 458 maxnsub = (*repp)->re_nsub; 459 free(re); 460 return (p); 461 } 462 463 /* 464 * Compile the substitution string of a regular expression and set res to 465 * point to a saved copy of it. Nsub is the number of parenthesized regular 466 * expressions. 467 */ 468 static char * 469 compile_subst(char *p, struct s_subst *s) 470 { 471 static char *lbuf; 472 static size_t bufsize; 473 size_t asize, ref, size; 474 char c, *text, *op, *sp; 475 int sawesc = 0; 476 477 c = *p++; /* Terminator character */ 478 if (c == '\0') 479 return (NULL); 480 481 s->maxbref = 0; 482 s->linenum = linenum; 483 text = NULL; 484 asize = size = 0; 485 do { 486 size_t len = ROUNDLEN(strlen(p) + 1); 487 if (asize - size < len) { 488 do { 489 asize += len; 490 } while (asize - size < len); 491 text = xrealloc(text, asize); 492 } 493 op = sp = text + size; 494 for (; *p; p++) { 495 if (*p == '\\' || sawesc) { 496 /* 497 * If this is a continuation from the last 498 * buffer, we won't have a character to 499 * skip over. 500 */ 501 if (sawesc) 502 sawesc = 0; 503 else 504 p++; 505 506 if (*p == '\0') { 507 /* 508 * This escaped character is continued 509 * in the next part of the line. Note 510 * this fact, then cause the loop to 511 * exit w/ normal EOL case and reenter 512 * above with the new buffer. 513 */ 514 sawesc = 1; 515 p--; 516 continue; 517 } else if (strchr("123456789", *p) != NULL) { 518 *sp++ = '\\'; 519 ref = *p - '0'; 520 if (s->re != NULL && 521 ref > s->re->re_nsub) 522 error(COMPILE, 523 "\\%c not defined in the RE", *p); 524 if (s->maxbref < ref) 525 s->maxbref = ref; 526 } else if (*p == '&' || *p == '\\') 527 *sp++ = '\\'; 528 } else if (*p == c) { 529 p++; 530 *sp++ = '\0'; 531 size += sp - op; 532 s->new = xrealloc(text, size); 533 return (p); 534 } else if (*p == '\n') { 535 error(COMPILE, 536 "unescaped newline inside substitute pattern"); 537 } 538 *sp++ = *p; 539 } 540 size += sp - op; 541 } while ((p = cu_fgets(&lbuf, &bufsize))); 542 error(COMPILE, "unterminated substitute in regular expression"); 543 } 544 545 /* 546 * Compile the flags of the s command 547 */ 548 static char * 549 compile_flags(char *p, struct s_subst *s) 550 { 551 int gn; /* True if we have seen g or n */ 552 long l; 553 554 s->n = 1; /* Default */ 555 s->p = 0; 556 s->wfile = NULL; 557 s->wfd = -1; 558 for (gn = 0;;) { 559 EATSPACE(); /* EXTENSION */ 560 switch (*p) { 561 case 'g': 562 if (gn) 563 error(COMPILE, "more than one number or 'g' in" 564 " substitute flags"); 565 gn = 1; 566 s->n = 0; 567 break; 568 case '\0': 569 case '\n': 570 case ';': 571 return (p); 572 case 'p': 573 s->p = 1; 574 break; 575 case '1': case '2': case '3': 576 case '4': case '5': case '6': 577 case '7': case '8': case '9': 578 if (gn) 579 error(COMPILE, "more than one number or 'g' in" 580 " substitute flags"); 581 gn = 1; 582 l = strtol(p, &p, 10); 583 if (l <= 0 || l >= INT_MAX) 584 error(COMPILE, 585 "number in substitute flags out of range"); 586 s->n = (int)l; 587 continue; 588 case 'w': 589 p++; 590 EATSPACE(); 591 if (*p == '\0') 592 error(COMPILE, "filename expected"); 593 s->wfile = duptoeol(p, "s command w flag", NULL); 594 *p = '\0'; 595 if (aflag) 596 pledge_wpath = 1; 597 else if ((s->wfd = open(s->wfile, 598 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 599 DEFFILEMODE)) == -1) 600 error(FATAL, "%s: %s", s->wfile, strerror(errno)); 601 return (p); 602 default: 603 error(COMPILE, 604 "bad flag in substitute command: '%c'", *p); 605 break; 606 } 607 p++; 608 } 609 } 610 611 /* 612 * Compile a translation set of strings into a lookup table. 613 */ 614 static char * 615 compile_tr(char *old, char **transtab) 616 { 617 int i; 618 char delimiter, check[UCHAR_MAX + 1]; 619 char *new, *end; 620 621 memset(check, 0, sizeof(check)); 622 delimiter = *old; 623 if (delimiter == '\\') 624 error(COMPILE, "\\ can not be used as a string delimiter"); 625 else if (delimiter == '\n' || delimiter == '\0') 626 error(COMPILE, "newline can not be used as a string delimiter"); 627 628 new = old++; 629 do { 630 if ((new = strchr(new + 1, delimiter)) == NULL) 631 error(COMPILE, "unterminated transform source string"); 632 } while (*(new - 1) == '\\' && *(new -2) != '\\'); 633 *new = '\0'; 634 end = new++; 635 do { 636 if ((end = strchr(end + 1, delimiter)) == NULL) 637 error(COMPILE, "unterminated transform target string"); 638 } while (*(end -1) == '\\' && *(end -2) != '\\'); 639 *end = '\0'; 640 641 /* We assume characters are 8 bits */ 642 *transtab = xmalloc(UCHAR_MAX + 1); 643 for (i = 0; i <= UCHAR_MAX; i++) 644 (*transtab)[i] = (char)i; 645 646 while (*old != '\0' && *new != '\0') { 647 if (*old == '\\') { 648 old++; 649 if (*old == 'n') 650 *old = '\n'; 651 else if (*old != delimiter && *old != '\\') 652 error(COMPILE, "Unexpected character after " 653 "backslash"); 654 } 655 if (*new == '\\') { 656 new++; 657 if (*new == 'n') 658 *new = '\n'; 659 else if (*new != delimiter && *new != '\\') 660 error(COMPILE, "Unexpected character after " 661 "backslash"); 662 } 663 if (check[(u_char) *old] == 1) 664 error(COMPILE, "Repeated character in source string"); 665 check[(u_char) *old] = 1; 666 (*transtab)[(u_char) *old++] = *new++; 667 } 668 if (*old != '\0' || *new != '\0') 669 error(COMPILE, "transform strings are not the same length"); 670 return end + 1; 671 } 672 673 /* 674 * Compile the text following an a, c, or i command. 675 */ 676 static char * 677 compile_text(void) 678 { 679 size_t asize, size, bufsize; 680 char *lbuf, *text, *p, *op, *s; 681 int esc_nl; 682 683 lbuf = text = NULL; 684 asize = size = 0; 685 while ((p = cu_fgets(&lbuf, &bufsize))) { 686 size_t len = ROUNDLEN(strlen(p) + 1); 687 if (asize - size < len) { 688 do { 689 asize += len; 690 } while (asize - size < len); 691 text = xrealloc(text, asize); 692 } 693 op = s = text + size; 694 for (esc_nl = 0; *p != '\0'; p++) { 695 if (*p == '\\' && p[1] != '\0' && *++p == '\n') 696 esc_nl = 1; 697 *s++ = *p; 698 } 699 size += s - op; 700 if (!esc_nl) { 701 *s = '\0'; 702 break; 703 } 704 } 705 free(lbuf); 706 text = xrealloc(text, size + 1); 707 text[size] = '\0'; 708 return (text); 709 } 710 711 /* 712 * Get an address and return a pointer to the first character after 713 * it. Fill the structure pointed to according to the address. 714 */ 715 static char * 716 compile_addr(char *p, struct s_addr *a) 717 { 718 char *end; 719 720 switch (*p) { 721 case '\\': /* Context address */ 722 ++p; 723 /* FALLTHROUGH */ 724 case '/': /* Context address */ 725 p = compile_re(p, &a->u.r); 726 if (p == NULL) 727 error(COMPILE, "unterminated regular expression"); 728 a->type = AT_RE; 729 return (p); 730 731 case '$': /* Last line */ 732 a->type = AT_LAST; 733 return (p + 1); 734 /* Line number */ 735 case '0': case '1': case '2': case '3': case '4': 736 case '5': case '6': case '7': case '8': case '9': 737 a->type = AT_LINE; 738 a->u.l = strtoul(p, &end, 10); 739 return (end); 740 default: 741 error(COMPILE, "expected context address"); 742 return (NULL); 743 } 744 } 745 746 /* 747 * duptoeol -- 748 * Return a copy of all the characters up to \n or \0. 749 */ 750 static char * 751 duptoeol(char *s, char *ctype, char **semi) 752 { 753 size_t len; 754 int ws; 755 char *start; 756 757 ws = 0; 758 if (semi) { 759 for (start = s; *s != '\0' && *s != '\n' && *s != ';'; ++s) 760 ws = isspace((unsigned char)*s); 761 } else { 762 for (start = s; *s != '\0' && *s != '\n'; ++s) 763 ws = isspace((unsigned char)*s); 764 *s = '\0'; 765 } 766 if (ws) 767 warning("whitespace after %s", ctype); 768 len = s - start + 1; 769 if (semi) 770 *semi = s; 771 s = xmalloc(len); 772 strlcpy(s, start, len); 773 return (s); 774 } 775 776 /* 777 * Convert goto label names to addresses, and count a and r commands, in 778 * the given subset of the script. Free the memory used by labels in b 779 * and t commands (but not by :). 780 * 781 * TODO: Remove } nodes 782 */ 783 static void 784 fixuplabel(struct s_command *cp, struct s_command *end) 785 { 786 787 for (; cp != end; cp = cp->next) 788 switch (cp->code) { 789 case 'a': 790 case 'r': 791 appendnum++; 792 break; 793 case 'b': 794 case 't': 795 /* Resolve branch target. */ 796 if (cp->t == NULL) { 797 cp->u.c = NULL; 798 break; 799 } 800 if ((cp->u.c = findlabel(cp->t)) == NULL) 801 error(COMPILE, "undefined label '%s'", cp->t); 802 free(cp->t); 803 break; 804 case '{': 805 /* Do interior commands. */ 806 fixuplabel(cp->u.c, cp->next); 807 break; 808 } 809 } 810 811 /* 812 * Associate the given command label for later lookup. 813 */ 814 static void 815 enterlabel(struct s_command *cp) 816 { 817 struct labhash **lhp, *lh; 818 u_char *p; 819 u_int h, c; 820 821 for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++) 822 h = (h << 5) + h + c; 823 lhp = &labels[h & LHMASK]; 824 for (lh = *lhp; lh != NULL; lh = lh->lh_next) 825 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0) 826 error(COMPILE, "duplicate label '%s'", cp->t); 827 lh = xmalloc(sizeof *lh); 828 lh->lh_next = *lhp; 829 lh->lh_hash = h; 830 lh->lh_cmd = cp; 831 lh->lh_ref = 0; 832 *lhp = lh; 833 } 834 835 /* 836 * Find the label contained in the command l in the command linked 837 * list cp. L is excluded from the search. Return NULL if not found. 838 */ 839 static struct s_command * 840 findlabel(char *name) 841 { 842 struct labhash *lh; 843 u_char *p; 844 u_int h, c; 845 846 for (h = 0, p = (u_char *)name; (c = *p) != 0; p++) 847 h = (h << 5) + h + c; 848 for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) { 849 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) { 850 lh->lh_ref = 1; 851 return (lh->lh_cmd); 852 } 853 } 854 return (NULL); 855 } 856 857 /* 858 * Warn about any unused labels. As a side effect, release the label hash 859 * table space. 860 */ 861 static void 862 uselabel(void) 863 { 864 struct labhash *lh, *next; 865 int i; 866 867 for (i = 0; i < LHSZ; i++) { 868 for (lh = labels[i]; lh != NULL; lh = next) { 869 next = lh->lh_next; 870 if (!lh->lh_ref) 871 warning("unused label '%s'", 872 lh->lh_cmd->t); 873 free(lh); 874 } 875 } 876 } 877