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 * %sccs.include.redist.c% 10 */ 11 12 #ifndef lint 13 static char sccsid[] = "@(#)compile.c 8.2 (Berkeley) 04/28/95"; 14 #endif /* not lint */ 15 16 #include <sys/types.h> 17 #include <sys/stat.h> 18 19 #include <ctype.h> 20 #include <errno.h> 21 #include <fcntl.h> 22 #include <limits.h> 23 #include <regex.h> 24 #include <stdio.h> 25 #include <stdlib.h> 26 #include <string.h> 27 28 #include "defs.h" 29 #include "extern.h" 30 31 #define LHSZ 128 32 #define LHMASK (LHSZ - 1) 33 static struct labhash { 34 struct labhash *lh_next; 35 u_int lh_hash; 36 struct s_command *lh_cmd; 37 int lh_ref; 38 } *labels[LHSZ]; 39 40 static char *compile_addr __P((char *, struct s_addr *)); 41 static char *compile_delimited __P((char *, char *)); 42 static char *compile_flags __P((char *, struct s_subst *)); 43 static char *compile_re __P((char *, regex_t **)); 44 static char *compile_subst __P((char *, struct s_subst *)); 45 static char *compile_text __P((void)); 46 static char *compile_tr __P((char *, char **)); 47 static struct s_command 48 **compile_stream __P((char *, struct s_command **, char *)); 49 static char *duptoeol __P((char *, char *)); 50 static void enterlabel __P((struct s_command *)); 51 static struct s_command 52 *findlabel __P((char *)); 53 static void fixuplabel __P((struct s_command *, struct s_command *)); 54 static void uselabel __P((void)); 55 56 /* 57 * Command specification. This is used to drive the command parser. 58 */ 59 struct s_format { 60 char code; /* Command code */ 61 int naddr; /* Number of address args */ 62 enum e_args args; /* Argument type */ 63 }; 64 65 static struct s_format cmd_fmts[] = { 66 {'{', 2, GROUP}, 67 {'a', 1, TEXT}, 68 {'b', 2, BRANCH}, 69 {'c', 2, TEXT}, 70 {'d', 2, EMPTY}, 71 {'D', 2, EMPTY}, 72 {'g', 2, EMPTY}, 73 {'G', 2, EMPTY}, 74 {'h', 2, EMPTY}, 75 {'H', 2, EMPTY}, 76 {'i', 1, TEXT}, 77 {'l', 2, EMPTY}, 78 {'n', 2, EMPTY}, 79 {'N', 2, EMPTY}, 80 {'p', 2, EMPTY}, 81 {'P', 2, EMPTY}, 82 {'q', 1, EMPTY}, 83 {'r', 1, RFILE}, 84 {'s', 2, SUBST}, 85 {'t', 2, BRANCH}, 86 {'w', 2, WFILE}, 87 {'x', 2, EMPTY}, 88 {'y', 2, TR}, 89 {'!', 2, NONSEL}, 90 {':', 0, LABEL}, 91 {'#', 0, COMMENT}, 92 {'=', 1, EMPTY}, 93 {'\0', 0, COMMENT}, 94 }; 95 96 /* The compiled program. */ 97 struct s_command *prog; 98 99 /* 100 * Compile the program into prog. 101 * Initialise appends. 102 */ 103 void 104 compile() 105 { 106 *compile_stream(NULL, &prog, NULL) = NULL; 107 fixuplabel(prog, NULL); 108 uselabel(); 109 appends = xmalloc(sizeof(struct s_appends) * appendnum); 110 match = xmalloc((maxnsub + 1) * sizeof(regmatch_t)); 111 } 112 113 #define EATSPACE() do { \ 114 if (p) \ 115 while (*p && isascii(*p) && isspace(*p)) \ 116 p++; \ 117 } while (0) 118 119 static struct s_command ** 120 compile_stream(terminator, link, p) 121 char *terminator; 122 struct s_command **link; 123 register char *p; 124 { 125 static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */ 126 struct s_command *cmd, *cmd2; 127 struct s_format *fp; 128 int naddr; /* Number of addresses */ 129 130 if (p != NULL) 131 goto semicolon; 132 for (;;) { 133 if ((p = cu_fgets(lbuf, sizeof(lbuf))) == NULL) { 134 if (terminator != NULL) 135 err(COMPILE, "unexpected EOF (pending }'s)"); 136 return (link); 137 } 138 139 semicolon: EATSPACE(); 140 if (p && (*p == '#' || *p == '\0')) 141 continue; 142 if (*p == '}') { 143 if (terminator == NULL) 144 err(COMPILE, "unexpected }"); 145 return (link); 146 } 147 *link = cmd = xmalloc(sizeof(struct s_command)); 148 link = &cmd->next; 149 cmd->nonsel = cmd->inrange = 0; 150 /* First parse the addresses */ 151 naddr = 0; 152 153 /* Valid characters to start an address */ 154 #define addrchar(c) (strchr("0123456789/\\$", (c))) 155 if (addrchar(*p)) { 156 naddr++; 157 cmd->a1 = xmalloc(sizeof(struct s_addr)); 158 p = compile_addr(p, cmd->a1); 159 EATSPACE(); /* EXTENSION */ 160 if (*p == ',') { 161 p++; 162 EATSPACE(); /* EXTENSION */ 163 naddr++; 164 cmd->a2 = xmalloc(sizeof(struct s_addr)); 165 p = compile_addr(p, cmd->a2); 166 EATSPACE(); 167 } else 168 cmd->a2 = 0; 169 } else 170 cmd->a1 = cmd->a2 = 0; 171 172 nonsel: /* Now parse the command */ 173 if (!*p) 174 err(COMPILE, "command expected"); 175 cmd->code = *p; 176 for (fp = cmd_fmts; fp->code; fp++) 177 if (fp->code == *p) 178 break; 179 if (!fp->code) 180 err(COMPILE, "invalid command code %c", *p); 181 if (naddr > fp->naddr) 182 err(COMPILE, 183 "command %c expects up to %d address(es), found %d", *p, fp->naddr, naddr); 184 switch (fp->args) { 185 case NONSEL: /* ! */ 186 p++; 187 EATSPACE(); 188 cmd->nonsel = ! cmd->nonsel; 189 goto nonsel; 190 case GROUP: /* { */ 191 p++; 192 EATSPACE(); 193 if (!*p) 194 p = NULL; 195 cmd2 = xmalloc(sizeof(struct s_command)); 196 cmd2->code = '}'; 197 *compile_stream("}", &cmd->u.c, p) = cmd2; 198 cmd->next = cmd2; 199 link = &cmd2->next; 200 /* 201 * Short-circuit command processing, since end of 202 * group is really just a noop. 203 */ 204 cmd2->nonsel = 1; 205 cmd2->a1 = cmd2->a2 = 0; 206 break; 207 case EMPTY: /* d D g G h H l n N p P q x = \0 */ 208 p++; 209 EATSPACE(); 210 if (*p == ';') { 211 p++; 212 link = &cmd->next; 213 goto semicolon; 214 } 215 if (*p) 216 err(COMPILE, 217 "extra characters at the end of %c command", cmd->code); 218 break; 219 case TEXT: /* a c i */ 220 p++; 221 EATSPACE(); 222 if (*p != '\\') 223 err(COMPILE, 224 "command %c expects \\ followed by text", cmd->code); 225 p++; 226 EATSPACE(); 227 if (*p) 228 err(COMPILE, 229 "extra characters after \\ at the end of %c command", cmd->code); 230 cmd->t = compile_text(); 231 break; 232 case COMMENT: /* \0 # */ 233 break; 234 case WFILE: /* w */ 235 p++; 236 EATSPACE(); 237 if (*p == '\0') 238 err(COMPILE, "filename expected"); 239 cmd->t = duptoeol(p, "w command"); 240 if (aflag) 241 cmd->u.fd = -1; 242 else if ((cmd->u.fd = open(p, 243 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 244 DEFFILEMODE)) == -1) 245 err(FATAL, "%s: %s\n", p, strerror(errno)); 246 break; 247 case RFILE: /* r */ 248 p++; 249 EATSPACE(); 250 if (*p == '\0') 251 err(COMPILE, "filename expected"); 252 else 253 cmd->t = duptoeol(p, "read command"); 254 break; 255 case BRANCH: /* b t */ 256 p++; 257 EATSPACE(); 258 if (*p == '\0') 259 cmd->t = NULL; 260 else 261 cmd->t = duptoeol(p, "branch"); 262 break; 263 case LABEL: /* : */ 264 p++; 265 EATSPACE(); 266 cmd->t = duptoeol(p, "label"); 267 if (strlen(p) == 0) 268 err(COMPILE, "empty label"); 269 enterlabel(cmd); 270 break; 271 case SUBST: /* s */ 272 p++; 273 if (*p == '\0' || *p == '\\') 274 err(COMPILE, 275 "substitute pattern can not be delimited by newline or backslash"); 276 cmd->u.s = xmalloc(sizeof(struct s_subst)); 277 p = compile_re(p, &cmd->u.s->re); 278 if (p == NULL) 279 err(COMPILE, "unterminated substitute pattern"); 280 --p; 281 p = compile_subst(p, cmd->u.s); 282 p = compile_flags(p, cmd->u.s); 283 EATSPACE(); 284 if (*p == ';') { 285 p++; 286 link = &cmd->next; 287 goto semicolon; 288 } 289 break; 290 case TR: /* y */ 291 p++; 292 p = compile_tr(p, (char **)&cmd->u.y); 293 EATSPACE(); 294 if (*p == ';') { 295 p++; 296 link = &cmd->next; 297 goto semicolon; 298 } 299 if (*p) 300 err(COMPILE, 301 "extra text at the end of a transform command"); 302 break; 303 } 304 } 305 } 306 307 /* 308 * Get a delimited string. P points to the delimeter of the string; d points 309 * to a buffer area. Newline and delimiter escapes are processed; other 310 * escapes are ignored. 311 * 312 * Returns a pointer to the first character after the final delimiter or NULL 313 * in the case of a non-terminated string. The character array d is filled 314 * with the processed string. 315 */ 316 static char * 317 compile_delimited(p, d) 318 char *p, *d; 319 { 320 char c; 321 322 c = *p++; 323 if (c == '\0') 324 return (NULL); 325 else if (c == '\\') 326 err(COMPILE, "\\ can not be used as a string delimiter"); 327 else if (c == '\n') 328 err(COMPILE, "newline can not be used as a string delimiter"); 329 while (*p) { 330 if (*p == '\\' && p[1] == c) 331 p++; 332 else if (*p == '\\' && p[1] == 'n') { 333 *d++ = '\n'; 334 p += 2; 335 continue; 336 } else if (*p == '\\' && p[1] == '\\') 337 *d++ = *p++; 338 else if (*p == c) { 339 *d = '\0'; 340 return (p + 1); 341 } 342 *d++ = *p++; 343 } 344 return (NULL); 345 } 346 347 /* 348 * Get a regular expression. P points to the delimiter of the regular 349 * expression; repp points to the address of a regexp pointer. Newline 350 * and delimiter escapes are processed; other escapes are ignored. 351 * Returns a pointer to the first character after the final delimiter 352 * or NULL in the case of a non terminated regular expression. The regexp 353 * pointer is set to the compiled regular expression. 354 * Cflags are passed to regcomp. 355 */ 356 static char * 357 compile_re(p, repp) 358 char *p; 359 regex_t **repp; 360 { 361 int eval; 362 char re[_POSIX2_LINE_MAX + 1]; 363 364 p = compile_delimited(p, re); 365 if (p && strlen(re) == 0) { 366 *repp = NULL; 367 return (p); 368 } 369 *repp = xmalloc(sizeof(regex_t)); 370 if (p && (eval = regcomp(*repp, re, 0)) != 0) 371 err(COMPILE, "RE error: %s", strregerror(eval, *repp)); 372 if (maxnsub < (*repp)->re_nsub) 373 maxnsub = (*repp)->re_nsub; 374 return (p); 375 } 376 377 /* 378 * Compile the substitution string of a regular expression and set res to 379 * point to a saved copy of it. Nsub is the number of parenthesized regular 380 * expressions. 381 */ 382 static char * 383 compile_subst(p, s) 384 char *p; 385 struct s_subst *s; 386 { 387 static char lbuf[_POSIX2_LINE_MAX + 1]; 388 int asize, ref, size; 389 char c, *text, *op, *sp; 390 391 c = *p++; /* Terminator character */ 392 if (c == '\0') 393 return (NULL); 394 395 s->maxbref = 0; 396 s->linenum = linenum; 397 asize = 2 * _POSIX2_LINE_MAX + 1; 398 text = xmalloc(asize); 399 size = 0; 400 do { 401 op = sp = text + size; 402 for (; *p; p++) { 403 if (*p == '\\') { 404 p++; 405 if (strchr("123456789", *p) != NULL) { 406 *sp++ = '\\'; 407 ref = *p - '0'; 408 if (s->re != NULL && 409 ref > s->re->re_nsub) 410 err(COMPILE, 411 "\\%c not defined in the RE", *p); 412 if (s->maxbref < ref) 413 s->maxbref = ref; 414 } else if (*p == '&' || *p == '\\') 415 *sp++ = '\\'; 416 } else if (*p == c) { 417 p++; 418 *sp++ = '\0'; 419 size += sp - op; 420 s->new = xrealloc(text, size); 421 return (p); 422 } else if (*p == '\n') { 423 err(COMPILE, 424 "unescaped newline inside substitute pattern"); 425 /* NOTREACHED */ 426 } 427 *sp++ = *p; 428 } 429 size += sp - op; 430 if (asize - size < _POSIX2_LINE_MAX + 1) { 431 asize *= 2; 432 text = xmalloc(asize); 433 } 434 } while (cu_fgets(p = lbuf, sizeof(lbuf))); 435 err(COMPILE, "unterminated substitute in regular expression"); 436 /* NOTREACHED */ 437 } 438 439 /* 440 * Compile the flags of the s command 441 */ 442 static char * 443 compile_flags(p, s) 444 char *p; 445 struct s_subst *s; 446 { 447 int gn; /* True if we have seen g or n */ 448 char wfile[_POSIX2_LINE_MAX + 1], *q; 449 450 s->n = 1; /* Default */ 451 s->p = 0; 452 s->wfile = NULL; 453 s->wfd = -1; 454 for (gn = 0;;) { 455 EATSPACE(); /* EXTENSION */ 456 switch (*p) { 457 case 'g': 458 if (gn) 459 err(COMPILE, 460 "more than one number or 'g' in substitute flags"); 461 gn = 1; 462 s->n = 0; 463 break; 464 case '\0': 465 case '\n': 466 case ';': 467 return (p); 468 case 'p': 469 s->p = 1; 470 break; 471 case '1': case '2': case '3': 472 case '4': case '5': case '6': 473 case '7': case '8': case '9': 474 if (gn) 475 err(COMPILE, 476 "more than one number or 'g' in substitute flags"); 477 gn = 1; 478 /* XXX Check for overflow */ 479 s->n = (int)strtol(p, &p, 10); 480 break; 481 case 'w': 482 p++; 483 #ifdef HISTORIC_PRACTICE 484 if (*p != ' ') { 485 err(WARNING, "space missing before w wfile"); 486 return (p); 487 } 488 #endif 489 EATSPACE(); 490 q = wfile; 491 while (*p) { 492 if (*p == '\n') 493 break; 494 *q++ = *p++; 495 } 496 *q = '\0'; 497 if (q == wfile) 498 err(COMPILE, "no wfile specified"); 499 s->wfile = strdup(wfile); 500 if (!aflag && (s->wfd = open(wfile, 501 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 502 DEFFILEMODE)) == -1) 503 err(FATAL, "%s: %s\n", wfile, strerror(errno)); 504 return (p); 505 default: 506 err(COMPILE, 507 "bad flag in substitute command: '%c'", *p); 508 break; 509 } 510 p++; 511 } 512 } 513 514 /* 515 * Compile a translation set of strings into a lookup table. 516 */ 517 static char * 518 compile_tr(p, transtab) 519 char *p; 520 char **transtab; 521 { 522 int i; 523 char *lt, *op, *np; 524 char old[_POSIX2_LINE_MAX + 1]; 525 char new[_POSIX2_LINE_MAX + 1]; 526 527 if (*p == '\0' || *p == '\\') 528 err(COMPILE, 529 "transform pattern can not be delimited by newline or backslash"); 530 p = compile_delimited(p, old); 531 if (p == NULL) { 532 err(COMPILE, "unterminated transform source string"); 533 return (NULL); 534 } 535 p = compile_delimited(--p, new); 536 if (p == NULL) { 537 err(COMPILE, "unterminated transform target string"); 538 return (NULL); 539 } 540 EATSPACE(); 541 if (strlen(new) != strlen(old)) { 542 err(COMPILE, "transform strings are not the same length"); 543 return (NULL); 544 } 545 /* We assume characters are 8 bits */ 546 lt = xmalloc(UCHAR_MAX); 547 for (i = 0; i <= UCHAR_MAX; i++) 548 lt[i] = (char)i; 549 for (op = old, np = new; *op; op++, np++) 550 lt[(u_char)*op] = *np; 551 *transtab = lt; 552 return (p); 553 } 554 555 /* 556 * Compile the text following an a or i command. 557 */ 558 static char * 559 compile_text() 560 { 561 int asize, size; 562 char *text, *p, *op, *s; 563 char lbuf[_POSIX2_LINE_MAX + 1]; 564 565 asize = 2 * _POSIX2_LINE_MAX + 1; 566 text = xmalloc(asize); 567 size = 0; 568 while (cu_fgets(lbuf, sizeof(lbuf))) { 569 op = s = text + size; 570 p = lbuf; 571 EATSPACE(); 572 for (; *p; p++) { 573 if (*p == '\\') 574 p++; 575 *s++ = *p; 576 } 577 size += s - op; 578 if (p[-2] != '\\') { 579 *s = '\0'; 580 break; 581 } 582 if (asize - size < _POSIX2_LINE_MAX + 1) { 583 asize *= 2; 584 text = xmalloc(asize); 585 } 586 } 587 return (xrealloc(text, size + 1)); 588 } 589 590 /* 591 * Get an address and return a pointer to the first character after 592 * it. Fill the structure pointed to according to the address. 593 */ 594 static char * 595 compile_addr(p, a) 596 char *p; 597 struct s_addr *a; 598 { 599 char *end; 600 601 switch (*p) { 602 case '\\': /* Context address */ 603 ++p; 604 /* FALLTHROUGH */ 605 case '/': /* Context address */ 606 p = compile_re(p, &a->u.r); 607 if (p == NULL) 608 err(COMPILE, "unterminated regular expression"); 609 a->type = AT_RE; 610 return (p); 611 612 case '$': /* Last line */ 613 a->type = AT_LAST; 614 return (p + 1); 615 /* Line number */ 616 case '0': case '1': case '2': case '3': case '4': 617 case '5': case '6': case '7': case '8': case '9': 618 a->type = AT_LINE; 619 a->u.l = strtol(p, &end, 10); 620 return (end); 621 default: 622 err(COMPILE, "expected context address"); 623 return (NULL); 624 } 625 } 626 627 /* 628 * duptoeol -- 629 * Return a copy of all the characters up to \n or \0. 630 */ 631 static char * 632 duptoeol(s, ctype) 633 register char *s; 634 char *ctype; 635 { 636 size_t len; 637 int ws; 638 char *start; 639 640 ws = 0; 641 for (start = s; *s != '\0' && *s != '\n'; ++s) 642 ws = isspace(*s); 643 *s = '\0'; 644 if (ws) 645 err(WARNING, "whitespace after %s", ctype); 646 len = s - start + 1; 647 return (memmove(xmalloc(len), start, len)); 648 } 649 650 /* 651 * Convert goto label names to addresses, and count a and r commands, in 652 * the given subset of the script. Free the memory used by labels in b 653 * and t commands (but not by :). 654 * 655 * TODO: Remove } nodes 656 */ 657 static void 658 fixuplabel(cp, end) 659 struct s_command *cp, *end; 660 { 661 662 for (; cp != end; cp = cp->next) 663 switch (cp->code) { 664 case 'a': 665 case 'r': 666 appendnum++; 667 break; 668 case 'b': 669 case 't': 670 /* Resolve branch target. */ 671 if (cp->t == NULL) { 672 cp->u.c = NULL; 673 break; 674 } 675 if ((cp->u.c = findlabel(cp->t)) == NULL) 676 err(COMPILE2, "undefined label '%s'", cp->t); 677 free(cp->t); 678 break; 679 case '{': 680 /* Do interior commands. */ 681 fixuplabel(cp->u.c, cp->next); 682 break; 683 } 684 } 685 686 /* 687 * Associate the given command label for later lookup. 688 */ 689 static void 690 enterlabel(cp) 691 struct s_command *cp; 692 { 693 register struct labhash **lhp, *lh; 694 register u_char *p; 695 register u_int h, c; 696 697 for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++) 698 h = (h << 5) + h + c; 699 lhp = &labels[h & LHMASK]; 700 for (lh = *lhp; lh != NULL; lh = lh->lh_next) 701 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0) 702 err(COMPILE2, "duplicate label '%s'", cp->t); 703 lh = xmalloc(sizeof *lh); 704 lh->lh_next = *lhp; 705 lh->lh_hash = h; 706 lh->lh_cmd = cp; 707 lh->lh_ref = 0; 708 *lhp = lh; 709 } 710 711 /* 712 * Find the label contained in the command l in the command linked 713 * list cp. L is excluded from the search. Return NULL if not found. 714 */ 715 static struct s_command * 716 findlabel(name) 717 char *name; 718 { 719 register struct labhash *lh; 720 register u_char *p; 721 register u_int h, c; 722 723 for (h = 0, p = (u_char *)name; (c = *p) != 0; p++) 724 h = (h << 5) + h + c; 725 for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) { 726 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) { 727 lh->lh_ref = 1; 728 return (lh->lh_cmd); 729 } 730 } 731 return (NULL); 732 } 733 734 /* 735 * Warn about any unused labels. As a side effect, release the label hash 736 * table space. 737 */ 738 static void 739 uselabel() 740 { 741 register struct labhash *lh, *next; 742 register int i; 743 744 for (i = 0; i < LHSZ; i++) { 745 for (lh = labels[i]; lh != NULL; lh = next) { 746 next = lh->lh_next; 747 if (!lh->lh_ref) 748 err(WARNING, "unused label '%s'", 749 lh->lh_cmd->t); 750 free(lh); 751 } 752 } 753 } 754