usr.bin/sed/compile.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   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/cdefs.h>
  37
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40
  41 #include <ctype.h>
  42 #include <err.h>
  43 #include <errno.h>
  44 #include <fcntl.h>
  45 #include <limits.h>
  46 #include <regex.h>
  47 #include <stdbool.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <wchar.h>
  52
  53 #include "defs.h"
  54 #include "extern.h"
  55
  56 #define LHSZ    128
  57 #define LHMASK  (LHSZ - 1)
  58 static struct labhash {
  59         struct  labhash *lh_next;
  60         u_int   lh_hash;
  61         struct  s_command *lh_cmd;
  62         int     lh_ref;
  63 } *labels[LHSZ];
  64
  65 static char      *compile_addr(char *, struct s_addr *);
  66 static char      *compile_ccl(char **, char *);
  67 static char      *compile_delimited(char *, char *, int);
  68 static char      *compile_flags(char *, struct s_subst *);
  69 static regex_t   *compile_re(char *, int);
  70 static char      *compile_subst(char *, struct s_subst *);
  71 static char      *compile_text(void);
  72 static char      *compile_tr(char *, struct s_tr **);
  73 static struct s_command
  74                 **compile_stream(struct s_command **);
  75 static char      *duptoeol(char *, const char *);
  76 static void       enterlabel(struct s_command *);
  77 static struct s_command
  78                  *findlabel(char *);
  79 static void       fixuplabel(struct s_command *, struct s_command *);
  80 static void       uselabel(void);
  81
  82 /*
  83  * Command specification.  This is used to drive the command parser.
  84  */
  85 struct s_format {
  86         char code;                              /* Command code */
  87         int naddr;                              /* Number of address args */
  88         enum e_args args;                       /* Argument type */
  89 };
  90
  91 static struct s_format cmd_fmts[] = {
  92         {'{', 2, GROUP},
  93         {'}', 0, ENDGROUP},
  94         {'a', 1, TEXT},
  95         {'b', 2, BRANCH},
  96         {'c', 2, TEXT},
  97         {'d', 2, EMPTY},
  98         {'D', 2, EMPTY},
  99         {'g', 2, EMPTY},
 100         {'G', 2, EMPTY},
 101         {'h', 2, EMPTY},
 102         {'H', 2, EMPTY},
 103         {'i', 1, TEXT},
 104         {'l', 2, EMPTY},
 105         {'n', 2, EMPTY},
 106         {'N', 2, EMPTY},
 107         {'p', 2, EMPTY},
 108         {'P', 2, EMPTY},
 109         {'q', 1, EMPTY},
 110         {'r', 1, RFILE},
 111         {'s', 2, SUBST},
 112         {'t', 2, BRANCH},
 113         {'w', 2, WFILE},
 114         {'x', 2, EMPTY},
 115         {'y', 2, TR},
 116         {'!', 2, NONSEL},
 117         {':', 0, LABEL},
 118         {'#', 0, COMMENT},
 119         {'=', 1, EMPTY},
 120         {'\0', 0, COMMENT},
 121 };
 122
 123 /* The compiled program. */
 124 struct s_command *prog;
 125
 126 /*
 127  * Compile the program into prog.
 128  * Initialise appends.
 129  */
 130 void
 131 compile(void)
 132 {
 133         *compile_stream(&prog) = NULL;
 134         fixuplabel(prog, NULL);
 135         uselabel();
 136         if (appendnum == 0)
 137                 appends = NULL;
 138         else if ((appends = malloc(sizeof(struct s_appends) * appendnum)) ==
 139             NULL)
 140                 err(1, "malloc");
 141         if ((match = malloc((maxnsub + 1) * sizeof(regmatch_t))) == NULL)
 142                 err(1, "malloc");
 143 }
 144
 145 #define EATSPACE() do {                                                 \
 146         if (p)                                                          \
 147                 while (*p && isspace((unsigned char)*p))                \
 148                         p++;                                            \
 149         } while (0)
 150
 151 static struct s_command **
 152 compile_stream(struct s_command **link)
 153 {
 154         char *p;
 155         static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */
 156         struct s_command *cmd, *cmd2, *stack;
 157         struct s_format *fp;
 158         char re[_POSIX2_LINE_MAX + 1];
 159         int naddr;                              /* Number of addresses */
 160
 161         stack = NULL;
 162         for (;;) {
 163                 if ((p = cu_fgets(lbuf, sizeof(lbuf), NULL)) == NULL) {
 164                         if (stack != NULL)
 165                                 errx(1, "%lu: %s: unexpected EOF (pending }'s)",
 166                                                         linenum, fname);
 167                         return (link);
 168                 }
 169
 170 semicolon:      EATSPACE();
 171                 if (p) {
 172                         if (*p == '#' || *p == '\0')
 173                                 continue;
 174                         else if (*p == ';') {
 175                                 p++;
 176                                 goto semicolon;
 177                         }
 178                 }
 179                 if ((*link = cmd = malloc(sizeof(struct s_command))) == NULL)
 180                         err(1, "malloc");
 181                 link = &cmd->next;
 182                 cmd->startline = cmd->nonsel = 0;
 183                 /* First parse the addresses */
 184                 naddr = 0;
 185
 186 /* Valid characters to start an address */
 187 #define addrchar(c)     (strchr("0123456789/\\$", (c)))
 188                 if (addrchar(*p)) {
 189                         naddr++;
 190                         if ((cmd->a1 = malloc(sizeof(struct s_addr))) == NULL)
 191                                 err(1, "malloc");
 192                         p = compile_addr(p, cmd->a1);
 193                         EATSPACE();                             /* EXTENSION */
 194                         if (*p == ',') {
 195                                 p++;
 196                                 EATSPACE();                     /* EXTENSION */
 197                                 naddr++;
 198                                 if ((cmd->a2 = malloc(sizeof(struct s_addr)))
 199                                     == NULL)
 200                                         err(1, "malloc");
 201                                 p = compile_addr(p, cmd->a2);
 202                                 EATSPACE();
 203                         } else
 204                                 cmd->a2 = NULL;
 205                 } else
 206                         cmd->a1 = cmd->a2 = NULL;
 207
 208 nonsel:         /* Now parse the command */
 209                 if (!*p)
 210                         errx(1, "%lu: %s: command expected", linenum, fname);
 211                 cmd->code = *p;
 212                 for (fp = cmd_fmts; fp->code; fp++)
 213                         if (fp->code == *p)
 214                                 break;
 215                 if (!fp->code)
 216                         errx(1, "%lu: %s: invalid command code %c", linenum, fname, *p);
 217                 if (naddr > fp->naddr)
 218                         errx(1,
 219                                 "%lu: %s: command %c expects up to %d address(es), found %d",
 220                                 linenum, fname, *p, fp->naddr, naddr);
 221                 switch (fp->args) {
 222                 case NONSEL:                    /* ! */
 223                         p++;
 224                         EATSPACE();
 225                         cmd->nonsel = 1;
 226                         goto nonsel;
 227                 case GROUP:                     /* { */
 228                         p++;
 229                         EATSPACE();
 230                         cmd->next = stack;
 231                         stack = cmd;
 232                         link = &cmd->u.c;
 233                         if (*p)
 234                                 goto semicolon;
 235                         break;
 236                 case ENDGROUP:
 237                         /*
 238                          * Short-circuit command processing, since end of
 239                          * group is really just a noop.
 240                          */
 241                         cmd->nonsel = 1;
 242                         if (stack == NULL)
 243                                 errx(1, "%lu: %s: unexpected }", linenum, fname);
 244                         cmd2 = stack;
 245                         stack = cmd2->next;
 246                         cmd2->next = cmd;
 247                         /*FALLTHROUGH*/
 248                 case EMPTY:             /* d D g G h H l n N p P q x = \0 */
 249                         p++;
 250                         EATSPACE();
 251                         if (*p == ';') {
 252                                 p++;
 253                                 link = &cmd->next;
 254                                 goto semicolon;
 255                         }
 256                         if (*p)
 257                                 errx(1, "%lu: %s: extra characters at the end of %c command",
 258                                                 linenum, fname, cmd->code);
 259                         break;
 260                 case TEXT:                      /* a c i */
 261                         p++;
 262                         EATSPACE();
 263                         if (*p != '\\')
 264                                 errx(1,
 265 "%lu: %s: command %c expects \\ followed by text", linenum, fname, cmd->code);
 266                         p++;
 267                         EATSPACE();
 268                         if (*p)
 269                                 errx(1,
 270                                 "%lu: %s: extra characters after \\ at the end of %c command",
 271                                 linenum, fname, cmd->code);
 272                         cmd->t = compile_text();
 273                         break;
 274                 case COMMENT:                   /* \0 # */
 275                         break;
 276                 case WFILE:                     /* w */
 277                         p++;
 278                         EATSPACE();
 279                         if (*p == '\0')
 280                                 errx(1, "%lu: %s: filename expected", linenum, fname);
 281                         cmd->t = duptoeol(p, "w command");
 282                         if (aflag)
 283                                 cmd->u.fd = -1;
 284                         else if ((cmd->u.fd = open(p,
 285                             O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
 286                             DEFFILEMODE)) == -1)
 287                                 err(1, "%s", p);
 288                         break;
 289                 case RFILE:                     /* r */
 290                         p++;
 291                         EATSPACE();
 292                         if (*p == '\0')
 293                                 errx(1, "%lu: %s: filename expected", linenum, fname);
 294                         else
 295                                 cmd->t = duptoeol(p, "read command");
 296                         break;
 297                 case BRANCH:                    /* b t */
 298                         p++;
 299                         EATSPACE();
 300                         if (*p == '\0')
 301                                 cmd->t = NULL;
 302                         else
 303                                 cmd->t = duptoeol(p, "branch");
 304                         break;
 305                 case LABEL:                     /* : */
 306                         p++;
 307                         EATSPACE();
 308                         cmd->t = duptoeol(p, "label");
 309                         if (strlen(p) == 0)
 310                                 errx(1, "%lu: %s: empty label", linenum, fname);
 311                         enterlabel(cmd);
 312                         break;
 313                 case SUBST:                     /* s */
 314                         p++;
 315                         if (*p == '\0' || *p == '\\')
 316                                 errx(1,
 317 "%lu: %s: substitute pattern can not be delimited by newline or backslash",
 318                                         linenum, fname);
 319                         if ((cmd->u.s = calloc(1, sizeof(struct s_subst))) == NULL)
 320                                 err(1, "malloc");
 321                         p = compile_delimited(p, re, 0);
 322                         if (p == NULL)
 323                                 errx(1,
 324                                 "%lu: %s: unterminated substitute pattern", linenum, fname);
 325
 326                         /* Compile RE with no case sensitivity temporarily */
 327                         if (*re == '\0')
 328                                 cmd->u.s->re = NULL;
 329                         else
 330                                 cmd->u.s->re = compile_re(re, 0);
 331                         --p;
 332                         p = compile_subst(p, cmd->u.s);
 333                         p = compile_flags(p, cmd->u.s);
 334
 335                         /* Recompile RE with case sensitivity from "I" flag if any */
 336                         if (*re == '\0')
 337                                 cmd->u.s->re = NULL;
 338                         else
 339                                 cmd->u.s->re = compile_re(re, cmd->u.s->icase);
 340                         EATSPACE();
 341                         if (*p == ';') {
 342                                 p++;
 343                                 link = &cmd->next;
 344                                 goto semicolon;
 345                         }
 346                         break;
 347                 case TR:                        /* y */
 348                         p++;
 349                         p = compile_tr(p, &cmd->u.y);
 350                         EATSPACE();
 351                         if (*p == ';') {
 352                                 p++;
 353                                 link = &cmd->next;
 354                                 goto semicolon;
 355                         }
 356                         if (*p)
 357                                 errx(1,
 358 "%lu: %s: extra text at the end of a transform command", linenum, fname);
 359                         break;
 360                 }
 361         }
 362 }
 363
 364 static int
 365 hex2char(const char *in, char *out, int len)
 366 {
 367         long ord;
 368         char *endptr, hexbuf[3];
 369
 370         hexbuf[0] = in[0];
 371         hexbuf[1] = len > 1 ? in[1] : '\0';
 372         hexbuf[2] = '\0';
 373
 374         errno = 0;
 375         ord = strtol(hexbuf, &endptr, 16);
 376         if (*endptr != '\0' || errno != 0)
 377                 return (ERANGE);
 378         *out = (char)ord;
 379         return (0);
 380 }
 381
 382 static bool
 383 hexdigit(char c)
 384 {
 385         int lc;
 386
 387         lc = tolower(c);
 388         return isdigit(lc) || (lc >= 'a' && lc <= 'f');
 389 }
 390
 391 static bool
 392 dohex(const char *in, char *out, int *len)
 393 {
 394         int tmplen;
 395
 396         if (!hexdigit(in[0]))
 397                 return (false);
 398         tmplen = 1;
 399         if (hexdigit(in[1]))
 400                 ++tmplen;
 401         if (hex2char(in, out, tmplen) == 0) {
 402                 *len = tmplen;
 403                 return (true);
 404         }
 405
 406         return (false);
 407 }
 408
 409 /*
 410  * Get a delimited string.  P points to the delimiter of the string; d points
 411  * to a buffer area.  Newline and delimiter escapes are processed; other
 412  * escapes are ignored.
 413  *
 414  * Returns a pointer to the first character after the final delimiter or NULL
 415  * in the case of a non-terminated string.  The character array d is filled
 416  * with the processed string.
 417  */
 418 static char *
 419 compile_delimited(char *p, char *d, int is_tr)
 420 {
 421         int hexlen;
 422         char c;
 423
 424         c = *p++;
 425         if (c == '\0')
 426                 return (NULL);
 427         else if (c == '\\')
 428                 errx(1, "%lu: %s: \\ can not be used as a string delimiter",
 429                                 linenum, fname);
 430         else if (c == '\n')
 431                 errx(1, "%lu: %s: newline can not be used as a string delimiter",
 432                                 linenum, fname);
 433         while (*p) {
 434                 if (*p == '[' && *p != c) {
 435                         if (!is_tr) {
 436                                 if ((d = compile_ccl(&p, d)) == NULL) {
 437                                         errx(1,
 438                                             "%lu: %s: unbalanced brackets ([])",
 439                                             linenum, fname);
 440                                 }
 441                                 continue;
 442                         }
 443                 } else if (*p == '\\' && p[1] == '[') {
 444                         if (is_tr)
 445                                 p++;
 446                         else
 447                                 *d++ = *p++;
 448                 } else if (*p == '\\' && p[1] == c) {
 449                         p++;
 450                 } else if (*p == '\\' &&
 451                     (p[1] == 'n' || p[1] == 'r' || p[1] == 't')) {
 452                         switch (p[1]) {
 453                         case 'n':
 454                                 *d++ = '\n';
 455                                 break;
 456                         case 'r':
 457                                 *d++ = '\r';
 458                                 break;
 459                         case 't':
 460                                 *d++ = '\t';
 461                                 break;
 462                         }
 463                         p += 2;
 464                         continue;
 465                 } else if (*p == '\\' && p[1] == 'x') {
 466                         if (dohex(&p[2], d, &hexlen)) {
 467                                 ++d;
 468                                 p += hexlen + 2;
 469                                 continue;
 470                         }
 471                 } else if (*p == '\\' && p[1] == '\\') {
 472                         if (is_tr)
 473                                 p++;
 474                         else
 475                                 *d++ = *p++;
 476                 } else if (*p == c) {
 477                         *d = '\0';
 478                         return (p + 1);
 479                 }
 480                 *d++ = *p++;
 481         }
 482         return (NULL);
 483 }
 484
 485
 486 /* compile_ccl: expand a POSIX character class */
 487 static char *
 488 compile_ccl(char **sp, char *t)
 489 {
 490         int c, d, hexlen;
 491         char *s = *sp;
 492
 493         *t++ = *s++;
 494         if (*s == '^')
 495                 *t++ = *s++;
 496         if (*s == ']')
 497                 *t++ = *s++;
 498         for (; *s && (*t = *s) != ']'; s++, t++) {
 499                 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) {
 500                         *++t = *++s, t++, s++;
 501                         for (c = *s; (*t = *s) != ']' || c != d; s++, t++)
 502                                 if ((c = *s) == '\0')
 503                                         return NULL;
 504                 } else if (*s == '\\') {
 505                         switch (s[1]) {
 506                         case 'n':
 507                                 *t = '\n';
 508                                 s++;
 509                                 break;
 510                         case 'r':
 511                                 *t = '\r';
 512                                 s++;
 513                                 break;
 514                         case 't':
 515                                 *t = '\t';
 516                                 s++;
 517                                 break;
 518                         case 'x':
 519                                 if (dohex(&s[2], t, &hexlen))
 520                                         s += hexlen + 1;
 521                                 break;
 522                         }
 523                 }
 524         }
 525         return (*s == ']') ? *sp = ++s, ++t : NULL;
 526 }
 527
 528 /*
 529  * Compiles the regular expression in RE and returns a pointer to the compiled
 530  * regular expression.
 531  * Cflags are passed to regcomp.
 532  */
 533 static regex_t *
 534 compile_re(char *re, int case_insensitive)
 535 {
 536         regex_t *rep;
 537         int eval, flags;
 538
 539
 540         flags = rflags;
 541         if (case_insensitive)
 542                 flags |= REG_ICASE;
 543         if ((rep = malloc(sizeof(regex_t))) == NULL)
 544                 err(1, "malloc");
 545         if ((eval = regcomp(rep, re, flags)) != 0)
 546                 errx(1, "%lu: %s: RE error: %s",
 547                                 linenum, fname, strregerror(eval, rep));
 548         if (maxnsub < rep->re_nsub)
 549                 maxnsub = rep->re_nsub;
 550         return (rep);
 551 }
 552
 553 /*
 554  * Compile the substitution string of a regular expression and set res to
 555  * point to a saved copy of it.  Nsub is the number of parenthesized regular
 556  * expressions.
 557  */
 558 static char *
 559 compile_subst(char *p, struct s_subst *s)
 560 {
 561         static char lbuf[_POSIX2_LINE_MAX + 1];
 562         int asize, hexlen, size;
 563         u_char ref;
 564         char c, *text, *op, *sp;
 565         int more = 1, sawesc = 0;
 566
 567         c = *p++;                       /* Terminator character */
 568         if (c == '\0')
 569                 return (NULL);
 570
 571         s->maxbref = 0;
 572         s->linenum = linenum;
 573         asize = 2 * _POSIX2_LINE_MAX + 1;
 574         if ((text = malloc(asize)) == NULL)
 575                 err(1, "malloc");
 576         size = 0;
 577         do {
 578                 op = sp = text + size;
 579                 for (; *p; p++) {
 580                         if (*p == '\\' || sawesc) {
 581                                 /*
 582                                  * If this is a continuation from the last
 583                                  * buffer, we won't have a character to
 584                                  * skip over.
 585                                  */
 586                                 if (sawesc)
 587                                         sawesc = 0;
 588                                 else
 589                                         p++;
 590
 591                                 if (*p == '\0') {
 592                                         /*
 593                                          * This escaped character is continued
 594                                          * in the next part of the line.  Note
 595                                          * this fact, then cause the loop to
 596                                          * exit w/ normal EOL case and reenter
 597                                          * above with the new buffer.
 598                                          */
 599                                         sawesc = 1;
 600                                         p--;
 601                                         continue;
 602                                 } else if (strchr("123456789", *p) != NULL) {
 603                                         *sp++ = '\\';
 604                                         ref = *p - '0';
 605                                         if (s->re != NULL &&
 606                                             ref > s->re->re_nsub)
 607                                                 errx(1, "%lu: %s: \\%c not defined in the RE",
 608                                                                 linenum, fname, *p);
 609                                         if (s->maxbref < ref)
 610                                                 s->maxbref = ref;
 611                                 } else {
 612                                         switch (*p) {
 613                                         case '&':
 614                                         case '\\':
 615                                                 *sp++ = '\\';
 616                                                 break;
 617                                         case 'n':
 618                                                 *p = '\n';
 619                                                 break;
 620                                         case 'r':
 621                                                 *p = '\r';
 622                                                 break;
 623                                         case 't':
 624                                                 *p = '\t';
 625                                                 break;
 626                                         case 'x':
 627 #define ADVANCE_N(s, n)                                 \
 628         do {                                            \
 629                 char *adv = (s);                        \
 630                 while (*(adv + (n) - 1) != '\0') {      \
 631                         *adv = *(adv + (n));            \
 632                         ++adv;                          \
 633                 }                                       \
 634                 *adv = '\0';                            \
 635         } while (0);
 636                                                 if (dohex(&p[1], p, &hexlen)) {
 637                                                         ADVANCE_N(p + 1,
 638                                                             hexlen);
 639                                                 }
 640                                                 break;
 641                                         }
 642                                 }
 643                         } else if (*p == c) {
 644                                 if (*++p == '\0' && more) {
 645                                         if (cu_fgets(lbuf, sizeof(lbuf), &more))
 646                                                 p = lbuf;
 647                                 }
 648                                 *sp++ = '\0';
 649                                 size += sp - op;
 650                                 if ((s->new = realloc(text, size)) == NULL)
 651                                         err(1, "realloc");
 652                                 return (p);
 653                         } else if (*p == '\n') {
 654                                 errx(1,
 655 "%lu: %s: unescaped newline inside substitute pattern", linenum, fname);
 656                                 /* NOTREACHED */
 657                         }
 658                         *sp++ = *p;
 659                 }
 660                 size += sp - op;
 661                 if (asize - size < _POSIX2_LINE_MAX + 1) {
 662                         asize *= 2;
 663                         if ((text = realloc(text, asize)) == NULL)
 664                                 err(1, "realloc");
 665                 }
 666         } while (cu_fgets(p = lbuf, sizeof(lbuf), &more) != NULL);
 667         errx(1, "%lu: %s: unterminated substitute in regular expression",
 668                         linenum, fname);
 669         /* NOTREACHED */
 670 }
 671
 672 /*
 673  * Compile the flags of the s command
 674  */
 675 static char *
 676 compile_flags(char *p, struct s_subst *s)
 677 {
 678         int gn;                 /* True if we have seen g or n */
 679         unsigned long nval;
 680         char wfile[_POSIX2_LINE_MAX + 1], *q, *eq;
 681
 682         s->n = 1;                               /* Default */
 683         s->p = 0;
 684         s->wfile = NULL;
 685         s->wfd = -1;
 686         s->icase = 0;
 687         for (gn = 0;;) {
 688                 EATSPACE();                     /* EXTENSION */
 689                 switch (*p) {
 690                 case 'g':
 691                         if (gn)
 692                                 errx(1,
 693 "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
 694                         gn = 1;
 695                         s->n = 0;
 696                         break;
 697                 case '\0':
 698                 case '\n':
 699                 case ';':
 700                         return (p);
 701                 case 'p':
 702                         s->p = 1;
 703                         break;
 704                 case 'i':
 705                 case 'I':
 706                         s->icase = 1;
 707                         break;
 708                 case '1': case '2': case '3':
 709                 case '4': case '5': case '6':
 710                 case '7': case '8': case '9':
 711                         if (gn)
 712                                 errx(1,
 713 "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
 714                         gn = 1;
 715                         errno = 0;
 716                         nval = strtol(p, &p, 10);
 717                         if (errno == ERANGE || nval > INT_MAX)
 718                                 errx(1,
 719 "%lu: %s: overflow in the 'N' substitute flag", linenum, fname);
 720                         s->n = nval;
 721                         p--;
 722                         break;
 723                 case 'w':
 724                         p++;
 725 #ifdef HISTORIC_PRACTICE
 726                         if (*p != ' ') {
 727                                 warnx("%lu: %s: space missing before w wfile", linenum, fname);
 728                                 return (p);
 729                         }
 730 #endif
 731                         EATSPACE();
 732                         q = wfile;
 733                         eq = wfile + sizeof(wfile) - 1;
 734                         while (*p) {
 735                                 if (*p == '\n')
 736                                         break;
 737                                 if (q >= eq)
 738                                         err(1, "wfile too long");
 739                                 *q++ = *p++;
 740                         }
 741                         *q = '\0';
 742                         if (q == wfile)
 743                                 errx(1, "%lu: %s: no wfile specified", linenum, fname);
 744                         s->wfile = strdup(wfile);
 745                         if (!aflag && (s->wfd = open(wfile,
 746                             O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
 747                             DEFFILEMODE)) == -1)
 748                                 err(1, "%s", wfile);
 749                         return (p);
 750                 default:
 751                         errx(1, "%lu: %s: bad flag in substitute command: '%c'",
 752                                         linenum, fname, *p);
 753                         break;
 754                 }
 755                 p++;
 756         }
 757 }
 758
 759 /*
 760  * Compile a translation set of strings into a lookup table.
 761  */
 762 static char *
 763 compile_tr(char *p, struct s_tr **py)
 764 {
 765         struct s_tr *y;
 766         int i;
 767         const char *op, *np;
 768         char old[_POSIX2_LINE_MAX + 1];
 769         char new[_POSIX2_LINE_MAX + 1];
 770         size_t oclen, oldlen, nclen, newlen;
 771         mbstate_t mbs1, mbs2;
 772
 773         if ((*py = y = malloc(sizeof(*y))) == NULL)
 774                 err(1, NULL);
 775         y->multis = NULL;
 776         y->nmultis = 0;
 777
 778         if (*p == '\0' || *p == '\\')
 779                 errx(1,
 780         "%lu: %s: transform pattern can not be delimited by newline or backslash",
 781                         linenum, fname);
 782         p = compile_delimited(p, old, 1);
 783         if (p == NULL)
 784                 errx(1, "%lu: %s: unterminated transform source string",
 785                                 linenum, fname);
 786         p = compile_delimited(p - 1, new, 1);
 787         if (p == NULL)
 788                 errx(1, "%lu: %s: unterminated transform target string",
 789                                 linenum, fname);
 790         EATSPACE();
 791         op = old;
 792         oldlen = mbsrtowcs(NULL, &op, 0, NULL);
 793         if (oldlen == (size_t)-1)
 794                 err(1, NULL);
 795         np = new;
 796         newlen = mbsrtowcs(NULL, &np, 0, NULL);
 797         if (newlen == (size_t)-1)
 798                 err(1, NULL);
 799         if (newlen != oldlen)
 800                 errx(1, "%lu: %s: transform strings are not the same length",
 801                                 linenum, fname);
 802         if (MB_CUR_MAX == 1) {
 803                 /*
 804                  * The single-byte encoding case is easy: generate a
 805                  * lookup table.
 806                  */
 807                 for (i = 0; i <= UCHAR_MAX; i++)
 808                         y->bytetab[i] = (char)i;
 809                 for (; *op; op++, np++)
 810                         y->bytetab[(u_char)*op] = *np;
 811         } else {
 812                 /*
 813                  * Multi-byte encoding case: generate a lookup table as
 814                  * above, but only for single-byte characters. The first
 815                  * bytes of multi-byte characters have their lookup table
 816                  * entries set to 0, which causes do_tr() to search through
 817                  * an auxiliary vector of multi-byte mappings.
 818                  */
 819                 memset(&mbs1, 0, sizeof(mbs1));
 820                 memset(&mbs2, 0, sizeof(mbs2));
 821                 for (i = 0; i <= UCHAR_MAX; i++)
 822                         y->bytetab[i] = (btowc(i) != WEOF) ? i : 0;
 823                 while (*op != '\0') {
 824                         oclen = mbrlen(op, MB_LEN_MAX, &mbs1);
 825                         if (oclen == (size_t)-1 || oclen == (size_t)-2)
 826                                 errc(1, EILSEQ, NULL);
 827                         nclen = mbrlen(np, MB_LEN_MAX, &mbs2);
 828                         if (nclen == (size_t)-1 || nclen == (size_t)-2)
 829                                 errc(1, EILSEQ, NULL);
 830                         if (oclen == 1 && nclen == 1)
 831                                 y->bytetab[(u_char)*op] = *np;
 832                         else {
 833                                 y->bytetab[(u_char)*op] = 0;
 834                                 y->multis = realloc(y->multis,
 835                                     (y->nmultis + 1) * sizeof(*y->multis));
 836                                 if (y->multis == NULL)
 837                                         err(1, NULL);
 838                                 i = y->nmultis++;
 839                                 y->multis[i].fromlen = oclen;
 840                                 memcpy(y->multis[i].from, op, oclen);
 841                                 y->multis[i].tolen = nclen;
 842                                 memcpy(y->multis[i].to, np, nclen);
 843                         }
 844                         op += oclen;
 845                         np += nclen;
 846                 }
 847         }
 848         return (p);
 849 }
 850
 851 /*
 852  * Compile the text following an a, c, or i command.
 853  */
 854 static char *
 855 compile_text(void)
 856 {
 857         int asize, esc_nl, size;
 858         char *text, *p, *op, *s;
 859         char lbuf[_POSIX2_LINE_MAX + 1];
 860
 861         asize = 2 * _POSIX2_LINE_MAX + 1;
 862         if ((text = malloc(asize)) == NULL)
 863                 err(1, "malloc");
 864         size = 0;
 865         while (cu_fgets(lbuf, sizeof(lbuf), NULL) != NULL) {
 866                 op = s = text + size;
 867                 p = lbuf;
 868 #ifdef LEGACY_BSDSED_COMPAT
 869                 EATSPACE();
 870 #endif
 871                 for (esc_nl = 0; *p != '\0'; p++) {
 872                         if (*p == '\\' && p[1] != '\0' && *++p == '\n')
 873                                 esc_nl = 1;
 874                         *s++ = *p;
 875                 }
 876                 size += s - op;
 877                 if (!esc_nl) {
 878                         *s = '\0';
 879                         break;
 880                 }
 881                 if (asize - size < _POSIX2_LINE_MAX + 1) {
 882                         asize *= 2;
 883                         if ((text = realloc(text, asize)) == NULL)
 884                                 err(1, "realloc");
 885                 }
 886         }
 887         text[size] = '\0';
 888         if ((p = realloc(text, size + 1)) == NULL)
 889                 err(1, "realloc");
 890         return (p);
 891 }
 892
 893 /*
 894  * Get an address and return a pointer to the first character after
 895  * it.  Fill the structure pointed to according to the address.
 896  */
 897 static char *
 898 compile_addr(char *p, struct s_addr *a)
 899 {
 900         char *end, re[_POSIX2_LINE_MAX + 1];
 901         int icase;
 902
 903         icase = 0;
 904
 905         a->type = 0;
 906         switch (*p) {
 907         case '\\':                              /* Context address */
 908                 ++p;
 909                 /* FALLTHROUGH */
 910         case '/':                               /* Context address */
 911                 p = compile_delimited(p, re, 0);
 912                 if (p == NULL)
 913                         errx(1, "%lu: %s: unterminated regular expression", linenum, fname);
 914                 /* Check for case insensitive regexp flag */
 915                 if (*p == 'I') {
 916                         icase = 1;
 917                         p++;
 918                 }
 919                 if (*re == '\0')
 920                         a->u.r = NULL;
 921                 else
 922                         a->u.r = compile_re(re, icase);
 923                 a->type = AT_RE;
 924                 return (p);
 925
 926         case '$':                               /* Last line */
 927                 a->type = AT_LAST;
 928                 return (p + 1);
 929
 930         case '+':                               /* Relative line number */
 931                 a->type = AT_RELLINE;
 932                 p++;
 933                 /* FALLTHROUGH */
 934                                                 /* Line number */
 935         case '0': case '1': case '2': case '3': case '4':
 936         case '5': case '6': case '7': case '8': case '9':
 937                 if (a->type == 0)
 938                         a->type = AT_LINE;
 939                 a->u.l = strtol(p, &end, 10);
 940                 return (end);
 941         default:
 942                 errx(1, "%lu: %s: expected context address", linenum, fname);
 943                 return (NULL);
 944         }
 945 }
 946
 947 /*
 948  * duptoeol --
 949  *      Return a copy of all the characters up to \n or \0.
 950  */
 951 static char *
 952 duptoeol(char *s, const char *ctype)
 953 {
 954         size_t len;
 955         int ws;
 956         char *p, *start;
 957
 958         ws = 0;
 959         for (start = s; *s != '\0' && *s != '\n'; ++s)
 960                 ws = isspace((unsigned char)*s);
 961         *s = '\0';
 962         if (ws)
 963                 warnx("%lu: %s: whitespace after %s", linenum, fname, ctype);
 964         len = s - start + 1;
 965         if ((p = malloc(len)) == NULL)
 966                 err(1, "malloc");
 967         return (memmove(p, start, len));
 968 }
 969
 970 /*
 971  * Convert goto label names to addresses, and count a and r commands, in
 972  * the given subset of the script.  Free the memory used by labels in b
 973  * and t commands (but not by :).
 974  *
 975  * TODO: Remove } nodes
 976  */
 977 static void
 978 fixuplabel(struct s_command *cp, struct s_command *end)
 979 {
 980
 981         for (; cp != end; cp = cp->next)
 982                 switch (cp->code) {
 983                 case 'a':
 984                 case 'r':
 985                         appendnum++;
 986                         break;
 987                 case 'b':
 988                 case 't':
 989                         /* Resolve branch target. */
 990                         if (cp->t == NULL) {
 991                                 cp->u.c = NULL;
 992                                 break;
 993                         }
 994                         if ((cp->u.c = findlabel(cp->t)) == NULL)
 995                                 errx(1, "%lu: %s: undefined label '%s'", linenum, fname, cp->t);
 996                         free(cp->t);
 997                         break;
 998                 case '{':
 999                         /* Do interior commands. */
1000                         fixuplabel(cp->u.c, cp->next);
1001                         break;
1002                 }
1003 }
1004
1005 /*
1006  * Associate the given command label for later lookup.
1007  */
1008 static void
1009 enterlabel(struct s_command *cp)
1010 {
1011         struct labhash **lhp, *lh;
1012         u_char *p;
1013         u_int h, c;
1014
1015         for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++)
1016                 h = (h << 5) + h + c;
1017         lhp = &labels[h & LHMASK];
1018         for (lh = *lhp; lh != NULL; lh = lh->lh_next)
1019                 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0)
1020                         errx(1, "%lu: %s: duplicate label '%s'", linenum, fname, cp->t);
1021         if ((lh = malloc(sizeof *lh)) == NULL)
1022                 err(1, "malloc");
1023         lh->lh_next = *lhp;
1024         lh->lh_hash = h;
1025         lh->lh_cmd = cp;
1026         lh->lh_ref = 0;
1027         *lhp = lh;
1028 }
1029
1030 /*
1031  * Find the label contained in the command l in the command linked
1032  * list cp.  L is excluded from the search.  Return NULL if not found.
1033  */
1034 static struct s_command *
1035 findlabel(char *name)
1036 {
1037         struct labhash *lh;
1038         u_char *p;
1039         u_int h, c;
1040
1041         for (h = 0, p = (u_char *)name; (c = *p) != 0; p++)
1042                 h = (h << 5) + h + c;
1043         for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) {
1044                 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) {
1045                         lh->lh_ref = 1;
1046                         return (lh->lh_cmd);
1047                 }
1048         }
1049         return (NULL);
1050 }
1051
1052 /*
1053  * Warn about any unused labels.  As a side effect, release the label hash
1054  * table space.
1055  */
1056 static void
1057 uselabel(void)
1058 {
1059         struct labhash *lh, *next;
1060         int i;
1061
1062         for (i = 0; i < LHSZ; i++) {
1063                 for (lh = labels[i]; lh != NULL; lh = next) {
1064                         next = lh->lh_next;
1065                         if (!lh->lh_ref)
1066                                 warnx("%lu: %s: unused label '%s'",
1067                                     linenum, fname, lh->lh_cmd->t);
1068                         free(lh);
1069                 }
1070         }
1071 }