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  * @(#)compile.c        8.1 (Berkeley) 6/6/93
  36  * $FreeBSD: head/usr.bin/sed/compile.c 361884 2020-06-07 04:32:38Z kevans $
  37  */
  38
  39 #include <sys/cdefs.h>
  40
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43
  44 #include <ctype.h>
  45 #include <err.h>
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #include <limits.h>
  49 #include <regex.h>
  50 #include <stdbool.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <wchar.h>
  55
  56 #include "defs.h"
  57 #include "extern.h"
  58
  59 #define LHSZ    128
  60 #define LHMASK  (LHSZ - 1)
  61 static struct labhash {
  62         struct  labhash *lh_next;
  63         u_int   lh_hash;
  64         struct  s_command *lh_cmd;
  65         int     lh_ref;
  66 } *labels[LHSZ];
  67
  68 static char      *compile_addr(char *, struct s_addr *);
  69 static char      *compile_ccl(char **, char *);
  70 static char      *compile_delimited(char *, char *, int);
  71 static char      *compile_flags(char *, struct s_subst *);
  72 static regex_t   *compile_re(char *, int);
  73 static char      *compile_subst(char *, struct s_subst *);
  74 static char      *compile_text(void);
  75 static char      *compile_tr(char *, struct s_tr **);
  76 static struct s_command
  77                 **compile_stream(struct s_command **);
  78 static char      *duptoeol(char *, const char *);
  79 static void       enterlabel(struct s_command *);
  80 static struct s_command
  81                  *findlabel(char *);
  82 static void       fixuplabel(struct s_command *, struct s_command *);
  83 static void       uselabel(void);
  84
  85 /*
  86  * Command specification.  This is used to drive the command parser.
  87  */
  88 struct s_format {
  89         char code;                              /* Command code */
  90         int naddr;                              /* Number of address args */
  91         enum e_args args;                       /* Argument type */
  92 };
  93
  94 static struct s_format cmd_fmts[] = {
  95         {'{', 2, GROUP},
  96         {'}', 0, ENDGROUP},
  97         {'a', 1, TEXT},
  98         {'b', 2, BRANCH},
  99         {'c', 2, TEXT},
 100         {'d', 2, EMPTY},
 101         {'D', 2, EMPTY},
 102         {'g', 2, EMPTY},
 103         {'G', 2, EMPTY},
 104         {'h', 2, EMPTY},
 105         {'H', 2, EMPTY},
 106         {'i', 1, TEXT},
 107         {'l', 2, EMPTY},
 108         {'n', 2, EMPTY},
 109         {'N', 2, EMPTY},
 110         {'p', 2, EMPTY},
 111         {'P', 2, EMPTY},
 112         {'q', 1, EMPTY},
 113         {'r', 1, RFILE},
 114         {'s', 2, SUBST},
 115         {'t', 2, BRANCH},
 116         {'w', 2, WFILE},
 117         {'x', 2, EMPTY},
 118         {'y', 2, TR},
 119         {'!', 2, NONSEL},
 120         {':', 0, LABEL},
 121         {'#', 0, COMMENT},
 122         {'=', 1, EMPTY},
 123         {'\0', 0, COMMENT},
 124 };
 125
 126 /* The compiled program. */
 127 struct s_command *prog;
 128
 129 /*
 130  * Compile the program into prog.
 131  * Initialise appends.
 132  */
 133 void
 134 compile(void)
 135 {
 136         *compile_stream(&prog) = NULL;
 137         fixuplabel(prog, NULL);
 138         uselabel();
 139         if (appendnum == 0)
 140                 appends = NULL;
 141         else if ((appends = malloc(sizeof(struct s_appends) * appendnum)) ==
 142             NULL)
 143                 err(1, "malloc");
 144         if ((match = malloc((maxnsub + 1) * sizeof(regmatch_t))) == NULL)
 145                 err(1, "malloc");
 146 }
 147
 148 #define EATSPACE() do {                                                 \
 149         if (p)                                                          \
 150                 while (*p && isspace((unsigned char)*p))                \
 151                         p++;                                            \
 152         } while (0)
 153
 154 static struct s_command **
 155 compile_stream(struct s_command **link)
 156 {
 157         char *p;
 158         static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */
 159         struct s_command *cmd, *cmd2, *stack;
 160         struct s_format *fp;
 161         char re[_POSIX2_LINE_MAX + 1];
 162         int naddr;                              /* Number of addresses */
 163
 164         stack = NULL;
 165         for (;;) {
 166                 if ((p = cu_fgets(lbuf, sizeof(lbuf), NULL)) == NULL) {
 167                         if (stack != NULL)
 168                                 errx(1, "%lu: %s: unexpected EOF (pending }'s)",
 169                                                         linenum, fname);
 170                         return (link);
 171                 }
 172
 173 semicolon:      EATSPACE();
 174                 if (p) {
 175                         if (*p == '#' || *p == '\0')
 176                                 continue;
 177                         else if (*p == ';') {
 178                                 p++;
 179                                 goto semicolon;
 180                         }
 181                 }
 182                 if ((*link = cmd = malloc(sizeof(struct s_command))) == NULL)
 183                         err(1, "malloc");
 184                 link = &cmd->next;
 185                 cmd->startline = cmd->nonsel = 0;
 186                 /* First parse the addresses */
 187                 naddr = 0;
 188
 189 /* Valid characters to start an address */
 190 #define addrchar(c)     (strchr("0123456789/\\$", (c)))
 191                 if (addrchar(*p)) {
 192                         naddr++;
 193                         if ((cmd->a1 = malloc(sizeof(struct s_addr))) == NULL)
 194                                 err(1, "malloc");
 195                         p = compile_addr(p, cmd->a1);
 196                         EATSPACE();                             /* EXTENSION */
 197                         if (*p == ',') {
 198                                 p++;
 199                                 EATSPACE();                     /* EXTENSION */
 200                                 naddr++;
 201                                 if ((cmd->a2 = malloc(sizeof(struct s_addr)))
 202                                     == NULL)
 203                                         err(1, "malloc");
 204                                 p = compile_addr(p, cmd->a2);
 205                                 EATSPACE();
 206                         } else
 207                                 cmd->a2 = NULL;
 208                 } else
 209                         cmd->a1 = cmd->a2 = NULL;
 210
 211 nonsel:         /* Now parse the command */
 212                 if (!*p)
 213                         errx(1, "%lu: %s: command expected", linenum, fname);
 214                 cmd->code = *p;
 215                 for (fp = cmd_fmts; fp->code; fp++)
 216                         if (fp->code == *p)
 217                                 break;
 218                 if (!fp->code)
 219                         errx(1, "%lu: %s: invalid command code %c", linenum, fname, *p);
 220                 if (naddr > fp->naddr)
 221                         errx(1,
 222                                 "%lu: %s: command %c expects up to %d address(es), found %d",
 223                                 linenum, fname, *p, fp->naddr, naddr);
 224                 switch (fp->args) {
 225                 case NONSEL:                    /* ! */
 226                         p++;
 227                         EATSPACE();
 228                         cmd->nonsel = 1;
 229                         goto nonsel;
 230                 case GROUP:                     /* { */
 231                         p++;
 232                         EATSPACE();
 233                         cmd->next = stack;
 234                         stack = cmd;
 235                         link = &cmd->u.c;
 236                         if (*p)
 237                                 goto semicolon;
 238                         break;
 239                 case ENDGROUP:
 240                         /*
 241                          * Short-circuit command processing, since end of
 242                          * group is really just a noop.
 243                          */
 244                         cmd->nonsel = 1;
 245                         if (stack == NULL)
 246                                 errx(1, "%lu: %s: unexpected }", linenum, fname);
 247                         cmd2 = stack;
 248                         stack = cmd2->next;
 249                         cmd2->next = cmd;
 250                         /*FALLTHROUGH*/
 251                 case EMPTY:             /* d D g G h H l n N p P q x = \0 */
 252                         p++;
 253                         EATSPACE();
 254                         if (*p == ';') {
 255                                 p++;
 256                                 link = &cmd->next;
 257                                 goto semicolon;
 258                         }
 259                         if (*p)
 260                                 errx(1, "%lu: %s: extra characters at the end of %c command",
 261                                                 linenum, fname, cmd->code);
 262                         break;
 263                 case TEXT:                      /* a c i */
 264                         p++;
 265                         EATSPACE();
 266                         if (*p != '\\')
 267                                 errx(1,
 268 "%lu: %s: command %c expects \\ followed by text", linenum, fname, cmd->code);
 269                         p++;
 270                         EATSPACE();
 271                         if (*p)
 272                                 errx(1,
 273                                 "%lu: %s: extra characters after \\ at the end of %c command",
 274                                 linenum, fname, cmd->code);
 275                         cmd->t = compile_text();
 276                         break;
 277                 case COMMENT:                   /* \0 # */
 278                         break;
 279                 case WFILE:                     /* w */
 280                         p++;
 281                         EATSPACE();
 282                         if (*p == '\0')
 283                                 errx(1, "%lu: %s: filename expected", linenum, fname);
 284                         cmd->t = duptoeol(p, "w command");
 285                         if (aflag)
 286                                 cmd->u.fd = -1;
 287                         else if ((cmd->u.fd = open(p,
 288                             O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
 289                             DEFFILEMODE)) == -1)
 290                                 err(1, "%s", p);
 291                         break;
 292                 case RFILE:                     /* r */
 293                         p++;
 294                         EATSPACE();
 295                         if (*p == '\0')
 296                                 errx(1, "%lu: %s: filename expected", linenum, fname);
 297                         else
 298                                 cmd->t = duptoeol(p, "read command");
 299                         break;
 300                 case BRANCH:                    /* b t */
 301                         p++;
 302                         EATSPACE();
 303                         if (*p == '\0')
 304                                 cmd->t = NULL;
 305                         else
 306                                 cmd->t = duptoeol(p, "branch");
 307                         break;
 308                 case LABEL:                     /* : */
 309                         p++;
 310                         EATSPACE();
 311                         cmd->t = duptoeol(p, "label");
 312                         if (strlen(p) == 0)
 313                                 errx(1, "%lu: %s: empty label", linenum, fname);
 314                         enterlabel(cmd);
 315                         break;
 316                 case SUBST:                     /* s */
 317                         p++;
 318                         if (*p == '\0' || *p == '\\')
 319                                 errx(1,
 320 "%lu: %s: substitute pattern can not be delimited by newline or backslash",
 321                                         linenum, fname);
 322                         if ((cmd->u.s = calloc(1, sizeof(struct s_subst))) == NULL)
 323                                 err(1, "malloc");
 324                         p = compile_delimited(p, re, 0);
 325                         if (p == NULL)
 326                                 errx(1,
 327                                 "%lu: %s: unterminated substitute pattern", linenum, fname);
 328
 329                         /* Compile RE with no case sensitivity temporarily */
 330                         if (*re == '\0')
 331                                 cmd->u.s->re = NULL;
 332                         else
 333                                 cmd->u.s->re = compile_re(re, 0);
 334                         --p;
 335                         p = compile_subst(p, cmd->u.s);
 336                         p = compile_flags(p, cmd->u.s);
 337
 338                         /* Recompile RE with case sensitivity from "I" flag if any */
 339                         if (*re == '\0')
 340                                 cmd->u.s->re = NULL;
 341                         else
 342                                 cmd->u.s->re = compile_re(re, cmd->u.s->icase);
 343                         EATSPACE();
 344                         if (*p == ';') {
 345                                 p++;
 346                                 link = &cmd->next;
 347                                 goto semicolon;
 348                         }
 349                         break;
 350                 case TR:                        /* y */
 351                         p++;
 352                         p = compile_tr(p, &cmd->u.y);
 353                         EATSPACE();
 354                         if (*p == ';') {
 355                                 p++;
 356                                 link = &cmd->next;
 357                                 goto semicolon;
 358                         }
 359                         if (*p)
 360                                 errx(1,
 361 "%lu: %s: extra text at the end of a transform command", linenum, fname);
 362                         break;
 363                 }
 364         }
 365 }
 366
 367 static int
 368 hex2char(const char *in, char *out, int len)
 369 {
 370         long ord;
 371         char *endptr, hexbuf[3];
 372
 373         hexbuf[0] = in[0];
 374         hexbuf[1] = len > 1 ? in[1] : '\0';
 375         hexbuf[2] = '\0';
 376
 377         errno = 0;
 378         ord = strtol(hexbuf, &endptr, 16);
 379         if (*endptr != '\0' || errno != 0)
 380                 return (ERANGE);
 381         *out = (char)ord;
 382         return (0);
 383 }
 384
 385 static bool
 386 hexdigit(char c)
 387 {
 388         int lc;
 389
 390         lc = tolower(c);
 391         return isdigit(lc) || (lc >= 'a' && lc <= 'f');
 392 }
 393
 394 static bool
 395 dohex(const char *in, char *out, int *len)
 396 {
 397         int tmplen;
 398
 399         if (!hexdigit(in[0]))
 400                 return (false);
 401         tmplen = 1;
 402         if (hexdigit(in[1]))
 403                 ++tmplen;
 404         if (hex2char(in, out, tmplen) == 0) {
 405                 *len = tmplen;
 406                 return (true);
 407         }
 408
 409         return (false);
 410 }
 411
 412 /*
 413  * Get a delimited string.  P points to the delimiter of the string; d points
 414  * to a buffer area.  Newline and delimiter escapes are processed; other
 415  * escapes are ignored.
 416  *
 417  * Returns a pointer to the first character after the final delimiter or NULL
 418  * in the case of a non-terminated string.  The character array d is filled
 419  * with the processed string.
 420  */
 421 static char *
 422 compile_delimited(char *p, char *d, int is_tr)
 423 {
 424         int hexlen;
 425         char c;
 426
 427         c = *p++;
 428         if (c == '\0')
 429                 return (NULL);
 430         else if (c == '\\')
 431                 errx(1, "%lu: %s: \\ can not be used as a string delimiter",
 432                                 linenum, fname);
 433         else if (c == '\n')
 434                 errx(1, "%lu: %s: newline can not be used as a string delimiter",
 435                                 linenum, fname);
 436         while (*p) {
 437                 if (*p == '[' && *p != c) {
 438                         if ((d = compile_ccl(&p, d)) == NULL)
 439                                 errx(1, "%lu: %s: unbalanced brackets ([])", linenum, fname);
 440                         continue;
 441                 } else if (*p == '\\' && p[1] == '[') {
 442                         *d++ = *p++;
 443                 } else if (*p == '\\' && p[1] == c) {
 444                         p++;
 445                 } else if (*p == '\\' &&
 446                     (p[1] == 'n' || p[1] == 'r' || p[1] == 't')) {
 447                         switch (p[1]) {
 448                         case 'n':
 449                                 *d++ = '\n';
 450                                 break;
 451                         case 'r':
 452                                 *d++ = '\r';
 453                                 break;
 454                         case 't':
 455                                 *d++ = '\t';
 456                                 break;
 457                         }
 458                         p += 2;
 459                         continue;
 460                 } else if (*p == '\\' && p[1] == 'x') {
 461                         if (dohex(&p[2], d, &hexlen)) {
 462                                 ++d;
 463                                 p += hexlen + 2;
 464                                 continue;
 465                         }
 466                 } else if (*p == '\\' && p[1] == '\\') {
 467                         if (is_tr)
 468                                 p++;
 469                         else
 470                                 *d++ = *p++;
 471                 } else if (*p == c) {
 472                         *d = '\0';
 473                         return (p + 1);
 474                 }
 475                 *d++ = *p++;
 476         }
 477         return (NULL);
 478 }
 479
 480
 481 /* compile_ccl: expand a POSIX character class */
 482 static char *
 483 compile_ccl(char **sp, char *t)
 484 {
 485         int c, d, hexlen;
 486         char *s = *sp;
 487
 488         *t++ = *s++;
 489         if (*s == '^')
 490                 *t++ = *s++;
 491         if (*s == ']')
 492                 *t++ = *s++;
 493         for (; *s && (*t = *s) != ']'; s++, t++) {
 494                 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) {
 495                         *++t = *++s, t++, s++;
 496                         for (c = *s; (*t = *s) != ']' || c != d; s++, t++)
 497                                 if ((c = *s) == '\0')
 498                                         return NULL;
 499                 } else if (*s == '\\') {
 500                         switch (s[1]) {
 501                         case 'n':
 502                                 *t = '\n';
 503                                 s++;
 504                                 break;
 505                         case 'r':
 506                                 *t = '\r';
 507                                 s++;
 508                                 break;
 509                         case 't':
 510                                 *t = '\t';
 511                                 s++;
 512                                 break;
 513                         case 'x':
 514                                 if (dohex(&s[2], t, &hexlen))
 515                                         s += hexlen + 1;
 516                                 break;
 517                         }
 518                 }
 519         }
 520         return (*s == ']') ? *sp = ++s, ++t : NULL;
 521 }
 522
 523 /*
 524  * Compiles the regular expression in RE and returns a pointer to the compiled
 525  * regular expression.
 526  * Cflags are passed to regcomp.
 527  */
 528 static regex_t *
 529 compile_re(char *re, int case_insensitive)
 530 {
 531         regex_t *rep;
 532         int eval, flags;
 533
 534
 535         flags = rflags;
 536         if (case_insensitive)
 537                 flags |= REG_ICASE;
 538         if ((rep = malloc(sizeof(regex_t))) == NULL)
 539                 err(1, "malloc");
 540         if ((eval = regcomp(rep, re, flags)) != 0)
 541                 errx(1, "%lu: %s: RE error: %s",
 542                                 linenum, fname, strregerror(eval, rep));
 543         if (maxnsub < rep->re_nsub)
 544                 maxnsub = rep->re_nsub;
 545         return (rep);
 546 }
 547
 548 /*
 549  * Compile the substitution string of a regular expression and set res to
 550  * point to a saved copy of it.  Nsub is the number of parenthesized regular
 551  * expressions.
 552  */
 553 static char *
 554 compile_subst(char *p, struct s_subst *s)
 555 {
 556         static char lbuf[_POSIX2_LINE_MAX + 1];
 557         int asize, hexlen, size;
 558         u_char ref;
 559         char c, *text, *op, *sp;
 560         int more = 1, sawesc = 0;
 561
 562         c = *p++;                       /* Terminator character */
 563         if (c == '\0')
 564                 return (NULL);
 565
 566         s->maxbref = 0;
 567         s->linenum = linenum;
 568         asize = 2 * _POSIX2_LINE_MAX + 1;
 569         if ((text = malloc(asize)) == NULL)
 570                 err(1, "malloc");
 571         size = 0;
 572         do {
 573                 op = sp = text + size;
 574                 for (; *p; p++) {
 575                         if (*p == '\\' || sawesc) {
 576                                 /*
 577                                  * If this is a continuation from the last
 578                                  * buffer, we won't have a character to
 579                                  * skip over.
 580                                  */
 581                                 if (sawesc)
 582                                         sawesc = 0;
 583                                 else
 584                                         p++;
 585
 586                                 if (*p == '\0') {
 587                                         /*
 588                                          * This escaped character is continued
 589                                          * in the next part of the line.  Note
 590                                          * this fact, then cause the loop to
 591                                          * exit w/ normal EOL case and reenter
 592                                          * above with the new buffer.
 593                                          */
 594                                         sawesc = 1;
 595                                         p--;
 596                                         continue;
 597                                 } else if (strchr("123456789", *p) != NULL) {
 598                                         *sp++ = '\\';
 599                                         ref = *p - '0';
 600                                         if (s->re != NULL &&
 601                                             ref > s->re->re_nsub)
 602                                                 errx(1, "%lu: %s: \\%c not defined in the RE",
 603                                                                 linenum, fname, *p);
 604                                         if (s->maxbref < ref)
 605                                                 s->maxbref = ref;
 606                                 } else {
 607                                         switch (*p) {
 608                                         case '&':
 609                                         case '\\':
 610                                                 *sp++ = '\\';
 611                                                 break;
 612                                         case 'n':
 613                                                 *p = '\n';
 614                                                 break;
 615                                         case 'r':
 616                                                 *p = '\r';
 617                                                 break;
 618                                         case 't':
 619                                                 *p = '\t';
 620                                                 break;
 621                                         case 'x':
 622 #define ADVANCE_N(s, n)                                 \
 623         do {                                            \
 624                 char *adv = (s);                        \
 625                 while (*(adv + (n) - 1) != '\0') {      \
 626                         *adv = *(adv + (n));            \
 627                         ++adv;                          \
 628                 }                                       \
 629                 *adv = '\0';                            \
 630         } while (0);
 631                                                 if (dohex(&p[1], p, &hexlen)) {
 632                                                         ADVANCE_N(p + 1,
 633                                                             hexlen);
 634                                                 }
 635                                                 break;
 636                                         }
 637                                 }
 638                         } else if (*p == c) {
 639                                 if (*++p == '\0' && more) {
 640                                         if (cu_fgets(lbuf, sizeof(lbuf), &more))
 641                                                 p = lbuf;
 642                                 }
 643                                 *sp++ = '\0';
 644                                 size += sp - op;
 645                                 if ((s->new = realloc(text, size)) == NULL)
 646                                         err(1, "realloc");
 647                                 return (p);
 648                         } else if (*p == '\n') {
 649                                 errx(1,
 650 "%lu: %s: unescaped newline inside substitute pattern", linenum, fname);
 651                                 /* NOTREACHED */
 652                         }
 653                         *sp++ = *p;
 654                 }
 655                 size += sp - op;
 656                 if (asize - size < _POSIX2_LINE_MAX + 1) {
 657                         asize *= 2;
 658                         if ((text = realloc(text, asize)) == NULL)
 659                                 err(1, "realloc");
 660                 }
 661         } while (cu_fgets(p = lbuf, sizeof(lbuf), &more) != NULL);
 662         errx(1, "%lu: %s: unterminated substitute in regular expression",
 663                         linenum, fname);
 664         /* NOTREACHED */
 665 }
 666
 667 /*
 668  * Compile the flags of the s command
 669  */
 670 static char *
 671 compile_flags(char *p, struct s_subst *s)
 672 {
 673         int gn;                 /* True if we have seen g or n */
 674         unsigned long nval;
 675         char wfile[_POSIX2_LINE_MAX + 1], *q, *eq;
 676
 677         s->n = 1;                               /* Default */
 678         s->p = 0;
 679         s->wfile = NULL;
 680         s->wfd = -1;
 681         s->icase = 0;
 682         for (gn = 0;;) {
 683                 EATSPACE();                     /* EXTENSION */
 684                 switch (*p) {
 685                 case 'g':
 686                         if (gn)
 687                                 errx(1,
 688 "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
 689                         gn = 1;
 690                         s->n = 0;
 691                         break;
 692                 case '\0':
 693                 case '\n':
 694                 case ';':
 695                         return (p);
 696                 case 'p':
 697                         s->p = 1;
 698                         break;
 699                 case 'i':
 700                 case 'I':
 701                         s->icase = 1;
 702                         break;
 703                 case '1': case '2': case '3':
 704                 case '4': case '5': case '6':
 705                 case '7': case '8': case '9':
 706                         if (gn)
 707                                 errx(1,
 708 "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
 709                         gn = 1;
 710                         errno = 0;
 711                         nval = strtol(p, &p, 10);
 712                         if (errno == ERANGE || nval > INT_MAX)
 713                                 errx(1,
 714 "%lu: %s: overflow in the 'N' substitute flag", linenum, fname);
 715                         s->n = nval;
 716                         p--;
 717                         break;
 718                 case 'w':
 719                         p++;
 720 #ifdef HISTORIC_PRACTICE
 721                         if (*p != ' ') {
 722                                 warnx("%lu: %s: space missing before w wfile", linenum, fname);
 723                                 return (p);
 724                         }
 725 #endif
 726                         EATSPACE();
 727                         q = wfile;
 728                         eq = wfile + sizeof(wfile) - 1;
 729                         while (*p) {
 730                                 if (*p == '\n')
 731                                         break;
 732                                 if (q >= eq)
 733                                         err(1, "wfile too long");
 734                                 *q++ = *p++;
 735                         }
 736                         *q = '\0';
 737                         if (q == wfile)
 738                                 errx(1, "%lu: %s: no wfile specified", linenum, fname);
 739                         s->wfile = strdup(wfile);
 740                         if (!aflag && (s->wfd = open(wfile,
 741                             O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
 742                             DEFFILEMODE)) == -1)
 743                                 err(1, "%s", wfile);
 744                         return (p);
 745                 default:
 746                         errx(1, "%lu: %s: bad flag in substitute command: '%c'",
 747                                         linenum, fname, *p);
 748                         break;
 749                 }
 750                 p++;
 751         }
 752 }
 753
 754 /*
 755  * Compile a translation set of strings into a lookup table.
 756  */
 757 static char *
 758 compile_tr(char *p, struct s_tr **py)
 759 {
 760         struct s_tr *y;
 761         int i;
 762         const char *op, *np;
 763         char old[_POSIX2_LINE_MAX + 1];
 764         char new[_POSIX2_LINE_MAX + 1];
 765         size_t oclen, oldlen, nclen, newlen;
 766         mbstate_t mbs1, mbs2;
 767
 768         if ((*py = y = malloc(sizeof(*y))) == NULL)
 769                 err(1, NULL);
 770         y->multis = NULL;
 771         y->nmultis = 0;
 772
 773         if (*p == '\0' || *p == '\\')
 774                 errx(1,
 775         "%lu: %s: transform pattern can not be delimited by newline or backslash",
 776                         linenum, fname);
 777         p = compile_delimited(p, old, 1);
 778         if (p == NULL)
 779                 errx(1, "%lu: %s: unterminated transform source string",
 780                                 linenum, fname);
 781         p = compile_delimited(p - 1, new, 1);
 782         if (p == NULL)
 783                 errx(1, "%lu: %s: unterminated transform target string",
 784                                 linenum, fname);
 785         EATSPACE();
 786         op = old;
 787         oldlen = mbsrtowcs(NULL, &op, 0, NULL);
 788         if (oldlen == (size_t)-1)
 789                 err(1, NULL);
 790         np = new;
 791         newlen = mbsrtowcs(NULL, &np, 0, NULL);
 792         if (newlen == (size_t)-1)
 793                 err(1, NULL);
 794         if (newlen != oldlen)
 795                 errx(1, "%lu: %s: transform strings are not the same length",
 796                                 linenum, fname);
 797         if (MB_CUR_MAX == 1) {
 798                 /*
 799                  * The single-byte encoding case is easy: generate a
 800                  * lookup table.
 801                  */
 802                 for (i = 0; i <= UCHAR_MAX; i++)
 803                         y->bytetab[i] = (char)i;
 804                 for (; *op; op++, np++)
 805                         y->bytetab[(u_char)*op] = *np;
 806         } else {
 807                 /*
 808                  * Multi-byte encoding case: generate a lookup table as
 809                  * above, but only for single-byte characters. The first
 810                  * bytes of multi-byte characters have their lookup table
 811                  * entries set to 0, which causes do_tr() to search through
 812                  * an auxiliary vector of multi-byte mappings.
 813                  */
 814                 memset(&mbs1, 0, sizeof(mbs1));
 815                 memset(&mbs2, 0, sizeof(mbs2));
 816                 for (i = 0; i <= UCHAR_MAX; i++)
 817                         y->bytetab[i] = (btowc(i) != WEOF) ? i : 0;
 818                 while (*op != '\0') {
 819                         oclen = mbrlen(op, MB_LEN_MAX, &mbs1);
 820                         if (oclen == (size_t)-1 || oclen == (size_t)-2)
 821                                 errc(1, EILSEQ, NULL);
 822                         nclen = mbrlen(np, MB_LEN_MAX, &mbs2);
 823                         if (nclen == (size_t)-1 || nclen == (size_t)-2)
 824                                 errc(1, EILSEQ, NULL);
 825                         if (oclen == 1 && nclen == 1)
 826                                 y->bytetab[(u_char)*op] = *np;
 827                         else {
 828                                 y->bytetab[(u_char)*op] = 0;
 829                                 y->multis = realloc(y->multis,
 830                                     (y->nmultis + 1) * sizeof(*y->multis));
 831                                 if (y->multis == NULL)
 832                                         err(1, NULL);
 833                                 i = y->nmultis++;
 834                                 y->multis[i].fromlen = oclen;
 835                                 memcpy(y->multis[i].from, op, oclen);
 836                                 y->multis[i].tolen = nclen;
 837                                 memcpy(y->multis[i].to, np, nclen);
 838                         }
 839                         op += oclen;
 840                         np += nclen;
 841                 }
 842         }
 843         return (p);
 844 }
 845
 846 /*
 847  * Compile the text following an a, c, or i command.
 848  */
 849 static char *
 850 compile_text(void)
 851 {
 852         int asize, esc_nl, size;
 853         char *text, *p, *op, *s;
 854         char lbuf[_POSIX2_LINE_MAX + 1];
 855
 856         asize = 2 * _POSIX2_LINE_MAX + 1;
 857         if ((text = malloc(asize)) == NULL)
 858                 err(1, "malloc");
 859         size = 0;
 860         while (cu_fgets(lbuf, sizeof(lbuf), NULL) != NULL) {
 861                 op = s = text + size;
 862                 p = lbuf;
 863 #ifdef LEGACY_BSDSED_COMPAT
 864                 EATSPACE();
 865 #endif
 866                 for (esc_nl = 0; *p != '\0'; p++) {
 867                         if (*p == '\\' && p[1] != '\0' && *++p == '\n')
 868                                 esc_nl = 1;
 869                         *s++ = *p;
 870                 }
 871                 size += s - op;
 872                 if (!esc_nl) {
 873                         *s = '\0';
 874                         break;
 875                 }
 876                 if (asize - size < _POSIX2_LINE_MAX + 1) {
 877                         asize *= 2;
 878                         if ((text = realloc(text, asize)) == NULL)
 879                                 err(1, "realloc");
 880                 }
 881         }
 882         text[size] = '\0';
 883         if ((p = realloc(text, size + 1)) == NULL)
 884                 err(1, "realloc");
 885         return (p);
 886 }
 887
 888 /*
 889  * Get an address and return a pointer to the first character after
 890  * it.  Fill the structure pointed to according to the address.
 891  */
 892 static char *
 893 compile_addr(char *p, struct s_addr *a)
 894 {
 895         char *end, re[_POSIX2_LINE_MAX + 1];
 896         int icase;
 897
 898         icase = 0;
 899
 900         a->type = 0;
 901         switch (*p) {
 902         case '\\':                              /* Context address */
 903                 ++p;
 904                 /* FALLTHROUGH */
 905         case '/':                               /* Context address */
 906                 p = compile_delimited(p, re, 0);
 907                 if (p == NULL)
 908                         errx(1, "%lu: %s: unterminated regular expression", linenum, fname);
 909                 /* Check for case insensitive regexp flag */
 910                 if (*p == 'I') {
 911                         icase = 1;
 912                         p++;
 913                 }
 914                 if (*re == '\0')
 915                         a->u.r = NULL;
 916                 else
 917                         a->u.r = compile_re(re, icase);
 918                 a->type = AT_RE;
 919                 return (p);
 920
 921         case '$':                               /* Last line */
 922                 a->type = AT_LAST;
 923                 return (p + 1);
 924
 925         case '+':                               /* Relative line number */
 926                 a->type = AT_RELLINE;
 927                 p++;
 928                 /* FALLTHROUGH */
 929                                                 /* Line number */
 930         case '0': case '1': case '2': case '3': case '4':
 931         case '5': case '6': case '7': case '8': case '9':
 932                 if (a->type == 0)
 933                         a->type = AT_LINE;
 934                 a->u.l = strtol(p, &end, 10);
 935                 return (end);
 936         default:
 937                 errx(1, "%lu: %s: expected context address", linenum, fname);
 938                 return (NULL);
 939         }
 940 }
 941
 942 /*
 943  * duptoeol --
 944  *      Return a copy of all the characters up to \n or \0.
 945  */
 946 static char *
 947 duptoeol(char *s, const char *ctype)
 948 {
 949         size_t len;
 950         int ws;
 951         char *p, *start;
 952
 953         ws = 0;
 954         for (start = s; *s != '\0' && *s != '\n'; ++s)
 955                 ws = isspace((unsigned char)*s);
 956         *s = '\0';
 957         if (ws)
 958                 warnx("%lu: %s: whitespace after %s", linenum, fname, ctype);
 959         len = s - start + 1;
 960         if ((p = malloc(len)) == NULL)
 961                 err(1, "malloc");
 962         return (memmove(p, start, len));
 963 }
 964
 965 /*
 966  * Convert goto label names to addresses, and count a and r commands, in
 967  * the given subset of the script.  Free the memory used by labels in b
 968  * and t commands (but not by :).
 969  *
 970  * TODO: Remove } nodes
 971  */
 972 static void
 973 fixuplabel(struct s_command *cp, struct s_command *end)
 974 {
 975
 976         for (; cp != end; cp = cp->next)
 977                 switch (cp->code) {
 978                 case 'a':
 979                 case 'r':
 980                         appendnum++;
 981                         break;
 982                 case 'b':
 983                 case 't':
 984                         /* Resolve branch target. */
 985                         if (cp->t == NULL) {
 986                                 cp->u.c = NULL;
 987                                 break;
 988                         }
 989                         if ((cp->u.c = findlabel(cp->t)) == NULL)
 990                                 errx(1, "%lu: %s: undefined label '%s'", linenum, fname, cp->t);
 991                         free(cp->t);
 992                         break;
 993                 case '{':
 994                         /* Do interior commands. */
 995                         fixuplabel(cp->u.c, cp->next);
 996                         break;
 997                 }
 998 }
 999
1000 /*
1001  * Associate the given command label for later lookup.
1002  */
1003 static void
1004 enterlabel(struct s_command *cp)
1005 {
1006         struct labhash **lhp, *lh;
1007         u_char *p;
1008         u_int h, c;
1009
1010         for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++)
1011                 h = (h << 5) + h + c;
1012         lhp = &labels[h & LHMASK];
1013         for (lh = *lhp; lh != NULL; lh = lh->lh_next)
1014                 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0)
1015                         errx(1, "%lu: %s: duplicate label '%s'", linenum, fname, cp->t);
1016         if ((lh = malloc(sizeof *lh)) == NULL)
1017                 err(1, "malloc");
1018         lh->lh_next = *lhp;
1019         lh->lh_hash = h;
1020         lh->lh_cmd = cp;
1021         lh->lh_ref = 0;
1022         *lhp = lh;
1023 }
1024
1025 /*
1026  * Find the label contained in the command l in the command linked
1027  * list cp.  L is excluded from the search.  Return NULL if not found.
1028  */
1029 static struct s_command *
1030 findlabel(char *name)
1031 {
1032         struct labhash *lh;
1033         u_char *p;
1034         u_int h, c;
1035
1036         for (h = 0, p = (u_char *)name; (c = *p) != 0; p++)
1037                 h = (h << 5) + h + c;
1038         for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) {
1039                 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) {
1040                         lh->lh_ref = 1;
1041                         return (lh->lh_cmd);
1042                 }
1043         }
1044         return (NULL);
1045 }
1046
1047 /*
1048  * Warn about any unused labels.  As a side effect, release the label hash
1049  * table space.
1050  */
1051 static void
1052 uselabel(void)
1053 {
1054         struct labhash *lh, *next;
1055         int i;
1056
1057         for (i = 0; i < LHSZ; i++) {
1058                 for (lh = labels[i]; lh != NULL; lh = next) {
1059                         next = lh->lh_next;
1060                         if (!lh->lh_ref)
1061                                 warnx("%lu: %s: unused label '%s'",
1062                                     linenum, fname, lh->lh_cmd->t);
1063                         free(lh);
1064                 }
1065         }
1066 }