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 __FBSDID("$FreeBSD$");
  38
  39 #ifndef lint
  40 static const char sccsid[] = "@(#)compile.c     8.1 (Berkeley) 6/6/93";
  41 #endif
  42
  43 #include <sys/types.h>
  44 #include <sys/stat.h>
  45
  46 #include <ctype.h>
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <fcntl.h>
  50 #include <limits.h>
  51 #include <regex.h>
  52 #include <stdbool.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <string.h>
  56 #include <wchar.h>
  57
  58 #include "defs.h"
  59 #include "extern.h"
  60
  61 #define LHSZ    128
  62 #define LHMASK  (LHSZ - 1)
  63 static struct labhash {
  64         struct  labhash *lh_next;
  65         u_int   lh_hash;
  66         struct  s_command *lh_cmd;
  67         int     lh_ref;
  68 } *labels[LHSZ];
  69
  70 static char      *compile_addr(char *, struct s_addr *);
  71 static char      *compile_ccl(char **, char *);
  72 static char      *compile_delimited(char *, char *, int);
  73 static char      *compile_flags(char *, struct s_subst *);
  74 static regex_t   *compile_re(char *, int);
  75 static char      *compile_subst(char *, struct s_subst *);
  76 static char      *compile_text(void);
  77 static char      *compile_tr(char *, struct s_tr **);
  78 static struct s_command
  79                 **compile_stream(struct s_command **);
  80 static char      *duptoeol(char *, const char *);
  81 static void       enterlabel(struct s_command *);
  82 static struct s_command
  83                  *findlabel(char *);
  84 static void       fixuplabel(struct s_command *, struct s_command *);
  85 static void       uselabel(void);
  86
  87 /*
  88  * Command specification.  This is used to drive the command parser.
  89  */
  90 struct s_format {
  91         char code;                              /* Command code */
  92         int naddr;                              /* Number of address args */
  93         enum e_args args;                       /* Argument type */
  94 };
  95
  96 static struct s_format cmd_fmts[] = {
  97         {'{', 2, GROUP},
  98         {'}', 0, ENDGROUP},
  99         {'a', 1, TEXT},
 100         {'b', 2, BRANCH},
 101         {'c', 2, TEXT},
 102         {'d', 2, EMPTY},
 103         {'D', 2, EMPTY},
 104         {'g', 2, EMPTY},
 105         {'G', 2, EMPTY},
 106         {'h', 2, EMPTY},
 107         {'H', 2, EMPTY},
 108         {'i', 1, TEXT},
 109         {'l', 2, EMPTY},
 110         {'n', 2, EMPTY},
 111         {'N', 2, EMPTY},
 112         {'p', 2, EMPTY},
 113         {'P', 2, EMPTY},
 114         {'q', 1, EMPTY},
 115         {'r', 1, RFILE},
 116         {'s', 2, SUBST},
 117         {'t', 2, BRANCH},
 118         {'w', 2, WFILE},
 119         {'x', 2, EMPTY},
 120         {'y', 2, TR},
 121         {'!', 2, NONSEL},
 122         {':', 0, LABEL},
 123         {'#', 0, COMMENT},
 124         {'=', 1, EMPTY},
 125         {'\0', 0, COMMENT},
 126 };
 127
 128 /* The compiled program. */
 129 struct s_command *prog;
 130
 131 /*
 132  * Compile the program into prog.
 133  * Initialise appends.
 134  */
 135 void
 136 compile(void)
 137 {
 138         *compile_stream(&prog) = NULL;
 139         fixuplabel(prog, NULL);
 140         uselabel();
 141         if (appendnum == 0)
 142                 appends = NULL;
 143         else if ((appends = malloc(sizeof(struct s_appends) * appendnum)) ==
 144             NULL)
 145                 err(1, "malloc");
 146         if ((match = malloc((maxnsub + 1) * sizeof(regmatch_t))) == NULL)
 147                 err(1, "malloc");
 148 }
 149
 150 #define EATSPACE() do {                                                 \
 151         if (p)                                                          \
 152                 while (*p && isspace((unsigned char)*p))                \
 153                         p++;                                            \
 154         } while (0)
 155
 156 static struct s_command **
 157 compile_stream(struct s_command **link)
 158 {
 159         char *p;
 160         static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */
 161         struct s_command *cmd, *cmd2, *stack;
 162         struct s_format *fp;
 163         char re[_POSIX2_LINE_MAX + 1];
 164         int naddr;                              /* Number of addresses */
 165
 166         stack = NULL;
 167         for (;;) {
 168                 if ((p = cu_fgets(lbuf, sizeof(lbuf), NULL)) == NULL) {
 169                         if (stack != NULL)
 170                                 errx(1, "%lu: %s: unexpected EOF (pending }'s)",
 171                                                         linenum, fname);
 172                         return (link);
 173                 }
 174
 175 semicolon:      EATSPACE();
 176                 if (p) {
 177                         if (*p == '#' || *p == '\0')
 178                                 continue;
 179                         else if (*p == ';') {
 180                                 p++;
 181                                 goto semicolon;
 182                         }
 183                 }
 184                 if ((*link = cmd = malloc(sizeof(struct s_command))) == NULL)
 185                         err(1, "malloc");
 186                 link = &cmd->next;
 187                 cmd->startline = cmd->nonsel = 0;
 188                 /* First parse the addresses */
 189                 naddr = 0;
 190
 191 /* Valid characters to start an address */
 192 #define addrchar(c)     (strchr("0123456789/\\$", (c)))
 193                 if (addrchar(*p)) {
 194                         naddr++;
 195                         if ((cmd->a1 = malloc(sizeof(struct s_addr))) == NULL)
 196                                 err(1, "malloc");
 197                         p = compile_addr(p, cmd->a1);
 198                         EATSPACE();                             /* EXTENSION */
 199                         if (*p == ',') {
 200                                 p++;
 201                                 EATSPACE();                     /* EXTENSION */
 202                                 naddr++;
 203                                 if ((cmd->a2 = malloc(sizeof(struct s_addr)))
 204                                     == NULL)
 205                                         err(1, "malloc");
 206                                 p = compile_addr(p, cmd->a2);
 207                                 EATSPACE();
 208                         } else
 209                                 cmd->a2 = NULL;
 210                 } else
 211                         cmd->a1 = cmd->a2 = NULL;
 212
 213 nonsel:         /* Now parse the command */
 214                 if (!*p)
 215                         errx(1, "%lu: %s: command expected", linenum, fname);
 216                 cmd->code = *p;
 217                 for (fp = cmd_fmts; fp->code; fp++)
 218                         if (fp->code == *p)
 219                                 break;
 220                 if (!fp->code)
 221                         errx(1, "%lu: %s: invalid command code %c", linenum, fname, *p);
 222                 if (naddr > fp->naddr)
 223                         errx(1,
 224                                 "%lu: %s: command %c expects up to %d address(es), found %d",
 225                                 linenum, fname, *p, fp->naddr, naddr);
 226                 switch (fp->args) {
 227                 case NONSEL:                    /* ! */
 228                         p++;
 229                         EATSPACE();
 230                         cmd->nonsel = 1;
 231                         goto nonsel;
 232                 case GROUP:                     /* { */
 233                         p++;
 234                         EATSPACE();
 235                         cmd->next = stack;
 236                         stack = cmd;
 237                         link = &cmd->u.c;
 238                         if (*p)
 239                                 goto semicolon;
 240                         break;
 241                 case ENDGROUP:
 242                         /*
 243                          * Short-circuit command processing, since end of
 244                          * group is really just a noop.
 245                          */
 246                         cmd->nonsel = 1;
 247                         if (stack == NULL)
 248                                 errx(1, "%lu: %s: unexpected }", linenum, fname);
 249                         cmd2 = stack;
 250                         stack = cmd2->next;
 251                         cmd2->next = cmd;
 252                         /*FALLTHROUGH*/
 253                 case EMPTY:             /* d D g G h H l n N p P q x = \0 */
 254                         p++;
 255                         EATSPACE();
 256                         if (*p == ';') {
 257                                 p++;
 258                                 link = &cmd->next;
 259                                 goto semicolon;
 260                         }
 261                         if (*p)
 262                                 errx(1, "%lu: %s: extra characters at the end of %c command",
 263                                                 linenum, fname, cmd->code);
 264                         break;
 265                 case TEXT:                      /* a c i */
 266                         p++;
 267                         EATSPACE();
 268                         if (*p != '\\')
 269                                 errx(1,
 270 "%lu: %s: command %c expects \\ followed by text", linenum, fname, cmd->code);
 271                         p++;
 272                         EATSPACE();
 273                         if (*p)
 274                                 errx(1,
 275                                 "%lu: %s: extra characters after \\ at the end of %c command",
 276                                 linenum, fname, cmd->code);
 277                         cmd->t = compile_text();
 278                         break;
 279                 case COMMENT:                   /* \0 # */
 280                         break;
 281                 case WFILE:                     /* w */
 282                         p++;
 283                         EATSPACE();
 284                         if (*p == '\0')
 285                                 errx(1, "%lu: %s: filename expected", linenum, fname);
 286                         cmd->t = duptoeol(p, "w command");
 287                         if (aflag)
 288                                 cmd->u.fd = -1;
 289                         else if ((cmd->u.fd = open(p,
 290                             O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
 291                             DEFFILEMODE)) == -1)
 292                                 err(1, "%s", p);
 293                         break;
 294                 case RFILE:                     /* r */
 295                         p++;
 296                         EATSPACE();
 297                         if (*p == '\0')
 298                                 errx(1, "%lu: %s: filename expected", linenum, fname);
 299                         else
 300                                 cmd->t = duptoeol(p, "read command");
 301                         break;
 302                 case BRANCH:                    /* b t */
 303                         p++;
 304                         EATSPACE();
 305                         if (*p == '\0')
 306                                 cmd->t = NULL;
 307                         else
 308                                 cmd->t = duptoeol(p, "branch");
 309                         break;
 310                 case LABEL:                     /* : */
 311                         p++;
 312                         EATSPACE();
 313                         cmd->t = duptoeol(p, "label");
 314                         if (strlen(p) == 0)
 315                                 errx(1, "%lu: %s: empty label", linenum, fname);
 316                         enterlabel(cmd);
 317                         break;
 318                 case SUBST:                     /* s */
 319                         p++;
 320                         if (*p == '\0' || *p == '\\')
 321                                 errx(1,
 322 "%lu: %s: substitute pattern can not be delimited by newline or backslash",
 323                                         linenum, fname);
 324                         if ((cmd->u.s = calloc(1, sizeof(struct s_subst))) == NULL)
 325                                 err(1, "malloc");
 326                         p = compile_delimited(p, re, 0);
 327                         if (p == NULL)
 328                                 errx(1,
 329                                 "%lu: %s: unterminated substitute pattern", linenum, fname);
 330
 331                         /* Compile RE with no case sensitivity temporarily */
 332                         if (*re == '\0')
 333                                 cmd->u.s->re = NULL;
 334                         else
 335                                 cmd->u.s->re = compile_re(re, 0);
 336                         --p;
 337                         p = compile_subst(p, cmd->u.s);
 338                         p = compile_flags(p, cmd->u.s);
 339
 340                         /* Recompile RE with case sensitivity from "I" flag if any */
 341                         if (*re == '\0')
 342                                 cmd->u.s->re = NULL;
 343                         else
 344                                 cmd->u.s->re = compile_re(re, cmd->u.s->icase);
 345                         EATSPACE();
 346                         if (*p == ';') {
 347                                 p++;
 348                                 link = &cmd->next;
 349                                 goto semicolon;
 350                         }
 351                         break;
 352                 case TR:                        /* y */
 353                         p++;
 354                         p = compile_tr(p, &cmd->u.y);
 355                         EATSPACE();
 356                         if (*p == ';') {
 357                                 p++;
 358                                 link = &cmd->next;
 359                                 goto semicolon;
 360                         }
 361                         if (*p)
 362                                 errx(1,
 363 "%lu: %s: extra text at the end of a transform command", linenum, fname);
 364                         break;
 365                 }
 366         }
 367 }
 368
 369 static int
 370 hex2char(const char *in, char *out, int len)
 371 {
 372         long ord;
 373         char *endptr, hexbuf[3];
 374
 375         hexbuf[0] = in[0];
 376         hexbuf[1] = len > 1 ? in[1] : '\0';
 377         hexbuf[2] = '\0';
 378
 379         errno = 0;
 380         ord = strtol(hexbuf, &endptr, 16);
 381         if (*endptr != '\0' || errno != 0)
 382                 return (ERANGE);
 383         *out = (char)ord;
 384         return (0);
 385 }
 386
 387 static bool
 388 hexdigit(char c)
 389 {
 390         int lc;
 391
 392         lc = tolower(c);
 393         return isdigit(lc) || (lc >= 'a' && lc <= 'f');
 394 }
 395
 396 static bool
 397 dohex(const char *in, char *out, int *len)
 398 {
 399         int tmplen;
 400
 401         if (!hexdigit(in[0]))
 402                 return (false);
 403         tmplen = 1;
 404         if (hexdigit(in[1]))
 405                 ++tmplen;
 406         if (hex2char(in, out, tmplen) == 0) {
 407                 *len = tmplen;
 408                 return (true);
 409         }
 410
 411         return (false);
 412 }
 413
 414 /*
 415  * Get a delimited string.  P points to the delimiter of the string; d points
 416  * to a buffer area.  Newline and delimiter escapes are processed; other
 417  * escapes are ignored.
 418  *
 419  * Returns a pointer to the first character after the final delimiter or NULL
 420  * in the case of a non-terminated string.  The character array d is filled
 421  * with the processed string.
 422  */
 423 static char *
 424 compile_delimited(char *p, char *d, int is_tr)
 425 {
 426         int hexlen;
 427         char c;
 428
 429         c = *p++;
 430         if (c == '\0')
 431                 return (NULL);
 432         else if (c == '\\')
 433                 errx(1, "%lu: %s: \\ can not be used as a string delimiter",
 434                                 linenum, fname);
 435         else if (c == '\n')
 436                 errx(1, "%lu: %s: newline can not be used as a string delimiter",
 437                                 linenum, fname);
 438         while (*p) {
 439                 if (*p == '[' && *p != c) {
 440                         if (!is_tr) {
 441                                 if ((d = compile_ccl(&p, d)) == NULL) {
 442                                         errx(1,
 443                                             "%lu: %s: unbalanced brackets ([])",
 444                                             linenum, fname);
 445                                 }
 446                                 continue;
 447                         }
 448                 } else if (*p == '\\' && p[1] == '[') {
 449                         if (is_tr)
 450                                 p++;
 451                         else
 452                                 *d++ = *p++;
 453                 } else if (*p == '\\' && p[1] == c) {
 454                         p++;
 455                 } else if (*p == '\\' &&
 456                     (p[1] == 'n' || p[1] == 'r' || p[1] == 't')) {
 457                         switch (p[1]) {
 458                         case 'n':
 459                                 *d++ = '\n';
 460                                 break;
 461                         case 'r':
 462                                 *d++ = '\r';
 463                                 break;
 464                         case 't':
 465                                 *d++ = '\t';
 466                                 break;
 467                         }
 468                         p += 2;
 469                         continue;
 470                 } else if (*p == '\\' && p[1] == 'x') {
 471                         if (dohex(&p[2], d, &hexlen)) {
 472                                 ++d;
 473                                 p += hexlen + 2;
 474                                 continue;
 475                         }
 476                 } else if (*p == '\\' && p[1] == '\\') {
 477                         if (is_tr)
 478                                 p++;
 479                         else
 480                                 *d++ = *p++;
 481                 } else if (*p == c) {
 482                         *d = '\0';
 483                         return (p + 1);
 484                 }
 485                 *d++ = *p++;
 486         }
 487         return (NULL);
 488 }
 489
 490
 491 /* compile_ccl: expand a POSIX character class */
 492 static char *
 493 compile_ccl(char **sp, char *t)
 494 {
 495         int c, d, hexlen;
 496         char *s = *sp;
 497
 498         *t++ = *s++;
 499         if (*s == '^')
 500                 *t++ = *s++;
 501         if (*s == ']')
 502                 *t++ = *s++;
 503         for (; *s && (*t = *s) != ']'; s++, t++) {
 504                 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) {
 505                         *++t = *++s, t++, s++;
 506                         for (c = *s; (*t = *s) != ']' || c != d; s++, t++)
 507                                 if ((c = *s) == '\0')
 508                                         return NULL;
 509                 } else if (*s == '\\') {
 510                         switch (s[1]) {
 511                         case 'n':
 512                                 *t = '\n';
 513                                 s++;
 514                                 break;
 515                         case 'r':
 516                                 *t = '\r';
 517                                 s++;
 518                                 break;
 519                         case 't':
 520                                 *t = '\t';
 521                                 s++;
 522                                 break;
 523                         case 'x':
 524                                 if (dohex(&s[2], t, &hexlen))
 525                                         s += hexlen + 1;
 526                                 break;
 527                         }
 528                 }
 529         }
 530         return (*s == ']') ? *sp = ++s, ++t : NULL;
 531 }
 532
 533 /*
 534  * Compiles the regular expression in RE and returns a pointer to the compiled
 535  * regular expression.
 536  * Cflags are passed to regcomp.
 537  */
 538 static regex_t *
 539 compile_re(char *re, int case_insensitive)
 540 {
 541         regex_t *rep;
 542         int eval, flags;
 543
 544
 545         flags = rflags;
 546         if (case_insensitive)
 547                 flags |= REG_ICASE;
 548         if ((rep = malloc(sizeof(regex_t))) == NULL)
 549                 err(1, "malloc");
 550         if ((eval = regcomp(rep, re, flags)) != 0)
 551                 errx(1, "%lu: %s: RE error: %s",
 552                                 linenum, fname, strregerror(eval, rep));
 553         if (maxnsub < rep->re_nsub)
 554                 maxnsub = rep->re_nsub;
 555         return (rep);
 556 }
 557
 558 /*
 559  * Compile the substitution string of a regular expression and set res to
 560  * point to a saved copy of it.  Nsub is the number of parenthesized regular
 561  * expressions.
 562  */
 563 static char *
 564 compile_subst(char *p, struct s_subst *s)
 565 {
 566         static char lbuf[_POSIX2_LINE_MAX + 1];
 567         int asize, hexlen, size;
 568         u_char ref;
 569         char c, *text, *op, *sp;
 570         int more = 1, sawesc = 0;
 571
 572         c = *p++;                       /* Terminator character */
 573         if (c == '\0')
 574                 return (NULL);
 575
 576         s->maxbref = 0;
 577         s->linenum = linenum;
 578         asize = 2 * _POSIX2_LINE_MAX + 1;
 579         if ((text = malloc(asize)) == NULL)
 580                 err(1, "malloc");
 581         size = 0;
 582         do {
 583                 op = sp = text + size;
 584                 for (; *p; p++) {
 585                         if (*p == '\\' || sawesc) {
 586                                 /*
 587                                  * If this is a continuation from the last
 588                                  * buffer, we won't have a character to
 589                                  * skip over.
 590                                  */
 591                                 if (sawesc)
 592                                         sawesc = 0;
 593                                 else
 594                                         p++;
 595
 596                                 if (*p == '\0') {
 597                                         /*
 598                                          * This escaped character is continued
 599                                          * in the next part of the line.  Note
 600                                          * this fact, then cause the loop to
 601                                          * exit w/ normal EOL case and reenter
 602                                          * above with the new buffer.
 603                                          */
 604                                         sawesc = 1;
 605                                         p--;
 606                                         continue;
 607                                 } else if (strchr("123456789", *p) != NULL) {
 608                                         *sp++ = '\\';
 609                                         ref = *p - '0';
 610                                         if (s->re != NULL &&
 611                                             ref > s->re->re_nsub)
 612                                                 errx(1, "%lu: %s: \\%c not defined in the RE",
 613                                                                 linenum, fname, *p);
 614                                         if (s->maxbref < ref)
 615                                                 s->maxbref = ref;
 616                                 } else {
 617                                         switch (*p) {
 618                                         case '&':
 619                                         case '\\':
 620                                                 *sp++ = '\\';
 621                                                 break;
 622                                         case 'n':
 623                                                 *p = '\n';
 624                                                 break;
 625                                         case 'r':
 626                                                 *p = '\r';
 627                                                 break;
 628                                         case 't':
 629                                                 *p = '\t';
 630                                                 break;
 631                                         case 'x':
 632 #define ADVANCE_N(s, n)                                 \
 633         do {                                            \
 634                 char *adv = (s);                        \
 635                 while (*(adv + (n) - 1) != '\0') {      \
 636                         *adv = *(adv + (n));            \
 637                         ++adv;                          \
 638                 }                                       \
 639                 *adv = '\0';                            \
 640         } while (0);
 641                                                 if (dohex(&p[1], p, &hexlen)) {
 642                                                         ADVANCE_N(p + 1,
 643                                                             hexlen);
 644                                                 }
 645                                                 break;
 646                                         }
 647                                 }
 648                         } else if (*p == c) {
 649                                 if (*++p == '\0' && more) {
 650                                         if (cu_fgets(lbuf, sizeof(lbuf), &more))
 651                                                 p = lbuf;
 652                                 }
 653                                 *sp++ = '\0';
 654                                 size += sp - op;
 655                                 if ((s->new = realloc(text, size)) == NULL)
 656                                         err(1, "realloc");
 657                                 return (p);
 658                         } else if (*p == '\n') {
 659                                 errx(1,
 660 "%lu: %s: unescaped newline inside substitute pattern", linenum, fname);
 661                                 /* NOTREACHED */
 662                         }
 663                         *sp++ = *p;
 664                 }
 665                 size += sp - op;
 666                 if (asize - size < _POSIX2_LINE_MAX + 1) {
 667                         asize *= 2;
 668                         if ((text = realloc(text, asize)) == NULL)
 669                                 err(1, "realloc");
 670                 }
 671         } while (cu_fgets(p = lbuf, sizeof(lbuf), &more) != NULL);
 672         errx(1, "%lu: %s: unterminated substitute in regular expression",
 673                         linenum, fname);
 674         /* NOTREACHED */
 675 }
 676
 677 /*
 678  * Compile the flags of the s command
 679  */
 680 static char *
 681 compile_flags(char *p, struct s_subst *s)
 682 {
 683         int gn;                 /* True if we have seen g or n */
 684         unsigned long nval;
 685         char wfile[_POSIX2_LINE_MAX + 1], *q, *eq;
 686
 687         s->n = 1;                               /* Default */
 688         s->p = 0;
 689         s->wfile = NULL;
 690         s->wfd = -1;
 691         s->icase = 0;
 692         for (gn = 0;;) {
 693                 EATSPACE();                     /* EXTENSION */
 694                 switch (*p) {
 695                 case 'g':
 696                         if (gn)
 697                                 errx(1,
 698 "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
 699                         gn = 1;
 700                         s->n = 0;
 701                         break;
 702                 case '\0':
 703                 case '\n':
 704                 case ';':
 705                         return (p);
 706                 case 'p':
 707                         s->p = 1;
 708                         break;
 709                 case 'i':
 710                 case 'I':
 711                         s->icase = 1;
 712                         break;
 713                 case '1': case '2': case '3':
 714                 case '4': case '5': case '6':
 715                 case '7': case '8': case '9':
 716                         if (gn)
 717                                 errx(1,
 718 "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
 719                         gn = 1;
 720                         errno = 0;
 721                         nval = strtol(p, &p, 10);
 722                         if (errno == ERANGE || nval > INT_MAX)
 723                                 errx(1,
 724 "%lu: %s: overflow in the 'N' substitute flag", linenum, fname);
 725                         s->n = nval;
 726                         p--;
 727                         break;
 728                 case 'w':
 729                         p++;
 730 #ifdef HISTORIC_PRACTICE
 731                         if (*p != ' ') {
 732                                 warnx("%lu: %s: space missing before w wfile", linenum, fname);
 733                                 return (p);
 734                         }
 735 #endif
 736                         EATSPACE();
 737                         q = wfile;
 738                         eq = wfile + sizeof(wfile) - 1;
 739                         while (*p) {
 740                                 if (*p == '\n')
 741                                         break;
 742                                 if (q >= eq)
 743                                         err(1, "wfile too long");
 744                                 *q++ = *p++;
 745                         }
 746                         *q = '\0';
 747                         if (q == wfile)
 748                                 errx(1, "%lu: %s: no wfile specified", linenum, fname);
 749                         s->wfile = strdup(wfile);
 750                         if (!aflag && (s->wfd = open(wfile,
 751                             O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
 752                             DEFFILEMODE)) == -1)
 753                                 err(1, "%s", wfile);
 754                         return (p);
 755                 default:
 756                         errx(1, "%lu: %s: bad flag in substitute command: '%c'",
 757                                         linenum, fname, *p);
 758                         break;
 759                 }
 760                 p++;
 761         }
 762 }
 763
 764 /*
 765  * Compile a translation set of strings into a lookup table.
 766  */
 767 static char *
 768 compile_tr(char *p, struct s_tr **py)
 769 {
 770         struct s_tr *y;
 771         int i;
 772         const char *op, *np;
 773         char old[_POSIX2_LINE_MAX + 1];
 774         char new[_POSIX2_LINE_MAX + 1];
 775         size_t oclen, oldlen, nclen, newlen;
 776         mbstate_t mbs1, mbs2;
 777
 778         if ((*py = y = malloc(sizeof(*y))) == NULL)
 779                 err(1, NULL);
 780         y->multis = NULL;
 781         y->nmultis = 0;
 782
 783         if (*p == '\0' || *p == '\\')
 784                 errx(1,
 785         "%lu: %s: transform pattern can not be delimited by newline or backslash",
 786                         linenum, fname);
 787         p = compile_delimited(p, old, 1);
 788         if (p == NULL)
 789                 errx(1, "%lu: %s: unterminated transform source string",
 790                                 linenum, fname);
 791         p = compile_delimited(p - 1, new, 1);
 792         if (p == NULL)
 793                 errx(1, "%lu: %s: unterminated transform target string",
 794                                 linenum, fname);
 795         EATSPACE();
 796         op = old;
 797         oldlen = mbsrtowcs(NULL, &op, 0, NULL);
 798         if (oldlen == (size_t)-1)
 799                 err(1, NULL);
 800         np = new;
 801         newlen = mbsrtowcs(NULL, &np, 0, NULL);
 802         if (newlen == (size_t)-1)
 803                 err(1, NULL);
 804         if (newlen != oldlen)
 805                 errx(1, "%lu: %s: transform strings are not the same length",
 806                                 linenum, fname);
 807         if (MB_CUR_MAX == 1) {
 808                 /*
 809                  * The single-byte encoding case is easy: generate a
 810                  * lookup table.
 811                  */
 812                 for (i = 0; i <= UCHAR_MAX; i++)
 813                         y->bytetab[i] = (char)i;
 814                 for (; *op; op++, np++)
 815                         y->bytetab[(u_char)*op] = *np;
 816         } else {
 817                 /*
 818                  * Multi-byte encoding case: generate a lookup table as
 819                  * above, but only for single-byte characters. The first
 820                  * bytes of multi-byte characters have their lookup table
 821                  * entries set to 0, which causes do_tr() to search through
 822                  * an auxiliary vector of multi-byte mappings.
 823                  */
 824                 memset(&mbs1, 0, sizeof(mbs1));
 825                 memset(&mbs2, 0, sizeof(mbs2));
 826                 for (i = 0; i <= UCHAR_MAX; i++)
 827                         y->bytetab[i] = (btowc(i) != WEOF) ? i : 0;
 828                 while (*op != '\0') {
 829                         oclen = mbrlen(op, MB_LEN_MAX, &mbs1);
 830                         if (oclen == (size_t)-1 || oclen == (size_t)-2)
 831                                 errc(1, EILSEQ, NULL);
 832                         nclen = mbrlen(np, MB_LEN_MAX, &mbs2);
 833                         if (nclen == (size_t)-1 || nclen == (size_t)-2)
 834                                 errc(1, EILSEQ, NULL);
 835                         if (oclen == 1 && nclen == 1)
 836                                 y->bytetab[(u_char)*op] = *np;
 837                         else {
 838                                 y->bytetab[(u_char)*op] = 0;
 839                                 y->multis = realloc(y->multis,
 840                                     (y->nmultis + 1) * sizeof(*y->multis));
 841                                 if (y->multis == NULL)
 842                                         err(1, NULL);
 843                                 i = y->nmultis++;
 844                                 y->multis[i].fromlen = oclen;
 845                                 memcpy(y->multis[i].from, op, oclen);
 846                                 y->multis[i].tolen = nclen;
 847                                 memcpy(y->multis[i].to, np, nclen);
 848                         }
 849                         op += oclen;
 850                         np += nclen;
 851                 }
 852         }
 853         return (p);
 854 }
 855
 856 /*
 857  * Compile the text following an a, c, or i command.
 858  */
 859 static char *
 860 compile_text(void)
 861 {
 862         int asize, esc_nl, size;
 863         char *text, *p, *op, *s;
 864         char lbuf[_POSIX2_LINE_MAX + 1];
 865
 866         asize = 2 * _POSIX2_LINE_MAX + 1;
 867         if ((text = malloc(asize)) == NULL)
 868                 err(1, "malloc");
 869         size = 0;
 870         while (cu_fgets(lbuf, sizeof(lbuf), NULL) != NULL) {
 871                 op = s = text + size;
 872                 p = lbuf;
 873 #ifdef LEGACY_BSDSED_COMPAT
 874                 EATSPACE();
 875 #endif
 876                 for (esc_nl = 0; *p != '\0'; p++) {
 877                         if (*p == '\\' && p[1] != '\0' && *++p == '\n')
 878                                 esc_nl = 1;
 879                         *s++ = *p;
 880                 }
 881                 size += s - op;
 882                 if (!esc_nl) {
 883                         *s = '\0';
 884                         break;
 885                 }
 886                 if (asize - size < _POSIX2_LINE_MAX + 1) {
 887                         asize *= 2;
 888                         if ((text = realloc(text, asize)) == NULL)
 889                                 err(1, "realloc");
 890                 }
 891         }
 892         text[size] = '\0';
 893         if ((p = realloc(text, size + 1)) == NULL)
 894                 err(1, "realloc");
 895         return (p);
 896 }
 897
 898 /*
 899  * Get an address and return a pointer to the first character after
 900  * it.  Fill the structure pointed to according to the address.
 901  */
 902 static char *
 903 compile_addr(char *p, struct s_addr *a)
 904 {
 905         char *end, re[_POSIX2_LINE_MAX + 1];
 906         int icase;
 907
 908         icase = 0;
 909
 910         a->type = 0;
 911         switch (*p) {
 912         case '\\':                              /* Context address */
 913                 ++p;
 914                 /* FALLTHROUGH */
 915         case '/':                               /* Context address */
 916                 p = compile_delimited(p, re, 0);
 917                 if (p == NULL)
 918                         errx(1, "%lu: %s: unterminated regular expression", linenum, fname);
 919                 /* Check for case insensitive regexp flag */
 920                 if (*p == 'I') {
 921                         icase = 1;
 922                         p++;
 923                 }
 924                 if (*re == '\0')
 925                         a->u.r = NULL;
 926                 else
 927                         a->u.r = compile_re(re, icase);
 928                 a->type = AT_RE;
 929                 return (p);
 930
 931         case '$':                               /* Last line */
 932                 a->type = AT_LAST;
 933                 return (p + 1);
 934
 935         case '+':                               /* Relative line number */
 936                 a->type = AT_RELLINE;
 937                 p++;
 938                 /* FALLTHROUGH */
 939                                                 /* Line number */
 940         case '0': case '1': case '2': case '3': case '4':
 941         case '5': case '6': case '7': case '8': case '9':
 942                 if (a->type == 0)
 943                         a->type = AT_LINE;
 944                 a->u.l = strtol(p, &end, 10);
 945                 return (end);
 946         default:
 947                 errx(1, "%lu: %s: expected context address", linenum, fname);
 948                 return (NULL);
 949         }
 950 }
 951
 952 /*
 953  * duptoeol --
 954  *      Return a copy of all the characters up to \n or \0.
 955  */
 956 static char *
 957 duptoeol(char *s, const char *ctype)
 958 {
 959         size_t len;
 960         int ws;
 961         char *p, *start;
 962
 963         ws = 0;
 964         for (start = s; *s != '\0' && *s != '\n'; ++s)
 965                 ws = isspace((unsigned char)*s);
 966         *s = '\0';
 967         if (ws)
 968                 warnx("%lu: %s: whitespace after %s", linenum, fname, ctype);
 969         len = s - start + 1;
 970         if ((p = malloc(len)) == NULL)
 971                 err(1, "malloc");
 972         return (memmove(p, start, len));
 973 }
 974
 975 /*
 976  * Convert goto label names to addresses, and count a and r commands, in
 977  * the given subset of the script.  Free the memory used by labels in b
 978  * and t commands (but not by :).
 979  *
 980  * TODO: Remove } nodes
 981  */
 982 static void
 983 fixuplabel(struct s_command *cp, struct s_command *end)
 984 {
 985
 986         for (; cp != end; cp = cp->next)
 987                 switch (cp->code) {
 988                 case 'a':
 989                 case 'r':
 990                         appendnum++;
 991                         break;
 992                 case 'b':
 993                 case 't':
 994                         /* Resolve branch target. */
 995                         if (cp->t == NULL) {
 996                                 cp->u.c = NULL;
 997                                 break;
 998                         }
 999                         if ((cp->u.c = findlabel(cp->t)) == NULL)
1000                                 errx(1, "%lu: %s: undefined label '%s'", linenum, fname, cp->t);
1001                         free(cp->t);
1002                         break;
1003                 case '{':
1004                         /* Do interior commands. */
1005                         fixuplabel(cp->u.c, cp->next);
1006                         break;
1007                 }
1008 }
1009
1010 /*
1011  * Associate the given command label for later lookup.
1012  */
1013 static void
1014 enterlabel(struct s_command *cp)
1015 {
1016         struct labhash **lhp, *lh;
1017         u_char *p;
1018         u_int h, c;
1019
1020         for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++)
1021                 h = (h << 5) + h + c;
1022         lhp = &labels[h & LHMASK];
1023         for (lh = *lhp; lh != NULL; lh = lh->lh_next)
1024                 if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0)
1025                         errx(1, "%lu: %s: duplicate label '%s'", linenum, fname, cp->t);
1026         if ((lh = malloc(sizeof *lh)) == NULL)
1027                 err(1, "malloc");
1028         lh->lh_next = *lhp;
1029         lh->lh_hash = h;
1030         lh->lh_cmd = cp;
1031         lh->lh_ref = 0;
1032         *lhp = lh;
1033 }
1034
1035 /*
1036  * Find the label contained in the command l in the command linked
1037  * list cp.  L is excluded from the search.  Return NULL if not found.
1038  */
1039 static struct s_command *
1040 findlabel(char *name)
1041 {
1042         struct labhash *lh;
1043         u_char *p;
1044         u_int h, c;
1045
1046         for (h = 0, p = (u_char *)name; (c = *p) != 0; p++)
1047                 h = (h << 5) + h + c;
1048         for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) {
1049                 if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) {
1050                         lh->lh_ref = 1;
1051                         return (lh->lh_cmd);
1052                 }
1053         }
1054         return (NULL);
1055 }
1056
1057 /*
1058  * Warn about any unused labels.  As a side effect, release the label hash
1059  * table space.
1060  */
1061 static void
1062 uselabel(void)
1063 {
1064         struct labhash *lh, *next;
1065         int i;
1066
1067         for (i = 0; i < LHSZ; i++) {
1068                 for (lh = labels[i]; lh != NULL; lh = next) {
1069                         next = lh->lh_next;
1070                         if (!lh->lh_ref)
1071                                 warnx("%lu: %s: unused label '%s'",
1072                                     linenum, fname, lh->lh_cmd->t);
1073                         free(lh);
1074                 }
1075         }
1076 }