1 /*        $NetBSD: compile.c,v 1.51 2023/01/20 01:26:02 msaitoh Exp $ */
2 
3 /*-
4  * Copyright (c) 1992 Diomidis Spinellis.
5  * Copyright (c) 1992, 1993
6  *        The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Diomidis Spinellis of Imperial College, University of London.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if HAVE_NBTOOL_CONFIG_H
37 #include "nbtool_config.h"
38 #endif
39 
40 #include <sys/cdefs.h>
41 __RCSID("$NetBSD: compile.c,v 1.51 2023/01/20 01:26:02 msaitoh Exp $");
42 #ifdef __FBSDID
43 __FBSDID("$FreeBSD: head/usr.bin/sed/compile.c 259132 2013-12-09 18:57:20Z eadler $");
44 #endif
45 
46 #if 0
47 static const char sccsid[] = "@(#)compile.c       8.1 (Berkeley) 6/6/93";
48 #endif
49 
50 #include <sys/types.h>
51 #include <sys/stat.h>
52 
53 #include <ctype.h>
54 #include <err.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <limits.h>
58 #include <regex.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <wchar.h>
63 
64 #include "defs.h"
65 #include "extern.h"
66 
67 #define LHSZ        128
68 #define   LHMASK    (LHSZ - 1)
69 static struct labhash {
70           struct    labhash *lh_next;
71           u_int     lh_hash;
72           struct    s_command *lh_cmd;
73           int       lh_ref;
74 } *labels[LHSZ];
75 
76 static char          *compile_addr(char *, struct s_addr *);
77 static char          *compile_ccl(char **, char *);
78 static char          *compile_delimited(char *, char *, int);
79 static char          *compile_flags(char *, struct s_subst *);
80 static regex_t       *compile_re(char *, int);
81 static char          *compile_subst(char *, struct s_subst *);
82 static char          *compile_text(void);
83 static char          *compile_tr(char *, struct s_tr **);
84 static struct s_command
85                     **compile_stream(struct s_command **);
86 static char          *duptoeol(char *, const char *);
87 static void           enterlabel(struct s_command *);
88 static struct s_command
89                      *findlabel(char *);
90 static void           fixuplabel(struct s_command *, struct s_command *);
91 static void           uselabel(void);
92 static void           parse_escapes(char *);
93 
94 /*
95  * Command specification.  This is used to drive the command parser.
96  */
97 struct s_format {
98           char code;                                        /* Command code */
99           int naddr;                                        /* Number of address args */
100           enum e_args args;                       /* Argument type */
101 };
102 
103 static struct s_format cmd_fmts[] = {
104           {'{', 2, GROUP},
105           {'}', 0, ENDGROUP},
106           {'a', 1, TEXT},
107           {'b', 2, BRANCH},
108           {'c', 2, TEXT},
109           {'d', 2, EMPTY},
110           {'D', 2, EMPTY},
111           {'g', 2, EMPTY},
112           {'G', 2, EMPTY},
113           {'h', 2, EMPTY},
114           {'H', 2, EMPTY},
115           {'i', 1, TEXT},
116           {'l', 2, EMPTY},
117           {'n', 2, EMPTY},
118           {'N', 2, EMPTY},
119           {'p', 2, EMPTY},
120           {'P', 2, EMPTY},
121           {'q', 1, EMPTY},
122           {'r', 1, RFILE},
123           {'s', 2, SUBST},
124           {'t', 2, BRANCH},
125           {'w', 2, WFILE},
126           {'x', 2, EMPTY},
127           {'y', 2, TR},
128           {'!', 2, NONSEL},
129           {':', 0, LABEL},
130           {'#', 0, COMMENT},
131           {'=', 1, EMPTY},
132           {'\0', 0, COMMENT},
133 };
134 
135 /* The compiled program. */
136 struct s_command *prog;
137 
138 /*
139  * Compile the program into prog.
140  * Initialise appends.
141  */
142 void
compile(void)143 compile(void)
144 {
145           *compile_stream(&prog) = NULL;
146           fixuplabel(prog, NULL);
147           uselabel();
148           if (appendnum > 0)
149                     appends = xmalloc(sizeof(struct s_appends) * appendnum);
150           match = xmalloc((maxnsub + 1) * sizeof(regmatch_t));
151 }
152 
153 #define EATSPACE() do {                                                                   \
154           if (p)                                                                          \
155                     while (*p && isspace((unsigned char)*p))                \
156                               p++;                                                        \
157           } while (0)
158 
159 static struct s_command **
compile_stream(struct s_command ** link)160 compile_stream(struct s_command **link)
161 {
162           char *p;
163           static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */
164           struct s_command *cmd, *cmd2, *stack;
165           struct s_format *fp;
166           char re[_POSIX2_LINE_MAX + 1];
167           int naddr;                                        /* Number of addresses */
168 
169           stack = 0;
170           for (;;) {
171                     if ((p = cu_fgets(lbuf, sizeof(lbuf), NULL)) == NULL) {
172                               if (stack != 0)
173                                         errx(1, "%lu: %s: unexpected EOF (pending }'s)",
174                                                                       linenum, fname);
175                               return (link);
176                     }
177 
178 semicolon:          EATSPACE();
179                     if (p) {
180                               if (*p == '#' || *p == '\0')
181                                         continue;
182                               else if (*p == ';') {
183                                         p++;
184                                         goto semicolon;
185                               }
186                     }
187                     *link = cmd = xmalloc(sizeof(struct s_command));
188                     link = &cmd->next;
189                     cmd->startline = cmd->nonsel = 0;
190                     /* First parse the addresses */
191                     naddr = 0;
192 
193 /* Valid characters to start an address */
194 #define   addrchar(c)         (strchr("0123456789/\\$", (c)))
195                     if (addrchar(*p)) {
196                               naddr++;
197                               cmd->a1 = xmalloc(sizeof(struct s_addr));
198                               p = compile_addr(p, cmd->a1);
199                               EATSPACE();                                       /* EXTENSION */
200                               if (*p == ',') {
201                                         p++;
202                                         EATSPACE();                             /* EXTENSION */
203                                         naddr++;
204                                         cmd->a2 = xmalloc(sizeof(struct s_addr));
205                                         p = compile_addr(p, cmd->a2);
206                                         EATSPACE();
207                               } else
208                                         cmd->a2 = 0;
209                     } else
210                               cmd->a1 = cmd->a2 = 0;
211 
212 nonsel:             /* Now parse the command */
213                     if (!*p)
214                               errx(1, "%lu: %s: command expected", linenum, fname);
215                     cmd->code = *p;
216                     for (fp = cmd_fmts; fp->code; fp++)
217                               if (fp->code == *p)
218                                         break;
219                     if (!fp->code)
220                               errx(1, "%lu: %s: invalid command code %c", linenum, fname, *p);
221                     if (naddr > fp->naddr)
222                               errx(1,
223                                         "%lu: %s: command %c expects up to %d address(es), found %d",
224                                         linenum, fname, *p, fp->naddr, naddr);
225                     switch (fp->args) {
226                     case NONSEL:                            /* ! */
227                               p++;
228                               EATSPACE();
229                               cmd->nonsel = ! cmd->nonsel;
230                               goto nonsel;
231                     case GROUP:                             /* { */
232                               p++;
233                               EATSPACE();
234                               cmd->next = stack;
235                               stack = cmd;
236                               link = &cmd->u.c;
237                               if (*p)
238                                         goto semicolon;
239                               break;
240                     case ENDGROUP:
241                               /*
242                                * Short-circuit command processing, since end of
243                                * group is really just a noop.
244                                */
245                               cmd->nonsel = 1;
246                               if (stack == 0)
247                                         errx(1, "%lu: %s: unexpected }", linenum, fname);
248                               cmd2 = stack;
249                               stack = cmd2->next;
250                               cmd2->next = cmd;
251                               /*FALLTHROUGH*/
252                     case EMPTY:                   /* d D g G h H l n N p P q x = \0 */
253                               p++;
254                               EATSPACE();
255                               switch (*p) {
256                               case ';':
257                                         p++;
258                                         link = &cmd->next;
259                                         goto semicolon;
260                               case '}':
261                                         goto semicolon;
262                               case '\0':
263                                         break;
264                               default:
265                                         errx(1, "%lu: %s: extra characters at the end of %c command",
266                                                             linenum, fname, cmd->code);
267                               }
268                               break;
269                     case TEXT:                              /* a c i */
270                               p++;
271                               EATSPACE();
272                               if (*p != '\\')
273                                         errx(1,
274 "%lu: %s: command %c expects \\ followed by text", linenum, fname, cmd->code);
275                               p++;
276                               EATSPACE();
277                               if (*p)
278                                         errx(1,
279                                         "%lu: %s: extra characters after \\ at the end of %c command",
280                                         linenum, fname, cmd->code);
281                               cmd->t = compile_text();
282                               break;
283                     case COMMENT:                           /* \0 # */
284                               break;
285                     case WFILE:                             /* w */
286                               p++;
287                               EATSPACE();
288                               if (*p == '\0')
289                                         errx(1, "%lu: %s: filename expected", linenum, fname);
290                               cmd->t = duptoeol(p, "w command");
291                               if (aflag)
292                                         cmd->u.fd = -1;
293                               else if ((cmd->u.fd = open(p,
294                                   O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
295                                   DEFFILEMODE)) == -1)
296                                         err(1, "%s", p);
297                               break;
298                     case RFILE:                             /* r */
299                               p++;
300                               EATSPACE();
301                               if (*p == '\0')
302                                         errx(1, "%lu: %s: filename expected", linenum, fname);
303                               else
304                                         cmd->t = duptoeol(p, "read command");
305                               break;
306                     case BRANCH:                            /* b t */
307                               p++;
308                               EATSPACE();
309                               if (*p == '\0')
310                                         cmd->t = NULL;
311                               else
312                                         cmd->t = duptoeol(p, "branch");
313                               break;
314                     case LABEL:                             /* : */
315                               p++;
316                               EATSPACE();
317                               cmd->t = duptoeol(p, "label");
318                               if (strlen(p) == 0)
319                                         errx(1, "%lu: %s: empty label", linenum, fname);
320                               enterlabel(cmd);
321                               break;
322                     case SUBST:                             /* s */
323                               p++;
324                               if (*p == '\0' || *p == '\\')
325                                         errx(1,
326 "%lu: %s: substitute pattern can not be delimited by newline or backslash",
327                                                   linenum, fname);
328                               cmd->u.s = xcalloc(1, sizeof(struct s_subst));
329                               p = compile_delimited(p, re, 0);
330                               if (p == NULL)
331                                         errx(1,
332                                         "%lu: %s: unterminated substitute pattern", linenum, fname);
333 
334                               /* Compile RE with no case sensitivity temporarily */
335                               if (*re == '\0')
336                                         cmd->u.s->re = NULL;
337                               else
338                                         cmd->u.s->re = compile_re(re, 0);
339                               --p;
340                               p = compile_subst(p, cmd->u.s);
341                               p = compile_flags(p, cmd->u.s);
342 
343                               /* Recompile RE with case sensitivity from "I" flag if any */
344                               if (*re == '\0')
345                                         cmd->u.s->re = NULL;
346                               else
347                                         cmd->u.s->re = compile_re(re, cmd->u.s->icase);
348                               EATSPACE();
349                               if (*p == ';') {
350                                         p++;
351                                         link = &cmd->next;
352                                         goto semicolon;
353                               }
354                               break;
355                     case TR:                      /* y */
356                               p++;
357                               p = compile_tr(p, &cmd->u.y);
358                               EATSPACE();
359                               switch (*p) {
360                               case ';':
361                                         p++;
362                                         link = &cmd->next;
363                                         goto semicolon;
364                               case '}':
365                                         goto semicolon;
366                               case '\0':
367                                         break;
368                               default:
369                                         errx(1,
370 "%lu: %s: extra text at the end of a transform command", linenum, fname);
371                               }
372                               if (*p)
373                               break;
374                     }
375           }
376 }
377 
378 /*
379  * Get a delimited string.  P points to the delimiter of the string; d points
380  * to a buffer area.  Newline and delimiter escapes are processed; other
381  * escapes are ignored.
382  *
383  * Returns a pointer to the first character after the final delimiter or NULL
384  * in the case of a non-terminated string.  The character array d is filled
385  * with the processed string.
386  */
387 static char *
compile_delimited(char * p,char * d,int is_tr)388 compile_delimited(char *p, char *d, int is_tr)
389 {
390           char c;
391 
392           c = *p++;
393           if (c == '\0')
394                     return (NULL);
395           else if (c == '\\')
396                     errx(1, "%lu: %s: \\ can not be used as a string delimiter",
397                                         linenum, fname);
398           else if (c == '\n')
399                     errx(1, "%lu: %s: newline can not be used as a string delimiter",
400                                         linenum, fname);
401           while (*p) {
402                     if (*p == '[' && *p != c) {
403                               if ((d = compile_ccl(&p, d)) == NULL)
404                                         errx(1, "%lu: %s: unbalanced brackets ([])", linenum, fname);
405                               continue;
406                     } else if (*p == '\\' && p[1] == '[') {
407                               *d++ = *p++;
408                     } else if (*p == '\\' && p[1] == c)
409                               p++;
410                     else if (*p == '\\' && p[1] == 'n') {
411                               *d++ = '\n';
412                               p += 2;
413                               continue;
414                     } else if (*p == '\\' && p[1] == '\\') {
415                               if (is_tr)
416                                         p++;
417                               else
418                                         *d++ = *p++;
419                     } else if (*p == c) {
420                               *d = '\0';
421                               return (p + 1);
422                     }
423                     *d++ = *p++;
424           }
425           return (NULL);
426 }
427 
428 
429 /* compile_ccl: expand a POSIX character class */
430 static char *
compile_ccl(char ** sp,char * t)431 compile_ccl(char **sp, char *t)
432 {
433           int c, d;
434           char *s = *sp;
435 
436           *t++ = *s++;
437           if (*s == '^')
438                     *t++ = *s++;
439           if (*s == ']')
440                     *t++ = *s++;
441           for (; *s && (*t = *s) != ']'; s++, t++)
442                     if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) {
443                               *++t = *++s, t++, s++;
444                               for (c = *s; (*t = *s) != ']' || c != d; s++, t++)
445                                         if ((c = *s) == '\0')
446                                                   return NULL;
447                     }
448           return (*s == ']') ? *sp = ++s, ++t : NULL;
449 }
450 
451 /*
452  * Compiles the regular expression in RE and returns a pointer to the compiled
453  * regular expression.
454  * Cflags are passed to regcomp.
455  */
456 static regex_t *
compile_re(char * re,int case_insensitive)457 compile_re(char *re, int case_insensitive)
458 {
459           regex_t *rep;
460           int eval, flags;
461 
462 
463           flags = rflags;
464           if (case_insensitive)
465                     flags |= REG_ICASE;
466           rep = xmalloc(sizeof(regex_t));
467           parse_escapes(re);
468           if ((eval = regcomp(rep, re, flags)) != 0)
469                     errx(1, "%lu: %s: RE error: %s",
470                                         linenum, fname, strregerror(eval, rep));
471           if (maxnsub < rep->re_nsub)
472                     maxnsub = rep->re_nsub;
473           return (rep);
474 }
475 
476 static char
cton(char c,int base)477 cton(char c, int base)
478 {
479           switch (c) {
480           case '0': case '1': case '2': case '3': case '4':
481           case '5': case '6': case '7':
482                     return (char)(c - '0');
483           case '8': case '9':
484                     return base == 8 ? '?' : (char)(c - '0');
485           case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
486                     return base == 16 ? (char)(c - 'a' + 10) : '?';
487           case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
488                     return base == 16 ? (char)(c - 'A' + 10) : '?';
489           default:
490                     return '?';
491           }
492 }
493 
494 static int
ston(char ** pp,char * sp,int base)495 ston(char **pp, char *sp, int base)
496 {
497           char *p = *pp, n;
498           int r = cton(p[1], base);
499 
500           if (r == '?')
501                     return 0;
502 
503           p++;
504           while ((n = cton(p[1], base)) != '?' && r < 255) {
505                     r = r * base + n;
506                     p++;
507           }
508           *sp = (char)r;
509           *pp = p;
510           return 1;
511 }
512 
513 static int
unescape(char ** pp,char ** spp)514 unescape(char **pp, char **spp)
515 {
516           char *p = *pp;
517           char *sp = *spp;
518 
519           switch (*p) {
520           case 'o':
521                     if (!ston(&p, sp, 8))
522                               return 0;
523                     break;
524           case 'd':
525                     if (!ston(&p, sp, 10))
526                               return 0;
527                     break;
528           case 'x':
529                     if (!ston(&p, sp, 16))
530                               return 0;
531                     break;
532           case 'a':
533                     *sp = '\a';
534                     break;
535 #if 0
536           // No, \b RE
537           case 'b':
538                     *sp = '\b';
539                     break;
540 #endif
541           case 'f':
542                     *sp = '\f';
543                     break;
544           case 'n':
545                     *sp = '\n';
546                     break;
547           case 'r':
548                     *sp = '\r';
549                     break;
550           case 't':
551                     *sp = '\t';
552                     break;
553           case 'v':
554                     *sp = '\v';
555                     break;
556           default:
557                     return 0;
558           }
559           *spp = sp + 1;
560           *pp = p;
561           return 1;
562 }
563 
564 static void
parse_escapes(char * buf)565 parse_escapes(char *buf)
566 {
567           char bracket = '\0';
568           char *p, *q;
569 
570           p = q = buf;
571 
572           for (p = q = buf; *p; p++) {
573                     if (*p == '\\' && p[1] && !bracket) {
574                               p++;
575                               if (unescape(&p, &q))
576                                         continue;
577                               *q++ = '\\';
578                     }
579                     switch (*p) {
580                     case '[':
581                               if (!bracket)
582                                         bracket = *p;
583                               break;
584                     case '.':
585                     case ':':
586                     case '=':
587                               if (bracket == '[' && p[-1] == '[')
588                                         bracket = *p;
589                               break;
590                     case ']':
591                               if (!bracket)
592                                   break;
593                               if (bracket == '[')
594                                         bracket = '\0';
595                               else if (p[-2] != bracket && p[-1] == bracket)
596                                         bracket = '[';
597                               break;
598                     default:
599                               break;
600                     }
601                     *q++ = *p;
602           }
603           *q = '\0';
604 }
605 
606 /*
607  * Compile the substitution string of a regular expression and set res to
608  * point to a saved copy of it.  Nsub is the number of parenthesized regular
609  * expressions.
610  */
611 static char *
compile_subst(char * p,struct s_subst * s)612 compile_subst(char *p, struct s_subst *s)
613 {
614           static char lbuf[_POSIX2_LINE_MAX + 1];
615           size_t asize, size;
616           u_char ref;
617           char c, *text, *op, *sp;
618           int more = 1, sawesc = 0;
619 
620           c = *p++;                     /* Terminator character */
621           if (c == '\0')
622                     return (NULL);
623 
624           s->maxbref = 0;
625           s->linenum = linenum;
626           asize = 2 * _POSIX2_LINE_MAX + 1;
627           text = xmalloc(asize);
628           size = 0;
629           do {
630                     op = sp = text + size;
631                     for (; *p; p++) {
632                               if (*p == '\\' || sawesc) {
633                                         /*
634                                          * If this is a continuation from the last
635                                          * buffer, we won't have a character to
636                                          * skip over.
637                                          */
638                                         if (sawesc)
639                                                   sawesc = 0;
640                                         else
641                                                   p++;
642 
643                                         switch (*p) {
644                                         case '\0':
645                                                   /*
646                                                    * This escaped character is continued
647                                                    * in the next part of the line.  Note
648                                                    * this fact, then cause the loop to
649                                                    * exit w/ normal EOL case and reenter
650                                                    * above with the new buffer.
651                                                    */
652                                                   sawesc = 1;
653                                                   p--;
654                                                   continue;
655                                         case '0': case '1': case '2': case '3':
656                                         case '4': case '5': case '6': case '7':
657                                         case '8': case '9':
658                                                   *sp++ = '\\';
659                                                   ref = (u_char)(*p - '0');
660                                                   if (s->re != NULL &&
661                                                       ref > s->re->re_nsub)
662                                                             errx(1, "%lu: %s: \\%c not defined in the RE",
663                                                                                 linenum, fname, *p);
664                                                   if (s->maxbref < ref)
665                                                             s->maxbref = ref;
666                                                   break;
667                                         case '&':
668                                         case '\\':
669                                                   *sp++ = '\\';
670                                                   break;
671                                         default:
672                                                   if (unescape(&p, &sp))
673                                                             continue;
674                                                   break;
675                                         }
676                               } else if (*p == c) {
677                                         if (*++p == '\0' && more) {
678                                                   if (cu_fgets(lbuf, sizeof(lbuf), &more))
679                                                             p = lbuf;
680                                         }
681                                         *sp++ = '\0';
682                                         size += (size_t)(sp - op);
683                                         s->new = xrealloc(text, size);
684                                         return (p);
685                               } else if (*p == '\n') {
686                                         errx(1,
687 "%lu: %s: unescaped newline inside substitute pattern", linenum, fname);
688                                         /* NOTREACHED */
689                               }
690                               *sp++ = *p;
691                     }
692                     size += (size_t)(sp - op);
693                     if (asize - size < _POSIX2_LINE_MAX + 1) {
694                               asize *= 2;
695                               text = xrealloc(text, asize);
696                     }
697           } while (cu_fgets(p = lbuf, sizeof(lbuf), &more));
698           errx(1, "%lu: %s: unterminated substitute in regular expression",
699                               linenum, fname);
700           /* NOTREACHED */
701 }
702 
703 /*
704  * Compile the flags of the s command
705  */
706 static char *
compile_flags(char * p,struct s_subst * s)707 compile_flags(char *p, struct s_subst *s)
708 {
709           int gn;                       /* True if we have seen g or n */
710           unsigned long nval;
711           char wfile[_POSIX2_LINE_MAX + 1], *q;
712 
713           s->n = 1;                               /* Default */
714           s->p = 0;
715           s->wfile = NULL;
716           s->wfd = -1;
717           s->icase = 0;
718           for (gn = 0;;) {
719                     EATSPACE();                             /* EXTENSION */
720                     switch (*p) {
721                     case 'g':
722                               if (gn)
723                                         errx(1,
724 "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
725                               gn = 1;
726                               s->n = 0;
727                               break;
728                     case '\0':
729                     case '\n':
730                     case ';':
731                               return (p);
732                     case 'p':
733                               s->p = 1;
734                               break;
735                     case 'i':
736                     case 'I':
737                               s->icase = 1;
738                               break;
739                     case '1': case '2': case '3':
740                     case '4': case '5': case '6':
741                     case '7': case '8': case '9':
742                               if (gn)
743                                         errx(1,
744 "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
745                               gn = 1;
746                               errno = 0;
747                               nval = strtoul(p, &p, 10);
748                               if (errno == ERANGE || nval > INT_MAX)
749                                         errx(1,
750 "%lu: %s: overflow in the 'N' substitute flag", linenum, fname);
751                               s->n = (int)nval;
752                               p--;
753                               break;
754                     case 'w':
755                               p++;
756 #ifdef HISTORIC_PRACTICE
757                               if (*p != ' ') {
758                                         warnx("%lu: %s: space missing before w wfile", linenum, fname);
759                                         return (p);
760                               }
761 #endif
762                               EATSPACE();
763                               q = wfile;
764                               while (*p) {
765                                         if (*p == '\n')
766                                                   break;
767                                         *q++ = *p++;
768                               }
769                               *q = '\0';
770                               if (q == wfile)
771                                         errx(1, "%lu: %s: no wfile specified", linenum, fname);
772                               s->wfile = strdup(wfile);
773                               if (!aflag && (s->wfd = open(wfile,
774                                   O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
775                                   DEFFILEMODE)) == -1)
776                                         err(1, "%s", wfile);
777                               return (p);
778                     default:
779                               errx(1, "%lu: %s: bad flag in substitute command: '%c'",
780                                                   linenum, fname, *p);
781                               break;
782                     }
783                     p++;
784           }
785 }
786 
787 /*
788  * Compile a translation set of strings into a lookup table.
789  */
790 static char *
compile_tr(char * p,struct s_tr ** py)791 compile_tr(char *p, struct s_tr **py)
792 {
793           struct s_tr *y;
794           size_t i;
795           const char *op, *np;
796           char old[_POSIX2_LINE_MAX + 1];
797           char new[_POSIX2_LINE_MAX + 1];
798           size_t oclen, oldlen, nclen, newlen;
799           mbstate_t mbs1, mbs2;
800 
801           *py = y = xmalloc(sizeof(*y));
802           y->multis = NULL;
803           y->nmultis = 0;
804 
805           if (*p == '\0' || *p == '\\')
806                     errx(1,
807           "%lu: %s: transform pattern can not be delimited by newline or backslash",
808                               linenum, fname);
809           p = compile_delimited(p, old, 1);
810           if (p == NULL)
811                     errx(1, "%lu: %s: unterminated transform source string",
812                                         linenum, fname);
813           p = compile_delimited(p - 1, new, 1);
814           if (p == NULL)
815                     errx(1, "%lu: %s: unterminated transform target string",
816                                         linenum, fname);
817           EATSPACE();
818           op = old;
819           oldlen = mbsrtowcs(NULL, &op, 0, NULL);
820           if (oldlen == (size_t)-1)
821                     err(1, NULL);
822           np = new;
823           newlen = mbsrtowcs(NULL, &np, 0, NULL);
824           if (newlen == (size_t)-1)
825                     err(1, NULL);
826           if (newlen != oldlen)
827                     errx(1, "%lu: %s: transform strings are not the same length",
828                                         linenum, fname);
829           if (MB_CUR_MAX == 1) {
830                     /*
831                      * The single-byte encoding case is easy: generate a
832                      * lookup table.
833                      */
834                     for (i = 0; i <= UCHAR_MAX; i++)
835                               y->bytetab[i] = (u_char)i;
836                     for (; *op; op++, np++)
837                               y->bytetab[(u_char)*op] = (u_char)*np;
838           } else {
839                     /*
840                      * Multi-byte encoding case: generate a lookup table as
841                      * above, but only for single-byte characters. The first
842                      * bytes of multi-byte characters have their lookup table
843                      * entries set to 0, which causes do_tr() to search through
844                      * an auxiliary vector of multi-byte mappings.
845                      */
846                     memset(&mbs1, 0, sizeof(mbs1));
847                     memset(&mbs2, 0, sizeof(mbs2));
848                     for (i = 0; i <= UCHAR_MAX; i++)
849                               y->bytetab[i] = (u_char)((btowc((int)i) != WEOF) ? i : 0);
850                     while (*op != '\0') {
851                               oclen = mbrlen(op, MB_LEN_MAX, &mbs1);
852                               if (oclen == (size_t)-1 || oclen == (size_t)-2)
853                                         errc(1, EILSEQ, NULL);
854                               nclen = mbrlen(np, MB_LEN_MAX, &mbs2);
855                               if (nclen == (size_t)-1 || nclen == (size_t)-2)
856                                         errc(1, EILSEQ, NULL);
857                               if (oclen == 1 && nclen == 1)
858                                         y->bytetab[(u_char)*op] = (u_char)*np;
859                               else {
860                                         y->bytetab[(u_char)*op] = 0;
861                                         y->multis = xrealloc(y->multis,
862                                             (y->nmultis + 1) * sizeof(*y->multis));
863                                         i = y->nmultis++;
864                                         y->multis[i].fromlen = oclen;
865                                         memcpy(y->multis[i].from, op, oclen);
866                                         y->multis[i].tolen = nclen;
867                                         memcpy(y->multis[i].to, np, nclen);
868                               }
869                               op += oclen;
870                               np += nclen;
871                     }
872           }
873           return (p);
874 }
875 
876 /*
877  * Compile the text following an a or i command.
878  */
879 static char *
compile_text(void)880 compile_text(void)
881 {
882           size_t asize, size;
883           int esc_nl;
884           char *text, *p, *op, *s;
885           char lbuf[_POSIX2_LINE_MAX + 1];
886 
887           asize = 2 * _POSIX2_LINE_MAX + 1;
888           text = xmalloc(asize);
889           size = 0;
890           while (cu_fgets(lbuf, sizeof(lbuf), NULL)) {
891                     op = s = text + size;
892                     p = lbuf;
893                     for (esc_nl = 0; *p != '\0'; p++) {
894                               if (*p == '\\' && p[1] != '\0' && *++p == '\n')
895                                         esc_nl = 1;
896                               *s++ = *p;
897                     }
898                     size += (size_t)(s - op);
899                     if (!esc_nl) {
900                               *s = '\0';
901                               break;
902                     }
903                     if (asize - size < _POSIX2_LINE_MAX + 1) {
904                               asize *= 2;
905                               text = xrealloc(text, asize);
906                     }
907           }
908           text[size] = '\0';
909           p = xrealloc(text, size + 1);
910           return (p);
911 }
912 
913 /*
914  * Get an address and return a pointer to the first character after
915  * it.  Fill the structure pointed to according to the address.
916  */
917 static char *
compile_addr(char * p,struct s_addr * a)918 compile_addr(char *p, struct s_addr *a)
919 {
920           char *end, re[_POSIX2_LINE_MAX + 1];
921           int icase;
922 
923           icase = 0;
924 
925           a->type = 0;
926           switch (*p) {
927           case '\\':                                        /* Context address */
928                     ++p;
929                     /* FALLTHROUGH */
930           case '/':                               /* Context address */
931                     p = compile_delimited(p, re, 0);
932                     if (p == NULL)
933                               errx(1, "%lu: %s: unterminated regular expression", linenum, fname);
934                     /* Check for case insensitive regexp flag */
935                     if (*p == 'I') {
936                               icase = 1;
937                               p++;
938                     }
939                     if (*re == '\0')
940                               a->u.r = NULL;
941                     else
942                               a->u.r = compile_re(re, icase);
943                     a->type = AT_RE;
944                     return (p);
945 
946           case '$':                               /* Last line */
947                     a->type = AT_LAST;
948                     return (p + 1);
949 
950           case '+':                               /* Relative line number */
951                     a->type = AT_RELLINE;
952                     p++;
953                     /* FALLTHROUGH */
954                                                             /* Line number */
955           case '0': case '1': case '2': case '3': case '4':
956           case '5': case '6': case '7': case '8': case '9':
957                     if (a->type == 0)
958                               a->type = AT_LINE;
959                     a->u.l = strtoul(p, &end, 10);
960                     return (end);
961           default:
962                     errx(1, "%lu: %s: expected context address", linenum, fname);
963                     return (NULL);
964           }
965 }
966 
967 /*
968  * duptoeol --
969  *        Return a copy of all the characters up to \n or \0.
970  */
971 static char *
duptoeol(char * s,const char * ctype)972 duptoeol(char *s, const char *ctype)
973 {
974           size_t len;
975           int ws;
976           char *p, *start;
977 
978           ws = 0;
979           for (start = s; *s != '\0' && *s != '\n'; ++s)
980                     ws = isspace((unsigned char)*s);
981           *s = '\0';
982           if (ws)
983                     warnx("%lu: %s: whitespace after %s", linenum, fname, ctype);
984           len = (size_t)(s - start + 1);
985           p = xmalloc(len);
986           return (memmove(p, start, len));
987 }
988 
989 /*
990  * Convert goto label names to addresses, and count a and r commands, in
991  * the given subset of the script.  Free the memory used by labels in b
992  * and t commands (but not by :).
993  *
994  * TODO: Remove } nodes
995  */
996 static void
fixuplabel(struct s_command * cp,struct s_command * end)997 fixuplabel(struct s_command *cp, struct s_command *end)
998 {
999 
1000           for (; cp != end; cp = cp->next)
1001                     switch (cp->code) {
1002                     case 'a':
1003                     case 'r':
1004                               appendnum++;
1005                               break;
1006                     case 'b':
1007                     case 't':
1008                               /* Resolve branch target. */
1009                               if (cp->t == NULL) {
1010                                         cp->u.c = NULL;
1011                                         break;
1012                               }
1013                               if ((cp->u.c = findlabel(cp->t)) == NULL)
1014                                         errx(1, "%lu: %s: undefined label '%s'", linenum, fname, cp->t);
1015                               free(cp->t);
1016                               break;
1017                     case '{':
1018                               /* Do interior commands. */
1019                               fixuplabel(cp->u.c, cp->next);
1020                               break;
1021                     }
1022 }
1023 
1024 /*
1025  * Associate the given command label for later lookup.
1026  */
1027 static void
enterlabel(struct s_command * cp)1028 enterlabel(struct s_command *cp)
1029 {
1030           struct labhash **lhp, *lh;
1031           u_char *p;
1032           u_int h, c;
1033 
1034           for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++)
1035                     h = (h << 5) + h + c;
1036           lhp = &labels[h & LHMASK];
1037           for (lh = *lhp; lh != NULL; lh = lh->lh_next)
1038                     if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0)
1039                               errx(1, "%lu: %s: duplicate label '%s'", linenum, fname, cp->t);
1040           lh = xmalloc(sizeof *lh);
1041           lh->lh_next = *lhp;
1042           lh->lh_hash = h;
1043           lh->lh_cmd = cp;
1044           lh->lh_ref = 0;
1045           *lhp = lh;
1046 }
1047 
1048 /*
1049  * Find the label contained in the command l in the command linked
1050  * list cp.  L is excluded from the search.  Return NULL if not found.
1051  */
1052 static struct s_command *
findlabel(char * name)1053 findlabel(char *name)
1054 {
1055           struct labhash *lh;
1056           u_char *p;
1057           u_int h, c;
1058 
1059           for (h = 0, p = (u_char *)name; (c = *p) != 0; p++)
1060                     h = (h << 5) + h + c;
1061           for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) {
1062                     if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) {
1063                               lh->lh_ref = 1;
1064                               return (lh->lh_cmd);
1065                     }
1066           }
1067           return (NULL);
1068 }
1069 
1070 /*
1071  * Warn about any unused labels.  As a side effect, release the label hash
1072  * table space.
1073  */
1074 static void
uselabel(void)1075 uselabel(void)
1076 {
1077           struct labhash *lh, *next;
1078           int i;
1079 
1080           for (i = 0; i < LHSZ; i++) {
1081                     for (lh = labels[i]; lh != NULL; lh = next) {
1082                               next = lh->lh_next;
1083                               if (!lh->lh_ref)
1084                                         warnx("%lu: %s: unused label '%s'",
1085                                             linenum, fname, lh->lh_cmd->t);
1086                               free(lh);
1087                     }
1088           }
1089 }
1090