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