compile.c revision 171206
1/*-
2 * Copyright (c) 1992 Diomidis Spinellis.
3 * Copyright (c) 1992, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Diomidis Spinellis of Imperial College, University of London.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: head/usr.bin/sed/compile.c 171206 2007-07-04 16:42:41Z ssouhlal $");
36
37#ifndef lint
38static const char sccsid[] = "@(#)compile.c	8.1 (Berkeley) 6/6/93";
39#endif
40
41#include <sys/types.h>
42#include <sys/stat.h>
43
44#include <ctype.h>
45#include <err.h>
46#include <errno.h>
47#include <fcntl.h>
48#include <limits.h>
49#include <regex.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <wchar.h>
54
55#include "defs.h"
56#include "extern.h"
57
58#define LHSZ	128
59#define	LHMASK	(LHSZ - 1)
60static struct labhash {
61	struct	labhash *lh_next;
62	u_int	lh_hash;
63	struct	s_command *lh_cmd;
64	int	lh_ref;
65} *labels[LHSZ];
66
67static char	 *compile_addr(char *, struct s_addr *);
68static char	 *compile_ccl(char **, char *);
69static char	 *compile_delimited(char *, char *);
70static char	 *compile_flags(char *, struct s_subst *);
71static regex_t	 *compile_re(char *, int);
72static char	 *compile_subst(char *, struct s_subst *);
73static char	 *compile_text(void);
74static char	 *compile_tr(char *, struct s_tr **);
75static struct s_command
76		**compile_stream(struct s_command **);
77static char	 *duptoeol(char *, const char *);
78static void	  enterlabel(struct s_command *);
79static struct s_command
80		 *findlabel(char *);
81static void	  fixuplabel(struct s_command *, struct s_command *);
82static void	  uselabel(void);
83
84/*
85 * Command specification.  This is used to drive the command parser.
86 */
87struct s_format {
88	char code;				/* Command code */
89	int naddr;				/* Number of address args */
90	enum e_args args;			/* Argument type */
91};
92
93static struct s_format cmd_fmts[] = {
94	{'{', 2, GROUP},
95	{'}', 0, ENDGROUP},
96	{'a', 1, TEXT},
97	{'b', 2, BRANCH},
98	{'c', 2, TEXT},
99	{'d', 2, EMPTY},
100	{'D', 2, EMPTY},
101	{'g', 2, EMPTY},
102	{'G', 2, EMPTY},
103	{'h', 2, EMPTY},
104	{'H', 2, EMPTY},
105	{'i', 1, TEXT},
106	{'l', 2, EMPTY},
107	{'n', 2, EMPTY},
108	{'N', 2, EMPTY},
109	{'p', 2, EMPTY},
110	{'P', 2, EMPTY},
111	{'q', 1, EMPTY},
112	{'r', 1, RFILE},
113	{'s', 2, SUBST},
114	{'t', 2, BRANCH},
115	{'w', 2, WFILE},
116	{'x', 2, EMPTY},
117	{'y', 2, TR},
118	{'!', 2, NONSEL},
119	{':', 0, LABEL},
120	{'#', 0, COMMENT},
121	{'=', 1, EMPTY},
122	{'\0', 0, COMMENT},
123};
124
125/* The compiled program. */
126struct s_command *prog;
127
128/*
129 * Compile the program into prog.
130 * Initialise appends.
131 */
132void
133compile(void)
134{
135	*compile_stream(&prog) = NULL;
136	fixuplabel(prog, NULL);
137	uselabel();
138	if (appendnum == 0)
139		appends = NULL;
140	else if ((appends = malloc(sizeof(struct s_appends) * appendnum)) ==
141	    NULL)
142		err(1, "malloc");
143	if ((match = malloc((maxnsub + 1) * sizeof(regmatch_t))) == NULL)
144		err(1, "malloc");
145}
146
147#define EATSPACE() do {							\
148	if (p)								\
149		while (*p && isspace((unsigned char)*p))                \
150			p++;						\
151	} while (0)
152
153static struct s_command **
154compile_stream(struct s_command **link)
155{
156	char *p;
157	static char lbuf[_POSIX2_LINE_MAX + 1];	/* To save stack */
158	struct s_command *cmd, *cmd2, *stack;
159	struct s_format *fp;
160	char re[_POSIX2_LINE_MAX + 1];
161	int naddr;				/* Number of addresses */
162
163	stack = 0;
164	for (;;) {
165		if ((p = cu_fgets(lbuf, sizeof(lbuf), NULL)) == NULL) {
166			if (stack != 0)
167				errx(1, "%lu: %s: unexpected EOF (pending }'s)",
168							linenum, fname);
169			return (link);
170		}
171
172semicolon:	EATSPACE();
173		if (p) {
174			if (*p == '#' || *p == '\0')
175				continue;
176			else if (*p == ';') {
177				p++;
178				goto semicolon;
179			}
180		}
181		if ((*link = cmd = malloc(sizeof(struct s_command))) == NULL)
182			err(1, "malloc");
183		link = &cmd->next;
184		cmd->nonsel = cmd->inrange = 0;
185		/* First parse the addresses */
186		naddr = 0;
187
188/* Valid characters to start an address */
189#define	addrchar(c)	(strchr("0123456789/\\$", (c)))
190		if (addrchar(*p)) {
191			naddr++;
192			if ((cmd->a1 = malloc(sizeof(struct s_addr))) == NULL)
193				err(1, "malloc");
194			p = compile_addr(p, cmd->a1);
195			EATSPACE();				/* EXTENSION */
196			if (*p == ',') {
197				p++;
198				EATSPACE();			/* EXTENSION */
199				naddr++;
200				if ((cmd->a2 = malloc(sizeof(struct s_addr)))
201				    == NULL)
202					err(1, "malloc");
203				p = compile_addr(p, cmd->a2);
204				EATSPACE();
205			} else
206				cmd->a2 = 0;
207		} else
208			cmd->a1 = cmd->a2 = 0;
209
210nonsel:		/* Now parse the command */
211		if (!*p)
212			errx(1, "%lu: %s: command expected", linenum, fname);
213		cmd->code = *p;
214		for (fp = cmd_fmts; fp->code; fp++)
215			if (fp->code == *p)
216				break;
217		if (!fp->code)
218			errx(1, "%lu: %s: invalid command code %c", linenum, fname, *p);
219		if (naddr > fp->naddr)
220			errx(1,
221				"%lu: %s: command %c expects up to %d address(es), found %d",
222				linenum, fname, *p, fp->naddr, naddr);
223		switch (fp->args) {
224		case NONSEL:			/* ! */
225			p++;
226			EATSPACE();
227			cmd->nonsel = ! cmd->nonsel;
228			goto nonsel;
229		case GROUP:			/* { */
230			p++;
231			EATSPACE();
232			cmd->next = stack;
233			stack = cmd;
234			link = &cmd->u.c;
235			if (*p)
236				goto semicolon;
237			break;
238		case ENDGROUP:
239			/*
240			 * Short-circuit command processing, since end of
241			 * group is really just a noop.
242			 */
243			cmd->nonsel = 1;
244			if (stack == 0)
245				errx(1, "%lu: %s: unexpected }", linenum, fname);
246			cmd2 = stack;
247			stack = cmd2->next;
248			cmd2->next = cmd;
249			/*FALLTHROUGH*/
250		case EMPTY:		/* d D g G h H l n N p P q x = \0 */
251			p++;
252			EATSPACE();
253			if (*p == ';') {
254				p++;
255				link = &cmd->next;
256				goto semicolon;
257			}
258			if (*p)
259				errx(1, "%lu: %s: extra characters at the end of %c command",
260						linenum, fname, cmd->code);
261			break;
262		case TEXT:			/* a c i */
263			p++;
264			EATSPACE();
265			if (*p != '\\')
266				errx(1,
267"%lu: %s: command %c expects \\ followed by text", linenum, fname, cmd->code);
268			p++;
269			EATSPACE();
270			if (*p)
271				errx(1,
272				"%lu: %s: extra characters after \\ at the end of %c command",
273				linenum, fname, cmd->code);
274			cmd->t = compile_text();
275			break;
276		case COMMENT:			/* \0 # */
277			break;
278		case WFILE:			/* w */
279			p++;
280			EATSPACE();
281			if (*p == '\0')
282				errx(1, "%lu: %s: filename expected", linenum, fname);
283			cmd->t = duptoeol(p, "w command");
284			if (aflag)
285				cmd->u.fd = -1;
286			else if ((cmd->u.fd = open(p,
287			    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
288			    DEFFILEMODE)) == -1)
289				err(1, "%s", p);
290			break;
291		case RFILE:			/* r */
292			p++;
293			EATSPACE();
294			if (*p == '\0')
295				errx(1, "%lu: %s: filename expected", linenum, fname);
296			else
297				cmd->t = duptoeol(p, "read command");
298			break;
299		case BRANCH:			/* b t */
300			p++;
301			EATSPACE();
302			if (*p == '\0')
303				cmd->t = NULL;
304			else
305				cmd->t = duptoeol(p, "branch");
306			break;
307		case LABEL:			/* : */
308			p++;
309			EATSPACE();
310			cmd->t = duptoeol(p, "label");
311			if (strlen(p) == 0)
312				errx(1, "%lu: %s: empty label", linenum, fname);
313			enterlabel(cmd);
314			break;
315		case SUBST:			/* s */
316			p++;
317			if (*p == '\0' || *p == '\\')
318				errx(1,
319"%lu: %s: substitute pattern can not be delimited by newline or backslash",
320					linenum, fname);
321			if ((cmd->u.s = malloc(sizeof(struct s_subst))) == NULL)
322				err(1, "malloc");
323			p = compile_delimited(p, re);
324			if (p == NULL)
325				errx(1,
326				"%lu: %s: unterminated substitute pattern", linenum, fname);
327			if (*re == '\0')
328				cmd->u.s->re = NULL;
329			else
330				cmd->u.s->re = compile_re(re, cmd->u.s->icase);
331			--p;
332			p = compile_subst(p, cmd->u.s);
333			p = compile_flags(p, cmd->u.s);
334			EATSPACE();
335			if (*p == ';') {
336				p++;
337				link = &cmd->next;
338				goto semicolon;
339			}
340			break;
341		case TR:			/* y */
342			p++;
343			p = compile_tr(p, &cmd->u.y);
344			EATSPACE();
345			if (*p == ';') {
346				p++;
347				link = &cmd->next;
348				goto semicolon;
349			}
350			if (*p)
351				errx(1,
352"%lu: %s: extra text at the end of a transform command", linenum, fname);
353			break;
354		}
355	}
356}
357
358/*
359 * Get a delimited string.  P points to the delimeter of the string; d points
360 * to a buffer area.  Newline and delimiter escapes are processed; other
361 * escapes are ignored.
362 *
363 * Returns a pointer to the first character after the final delimiter or NULL
364 * in the case of a non-terminated string.  The character array d is filled
365 * with the processed string.
366 */
367static char *
368compile_delimited(char *p, char *d)
369{
370	char c;
371
372	c = *p++;
373	if (c == '\0')
374		return (NULL);
375	else if (c == '\\')
376		errx(1, "%lu: %s: \\ can not be used as a string delimiter",
377				linenum, fname);
378	else if (c == '\n')
379		errx(1, "%lu: %s: newline can not be used as a string delimiter",
380				linenum, fname);
381	while (*p) {
382		if (*p == '[') {
383			if ((d = compile_ccl(&p, d)) == NULL)
384				errx(1, "%lu: %s: unbalanced brackets ([])", linenum, fname);
385			continue;
386		} else if (*p == '\\' && p[1] == '[') {
387			*d++ = *p++;
388		} else if (*p == '\\' && p[1] == c)
389			p++;
390		else if (*p == '\\' && p[1] == 'n') {
391			*d++ = '\n';
392			p += 2;
393			continue;
394		} else if (*p == '\\' && p[1] == '\\')
395			*d++ = *p++;
396		else if (*p == c) {
397			*d = '\0';
398			return (p + 1);
399		}
400		*d++ = *p++;
401	}
402	return (NULL);
403}
404
405
406/* compile_ccl: expand a POSIX character class */
407static char *
408compile_ccl(char **sp, char *t)
409{
410	int c, d;
411	char *s = *sp;
412
413	*t++ = *s++;
414	if (*s == '^')
415		*t++ = *s++;
416	if (*s == ']')
417		*t++ = *s++;
418	for (; *s && (*t = *s) != ']'; s++, t++)
419		if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) {
420			*++t = *++s, t++, s++;
421			for (c = *s; (*t = *s) != ']' || c != d; s++, t++)
422				if ((c = *s) == '\0')
423					return NULL;
424		} else if (*s == '\\' && s[1] == 'n')
425			    *t = '\n', s++;
426	return (*s == ']') ? *sp = ++s, ++t : NULL;
427}
428
429/*
430 * Compiles the regular expression in RE and returns a pointer to the compiled
431 * regular expression.
432 * Cflags are passed to regcomp.
433 */
434static regex_t *
435compile_re(char *re, int case_insensitive)
436{
437	regex_t *rep;
438	int eval, flags;
439
440
441	flags = rflags;
442	if (case_insensitive)
443		flags |= REG_ICASE;
444	if ((rep = malloc(sizeof(regex_t))) == NULL)
445		err(1, "malloc");
446	if (eval = regcomp(rep, re, flags) != 0)
447		errx(1, "%lu: %s: RE error: %s",
448				linenum, fname, strregerror(eval, rep));
449	if (maxnsub < rep->re_nsub)
450		maxnsub = rep->re_nsub;
451	return (rep);
452}
453
454/*
455 * Compile the substitution string of a regular expression and set res to
456 * point to a saved copy of it.  Nsub is the number of parenthesized regular
457 * expressions.
458 */
459static char *
460compile_subst(char *p, struct s_subst *s)
461{
462	static char lbuf[_POSIX2_LINE_MAX + 1];
463	int asize, size;
464	u_char ref;
465	char c, *text, *op, *sp;
466	int more = 1, sawesc = 0;
467
468	c = *p++;			/* Terminator character */
469	if (c == '\0')
470		return (NULL);
471
472	s->maxbref = 0;
473	s->linenum = linenum;
474	asize = 2 * _POSIX2_LINE_MAX + 1;
475	if ((text = malloc(asize)) == NULL)
476		err(1, "malloc");
477	size = 0;
478	do {
479		op = sp = text + size;
480		for (; *p; p++) {
481			if (*p == '\\' || sawesc) {
482				/*
483				 * If this is a continuation from the last
484				 * buffer, we won't have a character to
485				 * skip over.
486				 */
487				if (sawesc)
488					sawesc = 0;
489				else
490					p++;
491
492				if (*p == '\0') {
493					/*
494					 * This escaped character is continued
495					 * in the next part of the line.  Note
496					 * this fact, then cause the loop to
497					 * exit w/ normal EOL case and reenter
498					 * above with the new buffer.
499					 */
500					sawesc = 1;
501					p--;
502					continue;
503				} else if (strchr("123456789", *p) != NULL) {
504					*sp++ = '\\';
505					ref = *p - '0';
506					if (s->re != NULL &&
507					    ref > s->re->re_nsub)
508						errx(1, "%lu: %s: \\%c not defined in the RE",
509								linenum, fname, *p);
510					if (s->maxbref < ref)
511						s->maxbref = ref;
512				} else if (*p == '&' || *p == '\\')
513					*sp++ = '\\';
514			} else if (*p == c) {
515				if (*++p == '\0' && more) {
516					if (cu_fgets(lbuf, sizeof(lbuf), &more))
517						p = lbuf;
518				}
519				*sp++ = '\0';
520				size += sp - op;
521				if ((s->new = realloc(text, size)) == NULL)
522					err(1, "realloc");
523				return (p);
524			} else if (*p == '\n') {
525				errx(1,
526"%lu: %s: unescaped newline inside substitute pattern", linenum, fname);
527				/* NOTREACHED */
528			}
529			*sp++ = *p;
530		}
531		size += sp - op;
532		if (asize - size < _POSIX2_LINE_MAX + 1) {
533			asize *= 2;
534			if ((text = realloc(text, asize)) == NULL)
535				err(1, "realloc");
536		}
537	} while (cu_fgets(p = lbuf, sizeof(lbuf), &more));
538	errx(1, "%lu: %s: unterminated substitute in regular expression",
539			linenum, fname);
540	/* NOTREACHED */
541}
542
543/*
544 * Compile the flags of the s command
545 */
546static char *
547compile_flags(char *p, struct s_subst *s)
548{
549	int gn;			/* True if we have seen g or n */
550	unsigned long nval;
551	char wfile[_POSIX2_LINE_MAX + 1], *q;
552
553	s->n = 1;				/* Default */
554	s->p = 0;
555	s->wfile = NULL;
556	s->wfd = -1;
557	s->icase = 0;
558	for (gn = 0;;) {
559		EATSPACE();			/* EXTENSION */
560		switch (*p) {
561		case 'g':
562			if (gn)
563				errx(1,
564"%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
565			gn = 1;
566			s->n = 0;
567			break;
568		case '\0':
569		case '\n':
570		case ';':
571			return (p);
572		case 'p':
573			s->p = 1;
574			break;
575		case 'I':
576			s->icase = 1;
577			break;
578		case '1': case '2': case '3':
579		case '4': case '5': case '6':
580		case '7': case '8': case '9':
581			if (gn)
582				errx(1,
583"%lu: %s: more than one number or 'g' in substitute flags", linenum, fname);
584			gn = 1;
585			errno = 0;
586			nval = strtol(p, &p, 10);
587			if (errno == ERANGE || nval > INT_MAX)
588				errx(1,
589"%lu: %s: overflow in the 'N' substitute flag", linenum, fname);
590			s->n = nval;
591			p--;
592			break;
593		case 'w':
594			p++;
595#ifdef HISTORIC_PRACTICE
596			if (*p != ' ') {
597				warnx("%lu: %s: space missing before w wfile", linenum, fname);
598				return (p);
599			}
600#endif
601			EATSPACE();
602			q = wfile;
603			while (*p) {
604				if (*p == '\n')
605					break;
606				*q++ = *p++;
607			}
608			*q = '\0';
609			if (q == wfile)
610				errx(1, "%lu: %s: no wfile specified", linenum, fname);
611			s->wfile = strdup(wfile);
612			if (!aflag && (s->wfd = open(wfile,
613			    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
614			    DEFFILEMODE)) == -1)
615				err(1, "%s", wfile);
616			return (p);
617		default:
618			errx(1, "%lu: %s: bad flag in substitute command: '%c'",
619					linenum, fname, *p);
620			break;
621		}
622		p++;
623	}
624}
625
626/*
627 * Compile a translation set of strings into a lookup table.
628 */
629static char *
630compile_tr(char *p, struct s_tr **py)
631{
632	struct s_tr *y;
633	int i;
634	const char *op, *np;
635	char old[_POSIX2_LINE_MAX + 1];
636	char new[_POSIX2_LINE_MAX + 1];
637	size_t oclen, oldlen, nclen, newlen;
638	mbstate_t mbs1, mbs2;
639
640	if ((*py = y = malloc(sizeof(*y))) == NULL)
641		err(1, NULL);
642	y->multis = NULL;
643	y->nmultis = 0;
644
645	if (*p == '\0' || *p == '\\')
646		errx(1,
647	"%lu: %s: transform pattern can not be delimited by newline or backslash",
648			linenum, fname);
649	p = compile_delimited(p, old);
650	if (p == NULL)
651		errx(1, "%lu: %s: unterminated transform source string",
652				linenum, fname);
653	p = compile_delimited(p - 1, new);
654	if (p == NULL)
655		errx(1, "%lu: %s: unterminated transform target string",
656				linenum, fname);
657	EATSPACE();
658	op = old;
659	oldlen = mbsrtowcs(NULL, &op, 0, NULL);
660	if (oldlen == (size_t)-1)
661		err(1, NULL);
662	np = new;
663	newlen = mbsrtowcs(NULL, &np, 0, NULL);
664	if (newlen == (size_t)-1)
665		err(1, NULL);
666	if (newlen != oldlen)
667		errx(1, "%lu: %s: transform strings are not the same length",
668				linenum, fname);
669	if (MB_CUR_MAX == 1) {
670		/*
671		 * The single-byte encoding case is easy: generate a
672		 * lookup table.
673		 */
674		for (i = 0; i <= UCHAR_MAX; i++)
675			y->bytetab[i] = (char)i;
676		for (; *op; op++, np++)
677			y->bytetab[(u_char)*op] = *np;
678	} else {
679		/*
680		 * Multi-byte encoding case: generate a lookup table as
681		 * above, but only for single-byte characters. The first
682		 * bytes of multi-byte characters have their lookup table
683		 * entries set to 0, which causes do_tr() to search through
684		 * an auxiliary vector of multi-byte mappings.
685		 */
686		memset(&mbs1, 0, sizeof(mbs1));
687		memset(&mbs2, 0, sizeof(mbs2));
688		for (i = 0; i <= UCHAR_MAX; i++)
689			y->bytetab[i] = (btowc(i) != WEOF) ? i : 0;
690		while (*op != '\0') {
691			oclen = mbrlen(op, MB_LEN_MAX, &mbs1);
692			if (oclen == (size_t)-1 || oclen == (size_t)-2)
693				errc(1, EILSEQ, NULL);
694			nclen = mbrlen(np, MB_LEN_MAX, &mbs2);
695			if (nclen == (size_t)-1 || nclen == (size_t)-2)
696				errc(1, EILSEQ, NULL);
697			if (oclen == 1 && nclen == 1)
698				y->bytetab[(u_char)*op] = *np;
699			else {
700				y->bytetab[(u_char)*op] = 0;
701				y->multis = realloc(y->multis,
702				    (y->nmultis + 1) * sizeof(*y->multis));
703				if (y->multis == NULL)
704					err(1, NULL);
705				i = y->nmultis++;
706				y->multis[i].fromlen = oclen;
707				memcpy(y->multis[i].from, op, oclen);
708				y->multis[i].tolen = nclen;
709				memcpy(y->multis[i].to, np, nclen);
710			}
711			op += oclen;
712			np += nclen;
713		}
714	}
715	return (p);
716}
717
718/*
719 * Compile the text following an a or i command.
720 */
721static char *
722compile_text(void)
723{
724	int asize, esc_nl, size;
725	char *text, *p, *op, *s;
726	char lbuf[_POSIX2_LINE_MAX + 1];
727
728	asize = 2 * _POSIX2_LINE_MAX + 1;
729	if ((text = malloc(asize)) == NULL)
730		err(1, "malloc");
731	size = 0;
732	while (cu_fgets(lbuf, sizeof(lbuf), NULL)) {
733		op = s = text + size;
734		p = lbuf;
735		EATSPACE();
736		for (esc_nl = 0; *p != '\0'; p++) {
737			if (*p == '\\' && p[1] != '\0' && *++p == '\n')
738				esc_nl = 1;
739			*s++ = *p;
740		}
741		size += s - op;
742		if (!esc_nl) {
743			*s = '\0';
744			break;
745		}
746		if (asize - size < _POSIX2_LINE_MAX + 1) {
747			asize *= 2;
748			if ((text = realloc(text, asize)) == NULL)
749				err(1, "realloc");
750		}
751	}
752	text[size] = '\0';
753	if ((p = realloc(text, size + 1)) == NULL)
754		err(1, "realloc");
755	return (p);
756}
757
758/*
759 * Get an address and return a pointer to the first character after
760 * it.  Fill the structure pointed to according to the address.
761 */
762static char *
763compile_addr(char *p, struct s_addr *a)
764{
765	char *end, re[_POSIX2_LINE_MAX + 1];
766	int icase;
767
768	icase = 0;
769
770	switch (*p) {
771	case '\\':				/* Context address */
772		++p;
773		/* FALLTHROUGH */
774	case '/':				/* Context address */
775		p = compile_delimited(p, re);
776		if (p == NULL)
777			errx(1, "%lu: %s: unterminated regular expression", linenum, fname);
778		/* Check for case insensitive regexp flag */
779		if (*p == 'I') {
780			icase = 1;
781			p++;
782		}
783		if (*re == '\0')
784			a->u.r = NULL;
785		else
786			a->u.r = compile_re(re, icase);
787		a->type = AT_RE;
788		return (p);
789
790	case '$':				/* Last line */
791		a->type = AT_LAST;
792		return (p + 1);
793						/* Line number */
794	case '0': case '1': case '2': case '3': case '4':
795	case '5': case '6': case '7': case '8': case '9':
796		a->type = AT_LINE;
797		a->u.l = strtol(p, &end, 10);
798		return (end);
799	default:
800		errx(1, "%lu: %s: expected context address", linenum, fname);
801		return (NULL);
802	}
803}
804
805/*
806 * duptoeol --
807 *	Return a copy of all the characters up to \n or \0.
808 */
809static char *
810duptoeol(char *s, const char *ctype)
811{
812	size_t len;
813	int ws;
814	char *p, *start;
815
816	ws = 0;
817	for (start = s; *s != '\0' && *s != '\n'; ++s)
818		ws = isspace((unsigned char)*s);
819	*s = '\0';
820	if (ws)
821		warnx("%lu: %s: whitespace after %s", linenum, fname, ctype);
822	len = s - start + 1;
823	if ((p = malloc(len)) == NULL)
824		err(1, "malloc");
825	return (memmove(p, start, len));
826}
827
828/*
829 * Convert goto label names to addresses, and count a and r commands, in
830 * the given subset of the script.  Free the memory used by labels in b
831 * and t commands (but not by :).
832 *
833 * TODO: Remove } nodes
834 */
835static void
836fixuplabel(struct s_command *cp, struct s_command *end)
837{
838
839	for (; cp != end; cp = cp->next)
840		switch (cp->code) {
841		case 'a':
842		case 'r':
843			appendnum++;
844			break;
845		case 'b':
846		case 't':
847			/* Resolve branch target. */
848			if (cp->t == NULL) {
849				cp->u.c = NULL;
850				break;
851			}
852			if ((cp->u.c = findlabel(cp->t)) == NULL)
853				errx(1, "%lu: %s: undefined label '%s'", linenum, fname, cp->t);
854			free(cp->t);
855			break;
856		case '{':
857			/* Do interior commands. */
858			fixuplabel(cp->u.c, cp->next);
859			break;
860		}
861}
862
863/*
864 * Associate the given command label for later lookup.
865 */
866static void
867enterlabel(struct s_command *cp)
868{
869	struct labhash **lhp, *lh;
870	u_char *p;
871	u_int h, c;
872
873	for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++)
874		h = (h << 5) + h + c;
875	lhp = &labels[h & LHMASK];
876	for (lh = *lhp; lh != NULL; lh = lh->lh_next)
877		if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0)
878			errx(1, "%lu: %s: duplicate label '%s'", linenum, fname, cp->t);
879	if ((lh = malloc(sizeof *lh)) == NULL)
880		err(1, "malloc");
881	lh->lh_next = *lhp;
882	lh->lh_hash = h;
883	lh->lh_cmd = cp;
884	lh->lh_ref = 0;
885	*lhp = lh;
886}
887
888/*
889 * Find the label contained in the command l in the command linked
890 * list cp.  L is excluded from the search.  Return NULL if not found.
891 */
892static struct s_command *
893findlabel(char *name)
894{
895	struct labhash *lh;
896	u_char *p;
897	u_int h, c;
898
899	for (h = 0, p = (u_char *)name; (c = *p) != 0; p++)
900		h = (h << 5) + h + c;
901	for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) {
902		if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) {
903			lh->lh_ref = 1;
904			return (lh->lh_cmd);
905		}
906	}
907	return (NULL);
908}
909
910/*
911 * Warn about any unused labels.  As a side effect, release the label hash
912 * table space.
913 */
914static void
915uselabel(void)
916{
917	struct labhash *lh, *next;
918	int i;
919
920	for (i = 0; i < LHSZ; i++) {
921		for (lh = labels[i]; lh != NULL; lh = next) {
922			next = lh->lh_next;
923			if (!lh->lh_ref)
924				warnx("%lu: %s: unused label '%s'",
925				    linenum, fname, lh->lh_cmd->t);
926			free(lh);
927		}
928	}
929}
930