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Revision 1.13, Thu Aug 27 00:31:12 2009 UTC (12 years, 3 months ago) by dholland
Branch: MAIN
CVS Tags: yamt-pagecache-tag8, yamt-pagecache-base9, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, yamt-pagecache-base5, yamt-pagecache-base4, yamt-pagecache-base3, yamt-pagecache-base2, yamt-pagecache-base, yamt-pagecache, tls-maxphys-base, tls-maxphys, tls-earlyentropy-base, tls-earlyentropy, riastradh-xf86-video-intel-2-7-1-pre-2-21-15, riastradh-drm2-base3, riastradh-drm2-base2, riastradh-drm2-base1, riastradh-drm2-base, riastradh-drm2, prg-localcount2-base3, prg-localcount2-base2, prg-localcount2-base1, prg-localcount2-base, prg-localcount2, phil-wifi-base, phil-wifi-20200421, phil-wifi-20200411, phil-wifi-20200406, phil-wifi-20191119, phil-wifi-20190609, phil-wifi, pgoyette-localcount-base, pgoyette-localcount-20170426, pgoyette-localcount-20170320, pgoyette-localcount-20170107, pgoyette-localcount-20161104, pgoyette-localcount-20160806, pgoyette-localcount-20160726, pgoyette-localcount, pgoyette-compat-merge-20190127, pgoyette-compat-base, pgoyette-compat-20190127, pgoyette-compat-20190118, pgoyette-compat-1226, pgoyette-compat-1126, pgoyette-compat-1020, pgoyette-compat-0930, pgoyette-compat-0906, pgoyette-compat-0728, pgoyette-compat-0625, pgoyette-compat-0521, pgoyette-compat-0502, pgoyette-compat-0422, pgoyette-compat-0415, pgoyette-compat-0407, pgoyette-compat-0330, pgoyette-compat-0322, pgoyette-compat-0315, pgoyette-compat, perseant-stdc-iso10646-base, perseant-stdc-iso10646, netbsd-9-base, netbsd-9-2-RELEASE, netbsd-9-1-RELEASE, netbsd-9-0-RELEASE, netbsd-9-0-RC2, netbsd-9-0-RC1, netbsd-9, netbsd-8-base, netbsd-8-2-RELEASE, netbsd-8-1-RELEASE, netbsd-8-1-RC1, netbsd-8-0-RELEASE, netbsd-8-0-RC2, netbsd-8-0-RC1, netbsd-8, netbsd-7-nhusb-base-20170116, netbsd-7-nhusb-base, netbsd-7-nhusb, netbsd-7-base, netbsd-7-2-RELEASE, netbsd-7-1-RELEASE, netbsd-7-1-RC2, netbsd-7-1-RC1, netbsd-7-1-2-RELEASE, netbsd-7-1-1-RELEASE, netbsd-7-1, netbsd-7-0-RELEASE, netbsd-7-0-RC3, netbsd-7-0-RC2, netbsd-7-0-RC1, netbsd-7-0-2-RELEASE, netbsd-7-0-1-RELEASE, netbsd-7-0, netbsd-7, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-5-RELEASE, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-6-RELEASE, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, matt-premerge-20091211, matt-nb8-mediatek-base, matt-nb8-mediatek, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, matt-mips64-premerge-20101231, localcount-20160914, is-mlppp-base, is-mlppp, cjep_sun2x-base1, cjep_sun2x-base, cjep_sun2x, cjep_staticlib_x-base1, cjep_staticlib_x-base, cjep_staticlib_x, cherry-xenmp-base, cherry-xenmp, bouyer-socketcan-base1, bouyer-socketcan-base, bouyer-socketcan, bouyer-quota2-nbase, bouyer-quota2-base, bouyer-quota2, agc-symver-base, agc-symver
Changes since 1.12: +12 -18 lines

ANSIfy function definitions

/*	$NetBSD: rxp.c,v 1.13 2009/08/27 00:31:12 dholland Exp $	*/

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jim R. Oldroyd at The Instruction Set and Keith Gabryelski at
 * Commodore Business Machines.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)rxp.c	8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: rxp.c,v 1.13 2009/08/27 00:31:12 dholland Exp $");
#endif
#endif /* not lint */

/*
 * regular expression parser
 *
 * external functions and return values are:
 * rxp_compile(s)
 *	TRUE	success
 *	FALSE	parse failure; error message will be in char rxperr[]
 * metas are:
 *	{...}	optional pattern, equialent to [...|]
 *	|	alternate pattern
 *	[...]	pattern delimiters
 *
 * rxp_match(s)
 *	TRUE	string s matches compiled pattern
 *	FALSE	match failure or regexp error
 *
 * rxp_expand()
 *	char *	reverse-engineered regular expression string
 *	NULL	regexp error
 */

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include "quiz.h"
					/* regexp tokens,	arg */
#define	LIT	(-1)			/* literal character,	char */
#define	SOT	(-2)			/* start text anchor,	- */
#define	EOT	(-3)			/* end text anchor,	- */
#define	GRP_S	(-4)			/* start alternate grp,	ptr_to_end */
#define	GRP_E	(-5)			/* end group,		- */
#define	ALT_S	(-6)			/* alternate starts,	ptr_to_next */
#define	ALT_E	(-7)			/* alternate ends,	- */
#define	END	(-8)			/* end of regexp,	- */

typedef short Rxp_t;			/* type for regexp tokens */

static Rxp_t rxpbuf[RXP_LINE_SZ];	/* compiled regular expression buffer */
char rxperr[128];			/* parser error message */

static int	 rxp__compile(const char *, int);
static char	*rxp__expand(int);
static int	 rxp__match(const char *, int, Rxp_t *, Rxp_t *, const char *);

int
rxp_compile(const char *s)
{
	return (rxp__compile(s, TRUE));
}

static int
rxp__compile(const char *s, int first)
{
	static Rxp_t *rp;
	static const char *sp;
	Rxp_t *grp_ptr;
	Rxp_t *alt_ptr;
	int esc, err;

	esc = 0;
	if (first) {
		rp = rxpbuf;
		sp = s;
		*rp++ = SOT;	/* auto-anchor: pat is really ^pat$ */
		*rp++ = GRP_S;	/* auto-group: ^pat$ is really ^[pat]$ */
		*rp++ = 0;
	}
	*rp++ = ALT_S;
	alt_ptr = rp;
	*rp++ = 0;
	for (; *sp; ++sp) {
		if (rp - rxpbuf >= RXP_LINE_SZ - 4) {
			(void)snprintf(rxperr, sizeof(rxperr),
			    "regular expression too long %s", s);
			return (FALSE);
		}
		if (*sp == ':' && !esc)
			break;
		if (esc) {
			*rp++ = LIT;
			*rp++ = *sp;
			esc = 0;
		}
		else switch (*sp) {
		case '\\':
			esc = 1;
			break;
		case '{':
		case '[':
			*rp++ = GRP_S;
			grp_ptr = rp;
			*rp++ = 0;
			sp++;
			if ((err = rxp__compile(s, FALSE)) != TRUE)
				return (err);
			*rp++ = GRP_E;
			*grp_ptr = rp - rxpbuf;
			break;
		case '}':
		case ']':
		case '|':
			*rp++ = ALT_E;
			*alt_ptr = rp - rxpbuf;
			if (*sp != ']') {
				*rp++ = ALT_S;
				alt_ptr = rp;
				*rp++ = 0;
			}
			if (*sp != '|') {
				if (*sp != ']') {
					*rp++ = ALT_E;
					*alt_ptr = rp - rxpbuf;
				}
				if (first) {
					(void)snprintf(rxperr, sizeof(rxperr),
					    "unmatched alternator in regexp %s",
					     s);
					return (FALSE);
				}
				return (TRUE);
			}
			break;
		default:
			*rp++ = LIT;
			*rp++ = *sp;
			esc = 0;
			break;
		}
	}
	if (!first) {
		(void)snprintf(rxperr, sizeof(rxperr),
		    "unmatched alternator in regexp %s", s);
		return (FALSE);
	}
	*rp++ = ALT_E;
	*alt_ptr = rp - rxpbuf;
	*rp++ = GRP_E;
	*(rxpbuf + 2) = rp - rxpbuf;
	*rp++ = EOT;
	*rp = END;
	return (TRUE);
}

/*
 * match string against compiled regular expression
 */
int
rxp_match(const char *s)
{
	return (rxp__match(s, TRUE, NULL, NULL, NULL));
}

static int
rxp__match(const char *s,
	   int first,
	   Rxp_t *j_succ,		/* jump here on successful alt match */
	   Rxp_t *j_fail,		/* jump here on failed match */
	   const char *sp_fail)		/* reset sp to here on failed match */
{
	static Rxp_t *rp;
	static const char *sp;
	int ch;
	Rxp_t *grp_end = NULL;

	if (first) {
		rp = rxpbuf;
		sp = s;
	}
	while (rp < rxpbuf + RXP_LINE_SZ && *rp != END)
		switch(*rp) {
		case LIT:
			rp++;
			ch = isascii(*rp) && isupper(*rp) ? tolower(*rp) : *rp;
			if (ch != *sp++) {
				rp = j_fail;
				sp = sp_fail;
				return (FALSE);
			}
			rp++;
			break;
		case SOT:
			if (sp != s)
				return (FALSE);
			rp++;
			break;
		case EOT:
			if (*sp != 0)
				return (FALSE);
			rp++;
			break;
		case GRP_S:
			rp++;
			grp_end = rxpbuf + *rp++;
			break;
		case ALT_S:
			rp++;
			rxp__match(sp, FALSE, grp_end, rxpbuf + *rp++, sp);
			break;
		case ALT_E:
			rp = j_succ;
			return (TRUE);
		case GRP_E:
			rp = j_fail;
			sp = sp_fail;
			return (FALSE);
		default:
			abort();
		}
	return (*rp != END ? FALSE : TRUE);
}

/*
 * Reverse engineer the regular expression, by picking first of all alternates.
 */
char *
rxp_expand(void)
{
	return (rxp__expand(TRUE));
}

static char *
rxp__expand(int first)
{
	static char buf[RXP_LINE_SZ/2];
	static Rxp_t *rp;
	static char *bp;
	Rxp_t *grp_ptr;
	char *err;

	if (first) {
		rp = rxpbuf;
		bp = buf;
	}
	while (rp < rxpbuf + RXP_LINE_SZ && *rp != END)
		switch(*rp) {
		case LIT:
			rp++;
			*bp++ = *rp++;
			break;
		case GRP_S:
			rp++;
			grp_ptr = rxpbuf + *rp;
			rp++;
			if ((err = rxp__expand(FALSE)) == NULL)
				return (err);
			rp = grp_ptr;
			break;
		case ALT_E:
			return (buf);
		case ALT_S:
			rp++;
			/* FALLTHROUGH */
		case SOT:
		case EOT:
		case GRP_E:
			rp++;
			break;
		default:
			return (NULL);
		}
	if (first) {
		if (*rp != END)
			return (NULL);
		*bp = '\0';
	}
	return (buf);
}