/*	$OpenBSD: regex2.h,v 1.7 2004/11/30 17:04:23 otto Exp $	*/

/*-
 * Copyright (c) 1992, 1993, 1994 Henry Spencer.
 * Copyright (c) 1992, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Henry Spencer.
 *
 * 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.
 *
 *	@ (#)regex2.h	8.4 (Berkeley) 3/20/94
 */

/*
 * internals of regex_t
 */
#define MAGIC1 ((('r' ^ 0200) << 8) | 'e')

/*
 * The internal representation is a *strip*, a sequence of
 * operators ending with an endmarker. (Some terminology etc. is a
 * historical relic of earlier versions which used multiple strips.)
 * Certain oddities in the representation are there to permit running
 * the machinery backwards; in particular, any deviation from sequential
 * flow must be marked at both its source and its destination.  Some
 * fine points:
 *
 * - OPLUS_ and O_PLUS are *inside* the loop they create.
 * - OQUEST_ and O_QUEST are *outside* the bypass they create.
 * - OCH_ and O_CH are *outside* the multi-way branch they create, while
 *   OOR1 and OOR2 are respectively the end and the beginning of one of
 *   the branches.  Note that there is an implicit OOR2 following OCH_
 *   and an implicit OOR1 preceding O_CH.
 *
 * In state representations, an operator's bit is on to signify a state
 * immediately *preceding* "execution" of that operator.
 */
typedef unsigned long sop; /* strip operator */
typedef long sopno;
#define OPRMASK 0xf8000000LU
#define OPDMASK 0x07ffffffLU
#define OPSHIFT ((unsigned)27)
#define OP(n) ((n) & OPRMASK)
#define OPND(n) ((n) & OPDMASK)
#define SOP(op, opnd) ((op) | (opnd))
/* operators			   meaning	operand			*/
/*						(back, fwd are offsets)	*/
#define OEND (1LU << OPSHIFT) /* endmarker -   */
#define OCHAR (2LU << OPSHIFT) /* character unsigned char  */
#define OBOL (3LU << OPSHIFT) /* left anchor -   */
#define OEOL (4LU << OPSHIFT) /* right anchor -   */
#define OANY (5LU << OPSHIFT) /* .  -   */
#define OANYOF (6LU << OPSHIFT) /* [...] set number  */
#define OBACK_ (7LU << OPSHIFT) /* begin \d paren number  */
#define O_BACK (8LU << OPSHIFT) /* end \d paren number  */
#define OPLUS_ (9LU << OPSHIFT) /* + prefix fwd to suffix  */
#define O_PLUS (10LU << OPSHIFT) /* + suffix back to prefix  */
#define OQUEST_ (11LU << OPSHIFT) /*? prefix fwd to suffix  */
#define O_QUEST (12LU << OPSHIFT) /*? suffix back to prefix  */
#define OLPAREN (13LU << OPSHIFT) /*(  fwd to )  */
#define ORPAREN (14LU << OPSHIFT) /* )  back to (  */
#define OCH_ (15LU << OPSHIFT) /* begin choice fwd to OOR2  */
#define OOR1 (16LU << OPSHIFT) /* | pt. 1 back to OOR1 or OCH_ */
#define OOR2 (17LU << OPSHIFT) /* | pt. 2 fwd to OOR2 or O_CH */
#define O_CH (18LU << OPSHIFT) /* end choice back to OOR1  */
#define OBOW (19LU << OPSHIFT) /* begin word -   */
#define OEOW (20LU << OPSHIFT) /* end word -   */

/*
 * Structure for [] character-set representation.  Character sets are
 * done as bit vectors, grouped 8 to a byte vector for compactness.
 * The individual set therefore has both a pointer to the byte vector
 * and a mask to pick out the relevant bit of each byte.  A hash code
 * simplifies testing whether two sets could be identical.
 *
 * This will get trickier for multicharacter collating elements.  As
 * preliminary hooks for dealing with such things, we also carry along
 * a string of multi-character elements, and decide the size of the
 * vectors at run time.
 */
typedef struct {
	ut8 *ptr; /* -> ut8 [csetsize] */
	ut8 mask; /* bit within array */
	ut8 hash; /* hash code */
	size_t smultis;
	char *multis; /* -> char[smulti]  ab\0cd\0ef\0\0 */
} cset;
/* note that CHadd and CHsub are unsafe, and CHIN doesn't yield 0/1 */
#define CHadd(cs, c) ((cs)->ptr[(ut8) (c)] |= (cs)->mask, (cs)->hash += (c))
#define CHsub(cs, c) ((cs)->ptr[(ut8) (c)] &= ~ (cs)->mask, (cs)->hash -= (c))
#define CHIN(cs, c) ((cs)->ptr[(ut8) (c)] & (cs)->mask)
#define MCadd(p, cs, cp) mcadd(p, cs, cp) /* regcomp() internal fns */
#define MCsub(p, cs, cp) mcsub(p, cs, cp)
#define MCin(p, cs, cp) mcin(p, cs, cp)

/* stuff for character categories */
typedef unsigned char cat_t;

/*
 * main compiled-expression structure
 */
struct re_guts {
	int magic;
#define MAGIC2 ((('R' ^ 0200) << 8) | 'E')
	sop *strip; /* malloced area for strip */
	int csetsize; /* number of bits in a cset vector */
	int ncsets; /* number of csets in use */
	cset *sets; /* -> cset [ncsets] */
	ut8 *setbits; /* -> ut8[csetsize][ncsets/CHAR_BIT] */
	int cflags; /* copy of regcomp () cflags argument */
	sopno nstates; /* = number of sops */
	sopno firststate; /* the initial OEND (normally 0) */
	sopno laststate; /* the final OEND */
	int iflags; /* internal flags */
#define USEBOL 01 /* used ^ */
#define USEEOL 02 /* used $ */
#define BAD 04 /* something wrong */
	int nbol; /* number of ^ used */
	int neol; /* number of $ used */
	int ncategories; /* how many character categories */
	cat_t *categories; /* ->catspace[-CHAR_MIN] */
	char *must; /* match must contain this string */
	int mlen; /* length of must */
	size_t nsub; /* copy of re_nsub */
	int backrefs; /* does it use back references? */
	sopno nplus; /* how deep does it nest +s? */
	/* catspace must be last */
	cat_t catspace[1]; /* actually [NC] */
};

/* misc utilities */
#undef OUT
#define OUT (CHAR_MAX + 1) /* a non-character value */
#define ISWORD(c) (isalnum ((ut8) (c)) || (c) == '_')