regex2.h

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/*  $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_MIN + CHAR_MAX + 1) /* a non-character value */
#define ISWORD(c) (isalnum((ut8)(c)) || (c) == '_')