freebsd-skq/lib/libc/regex/regex2.h
Kyle Evans 15ae9efabe The impending libregex will implement GNU extensions to bring BREs and
EREs closer together. Prepare for this and reduce the diff of libregex changes by
refactoring and combining the top-level parsers for EREs/BREs ahead of time.

Branching functionality has been split out to make it easier to follow the combined
version of the top-level parser. It may also be enabled in the parsing context to make
it easier when libregex enables branching for BREs.

A branching context was also added for the various branching functions and so that
BREs, for instance, can determine if they're the first expression in a chain of expressions
within the current branch and treat '*' as ordinary if so.

This should have no functional impact and negligible performance impact.

Reviewed by:	cem, emaste, pfg
Approved by:	emaste (mentor)
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D10920
2017-07-06 17:01:51 +00:00

194 lines
6.8 KiB
C

/*-
* 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
* $FreeBSD$
*/
/*
* First, the stuff that ends up in the outside-world include file
= typedef off_t regoff_t;
= typedef struct {
= int re_magic;
= size_t re_nsub; // number of parenthesized subexpressions
= const char *re_endp; // end pointer for REG_PEND
= struct re_guts *re_g; // none of your business :-)
= } regex_t;
= typedef struct {
= regoff_t rm_so; // start of match
= regoff_t rm_eo; // end of match
= } regmatch_t;
*/
/*
* 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 unsigned long sopno;
#define OPRMASK 0xf8000000L
#define OPDMASK 0x07ffffffL
#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 (1L<<OPSHIFT) /* endmarker - */
#define OCHAR (2L<<OPSHIFT) /* character wide character */
#define OBOL (3L<<OPSHIFT) /* left anchor - */
#define OEOL (4L<<OPSHIFT) /* right anchor - */
#define OANY (5L<<OPSHIFT) /* . - */
#define OANYOF (6L<<OPSHIFT) /* [...] set number */
#define OBACK_ (7L<<OPSHIFT) /* begin \d paren number */
#define O_BACK (8L<<OPSHIFT) /* end \d paren number */
#define OPLUS_ (9L<<OPSHIFT) /* + prefix fwd to suffix */
#define O_PLUS (10L<<OPSHIFT) /* + suffix back to prefix */
#define OQUEST_ (11L<<OPSHIFT) /* ? prefix fwd to suffix */
#define O_QUEST (12L<<OPSHIFT) /* ? suffix back to prefix */
#define OLPAREN (13L<<OPSHIFT) /* ( fwd to ) */
#define ORPAREN (14L<<OPSHIFT) /* ) back to ( */
#define OCH_ (15L<<OPSHIFT) /* begin choice fwd to OOR2 */
#define OOR1 (16L<<OPSHIFT) /* | pt. 1 back to OOR1 or OCH_ */
#define OOR2 (17L<<OPSHIFT) /* | pt. 2 fwd to OOR2 or O_CH */
#define O_CH (18L<<OPSHIFT) /* end choice back to OOR1 */
#define OBOW (19L<<OPSHIFT) /* begin word - */
#define OEOW (20L<<OPSHIFT) /* end word - */
/*
* Structures for [] character-set representation.
*/
typedef struct {
wint_t min;
wint_t max;
} crange;
typedef struct {
unsigned char bmp[NC / 8];
wctype_t *types;
unsigned int ntypes;
wint_t *wides;
unsigned int nwides;
crange *ranges;
unsigned int nranges;
int invert;
int icase;
} cset;
static int
CHIN1(cset *cs, wint_t ch)
{
unsigned int i;
assert(ch >= 0);
if (ch < NC)
return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
cs->invert);
for (i = 0; i < cs->nwides; i++)
if (ch == cs->wides[i])
return (!cs->invert);
for (i = 0; i < cs->nranges; i++)
if (cs->ranges[i].min <= ch && ch <= cs->ranges[i].max)
return (!cs->invert);
for (i = 0; i < cs->ntypes; i++)
if (iswctype(ch, cs->types[i]))
return (!cs->invert);
return (cs->invert);
}
static __inline int
CHIN(cset *cs, wint_t ch)
{
assert(ch >= 0);
if (ch < NC)
return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
cs->invert);
else if (cs->icase)
return (CHIN1(cs, ch) || CHIN1(cs, towlower(ch)) ||
CHIN1(cs, towupper(ch)));
else
return (CHIN1(cs, ch));
}
/*
* main compiled-expression structure
*/
struct re_guts {
int magic;
# define MAGIC2 ((('R'^0200)<<8)|'E')
sop *strip; /* malloced area for strip */
unsigned int ncsets; /* number of csets in use */
cset *sets; /* -> cset [ncsets] */
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 */
char *must; /* match must contain this string */
int moffset; /* latest point at which must may be located */
int *charjump; /* Boyer-Moore char jump table */
int *matchjump; /* Boyer-Moore match jump table */
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? */
};
/* misc utilities */
#define OUT (CHAR_MIN - 1) /* a non-character value */
#define IGN (CHAR_MIN - 2)
#define ISWORD(c) (iswalnum((uch)(c)) || (c) == '_')