xref: /openbsd-src/lib/libc/regex/regex2.h (revision 33b4f39fbeffad07bc3206f173cff9f3c9901cd1)
1 /*	$OpenBSD: regex2.h,v 1.6 2003/06/02 20:18:36 millert Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
5  * Copyright (c) 1992, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Henry Spencer.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)regex2.h	8.4 (Berkeley) 3/20/94
36  */
37 
38 /*
39  * First, the stuff that ends up in the outside-world include file
40  = typedef off_t regoff_t;
41  = typedef struct {
42  = 	int re_magic;
43  = 	size_t re_nsub;		// number of parenthesized subexpressions
44  = 	const char *re_endp;	// end pointer for REG_PEND
45  = 	struct re_guts *re_g;	// none of your business :-)
46  = } regex_t;
47  = typedef struct {
48  = 	regoff_t rm_so;		// start of match
49  = 	regoff_t rm_eo;		// end of match
50  = } regmatch_t;
51  */
52 /*
53  * internals of regex_t
54  */
55 #define	MAGIC1	((('r'^0200)<<8) | 'e')
56 
57 /*
58  * The internal representation is a *strip*, a sequence of
59  * operators ending with an endmarker.  (Some terminology etc. is a
60  * historical relic of earlier versions which used multiple strips.)
61  * Certain oddities in the representation are there to permit running
62  * the machinery backwards; in particular, any deviation from sequential
63  * flow must be marked at both its source and its destination.  Some
64  * fine points:
65  *
66  * - OPLUS_ and O_PLUS are *inside* the loop they create.
67  * - OQUEST_ and O_QUEST are *outside* the bypass they create.
68  * - OCH_ and O_CH are *outside* the multi-way branch they create, while
69  *   OOR1 and OOR2 are respectively the end and the beginning of one of
70  *   the branches.  Note that there is an implicit OOR2 following OCH_
71  *   and an implicit OOR1 preceding O_CH.
72  *
73  * In state representations, an operator's bit is on to signify a state
74  * immediately *preceding* "execution" of that operator.
75  */
76 typedef unsigned long sop;	/* strip operator */
77 typedef long sopno;
78 #define	OPRMASK	0xf8000000LU
79 #define	OPDMASK	0x07ffffffLU
80 #define	OPSHIFT	((unsigned)27)
81 #define	OP(n)	((n)&OPRMASK)
82 #define	OPND(n)	((n)&OPDMASK)
83 #define	SOP(op, opnd)	((op)|(opnd))
84 /* operators			   meaning	operand			*/
85 /*						(back, fwd are offsets)	*/
86 #define	OEND	(1LU<<OPSHIFT)	/* endmarker	-			*/
87 #define	OCHAR	(2LU<<OPSHIFT)	/* character	unsigned char		*/
88 #define	OBOL	(3LU<<OPSHIFT)	/* left anchor	-			*/
89 #define	OEOL	(4LU<<OPSHIFT)	/* right anchor	-			*/
90 #define	OANY	(5LU<<OPSHIFT)	/* .		-			*/
91 #define	OANYOF	(6LU<<OPSHIFT)	/* [...]	set number		*/
92 #define	OBACK_	(7LU<<OPSHIFT)	/* begin \d	paren number		*/
93 #define	O_BACK	(8LU<<OPSHIFT)	/* end \d	paren number		*/
94 #define	OPLUS_	(9LU<<OPSHIFT)	/* + prefix	fwd to suffix		*/
95 #define	O_PLUS	(10LU<<OPSHIFT)	/* + suffix	back to prefix		*/
96 #define	OQUEST_	(11LU<<OPSHIFT)	/* ? prefix	fwd to suffix		*/
97 #define	O_QUEST	(12LU<<OPSHIFT)	/* ? suffix	back to prefix		*/
98 #define	OLPAREN	(13LU<<OPSHIFT)	/* (		fwd to )		*/
99 #define	ORPAREN	(14LU<<OPSHIFT)	/* )		back to (		*/
100 #define	OCH_	(15LU<<OPSHIFT)	/* begin choice	fwd to OOR2		*/
101 #define	OOR1	(16LU<<OPSHIFT)	/* | pt. 1	back to OOR1 or OCH_	*/
102 #define	OOR2	(17LU<<OPSHIFT)	/* | pt. 2	fwd to OOR2 or O_CH	*/
103 #define	O_CH	(18LU<<OPSHIFT)	/* end choice	back to OOR1		*/
104 #define	OBOW	(19LU<<OPSHIFT)	/* begin word	-			*/
105 #define	OEOW	(20LU<<OPSHIFT)	/* end word	-			*/
106 
107 /*
108  * Structure for [] character-set representation.  Character sets are
109  * done as bit vectors, grouped 8 to a byte vector for compactness.
110  * The individual set therefore has both a pointer to the byte vector
111  * and a mask to pick out the relevant bit of each byte.  A hash code
112  * simplifies testing whether two sets could be identical.
113  *
114  * This will get trickier for multicharacter collating elements.  As
115  * preliminary hooks for dealing with such things, we also carry along
116  * a string of multi-character elements, and decide the size of the
117  * vectors at run time.
118  */
119 typedef struct {
120 	uch *ptr;		/* -> uch [csetsize] */
121 	uch mask;		/* bit within array */
122 	uch hash;		/* hash code */
123 	size_t smultis;
124 	char *multis;		/* -> char[smulti]  ab\0cd\0ef\0\0 */
125 } cset;
126 /* note that CHadd and CHsub are unsafe, and CHIN doesn't yield 0/1 */
127 #define	CHadd(cs, c)	((cs)->ptr[(uch)(c)] |= (cs)->mask, (cs)->hash += (c))
128 #define	CHsub(cs, c)	((cs)->ptr[(uch)(c)] &= ~(cs)->mask, (cs)->hash -= (c))
129 #define	CHIN(cs, c)	((cs)->ptr[(uch)(c)] & (cs)->mask)
130 #define	MCadd(p, cs, cp)	mcadd(p, cs, cp)	/* regcomp() internal fns */
131 #define	MCsub(p, cs, cp)	mcsub(p, cs, cp)
132 #define	MCin(p, cs, cp)	mcin(p, cs, cp)
133 
134 /* stuff for character categories */
135 typedef unsigned char cat_t;
136 
137 /*
138  * main compiled-expression structure
139  */
140 struct re_guts {
141 	int magic;
142 #		define	MAGIC2	((('R'^0200)<<8)|'E')
143 	sop *strip;		/* malloced area for strip */
144 	int csetsize;		/* number of bits in a cset vector */
145 	int ncsets;		/* number of csets in use */
146 	cset *sets;		/* -> cset [ncsets] */
147 	uch *setbits;		/* -> uch[csetsize][ncsets/CHAR_BIT] */
148 	int cflags;		/* copy of regcomp() cflags argument */
149 	sopno nstates;		/* = number of sops */
150 	sopno firststate;	/* the initial OEND (normally 0) */
151 	sopno laststate;	/* the final OEND */
152 	int iflags;		/* internal flags */
153 #		define	USEBOL	01	/* used ^ */
154 #		define	USEEOL	02	/* used $ */
155 #		define	BAD	04	/* something wrong */
156 	int nbol;		/* number of ^ used */
157 	int neol;		/* number of $ used */
158 	int ncategories;	/* how many character categories */
159 	cat_t *categories;	/* ->catspace[-CHAR_MIN] */
160 	char *must;		/* match must contain this string */
161 	int mlen;		/* length of must */
162 	size_t nsub;		/* copy of re_nsub */
163 	int backrefs;		/* does it use back references? */
164 	sopno nplus;		/* how deep does it nest +s? */
165 	/* catspace must be last */
166 	cat_t catspace[1];	/* actually [NC] */
167 };
168 
169 /* misc utilities */
170 #define	OUT	(CHAR_MAX+1)	/* a non-character value */
171 #define	ISWORD(c)	(isalnum(c) || (c) == '_')
172