xref: /freebsd/lib/libc/regex/regex2.h (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 unsigned long sopno;
78 #define	OPRMASK	0xf8000000L
79 #define	OPDMASK	0x07ffffffL
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	(1L<<OPSHIFT)	/* endmarker	-			*/
87 #define	OCHAR	(2L<<OPSHIFT)	/* character	wide character		*/
88 #define	OBOL	(3L<<OPSHIFT)	/* left anchor	-			*/
89 #define	OEOL	(4L<<OPSHIFT)	/* right anchor	-			*/
90 #define	OANY	(5L<<OPSHIFT)	/* .		-			*/
91 #define	OANYOF	(6L<<OPSHIFT)	/* [...]	set number		*/
92 #define	OBACK_	(7L<<OPSHIFT)	/* begin \d	paren number		*/
93 #define	O_BACK	(8L<<OPSHIFT)	/* end \d	paren number		*/
94 #define	OPLUS_	(9L<<OPSHIFT)	/* + prefix	fwd to suffix		*/
95 #define	O_PLUS	(10L<<OPSHIFT)	/* + suffix	back to prefix		*/
96 #define	OQUEST_	(11L<<OPSHIFT)	/* ? prefix	fwd to suffix		*/
97 #define	O_QUEST	(12L<<OPSHIFT)	/* ? suffix	back to prefix		*/
98 #define	OLPAREN	(13L<<OPSHIFT)	/* (		fwd to )		*/
99 #define	ORPAREN	(14L<<OPSHIFT)	/* )		back to (		*/
100 #define	OCH_	(15L<<OPSHIFT)	/* begin choice	fwd to OOR2		*/
101 #define	OOR1	(16L<<OPSHIFT)	/* | pt. 1	back to OOR1 or OCH_	*/
102 #define	OOR2	(17L<<OPSHIFT)	/* | pt. 2	fwd to OOR2 or O_CH	*/
103 #define	O_CH	(18L<<OPSHIFT)	/* end choice	back to OOR1		*/
104 #define	OBOW	(19L<<OPSHIFT)	/* begin word	-			*/
105 #define	OEOW	(20L<<OPSHIFT)	/* end word	-			*/
106 #define	OBOS	(21L<<OPSHIFT)	/* begin subj.  -			*/
107 #define	OEOS	(22L<<OPSHIFT)	/* end subj.	-			*/
108 #define	OWBND	(23L<<OPSHIFT)	/* word bound	-			*/
109 #define	ONWBND	(24L<<OPSHIFT)	/* not bound	-			*/
110 
111 /*
112  * Structures for [] character-set representation.
113  */
114 typedef struct {
115 	wint_t		min;
116 	wint_t		max;
117 } crange;
118 typedef struct {
119 	unsigned char	bmp[NC_MAX / 8];
120 	wctype_t	*types;
121 	unsigned int	ntypes;
122 	wint_t		*wides;
123 	unsigned int	nwides;
124 	crange		*ranges;
125 	unsigned int	nranges;
126 	int		invert;
127 	int		icase;
128 } cset;
129 
130 static int
131 CHIN1(cset *cs, wint_t ch)
132 {
133 	unsigned int i;
134 
135 	assert(ch >= 0);
136 	if (ch < NC)
137 		return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
138 		    cs->invert);
139 	for (i = 0; i < cs->nwides; i++) {
140 		if (cs->icase) {
141 			if (ch == towlower(cs->wides[i]) ||
142 			    ch == towupper(cs->wides[i]))
143 				return (!cs->invert);
144 		} else if (ch == cs->wides[i])
145 			return (!cs->invert);
146 	}
147 	for (i = 0; i < cs->nranges; i++)
148 		if (cs->ranges[i].min <= ch && ch <= cs->ranges[i].max)
149 			return (!cs->invert);
150 	for (i = 0; i < cs->ntypes; i++)
151 		if (iswctype(ch, cs->types[i]))
152 			return (!cs->invert);
153 	return (cs->invert);
154 }
155 
156 static __inline int
157 CHIN(cset *cs, wint_t ch)
158 {
159 
160 	assert(ch >= 0);
161 	if (ch < NC)
162 		return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
163 		    cs->invert);
164 	else if (cs->icase)
165 		return (CHIN1(cs, ch) || CHIN1(cs, towlower(ch)) ||
166 		    CHIN1(cs, towupper(ch)));
167 	else
168 		return (CHIN1(cs, ch));
169 }
170 
171 /*
172  * main compiled-expression structure
173  */
174 struct re_guts {
175 	int magic;
176 #		define	MAGIC2	((('R'^0200)<<8)|'E')
177 	sop *strip;		/* malloced area for strip */
178 	unsigned int ncsets;	/* number of csets in use */
179 	cset *sets;		/* -> cset [ncsets] */
180 	int cflags;		/* copy of regcomp() cflags argument */
181 	sopno nstates;		/* = number of sops */
182 	sopno firststate;	/* the initial OEND (normally 0) */
183 	sopno laststate;	/* the final OEND */
184 	int iflags;		/* internal flags */
185 #		define	USEBOL	01	/* used ^ */
186 #		define	USEEOL	02	/* used $ */
187 #		define	BAD	04	/* something wrong */
188 	int nbol;		/* number of ^ used */
189 	int neol;		/* number of $ used */
190 	char *must;		/* match must contain this string */
191 	int moffset;		/* latest point at which must may be located */
192 	int *charjump;		/* Boyer-Moore char jump table */
193 	int *matchjump;		/* Boyer-Moore match jump table */
194 	int mlen;		/* length of must */
195 	size_t nsub;		/* copy of re_nsub */
196 	int backrefs;		/* does it use back references? */
197 	sopno nplus;		/* how deep does it nest +s? */
198 };
199 
200 /* misc utilities */
201 #define	OUT	(CHAR_MIN - 1)	/* a non-character value */
202 #define	IGN	(CHAR_MIN - 2)
203 #define ISWORD(c)       (iswalnum((uch)(c)) || (c) == '_')
204