xref: /freebsd/lib/libc/regex/regex2.h (revision d37eb51047221dc3322b34db1038ff3aa533883f)
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 
36 /*
37  * First, the stuff that ends up in the outside-world include file
38  = typedef off_t regoff_t;
39  = typedef struct {
40  = 	int re_magic;
41  = 	size_t re_nsub;		// number of parenthesized subexpressions
42  = 	const char *re_endp;	// end pointer for REG_PEND
43  = 	struct re_guts *re_g;	// none of your business :-)
44  = } regex_t;
45  = typedef struct {
46  = 	regoff_t rm_so;		// start of match
47  = 	regoff_t rm_eo;		// end of match
48  = } regmatch_t;
49  */
50 /*
51  * internals of regex_t
52  */
53 #define	MAGIC1	((('r'^0200)<<8) | 'e')
54 
55 /*
56  * The internal representation is a *strip*, a sequence of
57  * operators ending with an endmarker.  (Some terminology etc. is a
58  * historical relic of earlier versions which used multiple strips.)
59  * Certain oddities in the representation are there to permit running
60  * the machinery backwards; in particular, any deviation from sequential
61  * flow must be marked at both its source and its destination.  Some
62  * fine points:
63  *
64  * - OPLUS_ and O_PLUS are *inside* the loop they create.
65  * - OQUEST_ and O_QUEST are *outside* the bypass they create.
66  * - OCH_ and O_CH are *outside* the multi-way branch they create, while
67  *   OOR1 and OOR2 are respectively the end and the beginning of one of
68  *   the branches.  Note that there is an implicit OOR2 following OCH_
69  *   and an implicit OOR1 preceding O_CH.
70  *
71  * In state representations, an operator's bit is on to signify a state
72  * immediately *preceding* "execution" of that operator.
73  */
74 typedef unsigned long sop;	/* strip operator */
75 typedef unsigned long sopno;
76 #define	OPRMASK	0xf8000000L
77 #define	OPDMASK	0x07ffffffL
78 #define	OPSHIFT	((unsigned)27)
79 #define	OP(n)	((n)&OPRMASK)
80 #define	OPND(n)	((n)&OPDMASK)
81 #define	SOP(op, opnd)	((op)|(opnd))
82 /* operators			   meaning	operand			*/
83 /*						(back, fwd are offsets)	*/
84 #define	OEND	(1L<<OPSHIFT)	/* endmarker	-			*/
85 #define	OCHAR	(2L<<OPSHIFT)	/* character	wide character		*/
86 #define	OBOL	(3L<<OPSHIFT)	/* left anchor	-			*/
87 #define	OEOL	(4L<<OPSHIFT)	/* right anchor	-			*/
88 #define	OANY	(5L<<OPSHIFT)	/* .		-			*/
89 #define	OANYOF	(6L<<OPSHIFT)	/* [...]	set number		*/
90 #define	OBACK_	(7L<<OPSHIFT)	/* begin \d	paren number		*/
91 #define	O_BACK	(8L<<OPSHIFT)	/* end \d	paren number		*/
92 #define	OPLUS_	(9L<<OPSHIFT)	/* + prefix	fwd to suffix		*/
93 #define	O_PLUS	(10L<<OPSHIFT)	/* + suffix	back to prefix		*/
94 #define	OQUEST_	(11L<<OPSHIFT)	/* ? prefix	fwd to suffix		*/
95 #define	O_QUEST	(12L<<OPSHIFT)	/* ? suffix	back to prefix		*/
96 #define	OLPAREN	(13L<<OPSHIFT)	/* (		fwd to )		*/
97 #define	ORPAREN	(14L<<OPSHIFT)	/* )		back to (		*/
98 #define	OCH_	(15L<<OPSHIFT)	/* begin choice	fwd to OOR2		*/
99 #define	OOR1	(16L<<OPSHIFT)	/* | pt. 1	back to OOR1 or OCH_	*/
100 #define	OOR2	(17L<<OPSHIFT)	/* | pt. 2	fwd to OOR2 or O_CH	*/
101 #define	O_CH	(18L<<OPSHIFT)	/* end choice	back to OOR1		*/
102 #define	OBOW	(19L<<OPSHIFT)	/* begin word	-			*/
103 #define	OEOW	(20L<<OPSHIFT)	/* end word	-			*/
104 #define	OBOS	(21L<<OPSHIFT)	/* begin subj.  -			*/
105 #define	OEOS	(22L<<OPSHIFT)	/* end subj.	-			*/
106 #define	OWBND	(23L<<OPSHIFT)	/* word bound	-			*/
107 #define	ONWBND	(24L<<OPSHIFT)	/* not bound	-			*/
108 
109 /*
110  * Structures for [] character-set representation.
111  */
112 typedef struct {
113 	wint_t		min;
114 	wint_t		max;
115 } crange;
116 typedef struct {
117 	unsigned char	bmp[NC_MAX / 8];
118 	wctype_t	*types;
119 	unsigned int	ntypes;
120 	wint_t		*wides;
121 	unsigned int	nwides;
122 	crange		*ranges;
123 	unsigned int	nranges;
124 	int		invert;
125 	int		icase;
126 } cset;
127 
128 static int
129 CHIN1(cset *cs, wint_t ch)
130 {
131 	unsigned int i;
132 
133 	assert(ch >= 0);
134 	if (ch < NC)
135 		return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
136 		    cs->invert);
137 	for (i = 0; i < cs->nwides; i++) {
138 		if (cs->icase) {
139 			if (ch == towlower(cs->wides[i]) ||
140 			    ch == towupper(cs->wides[i]))
141 				return (!cs->invert);
142 		} else if (ch == cs->wides[i])
143 			return (!cs->invert);
144 	}
145 	for (i = 0; i < cs->nranges; i++)
146 		if (cs->ranges[i].min <= ch && ch <= cs->ranges[i].max)
147 			return (!cs->invert);
148 	for (i = 0; i < cs->ntypes; i++)
149 		if (iswctype(ch, cs->types[i]))
150 			return (!cs->invert);
151 	return (cs->invert);
152 }
153 
154 static __inline int
155 CHIN(cset *cs, wint_t ch)
156 {
157 
158 	assert(ch >= 0);
159 	if (ch < NC)
160 		return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
161 		    cs->invert);
162 	else if (cs->icase)
163 		return (CHIN1(cs, ch) || CHIN1(cs, towlower(ch)) ||
164 		    CHIN1(cs, towupper(ch)));
165 	else
166 		return (CHIN1(cs, ch));
167 }
168 
169 /*
170  * main compiled-expression structure
171  */
172 struct re_guts {
173 	int magic;
174 #		define	MAGIC2	((('R'^0200)<<8)|'E')
175 	sop *strip;		/* malloced area for strip */
176 	unsigned int ncsets;	/* number of csets in use */
177 	cset *sets;		/* -> cset [ncsets] */
178 	int cflags;		/* copy of regcomp() cflags argument */
179 	sopno nstates;		/* = number of sops */
180 	sopno firststate;	/* the initial OEND (normally 0) */
181 	sopno laststate;	/* the final OEND */
182 	int iflags;		/* internal flags */
183 #		define	USEBOL	01	/* used ^ */
184 #		define	USEEOL	02	/* used $ */
185 #		define	BAD	04	/* something wrong */
186 	int nbol;		/* number of ^ used */
187 	int neol;		/* number of $ used */
188 	char *must;		/* match must contain this string */
189 	int moffset;		/* latest point at which must may be located */
190 	int *charjump;		/* Boyer-Moore char jump table */
191 	int *matchjump;		/* Boyer-Moore match jump table */
192 	int mlen;		/* length of must */
193 	size_t nsub;		/* copy of re_nsub */
194 	int backrefs;		/* does it use back references? */
195 	sopno nplus;		/* how deep does it nest +s? */
196 };
197 
198 /* misc utilities */
199 #define	OUT	(CHAR_MIN - 1)	/* a non-character value */
200 #define	IGN	(CHAR_MIN - 2)
201 #define ISWORD(c)       (iswalnum((uch)(c)) || (c) == '_')
202