1 /* $OpenBSD: regex2.h,v 1.12 2021/01/03 17:07:58 tb 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 * internals of regex_t
40 */
41 #define MAGIC1 ((('r'^0200)<<8) | 'e')
42
43 /*
44 * The internal representation is a *strip*, a sequence of
45 * operators ending with an endmarker. (Some terminology etc. is a
46 * historical relic of earlier versions which used multiple strips.)
47 * Certain oddities in the representation are there to permit running
48 * the machinery backwards; in particular, any deviation from sequential
49 * flow must be marked at both its source and its destination. Some
50 * fine points:
51 *
52 * - OPLUS_ and O_PLUS are *inside* the loop they create.
53 * - OQUEST_ and O_QUEST are *outside* the bypass they create.
54 * - OCH_ and O_CH are *outside* the multi-way branch they create, while
55 * OOR1 and OOR2 are respectively the end and the beginning of one of
56 * the branches. Note that there is an implicit OOR2 following OCH_
57 * and an implicit OOR1 preceding O_CH.
58 *
59 * In state representations, an operator's bit is on to signify a state
60 * immediately *preceding* "execution" of that operator.
61 */
62 typedef unsigned long sop; /* strip operator */
63 typedef long sopno;
64 #define OPRMASK 0xf8000000LU
65 #define OPDMASK 0x07ffffffLU
66 #define OPSHIFT ((unsigned)27)
67 #define OP(n) ((n)&OPRMASK)
68 #define OPND(n) ((n)&OPDMASK)
69 #define SOP(op, opnd) ((op)|(opnd))
70 /* operators meaning operand */
71 /* (back, fwd are offsets) */
72 #define OEND (1LU<<OPSHIFT) /* endmarker - */
73 #define OCHAR (2LU<<OPSHIFT) /* character unsigned char */
74 #define OBOL (3LU<<OPSHIFT) /* left anchor - */
75 #define OEOL (4LU<<OPSHIFT) /* right anchor - */
76 #define OANY (5LU<<OPSHIFT) /* . - */
77 #define OANYOF (6LU<<OPSHIFT) /* [...] set number */
78 #define OBACK_ (7LU<<OPSHIFT) /* begin \d paren number */
79 #define O_BACK (8LU<<OPSHIFT) /* end \d paren number */
80 #define OPLUS_ (9LU<<OPSHIFT) /* + prefix fwd to suffix */
81 #define O_PLUS (10LU<<OPSHIFT) /* + suffix back to prefix */
82 #define OQUEST_ (11LU<<OPSHIFT) /* ? prefix fwd to suffix */
83 #define O_QUEST (12LU<<OPSHIFT) /* ? suffix back to prefix */
84 #define OLPAREN (13LU<<OPSHIFT) /* ( fwd to ) */
85 #define ORPAREN (14LU<<OPSHIFT) /* ) back to ( */
86 #define OCH_ (15LU<<OPSHIFT) /* begin choice fwd to OOR2 */
87 #define OOR1 (16LU<<OPSHIFT) /* | pt. 1 back to OOR1 or OCH_ */
88 #define OOR2 (17LU<<OPSHIFT) /* | pt. 2 fwd to OOR2 or O_CH */
89 #define O_CH (18LU<<OPSHIFT) /* end choice back to OOR1 */
90 #define OBOW (19LU<<OPSHIFT) /* begin word - */
91 #define OEOW (20LU<<OPSHIFT) /* end word - */
92
93 /*
94 * Structure for [] character-set representation. Character sets are
95 * done as bit vectors, grouped 8 to a byte vector for compactness.
96 * The individual set therefore has both a pointer to the byte vector
97 * and a mask to pick out the relevant bit of each byte. A hash code
98 * simplifies testing whether two sets could be identical.
99 *
100 * This will get trickier for multicharacter collating elements. As
101 * preliminary hooks for dealing with such things, we also carry along
102 * a string of multi-character elements, and decide the size of the
103 * vectors at run time.
104 */
105 typedef struct {
106 uch *ptr; /* -> uch [csetsize] */
107 uch mask; /* bit within array */
108 uch hash; /* hash code */
109 } cset;
110
111 static inline void
CHadd(cset * cs,char c)112 CHadd(cset *cs, char c)
113 {
114 cs->ptr[(uch)c] |= cs->mask;
115 cs->hash += c;
116 }
117
118 static inline void
CHsub(cset * cs,char c)119 CHsub(cset *cs, char c)
120 {
121 cs->ptr[(uch)c] &= ~cs->mask;
122 cs->hash -= c;
123 }
124
125 static inline int
CHIN(const cset * cs,char c)126 CHIN(const cset *cs, char c)
127 {
128 return (cs->ptr[(uch)c] & cs->mask) != 0;
129 }
130
131 /*
132 * main compiled-expression structure
133 */
134 struct re_guts {
135 int magic;
136 # define MAGIC2 ((('R'^0200)<<8)|'E')
137 sop *strip; /* malloced area for strip */
138 int csetsize; /* number of bits in a cset vector */
139 int ncsets; /* number of csets in use */
140 cset *sets; /* -> cset [ncsets] */
141 uch *setbits; /* -> uch[csetsize][ncsets/CHAR_BIT] */
142 int cflags; /* copy of regcomp() cflags argument */
143 sopno nstates; /* = number of sops */
144 sopno firststate; /* the initial OEND (normally 0) */
145 sopno laststate; /* the final OEND */
146 int iflags; /* internal flags */
147 # define USEBOL 01 /* used ^ */
148 # define USEEOL 02 /* used $ */
149 # define BAD 04 /* something wrong */
150 int nbol; /* number of ^ used */
151 int neol; /* number of $ used */
152 char *must; /* match must contain this string */
153 int mlen; /* length of must */
154 size_t nsub; /* copy of re_nsub */
155 int backrefs; /* does it use back references? */
156 sopno nplus; /* how deep does it nest +s? */
157 };
158
159 /* misc utilities */
160 #define OUT (CHAR_MAX+1) /* a non-character value */
161 #define ISWORD(c) (isalnum(c) || (c) == '_')
162