1 /*
2 * Copyright 2023 Bill Sommerfeld <sommerfeld@hamachi.org>
3 * Copyright (c) 1992, 1993, 1994 Henry Spencer.
4 * Copyright (c) 1992, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Henry Spencer.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 /*
36 * First, the stuff that ends up in the outside-world include file
37 * typedef off_t regoff_t;
38 * typedef struct {
39 * int re_magic;
40 * size_t re_nsub; // number of parenthesized subexpressions
41 * const char *re_endp; // end pointer for REG_PEND
42 * struct re_guts *re_g; // none of your business :-)
43 * } regex_t;
44 * typedef struct {
45 * regoff_t rm_so; // start of match
46 * regoff_t rm_eo; // end of match
47 * } regmatch_t;
48 */
49 /*
50 * internals of regex_t
51 */
52 #define MAGIC1 ((('r'^0200)<<8) | 'e')
53
54 /*
55 * The internal representation is a *strip*, a sequence of
56 * operators ending with an endmarker. (Some terminology etc. is a
57 * historical relic of earlier versions which used multiple strips.)
58 * Certain oddities in the representation are there to permit running
59 * the machinery backwards; in particular, any deviation from sequential
60 * flow must be marked at both its source and its destination. Some
61 * fine points:
62 *
63 * - OPLUS_ and O_PLUS are *inside* the loop they create.
64 * - OQUEST_ and O_QUEST are *outside* the bypass they create.
65 * - OCH_ and O_CH are *outside* the multi-way branch they create, while
66 * OOR1 and OOR2 are respectively the end and the beginning of one of
67 * the branches. Note that there is an implicit OOR2 following OCH_
68 * and an implicit OOR1 preceding O_CH.
69 *
70 * In state representations, an operator's bit is on to signify a state
71 * immediately *preceding* "execution" of that operator.
72 */
73 typedef unsigned int sop; /* strip operator */
74 typedef unsigned int sopno;
75 #define OPRMASK 0xf8000000U
76 #define OPDMASK 0x07ffffffU
77 #define OPSHIFT ((unsigned)27)
78 #define OP(n) ((n)&OPRMASK)
79 #define OPND(n) ((n)&OPDMASK)
80 #define SOP(op, opnd) ((op)|(opnd))
81 /* operators meaning operand */
82 /* (back, fwd are offsets) */
83 #define OEND (1U<<OPSHIFT) /* endmarker - */
84 #define OCHAR (2U<<OPSHIFT) /* character wide character */
85 #define OBOL (3U<<OPSHIFT) /* left anchor - */
86 #define OEOL (4U<<OPSHIFT) /* right anchor - */
87 #define OANY (5U<<OPSHIFT) /* . - */
88 #define OANYOF (6U<<OPSHIFT) /* [...] set number */
89 #define OBACK_ (7U<<OPSHIFT) /* begin \d paren number */
90 #define O_BACK (8U<<OPSHIFT) /* end \d paren number */
91 #define OPLUS_ (9U<<OPSHIFT) /* + prefix fwd to suffix */
92 #define O_PLUS (10U<<OPSHIFT) /* + suffix back to prefix */
93 #define OQUEST_ (11U<<OPSHIFT) /* ? prefix fwd to suffix */
94 #define O_QUEST (12U<<OPSHIFT) /* ? suffix back to prefix */
95 #define OLPAREN (13U<<OPSHIFT) /* ( fwd to ) */
96 #define ORPAREN (14U<<OPSHIFT) /* ) back to ( */
97 #define OCH_ (15U<<OPSHIFT) /* begin choice fwd to OOR2 */
98 #define OOR1 (16U<<OPSHIFT) /* | pt. 1 back to OOR1 or OCH_ */
99 #define OOR2 (17U<<OPSHIFT) /* | pt. 2 fwd to OOR2 or O_CH */
100 #define O_CH (18U<<OPSHIFT) /* end choice back to OOR1 */
101 #define OBOW (19U<<OPSHIFT) /* begin word - */
102 #define OEOW (20U<<OPSHIFT) /* end word - */
103
104 /*
105 * Structures for [] character-set representation.
106 */
107 typedef struct {
108 wint_t min;
109 wint_t max;
110 } crange;
111 typedef struct {
112 unsigned char bmp[NC_MAX / 8];
113 wctype_t *types;
114 unsigned int ntypes;
115 wint_t *wides;
116 unsigned int nwides;
117 crange *ranges;
118 unsigned int nranges;
119 int invert;
120 int icase;
121 } cset;
122
123 static inline int
CHIN1(int nc,cset * cs,wint_t ch)124 CHIN1(int nc, cset *cs, wint_t ch)
125 {
126 unsigned int i;
127
128 assert(ch >= 0);
129 if (ch < nc)
130 return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
131 cs->invert);
132 for (i = 0; i < cs->nwides; i++) {
133 if (cs->icase) {
134 if (ch == towlower(cs->wides[i]) ||
135 ch == towupper(cs->wides[i]))
136 return (!cs->invert);
137 } else if (ch == cs->wides[i])
138 return (!cs->invert);
139 }
140 for (i = 0; i < cs->nranges; i++)
141 if (cs->ranges[i].min <= ch && ch <= cs->ranges[i].max)
142 return (!cs->invert);
143 for (i = 0; i < cs->ntypes; i++)
144 if (iswctype(ch, cs->types[i]))
145 return (!cs->invert);
146 return (cs->invert);
147 }
148
149 static inline int
CHIN(int nc,cset * cs,wint_t ch)150 CHIN(int nc, cset *cs, wint_t ch)
151 {
152
153 assert(ch >= 0);
154 if (ch < nc)
155 return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
156 cs->invert);
157 else if (cs->icase)
158 return (CHIN1(nc, cs, ch) || CHIN1(nc, cs, towlower(ch)) ||
159 CHIN1(nc, cs, towupper(ch)));
160 else
161 return (CHIN1(nc, cs, ch));
162 }
163
164 /*
165 * main compiled-expression structure
166 */
167 struct re_guts {
168 int magic;
169 #define MAGIC2 ((('R'^0200)<<8)|'E')
170 sop *strip; /* malloced area for strip */
171 unsigned int ncsets; /* number of csets in use */
172 cset *sets; /* -> cset [ncsets] */
173 int cflags; /* copy of regcomp() cflags argument */
174 sopno nstates; /* = number of sops */
175 sopno firststate; /* the initial OEND (normally 0) */
176 sopno laststate; /* the final OEND */
177 int iflags; /* internal flags */
178 #define USEBOL 01 /* used ^ */
179 #define USEEOL 02 /* used $ */
180 #define BAD 04 /* something wrong */
181 int nbol; /* number of ^ used */
182 int neol; /* number of $ used */
183 char *must; /* match must contain this string */
184 int moffset; /* latest point at which must may be located */
185 int *charjump; /* Boyer-Moore char jump table */
186 int *matchjump; /* Boyer-Moore match jump table */
187 int mlen; /* length of must */
188 size_t nsub; /* copy of re_nsub */
189 int backrefs; /* does it use back references? */
190 sopno nplus; /* how deep does it nest +s? */
191 unsigned int mb_cur_max;
192 };
193
194 /* misc utilities */
195 #define OUT (CHAR_MIN - 1) /* a non-character value */
196 #define IGN (CHAR_MIN - 2)
197 #define ISWORD(c) (iswalnum((uch)(c)) || (c) == '_')
198