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