xref: /freebsd/lib/libc/regex/regexec.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
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. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	@(#)regexec.c	8.3 (Berkeley) 3/20/94
38  */
39 
40 #if defined(LIBC_SCCS) && !defined(lint)
41 static char sccsid[] = "@(#)regexec.c	8.3 (Berkeley) 3/20/94";
42 #endif /* LIBC_SCCS and not lint */
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 /*
47  * the outer shell of regexec()
48  *
49  * This file includes engine.c three times, after muchos fiddling with the
50  * macros that code uses.  This lets the same code operate on two different
51  * representations for state sets and characters.
52  */
53 #include <sys/types.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <limits.h>
58 #include <ctype.h>
59 #include <regex.h>
60 #include <wchar.h>
61 #include <wctype.h>
62 
63 #include "utils.h"
64 #include "regex2.h"
65 
66 static int nope __unused = 0;	/* for use in asserts; shuts lint up */
67 
68 static __inline size_t
69 xmbrtowc(wi, s, n, mbs, dummy)
70 wint_t *wi;
71 const char *s;
72 size_t n;
73 mbstate_t *mbs;
74 wint_t dummy;
75 {
76 	size_t nr;
77 	wchar_t wc;
78 
79 	nr = mbrtowc(&wc, s, n, mbs);
80 	if (wi != NULL)
81 		*wi = wc;
82 	if (nr == 0)
83 		return (1);
84 	else if (nr == (size_t)-1 || nr == (size_t)-2) {
85 		memset(mbs, 0, sizeof(*mbs));
86 		if (wi != NULL)
87 			*wi = dummy;
88 		return (1);
89 	} else
90                 return (nr);
91 }
92 
93 static __inline size_t
94 xmbrtowc_dummy(wi, s, n, mbs, dummy)
95 wint_t *wi;
96 const char *s;
97 size_t n __unused;
98 mbstate_t *mbs __unused;
99 wint_t dummy __unused;
100 {
101 
102 	if (wi != NULL)
103 		*wi = (unsigned char)*s;
104 	return (1);
105 }
106 
107 /* macros for manipulating states, small version */
108 #define	states	long
109 #define	states1	states		/* for later use in regexec() decision */
110 #define	CLEAR(v)	((v) = 0)
111 #define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
112 #define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
113 #define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
114 #define	ASSIGN(d, s)	((d) = (s))
115 #define	EQ(a, b)	((a) == (b))
116 #define	STATEVARS	long dummy	/* dummy version */
117 #define	STATESETUP(m, n)	/* nothing */
118 #define	STATETEARDOWN(m)	/* nothing */
119 #define	SETUP(v)	((v) = 0)
120 #define	onestate	long
121 #define	INIT(o, n)	((o) = (unsigned long)1 << (n))
122 #define	INC(o)	((o) <<= 1)
123 #define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
124 /* some abbreviations; note that some of these know variable names! */
125 /* do "if I'm here, I can also be there" etc without branches */
126 #define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
127 #define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
128 #define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
129 /* no multibyte support */
130 #define	XMBRTOWC	xmbrtowc_dummy
131 #define	ZAPSTATE(mbs)	((void)(mbs))
132 /* function names */
133 #define SNAMES			/* engine.c looks after details */
134 
135 #include "engine.c"
136 
137 /* now undo things */
138 #undef	states
139 #undef	CLEAR
140 #undef	SET0
141 #undef	SET1
142 #undef	ISSET
143 #undef	ASSIGN
144 #undef	EQ
145 #undef	STATEVARS
146 #undef	STATESETUP
147 #undef	STATETEARDOWN
148 #undef	SETUP
149 #undef	onestate
150 #undef	INIT
151 #undef	INC
152 #undef	ISSTATEIN
153 #undef	FWD
154 #undef	BACK
155 #undef	ISSETBACK
156 #undef	SNAMES
157 #undef	XMBRTOWC
158 #undef	ZAPSTATE
159 
160 /* macros for manipulating states, large version */
161 #define	states	char *
162 #define	CLEAR(v)	memset(v, 0, m->g->nstates)
163 #define	SET0(v, n)	((v)[n] = 0)
164 #define	SET1(v, n)	((v)[n] = 1)
165 #define	ISSET(v, n)	((v)[n])
166 #define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
167 #define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
168 #define	STATEVARS	long vn; char *space
169 #define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
170 				if ((m)->space == NULL) return(REG_ESPACE); \
171 				(m)->vn = 0; }
172 #define	STATETEARDOWN(m)	{ free((m)->space); }
173 #define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
174 #define	onestate	long
175 #define	INIT(o, n)	((o) = (n))
176 #define	INC(o)	((o)++)
177 #define	ISSTATEIN(v, o)	((v)[o])
178 /* some abbreviations; note that some of these know variable names! */
179 /* do "if I'm here, I can also be there" etc without branches */
180 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
181 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
182 #define	ISSETBACK(v, n)	((v)[here - (n)])
183 /* no multibyte support */
184 #define	XMBRTOWC	xmbrtowc_dummy
185 #define	ZAPSTATE(mbs)	((void)(mbs))
186 /* function names */
187 #define	LNAMES			/* flag */
188 
189 #include "engine.c"
190 
191 /* multibyte character & large states version */
192 #undef	LNAMES
193 #undef	XMBRTOWC
194 #undef	ZAPSTATE
195 #define	XMBRTOWC	xmbrtowc
196 #define	ZAPSTATE(mbs)	memset((mbs), 0, sizeof(*(mbs)))
197 #define	MNAMES
198 
199 #include "engine.c"
200 
201 /*
202  - regexec - interface for matching
203  = extern int regexec(const regex_t *, const char *, size_t, \
204  =					regmatch_t [], int);
205  = #define	REG_NOTBOL	00001
206  = #define	REG_NOTEOL	00002
207  = #define	REG_STARTEND	00004
208  = #define	REG_TRACE	00400	// tracing of execution
209  = #define	REG_LARGE	01000	// force large representation
210  = #define	REG_BACKR	02000	// force use of backref code
211  *
212  * We put this here so we can exploit knowledge of the state representation
213  * when choosing which matcher to call.  Also, by this point the matchers
214  * have been prototyped.
215  */
216 int				/* 0 success, REG_NOMATCH failure */
217 regexec(preg, string, nmatch, pmatch, eflags)
218 const regex_t * __restrict preg;
219 const char * __restrict string;
220 size_t nmatch;
221 regmatch_t pmatch[__restrict];
222 int eflags;
223 {
224 	struct re_guts *g = preg->re_g;
225 #ifdef REDEBUG
226 #	define	GOODFLAGS(f)	(f)
227 #else
228 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
229 #endif
230 
231 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
232 		return(REG_BADPAT);
233 	assert(!(g->iflags&BAD));
234 	if (g->iflags&BAD)		/* backstop for no-debug case */
235 		return(REG_BADPAT);
236 	eflags = GOODFLAGS(eflags);
237 
238 	if (MB_CUR_MAX > 1)
239 		return(mmatcher(g, (char *)string, nmatch, pmatch, eflags));
240 	else if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
241 		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
242 	else
243 		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
244 }
245