xref: /original-bsd/lib/libc/regex/regexec.c (revision 079b85dd)
1 /*-
2  * Copyright (c) 1992 Henry Spencer.
3  * Copyright (c) 1992 The Regents of the University of California.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Henry Spencer of the University of Toronto.
8  *
9  * %sccs.include.redist.c%
10  *
11  *	@(#)regexec.c	5.1 (Berkeley) 08/06/92
12  */
13 
14 #if defined(LIBC_SCCS) && !defined(lint)
15 static char sccsid[] = "@(#)regexec.c	5.1 (Berkeley) 08/06/92";
16 #endif /* LIBC_SCCS and not lint */
17 
18 #include <sys/types.h>
19 
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <assert.h>
24 #include <limits.h>
25 #include <regex.h>
26 
27 #include "utils.h"
28 #include "regex2.h"
29 
30 /*
31  - regexec - interface for matching
32  */
33 int				/* 0 success, REG_NOMATCH failure */
34 regexec(preg, string, nmatch, pmatch, eflags)
35 const regex_t *preg;
36 const char *string;
37 size_t nmatch;
38 regmatch_t pmatch[];
39 int eflags;
40 {
41 	register struct re_guts *g = preg->re_g;
42 	STATIC int smatcher();
43 	STATIC int lmatcher();
44 #ifndef NDEBUG
45 #	define	GOODFLAGS(f)	(f)
46 #else
47 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
48 #endif
49 
50 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
51 		return(REG_BADPAT);
52 	assert(!(g->iflags&BAD));
53 	if (g->iflags&BAD)		/* backstop for NDEBUG case */
54 		return(REG_BADPAT);
55 	eflags = GOODFLAGS(eflags);	/* xxx should we complain? */
56 
57 	if (g->nstates <= 32 && !(eflags&REG_LARGE))
58 		return(smatcher(g, string, nmatch, pmatch, eflags));
59 	else
60 		return(lmatcher(g, string, nmatch, pmatch, eflags));
61 }
62 
63 /* macros for manipulating states, small version */
64 #define	states	long
65 #define	CLEAR(v)	((v) = 0)
66 #define	SET0(v, n)	((v) &= ~(1 << (n)))
67 #define	SET1(v, n)	((v) |= 1 << (n))
68 #define	ISSET(v, n)	((v) & (1 << (n)))
69 #define	ASSIGN(d, s)	((d) = (s))
70 #define	EQ(a, b)	((a) == (b))
71 #define	STATEVARS	int dummy	/* dummy version */
72 #define	STATESETUP(m, n)	/* nothing */
73 #define	STATETEARDOWN(m)	/* nothing */
74 #define	SETUP(v)	/* nothing */
75 #define	onestate	int
76 #define	INIT(o, n)	((o) = 1 << (n))
77 #define	INC(o)	((o) <<= 1)
78 #define	ISSTATEIN(v, o)	((v) & (o))
79 /* some abbreviations; note that some of these know variable names! */
80 /* do "if I'm here, I can also be there" etc without branches */
81 #define	FWD(dst, src, n)	((dst) |= ((src)&(here)) << (n))
82 #define	BACK(dst, src, n)	((dst) |= ((src)&(here)) >> (n))
83 #define	ISSETBACK(v, n)	((v) & (here >> (n)))
84 /* function names */
85 #define SNAMES			/* engine.c looks after details */
86 
87 #include "engine.c"
88 
89 /* now undo things */
90 #undef	states
91 #undef	CLEAR
92 #undef	SET0
93 #undef	SET1
94 #undef	ISSET
95 #undef	ASSIGN
96 #undef	EQ
97 #undef	STATEVARS
98 #undef	STATESETUP
99 #undef	STATETEARDOWN
100 #undef	SETUP
101 #undef	onestate
102 #undef	INIT
103 #undef	INC
104 #undef	ISSTATEIN
105 #undef	FWD
106 #undef	BACK
107 #undef	ISSETBACK
108 #undef	SNAMES
109 
110 /* macros for manipulating states, large version */
111 #define	states	char *
112 #define	CLEAR(v)	memset(v, 0, m->g->nstates)
113 #define	SET0(v, n)	((v)[n] = 0)
114 #define	SET1(v, n)	((v)[n] = 1)
115 #define	ISSET(v, n)	((v)[n])
116 #define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
117 #define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
118 #define	STATEVARS	int vn; char *space
119 #define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
120 				if ((m)->space == NULL) return(REG_ESPACE); \
121 				(m)->vn = 0; }
122 #define	STATETEARDOWN(m)	{ free((m)->space); }
123 #define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
124 #define	onestate	int
125 #define	INIT(o, n)	((o) = (n))
126 #define	INC(o)	((o)++)
127 #define	ISSTATEIN(v, o)	((v)[o])
128 /* some abbreviations; note that some of these know variable names! */
129 /* do "if I'm here, I can also be there" etc without branches */
130 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
131 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
132 #define	ISSETBACK(v, n)	((v)[here - (n)])
133 /* function names */
134 #define	LNAMES			/* flag */
135 
136 #include "engine.c"
137