1/*
2 * the outer shell of regexec()
3 *
4 * This file includes engine.c *twice*, after muchos fiddling with the
5 * macros that code uses.  This lets the same code operate on two different
6 * representations for state sets.
7 */
8#include <sys/types.h>
9#include <stdio.h>
10#include <stdlib.h>
11#include <string.h>
12#include <limits.h>
13#include <ctype.h>
14#include <regex.h>
15
16#include "utils.h"
17#include "regex2.h"
18
19static int nope = 0;		/* for use in asserts; shuts lint up */
20
21/* macros for manipulating states, small version */
22#define	states	unsigned
23#define	states1	unsigned	/* for later use in regexec() decision */
24#define	CLEAR(v)	((v) = 0)
25#define	SET0(v, n)	((v) &= ~((unsigned)1 << (n)))
26#define	SET1(v, n)	((v) |= (unsigned)1 << (n))
27#define	ISSET(v, n)	((v) & ((unsigned)1 << (n)))
28#define	ASSIGN(d, s)	((d) = (s))
29#define	EQ(a, b)	((a) == (b))
30#define	STATEVARS	int dummy	/* dummy version */
31#define	STATESETUP(m, n)	/* nothing */
32#define	STATETEARDOWN(m)	/* nothing */
33#define	SETUP(v)	((v) = 0)
34#define	onestate	unsigned
35#define	INIT(o, n)	((o) = (unsigned)1 << (n))
36#define	INC(o)	((o) <<= 1)
37#define	ISSTATEIN(v, o)	((v) & (o))
38/* some abbreviations; note that some of these know variable names! */
39/* do "if I'm here, I can also be there" etc without branches */
40#define	FWD(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) << (n))
41#define	BACK(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) >> (n))
42#define	ISSETBACK(v, n)	((v) & ((unsigned)here >> (n)))
43/* function names */
44#define SNAMES			/* engine.c looks after details */
45
46#include "engine.c"
47
48/* now undo things */
49#undef	states
50#undef	CLEAR
51#undef	SET0
52#undef	SET1
53#undef	ISSET
54#undef	ASSIGN
55#undef	EQ
56#undef	STATEVARS
57#undef	STATESETUP
58#undef	STATETEARDOWN
59#undef	SETUP
60#undef	onestate
61#undef	INIT
62#undef	INC
63#undef	ISSTATEIN
64#undef	FWD
65#undef	BACK
66#undef	ISSETBACK
67#undef	SNAMES
68
69/* macros for manipulating states, large version */
70#define	states	char *
71#define	CLEAR(v)	memset(v, 0, m->g->nstates)
72#define	SET0(v, n)	((v)[n] = 0)
73#define	SET1(v, n)	((v)[n] = 1)
74#define	ISSET(v, n)	((v)[n])
75#define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
76#define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
77#define	STATEVARS	int vn; char *space
78#define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
79				if ((m)->space == NULL) return(REG_ESPACE); \
80				(m)->vn = 0; }
81#define	STATETEARDOWN(m)	{ free((m)->space); }
82#define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
83#define	onestate	int
84#define	INIT(o, n)	((o) = (n))
85#define	INC(o)	((o)++)
86#define	ISSTATEIN(v, o)	((v)[o])
87/* some abbreviations; note that some of these know variable names! */
88/* do "if I'm here, I can also be there" etc without branches */
89#define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
90#define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
91#define	ISSETBACK(v, n)	((v)[here - (n)])
92/* function names */
93#define	LNAMES			/* flag */
94
95#include "engine.c"
96
97/*
98 - regexec - interface for matching
99 = extern int regexec(const regex_t *, const char *, size_t, \
100 =					regmatch_t [], int);
101 = #define	REG_NOTBOL	00001
102 = #define	REG_NOTEOL	00002
103 = #define	REG_STARTEND	00004
104 = #define	REG_TRACE	00400	// tracing of execution
105 = #define	REG_LARGE	01000	// force large representation
106 = #define	REG_BACKR	02000	// force use of backref code
107 *
108 * We put this here so we can exploit knowledge of the state representation
109 * when choosing which matcher to call.  Also, by this point the matchers
110 * have been prototyped.
111 */
112int				/* 0 success, REG_NOMATCH failure */
113regexec(preg, string, nmatch, pmatch, eflags)
114const regex_t *preg;
115const char *string;
116size_t nmatch;
117regmatch_t pmatch[];
118int eflags;
119{
120	register struct re_guts *g = preg->re_g;
121#ifdef REDEBUG
122#	define	GOODFLAGS(f)	(f)
123#else
124#	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
125#endif
126
127	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
128		return(REG_BADPAT);
129	assert(!(g->iflags&BAD));
130	if (g->iflags&BAD)		/* backstop for no-debug case */
131		return(REG_BADPAT);
132	eflags = GOODFLAGS(eflags);
133
134	if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
135		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
136	else
137		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
138}
139