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regexec.c
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regexec.c
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/*
* the outer shell of regexec()
*
* This file includes engine.c *twice*, after muchos fiddling with the
* macros that code uses. This lets the same code operate on two different
* representations for state sets.
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>
/* local headers */
#include "regex.h"
#include "utils.h"
#include "regex2.h"
/* Prevent warning: ‘nope’ defined but not used [-Wunused-variable] */
/* static int nope = 0; */ /* for use in asserts; shuts lint up */
/* macros for manipulating states, small version */
#define states unsigned
#define states1 unsigned /* for later use in regexec() decision */
#define CLEAR(v) ((v) = 0)
#define SET0(v, n) ((v) &= ~((unsigned)1 << (n)))
#define SET1(v, n) ((v) |= (unsigned)1 << (n))
#define ISSET(v, n) ((v) & ((unsigned)1 << (n)))
#define ASSIGN(d, s) ((d) = (s))
#define EQ(a, b) ((a) == (b))
#define STATEVARS int dummy /* dummy version */
#define STATESETUP(m, n) /* nothing */
#define STATETEARDOWN(m) /* nothing */
#define SETUP(v) ((v) = 0)
#define onestate unsigned
#define INIT(o, n) ((o) = (unsigned)1 << (n))
#define INC(o) ((o) <<= 1)
#define ISSTATEIN(v, o) ((v) & (o))
/* some abbreviations; note that some of these know variable names! */
/* do "if I'm here, I can also be there" etc without branches */
#define FWD(dst, src, n) ((dst) |= ((unsigned)(src)&(here)) << (n))
#define BACK(dst, src, n) ((dst) |= ((unsigned)(src)&(here)) >> (n))
#define ISSETBACK(v, n) ((v) & ((unsigned)here >> (n)))
/* function names */
#define SNAMES /* engine.c looks after details */
#include "engine.c"
/* now undo things */
#undef states
#undef CLEAR
#undef SET0
#undef SET1
#undef ISSET
#undef ASSIGN
#undef EQ
#undef STATEVARS
#undef STATESETUP
#undef STATETEARDOWN
#undef SETUP
#undef onestate
#undef INIT
#undef INC
#undef ISSTATEIN
#undef FWD
#undef BACK
#undef ISSETBACK
#undef SNAMES
/* macros for manipulating states, large version */
#define states char *
#define CLEAR(v) memset(v, 0, m->g->nstates)
#define SET0(v, n) ((v)[n] = 0)
#define SET1(v, n) ((v)[n] = 1)
#define ISSET(v, n) ((v)[n])
#define ASSIGN(d, s) memcpy(d, s, m->g->nstates)
#define EQ(a, b) (memcmp(a, b, m->g->nstates) == 0)
#define STATEVARS int vn; char *space
#define STATESETUP(m, nv) { (m)->space = malloc((nv)*(m)->g->nstates); \
if ((m)->space == NULL) return(REG_ESPACE); \
(m)->vn = 0; }
#define STATETEARDOWN(m) { free((m)->space); }
#define SETUP(v) ((v) = &m->space[m->vn++ * m->g->nstates])
#define onestate int
#define INIT(o, n) ((o) = (n))
#define INC(o) ((o)++)
#define ISSTATEIN(v, o) ((v)[o])
/* some abbreviations; note that some of these know variable names! */
/* do "if I'm here, I can also be there" etc without branches */
#define FWD(dst, src, n) ((dst)[here+(n)] |= (src)[here])
#define BACK(dst, src, n) ((dst)[here-(n)] |= (src)[here])
#define ISSETBACK(v, n) ((v)[here - (n)])
/* function names */
#define LNAMES /* flag */
#include "engine.c"
/*
- regexec - interface for matching
= extern int regexec(const regex_t *, const char *, size_t, \
= regmatch_t [], int);
= #define REG_NOTBOL 00001
= #define REG_NOTEOL 00002
= #define REG_STARTEND 00004
= #define REG_TRACE 00400 // tracing of execution
= #define REG_LARGE 01000 // force large representation
= #define REG_BACKR 02000 // force use of backref code
*
* We put this here so we can exploit knowledge of the state representation
* when choosing which matcher to call. Also, by this point the matchers
* have been prototyped.
*/
int /* 0 success, REG_NOMATCH failure */
regexec(preg, string, nmatch, pmatch, eflags)
const regex_t *preg;
const char *string;
size_t nmatch;
regmatch_t pmatch[];
int eflags;
{
register struct re_guts *g = preg->re_g;
#ifdef REDEBUG
# define GOODFLAGS(f) (f)
#else
# define GOODFLAGS(f) ((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
#endif
if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
return(REG_BADPAT);
assert(!(g->iflags&BAD));
if (g->iflags&BAD) /* backstop for no-debug case */
return(REG_BADPAT);
eflags = GOODFLAGS(eflags);
if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags®_LARGE))
return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
else
return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
}