Logo Search packages:      
Sourcecode: pwlib version File versions  Download package

regexec.c

/*
 * 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>
#include <regex.h>

#include "utils.h"
#include "regex2.h"

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&REG_LARGE))
            return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
      else
            return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
}

Generated by  Doxygen 1.6.0   Back to index