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 <my_global.h>
#include <m_string.h>
#include <m_ctype.h>
#ifdef __WIN__
#include  <limits.h>
#endif
#include "my_regex.h"
#include "utils.h"
#include "regex2.h"

/* for use in asserts */
#define nope 0

/* macros for manipulating states, small version */
#define states  long
#define states1 long            /* for later use in regexec() decision. Ensure Win64 definition is correct.*/
#define CLEAR(v)        ((v) = 0)
#define SET0(v, n)      ((v) &= ~((states) 1 << (n)))
#define SET1(v, n)      ((v) |= (states) 1 << (n))
#define ISSET(v, n)     ((v) & ((states) 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        long                    /* Changed from int by Monty */
#define INIT(o, n)      ((o) = (unsigned states)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 states)(src)&(here)) << (n))
#define BACK(dst, src, n)       ((dst) |= ((unsigned states)(src)&(here)) >> (n))
#define ISSETBACK(v, n) ((v) & ((unsigned states)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(MY_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      MY_REG_NOTBOL   00001
 = #define      MY_REG_NOTEOL   00002
 = #define      MY_REG_STARTEND 00004
 = #define      MY_REG_TRACE    00400   // tracing of execution
 = #define      MY_REG_LARGE    01000   // force large representation
 = #define      MY_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, MY_REG_NOMATCH failure */
my_regexec(preg, str, nmatch, pmatch, eflags)
const my_regex_t *preg;
const char *str;
size_t nmatch;
my_regmatch_t pmatch[];
int eflags;
{
        char *pstr = (char *) str;
        register struct re_guts *g = preg->re_g;
#ifdef REDEBUG
#       define  GOODFLAGS(f)    (f)
#else
#       define  GOODFLAGS(f)    ((f)&(MY_REG_NOTBOL|MY_REG_NOTEOL|MY_REG_STARTEND))
#endif

        if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
                return(MY_REG_BADPAT);
        assert(!(g->iflags&BAD));
        if (g->iflags&BAD)              /* backstop for no-debug case */
                return(MY_REG_BADPAT);
        eflags = GOODFLAGS(eflags);

        if ((size_t) g->nstates <= CHAR_BIT*sizeof(states1) &&
            !(eflags&MY_REG_LARGE))
                return(smatcher(preg->charset, g, pstr, nmatch, pmatch, eflags));
        else
                return(lmatcher(preg->charset, g, pstr, nmatch, pmatch, eflags));
}