regexec.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:4k
- /*
- * 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"
- static int nope = 0; /* for use in asserts; shuts lint up */
- /* macros for manipulating states, small version */
- #define states long
- #define states1 states /* for later use in regexec() decision */
- #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(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 */
- my_regexec(preg, str, nmatch, pmatch, eflags)
- const my_regex_t *preg;
- const char *str;
- size_t nmatch;
- my_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 ((size_t) g->nstates <= CHAR_BIT*sizeof(states1) &&
- !(eflags®_LARGE))
- return(smatcher(preg->charset, g, (char *)str, nmatch, pmatch, eflags));
- else
- return(lmatcher(preg->charset, g, (char *)str, nmatch, pmatch, eflags));
- }