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Use backtracking for regular patterns, but not ksh-specific ones [*?!+@](...) 

which still use recursion.
This commit is contained in:
christos 2017-04-30 17:34:29 +00:00
parent c08af49426
commit b9dfc8dc3f
1 changed files with 51 additions and 39 deletions
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90
bin/ksh/misc.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: misc.c,v 1.15 2011/10/16 17:12:11 joerg Exp $ */
/* $NetBSD: misc.c,v 1.16 2017/04/30 17:34:29 christos Exp $ */
/*
* Miscellaneous functions
@ -6,7 +6,7 @@
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: misc.c,v 1.15 2011/10/16 17:12:11 joerg Exp $");
__RCSID("$NetBSD: misc.c,v 1.16 2017/04/30 17:34:29 christos Exp $");
#endif
@ -631,46 +631,50 @@ do_gmatch(s, se, p, pe, isfile)
const unsigned char *se, *pe;
int isfile;
{
register int sc, pc;
int sc, pc;
const unsigned char *prest, *psub, *pnext;
const unsigned char *srest;
const unsigned char *sNext, *pNext, *sStart;
if (s == NULL || p == NULL)
return 0;
while (p < pe) {
pc = *p++;
sNext = sStart = s;
pNext = p;
while (p < pe || s < se) {
pc = *p;
sc = s < se ? *s : '\0';
s++;
if (isfile) {
sc = FILECHCONV((unsigned char)sc);
pc = FILECHCONV((unsigned char)pc);
}
if (!ISMAGIC(pc)) {
if (sc != pc)
return 0;
goto backtrack;
p++;
s++;
continue;
}
switch (*p++) {
} else
pc = *++p;
switch (pc) {
case '[':
p++;
s++;
if (sc == 0 || (p = cclass(p, sc)) == NULL)
return 0;
break;
break;
continue;
case '?':
if (sc == 0)
return 0;
break;
break;
p++;
s++;
continue;
case '*':
if (p == pe)
return 1;
s--;
do {
if (do_gmatch(s, se, p, pe, isfile))
return 1;
} while (s++ < se);
return 0;
pNext = p - 1;
sNext = s + 1;
p++;
continue;
/*
* [*+?@!](pattern|pattern|..)
*
@ -678,13 +682,13 @@ do_gmatch(s, se, p, pe, isfile)
*/
case 0x80|'+': /* matches one or more times */
case 0x80|'*': /* matches zero or more times */
if (!(prest = pat_scan(p, pe, 0)))
return 0;
if (!(prest = pat_scan(++p, pe, 0)))
break;
s--;
/* take care of zero matches */
if (p[-1] == (0x80 | '*')
&& do_gmatch(s, se, prest, pe, isfile))
return 1;
continue;
for (psub = p; ; psub = pnext) {
pnext = pat_scan(psub, pe, 1);
for (srest = s; srest <= se; srest++) {
@ -700,18 +704,18 @@ do_gmatch(s, se, p, pe, isfile)
if (pnext == prest)
break;
}
return 0;
break;
case 0x80|'?': /* matches zero or once */
case 0x80|'@': /* matches one of the patterns */
case 0x80|' ': /* simile for @ */
if (!(prest = pat_scan(p, pe, 0)))
return 0;
if (!(prest = pat_scan(++p, pe, 0)))
break;
s--;
/* Take care of zero matches */
if (p[-1] == (0x80 | '?')
&& do_gmatch(s, se, prest, pe, isfile))
return 1;
continue;
for (psub = p; ; psub = pnext) {
pnext = pat_scan(psub, pe, 1);
srest = prest == pe ? se : s;
@ -720,16 +724,16 @@ do_gmatch(s, se, p, pe, isfile)
psub, pnext - 2, isfile)
&& do_gmatch(srest, se,
prest, pe, isfile))
return 1;
continue;
}
if (pnext == prest)
break;
}
return 0;
break;
case 0x80|'!': /* matches none of the patterns */
if (!(prest = pat_scan(p, pe, 0)))
return 0;
if (!(prest = pat_scan(++p, pe, 0)))
break;
s--;
for (srest = s; srest <= se; srest++) {
int matched = 0;
@ -747,17 +751,25 @@ do_gmatch(s, se, p, pe, isfile)
}
if (!matched && do_gmatch(srest, se,
prest, pe, isfile))
return 1;
continue;
}
return 0;
break;
default:
if (sc != p[-1])
return 0;
break;
if (sc != pc)
break;
p++;
s++;
continue;
}
backtrack: if (sNext != sStart && sNext <= se) {
p = pNext;
s = sNext;
continue;
}
return 0;
}
return s == se;
return 1;
}
static const unsigned char *