freebsd-dev/contrib/bison/symtab.c
1999-08-14 21:39:07 +00:00

151 lines
2.6 KiB
C

/* Symbol table manager for Bison,
Copyright (C) 1984, 1989 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
Bison is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
Bison is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Bison; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <stdio.h>
#include "system.h"
#include "alloc.h"
#include "symtab.h"
#include "gram.h"
bucket **symtab;
bucket *firstsymbol;
bucket *lastsymbol;
void tabinit PARAMS((void));
void free_symtab PARAMS((void));
static int
hash (char *key)
{
register char *cp;
register int k;
cp = key;
k = 0;
while (*cp)
k = ((k << 1) ^ (*cp++)) & 0x3fff;
return (k % TABSIZE);
}
static char *
copys (char *s)
{
register int i;
register char *cp;
register char *result;
i = 1;
for (cp = s; *cp; cp++)
i++;
result = xmalloc((unsigned int)i);
strcpy(result, s);
return (result);
}
void
tabinit (void)
{
/* register int i; JF unused */
symtab = NEW2(TABSIZE, bucket *);
firstsymbol = NULL;
lastsymbol = NULL;
}
bucket *
getsym (char *key)
{
register int hashval;
register bucket *bp;
register int found;
hashval = hash(key);
bp = symtab[hashval];
found = 0;
while (bp != NULL && found == 0)
{
if (strcmp(key, bp->tag) == 0)
found = 1;
else
bp = bp->link;
}
if (found == 0)
{
nsyms++;
bp = NEW(bucket);
bp->link = symtab[hashval];
bp->next = NULL;
bp->tag = copys(key);
bp->class = SUNKNOWN;
if (firstsymbol == NULL)
{
firstsymbol = bp;
lastsymbol = bp;
}
else
{
lastsymbol->next = bp;
lastsymbol = bp;
}
symtab[hashval] = bp;
}
return (bp);
}
void
free_symtab (void)
{
register int i;
register bucket *bp,*bptmp;/* JF don't use ptr after free */
for (i = 0; i < TABSIZE; i++)
{
bp = symtab[i];
while (bp)
{
bptmp = bp->link;
#if 0 /* This causes crashes because one string can appear more than once. */
if (bp->type_name)
FREE(bp->type_name);
#endif
FREE(bp);
bp = bptmp;
}
}
FREE(symtab);
}