minix/commands/yacc/symtab.c

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/* $NetBSD: symtab.c,v 1.12 2009/04/14 09:41:31 lukem Exp $ */
/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Robert Paul Corbett.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(lint)
#if 0
static char sccsid[] = "@(#)symtab.c 5.3 (Berkeley) 6/1/90";
#else
__RCSID("$NetBSD: symtab.c,v 1.12 2009/04/14 09:41:31 lukem Exp $");
#endif
#endif /* not lint */
#include "defs.h"
/* TABLE_SIZE is the number of entries in the symbol table. */
/* TABLE_SIZE must be a power of two. */
#define TABLE_SIZE 1024
bucket *first_symbol;
bucket *last_symbol;
static bucket **symbol_table;
static int hash(const char *);
static int
hash(const char *name)
{
const char *s;
int c, k;
assert(name && *name);
s = name;
k = *s;
while ((c = *++s) != '\0')
k = (31*k + c) & (TABLE_SIZE - 1);
return (k);
}
bucket *
make_bucket(const char *name)
{
bucket *bp;
assert(name);
bp = (bucket *) MALLOC(sizeof(bucket));
if (bp == 0) no_space();
bp->link = 0;
bp->next = 0;
bp->name = strdup(name);
if (bp->name == 0) no_space();
bp->tag = 0;
bp->value = UNDEFINED;
bp->index = 0;
bp->prec = 0;
bp-> class = UNKNOWN;
bp->assoc = TOKEN;
return (bp);
}
bucket *
lookup(char *name)
{
bucket *bp, **bpp;
bpp = symbol_table + hash(name);
bp = *bpp;
while (bp)
{
if (strcmp(name, bp->name) == 0) return (bp);
bpp = &bp->link;
bp = *bpp;
}
*bpp = bp = make_bucket(name);
last_symbol->next = bp;
last_symbol = bp;
return (bp);
}
void
create_symbol_table(void)
{
int i;
bucket *bp;
symbol_table = (bucket **) MALLOC(TABLE_SIZE*sizeof(bucket *));
if (symbol_table == 0) no_space();
for (i = 0; i < TABLE_SIZE; i++)
symbol_table[i] = 0;
bp = make_bucket("error");
bp->index = 1;
bp->class = TERM;
first_symbol = bp;
last_symbol = bp;
symbol_table[hash("error")] = bp;
}
void
free_symbol_table(void)
{
FREE(symbol_table);
symbol_table = 0;
}
void
free_symbols(void)
{
bucket *p, *q;
for (p = first_symbol; p; p = q)
{
q = p->next;
FREE(p);
}
}