minix/commands/yacc/symtab.c

/*	$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);
    }
}