/* $OpenBSD: symtab.c,v 1.17 2014/03/13 00:56:39 tedu Exp $      */
/* $NetBSD: symtab.c,v 1.4 1996/03/19 03:21:48 jtc 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 "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 **symbol_table;
bucket *first_symbol;
bucket *last_symbol;

int hash(char *);


int
hash(char *name)
{
        char *s;
        int c, k;

        assert(name && *name);
        s = name;
        k = *s;
        while ((c = *++s))
                k = (31 * k + c) & (TABLE_SIZE - 1);

        return (k);
}


bucket *
make_bucket(char *name)
{
        bucket *bp;

        assert(name);
        bp = malloc(sizeof(bucket));
        if (bp == NULL)
                no_space();
        bp->link = 0;
        bp->next = 0;
        bp->name = strdup(name);
        if (bp->name == NULL)
                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)
{
        bucket *bp;

        symbol_table = calloc(TABLE_SIZE, sizeof(bucket *));
        if (symbol_table == NULL)
                no_space();

        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);
        }
}