xref: /openbsd-src/usr.bin/yacc/symtab.c (revision bbfc4b6ece250468820c0645240f8b59dd6c31e9)

/* $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);
	}
}