/usr.bin/xlint/lint2/hash.c

  1/*	$NetBSD: hash.c,v 1.7 2002/01/21 19:49:52 tv Exp $	*/
  2
  3/*
  4 * Copyright (c) 1994, 1995 Jochen Pohl
  5 * All Rights Reserved.
  6 *
  7 * Redistribution and use in source and binary forms, with or without
  8 * modification, are permitted provided that the following conditions
  9 * are met:
 10 * 1. Redistributions of source code must retain the above copyright
 11 *    notice, this list of conditions and the following disclaimer.
 12 * 2. Redistributions in binary form must reproduce the above copyright
 13 *    notice, this list of conditions and the following disclaimer in the
 14 *    documentation and/or other materials provided with the distribution.
 15 * 3. All advertising materials mentioning features or use of this software
 16 *    must display the following acknowledgement:
 17 *      This product includes software developed by Jochen Pohl for
 18 *	The NetBSD Project.
 19 * 4. The name of the author may not be used to endorse or promote products
 20 *    derived from this software without specific prior written permission.
 21 *
 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 32 */
 33
 34#include <sys/cdefs.h>
 35#if defined(__RCSID) && !defined(lint)
 36__RCSID("$NetBSD: hash.c,v 1.7 2002/01/21 19:49:52 tv Exp $");
 37#endif
 38__FBSDID("$FreeBSD$");
 39
 40/*
 41 * XXX Really need a generalized hash table package
 42 */
 43
 44#include <err.h>
 45#include <limits.h>
 46#include <stddef.h>
 47#include <stdlib.h>
 48#include <string.h>
 49
 50#include "lint2.h"
 51
 52/* pointer to hash table, initialized in inithash() */
 53static	hte_t	**htab;
 54
 55static	int	hash(const char *);
 56
 57/*
 58 * Initialize hash table.
 59 */
 60void
 61_inithash(hte_t ***tablep)
 62{
 63
 64	if (tablep == NULL)
 65		tablep = &htab;
 66
 67	*tablep = xcalloc(HSHSIZ2, sizeof (hte_t *));
 68}
 69
 70/*
 71 * Compute hash value from a string.
 72 */
 73static int
 74hash(const char *s)
 75{
 76	u_int	v;
 77	const	u_char *us;
 78
 79	v = 0;
 80	for (us = (const u_char *)s; *us != '\0'; us++) {
 81		v = (v << sizeof (v)) + *us;
 82		v ^= v >> (sizeof (v) * CHAR_BIT - sizeof (v));
 83	}
 84	return (v % HSHSIZ2);
 85}
 86
 87/*
 88 * Look for a hash table entry. If no hash table entry for the
 89 * given name exists and mknew is set, create a new one.
 90 */
 91hte_t *
 92_hsearch(hte_t **table, const char *s, int mknew)
 93{
 94	int	h;
 95	hte_t	*hte;
 96
 97	if (table == NULL)
 98		table = htab;
 99
100	h = hash(s);
101	for (hte = table[h]; hte != NULL; hte = hte->h_link) {
102		if (strcmp(hte->h_name, s) == 0)
103			break;
104	}
105
106	if (hte != NULL || !mknew)
107		return (hte);
108
109	/* create a new hte */
110	hte = xmalloc(sizeof (hte_t));
111	hte->h_name = xstrdup(s);
112	hte->h_used = 0;
113	hte->h_def = 0;
114	hte->h_static = 0;
115	hte->h_syms = NULL;
116	hte->h_lsym = &hte->h_syms;
117	hte->h_calls = NULL;
118	hte->h_lcall = &hte->h_calls;
119	hte->h_usyms = NULL;
120	hte->h_lusym = &hte->h_usyms;
121	hte->h_link = table[h];
122	hte->h_hte = NULL;
123	table[h] = hte;
124
125	return (hte);
126}
127
128/*
129 * Call function f for each name in the hash table.
130 */
131void
132_forall(hte_t **table, void (*f)(hte_t *))
133{
134	int	i;
135	hte_t	*hte;
136
137	if (table == NULL)
138		table = htab;
139
140	for (i = 0; i < HSHSIZ2; i++) {
141		for (hte = table[i]; hte != NULL; hte = hte->h_link)
142			(*f)(hte);
143	}
144}
145
146/*
147 * Free all contents of the hash table that this module allocated.
148 */
149void
150_destroyhash(hte_t **table)
151{
152	int	i;
153	hte_t	*hte, *nexthte;
154
155	if (table == NULL)
156		err(1, "_destroyhash called on main hash table");
157
158	for (i = 0; i < HSHSIZ2; i++) {
159		for (hte = table[i]; hte != NULL; hte = nexthte) {
160			free((void *)hte->h_name);
161			nexthte = hte->h_link;
162			free(hte);
163		}
164	}
165	free(table);
166}