freebsd-dev/usr.bin/xlint/lint2/hash.c

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/* $NetBSD: hash.c,v 1.7 2002/01/21 19:49:52 tv Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
* All Rights Reserved.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Jochen Pohl for
* The NetBSD Project.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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)
__RCSID("$NetBSD: hash.c,v 1.7 2002/01/21 19:49:52 tv Exp $");
#endif
/*
* XXX Really need a generalized hash table package
*/
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "lint2.h"
/* pointer to hash table, initialized in inithash() */
static hte_t **htab;
static int hash(const char *);
/*
* Initialize hash table.
*/
void
_inithash(hte_t ***tablep)
{
if (tablep == NULL)
tablep = &htab;
*tablep = xcalloc(HSHSIZ2, sizeof (hte_t *));
}
/*
* Compute hash value from a string.
*/
static int
hash(const char *s)
{
u_int v;
const u_char *us;
v = 0;
for (us = (const u_char *)s; *us != '\0'; us++) {
v = (v << sizeof (v)) + *us;
v ^= v >> (sizeof (v) * CHAR_BIT - sizeof (v));
}
return (v % HSHSIZ2);
}
/*
* Look for a hash table entry. If no hash table entry for the
* given name exists and mknew is set, create a new one.
*/
hte_t *
_hsearch(hte_t **table, const char *s, int mknew)
{
int h;
hte_t *hte;
if (table == NULL)
table = htab;
h = hash(s);
for (hte = table[h]; hte != NULL; hte = hte->h_link) {
if (strcmp(hte->h_name, s) == 0)
break;
}
if (hte != NULL || !mknew)
return (hte);
/* create a new hte */
hte = xmalloc(sizeof (hte_t));
hte->h_name = xstrdup(s);
hte->h_used = 0;
hte->h_def = 0;
hte->h_static = 0;
hte->h_syms = NULL;
hte->h_lsym = &hte->h_syms;
hte->h_calls = NULL;
hte->h_lcall = &hte->h_calls;
hte->h_usyms = NULL;
hte->h_lusym = &hte->h_usyms;
hte->h_link = table[h];
hte->h_hte = NULL;
table[h] = hte;
return (hte);
}
/*
* Call function f for each name in the hash table.
*/
void
_forall(hte_t **table, void (*f)(hte_t *))
{
int i;
hte_t *hte;
if (table == NULL)
table = htab;
for (i = 0; i < HSHSIZ2; i++) {
for (hte = table[i]; hte != NULL; hte = hte->h_link)
(*f)(hte);
}
}
/*
* Free all contents of the hash table that this module allocated.
*/
void
_destroyhash(hte_t **table)
{
int i;
hte_t *hte, *nexthte;
if (table == NULL)
err(1, "_destroyhash called on main hash table");
for (i = 0; i < HSHSIZ2; i++) {
for (hte = table[i]; hte != NULL; hte = nexthte) {
free((void *)hte->h_name);
nexthte = hte->h_link;
free(hte);
}
}
free(table);
}