Home | History | Annotate | Line # | Download | only in lint2
hash.c revision 1.7 
      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 #ifndef lint
     36 __RCSID("$NetBSD: hash.c,v 1.7 2002/01/21 19:49:52 tv Exp $");
     37 #endif
     38 
     39 /*
     40  * XXX Really need a generalized hash table package
     41  */
     42 
     43 #include <limits.h>
     44 #include <stddef.h>
     45 #include <stdlib.h>
     46 #include <string.h>
     47 
     48 #include "lint2.h"
     49 
     50 /* pointer to hash table, initialized in inithash() */
     51 static	hte_t	**htab;
     52 
     53 static	int	hash(const char *);
     54 
     55 /*
     56  * Initialize hash table.
     57  */
     58 void
     59 _inithash(hte_t ***tablep)
     60 {
     61 
     62 	if (tablep == NULL)
     63 		tablep = &htab;
     64 
     65 	*tablep = xcalloc(HSHSIZ2, sizeof (hte_t *));
     66 }
     67 
     68 /*
     69  * Compute hash value from a string.
     70  */
     71 static int
     72 hash(const char *s)
     73 {
     74 	u_int	v;
     75 	const	u_char *us;
     76 
     77 	v = 0;
     78 	for (us = (const u_char *)s; *us != '\0'; us++) {
     79 		v = (v << sizeof (v)) + *us;
     80 		v ^= v >> (sizeof (v) * CHAR_BIT - sizeof (v));
     81 	}
     82 	return (v % HSHSIZ2);
     83 }
     84 
     85 /*
     86  * Look for a hash table entry. If no hash table entry for the
     87  * given name exists and mknew is set, create a new one.
     88  */
     89 hte_t *
     90 _hsearch(hte_t **table, const char *s, int mknew)
     91 {
     92 	int	h;
     93 	hte_t	*hte;
     94 
     95 	if (table == NULL)
     96 		table = htab;
     97 
     98 	h = hash(s);
     99 	for (hte = table[h]; hte != NULL; hte = hte->h_link) {
    100 		if (strcmp(hte->h_name, s) == 0)
    101 			break;
    102 	}
    103 
    104 	if (hte != NULL || !mknew)
    105 		return (hte);
    106 
    107 	/* create a new hte */
    108 	hte = xmalloc(sizeof (hte_t));
    109 	hte->h_name = xstrdup(s);
    110 	hte->h_used = 0;
    111 	hte->h_def = 0;
    112 	hte->h_static = 0;
    113 	hte->h_syms = NULL;
    114 	hte->h_lsym = &hte->h_syms;
    115 	hte->h_calls = NULL;
    116 	hte->h_lcall = &hte->h_calls;
    117 	hte->h_usyms = NULL;
    118 	hte->h_lusym = &hte->h_usyms;
    119 	hte->h_link = table[h];
    120 	hte->h_hte = NULL;
    121 	table[h] = hte;
    122 
    123 	return (hte);
    124 }
    125 
    126 /*
    127  * Call function f for each name in the hash table.
    128  */
    129 void
    130 _forall(hte_t **table, void (*f)(hte_t *))
    131 {
    132 	int	i;
    133 	hte_t	*hte;
    134 
    135 	if (table == NULL)
    136 		table = htab;
    137 
    138 	for (i = 0; i < HSHSIZ2; i++) {
    139 		for (hte = table[i]; hte != NULL; hte = hte->h_link)
    140 			(*f)(hte);
    141 	}
    142 }
    143 
    144 /*
    145  * Free all contents of the hash table that this module allocated.
    146  */
    147 void
    148 _destroyhash(hte_t **table)
    149 {
    150 	int	i;
    151 	hte_t	*hte, *nexthte;
    152 
    153 	if (table == NULL)
    154 		err(1, "_destroyhash called on main hash table");
    155 
    156 	for (i = 0; i < HSHSIZ2; i++) {
    157 		for (hte = table[i]; hte != NULL; hte = nexthte) {
    158 			free((void *)hte->h_name);
    159 			nexthte = hte->h_link;
    160 			free(hte);
    161 		}
    162 	}
    163 	free(table);
    164 }
    165