usr.bin/xlint/lint2/hash.c

   1 /*      $NetBSD: hash.c,v 1.10 2009/04/14 08:59:45 lukem 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 #if HAVE_NBTOOL_CONFIG_H
  35 #include "nbtool_config.h"
  36 #endif
  37
  38 #include <sys/cdefs.h>
  39 #if defined(__RCSID) && !defined(lint)
  40 __RCSID("$NetBSD: hash.c,v 1.10 2009/04/14 08:59:45 lukem Exp $");
  41 #endif
  42
  43 /*
  44  * XXX Really need a generalized hash table package
  45  */
  46
  47 #include <limits.h>
  48 #include <stddef.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51
  52 #include "lint2.h"
  53
  54 /* pointer to hash table, initialized in inithash() */
  55 static  hte_t   **htab;
  56
  57 static  int     hash(const char *);
  58
  59 /*
  60  * Initialize hash table.
  61  */
  62 void
  63 _inithash(hte_t ***tablep)
  64 {
  65
  66         if (tablep == NULL)
  67                 tablep = &htab;
  68
  69         *tablep = xcalloc(HSHSIZ2, sizeof (hte_t *));
  70 }
  71
  72 /*
  73  * Compute hash value from a string.
  74  */
  75 static int
  76 hash(const char *s)
  77 {
  78         u_int   v;
  79         const   u_char *us;
  80
  81         v = 0;
  82         for (us = (const u_char *)s; *us != '\0'; us++) {
  83                 v = (v << sizeof (v)) + *us;
  84                 v ^= v >> (sizeof (v) * CHAR_BIT - sizeof (v));
  85         }
  86         return (v % HSHSIZ2);
  87 }
  88
  89 /*
  90  * Look for a hash table entry. If no hash table entry for the
  91  * given name exists and mknew is set, create a new one.
  92  */
  93 hte_t *
  94 _hsearch(hte_t **table, const char *s, int mknew)
  95 {
  96         int     h;
  97         hte_t   *hte;
  98
  99         if (table == NULL)
 100                 table = htab;
 101
 102         h = hash(s);
 103         for (hte = table[h]; hte != NULL; hte = hte->h_link) {
 104                 if (strcmp(hte->h_name, s) == 0)
 105                         break;
 106         }
 107
 108         if (hte != NULL || !mknew)
 109                 return (hte);
 110
 111         /* create a new hte */
 112         hte = xmalloc(sizeof (hte_t));
 113         hte->h_name = xstrdup(s);
 114         hte->h_used = 0;
 115         hte->h_def = 0;
 116         hte->h_static = 0;
 117         hte->h_syms = NULL;
 118         hte->h_lsym = &hte->h_syms;
 119         hte->h_calls = NULL;
 120         hte->h_lcall = &hte->h_calls;
 121         hte->h_usyms = NULL;
 122         hte->h_lusym = &hte->h_usyms;
 123         hte->h_link = table[h];
 124         hte->h_hte = NULL;
 125         table[h] = hte;
 126
 127         return (hte);
 128 }
 129
 130 /*
 131  * Call function f for each name in the hash table.
 132  */
 133 void
 134 _forall(hte_t **table, void (*f)(hte_t *))
 135 {
 136         int     i;
 137         hte_t   *hte;
 138
 139         if (table == NULL)
 140                 table = htab;
 141
 142         for (i = 0; i < HSHSIZ2; i++) {
 143                 for (hte = table[i]; hte != NULL; hte = hte->h_link)
 144                         (*f)(hte);
 145         }
 146 }
 147
 148 /*
 149  * Free all contents of the hash table that this module allocated.
 150  */
 151 void
 152 _destroyhash(hte_t **table)
 153 {
 154         int     i;
 155         hte_t   *hte, *nexthte;
 156
 157         if (table == NULL)
 158                 err(1, "_destroyhash called on main hash table");
 159
 160         for (i = 0; i < HSHSIZ2; i++) {
 161                 for (hte = table[i]; hte != NULL; hte = nexthte) {
 162                         free(__UNCONST(hte->h_name));
 163                         nexthte = hte->h_link;
 164                         free(hte);
 165                 }
 166         }
 167         free(table);
 168 }