Home | History | Annotate | Line # | Download | only in lint2 
      1 /*	$NetBSD: hash.c,v 1.30 2025/05/24 07:38:59 rillig 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)
     40 __RCSID("$NetBSD: hash.c,v 1.30 2025/05/24 07:38:59 rillig Exp $");
     41 #endif
     42 
     43 #include <limits.h>
     44 #include <stddef.h>
     45 #include <stdlib.h>
     46 #include <string.h>
     47 
     48 #include "lint2.h"
     49 
     50 #define HTAB_BUCKETS		1009
     51 
     52 static hte_t **htab;
     53 
     54 hte_t **
     55 htab_new(void)
     56 {
     57 	return xcalloc(HTAB_BUCKETS, sizeof(*htab_new()));
     58 }
     59 
     60 static unsigned int
     61 hash(const char *s)
     62 {
     63 	unsigned int v;
     64 	const char *p;
     65 
     66 	v = 0;
     67 	for (p = s; *p != '\0'; p++) {
     68 		v = (v << 4) + (unsigned char)*p;
     69 		v ^= v >> 28;
     70 	}
     71 	return v % HTAB_BUCKETS;
     72 }
     73 
     74 /*
     75  * Look for a hash table entry. If no hash table entry for the
     76  * given name exists and mknew is set, create a new one.
     77  */
     78 hte_t *
     79 hash_search(hte_t **table, const char *s, bool mknew)
     80 {
     81 	unsigned int h;
     82 	hte_t *hte;
     83 
     84 	if (table == NULL)
     85 		table = htab;
     86 
     87 	h = hash(s);
     88 	for (hte = table[h]; hte != NULL; hte = hte->h_link) {
     89 		if (strcmp(hte->h_name, s) == 0)
     90 			break;
     91 	}
     92 
     93 	if (hte != NULL || !mknew)
     94 		return hte;
     95 
     96 	/* create a new hte */
     97 	hte = xmalloc(sizeof(*hte));
     98 	hte->h_name = xstrdup(s);
     99 	hte->h_used = false;
    100 	hte->h_def = false;
    101 	hte->h_static = false;
    102 	hte->h_syms = NULL;
    103 	hte->h_lsym = &hte->h_syms;
    104 	hte->h_calls = NULL;
    105 	hte->h_lcall = &hte->h_calls;
    106 	hte->h_usyms = NULL;
    107 	hte->h_lusym = &hte->h_usyms;
    108 	hte->h_link = table[h];
    109 	hte->h_hte = NULL;
    110 	table[h] = hte;
    111 
    112 	return hte;
    113 }
    114 
    115 struct hte_list {
    116 	hte_t **items;
    117 	size_t len;
    118 	size_t cap;
    119 };
    120 
    121 static void
    122 hte_list_add(struct hte_list *list, hte_t *item)
    123 {
    124 	if (list->len >= list->cap) {
    125 		list->cap = list->cap == 0 ? 1024 : 2 * list->cap;
    126 		list->items = xrealloc(list->items,
    127 		    sizeof(list->items[0]) * list->cap);
    128 	}
    129 	list->items[list->len++] = item;
    130 }
    131 
    132 static int
    133 hte_by_name(const void *va, const void *vb)
    134 {
    135 	const hte_t *a = *((const hte_t *const *)va);
    136 	const hte_t *b = *((const hte_t *const *)vb);
    137 
    138 	return strcmp(a->h_name, b->h_name);
    139 }
    140 
    141 void
    142 symtab_init(void)
    143 {
    144 	htab = htab_new();
    145 }
    146 
    147 /*
    148  * Call the action for each name in the hash table.
    149  */
    150 void
    151 symtab_forall(void (*action)(hte_t *))
    152 {
    153 	int i;
    154 	hte_t *hte;
    155 	hte_t **table = htab;
    156 
    157 	for (i = 0; i < HTAB_BUCKETS; i++) {
    158 		for (hte = table[i]; hte != NULL; hte = hte->h_link)
    159 			action(hte);
    160 	}
    161 }
    162 
    163 /* Run the action for each name in the symbol table, in alphabetic order. */
    164 void
    165 symtab_forall_sorted(void (*action)(const hte_t *))
    166 {
    167 	hte_t *hte;
    168 	struct hte_list sorted = { NULL, 0, 0 };
    169 	size_t i;
    170 	hte_t **table = htab;
    171 
    172 	for (i = 0; i < HTAB_BUCKETS; i++)
    173 		for (hte = table[i]; hte != NULL; hte = hte->h_link)
    174 			hte_list_add(&sorted, hte);
    175 
    176 	qsort(sorted.items, sorted.len, sizeof(sorted.items[0]), hte_by_name);
    177 
    178 	for (i = 0; i < sorted.len; i++)
    179 		action(sorted.items[i]);
    180 
    181 	free(sorted.items);
    182 }
    183 
    184 /*
    185  * Free all contents of the hash table that this module allocated.
    186  */
    187 void
    188 hash_free(hte_t **table)
    189 {
    190 	int i;
    191 	hte_t *hte, *nexthte;
    192 
    193 	for (i = 0; i < HTAB_BUCKETS; i++) {
    194 		for (hte = table[i]; hte != NULL; hte = nexthte) {
    195 			free(__UNCONST(hte->h_name));
    196 			nexthte = hte->h_link;
    197 			free(hte);
    198 		}
    199 	}
    200 	free(table);
    201 }
    202