Merge remote-tracking branch 'remotes/alistair23/tags/pull-riscv-to-apply-20210921...
[qemu.git] / util / id.c
1 /*
2 * Dealing with identifiers
3 *
4 * Copyright (C) 2014 Red Hat, Inc.
5 *
6 * Authors:
7 * Markus Armbruster <armbru@redhat.com>,
8 *
9 * This work is licensed under the terms of the GNU LGPL, version 2.1
10 * or later. See the COPYING.LIB file in the top-level directory.
11 */
12
13 #include "qemu/osdep.h"
14 #include "qemu/ctype.h"
15 #include "qemu/id.h"
16
17 bool id_wellformed(const char *id)
18 {
19 int i;
20
21 if (!qemu_isalpha(id[0])) {
22 return false;
23 }
24 for (i = 1; id[i]; i++) {
25 if (!qemu_isalnum(id[i]) && !strchr("-._", id[i])) {
26 return false;
27 }
28 }
29 return true;
30 }
31
32 #define ID_SPECIAL_CHAR '#'
33
34 static const char *const id_subsys_str[ID_MAX] = {
35 [ID_QDEV] = "qdev",
36 [ID_BLOCK] = "block",
37 [ID_CHR] = "chr",
38 [ID_NET] = "net",
39 };
40
41 /*
42 * Generates an ID of the form PREFIX SUBSYSTEM NUMBER
43 * where:
44 *
45 * - PREFIX is the reserved character '#'
46 * - SUBSYSTEM identifies the subsystem creating the ID
47 * - NUMBER is a decimal number unique within SUBSYSTEM.
48 *
49 * Example: "#block146"
50 *
51 * Note that these IDs do not satisfy id_wellformed().
52 *
53 * The caller is responsible for freeing the returned string with g_free()
54 */
55 char *id_generate(IdSubSystems id)
56 {
57 static uint64_t id_counters[ID_MAX];
58 uint32_t rnd;
59
60 assert(id < ARRAY_SIZE(id_subsys_str));
61 assert(id_subsys_str[id]);
62
63 rnd = g_random_int_range(0, 100);
64
65 return g_strdup_printf("%c%s%" PRIu64 "%02" PRId32, ID_SPECIAL_CHAR,
66 id_subsys_str[id],
67 id_counters[id]++,
68 rnd);
69 }