parsers: avoid NULL dereference when option strings are empty
[sigrok-cli/gsi.git] / device.c
blob7da744431154c134b5bee897bc24f817cc774e46
1 /*
2 * This file is part of the sigrok-cli project.
4 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <config.h>
21 #include <glib.h>
22 #include <string.h>
23 #include "sigrok-cli.h"
25 static void free_drvopts(struct sr_config *src)
27 g_variant_unref(src->data);
28 g_free(src);
31 GSList *device_scan(void)
33 struct sr_dev_driver **drivers, *driver;
34 GSList *drvopts, *devices, *tmpdevs, *l;
35 int i;
37 if (opt_drv) {
38 /* Caller specified driver. Use it. Only this one. */
39 if (!parse_driver(opt_drv, &driver, &drvopts))
40 return NULL;
41 devices = sr_driver_scan(driver, drvopts);
42 g_slist_free_full(drvopts, (GDestroyNotify)free_drvopts);
43 } else if (opt_dont_scan) {
44 /* No -d choice, and -D "don't scan" requested. Do nothing. */
45 devices = NULL;
46 } else {
47 /* No driver specified. Scan all available drivers. */
48 devices = NULL;
49 drivers = sr_driver_list(sr_ctx);
50 for (i = 0; drivers[i]; i++) {
51 driver = drivers[i];
52 if (sr_driver_init(sr_ctx, driver) != SR_OK) {
53 g_critical("Failed to initialize driver.");
54 return NULL;
56 tmpdevs = sr_driver_scan(driver, NULL);
57 for (l = tmpdevs; l; l = l->next)
58 devices = g_slist_append(devices, l->data);
59 g_slist_free(tmpdevs);
63 return devices;
66 /**
67 * Lookup a channel group from its name.
69 * Uses the caller specified channel group name, or a previously stored
70 * option value as a fallback. Returns a reference to the channel group
71 * when the lookup succeeded, or #NULL after lookup failure, as well as
72 * #NULL for the global channel group (the device).
74 * Accepts either #NULL pointer, or an empty string, or the "global"
75 * literal to address the global channel group (the device). Emits an
76 * error message when the lookup failed while a name was specified.
78 * @param[in] sdi Device instance.
79 * @param[in] cg_name Caller provided channel group name.
81 * @returns The channel group, or #NULL for failed lookup.
83 struct sr_channel_group *lookup_channel_group(struct sr_dev_inst *sdi,
84 const char *cg_name)
86 struct sr_channel_group *cg;
87 GSList *l, *channel_groups;
89 if (!cg_name)
90 cg_name = opt_channel_group;
91 if (cg_name && g_ascii_strcasecmp(cg_name, "global") == 0)
92 cg_name = NULL;
93 if (!cg_name || !*cg_name)
94 return NULL;
96 channel_groups = sr_dev_inst_channel_groups_get(sdi);
97 if (!channel_groups) {
98 g_critical("This device does not have any channel groups.");
99 return NULL;
102 for (l = channel_groups; l; l = l->next) {
103 cg = l->data;
104 if (g_ascii_strcasecmp(cg_name, cg->name) != 0)
105 continue;
106 return cg;
108 g_critical("Invalid channel group '%s'", cg_name);
110 return NULL;