xref: /third_party/alsa-lib/src/error.c (revision d5ac70f0)
1/**
2 * \file error.c
3 * \brief Error code handling routines
4 * \author Jaroslav Kysela <perex@perex.cz>
5 * \date 1998-2001
6 *
7 * Error code handling routines.
8 */
9/*
10 *  Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>
11 *
12 *  snd_strerror routine needs to be recoded for the locale support
13 *
14 *
15 *   This library is free software; you can redistribute it and/or modify
16 *   it under the terms of the GNU Lesser General Public License as
17 *   published by the Free Software Foundation; either version 2.1 of
18 *   the License, or (at your option) any later version.
19 *
20 *   This program is distributed in the hope that it will be useful,
21 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
22 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23 *   GNU Lesser General Public License for more details.
24 *
25 *   You should have received a copy of the GNU Lesser General Public
26 *   License along with this library; if not, write to the Free Software
27 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
28 *
29 */
30
31#include "local.h"
32#include <stdio.h>
33#include <stdlib.h>
34#include <stdarg.h>
35#include <string.h>
36
37/**
38 * Array of error codes in US ASCII.
39 */
40static const char *snd_error_codes[] =
41{
42	"Sound protocol is not compatible"
43};
44
45/**
46 * \brief Returns the message for an error code.
47 * \param errnum The error code number, which must be a system error code
48 *               or an ALSA error code.
49 * \return The ASCII description of the given numeric error code.
50 */
51const char *snd_strerror(int errnum)
52{
53	if (errnum < 0)
54		errnum = -errnum;
55	if (errnum < SND_ERROR_BEGIN)
56		return (const char *) strerror(errnum);
57	errnum -= SND_ERROR_BEGIN;
58	if ((unsigned int) errnum >= sizeof(snd_error_codes) / sizeof(const char *))
59		 return "Unknown error";
60	return snd_error_codes[errnum];
61}
62
63#ifndef DOC_HIDDEN
64#ifdef HAVE___THREAD
65#define TLS_PFX		__thread
66#else
67#define TLS_PFX		/* NOP */
68#endif
69#endif
70
71static TLS_PFX snd_local_error_handler_t local_error = NULL;
72
73/**
74 * \brief Install local error handler
75 * \param func The local error handler function
76 * \retval Previous local error handler function
77 */
78snd_local_error_handler_t snd_lib_error_set_local(snd_local_error_handler_t func)
79{
80	snd_local_error_handler_t old = local_error;
81	local_error = func;
82	return old;
83}
84
85/**
86 * \brief The default error handler function.
87 * \param file The filename where the error was hit.
88 * \param line The line number.
89 * \param function The function name.
90 * \param err The error code.
91 * \param fmt The message (including the format characters).
92 * \param ... Optional arguments.
93 *
94 * If a local error function has been installed for the current thread by
95 * \ref snd_lib_error_set_local, it is called. Otherwise, prints the error
96 * message including location to \c stderr.
97 */
98static void snd_lib_error_default(const char *file, int line, const char *function, int err, const char *fmt, ...)
99{
100	va_list arg;
101	va_start(arg, fmt);
102	if (local_error) {
103		local_error(file, line, function, err, fmt, arg);
104		va_end(arg);
105		return;
106	}
107	fprintf(stderr, "ALSA lib %s:%i:(%s) ", file, line, function);
108	vfprintf(stderr, fmt, arg);
109	if (err)
110		fprintf(stderr, ": %s", snd_strerror(err));
111	putc('\n', stderr);
112	va_end(arg);
113}
114
115/**
116 * \ingroup Error
117 * Pointer to the error handler function.
118 * For internal use only.
119 */
120snd_lib_error_handler_t snd_lib_error = snd_lib_error_default;
121
122/**
123 * \brief Sets the error handler.
124 * \param handler The pointer to the new error handler function.
125 *
126 * This function sets a new error handler, or (if \c handler is \c NULL)
127 * the default one which prints the error messages to \c stderr.
128 */
129int snd_lib_error_set_handler(snd_lib_error_handler_t handler)
130{
131	snd_lib_error = handler == NULL ? snd_lib_error_default : handler;
132#ifndef NDEBUG
133	if (snd_lib_error != snd_lib_error_default)
134		snd_err_msg = snd_lib_error;
135#endif
136	return 0;
137}
138
139/**
140 * \brief Returns the ALSA sound library version in ASCII format
141 * \return The ASCII description of the used ALSA sound library.
142 */
143const char *snd_asoundlib_version(void)
144{
145	return SND_LIB_VERSION_STR;
146}
147
148#ifndef NDEBUG
149/*
150 * internal error handling
151 */
152static void snd_err_msg_default(const char *file, int line, const char *function, int err, const char *fmt, ...)
153{
154	va_list arg;
155	const char *verbose;
156
157	verbose = getenv("LIBASOUND_DEBUG");
158	if (! verbose || ! *verbose)
159		return;
160	va_start(arg, fmt);
161	fprintf(stderr, "ALSA lib %s:%i:(%s) ", file, line, function);
162	vfprintf(stderr, fmt, arg);
163	if (err)
164		fprintf(stderr, ": %s", snd_strerror(err));
165	putc('\n', stderr);
166	va_end(arg);
167#ifdef ALSA_DEBUG_ASSERT
168	verbose = getenv("LIBASOUND_DEBUG_ASSERT");
169	if (verbose && *verbose)
170		assert(0);
171#endif
172}
173
174/**
175 * The ALSA error message handler
176 */
177snd_lib_error_handler_t snd_err_msg = snd_err_msg_default;
178
179#endif
180
181/**
182 * \brief Copy a C-string into a sized buffer
183 * \param dst Where to copy the string to
184 * \param src Where to copy the string from
185 * \param size Size of destination buffer
186 * \retval The source string length
187 *
188 * The result is always a valid NUL-terminated string that fits
189 * in the buffer (unless, of course, the buffer size is zero).
190 * It does not pad out the result like strncpy() does.
191 */
192size_t snd_strlcpy(char *dst, const char *src, size_t size)
193{
194  size_t ret = strlen(src);
195  if (size) {
196    size_t len = ret >= size ? size - 1 : ret;
197    memcpy(dst, src, len);
198    dst[len] = '\0';
199  }
200  return ret;
201}
202