[PATCH 13/14] Implement av_strerror().

[Stefano Sabatini]

---
 configure          |    2 +
 libavutil/Makefile |    1 +
 libavutil/avutil.h |    2 +-
 libavutil/error.c  |   80 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 libavutil/error.h  |    9 ++++++
 5 files changed, 93 insertions(+), 1 deletions(-)
 create mode 100644 libavutil/error.c

diff --git a/configure b/configure
index 0682006..e6706b9 100755
--- a/configure
+++ b/configure
@@ -1074,6 +1074,7 @@ HAVE_LIST="
     soundcard_h
     poll_h
     setrlimit
+    strerror_r
     struct_addrinfo
     struct_ipv6_mreq
     struct_sockaddr_in6
@@ -2531,6 +2532,7 @@ check_func  ${malloc_prefix}memalign            && enable memalign
 check_func  mkstemp
 check_func  ${malloc_prefix}posix_memalign      && enable posix_memalign
 check_func  setrlimit
+check_func  strerror_r
 check_func_headers io.h setmode
 check_func_headers lzo/lzo1x.h lzo1x_999_compress
 check_lib2 "windows.h psapi.h" GetProcessMemoryInfo -lpsapi
diff --git a/libavutil/Makefile b/libavutil/Makefile
index 5b6cd0e..79506c0 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -30,6 +30,7 @@ OBJS = adler32.o                                                        \
        base64.o                                                         \
        crc.o                                                            \
        des.o                                                            \
+       error.o                                                          \
        fifo.o                                                           \
        intfloat_readwrite.o                                             \
        lfg.o                                                            \
diff --git a/libavutil/avutil.h b/libavutil/avutil.h
index 47630a7..968787c 100644
--- a/libavutil/avutil.h
+++ b/libavutil/avutil.h
@@ -40,7 +40,7 @@
 #define AV_VERSION(a, b, c) AV_VERSION_DOT(a, b, c)
 
 #define LIBAVUTIL_VERSION_MAJOR 50
-#define LIBAVUTIL_VERSION_MINOR 12
+#define LIBAVUTIL_VERSION_MINOR 13
 #define LIBAVUTIL_VERSION_MICRO  0
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
diff --git a/libavutil/error.c b/libavutil/error.c
new file mode 100644
index 0000000..cf7a3f0
--- /dev/null
+++ b/libavutil/error.c
@@ -0,0 +1,80 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "avutil.h"
+#include "avstring.h"
+
+int av_strerror(int errnum, char *errbuf, size_t errbuf_size)
+{
+    int ret = 0;
+    const char *errstr = NULL;
+
+    switch (errnum) {
+    case AVERROR_EOF:          errstr = "End of file"; break;
+    case AVERROR_INVALIDDATA:  errstr = "Invalid data found when processing input"; break;
+    case AVERROR_NOFMT:        errstr = "Unknown format"; break;
+    case AVERROR_NOTSUPP:      errstr = "Operation not supported"; break;
+    case AVERROR_NUMEXPECTED:  errstr = "Number syntax expected in filename"; break;
+    case AVERROR_PATCHWELCOME: errstr = "Not yet implemented in FFmpeg, patches welcome"; break;
+    }
+
+    if (errstr) {
+        av_strlcpy(errbuf, errstr, errbuf_size);
+    } else {
+#if HAVE_STRERROR_R
+        /* '1 *' added for getting an easy to debug error if the system uses non-standard GNU strerror_r */
+        ret = 1 * strerror_r(AVUNERROR(errnum), errbuf, errbuf_size);
+#else
+        snprintf(errbuf, errbuf_size, "Error number %d", errnum);
+#endif
+    }
+
+    return ret;
+}
+
+#ifdef TEST
+
+#undef printf
+
+int main(void)
+{
+    int i, ret;
+    char errbuf[256];
+
+    for (i = 0; i > -256; i--) {
+        *errbuf = 0;
+        ret = av_strerror(i, errbuf, sizeof(errbuf));
+        printf("code:%d: str:'%s' ret:%d\n", i, errbuf, ret);
+    }
+
+#define PRINTERR(ERR)                                         \
+    av_strerror(AVERROR_##ERR, errbuf, sizeof(errbuf));       \
+    printf("%d[%s]: %s\n", AVERROR_##ERR, #ERR, errbuf)
+
+    PRINTERR(IO);
+    PRINTERR(NOENT);
+    PRINTERR(NOMEM);
+    PRINTERR(EOF);
+    PRINTERR(INVALIDDATA);
+    PRINTERR(NOFMT);
+    PRINTERR(NOTSUPP);
+    PRINTERR(NUMEXPECTED);
+    PRINTERR(PATCHWELCOME);
+}
+
+#endif
diff --git a/libavutil/error.h b/libavutil/error.h
index 8b8a8e6..dc1cc9a 100644
--- a/libavutil/error.h
+++ b/libavutil/error.h
@@ -58,4 +58,13 @@
 #define AVERROR_NUMEXPECTED     (-MKTAG('N','U','E','X')) /**< Number syntax expected in filename. */
 #endif
 
+/**
+ * Puts a description of the AVERROR code errnum in errbuf.
+ * In case of failure errno is set to indicate the error.
+ *
+ * @param errbuf_size the size in bytes of errbuf
+ * @return 0 on success, -1 otherwise
+ */
+int av_strerror(int errnum, char *errbuf, size_t errbuf_size);
+
 #endif /* AVUTIL_ERROR_H */
-- 
1.7.0


--KsGdsel6WgEHnImy--