Add libexif to deps/third_party.

libexif/sources/libexif/exif-log.h

+/*! \file exif-log.h
+ *  \brief Log message infrastructure
+ */
+/*
+ * Copyright (c) 2004 Lutz Mueller <lutz@users.sourceforge.net>
+ *
+ * This library 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 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA  02110-1301  USA.
+ */
+
+#ifndef __EXIF_LOG_H__
+#define __EXIF_LOG_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+#include <libexif/exif-mem.h>
+#include <stdarg.h>
+
+/*! State maintained by the logging interface */
+typedef struct _ExifLog        ExifLog;
+
+/*! Create a new logging instance.
+ * \see exif_log_free
+ *
+ * \return new instance of #ExifLog
+ */
+ExifLog *exif_log_new     (void);
+ExifLog *exif_log_new_mem (ExifMem *);
+void     exif_log_ref     (ExifLog *log);
+void     exif_log_unref   (ExifLog *log);
+
+/*! Delete instance of #ExifLog.
+ * \see exif_log_new
+ *
+ * \param[in] log #ExifLog
+ * \return new instance of #ExifLog
+ */
+void     exif_log_free    (ExifLog *log);
+
+typedef enum {
+        EXIF_LOG_CODE_NONE,
+        EXIF_LOG_CODE_DEBUG,
+        EXIF_LOG_CODE_NO_MEMORY,
+        EXIF_LOG_CODE_CORRUPT_DATA
+} ExifLogCode;
+
+/*! Return a textual description of the given class of error log.
+ *
+ * \param[in] code logging message class
+ * \return textual description of the log class
+ */
+const char *exif_log_code_get_title   (ExifLogCode code);
+
+/*! Return a verbose description of the given class of error log.
+ *
+ * \param[in] code logging message class
+ * \return verbose description of the log class
+ */
+const char *exif_log_code_get_message (ExifLogCode code);
+
+/*! Log callback function prototype.
+ */
+typedef void (* ExifLogFunc) (ExifLog *log, ExifLogCode, const char *domain,
+                              const char *format, va_list args, void *data);
+
+/*! Register log callback function.
+ * Calls to the log callback function are purely for diagnostic purposes.
+ *
+ * \param[in] log logging state variable
+ * \param[in] func callback function to set
+ * \param[in] data data to pass into callback function
+ */
+void     exif_log_set_func (ExifLog *log, ExifLogFunc func, void *data);
+
+#ifndef NO_VERBOSE_TAG_STRINGS
+void     exif_log  (ExifLog *log, ExifLogCode, const char *domain,
+                    const char *format, ...)
+#ifdef __GNUC__
+                        __attribute__((__format__(printf,4,5)))
+#endif
+;
+#else
+#if defined(__STDC_VERSION__) &&  __STDC_VERSION__ >= 199901L
+#define exif_log(...) do { } while (0)
+#elif defined(__GNUC__)
+#define exif_log(x...) do { } while (0)
+#else
+#define exif_log (void)
+#endif
+#endif
+
+void     exif_logv (ExifLog *log, ExifLogCode, const char *domain,
+                    const char *format, va_list args);
+
+/* For your convenience */
+#define EXIF_LOG_NO_MEMORY(l,d,s) exif_log ((l), EXIF_LOG_CODE_NO_MEMORY, (d), "Could not allocate %lu byte(s).", (unsigned long)(s))
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* __EXIF_LOG_H__ */