mdbx: new testset (initial, stub).

Initial stub for https://github.com/ReOpen/libmdbx/issues/8

test/log.h

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2017 Leonid Yuriev <leo@yuriev.ru>
+ * and other libmdbx authors: please see AUTHORS file.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+
+#pragma once
+
+#include "base.h"
+
+void __noreturn usage(void);
+
+void __noreturn
+#ifdef __GNUC__
+    __attribute__((format(printf, 1, 2)))
+#endif
+    failure(const char *fmt, ...);
+
+void __noreturn failure_perror(const char *what, int errnum);
+const char *test_strerror(int errnum);
+
+namespace loggging {
+
+enum loglevel {
+  trace,
+  info,
+  notice,
+  warning,
+  error,
+  failure,
+};
+
+const char *level2str(const loglevel level);
+void setup(loglevel level, const std::string &prefix);
+void setup(const std::string &prefix);
+
+void output(loglevel priority, const char *format, va_list ap);
+
+} /* namespace log */
+
+void log_trace(const char *msg, ...);
+void log_info(const char *msg, ...);
+void log_notice(const char *msg, ...);
+void log_warning(const char *msg, ...);
+void log_error(const char *msg, ...);
+
+void log_touble(const char *where, const char *what, int errnum);
+
+#ifdef _DEBUG
+#define TRACE(...) log_trace(__VA_ARGS__)
+#else
+#define TRACE(...) __noop(__VA_ARGS__)
+#endif