MXS-2014 Add maxbase/assert.h

Basically a copy of maxscale/debug.h, but with some name changes.

- ss_dassert      -> mxb_assert
- ss_info_dassert -> mxb_assert_message
- ss_debug        -> MXB_AT_DEBUG

maxutils/maxbase/include/maxbase/assert.h

@@ -0,0 +1,49 @@
+#pragma once
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2022-01-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+#include <maxbase/cdefs.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <maxbase/log.h>
+
+MXB_BEGIN_DECLS
+
+// TODO: Provide an MXB_DEBUG with the same meaning.
+#if defined(SS_DEBUG)
+
+#define mxb_assert(exp) do { if(!(exp)){\
+            const char *debug_expr = #exp;  /** The MXB_ERROR marco doesn't seem to like stringification */ \
+            MXB_ERROR("debug assert at %s:%d failed: %s\n", (char*)__FILE__, __LINE__, debug_expr); \
+            fprintf(stderr, "debug assert at %s:%d failed: %s\n", (char*)__FILE__, __LINE__, debug_expr); \
+            raise(SIGABRT);} } while (false)
+
+#define mxb_assert_message(exp,message) do { if(!(exp)){     \
+            const char *debug_expr = #exp; \
+            MXS_ERROR("debug assert at %s:%d failed: %s (%s)\n", (char*)__FILE__, __LINE__, message, debug_expr); \
+            fprintf(stderr, "debug assert at %s:%d failed: %s (%s)\n", (char*)__FILE__, __LINE__, message, debug_expr); \
+            raise(SIGABRT);} } while (false)
+
+#define MXB_AT_DEBUG(exp) exp
+
+#else /* SS_DEBUG */
+
+#define mxb_assert(exp)
+#define mxb_assert_message(exp, message)
+
+#define MXB_AT_DEBUG(exp)
+
+#endif /* SS_DEBUG */
+
+MXB_END_DECLS