core/include: add xtstr macro

core/doc.txt

@@ -31,3 +31,9 @@
   * @ingroup     core
   * @brief       Thread synchronization mechanisms of the kernel
   */
+
+/**
+ * @defgroup    core_macros Common Macros
+ * @ingroup     core
+ * @brief       Commonly used macros header definitions
+ */

core/include/macros/xtstr.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2019 Gunar Schorcht
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     core_macros
+ * @{
+ *
+ * @file
+ * @brief       Macro to return string representation of x
+ *
+ * @author      Gunar Schorcht <gunar@schorcht.net>
+ */
+
+#ifndef MACROS_XTSTR_H
+#define MACROS_XTSTR_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @def     XTSTR
+ *
+ * @brief   A macro to return the string respresentation of x
+ */
+#ifndef XTSTR
+#define _XTSTR(x)    # x
+#define XTSTR(x)    _XTSTR(x)
+#endif /* XTSTR */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MACROS_XTSTR_H */
+/** @} */