[rtdbg] Add for cpp support.

include/rtdbg.h

@@ -32,6 +32,10 @@
 
 #include <rtconfig.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* the debug log will force enable when RT_DEBUG macro is defined */
 #if defined(RT_DEBUG) && !defined(DBG_ENABLE)
 #define DBG_ENABLE
@@ -91,13 +95,13 @@
 #ifdef DBG_COLOR
 #define _DBG_COLOR(n)        rt_kprintf("\033["#n"m")
 #define _DBG_LOG_HDR(lvl_name, color_n)                    \
-    rt_kprintf("\033["#color_n"m["lvl_name"/"DBG_SECTION_NAME"] ")
+    rt_kprintf("\033["#color_n"m[" lvl_name "/" DBG_SECTION_NAME "] ")
 #define _DBG_LOG_X_END                                     \
     rt_kprintf("\033[0m\n")
 #else
 #define _DBG_COLOR(n)
 #define _DBG_LOG_HDR(lvl_name, color_n)                    \
-    rt_kprintf("["lvl_name"/"DBG_SECTION_NAME"] ")
+    rt_kprintf("[" lvl_name "/" DBG_SECTION_NAME "] ")
 #define _DBG_LOG_X_END                                     \
     rt_kprintf("\n")
 #endif /* DBG_COLOR */
@@ -176,4 +180,8 @@
 
 #endif /* defined(RT_USING_ULOG) && define(DBG_ENABLE) */
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* RT_DBG_H__ */