msh: free is only available when HEAP is enabled

components/finsh/msh_cmd.c

@@ -276,6 +276,7 @@ int cmd_time(int argc, char** argv)
 }
 FINSH_FUNCTION_EXPORT_ALIAS(cmd_time, __cmd_time, Execute command with time.);
 
+#ifdef RT_USING_HEAP
 int cmd_free(int argc, char** argv)
 {
     extern void list_mem(void);
@@ -284,6 +285,7 @@ int cmd_free(int argc, char** argv)
     return 0;
 }
 FINSH_FUNCTION_EXPORT_ALIAS(cmd_free, __cmd_free, Show the memory usage in the system.);
+#endif
 
 #endif