fix(stats): Add license, usage note and C++ guards

Author: me-no-dev

Diff for: cores/esp32/freertos_stats.cpp

@@ -1,7 +1,19 @@
+// Copyright 2024 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #include "freertos_stats.h"
 #include "sdkconfig.h"
-//#undef CONFIG_FREERTOS_VTASKLIST_INCLUDE_COREID
-//#undef CONFIG_FREERTOS_GENERATE_RUN_TIME_STATS
 
 #if CONFIG_FREERTOS_USE_TRACE_FACILITY
 #include "freertos/FreeRTOS.h"
@@ -97,5 +109,7 @@ void printRunningTasks(Print & printer) {
     vPortFree( pxTaskStatusArray );
     printer.println();
   }
+#else
+  printer.println("FreeRTOS trace facility is not enabled.");
 #endif /* CONFIG_FREERTOS_USE_TRACE_FACILITY */
 }

Diff for: cores/esp32/freertos_stats.h

@@ -1,4 +1,28 @@
+// Copyright 2024 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #pragma once
+
+#ifdef __cplusplus
+
 #include "Print.h"
 
+/*
+ * Executing this function will cause interrupts and
+ * the scheduler to be blocked for some time.
+ * Please use only for debugging purposes.
+ */
 void printRunningTasks(Print & printer);
+
+#endif