From 0c754bb09d043169615f71f390fe305d9cf6c852 Mon Sep 17 00:00:00 2001
From: Simon Lin <simonlin@google.com>
Date: Wed, 13 Apr 2022 03:36:00 +0800
Subject: [PATCH] [logging] add log level platform handler (#7545)

Adds a log level platform handler that allow platform code to handle
OT log level changes.
---
 include/openthread/instance.h         |  2 +-
 include/openthread/platform/logging.h | 13 +++++++++++++
 src/core/common/instance.cpp          | 18 ++++++++++++++++++
 src/core/common/instance.hpp          |  2 +-
 4 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/include/openthread/instance.h b/include/openthread/instance.h
index 8b2457196..c57b31274 100644
--- a/include/openthread/instance.h
+++ b/include/openthread/instance.h
@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (201)
+#define OPENTHREAD_API_VERSION (202)
 
 /**
  * @addtogroup api-instance
diff --git a/include/openthread/platform/logging.h b/include/openthread/platform/logging.h
index 8d9d36f11..adf123f44 100644
--- a/include/openthread/platform/logging.h
+++ b/include/openthread/platform/logging.h
@@ -161,6 +161,19 @@ typedef enum otLogRegion
  */
 void otPlatLog(otLogLevel aLogLevel, otLogRegion aLogRegion, const char *aFormat, ...);
 
+/**
+ * This function handles OpenThread log level changes.
+ *
+ * This platform function is called whenever the OpenThread log level changes.
+ * This platform function is optional since an empty weak implementation has been provided.
+ *
+ * @note Only applicable when `OPENTHREAD_CONFIG_LOG_LEVEL_DYNAMIC_ENABLE=1`.
+ *
+ * @param[in]  aLogLevel  The new OpenThread log level.
+ *
+ */
+void otPlatLogHandleLevelChanged(otLogLevel aLogLevel);
+
 /**
  * @}
  *
diff --git a/src/core/common/instance.cpp b/src/core/common/instance.cpp
index 2262f02a0..122eb4327 100644
--- a/src/core/common/instance.cpp
+++ b/src/core/common/instance.cpp
@@ -294,4 +294,22 @@ void Instance::GetBufferInfo(BufferInfo &aInfo)
 
 #endif // OPENTHREAD_MTD || OPENTHREAD_FTD
 
+#if OPENTHREAD_CONFIG_LOG_LEVEL_DYNAMIC_ENABLE
+
+void Instance::SetLogLevel(LogLevel aLogLevel)
+{
+    if (aLogLevel != sLogLevel)
+    {
+        sLogLevel = aLogLevel;
+        otPlatLogHandleLevelChanged(sLogLevel);
+    }
+}
+
+extern "C" OT_TOOL_WEAK void otPlatLogHandleLevelChanged(otLogLevel aLogLevel)
+{
+    OT_UNUSED_VARIABLE(aLogLevel);
+}
+
+#endif
+
 } // namespace ot
diff --git a/src/core/common/instance.hpp b/src/core/common/instance.hpp
index 026613e7e..a184a09b1 100644
--- a/src/core/common/instance.hpp
+++ b/src/core/common/instance.hpp
@@ -207,7 +207,7 @@ public:
      * @param[in] aLogLevel  A log level.
      *
      */
-    static void SetLogLevel(LogLevel aLogLevel) { sLogLevel = aLogLevel; }
+    static void SetLogLevel(LogLevel aLogLevel);
 #endif
 
     /**