From fa9f9772a32804c1e8ed945c6e47fbb1b4d3cc86 Mon Sep 17 00:00:00 2001
From: Peter Qiu <114182543+zqiu-nest@users.noreply.github.com>
Date: Tue, 4 Oct 2022 16:08:10 -0400
Subject: [PATCH] [Linux]Add build arg to allow external logging implementation
 (#22829)

* Linux: add build arg to allow external logging implementation

The will allow target platform/application to provide its own
logging implementation, such as writing logs to file, instead
of logging to stdout.

* Update core.gni
---
 src/lib/core/core.gni       | 5 +++++
 src/platform/Linux/BUILD.gn | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/lib/core/core.gni b/src/lib/core/core.gni
index c49357dffcab68..da4cf547e7c80a 100644
--- a/src/lib/core/core.gni
+++ b/src/lib/core/core.gni
@@ -47,6 +47,11 @@ declare_args() {
   # Configure chip logging to output through pigweed logging.
   chip_use_pw_logging = false
 
+  # Configure chip logging to output through external logging implementation.
+  # External code will need to provide implementation for CHIP log output
+  # function (LogV), which is defined in "src/platform/logging/LogV.h".
+  chip_use_external_logging = false
+
   # Enable short error strings.
   chip_config_short_error_str = false
 
diff --git a/src/platform/Linux/BUILD.gn b/src/platform/Linux/BUILD.gn
index 5a66ab0ccc335d..2088bfb83daf00 100644
--- a/src/platform/Linux/BUILD.gn
+++ b/src/platform/Linux/BUILD.gn
@@ -67,7 +67,6 @@ static_library("Linux") {
     "InetPlatformConfig.h",
     "KeyValueStoreManagerImpl.cpp",
     "KeyValueStoreManagerImpl.h",
-    "Logging.cpp",
     "NetworkCommissioningDriver.h",
     "NetworkCommissioningEthernetDriver.cpp",
     "PlatformManagerImpl.cpp",
@@ -78,6 +77,10 @@ static_library("Linux") {
     "SystemTimeSupport.cpp",
   ]
 
+  if (!chip_use_external_logging) {
+    sources += [ "Logging.cpp" ]
+  }
+
   if (chip_enable_openthread) {
     sources += [ "NetworkCommissioningThreadDriver.cpp" ]
   }