pw_log_android

Android logging backend

Unstable C++

pw_log_android is a pw_log backend for Android.

Overview

pw_log_android is a pw_log backend that directs logs to the Android logging system (liblog). It’s the default logging backend selected by the pw_android_common_backends rule. See Common Android backends.

Logging to standard error

By default, logs are written to logd (the logger daemon) and can be viewed using the logcat command-line tool. This is useful for system services.

Logs can alternatively be written directly to standard error (stderr), which is useful for short-lived command-line utilities. Pigweed facilitates this by providing the pw_log_android_stderr library. Include it in your executable via whole_static_libs as seen here:

cc_binary {
    name: "my_app",
    host_supported: true,
    vendor: true,
    defaults: [
        "pw_android_common_backends",
    ],
    srcs: [
        "main.cc",
    ],
    whole_static_libs: [
         "pw_log_android_stderr",
    ],
}

Warning

pw_log_android_stderr should only be used in executables (cc_binary).

Using it with a library would affect the logging behavior for all consumers of that library.

Log level mapping

This table shows the mapping of Pigweed log levels to Android log levels.

Log level mapping

Pigweed level	Android level
DEBUG	ANDROID_LOG_DEBUG
INFO	ANDROID_LOG_INFO
WARN	ANDROID_LOG_WARN
ERROR	ANDROID_LOG_ERROR
CRITICAL	ANDROID_LOG_ERROR
FATAL	ANDROID_LOG_FATAL