One of the android Modules (AudioFlinger) has support for verbose logging (with Tag=AudioFlinger). Question is how can I see those logs in the logcat?
I did the setprop log.tag.AudioFlinger VERBOSE - but it doesn't seem to work. Do I need to change something and then rebuild the android source again?
The logcat documentation doesn't really help. But with more digging I was able to find the answer, as I was expecting the VERBOSE logging is by default OFF at compile time.
Looking at the cutils/log.h helps to find the answer: http://www.netmite.com/android/mydroid/system/core/include/cutils/log.h
/*
* Normally we strip LOGV (VERBOSE messages) from release builds.
* You can modify this (for example with "#define LOG_NDEBUG 0"
* at the top of your source file) to change that behavior.
*/
So to enable VERBOSE for any source file/module : We have to define LOG_NDEBUG as 0
Use any of the below methods.
1) Add or uncomment "`#define LOG_NDEBUG 0`" at top of any module file.
2) In Android.mk or <module>.mk file, add `LOCAL_CFLAGS += -DLOG_NDEBUG=0`
In logcat, logcat | grep -E 'tag1|tag2'.
来源：https://stackoverflow.com/questions/7964685/how-to-get-verbose-logging-in-logcat-for-a-specific-module