build: enable Perfetto by default Perfetto has been enabled by default on Pixel devices since P and has proved to be stable and helped find performance issues on both P and Q. On R+, iorapd has a dependency on Perfetto and thus we need to be enabled by default. Note that CTS tests have ensured that any downstream consumers of Android have not accidentally broken Perfetto in old releases so this should be safe to introduce and maintain going forward. The two daemons of Perfetto (traced and traced_probes) are located on the /system partition so for consistency, we have chosen to also enable the build property on the system partition. Googlers can see the below link for more context and detailed info. Change-Id: I00fa7d4c97eda4d0ab83520d0f428bca83707d8a Context (Googlers only): go/perfetto-by-default Bug: 137963570 Test: checking product/build.prop in Treehugger builds
This is the Makefile-based portion of the Android Build System.
For documentation on how to run a build, see Usage.txt
For a list of behavioral changes useful for Android.mk writers see Changes.md
For an outdated reference on Android.mk files, see build-system.html. Our Android.mk files look similar, but are entirely different from the Android.mk files used by the NDK build system. When searching for documentation elsewhere, ensure that it is for the platform build system -- most are not.
This Makefile-based system is in the process of being replaced with Soong, a new build system written in Go. During the transition, all of these makefiles are read by Kati, and generate a ninja file instead of being executed directly. That's combined with a ninja file read by Soong so that the build graph of the two systems can be combined and run as one.