b302cdf6a4
As the final step for the refactoring of sysprop configuration, this change adds BUILD_BROKEN_DUP_SYSPROP which is the escape hatch for the new restriction. When it is turned on, the new syntax `a ?= b` collapses to the old syntax `a = b`, duplicated assignments are allowed, and the dups are resolved following the legacy rule of preferring the first. This change also summarizes all the user-facing changes to the Change.md file. Lastly, post_process_prop.py is refactored to accept new argument '--allow-dup' which when turned on allowes duplicated sysprops. Bug: 117892318 Bug: 158735147 Test: atest --host post_process_prop_unittest Change-Id: I7bdfffd47d50aad66a78e28a30c3dad7ebac080c
Android Make Build System
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For an outdated reference on Android.mk files, see build-system.html.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.