Build.VERSION.INCREMENTAL、ro.build.version.incremental、BUILD_NUMBER、AOSP、Android源码、Android11
0. 需求背景
系统INCREMENTAL版本号默认是eng..20240717.154301格式，希望在必要时可以自定义版本号
1. 搜索路径
从Android SDK源码可知Build.VERSION.INCREMENTAL实际读取的是系统属性ro.build.version.incremental，线索可以自从ro.build.version.incremental入手。
结合之前对build属性的了解，直接在aosp/build目录进行搜索，先搜索.mk文件没发现ro.build.version.incremental，再搜索.sh文件找到位置
./make/tools/buildinfo.sh:8:echo "ro.build.version.incremental=$BUILD_NUMBER"
继续在.mk中搜索BUILD_NUMBER，发现主要是在version_defaults.mk文件中处理
/make/core/version_defaults.mk:26:# BUILD_NUMBER
./make/core/version_defaults.mk:282:# BUILD_DATETIME and DATE can be removed once BUILD_NUMBER moves
./make/core/version_defaults.mk:286:HAS_BUILD_NUMBER := true
./make/core/version_defaults.mk:287:ifndef BUILD_NUMBER
./make/core/version_defaults.mk:288: # BUILD_NUMBER should be set to the source control value that
./make/core/version_defaults.mk:294: # If no BUILD_NUMBER is set, create a useful "I am an engineering build
./make/core/version_defaults.mk:297: BUILD_NUMBER := eng.$(shell echo $${BUILD_USERNAME:0:6}).$(shell $(DATE) +%Y%m%d.%H%M%S)
./make/core/version_defaults.mk:298: HAS_BUILD_NUMBER := false
./make/core/version_defaults.mk:300:.KATI_READONLY := BUILD_NUMBER HAS_BUILD_NUMBER
打开version_defaults.mk文件，其中关键代码为
HAS_BUILD_NUMBER := true
ifndef BUILD_NUMBER
# BUILD_NUMBER should be set to the source control value that
# represents the current state of the source code. E.g., a
# perforce changelist number or a git hash. Can be an arbitrary string
# (to allow for source control that uses something other than numbers),
# but must be a single word and a valid file name.
#
# If no BUILD_NUMBER is set, create a useful "I am an engineering build
# from this date/time" value. Make it start with a non-digit so that
# anyone trying to parse it as an integer will probably get "0".
BUILD_NUMBER := eng.$(shell echo $${BUILD_USERNAME:0:6}).$(shell $(DATE) +%Y%m%d.%H%M%S)
HAS_BUILD_NUMBER := false
endif
那就好吧了，直接在环境变量中定义BUILD_NUMBER即可。
2. 解决方案
在编译时增加环境变量
source build/envsetup.sh &&
lunch ${DEVICE}-${BUILD_VARIANT} &&
BUILD_NUMBER=${Your_Version} PRODUCT_NAME=${Your_ProductName} ./build.sh -AUCKuo -J32
