在 Android 7.0 之前，Android 编译系统使用 GNU Make 描述和shell来构建编译规则，模块定义都使用Android.mk进行定义，Android.mk的本质就是Makefile，但是随着Android的工程越来越大，模块越来越多，Makefile组织的项目编译时间越来越长。这样下去Google工程师觉得不行，得要优化。
function validate_current_shell() { local current_sh="$(ps -o command -p $$)" case "$current_sh" in *bash*) function check_type() { type -t "$1"; } ;; *zsh*) function check_type() { type "$1"; } enable_zsh_completion ;; *) echo -e "WARNING: Only bash and zsh are supported.\\nUse of other shell would lead to erroneous results." ;; esac }
function source_vendorsetup() { allowed= for f in $(find -L device vendor product -maxdepth 4 -name 'allowed-vendorsetup_sh-files' 2>/dev/null | sort); do if [ -n "$allowed" ]; then echo "More than one 'allowed_vendorsetup_sh-files' file found, not including any vendorsetup.sh files:" echo " $allowed" echo " $f" return fi allowed="$f" done
allowed_files= [ -n "$allowed" ] && allowed_files=$(cat "$allowed") for dir in device vendor product; do for f in $(test -d $dir && \\ find -L $dir -maxdepth 4 -name 'vendorsetup.sh' 2>/dev/null | sort); do
if [[ -z "$allowed" || "$allowed_files" =~ $f ]]; then echo "including $f"; . "$f" else echo "ignoring $f, not in $allowed" fi done done }
# Keep us from trying to run in something that's neither bash nor zsh. # 检测shell版本字符串BASH_VERSION 或ZSH_VERSION长度为0时，返回 if [ -z "$BASH_VERSION" -a -z "$ZSH_VERSION" ]; then return fi
# Keep us from trying to run in bash that's too old. # 检测bash主版本低于3时返回 if [ -n "$BASH_VERSION" -a ${BASH_VERSINFO[0]} -lt 3 ]; then return fi
# 指定bash文件目录并检查是否存在 local completion_files=( system/core/adb/adb.bash system/core/fastboot/fastboot.bash tools/asuite/asuite.sh ) # Completion can be disabled selectively to allow users to use non-standard completion. # e.g. # ENVSETUP_NO_COMPLETION=adb # -> disable adb completion # ENVSETUP_NO_COMPLETION=adb:bit # -> disable adb and bit completion #*.bash文件列表，并将这些*.bash文件包含进来 for f in ${completion_files[*]}; do if [ -f "$f" ] && should_add_completion "$f"; then # 对*.bash文件执行'.'操作 . $f fi done
if should_add_completion bit ; then complete -C "bit --tab" bit fi if [ -z "$ZSH_VERSION" ]; then # Doesn't work in zsh. complete -o nospace -F _croot croot fi complete -F _lunch lunch # _lunch命令提供lunch命令的补全操作
complete -F _complete_android_module_names gomod complete -F _complete_android_module_names m }
function lunch() { local answer # 获取lunch操作的参数 if [ "$1" ] ; then answer=$1 else # lunch操作不带参数，则先显示lunch menu，然后读取用户输入 print_lunch_menu echo -n "Which would you like? [aosp_arm-eng] " read answer fi
local selection= # lunch操作得到的结果为空（例如用户直接在lunch要求输入时回车的情况） # 则将选项默认为"aosp_arm-eng" if [ -z "$answer" ] then selection=aosp_arm-eng # lunch操作得到的输入是数字，则将数字转换为LUNCH_MENU_CHOICES中的字符串 elif (echo -n $answer | grep -q -e "^[0-9][0-9]*$") then local choices=($(TARGET_BUILD_APPS= get_build_var COMMON_LUNCH_CHOICES)) if [ $answer -le ${#choices[@]} ] then # array in zsh starts from 1 instead of 0. if [ -n "$ZSH_VERSION" ] then selection=${choices[$(($answer))]} else selection=${choices[$(($answer-1))]} fi fi else selection=$answer fi
export TARGET_BUILD_APPS=
local product variant_and_version variant version
product=${selection%%-*} # Trim everything after first dash variant_and_version=${selection#*-} # Trim everything up to first dash if [ "$variant_and_version" != "$selection" ]; then variant=${variant_and_version%%-*} if [ "$variant" != "$variant_and_version" ]; then version=${variant_and_version#*-} fi fi
if [ -z "$product" ] then echo echo "Invalid lunch combo: $selection" return 1 fi
# A list of SEPolicy versions, besides PLATFORM_SEPOLICY_VERSION, that the framework supports. #框架支持的SEPolicy版本列表，除了PLATFORM_SEPOLICY_VERSION PLATFORM_SEPOLICY_COMPAT_VERSIONS := \\ 26.0 \\ 27.0 \\ 28.0 \\
... # --------------------------------------------------------------- # Include the product definitions. # We need to do this to translate TARGET_PRODUCT into its # underlying TARGET_DEVICE before we start defining any rules. # include$(BUILD_SYSTEM)/node_fns.mk include$(BUILD_SYSTEM)/product.mk include$(BUILD_SYSTEM)/device.mk
... # Boards may be defined under $(SRC_TARGET_DIR)/board/$(TARGET_DEVICE) # or under vendor/*/$(TARGET_DEVICE). Search in both places, but # make sure only one exists. # Real boards should always be associated with an OEM vendor. ifdef TARGET_DEVICE_DIR ifneq ($(origin TARGET_DEVICE_DIR),command line) $(error TARGET_DEVICE_DIR may not be set manually) endif board_config_mk := $(TARGET_DEVICE_DIR)/BoardConfig.mk else board_config_mk := \\ $(strip $(sort $(wildcard \\ $(SRC_TARGET_DIR)/board/$(TARGET_DEVICE)/BoardConfig.mk \\ $(shell test -d device && find -L device -maxdepth 4 -path '*/$(TARGET_DEVICE)/BoardConfig.mk') \\ $(shell test -d vendor && find -L vendor -maxdepth 4 -path '*/$(TARGET_DEVICE)/BoardConfig.mk') \\ ))) ifeq ($(board_config_mk),) $(error No config file found for TARGET_DEVICE $(TARGET_DEVICE)) endif ifneq ($(words $(board_config_mk)),1) $(error Multiple board config files for TARGET_DEVICE $(TARGET_DEVICE): $(board_config_mk)) endif TARGET_DEVICE_DIR := $(patsubst %/,%,$(dir$(board_config_mk))) .KATI_READONLY := TARGET_DEVICE_DIR endif include$(board_config_mk) ...
