build/envsetup.sh内lunch解析

........
#    测试device是否存在且是一个目录 并且 只查找device目录4层以上的子目录，名字为vendorsetup.sh 并且 将命令执行的错误报告直接送往回收站 不显示在屏幕上
#    测试vendor是否存在且是一个目录 并且 只查找vendor目录4层以上的子目录，名字为vendorsetup.sh 并且 将命令执行的错误报告直接送往回收站 不显示在屏幕上
for f in `test -d device && find -L device -maxdepth 4 -name 'vendorsetup.sh' 2> /dev/null` \
         `test -d vendor && find -L vendor -maxdepth 4 -name 'vendorsetup.sh' 2> /dev/null`
do
#    打印包含这些vendorsetup.sh 并 执行这些vendorsetup.sh
    echo "including $f"
    . $f
done
unset f
........

 ↑第一步：build/envsetup.sh中vendrosetup.sh脚本执行

root@book-virtual-machine:/work/android-5.0.2# source build/envsetup.sh 
including device/asus/deb/vendorsetup.sh
including device/asus/fugu/vendorsetup.sh
including device/asus/tilapia/vendorsetup.sh
including device/asus/flo/vendorsetup.sh
including device/asus/grouper/vendorsetup.sh
including device/samsung/manta/vendorsetup.sh
including device/friendly-arm/tiny4412/vendorsetup.sh
including device/lge/mako/vendorsetup.sh
including device/lge/hammerhead/vendorsetup.sh
including device/moto/shamu/vendorsetup.sh
including device/generic/mini-emulator-mips/vendorsetup.sh
including device/generic/mini-emulator-armv7-a-neon/vendorsetup.sh
including device/generic/mini-emulator-arm64/vendorsetup.sh
including device/generic/mini-emulator-x86/vendorsetup.sh
including device/generic/mini-emulator-x86_64/vendorsetup.sh
including sdk/bash_completion/adb.bash

 ↑第二步：build/envsetup.sh中vendrosetup.sh脚本执行部分的执行效果

 add_lunch_combo full_tiny4412-userdebug 2 add_lunch_combo full_tiny4412-eng 

↑第三步：举例：including device/friendly-arm/tiny4412/vendorsetup.sh内容

#    清空LUNCH_MENU_CHOICES
unset LUNCH_MENU_CHOICES
function add_lunch_combo()
{
#    new_combo局部变量化，且赋值为add_lunch_combo的参数
#    即add_lunch_combo full_tiny4412-userdebug的full_tiny4412-userdebug
#    局部变量化c
    local new_combo=$1
    local c
#    如果LUNCH_MENU_CHOICES有参数
    for c in ${LUNCH_MENU_CHOICES[@]} ; do
#    如果add_lunch_combo参数1存在于LUNCH_MENU_CHOICES中 则返回
        if [ "$new_combo" = "$c" ] ; then
            return
        fi
    done
#   如果LUNCH_MENU_CHOICES无参数，则将add_lunch_combo的参数1放入LUNCH_MENU_CHOICES
    LUNCH_MENU_CHOICES=(${LUNCH_MENU_CHOICES[@]} $new_combo)
}

 ↑第四步：build/envsetup.sh中add_lunch_combo功能函数

function lunch()
{
#    answer局部变量化
    local answer
#    lunch如果有参数则answer=参数1
    if [ "$1" ] ; then
        answer=$1
    else
#    如果没有参数则打印lunch目录
        print_lunch_menu
.......
}

 ↑第五步：build/envsetup.sh中lunch功能函数的第一步，打印选项

function print_lunch_menu()
{
#    系统名称局部变量化，并打印帮助信息
    local uname=$(uname)
    echo
    echo "You're building on" $uname
    echo
    echo "Lunch menu... pick a combo:"
#    初始化局部变量i=1，这个是索引编号
    local i=1
#    初始化局部变量，这个是用户输入编号或选项英文
    local choice
#    从LUNCH_MENU_CHOICES中取出放到choice中
#    并打印 “编号.LUNCH_MENU_CHOICE中的英文选项”
#    编号i累加
    for choice in ${LUNCH_MENU_CHOICES[@]}
    do
        echo "     $i. $choice"
        i=$(($i+1))
    done

    echo
}

 ↑第六步：build/envsetup.sh中print_lunch_menu功能函数

 

......#接上面打印菜单
        echo -n "Which would you like? [aosp_arm-eng] "
#    读取用户输入的编号或者英文选项
        read answer
    fi

    local selection=
#    如果没有输入编号或者英文选项，则默认选择了aosp_arm-eng
    if [ -z "$answer" ]
    then
        selection=aosp_arm-eng
#    如果输入信息为数字，且数字小于LUNCH_MENU_CHOICES个数
    elif (echo -n $answer | grep -q -e "^[0-9][0-9]*$")
    then
        if [ $answer -le ${#LUNCH_MENU_CHOICES[@]} ]
#    将输入编号-1的英文选项放入selection（因为数组是从0开始，0对应索引1）
        then
            selection=${LUNCH_MENU_CHOICES[$(($answer-1))]}
        fi
#    如果输入信息为具有-符号的则为英文 直接放入selection
    elif (echo -n $answer | grep -q -e "^[^\-][^\-]*-[^\-][^\-]*$")
    then
        selection=$answer
    fi
#    如果此时selection依旧为0，则打印无效lunch combo:输入值
    if [ -z "$selection" ]
    then
        echo
        echo "Invalid lunch combo: $answer"
        return 1
    fi
#    导出编译使用的环境变量 
    export TARGET_BUILD_APPS=
#    提取"-"位置以前的字符串放入product，比如“full_tiny4412”
    local product=$(echo -n $selection | sed -e "s/-.*$//")
    check_product $product
    if [ $? -ne 0 ]
    then
        echo
        echo "** Don't have a product spec for: '$product'"
        echo "** Do you have the right repo manifest?"
        product=
    fi
#    提取"-"位置以后的字符串放入variant，比如“userdebug”
    local variant=$(echo -n $selection | sed -e "s/^[^\-]*-//")
    check_variant $variant
    if [ $? -ne 0 ]
    then
        echo
        echo "** Invalid variant: '$variant'"
        echo "** Must be one of ${VARIANT_CHOICES[@]}"
        variant=
    fi
#    如果product、variant为空则返回1
    if [ -z "$product" -o -z "$variant" ]
    then
        echo
        return 1
    fi
#    导出TARGET_PRODUCT=刚刚得到的product
#    导出TARGET_BUILD_VARIANT=刚刚得到的variant
#    导出TARGET_BUILD_TYPE=release

    export TARGET_PRODUCT=$product
    export TARGET_BUILD_VARIANT=$variant
    export TARGET_BUILD_TYPE=release

    echo
#    设置编译相关的环境功能函数
    set_stuff_for_environment
#    后面会调用get_build_var report_config
#    里面会执行make --no-print-directory -C "$T" -f build/core/config.mk dumpvar-$1
#    即 编译config.mk
    printconfig
}

 ↑第七步：build/envsetup.sh中lunch功能函数

function set_stuff_for_environment()
{
#    设置名称变量，比如架构、产品、主板、应用、命令行提示符
    settitle
#    设置JAVA jdk环境变量
    set_java_home
#    设置Android PATH、ANDROID_TOOLCHAIN、ANDROID_KERNEL_TOOLCHAIN_PATH、ANDROID_EMULATOR_PREBUILTS等路径
    setpaths
#    设置BUILD_ENV_SEQUENCE_NUMBER
    set_sequence_number

    export ANDROID_BUILD_TOP=$(gettop)
#    设置gcc的警告和错误可以彩色显示
    export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'
}

 ↑第八步：build/envsetup.sh中set_stuff_for_environment功能函数

function settitle()
{
    if [ "$STAY_OFF_MY_LAWN" = "" ]; then
        local arch=$(gettargetarch)
        local product=$TARGET_PRODUCT
        local variant=$TARGET_BUILD_VARIANT
        local apps=$TARGET_BUILD_APPS
#    导出PROMPT_COMMAND，配合HISTORY_FILE设置的文件，进行记录什么用户，在什么时间，做了什么操作。
#    PROMPT_COMMAND主要是设置打印信息格式
        if [ -z "$apps" ]; then
            export PROMPT_COMMAND="echo -ne \"\033]0;[${arch}-${product}-${variant}] ${USER}@${HOSTNAME}: ${PWD}\007\""
        else
            export PROMPT_COMMAND="echo -ne \"\033]0;[$arch $apps $variant] ${USER}@${HOSTNAME}: ${PWD}\007\""
        fi
    fi
}

 ↑第九步：build/envsetup.sh中settitle功能函数

关于set_java_home setpaths set_sequence_number设置函数不在赘述，同类方法

 

function printconfig()
{
    T=$(gettop)
    if [ ! "$T" ]; then
        echo "Couldn't locate the top of the tree.  Try setting TOP." >&2
        return
    fi
#    这里继续调用get_build_var report_config
#    get_build_var会编译config.mk详见hmm笔记
#    report_config作为dumpvar-report_config
#    dumpvar.mk中ifneq ($(dumpvar_goals),report_config)中会将PRINT_BUILD_CONFIG置空
#    ifneq ($(PRINT_BUILD_CONFIG),) ：PRINT_BUILD_CONFIG为空则执行打印描述编译环境配置的变量信息
    get_build_var report_config
}

↑第十步：build/envsetup.sh中printconfig功能函数与build/core/dumpvar.mk中打印编译环境配置

最后编译config.mk，config.mk内容见config.mk笔记