build/envsetup.sh內lunch解析

 1 ........
 2 #    測試device是否存在且是一個目錄 而且 只查找device目錄4層以上的子目錄，名字爲vendorsetup.sh 而且 將命令執行的錯誤報告直接送往回收站 不顯示在屏幕上
 3 #    測試vendor是否存在且是一個目錄 而且 只查找vendor目錄4層以上的子目錄，名字爲vendorsetup.sh 而且 將命令執行的錯誤報告直接送往回收站 不顯示在屏幕上
 4 for f in `test -d device && find -L device -maxdepth 4 -name 'vendorsetup.sh' 2> /dev/null` \
 5          `test -d vendor && find -L vendor -maxdepth 4 -name 'vendorsetup.sh' 2> /dev/null`
 6 do
 7 #    打印包含這些vendorsetup.sh 並 執行這些vendorsetup.sh
 8     echo "including $f"
 9     . $f
10 done
11 unset f
12 ........

 ↑第一步：build/envsetup.sh中vendrosetup.sh腳本執行

 1 root@book-virtual-machine:/work/android-5.0.2# source build/envsetup.sh 
 2 including device/asus/deb/vendorsetup.sh
 3 including device/asus/fugu/vendorsetup.sh
 4 including device/asus/tilapia/vendorsetup.sh
 5 including device/asus/flo/vendorsetup.sh
 6 including device/asus/grouper/vendorsetup.sh
 7 including device/samsung/manta/vendorsetup.sh
 8 including device/friendly-arm/tiny4412/vendorsetup.sh
 9 including device/lge/mako/vendorsetup.sh
10 including device/lge/hammerhead/vendorsetup.sh
11 including device/moto/shamu/vendorsetup.sh
12 including device/generic/mini-emulator-mips/vendorsetup.sh
13 including device/generic/mini-emulator-armv7-a-neon/vendorsetup.sh
14 including device/generic/mini-emulator-arm64/vendorsetup.sh
15 including device/generic/mini-emulator-x86/vendorsetup.sh
16 including device/generic/mini-emulator-x86_64/vendorsetup.sh
17 including sdk/bash_completion/adb.bash

 ↑第二步：build/envsetup.sh中vendrosetup.sh腳本執行部分的執行效果

 1 add_lunch_combo full_tiny4412-userdebug 2 add_lunch_combo full_tiny4412-eng 

↑第三步：舉例：including device/friendly-arm/tiny4412/vendorsetup.sh內容

 1 #    清空LUNCH_MENU_CHOICES
 2 unset LUNCH_MENU_CHOICES
 3 function add_lunch_combo()
 4 {
 5 #    new_combo局部變量化，且賦值爲add_lunch_combo的參數
 6 #    即add_lunch_combo full_tiny4412-userdebug的full_tiny4412-userdebug
 7 #    局部變量化c
 8     local new_combo=$1
 9     local c
10 #    若是LUNCH_MENU_CHOICES有參數
11     for c in ${LUNCH_MENU_CHOICES[@]} ; do
12 #    若是add_lunch_combo參數1存在於LUNCH_MENU_CHOICES中 則返回
13         if [ "$new_combo" = "$c" ] ; then
14             return
15         fi
16     done
17 #   若是LUNCH_MENU_CHOICES無參數，則將add_lunch_combo的參數1放入LUNCH_MENU_CHOICES
18     LUNCH_MENU_CHOICES=(${LUNCH_MENU_CHOICES[@]} $new_combo)
19 }

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

 1 function lunch()
 2 {
 3 #    answer局部變量化
 4     local answer
 5 #    lunch若是有參數則answer=參數1
 6     if [ "$1" ] ; then
 7         answer=$1
 8     else
 9 #    若是沒有參數則打印lunch目錄
10         print_lunch_menu
11 .......
12 }

 ↑第五步：build/envsetup.sh中lunch功能函數的第一步，打印選項

 1 function print_lunch_menu()
 2 {
 3 #    系統名稱局部變量化，並打印幫助信息
 4     local uname=$(uname)
 5     echo
 6     echo "You're building on" $uname
 7     echo
 8     echo "Lunch menu... pick a combo:"
 9 #    初始化局部變量i=1，這個是索引編號
10     local i=1
11 #    初始化局部變量，這個是用戶輸入編號或選項英文
12     local choice
13 #    從LUNCH_MENU_CHOICES中取出放到choice中
14 #    並打印 「編號.LUNCH_MENU_CHOICE中的英文選項」
15 #    編號i累加
16     for choice in ${LUNCH_MENU_CHOICES[@]}
17     do
18         echo "     $i. $choice"
19         i=$(($i+1))
20     done
21 
22     echo
23 }

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

 

 1 ......#接上面打印菜單
 2         echo -n "Which would you like? [aosp_arm-eng] "
 3 #    讀取用戶輸入的編號或者英文選項
 4         read answer
 5     fi
 6 
 7     local selection=
 8 #    若是沒有輸入編號或者英文選項，則默認選擇了aosp_arm-eng
 9     if [ -z "$answer" ]
10     then
11         selection=aosp_arm-eng
12 #    若是輸入信息爲數字，且數字小於LUNCH_MENU_CHOICES個數
13     elif (echo -n $answer | grep -q -e "^[0-9][0-9]*$")
14     then
15         if [ $answer -le ${#LUNCH_MENU_CHOICES[@]} ]
16 #    將輸入編號-1的英文選項放入selection（由於數組是從0開始，0對應索引1）
17         then
18             selection=${LUNCH_MENU_CHOICES[$(($answer-1))]}
19         fi
20 #    若是輸入信息爲具備-符號的則爲英文 直接放入selection
21     elif (echo -n $answer | grep -q -e "^[^\-][^\-]*-[^\-][^\-]*$")
22     then
23         selection=$answer
24     fi
25 #    若是此時selection依舊爲0，則打印無效lunch combo:輸入值
26     if [ -z "$selection" ]
27     then
28         echo
29         echo "Invalid lunch combo: $answer"
30         return 1
31     fi
32 #    導出編譯使用的環境變量 
33     export TARGET_BUILD_APPS=
34 #    提取"-"位置之前的字符串放入product，好比「full_tiny4412」
35     local product=$(echo -n $selection | sed -e "s/-.*$//")
36     check_product $product
37     if [ $? -ne 0 ]
38     then
39         echo
40         echo "** Don't have a product spec for: '$product'"
41         echo "** Do you have the right repo manifest?"
42         product=
43     fi
44 #    提取"-"位置之後的字符串放入variant，好比「userdebug」
45     local variant=$(echo -n $selection | sed -e "s/^[^\-]*-//")
46     check_variant $variant
47     if [ $? -ne 0 ]
48     then
49         echo
50         echo "** Invalid variant: '$variant'"
51         echo "** Must be one of ${VARIANT_CHOICES[@]}"
52         variant=
53     fi
54 #    若是product、variant爲空則返回1
55     if [ -z "$product" -o -z "$variant" ]
56     then
57         echo
58         return 1
59     fi
60 #    導出TARGET_PRODUCT=剛剛獲得的product
61 #    導出TARGET_BUILD_VARIANT=剛剛獲得的variant
62 #    導出TARGET_BUILD_TYPE=release
63 
64     export TARGET_PRODUCT=$product
65     export TARGET_BUILD_VARIANT=$variant
66     export TARGET_BUILD_TYPE=release
67 
68     echo
69 #    設置編譯相關的環境功能函數
70     set_stuff_for_environment
71 #    後面會調用get_build_var report_config
72 #    裏面會執行make --no-print-directory -C "$T" -f build/core/config.mk dumpvar-$1
73 #    即 編譯config.mk
74     printconfig
75 }

 ↑第七步：build/envsetup.sh中lunch功能函數

 1 function set_stuff_for_environment()
 2 {
 3 #    設置名稱變量，好比架構、產品、主板、應用、命令行提示符
 4     settitle
 5 #    設置JAVA jdk環境變量
 6     set_java_home
 7 #    設置Android PATH、ANDROID_TOOLCHAIN、ANDROID_KERNEL_TOOLCHAIN_PATH、ANDROID_EMULATOR_PREBUILTS等路徑
 8     setpaths
 9 #    設置BUILD_ENV_SEQUENCE_NUMBER
10     set_sequence_number
11 
12     export ANDROID_BUILD_TOP=$(gettop)
13 #    設置gcc的警告和錯誤能夠彩色顯示
14     export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'
15 }

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

 1 function settitle()
 2 {
 3     if [ "$STAY_OFF_MY_LAWN" = "" ]; then
 4         local arch=$(gettargetarch)
 5         local product=$TARGET_PRODUCT
 6         local variant=$TARGET_BUILD_VARIANT
 7         local apps=$TARGET_BUILD_APPS
 8 #    導出PROMPT_COMMAND，配合HISTORY_FILE設置的文件，進行記錄什麼用戶，在什麼時間，作了什麼操做。
 9 #    PROMPT_COMMAND主要是設置打印信息格式
10         if [ -z "$apps" ]; then
11             export PROMPT_COMMAND="echo -ne \"\033]0;[${arch}-${product}-${variant}] ${USER}@${HOSTNAME}: ${PWD}\007\""
12         else
13             export PROMPT_COMMAND="echo -ne \"\033]0;[$arch $apps $variant] ${USER}@${HOSTNAME}: ${PWD}\007\""
14         fi
15     fi
16 }

 ↑第九步：build/envsetup.sh中settitle功能函數

關於set_java_home setpaths set_sequence_number設置函數不在贅述，同類方法

 

 1 function printconfig()
 2 {
 3     T=$(gettop)
 4     if [ ! "$T" ]; then
 5         echo "Couldn't locate the top of the tree.  Try setting TOP." >&2
 6         return
 7     fi
 8 #    這裏繼續調用get_build_var report_config
 9 #    get_build_var會編譯config.mk詳見hmm筆記
10 #    report_config做爲dumpvar-report_config
11 #    dumpvar.mk中ifneq ($(dumpvar_goals),report_config)中會將PRINT_BUILD_CONFIG置空
12 #    ifneq ($(PRINT_BUILD_CONFIG),) ：PRINT_BUILD_CONFIG爲空則執行打印描述編譯環境配置的變量信息
13     get_build_var report_config
14 }

↑第十步：build/envsetup.sh中printconfig功能函數與build/core/dumpvar.mk中打印編譯環境配置

最後編譯config.mk，config.mk內容見config.mk筆記