[转]Android编译常用语法

古城微笑少年丶 2022-04-12 08:22 320阅读 0赞

\[url\]http://blog.csdn.net/yili\_xie/article/details/4906865\[/url\]  
  
1. Android编译系统分析  
编译脚本及系统变量  
build/envsetup.sh脚本分析  
在编译源代码之前通常需要在android源代码顶层目录执行 . ./build/envsetup.sh 目的是为了使用  
脚本 envsetup.sh 里面定义了一些函数：  
function help()  
function get\_abs\_build\_var()  
function get\_build\_var()  
function check\_product()  
function check\_variant()  
function setpaths()  
function printconfig()  
function set\_stuff\_for\_environment()  
function set\_sequence\_number()  
function settitle()  
function choosetype()  
function chooseproduct()  
function choosevariant()  
function tapas()  
function choosecombo()  
function print\_lunch\_menu()  
function lunch()  
function gettop  
function m()  
function findmakefile()  
function mm()  
function mmm()  
function croot()  
function pid()  
function gdbclient()  
function jgrep()  
function cgrep()  
function resgrep()  
function getprebuilt  
function tracedmdump()  
function runhat()  
function getbugreports()  
function startviewserver()  
function stopviewserver()  
function isviewserverstarted()  
function smoketest()  
function runtest()  
function runtest\_py()  
function godir ()  
  
choosecombo 命令分析：  
function choosecombo()  
\{  
choosesim $1  
echo  
echo  
choosetype $2  
  
echo  
echo  
chooseproduct $3  
  
echo  
echo  
choosevariant $4  
  
echo  
set\_stuff\_for\_environment  
printconfig  
\}  
会依次进行如下选择：  
Build for the simulator or the device?  
1. Device  
2. Simulator  
Which would you like? \[1\]  
  
Build type choices are:  
1. release  
2. debug  
Which would you like? \[1\]  
  
Product choices are:  
1. emulator  
2. generic  
3. sim  
4. littleton  
You can also type the name of a product if you know it.  
Which would you like? \[littleton\]  
  
Variant choices are:  
1. user  
2. userdebug  
3. eng  
Which would you like? \[eng\] user  
默认选择以后会出现：  
TARGET\_PRODUCT=littleton  
TARGET\_BUILD\_VARIANT=user  
TARGET\_SIMULATOR=false  
TARGET\_BUILD\_TYPE=release  
TARGET\_ARCH=arm  
HOST\_ARCH=x86  
HOST\_OS=linux  
HOST\_BUILD\_TYPE=release  
BUILD\_ID=  
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function chooseproduct()函数分析：  
choices=(\`/bin/ls build/target/board/\*/BoardConfig.mk vendor/\*/\*/BoardConfig.mk 2> /dev/null\`)  
读取 build/target/board/\* 目录下的板配置文件：BoardConfig.mk  
读取 vendor/\*/\*/目录下的板配置文件：BoardConfig.mk  
choices 的值为：  
build/target/board/emulator/BoardConfig.mk  
build/target/board/generic/BoardConfig.mk  
build/target/board/sim/BoardConfig.mk  
vendor/marvell/littleton/BoardConfig.mk  
经过：  
for choice in $\{choices\[@\]\}  
do  
\# The product name is the name of the directory containing  
\# the makefile we found, above.  
prodlist=($\{prodlist\[@\]\} \`dirname $\{choice\} | xargs basename\`)  
done  
的处理，prodlist的值为：  
emulator generic sim littleton  
所以选择菜单为：  
Product choices are:  
1. emulator  
2. generic  
3. sim  
4. littleton  
如果选择 4，那么 TARGET\_PRODUCT 被赋值为： littleton。  
  
  
board\_config\_mk := /  
$(strip $(wildcard /  
$(SRC\_TARGET\_DIR)/board/$(TARGET\_DEVICE)/BoardConfig.mk /  
vendor/\*/$(TARGET\_DEVICE)/BoardConfig.mk /  
))  
  
  
怎样添加一个模块  
LOCAL\_PATH:= $(call my-dir)  
\#编译静态库  
include $(CLEAR\_VARS)  
LOCAL\_MODULE = libhellos  
LOCAL\_CFLAGS = $(L\_CFLAGS)  
LOCAL\_SRC\_FILES = hellos.c  
LOCAL\_C\_INCLUDES = $(INCLUDES)  
LOCAL\_SHARED\_LIBRARIES := libcutils  
LOCAL\_COPY\_HEADERS\_TO := libhellos  
LOCAL\_COPY\_HEADERS := hellos.h  
include $(BUILD\_STATIC\_LIBRARY)  
  
\#编译动态库  
include $(CLEAR\_VARS)  
LOCAL\_MODULE = libhellod  
LOCAL\_CFLAGS = $(L\_CFLAGS)  
LOCAL\_SRC\_FILES = hellod.c  
LOCAL\_C\_INCLUDES = $(INCLUDES)  
LOCAL\_SHARED\_LIBRARIES := libcutils  
LOCAL\_COPY\_HEADERS\_TO := libhellod  
LOCAL\_COPY\_HEADERS := hellod.h  
include $(BUILD\_SHARED\_LIBRARY)  
  
BUILD\_TEST=true  
ifeq ($(BUILD\_TEST),true)  
\#使用静态库  
include $(CLEAR\_VARS)  
LOCAL\_MODULE := hellos  
LOCAL\_STATIC\_LIBRARIES := libhellos  
LOCAL\_SHARED\_LIBRARIES :=  
LOCAL\_LDLIBS += -ldl  
LOCAL\_CFLAGS := $(L\_CFLAGS)  
LOCAL\_SRC\_FILES := mains.c  
LOCAL\_C\_INCLUDES := $(INCLUDES)  
include $(BUILD\_EXECUTABLE)  
  
\#使用动态库  
include $(CLEAR\_VARS)  
LOCAL\_MODULE := hellod  
LOCAL\_MODULE\_TAGS := debug  
LOCAL\_SHARED\_LIBRARIES := libc libcutils libhellod  
LOCAL\_LDLIBS += -ldl  
LOCAL\_CFLAGS := $(L\_CFLAGS)  
LOCAL\_SRC\_FILES := maind.c  
LOCAL\_C\_INCLUDES := $(INCLUDES)  
include $(BUILD\_EXECUTABLE)  
endif \# ifeq ($(WPA\_BUILD\_SUPPLICANT),true)  
  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\#local\_target\_dir := $(TARGET\_OUT)/etc/wifi  
\#include $(CLEAR\_VARS)  
\#LOCAL\_MODULE := wpa\_supplicant.conf  
\#LOCAL\_MODULE\_TAGS := user  
\#LOCAL\_MODULE\_CLASS := ETC  
\#LOCAL\_MODULE\_PATH := $(local\_target\_dir)  
\#LOCAL\_SRC\_FILES := $(LOCAL\_MODULE)  
\#include $(BUILD\_PREBUILT)  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
系统变量解析  
LOCAL\_MODULE － 编译的目标对象  
LOCAL\_SRC\_FILES － 编译的源文件  
LOCAL\_C\_INCLUDES － 需要包含的头文件目录  
LOCAL\_SHARED\_LIBRARIES － 链接时需要的外部库  
LOCAL\_PRELINK\_MODULE － 是否需要prelink处理  
BUILD\_SHARED\_LIBRARY － 指明要编译成动态库  
  
  
LOCAL\_PATH - 编译时的目录  
$(call 目录，目录….) 目录引入操作符  
如该目录下有个文件夹名称 src，则可以这样写 $(call src)，那么就会得到 src 目录的完整路径  
  
include $(CLEAR\_VARS) -清除之前的一些系统变量  
CLEAR\_VARS:= $(BUILD\_SYSTEM)/clear\_vars.mk  
在 build/core/config.mk 定义 CLEAR\_VARS:= $(BUILD\_SYSTEM)/clear\_vars.mk  
通过include 包含自定义的.mk文件（即是自定义编译规则）或是引用系统其他的.mk文件（系统定义的编译规则）。  
  
LOCAL\_SRC\_FILES － 编译的源文件  
可以是.c, .cpp, .java, .S（汇编文件）或是.aidl等格式  
不同的文件用空格隔开。如果编译目录子目录，采用相对路径，如子目录/文件名。也可以通过$(call 目录)，指明编译某目录  
下所有.c/.cpp/.java/.S/ .aidl文件.追加文件 LOCAL\_SRC\_FILES += 文件  
  
LOCAL\_C\_INCLUDES － 需要包含的头文件目录  
可以是系统定义路径，也可以是相对路径. 如该编译目录下有个include目录，写法是include/\*.h  
  
LOCAL\_SHARED\_LIBRARIES － 链接时需要的外部共享库  
LOCAL\_STATIC\_LIBRA RIES － 链接时需要的外部外部静态  
LOCAL\_JAVA\_LIBRARIES 加入jar包  
  
LOCAL\_MODULE － 编译的目标对象  
module 是指系统的 native code，通常针对c,c++代码  
./system/core/sh/Android.mk:32:LOCAL\_MODULE:= sh  
./system/core/libcutils/Android.mk:71:LOCAL\_MODULE := libcutils  
./system/core/cpio/Android.mk:9:LOCAL\_MODULE := mkbootfs  
./system/core/mkbootimg/Android.mk:8:LOCAL\_MODULE := mkbootimg  
./system/core/toolbox/Android.mk:61:LOCAL\_MODULE:= toolbox  
./system/core/logcat/Android.mk:10:LOCAL\_MODULE:= logcat  
./system/core/adb/Android.mk:65:LOCAL\_MODULE := adb  
./system/core/adb/Android.mk:125:LOCAL\_MODULE := adbd  
./system/core/init/Android.mk:20:LOCAL\_MODULE:= init  
./system/core/vold/Android.mk:24:LOCAL\_MODULE:= vold  
./system/core/mountd/Android.mk:13:LOCAL\_MODULE:= mountd  
  
LOCAL\_PACKAGE\_NAME  
Java 应用程序的名字用该变量定义  
./packages/apps/Music/Android.mk:9:LOCAL\_PACKAGE\_NAME := Music  
./packages/apps/Browser/Android.mk:14:LOCAL\_PACKAGE\_NAME := Browser  
./packages/apps/Settings/Android.mk:8:LOCAL\_PACKAGE\_NAME := Settings  
./packages/apps/Stk/Android.mk:10:LOCAL\_PACKAGE\_NAME := Stk  
./packages/apps/Contacts/Android.mk:10:LOCAL\_PACKAGE\_NAME := Contacts  
./packages/apps/Mms/Android.mk:8:LOCAL\_PACKAGE\_NAME := Mms  
./packages/apps/Camera/Android.mk:8:LOCAL\_PACKAGE\_NAME := Camera  
./packages/apps/Phone/Android.mk:11:LOCAL\_PACKAGE\_NAME := Phone  
./packages/apps/VoiceDialer/Android.mk:8:LOCAL\_PACKAGE\_NAME := VoiceDialer  
  
  
BUILD\_SHARED\_LIBRARY － 指明要编译成动态库。  
编译的目标，用include 操作符  
UILD\_STATIC\_LIBRARY来指明要编译成静态库。  
如果是java文件的话，会用到系统的编译脚本host\_java\_library.mk，用BUILD\_PACKAGE来指明。三个编译  
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include $(BUILD\_STATIC\_LIBRARY)  
BUILD\_STATIC\_LIBRARY:= $(BUILD\_SYSTEM)/static\_library.mk  
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include $(BUILD\_SHARED\_LIBRARY)  
./build/core/config.mk:50:BUILD\_SHARED\_LIBRARY:= $(BUILD\_SYSTEM)/shared\_library.mk  
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include $(BUILD\_HOST\_SHARED\_LIBRARY)  
BUILD\_HOST\_SHARED\_LIBRARY:= $(BUILD\_SYSTEM)/host\_shared\_library.mk  
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include $(BUILD\_EXECUTABLE)  
build/core/config.mk:51:BUILD\_EXECUTABLE:= $(BUILD\_SYSTEM)/executable.mk  
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include $(BUILD\_HOST\_EXECUTABLE)  
./build/core/config.mk:53:BUILD\_HOST\_EXECUTABLE:= $(BUILD\_SYSTEM)/host\_executable.mk  
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BUILD\_HOST\_JAVA\_LIBRARY:= $(BUILD\_SYSTEM)/host\_java\_library.mk  
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BUILD\_JAVA\_LIBRARY  
./build/core/config.mk:58:BUILD\_JAVA\_LIBRARY:= $(BUILD\_SYSTEM)/java\_library.mk  
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BUILD\_STATIC\_JAVA\_LIBRARY 编译静态JAVA库  
./build/core/config.mk:59:BUILD\_STATIC\_JAVA\_LIBRARY:= $(BUILD\_SYSTEM)/static\_java\_library.mk  
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BUILD\_HOST\_JAVA\_LIBRARY 编译本机用的JAVA库  
./build/core/config.mk:60:BUILD\_HOST\_JAVA\_LIBRARY:= $(BUILD\_SYSTEM)/host\_java\_library.mk  
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BUILD\_HOST\_STATIC\_LIBRARY:= $(BUILD\_SYSTEM)/host\_static\_library.mk  
BUILD\_HOST\_SHARED\_LIBRARY:= $(BUILD\_SYSTEM)/host\_shared\_library.mk  
BUILD\_STATIC\_LIBRARY:= $(BUILD\_SYSTEM)/static\_library.mk  
BUILD\_RAW\_STATIC\_LIBRARY := $(BUILD\_SYSTEM)/raw\_static\_library.mk  
BUILD\_SHARED\_LIBRARY:= $(BUILD\_SYSTEM)/shared\_library.mk  
BUILD\_EXECUTABLE:= $(BUILD\_SYSTEM)/executable.mk  
BUILD\_RAW\_EXECUTABLE:= $(BUILD\_SYSTEM)/raw\_executable.mk  
BUILD\_HOST\_EXECUTABLE:= $(BUILD\_SYSTEM)/host\_executable.mk  
BUILD\_PACKAGE:= $(BUILD\_SYSTEM)/package.mk  
BUILD\_HOST\_PREBUILT:= $(BUILD\_SYSTEM)/host\_prebuilt.mk  
BUILD\_PREBUILT:= $(BUILD\_SYSTEM)/prebuilt.mk  
BUILD\_MULTI\_PREBUILT:= $(BUILD\_SYSTEM)/multi\_prebuilt.mk  
BUILD\_JAVA\_LIBRARY:= $(BUILD\_SYSTEM)/java\_library.mk  
BUILD\_STATIC\_JAVA\_LIBRARY:= $(BUILD\_SYSTEM)/static\_java\_library.mk  
BUILD\_HOST\_JAVA\_LIBRARY:= $(BUILD\_SYSTEM)/host\_java\_library.mk  
BUILD\_DROIDDOC:= $(BUILD\_SYSTEM)/droiddoc.mk  
BUILD\_COPY\_HEADERS := $(BUILD\_SYSTEM)/copy\_headers.mk  
BUILD\_KEY\_CHAR\_MAP := $(BUILD\_SYSTEM)/key\_char\_map.mk  
  
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LOCAL\_PRELINK\_MODULE  
Prelink利用事先链接代替运行时链接的方法来加速共享库的加载，它不仅可以加快起动速度，还可以减少部分内存开销，  
是各种Linux架构上用于减少程序加载时间、缩短系统启动时间和加快应用程序启动的很受欢迎的一个工具。程序运行时的  
动态链接尤其是重定位(relocation)的开销对于大型系统来说是很大的。  
动态链接和加载的过程开销很大，并且在大多数的系统上, 函数库并不会常常被更动, 每次程序被执行时所进行的链接  
动作都是完全相同的，对于嵌入式系统来说尤其如此。因此，这一过程可以改在运行时之前就可以预先处理好，即花一些时间  
利用Prelink工具对动态共享库和可执行文件进行处理，修改这些二进制文件并加入相应的重定位等信息，节约了本来在程序  
启动时的比较耗时的查询函数地址等工作，这样可以减少程序启动的时间，同时也减少了内存的耗用。  
Prelink的这种做法当然也有代价：每次更新动态共享库时，相关的可执行文件都需要重新执行一遍Prelink才能保  
证有效，因为新的共享库中的符号信息、地址等很可能与原来的已经不同了，这就是为什么 android framework代码一改动，  
这时候就会导致相关的应用程序重新被编译。  
这种代价对于嵌入式系统的开发者来说可能稍微带来一些复杂度，不过好在对用户来说几乎是可以忽略的。  
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变量设置为false那么将不做prelink操作  
LOCAL\_PRELINK\_MODULE := false  
默认是需要prlink的，同时需要在 build/core/prelink-linux-arm.map 中加入  
libhellod.so 0x96000000  
这个map文件好像是制定动态库的地址的，在前面注释上面有一些地址范围的信息，注意库与库之间的间隔数，  
如果指定不好的话编译的时候会提示说地址空间冲突的问题。另外，注意排序，这里要把数大的放到前面去，  
按照大小降序排序。  
解析 LOCAL\_PRELINK\_MODULE 变量  
build/core/dynamic\_binary.mk:94:ifeq ($(LOCAL\_PRELINK\_MODULE),true)  
ifeq ($(LOCAL\_PRELINK\_MODULE),true)  
$(prelink\_output): $(prelink\_input) $(TARGET\_PRELINKER\_MAP) $(APRIORI)  
$(transform-to-prelinked)  
transform-to-prelinked定义：  
./build/core/definitions.mk:1002:define transform-to-prelinked  
define transform-to-prelinked  
@mkdir -p $(dir $@)  
@echo "target Prelink: $(PRIVATE\_MODULE) ($@)"  
$(hide) $(APRIORI) /  
\--prelinkmap $(TARGET\_PRELINKER\_MAP) /  
\--locals-only /  
\--quiet /  
$< /  
\--output $@  
endef  
./build/core/config.mk:183:APRIORI := $(HOST\_OUT\_EXECUTABLES)/apriori$(HOST\_EXECUTABLE\_SUFFIX)  
prelink工具不是常用的prelink而是apriori，其源代码位于” <your\_android>/build/tools/apriori”  
参考文档：  
动态库优化——Prelink（预连接）技术  
http://www.eefocus.com/article/09-04/71629s.html  
  
  
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LOCAL\_ARM\_MODE := arm  
目前Android大部分都是基于Arm处理器的，Arm指令用两种模式Thumb(每条指令两个字节)和arm指令（每条指令四个字节）  
  
LOCAL\_CFLAGS += -O3 -fstrict-aliasing -fprefetch-loop-arrays  
通过设定编译器操作，优化级别，-O0表示没有优化,-O1为缺省值，-O3优化级别最高  
LOCAL\_CFLAGS += -W -Wall  
LOCAL\_CFLAGS += -fPIC -DPIC  
LOCAL\_CFLAGS += -O2 -g -DADB\_HOST=1 -Wall -Wno-unused-parameter  
LOCAL\_CFLAGS += -D\_XOPEN\_SOURCE -D\_GNU\_SOURCE -DSH\_HISTORY  
LOCAL\_CFLAGS += -DUSEOVERLAY2  
根据条件选择相应的编译参数  
ifeq ($(TARGET\_ARCH),arm)  
LOCAL\_CFLAGS += -DANDROID\_GADGET=1  
LOCAL\_CFLAGS := $(PV\_CFLAGS)  
endif  
ifeq ($(TARGET\_BUILD\_TYPE),release)  
LOCAL\_CFLAGS += -O2  
endif  
  
LOCAL\_LDLIBS := -lpthread  
LOCAL\_LDLIBS += -ldl  
  
ifdef USE\_MARVELL\_MVED  
LOCAL\_WHOLE\_STATIC\_LIBRARIES += lib\_il\_mpeg4aspdecmved\_wmmx2lnx lib\_il\_h264decmved\_wmmx2lnx  
LOCAL\_SHARED\_LIBRARIES += libMrvlMVED  
else  
LOCAL\_WHOLE\_STATIC\_LIBRARIES += lib\_il\_h264dec\_wmmx2lnx lib\_il\_mpeg4aspdec\_wmmx2lnx  
endif  
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