Android源码编译反思 收藏

【初步构想】

如果是在一台PC上先完整的编译一次Android源码，然后将整个编译好的源码移到另一台PC，然后再在移到的PC上编译，这样估计是可以减少时间的吧？

【初步测试】

初步测试结果，很令我感动意外，似乎所花费的时间跟make clean后，再make所花的时间差不多，这是为啥呢？看来得好好研究一下make的规则。

【今天测试进展-20091024】

在看了有关Makefile的介绍后，才了解到Makefile跟时间戳关联很紧密，于是，我采用了如下方法编译Android源码：

1、拷贝一份已经编译好的源码到另一个路劲下，这样整个源码的时间都会被修改；

2、修改out目录下所有文件的时间戳为当前时间(请参考linux时间戳一文)，这样保证目标文件总比依赖文件新；

3、开始编译源码，编译时终于发现一些令人惊喜的log，即源码好像不再是从C/C++源码开始编译，而是做一些拷贝或者格式转换的工作，对于动态链接库主要有三步，分别是：target SharedLib， target Prelink， target Strip，值得特别说明的是libwebcore.so档是唯一重新编译的一个动态链接库，原因尚未找出来。

1)、target SharedLib

target SharedLib: libwebcore (out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/LINKED/libwebcore.so)

prrebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/arm-eabi g++ -nostdlib -wl,-soname,libwebcore.so -wl .......

2)、target Prelink

target Prelink: libwebcore (out/target/product/generic/symbols/system/lib/libwebcore.so)
out/host/linux-x86/bin/apriori --prelinkmap build/core/prelink-linux-arm.map --locals-only --quiet out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/LINKED/libwebcore.so --output out/target/product/generic/symbols/system/lib/libwebcore.so

3)、 target Strip

target Strip: libwebcore (out/target/product/generic/obj/lib/libwebcore.so)
out/host/linux-x86/bin/soslim --strip --shady --quiet out/target/product/generic/symbols/system/lib/libwebcore.so --outfile out/target/product/generic/obj/lib/libwebcore.so

libwebcore.so在三个文件夹中出现

obj/SHARED_LIBRARIES/libwebcore_intermediates/LINKED/libwebcore.so(258MB)-> symbols/system/lib/libwebcore.so(257MB)-> obj/lib/libwebcore.so(3.9MB)

4)、其他举例

对于JAR

target Java: am (out/target/common/obj/JAVA_LIBRARIES/am_intermediates/classes)
Copying out/target/common/obj/JAVA_LIBRARIES/am_intermediates/classes-full-debug.jar
Copying: out/target/common/obj/JAVA_LIBRARIES/am_intermediates/classes.jar
target Dex: am
target Jar: am (out/target/common/obj/JAVA_LIBRARIES/am_intermediates/javalib.jar)

对于APK：

target Java : Camera (out/target/common/obj/APPS/Camera_intermediates/classes)
Copying out/target/common/obj/APPS/Camera_intermediates/classes-full-debug.jar
Copying: out/target/common/obj/APPS/Camera_intermediates/classes.jar
target Dex : Camera
target Package : Camera (out/target/product/generic/obj/APPS/Camera_intermediates/package.apk)

对于可执行文件：

target Executable : ssh (out/target/product/generic/obj/EXECUTABLES/ssh_intermediates/LINKED/ssh)
target Non-prelinked : ssh (out/target/product/generic/symbols/system/bin/ssh)
target Strip : ssh (out/target/product/generic/obj/EXECUTABLES/ssh_intermediates/ssh)

4、img文件的生成过程描述

1)、system.img

Target system fs image : out/target/product/generic/obj/PACKAGING/systemimage_unopt_intermediates/system.img
out/host/linux-x86/bin/mkyaffs2image -f out/target/product/generic/system out/target/product/generic/obj/PACKAGING/systemimage_unopt_intermediates/system.img

Install system fs image : out/target/product/generic/system.img
out/host/linux-x86/bin/acp -fpt out/target/product/generic/obj/PACKAGING/systemimage_unopt_intermediates/system.img out/target/product/generic/system.img

2)、ramdisk.img
Target ram disk : out/target/product/generic/ramdisk.img

out/host/linux-x86/bin/mkbootfs out/target/product/generic/root | gzip > out/target/product/generic/ramdisk.img

3)、userdata.img(此种方法userdata.img并未重新生成，怪事啊)

out/host/linux-x86/bin/mkyaffs2image -f out/target/product/generic/data out/target/product/generic/userdata.img

5、对于整个编译过程的描述

1)、更新动态链接库

2)、生成javalib.jar

3)、生成APK

4)、生成可执行文件

5)、编译生成libwebcore.so(很费时间)

6)、生成img

6、附件说明

1)、整个编译过程log摘要：

host Executable: acp (out/host/linux-x86/obj/EXECUTABLES/acp_intermediates/acp)
true
Install: out/host/linux-x86/bin/acp
host Java: droiddoc (out/host/common/obj/JAVA_LIBRARIES/droiddoc_intermediates/classes)
Install: out/host/linux-x86/framework/droiddoc.jar
Install: out/host/linux-x86/lib/libneo_util.so
Install: out/host/linux-x86/lib/libneo_cs.so
Install: out/host/linux-x86/lib/libneo_cgi.so
Install: out/host/linux-x86/lib/libclearsilver-jni.so
Install: out/host/linux-x86/bin/dx
host Executable: aapt (out/host/linux-x86/obj/EXECUTABLES/aapt_intermediates/aapt)

host SharedLib: libSR_Core (out/host/linux-x86/obj/lib/libSR_Core.so)
host SharedLib: libSR_AcousticModels (out/host/linux-x86/obj/lib/libSR_AcousticModels.so)
host SharedLib: libSR_AcousticState (out/host/linux-x86/obj/lib/libSR_AcousticState.so)
host SharedLib: libSR_Semproc (out/host/linux-x86/obj/lib/libSR_Semproc.so)
host SharedLib: libSR_Vocabulary (out/host/linux-x86/obj/lib/libSR_Vocabulary.so)
host SharedLib: libSR_Grammar (out/host/linux-x86/obj/lib/libSR_Grammar.so)
host SharedLib: libSR_Nametag (out/host/linux-x86/obj/lib/libSR_Nametag.so)
host SharedLib: libSR_Session (out/host/linux-x86/obj/lib/libSR_Session.so)
host Executable: grxmlcompile (out/host/linux-x86/obj/EXECUTABLES/grxmlcompile_intermediates/grxmlcompile)
true
Install: out/host/linux-x86/lib/libESR_Portable.so
Install: out/host/linux-x86/lib/libESR_Shared.so
Install: out/host/linux-x86/lib/libSR_EventLog.so
Install: out/host/linux-x86/lib/libSR_Core.so
Install: out/host/linux-x86/lib/libSR_AcousticModels.so
Install: out/host/linux-x86/lib/libSR_AcousticState.so
Install: out/host/linux-x86/lib/libSR_G2P.so
Install: out/host/linux-x86/lib/libSR_Semproc.so
Install: out/host/linux-x86/lib/libSR_Vocabulary.so
Install: out/host/linux-x86/lib/libSR_Grammar.so
Install: out/host/linux-x86/lib/libSR_Nametag.so
Install: out/host/linux-x86/lib/libSR_Session.so
Install: out/host/linux-x86/lib/libfst.so
Install: out/host/linux-x86/bin/grxmlcompile

2)、libwebcore.so编译过程摘要：

target thumb C++: libwebcore <= external/webkit/ JavaScriptCore/bytecode/CodeBlock.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/bytecode/JumpTable.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/bytecode/Opcode.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/bytecode/SamplingTool.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/bytecode/StructureStubInfo.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/debugger/Debugger.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/debugger/DebuggerActivation.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/debugger/DebuggerCallFrame.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/interpreter/CallFrame.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/interpreter/Interpreter.cpp
target thumb C++: libwebcore <= external/webkit/JavaScriptCore/interpreter/RegisterFile.cpp

.........................................

target thumb C++: libwebcore <= external/webkit/WebKit/android/plugins/ANPSoundInterface.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/plugins/ANPTypefaceInterface.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/plugins/ANPWindowInterface.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/plugins/PluginTimer.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/plugins/PluginViewBridgeAndroid.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/plugins/PluginWidgetAndroid.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/plugins/SkANP.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/wds/Command.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/wds/Connection.cpp
target thumb C++: libwebcore <= external/webkit/WebKit/android/wds/DebugServer.cpp

target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/ JavaScriptCore/parser/Grammar.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/CSSGrammar.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/XPathGrammar.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/UserAgentStyleSheets.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSCharsetRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSFontFaceRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSImportRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSMediaRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSPageRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSPrimitiveValue.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSRuleList.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSStyleDeclaration.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSStyleRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSStyleSheet.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSUnknownRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSValue.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSValueList.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSVariablesDeclaration.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCSSVariablesRule.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSCounter.cpp
target thumb C++: libwebcore <= out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/WebCore/css/JSMediaList.cpp

target SharedLib: libwebcore (out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates/LINKED/libwebcore.so)
target Prelink: libwebcore (out/target/product/generic/symbols/system/lib/libwebcore.so)
target Strip: libwebcore (out/target/product/generic/obj/lib/libwebcore.so)

【今天测试进展-20091025】

1、昨天提到“值得特别说明的是libwebcore.so档是唯一重新编译的一个动态链接库，原因尚未找出来。”这个问题，已经得到解决了，原来在out目录下( out/target/product/generic/obj/SHARED_LIBRARIES/libwebcore_intermediates )，也有.java及其.cpp文件，所以会重新编译了。 我昨天在out目录下使用指令find ./* -exec touch {} \;，结果把out下的文件的时间戳都改为当前时间，其中也包括.java及其.cpp文件，如果是要解决这个问题，必须把.java及其.cpp文件排除在外啊。

如果是要排除某一类型文件，可以执行类似命令：

find . -type f ! -name "*.cpp" -exec touch {} \;

find . -type f ! -name "*.java" -exec touch {} \;

但是要同时排除这两种类型的文件，该怎么执行指令呢？

find . -type f \( ! -name "*.java" -and ! -name "*.cpp" \) -exec touch {} \;

如果不用这个办法，还有一种方法是理清整个编译过程所产生的文件，比如链接库的产生过程是：*.c/cpp---->*.o--->*.a/*.so，只要保证目标文件是最新的就行。除了静态、动态连接库外，还有jar文件的产生过程也要清楚。

找出out目录下的所有*.cpp， *.o， *.a， *.so文件，并保存在txt文件中。

today=`date +%y-%m-%d`

find ./out -type f \( -name "*.cpp" -or -name "*.o" -or -name "*.a" -or -name "*.so" \) -exec echo {} >> cpp_o_a_so_$today.txt \;

找出out目录下的所有*.java， *.class， *.jar， *.dex，*.apk文件，并保存在txt文件中。

find ./out -type f \( -name "*.java" -or -name "*.class" -or -name "*.jar" -or -name "*.dex" -name "*.apk" \) -exec echo {} >> java_class_jar_dex_$today.txt \;

2、今天无意中发现了几个包含"timestamp"字样的文件，其中的文件作用可能与时间戳有紧密关联，也和make紧密关联，得研究一下才行。

-rw-rw-r-- 1 san san 0 2009-10-27 03:20 ./out/target/common/docs/offline-sdk-timestamp
-rw-rw-r-- 1 san san 0 2009-10-27 03:20 ./out/target/common/obj/PACKAGING/checkapi-current-timestamp
-rw-rw-r-- 1 san san 0 2009-10-27 03:20 ./out/target/common/obj/PACKAGING/checkapi-last-timestamp
-rw-rw-r-- 1 san san 0 2009-10-27 03:20 ./out/target/product/generic/obj/NOTICE_FILES/hash-timestamp

【今天测试进展-20091027】

1、今天的做法仍然是保证目标文件是最新的，测试结果是编译时间大概需要50分钟，比当初的重新编译所需的两个小时缩短了很多。

find ./out -type f \( ! -name "*.java" -and ! -name "*.cpp" \) -exec touch {} \;

或者

find ./out -type f \( -name "*.o" -or -name "*.a" -or -name "*.so" \) -exec touch {} \;
find ./out -type f \( -name "*.class" -or -name "*.jar" -or -name "*.dex" -or -name "*.apk" \) -exec touch {} \;

2、编译的过程中有几个地方比较花时间，至今尚未找到解决办法。

(1)、产生libwebcore.so(258MB)

(2)、从jar产生dex

(3)、soslim链接可执行文件

3、关于timestamp

今天测试修改了"timestamp"字样的文件的时间戳，但好像没什么效果。

find ./out -type f -name "*timestamp" -exec touch {} \;

4、待测试，修改*intermediates下所有文件的时间戳

find ./out -type d -name "*intermediates" -exec touch {} \;

【今天测试进展-20091101】

查找并显示所有Makefile的文件内容

find . -type f -name "*.mk" -print -exec cat {} \; > all_android_mk_file.txt

find . -type f -name "*.mk" -printf "\n# ===========================================\n" -print -printf "# ===========================================\n\n" -exec cat {} \; > ~/Desktop/android_mk.txt

研究过了Android编译过程的一些Log，现在该好好看一下MK是怎么写的了，其实，MK只是Log的浓缩而已了。