openjdk8 源碼最新版

openjdk-8u40-src-b25-10_feb_2015.7z openjdk8官方源代碼,編譯OpenJDK8u的源代碼需要先安裝JDK。

在Ubuntu 12.04 上編譯調試 OpenJDK8

現在看的資料都是編譯 openjdk7 的，openjdk8好像已經 openjdk7 編譯方式大一樣，按照前輩的文章使用

make sanity

會提示找不到 sanity 規則，然後編譯過程其實基本就直接

./configure make all

官方的 README 寫的很清楚。

下麵記錄下過程

下載代碼

hg clone http://hg.openjdk.java.net/jdk8u/jdk8u jdk8u cd jdk8u bash ./get_source.sh

然後下載代碼，進入代碼目錄：

cd jdk8u

代碼目錄中有一個 README-builds.html 描述了如何　build 整個係統,一些細節需要自己去尋找。

安裝依賴

sudo aptitude build-dep openjdk-7 sudo aptitude install openjdk-7-jdk

配置

環境變量

export export PATH="/usr/lib/jvm/java-7-openjdk/bin:${PATH}"

配置編譯選項

bash ./configure

這樣生成相應默認配置，如果有需要，比如想編譯出調試版本的，可以給 configure 加參數。

A new configuration has been successfully created in /home/minix/SourceCode/openjdk8/jdk8u/build/linux-x86-normal-server-release using default settings. Configuration summary: * Debug level: release * JDK variant: normal * JVM variants: server * OpenJDK target: OS: linux, CPU architecture: x86, address length: 32 Tools summary: * Boot JDK: java version "1.7.0_17" Java(TM) SE Runtime Environment (build 1.7.0_17-b02) Java HotSpot(TM) Server VM (build 23.7-b01, mixed mode) (at /home/minix/Software/jdk1.7.0_17) * C Compiler: gcc-4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) version 4.6.3 (at /usr/bin/gcc-4.6) * C++ Compiler: g++-4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) version 4.6.3 (at /usr/bin/g++-4.6) Build performance summary: * Cores to use: 3 * Memory limit: 3878 MB * ccache status: not installed (consider installing) Build performance tip: ccache gives a tremendous speedup for C++ recompilations. You do not have ccache installed. Try installing it. You might be able to fix this by running 'sudo apt-get install ccache'.

可以看出提示缺少 ccache 包，按提示安裝就可以了。從提示可以看出，編譯級別是 release，另外還有幾種編譯級別，可以在調試時候提供更多的信息。例如：

bash ./configure --enable-debug

這樣會生成 fastdebug 版本的配置信息：

A new configuration has been successfully created in /home/minix/openjdk8/jdk8u/build/linux-x86-normal-server-fastdebug using configure arguments '--enable-debug'. Configuration summary: * Debug level: fastdebug * JDK variant: normal * JVM variants: server * OpenJDK target: OS: linux, CPU architecture: x86, address length: 32 Tools summary: * Boot JDK: java version "1.7.0_17" Java(TM) SE Runtime Environment (build 1.7.0_17-b02) Java HotSpot(TM) Server VM (build 23.7-b01, mixed mode) (at /home/minix/Software/jdk1.7.0_17) * C Compiler: gcc-4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) version 4.6.3 (at /usr/bin/gcc-4.6) * C++ Compiler: g++-4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) version 4.6.3 (at /usr/bin/g++-4.6) Build performance summary: * Cores to use: 3 * Memory limit: 3878 MB * ccache status: installed and in use

注意編譯的級別已經變成 fastdebug 了。

--enable-debug 其實相當於--with-debug-level=fastdebug,　可以通過這樣的參數選項指定編譯級別。一共可以指定三種級別: release, fastdebug, slowdebug, slowdebug 含有最豐富的調試信息，沒有這些信息，很多執行可能被優化掉，我們單步執行時，可能看不到一些變量的值。所以最好指定slowdebug 為編譯級別

編譯

編譯直接

make

就可以了，如果提示

No CONF given, but more than one configuration found in /home/minix/openjdk8/jdk8u//build. Available configurations: * linux-x86-normal-server-fastdebug * linux-x86-normal-server-release Please retry building with CONF= (or SPEC=)

需要指定使用哪個編譯配置：

make CONF=linux-x86-normal-server-fastdebug

最後編譯成功後，會提示：

----- Build times ------- Start 2014-08-22 10:56:52 End 2014-08-22 11:16:31 00:00:30 corba 00:13:38 hotspot 00:00:22 jaxp 00:00:30 jaxws 00:04:10 jdk 00:00:29 langtools 00:19:39 TOTAL

查看 build 目錄，可以看到 linux-x86-normal-server-fastdebug

切換到 jdk/bin 目錄：

cd linux-x86-normal-server-fastdebug/jdk/bin/

運行可執行文件 java

./java -version

會得到提示

openjdk version "1.8.0-internal-fastdebug" OpenJDK Runtime Environment (build 1.8.0-internal-fastdebug-minix_2014_08_22_10_56-b00) OpenJDK Server VM (build 25.40-b05-fastdebug, mixed mode)

調試

下麵展示一個啟動 GDB, 加斷點，並運行一個 Java 程序的過程。

$ gdb java GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2.1) 7.4-2012.04 Copyright (C) 2012 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i686-linux-gnu". For bug reporting instructions, please see: ... Reading symbols from /home/minix/openjdk8/jdk8u/build/fastdebug/jdk/bin/java...done. (gdb) b main Breakpoint 1 at 0x8048410: file /home/minix/openjdk8/jdk8u/jdk/src/share/bin/main.c, line 94. (gdb) r -classpath PossibleReordering Starting program: /home/minix/openjdk8/jdk8u/build/fastdebug/jdk/bin/java -classpath PossibleReordering [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1". Breakpoint 1, main (argc=3, argv=0xbfffeca4) at /home/minix/openjdk8/jdk8u/jdk/src/share/bin/main.c:94