根据《深入理解Java虚拟机》一书，编译java虚拟机源码

系统环境：centos7

编译jdk版本：jdk7u-dev

本地java环境：jdk-7u40

ant版本为：1.8.2

1.安装相关依赖

yum install freetype-devel
yum install alsa-lib-devel
yum install cups-devel
yum install libX*
yum install gcc gcc-c++
yum install libstdc++-static

ant手动安装

wget https://archive.apache.org/dist/ant/binaries/apache-ant-1.8.2-bin.tar.gz

tar zxvf apache-ant-1.8.2-bin.tar.gz

ln -s /work/install/apache-ant-1.8.2/bin/ant /usr/bin/ant (应该是这步很重要)

本地java环境：jdk-7u40

下载地址：https://download.oracle.com/otn/java/jdk/7u40-b43/jdk-7u40-linux-x64.tar.gz

OpenJdk7源码获取：

yum install mercurial

hg clone http://hg.openjdk.java.net/jdk7u/jdk7u-dev

2.修改环境变量

vi /ect/profile

3.编写构建OpenJdk7脚本

[root@dev openjdk]# vi build.sh

export LANG=C
export ALT_BOOTDIR=/work/install/jdk1.7
export ALT_JDK_IMPORT_PATH=/work/install/jdk1.7
export ALLOW_DOWNLOADS=true
export HOTSPOT_BUILD_JOBS=1
export ANT_HOME=/work/install/apache-ant-1.8.2
export ANT_VERSION=1.8.2
export ALT_PARALLEL_COMPILE_JOBS=1
export SKIP_COMPARE_IMAGES=true
export USE_PRECOMPILED_HEADER=true
export BUILD_LANGTOOLS=true
#export BUILD_JAXP=false
export BUILD_JAXWS=false
#export BUILD_CORBA=false
export BUILD_HOTSPOT=true
export BUILD_JDK=true
export DISABLE_HOTSPOT_OS_VERSION_CHECK=ok
export SKIP_DEBUG_BUILD=false
export SKIP_FASTDEBUG_BUILD=true
export DEBUG_NAME=debug
BUILD_DEPLOY=false
BUILD_INSTALL=false
export ALT_OUTPUTDIR=/work/install/jdk1.7_build
unset JAVA_HOME
unset CLASSPATH
unset LD_LIBRARY_PATH
make sanity

make sanity && make 2>&1 | tee $ALT_OUTPUTDIR/build.log

4.最终经历千辛万苦OpenJdk7编译完成

坑1：本地尝试手动安装多个版本的ant，确认指定编译的ant版本无误。还是报下图错误：

坑2：手动安装ant，make sanity验证不通过。网上说通过yum install ant，就ok。但是后续却报找不到Launcher主类错误。强制在环境变量中配置的该类路径仍然，无法生效。一直卡ant编译这个问题上，后续看到别人编译要建立ant软件，才最终解决该问题！！！ln -s /work/install/apache-ant-1.8.2/bin/ant /usr/bin/ant

找不到或无法加载主类 org.apache.tools.ant.launch.Launcher

坑3 使用centos 的ant版本1.7.1会报如下错误