Building OpenJDK

[This might be already out of date.]

Here's how I build a 32 bit OpenJDK (build 31) on my Ubuntu 8.04 (Hardy Heron) system.

1. Download
Download the following two files

• the source bundle,
  
• the binary plug which contains a small amount of the binary-only components
  

from the download page, into the directory ~/openjdk7-ws/ and you get two files: the source bundle

~/openjdk7-ws/openjdk-7-ea-src-b31-17_jul_2008.zip

and the binary plugs

~/openjdk7-ws/jdk-7-ea-plug-b31-linux-i586-17_jul_2008.jar

2. Install required packages
Make sure that you install the following Ubuntu packages (I use the Synaptic Package Manger)

• ant
• ant-optional
• gawk
• gcc
• g++
• libasound2-dev
• libcupsys2-dev
• libfreetype6-dev
• libmotif-dev
• libx11proto-print-dev
• libxi-dev
• libxrender-dev
• libxt-dev
• libxext-dev
• libxtst-dev
• sun-java6-jdk

3. Unpack the source
Unzip the source bundle by typing

$ cd ~/openjdk7-ws
$ unzip openjdk-7-ea-src-b31-17_jul_2008.zip

and you will get the source directory

~/openjdk7-ws/openjdk.

4. Unpack the binary plugs
Expand the binary plugs by typing

$ cd ~/openjdk7-ws
$ java -jar jdk-7-ea-plug-b31-linux-i586-17_jul_2008.jar

which invokes a Java GUI extractor. Accept the license and select ~/openjdk7-ws as the destination and you get the binary plugs directory

~/openjdk7-ws/openjdk-binary-plugs.

5. Suppress compiler warnings and errors
Edit the file

~/openjdk7-ws/openjdk/hotspot/make/linux/makefiles

and add the following compiler option

CFLAGS += -Wno-write-strings

at the end of the list of the compiler options (line 60.)

And replace

#!/bin/sh

with

#!/bin/bash

in the first line of the six .sh files under

~/openjdk7-ws/openjdk/jdk/make/java/nio/

and change the value of variable SH from sh to bash in line 121 of

~/openjdk7-ws/openjdk/jdk/make/common/shared/Defs-utils.gmk

6. Build
Start the build by typing the following

$ cd ~/openjdk7-ws
$ unset JAVA_HOME
$ export ALT_BOOTDIR=/usr/lib/jvm/java-6-sun
$ export ALT_BINARY_PLUGS_PATH=~/openjdk7-ws/openjdk-binary-plugs
$ export LANG=C
$ make debug_build

and wait for a while and you will get the debug build in

$ ~/openjdk7-ws/openjdk/build/linux-i586-debug/j2sdk-image

To build a product build, type

$ make product_build

and you will get the product build in

$ ~/openjdk7-ws/openjdk/build/linux-i586/j2sdk-image

To clean the build directory, use

$ make clobber