![OpenJDK](http://openjdk.java.net/images/openjdk.png)

# OpenJDK Build README

*****

<a name="introduction"></a>

## Introduction

This README file contains build instructions for the

[OpenJDK](http://openjdk.java.net). Building the source code for the OpenJDK

requires a certain degree of technical expertise.

### !!!!!!!!!!!!!!! THIS IS A MAJOR RE-WRITE of this document. !!!!!!!!!!!!!

Some Headlines:

 * The build is now a "`configure && make`" style build

 * Any GNU make 3.81 or newer should work, except on Windows where 4.0 or newer

   is recommended.

 * The build should scale, i.e. more processors should cause the build to be

   done in less wall-clock time

 * Nested or recursive make invocations have been significantly reduced,

   as has the total fork/exec or spawning of sub processes during the build

 * Windows MKS usage is no longer supported

 * Windows Visual Studio `vsvars*.bat` and `vcvars*.bat` files are run

   automatically

 * Ant is no longer used when building the OpenJDK

 * Use of ALT_* environment variables for configuring the build is no longer

   supported

*****

## Contents

  * [Introduction](#introduction)

  * [Use of Mercurial](#hg)

    * [Getting the Source](#get_source)

    * [Repositories](#repositories)

  * [Building](#building)

    * [System Setup](#setup)

      * [Linux](#linux)

      * [Solaris](#solaris)

      * [Mac OS X](#macosx)

      * [Windows](#windows)

    * [Configure](#configure)

    * [Make](#make)

  * [Testing](#testing)

*****

  * [Appendix A: Hints and Tips](#hints)

    * [FAQ](#faq)

    * [Build Performance Tips](#performance)

    * [Troubleshooting](#troubleshooting)

  * [Appendix B: GNU Make Information](#gmake)

  * [Appendix C: Build Environments](#buildenvironments)

*****

<a name="hg"></a>

## Use of Mercurial

The OpenJDK sources are maintained with the revision control system

[Mercurial](http://mercurial.selenic.com/wiki/Mercurial). If you are new to

Mercurial, please see the [Beginner Guides](http://mercurial.selenic.com/wiki/

BeginnersGuides) or refer to the [Mercurial Book](http://hgbook.red-bean.com/).

The first few chapters of the book provide an excellent overview of Mercurial,

what it is and how it works.

For using Mercurial with the OpenJDK refer to the [Developer Guide: Installing

and Configuring Mercurial](http://openjdk.java.net/guide/

repositories.html#installConfig) section for more information.

<a name="get_source"></a>

### Getting the Source

To get the entire set of OpenJDK Mercurial repositories use the script

`get_source.sh` located in the root repository:

      hg clone http://hg.openjdk.java.net/jdk9/jdk9 YourOpenJDK

      cd YourOpenJDK

      bash ./get_source.sh

Once you have all the repositories, keep in mind that each repository is its

own independent repository. You can also re-run `./get_source.sh` anytime to

pull over all the latest changesets in all the repositories. This set of

nested repositories has been given the term "forest" and there are various

ways to apply the same `hg` command to each of the repositories. For

example, the script `make/scripts/hgforest.sh` can be used to repeat the

same `hg` command on every repository, e.g.

      cd YourOpenJDK

      bash ./make/scripts/hgforest.sh status

<a name="repositories"></a>

### Repositories

The set of repositories and what they contain:

 * **. (root)** contains common configure and makefile logic

 * **hotspot** contains source code and make files for building the OpenJDK

   Hotspot Virtual Machine

 * **langtools** contains source code for the OpenJDK javac and language tools

 * **jdk** contains source code and make files for building the OpenJDK runtime

   libraries and misc files

 * **jaxp** contains source code for the OpenJDK JAXP functionality

 * **jaxws** contains source code for the OpenJDK JAX-WS functionality

 * **corba** contains source code for the OpenJDK Corba functionality

 * **nashorn** contains source code for the OpenJDK JavaScript implementation

### Repository Source Guidelines

There are some very basic guidelines:

 * Use of whitespace in source files (.java, .c, .h, .cpp, and .hpp files) is

   restricted. No TABs, no trailing whitespace on lines, and files should not

   terminate in more than one blank line.

 * Files with execute permissions should not be added to the source

   repositories.

 * All generated files need to be kept isolated from the files maintained or

   managed by the source control system. The standard area for generated files

   is the top level `build/` directory.

 * The default build process should be to build the product and nothing else,

   in one form, e.g. a product (optimized), debug (non-optimized, -g plus

   assert logic), or fastdebug (optimized, -g plus assert logic).

 * The `.hgignore` file in each repository must exist and should include

   `^build/`, `^dist/` and optionally any `nbproject/private` directories. **It

   should NEVER** include anything in the `src/` or `test/` or any managed

   directory area of a repository.

 * Directory names and file names should never contain blanks or non-printing

   characters.

 * Generated source or binary files should NEVER be added to the repository

   (that includes `javah` output). There are some exceptions to this rule, in

   particular with some of the generated configure scripts.

 * Files not needed for typical building or testing of the repository should

   not be added to the repository.

*****

<a name="building"></a>

## Building

The very first step in building the OpenJDK is making sure the system itself

has everything it needs to do OpenJDK builds. Once a system is setup, it

generally doesn't need to be done again.

Building the OpenJDK is now done with running a `configure` script which will

try and find and verify you have everything you need, followed by running

`make`, e.g.

>  **`bash ./configure`**  

>  **`make all`**

Where possible the `configure` script will attempt to located the various

components in the default locations or via component specific variable

settings. When the normal defaults fail or components cannot be found,

additional `configure` options may be necessary to help `configure` find the

necessary tools for the build, or you may need to re-visit the setup of your

system due to missing software packages.

**NOTE:** The `configure` script file does not have execute permissions and

will need to be explicitly run with `bash`, see the source guidelines.

*****

<a name="setup"></a>

### System Setup

Before even attempting to use a system to build the OpenJDK there are some very

basic system setups needed. For all systems:

 * Be sure the GNU make utility is version 3.81 (4.0 on windows) or newer, e.g.

   run "`make -version`"

   <a name="bootjdk"></a>

 * Install a Bootstrap JDK. All OpenJDK builds require access to a previously

   released JDK called the _bootstrap JDK_ or _boot JDK._ The general rule is

   that the bootstrap JDK must be an instance of the previous major release of

   the JDK. In addition, there may be a requirement to use a release at or

   beyond a particular update level.

   **_Building JDK 9 requires JDK 8. JDK 9 developers should not use JDK 9 as

   the boot JDK, to ensure that JDK 9 dependencies are not introduced into the

   parts of the system that are built with JDK 8._**

   The JDK 8 binaries can be downloaded from Oracle's [JDK 8 download

   site](http://www.oracle.com/technetwork/java/javase/downloads/index.html).

   For build performance reasons it is very important that this bootstrap JDK

   be made available on the local disk of the machine doing the build. You

   should add its `bin` directory to the `PATH` environment variable. If

   `configure` has any issues finding this JDK, you may need to use the

   `configure` option `--with-boot-jdk`.

 * Ensure that GNU make, the Bootstrap JDK, and the compilers are all in your

   PATH environment variable.

And for specific systems:

 * **Linux**

   Install all the software development packages needed including

   [alsa](#alsa), [freetype](#freetype), [cups](#cups), and

   [xrender](#xrender). See [specific system packages](#SDBE).

 * **Solaris**

   Install all the software development packages needed including [Studio

   Compilers](#studio), [freetype](#freetype), [cups](#cups), and

   [xrender](#xrender). See [specific system packages](#SDBE).

 * **Windows**

   * Install one of [CYGWIN](#cygwin) or [MinGW/MSYS](#msys)

   * Install [Visual Studio 2013](#vs2013)

 * **Mac OS X**

   Install [XCode 6.3](https://developer.apple.com/xcode/)

<a name="linux"></a>

#### Linux

With Linux, try and favor the system packages over building your own or getting

packages from other areas. Most Linux builds should be possible with the

system's available packages.

Note that some Linux systems have a habit of pre-populating your environment

variables for you, for example `JAVA_HOME` might get pre-defined for you to

refer to the JDK installed on your Linux system. You will need to unset

`JAVA_HOME`. It's a good idea to run `env` and verify the environment variables

you are getting from the default system settings make sense for building the

OpenJDK.

<a name="solaris"></a>

#### Solaris

<a name="studio"></a>

##### Studio Compilers

At a minimum, the [Studio 12 Update 4 Compilers](http://www.oracle.com/

technetwork/server-storage/solarisstudio/downloads/index.htm) (containing

version 5.13 of the C and C++ compilers) is required, including specific

patches.

The Solaris Studio installation should contain at least these packages:

>  <table border="1">

     <thead>

       <tr>

         <td>**Package**</td>

         <td>**Version**</td>

       </tr>

     </thead>

     <tbody>

       <tr>

         <td>developer/solarisstudio-124/backend</td>

         <td>12.4-1.0.6.0</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/c++</td>

         <td>12.4-1.0.10.0</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/cc</td>

         <td>12.4-1.0.4.0</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/library/c++-libs</td>

         <td>12.4-1.0.10.0</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/library/math-libs</td>

         <td>12.4-1.0.0.1</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/library/studio-gccrt</td>

         <td>12.4-1.0.0.1</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/studio-common</td>

         <td>12.4-1.0.0.1</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/studio-ja</td>

         <td>12.4-1.0.0.1</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/studio-legal</td>

         <td>12.4-1.0.0.1</td>

       </tr>

       <tr>

         <td>developer/solarisstudio-124/studio-zhCN</td>

         <td>12.4-1.0.0.1</td>

       </tr>

     </tbody>

   </table>

In particular backend 12.4-1.0.6.0 contains a critical patch for the sparc

version.

Place the `bin` directory in `PATH`.

The Oracle Solaris Studio Express compilers at: [Oracle Solaris Studio Express

Download site](http://www.oracle.com/technetwork/server-storage/solarisstudio/

downloads/index-jsp-142582.html) are also an option, although these compilers

have not been extensively used yet.

<a name="windows"></a>

#### Windows

##### Windows Unix Toolkit

Building on Windows requires a Unix-like environment, notably a Unix-like

shell. There are several such environments available of which

[Cygwin](http://www.cygwin.com/) and

[MinGW/MSYS](http://www.mingw.org/wiki/MSYS) are currently supported for the

OpenJDK build. One of the differences of these systems from standard Windows

tools is the way they handle Windows path names, particularly path names which

contain spaces, backslashes as path separators and possibly drive letters.

Depending on the use case and the specifics of each environment these path

problems can be solved by a combination of quoting whole paths, translating

backslashes to forward slashes, escaping backslashes with additional

backslashes and translating the path names to their ["8.3"

version](http://en.wikipedia.org/wiki/8.3_filename).

<a name="cygwin"></a>

###### CYGWIN

CYGWIN is an open source, Linux-like environment which tries to emulate a

complete POSIX layer on Windows. It tries to be smart about path names and can

usually handle all kinds of paths if they are correctly quoted or escaped

although internally it maps drive letters `<drive>:` to a virtual directory

`/cygdrive/<drive>`.

You can always use the `cygpath` utility to map pathnames with spaces or the

backslash character into the `C:/` style of pathname (called 'mixed'), e.g.

`cygpath -s -m "<path>"`.

Note that the use of CYGWIN creates a unique problem with regards to setting

[`PATH`](#path). Normally on Windows the `PATH` variable contains directories

separated with the ";" character (Solaris and Linux use ":"). With CYGWIN, it

uses ":", but that means that paths like "C:/path" cannot be placed in the

CYGWIN version of `PATH` and instead CYGWIN uses something like

`/cygdrive/c/path` which CYGWIN understands, but only CYGWIN understands.

The OpenJDK build requires CYGWIN version 1.7.16 or newer. Information about

CYGWIN can be obtained from the CYGWIN website at

[www.cygwin.com](http://www.cygwin.com).

By default CYGWIN doesn't install all the tools required for building the

OpenJDK. Along with the default installation, you need to install the following

tools.

>  <table border="1">

     <thead>

       <tr>

         <td>Binary Name</td>

         <td>Category</td>

         <td>Package</td>

         <td>Description</td>

      </tr>

     </thead>

     <tbody>

       <tr>

         <td>ar.exe</td>

         <td>Devel</td>

         <td>binutils</td>

         <td>The GNU assembler, linker and binary utilities</td>

       </tr>

       <tr>

         <td>make.exe</td>

         <td>Devel</td>

         <td>make</td>

         <td>The GNU version of the 'make' utility built for CYGWIN</td>

       </tr>

       <tr>

         <td>m4.exe</td>

         <td>Interpreters</td>

         <td>m4</td>

         <td>GNU implementation of the traditional Unix macro processor</td>

       </tr>

       <tr>

         <td>cpio.exe</td>

         <td>Utils</td>

         <td>cpio</td>

         <td>A program to manage archives of files</td>

       </tr>

       <tr>

         <td>gawk.exe</td>

         <td>Utils</td>

         <td>awk</td>

         <td>Pattern-directed scanning and processing language</td>

       </tr>

       <tr>

         <td>file.exe</td>

         <td>Utils</td>

         <td>file</td>

         <td>Determines file type using 'magic' numbers</td>

       </tr>

       <tr>

         <td>zip.exe</td>

         <td>Archive</td>

         <td>zip</td>

         <td>Package and compress (archive) files</td>

       </tr>

       <tr>

         <td>unzip.exe</td>

         <td>Archive</td>

         <td>unzip</td>

         <td>Extract compressed files in a ZIP archive</td>

       </tr>

       <tr>

         <td>free.exe</td>

         <td>System</td>

         <td>procps</td>

         <td>Display amount of free and used memory in the system</td>

       </tr>

     </tbody>

   </table>

Note that the CYGWIN software can conflict with other non-CYGWIN software on

your Windows system. CYGWIN provides a [FAQ](http://cygwin.com/faq/

faq.using.html) for known issues and problems, of particular interest is the

section on [BLODA (applications that interfere with

CYGWIN)](http://cygwin.com/faq/faq.using.html#faq.using.bloda).

<a name="msys"></a>

###### MinGW/MSYS

MinGW ("Minimalist GNU for Windows") is a collection of free Windows specific

header files and import libraries combined with GNU toolsets that allow one to

produce native Windows programs that do not rely on any 3rd-party C runtime

DLLs. MSYS is a supplement to MinGW which allows building applications and

programs which rely on traditional UNIX tools to be present. Among others this

includes tools like `bash` and `make`. See [MinGW/MSYS](http://www.mingw.org/

wiki/MSYS) for more information.

Like Cygwin, MinGW/MSYS can handle different types of path formats. They are

internally converted to paths with forward slashes and drive letters

`<drive>:` replaced by a virtual directory `/<drive>`. Additionally, MSYS

automatically detects binaries compiled for the MSYS environment and feeds them

with the internal, Unix-style path names. If native Windows applications are

called from within MSYS programs their path arguments are automatically

converted back to Windows style path names with drive letters and backslashes

as path separators. This may cause problems for Windows applications which use

forward slashes as parameter separator (e.g. `cl /nologo /I`) because MSYS may

wrongly [replace such parameters by drive letters](http://mingw.org/wiki/

Posix_path_conversion).

In addition to the tools which will be installed by default, you have to

manually install the `msys-zip` and `msys-unzip` packages. This can be easily

done with the MinGW command line installer:

      mingw-get.exe install msys-zip

      mingw-get.exe install msys-unzip

<a name="vs2013"></a>

##### Visual Studio 2013 Compilers

The 32-bit and 64-bit OpenJDK Windows build requires Microsoft Visual Studio

C++ 2013 (VS2013) Professional Edition or Express compiler. The compiler and

other tools are expected to reside in the location defined by the variable

`VS120COMNTOOLS` which is set by the Microsoft Visual Studio installer.

Only the C++ part of VS2013 is needed. Try to let the installation go to the

default install directory. Always reboot your system after installing VS2013.

The system environment variable VS120COMNTOOLS should be set in your

environment.

Make sure that TMP and TEMP are also set in the environment and refer to

Windows paths that exist, like `C:\temp`, not `/tmp`, not `/cygdrive/c/temp`,

and not `C:/temp`. `C:\temp` is just an example, it is assumed that this area

is private to the user, so by default after installs you should see a unique

user path in these variables.

<a name="macosx"></a>

#### Mac OS X

Make sure you get the right XCode version.

*****

<a name="configure"></a>

### Configure

The basic invocation of the `configure` script looks like:

>  **`bash ./configure [options]`**

This will create an output directory containing the "configuration" and setup

an area for the build result. This directory typically looks like:

>  **`build/linux-x64-normal-server-release`**

`configure` will try to figure out what system you are running on and where all

necessary build components are. If you have all prerequisites for building

installed, it should find everything. If it fails to detect any component

automatically, it will exit and inform you about the problem. When this

happens, read more below in [the `configure` options](#configureoptions).

Some examples:

>  **Windows 32bit build with freetype specified:**  

>  `bash ./configure --with-freetype=/cygdrive/c/freetype-i586 --with-target-

bits=32`

>  **Debug 64bit Build:**  

>  `bash ./configure --enable-debug --with-target-bits=64`

<a name="configureoptions"></a>

#### Configure Options

Complete details on all the OpenJDK `configure` options can be seen with:

>  **`bash ./configure --help=short`**

Use `-help` to see all the `configure` options available. You can generate any

number of different configurations, e.g. debug, release, 32, 64, etc.

Some of the more commonly used `configure` options are:

>  **`--enable-debug`**  

>  set the debug level to fastdebug (this is a shorthand for `--with-debug-

   level=fastdebug`)