% OpenJDK Build README

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

--------------------------------------------------------------------------------

## 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)

-------------------------------------------------------------------------------

## 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.

### 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

### 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.

-------------------------------------------------------------------------------

## 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.

-------------------------------------------------------------------------------

### 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/)

#### 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.

#### Solaris

##### 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:

  Package                                            Version

  -------------------------------------------------- ---------------

  developer/solarisstudio-124/backend                12.4-1.0.6.0

  developer/solarisstudio-124/c++                    12.4-1.0.10.0

  developer/solarisstudio-124/cc                     12.4-1.0.4.0

  developer/solarisstudio-124/library/c++-libs       12.4-1.0.10.0

  developer/solarisstudio-124/library/math-libs      12.4-1.0.0.1

  developer/solarisstudio-124/library/studio-gccrt   12.4-1.0.0.1

  developer/solarisstudio-124/studio-common          12.4-1.0.0.1

  developer/solarisstudio-124/studio-ja              12.4-1.0.0.1

  developer/solarisstudio-124/studio-legal           12.4-1.0.0.1

  developer/solarisstudio-124/studio-zhCN            12.4-1.0.0.1

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.

#### 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).

###### 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.

  Binary Name   Category       Package    Description

  ------------- -------------- ---------- ------------------------------------------------------------

  ar.exe        Devel          binutils   The GNU assembler, linker and binary utilities

  make.exe      Devel          make       The GNU version of the 'make' utility built for CYGWIN

  m4.exe        Interpreters   m4         GNU implementation of the traditional Unix macro processor

  cpio.exe      Utils          cpio       A program to manage archives of files

  gawk.exe      Utils          awk        Pattern-directed scanning and processing language

  file.exe      Utils          file       Determines file type using 'magic' numbers

  zip.exe       Archive        zip        Package and compress (archive) files

  unzip.exe     Archive        unzip      Extract compressed files in a ZIP archive

  free.exe      System         procps     Display amount of free and used memory in the system

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).

###### 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

##### 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.

#### Mac OS X

Make sure you get the right XCode version.

-------------------------------------------------------------------------------

### 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`

#### 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`)

<a name="alsa"></a>

>  **`--with-alsa=`**_path_ \

>  select the location of the Advanced Linux Sound Architecture (ALSA)

>  Version 0.9.1 or newer of the ALSA files are required for building the

   OpenJDK on Linux. These Linux files are usually available from an "alsa" of

   "libasound" development package, and it's highly recommended that you try

   and use the package provided by the particular version of Linux that you are

   using.

>  **`--with-boot-jdk=`**_path_ \

>  select the [Bootstrap JDK](#bootjdk)

>  **`--with-boot-jdk-jvmargs=`**"_args_" \

>  provide the JVM options to be used to run the [Bootstrap JDK](#bootjdk)

>  **`--with-cacerts=`**_path_ \

>  select the path to the cacerts file.

>  See [Certificate Authority on

   Wikipedia](http://en.wikipedia.org/wiki/Certificate_Authority) for a

   better understanding of the Certificate Authority (CA). A certificates file

   named "cacerts" represents a system-wide keystore with CA certificates. In

   JDK and JRE binary bundles, the "cacerts" file contains root CA certificates

   from several public CAs (e.g., VeriSign, Thawte, and Baltimore). The source

   contain a cacerts file without CA root certificates. Formal JDK builders will

   need to secure permission from each public CA and include the certificates

   into their own custom cacerts file. Failure to provide a populated cacerts

   file will result in verification errors of a certificate chain during

   runtime. By default an empty cacerts file is provided and that should be fine

   for most JDK developers.

<a name="cups"></a>

>  **`--with-cups=`**_path_ \

>  select the CUPS install location

>  The Common UNIX Printing System (CUPS) Headers are required for building the

   OpenJDK on Solaris and Linux. The Solaris header files can be obtained by

   installing the package **print/cups**.

>  The CUPS header files can always be downloaded from

   [www.cups.org](http://www.cups.org).

>  **`--with-cups-include=`**_path_ \

>  select the CUPS include directory location

>  **`--with-debug-level=`**_level_ \

>  select the debug information level of release, fastdebug, or slowdebug

>  **`--with-dev-kit=`**_path_ \

>  select location of the compiler install or developer install location

<a name="freetype"></a>

>  **`--with-freetype=`**_path_ \

>  select the freetype files to use.

>  Expecting the freetype libraries under `lib/` and the headers under

   `include/`.

>  Version 2.3 or newer of FreeType is required. On Unix systems required files

   can be available as part of your distribution (while you still may need to

   upgrade them). Note that you need development version of package that

   includes both the FreeType library and header files.

>  You can always download latest FreeType version from the [FreeType

   website](http://www.freetype.org). Building the freetype 2 libraries from

   scratch is also possible, however on Windows refer to the [Windows FreeType

   DLL build instructions](http://freetype.freedesktop.org/wiki/FreeType_DLL).

>  Note that by default FreeType is built with byte code hinting support

   disabled due to licensing restrictions. In this case, text appearance and

   metrics are expected to differ from Sun's official JDK build. See the

   [SourceForge FreeType2 Home Page](http://freetype.sourceforge.net/freetype2)

   for more information.

>  **`--with-import-hotspot=`**_path_ \

>  select the location to find hotspot binaries from a previous build to avoid

   building hotspot

>  **`--with-target-bits=`**_arg_ \

>  select 32 or 64 bit build

>  **`--with-jvm-variants=`**_variants_ \

>  select the JVM variants to build from, comma separated list that can

   include: server, client, kernel, zero and zeroshark

>  **`--with-memory-size=`**_size_ \

>  select the RAM size that GNU make will think this system has

>  **`--with-msvcr-dll=`**_path_ \

>  select the `msvcr100.dll` file to include in the Windows builds (C/C++

   runtime library for Visual Studio).