docs/howto_build_SDK.txt

Copyright (C) 2009 The Android Open Source Project

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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     http://www.apache.org/licenses/LICENSE-2.0

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Subject: How to build an Android SDK & ADT Eclipse plugin.
Date:    2009/03/27
Updated: 2010/03/30


Table of content:
  0- License
  1- Foreword
  2- Building an SDK for MacOS and Linux
  3- Building an SDK for Windows
  4- Building an ADT plugin for Eclipse
  5- Conclusion



----------
0- License
----------

 Copyright (C) 2009 The Android Open Source Project

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.



-----------
1- Foreword
-----------

This document explains how to build the Android SDK and the ADT Eclipse plugin.

It is designed for advanced users which are proficient with command-line
operations and know how to setup the pre-required software.

Basically it's not trivial yet when done right it's not that complicated.



--------------------------------------
2- Building an SDK for MacOS and Linux
--------------------------------------

First, setup your development environment and get the Android source code from
git as explained here:

  http://source.android.com/source/download.html

For example for the cupcake branch:

  $ mkdir ~/my-android-git
  $ cd ~/my-android-git
  $ repo init -u https://android.googlesource.com/platform/manifest -b master
  $ repo sync

Then once you have all the source, simply build the SDK using:

  $ cd ~/my-android-git
  $ . build/envsetup.sh
  $ lunch sdk-eng
  $ make sdk

This will take a while, maybe between 20 minutes and several hours depending on
your machine. After a while you'll see this in the output:

  Package SDK: out/host/darwin-x86/sdk/android-sdk_eng.<build-id>_mac-x86.zip

Some options:

- Depending on your machine you can tell 'make' to build more things in
  parallel, e.g. if you have a dual core, use "make -j4 sdk" to build faster.

- You can define "BUILD_NUMBER" to control the build identifier that gets
  incorporated in the resulting archive. The default is to use your username.
  One suggestion is to include the date, e.g.:

  $ export BUILD_NUMBER=${USER}-`date +%Y%m%d-%H%M%S`

  There are certain characters you should avoid in the build number, typically
  everything that might confuse 'make' or your shell. So for example avoid
  punctuation and characters like $ & : / \ < > , and .



------------------------------
3- Building an SDK for Windows
------------------------------

Full Windows SDK builds are now only supported on Linux -- most of the framework is
not designed to be built on Windows so technically the Windows SDK is build on top
of a Linux SDK where a few binaries are replaced. So it cannot be built on Windows,
and it cannot be built on Mac, only on Linux.

I'll repeat this again because it's important:

  To build the Android SDK for Windows, you need to use a *Linux* box.

A- Pre-requisites
-----------------

Before you can even think of building the Android SDK for Windows, you need to
perform the steps from section "2- Building an SDK for MacOS and Linux" above:
setup and build a regular Linux SDK. Once this working, please continue here.

Under Ubuntu, you will need the following extra packages: 

$ sudo apt-get install mingw32 tofrodos

mingw32 is the cross-compiler, tofrodos adds a unix2dos command


B- Building
-----------

To build, perform the following steps:

$ . build/envsetup.sh
$ lunch sdk-eng
$ make win_sdk

Note that this will build both a Linux SDK then a Windows SDK. The result is located at
   out/host/windows/sdk/android-sdk_eng.${USER}_windows/



----------------------------
4- Partial SDK Windows Tools
----------------------------

As explained above, you can only build a *full* SDK for Windows using Linux.
However sometimes you need to develop one specific tools, e.g. adb.exe or
aapt.exe, and it's just more convenient to do it on the same platform where
you can actually test it. This is what this section explains.

   
A- Cygwin pre-requisite & code checkout
---------------------------------------

You must have Cygwin installed. You can use the latest Cygwin 1.7 or the
the "legacy Cygwin 1.5" from:

  http://cygwin.org/

Now configure it:
- When installing Cygwin, set Default Text File Type to Unix/binary, not DOS/text.
  This is really important, otherwise you will get errors when trying to
  checkout code using git.
- Packages that you must install or not:
  - Required packages: autoconf, bison, curl, flex, gcc, g++, git, gnupg, make,
                       mingw-zlib, python, zip, unzip.
  - Suggested extra packages: diffutils, emacs, openssh, rsync, vim, wget.
  - Packages that must not be installed: readline.

Once you installed Cygwin properly, checkout the code from git as you did
for MacOS or Linux (see section 2 above.)



C- Building the Windows Tools
-----------------------------

This is the easy part: run make on the tool you want.
How do you know which tools you can build? Well obviously all the ones
that come in an installed SDK/tools or SDK/platform-tools folder!

Example, to build adb:

  $ cd ~/my-android-git
  $ . build/envsetup.sh
  $ lunch sdk-eng
  $ make adb

The result will be somewhere in out/host/windows-x86/bin/. Just look at
the output from make to get the exact path. Since you are building this
under cygwin, you get an unstripped binary that you can happily feed to
gdb to get debugger symbols:

  $ gdb --args out/host/windows-x86/bin/adb.exe <adb arguments>


And before you ask, msys is not supported, nor is MSVC or windbg.

So you can build a lot of little parts of the SDK on Windows, one tool
at a time, but not the full thing because basically building the whole
platform is not supported. This means you cannot build "android.jar"
nor "layoutlib.jar" under Windows. For this you want Linux.



D- Building the Windows Tools on Linux
--------------------------------------

You can also build isolated windows tools directly on Linux.
Again, it requires a checkout of the full android code and the usual
setup like described above to build an SDK.

Then to build an isolated Windows binary, you'd do something like this:
  
  $ cd ~/my-android-git
  $ . build/envsetup.sh
  $ lunch sdk-eng
  $ USE_MINGW=1 make adb

The special environment variable "USE_MINGW" must be set to 1. This is
the clue to switch the make logic to cross-compiling to Windows under
Linux.



-------------------------------------
4- Building an ADT plugin for Eclipse
-------------------------------------

Requirements:
- You can currently only build an ADT plugin for Eclipse under Linux.
- You must have a working version of Eclipse 3.6 "helios" RCP installed.
- You need X11 to run Eclipse at least once.
- You need a lot of patience. The trick is to do the initial setup correctly
  once, after it's a piece of cake.



A- Pre-requisites
-----------------

Note for Ubuntu or Debian users: your apt repository probably only has Eclipse
3.2 available and it's probably not suitable to build plugins in the first
place. Forget that and install a working 3.6 manually as described below.

- Visit http://www.eclipse.org/downloads/ to grab the
  "Eclipse for RCP/Plug-in Developers (176 MB)" download for Linux.
  32-bit and 64-bit versions are available, depending on your Linux installation.

  Note: Eclipse comes in various editions. Do yourself a favor and just stick
  to the RCP for building this plugin. For example the J2EE contains too many
  useless features that will get in the way, and the "Java" version lacks some
  plugins you need to build other plugins. Please just use the RCP one.

  Note: You will need the CDT plugin but don't take a "CDT" flavor build as it
  will lack the RCP tools. Instead take an RCP and then add CDT.
  
- Unpack "eclipse-rcp-*-linux-gtk.tar.gz" in the directory of
  your choice, e.g.:

  $ mkdir ~/eclipse-3.6
  $ cd ~/eclipse-3.6
  $ tar xvzf eclipse-rcp-????-linux-gtk.tar.gz

  This will create an "eclipse" directory in the current directory.

- Set ECLIPSE_HOME to that "eclipse" directory:

  $ export ECLIPSE_HOME=~/eclipse-3.6/eclipse

  Note: it is important you set ECLIPSE_HOME before starting the build.
  Otherwise the build process will try to download and install its own Eclipse
  installation in /buildroot, which is probably limited to root.

- Now, before you can build anything, it is important that you start Eclipse
  *manually* once using the same user that you will use to build later. That's
  because your Eclipse installation is not finished: Eclipse must be run at
  least once to create some files in ~/.eclipse/. So run Eclipse now:

  $ ~/eclipse-3.6/eclipse/eclipse &

- Since you have Eclipse loaded, now is a perfect time to pick up the
  CDT plugin. (Another alternative is is to fetch the CDT from its archives
  and manually dump all the *.jar in eclipse/plugins.)
  
  That's it. You won't need to run it manually again.



B- Building ADT
---------------

Finally, you have Eclipse, it's installed and it created its own config files,
so now you can build your ADT plugin. To do that you'll change directories to
your git repository and invoke the build script by giving it a destination
directory and an optional build number:

  $ mkdir ~/mysdk
  $ cd ~/my-android-git   # <-- this is where you did your "repo sync"
  $ sdk/eclipse/scripts/build_server.sh ~/mysdk $USER

The first argument is the destination directory. It must be absolute. Do not
give a relative destination directory such as "../mysdk". This will make the
Eclipse build fail with a cryptic message:

  BUILD SUCCESSFUL
  Total time: 1 minute 5 seconds
  **** Package in ../mysdk
  Error: Build failed to produce ../mysdk/android-eclipse
  Aborting

The second argument is the build "number". The example used "$USER" but it
really is a free identifier of your choice. It cannot contain spaces nor
periods (dashes are ok.) If the build number is missing, a build timestamp will
be used instead in the filename.

The build should take something like 5-10 minutes.


When the build succeeds, you'll see something like this at the end of the
output:

  ZIP of Update site available at ~/mysdk/android-eclipse-v200903272328.zip
or
  ZIP of Update site available at ~/mysdk/android-eclipse-<buildnumber>.zip

When you load the plugin in Eclipse, its feature and plugin name will look like
"com.android.ide.eclipse.adt_0.9.0.v200903272328-<buildnumber>.jar". The
internal plugin ID is always composed of the package, the build timestamp and
then your own build identifier (a.k.a. the "build number"), if provided. This
means successive builds with the same build identifier are incremental and
Eclipse will know how to update to more recent ones.



-------------
5- Conclusion
-------------

This completes the howto guide on building your own SDK and ADT plugin.
Feedback is welcome on the public Android Open Source forums:
  http://source.android.com/discuss

If you are upgrading from a pre-cupcake to a cupcake or later SDK please read
the accompanying document "howto_use_cupcake_sdk.txt".

-end-