xref: /core/

Cross-compiling LibreOffice
***************************

Cross-compilation works, to various degree, to the following
platforms: iOS, Android, and Raspbian.

Note that this document has not been updated very often, and not
everything here necessarily is true any more.


General
-------

In GNU Autoconf terminology, "build" is the platform on which you are
running a build of some software and "host" is the platform on which
the software you are building will run. Only in the specific case of
building compilers and other programming tools is the term "target"
used to indicate the platform for which the tools your are building
will produce code. As LibreOffice is not a compiler, the "target" term
should not be used in the context of cross-compilation.

(For a case where all three of "build", "host" and "target" are
different: consider a gcc cross-compiler running on Windows, producing
code for Android, where the cross-compiler itself was built on
Linux. (This is a real case.) An interesting tidbit is that such
configurations are called "Canadian Cross".)

Even though the LibreOffice build mechanism is highly unorthodox, the
configure script takes the normal --build and --host options like any
GNU Autoconf -based configure script. To cross-compile, you basically
need just to specify a suitable --host option and things should work
out nicely. In practice, many details need to be handled. See examples
below.

Note that in the case of LibreOffice, it is uncommon to run the
configure script directly. Normally one uses the autogen.sh script.
The autogen.sh script reads command-line options from file called
autogen.input if it exists. The typical way of working is to keep
the configure parameters in that file and edit it as needed.


What is so hard, then?
----------------------

Despite the fact that the configure script takes normal --build and
--host options, that is just the beginning. It was necessary to
separate tests for "host" and "build" platforms in the configure
script. See the git log for details. And the reasonably "standard"
configure.in is just the top level; when we get down to the actual
makefilery used to build the bits of LibreOffice, it gets much worse.


iOS
***

iOS is the operating system on Apple's mobile devices. Clearly for a
device like the iPad it would not be acceptable to run a normal
LibreOffice application with overlapping windows and mouse-oriented
GUI widgets.

It makes sense to use only a part of LibreOffice's code for iOS. Lots
of the GUI-oriented code should be left out. iOS apps that want to use
the applicable LibreOffice code will handle all their GUI in a
platform-dependent manner. How well it will be possible to do such a
split remains to be seen.

Obviously we want it to be possible to eventually distribute apps
using LibreOffice code through the App Store. Technically, one
important special aspect of iOS is that apps in the App Store are not
allowed to load own dynamic libraries. (System libraries are used in
the form of dynamic libraries, just like on Mac OS X, of which iOS is
a variant.)

Thus all the libraries in LibreOffice that normally are shared
libraries (DLLs on Windows, shared objects (.so) on Linux, dynamic
libraries on Mac OS X (.dylib)) must be built as static archives
instead. This has some interesting consequences for how UNO is
implemented and used.

An iOS app is a "bundle" that contains a single executable. In an app
using LibreOffice code, that executable then contains the necessary
LibreOffice libraries and UNO components statically linked.

The Apple tool-chain for iOS cross-building is available only for OS
X. In order to be able to run and debug an app on an actual device
(and not just the iOS Simulator) you need to be registered in the iOS
Developer Program.

Here is an autogen.input for iOS (device) using Xcode 4.6, on OS X 10.8:

--build=i386-apple-darwin10.7.0
--host=arm-apple-darwin10
--enable-dbgutil
--enable-debug
--enable-werror

For the iOS Simulator, but note that building for the simulator is
broken at the moment (July 2014):

--build=i386-apple-darwin10.7.0
--host=arm-apple-darwin10
--enable-ios-simulator
--enable-dbgutil
--enable-debug
--enable-werror

You will have to install autoconf and automake yourself before running
autogen.sh. They are no longer included in Xcode 4.3 and later (not
even in the add-on "command line tools").

The -mmacosx-version-min=10.7 is necessary when building for the iOS
simulator to avoid clang replacing simple calls to fprintf with calls
to fwrite$UNIX2003 which Xcode then warns that doesn't exist on iOS.


Android
*******

From a technical point of view the core Android OS (the kernel) is
Linux, but everything else is different. Unlike iOS, an Android app
can use shared objects just fine, so that aspect of UNO doesn't need
special handling. Except that there is a silly low limit in the
Android dynamic linker on the number of libraries you can dlopen. This
is a limitation in user-level (but system-provided and not really
replaceable) code, not the kernel.

Thus, just like for iOS, also for Android the LibreOffice libraries
and UNO components are built as static archives. For Android, those
static archives, and any app-specific native code, are linked into one
single app-specific shared library, called liblo-native-code.so.

For the GUI, the same holds as said above for iOS. The GUI layer needs
to be platform-specific, written in Java.

Android cross-compilation work has been done mainly on Linux (openSUSE
in particular). Earlier also cross-compiling from OS X was tried. The
Android cross-compilation tool-chain (the "Native Development Kit", or
NDK) is available for Linux, OS X and Windows, but trying to
cross-compile LibreOffice from Windows will probably drive you insane.

You will also need the Android SDK as full "make" also builds a couple
of Android apps where the upper layer is written in Java.

Use the "android" tool from the SDK to install the SDK Tools, SDK
Platform Tools, the API 15 SDK Platform and the Android Support
Library. If you want to run the Android apps in the emulator, you of
course need an appropriate system image for that.

Here is an autogen.input for Android on ARM when cross-compiling
from Linux:

--enable-dbgutil
--enable-werror
--with-distro=LibreOfficeAndroid

And here is an (quite old) autogen.input for Android on X86:

--with-android-ndk=/opt/libreoffice/android-ndk-r8b
--with-android-ndk-toolchain-version=4.6
--with-android-sdk=/opt/libreoffice/android-sdk-linux
--build=i586-suse-linux
--enable-ccache
--with-distro=LibreOfficeAndroidX86

A LibreOffice app for Android is being developed progress in the
android/source directory.

To run the app, do "make install" followed by either "make run" or
starting it from Android itself. You most likely want to have an "adb logcat"
running in another window. To debug, run "make debugrun".

NB: If you happen to upgrade to Android SDK Tools 23, and the build (using
'make verbose=t android') fails for you with:

       [dx] UNEXPECTED TOP-LEVEL EXCEPTION:
       [dx] java.io.FileNotFoundException: /local/libreoffice/android-sdk-linux/tools/support/annotations.jar (no such file or directory)

you need to copy the annotations.jar from an older sdk; like

wget 'http://dl-ssl.google.com/android/repository/tools_r22.6.2-linux.zip'
unzip tools_r22.6.2-linux.zip
cp tools/support/annotations.jar <android-sdk-linux>/tools/support/

Raspbian
********

In theory, this should work also for another Linux, it does not need to be Raspbian.
But this cross-compilation work is tested from Debian and openSUSE to Raspbian.

You will need headers, pkg-config files and libraries from a Raspbian
system to build against. Available at
https://dev-www.libreoffice.org/extern/ . Look for the latest
raspbian-root-*.tar.gz . For instance:

$ wget https://dev-www.libreoffice.org/extern/raspbian-root-20140120.tar.gz
$ mkdir raspbian-root
$ cd raspbian-root
$ tar -xf raspbian-root-20140120.tar.gz

You can build cross-compiler yourself or get the executables here:
$ git clone git://github.com/raspberrypi/tools

tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian is known to work.

Then create pkg-config wrapper, something like:
$ cat > pkg-config-wrapper-host << _EOF
#!/bin/sh

if [ "$CROSS_COMPILING" = TRUE ]; then
   SYSROOT=$HOME/lo/raspbian-root
   export PKG_CONFIG_PATH=${SYSROOT}/usr/lib/arm-linux-gnueabihf/pkgconfig:${SYSROOT}/usr/share/pkgconfig
   export PKG_CONFIG_LIBDIR=${SYSROOT}/usr/lib/pkgconfig
   export PKG_CONFIG_SYSROOT_DIR=${SYSROOT}
fi

exec pkg-config "\$@"
_EOF
$ chmod +x pkg-config-wrapper-host

This does not work with pkg-config 0.23. 0.26 is known to work.

And you are ready to build with autogen.input similar to:

PKG_CONFIG=<path-to-pkg-config-wrapper-host>
CC=<path-to-arm-linux-gnueabihf-gcc> --sysroot=<path-to-raspbian_rootfs>
CXX=<path-to-arm-linux-gnueabihf-g++> --sysroot=<path-to-raspbian_rootfs>
--build=x86_64-unknown-linux-gnu
--host=arm-unknown-linux-gnueabihf
--disable-sdk
--enable-python=system
PYTHON_CFLAGS=-I<path-to-raspbian_rootfs>/usr/include/python2.7
PYTHON_LIBS=-lpython2.7
--with-java
JAVAINC=-I<path-to-raspbian_rootfs>/usr/lib/jvm/java-6-openjdk-armhf/include
--with-system-cairo
--with-system-cppunit
--with-system-icu
--with-system-neon
--with-system-nss
--with-system-openldap
--with-system-openssl
--with-system-redland

Finally, when you are ready to run the binaries in Raspbian,
you may need to get more system libraries, who knows.
$ sudo apt-get install libreoffice # or similar
That installs libreoffice too, which you don't need because you have
just built one, but I don't know how to avoid it easily.

# LibreOffice
[![Coverity Scan Build Status](https://scan.coverity.com/projects/211/badge.svg)](https://scan.coverity.com/projects/211) [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/307/badge)](https://bestpractices.coreinfrastructure.org/projects/307)

LibreOffice is an integrated office suite based on copyleft licenses
and compatible with most document formats and standards. Libreoffice
is backed by The Document Foundation, which represents a large
independent community of enterprises, developers and other volunteers
moved by the common goal of bringing to the market the best software
for personal productivity. LibreOffice is open source, and free to
download, use and distribute.

A quick overview of the LibreOffice code structure.

## Overview

You can develop for LibreOffice in one of two ways, one
recommended and one much less so. First the somewhat less recommended
way: it is possible to use the SDK to develop an extension,
for which you can read the API docs [here](http://api.libreoffice.org/)
and [here](http://wiki.services.openoffice.org/wiki/Documentation/DevGuide).
This re-uses the (extremely generic) UNO APIs that are also used by
macro scripting in StarBasic.

The best way to add a generally useful feature to LibreOffice
is to work on the code base however. Overall this way makes it easier
to compile and build your code, it avoids any arbitrary limitations of
our scripting APIs, and in general is far more simple and intuitive -
if you are a reasonably able C++ programmer.

## The build chain and runtime baselines

These are the current minimal operating system and compiler versions to
run and compile LibreOffice, also used by the TDF builds:

* Windows:
    * Runtime: Windows 7
    * Build: Cygwin + Visual Studio 2015 Update 3
* macOS:
    * Runtime: 10.9
    * Build: 10.12 + Xcode 8
* Linux:
    * Runtime: RHEL 6 or CentOS 6
    * Build: GCC 4.8.1 or Clang
* iOS (only for LibreOfficeKit):
    * Runtime: 11.2 (only support for newer i devices == 64 bit)
    * Build: Xcode 9.0 and iPhone SDK 11.2

At least Clang 3.4.2 is known to be too old to pass the configure.ac check "whether $CXX supports
C++17, C++14, or C++11" in its current form (due to the #pragma GCC diagnostic ignored "-Wpragmas"
that it does not understand).

If you want to use Clang with the LibreOffice compiler plugins, the minimal
version of Clang is 3.8. Since Xcode doesn't provide the compiler plugin
headers, you have to compile your own Clang to use them on macOS.

You can find the TDF configure switches in the distro-configs/ directory.

To setup your initial build environment on Windows and macOS, we provide
the LibreOffice Development Environment
([LODE](https://wiki.documentfoundation.org/Development/lode)) scripts.

For more information see the build instructions for your platform in the
[TDF wiki](https://wiki.documentfoundation.org/Development).

## The important bits of code

Each module should have a `README` file inside it which has some
degree of documentation for that module; patches are most welcome to
improve those. We have those turned into a web page here:

http://docs.libreoffice.org/

However, there are two hundred modules, many of them of only
peripheral interest for a specialist audience. So - where is the
good stuff, the code that is most useful. Here is a quick overview of
the most important ones:

Module    | Description
----------|-------------------------------------------------
sal/      | this provides a simple System Abstraction Layer
tools/    | this provides basic internal types: 'Rectangle', 'Color' etc.
vcl/      | this is the widget toolkit library and one rendering abstraction
framework | UNO framework, responsible for building toolbars, menus, status bars, and the chrome around the document using widgets from VCL, and XML descriptions from */uiconfig/* files
sfx2/     | legacy core framework used by Writer/Calc/Draw: document model / load/save / signals for actions etc.
svx/      | drawing model related helper code, including much of Draw/Impress

Then applications

Module    | Description
----------|-------------------------------------------------
desktop/  | this is where the 'main' for the application lives, init / bootstrap. the name dates back to an ancient StarOffice that also drew a desktop
sw/       | Writer
sc/       | Calc
sd/       | Draw / Impress

There are several other libraries that are helpful from a graphical perspective:

Module    | Description
----------|-------------------------------------------------
basegfx/  | algorithms and data-types for graphics as used in the canvas
canvas/   | new (UNO) canvas rendering model with various backends
cppcanvas/ | C++ helper classes for using the UNO canvas
drawinglayer/ | View code to render drawable objects and break them down into primitives we can render more easily.

## Rules for #include directives (C/C++)

Use the `"..."` form if and only if the included file is found next to the
including file. Otherwise, use the `<...>` form. (For further details, see the
mail [Re: C[++]: Normalizing include syntax ("" vs
<>)](https://lists.freedesktop.org/archives/libreoffice/2017-November/078778.html).)

The UNO API include files should consistently use double quotes, for the
benefit of external users of this API.


## Finding out more

Beyond this, you can read the `README` files, send us patches, ask
on the mailing list libreoffice@lists.freedesktop.org (no subscription
required) or poke people on IRC `#libreoffice-dev` on irc.freenode.net -
we're a friendly and generally helpful mob. We know the code can be
hard to get into at first, and so there are no silly questions.

Instructions to compile LO on Solaris with gcc

Disclaimer
----------
This is still work in progress
Compiling LO on Solaris with gcc is a work done by Lanedo ( www.lanedo.com )
Any inquiry could be sent to office-solaris@lanedo.com


Prerequisites
-------------

A working Oracle Solaris 11 installation


Installing Dependencies
-----------------------

sudo -s

pkg install git make gcc-45 autoconf autogen automake-110 gnu-m4

pkg install pkg:/system/header@0.5.11-0.175.0.0.0.2.1
pkg install pkg:/developer/gperf@3.0.3-0.175.0.0.0.2.537
pkg install pkg:/developer/parser/bison@2.3-0.175.0.0.0.2.537
pkg install pkg:/developer/lexer/flex@2.5.35-0.175.0.0.0.2.537
pkg install pkg:/developer/documentation-tool/doxygen@1.5.7.1-0.175.0.0.0.2.537


Compiling
---------

CC="gcc" CXX="g++" ./autogen.sh --with-num-cpus=2 --with-max-jobs=4 --without-junit --disable-mozilla --with-system-curl --without-help --disable-cups --without-java --with-system-cairo --with-lang= --enable-gio --disable-gnome-vfs --disable-gstreamer --without-fonts --with-system-dicts --disable-mozilla --without-system-mozilla --disable-xmlsec --with-system-openssl

gmake

Indexes created Wed Jan 03 00:38:09 CET 2018