Cross-compiling LibreOffice *************************** Cross-compilation works, to various degree, to the following platforms: Windows, iOS, Android, and Raspbian. 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. Windows ******* There was some support in LibreOffice already from OpenOffice.org days for building it locally on Windows with the GNU tool-chain (MinGW). Apparently, those doing that work never attempted cross-compilation. This OOo-originated MinGW support attempts to be for both running the Cygwin gcc in its -mno-cygwin mode, and a Windows-native MinGW compiler. The -mno-cygwin mechanism in the Cygwin gcc is rapidly being obsoleted, if it isn't already, and we have not attempted to try to keep it working; in fact we have actively cleaned out mechanisms related to this. Ditto for native MinGW. If one compiles natively on Windows, just use a version of Microsoft's compiler. OpenOffice.org and LibreOffice have been built for Windows all the time using that. The only case where it makes sense to use MinGW is for cross-compilation. There is just too much crack involved on Windows anyway, and it is a semi-miracle that the MSVC build under Cygwin works as nicely as it does. MinGW is available as cross-build toolchains pre-packaged in more or less official packages for many Linux distros including Debian, Fedora and openSUSE. For instance, the mingw32 packages in the Open Build Service, running on openSUSE, can be found at: http://download.opensuse.org/repositories/windows:/mingw:/win32/ For example, you can install it like this: zypper ar http://download.opensuse.org/repositories/windows:/mingw:/win32//windows:mingw:win32.repo where is one of SLE_11, SLE_11_SP1, openSUSE_XX.Y, or openSUSE_Factory. zypper in mingw32-cross-gcc mingw32-cross-gcc-c++ mingw32-python-devel \ mingw32-python mingw32-libboost_date_time \ mingw32-libexpat-devel mingw32-libexpat mingw32-boost-devel \ mingw32-libhyphen-devel mingw32-libhyphen mingw32-hyphen-en \ mingw32-liblpsolve mingw32-liblpsolve-devel \ mingw32-libxml2-devel mingw32-libxslt-devel mingw32-libicu \ mingw32-libicu-devel mingw32-libgraphite2 mingw32-libgraphite2-devel \ mingw32-libcairo2 mingw32-cairo-devel mingw32-librsvg mingw32-librsvg-devel \ mingw32-hunspell mingw32-hunspell-devel mingw32-libcurl \ mingw32-libcurl-devel mingw32-libneon mingw32-libneon-devel \ mingw32-libopenssl mingw32-libopenssl-devel mingw32-libexttextcat \ mingw32-libexttextcat-devel mingw32-libdb mingw32-libdb-devel \ mingw32-cross-pkg-config mingw32-pkg-config mingw32-libcppunit \ mingw32-libcppunit-devel mingw32-libredland mingw32-libredland-devel \ mingw32-libmythes mingw32-libmythes-devel mingw32-mozilla-nss \ mingw32-mozilla-nss-devel mingw32-mozilla-nspr \ mingw32-mozilla-nspr-devel mingw32-libpoppler mingw32-libpoppler-devel You also need wine, ideally: zypper ar http://download.opensuse.org/repositories/Emulators:/Wine//Emulators:Wine.repo zypper in wine wine-devel wine-devel-32bit And in order to be able to use 'winegcc -m32', also zypper in glibc-devel-32bit gcc-32bit There might be more that are missing, please read carefully what autogen.sh tells you, and either remove one of the --with-system-*, or install the missing dependency. It also looks like graphite2.pc needs tweaking in order to work right; but that's likely to be fixed in the openSUSE project. It is somewhat unclear how well thought-out the conditionals and code for MinGW inside the OOo-originated code in LibreOffice actually are. It often seems a bit randomish, with copy-pasting having been preferred to factoring out differences. Most of the configuration settings are maintained in the distro-configs/LibreOfficeMinGW.conf file, so in your autogen.input, you can use: CC=ccache i686-w64-mingw32-gcc CXX=ccache i686-w64-mingw32-g++ CC_FOR_BUILD=ccache gcc CXX_FOR_BUILD=ccache g++ --with-distro=LibreOfficeMinGW Alternatively, you can use something like the following; but the preferred way is to keep the LibreOfficeMinGW.conf file up-to-date. CC=ccache i686-w64-mingw32-gcc CXX=ccache i686-w64-mingw32-g++ CC_FOR_BUILD=ccache gcc CXX_FOR_BUILD=ccache g++ --build=x86_64-unknown-linux-gnu --host=i686-w64-mingw32 --with-distro=LibreOfficeWin32 --disable-activex --disable-directx --disable-ext-nlpsolver --disable-report-builder --disable-scripting-beanshell --disable-scripting-javascript --disable-ext-wiki-publisher --disable-pdfimport --enable-python=system --with-system-altlinuxhyph --with-system-boost --with-system-cairo --with-system-cppunit --with-system-curl --with-system-expat --with-system-hunspell --with-system-icu --with-system-libpng --with-system-libwpd --with-system-libwpg --with-system-libwps --with-system-libxml --with-system-lpsolve --with-system-mythes --with-system-neon --with-system-openssl --with-system-redland --with-vendor=no --without-help --without-helppack-integration --without-myspell-dicts Once you have compiled it, you may want to try to run it, for instance using Wine: $ cd /tmp $ tar xf /workdir/wntgcci.pro/installation/LibreOffice_Dev/archive/install/en-US/LibO-Dev_4.1.0.0.alpha0_Win_x86_archive.tar.gz $ cd LibO-Dev_4.1.0.0.alpha0_Win_x86_archive/LOdev\ 4.1/program/ $ wine soffice.exe NB. it is important to unpack somewhere low in the hierarchy structure (like in /tmp as advised above), otherwise you'll get BerkeleyDB errors on startup. And if you are brave enough, you can even debug it. First you have to add the URE dll's to the wine's PATH using 'wine regedit' - see http://www.winehq.org/docs/wineusr-guide/environment-variables, and add Z:\tmp\LibO-Dev_4.1.0.0.alpha0_Win_x86_archive/LOdev\ 4.1\URE\bin to "Path" in My Computer->HKEY_CURRENT_USER->Environment. And start debugging: $ winedbg soffice.bin Would be great to be able to use winedbg --gdb, but it was crashing here :-( - but maybe you'll be more lucky. Tricks of some use with winedbg: -------------------------------- To examine OUStrings, you might want to use the following trick (prints 50 unicode characters of rLibName OUString - the +10 is where the buffer starts): Wine-dbg>x /50u rLibName->pData+10 0x0909b6c8: vnd.sun.star.expand:$LO_LIB_DIR/abplo.dll TODO: - make the debugging more convenient on (native) Windows - check possibilities like WinGDB - http://www.wingdb.com/ - or find / write a MSVS / WinDBG extension that can read MinGW debugging symbols natively; more info http://windbg.info/forum/12-symbol-and-source-files-/21-debugging-mingwgcc-built-dll-in-visual-studio.html - installation - so far the make_installer.pl calls makecab.exe, uuidgen.exe, and others; would be best to avoid that if at all possible (using a free cab implementation, part of Wine or something) - MSI generation - runtime - no idea if the entire thing works after the installation at all; I suppose there will be runtime problems to look at too - cleanup - enable & fix pieces that are currently disabled - --without-myspell-dicts - --disable-directx - --disable-activex - much of the stuff currently relies on --with-system-*, and consequently on the mingw32-* openSUSE packages; might be good to be able to build with as few dependencies as possible - but that is low prio - profiling - when all the above is sorted out, we should look at the speed of this vs. the speed of the MSVC version 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 eecutable then congtains 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 There are a couple of (more or less) interactive apps that you can run on the emulator or on a device that use LibreOffice code. Look in android/experimental. DocumentLoader is just a testbench, really for code to load a document (just Writer ones so far) and display one page at a time. LibreOffice4Android is what resulted from a Google Summer of Code project in 2012, a document viewer. desktop is a totally different app, where the actual LibreOffice desktop GUI is present. Note that none of these apps in any way are claimed to be ready for end-users. No "beta testing" offers needed, it is painfully obvious what problems they have. To run some of the apps, 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 /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 http://dev-www.libreoffice.org/extern/ . Look for the latest raspbian-root-*.tar.gz . For instance: $ wget http://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= CC= --sysroot= CXX= --sysroot= --build=x86_64-unknown-linux-gnu --host=arm-unknown-linux-gnueabihf --disable-sdk --enable-python=system PYTHON_CFLAGS=-I/usr/include/python2.7 PYTHON_LIBS=-lpython2.7 --with-java JAVAINC=-I/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.