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Changes in WidelandsGoingCMake

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Cleanup, Launchpad migration


Revision Differences of Revision 27

# Widelands going CMake ¶

Widelands project plans to move from the current build system SCons to CMake. ¶

This page is to track progress and collect important information in the transition process. ¶

## Table of Contents: ¶
[TOC] ¶



## Important Links ¶

* [SCons](http://www.scons.org) ¶
* [CMake](http://www.cmake.org) ¶
* [CMake Tutorial \(PDF\]](http://www-flc.desy.de/ldcoptimization/documents/talks/CMake_Tutorial.pdf) ¶

## I
dentified Tasks ¶
### Changes to do Build ¶
* *make install* does not exclude SVN directories ¶
* add "PATTERN "\*.svn\*" EXCLUDE" to global CMakeLists.txt file *INSTALL* directive ¶
* SOLVED in SVN ¶
* *make install* includes the *doc* directory which is not necessary for release, but maybe interesting for debug ¶
* SOLVED in SVN ¶
* Doxygen integration (make doc) ¶
* change Doxyfile (vars), additionally global CMakeLists.txt ¶
* SOLVED in SVN ¶
* Versioning must be modified ¶
* move build/scons-tools/detect_revision.py to utils (this is no scons tool, just plain python) ¶
* SOLVED in SVN ¶
* Processing the pics is different ¶
* Was SCons/Python script ¶
* Now done in CMake ¶
* SOLVED in SVN, but only for Linux yet. Need Windows/Darwin testers ¶
### Transition tasks ¶
* CMake's "make install" installs in /usr/local - needs root. Just "make" creates the executables but does not lay out a usable installation of widelands. The "make" should create a runnable widelands installation in a subdirectory of the build directory, since we don't need root to run widelands. Then "make install" could just copy the files to /usr/local. Discuss? ¶
* SOLVED. It should be kept the way it is, this is standard. The executable binary works nevertheless, but is usually not needed. GNU style make defines only installed files need to be working. ¶
* CMake currently always creates a Debug build (at least it seems so). It should be possible to build a Release. ¶
* SOLVED in SVN ¶
* Identify SCons tasks and targets used by widelands, replace using cmake & make ¶
* scons ¶
* make ¶
* scons -c ¶
* make clean ¶
* scons doc ¶
* make doc (no dependency to make) ¶
* make install (no scons target?) ¶
* CMake 2.6 should be used. Do we need CMake 2.8? ¶
* Identify bugs/improvements from bug tracker and mailing list ¶
* Working cmake on win32 http://sourceforge.net/tracker/?func=detail&aid=2929259&group_id=40163&atid=427221 ¶
* Identify additional tasks, build tools etc. ¶
* build/scons-tools/Distribute.py ¶
* Script for packaging a complete binary distribution (Release?) ¶
* Scons and Python tool ¶
* proposal: make dist with new CMake script ¶
* build/scons-tools/CodeCheck.py ¶
* Code-Checker ¶
* Scons and Python tool ¶
###Issues ¶
* Running widelands writes to console: "WARNING: either we can not detect your home directory or you do not have one! Please contact the developers. Instead of your home directory, '.' will be used. Set home directory: ./.widelands". There's something missing. ¶
* Found the problem. config.h.cmake is missing #define HAS_GETENV which is done by Scons. Can we set this in any case? How does Windows react to that? ¶
* Changing language doesn't work. English only. ¶
* Found the problem. The locales do not get compiled. Doesn't work on the fly because of out-of-source build (cmake) conflicting with the script which creates the locales (expects to be run from base dir and writes there). Either modify script or find a way to run it out-of-source. ¶
* Finding doxygen works. Test with non-working doxygen and about working doxygen without dot to be done. ¶
* Find some Windows/MinGW system to test. ¶
* Do we really need 3 tools to optimize the PNG files? pngrewrite, optipng and advdef? ¶
* "make pics" needs testers for Windows and Darwin, trying to find pngrewrite and optipng. ¶
* CPack issue with path names and components package, always generating empty assemblies. ¶
* Either we get that sorted out, or we'd have to write own packaging scripts (not nice) ¶

## Build systems for testing ¶
### System1 ¶
* Intel Core2 Duo, Gentoo Linux 32bit ¶
* gcc 4.3.4, cmake 2.6, libsdl 1.2.13, lua 5.1.4, boost 1.35 ¶

## Important notes ¶
### Things to know about the transition ¶
* Transition uses a SVN branch called "cmake-transition", not "trunk" ¶
* cmake-transition trunk is not being kept up to date, if you want bleeding edge builds, use svn trunk and scons building ¶

### Starting with CMake in the transition (this is for Linux; Windows will differ) ¶
#### 1. Preparation ¶
* $ cd ~ ¶
* $ svn co https://widelands.svn.sourceforge.net/svnroot/widelands/branches/cmake-migration widelands-cmake ¶
* $ mkdir widelands-cmake/build-cmake ¶

#### 2. Using CMake ¶
* $ cd ~/widelands-cmake/build-cmake ¶
* go to the build directory ¶
* $ cmake .. ¶
* let CMake create the Makefiles in the current directory, regarding the CMakeLists.txt files in the parent (widelands-cmake) directory (this is out-of-source) ¶
* $ cmake -DCMAKE_INSTALL_PREFIX=~/widelands-cmake-install .. ¶
* if you want to have a different install directory for "make install" instead of /usr/local ¶

#### 3. Using make ¶
* $ cd ~/widelands-cmake/build-cmake ¶
* go to the build directory ¶
* $ make -j3 ¶
* this compiles the sources ¶
* -j3 tells make to run 3 concurrent tasks, which is recommended for DualCore CPUs. Basic rule is -j(number of cores + 1) as recommendation, but beware, gcc takes lots of RAM. ¶
* $ make install -j3 ¶
* this compiles the sources and then installs in either /usr/local (which you need root privileges for), or in the directory mentioned in 2. with -DCMAKE_INSTALL_PREFIX ¶
* -j3 tells make to run 3 concurrent tasks, which is recommended for DualCore CPUs. Basic rule is -j(number of cores + 1) as recommendation, but beware, gcc takes lots of RAM. ¶
* make install includes make, so "make install" is basically the same like "make && make install" ¶

#### 4. Running freshly built widelands ¶
* if you did just "make" ¶
* From your widelands-cmake directory (e.g. "cd ..") ¶
* ./build-cmake/src/widelands ¶
* if you did "make install" and were root ¶
* $ /usr/local/bin/widelands ¶
* if you were not root, used "make install" and specified "-DCMAKE_INSTALL_PREFIX" as above ¶
* cd ~/widelands-cmake-install/share/widelands && ../../bin/widelands
mportant notes ¶
### Things to know about CMake/make ¶
* SCons and CMake use a very different approach on building. With SCons you build within the source path, with CMake you are very obligued not to do so, but build in a different path instead. This is called "out of source build". ¶
* With SCons you only use one command for building, with CMake you use two. CMake is a tool to generate Makefiles, which are then used to build. So it is "scons" vs. "cmake;make". But don't worry, most of the time you don't need to think about this. ¶

### Things to know about the transition ¶
* CMake transition is now on the main repository (bzr) in Launchpad. If you check out from there, and build using scons, you can also try building using cmake/make ¶

### Starting with CMake in the transition (this is for Linux; Windows will differ) ¶
#### 1. Preparation ¶
* Get the sources, as written in BzrPrimer ¶
* $ mkdir widelands-cmake/build-cmake ¶

#### 2. Using CMake ¶
* $ cd ~/widelands-cmake/build-cmake ¶
* go to the build directory ¶
* $ cmake .. ¶
* let CMake create the Makefiles in the current directory, regarding the CMakeLists.txt files in the parent (widelands-cmake) directory (this is out-of-source) ¶
* $ cmake -DCMAKE_INSTALL_PREFIX=~/widelands-cmake-install .. ¶
* if you want to have a different install directory for "make install" instead of /usr/local ¶

#### 3. Using make ¶
* $ cd ~/widelands-cmake/build-cmake ¶
* go to the build directory ¶
* $ make -j3 ¶
* this compiles the sources ¶
* -j3 tells make to run 3 concurrent tasks, which is recommended for DualCore CPUs. Basic rule is -j(number of cores + 1) as recommendation, but beware, gcc takes lots of RAM. ¶
* $ make install -j3 ¶
* this compiles the sources and then installs in either /usr/local (which you need root privileges for), or in the directory mentioned in 2. with -DCMAKE_INSTALL_PREFIX ¶
* -j3 tells make to run 3 concurrent tasks, which is recommended for DualCore CPUs. Basic rule is -j(number of cores + 1) as recommendation, but beware, gcc takes lots of RAM. ¶
* make install includes make, so "make install" is basically the same like "make && make install" ¶

#### 4. Running freshly built widelands ¶
* if you did just "make" ¶
* From your widelands-cmake directory (e.g. "cd ..") ¶
* ./build-cmake/src/widelands ¶
* if you did "make install" and were root ¶
* $ /usr/local/bin/widelands ¶
* if you were not root, used "make install" and specified "-DCMAKE_INSTALL_PREFIX" as above ¶
* cd ~/widelands-cmake-install/share/widelands && ../../bin/widelands ¶

## Identified Tasks ¶
### Transition tasks ¶
* Identify SCons tasks and targets used by widelands, replace using cmake & make ¶
* scons ¶
* make ¶
* scons -c ¶
* make clean ¶
* scons doc ¶
* make doc (no dependency to make) ¶
* make install (no scons target?) ¶
* CMake 2.6 should be used. Do we need CMake 2.8? ¶
* Identify bugs/improvements from bug tracker and mailing list ¶
* Identify additional tasks, build tools etc. ¶
* build/scons-tools/Distribute.py ¶
* Script for packaging a complete binary distribution (Release?) ¶
* Scons and Python tool ¶
* proposal: make package with new CMake script ¶
###Issues ¶
* Running widelands writes to console: "WARNING: either we can not detect your home directory or you do not have one! Please contact the developers. Instead of your home directory, '.' will be used. Set home directory: ./.widelands". There's something missing. ¶
* Found the problem. config.h.cmake is missing #define HAS_GETENV which is done by Scons. Can we set this in any case? How does Windows react to that? ¶
* done in SVN/BZR, awaiting testers ¶
* Changing language doesn't work. English only. ¶
* Found the problem. The locales do not get compiled. Doesn't work on the fly because of out-of-source build (cmake) conflicting with the script which creates the locales (expects to be run from base dir and writes there). Either modify script or find a way to run it out-of-source. ¶
* Hopefully we will use Launchpad translation so this becomes not an issue anymore. ¶
* Finding doxygen works. Test with non-working doxygen and about working doxygen without dot to be done. ¶
* Find some Windows/MinGW system to test. ¶
* Do we really need 3 tools to optimize the PNG files? pngrewrite, optipng and advdef? ¶
* "make pics" needs testers for Windows and Darwin, trying to find pngrewrite and optipng. ¶
* CPack issue with path names and components package, always generating empty assemblies. ¶
* Either we get that sorted out, or we'd have to write own packaging scripts (not nice) ¶

## Build systems for testing ¶
### System1 (maintained by Qcumber-some) ¶
* Intel Core2 Duo, Gentoo Linux 32bit ¶
* gcc 4.3.4, cmake 2.6, libsdl 1.2.13, lua 5.1.4, boost 1.35