Development/CMake KDE 4 5

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Changes in the buildsystem from KDE 4.4 to KDE 4.5

Starting with KDE 4.5, CMake >= 2.6.4 is required.

Incompatible Changes

FindQt4.cmake: Imported Targets for the libraries

Other Changes

Required CMake version

Starting with KDE 4.5, CMake >= 2.6.4 is required (KDE 4.2 to 4.4 required 2.6.2).

Commit Policy for kdelibs/cmake/modules/

The commit policy introduced during the 4.3 development cycle is still active and must be followed.

Major FindQt4.cmake improvements

A lot of work went into FindQt4.cmake. This includes:

  • Synced with FindQt4.cmake from CMake 2.8.0. Our version and the one shipped with CMake 2.8.0 are now almost identical again, there are only a bunch of minor differences left.
  • Support for Qt 4.6 added. I.e. support for the QtMultimedia and QtScriptTools libraries has been added.
  • Support for ActiveQt (Windows only) has been added.
  • Improved support for Mac OSX, including Qt installed as frameworks
  • Improved support for Windows, including handling release/debug libraries (see "Imported targets")
  • Support for static Qt libraries and the UseQt.cmake file fixed.
  • FindQt4.cmake has been split into FindQt4.cmake, Qt4Macros.cmake and Qt4ConfigDependentSettings.cmake.
  • Improved support for flexible Qt install locations under Windows (see "Imported targets")

Imported Targets

FindQt4.cmake now creates an imported library target for each of the Qt libraries which has been found. These imported targets can then be used like "normal" targets in CMakeLists.txt, e.g. in TARGET_LINK_LIBRARIES(). These imported targets are named "Qt4::<library name>", e.g. Qt4::QtCore or Qt4::QtGui. This brings several advantages:

  • one imported library can have different locations for different buildtypes, i.e. for debug builds its IMPORTED_LOCATION_DEBUG property can point to the debug version of the library, while its IMPORTED_LOCATION_RELEASE property can point to the release version of the library
  • If some library kfoo links against such an imported Qt4 library, and kfoo is exported, the export file will list Qt4::QtCore etc. as dependency, and not the absolute file path to the QtCore library. This has the big advantage, that the location of the QtCore library (and the other Qt libraries) is resolved at cmake-time of the software which uses kfoo, and not fixed to the location of QtCore where it was when kfoo was built. This is especially helpful for installing and building against KDE on Windows.

If the variable QT_USE_IMPORTED_TARGETS is set to TRUE before FindQt4.cmake is executed, also the Qt library variables like QT_QTCORE_LIBRARY are set to point to these imported targets instead to the file path. This is the case automatically when doing a find_package(KDE4).

New libraries: kemoticons, kidletime, kcmutils and kprintutils

With KDE 4.5 3 four new libraries were added to kdelibs: the kemoticons library, the kidletime library, the kcmutils library and the kprintutils library. These libraries come with their associated variables. So if you want to link against these libraries, use ${KDE4_KEMOTICONS_LIBS}, ${KDE4_KIDLETIME_LIBS}, ${KDE4_KCMUTILS_LIBS} and ${KDE4_KPRINTUTILS_LIBS} respectively. They don't require an additional include directory.

Improved RPATH settings

In the previous releases of KDE 4, the library installation directory was always added to the RPATH of libraries and executables. With KDE 4.5 this is now only done if the library installation directory is not one of the system default library directories. This means that e.g. /usr/lib is not added anymore to the RPATH.

Other minor changes

  • A cache variable KDE4_SERIALIZE_TOOL has been added. It is empty by default,

but you can set it to a tool to serialize resource-intensive commands in parallel builds.

  • Some improvements to make cross compiling KDE easier were committed to FindKDE4Internal.cmake, but we are still not ready for cross compiling.
  • The documentation was improved, e.g. the macro KDE4_ADD_APP_ICON() was undocumented before.

New Modules

Some completely new installed modules have been added during this cycle:

  • FindDBusMenuQt.cmake

Also added were FindDocBookXML.cmake and FindDocBookXSL.cmake, but both are used only internally inside kdelibs and both are not installed.

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