KDE/kdelibs

[Alexander Neundorf]

Hi Harald,

On Saturday 20 February 2010, Harald Fernengel wrote:
> SVN commit 1093415 by harald:
>
> Bring Cross compilation to kdelibs

nice that you are working on this :-)

But there are several things which should be done differently.
Posting the patches for review first would have been nice actually.
Comments below...

> With these changes, I was able to cross-compile kdelibs for Maemo 5
> using MADDE.  See http://techbase.kde.org/Projects/KDE_on_Maemo/MADDE
> for more details.
>
> CCMAIL: kde-maemo at kde.org
>
>  M  +3 -1      CMakeLists.txt
>  M  +2 -2      cmake/modules/FindKDE4Internal.cmake
>  M  +19 -0     cmake/modules/KDE4Macros.cmake
>  M  +16 -6     kdecore/kconfig_compiler/CMakeLists.txt
>  M  +20 -10    kdoctools/CMakeLists.txt
>  M  +20 -13    kjs/CMakeLists.txt
>
>
> --- trunk/KDE/kdelibs/cmake/modules/FindKDE4Internal.cmake #1093414:1093415
> @@ -1159,7 +1159,7 @@
>        string(REGEX MATCH "(--enable-libstdcxx-allocator=mt)"
> _GCC_COMPILED_WITH_BAD_ALLOCATOR "${_gcc_alloc_info}") endif
> (GCC_IS_NEWER_THAN_4_1)
>
> -   if (__KDE_HAVE_GCC_VISIBILITY AND GCC_IS_NEWER_THAN_4_1 AND NOT
>         _GCC_COMPILED_WITH_BAD_ALLOCATOR AND NOT WIN32) 
> +   if (__KDE_HAVE_GCC_VISIBILITY AND GCC_IS_NEWER_THAN_4_1 AND NOT
>         _GCC_COMPILED_WITH_BAD_ALLOCATOR AND NOT WIN32 AND NOT
>         CMAKE_CROSSCOMPILING)
> set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")
> set (KDE4_C_FLAGS "-fvisibility=hidden")


Why do you need the NOT CMAKE_CROSSCOMPILING here ?
I think there must be some actual condition which should be tested against.

> --- trunk/KDE/kdelibs/cmake/modules/KDE4Macros.cmake #1093414:1093415
> @@ -106,6 +106,12 @@
>             file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${_rel_PATH})
>         endif(NOT EXISTS "${CMAKE_CURRENT_BINARY_DIR}/${_rel_PATH}")
>
> +       if (CMAKE_CROSSCOMPILING)
> +           set(IMPORT_KCONFIG_COMPILER_EXECUTABLE
> "${KDE_HOST_TOOLS_PATH}/ImportKConfigCompilerExecutable.cmake" CACHE
> FILEPATH "Point it to the export file of kconfig_compiler from a native
> build")
> +           include(${IMPORT_KCONFIG_COMPILER_EXECUTABLE})
> +           set(KDE4_KCFGC_EXECUTABLE kconfig_compiler)
> +       endif (CMAKE_CROSSCOMPILING)
> +
>         # the command for creating the source file from the kcfg file
>         add_custom_command(OUTPUT ${_header_FILE} ${_src_FILE}
>            COMMAND ${KDE4_KCFGC_EXECUTABLE}


Ok, this part needs to be changed, along with all other places where such an 
import-file is included. For more see below.


> trunk/KDE/kdelibs/kdecore/kconfig_compiler/CMakeLists.txt #1093414:1093415
> @@ -1,18 +1,28 @@
>
>  ########### next target ###############
>
> -set(kconfig_compiler_SRCS kconfig_compiler.cpp)
> +if (CMAKE_CROSSCOMPILING)
> +   SET(IMPORT_KCONFIG_COMPILER_EXECUTABLE
> "${KDE_HOST_TOOLS_PATH}/ImportKConfigCompilerExecutable.cmake" CACHE
> FILEPATH "Point it to the export file of kconfig_compiler from a native
> build") 
> +   INCLUDE(${IMPORT_KCONFIG_COMPILER_EXECUTABLE})
> +   SET(KDE4_KCFGC_EXECUTABLE kconfig_compiler)
> +else (CMAKE_CROSSCOMPILING)
>
> +   set(kconfig_compiler_SRCS kconfig_compiler.cpp)
>
> -kde4_add_executable(kconfig_compiler NOGUI ${kconfig_compiler_SRCS})
>
> -target_link_libraries(kconfig_compiler  ${QT_QTCORE_LIBRARY}
> ${QT_QTXML_LIBRARY} ) +    kde4_add_executable(kconfig_compiler NOGUI
> ${kconfig_compiler_SRCS})
>
> -# "export" this target too so we can use the LOCATION property of the
> imported target in 
> -# FindKDE4Internal.cmake to get the full path to the
> installed executable instead of using FIND_PROGRAM(), Alex 
> -install(TARGETS
> kconfig_compiler EXPORT kdelibsToolsTargets ${INSTALL_TARGETS_DEFAULT_ARGS}
> ) 
> +    target_link_libraries(kconfig_compiler  ${QT_QTCORE_LIBRARY}
> ${QT_QTXML_LIBRARY} )
>
> +    # "export" this target too so we can use the LOCATION property of the
> imported target in 
> +    # FindKDE4Internal.cmake to get the full path to
> the installed executable instead of using FIND_PROGRAM(), Alex 
> +   install(TARGETS kconfig_compiler EXPORT kdelibsToolsTargets
> ${INSTALL_TARGETS_DEFAULT_ARGS} )
>
> +    # export this binary for cross-compilation
> +    EXPORT(TARGETS kconfig_compiler FILE
> ${CMAKE_BINARY_DIR}/ImportKConfigCompilerExecutable.cmake) 
> +endif(CMAKE_CROSSCOMPILING)

This should not be done.
As you have seen, there is already an export set with all the tools from 
kdelibs created, named kdelibsToolsTargets and installed 
as "KDELibs4ToolsTargets.cmake".

This file should be included in the cross compiling case, and the targets from 
it should be used in the custom commands.
This should be done in FindKDE4Internal.cmake, where all the executables are 
set up.
In the toplevel CMakeLists.txt of kdelibs a custom target 
like "BuildKDELibs4Tools" should be created, and via add_dependencies() all 
the executables which belong to this should be added as dependencies, so you 
can just do "make BuildKDELibs4Tools" and it will build all these tools.

The logic not to build a native kconfig_compiler for e.g. ARM in the cross 
compiling case is probably ok, we will see.

So, main point: try to use the existing KDELibs4ToolsTargets.cmake, include it 
in FindKDE4Internal.cmake and set the KDE4_xxx_EXECUTABLE variables there 
accordingly.

Alex