Hi Clint Am 29.07.2015 um 16:47 schrieb Clinton Stimpson: > On Wednesday, July 29, 2015 04:05:41 PM Pascal Bach wrote: >> Hi Clint >> >> Am 29.07.2015 um 15:45 schrieb Clinton Stimpson: >>> Hi Pascal, >>> >>> Thanks for the patches. >>> >>> Can you share with us why setting CMAKE_FIND_ROOT_PATH does not work, or >>> how this new method compares? >>> >>> For example, in the toolchain file: >>> SET(CMAKE_FIND_ROOT_PATH /path/to/Qt ...) >> The problem is how FindQt4 does find the locations using qmake. >> >> let's assume there are two sysroots one is /sysroots/x86_64 which contains >> binaries usable on the host machine, and there is /sysroots/arm which >> contains libraries for the target system. this are both set via: >> set( CMAKE_FIND_ROOT_PATH /sysroots/arm /sysroots/x86_64 ) >> set( CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY ) >> set( CMAKE_FIND_ROOT_PATH_MODE_PROGRAM ONLY ) >> set( CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY ) >> set( CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY ) > Yes, this concern of 2 sysroots has been brought up before. Thanks for > addressing this. > >> Here is what happens when only setting CMAKE_FIND_ROOT_PATH: >> >> 1. FindQt4 is trying to find the qmake executable. As there is no qmake in >> /sysroots/arm (it would not be runnable on the host) it will find qmake >> from the /sysroots/x86_64 directory. 2. FindQt4 is asking qmake for the >> path to the Qt installation. As the qmake found is the one from >> /sysroots/x86_64 it will point to the libraries from /sysroots/x86_64 which >> will obviously not run on arm! >> >> Currently I didn't find a way to override this behaviour of FindQt4, except >> by setting all the variables usually set by FindQt4 manually. It is usually >> accepted to set some variables manually when doing cross compilation. With >> this patchset I tried to reduce this variable to a minumum and let FindQt4 >> figure out the rest. >> >> The minimum variables required with the patch are: >> >> QT_BINARY_DIR is necessary to find the correct qmake >> QT_LIBRARY_DIR is necessary to find the library directory >> QT_INCLUDE_DIR is necessary to find the include directory (might be possible >> to figure this out from QT_INCLUDE_DIR if some assumptions are made) >> QT_MKSPECS_DIR necessary to have the correct prefixes (E in the case of >> qt4-embedded). >> >> >> I hope my explanation is clear. If there is a better way to achive this I'm >> all ears. >> > I'm fine with this, and don't think it'll conflict with any other use cases. I don't see a conflict either. > > However, I do think we should first document setting CMAKE_FIND_ROOT_PATH, > then > afterwards document the other variables for those users which need more > control. Does that sound reasonable? I'm not sure I understand what you mean. I think how to set CMAKE_FIND_ROOT_PATH is already documented in cmake. Are you suggesting extending the docuemntation of FindQt4below with a paragraph documenting how to work with two sysroots? With an example like this?
set( CMAKE_FIND_ROOT_PATH /sysroots/arm /sysroots/x86_64 ) set( CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY ) set( CMAKE_FIND_ROOT_PATH_MODE_PROGRAM ONLY ) set( CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY ) set( CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY ) Pascal > > Clint > >> Pascal >> >>> Clint >>> >>> On Wednesday, July 29, 2015 02:32:48 PM Pascal Bach wrote: >>>> --- >>>> >>>> Modules/FindQt4.cmake | 20 ++++++++++++++++++++ >>>> 1 file changed, 20 insertions(+) >>>> >>>> diff --git a/Modules/FindQt4.cmake b/Modules/FindQt4.cmake >>>> index 9d03378..64c06e1 100644 >>>> --- a/Modules/FindQt4.cmake >>>> +++ b/Modules/FindQt4.cmake >>>> @@ -29,6 +29,26 @@ >>>> >>>> # for a particular executable, set the ``QT4_NO_LINK_QTMAIN`` target >>>> # property to ``TRUE`` on the executable. >>>> # >>>> >>>> +# Cross Compile >>>> +# ^^^^^^^^^^^^^ >>>> +# >>>> +# To find Qt in a cross compile environment set the following variables >>>> in >>>> your toolchain file: +# >>>> +# >>>> +# ``QT_BINARY_DIR`` => Path to native Qt binary directory >>>> +# ``QT_LIBRARY_DIR`` => Path to target Qt library directory >>>> +# ``QT_INCLUDE_DIR`` => Path to target Qt include directory >>>> +# ``QT_MKSPECS_DIR`` => Path to target Qt mkspecs directory >>>> + >>>> +# example >>>> +# >>>> +# :: >>>> +# set( QT_BINARY_DIR /sysroots/x86_64-linux/usr/bin ) >>>> +# set( QT_LIBRARY_DIR /sysroots/arm/usr/lib ) >>>> +# set( QT_INCLUDE_DIR /sysroots/arm/usr/include/qtopia ) >>>> +# set( QT_MKSPECS_DIR /sysroots/arm/usr/share/qtopia/mkspecs ) >>>> +# >>>> +# >>>> >>>> # Qt Build Tools >>>> # ^^^^^^^^^^^^^^ >>>> # -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake-developers
