[cmake-developers] [CMake] CMake 2.8.3-rc1 ready for testing!

[Clinton Stimpson]

On Thursday, September 23, 2010 02:01:40 pm Alexander Neundorf wrote:
> On Thursday 23 September 2010, Clinton Stimpson wrote:
> > On Thursday, September 23, 2010 01:40:02 pm Alexander Neundorf wrote:
> ...
> 
> > > This was committed here:
> > > http://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=b55da4c688bbf55b4429
> > > 08
> > >
> > >46 4e0f7e2e41c937a3 which has as commit message "Add cross-compiling
> > >
> > > support to FindQt4.cmake"
> > > 
> > > What speaks against adding the NO_DEFAULT_PATH again ?
> > 
> > It was removed so it would be possible to use CMAKE_PREFIX_* for cross-
> > compiling with Qt.  This is because the output of "qmake -query" cannot
> > be relied on when cross-compiling, because it only has native Qt paths.
> 
> We assume that the qmake which is found belongs to the Qt which is wanted,
> right ? This qmake is, also when crosscompiling, a native host binary in
> general, right ? Because I guess when cross compiling with qmake (not
> cmake), this qmake is used to generate the makefiles for cross compiling.
> And this one really reports the library dir for the host, not for the
> cross compiling target ?

Where is one getting this kind of setup?  I'm not aware of qmake supporting 
cross compiling (I thought jumping through hoops was the only way to get 
there).
I've done this kind of setup before and it required extra compiles and 
modifying Qt installations.  I've told others they can do it this way, but I 
got push back.

The setup which I was trying to support was a native Qt install, with a non-
native Qt install copied from another machine.  So one can pick pieces from 
both installations, and use the native binaries.  I think this is a more 
general setup.

> 
> How about something like this:
> 
> GET_FILENAME_COMPONENT(_qt_base_dir ${QT_QMAKE_EXECUTABLE} PATH)
> GET_FILENAME_COMPONENT(_qt_base_dir ${_qt_base_dir} PATH)
> ...
> FIND_LIBRARY(QT_QTCORE_LIBRARY_RELEASE
>              NAMES QtCore${QT_LIBINFIX} QtCore${QT_LIBINFIX}4
>              HINTS ${QT_LIBRARY_DIR_TMP} ${_qt_base_dir}/lib
>              NO_DEFAULT_PATH )
>     )
> 
> I.e. we check only in the directory reported by qmake and additionally in
> {qmake_dir}/../lib/ ? The order of the two could also be exchanged.

That wouldn't work for the setup I was testing with.
Maybe we can do 2 find_library() calls.  The first with NO_DEFAULT_PATH, and the 
second without.

Clint

> 
> > So are you saying the problem only comes up if CMAKE_PREFIX_PATH contains
> > the root directory of a Qt installation that you don't want to use, and
> > QT_QMAKE_EXECUTABLE is set to the qmake of the installation you want to
> > use?
> 
> Yes.
> 
> Alex