[CMake] Cross-compilation vs FindQt4.cmake

[Alexander Neundorf]

Hi Andrey,

On Thursday 27 May 2010, Andrey. wrote:
> Hi Alexander,
>
> I would like to know whether there is some progress on making FindQt4.cmake
> friends with cross-compilation.

Not much, unfortunately.

> I've read a discussion for this topic at [1] and [2].
> Also, at your blog, you wrote [3], that Harald Fernengel doing some work on
> this. I looked at cmake and KDE repositories, but didn't find any progress
> there. Maybe you could just point an appropriate branch.
>
> Writing to you, as you seems to be a maintainer of FindQt4.cmake in both
> Cmake and KDE repositories.

Well, Clinton Stimpson is the maintainer of FindQt4.cmake in CMake, and I 
mostly merge the fixes there to the version in KDE.
So actually he's the maintainer, but I'm also not the completely wrong person 
here :-)

> Also, I'm interested to know, why FindQt4.cmake doesn't utilize pkg-config
> for most introspection of Qt. Qt4 provides nice .pc files.
>
> pkg-config has some built-in support for cross-compilation through
> PKG_CONFIG_SYSROOT_DIR and PKG_CONFIG_LIBDIR while qmake doesn't. Simply
> compiling qmake to be used during cross-compilation and compiling qmake to
> return correct include/library paths are two different tasks. In first
> case, qmake can be used for multiple cross-compilation environments.

In general, CMake tries not to rely on any additional external tools, and 
pkg-config is one of those tools.

I have (until now) never cross compiled anything with Qt.

How does a typical Qt installation for cross compiling look like ?
I guess it has native tools (qmake, moc, uic), etc.

When FindQt4.cmake is executed, it queries qmake for information. 
Does this also work for a cross-compilation installation of Qt ?
What are the results of a FindQt4.cmake with a cross-compiling qmake ?

> Currently, I'm going to use simple FindQt4.cmake with some hardcoded paths,
> that will override system wide one.
>
> Sorry for writing you directly instead of posting to a mailing list.
> I just wasn't sure to which of cmake or kde-buildsystem mailing lists to
> post. :) I'm all for moving this discussion to a public list.

CC'ing the cmake -list.

Alex