[Buildroot] [PATCH] pacakge/qt5/qt5base: fix build with ccache

[Thomas Petazzoni]

Hello,

On Thu, 27 Aug 2015 10:12:44 +0200, Benoît Thébaudeau wrote:

> > As explained in this report, I think that your suggestion would work
> > for Buildroot (not yet tested), but not for upstream Qt.
> > 
> > My point with this patch was that upstream could consider this
> > Buildroot use case as illegal because the definition of QMAKE_CXX
> > (http://doc.qt.io/qt-5/qmake-variable-reference.html#qmake-cxx) only
> > mentions a filename and a path as possibilities. In that case, the bug
> > is in Buildroot, and since this sanity check of the compiler is not
> > needed for Buildroot, we can just remove this test. If we don't want a
> > local patch for this, maybe we could use a wrapper above ccache, or
> > put ccache into QMAKE_CXX and the compiler into QMAKE_CXXFLAGS (not
> > tested, and a bit ugly).
> > 
> > Wait and see what upstream says.
> 
> Upstream recommends this approach:
> http://lists.qt-project.org/pipermail/qt-creator/2014-January/003148.html
> 
> What do you think?

Well, we already have a wrapper for the compiler in the case of the
external toolchain. And we will probably also extend the wrapper in the
future to the internal toolchain case, in order to support per-package
staging directory. In this case, we could take advantage of this
wrapper to include the ccache functionality, and avoid having CC and
CXX values that have two words.

I really would like to have the wrapper suggested in this e-mail
calling our wrapper, then calling the real compiler.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com