[Buildroot] [PATCH v2 1/1] package/pkg-cmake: Use CMAKE_<LANG>_COMPILER_LAUNCHER for ccache

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello,

On Tue, 14 Mar 2017 09:24:25 +1100, Daniel Black wrote:

> > On 09-03-17 06:07, Daniel Black wrote:  
> >> Since cmake version 3.4.0 CMAKE_<LANG>_COMPILER_LAUNCHER is used as
> >> the way to invoke things like ccache. We set this to ccache for
> >> the host and for cross compilers in toolchain.cmake.in. This
> >> leaves CMAKE_<C,CXX>_COMPILER pointing at the real compiler and
> >> still uses ccache.
> >>
> >> Update minimium dependency version in check-host-cmake.mk accordingly.  
> > 
> >  This is very unfortunate, it means a substantial slowdown in the build for
> > people who have an older system CMake.  
> 
> I didn't think it was that substantial for a one-off host package
> upgrade. I do realize it is a non-zero imposition for that installed
> cmake before it was updated to 3.4.0 in
> 7453c4bf6010b3a8dd794c39e327641abea15503 (Nov 13 2015).
> 
> >  Although it is indeed cleaner to handle ccache this way, I don't think it
> > really fixes anything, does it?  
> 
> Might fix some subtle build errors for packages that do odd things
> however no, there isn't an definite breakage I can point to.
> 
> > In that case, I think we should just stick with
> > the old way of doing things. We can revisit when we need to CMake 3.4 for some
> > other package.  
> 
> Works for me.

Thanks for your feedback, and to Arnout for reviewing the patch.
Following your discussion, I've marked the patch as "Rejected" in
patchwork.

Best regards,

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