[Buildroot] [PATCH v1, next] package/llvm-project/compiler-rt: fix build with Ninja

[Thomas Petazzoni]

On Tue, 8 Aug 2023 13:22:21 +0200
Thomas Devoogdt <thomas at devoogdt.com> wrote:

> > Not sure to understand: the default backend for CMake is still
> > makefiles, and compiler-rt was not switched to using ninja. So?  
> 
> No, ninja is not yet the default.
> Yann did some tests to find out if it makes sense to make ninja the default.
> If only a few packages break on it, then we can force them to use make.
> But if there are too many of them, then we can just keep make as the default.
> 
> Either way, see this mail:
> https://lore.kernel.org/buildroot/20230806205447.GW421096@scaer/,
> where Yann told me that compiler-rt fails on ninja, so that's the
> reason for the patch.

Right, but changing compiler-rt to use out of tree build makes sense
together with switching to ninja. So in the same patch, you should have:

COMPILER_RT_SUPPORTS_IN_SOURCE_BUILD = NO
COMPILER_RT_CMAKE_BACKEND = ninja

And then later, when we are ready to make ninja the default backend of
cmake, we can remove in one batch all "<pkg>_CMAKE_BACKEND = ninja"
statements from all packages. We can also progressively mark as
"<pkg>_CMAKE_BACKEND = make" the packages that we know are not
compatible with ninja.

At least, that's how I see the transition period. What do you think?

Thomas
-- 
Thomas Petazzoni, co-owner and CEO, Bootlin
Embedded Linux and Kernel engineering and training
https://bootlin.com