[Buildroot] Making the Meson integration compatible with per-package folders

[Peter Seiderer]

Hello Thomas,

On Fri, 16 Nov 2018 16:48:59 +0100, Thomas Petazzoni <thomas.petazzoni at bootlin.com> wrote:

> Eric, Peter,
> 
> I don't know if you have followed the discussion, but I recently sent a
> new iteration of the per-package folder series [1], which allows to
> support top-level parallel build.

Not in details (and did no test the patches yet)...

> 
> Currently the Meson integration in Buildroot doesn't work with this
> per-package folder stuff.
> 
> The initial issue is that:
> 
>    --cross-file=$(HOST_DIR)/etc/meson/cross-compilation.conf
> 
> should be:
> 
>    --cross-file=$$(HOST_DIR)/etc/meson/cross-compilation.conf
> 
> But of course, behind that, there's a bigger issue: this
> cross-compilation.conf hardcodes the compiler path, library path, etc.
> However, with per-package folders, we really need to use the compiler
> and libraries from the per-package folder of the current package.
> 
> To achieve this, we will need to generate a per-package
> cross-compilation.conf, which is something Peter was already proposing
> in http://patchwork.ozlabs.org/patch/946599/. However, compared to this
> patch, we would need:
> 
>  (1) Replacing not only the CFLAGS, but also the compiler/library paths.
> 

First draft version:

    http://patchwork.ozlabs.org/patch/999406/

Maybe $$($$(PKG)_SRCDIR) could be exchanged with $$(HOST_DIR)...

>  (2) Producing a final cross-compilation.conf, which can be used by
>      people using the toolchain outside of Buildroot.
> 

No problem, just keep the original code in package/meson/meson.mk?

Regards,
Peter

> I am sending this e-mail to see if you are willing/available to help on
> this, or if you would like me to take over this work and propose a
> patch series.
> 
> Thanks a lot!
> 
> Thomas
> 
> [1] http://patchwork.ozlabs.org/project/buildroot/list/?series=75909