[PATCH RFC 01/12] kbuild: create destination directory for _shipped handling

[Masahiro Yamada]

On Mon, Feb 26, 2024 at 8:01 PM Dmitry Baryshkov
<dmitry.baryshkov at linaro.org> wrote:
>
> On Mon, 26 Feb 2024 at 08:33, Masahiro Yamada <masahiroy at kernel.org> wrote:
> >
> > On Mon, Feb 26, 2024 at 11:11 AM Dmitry Baryshkov
> > <dmitry.baryshkov at linaro.org> wrote:
> > >
> > > The driver might decide to put the _shipped files to the subdir.
> >
> >
> >
> > Please stop this sentence.
> >
> > This sounds like we are not learning.
> >
> > https://lore.kernel.org/all/CAHk-=wgSEi_ZrHdqr=20xv+d6dr5G895CbOAi8ok+7-CQUN=fQ@mail.gmail.com/
> >
> >
> >
> >
> > > In such
> > > case the cmd_copy might fail because the destination directory is not
> > > present. Call mkdir -p to make sure that the destination directory is
> > > present.
> >
> >
> > There is no justification for this.
> >
> > If you need a single generated directory
> > (drivers/gpu/drm/msm/registers/, divers/gpu/drm/msm/generated/ or whatever)
> > that should be super simple.
> >
> > Why does scripts/Makefile.lib need the modification?
>
> Could you please tell me how I should handle this?
> I was looking for a way to generate
> drivers/gpu/drm/msm/registers/foo.xml.h and then use it during
> compilation.
> In drivers/gpu/drm/msm/Makefile I added $(obj)/registers/foo.xml.h as
> a dependency to the corresponding object files and then added
> drivers/gpu/drm/msm/registers/foo.xml.h_shipped file.
> This way Kbuild/make will attempt to call cmd_copy to generate target
> file, which thanks to VPATH expansion boils down to `cat
> $(srctree)/$(src)/registers/foo.xml.h_shopped >
> $(obj)/registers/foo.xml.h`. However this breaks as there is no
> $(obj)/registers.
>



One simple solution is to use $(shell mkdir -p ...)
to create the output directory.

scripts/Makefile.build does a similar thing.



You can add the following to drivers/gpu/drm/msm/Makefile.



# Create output directory when CONFIG_DRM_MSM is defined.
# This avoids creating the output directory during 'make clean'
ifdef CONFIG_DRM_MSM
$(shell mkdir -p $(obj)/registers)
endif











-- 
Best Regards
Masahiro Yamada