Re: [PATCH v2 4/4] kbuild: use $(src) instead of $(srctree)/$(src) for source directory

From: Masahiro Yamada
Date: Thu May 09 2024 - 15:37:21 EST


On Thu, May 9, 2024 at 5:59 PM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
>
> On 27/04/2024 16:55, Masahiro Yamada wrote:
> > Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
> > checked-in source files. It is merely a convention without any functional
> > difference. In fact, $(obj) and $(src) are exactly the same, as defined
> > in scripts/Makefile.build:
> >
> > src := $(obj)
> >
> > When the kernel is built in a separate output directory, $(src) does
> > not accurately reflect the source directory location. While Kbuild
> > resolves this discrepancy by specifying VPATH=$(srctree) to search for
> > source files, it does not cover all cases. For example, when adding a
> > header search path for local headers, -I$(srctree)/$(src) is typically
> > passed to the compiler.
> >
> > This introduces inconsistency between upstream and downstream Makefiles
> > because $(src) is used instead of $(srctree)/$(src) for the latter.
> >
> > To address this inconsistency, this commit changes the semantics of
> > $(src) so that it always points to the directory in the source tree.
> >
> > Going forward, the variables used in Makefiles will have the following
> > meanings:
> >
> > $(obj) - directory in the object tree
> > $(src) - directory in the source tree (changed by this commit)
> > $(objtree) - the top of the kernel object tree
> > $(srctree) - the top of the kernel source tree
> >
> > Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
> > with $(src).
> >
>
> This patch, since yesterday's next, causes build issues with my
> (completely) standard and typical workflow:
>
> alias crosc64='CROSS_COMPILE="ccache aarch64-linux-gnu-" ARCH=arm64 KBUILD_OUTPUT=out/'
> crosc64 make defconfig
> crosc64 make dt_binding_check
>
> Errors:
>
> No rule to make target 'Documentation/devicetree/bindings/i3c/snps,dw-i3c-master.example.dtb', needed by 'dt_binding_check'. Stop.
>
> Please revert/drop from next.


Or, fix the code.


Now fixed. Thanks for the report.




--
Best Regards
Masahiro Yamada