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

[Krzysztof Kozlowski]

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.

Best regards,
Krzysztof