Re: [PATCH 4/4] kbuild: use $(src) instead of $(srctree)/$(src) for source directory
From: Rob Herring
Date: Thu Apr 18 2024 - 09:43:57 EST
On Tue, Apr 16, 2024 at 09:18:38PM +0900, 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 match the directory in the source tree. It still works because the
> top Makefile sets VPATH to $(srctree). However, VPATH does not cover
> all cases. There are many places where the exact path to the source
> directory is needed. For example, when adding a header search path for
> local headers, it is typical to pass -I$(srctree)/$(src) to the compiler.
>
> However, it introduces inconsistency between upstream Makefiles and
> downstream Makefiles; when the source directory path is needed,
> $(srctree)/$(src) is used in the upstream kernel, while $(src) is used
> in external modules.
>
> To resolve the distortion, 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 work as follows:
>
> $(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
>
> This is a tweewide Makefile conversion for replacing $(srctree)/$(src)
> with $(src).
>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
> Documentation/Makefile | 8 ++++----
> Documentation/devicetree/bindings/Makefile | 10 +++++-----
Acked-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
However, this is going to conflict with my series here[1]. Can you pick
it up?
Rob
[1] https://lore.kernel.org/all/20240405-dt-kbuild-rework-v2-0-3a035caee357@xxxxxxxxxx/