linux/arch/arm/Kbuild
Masahiro Yamada b1992c3772 kbuild: use $(src) instead of $(srctree)/$(src) for source directory
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).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-10 04:34:52 +09:00

15 lines
396 B
Makefile

# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_FPE_NWFPE) += nwfpe/
# Put arch/arm/fastfpe/ to use this.
obj-$(CONFIG_FPE_FASTFPE) += $(patsubst $(src)/%,%,$(wildcard $(src)/fastfpe/))
obj-$(CONFIG_VFP) += vfp/
obj-$(CONFIG_XEN) += xen/
obj-$(CONFIG_VDSO) += vdso/
obj-y += kernel/ mm/ common/
obj-y += probes/
obj-y += net/
obj-y += crypto/
# for cleaning
subdir- += boot