b1992c3772
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>
18 lines
357 B
Makefile
18 lines
357 B
Makefile
# SPDX-License-Identifier: GPL-2.0-or-later
|
|
#
|
|
# Copyright (c) 2019 Oracle.
|
|
# All Rights Reserved.
|
|
#
|
|
|
|
ccflags-y += -I $(src) # needed for trace events
|
|
|
|
obj-$(CONFIG_FS_IOMAP) += iomap.o
|
|
|
|
iomap-y += trace.o \
|
|
iter.o
|
|
iomap-$(CONFIG_BLOCK) += buffered-io.o \
|
|
direct-io.o \
|
|
fiemap.o \
|
|
seek.o
|
|
iomap-$(CONFIG_SWAP) += swapfile.o
|