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 $(src).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
1.5 KiB
SPDX-License-Identifier: GPL-2.0
linux/arch/arm/tools/Makefile
Copyright (C) 2001 Russell King
gen := arch/$(ARCH)/include/generated kapi := $(gen)/asm uapi := $(gen)/uapi/asm syshdr := $(srctree)/scripts/syscallhdr.sh sysnr := $(src)/syscallnr.sh systbl := $(srctree)/scripts/syscalltbl.sh syscall := $(src)/syscall.tbl
gen-y := $(gen)/calls-oabi.S gen-y += $(gen)/calls-eabi.S kapi-hdrs-y := $(kapi)/unistd-nr.h kapi-hdrs-y += $(kapi)/mach-types.h uapi-hdrs-y += $(uapi)/unistd-oabi.h uapi-hdrs-y += $(uapi)/unistd-eabi.h
targets += $(addprefix ../../../,$(gen-y) $(kapi-hdrs-y) $(uapi-hdrs-y))
PHONY += kapi uapi
kapi: $(kapi-hdrs-y) $(gen-y)
uapi: $(uapi-hdrs-y)
Create output directory if not already present
$(shell mkdir -p $(kapi) $(uapi))
quiet_cmd_gen_mach = GEN $@ cmd_gen_mach = $(AWK) -f $(real-prereqs) > $@
$(kapi)/mach-types.h: $(src)/gen-mach-types $(src)/mach-types FORCE $(call if_changed,gen_mach)
quiet_cmd_syshdr = SYSHDR $@
cmd_syshdr = $(CONFIG_SHELL) $(syshdr) --abis common,$*
--offset __NR_SYSCALL_BASE $< $@
quiet_cmd_systbl = SYSTBL $@ cmd_systbl = $(CONFIG_SHELL) $(systbl) --abis common,$* $< $@
quiet_cmd_sysnr = SYSNR $@ cmd_sysnr = $(CONFIG_SHELL) $(sysnr) $< $@
$(uapi)/unistd-%.h: $(syscall) $(syshdr) FORCE $(call if_changed,syshdr)
$(kapi)/unistd-nr.h: $(syscall) $(sysnr) FORCE $(call if_changed,sysnr)
$(gen)/calls-%.S: $(syscall) $(systbl) FORCE $(call if_changed,systbl)