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linux/scripts/Makefile.clean
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

64 lines
1.9 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
# ==========================================================================
# Cleaning up
# ==========================================================================
src := $(if $(VPATH),$(VPATH)/)$(obj)
PHONY := __clean
__clean:
include $(srctree)/scripts/Kbuild.include
include $(kbuild-file)
# Figure out what we need to build from the various variables
# ==========================================================================
subdir-ymn := $(sort $(subdir-y) $(subdir-m) $(subdir-) \
$(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m) $(obj-))))
# Add subdir path
subdir-ymn := $(addprefix $(obj)/,$(subdir-ymn))
# build a list of files to remove, usually relative to the current
# directory
__clean-files := \
$(clean-files) $(targets) $(hostprogs) $(userprogs) \
$(extra-y) $(extra-m) $(extra-) \
$(always-y) $(always-m) $(always-) \
$(hostprogs-always-y) $(hostprogs-always-m) $(hostprogs-always-) \
$(userprogs-always-y) $(userprogs-always-m) $(userprogs-always-)
__clean-files := $(filter-out $(no-clean-files), $(__clean-files))
__clean-files := $(wildcard $(addprefix $(obj)/, $(__clean-files)))
# ==========================================================================
# To make this rule robust against "Argument list too long" error,
# remove $(obj)/ prefix, and restore it by a shell command.
quiet_cmd_clean = CLEAN $(obj)
cmd_clean = printf '$(obj)/%s ' $(patsubst $(obj)/%,%,$(__clean-files)) | xargs rm -rf
__clean: $(subdir-ymn)
ifneq ($(strip $(__clean-files)),)
$(call cmd,clean)
endif
@:
# ===========================================================================
# Generic stuff
# ===========================================================================
# Descending
# ---------------------------------------------------------------------------
PHONY += $(subdir-ymn)
$(subdir-ymn):
$(Q)$(MAKE) $(clean)=$@
.PHONY: $(PHONY)