android_kernel_motorola_sm6225/scripts/Makefile.clean
Sam Ravnborg db8c1a7b2c kbuild: fix building external modules
kbuild failed to locate Makefile for external modules.
This brought to my attention how the variables for directories
have different values in different usage scenarios.

Different kbuild usage scenarios:
make       - plain make in same directory where kernel source lives
make O=    - kbuild is told to store output files in another directory
make M=    - building an external module
make O= M= - building an external module with kernel output seperate from src

Value assigned to the different variables:

           |$(src)          |$(obj) |$(srctree)        |$(objtree)
make       |reldir to k src |as src |abs path to k src |abs path to k src
make O=    |reldir to k src |as src |abs path to k src |abs path to output dir
make M=    |abs path to src |as src |abs path to k src |abs path to k src
make O= M= |abs path to src |as src |abs path to k src |abs path to k output

path to kbuild file:

make       | $(srctree)/$(src), $(src)
make O=    | $(srctree)/$(src)
make M=    | $(src)
make O= M= | $(src)

From the table above it can be seen that the only good way to find the
home directory of the kbuild file is to locate the one of the two variants
that is an absolute path. If $(src) is an absolute path (starts with /)
then use it, otherwise prefix $(src) with $(srctree).

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-07-27 22:11:01 +02:00

96 lines
3 KiB
Makefile

# ==========================================================================
# Cleaning up
# ==========================================================================
src := $(obj)
.PHONY: __clean
__clean:
# Shorthand for $(Q)$(MAKE) scripts/Makefile.clean obj=dir
# Usage:
# $(Q)$(MAKE) $(clean)=dir
clean := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.clean obj
# The filename Kbuild has precedence over Makefile
kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
include $(if $(wildcard $(kbuild-dir)/Kbuild), $(kbuild-dir)/Kbuild, $(kbuild-dir)/Makefile)
# Figure out what we need to build from the various variables
# ==========================================================================
__subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
subdir-y += $(__subdir-y)
__subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
subdir-m += $(__subdir-m)
__subdir-n := $(patsubst %/,%,$(filter %/, $(obj-n)))
subdir-n += $(__subdir-n)
__subdir- := $(patsubst %/,%,$(filter %/, $(obj-)))
subdir- += $(__subdir-)
# Subdirectories we need to descend into
subdir-ym := $(sort $(subdir-y) $(subdir-m))
subdir-ymn := $(sort $(subdir-ym) $(subdir-n) $(subdir-))
# Add subdir path
subdir-ymn := $(addprefix $(obj)/,$(subdir-ymn))
# build a list of files to remove, usually releative to the current
# directory
__clean-files := $(extra-y) $(EXTRA_TARGETS) $(always) \
$(targets) $(clean-files) \
$(host-progs) \
$(hostprogs-y) $(hostprogs-m) $(hostprogs-)
# as clean-files is given relative to the current directory, this adds
# a $(obj) prefix, except for absolute paths
__clean-files := $(wildcard \
$(addprefix $(obj)/, $(filter-out /%, $(__clean-files))) \
$(filter /%, $(__clean-files)))
# as clean-dirs is given relative to the current directory, this adds
# a $(obj) prefix, except for absolute paths
__clean-dirs := $(wildcard \
$(addprefix $(obj)/, $(filter-out /%, $(clean-dirs))) \
$(filter /%, $(clean-dirs)))
# ==========================================================================
quiet_cmd_clean = CLEAN $(obj)
cmd_clean = rm -f $(__clean-files)
quiet_cmd_cleandir = CLEAN $(__clean-dirs)
cmd_cleandir = rm -rf $(__clean-dirs)
__clean: $(subdir-ymn)
ifneq ($(strip $(__clean-files)),)
+$(call cmd,clean)
endif
ifneq ($(strip $(__clean-dirs)),)
+$(call cmd,cleandir)
endif
ifneq ($(strip $(clean-rule)),)
+$(clean-rule)
endif
@:
# ===========================================================================
# Generic stuff
# ===========================================================================
# Descending
# ---------------------------------------------------------------------------
.PHONY: $(subdir-ymn)
$(subdir-ymn):
$(Q)$(MAKE) $(clean)=$@
# If quiet is set, only print short version of command
cmd = @$(if $($(quiet)cmd_$(1)),echo ' $($(quiet)cmd_$(1))' &&) $(cmd_$(1))