linux/scripts/Makefile.clean
Paul Smith 4f1933620f kbuild: change kbuild to not rely on incorrect GNU make behavior
The kbuild system takes advantage of an incorrect behavior in GNU make.
Once this behavior is fixed, all files in the kernel rebuild every time,
even if nothing has changed.  This patch ensures kbuild works with both
the incorrect and correct behaviors of GNU make.

For more details on the incorrect behavior, see:

http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html

Changes in this patch:
  - Keep all targets that are to be marked .PHONY in a variable, PHONY.
  - Add .PHONY: $(PHONY) to mark them properly.
  - Remove any $(PHONY) files from the $? list when determining whether
    targets are up-to-date or not.

Signed-off-by: Paul Smith <psmith@gnu.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-03-06 00:09:51 +01:00

102 lines
3.2 KiB
Text

# ==========================================================================
# 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))
# Declare the contents of the .PHONY variable as phony. We keep that
# information in a variable se we can use it in if_changed and friends.
.PHONY: $(PHONY)