kernel_optimize_test/scripts/Makefile.headersinst
Masahiro Yamada 919987318a kbuild: generate asm-generic wrappers if mandatory headers are missing
Some time ago, Sam pointed out a certain degree of overwrap between
generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121)

I tweaked the meaning of mandatory-y a little bit; now it defines the
minimum set of ASM headers that all architectures must have.

If arch does not have specific implementation of a mandatory header,
Kbuild will let it fallback to the asm-generic one by automatically
generating a wrapper. This will allow to drop lots of redundant
generic-y defines.

Previously, "mandatory" was used in the context of UAPI, but I guess
this can be extended to kernel space ASM headers.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
2019-01-06 09:46:51 +09:00

123 lines
3.8 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
# ==========================================================================
# Installing headers
#
# All headers under include/uapi, include/generated/uapi,
# arch/<arch>/include/uapi and arch/<arch>/include/generated/uapi are
# exported.
# They are preprocessed to remove __KERNEL__ section of the file.
#
# ==========================================================================
PHONY := __headers
__headers:
include scripts/Kbuild.include
srcdir := $(srctree)/$(obj)
# When make is run under a fakechroot environment, the function
# $(wildcard $(srcdir)/*/.) doesn't only return directories, but also regular
# files. So, we are using a combination of sort/dir/wildcard which works
# with fakechroot.
subdirs := $(patsubst $(srcdir)/%/,%,\
$(filter-out $(srcdir)/,\
$(sort $(dir $(wildcard $(srcdir)/*/)))))
# Recursion
__headers: $(subdirs)
PHONY += $(subdirs)
$(subdirs):
$(Q)$(MAKE) $(hdr-inst)=$(obj)/$@ dst=$(dst)/$@
# Skip header install/check for include/uapi and arch/$(SRCARCH)/include/uapi.
# We have only sub-directories there.
skip-inst := $(if $(filter %/uapi,$(obj)),1)
ifeq ($(skip-inst),)
# Kbuild file is optional
kbuild-file := $(srctree)/$(obj)/Kbuild
-include $(kbuild-file)
installdir := $(INSTALL_HDR_PATH)/$(dst)
gendir := $(objtree)/$(subst include/,include/generated/,$(obj))
header-files := $(notdir $(wildcard $(srcdir)/*.h))
header-files := $(filter-out $(no-export-headers), $(header-files))
genhdr-files := $(notdir $(wildcard $(gendir)/*.h))
genhdr-files := $(filter-out $(header-files), $(genhdr-files))
# files used to track state of install/check
install-file := $(installdir)/.install
check-file := $(installdir)/.check
# all headers files for this dir
all-files := $(header-files) $(genhdr-files)
output-files := $(addprefix $(installdir)/, $(all-files))
# Work out what needs to be removed
oldheaders := $(patsubst $(installdir)/%,%,$(wildcard $(installdir)/*.h))
unwanted := $(filter-out $(all-files),$(oldheaders))
# Prefix unwanted with full paths to $(INSTALL_HDR_PATH)
unwanted-file := $(addprefix $(installdir)/, $(unwanted))
printdir = $(patsubst $(INSTALL_HDR_PATH)/%/,%,$(dir $@))
quiet_cmd_install = INSTALL $(printdir) ($(words $(all-files))\
file$(if $(word 2, $(all-files)),s))
cmd_install = \
$(CONFIG_SHELL) $< $(installdir) $(srcdir) $(header-files); \
$(CONFIG_SHELL) $< $(installdir) $(gendir) $(genhdr-files); \
touch $@
quiet_cmd_remove = REMOVE $(unwanted)
cmd_remove = rm -f $(unwanted-file)
quiet_cmd_check = CHECK $(printdir) ($(words $(all-files)) files)
# Headers list can be pretty long, xargs helps to avoid
# the "Argument list too long" error.
cmd_check = for f in $(all-files); do \
echo "$(installdir)/$${f}"; done \
| xargs \
$(PERL) $< $(INSTALL_HDR_PATH)/include $(SRCARCH); \
touch $@
ifndef HDRCHECK
# Rules for installing headers
__headers: $(install-file)
@:
targets += $(install-file)
$(install-file): scripts/headers_install.sh \
$(addprefix $(srcdir)/,$(header-files)) \
$(addprefix $(gendir)/,$(genhdr-files)) FORCE
$(if $(unwanted),$(call cmd,remove),)
$(if $(wildcard $(dir $@)),,$(shell mkdir -p $(dir $@)))
$(call if_changed,install)
else
__headers: $(check-file)
@:
targets += $(check-file)
$(check-file): scripts/headers_check.pl $(output-files) FORCE
$(call if_changed,check)
endif
cmd_files := $(wildcard \
$(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
ifneq ($(cmd_files),)
include $(cmd_files)
endif
endif # skip-inst
PHONY += FORCE
FORCE: ;
.PHONY: $(PHONY)