kbuild: introduce hostprogs-always-y and userprogs-always-y

To build host programs, you need to add the program names to 'hostprogs'
to use the necessary build rule, but it is not enough to build them
because there is no dependency.

There are two types of host programs: built as the prerequisite of
another (e.g. gen_crc32table in lib/Makefile), or always built when
Kbuild visits the Makefile (e.g. genksyms in scripts/genksyms/Makefile).

The latter is typical in Makefiles under scripts/, which contains host
programs globally used during the kernel build. To build them, you need
to add them to both 'hostprogs' and 'always-y'.

This commit adds hostprogs-always-y as a shorthand.

The same applies to user programs. net/bpfilter/Makefile builds
bpfilter_umh on demand, hence always-y is unneeded. In contrast,
programs under samples/ are added to both 'userprogs' and 'always-y'
so they are always built when Kbuild visits the Makefiles.

userprogs-always-y works as a shorthand.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
This commit is contained in:
Masahiro Yamada 2020-08-01 21:27:18 +09:00
parent 85569d19d0
commit faabed295c
22 changed files with 78 additions and 55 deletions

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@ -749,6 +749,10 @@ Both possibilities are described in the following.
hostprogs := lxdialog
always-y := $(hostprogs)
Kbuild provides the following shorthand for this:
hostprogs-always-y := lxdialog
This will tell kbuild to build lxdialog even if not referenced in
any rule.
@ -831,7 +835,32 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
5.4 When userspace programs are actually built
----------------------------------------------
Same as "When host programs are actually built".
Kbuild builds userspace programs only when told to do so.
There are two ways to do this.
(1) Add it as the prerequisite of another file
Example::
#net/bpfilter/Makefile
userprogs := bpfilter_umh
$(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
$(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
(2) Use always-y
Example::
userprogs := binderfs_example
always-y := $(userprogs)
Kbuild provides the following shorthand for this:
userprogs-always-y := binderfs_example
This will tell Kbuild to build binderfs_example when it visits this
Makefile.
6 Kbuild clean infrastructure
=============================

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@ -1,3 +1,2 @@
# SPDX-License-Identifier: GPL-2.0
userprogs := cfag12864b-example
always-y := $(userprogs)
userprogs-always-y += cfag12864b-example

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@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
userprogs := binderfs_example
always-y := $(userprogs)
userprogs-always-y += binderfs_example
userccflags += -I usr/include

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@ -1,7 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_SAMPLE_CONNECTOR) += cn_test.o
userprogs := ucon
always-$(CONFIG_CC_CAN_LINK) := $(userprogs)
userprogs-always-$(CONFIG_CC_CAN_LINK) += ucon
userccflags += -I usr/include

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@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
userprogs := hid-example
always-y := $(userprogs)
userprogs-always-y += hid-example
userccflags += -I usr/include

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@ -1,7 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2012-2019, Intel Corporation. All rights reserved.
userprogs := mei-amt-version
always-y := $(userprogs)
userprogs-always-y += mei-amt-version
userccflags += -I usr/include

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@ -1,6 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
usertprogs := pidfd-metadata
always-y := $(userprogs)
usertprogs-always-y += pidfd-metadata
userccflags += -I usr/include

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@ -1,8 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
userprogs := bpf-fancy dropper bpf-direct user-trap
userprogs-always-y += bpf-fancy dropper bpf-direct user-trap
bpf-fancy-objs := bpf-fancy.o bpf-helper.o
userccflags += -I usr/include
always-y := $(userprogs)

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@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
userprogs := hpet_example
always-y := $(userprogs)
userprogs-always-y += hpet_example
userccflags += -I usr/include

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@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
userprogs := uhid-example
always-y := $(userprogs)
userprogs-always-y += uhid-example
userccflags += -I usr/include

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@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
userprogs := test-fsmount test-statx
always-y := $(userprogs)
userprogs-always-y += test-fsmount test-statx
userccflags += -I usr/include

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@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
userprogs := watch_test
always-y := $(userprogs)
userprogs-always-y += watch_test
userccflags += -I usr/include

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@ -1,3 +1,2 @@
# SPDX-License-Identifier: GPL-2.0
userprogs := watchdog-simple
always-y := $(userprogs)
userprogs-always-y += watchdog-simple

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@ -3,14 +3,14 @@
# scripts contains sources for various helper programs used throughout
# the kernel for the build process.
always-$(CONFIG_BUILD_BIN2C) += bin2c
always-$(CONFIG_KALLSYMS) += kallsyms
always-$(BUILD_C_RECORDMCOUNT) += recordmcount
always-$(CONFIG_BUILDTIME_TABLE_SORT) += sorttable
always-$(CONFIG_ASN1) += asn1_compiler
always-$(CONFIG_MODULE_SIG_FORMAT) += sign-file
always-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += extract-cert
always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
hostprogs-always-$(CONFIG_BUILD_BIN2C) += bin2c
hostprogs-always-$(CONFIG_KALLSYMS) += kallsyms
hostprogs-always-$(BUILD_C_RECORDMCOUNT) += recordmcount
hostprogs-always-$(CONFIG_BUILDTIME_TABLE_SORT) += sorttable
hostprogs-always-$(CONFIG_ASN1) += asn1_compiler
hostprogs-always-$(CONFIG_MODULE_SIG_FORMAT) += sign-file
hostprogs-always-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += extract-cert
hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
@ -26,8 +26,6 @@ HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED
HOSTLDLIBS_sorttable = -lpthread
endif
hostprogs := $(always-y) $(always-m)
# The following programs are only built on demand
hostprogs += unifdef

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@ -27,9 +27,15 @@ subdir-ymn := $(addprefix $(obj)/,$(subdir-ymn))
# build a list of files to remove, usually relative to the current
# directory
__clean-files := $(extra-y) $(extra-m) $(extra-) \
$(always) $(always-y) $(always-m) $(always-) $(targets) $(clean-files) \
$(hostprogs) $(hostprogs-y) $(hostprogs-m) $(hostprogs-) $(userprogs)
__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-)
# deprecated
__clean-files += $(always) $(hostprogs-y) $(hostprogs-m) $(hostprogs-)
__clean-files := $(filter-out $(no-clean-files), $(__clean-files))

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@ -68,6 +68,17 @@ real-obj-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))
always-y += $(always-m)
# hostprogs-always-y += foo
# ... is a shorthand for
# hostprogs += foo
# always-y += foo
hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
always-y += $(hostprogs-always-y) $(hostprogs-always-m)
# userprogs-always-y is likewise.
userprogs += $(userprogs-always-y) $(userprogs-always-m)
always-y += $(userprogs-always-y) $(userprogs-always-m)
# DTB
# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
extra-y += $(dtb-y)

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@ -2,5 +2,4 @@
#
# fixdep: used to generate dependency information during build process
hostprogs := fixdep
always-y := $(hostprogs)
hostprogs-always-y += fixdep

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@ -1,9 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
# scripts/dtc makefile
hostprogs := dtc
always-$(CONFIG_DTC) += $(hostprogs)
always-$(CHECK_DT_BINDING) += $(hostprogs)
hostprogs-always-$(CONFIG_DTC) += dtc
hostprogs-always-$(CHECK_DT_BINDING) += dtc
dtc-objs := dtc.o flattree.o fstree.o data.o livetree.o treesource.o \
srcpos.o checks.o util.o

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@ -1,7 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
hostprogs := genksyms
always-y := $(hostprogs)
hostprogs-always-y += genksyms
genksyms-objs := genksyms.o parse.tab.o lex.lex.o

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@ -1,8 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
OBJECT_FILES_NON_STANDARD := y
hostprogs := modpost mk_elfconfig
always-y := $(hostprogs) empty.o
hostprogs-always-y += modpost mk_elfconfig
always-y += empty.o
modpost-objs := modpost.o file2alias.o sumversion.o

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@ -1,7 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
hostprogs := genheaders
hostprogs-always-y += genheaders
HOST_EXTRACFLAGS += \
-I$(srctree)/include/uapi -I$(srctree)/include \
-I$(srctree)/security/selinux/include
always-y := $(hostprogs)

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@ -1,8 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
hostprogs := mdp
hostprogs-always-y += mdp
HOST_EXTRACFLAGS += \
-I$(srctree)/include/uapi -I$(srctree)/include \
-I$(srctree)/security/selinux/include -I$(objtree)/include
always-y := $(hostprogs)
clean-files := policy.* file_contexts