kbuild: move vmlinux.a build rule to scripts/Makefile.vmlinux_a

Move the build rule for vmlinux.a to a separate file in preparation
for supporting distributed builds with Clang ThinLTO.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Rong Xu <xur@google.com>
Tested-by: Piotr Gorski <piotrgorski@cachyos.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Rong Xu <xur@google.com>
Link: https://patch.msgid.link/20260529185347.2418373-2-xur@google.com
[nathan: Squash in forward fix from Rong around '--thin' to $(AR)
         https://patch.msgid.link/20260529185347.2418373-3-xur@google.com]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
This commit is contained in:
Masahiro Yamada
2026-05-29 11:53:44 -07:00
committed by Nathan Chancellor
parent d7231d8cb2
commit 9c72d26e9f
2 changed files with 52 additions and 10 deletions
+6 -10
View File
@@ -1291,7 +1291,7 @@ export ARCH_DRIVERS := $(drivers-y) $(drivers-m)
KBUILD_VMLINUX_OBJS := built-in.a $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
export KBUILD_VMLINUX_LIBS
export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
ifdef CONFIG_TRIM_UNUSED_KSYMS
@@ -1300,16 +1300,12 @@ ifdef CONFIG_TRIM_UNUSED_KSYMS
KBUILD_MODULES := y
endif
# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
quiet_cmd_ar_vmlinux.a = AR $@
cmd_ar_vmlinux.a = \
rm -f $@; \
$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
PHONY += vmlinux_a
vmlinux_a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_a
targets += vmlinux.a
vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
$(call if_changed,ar_vmlinux.a)
vmlinux.a: vmlinux_a
@:
PHONY += vmlinux_o
vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
+46
View File
@@ -0,0 +1,46 @@
# SPDX-License-Identifier: GPL-2.0-only
PHONY := __default
__default: vmlinux.a
include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
include $(srctree)/scripts/Makefile.lib
# Link of built-in-fixup.a
# ---------------------------------------------------------------------------
# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
quiet_cmd_ar_builtin_fixup = AR $@
cmd_ar_builtin_fixup = \
rm -f $@; \
$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
targets += built-in-fixup.a
built-in-fixup.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
$(call if_changed,ar_builtin_fixup)
# vmlinux.a
# ---------------------------------------------------------------------------
targets += vmlinux.a
vmlinux.a: built-in-fixup.a FORCE
$(call if_changed,copy)
# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
PHONY += FORCE
FORCE:
# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.
existing-targets := $(wildcard $(sort $(targets)))
-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
.PHONY: $(PHONY)