[PATCH] kbuild: remove ar-option and KBUILD_ARFLAGS

[Masahiro Yamada]

Commit 40df759e2b9e ("kbuild: Fix build with binutils <= 2.19")
introduced ar-option and KBUILD_ARFLAGS to cope with old binutils.

According to Documentation/process/changes.rst, the current minimal
supported version of binutils is 2.21 so you can assume the 'D' option
is always supported. Not only GNU ar but also llvm-ar supports it.

With the 'D' option hard-coded, there is no more user of ar-option
or KBUILD_ARFLAGS.

Signed-off-by: Masahiro Yamada <yamada....@socionext.com>
---

Documentation/kbuild/makefiles.rst | 5 -----
Makefile | 4 ----
arch/powerpc/boot/Makefile | 2 +-
scripts/Kbuild.include | 5 -----
scripts/Makefile.build | 2 +-
scripts/Makefile.lib | 2 +-
6 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 6ba9d5365ff3..b89c88168d6a 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -954,11 +954,6 @@ When kbuild executes, the following steps are followed (roughly):

From commandline LDFLAGS_MODULE shall be used (see kbuild.txt).

- KBUILD_ARFLAGS Options for $(AR) when creating archives
-
- $(KBUILD_ARFLAGS) set by the top level Makefile to "D" (deterministic
- mode) if this option is supported by $(AR).
-
KBUILD_LDS

The linker script with full path. Assigned by the top-level Makefile.
diff --git a/Makefile b/Makefile
index 656a8c95789d..88b180b2cb64 100644
--- a/Makefile
+++ b/Makefile
@@ -498,7 +498,6 @@ export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
-export KBUILD_ARFLAGS

# Files to ignore in find ... statements

@@ -914,9 +913,6 @@ ifdef CONFIG_RETPOLINE
KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
endif

-# use the deterministic mode of AR if available
-KBUILD_ARFLAGS := $(call ar-option,D)
-
include scripts/Makefile.kasan
include scripts/Makefile.extrawarn
include scripts/Makefile.ubsan
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 6841bd52738b..dfbd7f22eef5 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -50,7 +50,7 @@ endif

BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -nostdinc

-BOOTARFLAGS := -cr$(KBUILD_ARFLAGS)
+BOOTARFLAGS := -crD

ifdef CONFIG_CC_IS_CLANG
BOOTCFLAGS += $(CLANG_FLAGS)
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index e31fd6a8b2a3..956668239ef5 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -143,11 +143,6 @@ cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || e
# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))

-# ar-option
-# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
-# Important: no spaces around options
-ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
-
# ld-version
# Note this is mainly for HJ Lu's 3 number binutil versions
ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 611bda95ac5e..f199341f04eb 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -395,7 +395,7 @@ $(sort $(subdir-obj-y)): $(subdir-ym) ;
ifdef builtin-target

quiet_cmd_ar_builtin = AR $@
- cmd_ar_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(real-prereqs)
+ cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)

$(builtin-target): $(real-obj-y) FORCE
$(call if_changed,ar_builtin)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 23e524027740..15895fd4ef9f 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -238,7 +238,7 @@ quiet_cmd_ld = LD $@
# ---------------------------------------------------------------------------

quiet_cmd_ar = AR $@
- cmd_ar = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(real-prereqs)
+ cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)

# Objcopy
# ---------------------------------------------------------------------------
--
2.17.1

[Nick Desaulniers]

On Tue, Sep 24, 2019 at 9:38 AM Masahiro Yamada
<yamada....@socionext.com> wrote:
>
> Commit 40df759e2b9e ("kbuild: Fix build with binutils <= 2.19")
> introduced ar-option and KBUILD_ARFLAGS to cope with old binutils.
>
> According to Documentation/process/changes.rst, the current minimal
> supported version of binutils is 2.21 so you can assume the 'D' option
> is always supported. Not only GNU ar but also llvm-ar supports it.

Yep, a nice cleanup. Thanks for the patch and I appreciate checking llvm-ar.
Reviewed-by: Nick Desaulniers <ndesau...@google.com>
Tested-by: Nick Desaulniers <ndesau...@google.com>

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--
Thanks,
~Nick Desaulniers