[PATCH 2/5] kbuild: Add CONFIG_PAHOLE_VERSION

[maennich@google.com]

From: Nathan Chancellor <nathan@kernel.org>

There are a few different places where pahole's version is turned into a
three digit form with the exact same command. Move this command into
scripts/pahole-version.sh to reduce the amount of duplication across the
tree.

Create CONFIG_PAHOLE_VERSION so the version code can be used in Kconfig
to enable and disable configuration options based on the pahole version,
which is already done in a couple of places.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220201205624.652313-3-nathan@kernel.org
Signed-off-by: Matthias Maennich <maennich@google.com>
---
 MAINTAINERS               |  1 +
 init/Kconfig              |  4 ++++
 scripts/pahole-version.sh | 13 +++++++++++++
 3 files changed, 18 insertions(+)
 create mode 100755 scripts/pahole-version.sh

diff --git a/MAINTAINERS b/MAINTAINERS
index 176485e625a0..ee8a1b5c28a6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3408,6 +3408,7 @@ F:	net/sched/cls_bpf.c
 F:	samples/bpf/
 F:	scripts/bpf_doc.py
 F:	scripts/pahole-flags.sh
+F:	scripts/pahole-version.sh
 F:	tools/bpf/
 F:	tools/lib/bpf/
 F:	tools/testing/selftests/bpf/
diff --git a/init/Kconfig b/init/Kconfig
index a4144393717b..dafc3ba6fa7a 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -91,6 +91,10 @@ config CC_HAS_ASM_INLINE
 config CC_HAS_NO_PROFILE_FN_ATTR
 	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
 
+config PAHOLE_VERSION
+	int
+	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
+
 config CONSTRUCTORS
 	bool
 
diff --git a/scripts/pahole-version.sh b/scripts/pahole-version.sh
new file mode 100755
index 000000000000..f8a32ab93ad1
--- /dev/null
+++ b/scripts/pahole-version.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Usage: $ ./pahole-version.sh pahole
+#
+# Prints pahole's version in a 3-digit form, such as 119 for v1.19.
+
+if [ ! -x "$(command -v "$@")" ]; then
+	echo 0
+	exit 1
+fi
+
+"$@" --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'
-- 
2.39.2.637.g21b0678d19-goog