kbuild: rewrite ld-version.sh in shell script

This script was written in awk in spite of the file extension '.sh'.
Rewrite it as a shell script.

The code was mostly copy-pasted from scripts/lld-version.sh.
The two scripts can be merged, but I am keeping this as a separate
file for now.

I tested this script for some corner cases reported in the past:

 - GNU ld version 2.25-15.fc23
   as reported by commit 8083013 ("ld-version: Fix it on Fedora")

 - GNU ld (GNU Binutils) 2.20.1.20100303
   as reported by commit 0d61ed1 ("ld-version: Drop the 4th and
   5th version components")

I also cleaned up the macros in scripts/Kbuild.include. Remove
ld-version, which has no direct user. You can use CONFIG_LD_VERSION
if you need the version string in a Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

init/Kconfig

@@ -35,7 +35,7 @@ config GCC_VERSION
 
 config LD_VERSION
 	int
-	default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh)
+	default $(shell,$(srctree)/scripts/ld-version.sh $(LD))
 
 config CC_IS_CLANG
 	def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q clang)

scripts/Kbuild.include

@@ -141,13 +141,9 @@ 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))
 
-# ld-version
-# Note this is mainly for HJ Lu's 3 number binutil versions
-ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
-
 # ld-ifversion
 # Usage:  $(call ld-ifversion, -ge, 22252, y)
-ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
+ld-ifversion = $(shell [ $(CONFIG_LD_VERSION) $(1) $(2) ] && echo $(3) || echo $(4))
 
 ######
 

scripts/ld-version.sh

@@ -1,11 +1,22 @@
-#!/usr/bin/awk -f
+#!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
-# extract linker version number from stdin and turn into single number
-	{
-	gsub(".*\\)", "");
-	gsub(".*version ", "");
-	gsub("-.*", "");
-	split($1,a, ".");
-	print a[1]*10000 + a[2]*100 + a[3];
-	exit
-	}
+#
+# Usage: $ ./scripts/ld-version.sh ld
+#
+# Print the linker version of `ld' in a 5 or 6-digit form
+# such as `23501' for GNU ld 2.35.1 etc.
+
+first_line="$($* --version | head -n 1)"
+
+if ! ( echo $first_line | grep -q "GNU ld"); then
+	echo 0
+	exit 1
+fi
+
+# Distributions may append an extra string like 2.35-15.fc33
+# Take the part that consists of numbers and dots.
+VERSION=$(echo $first_line | sed 's/.* \([^ ]*\)$/\1/' | sed 's/^\(^[0-9.]*\).*/\1/')
+MAJOR=$(echo $VERSION | cut -d . -f 1)
+MINOR=$(echo $VERSION | cut -d . -f 2)
+PATCHLEVEL=$(echo $VERSION | cut -d . -f 3)
+printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL