kbuild: check the minimum linker version in Kconfig

Unify the two scripts/ld-version.sh and scripts/lld-version.sh, and
check the minimum linker version like scripts/cc-version.sh did.

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

 - GNU ld version 2.25-15.fc23
   as reported by commit 8083013fc320 ("ld-version: Fix it on Fedora")

 - GNU ld (GNU Binutils) 2.20.1.20100303
   as reported by commit 0d61ed17dd30 ("ld-version: Drop the 4th and
   5th version components")

This script show an error message if the linker is too old:

  $ make LD=ld.lld-9
    SYNC    include/config/auto.conf
  ***
  *** Linker is too old.
  ***   Your LLD version:    9.0.1
  ***   Minimum LLD version: 10.0.1
  ***
  scripts/Kconfig.include:50: Sorry, this linker is not supported.
  make[2]: *** [scripts/kconfig/Makefile:71: syncconfig] Error 1
  make[1]: *** [Makefile:600: syncconfig] Error 2
  make: *** [Makefile:708: include/config/auto.conf] Error 2

I also moved the check for gold to this script, so gold is still rejected:

  $ make LD=gold
    SYNC    include/config/auto.conf
  gold linker is not supported as it is not capable of linking the kernel proper.
  scripts/Kconfig.include:50: Sorry, this linker is not supported.
  make[2]: *** [scripts/kconfig/Makefile:71: syncconfig] Error 1
  make[1]: *** [Makefile:600: syncconfig] Error 2
  make: *** [Makefile:708: include/config/auto.conf] Error 2

Thanks to David Laight for suggesting shell script improvements.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include
index 0228cb9c74aa..58fdb5308725 100644
--- a/scripts/Kconfig.include
+++ b/scripts/Kconfig.include
@@ -45,8 +45,11 @@ $(error-if,$(success,test -z "$(cc-info)"),Sorry$(comma) this compiler is not su
 cc-name := $(shell,set -- $(cc-info) && echo $1)
 cc-version := $(shell,set -- $(cc-info) && echo $2)
 
-# Fail if the linker is gold as it's not capable of linking the kernel proper
-$(error-if,$(success, $(LD) -v | grep -q gold), gold linker '$(LD)' not supported)
+# Get the linker name, version, and error out if it is not supported.
+ld-info := $(shell,$(srctree)/scripts/ld-version.sh $(LD))
+$(error-if,$(success,test -z "$(ld-info)"),Sorry$(comma) this linker is not supported.)
+ld-name := $(shell,set -- $(ld-info) && echo $1)
+ld-version := $(shell,set -- $(ld-info) && echo $2)
 
 # machine bit flags
 #  $(m32-flag): -m32 if the compiler supports it, or an empty string otherwise.