[PATCH 2/4] kbuild: collect minimum tool versions into scripts/tool-version.sh

[Masahiro Yamada]

The kernel build uses various tools, many of which are provided by the
same software suite, for example, LLVM and Binutils.

When we raise the minimal version of Clang/LLVM, we need to update
clang_min_version in scripts/cc-version.sh and also lld_min_version in
scripts/ld-version.sh.

In fact, Kbuild can handle CC=clang and LD=ld.lld independently, and we
could manage their minimal version separately, but it does not make
much sense.

Make scripts/tool-version.sh a central place of minimum tool versions
so that we do not need to touch multiple files.

This script prints the minimal version of the given tool.

$ scripts/tool-version.sh gcc
4.9.0
$ scripts/tool-version.sh llvm
10.0.1
$ scripts/tool-version.sh binutils
2.23.0
$ scripts/tool-version.sh foo
foo: unknown tool

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

scripts/cc-version.sh | 20 +++++---------------
scripts/ld-version.sh | 11 ++++-------
scripts/tool-version.sh | 27 +++++++++++++++++++++++++++
3 files changed, 36 insertions(+), 22 deletions(-)
create mode 100755 scripts/tool-version.sh

diff --git a/scripts/cc-version.sh b/scripts/cc-version.sh
index 3f2ee885b116..4772f1ef9cac 100755
--- a/scripts/cc-version.sh
+++ b/scripts/cc-version.sh
@@ -6,18 +6,6 @@

set -e

-# When you raise the minimum compiler version, please update
-# Documentation/process/changes.rst as well.
-gcc_min_version=4.9.0
-clang_min_version=10.0.1
-icc_min_version=16.0.3 # temporary
-
-# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293
-# https://lore.kernel.org/r/2021010711...@shell.armlinux.org.uk
-if [ "$SRCARCH" = arm64 ]; then
- gcc_min_version=5.1.0
-fi
-
# Print the compiler name and some version components.
get_compiler_info()
{
@@ -48,18 +36,20 @@ set -- $(get_compiler_info "$@")

name=$1

+tool_version=$(dirname $0)/tool-version.sh
+
case "$name" in
GCC)
version=$2.$3.$4
- min_version=$gcc_min_version
+ min_version=$($tool_version gcc)
;;
Clang)
version=$2.$3.$4
- min_version=$clang_min_version
+ min_version=$($tool_version llvm)
;;
ICC)
version=$(($2 / 100)).$(($2 % 100)).$3
- min_version=$icc_min_version
+ min_version=$($tool_version icc)
;;
*)
echo "$orig_args: unknown compiler" >&2
diff --git a/scripts/ld-version.sh b/scripts/ld-version.sh
index a463273509b5..e824f7675693 100755
--- a/scripts/ld-version.sh
+++ b/scripts/ld-version.sh
@@ -6,11 +6,6 @@

set -e

-# When you raise the minimum linker version, please update
-# Documentation/process/changes.rst as well.
-bfd_min_version=2.23.0
-lld_min_version=10.0.1
-
# Convert the version string x.y.z to a canonical 5 or 6-digit form.
get_canonical_version()
{
@@ -35,10 +30,12 @@ set -- $("$@" --version)
IFS=' '
set -- $1

+tool_version=$(dirname $0)/tool-version.sh
+
if [ "$1" = GNU -a "$2" = ld ]; then
shift $(($# - 1))
version=$1
- min_version=$bfd_min_version
+ min_version=$($tool_version binutils)
name=BFD
disp_name="GNU ld"
elif [ "$1" = GNU -a "$2" = gold ]; then
@@ -46,7 +43,7 @@ elif [ "$1" = GNU -a "$2" = gold ]; then
exit 1
elif [ "$1" = LLD ]; then
version=$2
- min_version=$lld_min_version
+ min_version=$($tool_version llvm)
name=LLD
disp_name=LLD
else
diff --git a/scripts/tool-version.sh b/scripts/tool-version.sh
new file mode 100755
index 000000000000..b4aa27e2c3d3
--- /dev/null
+++ b/scripts/tool-version.sh
@@ -0,0 +1,27 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Print the minimum supported version of the given tool.
+
+set -e
+
+# When you raise the minimum version, please update
+# Documentation/process/changes.rst as well.
+gcc_min_version=4.9.0
+llvm_min_version=10.0.1
+icc_min_version=16.0.3 # temporary
+binutils_min_version=2.23.0
+
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293
+# https://lore.kernel.org/r/2021010711...@shell.armlinux.org.uk
+if [ "$SRCARCH" = arm64 ]; then
+ gcc_min_version=5.1.0
+fi
+
+eval min_version="\$${1}_min_version"
+if [ -z "$min_version" ]; then
+ echo "$1: unknown tool" >&2
+ exit 1
+fi
+
+echo "$min_version"
--
2.27.0

[Nathan Chancellor]

On Thu, Mar 04, 2021 at 03:33:31AM +0900, Masahiro Yamada wrote:
> The kernel build uses various tools, many of which are provided by the
> same software suite, for example, LLVM and Binutils.
>
> When we raise the minimal version of Clang/LLVM, we need to update
> clang_min_version in scripts/cc-version.sh and also lld_min_version in
> scripts/ld-version.sh.
>
> In fact, Kbuild can handle CC=clang and LD=ld.lld independently, and we
> could manage their minimal version separately, but it does not make
> much sense.
>
> Make scripts/tool-version.sh a central place of minimum tool versions
> so that we do not need to touch multiple files.
>
> This script prints the minimal version of the given tool.
>
> $ scripts/tool-version.sh gcc
> 4.9.0
> $ scripts/tool-version.sh llvm
> 10.0.1
> $ scripts/tool-version.sh binutils
> 2.23.0
> $ scripts/tool-version.sh foo
> foo: unknown tool
>
> Signed-off-by: Masahiro Yamada <masa...@kernel.org>

Reviewed-by: Nathan Chancellor <nat...@kernel.org>

Two comments below.

I realize these scripts are currently called by their full path but is
it worth making this '$(dirname "$(readlink -f "$0")")' here and in
ld-version.sh just in case that does not happen?

Would scripts/tool-version.sh be easier to read and interpret using a
case statement?

#!/bin/sh
# SPDX-License-Identifier: GPL-2.0-only
#

# Print the minimum supported version of the given tool.

# When you raise the minimum version, please update

# Documentation/process/changes.rst as well.

case "$1" in
binutils)
echo "2.23.0"
;;
gcc)
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293
# https://lore.kernel.org/r/2021010711...@shell.armlinux.org.uk
if [ "$SRCARCH" = arm64 ]; then
echo "5.1.0"
else
echo "4.9.0"
fi
;;
icc)
# temporary
echo "16.0.3"
;;
llvm)
echo "10.0.1"
;;
*)

echo "$1: unknown tool" >&2

exit 1
;;
esac

[Nicolas Pitre]

On Thu, 4 Mar 2021, Masahiro Yamada wrote:

> The kernel build uses various tools, many of which are provided by the
> same software suite, for example, LLVM and Binutils.
>
> When we raise the minimal version of Clang/LLVM, we need to update
> clang_min_version in scripts/cc-version.sh and also lld_min_version in
> scripts/ld-version.sh.
>
> In fact, Kbuild can handle CC=clang and LD=ld.lld independently, and we
> could manage their minimal version separately, but it does not make
> much sense.
>
> Make scripts/tool-version.sh a central place of minimum tool versions
> so that we do not need to touch multiple files.

It would be better and self-explanatory if a script that provides the
minimum version of a tool was actually called ... min_tool-version.sh or
the like. Otherwise one might think it would give e.g. the current
version of installed tools.


Nicolas

[Masahiro Yamada]

Not sure.
A relative path still works.
So, I did not do what I did not need to do.

Actually, I wrote code that way.

But, I liked shorter code, and
wanted to collect magic numbers
to the top of this file.

Only the tricky part is the 'eval' statement,
but I hope it would not be too difficult to understand.

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--
Best Regards
Masahiro Yamada

[Masahiro Yamada]

You are right. I will rename it.

[Masahiro Yamada]

On Thu, Mar 4, 2021 at 9:11 AM Nathan Chancellor <nat...@kernel.org> wrote:
>

After some more thoughts, I think
your suggestion is better.


My patch is fragile in case the user sets
an environment variable "foo_min_version".