kbuild: rust_is_available: fix confusion when a version appears in the path

[ Upstream commit 9eb7e20e0c5cd069457845f965b3e8a7d736ecb7 ]

`bindgen`'s output for `libclang`'s version check contains paths, which
in turn may contain strings that look like version numbers [1][2]:

    .../6.1.0-dev/.../rust_is_available_bindgen_libclang.h:2:9: warning: clang version 11.1.0  [-W#pragma-messages], err: false

which the script will pick up as the version instead of the latter.

It is also the case that versions may appear after the actual version
(e.g. distribution's version text), which was the reason behind `head` [3]:

    .../rust-is-available-bindgen-libclang.h:2:9: warning: clang version 13.0.0 (Fedora 13.0.0-3.fc35) [-W#pragma-messages], err: false

Thus instead ask for a match after the `clang version` string.

Reported-by: Jordan Isaacs <mail@jdisaacs.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/942 [1]
Reported-by: "Ethan D. Twardy" <ethan.twardy@gmail.com>
Closes: https://lore.kernel.org/rust-for-linux/20230528131802.6390-2-ethan.twardy@gmail.com/ [2]
Reported-by: Tiago Lam <tiagolam@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/pull/789 [3]
Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Ethan Twardy <ethan.twardy@gmail.com>
Tested-by: Ethan Twardy <ethan.twardy@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230616001631.463536-8-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
index c965895d80b97b32ca0c64a209a6d9cf45b26b9f..7a925d2b20fc7193de608907953e328511a88683 100755 (executable)
--- a/scripts/rust_is_available.sh
+++ b/scripts/rust_is_available.sh
@@ -112,9 +112,7 @@ fi
 # of the `libclang` found by the Rust bindings generator is suitable.
 bindgen_libclang_version=$( \
        echo "$bindgen_libclang_output" \
-               | grep -F 'clang version ' \
-               | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
-               | head -n 1 \
+               | sed -nE 's:.*clang version ([0-9]+\.[0-9]+\.[0-9]+).*:\1:p'
 )
 bindgen_libclang_min_version=$($min_tool_version llvm)
 bindgen_libclang_cversion=$(get_canonical_version $bindgen_libclang_version)