On Fri, Aug 09, 2024 at 12:11:33AM +0200, Miguel Ojeda wrote:
> Now that we support several Rust versions, introduce
> `CONFIG_RUSTC_VERSION` so that it can be used in Kconfig to enable and
> disable configuration options based on the `rustc` version.
>
> The approach taken resembles `pahole`'s -- see commit 613fe1692377
> ("kbuild: Add CONFIG_PAHOLE_VERSION"), i.e. a simple version parsing
> without trying to identify several kinds of compilers, since so far
> there is only one (`rustc`).
>
> However, unlike `pahole`'s, we also print a zero if executing failed for
> any reason, rather than checking if the command is found and executable
> (which still leaves things like a file that exists and is executable,
> but e.g. is built for another platform [1]). An equivalent approach to
> the one here has also been submitted for `pahole` [2].
>
> Link: https://lore.kernel.org/rust-for-linux/CANiq72=4vX_tJMJLE6e+bg7ZECHkS-AQpm8GBzuK75G1EB7+Nw@xxxxxxxxxxxxxx/ [1]
> Link: https://lore.kernel.org/linux-kbuild/20240728125527.690726-1-ojeda@xxxxxxxxxx/ [2]
> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
> ---
> init/Kconfig | 7 +++++++
> scripts/rustc-version.sh | 26 ++++++++++++++++++++++++++
> 2 files changed, 33 insertions(+)
> create mode 100755 scripts/rustc-version.sh
>
> diff --git a/init/Kconfig b/init/Kconfig
> index 3ada33b1d681..47e2c3227b99 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -60,6 +60,13 @@ config LLD_VERSION
> default $(ld-version) if LD_IS_LLD
> default 0
>
> +config RUSTC_VERSION
> + int
> + default $(shell,$(srctree)/scripts/rustc-version.sh $(RUSTC))
> + help
> + It does not depend on `RUST` since that one may need to use the version
> + in a `depends on`.
> +
> config RUST_IS_AVAILABLE
> def_bool $(success,$(srctree)/scripts/rust_is_available.sh)
> help
> diff --git a/scripts/rustc-version.sh b/scripts/rustc-version.sh
> new file mode 100755
> index 000000000000..62ea510be71b
> --- /dev/null
> +++ b/scripts/rustc-version.sh
> @@ -0,0 +1,26 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Usage: $ ./rustc-version.sh rustc
> +#
> +# Print the Rust compiler name and its version in a 6 or 7-digit form.
> +
> +# Convert the version string x.y.z to a canonical up-to-7-digits form.
> +#
> +# Note that this function uses one more digit (compared to other
> +# instances in other version scripts) to give a bit more space to
> +# `rustc` since it will reach 1.100.0 in late 2026.
> +get_canonical_version()
> +{
> + IFS=.
> + set -- $1
> + echo $((100000 * $1 + 100 * $2 + $3))
> +}
> +
> +if output=$("$@" --version 2>/dev/null); then
> + set -- $output
> + get_canonical_version $2
> +else
> + echo 0
> + exit 1
> +fi
> --
> 2.46.0
>
Reviewed-by: Nicolas Schier <nicolas@xxxxxxxxx>
