[v2,05/11] kbuild: rust_is_available: add check for `bindgen` invocation

Message ID 20230616001631.463536-6-ojeda@kernel.org
State New
Headers
Series `scripts/rust_is_available.sh` improvements |

Commit Message

Miguel Ojeda June 16, 2023, 12:16 a.m. UTC
  `scripts/rust_is_available.sh` calls `bindgen` with a special
header in order to check whether the `libclang` version in use
is suitable.

However, the invocation itself may fail if, for instance, `bindgen`
cannot locate `libclang`. This is fine for Kconfig (since the
script will still fail and therefore disable Rust as it should),
but it is pretty confusing for users of the `rustavailable` target
given the error will be unrelated:

    ./scripts/rust_is_available.sh: 21: arithmetic expression: expecting primary: "100000 *  + 100 *  + "
    make: *** [Makefile:1816: rustavailable] Error 2

Instead, run the `bindgen` invocation independently in a previous
step, saving its output and return code. If it fails, then show
the user a proper error message. Otherwise, continue as usual
with the saved output.

Since the previous patch we show a reference to the docs, and
the docs now explain how `bindgen` looks for `libclang`,
thus the error message can leverage the documentation, avoiding
duplication here (and making users aware of the setup guide in
the documentation).

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/
Reported-by: François Valenduc <francoisvalenduc@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/934
Reported-by: Alexandru Radovici <msg4alex@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/pull/921
Reported-by: Matthew Leach <dev@mattleach.net>
Closes: https://lore.kernel.org/rust-for-linux/20230507084116.1099067-1-dev@mattleach.net/
Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 scripts/rust_is_available.sh | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)
  

Comments

Martin Rodriguez Reboredo June 16, 2023, 2:06 p.m. UTC | #1
On 6/15/23 21:16, Miguel Ojeda wrote:
> `scripts/rust_is_available.sh` calls `bindgen` with a special
> header in order to check whether the `libclang` version in use
> is suitable.
> 
> However, the invocation itself may fail if, for instance, `bindgen`
> cannot locate `libclang`. This is fine for Kconfig (since the
> script will still fail and therefore disable Rust as it should),
> but it is pretty confusing for users of the `rustavailable` target
> given the error will be unrelated:
> 
>      ./scripts/rust_is_available.sh: 21: arithmetic expression: expecting primary: "100000 *  + 100 *  + "
>      make: *** [Makefile:1816: rustavailable] Error 2
> 
> Instead, run the `bindgen` invocation independently in a previous
> step, saving its output and return code. If it fails, then show
> the user a proper error message. Otherwise, continue as usual
> with the saved output.
> 
> Since the previous patch we show a reference to the docs, and
> the docs now explain how `bindgen` looks for `libclang`,
> thus the error message can leverage the documentation, avoiding
> duplication here (and making users aware of the setup guide in
> the documentation).
> 
> Reported-by: Nick Desaulniers <ndesaulniers@google.com>
> Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/
> Reported-by: François Valenduc <francoisvalenduc@gmail.com>
> Closes: https://github.com/Rust-for-Linux/linux/issues/934
> Reported-by: Alexandru Radovici <msg4alex@gmail.com>
> Closes: https://github.com/Rust-for-Linux/linux/pull/921
> Reported-by: Matthew Leach <dev@mattleach.net>
> Closes: https://lore.kernel.org/rust-for-linux/20230507084116.1099067-1-dev@mattleach.net/
> Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
> [...]

Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
  
Nathan Chancellor June 16, 2023, 5:11 p.m. UTC | #2
On Fri, Jun 16, 2023 at 02:16:25AM +0200, Miguel Ojeda wrote:
> `scripts/rust_is_available.sh` calls `bindgen` with a special
> header in order to check whether the `libclang` version in use
> is suitable.
> 
> However, the invocation itself may fail if, for instance, `bindgen`
> cannot locate `libclang`. This is fine for Kconfig (since the
> script will still fail and therefore disable Rust as it should),
> but it is pretty confusing for users of the `rustavailable` target
> given the error will be unrelated:
> 
>     ./scripts/rust_is_available.sh: 21: arithmetic expression: expecting primary: "100000 *  + 100 *  + "
>     make: *** [Makefile:1816: rustavailable] Error 2
> 
> Instead, run the `bindgen` invocation independently in a previous
> step, saving its output and return code. If it fails, then show
> the user a proper error message. Otherwise, continue as usual
> with the saved output.
> 
> Since the previous patch we show a reference to the docs, and
> the docs now explain how `bindgen` looks for `libclang`,
> thus the error message can leverage the documentation, avoiding
> duplication here (and making users aware of the setup guide in
> the documentation).
> 
> Reported-by: Nick Desaulniers <ndesaulniers@google.com>
> Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/
> Reported-by: François Valenduc <francoisvalenduc@gmail.com>
> Closes: https://github.com/Rust-for-Linux/linux/issues/934
> Reported-by: Alexandru Radovici <msg4alex@gmail.com>
> Closes: https://github.com/Rust-for-Linux/linux/pull/921
> Reported-by: Matthew Leach <dev@mattleach.net>
> Closes: https://lore.kernel.org/rust-for-linux/20230507084116.1099067-1-dev@mattleach.net/
> Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

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

> ---
>  scripts/rust_is_available.sh | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
> index 6b8131d5b547..1bdff4472cbe 100755
> --- a/scripts/rust_is_available.sh
> +++ b/scripts/rust_is_available.sh
> @@ -106,8 +106,28 @@ if [ "$rust_bindings_generator_cversion" -gt "$rust_bindings_generator_min_cvers
>  fi
>  
>  # Check that the `libclang` used by the Rust bindings generator is suitable.
> +#
> +# In order to do that, first invoke `bindgen` to get the `libclang` version
> +# found by `bindgen`. This step may already fail if, for instance, `libclang`
> +# is not found, thus inform the user in such a case.
> +bindgen_libclang_output=$( \
> +	LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null
> +) || bindgen_libclang_code=$?
> +if [ -n "$bindgen_libclang_code" ]; then
> +	echo >&2 "***"
> +	echo >&2 "*** Running '$BINDGEN' to check the libclang version (used by the Rust"
> +	echo >&2 "*** bindings generator) failed with code $bindgen_libclang_code. This may be caused by"
> +	echo >&2 "*** a failure to locate libclang. See output and docs below for details:"
> +	echo >&2 "***"
> +	echo >&2 "$bindgen_libclang_output"
> +	echo >&2 "***"
> +	exit 1
> +fi
> +
> +# `bindgen` returned successfully, thus use the output to check that the version
> +# of the `libclang` found by the Rust bindings generator is suitable.
>  bindgen_libclang_version=$( \
> -	LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null \
> +	echo "$bindgen_libclang_output" \
>  		| grep -F 'clang version ' \
>  		| grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
>  		| head -n 1 \
> -- 
> 2.41.0
>
  
Masahiro Yamada June 20, 2023, 4:40 a.m. UTC | #3
On Fri, Jun 16, 2023 at 9:17 AM Miguel Ojeda <ojeda@kernel.org> wrote:
>
> `scripts/rust_is_available.sh` calls `bindgen` with a special
> header in order to check whether the `libclang` version in use
> is suitable.
>
> However, the invocation itself may fail if, for instance, `bindgen`
> cannot locate `libclang`. This is fine for Kconfig (since the
> script will still fail and therefore disable Rust as it should),
> but it is pretty confusing for users of the `rustavailable` target
> given the error will be unrelated:
>
>     ./scripts/rust_is_available.sh: 21: arithmetic expression: expecting primary: "100000 *  + 100 *  + "
>     make: *** [Makefile:1816: rustavailable] Error 2
>
> Instead, run the `bindgen` invocation independently in a previous
> step, saving its output and return code. If it fails, then show
> the user a proper error message. Otherwise, continue as usual
> with the saved output.
>
> Since the previous patch we show a reference to the docs, and
> the docs now explain how `bindgen` looks for `libclang`,
> thus the error message can leverage the documentation, avoiding
> duplication here (and making users aware of the setup guide in
> the documentation).
>
> Reported-by: Nick Desaulniers <ndesaulniers@google.com>
> Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/
> Reported-by: François Valenduc <francoisvalenduc@gmail.com>
> Closes: https://github.com/Rust-for-Linux/linux/issues/934
> Reported-by: Alexandru Radovici <msg4alex@gmail.com>
> Closes: https://github.com/Rust-for-Linux/linux/pull/921
> Reported-by: Matthew Leach <dev@mattleach.net>
> Closes: https://lore.kernel.org/rust-for-linux/20230507084116.1099067-1-dev@mattleach.net/
> Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---


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




>  scripts/rust_is_available.sh | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
> index 6b8131d5b547..1bdff4472cbe 100755
> --- a/scripts/rust_is_available.sh
> +++ b/scripts/rust_is_available.sh
> @@ -106,8 +106,28 @@ if [ "$rust_bindings_generator_cversion" -gt "$rust_bindings_generator_min_cvers
>  fi
>
>  # Check that the `libclang` used by the Rust bindings generator is suitable.
> +#
> +# In order to do that, first invoke `bindgen` to get the `libclang` version
> +# found by `bindgen`. This step may already fail if, for instance, `libclang`
> +# is not found, thus inform the user in such a case.
> +bindgen_libclang_output=$( \
> +       LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null


Nit.

To avoid shellcheck warnings, you can quote as follows:

"$(dirname "$0")/rust_is_available_bindgen_libclang.h"


You can do shellcheck scanning to avoid new warnings.

(Of course, 02/11 intentionally unquote $CC, though)



> +) || bindgen_libclang_code=$?
> +if [ -n "$bindgen_libclang_code" ]; then
> +       echo >&2 "***"
> +       echo >&2 "*** Running '$BINDGEN' to check the libclang version (used by the Rust"
> +       echo >&2 "*** bindings generator) failed with code $bindgen_libclang_code. This may be caused by"
> +       echo >&2 "*** a failure to locate libclang. See output and docs below for details:"
> +       echo >&2 "***"
> +       echo >&2 "$bindgen_libclang_output"
> +       echo >&2 "***"
> +       exit 1
> +fi
> +
> +# `bindgen` returned successfully, thus use the output to check that the version
> +# of the `libclang` found by the Rust bindings generator is suitable.
>  bindgen_libclang_version=$( \
> -       LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null \
> +       echo "$bindgen_libclang_output" \
>                 | grep -F 'clang version ' \
>                 | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
>                 | head -n 1 \
> --
> 2.41.0
>
  

Patch

diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
index 6b8131d5b547..1bdff4472cbe 100755
--- a/scripts/rust_is_available.sh
+++ b/scripts/rust_is_available.sh
@@ -106,8 +106,28 @@  if [ "$rust_bindings_generator_cversion" -gt "$rust_bindings_generator_min_cvers
 fi
 
 # Check that the `libclang` used by the Rust bindings generator is suitable.
+#
+# In order to do that, first invoke `bindgen` to get the `libclang` version
+# found by `bindgen`. This step may already fail if, for instance, `libclang`
+# is not found, thus inform the user in such a case.
+bindgen_libclang_output=$( \
+	LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null
+) || bindgen_libclang_code=$?
+if [ -n "$bindgen_libclang_code" ]; then
+	echo >&2 "***"
+	echo >&2 "*** Running '$BINDGEN' to check the libclang version (used by the Rust"
+	echo >&2 "*** bindings generator) failed with code $bindgen_libclang_code. This may be caused by"
+	echo >&2 "*** a failure to locate libclang. See output and docs below for details:"
+	echo >&2 "***"
+	echo >&2 "$bindgen_libclang_output"
+	echo >&2 "***"
+	exit 1
+fi
+
+# `bindgen` returned successfully, thus use the output to check that the version
+# of the `libclang` found by the Rust bindings generator is suitable.
 bindgen_libclang_version=$( \
-	LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null \
+	echo "$bindgen_libclang_output" \
 		| grep -F 'clang version ' \
 		| grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
 		| head -n 1 \