[PATCH v2] rust: Add -fdiagnostics-show-context to bindgen_skip_c_flags

[PATCH v2] rust: Add -fdiagnostics-show-context to bindgen_skip_c_flags

[Siddhesh Poyarekar]

This got added with:

  7454048db27d6 ("kbuild: Enable GCC diagnostic context for value-tracking warnings")

but clang does not have this option, so avoid passing it to bindgen.

Cc: stable@vger.kernel.org
Fixes: 7454048db27d6 ("kbuild: Enable GCC diagnostic context for value-tracking warnings")
Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
---
 rust/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/rust/Makefile b/rust/Makefile
index 5d357dce1704..4dcc2eff51cb 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -383,6 +383,7 @@ bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \
 	-fno-inline-functions-called-once -fsanitize=bounds-strict \
 	-fstrict-flex-arrays=% -fmin-function-alignment=% \
 	-fzero-init-padding-bits=% -mno-fdpic \
+	-fdiagnostics-show-context -fdiagnostics-show-context=% \
 	--param=% --param asan-% -fno-isolate-erroneous-paths-dereference
 
 # Derived from `scripts/Makefile.clang`.
-- 
2.52.0

Re: [PATCH v2] rust: Add -fdiagnostics-show-context to bindgen_skip_c_flags

[Miguel Ojeda]

On Wed, Dec 17, 2025 at 11:41 PM Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
>
> but clang does not have this option, so avoid passing it to bindgen.

This looks indeed correct, although it is not yet in a released GCC
(testing quickly in Compiler Explorer, GCC 15.2 doesn't have it, but
GCC trunk has).

I will apply it -- Cc'ing ClangBuiltLinux and Kbuild so that they are aware.

Thanks!

Cheers,
Miguel

Re: [PATCH v2] rust: Add -fdiagnostics-show-context to bindgen_skip_c_flags

[Siddhesh Poyarekar]

On 2026-01-04 15:53, Miguel Ojeda wrote:
> On Wed, Dec 17, 2025 at 11:41 PM Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
>>
>> but clang does not have this option, so avoid passing it to bindgen.
> 
> This looks indeed correct, although it is not yet in a released GCC
> (testing quickly in Compiler Explorer, GCC 15.2 doesn't have it, but
> GCC trunk has).

Yes, sorry I didn't mention that in my commit message; it's mentioned in 
Kees' commit message (7454048db27d6).

> I will apply it -- Cc'ing ClangBuiltLinux and Kbuild so that they are aware.

Thank you!

Sid

Re: [PATCH v2] rust: Add -fdiagnostics-show-context to bindgen_skip_c_flags

[Nathan Chancellor]

On Sun, Jan 04, 2026 at 09:53:25PM +0100, Miguel Ojeda wrote:
> On Wed, Dec 17, 2025 at 11:41 PM Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
> >
> > but clang does not have this option, so avoid passing it to bindgen.
> 
> This looks indeed correct, although it is not yet in a released GCC
> (testing quickly in Compiler Explorer, GCC 15.2 doesn't have it, but
> GCC trunk has).
> 
> I will apply it -- Cc'ing ClangBuiltLinux and Kbuild so that they are aware.

Right, this does look correct, as this option is specific to GCC for the
purpose of exposing more information from GCC internals to the user for
understanding diagnostics better.

I will say if this makes 6.19, the stable tag is not necessary since
7454048db27d6 landed in 6.19-rc1 and I would not expect it to get
backported (but even if it did via AUTOSEL or something, the Fixes tag
should ensure it gets included).

Cheers,
Nathan

Re: [PATCH v2] rust: Add -fdiagnostics-show-context to bindgen_skip_c_flags

[Miguel Ojeda]

On Wed, Dec 17, 2025 at 11:41 PM Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
>
> This got added with:
>
>   7454048db27d6 ("kbuild: Enable GCC diagnostic context for value-tracking warnings")
>
> but clang does not have this option, so avoid passing it to bindgen.
>
> Cc: stable@vger.kernel.org
> Fixes: 7454048db27d6 ("kbuild: Enable GCC diagnostic context for value-tracking warnings")
> Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>

Applied to `rust-fixes` -- thanks everyone!

    [ Details about what the option does are in the commit above. Nathan
      also expands on this:

        Right, this does look correct, as this option is specific to GCC
        for the purpose of exposing more information from GCC internals to
        the user for understanding diagnostics better.

      I checked that in Compiler Explorer GCC 15.2 doesn't have it, but GCC
      trunk indeed has. - Miguel ]

    [ Removed Cc: stable. Added title prefix. - Miguel ]

Cheers,
Miguel