From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2D54C392824; Sun, 19 Jul 2026 12:05:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784462742; cv=none; b=mb5C8Kb3Jq3vAMQ7EfYXGunrQjUOfdE1unXIdtWT8EnIrAOI+K+brBEu9J0kB0O1j7fEUDrzY8UCCtmNJyQq1x6OwJ1qJUK8OzoiGjVkvfjGjtnaPdaOwzDw5a/V6ZNUVZbmB/gaqooL7ekjjltkzTKNm2BRd9Y/9TRyD3QyFys= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784462742; c=relaxed/simple; bh=/F515Mggx/LfPwvCWJhHNDaxr8uq2KwLMOLCbYae0cY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=AIEAVhv8t8ISlS5G9VmjKvzpEaDUkOXkgXNuNR2VNDkEkrkgYEn4QnUpRhsMn4+XUKfNwA+V+lpTm/GBnmI6zsPQoObDBmUOMtX+gbKABd6Wvc+V+FOWe7kPx77VsZD85G4oTezxbrn0q1W2DA9By45kjtY0Ic6KagmMRnz+FAQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RZR0RyfD; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RZR0RyfD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7D481F00A3A; Sun, 19 Jul 2026 12:05:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784462741; bh=JMGd2uoPB7NsKyb94n7h+QsK/jkUxl/G3pG+G3sr+Rg=; h=From:To:Cc:Subject:Date; b=RZR0RyfDoAkuFSxusYk3tvLzrspRkRJBqd7YC98PsWhMrgDKvhz/DH49BIsSZXJwm QJF+p2kKddvR723wUdn5nqA9LI6ktYrAyoYyaIYxUBlBv/mrSAdV7v3TWHXGuwBtRs EEXA5U8LjUH+8AicvVsFH1DnucP9wbItQ821n0PJqcgSODrNEK8LV1FoKGarhcr2+4 DFmgqJmGZzu2b9ClysKUc9DHoiCpWuXeOOKrDM2eq+zUwq4Z95iNpLipko8mOEpJC5 SketreBRo3yE9qw+8p6YHBCoSD0YCMTKpqo+OFFgivIN/1puY1s6qW4jJvirty/ebg +PB4PcQO5dqXA== From: Miguel Ojeda To: Miguel Ojeda , Nathan Chancellor , Nicolas Schier Cc: Boqun Feng , Gary Guo , =?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , =?UTF-8?q?Onur=20=C3=96zkan?= , rust-for-linux@vger.kernel.org, linux-kbuild@vger.kernel.org, Burak Emir Subject: [PATCH] rust: rust_is_available: warn for `bindgen` < 0.72.1 && libclang >= 22 Date: Sun, 19 Jul 2026 14:05:14 +0200 Message-ID: <20260719120514.159914-1-ojeda@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Starting with LLVM 22, `clang_getTypeDeclaration()` may return a forward declaration instead of the type definition. This made `bindgen` generate opaque types [1][2], which in turn made us fail with e.g. error[E0609]: no field `__bindgen_anon_1` on type `bindings::kernel_param` --> rust/kernel/module_param.rs:78:46 | 78 | let container = unsafe { &*((*param).__bindgen_anon_1.arg.cast::>()) }; | ^^^^^^^^^^^^^^^^ unknown field | = note: available field is: `_address` This was fixed in `bindgen` 0.72.1 [3]. In order to clarify what is going on and avoid confusion [4][5], add a warning to `rust_is_available.sh` about it when the versions match, similar to past warnings like the one removed in: commit ae64324ad5c1 ("rust: rust_is_available: remove warning for `bindgen` < 0.69.5 && libclang >= 19.1") In addition, even if the versions match, check if the issue appears to not reproduce with the given binaries, to avoid a warning in such a case. Finally, include tests. Link: https://github.com/rust-lang/rust-bindgen/issues/3264 [1] Link: https://github.com/Rust-for-Linux/linux/issues/353 [2] # "Missing fields in nested class with LLVM 22." Link: https://github.com/rust-lang/rust-bindgen/pull/3278 [3] Reported-by: Burak Emir Link: https://github.com/Rust-for-Linux/linux/issues/1247 [4] Link: https://lore.kernel.org/rust-for-linux/CABwQupNfMAJOGqRM9ke6tj4f53dCCsBDKU7Vp+zf8mwk7bqt8Q@mail.gmail.com/ [5] Signed-off-by: Miguel Ojeda --- While it was known, I added Reported-by anyway -- please let me know if you prefer otherwise. Would you mind confirming you get the warning? Thanks! scripts/rust_is_available.sh | 14 +++++++++ .../rust_is_available_bindgen_libclang_22.h | 5 ++++ scripts/rust_is_available_test.py | 30 ++++++++++++++++++- 3 files changed, 48 insertions(+), 1 deletion(-) create mode 100644 scripts/rust_is_available_bindgen_libclang_22.h diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh index 551f1ebd0dcb..c30983562a2f 100755 --- a/scripts/rust_is_available.sh +++ b/scripts/rust_is_available.sh @@ -208,6 +208,20 @@ if [ "$bindgen_libclang_cversion" -lt "$bindgen_libclang_min_cversion" ]; then exit 1 fi +if [ "$bindgen_libclang_cversion" -ge 2200000 ] && + [ "$rust_bindings_generator_cversion" -lt 7201 ]; then + # Distributions may have patched the issue. + if ! "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang_22.h | grep -q 'pub foo'; then + echo >&2 "***" + echo >&2 "*** Rust bindings generator '$BINDGEN' < 0.72.1 together with libclang >= 22" + echo >&2 "*** may not work due to a bug (https://github.com/rust-lang/rust-bindgen/pull/3278)." + echo >&2 "*** Your bindgen version: $rust_bindings_generator_version" + echo >&2 "*** Your libclang version: $bindgen_libclang_version" + echo >&2 "***" + warning=1 + fi +fi + # If the C compiler is Clang, then we can also check whether its version # matches the `libclang` version used by the Rust bindings generator. # diff --git a/scripts/rust_is_available_bindgen_libclang_22.h b/scripts/rust_is_available_bindgen_libclang_22.h new file mode 100644 index 000000000000..6b33544c14a8 --- /dev/null +++ b/scripts/rust_is_available_bindgen_libclang_22.h @@ -0,0 +1,5 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +struct S; +struct S { + int foo; +}; diff --git a/scripts/rust_is_available_test.py b/scripts/rust_is_available_test.py index d6d54b7ea42a..e14cf2c5695e 100755 --- a/scripts/rust_is_available_test.py +++ b/scripts/rust_is_available_test.py @@ -54,16 +54,23 @@ else: """) @classmethod - def generate_bindgen(cls, version_stdout, libclang_stderr): + def generate_bindgen(cls, version_stdout, libclang_stderr, libclang_22_patched=False): if libclang_stderr is None: libclang_case = f"raise SystemExit({cls.bindgen_default_bindgen_libclang_failure_exit_code})" else: libclang_case = f"print({repr(libclang_stderr)}, file=sys.stderr)" + if libclang_22_patched: + libclang_22_case = "print('pub foo: ::std::os::raw::c_int,')" + else: + libclang_22_case = "pass" + return cls.generate_executable(f"""#!/usr/bin/env python3 import sys if "rust_is_available_bindgen_libclang.h" in " ".join(sys.argv): {libclang_case} +elif "rust_is_available_bindgen_libclang_22.h" in " ".join(sys.argv): + {libclang_22_case} else: print({repr(version_stdout)}) """) @@ -248,6 +255,27 @@ else: result = self.run_script(self.Expected.FAILURE, { "BINDGEN": bindgen }) self.assertIn(f"libclang (used by the Rust bindings generator '{bindgen}') is too old.", result.stderr) + def test_bindgen_bad_libclang_22(self): + for (bindgen_version, libclang_version, expected_not_patched) in ( + ("0.71.1", "21.1.0", self.Expected.SUCCESS), + ("0.71.1", "22.0.0", self.Expected.SUCCESS_WITH_WARNINGS), + ("0.71.1", "22.1.0", self.Expected.SUCCESS_WITH_WARNINGS), + + ("0.72.0", "22.0.0", self.Expected.SUCCESS_WITH_WARNINGS), + + ("0.72.1", "22.0.0", self.Expected.SUCCESS), + ): + with self.subTest(bindgen_version=bindgen_version, libclang_version=libclang_version): + cc = self.generate_clang(f"clang version {libclang_version}") + libclang_stderr = f"scripts/rust_is_available_bindgen_libclang.h:2:9: warning: clang version {libclang_version} [-W#pragma-messages], err: false" + bindgen = self.generate_bindgen(f"bindgen {bindgen_version}", libclang_stderr) + result = self.run_script(expected_not_patched, { "BINDGEN": bindgen, "CC": cc }) + if expected_not_patched == self.Expected.SUCCESS_WITH_WARNINGS: + self.assertIn(f"Rust bindings generator '{bindgen}' < 0.72.1 together with libclang >= 22", result.stderr) + + bindgen = self.generate_bindgen(f"bindgen {bindgen_version}", libclang_stderr, libclang_22_patched=True) + result = self.run_script(self.Expected.SUCCESS, { "BINDGEN": bindgen, "CC": cc }) + def test_clang_matches_bindgen_libclang_different_bindgen(self): bindgen = self.generate_bindgen_libclang("scripts/rust_is_available_bindgen_libclang.h:2:9: warning: clang version 999.0.0 [-W#pragma-messages], err: false") result = self.run_script(self.Expected.SUCCESS_WITH_WARNINGS, { "BINDGEN": bindgen }) base-commit: 880c43b185ca52239e75bc546cc4f4d9154d0fed -- 2.55.0