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charset=UTF-8 Date: Fri, 24 Apr 2026 23:35:48 +0900 Message-Id: To: "Gary Guo" Cc: "Danilo Krummrich" , "Alice Ryhl" , "David Airlie" , "Simona Vetter" , "Bjorn Helgaas" , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , "Miguel Ojeda" , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , "Benno Lossin" , "Andreas Hindborg" , "Trevor Gross" , "Boqun Feng" , "John Hubbard" , "Alistair Popple" , "Joel Fernandes" , "Timur Tabi" , "Eliot Courtney" , , , , , Subject: Re: [PATCH v2 1/5] rust: add warn_on_err macro From: "Alexandre Courbot" References: <20260421-nova-unload-v2-0-2fe54963af8b@nvidia.com> <20260421-nova-unload-v2-1-2fe54963af8b@nvidia.com> In-Reply-To: X-ClientProxiedBy: OS7PR01CA0043.jpnprd01.prod.outlook.com (2603:1096:604:257::12) To CH2PR12MB3990.namprd12.prod.outlook.com (2603:10b6:610:28::18) Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH2PR12MB3990:EE_|PH7PR12MB6491:EE_ X-MS-Office365-Filtering-Correlation-Id: f723a6fd-9448-479a-ac57-08dea20ec934 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|10070799003|1800799024|366016|18002099003|56012099003|22082099003; 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Add a helper macro that >> allows this. >> >> Signed-off-by: Alexandre Courbot >> --- >> rust/kernel/bug.rs | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/rust/kernel/bug.rs b/rust/kernel/bug.rs >> index ed943960f851..2fefc0aeef81 100644 >> --- a/rust/kernel/bug.rs >> +++ b/rust/kernel/bug.rs >> @@ -130,3 +130,13 @@ macro_rules! warn_on { >> cond >> }}; >> } >> + >> +/// Report a warning if `res` is an error and return it unmodified. >> +#[macro_export] >> +macro_rules! warn_on_err { >> + ($res:expr) =3D> {{ >> + let res =3D $res; >> + let _ =3D $crate::warn_on!(res.is_err()); >> + res >> + }}; >> +} > > > I think `warn_on_err` could just be expressed as > > res.inspect_err(|_| warn_on!(true)) This would turn the verbose error message into something like [true] module.rs I.e. the expression passed as argument won't be printed. That being said, my version has the exact same problem and I don't see how we can fix this without splitting `warn_on` and making it more complex. Since this was done as a small convenience, I think I will just remove this from this patchset and revisit later as a separate series.