From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f74.google.com (mail-ej1-f74.google.com [209.85.218.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D31CA25F99B for ; Tue, 24 Feb 2026 07:49:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771919389; cv=none; b=Mniu/ZC4WQReLoDH+yBJ5LV9TmdzDHx6Fl2W2Mch+hP5Qv5P4Z5q1t69BHEJZ2slFov/UnSAL3Yg74uPvNqxqOpqRLVpbBz8sPCaSAGAXzbSt2uXSm05lUw36Hl/Fm3yvwIkNh9BmMRx90JMoFlWd9RBs19YeS53IM+xcAayGho= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771919389; c=relaxed/simple; bh=S1AMswh1lQbv6HKMYTWuP/EFtpAZzTkpPRr5/NqjPXM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ZI8NMD2vfI/S021jIfAmL0Q1cJcOyg+PprTNl6oLiDDyBMURoZhh8xmffAuQ3H4C7bLUTPWQ1cBUBAVXspiskUKHBMckbIDPuIQVDFqyCAGhN9jxXoobrRLwZwgCNkJ7OwoZIKhEppuV4G21uxfJ7f6qxs/nRyuFl3dHdHMM2Gc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=KdSDC853; arc=none smtp.client-ip=209.85.218.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KdSDC853" Received: by mail-ej1-f74.google.com with SMTP id a640c23a62f3a-b8fc132b0b4so514293966b.1 for ; Mon, 23 Feb 2026 23:49:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1771919386; x=1772524186; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=/7Hi1B2QR1arEGlsvfgWO32ZZtaRVb/wfgOh/rBlJpc=; b=KdSDC85304TK6a9uNt0lP330VpGlHf9ippEhIqB8zcRp3ML6BcNHHOXcmPtX0mazT0 lhihb2lHBbLmX3QK3GsNaF1KzizJHegBpnRkgOrgZFfkOKn5sKN7qhr6iBlcnUA2s8el FMgw8wckw9TLJsovHIHYiUCxeZ26mmXkXa4pmAAeVUUR4BMNgUQqJH4fhzNMemwh4SOZ lOoKHc+7ypRCBPsJ9HnmcR2xissbSLlUXENe++xPNRlk9+fTeUmbXst2L6nQVmPW0QLi 2HDb4IScXukKyXmZJwQCsAV5mMLKTs7pdxcc8jyJxZJ9L9VgHmrQGxT5ydytd9GwPE5s QUgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771919386; x=1772524186; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=/7Hi1B2QR1arEGlsvfgWO32ZZtaRVb/wfgOh/rBlJpc=; b=uy3pJnV4+8neNPYJ9ATRxKnn3ypaueaO/1nOjIutBhfocYDgDPCXsjFKPgua9mwYBS grnI2UIsdQ+K++ypYW+FIdfXuRo9yZe/K5m2lrgiMk/fAkG2lpvbSsWdAMZCAaiMqBj4 ofFl8Yd535dNEhq/ZzJhH4wl+fr3Q9T92sv4tu7lRflBetgVRusZVgV/8Tzt9A1kdEZn fJ+kSF/v+xuWTsHBKmVPqhNPS59OfDlU0TxSO1f1U5KBhEqgaBzd3wgKYb9HXPm5AW/n zf40k+Kv39vKTgVwV7+ihdEolUCivKxbLluF3d0H+fQS8VANOBeq58/G7qOaG15ia+z3 lxww== X-Forwarded-Encrypted: i=1; AJvYcCWKYbme/OIzrwde0adTNeO0KUCc0xaewsYbBMcrdrqNbmECHr1qqPwJN//RTTfI2bADPIumyN4NEZF5GDw=@vger.kernel.org X-Gm-Message-State: AOJu0YyUYs73L7+vuE5A6poyRhZSpQbFgdVWKCu5FZwFqFrpxNDs78s7 SAjRsNMBpSfxGehWokN4eRREvo51sJbMpSeZxFc0SDqmyqlQCntMIGoVFWup8RvnI1grsSVVye7 EZCe5vG0QYJo/728uOQ== X-Received: from ejdce12.prod.google.com ([2002:a17:907:d2cc:b0:b8f:8b56:4a97]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a17:907:9301:b0:b87:2abc:4a32 with SMTP id a640c23a62f3a-b9081a2cd50mr766450566b.18.1771919385883; Mon, 23 Feb 2026 23:49:45 -0800 (PST) Date: Tue, 24 Feb 2026 07:49:45 +0000 In-Reply-To: <20260224-unused_var_err-v1-1-c51d805eceb5@nvidia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260224-unused_var_err-v1-1-c51d805eceb5@nvidia.com> Message-ID: Subject: Re: [PATCH] rust: kunit: fix warning when !CONFIG_PRINTK From: Alice Ryhl To: Alexandre Courbot Cc: Brendan Higgins , David Gow , Rae Moar , Miguel Ojeda , Boqun Feng , Gary Guo , "=?utf-8?B?QmrDtnJu?= Roy Baron" , Benno Lossin , Andreas Hindborg , Trevor Gross , Danilo Krummrich , Shuah Khan , linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" On Tue, Feb 24, 2026 at 04:45:30PM +0900, Alexandre Courbot wrote: > If `CONFIG_PRINTK` is not set, then the following warnings are issued > during build: > > warning: unused variable: `args` > --> ../rust/kernel/kunit.rs:16:12 > | > 16 | pub fn err(args: fmt::Arguments<'_>) { > | ^^^^ help: if this is intentional, prefix it with an underscore: `_args` > | > = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default > > warning: unused variable: `args` > --> ../rust/kernel/kunit.rs:32:13 > | > 32 | pub fn info(args: fmt::Arguments<'_>) { > | ^^^^ help: if this is intentional, prefix it with an underscore: `_args` > > Fix this by allowing unused variables on these methods for this > (arguably rare) case. > > Fixes: a66d733da801 ("rust: support running Rust documentation tests as KUnit ones") > Signed-off-by: Alexandre Courbot I think this would be a better fix: diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index f93f24a60bdd..dbf3c62ffa09 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -23,6 +23,9 @@ pub fn err(args: fmt::Arguments<'_>) { core::ptr::from_ref(&args).cast::(), ); } + + #[cfg(not(CONFIG_PRINTK))] + let _ = args; } /// Prints a KUnit info-level message. @@ -39,6 +42,9 @@ pub fn info(args: fmt::Arguments<'_>) { core::ptr::from_ref(&args).cast::(), ); } + + #[cfg(not(CONFIG_PRINTK))] + let _ = args; } /// Asserts that a boolean expression is `true` at runtime.