From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 42327CA5FCB for ; Thu, 1 Oct 2026 15:17:47 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xCISg-0000qD-Mg; Thu, 01 Oct 2026 11:12:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xCISe-0000pS-3r for qemu-devel@nongnu.org; Thu, 01 Oct 2026 11:12:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xCISc-0000uH-Aj for qemu-devel@nongnu.org; Thu, 01 Oct 2026 11:12:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1790867557; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=f2c4XpE3ZdexjMElI2n5rNHArTQqEYsq1YF9TekGdwM=; b=NjS7id8N/p3vN35pqhteoEpON+hPzJcjSha//q2BTuNvi9FxviVkzJryzg5Zuw+ZyWwDZX 5B18Lf+wdSmcRWJEnzt5G5PJfW7VvjSsUw3OuedApoCkcu0Hjswny+ItxrwW2qplWxaZX8 lZ239WW/VSJxX36i4jHPAQ1O5K7t5bY= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-52-aeeA_tLPNpaLZ-d1E6QANA-1; Thu, 01 Oct 2026 11:12:33 -0400 X-MC-Unique: aeeA_tLPNpaLZ-d1E6QANA-1 X-Mimecast-MFC-AGG-ID: aeeA_tLPNpaLZ-d1E6QANA_1790867552 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 128901865D8A for ; Thu, 1 Oct 2026 15:12:32 +0000 (UTC) Received: from berrange.csb (headnet05.pony-001.prod.iad2.dc.redhat.com [10.2.32.117]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 29B7C1956045; Thu, 1 Oct 2026 15:12:30 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Subject: [PATCH 01/20] osdep: add 'ignore_value(x)' macro Date: Thu, 1 Oct 2026 16:12:09 +0100 Message-ID: <20261001151228.3373747-2-berrange@redhat.com> In-Reply-To: <20261001151228.3373747-1-berrange@redhat.com> References: <20261001151228.3373747-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.331, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Functions annotated with 'warn_unused_result' cannot be cast to (void) to silence the compiler. Add the ignore_vaule() macro which tricks the compiler into thinking the result is genuinely used, avoiding the need for manual workarounds where the return value is intentionally ignored. This clever macro is derived from one originating with the GNULIB project: https://gitweb.git.savannah.gnu.org/gitweb/?p=gnulib.git;a=blob;f=lib/ignore-value.h;hb=HEAD but simplified since we don't need compat with old GCC and optimizing on clang is overkill. Signed-off-by: Daniel P. Berrangé --- include/qemu/osdep.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 1ec5b42230b..c1ca2c127b6 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -251,6 +251,14 @@ extern "C" { #endif +/* + * Merely casting to (void) is not sufficient for functions + * annotated with the "warn_unused_result" attribute + */ +#define ignore_value(x) \ + (__extension__ ({ __typeof__(x) __x = (x); (void) __x; })) + + /* * For mingw, as of v6.0.0, the function implementing the assert macro is * not marked as noreturn, so the compiler cannot delete code following an -- 2.55.0