{"id":23916,"url":"https://patchwork.libcamera.org/api/1.1/patches/23916/?format=json","web_url":"https://patchwork.libcamera.org/patch/23916/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20250723223914.23733-1-laurent.pinchart@ideasonboard.com>","date":"2025-07-23T22:39:14","name":"qcam: Silence false positive warnings with Qt 6.9.0 and newer","commit_ref":"2e8de41413d3fa6da0bd5f4dc51ebad0eff14f3b","pull_url":null,"state":"accepted","archived":false,"hash":"28ec8fbc34e3e735197468a9080fee0d77a88cde","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/1.1/people/2/?format=json","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/23916/mbox/","series":[{"id":5318,"url":"https://patchwork.libcamera.org/api/1.1/series/5318/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5318","date":"2025-07-23T22:39:14","name":"qcam: Silence false positive warnings with Qt 6.9.0 and newer","version":1,"mbox":"https://patchwork.libcamera.org/series/5318/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/23916/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/23916/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 657CFBDCC1\n\tfor ;\n\tWed, 23 Jul 2025 22:39:20 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 079D069076;\n\tThu, 24 Jul 2025 00:39:20 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id D4BB469068\n\tfor ;\n\tThu, 24 Jul 2025 00:39:17 +0200 (CEST)","from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi\n\t[81.175.209.231])\n\tby perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 23F79B0B\n\tfor ;\n\tThu, 24 Jul 2025 00:38:39 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"T4qvrHxK\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1753310319;\n\tbh=7+38HEgMp3dG2pU0DcJ3oeCCt8lT2HshM9QSqjZEPBg=;\n\th=From:To:Subject:Date:From;\n\tb=T4qvrHxKgp3YZchxEVodMqFKxHfl+yRZv0iiIGNSWwSJo8sEbVVZOBwJpTJWP81X1\n\tZs2XytpAsB9oQ/mvqFFwmctMPDpJXHNHNR+8moDkd8FmctQhgtLTzJoOgT7AW53fp1\n\tsw9xSCxTGjQdU5TfkQ9l8pqgl52su3S1dhGPNcYY=","From":"Laurent Pinchart ","To":"libcamera-devel@lists.libcamera.org","Subject":"[PATCH] qcam: Silence false positive warnings with Qt 6.9.0 and\n\tnewer","Date":"Thu, 24 Jul 2025 01:39:14 +0300","Message-ID":"<20250723223914.23733-1-laurent.pinchart@ideasonboard.com>","X-Mailer":"git-send-email 2.49.1","MIME-Version":"1.0","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"8bit","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"In Qt 6.9.0 the qtmochelpers.h header introduced a construct that gcc 12\nand gcc 13 incorrectly flag as variable shadowing:\n\nIn file included from src/apps/qcam/qcam.p/moc_viewfinder_gl.cpp:12:\n/usr/include/qt6/QtCore/qtmochelpers.h: In instantiation of ‘constexpr void QtMocHelpers::detail::UintDataStorage, T ...>::forEach(F&&) const [with F = QtMocHelpers::UintData >::copyTo<{anonymous}::qt_meta_tag_ZN12ViewFinderGLE_t, QtMocHelpers::MetaObjectContents<24, 10, 60, 3> >(QtMocHelpers::MetaObjectContents<24, 10, 60, 3>&, size_t, uint&) const::; int ...Idx = {0}; T = {QtMocHelpers::SignalData}]’:\n/usr/include/qt6/QtCore/qtmochelpers.h:255:21: required from ‘constexpr const QtMocHelpers::MetaObjectContents<24, 10, 60, 3> ViewFinderGL::qt_staticMetaObjectContent<{anonymous}::qt_meta_tag_ZN12ViewFinderGLE_t>’\nsrc/apps/qcam/qcam.p/../../../../../../src/apps/qcam/viewfinder_gl.h:32:2: required from ‘constexpr const auto ViewFinderGL::qt_staticMetaObjectStaticContent<{anonymous}::qt_meta_tag_ZN12ViewFinderGLE_t>’\nsrc/apps/qcam/qcam.p/moc_viewfinder_gl.cpp:63:5: required from here\nsrc/apps/qcam/qcam.p/../../../../../../src/apps/qcam/viewfinder_gl.h:32:2: in ‘constexpr’ expansion of ‘ViewFinderGL::qt_create_metaobjectdata<{anonymous}::qt_meta_tag_ZN12ViewFinderGLE_t>()’\nsrc/apps/qcam/qcam.p/moc_viewfinder_gl.cpp:58:87: in ‘constexpr’ expansion of ‘QtMocHelpers::metaObjectData, UintData >, UintData<>, UintData<> >(0, qt_stringData, qt_methods, qt_properties, qt_enums, QtMocHelpers::UintData<>(), const QtMocHelpers::detail::UintDataBlock<0, 0>{uint [1](), uint [1]()})’\n/usr/include/qt6/QtCore/qtmochelpers.h:563:36: in ‘constexpr’ expansion of ‘(& methods)->QtMocHelpers::UintData >::copyTo<{anonymous}::qt_meta_tag_ZN12ViewFinderGLE_t, QtMocHelpers::MetaObjectContents<24, 10, 60, 3> >(result, ((size_t)dataoffset), metatypeoffset)’\n/usr/include/qt6/QtCore/qtmochelpers.h:201:57: error: declaration of ‘entry’ shadows a member of ‘QtMocHelpers::detail::UintDataStorage, QtMocHelpers::SignalData >’ [-Werror=shadow]\n 201 | [[maybe_unused]] auto invoke = [&f](const auto &entry) { f(entry.entry); return 0; };\n | ~~~~~~~~~~~~^~~~~\n/usr/include/qt6/QtCore/qtmochelpers.h:180:7: note: shadowed declaration is here\n 180 | T entry;\n | ^~~~~\n\nThere is little we can do but silence the warning. Do so selectively\nbased on the Qt and gcc versions, to still detect variable shadowing\nwith compilers unaffected by the issue.\n\nSigned-off-by: Laurent Pinchart \n---\n src/apps/qcam/meson.build | 7 +++++++\n 1 file changed, 7 insertions(+)\n\n\nbase-commit: b65df7e7554b45e2d3d7fdb5b37c2ab7df3db4fe","diff":"diff --git a/src/apps/qcam/meson.build b/src/apps/qcam/meson.build\nindex f7c140643373..9ca047b0f927 100644\n--- a/src/apps/qcam/meson.build\n+++ b/src/apps/qcam/meson.build\n@@ -42,6 +42,13 @@ qt6_cpp_args = [\n '-Wno-extra-semi',\n ]\n \n+# gcc 12 and 13 output a false positive variable shadowing warning with Qt\n+# 6.9.0 and newer. Silence it.\n+if qt6_dep.version().version_compare('>=6.9.0') and \\\n+ cxx.version().version_compare('>=12') and cxx.version().version_compare('<14')\n+ qt6_cpp_args += ['-Wno-shadow']\n+endif\n+\n resources = qt6.preprocess(moc_headers : qcam_moc_headers,\n qresources : qcam_resources,\n dependencies : qt6_dep)\n","prefixes":[]}