Replace `Q_UNUSED` with `[[maybe_unused]]` attribute

PR #19471.

src/app/application.cpp

@@ -1110,10 +1110,8 @@ void Application::initializeTranslation()
 }
 
 #if (!defined(DISABLE_GUI) && defined(Q_OS_WIN))
-void Application::shutdownCleanup(QSessionManager &manager)
+void Application::shutdownCleanup([[maybe_unused]] QSessionManager &manager)
 {
-    Q_UNUSED(manager);
-
     // This is only needed for a special case on Windows XP.
     // (but is called for every Windows version)
     // If a process takes too much time to exit during OS

src/base/bittorrent/sessionimpl.cpp

@@ -2541,9 +2541,8 @@ void SessionImpl::handleTorrentSaveResumeDataRequested(const TorrentImpl *torren
     ++m_numResumeData;
 }
 
-void SessionImpl::handleTorrentSaveResumeDataFailed(const TorrentImpl *torrent)
+void SessionImpl::handleTorrentSaveResumeDataFailed([[maybe_unused]] const TorrentImpl *torrent)
 {
-    Q_UNUSED(torrent);
     --m_numResumeData;
 }
 

src/base/bittorrent/torrentimpl.cpp

@@ -1866,10 +1866,8 @@ void TorrentImpl::handleMoveStorageJobFinished(const Path &path, const MoveStora
     }
 }
 
-void TorrentImpl::handleTorrentCheckedAlert(const lt::torrent_checked_alert *p)
+void TorrentImpl::handleTorrentCheckedAlert([[maybe_unused]] const lt::torrent_checked_alert *p)
 {
-    Q_UNUSED(p);
-
     if (!hasMetadata())
     {
         // The torrent is checked due to metadata received, but we should not process
@@ -1911,10 +1909,8 @@ void TorrentImpl::handleTorrentCheckedAlert(const lt::torrent_checked_alert *p)
     });
 }
 
-void TorrentImpl::handleTorrentFinishedAlert(const lt::torrent_finished_alert *p)
+void TorrentImpl::handleTorrentFinishedAlert([[maybe_unused]] const lt::torrent_finished_alert *p)
 {
-    Q_UNUSED(p);
-
     m_hasMissingFiles = false;
     if (m_hasFinishedStatus)
         return;
@@ -1943,14 +1939,12 @@ void TorrentImpl::handleTorrentFinishedAlert(const lt::torrent_finished_alert *p
     });
 }
 
-void TorrentImpl::handleTorrentPausedAlert(const lt::torrent_paused_alert *p)
+void TorrentImpl::handleTorrentPausedAlert([[maybe_unused]] const lt::torrent_paused_alert *p)
 {
-    Q_UNUSED(p);
 }
 
-void TorrentImpl::handleTorrentResumedAlert(const lt::torrent_resumed_alert *p)
+void TorrentImpl::handleTorrentResumedAlert([[maybe_unused]] const lt::torrent_resumed_alert *p)
 {
-    Q_UNUSED(p);
 }
 
 void TorrentImpl::handleSaveResumeDataAlert(const lt::save_resume_data_alert *p)
@@ -2165,9 +2159,8 @@ void TorrentImpl::handleFilePrioAlert(const lt::file_prio_alert *)
 }
 #endif
 
-void TorrentImpl::handleMetadataReceivedAlert(const lt::metadata_received_alert *p)
+void TorrentImpl::handleMetadataReceivedAlert([[maybe_unused]] const lt::metadata_received_alert *p)
 {
-    Q_UNUSED(p);
     qDebug("Metadata received for torrent %s.", qUtf8Printable(name()));
 
 #ifdef QBT_USES_LIBTORRENT2

src/base/net/geoipdatabase.cpp

@@ -462,13 +462,10 @@ bool GeoIPDatabase::readDataFieldDescriptor(quint32 &offset, DataFieldDescriptor
     return true;
 }
 
-void GeoIPDatabase::fromBigEndian(uchar *buf, const quint32 len) const
+void GeoIPDatabase::fromBigEndian([[maybe_unused]] uchar *buf, [[maybe_unused]] const quint32 len) const
 {
 #if (Q_BYTE_ORDER == Q_LITTLE_ENDIAN)
     std::reverse(buf, buf + len);
-#else
-    Q_UNUSED(buf);
-    Q_UNUSED(len);
 #endif
 }
 

src/base/rss/rss_autodownloader.cpp

@@ -612,8 +612,7 @@ void AutoDownloader::setProcessingEnabled(const bool enabled)
     }
 }
 
-void AutoDownloader::timerEvent(QTimerEvent *event)
+void AutoDownloader::timerEvent([[maybe_unused]] QTimerEvent *event)
 {
-    Q_UNUSED(event);
     store();
 }

src/base/rss/rss_feed.cpp

@@ -560,8 +560,7 @@ void Feed::cleanup()
     Utils::Fs::removeFile(m_iconPath);
 }
 
-void Feed::timerEvent(QTimerEvent *event)
+void Feed::timerEvent([[maybe_unused]] QTimerEvent *event)
 {
-    Q_UNUSED(event);
     store();
 }

src/base/utils/misc.cpp

@@ -111,7 +111,7 @@ namespace
     }
 }
 
-void Utils::Misc::shutdownComputer(const ShutdownDialogAction &action)
+void Utils::Misc::shutdownComputer([[maybe_unused]] const ShutdownDialogAction &action)
 {
 #if defined(Q_OS_WIN)
     HANDLE hToken;            // handle to process token
@@ -247,9 +247,6 @@ void Utils::Misc::shutdownComputer(const ShutdownDialogAction &action)
                                 QDBusConnection::systemBus());
         halIface.call(u"Shutdown"_s);
     }
-
-#else
-    Q_UNUSED(action);
 #endif
 }
 

src/gui/addnewtorrentdialog.cpp

@@ -502,17 +502,15 @@ void AddNewTorrentDialog::updateDiskSpaceLabel()
     m_ui->labelSizeData->setText(sizeString);
 }
 
-void AddNewTorrentDialog::onSavePathChanged(const Path &newPath)
+void AddNewTorrentDialog::onSavePathChanged([[maybe_unused]] const Path &newPath)
 {
-    Q_UNUSED(newPath);
     // Remember index
     m_savePathIndex = m_ui->savePath->currentIndex();
     updateDiskSpaceLabel();
 }
 
-void AddNewTorrentDialog::onDownloadPathChanged(const Path &newPath)
+void AddNewTorrentDialog::onDownloadPathChanged([[maybe_unused]] const Path &newPath)
 {
-    Q_UNUSED(newPath);
     // Remember index
     const int currentPathIndex = m_ui->downloadPath->currentIndex();
     if (currentPathIndex >= 0)
@@ -525,10 +523,8 @@ void AddNewTorrentDialog::onUseDownloadPathChanged(const bool checked)
     m_ui->downloadPath->setCurrentIndex(checked ? m_downloadPathIndex : -1);
 }
 
-void AddNewTorrentDialog::categoryChanged(int index)
+void AddNewTorrentDialog::categoryChanged([[maybe_unused]] const int index)
 {
-    Q_UNUSED(index);
-
     if (m_ui->comboTTM->currentIndex() == 1)
     {
         const auto *btSession = BitTorrent::Session::instance();

src/gui/cookiesmodel.cpp

@@ -73,9 +73,8 @@ QModelIndex CookiesModel::index(int row, int column, const QModelIndex &parent)
     return createIndex(row, column, &m_cookies[row]);
 }
 
-QModelIndex CookiesModel::parent(const QModelIndex &index) const
+QModelIndex CookiesModel::parent([[maybe_unused]] const QModelIndex &index) const
 {
-    Q_UNUSED(index);
     return {};
 }
 
@@ -86,9 +85,8 @@ int CookiesModel::rowCount(const QModelIndex &parent) const
     return m_cookies.size();
 }
 
-int CookiesModel::columnCount(const QModelIndex &parent) const
+int CookiesModel::columnCount([[maybe_unused]] const QModelIndex &parent) const
 {
-    Q_UNUSED(parent);
     return NB_COLUMNS;
 }
 

src/gui/desktopintegration.cpp

@@ -54,11 +54,8 @@ namespace
 #ifdef Q_OS_MACOS
     DesktopIntegration *desktopIntegrationInstance = nullptr;
 
-    bool handleDockClicked(id self, SEL cmd, ...)
+    bool handleDockClicked([[maybe_unused]] id self, [[maybe_unused]] SEL cmd, ...)
     {
-        Q_UNUSED(self);
-        Q_UNUSED(cmd);
-
         Q_ASSERT(desktopIntegrationInstance);
         emit desktopIntegrationInstance->activationRequested();
 

src/gui/fspathedit_p.cpp

@@ -146,10 +146,9 @@ QValidator::State Private::FileSystemPathValidator::lastValidationState() const
     return m_lastValidationState;
 }
 
-QValidator::State Private::FileSystemPathValidator::validate(QString &input, int &pos) const
+QValidator::State Private::FileSystemPathValidator::validate(QString &input, [[maybe_unused]] int &pos) const
 {
-    // ignore cursor position and validate the full path anyway
+    // we ignore cursor position and validate the full path anyway
-    Q_UNUSED(pos);
 
     m_lastTestResult = testPath(Path(input));
     m_lastValidationState = (m_lastTestResult == TestResult::OK)

src/gui/mainwindow.cpp

@@ -743,9 +743,8 @@ void MainWindow::on_actionDocumentation_triggered() const
     QDesktopServices::openUrl(QUrl(u"https://doc.qbittorrent.org"_s));
 }
 
-void MainWindow::tabChanged(int newTab)
+void MainWindow::tabChanged([[maybe_unused]] const int newTab)
 {
-    Q_UNUSED(newTab);
     // We cannot rely on the index newTab
     // because the tab order is undetermined now
     if (m_tabs->currentWidget() == m_splitter)

src/gui/notifications/dbusnotifier.cpp

@@ -76,19 +76,15 @@ void DBusNotifier::showMessage(const QString &title, const QString &message, con
     });
 }
 
-void DBusNotifier::onActionInvoked(const uint messageID, const QString &action)
+void DBusNotifier::onActionInvoked(const uint messageID, [[maybe_unused]] const QString &action)
 {
-    Q_UNUSED(action);
-
     // Check whether the notification is sent by qBittorrent
     // to avoid reacting to unrelated notifications
     if (m_activeMessages.contains(messageID))
         emit messageClicked();
 }
 
-void DBusNotifier::onNotificationClosed(const uint messageID, const uint reason)
+void DBusNotifier::onNotificationClosed(const uint messageID, [[maybe_unused]] const uint reason)
 {
-    Q_UNUSED(reason);
-
     m_activeMessages.remove(messageID);
 }

src/gui/search/searchwidget.cpp

@@ -255,16 +255,15 @@ SearchWidget::~SearchWidget()
     delete m_ui;
 }
 
-void SearchWidget::tabChanged(int index)
+void SearchWidget::tabChanged(const int index)
 {
     // when we switch from a tab that is not empty to another that is empty
     // the download button doesn't have to be available
     m_currentSearchTab = ((index < 0) ? nullptr : m_allTabs.at(m_ui->tabWidget->currentIndex()));
 }
 
-void SearchWidget::selectMultipleBox(int index)
+void SearchWidget::selectMultipleBox([[maybe_unused]] const int index)
 {
-    Q_UNUSED(index);
     if (selectedPlugin() == u"multi")
         on_pluginsButton_clicked();
 }

src/gui/torrentcontentmodel.cpp

@@ -293,9 +293,8 @@ QVector<BitTorrent::DownloadPriority> TorrentContentModel::getFilePriorities() c
     return prio;
 }
 
-int TorrentContentModel::columnCount(const QModelIndex &parent) const
+int TorrentContentModel::columnCount([[maybe_unused]] const QModelIndex &parent) const
 {
-    Q_UNUSED(parent);
     return TorrentContentModelItem::NB_COL;
 }
 

src/gui/torrentoptionsdialog.cpp

@@ -543,10 +543,8 @@ int TorrentOptionsDialog::getInactiveSeedingTime() const
     return m_ui->spinInactiveTimeLimit->value();
 }
 
-void TorrentOptionsDialog::handleCategoryChanged(const int index)
+void TorrentOptionsDialog::handleCategoryChanged([[maybe_unused]] const int index)
 {
-    Q_UNUSED(index);
-
     if (m_ui->checkAutoTMM->checkState() == Qt::Checked)
     {
         if (!m_allSameCategory && (m_ui->comboCategory->currentIndex() == 0))

src/gui/transferlistfilters/categoryfilterwidget.cpp

@@ -97,10 +97,8 @@ QString CategoryFilterWidget::currentCategory() const
     return getCategoryFilter(static_cast<CategoryFilterProxyModel *>(model()), current);
 }
 
-void CategoryFilterWidget::onCurrentRowChanged(const QModelIndex &current, const QModelIndex &previous)
+void CategoryFilterWidget::onCurrentRowChanged(const QModelIndex &current, [[maybe_unused]] const QModelIndex &previous)
 {
-    Q_UNUSED(previous);
-
     emit categoryChanged(getCategoryFilter(static_cast<CategoryFilterProxyModel *>(model()), current));
 }
 

src/gui/transferlistfilters/tagfilterwidget.cpp

@@ -95,10 +95,8 @@ QString TagFilterWidget::currentTag() const
     return getTagFilter(static_cast<TagFilterProxyModel *>(model()), current);
 }
 
-void TagFilterWidget::onCurrentRowChanged(const QModelIndex &current, const QModelIndex &previous)
+void TagFilterWidget::onCurrentRowChanged(const QModelIndex &current, [[maybe_unused]] const QModelIndex &previous)
 {
-    Q_UNUSED(previous);
-
     emit tagChanged(getTagFilter(static_cast<TagFilterProxyModel *>(model()), current));
 }
 

src/gui/watchedfoldersmodel.cpp

@@ -49,9 +49,8 @@ int WatchedFoldersModel::rowCount(const QModelIndex &parent) const
     return parent.isValid() ? 0 : m_watchedFolders.count();
 }
 
-int WatchedFoldersModel::columnCount(const QModelIndex &parent) const
+int WatchedFoldersModel::columnCount([[maybe_unused]] const QModelIndex &parent) const
 {
-    Q_UNUSED(parent);
     return 1;
 }
 

test/testalgorithm.cpp

@@ -69,9 +69,8 @@ private slots:
                 {3, 'b'},
                 {4, 'd'}
             };
-            Algorithm::removeIf(data, [](const int key, const char value)
+            Algorithm::removeIf(data, []([[maybe_unused]] const int key, const char value)
             {
-                Q_UNUSED(key);
                 return (value == 'b');
             });
             QCOMPARE(data.size(), 3);
@@ -83,9 +82,8 @@ private slots:
         }
         {
             QHash<int, char> data;
-            Algorithm::removeIf(data, [](const int key, const char value)
+            Algorithm::removeIf(data, []([[maybe_unused]] const int key, const char value)
             {
-                Q_UNUSED(key);
                 return (value == 'b');
             });
             QVERIFY(data.empty());