Replace `QString` with `QStringLiteral` when wrapping a string literal

Instantiates the utf-16 string at compile time rather performing a
unicode conversion at run-time

Pick-to: 6.5 6.6 6.7
Change-Id: I7c2e89437ad7f6c80022ac0dbb62c8dd46906ed5
Reviewed-by: Jøger Hansegård <joger.hansegard@qt.io>

24 files changed, 212 insertions, 119 deletions

diff --git a/examples/multimedia/audiodevices/audiodevices.cpp b/examples/multimedia/audiodevices/audiodevices.cpp
index 453f055f7..30f52e0c9 100644
--- a/examples/multimedia/audiodevices/audiodevices.cpp
+++ b/examples/multimedia/audiodevices/audiodevices.cpp
@@ -103,8 +103,8 @@ void AudioTest::test()
         } else {
             QAudioFormat nearest = m_deviceInfo.preferredFormat();
             testResult->setText(tr("Failed"));
-            nearestSampleRate->setText(QString("%1").arg(nearest.sampleRate()));
-            nearestChannel->setText(QString("%1").arg(nearest.channelCount()));
+            nearestSampleRate->setText(QStringLiteral("%1").arg(nearest.sampleRate()));
+            nearestChannel->setText(QStringLiteral("%1").arg(nearest.channelCount()));
             nearestSampleFormat->setText(toString(nearest.sampleFormat()));
         }
     } else
@@ -175,13 +175,13 @@ void AudioTest::populateTable()
         allFormatsTable->setItem(row, 2, sampleTypeItem);
 
         QTableWidgetItem *sampleRateItem =
-                new QTableWidgetItem(QString("%1 - %2")
+                new QTableWidgetItem(QStringLiteral("%1 - %2")
                                              .arg(m_deviceInfo.minimumSampleRate())
                                              .arg(m_deviceInfo.maximumSampleRate()));
         allFormatsTable->setItem(row, 0, sampleRateItem);
 
         QTableWidgetItem *channelsItem =
-                new QTableWidgetItem(QString("%1 - %2")
+                new QTableWidgetItem(QStringLiteral("%1 - %2")
                                              .arg(m_deviceInfo.minimumChannelCount())
                                              .arg(m_deviceInfo.maximumChannelCount()));
         allFormatsTable->setItem(row, 1, channelsItem);
diff --git a/examples/multimedia/player/player.cpp b/examples/multimedia/player/player.cpp
index 68b23ce34..771fd45cb 100644
--- a/examples/multimedia/player/player.cpp
+++ b/examples/multimedia/player/player.cpp
@@ -266,7 +266,7 @@ void Player::positionChanged(qint64 progress)
 void Player::metaDataChanged()
 {
     auto metaData = m_player->metaData();
-    setTrackInfo(QString("%1 - %2")
+    setTrackInfo(QStringLiteral("%1 - %2")
                          .arg(metaData.value(QMediaMetaData::AlbumArtist).toString())
                          .arg(metaData.value(QMediaMetaData::Title).toString()));
 
@@ -319,7 +319,7 @@ QString Player::trackName(const QMediaMetaData &metaData, int index)
         if (lang == QLocale::Language::AnyLanguage)
             name = title;
         else
-            name = QString("%1 - [%2]").arg(title).arg(QLocale::languageToString(lang));
+            name = QStringLiteral("%1 - [%2]").arg(title).arg(QLocale::languageToString(lang));
     }
     return name;
 }
@@ -474,7 +474,7 @@ void Player::setTrackInfo(const QString &info)
         m_statusLabel->setText(m_statusInfo);
     } else {
         if (!m_statusInfo.isEmpty())
-            setWindowTitle(QString("%1 | %2").arg(m_trackInfo).arg(m_statusInfo));
+            setWindowTitle(QStringLiteral("%1 | %2").arg(m_trackInfo).arg(m_statusInfo));
         else
             setWindowTitle(m_trackInfo);
     }
@@ -489,7 +489,7 @@ void Player::setStatusInfo(const QString &info)
         m_statusLabel->setText(m_statusInfo);
     } else {
         if (!m_statusInfo.isEmpty())
-            setWindowTitle(QString("%1 | %2").arg(m_trackInfo).arg(m_statusInfo));
+            setWindowTitle(QStringLiteral("%1 | %2").arg(m_trackInfo).arg(m_statusInfo));
         else
             setWindowTitle(m_trackInfo);
     }
diff --git a/examples/multimedia/player/playercontrols.cpp b/examples/multimedia/player/playercontrols.cpp
index d0c8c52d3..4933bf8cf 100644
--- a/examples/multimedia/player/playercontrols.cpp
+++ b/examples/multimedia/player/playercontrols.cpp
@@ -159,7 +159,7 @@ void PlayerControls::setPlaybackRate(float rate)
         }
     }
 
-    m_rateBox->addItem(QString("%1x").arg(rate), QVariant(rate));
+    m_rateBox->addItem(QStringLiteral("%1x").arg(rate), QVariant(rate));
     m_rateBox->setCurrentIndex(m_rateBox->count() - 1);
 }
 
diff --git a/examples/multimedia/spectrum/spectrograph.cpp b/examples/multimedia/spectrum/spectrograph.cpp
index 5a0584d9a..96274b50b 100644
--- a/examples/multimedia/spectrum/spectrograph.cpp
+++ b/examples/multimedia/spectrum/spectrograph.cpp
@@ -188,7 +188,7 @@ void Spectrograph::selectBar(int index)
 {
     const QPair<qreal, qreal> frequencyRange = barRange(index);
     const QString message =
-            QString("%1 - %2 Hz").arg(frequencyRange.first).arg(frequencyRange.second);
+            QStringLiteral("%1 - %2 Hz").arg(frequencyRange.first).arg(frequencyRange.second);
     emit infoMessage(message, BarSelectionInterval);
 
     if (NullTimerId != m_timerId)
diff --git a/examples/multimedia/spectrum/spectrumanalyser.cpp b/examples/multimedia/spectrum/spectrumanalyser.cpp
index d4c767e5e..c309c6a73 100644
--- a/examples/multimedia/spectrum/spectrumanalyser.cpp
+++ b/examples/multimedia/spectrum/spectrumanalyser.cpp
@@ -170,7 +170,7 @@ void SpectrumAnalyser::calculate(const QByteArray &buffer, const QAudioFormat &f
 #ifdef DUMP_SPECTRUMANALYSER
         m_count++;
         const QString pcmFileName =
-                m_outputDir.filePath(QString("spectrum_%1.pcm").arg(m_count, 4, 10, QChar('0')));
+                m_outputDir.filePath(QStringLiteral("spectrum_%1.pcm").arg(m_count, 4, 10, QChar('0')));
         QFile pcmFile(pcmFileName);
         pcmFile.open(QIODevice::WriteOnly);
         const int bufferLength = m_numSamples * bytesPerFrame;
diff --git a/examples/multimedia/spectrum/utils.cpp b/examples/multimedia/spectrum/utils.cpp
index f73571569..3b4146a51 100644
--- a/examples/multimedia/spectrum/utils.cpp
+++ b/examples/multimedia/spectrum/utils.cpp
@@ -34,7 +34,7 @@ QString formatToString(const QAudioFormat &format)
             break;
         }
 
-        QString formatChannels = QString("%1 channels").arg(format.channelCount());
+        QString formatChannels = QStringLiteral("%1 channels").arg(format.channelCount());
         switch (format.channelCount()) {
         case 1:
             formatChannels = "mono";
@@ -44,7 +44,7 @@ QString formatToString(const QAudioFormat &format)
             break;
         }
 
-        result = QString("%1 Hz %2 bit %3 %4")
+        result = QStringLiteral("%1 Hz %2 bit %3 %4")
                          .arg(format.sampleRate())
                          .arg(format.bytesPerSample() * 8)
                          .arg(formatType)
diff --git a/src/plugins/multimedia/ffmpeg/qffmpegmediaintegration.cpp b/src/plugins/multimedia/ffmpeg/qffmpegmediaintegration.cpp
index c6e41042c..291ca1111 100644
--- a/src/plugins/multimedia/ffmpeg/qffmpegmediaintegration.cpp
+++ b/src/plugins/multimedia/ffmpeg/qffmpegmediaintegration.cpp
@@ -99,7 +99,7 @@ static void qffmpegLogCallback(void *ptr, int level, const char *fmt, va_list vl
     if (level < 0 || level > av_log_get_level())
         return;
 
-    QString message = QString("FFmpeg log: %1").arg(QString::vasprintf(fmt, vl));
+    QString message = QStringLiteral("FFmpeg log: %1").arg(QString::vasprintf(fmt, vl));
     if (message.endsWith("\n"))
         message.removeLast();
 
diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
index 2f22c2ab7..13d7c0deb 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
@@ -130,7 +130,7 @@ bool QGstreamerAudioDecoder::processBusMessage(const QGstreamerMessage &message)
                        << "GST_STATE_PAUSED"
                        << "GST_STATE_PLAYING";
 
-                qDebug() << QString("state changed: old: %1  new: %2  pending: %3")
+                qDebug() << QStringLiteral("state changed: old: %1  new: %2  pending: %3")
                                     .arg(states[oldState])
                                     .arg(states[newState])
                                     .arg(states[pending])
diff --git a/tests/auto/integration/qaudiodecoderbackend/tst_qaudiodecoderbackend.cpp b/tests/auto/integration/qaudiodecoderbackend/tst_qaudiodecoderbackend.cpp
index 1961731b8..294b6cfc4 100644
--- a/tests/auto/integration/qaudiodecoderbackend/tst_qaudiodecoderbackend.cpp
+++ b/tests/auto/integration/qaudiodecoderbackend/tst_qaudiodecoderbackend.cpp
@@ -360,7 +360,7 @@ void tst_QAudioDecoderBackend::fileTest()
 
     QVERIFY(!d.isDecoding());
     QVERIFY(d.bufferAvailable() == false);
-    QCOMPARE(d.source(), QString(""));
+    QCOMPARE(d.source(), QStringLiteral(""));
     QVERIFY(d.audioFormat() == QAudioFormat());
 
     // Test local file
@@ -547,7 +547,7 @@ void tst_QAudioDecoderBackend::unsupportedFileTest()
 
     QVERIFY(!d.isDecoding());
     QVERIFY(d.bufferAvailable() == false);
-    QCOMPARE(d.source(), QString(""));
+    QCOMPARE(d.source(), QStringLiteral(""));
     QVERIFY(d.audioFormat() == QAudioFormat());
 
     // Test local file
@@ -802,7 +802,7 @@ void tst_QAudioDecoderBackend::deviceTest()
 
     QVERIFY(!d.isDecoding());
     QVERIFY(d.bufferAvailable() == false);
-    QCOMPARE(d.source(), QString(""));
+    QCOMPARE(d.source(), QStringLiteral(""));
     QVERIFY(d.audioFormat() == QAudioFormat());
     QFile file(m_wavFile->toString());
     QVERIFY(file.open(QIODevice::ReadOnly));
diff --git a/tests/auto/integration/qaudiosink/tst_qaudiosink.cpp b/tests/auto/integration/qaudiosink/tst_qaudiosink.cpp
index 486e437bd..cb16f02ce 100644
--- a/tests/auto/integration/qaudiosink/tst_qaudiosink.cpp
+++ b/tests/auto/integration/qaudiosink/tst_qaudiosink.cpp
@@ -85,10 +85,10 @@ private:
 
 QString tst_QAudioSink::formatToFileName(const QAudioFormat &format)
 {
-    return QString("%1_%2_%3")
-        .arg(format.sampleRate())
-        .arg(format.bytesPerSample())
-        .arg(format.channelCount());
+    return QStringLiteral("%1_%2_%3")
+            .arg(format.sampleRate())
+            .arg(format.bytesPerSample())
+            .arg(format.channelCount());
 }
 
 void tst_QAudioSink::createSineWaveData(const QAudioFormat &format, qint64 length, int sampleRate)
@@ -201,7 +201,7 @@ void tst_QAudioSink::generate_audiofile_testrows()
     QTest::addColumn<QAudioFormat>("audioFormat");
 
     for (int i=0; i<audioFiles.size(); i++) {
-        QTest::newRow(QString("Audio File %1").arg(i).toUtf8().constData())
+        QTest::newRow(QStringLiteral("Audio File %1").arg(i).toUtf8().constData())
                 << audioFiles.at(i) << testFormats.at(i);
     }
 }
@@ -296,11 +296,23 @@ void tst_QAudioSink::format()
     QAudioFormat actual    = audioOutput.format();
 
     QVERIFY2((requested.channelCount() == actual.channelCount()),
-            QString("channels: requested=%1, actual=%2").arg(requested.channelCount()).arg(actual.channelCount()).toUtf8().constData());
+             QStringLiteral("channels: requested=%1, actual=%2")
+                     .arg(requested.channelCount())
+                     .arg(actual.channelCount())
+                     .toUtf8()
+                     .constData());
     QVERIFY2((requested.sampleRate() == actual.sampleRate()),
-            QString("sampleRate: requested=%1, actual=%2").arg(requested.sampleRate()).arg(actual.sampleRate()).toUtf8().constData());
+             QStringLiteral("sampleRate: requested=%1, actual=%2")
+                     .arg(requested.sampleRate())
+                     .arg(actual.sampleRate())
+                     .toUtf8()
+                     .constData());
     QVERIFY2((requested.sampleFormat() == actual.sampleFormat()),
-            QString("sampleFormat: requested=%1, actual=%2").arg((ushort)requested.sampleFormat()).arg((ushort)actual.sampleFormat()).toUtf8().constData());
+             QStringLiteral("sampleFormat: requested=%1, actual=%2")
+                     .arg((ushort)requested.sampleFormat())
+                     .arg((ushort)actual.sampleFormat())
+                     .toUtf8()
+                     .constData());
     QVERIFY(requested == actual);
 }
 
@@ -360,12 +372,20 @@ void tst_QAudioSink::bufferSize()
     QFETCH(int, bufferSize);
     QAudioSink audioOutput(audioDevice.preferredFormat(), this);
 
-    QVERIFY2((audioOutput.error() == QAudio::NoError), QString("error() was not set to QAudio::NoError on creation(%1)").arg(bufferSize).toUtf8().constData());
+    QVERIFY2((audioOutput.error() == QAudio::NoError),
+             QStringLiteral("error() was not set to QAudio::NoError on creation(%1)")
+                     .arg(bufferSize)
+                     .toUtf8()
+                     .constData());
 
     audioOutput.setBufferSize(bufferSize);
     QVERIFY2((audioOutput.error() == QAudio::NoError), "error() is not QAudio::NoError after setBufferSize");
     QVERIFY2((audioOutput.bufferSize() == bufferSize),
-             QString("bufferSize: requested=%1, actual=%2").arg(bufferSize).arg(audioOutput.bufferSize()).toUtf8().constData());
+             QStringLiteral("bufferSize: requested=%1, actual=%2")
+                     .arg(bufferSize)
+                     .arg(audioOutput.bufferSize())
+                     .toUtf8()
+                     .constData());
 }
 
 void tst_QAudioSink::stopWhileStopped()
@@ -452,7 +472,7 @@ void tst_QAudioSink::pull()
 
     // Check that QAudioSink immediately transitions to ActiveState
     QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal on start(), got %1 signals instead")
+                 QStringLiteral("didn't emit signal on start(), got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -476,7 +496,7 @@ void tst_QAudioSink::pull()
     audioOutput.stop();
     QTest::qWait(40);
     QVERIFY2((stateSignal.size() == 1),
-             QString("didn't emit StoppedState signal after stop(), got %1 signals instead")
+             QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
                      .arg(dumpStateSignalSpy(stateSignal))
                      .toUtf8()
                      .constData());
@@ -510,7 +530,7 @@ void tst_QAudioSink::pullSuspendResume()
     audioOutput.start(audioFile.data());
     // Check that QAudioSink immediately transitions to ActiveState
     QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal on start(), got %1 signals instead")
+                 QStringLiteral("didn't emit signal on start(), got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -525,9 +545,13 @@ void tst_QAudioSink::pullSuspendResume()
     audioOutput.suspend();
     QTest::qWait(100);
 
-    QTRY_VERIFY2((stateSignal.size() == 1),
-             QString("didn't emit SuspendedState signal after suspend(), got %1 signals instead")
-             .arg(dumpStateSignalSpy(stateSignal)).toUtf8().constData());
+    QTRY_VERIFY2(
+            (stateSignal.size() == 1),
+            QStringLiteral(
+                    "didn't emit SuspendedState signal after suspend(), got %1 signals instead")
+                    .arg(dumpStateSignalSpy(stateSignal))
+                    .toUtf8()
+                    .constData());
     QVERIFY2((audioOutput.state() == QAudio::SuspendedState), "didn't transition to SuspendedState after suspend()");
     QVERIFY2((audioOutput.error() == QAudio::NoError), "error state is not equal to QAudio::NoError after suspend()");
     stateSignal.clear();
@@ -543,7 +567,7 @@ void tst_QAudioSink::pullSuspendResume()
 
     // Check that QAudioSink immediately transitions to ActiveState
     QVERIFY2((stateSignal.size() == 1),
-             QString("didn't emit signal after resume(), got %1 signals instead")
+             QStringLiteral("didn't emit signal after resume(), got %1 signals instead")
                      .arg(dumpStateSignalSpy(stateSignal))
                      .toUtf8()
                      .constData());
@@ -563,7 +587,7 @@ void tst_QAudioSink::pullSuspendResume()
     audioOutput.stop();
     QTest::qWait(40);
     QVERIFY2((stateSignal.size() == 1),
-             QString("didn't emit StoppedState signal after stop(), got %1 signals instead")
+             QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
                      .arg(dumpStateSignalSpy(stateSignal))
                      .toUtf8()
                      .constData());
@@ -666,7 +690,7 @@ void tst_QAudioSink::push()
 
     // Check that QAudioSink immediately transitions to IdleState
     QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal on start(), got %1 signals instead")
+                 QStringLiteral("didn't emit signal on start(), got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -684,7 +708,7 @@ void tst_QAudioSink::push()
     auto checker = [&]() {
         // Check for transition to ActiveState when data is provided
         QVERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal after receiving data, got %1 signals instead")
+                 QStringLiteral("didn't emit signal after receiving data, got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -711,7 +735,10 @@ void tst_QAudioSink::push()
     audioOutput.stop();
     QTest::qWait(40);
     QVERIFY2((stateSignal.size() == 1),
-             QString("didn't emit StoppedState signal after stop(), got %1 signals instead").arg(dumpStateSignalSpy(stateSignal)).toUtf8().constData());
+             QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
+                     .arg(dumpStateSignalSpy(stateSignal))
+                     .toUtf8()
+                     .constData());
     QVERIFY2((audioOutput.state() == QAudio::StoppedState), "didn't transitions to StoppedState after stop()");
 
     QVERIFY2((audioOutput.error() == QAudio::NoError), "error() is not QAudio::NoError after stop()");
@@ -744,7 +771,7 @@ void tst_QAudioSink::pushSuspendResume()
 
     // Check that QAudioSink immediately transitions to IdleState
     QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal on start(), got %1 signals instead")
+                 QStringLiteral("didn't emit signal on start(), got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -759,7 +786,7 @@ void tst_QAudioSink::pushSuspendResume()
 
     auto firstHalfChecker = [&]() {
         QVERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal after receiving data, got %1 signals instead")
+                 QStringLiteral("didn't emit signal after receiving data, got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -779,9 +806,13 @@ void tst_QAudioSink::pushSuspendResume()
     const auto suspendedInState = audioOutput.state();
     audioOutput.suspend();
 
-    QTRY_VERIFY2((stateSignal.size() == 1),
-             QString("didn't emit SuspendedState signal after suspend(), got %1 signals instead")
-             .arg(dumpStateSignalSpy(stateSignal)).toUtf8().constData());
+    QTRY_VERIFY2(
+            (stateSignal.size() == 1),
+            QStringLiteral(
+                    "didn't emit SuspendedState signal after suspend(), got %1 signals instead")
+                    .arg(dumpStateSignalSpy(stateSignal))
+                    .toUtf8()
+                    .constData());
     QVERIFY2((audioOutput.state() == QAudio::SuspendedState), "didn't transition to SuspendedState after suspend()");
     QVERIFY2((audioOutput.error() == QAudio::NoError), "error state is not equal to QAudio::NoError after suspend()");
     stateSignal.clear();
@@ -801,7 +832,7 @@ void tst_QAudioSink::pushSuspendResume()
 
     // Check that QAudioSink immediately transitions to IdleState
     QVERIFY2((stateSignal.size() == 1),
-             QString("didn't emit signal after resume(), got %1 signals instead")
+             QStringLiteral("didn't emit signal after resume(), got %1 signals instead")
                      .arg(dumpStateSignalSpy(stateSignal))
                      .toUtf8()
                      .constData());
@@ -832,7 +863,7 @@ void tst_QAudioSink::pushSuspendResume()
     audioOutput.stop();
     QTest::qWait(40);
     QVERIFY2((stateSignal.size() == 1),
-             QString("didn't emit StoppedState signal after stop(), got %1 signals instead")
+             QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
                      .arg(dumpStateSignalSpy(stateSignal))
                      .toUtf8()
                      .constData());
@@ -908,7 +939,7 @@ void tst_QAudioSink::pushUnderrun()
 
     // Check that QAudioSink immediately transitions to IdleState
     QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal on start(), got %1 signals instead")
+                 QStringLiteral("didn't emit signal on start(), got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -927,7 +958,7 @@ void tst_QAudioSink::pushUnderrun()
 
     auto firstHalfChecker = [&]() {
         QVERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal after receiving data, got %1 signals instead")
+                 QStringLiteral("didn't emit signal after receiving data, got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -946,8 +977,10 @@ void tst_QAudioSink::pushUnderrun()
     QTest::qWait(700);
 
     QVERIFY2((stateSignal.size() == 1),
-             QString("didn't emit IdleState signal after suspend(), got %1 signals instead")
-             .arg(dumpStateSignalSpy(stateSignal)).toUtf8().constData());
+             QStringLiteral("didn't emit IdleState signal after suspend(), got %1 signals instead")
+                     .arg(dumpStateSignalSpy(stateSignal))
+                     .toUtf8()
+                     .constData());
     QVERIFY2((audioOutput.state() == QAudio::IdleState), "didn't transition to IdleState, no data");
     QVERIFY2((audioOutput.error() == QAudio::UnderrunError), "error state is not equal to QAudio::UnderrunError, no data");
     stateSignal.clear();
@@ -955,7 +988,7 @@ void tst_QAudioSink::pushUnderrun()
     // Play rest of the clip
     auto restChecker = [&]() {
         QVERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit signal after receiving data, got %1 signals instead")
+                 QStringLiteral("didn't emit signal after receiving data, got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -971,7 +1004,7 @@ void tst_QAudioSink::pushUnderrun()
     // Wait until playback finishes
     QVERIFY2(audioFile->atEnd(), "didn't play to EOF");
     QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit IdleState signal when at EOF, got %1 signals instead")
+                 QStringLiteral("didn't emit IdleState signal when at EOF, got %1 signals instead")
                          .arg(dumpStateSignalSpy(stateSignal))
                          .toUtf8()
                          .constData());
@@ -983,7 +1016,7 @@ void tst_QAudioSink::pushUnderrun()
     audioOutput.stop();
     QTest::qWait(40);
     QVERIFY2((stateSignal.size() == 1),
-             QString("didn't emit StoppedState signal after stop(), got %1 signals instead")
+             QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
                      .arg(dumpStateSignalSpy(stateSignal))
                      .toUtf8()
                      .constData());
diff --git a/tests/auto/integration/qaudiosource/tst_qaudiosource.cpp b/tests/auto/integration/qaudiosource/tst_qaudiosource.cpp
index 545dc5d4a..cc4128e97 100644
--- a/tests/auto/integration/qaudiosource/tst_qaudiosource.cpp
+++ b/tests/auto/integration/qaudiosource/tst_qaudiosource.cpp
@@ -85,7 +85,7 @@ void tst_QAudioSource::generate_audiofile_testrows()
     QTest::addColumn<QAudioFormat>("audioFormat");
 
     for (int i=0; i<audioFiles.size(); i++) {
-        QTest::newRow(QString("%1").arg(i).toUtf8().constData())
+        QTest::newRow(QStringLiteral("%1").arg(i).toUtf8().constData())
                 << audioFiles.at(i) << testFormats.at(i);
 
         // Only run first format in CI system to reduce test times
@@ -96,10 +96,10 @@ void tst_QAudioSource::generate_audiofile_testrows()
 
 QString tst_QAudioSource::formatToFileName(const QAudioFormat &format)
 {
-    return QString("%1_%2_%3")
-        .arg(format.sampleRate())
-        .arg(format.bytesPerSample())
-        .arg(format.channelCount());
+    return QStringLiteral("%1_%2_%3")
+            .arg(format.sampleRate())
+            .arg(format.bytesPerSample())
+            .arg(format.channelCount());
 }
 
 void tst_QAudioSource::initTestCase()
@@ -187,11 +187,23 @@ void tst_QAudioSource::format()
     QAudioFormat actual    = audioInput.format();
 
     QVERIFY2((requested.channelCount() == actual.channelCount()),
-            QString("channels: requested=%1, actual=%2").arg(requested.channelCount()).arg(actual.channelCount()).toUtf8().constData());
+             QStringLiteral("channels: requested=%1, actual=%2")
+                     .arg(requested.channelCount())
+                     .arg(actual.channelCount())
+                     .toUtf8()
+                     .constData());
     QVERIFY2((requested.sampleRate() == actual.sampleRate()),
-            QString("sampleRate: requested=%1, actual=%2").arg(requested.sampleRate()).arg(actual.sampleRate()).toUtf8().constData());
+             QStringLiteral("sampleRate: requested=%1, actual=%2")
+                     .arg(requested.sampleRate())
+                     .arg(actual.sampleRate())
+                     .toUtf8()
+                     .constData());
     QVERIFY2((requested.sampleFormat() == actual.sampleFormat()),
-            QString("sampleFormat: requested=%1, actual=%2").arg((ushort)requested.sampleFormat()).arg((ushort)actual.sampleFormat()).toUtf8().constData());
+             QStringLiteral("sampleFormat: requested=%1, actual=%2")
+                     .arg((ushort)requested.sampleFormat())
+                     .arg((ushort)actual.sampleFormat())
+                     .toUtf8()
+                     .constData());
     QCOMPARE(actual, requested);
 }
 
@@ -248,17 +260,26 @@ void tst_QAudioSource::bufferSize()
     audioInput.setBufferSize(512);
     QVERIFY2((audioInput.error() == QAudio::NoError), "error() is not QAudio::NoError after setBufferSize(512)");
     QVERIFY2((audioInput.bufferSize() == 512),
-            QString("bufferSize: requested=512, actual=%2").arg(audioInput.bufferSize()).toUtf8().constData());
+             QStringLiteral("bufferSize: requested=512, actual=%2")
+                     .arg(audioInput.bufferSize())
+                     .toUtf8()
+                     .constData());
 
     audioInput.setBufferSize(4096);
     QVERIFY2((audioInput.error() == QAudio::NoError), "error() is not QAudio::NoError after setBufferSize(4096)");
     QVERIFY2((audioInput.bufferSize() == 4096),
-            QString("bufferSize: requested=4096, actual=%2").arg(audioInput.bufferSize()).toUtf8().constData());
+             QStringLiteral("bufferSize: requested=4096, actual=%2")
+                     .arg(audioInput.bufferSize())
+                     .toUtf8()
+                     .constData());
 
     audioInput.setBufferSize(8192);
     QVERIFY2((audioInput.error() == QAudio::NoError), "error() is not QAudio::NoError after setBufferSize(8192)");
     QVERIFY2((audioInput.bufferSize() == 8192),
-            QString("bufferSize: requested=8192, actual=%2").arg(audioInput.bufferSize()).toUtf8().constData());
+             QStringLiteral("bufferSize: requested=8192, actual=%2")
+                     .arg(audioInput.bufferSize())
+                     .toUtf8()
+                     .constData());
 }
 
 void tst_QAudioSource::stopWhileStopped()
@@ -365,14 +386,19 @@ void tst_QAudioSource::pull()
 
     qint64 processedUs = audioInput.processedUSecs();
     QVERIFY2(qTolerantCompare(processedUs, 3000000LL),
-             QString("processedUSecs() doesn't fall in acceptable range, should be 3000000 (%1)")
+             QStringLiteral(
+                     "processedUSecs() doesn't fall in acceptable range, should be 3000000 (%1)")
                      .arg(processedUs)
                      .toUtf8()
                      .constData());
 
     audioInput.stop();
-    QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit StoppedState signal after stop(), got %1 signals instead").arg(stateSignal.size()).toUtf8().constData());
+    QTRY_VERIFY2(
+            (stateSignal.size() == 1),
+            QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
+                    .arg(stateSignal.size())
+                    .toUtf8()
+                    .constData());
     QVERIFY2((audioInput.state() == QAudio::StoppedState), "didn't transitions to StoppedState after stop()");
 
     QVERIFY2((audioInput.error() == QAudio::NoError), "error() is not QAudio::NoError after stop()");
@@ -433,8 +459,13 @@ void tst_QAudioSource::pullSuspendResume()
 
     audioInput.suspend();
 
-    QTRY_VERIFY2((stateSignal.size() == 1),
-             QString("didn't emit SuspendedState signal after suspend(), got %1 signals instead").arg(stateSignal.size()).toUtf8().constData());
+    QTRY_VERIFY2(
+            (stateSignal.size() == 1),
+            QStringLiteral(
+                    "didn't emit SuspendedState signal after suspend(), got %1 signals instead")
+                    .arg(stateSignal.size())
+                    .toUtf8()
+                    .constData());
     QVERIFY2((audioInput.state() == QAudio::SuspendedState), "didn't transitions to SuspendedState after stop()");
     QVERIFY2((audioInput.error() == QAudio::NoError), "error() is not QAudio::NoError after stop()");
     stateSignal.clear();
@@ -443,7 +474,8 @@ void tst_QAudioSource::pullSuspendResume()
     qint64 elapsedUs = audioInput.elapsedUSecs();
     qint64 processedUs = audioInput.processedUSecs();
     QVERIFY2(qTolerantCompare(processedUs, 3000000LL),
-             QString("processedUSecs() doesn't fall in acceptable range, should be 3000000 (%1)")
+             QStringLiteral(
+                     "processedUSecs() doesn't fall in acceptable range, should be 3000000 (%1)")
                      .arg(processedUs)
                      .toUtf8()
                      .constData());
@@ -454,15 +486,22 @@ void tst_QAudioSource::pullSuspendResume()
 
     // Check that QAudioSource immediately transitions to ActiveState
     QTRY_VERIFY2((stateSignal.size() == 1),
-             QString("didn't emit signal after resume(), got %1 signals instead").arg(stateSignal.size()).toUtf8().constData());
+                 QStringLiteral("didn't emit signal after resume(), got %1 signals instead")
+                         .arg(stateSignal.size())
+                         .toUtf8()
+                         .constData());
     QVERIFY2((audioInput.state() == QAudio::ActiveState), "didn't transition to ActiveState after resume()");
     QVERIFY2((audioInput.error() == QAudio::NoError), "error state is not equal to QAudio::NoError after resume()");
     stateSignal.clear();
 
     audioInput.stop();
     QTest::qWait(40);
-    QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit StoppedState signal after stop(), got %1 signals instead").arg(stateSignal.size()).toUtf8().constData());
+    QTRY_VERIFY2(
+            (stateSignal.size() == 1),
+            QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
+                    .arg(stateSignal.size())
+                    .toUtf8()
+                    .constData());
     QVERIFY2((audioInput.state() == QAudio::StoppedState), "didn't transitions to StoppedState after stop()");
 
     QVERIFY2((audioInput.error() == QAudio::NoError), "error() is not QAudio::NoError after stop()");
@@ -537,12 +576,20 @@ void tst_QAudioSource::push()
     qint64 processedUs = audioInput.processedUSecs();
 
     audioInput.stop();
-    QTRY_VERIFY2((stateSignal.size() == 1),
-                 QString("didn't emit StoppedState signal after stop(), got %1 signals instead").arg(stateSignal.size()).toUtf8().constData());
+    QTRY_VERIFY2(
+            (stateSignal.size() == 1),
+            QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
+                    .arg(stateSignal.size())
+                    .toUtf8()
+                    .constData());
     QVERIFY2((audioInput.state() == QAudio::StoppedState), "didn't transitions to StoppedState after stop()");
 
     QVERIFY2(qTolerantCompare(processedUs, 500000LL),
-             QString("processedUSecs() doesn't fall in acceptable range, should be 500000 (%1)").arg(processedUs).toUtf8().constData());
+             QStringLiteral(
+                     "processedUSecs() doesn't fall in acceptable range, should be 500000 (%1)")
+                     .arg(processedUs)
+                     .toUtf8()
+                     .constData());
     QVERIFY2((audioInput.error() == QAudio::NoError), "error() is not QAudio::NoError after stop()");
     QVERIFY2((audioInput.elapsedUSecs() == (qint64)0), "elapsedUSecs() not equal to zero in StoppedState");
 
@@ -614,8 +661,13 @@ void tst_QAudioSource::pushSuspendResume()
 
     audioInput.suspend();
 
-    QTRY_VERIFY2((stateSignal.size() == 1),
-             QString("didn't emit SuspendedState signal after suspend(), got %1 signals instead").arg(stateSignal.size()).toUtf8().constData());
+    QTRY_VERIFY2(
+            (stateSignal.size() == 1),
+            QStringLiteral(
+                    "didn't emit SuspendedState signal after suspend(), got %1 signals instead")
+                    .arg(stateSignal.size())
+                    .toUtf8()
+                    .constData());
     QVERIFY2((audioInput.state() == QAudio::SuspendedState), "didn't transitions to SuspendedState after stop()");
     QVERIFY2((audioInput.error() == QAudio::NoError), "error() is not QAudio::NoError after stop()");
     stateSignal.clear();
@@ -655,12 +707,20 @@ void tst_QAudioSource::pushSuspendResume()
     processedUs = audioInput.processedUSecs();
 
     audioInput.stop();
-    QTRY_VERIFY2((stateSignal.size() == 1),
-             QString("didn't emit StoppedState signal after stop(), got %1 signals instead").arg(stateSignal.size()).toUtf8().constData());
+    QTRY_VERIFY2(
+            (stateSignal.size() == 1),
+            QStringLiteral("didn't emit StoppedState signal after stop(), got %1 signals instead")
+                    .arg(stateSignal.size())
+                    .toUtf8()
+                    .constData());
     QVERIFY2((audioInput.state() == QAudio::StoppedState), "didn't transitions to StoppedState after stop()");
 
     QVERIFY2(qTolerantCompare(processedUs, 1000000LL),
-             QString("processedUSecs() doesn't fall in acceptable range, should be 2040000 (%1)").arg(processedUs).toUtf8().constData());
+             QStringLiteral(
+                     "processedUSecs() doesn't fall in acceptable range, should be 2040000 (%1)")
+                     .arg(processedUs)
+                     .toUtf8()
+                     .constData());
     QVERIFY2((audioInput.elapsedUSecs() == (qint64)0), "elapsedUSecs() not equal to zero in StoppedState");
 
     //WavHeader::writeDataLength(*audioFile,audioFile->pos()-WavHeader::headerLength());
diff --git a/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp b/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp
index 2343bfdb3..bf736b490 100644
--- a/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp
+++ b/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp
@@ -2110,7 +2110,7 @@ void tst_QMediaPlayerBackend::surfaceTest()
     player.setSource(*m_localVideoFile);
     player.play();
     QTRY_VERIFY(player.position() >= 1000);
-    QVERIFY2(surface.m_totalFrames >= 25, qPrintable(QString("Expected >= 25, got %1").arg(surface.m_totalFrames)));
+    QVERIFY2(surface.m_totalFrames >= 25, qPrintable(QStringLiteral("Expected >= 25, got %1").arg(surface.m_totalFrames)));
 }
 
 void tst_QMediaPlayerBackend::metadata()
@@ -2216,7 +2216,7 @@ void tst_QMediaPlayerBackend::playFromBuffer()
     player.setSourceDevice(&file, *m_localVideoFile);
     player.play();
     QTRY_VERIFY(player.position() >= 1000);
-    QVERIFY2(surface.m_totalFrames >= 25, qPrintable(QString("Expected >= 25, got %1").arg(surface.m_totalFrames)));
+    QVERIFY2(surface.m_totalFrames >= 25, qPrintable(QStringLiteral("Expected >= 25, got %1").arg(surface.m_totalFrames)));
 }
 
 void tst_QMediaPlayerBackend::audioVideoAvailable()
diff --git a/tests/auto/integration/qscreencapturebackend/tst_qscreencapturebackend.cpp b/tests/auto/integration/qscreencapturebackend/tst_qscreencapturebackend.cpp
index fff6c3be7..217f3dfc7 100644
--- a/tests/auto/integration/qscreencapturebackend/tst_qscreencapturebackend.cpp
+++ b/tests/auto/integration/qscreencapturebackend/tst_qscreencapturebackend.cpp
@@ -464,7 +464,7 @@ void tst_QScreenCaptureBackend::capture_capturesToFile_whenConnectedToMediaRecor
         QImage image = sink.images().at(i);
         QVERIFY(!image.isNull());
         QRgb rgb = image.pixel(point);
-//        qDebug() << QString("RGB: %1, %2, %3").arg(qRed(rgb)).arg(qGreen(rgb)).arg(qBlue(rgb));
+//        qDebug() << QStringLiteral("RGB: %1, %2, %3").arg(qRed(rgb)).arg(qGreen(rgb)).arg(qBlue(rgb));
 
         // RGB values should be 0, 0, 255. Compensating for inaccurate video encoding.
         QVERIFY(qRed(rgb) <= 60);
@@ -477,7 +477,7 @@ void tst_QScreenCaptureBackend::capture_capturesToFile_whenConnectedToMediaRecor
         QImage image = sink.images().at(i);
         QVERIFY(!image.isNull());
         QRgb rgb = image.pixel(point);
-//        qDebug() << QString("RGB: %1, %2, %3").arg(qRed(rgb)).arg(qGreen(rgb)).arg(qBlue(rgb));
+//        qDebug() << QStringLiteral("RGB: %1, %2, %3").arg(qRed(rgb)).arg(qGreen(rgb)).arg(qBlue(rgb));
 
         // RGB values should be 0, 255, 0. Compensating for inaccurate video encoding.
         QVERIFY(qRed(rgb) <= 60);
diff --git a/tests/auto/integration/qwindowcapturebackend/fixture.cpp b/tests/auto/integration/qwindowcapturebackend/fixture.cpp
index 953b88ba7..43a8c869d 100644
--- a/tests/auto/integration/qwindowcapturebackend/fixture.cpp
+++ b/tests/auto/integration/qwindowcapturebackend/fixture.cpp
@@ -58,11 +58,11 @@ bool WindowCaptureFixture::compareImages(QImage actual, const QImage &expected,
     qWarning() << "Expected image:";
     qWarning() << expected;
 
-    const QString actualName = getResultsPath(QString("actual%1.png").arg(fileSuffix));
+    const QString actualName = getResultsPath(QStringLiteral("actual%1.png").arg(fileSuffix));
     if (!actual.save(actualName))
         qWarning() << "Failed to save actual file to " << actualName;
 
-    const QString expectedName = getResultsPath(QString("expected%1.png").arg(fileSuffix));
+    const QString expectedName = getResultsPath(QStringLiteral("expected%1.png").arg(fileSuffix));
     if (!expected.save(expectedName))
         qWarning() << "Failed to save expected file to " << expectedName;
 
diff --git a/tests/auto/unit/multimedia/qaudiodecoder/tst_qaudiodecoder.cpp b/tests/auto/unit/multimedia/qaudiodecoder/tst_qaudiodecoder.cpp
index cde83423d..1d2c39e7f 100644
--- a/tests/auto/unit/multimedia/qaudiodecoder/tst_qaudiodecoder.cpp
+++ b/tests/auto/unit/multimedia/qaudiodecoder/tst_qaudiodecoder.cpp
@@ -40,7 +40,7 @@ void tst_QAudioDecoder::ctors()
     QAudioDecoder d;
     QVERIFY(!d.isDecoding());
     QVERIFY(d.bufferAvailable() == false);
-    QCOMPARE(d.source(), QString(""));
+    QCOMPARE(d.source(), QStringLiteral(""));
 
     d.setSource(QUrl());
     QVERIFY(!d.isDecoding());
diff --git a/tests/auto/unit/multimedia/qaudionamespace/tst_qaudionamespace.cpp b/tests/auto/unit/multimedia/qaudionamespace/tst_qaudionamespace.cpp
index 4dcc05c0c..56d710087 100644
--- a/tests/auto/unit/multimedia/qaudionamespace/tst_qaudionamespace.cpp
+++ b/tests/auto/unit/multimedia/qaudionamespace/tst_qaudionamespace.cpp
@@ -210,7 +210,7 @@ void tst_QAudioNamespace::convertVolume()
 
     qreal actualOutput = QAudio::convertVolume(input, from, to);
     QVERIFY2(qAbs(actualOutput - expectedOutput) < 0.01,
-             QString("actual: %1, expected: %2").arg(actualOutput).arg(expectedOutput).toLocal8Bit().constData());
+             QStringLiteral("actual: %1, expected: %2").arg(actualOutput).arg(expectedOutput).toLocal8Bit().constData());
 }
 
 QTEST_MAIN(tst_QAudioNamespace)
diff --git a/tests/auto/unit/multimedia/qcamera/tst_qcamera.cpp b/tests/auto/unit/multimedia/qcamera/tst_qcamera.cpp
index 38838f7f7..d2091330e 100644
--- a/tests/auto/unit/multimedia/qcamera/tst_qcamera.cpp
+++ b/tests/auto/unit/multimedia/qcamera/tst_qcamera.cpp
@@ -609,7 +609,7 @@ void tst_QCamera::testErrorSignal()
     QSignalSpy spyError(&camera, SIGNAL(errorOccurred(QCamera::Error,const QString&)));
 
     /* Set the QPlatformCamera error and verify if the signal is emitted correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("Camera Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("Camera Error"));
 
     QVERIFY(spyError.size() == 1);
     QCamera::Error err = qvariant_cast<QCamera::Error >(spyError.at(0).at(0));
@@ -618,7 +618,7 @@ void tst_QCamera::testErrorSignal()
     spyError.clear();
 
     /* Set the QPlatformCamera error and verify if the signal is emitted correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("InvalidRequestError Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("InvalidRequestError Error"));
     QVERIFY(spyError.size() == 1);
     err = qvariant_cast<QCamera::Error >(spyError.at(0).at(0));
     QVERIFY(err == QCamera::CameraError);
@@ -626,7 +626,7 @@ void tst_QCamera::testErrorSignal()
     spyError.clear();
 
     /* Set the QPlatformCamera error and verify if the signal is emitted correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("NotSupportedFeatureError Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("NotSupportedFeatureError Error"));
     QVERIFY(spyError.size() == 1);
     err = qvariant_cast<QCamera::Error >(spyError.at(0).at(0));
     QVERIFY(err == QCamera::CameraError);
@@ -642,15 +642,15 @@ void tst_QCamera::testError()
     auto *service = QMockIntegration::instance()->lastCaptureService();
 
     /* Set the QPlatformCamera error and verify if it is set correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("Camera Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("Camera Error"));
     QVERIFY(camera.error() == QCamera::CameraError);
 
     /* Set the QPlatformCamera error and verify if it is set correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("InvalidRequestError Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("InvalidRequestError Error"));
     QVERIFY(camera.error() == QCamera::CameraError);
 
     /* Set the QPlatformCamera error and verify if it is set correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("CameraError Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("CameraError Error"));
     QVERIFY(camera.error() == QCamera::CameraError);
 
 }
@@ -664,16 +664,16 @@ void tst_QCamera::testErrorString()
     auto *service = QMockIntegration::instance()->lastCaptureService();
 
     /* Set the QPlatformCamera error and verify if it is set correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("Camera Error"));
-    QVERIFY(camera.errorString() == QString("Camera Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("Camera Error"));
+    QVERIFY(camera.errorString() == QStringLiteral("Camera Error"));
 
     /* Set the QPlatformCamera error and verify if it is set correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("InvalidRequestError Error"));
-    QVERIFY(camera.errorString() == QString("InvalidRequestError Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("InvalidRequestError Error"));
+    QVERIFY(camera.errorString() == QStringLiteral("InvalidRequestError Error"));
 
     /* Set the QPlatformCamera error and verify if it is set correctly in QCamera */
-    service->mockCameraControl->setError(QCamera::CameraError,QString("CameraError Error"));
-    QVERIFY(camera.errorString() == QString("CameraError Error"));
+    service->mockCameraControl->setError(QCamera::CameraError,QStringLiteral("CameraError Error"));
+    QVERIFY(camera.errorString() == QStringLiteral("CameraError Error"));
 }
 
 void tst_QCamera::testSetCameraFormat()
diff --git a/tests/auto/unit/multimedia/qerrorinfo/tst_qerrorinfo.cpp b/tests/auto/unit/multimedia/qerrorinfo/tst_qerrorinfo.cpp
index 4528f7c5f..0d266705d 100644
--- a/tests/auto/unit/multimedia/qerrorinfo/tst_qerrorinfo.cpp
+++ b/tests/auto/unit/multimedia/qerrorinfo/tst_qerrorinfo.cpp
@@ -62,22 +62,22 @@ void tst_QErrorInfo::setAndNotify_setsErrorAndNotifes_data()
     QTest::newRow("No error -> An error with empty string")
             << TestError::NoError << QString() << TestError::ErrorA << QString() << true << true;
     QTest::newRow("No error -> An error with non-empty string")
-            << TestError::NoError << QString() << TestError::ErrorB << QString("error") << true
+            << TestError::NoError << QString() << TestError::ErrorB << QStringLiteral("error") << true
             << true;
     QTest::newRow("An error with empty string -> No error")
             << TestError::ErrorA << QString() << TestError::NoError << QString() << true << false;
     QTest::newRow("An error with non-empty string -> No Error")
-            << TestError::ErrorA << QString("error") << TestError::NoError << QString() << true
+            << TestError::ErrorA << QStringLiteral("error") << TestError::NoError << QString() << true
             << false;
     QTest::newRow("An error -> Another error")
-            << TestError::ErrorA << QString("error A") << TestError::ErrorB << QString("error B")
+            << TestError::ErrorA << QStringLiteral("error A") << TestError::ErrorB << QStringLiteral("error B")
             << true << true;
     QTest::newRow("An error -> Another error with empty string")
-            << TestError::ErrorA << QString("error A") << TestError::ErrorB << QString() << true
+            << TestError::ErrorA << QStringLiteral("error A") << TestError::ErrorB << QString() << true
             << true;
     QTest::newRow("An error -> The same error with changed string")
-            << TestError::ErrorA << QString("error") << TestError::ErrorA
-            << QString("another error") << true << true;
+            << TestError::ErrorA << QStringLiteral("error") << TestError::ErrorA
+            << QStringLiteral("another error") << true << true;
 }
 
 void tst_QErrorInfo::setAndNotify_setsErrorAndNotifes()
diff --git a/tests/auto/unit/multimedia/qmediaplayer/tst_qmediaplayer.cpp b/tests/auto/unit/multimedia/qmediaplayer/tst_qmediaplayer.cpp
index 5062f8adf..772584d68 100644
--- a/tests/auto/unit/multimedia/qmediaplayer/tst_qmediaplayer.cpp
+++ b/tests/auto/unit/multimedia/qmediaplayer/tst_qmediaplayer.cpp
@@ -176,7 +176,7 @@ void tst_QMediaPlayer::setupCommonTestData()
                                 qreal(1)  << QMediaPlayer::NoError << QString();
     QTest::newRow("valid+error") << true << QMediaPlayer::StoppedState << QMediaPlayer::InvalidMedia <<
                                 QUrl(QUrl("http://example.com/stream")) << qint64(0) << qint64(0) << false << 50 << false << false << 0 <<
-                                qreal(0) << QMediaPlayer::ResourceError << QString("Resource unavailable");
+                                qreal(0) << QMediaPlayer::ResourceError << QStringLiteral("Resource unavailable");
 }
 
 void tst_QMediaPlayer::initTestCase()
diff --git a/tests/auto/unit/multimedia/qmediarecorder/tst_qmediarecorder.cpp b/tests/auto/unit/multimedia/qmediarecorder/tst_qmediarecorder.cpp
index 11520e066..41e971b14 100644
--- a/tests/auto/unit/multimedia/qmediarecorder/tst_qmediarecorder.cpp
+++ b/tests/auto/unit/multimedia/qmediarecorder/tst_qmediarecorder.cpp
@@ -209,14 +209,14 @@ void tst_QMediaRecorder::testSink()
 {
     encoder->setOutputLocation(QUrl("test.tmp"));
     QUrl s = encoder->outputLocation();
-    QCOMPARE(s.toString(), QString("test.tmp"));
+    QCOMPARE(s.toString(), QStringLiteral("test.tmp"));
     QCOMPARE(encoder->actualLocation(), QUrl());
 
     //the actual location is available after record
     encoder->record();
-    QCOMPARE(encoder->actualLocation().toString(), QString("test.tmp"));
+    QCOMPARE(encoder->actualLocation().toString(), QStringLiteral("test.tmp"));
     encoder->stop();
-    QCOMPARE(encoder->actualLocation().toString(), QString("test.tmp"));
+    QCOMPARE(encoder->actualLocation().toString(), QStringLiteral("test.tmp"));
 
     //setOutputLocation resets the actual location
     encoder->setOutputLocation(QUrl());
@@ -473,7 +473,7 @@ void tst_QMediaRecorder::testApplicationInative()
     encoder.setQuality(QMediaRecorder::VeryHighQuality);
 
     encoder.setOutputLocation(QUrl("test.tmp"));
-    QCOMPARE(encoder.outputLocation().toString(), QString("test.tmp"));
+    QCOMPARE(encoder.outputLocation().toString(), QStringLiteral("test.tmp"));
     QCOMPARE(encoder.actualLocation(), QUrl());
 
     encoder.record();
@@ -487,7 +487,7 @@ void tst_QMediaRecorder::testApplicationInative()
     encoder.stop();
 
     // the actual location is available after record
-    QCOMPARE(encoder.actualLocation().toString(), QString("test.tmp"));
+    QCOMPARE(encoder.actualLocation().toString(), QStringLiteral("test.tmp"));
 }
 
 QTEST_GUILESS_MAIN(tst_QMediaRecorder)
diff --git a/tests/auto/unit/multimedia/qvideobuffers/tst_qvideobuffers.cpp b/tests/auto/unit/multimedia/qvideobuffers/tst_qvideobuffers.cpp
index f966cdfb5..97f5e3b62 100644
--- a/tests/auto/unit/multimedia/qvideobuffers/tst_qvideobuffers.cpp
+++ b/tests/auto/unit/multimedia/qvideobuffers/tst_qvideobuffers.cpp
@@ -67,9 +67,9 @@ private:
         QTest::addColumn<QVideoFrame::MapMode>("mapMode");
 
         for (auto mode : modes) {
-            QTest::newRow(QString("ImageBuffer, %1").arg(mapModeToString(mode)).toUtf8().constData())
+            QTest::newRow(QStringLiteral("ImageBuffer, %1").arg(mapModeToString(mode)).toUtf8().constData())
                     << createImageBuffer() << mode;
-            QTest::newRow(QString("MemoryBuffer, %1").arg(mapModeToString(mode)).toUtf8().constData())
+            QTest::newRow(QStringLiteral("MemoryBuffer, %1").arg(mapModeToString(mode)).toUtf8().constData())
                     << createMemoryBuffer() << mode;
         }
     }
diff --git a/tests/auto/unit/multimedia/qvideoframecolormanagement/tst_qvideoframecolormanagement.cpp b/tests/auto/unit/multimedia/qvideoframecolormanagement/tst_qvideoframecolormanagement.cpp
index c8e4330b7..31337603e 100644
--- a/tests/auto/unit/multimedia/qvideoframecolormanagement/tst_qvideoframecolormanagement.cpp
+++ b/tests/auto/unit/multimedia/qvideoframecolormanagement/tst_qvideoframecolormanagement.cpp
@@ -101,7 +101,7 @@ std::vector<QVideoFrameFormat::ColorSpace> colorSpaces()
 
 QString name(const TestParams &p)
 {
-    return QString("%1_%2_%3_%4")
+    return QStringLiteral("%1_%2_%3_%4")
             .arg(p.fileName)
             .arg(toString(p.pixelFormat))
             .arg(toString(p.colorSpace))
diff --git a/tests/auto/unit/multimedia/qwavedecoder/tst_qwavedecoder.cpp b/tests/auto/unit/multimedia/qwavedecoder/tst_qwavedecoder.cpp
index 2a079d9f9..36a9bf7ab 100644
--- a/tests/auto/unit/multimedia/qwavedecoder/tst_qwavedecoder.cpp
+++ b/tests/auto/unit/multimedia/qwavedecoder/tst_qwavedecoder.cpp
@@ -60,7 +60,7 @@ void tst_QWaveDecoder::cleanupTestCase()
 
 static QString testFilePath(const char *filename)
 {
-    QString path = QString("data/%1").arg(filename);
+    QString path = QStringLiteral("data/%1").arg(filename);
     return QFINDTESTDATA(path);
 }
 
diff --git a/tests/manual/devices/main.cpp b/tests/manual/devices/main.cpp
index f8ab3c074..67b277812 100644
--- a/tests/manual/devices/main.cpp
+++ b/tests/manual/devices/main.cpp
@@ -93,7 +93,7 @@ static void printVideoDeviceInfo(QTextStream &out, const QCameraDevice &cameraDe
     out.setFieldWidth(30);
     out << "Photo Resolutions: ";
     for (auto &resolution : photoResolutions) {
-        QString s = QString("%1x%2").arg(resolution.width()).arg(resolution.height());
+        QString s = QStringLiteral("%1x%2").arg(resolution.width()).arg(resolution.height());
         out << qSetFieldWidth(0) << s << ", ";
     }
     out.setFieldWidth(10);
@@ -102,7 +102,7 @@ static void printVideoDeviceInfo(QTextStream &out, const QCameraDevice &cameraDe
     for (auto &format : videoFormats) {
         out.setFieldWidth(30);
         QString s =
-                QString("%1x%2").arg(format.resolution().width()).arg(format.resolution().height());
+                QStringLiteral("%1x%2").arg(format.resolution().width()).arg(format.resolution().height());
         out << "Resolution: " << s << qSetFieldWidth(0) << Qt::endl;
         out.setFieldWidth(30);
         out << "Frame Rate: " << qSetFieldWidth(0) << "Min:" << format.minFrameRate()