diff --git a/src/corelib/codecs/qicucodec.cpp b/src/corelib/codecs/qicucodec.cpp
index aa2095d9da..ee9f1d0048 100644
--- a/src/corelib/codecs/qicucodec.cpp
+++ b/src/corelib/codecs/qicucodec.cpp
@@ -527,7 +527,7 @@ QTextCodec *QIcuCodec::codecForNameUnlocked(const char *name)
     // check whether there is really a converter for the name available.
     UConverter *conv = ucnv_open(standardName, &error);
     if (!conv) {
-        qDebug() << "codecForName: ucnv_open failed" << standardName << u_errorName(error);
+        qDebug("codecForName: ucnv_open failed %s %s", standardName, u_errorName(error));
         return 0;
     }
     //qDebug() << "QIcuCodec: Standard name for " << name << "is" << standardName;
@@ -577,7 +577,7 @@ UConverter *QIcuCodec::getConverter(QTextCodec::ConverterState *state) const
             ucnv_setSubstChars(static_cast<UConverter *>(state->d),
                                state->flags & QTextCodec::ConvertInvalidToNull ? "\0" : "?", 1, &error);
             if (U_FAILURE(error))
-                qDebug() << "getConverter(state) ucnv_open failed" << m_name << u_errorName(error);
+                qDebug("getConverter(state) ucnv_open failed %s %s", m_name, u_errorName(error));
         }
         conv = static_cast<UConverter *>(state->d);
     }
@@ -587,7 +587,7 @@ UConverter *QIcuCodec::getConverter(QTextCodec::ConverterState *state) const
         conv = ucnv_open(m_name, &error);
         ucnv_setSubstChars(conv, "?", 1, &error);
         if (U_FAILURE(error))
-            qDebug() << "getConverter(no state) ucnv_open failed" << m_name << u_errorName(error);
+            qDebug("getConverter(no state) ucnv_open failed %s %s", m_name, u_errorName(error));
     }
     return conv;
 }
@@ -610,7 +610,7 @@ QString QIcuCodec::convertToUnicode(const char *chars, int length, QTextCodec::C
                        &chars, end,
                        0, false, &error);
         if (!U_SUCCESS(error) && error != U_BUFFER_OVERFLOW_ERROR) {
-            qDebug() << "convertToUnicode failed:" << u_errorName(error);
+            qDebug("convertToUnicode failed: %s", u_errorName(error));
             break;
         }
 
@@ -647,7 +647,7 @@ QByteArray QIcuCodec::convertFromUnicode(const QChar *unicode, int length, QText
                          &uc, end,
                          0, false, &error);
         if (!U_SUCCESS(error))
-            qDebug() << "convertFromUnicode failed:" << u_errorName(error);
+            qDebug("convertFromUnicode failed: %s", u_errorName(error));
         convertedChars = ch - string.data();
         if (uc >= end)
             break;
diff --git a/src/corelib/io/qfsfileengine.cpp b/src/corelib/io/qfsfileengine.cpp
index 7a04939cdb..098bc49468 100644
--- a/src/corelib/io/qfsfileengine.cpp
+++ b/src/corelib/io/qfsfileengine.cpp
@@ -545,7 +545,7 @@ bool QFSFileEnginePrivate::seekFdFh(qint64 pos)
     } else {
         // Unbuffered stdio mode.
         if (QT_LSEEK(fd, QT_OFF_T(pos), SEEK_SET) == -1) {
-            qWarning() << "QFile::at: Cannot set file position" << pos;
+            qWarning("QFile::at: Cannot set file position %lld", pos);
             q->setError(QFile::PositionError, qt_error_string(errno));
             return false;
         }
diff --git a/src/corelib/io/qlockfile_win.cpp b/src/corelib/io/qlockfile_win.cpp
index 261363f320..ba4a091965 100644
--- a/src/corelib/io/qlockfile_win.cpp
+++ b/src/corelib/io/qlockfile_win.cpp
@@ -100,7 +100,7 @@ QLockFile::LockError QLockFilePrivate::tryLock_sys()
                 ? QLockFile::LockFailedError
                 : QLockFile::PermissionError;
         default:
-            qWarning() << "Got unexpected locking error" << lastError;
+            qWarning("Got unexpected locking error %llu", quint64(lastError));
             return QLockFile::UnknownError;
         }
     }
diff --git a/src/corelib/kernel/qppsobject.cpp b/src/corelib/kernel/qppsobject.cpp
index dbff997c88..f716c1a92e 100644
--- a/src/corelib/kernel/qppsobject.cpp
+++ b/src/corelib/kernel/qppsobject.cpp
@@ -397,12 +397,12 @@ QByteArray QPpsObjectPrivate::encode(const QVariantMap &ppsData, bool *ok)
 void QPpsObjectPrivate::encodeData(pps_encoder_t *encoder, const char *name, const QVariant &data,
                                    bool *ok)
 {
-    QString errorFunction;
+    const char *errorFunction;
     pps_encoder_error_t error = PPS_ENCODER_OK;
     switch (data.type()) {
     case QVariant::Bool:
         error = pps_encoder_add_bool(encoder, name, data.toBool());
-        errorFunction = QStringLiteral("pps_encoder_add_bool");
+        errorFunction = "pps_encoder_add_bool";
         break;
     // We want to support encoding uint even though libpps doesn't support it directly.
     // We can't encode uint as an int since that will lose precision (e.g. 2^31+1 can't be
@@ -411,41 +411,41 @@ void QPpsObjectPrivate::encodeData(pps_encoder_t *encoder, const char *name, con
     case QVariant::UInt:
     case QVariant::Double:
         error = pps_encoder_add_double(encoder, name, data.toDouble());
-        errorFunction = QStringLiteral("pps_encoder_add_double");
+        errorFunction = "pps_encoder_add_double";
         break;
     case QVariant::Int:
         error = pps_encoder_add_int(encoder, name, data.toInt());
-        errorFunction = QStringLiteral("pps_encoder_add_int");
+        errorFunction = "pps_encoder_add_int";
         break;
     case QVariant::LongLong:
         error = pps_encoder_add_int64(encoder, name, data.toLongLong());
-        errorFunction = QStringLiteral("pps_encoder_add_int64");
+        errorFunction = "pps_encoder_add_int64";
         break;
     case QVariant::String:
         error = pps_encoder_add_string(encoder, name, data.toString().toUtf8().constData());
-        errorFunction = QStringLiteral("pps_encoder_add_string");
+        errorFunction = "pps_encoder_add_string";
         break;
     case QVariant::List:
         error = pps_encoder_start_array(encoder, name);
-        errorFunction = QStringLiteral("pps_encoder_start_array");
+        errorFunction = "pps_encoder_start_array";
         if (error == PPS_ENCODER_OK) {
             encodeArray(encoder, data.toList(), ok);
             error = pps_encoder_end_array(encoder);
-            errorFunction = QStringLiteral("pps_encoder_end_array");
+            errorFunction = "pps_encoder_end_array";
         }
         break;
     case QVariant::Map:
         error = pps_encoder_start_object(encoder, name);
-        errorFunction = QStringLiteral("pps_encoder_start_object");
+        errorFunction = "pps_encoder_start_object";
         if (error == PPS_ENCODER_OK) {
             encodeObject(encoder, data.toMap(), ok);
             error = pps_encoder_end_object(encoder);
-            errorFunction = QStringLiteral("pps_encoder_end_object");
+            errorFunction = "pps_encoder_end_object";
         }
         break;
     case QVariant::Invalid:
         error = pps_encoder_add_null(encoder, name);
-        errorFunction = QStringLiteral("pps_encoder_add_null");
+        errorFunction = "pps_encoder_add_null";
         break;
     default:
         qWarning("QPpsObjectPrivate::encodeData: the type of the parameter data is invalid");
@@ -454,7 +454,7 @@ void QPpsObjectPrivate::encodeData(pps_encoder_t *encoder, const char *name, con
     }
 
     if (error != PPS_ENCODER_OK) {
-        qWarning() << "QPpsObjectPrivate::encodeData: " << errorFunction << " failed";
+        qWarning("QPpsObjectPrivate::encodeData: %s failed", errorFunction);
         *ok = false;
     } else {
         *ok = true;
diff --git a/src/corelib/kernel/qsystemsemaphore_posix.cpp b/src/corelib/kernel/qsystemsemaphore_posix.cpp
index 6137239467..9fbf5779b8 100644
--- a/src/corelib/kernel/qsystemsemaphore_posix.cpp
+++ b/src/corelib/kernel/qsystemsemaphore_posix.cpp
@@ -147,7 +147,7 @@ bool QSystemSemaphorePrivate::modifySemaphore(int count)
             if (::sem_post(semaphore) == -1) {
                 setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore (sem_post)"));
 #if defined QSYSTEMSEMAPHORE_DEBUG
-                qDebug() << QLatin1String("QSystemSemaphore::modify sem_post failed") << count << errno;
+                qDebug("QSystemSemaphore::modify sem_post failed %d %d", count, errno);
 #endif
                 // rollback changes to preserve the SysV semaphore behavior
                 for ( ; cnt < count; ++cnt) {
@@ -169,7 +169,7 @@ bool QSystemSemaphorePrivate::modifySemaphore(int count)
             }
             setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore (sem_wait)"));
 #if defined QSYSTEMSEMAPHORE_DEBUG
-            qDebug() << QLatin1String("QSystemSemaphore::modify sem_wait failed") << count << errno;
+            qDebug("QSystemSemaphore::modify sem_wait failed %d %d", count, errno);
 #endif
             return false;
         }
diff --git a/src/corelib/kernel/qsystemsemaphore_systemv.cpp b/src/corelib/kernel/qsystemsemaphore_systemv.cpp
index f4fdfa5f58..1967899a58 100644
--- a/src/corelib/kernel/qsystemsemaphore_systemv.cpp
+++ b/src/corelib/kernel/qsystemsemaphore_systemv.cpp
@@ -187,7 +187,8 @@ bool QSystemSemaphorePrivate::modifySemaphore(int count)
         }
         setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore"));
 #if defined QSYSTEMSEMAPHORE_DEBUG
-        qDebug() << QLatin1String("QSystemSemaphore::modify failed") << count << semctl(semaphore, 0, GETVAL) << errno << EIDRM << EINVAL;
+        qDebug("QSystemSemaphore::modify failed %d %d %d %d %d",
+               count, int(semctl(semaphore, 0, GETVAL)), int(errno), int(EIDRM), int(EINVAL);
 #endif
         return false;
     }
diff --git a/src/gui/image/qimagereader.cpp b/src/gui/image/qimagereader.cpp
index 8bf0ce3523..dd1f0c8943 100644
--- a/src/gui/image/qimagereader.cpp
+++ b/src/gui/image/qimagereader.cpp
@@ -450,8 +450,8 @@ static QImageIOHandler *createReadHandlerHelper(QIODevice *device,
 
             if (handler) {
 #ifdef QIMAGEREADER_DEBUG
-                qDebug() << "QImageReader::createReadHandler: the" << _qt_BuiltInFormats[currentFormat].extension
-                         << "built-in handler can read this data";
+                qDebug("QImageReader::createReadHandler: the %s built-in handler can read this data",
+                       _qt_BuiltInFormats[currentFormat].extension);
 #endif
                 break;
             }
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 129e93db8d..1f102dcec5 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -1186,7 +1186,7 @@ static void init_plugins(const QList<QByteArray> &pluginList)
         if (plugin)
             QGuiApplicationPrivate::generic_plugin_list.append(plugin);
         else
-            qWarning() << "No such plugin for spec " << pluginSpec;
+            qWarning("No such plugin for spec \"%s\"", pluginSpec.constData());
     }
 }
 
diff --git a/src/gui/kernel/qhighdpiscaling.cpp b/src/gui/kernel/qhighdpiscaling.cpp
index 4cc9e95e81..d6e467db59 100644
--- a/src/gui/kernel/qhighdpiscaling.cpp
+++ b/src/gui/kernel/qhighdpiscaling.cpp
@@ -68,10 +68,11 @@ static inline qreal initialGlobalScaleFactor()
         }
     } else {
         if (qEnvironmentVariableIsSet(legacyDevicePixelEnvVar)) {
-            qWarning() << "Warning:" << legacyDevicePixelEnvVar << "is deprecated. Instead use:" << endl
-                       << "   " << autoScreenEnvVar << "to enable platform plugin controlled per-screen factors." << endl
-                       << "   " << screenFactorsEnvVar << "to set per-screen factors." << endl
-                       << "   " << scaleFactorEnvVar << "to set the application global scale factor.";
+            qWarning("Warning: %s is deprecated. Instead use:\n"
+                     "   %s to enable platform plugin controlled per-screen factors.\n"
+                     "   %s to set per-screen factors.\n"
+                     "   %s to set the application global scale factor.",
+                     legacyDevicePixelEnvVar, autoScreenEnvVar, screenFactorsEnvVar, scaleFactorEnvVar);
 
             int dpr = qEnvironmentVariableIntValue(legacyDevicePixelEnvVar);
             if (dpr > 0)
diff --git a/src/gui/opengl/qopenglengineshadermanager.cpp b/src/gui/opengl/qopenglengineshadermanager.cpp
index 4e3d14ba37..1d3e47f93b 100644
--- a/src/gui/opengl/qopenglengineshadermanager.cpp
+++ b/src/gui/opengl/qopenglengineshadermanager.cpp
@@ -390,7 +390,7 @@ QOpenGLEngineShaderProg *QOpenGLEngineSharedShaders::findProgramInCache(const QO
             fragShader->setObjectName(QString::fromLatin1(description));
 #endif
             if (!fragShader->compileSourceCode(fragSource)) {
-                qWarning() << "Warning:" << description << "failed to compile!";
+                qWarning("Warning: \"%s\" failed to compile!", description.constData());
                 break;
             }
 
@@ -405,7 +405,7 @@ QOpenGLEngineShaderProg *QOpenGLEngineSharedShaders::findProgramInCache(const QO
             vertexShader->setObjectName(QString::fromLatin1(description));
 #endif
             if (!vertexShader->compileSourceCode(vertexSource)) {
-                qWarning() << "Warning:" << description << "failed to compile!";
+                qWarning("Warning: \"%s\" failed to compile!", description.constData());
                 break;
             }
 
diff --git a/src/gui/opengl/qopenglshaderprogram.cpp b/src/gui/opengl/qopenglshaderprogram.cpp
index 4134513210..f076e10e20 100644
--- a/src/gui/opengl/qopenglshaderprogram.cpp
+++ b/src/gui/opengl/qopenglshaderprogram.cpp
@@ -337,9 +337,10 @@ bool QOpenGLShaderPrivate::compile(QOpenGLShader *q)
 
         // Dump the source code if we got it
         if (sourceCodeBuffer) {
-            qWarning("*** Problematic %s shader source code ***", type);
-            qWarning() << qPrintable(QString::fromLatin1(sourceCodeBuffer));
-            qWarning("***");
+            qWarning("*** Problematic %s shader source code ***\n"
+                     "%ls\n"
+                     "***",
+                     type, qUtf16Printable(QString::fromLatin1(sourceCodeBuffer)));
         }
 
         // Cleanup
@@ -1215,8 +1216,7 @@ int QOpenGLShaderProgram::attributeLocation(const char *name) const
     if (d->linked && d->programGuard && d->programGuard->id()) {
         return d->glfuncs->glGetAttribLocation(d->programGuard->id(), name);
     } else {
-        qWarning() << "QOpenGLShaderProgram::attributeLocation(" << name
-                   << "): shader program is not linked";
+        qWarning("QOpenGLShaderProgram::attributeLocation(%s): shader program is not linked", name);
         return -1;
     }
 }
@@ -1479,7 +1479,7 @@ void QOpenGLShaderProgram::setAttributeValue
     Q_D(QOpenGLShaderProgram);
     Q_UNUSED(d);
     if (rows < 1 || rows > 4) {
-        qWarning() << "QOpenGLShaderProgram::setAttributeValue: rows" << rows << "not supported";
+        qWarning("QOpenGLShaderProgram::setAttributeValue: rows %d not supported", rows);
         return;
     }
     if (location != -1) {
@@ -1891,8 +1891,7 @@ int QOpenGLShaderProgram::uniformLocation(const char *name) const
     if (d->linked && d->programGuard && d->programGuard->id()) {
         return d->glfuncs->glGetUniformLocation(d->programGuard->id(), name);
     } else {
-        qWarning() << "QOpenGLShaderProgram::uniformLocation(" << name
-                   << "): shader program is not linked";
+        qWarning("QOpenGLShaderProgram::uniformLocation(%s): shader program is not linked", name);
         return -1;
     }
 }
@@ -2819,7 +2818,7 @@ void QOpenGLShaderProgram::setUniformValueArray(int location, const GLfloat *val
         else if (tupleSize == 4)
             d->glfuncs->glUniform4fv(location, count, values);
         else
-            qWarning() << "QOpenGLShaderProgram::setUniformValue: size" << tupleSize << "not supported";
+            qWarning("QOpenGLShaderProgram::setUniformValue: size %d not supported", tupleSize);
     }
 }
 
diff --git a/src/network/access/qspdyprotocolhandler.cpp b/src/network/access/qspdyprotocolhandler.cpp
index 1a6dd04ecb..4641516549 100644
--- a/src/network/access/qspdyprotocolhandler.cpp
+++ b/src/network/access/qspdyprotocolhandler.cpp
@@ -458,7 +458,7 @@ bool QSpdyProtocolHandler::uncompressHeader(const QByteArray &input, QByteArray
             break;
         }
         default: {
-            qWarning() << "got unexpected zlib return value:" << zlibRet;
+            qWarning("got unexpected zlib return value: %d", zlibRet);
             return false;
         }
         }
@@ -849,7 +849,7 @@ void QSpdyProtocolHandler::handleControlFrame(const QByteArray &frameHeaders) //
         break;
     }
     default:
-        qWarning() << "cannot handle frame of type" << type;
+        qWarning("cannot handle frame of type %d", int(type));
     }
 }
 
@@ -1085,7 +1085,7 @@ void QSpdyProtocolHandler::handleSETTINGS(char flags, quint32 /*length*/, const
             break;
         }
         default:
-            qWarning() << "found unknown settings value" << value;
+            qWarning("found unknown settings value %u", uint(value));
         }
     }
 }
@@ -1124,7 +1124,7 @@ void QSpdyProtocolHandler::handleGOAWAY(char /*flags*/, quint32 /*length*/,
         break;
     }
     default:
-        qWarning() << "unexpected status code" << statusCode;
+        qWarning("unexpected status code %d", int(statusCode));
         errorCode = QNetworkReply::ProtocolUnknownError;
     }
 
diff --git a/src/plugins/platforms/qnx/qqnxbuttoneventnotifier.cpp b/src/plugins/platforms/qnx/qqnxbuttoneventnotifier.cpp
index a08ac2b839..90a09d3087 100644
--- a/src/plugins/platforms/qnx/qqnxbuttoneventnotifier.cpp
+++ b/src/plugins/platforms/qnx/qqnxbuttoneventnotifier.cpp
@@ -97,7 +97,7 @@ void QQnxButtonEventNotifier::start()
     m_readNotifier = new QSocketNotifier(m_fd, QSocketNotifier::Read);
     QObject::connect(m_readNotifier, SIGNAL(activated(int)), this, SLOT(updateButtonStates()));
 
-    qButtonDebug() << "successfully connected to Navigator. fd =" << m_fd;
+    qButtonDebug("successfully connected to Navigator. fd = %d", m_fd);
 }
 
 void QQnxButtonEventNotifier::updateButtonStates()
@@ -121,7 +121,7 @@ void QQnxButtonEventNotifier::updateButtonStates()
     // Ensure data is null terminated
     buffer[bytes] = '\0';
 
-    qButtonDebug() << "received PPS message:\n" << buffer;
+    qButtonDebug("received PPS message:\n%s", buffer);
 
     // Process received message
     QByteArray ppsData = QByteArray::fromRawData(buffer, bytes);
diff --git a/src/plugins/platforms/qnx/qqnxinputcontext_imf.cpp b/src/plugins/platforms/qnx/qqnxinputcontext_imf.cpp
index 79ff74b113..ce3a445d7c 100644
--- a/src/plugins/platforms/qnx/qqnxinputcontext_imf.cpp
+++ b/src/plugins/platforms/qnx/qqnxinputcontext_imf.cpp
@@ -721,7 +721,7 @@ void QQnxInputContext::update(Qt::InputMethodQueries queries)
             initEvent(&caretEvent.event, sInputSession, EVENT_CARET, CARET_POS_CHANGED, sizeof(caretEvent));
             caretEvent.old_pos = lastCaret;
             caretEvent.new_pos = m_caretPosition;
-            qInputContextDebug() << "ictrl_dispatch_event caret changed" << lastCaret << m_caretPosition;
+            qInputContextDebug("ictrl_dispatch_event caret changed %d %d", lastCaret, m_caretPosition);
             p_ictrl_dispatch_event(&caretEvent.event);
         }
     }
@@ -914,7 +914,7 @@ bool QQnxInputContext::handleKeyboardEvent(int flags, int sym, int mod, int scan
             navigation_event_t navEvent;
             initEvent(&navEvent.event, sInputSession, EVENT_NAVIGATION, key, sizeof(navEvent));
             navEvent.magnitude = 1;
-            qInputContextDebug() << "ictrl_dispatch_even navigation" << key;
+            qInputContextDebug("ictrl_dispatch_even navigation %d", key);
             p_ictrl_dispatch_event(&navEvent.event);
         }
     } else {
@@ -927,7 +927,7 @@ bool QQnxInputContext::handleKeyboardEvent(int flags, int sym, int mod, int scan
         keyEvent.sequence_id = sequenceId;
 
         p_ictrl_dispatch_event(&keyEvent.event);
-        qInputContextDebug() << "ictrl_dispatch_even key" << key;
+        qInputContextDebug("ictrl_dispatch_even key %d", key);
     }
 
     return true;
@@ -943,7 +943,7 @@ void QQnxInputContext::updateCursorPosition()
     QCoreApplication::sendEvent(input, &query);
     m_caretPosition = query.value(Qt::ImCursorPosition).toInt();
 
-    qInputContextDebug() << m_caretPosition;
+    qInputContextDebug("%d", m_caretPosition);
 }
 
 void QQnxInputContext::endComposition()
@@ -1116,7 +1116,7 @@ int32_t QQnxInputContext::processEvent(event_t *event)
         int flags = KEY_SYM_VALID | KEY_CAP_VALID;
         if (event->event_id == IMF_KEY_DOWN)
             flags |= KEY_DOWN;
-        qInputContextDebug() << "EVENT_KEY" << flags << keySym;
+        qInputContextDebug("EVENT_KEY %d %d", flags, keySym);
         QQnxScreenEventHandler::injectKeyboardEvent(flags, keySym, modifiers, 0, keyCap);
         result = 0;
         break;
@@ -1156,7 +1156,7 @@ int32_t QQnxInputContext::onCommitText(spannable_string_t *text, int32_t new_cur
 
 int32_t QQnxInputContext::onDeleteSurroundingText(int32_t left_length, int32_t right_length)
 {
-    qInputContextDebug() << "L:" << left_length << " R:" << right_length;
+    qInputContextDebug("L: %d R: %d", int(left_length), int(right_length));
 
     QObject *input = qGuiApp->focusObject();
     if (!input)
diff --git a/src/plugins/platforms/qnx/qqnxintegration.cpp b/src/plugins/platforms/qnx/qqnxintegration.cpp
index 3a0e97af6e..9d38742d6f 100644
--- a/src/plugins/platforms/qnx/qqnxintegration.cpp
+++ b/src/plugins/platforms/qnx/qqnxintegration.cpp
@@ -453,11 +453,11 @@ void QQnxIntegration::createDisplays()
         Q_SCREEN_CHECKERROR(result, "Failed to query display attachment");
 
         if (!isAttached) {
-            qIntegrationDebug() << "Skipping non-attached display" << i;
+            qIntegrationDebug("Skipping non-attached display %d", i);
             continue;
         }
 
-        qIntegrationDebug() << "Creating screen for display" << i;
+        qIntegrationDebug("Creating screen for display %d", i);
         createDisplay(displays[i], /*isPrimary=*/false);
     } // of displays iteration
 }
diff --git a/src/plugins/platforms/qnx/qqnxnavigatoreventhandler.cpp b/src/plugins/platforms/qnx/qqnxnavigatoreventhandler.cpp
index 4955938a3a..0e16764b79 100644
--- a/src/plugins/platforms/qnx/qqnxnavigatoreventhandler.cpp
+++ b/src/plugins/platforms/qnx/qqnxnavigatoreventhandler.cpp
@@ -63,14 +63,14 @@ bool QQnxNavigatorEventHandler::handleOrientationCheck(int angle)
 {
     // reply to navigator that (any) orientation is acceptable
     // TODO: check if top window flags prohibit orientation change
-    qNavigatorEventHandlerDebug() << "angle=" << angle;
+    qNavigatorEventHandlerDebug("angle=%d", angle);
     return true;
 }
 
 void QQnxNavigatorEventHandler::handleOrientationChange(int angle)
 {
     // update screen geometry and reply to navigator that we're ready
-    qNavigatorEventHandlerDebug() << "angle=" << angle;
+    qNavigatorEventHandlerDebug("angle=%d", angle);
     emit rotationChanged(angle);
 }
 
diff --git a/src/plugins/platforms/qnx/qqnxnavigatoreventnotifier.cpp b/src/plugins/platforms/qnx/qqnxnavigatoreventnotifier.cpp
index 9ccda2d94a..1f630863b7 100644
--- a/src/plugins/platforms/qnx/qqnxnavigatoreventnotifier.cpp
+++ b/src/plugins/platforms/qnx/qqnxnavigatoreventnotifier.cpp
@@ -91,8 +91,7 @@ void QQnxNavigatorEventNotifier::start()
     errno = 0;
     m_fd = open(navigatorControlPath, O_RDWR);
     if (m_fd == -1) {
-        qNavigatorEventNotifierDebug() << "failed to open navigator pps:"
-                                                      << strerror(errno);
+        qNavigatorEventNotifierDebug("failed to open navigator pps: %s", strerror(errno));
         return;
     }
 
diff --git a/src/plugins/platforms/qnx/qqnxnavigatorpps.cpp b/src/plugins/platforms/qnx/qqnxnavigatorpps.cpp
index fd1bbc4a85..d5234ca92f 100644
--- a/src/plugins/platforms/qnx/qqnxnavigatorpps.cpp
+++ b/src/plugins/platforms/qnx/qqnxnavigatorpps.cpp
@@ -79,7 +79,7 @@ bool QQnxNavigatorPps::openPpsConnection()
         return false;
     }
 
-    qNavigatorDebug() << "successfully connected to Navigator. fd=" << m_fd;
+    qNavigatorDebug("successfully connected to Navigator. fd=%d", m_fd);
 
     return true;
 }
diff --git a/src/plugins/platforms/qnx/qqnxscreen.cpp b/src/plugins/platforms/qnx/qqnxscreen.cpp
index 16ddcd784b..678e83cd57 100644
--- a/src/plugins/platforms/qnx/qqnxscreen.cpp
+++ b/src/plugins/platforms/qnx/qqnxscreen.cpp
@@ -340,11 +340,12 @@ qreal QQnxScreen::refreshRate() const
         qWarning("QQnxScreen: Failed to query screen mode. Using default value of 60Hz");
         return 60.0;
     }
-    qScreenDebug() << "screen mode:" << endl
-                   << "      width =" << displayMode.width << endl
-                   << "     height =" << displayMode.height << endl
-                   << "    refresh =" << displayMode.refresh << endl
-                   << " interlaced =" << displayMode.interlaced;
+    qScreenDebug("screen mode:\n"
+                 "      width = %u\n"
+                 "     height = %u\n"
+                 "    refresh = %u\n"
+                 " interlaced = %u",
+                 uint(displayMode.width), uint(displayMode.height), uint(displayMode.refresh), uint(displayMode.interlaced));
     return static_cast<qreal>(displayMode.refresh);
 }
 
@@ -404,7 +405,7 @@ static bool isOrthogonal(int angle1, int angle2)
 
 void QQnxScreen::setRotation(int rotation)
 {
-    qScreenDebug() << "orientation =" << rotation;
+    qScreenDebug("orientation = %d", rotation);
     // Check if rotation changed
     // We only want to rotate if we are the primary screen
     if (m_currentRotation != rotation && isPrimaryScreen()) {
diff --git a/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp b/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
index 599d43a8c8..42651732c2 100644
--- a/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
+++ b/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
@@ -147,7 +147,7 @@ bool QQnxScreenEventHandler::handleEvent(screen_event_t event, int qnxType)
 
     default:
         // event ignored
-        qScreenEventDebug() << "unknown event" << qnxType;
+        qScreenEventDebug("unknown event %d", qnxType);
         return false;
     }
 
diff --git a/src/plugins/platforms/qnx/qqnxvirtualkeyboardpps.cpp b/src/plugins/platforms/qnx/qqnxvirtualkeyboardpps.cpp
index 1174dc6ab3..025c03c058 100644
--- a/src/plugins/platforms/qnx/qqnxvirtualkeyboardpps.cpp
+++ b/src/plugins/platforms/qnx/qqnxvirtualkeyboardpps.cpp
@@ -164,7 +164,7 @@ void QQnxVirtualKeyboardPps::ppsDataReady()
 {
     ssize_t nread = qt_safe_read(m_fd, m_buffer, ms_bufferSize - 1);
 
-    qVirtualKeyboardDebug() << "keyboardMessage size: " << nread;
+    qVirtualKeyboardDebug("keyboardMessage size: %zd", nread);
     if (nread < 0){
         connect(); // reconnect
         return;
@@ -230,7 +230,7 @@ void QQnxVirtualKeyboardPps::handleKeyboardInfoMessage()
     }
     setHeight(newHeight);
 
-    qVirtualKeyboardDebug() << "size=" << newHeight;
+    qVirtualKeyboardDebug("size=%d", newHeight);
 }
 
 bool QQnxVirtualKeyboardPps::showKeyboard()
diff --git a/src/widgets/accessible/itemviews.cpp b/src/widgets/accessible/itemviews.cpp
index ebe8efc79e..ecb84d8b50 100644
--- a/src/widgets/accessible/itemviews.cpp
+++ b/src/widgets/accessible/itemviews.cpp
@@ -512,7 +512,7 @@ QAccessibleInterface *QAccessibleTable::child(int logicalIndex) const
     if (!iface) {
         QModelIndex index = view()->model()->index(row, column, view()->rootIndex());
         if (Q_UNLIKELY(!index.isValid())) {
-            qWarning() << "QAccessibleTable::child: Invalid index at: " << row << column;
+            qWarning("QAccessibleTable::child: Invalid index at: %d %d", row, column);
             return 0;
         }
         iface = new QAccessibleTableCell(view(), index, cellRole());
@@ -783,7 +783,7 @@ QAccessibleInterface *QAccessibleTree::cellAt(int row, int column) const
 {
     QModelIndex index = indexFromLogical(row, column);
     if (Q_UNLIKELY(!index.isValid())) {
-        qWarning() << "Requested invalid tree cell: " << row << column;
+        qWarning("Requested invalid tree cell: %d %d", row, column);
         return 0;
     }
     const QTreeView *treeView = qobject_cast<const QTreeView*>(view());
diff --git a/src/widgets/kernel/qgesturemanager.cpp b/src/widgets/kernel/qgesturemanager.cpp
index 8af3516d4b..777be8525e 100644
--- a/src/widgets/kernel/qgesturemanager.cpp
+++ b/src/widgets/kernel/qgesturemanager.cpp
@@ -75,7 +75,7 @@ static inline int panTouchPoints()
         const int result = qEnvironmentVariableIntValue(panTouchPointVariable, &ok);
         if (ok && result >= 1)
             return result;
-        qWarning() << "Ignoring invalid value of " << panTouchPointVariable;
+        qWarning("Ignoring invalid value of %s", panTouchPointVariable);
     }
     // Pan should use 1 finger on a touch screen and 2 fingers on touch pads etc.
     // where 1 finger movements are used for mouse event synthetization. For now,
diff --git a/src/widgets/widgets/qmaccocoaviewcontainer_mac.mm b/src/widgets/widgets/qmaccocoaviewcontainer_mac.mm
index 477bb92601..2d19780461 100644
--- a/src/widgets/widgets/qmaccocoaviewcontainer_mac.mm
+++ b/src/widgets/widgets/qmaccocoaviewcontainer_mac.mm
@@ -100,8 +100,9 @@ inline QPlatformNativeInterface::NativeResourceForIntegrationFunction resolvePla
     QPlatformNativeInterface::NativeResourceForIntegrationFunction function =
         nativeInterface->nativeResourceFunctionForIntegration(functionName);
     if (Q_UNLIKELY(!function))
-         qWarning() << "Qt could not resolve function" << functionName
-                    << "from QGuiApplication::platformNativeInterface()->nativeResourceFunctionForIntegration()";
+         qWarning("Qt could not resolve function %s from "
+                  "QGuiApplication::platformNativeInterface()->nativeResourceFunctionForIntegration()",
+                  functionName.constData());
     return function;
 }
 } //namespsace
diff --git a/src/widgets/widgets/qmacnativewidget_mac.mm b/src/widgets/widgets/qmacnativewidget_mac.mm
index 6c113b556f..b6c5179989 100644
--- a/src/widgets/widgets/qmacnativewidget_mac.mm
+++ b/src/widgets/widgets/qmacnativewidget_mac.mm
@@ -89,8 +89,9 @@ inline QPlatformNativeInterface::NativeResourceForIntegrationFunction resolvePla
     QPlatformNativeInterface::NativeResourceForIntegrationFunction function =
         nativeInterface->nativeResourceFunctionForIntegration(functionName);
     if (Q_UNLIKELY(!function))
-         qWarning() << "Qt could not resolve function" << functionName
-                    << "from QGuiApplication::platformNativeInterface()->nativeResourceFunctionForIntegration()";
+         qWarning("Qt could not resolve function %s from "
+                  "QGuiApplication::platformNativeInterface()->nativeResourceFunctionForIntegration()",
+                  functionName.constData());
     return function;
 }
 } //namespsace
diff --git a/src/widgets/widgets/qmenu_mac.mm b/src/widgets/widgets/qmenu_mac.mm
index 29f5913b5d..d48041b385 100644
--- a/src/widgets/widgets/qmenu_mac.mm
+++ b/src/widgets/widgets/qmenu_mac.mm
@@ -62,8 +62,9 @@ inline QPlatformNativeInterface::NativeResourceForIntegrationFunction resolvePla
     QPlatformNativeInterface::NativeResourceForIntegrationFunction function =
         nativeInterface->nativeResourceFunctionForIntegration(functionName);
     if (Q_UNLIKELY(!function))
-         qWarning() << "Qt could not resolve function" << functionName
-                    << "from QGuiApplication::platformNativeInterface()->nativeResourceFunctionForIntegration()";
+         qWarning("Qt could not resolve function %s from "
+                  "QGuiApplication::platformNativeInterface()->nativeResourceFunctionForIntegration()",
+                  functionName.constData());
     return function;
 }
 } //namespsace