diff --git a/src/plugins/qtsupport/baseqtversion.cpp b/src/plugins/qtsupport/baseqtversion.cpp
index 4314c53c1c1..43c95a15baf 100644
--- a/src/plugins/qtsupport/baseqtversion.cpp
+++ b/src/plugins/qtsupport/baseqtversion.cpp
@@ -92,11 +92,11 @@ QtVersionNumber::QtVersionNumber()
 bool QtVersionNumber::checkVersionString(const QString &version) const
 {
     int dots = 0;
-    QString validChars = "0123456789.";
+    const QString validChars = QLatin1String("0123456789.");
     foreach (const QChar &c, version) {
         if (!validChars.contains(c))
             return false;
-        if (c == '.')
+        if (c == QLatin1Char('.'))
             ++dots;
     }
     if (dots != 2)
@@ -272,7 +272,7 @@ void BaseQtVersion::fromMap(const QVariantMap &map)
     if (m_isAutodetected)
         m_autodetectionSource = map.value(QLatin1String(QTVERSIONAUTODETECTIONSOURCE)).toString();
     QString string = map.value(QLatin1String(QTVERSIONQMAKEPATH)).toString();
-    if (string.startsWith('~'))
+    if (string.startsWith(QLatin1Char('~')))
         string.remove(0, 1).prepend(QDir::homePath());
     ctor(Utils::FileName::fromUserInput(string));
 }
@@ -298,7 +298,7 @@ bool BaseQtVersion::isValid() const
 
     return  !qmakeCommand().isEmpty()
             && m_installed
-            && m_versionInfo.contains("QT_INSTALL_BINS")
+            && m_versionInfo.contains(QLatin1String("QT_INSTALL_BINS"))
             && !m_mkspecFullPath.isEmpty()
             && m_qmakeIsExecutable;
 }
@@ -313,7 +313,7 @@ QString BaseQtVersion::invalidReason() const
         return QCoreApplication::translate("QtVersion", "qmake does not exist or is not executable");
     if (!m_installed)
         return QCoreApplication::translate("QtVersion", "Qt version is not properly installed, please run make install");
-    if (!m_versionInfo.contains("QT_INSTALL_BINS"))
+    if (!m_versionInfo.contains(QLatin1String("QT_INSTALL_BINS")))
         return QCoreApplication::translate("QtVersion",
                                            "Could not determine the path to the binaries of the Qt installation, maybe the qmake path is wrong?");
     if (m_mkspecUpToDate && m_mkspecFullPath.isEmpty())
@@ -401,12 +401,17 @@ QString BaseQtVersion::toHtml(bool verbose) const
     str << "<tr><td><b>" << QCoreApplication::translate("BaseQtVersion", "Name:")
         << "</b></td><td>" << displayName() << "</td></tr>";
     if (!isValid()) {
-        str << "<tr><td colspan=2><b>" + QCoreApplication::translate("BaseQtVersion", "Invalid Qt version") +"</b></td></tr>";
+        str << "<tr><td colspan=2><b>"
+            << QCoreApplication::translate("BaseQtVersion", "Invalid Qt version")
+            << "</b></td></tr>";
     } else {
-        QString prefix = QLatin1String("<tr><td><b>") + QCoreApplication::translate("BaseQtVersion", "ABI:") + QLatin1String("</b></td>");
-        foreach (const ProjectExplorer::Abi &abi, qtAbis()) {
-            str << prefix << "<td>" << abi.toString() << "</td></tr>";
-            prefix = QLatin1String("<tr><td></td>");
+        str << "<tr><td><b>" << QCoreApplication::translate("BaseQtVersion", "ABI:")
+            << "</b></td>";
+        const QList<ProjectExplorer::Abi> abis = qtAbis();
+        for (int i = 0; i < abis.size(); ++i) {
+            if (i)
+                str << "<tr><td></td>";
+            str << "<td>" << abis.at(i).toString() << "</td></tr>";
         }
         str << "<tr><td><b>" << QCoreApplication::translate("BaseQtVersion", "Source:")
             << "</b></td><td>" << sourcePath().toUserOutput() << "</td></tr>";
@@ -444,7 +449,7 @@ void BaseQtVersion::updateSourcePath() const
     if (!m_sourcePath.isEmpty())
         return;
     updateVersionInfo();
-    const QString installData = m_versionInfo["QT_INSTALL_DATA"];
+    const QString installData = m_versionInfo.value(QLatin1String("QT_INSTALL_DATA"));
     QString sourcePath = installData;
     QFile qmakeCache(installData + QLatin1String("/.qmake.cache"));
     if (qmakeCache.exists()) {
@@ -508,11 +513,11 @@ QString BaseQtVersion::findQtBinary(Binaries binary) const
         ensureMkSpecParsed();
         switch (binary) {
         case QmlViewer:
-            baseDir = m_mkspecValues.value("QT.declarative.bins");
+            baseDir = m_mkspecValues.value(QLatin1String("QT.declarative.bins"));
             break;
         case Designer:
         case Linguist:
-            baseDir = m_mkspecValues.value("QT.designer.bins");
+            baseDir = m_mkspecValues.value(QLatin1String("QT.designer.bins"));
             break;
         case Uic:
             baseDir = versionInfo().value(QLatin1String("QT_INSTALL_BINS"));
@@ -525,7 +530,7 @@ QString BaseQtVersion::findQtBinary(Binaries binary) const
 
     if (baseDir.isEmpty())
         return QString();
-    if (!baseDir.endsWith('/'))
+    if (!baseDir.endsWith(QLatin1Char('/')))
         baseDir += QLatin1Char('/');
 
     QStringList possibleCommands;
@@ -611,15 +616,16 @@ void BaseQtVersion::updateMkspec() const
     if (m_mkspecFullPath.isEmpty())
         return;
 
-    Utils::FileName baseMkspecDir = Utils::FileName::fromUserInput(versionInfo().value("QMAKE_MKSPECS"));
+    Utils::FileName baseMkspecDir = Utils::FileName::fromUserInput(versionInfo().value(QLatin1String("QMAKE_MKSPECS")));
     if (baseMkspecDir.isEmpty())
-        baseMkspecDir = Utils::FileName::fromUserInput(versionInfo().value("QT_INSTALL_DATA") + "/mkspecs");
+        baseMkspecDir = Utils::FileName::fromUserInput(versionInfo().value(QLatin1String("QT_INSTALL_DATA"))
+                                                       + QLatin1String("/mkspecs"));
 
     if (m_mkspec.isChildOf(baseMkspecDir)) {
         m_mkspec = m_mkspec.relativeChildPath(baseMkspecDir);
 //        qDebug() << "Setting mkspec to"<<mkspec;
     } else {
-        Utils::FileName sourceMkSpecPath = sourcePath().appendPath("mkspecs");
+        Utils::FileName sourceMkSpecPath = sourcePath().appendPath(QLatin1String("mkspecs"));
         if (m_mkspec.isChildOf(sourceMkSpecPath)) {
             m_mkspec = m_mkspec.relativeChildPath(sourceMkSpecPath);
         } else {
@@ -643,7 +649,7 @@ void BaseQtVersion::ensureMkSpecParsed() const
     ProFileCacheManager::instance()->incRefCount();
     ProFileParser parser(ProFileCacheManager::instance()->cache(), &msgHandler);
     ProFileEvaluator evaluator(&option, &parser, &msgHandler);
-    if (ProFile *pro = parser.parsedProFile(mkspecPath().toString() + "/qmake.conf")) {
+    if (ProFile *pro = parser.parsedProFile(mkspecPath().toString() + QLatin1String("/qmake.conf"))) {
         evaluator.setCumulative(false);
         evaluator.accept(pro, ProFileEvaluator::LoadProOnly);
         pro->deref();
@@ -656,19 +662,20 @@ void BaseQtVersion::ensureMkSpecParsed() const
 
 void BaseQtVersion::parseMkSpec(ProFileEvaluator *evaluator) const
 {
-    QStringList configValues = evaluator->values("CONFIG");
+    QStringList configValues = evaluator->values(QLatin1String("CONFIG"));
     m_defaultConfigIsDebugAndRelease = false;
     foreach (const QString &value, configValues) {
-        if (value == "debug")
+        if (value == QLatin1String("debug"))
             m_defaultConfigIsDebug = true;
-        else if (value == "release")
+        else if (value == QLatin1String("release"))
             m_defaultConfigIsDebug = false;
-        else if (value == "build_all")
+        else if (value == QLatin1String("build_all"))
             m_defaultConfigIsDebugAndRelease = true;
     }
-
-    m_mkspecValues.insert("QT.designer.bins", evaluator->value("QT.designer.bins"));
-    m_mkspecValues.insert("QT.declarative.bins", evaluator->value("QT.declarative.bins"));
+    const QString designerBins = QLatin1String("QT.designer.bins");
+    const QString declarativeBins = QLatin1String("QT.declarative.bins");
+    m_mkspecValues.insert(designerBins, evaluator->value(designerBins));
+    m_mkspecValues.insert(declarativeBins, evaluator->value(declarativeBins));
 }
 
 Utils::FileName BaseQtVersion::mkspec() const
@@ -687,7 +694,8 @@ bool BaseQtVersion::hasMkspec(const Utils::FileName &spec) const
 {
     updateVersionInfo();
     QFileInfo fi;
-    fi.setFile(QDir::fromNativeSeparators(m_versionInfo.value("QMAKE_MKSPECS")) + '/' + spec.toString());
+    fi.setFile(QDir::fromNativeSeparators(m_versionInfo.value(QLatin1String("QMAKE_MKSPECS")))
+               + QLatin1Char('/') + spec.toString());
     if (fi.isDir())
         return true;
     fi.setFile(sourcePath().toString() + QLatin1String("/mkspecs/") + spec.toString());
@@ -749,11 +757,15 @@ void BaseQtVersion::updateVersionInfo() const
     if (!queryQMakeVariables(qmakeCommand(), &m_versionInfo, &m_qmakeIsExecutable))
         return;
 
-    if (m_versionInfo.contains("QT_INSTALL_DATA")) {
-        QString qtInstallData = m_versionInfo.value("QT_INSTALL_DATA");
-        QString qtInstallBins = m_versionInfo.value("QT_INSTALL_BINS");
-        QString qtHeaderData = m_versionInfo.value("QT_INSTALL_HEADERS");
-        m_versionInfo.insert("QMAKE_MKSPECS", QDir::cleanPath(qtInstallData+"/mkspecs"));
+    const QString installDataKey = QLatin1String("QT_INSTALL_DATA");
+    const QString installBinsKey = QLatin1String("QT_INSTALL_BINS");
+    const QString installHeadersKey = QLatin1String("QT_INSTALL_HEADERS");
+    if (m_versionInfo.contains(installDataKey)) {
+        const QString qtInstallData = m_versionInfo.value(installDataKey);
+        const QString qtInstallBins = m_versionInfo.value(installBinsKey);
+        const QString qtHeaderData = m_versionInfo.value(installHeadersKey);
+        m_versionInfo.insert(QLatin1String("QMAKE_MKSPECS"),
+                             QDir::cleanPath(qtInstallData + QLatin1String("/mkspecs")));
 
         if (!qtInstallData.isEmpty()) {
             m_hasDebuggingHelper = !ProjectExplorer::DebuggingHelperLibrary::debuggingHelperLibraryByInstallData(qtInstallData).isEmpty();
@@ -768,28 +780,31 @@ void BaseQtVersion::updateVersionInfo() const
     }
 
     // Now check for a qt that is configured with a prefix but not installed
-    if (m_versionInfo.contains("QT_INSTALL_BINS")) {
-        QFileInfo fi(m_versionInfo.value("QT_INSTALL_BINS"));
+    if (m_versionInfo.contains(installBinsKey)) {
+        QFileInfo fi(m_versionInfo.value(installBinsKey));
         if (!fi.exists())
             m_installed = false;
     }
-    if (m_versionInfo.contains("QT_INSTALL_HEADERS")){
-        QFileInfo fi(m_versionInfo.value("QT_INSTALL_HEADERS"));
+    if (m_versionInfo.contains(installHeadersKey)) {
+        const QFileInfo fi(m_versionInfo.value(installHeadersKey));
         if (!fi.exists())
             m_installed = false;
     }
-    if (m_versionInfo.contains("QT_INSTALL_DOCS")){
-        QFileInfo fi(m_versionInfo.value("QT_INSTALL_DOCS"));
+    const QString installDocsKey = QLatin1String("QT_INSTALL_DOCS");
+    if (m_versionInfo.contains(installDocsKey)) {
+        const QFileInfo fi(m_versionInfo.value(installDocsKey));
         if (fi.exists())
             m_hasDocumentation = true;
     }
-    if (m_versionInfo.contains("QT_INSTALL_EXAMPLES")){
-        QFileInfo fi(m_versionInfo.value("QT_INSTALL_EXAMPLES"));
+    const QString installExamplesKey = QLatin1String("QT_INSTALL_EXAMPLES");
+    if (m_versionInfo.contains(installExamplesKey)) {
+        const QFileInfo fi(m_versionInfo.value(installExamplesKey));
         if (fi.exists())
             m_hasExamples = true;
     }
-    if (m_versionInfo.contains("QT_INSTALL_DEMOS")){
-        QFileInfo fi(m_versionInfo.value("QT_INSTALL_DEMOS"));
+    const QString installDemosKey = QLatin1String("QT_INSTALL_DEMOS");
+    if (m_versionInfo.contains(installDemosKey)) {
+        const QFileInfo fi(m_versionInfo.value(installDemosKey));
         if (fi.exists())
             m_hasDemos = true;
     }
@@ -812,7 +827,7 @@ bool BaseQtVersion::hasDocumentation() const
 QString BaseQtVersion::documentationPath() const
 {
     updateVersionInfo();
-    return m_versionInfo["QT_INSTALL_DOCS"];
+    return m_versionInfo.value(QLatin1String("QT_INSTALL_DOCS"));
 }
 
 bool BaseQtVersion::hasDemos() const
@@ -824,14 +839,14 @@ bool BaseQtVersion::hasDemos() const
 QString BaseQtVersion::demosPath() const
 {
     updateVersionInfo();
-    return m_versionInfo["QT_INSTALL_DEMOS"];
+    return m_versionInfo.value(QLatin1String("QT_INSTALL_DEMOS"));
 }
 
 QString BaseQtVersion::frameworkInstallPath() const
 {
 #ifdef Q_OS_MAC
     updateVersionInfo();
-    return m_versionInfo["QT_INSTALL_LIBS"];
+    return m_versionInfo.value(QLatin1String("QT_INSTALL_LIBS"));
 #else
     return QString();
 #endif
@@ -846,7 +861,7 @@ bool BaseQtVersion::hasExamples() const
 QString BaseQtVersion::examplesPath() const
 {
     updateVersionInfo();
-    return m_versionInfo["QT_INSTALL_EXAMPLES"];
+    return m_versionInfo.value(QLatin1String("QT_INSTALL_EXAMPLES"));
 }
 
 QList<ProjectExplorer::HeaderPath> BaseQtVersion::systemHeaderPathes() const
@@ -858,9 +873,9 @@ QList<ProjectExplorer::HeaderPath> BaseQtVersion::systemHeaderPathes() const
 
 void BaseQtVersion::addToEnvironment(Utils::Environment &env) const
 {
-    env.set("QTDIR", QDir::toNativeSeparators(versionInfo().value("QT_INSTALL_DATA")));
-    env.prependOrSetPath(versionInfo().value("QT_INSTALL_BINS"));
-    env.prependOrSetLibrarySearchPath(versionInfo().value("QT_INSTALL_LIBS"));
+    env.set(QLatin1String("QTDIR"), QDir::toNativeSeparators(versionInfo().value(QLatin1String("QT_INSTALL_DATA"))));
+    env.prependOrSetPath(versionInfo().value(QLatin1String("QT_INSTALL_BINS")));
+    env.prependOrSetLibrarySearchPath(versionInfo().value(QLatin1String("QT_INSTALL_LIBS")));
 }
 
 bool BaseQtVersion::hasGdbDebuggingHelper() const
@@ -919,7 +934,7 @@ Utils::Environment BaseQtVersion::qmlToolsEnvironment() const
 
 QString BaseQtVersion::gdbDebuggingHelperLibrary() const
 {
-    QString qtInstallData = versionInfo().value("QT_INSTALL_DATA");
+    QString qtInstallData = versionInfo().value(QLatin1String("QT_INSTALL_DATA"));
     if (qtInstallData.isEmpty())
         return QString();
     return ProjectExplorer::DebuggingHelperLibrary::debuggingHelperLibraryByInstallData(qtInstallData);
@@ -927,17 +942,17 @@ QString BaseQtVersion::gdbDebuggingHelperLibrary() const
 
 QString BaseQtVersion::qmlDumpTool(bool debugVersion) const
 {
-    QString qtInstallData = versionInfo().value("QT_INSTALL_DATA");
-    QString qtInstallBins = versionInfo().value("QT_INSTALL_BINS");
-    QString qtHeaderData = versionInfo().value("QT_INSTALL_HEADERS");
+    const QString qtInstallData = versionInfo().value(QLatin1String("QT_INSTALL_DATA"));
     if (qtInstallData.isEmpty())
         return QString();
+    const QString qtInstallBins = versionInfo().value(QLatin1String("QT_INSTALL_BINS"));
+    const QString qtHeaderData = versionInfo().value(QLatin1String("QT_INSTALL_HEADERS"));
     return QmlDumpTool::toolForQtPaths(qtInstallData, qtInstallBins, qtHeaderData, debugVersion);
 }
 
 QString BaseQtVersion::qmlDebuggingHelperLibrary(bool debugVersion) const
 {
-    QString qtInstallData = versionInfo().value("QT_INSTALL_DATA");
+    QString qtInstallData = versionInfo().value(QLatin1String("QT_INSTALL_DATA"));
     if (qtInstallData.isEmpty())
         return QString();
     return QmlDebuggingLibrary::libraryByInstallData(qtInstallData, debugVersion);
@@ -945,7 +960,7 @@ QString BaseQtVersion::qmlDebuggingHelperLibrary(bool debugVersion) const
 
 QString BaseQtVersion::qmlObserverTool() const
 {
-    QString qtInstallData = versionInfo().value("QT_INSTALL_DATA");
+    QString qtInstallData = versionInfo().value(QLatin1String("QT_INSTALL_DATA"));
     if (qtInstallData.isEmpty())
         return QString();
     return QmlObserverTool::toolByInstallData(qtInstallData);
@@ -953,7 +968,7 @@ QString BaseQtVersion::qmlObserverTool() const
 
 QStringList BaseQtVersion::debuggingHelperLibraryLocations() const
 {
-    QString qtInstallData = versionInfo().value("QT_INSTALL_DATA");
+    QString qtInstallData = versionInfo().value(QLatin1String("QT_INSTALL_DATA"));
     if (qtInstallData.isEmpty())
         return QStringList();
     return ProjectExplorer::DebuggingHelperLibrary::debuggingHelperLibraryDirectories(qtInstallData);
@@ -1002,14 +1017,15 @@ QList<ProjectExplorer::Task> BaseQtVersion::reportIssuesImpl(const QString &proF
     }
 
     QString sourcePath = QFileInfo(proFile).absolutePath();
-    if (!sourcePath.endsWith(QLatin1Char('/')))
-        sourcePath.append(QLatin1Char('/'));
+    const QChar slash = QLatin1Char('/');
+    if (!sourcePath.endsWith(slash))
+        sourcePath.append(slash);
     if ((tmpBuildDir.startsWith(sourcePath)) && (tmpBuildDir != sourcePath)) {
         const QString msg = QCoreApplication::translate("Qt4ProjectManager::QtVersion",
                                                         "Qmake does not support build directories below the source directory.");
         results.append(ProjectExplorer::Task(ProjectExplorer::Task::Warning, msg, QString(), -1,
                                              QLatin1String(ProjectExplorer::Constants::TASK_CATEGORY_BUILDSYSTEM)));
-    } else if (tmpBuildDir.count(QChar('/')) != sourcePath.count(QChar('/')) && qtVersion() < QtVersionNumber(4,8, 0)) {
+    } else if (tmpBuildDir.count(slash) != sourcePath.count(slash) && qtVersion() < QtVersionNumber(4,8, 0)) {
         const QString msg = QCoreApplication::translate("Qt4ProjectManager::QtVersion",
                                                         "The build directory needs to be at the same level as the source directory.");
 
@@ -1071,7 +1087,7 @@ bool BaseQtVersion::queryQMakeVariables(const Utils::FileName &binary, QHash<QSt
     const QString queryArg = QLatin1String("-query");
     QStringList args;
     for (uint i = 0; i < sizeof variables / sizeof variables[0]; ++i)
-        args << queryArg << variables[i];
+        args << queryArg << QLatin1String(variables[i]);
     QProcess process;
     process.start(qmake.absoluteFilePath(), args, QIODevice::ReadOnly);
     if (!process.waitForStarted()) {
@@ -1096,7 +1112,7 @@ bool BaseQtVersion::queryQMakeVariables(const Utils::FileName &binary, QHash<QSt
         const int index = line.indexOf(QLatin1Char(':'));
         if (index != -1) {
             const QString value = QDir::fromNativeSeparators(line.mid(index+1));
-            if (value != "**Unknown**")
+            if (value != QLatin1String("**Unknown**"))
                 versionInfo->insert(line.left(index), value);
         }
     }
@@ -1105,13 +1121,13 @@ bool BaseQtVersion::queryQMakeVariables(const Utils::FileName &binary, QHash<QSt
 
 Utils::FileName BaseQtVersion::mkspecFromVersionInfo(const QHash<QString, QString> &versionInfo)
 {
-    Utils::FileName baseMkspecDir = Utils::FileName::fromUserInput(versionInfo.value("QMAKE_MKSPECS"));
+    Utils::FileName baseMkspecDir = Utils::FileName::fromUserInput(versionInfo.value(QLatin1String("QMAKE_MKSPECS")));
     if (baseMkspecDir.isEmpty())
-        baseMkspecDir = Utils::FileName::fromUserInput(versionInfo.value("QT_INSTALL_DATA") + "/mkspecs");
+        baseMkspecDir = Utils::FileName::fromUserInput(versionInfo.value(QLatin1String("QT_INSTALL_DATA")) + QLatin1String("/mkspecs"));
     if (baseMkspecDir.isEmpty())
         return Utils::FileName();
 
-    Utils::FileName mkspecFullPath = Utils::FileName::fromString(baseMkspecDir.toString() + "/default");
+    Utils::FileName mkspecFullPath = Utils::FileName::fromString(baseMkspecDir.toString() + QLatin1String("/default"));
 
     // qDebug() << "default mkspec is located at" << mkspecFullPath;
 
@@ -1181,14 +1197,14 @@ QString BaseQtVersion::qtCorePath(const QHash<QString,QString> &versionInfo, con
                     && file.startsWith(QLatin1String("QtCore"))
                     && file.endsWith(QLatin1String(".framework"))) {
                 // handle Framework
-                const QString libName = file.left(file.lastIndexOf('.'));
-                return info.absoluteFilePath() + '/' + libName;
+                const QString libName = file.left(file.lastIndexOf(QLatin1Char('.')));
+                return info.absoluteFilePath() + QLatin1Char('/') + libName;
             }
             if (info.isReadable()) {
                 if (file.startsWith(QLatin1String("libQtCore"))
                         || file.startsWith(QLatin1String("QtCore"))) {
                     // Only handle static libs if we can not find dynamic ones:
-                    if (file.endsWith(".a") || file.endsWith(".lib"))
+                    if (file.endsWith(QLatin1String(".a")) || file.endsWith(QLatin1String(".lib")))
                         staticLibs.append(info);
                     else if (file.endsWith(QLatin1String(".dll"))
                              || file.endsWith(QString::fromLatin1(".so.") + versionString)
diff --git a/src/plugins/qtsupport/debugginghelperbuildtask.cpp b/src/plugins/qtsupport/debugginghelperbuildtask.cpp
index 4353f84db21..ecb121c0448 100644
--- a/src/plugins/qtsupport/debugginghelperbuildtask.cpp
+++ b/src/plugins/qtsupport/debugginghelperbuildtask.cpp
@@ -75,7 +75,7 @@ DebuggingHelperBuildTask::DebuggingHelperBuildTask(const BaseQtVersion *version,
     // of the version pointer while compiling
     //
     m_qtId = version->uniqueId();
-    m_qtInstallData = version->versionInfo().value("QT_INSTALL_DATA");
+    m_qtInstallData = version->versionInfo().value(QLatin1String("QT_INSTALL_DATA"));
     if (m_qtInstallData.isEmpty()) {
         const QString error
                 = QCoreApplication::translate(
@@ -235,8 +235,12 @@ bool DebuggingHelperBuildTask::buildDebuggingHelper(QFutureInterface<void> &futu
         bool success = true;
 
         arguments.directory = QmlObserverTool::copy(m_qtInstallData, &error);
-        arguments.qmakeArguments << QLatin1String("INCLUDEPATH+=\"\\\"") + qmlDebuggingDirectory + "include\\\"\"";
-        arguments.qmakeArguments << QLatin1String("LIBS+=-L\"\\\"") + qmlDebuggingDirectory + QLatin1String("\\\"\"");
+        arguments.qmakeArguments << QLatin1String("INCLUDEPATH+=\"\\\"")
+                                    + qmlDebuggingDirectory
+                                    + QLatin1String("include\\\"\"");
+        arguments.qmakeArguments << QLatin1String("LIBS+=-L\"\\\"")
+                                    + qmlDebuggingDirectory
+                                    + QLatin1String("\\\"\"");
 
         if (arguments.directory.isEmpty()
                 || !QmlObserverTool::build(arguments, &output, &error)) {
diff --git a/src/plugins/qtsupport/exampleslistmodel.cpp b/src/plugins/qtsupport/exampleslistmodel.cpp
index 3ec12b1a653..4b0cafe9242 100644
--- a/src/plugins/qtsupport/exampleslistmodel.cpp
+++ b/src/plugins/qtsupport/exampleslistmodel.cpp
@@ -91,6 +91,7 @@ QList<ExampleItem> ExamplesListModel::parseExamples(QXmlStreamReader* reader, co
 {
     QList<ExampleItem> examples;
     ExampleItem item;
+    const QChar slash = QLatin1Char('/');
     while (!reader->atEnd()) {
         switch (reader->readNext()) {
         case QXmlStreamReader::StartElement:
@@ -101,18 +102,18 @@ QList<ExampleItem> ExamplesListModel::parseExamples(QXmlStreamReader* reader, co
                 item.name = attributes.value(QLatin1String("name")).toString();
                 item.projectPath = attributes.value(QLatin1String("projectPath")).toString();
                 item.hasSourceCode = !item.projectPath.isEmpty();
-                item.projectPath.prepend('/');
+                item.projectPath.prepend(slash);
                 item.projectPath.prepend(projectsOffset);
                 item.imageUrl = attributes.value(QLatin1String("imageUrl")).toString();
                 item.docUrl = attributes.value(QLatin1String("docUrl")).toString();
             } else if (reader->name() == QLatin1String("fileToOpen")) {
-                item.filesToOpen.append(projectsOffset + '/' + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
+                item.filesToOpen.append(projectsOffset + slash + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("description")) {
                 item.description =  fixStringForTags(reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("dependency")) {
-                item.dependencies.append(projectsOffset + '/' + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
+                item.dependencies.append(projectsOffset + slash + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("tags")) {
-                item.tags = reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement).split(",");
+                item.tags = reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement).split(QLatin1Char(','));
                 m_tags.append(item.tags);
             }
             break;
@@ -133,6 +134,7 @@ QList<ExampleItem> ExamplesListModel::parseDemos(QXmlStreamReader* reader, const
 {
     QList<ExampleItem> demos;
     ExampleItem item;
+    const QChar slash = QLatin1Char('/');
     while (!reader->atEnd()) {
         switch (reader->readNext()) {
         case QXmlStreamReader::StartElement:
@@ -143,18 +145,18 @@ QList<ExampleItem> ExamplesListModel::parseDemos(QXmlStreamReader* reader, const
                 item.name = attributes.value(QLatin1String("name")).toString();
                 item.projectPath = attributes.value(QLatin1String("projectPath")).toString();
                 item.hasSourceCode = !item.projectPath.isEmpty();
-                item.projectPath.prepend('/');
+                item.projectPath.prepend(slash);
                 item.projectPath.prepend(projectsOffset);
                 item.imageUrl = attributes.value(QLatin1String("imageUrl")).toString();
                 item.docUrl = attributes.value(QLatin1String("docUrl")).toString();
             } else if (reader->name() == QLatin1String("fileToOpen")) {
-                item.filesToOpen.append(projectsOffset + '/' + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
+                item.filesToOpen.append(projectsOffset + slash + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("description")) {
                 item.description =  fixStringForTags(reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("dependency")) {
-                item.dependencies.append(projectsOffset + '/' + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
+                item.dependencies.append(projectsOffset + slash + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("tags")) {
-                item.tags = reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement).split(",");
+                item.tags = reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement).split(QLatin1Char(','));
             }
             break;
         case QXmlStreamReader::EndElement:
@@ -174,6 +176,7 @@ QList<ExampleItem> ExamplesListModel::parseTutorials(QXmlStreamReader* reader, c
 {
     QList<ExampleItem> tutorials;
     ExampleItem item;
+    const QChar slash = QLatin1Char('/');
     while (!reader->atEnd()) {
         switch (reader->readNext()) {
         case QXmlStreamReader::StartElement:
@@ -184,7 +187,7 @@ QList<ExampleItem> ExamplesListModel::parseTutorials(QXmlStreamReader* reader, c
                 item.name = attributes.value(QLatin1String("name")).toString();
                 item.projectPath = attributes.value(QLatin1String("projectPath")).toString();
                 item.hasSourceCode = !item.projectPath.isEmpty();
-                item.projectPath.prepend('/');
+                item.projectPath.prepend(slash);
                 item.projectPath.prepend(projectsOffset);
                 if (attributes.hasAttribute(QLatin1String("imageUrl")))
                     item.imageUrl = attributes.value(QLatin1String("imageUrl")).toString();
@@ -197,13 +200,13 @@ QList<ExampleItem> ExamplesListModel::parseTutorials(QXmlStreamReader* reader, c
                 if (attributes.hasAttribute(QLatin1String("videoLength")))
                     item.videoLength = attributes.value(QLatin1String("videoLength")).toString();
             } else if (reader->name() == QLatin1String("fileToOpen")) {
-                item.filesToOpen.append(projectsOffset + '/' + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
+                item.filesToOpen.append(projectsOffset + slash + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("description")) {
                 item.description =  fixStringForTags(reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("dependency")) {
-                item.dependencies.append(projectsOffset + '/' + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
+                item.dependencies.append(projectsOffset + slash + reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement));
             } else if (reader->name() == QLatin1String("tags")) {
-                item.tags = reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement).split(",");
+                item.tags = reader->readElementText(QXmlStreamReader::ErrorOnUnexpectedElement).split(QLatin1Char(','));
             }
             break;
         case QXmlStreamReader::EndElement:
@@ -278,10 +281,10 @@ QStringList ExamplesListModel::exampleSources() const
 
     // Read keys from SDK installer
     QSettings *settings = Core::ICore::instance()->settings(QSettings::SystemScope);
-    int size = settings->beginReadArray("ExampleManifests");
+    int size = settings->beginReadArray(QLatin1String("ExampleManifests"));
     for (int i = 0; i < size; ++i) {
         settings->setArrayIndex(i);
-        sources.append(settings->value("Location").toString());
+        sources.append(settings->value(QLatin1String("Location")).toString());
     }
     settings->endArray();
 
@@ -361,7 +364,7 @@ QVariant ExamplesListModel::data(const QModelIndex &index, int role) const
     switch (role)
     {
     case Qt::DisplayRole: // for search only
-        return QString(item.name + ' ' + item.tags.join(" "));
+        return QString(item.name + QLatin1Char(' ') + item.tags.join(QLatin1String(" ")));
     case Name:
         return item.name;
     case ProjectPath:
@@ -506,7 +509,7 @@ struct SearchStringLexer {
     SearchStringLexer(const QString &code)
         : code(code)
         , codePtr(code.unicode())
-        , yychar(' ') { }
+        , yychar(QLatin1Char(' ')) { }
 
     int operator()() { return yylex(); }
 
@@ -532,12 +535,12 @@ struct SearchStringLexer {
                 if (yychar == quote) {
                     yyinp();
                     break;
-                } if (yychar == '\\') {
+                } if (yychar == QLatin1Char('\\')) {
                     yyinp();
                     switch (yychar.unicode()) {
-                    case '"': yytext += '"'; yyinp(); break;
-                    case '\'': yytext += '\''; yyinp(); break;
-                    case '\\': yytext += '\\'; yyinp(); break;
+                    case '"': yytext += QLatin1Char('"'); yyinp(); break;
+                    case '\'': yytext += QLatin1Char('\''); yyinp(); break;
+                    case '\\': yytext += QLatin1Char('\\'); yyinp(); break;
                     }
                 } else {
                     yytext += yychar;
@@ -548,14 +551,14 @@ struct SearchStringLexer {
         }
 
         default:
-            if (ch.isLetterOrNumber() || ch == '_') {
+            if (ch.isLetterOrNumber() || ch == QLatin1Char('_')) {
                 yytext.clear();
                 yytext += ch;
-                while (yychar.isLetterOrNumber() || yychar == '_') {
+                while (yychar.isLetterOrNumber() || yychar == QLatin1Char('_')) {
                     yytext += yychar;
                     yyinp();
                 }
-                if (yychar == ':' && yytext == QLatin1String("tag")) {
+                if (yychar == QLatin1Char(':') && yytext == QLatin1String("tag")) {
                     yyinp();
                     return TAG;
                 }
diff --git a/src/plugins/qtsupport/gettingstartedwelcomepage.cpp b/src/plugins/qtsupport/gettingstartedwelcomepage.cpp
index 39318f97680..d61c67f289f 100644
--- a/src/plugins/qtsupport/gettingstartedwelcomepage.cpp
+++ b/src/plugins/qtsupport/gettingstartedwelcomepage.cpp
@@ -352,11 +352,11 @@ QString ExamplesWelcomePage::copyToAlternativeLocation(const QFileInfo& proFileI
             return QString();
         } else {
             QString error;
-            QString targetDir = destBaseDir + '/' + exampleDirName;
+            QString targetDir = destBaseDir + QLatin1Char('/') + exampleDirName;
             if (Utils::FileUtils::copyRecursively(projectDir, targetDir, &error)) {
                 // set vars to new location
-                QStringList::Iterator it;
-                for (it = filesToOpen.begin(); it != filesToOpen.end(); ++it)
+                const QStringList::Iterator end = filesToOpen.end();
+                for (QStringList::Iterator it = filesToOpen.begin(); it != end; ++it)
                     it->replace(projectDir, targetDir);
 
                 foreach (const QString &dependency, dependencies) {
@@ -368,7 +368,7 @@ QString ExamplesWelcomePage::copyToAlternativeLocation(const QFileInfo& proFileI
                 }
 
 
-                return targetDir+ '/' + proFileInfo.fileName();
+                return targetDir + QLatin1Char('/') + proFileInfo.fileName();
             } else {
                 QMessageBox::warning(Core::ICore::instance()->mainWindow(), tr("Cannot Copy Project"), error);
             }
diff --git a/src/plugins/qtsupport/qmldebugginglibrary.cpp b/src/plugins/qtsupport/qmldebugginglibrary.cpp
index ec8d800d40b..ed6a45735dc 100644
--- a/src/plugins/qtsupport/qmldebugginglibrary.cpp
+++ b/src/plugins/qtsupport/qmldebugginglibrary.cpp
@@ -127,8 +127,8 @@ QStringList QmlDebuggingLibrary::recursiveFileList(const QDir &dir, const QStrin
     QStringList files;
 
     QString _prefix = prefix;
-    if (!_prefix.isEmpty() && !_prefix.endsWith('/')) {
-        _prefix = _prefix + '/';
+    if (!_prefix.isEmpty() && !_prefix.endsWith(QLatin1Char('/'))) {
+        _prefix = _prefix + QLatin1Char('/');
     }
     foreach (const QString &fileName, dir.entryList(QDir::Files)) {
         files << _prefix + fileName;
diff --git a/src/plugins/qtsupport/qmldumptool.cpp b/src/plugins/qtsupport/qmldumptool.cpp
index e84193bdab1..e27f988274e 100644
--- a/src/plugins/qtsupport/qmldumptool.cpp
+++ b/src/plugins/qtsupport/qmldumptool.cpp
@@ -196,10 +196,10 @@ static bool hasPrivateHeaders(const QString &qtInstallHeaders) {
 
 bool QmlDumpTool::canBuild(const BaseQtVersion *qtVersion, QString *reason)
 {
-    const QString installHeaders = qtVersion->versionInfo().value("QT_INSTALL_HEADERS");
+    const QString installHeaders = qtVersion->versionInfo().value(QLatin1String("QT_INSTALL_HEADERS"));
 
-    if (qtVersion->type() != Constants::DESKTOPQT
-            && qtVersion->type() != Constants::SIMULATORQT) {
+    if (qtVersion->type() != QLatin1String(Constants::DESKTOPQT)
+            && qtVersion->type() != QLatin1String(Constants::SIMULATORQT)) {
         if (reason)
             *reason = QCoreApplication::translate("Qt4ProjectManager::QmlDumpTool", "Only available for Qt for Desktop and Qt for Qt Simulator.");
         return false;
@@ -227,11 +227,10 @@ bool QmlDumpTool::canBuild(const BaseQtVersion *qtVersion, QString *reason)
 QString QmlDumpTool::toolForVersion(BaseQtVersion *version, bool debugDump)
 {
     if (version) {
-        QString qtInstallData = version->versionInfo().value("QT_INSTALL_DATA");
-        QString qtInstallBins = version->versionInfo().value("QT_INSTALL_BINS");
-        QString qtInstallHeaders = version->versionInfo().value("QT_INSTALL_HEADERS");
-        QString toolPath = toolForQtPaths(qtInstallData, qtInstallBins, qtInstallHeaders, debugDump);
-        return toolPath;
+        const QString qtInstallData = version->versionInfo().value(QLatin1String("QT_INSTALL_DATA"));
+        const QString qtInstallBins = version->versionInfo().value(QLatin1String("QT_INSTALL_BINS"));
+        const QString qtInstallHeaders = version->versionInfo().value(QLatin1String("QT_INSTALL_HEADERS"));
+        return toolForQtPaths(qtInstallData, qtInstallBins, qtInstallHeaders, debugDump);
     }
 
     return QString();
diff --git a/src/plugins/qtsupport/qmlobservertool.cpp b/src/plugins/qtsupport/qmlobservertool.cpp
index 5e6158a407c..1584385f433 100644
--- a/src/plugins/qtsupport/qmlobservertool.cpp
+++ b/src/plugins/qtsupport/qmlobservertool.cpp
@@ -56,8 +56,8 @@ static inline QStringList validBinaryFilenames()
 
 bool QmlObserverTool::canBuild(const BaseQtVersion *qtVersion, QString *reason)
 {
-    if (qtVersion->type() != Constants::DESKTOPQT
-            && qtVersion->type() != Constants::SIMULATORQT) {
+    if (qtVersion->type() != QLatin1String(Constants::DESKTOPQT)
+            && qtVersion->type() != QLatin1String(Constants::SIMULATORQT)) {
         if (reason)
             *reason = QCoreApplication::translate("Qt4ProjectManager::QmlObserverTool", "Only available for Qt for Desktop or Qt for Qt Simulator.");
         return false;
@@ -144,8 +144,8 @@ QStringList QmlObserverTool::recursiveFileList(const QDir &dir, const QString &p
     QStringList files;
 
     QString _prefix = prefix;
-    if (!_prefix.isEmpty() && !_prefix.endsWith('/')) {
-        _prefix = _prefix + '/';
+    if (!_prefix.isEmpty() && !_prefix.endsWith(QLatin1Char('/'))) {
+        _prefix.append(QLatin1Char('/'));
     }
     foreach (const QString &fileName, dir.entryList(QDir::Files)) {
         files << _prefix + fileName;
diff --git a/src/plugins/qtsupport/qtoptionspage.cpp b/src/plugins/qtsupport/qtoptionspage.cpp
index 9936e7308c1..03197293b0b 100644
--- a/src/plugins/qtsupport/qtoptionspage.cpp
+++ b/src/plugins/qtsupport/qtoptionspage.cpp
@@ -96,7 +96,7 @@ QString QtOptionsPage::displayCategory() const
 
 QIcon QtOptionsPage::categoryIcon() const
 {
-    return QIcon(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY_ICON);
+    return QIcon(QLatin1String(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY_ICON));
 }
 
 QWidget *QtOptionsPage::createPage(QWidget *parent)
@@ -132,8 +132,8 @@ QtOptionsPageWidget::QtOptionsPageWidget(QWidget *parent, QList<BaseQtVersion *>
     , m_ui(new Internal::Ui::QtVersionManager())
     , m_versionUi(new Internal::Ui::QtVersionInfo())
     , m_debuggingHelperUi(new Internal::Ui::DebuggingHelper())
-    , m_invalidVersionIcon(":/projectexplorer/images/compile_error.png")
-    , m_warningVersionIcon(":/projectexplorer/images/compile_warning.png")
+    , m_invalidVersionIcon(QLatin1String(":/projectexplorer/images/compile_error.png"))
+    , m_warningVersionIcon(QLatin1String(":/projectexplorer/images/compile_warning.png"))
     , m_configurationWidget(0)
 {
     // Initialize m_versions
@@ -425,7 +425,7 @@ QtOptionsPageWidget::ValidityInfo QtOptionsPageWidget::validInformation(const Ba
         QString warning = version->warningReason();
         if (!warning.isEmpty()) {
             if (!info.message.isEmpty())
-                info.message.append('\n');
+                info.message.append(QLatin1Char('\n'));
             info.message += warning;
             info.icon = m_warningVersionIcon;
         }
@@ -578,7 +578,7 @@ QtOptionsPageWidget::~QtOptionsPageWidget()
 
 static QString filterForQmakeFileDialog()
 {
-    QString filter("qmake (");
+    QString filter = QLatin1String("qmake (");
     foreach (const QString &s, Utils::BuildableHelperLibrary::possibleQMakeCommands()) {
 #ifdef Q_WS_MAC
         // work around QTBUG-7739 that prohibits filters that don't start with *
@@ -713,14 +713,15 @@ void QtOptionsPageWidget::updateDebuggingHelperUi()
 
         // get names of tools from labels
         QStringList helperNames;
+        const QChar colon = QLatin1Char(':');
         if (hasGdbHelper)
-            helperNames << m_debuggingHelperUi->gdbHelperLabel->text().remove(':');
+            helperNames << m_debuggingHelperUi->gdbHelperLabel->text().remove(colon);
         if (hasQmlDumper)
-            helperNames << m_debuggingHelperUi->qmlDumpLabel->text().remove(':');
+            helperNames << m_debuggingHelperUi->qmlDumpLabel->text().remove(colon);
         if (hasQmlDebuggingLib)
-            helperNames << m_debuggingHelperUi->qmlDebuggingLibLabel->text().remove(':');
+            helperNames << m_debuggingHelperUi->qmlDebuggingLibLabel->text().remove(colon);
         if (hasQmlObserver)
-            helperNames << m_debuggingHelperUi->qmlObserverLabel->text().remove(':');
+            helperNames << m_debuggingHelperUi->qmlObserverLabel->text().remove(colon);
 
         QString status;
         if (helperNames.isEmpty()) {
@@ -995,7 +996,7 @@ void QtOptionsPageWidget::fixQtVersionName(int index)
         if (i != index) {
             if (m_versions.at(i)->displayName() == m_versions.at(index)->displayName()) {
                 // Same name, find new name
-                QRegExp regexp("^(.*)\\((\\d)\\)$");
+                QRegExp regexp(QLatin1String("^(.*)\\((\\d)\\)$"));
                 if (regexp.exactMatch(name)) {
                     // Already in Name (#) format
                     name = regexp.cap(1);
diff --git a/src/plugins/qtsupport/qtparser.cpp b/src/plugins/qtsupport/qtparser.cpp
index fabaf5c6dbd..43af20b935e 100644
--- a/src/plugins/qtsupport/qtparser.cpp
+++ b/src/plugins/qtsupport/qtparser.cpp
@@ -62,7 +62,7 @@ void QtParser::stdError(const QString &line)
                   m_mocRegExp.cap(5).trimmed(),
                   m_mocRegExp.cap(1) /* filename */,
                   lineno,
-                  ProjectExplorer::Constants::TASK_CATEGORY_COMPILE);
+                  QLatin1String(ProjectExplorer::Constants::TASK_CATEGORY_COMPILE));
         if (m_mocRegExp.cap(4) == QLatin1String("Warning"))
             task.type = Task::Warning;
         emit addTask(task);
@@ -126,7 +126,7 @@ void QtSupportPlugin::testQtOutputParser_data()
             << (QList<ProjectExplorer::Task>() << Task(Task::Warning,
                                                        QLatin1String("No relevant classes found. No output generated."),
                                                        QLatin1String("..\\untitled\\errorfile.h"), 0,
-                                                       ProjectExplorer::Constants::TASK_CATEGORY_COMPILE))
+                                                       QLatin1String(ProjectExplorer::Constants::TASK_CATEGORY_COMPILE)))
             << QString();
     QTest::newRow("moc warning 2")
             << QString::fromLatin1("c:\\code\\test.h(96): Warning: Property declaration ) has no READ accessor function. The property will be invalid.")
@@ -135,7 +135,7 @@ void QtSupportPlugin::testQtOutputParser_data()
             << (QList<ProjectExplorer::Task>() << Task(Task::Warning,
                                                        QLatin1String("Property declaration ) has no READ accessor function. The property will be invalid."),
                                                        QLatin1String("c:\\code\\test.h"), 96,
-                                                       ProjectExplorer::Constants::TASK_CATEGORY_COMPILE))
+                                                       QLatin1String(ProjectExplorer::Constants::TASK_CATEGORY_COMPILE)))
             << QString();
 }
 
diff --git a/src/plugins/qtsupport/qtversionfactory.cpp b/src/plugins/qtsupport/qtversionfactory.cpp
index 3713792b0b8..04429508bb5 100644
--- a/src/plugins/qtsupport/qtversionfactory.cpp
+++ b/src/plugins/qtsupport/qtversionfactory.cpp
@@ -63,7 +63,7 @@ BaseQtVersion *QtVersionFactory::createQtVersionFromLegacySettings(const Utils::
     if (!v)
         return 0;
     v->setId(id);
-    v->setDisplayName(s->value("Name").toString());
+    v->setDisplayName(s->value(QLatin1String("Name")).toString());
     v->restoreLegacySettings(s);
     return v;
 }
@@ -82,7 +82,7 @@ BaseQtVersion *QtVersionFactory::createQtVersionFromQMakePath(const Utils::FileN
     ProFileCacheManager::instance()->incRefCount();
     ProFileParser parser(ProFileCacheManager::instance()->cache(), &msgHandler);
     ProFileEvaluator evaluator(&option, &parser, &msgHandler);
-    if (ProFile *pro = parser.parsedProFile(mkspec.toString() + "/qmake.conf")) {
+    if (ProFile *pro = parser.parsedProFile(mkspec.toString() + QLatin1String("/qmake.conf"))) {
         evaluator.setCumulative(false);
         evaluator.accept(pro, ProFileEvaluator::LoadProOnly);
         pro->deref();
diff --git a/src/plugins/qtsupport/qtversionmanager.cpp b/src/plugins/qtsupport/qtversionmanager.cpp
index def45c3f367..31516ad0133 100644
--- a/src/plugins/qtsupport/qtversionmanager.cpp
+++ b/src/plugins/qtsupport/qtversionmanager.cpp
@@ -173,7 +173,7 @@ bool QtVersionManager::restoreQtVersions()
             break;
 
         const QVariantMap qtversionMap = data.value(key).toMap();
-        const QString type = qtversionMap.value(QTVERSION_TYPE_KEY).toString();
+        const QString type = qtversionMap.value(QLatin1String(QTVERSION_TYPE_KEY)).toString();
 
         bool restored = false;
         foreach (QtVersionFactory *f, factories) {
@@ -227,8 +227,8 @@ void QtVersionManager::updateFromInstaller()
         if (!data.contains(key))
             break;
         QVariantMap map = data.value(key).toMap();
-        Utils::FileName path = Utils::FileName::fromString(map.value(OLDQTVERSION_PATH).toString());
-        QString autodetectionSource = map.value(OLDQTVERSION_SDKSOURCE).toString();
+        Utils::FileName path = Utils::FileName::fromString(map.value(QLatin1String(OLDQTVERSION_PATH)).toString());
+        QString autodetectionSource = map.value(QLatin1String(OLDQTVERSION_SDKSOURCE)).toString();
         foreach (BaseQtVersion *v, m_versions) {
             if (v->qmakeCommand() == path) {
                 if (v->autodetectionSource().isEmpty()) {
@@ -265,7 +265,7 @@ void QtVersionManager::updateFromInstaller()
             break;
 
         QVariantMap qtversionMap = data.value(key).toMap();
-        const QString type = qtversionMap.value(QTVERSION_TYPE_KEY).toString();
+        const QString type = qtversionMap.value(QLatin1String(QTVERSION_TYPE_KEY)).toString();
         const QString autoDetectionSource = qtversionMap.value(QLatin1String("autodetectionSource")).toString();
         sdkVersions << autoDetectionSource;
         int id = -1; // see BaseQtVersion::fromMap()
@@ -322,7 +322,7 @@ void QtVersionManager::updateFromInstaller()
         }
     }
     foreach (BaseQtVersion *qtVersion, QtVersionManager::instance()->versions()) {
-        if (qtVersion->autodetectionSource().startsWith("SDK.")) {
+        if (qtVersion->autodetectionSource().startsWith(QLatin1String("SDK."))) {
             if (!sdkVersions.contains(qtVersion->autodetectionSource())) {
                 if (debug)
                     qDebug() << "  removing version"<<qtVersion->autodetectionSource();
@@ -351,13 +351,13 @@ void QtVersionManager::saveQtVersions()
         QVariantMap tmp = qtv->toMap();
         if (tmp.isEmpty())
             continue;
-        tmp.insert(QTVERSION_TYPE_KEY, qtv->type());
+        tmp.insert(QLatin1String(QTVERSION_TYPE_KEY), qtv->type());
         writer.saveValue(QString::fromLatin1(QTVERSION_DATA_KEY) + QString::number(count), tmp);
         ++count;
 
     }
     writer.saveValue(QLatin1String(QTVERSION_COUNT_KEY), count);
-    writer.save(settingsFileName(), "QtCreatorQtVersions", Core::ICore::instance()->mainWindow());
+    writer.save(settingsFileName(), QLatin1String("QtCreatorQtVersions"), Core::ICore::instance()->mainWindow());
 }
 
 void QtVersionManager::findSystemQt()
@@ -374,22 +374,23 @@ void QtVersionManager::findSystemQt()
 bool QtVersionManager::legacyRestore()
 {
     QSettings *s = Core::ICore::instance()->settings();
-    if (!s->contains(QLatin1String(QtVersionsSectionName) + QLatin1String("/size")))
+    const QString qtVersionSection = QLatin1String(QtVersionsSectionName);
+    if (!s->contains(qtVersionSection + QLatin1String("/size")))
         return false;
-    int size = s->beginReadArray(QtVersionsSectionName);
+    int size = s->beginReadArray(qtVersionSection);
     for (int i = 0; i < size; ++i) {
         s->setArrayIndex(i);
         // Find the right id
         // Either something saved or something generated
         // Note: This code assumes that either all ids are read from the settings
         // or generated on the fly.
-        int id = s->value("Id", -1).toInt();
+        int id = s->value(QLatin1String("Id"), -1).toInt();
         if (id == -1)
             id = getUniqueId();
         else if (m_idcount < id)
             m_idcount = id + 1;
 
-        Utils::FileName qmakePath = Utils::FileName::fromString(s->value("QMakePath").toString());
+        Utils::FileName qmakePath = Utils::FileName::fromString(s->value(QLatin1String("QMakePath")).toString());
         if (qmakePath.isEmpty())
             continue; //skip this version
 
@@ -408,7 +409,7 @@ bool QtVersionManager::legacyRestore()
         if (!mingwDir.isEmpty()) {
             QFileInfo fi(mingwDir + QLatin1String("/bin/g++.exe"));
             if (fi.exists() && fi.isExecutable()) {
-                ProjectExplorer::MingwToolChain *tc = createToolChain<ProjectExplorer::MingwToolChain>(ProjectExplorer::Constants::MINGW_TOOLCHAIN_ID);
+                ProjectExplorer::MingwToolChain *tc = createToolChain<ProjectExplorer::MingwToolChain>(QLatin1String(ProjectExplorer::Constants::MINGW_TOOLCHAIN_ID));
                 if (tc) {
                     tc->setCompilerPath(fi.absoluteFilePath());
                     tc->setDisplayName(tr("MinGW from %1").arg(version->displayName()));
@@ -427,7 +428,7 @@ bool QtVersionManager::legacyRestore()
 
     }
     s->endArray();
-    s->remove(QtVersionsSectionName);
+    s->remove(qtVersionSection);
     return true;
 }
 
@@ -540,7 +541,7 @@ void QtVersionManager::updateSettings()
 
     // prefer versions with declarative examples
     foreach (version, candidates) {
-        if (QDir(version->examplesPath()+"/declarative").exists()) {
+        if (QDir(version->examplesPath() + QLatin1String("/declarative")).exists()) {
             emit updateExamples(version->examplesPath(), version->demosPath(), version->sourcePath().toString());
             return;
         }
@@ -693,7 +694,7 @@ Utils::FileName QtVersionManager::findQMakeBinaryFromMakefile(const QString &mak
     QFile fi(makefile);
     if (fi.exists() && fi.open(QFile::ReadOnly)) {
         QTextStream ts(&fi);
-        QRegExp r1("QMAKE\\s*=(.*)");
+        QRegExp r1(QLatin1String("QMAKE\\s*=(.*)"));
         while (!ts.atEnd()) {
             QString line = ts.readLine();
             if (r1.exactMatch(line)) {
@@ -747,7 +748,7 @@ QtVersionManager::MakefileCompatible QtVersionManager::makefileIsFor(const QStri
     if (line.isEmpty())
         return CouldNotParse;
 
-    line = line.mid(line.indexOf(QChar(':')) + 1);
+    line.remove(0, line.indexOf(QLatin1Char(':')) + 1);
     line = line.trimmed();
 
     QFileInfo srcFileInfo(QFileInfo(makefile).absoluteDir(), line);
@@ -798,7 +799,7 @@ QPair<BaseQtVersion::QmakeBuildConfigs, QString> QtVersionManager::scanMakeFile(
     if (debug) {
         qDebug()<<"\n\nDumping information from scanMakeFile";
         qDebug()<<"QMake CONFIG variable parsing";
-        qDebug()<<"  "<< (result & BaseQtVersion::NoBuild ? "No Build" : QString::number(int(result)));
+        qDebug()<<"  "<< (result & BaseQtVersion::NoBuild ? QByteArray("No Build") : QByteArray::number(int(result)));
         qDebug()<<"  "<< (result & BaseQtVersion::DebugBuild ? "debug" : "release");
         qDebug()<<"  "<< (result & BaseQtVersion::BuildAll ? "debug_and_release" : "no debug_and_release");
         qDebug()<<"\nAddtional Arguments";
@@ -833,7 +834,7 @@ QString QtVersionManager::trimLine(const QString line)
 
 void QtVersionManager::parseArgs(const QString &args, QList<QMakeAssignment> *assignments, QList<QMakeAssignment> *afterAssignments, QString *additionalArguments)
 {
-    QRegExp regExp("([^\\s\\+-]*)\\s*(\\+=|=|-=|~=)(.*)");
+    QRegExp regExp(QLatin1String("([^\\s\\+-]*)\\s*(\\+=|=|-=|~=)(.*)"));
     bool after = false;
     bool ignoreNext = false;
     *additionalArguments = args;
@@ -885,22 +886,22 @@ BaseQtVersion::QmakeBuildConfigs QtVersionManager::qmakeBuildConfigFromCmdArgs(Q
     QList<QMakeAssignment> oldAssignments = *assignments;
     assignments->clear();
     foreach(const QMakeAssignment &qa, oldAssignments) {
-        if (qa.variable == "CONFIG") {
-            QStringList values = qa.value.split(' ');
+        if (qa.variable == QLatin1String("CONFIG")) {
+            QStringList values = qa.value.split(QLatin1Char(' '));
             QStringList newValues;
             foreach(const QString &value, values) {
-                if (value == "debug") {
-                    if (qa.op == "+=")
+                if (value == QLatin1String("debug")) {
+                    if (qa.op == QLatin1String("+="))
                         result = result  | BaseQtVersion::DebugBuild;
                     else
                         result = result  & ~BaseQtVersion::DebugBuild;
-                } else if (value == "release") {
-                    if (qa.op == "+=")
+                } else if (value == QLatin1String("release")) {
+                    if (qa.op == QLatin1String("+="))
                         result = result & ~BaseQtVersion::DebugBuild;
                     else
                         result = result | BaseQtVersion::DebugBuild;
-                } else if (value == "debug_and_release") {
-                    if (qa.op == "+=")
+                } else if (value == QLatin1String("debug_and_release")) {
+                    if (qa.op == QLatin1String("+="))
                         result = result | BaseQtVersion::BuildAll;
                     else
                         result = result & ~BaseQtVersion::BuildAll;
@@ -908,7 +909,7 @@ BaseQtVersion::QmakeBuildConfigs QtVersionManager::qmakeBuildConfigFromCmdArgs(Q
                     newValues.append(value);
                 }
                 QMakeAssignment newQA = qa;
-                newQA.value = newValues.join(" ");
+                newQA.value = newValues.join(QLatin1String(" "));
                 if (!newValues.isEmpty())
                     assignments->append(newQA);
             }