diff --git a/src/app/main.cpp b/src/app/main.cpp
index f11e81764d1568d1f19823e122eeadacaa047d0b..2efc04f14519bde7f49c1e46b068c60de9b59a8c 100644
--- a/src/app/main.cpp
+++ b/src/app/main.cpp
@@ -98,12 +98,12 @@ static void displayError(const QString &t) // No console on Windows.
 
 static void displayHelpText(const QString &t)
 {
-    qWarning(t.toUtf8().constData());
+    qWarning("%s", qPrintable(t));
 }
 
 static void displayError(const QString &t)
 {
-    qCritical(t.toUtf8().constData());
+    qCritical("%s", qPrintable(t));
 }
 
 #endif
diff --git a/src/plugins/cmakeprojectmanager/cmakestep.cpp b/src/plugins/cmakeprojectmanager/cmakestep.cpp
index 88572968040caea7f0e29c9bc8d6b388853fee55..13963273287384406c71e0567df104d9fae80eb8 100644
--- a/src/plugins/cmakeprojectmanager/cmakestep.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakestep.cpp
@@ -99,7 +99,7 @@ QString CMakeBuildStepConfigWidget::displayName() const
     return "CMake";
 }
 
-void CMakeBuildStepConfigWidget::init(const QString &buildConfiguration)
+void CMakeBuildStepConfigWidget::init(const QString & /*buildConfiguration */)
 {
     // TODO
 }
@@ -121,12 +121,12 @@ ProjectExplorer::BuildStep *CMakeBuildStepFactory::create(ProjectExplorer::Proje
     return new CMakeStep(pro);
 }
 
-QStringList CMakeBuildStepFactory::canCreateForProject(ProjectExplorer::Project *pro) const
+QStringList CMakeBuildStepFactory::canCreateForProject(ProjectExplorer::Project * /* pro */) const
 {
     return QStringList();
 }
 
-QString CMakeBuildStepFactory::displayNameForName(const QString &name) const
+QString CMakeBuildStepFactory::displayNameForName(const QString & /* name */) const
 {
     return "CMake";
 }
diff --git a/src/plugins/cmakeprojectmanager/makestep.cpp b/src/plugins/cmakeprojectmanager/makestep.cpp
index 1c7e7f055f5dc3d7030e6e02f9b5a727e3e36916..abd77cd10aadb36f196a81e1f5dcb350ca18507b 100644
--- a/src/plugins/cmakeprojectmanager/makestep.cpp
+++ b/src/plugins/cmakeprojectmanager/makestep.cpp
@@ -93,7 +93,7 @@ QString MakeBuildStepConfigWidget::displayName() const
     return "Make";
 }
 
-void MakeBuildStepConfigWidget::init(const QString &buildConfiguration)
+void MakeBuildStepConfigWidget::init(const QString & /* buildConfiguration */)
 {
     // TODO
 }
@@ -115,12 +115,12 @@ ProjectExplorer::BuildStep *MakeBuildStepFactory::create(ProjectExplorer::Projec
     return new MakeStep(pro);
 }
 
-QStringList MakeBuildStepFactory::canCreateForProject(ProjectExplorer::Project *pro) const
+QStringList MakeBuildStepFactory::canCreateForProject(ProjectExplorer::Project * /* pro */) const
 {
     return QStringList();
 }
 
-QString MakeBuildStepFactory::displayNameForName(const QString &name) const
+QString MakeBuildStepFactory::displayNameForName(const QString & /* name */) const
 {
     return "Make";
 }
diff --git a/src/plugins/coreplugin/inavigationwidgetfactory.cpp b/src/plugins/coreplugin/inavigationwidgetfactory.cpp
index 885277434d7843f7f25ff5d90b687e4201f8124b..f2ac6d8d5395f971f91bd2aec655e6a9062a9d8a 100644
--- a/src/plugins/coreplugin/inavigationwidgetfactory.cpp
+++ b/src/plugins/coreplugin/inavigationwidgetfactory.cpp
@@ -49,12 +49,12 @@ QKeySequence INavigationWidgetFactory::activationSequence()
 }
 
 
-void INavigationWidgetFactory::saveSettings(int position, QWidget *widget)
+void INavigationWidgetFactory::saveSettings(int /* position */, QWidget * /* widget */)
 {
 
 }
 
-void INavigationWidgetFactory::restoreSettings(int position, QWidget *widget)
+void INavigationWidgetFactory::restoreSettings(int /* position */, QWidget * /* widget */)
 {
 
 }
diff --git a/src/plugins/git/gitclient.cpp b/src/plugins/git/gitclient.cpp
index 3113ebf3f862676cf251704ab5c5ca750566547b..f4a0feb33e7f60ce8a56a83b794505535d9bc6f5 100644
--- a/src/plugins/git/gitclient.cpp
+++ b/src/plugins/git/gitclient.cpp
@@ -476,7 +476,7 @@ static inline QString trimFileSpecification(QString fileSpec)
         // Collapse the sequence of spaces
         const int filePos = colonIndex + 2;
         int nonBlankPos = filePos;
-        for ( ; fileSpec.at(nonBlankPos).isSpace(); nonBlankPos++);
+        for ( ; fileSpec.at(nonBlankPos).isSpace(); nonBlankPos++) ;
         if (nonBlankPos > filePos)
             fileSpec.remove(filePos, nonBlankPos - filePos);
     }
diff --git a/src/plugins/perforce/perforceeditor.cpp b/src/plugins/perforce/perforceeditor.cpp
index 5a0b1d2340eb9d7bf22de0a575ce85e06dac58c4..d54ce10de5ffd59156d133e205d5a61796f9933b 100644
--- a/src/plugins/perforce/perforceeditor.cpp
+++ b/src/plugins/perforce/perforceeditor.cpp
@@ -151,7 +151,7 @@ QString PerforceEditor::fileNameFromDiffSpecification(const QTextBlock &inBlock)
             // Ask plugin to map back
             const QString fileName = m_plugin->fileNameFromPerforceName(diffFileName.trimmed(), &errorMessage);
             if (fileName.isEmpty())
-                qWarning(errorMessage.toUtf8().constData());
+                qWarning("%s", qPrintable(errorMessage));
             return fileName;
         }
     }
diff --git a/src/plugins/qt4projectmanager/directorywatcher.cpp b/src/plugins/qt4projectmanager/directorywatcher.cpp
index 3434b0284d4469824a70ce60ae7bcad6d2f9b829..e2e0828219fe934125cfaabcb406ccac437759b3 100644
--- a/src/plugins/qt4projectmanager/directorywatcher.cpp
+++ b/src/plugins/qt4projectmanager/directorywatcher.cpp
@@ -207,7 +207,8 @@ int FileWatcher::m_objectCount = 0;
 QHash<QString,int> FileWatcher::m_fileCount;
 QFileSystemWatcher *FileWatcher::m_watcher = 0;
 
-FileWatcher::FileWatcher(QObject *parent)
+FileWatcher::FileWatcher(QObject *parent) :
+    QObject(parent)
 {
     if (!m_watcher)
         m_watcher = new QFileSystemWatcher();