diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -112,10 +112,12 @@
 # Turn off missing-field-initializers warning for GCC to avoid noise from false positives with empty {}
 # See discussion: http://mail.kde.org/pipermail/kdevelop-devel/2014-February/046910.html
 add_compile_flag_if_supported(-Wno-missing-field-initializers)
+add_compile_flag_if_supported(-Werror=switch)
 add_compile_flag_if_supported(-Werror=undefined-bool-conversion)
 add_compile_flag_if_supported(-Werror=tautological-undefined-compare)
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     add_compile_flag_if_supported(-Wdocumentation)
+    add_compile_flag_if_supported(-Wcovered-switch-default)
     # This warning is triggered by every call to qCDebug()
     add_compile_flag_if_supported(-Wno-gnu-zero-variadic-macro-arguments)
 endif()
diff --git a/kdevplatform/debugger/variable/variablecollection.cpp b/kdevplatform/debugger/variable/variablecollection.cpp
--- a/kdevplatform/debugger/variable/variablecollection.cpp
+++ b/kdevplatform/debugger/variable/variablecollection.cpp
@@ -189,8 +189,8 @@
         case Octal:         return QStringLiteral("octal");
         case Decimal:       return QStringLiteral("decimal");
         case Hexadecimal:   return QStringLiteral("hexadecimal");
-        default:            return QString();
     }
+    return QString();
 }
 
 
diff --git a/kdevplatform/language/duchain/navigation/abstractdeclarationnavigationcontext.cpp b/kdevplatform/language/duchain/navigation/abstractdeclarationnavigationcontext.cpp
--- a/kdevplatform/language/duchain/navigation/abstractdeclarationnavigationcontext.cpp
+++ b/kdevplatform/language/duchain/navigation/abstractdeclarationnavigationcontext.cpp
@@ -568,9 +568,6 @@
       case ClassDeclarationData::Trait:
         modifyHtml() += QStringLiteral("trait ");
         break;
-      default:
-        modifyHtml() += QStringLiteral("<unknown type> ");
-        break;
     }
     eventuallyMakeTypeLinks( klass.cast<AbstractType>() );
 
diff --git a/kdevplatform/outputview/outputexecutejob.cpp b/kdevplatform/outputview/outputexecutejob.cpp
--- a/kdevplatform/outputview/outputexecutejob.cpp
+++ b/kdevplatform/outputview/outputexecutejob.cpp
@@ -344,7 +344,6 @@
             errorValue = i18n("Waiting for the process has timed out");
             break;
 
-        default:
         case QProcess::UnknownError:
             errorValue = i18n("Exit code %1", d->m_process->exitCode());
             break;
diff --git a/kdevplatform/outputview/outputmodel.cpp b/kdevplatform/outputview/outputmodel.cpp
--- a/kdevplatform/outputview/outputmodel.cpp
+++ b/kdevplatform/outputview/outputmodel.cpp
@@ -423,12 +423,10 @@
         case StaticAnalysisFilter:
             filter = new StaticAnalysisFilterStrategy;
             break;
-        default:
-            // assert(false);
-            filter = new NoFilterStrategy;
-            break;
     }
-    Q_ASSERT(filter);
+    if (!filter) {
+        filter = new NoFilterStrategy;
+    }
 
     QMetaObject::invokeMethod(d->worker, "changeFilterStrategy",
                               Q_ARG(KDevelop::IFilterStrategy*, filter));
diff --git a/kdevplatform/outputview/tests/test_filteringstrategy.cpp b/kdevplatform/outputview/tests/test_filteringstrategy.cpp
--- a/kdevplatform/outputview/tests/test_filteringstrategy.cpp
+++ b/kdevplatform/outputview/tests/test_filteringstrategy.cpp
@@ -63,9 +63,8 @@
             return QTest::newRow(QString(QLatin1String(dataTag)+QLatin1String("-windows-ns")).toUtf8().constData());
         case WindowsFilePathWithSpaces:
             return QTest::newRow(QString(QLatin1String(dataTag)+QLatin1String("-windows-ws")).toUtf8().constData());
-        default:
-            return QTest::newRow(dataTag);
     }
+    Q_UNREACHABLE();
 }
 
 }
diff --git a/kdevplatform/outputview/tests/testlinebuilderfunctions.h b/kdevplatform/outputview/tests/testlinebuilderfunctions.h
--- a/kdevplatform/outputview/tests/testlinebuilderfunctions.h
+++ b/kdevplatform/outputview/tests/testlinebuilderfunctions.h
@@ -50,10 +50,8 @@
             return QStringLiteral("/some/path/to/a/project");
         case UnixFilePathWithSpaces:
             return QStringLiteral("/some/path with spaces/to/a/project");
-        default:
-            Q_ASSERT(0);
-            return QStringLiteral("/we/should/never/end/up/here");
     }
+    Q_UNREACHABLE();
 }
 
 QString buildCppCheckErrorLine(TestPathType pathType = UnixFilePathNoSpaces)
diff --git a/kdevplatform/project/builderjob.cpp b/kdevplatform/project/builderjob.cpp
--- a/kdevplatform/project/builderjob.cpp
+++ b/kdevplatform/project/builderjob.cpp
@@ -96,9 +96,8 @@
             return i18nc( "@info:status", "install" );
         case BuilderJob::Prune:
             return i18nc( "@info:status", "prune" );
-        default:
-            return QString();
     }
+    return QString();
 }
 
 void BuilderJobPrivate::addJob( BuilderJob::BuildType t, ProjectBaseItem* item )
@@ -138,8 +137,6 @@
                 j = item->project()->buildSystemManager()->builder()->configure( item->project() );
             }
             break;
-        default:
-            break;
     }
     if( j )
     {
diff --git a/plugins/debuggercommon/mi/micommand.cpp b/plugins/debuggercommon/mi/micommand.cpp
--- a/plugins/debuggercommon/mi/micommand.cpp
+++ b/plugins/debuggercommon/mi/micommand.cpp
@@ -146,276 +146,189 @@
 
 QString MICommand::miCommand() const
 {
-    QString command;
-
     switch (type()) {
         case NonMI:
-            command = QLatin1String("");
-            break;
+            return QStringLiteral("-");
         case BreakAfter:
-            command = QStringLiteral("break-after");//"ignore"
-            break;
+            return QStringLiteral("-break-after");//"ignore"
         case BreakCommands:
-            command = QStringLiteral("break-commands");
-            break;
+            return QStringLiteral("-break-commands");
         case BreakCondition:
-            command = QStringLiteral("break-condition");//"cond"
-            break;
+            return QStringLiteral("-break-condition");//"cond"
         case BreakDelete:
-            command = QStringLiteral("break-delete");//"delete breakpoint"
-            break;
+            return QStringLiteral("-break-delete");//"delete breakpoint"
         case BreakDisable:
-            command = QStringLiteral("break-disable");//"disable breakpoint"
-            break;
+            return QStringLiteral("-break-disable");//"disable breakpoint"
         case BreakEnable:
-            command = QStringLiteral("break-enable");//"enable breakpoint"
-            break;
+            return QStringLiteral("-break-enable");//"enable breakpoint"
         case BreakInfo:
-            command = QStringLiteral("break-info");//"info break"
-            break;
+            return QStringLiteral("-break-info");//"info break"
         case BreakInsert:
-            command = QStringLiteral("break-insert -f");
-            break;
+            return QStringLiteral("-break-insert -f");
         case BreakList:
-            command = QStringLiteral("break-list");//"info break"
-            break;
+            return QStringLiteral("-break-list");//"info break"
         case BreakWatch:
-            command = QStringLiteral("break-watch");
-            break;
+            return QStringLiteral("-break-watch");
 
         case DataDisassemble:
-            command = QStringLiteral("data-disassemble");
-            break;
+            return QStringLiteral("-data-disassemble");
         case DataEvaluateExpression:
-            command = QStringLiteral("data-evaluate-expression");
-            break;
+            return QStringLiteral("-data-evaluate-expression");
         case DataListChangedRegisters:
-            command = QStringLiteral("data-list-changed-registers");
-            break;
+            return QStringLiteral("-data-list-changed-registers");
         case DataListRegisterNames:
-            command = QStringLiteral("data-list-register-names");
-            break;
+            return QStringLiteral("-data-list-register-names");
         case DataListRegisterValues:
-            command = QStringLiteral("data-list-register-values");
-            break;
+            return QStringLiteral("-data-list-register-values");
         case DataReadMemory:
-            command = QStringLiteral("data-read-memory");
-            break;
+            return QStringLiteral("-data-read-memory");
         case DataWriteMemory:
-            command = QStringLiteral("data-write-memory");
-            break;
+            return QStringLiteral("-data-write-memory");
         case DataWriteRegisterVariables:
-            command = QStringLiteral("data-write-register-values");
-            break;
+            return QStringLiteral("-data-write-register-values");
 
         case EnablePrettyPrinting:
-            command = QStringLiteral("enable-pretty-printing");
-            break;
+            return QStringLiteral("-enable-pretty-printing");
         case EnableTimings:
-            command = QStringLiteral("enable-timings");
-            break;
+            return QStringLiteral("-enable-timings");
 
         case EnvironmentCd:
-            command = QStringLiteral("environment-cd");
-            break;
+            return QStringLiteral("-environment-cd");
         case EnvironmentDirectory:
-            command = QStringLiteral("environment-directory");
-            break;
+            return QStringLiteral("-environment-directory");
         case EnvironmentPath:
-            command = QStringLiteral("environment-path");
-            break;
+            return QStringLiteral("-environment-path");
         case EnvironmentPwd:
-            command = QStringLiteral("environment-pwd");
-            break;
+            return QStringLiteral("-environment-pwd");
 
         case ExecAbort:
-            command = QStringLiteral("exec-abort");
-            break;
+            return QStringLiteral("-exec-abort");
         case ExecArguments:
-            command = QStringLiteral("exec-arguments");//"set args"
-            break;
+            return QStringLiteral("-exec-arguments");//"set args"
         case ExecContinue:
-            command = QStringLiteral("exec-continue");
-            break;
+            return QStringLiteral("-exec-continue");
         case ExecFinish:
-            command = QStringLiteral("exec-finish");
-            break;
+            return QStringLiteral("-exec-finish");
         case ExecInterrupt:
-            command = QStringLiteral("exec-interrupt");
-            break;
+            return QStringLiteral("-exec-interrupt");
         case ExecNext:
-            command = QStringLiteral("exec-next");
-            break;
+            return QStringLiteral("-exec-next");
         case ExecNextInstruction:
-            command = QStringLiteral("exec-next-instruction");
-            break;
+            return QStringLiteral("-exec-next-instruction");
         case ExecRun:
-            command = QStringLiteral("exec-run");
-            break;
+            return QStringLiteral("-exec-run");
         case ExecStep:
-            command = QStringLiteral("exec-step");
-            break;
+            return QStringLiteral("-exec-step");
         case ExecStepInstruction:
-            command = QStringLiteral("exec-step-instruction");
-            break;
+            return QStringLiteral("-exec-step-instruction");
         case ExecUntil:
-            command = QStringLiteral("exec-until");
-            break;
+            return QStringLiteral("-exec-until");
 
         case FileExecAndSymbols:
-            command = QStringLiteral("file-exec-and-symbols");//"file"
-            break;
+            return QStringLiteral("-file-exec-and-symbols");//"file"
         case FileExecFile:
-            command = QStringLiteral("file-exec-file");//"exec-file"
-            break;
+            return QStringLiteral("-file-exec-file");//"exec-file"
         case FileListExecSourceFile:
-            command = QStringLiteral("file-list-exec-source-file");
-            break;
+            return QStringLiteral("-file-list-exec-source-file");
         case FileListExecSourceFiles:
-            command = QStringLiteral("file-list-exec-source-files");
-            break;
+            return QStringLiteral("-file-list-exec-source-files");
         case FileSymbolFile:
-            command = QStringLiteral("file-symbol-file");//"symbol-file"
-            break;
+            return QStringLiteral("-file-symbol-file");//"symbol-file"
 
         case GdbExit:
-            command = QStringLiteral("gdb-exit");
-            break;
+            return QStringLiteral("-gdb-exit");
         case GdbSet:
-            command = QStringLiteral("gdb-set");//"set"
-            break;
+            return QStringLiteral("-gdb-set");//"set"
         case GdbShow:
-            command = QStringLiteral("gdb-show");//"show"
-            break;
+            return QStringLiteral("-gdb-show");//"show"
         case GdbVersion:
-            command = QStringLiteral("gdb-version");//"show version"
-            break;
+            return QStringLiteral("-gdb-version");//"show version"
 
         case InferiorTtySet:
-            command = QStringLiteral("inferior-tty-set");
-            break;
+            return QStringLiteral("-inferior-tty-set");
         case InferiorTtyShow:
-            command = QStringLiteral("inferior-tty-show");
-            break;
+            return QStringLiteral("-inferior-tty-show");
 
         case InterpreterExec:
-            command = QStringLiteral("interpreter-exec");
-            break;
+            return QStringLiteral("-interpreter-exec");
 
         case ListFeatures:
-            command = QStringLiteral("list-features");
-            break;
+            return QStringLiteral("-list-features");
 
         case SignalHandle:
             return QStringLiteral("handle");
-            //command = "signal-handle";
-            break;
+            //return QStringLiteral("-signal-handle");
 
         case StackInfoDepth:
-            command = QStringLiteral("stack-info-depth");
-            break;
+            return QStringLiteral("-stack-info-depth");
         case StackInfoFrame:
-            command = QStringLiteral("stack-info-frame");
-            break;
+            return QStringLiteral("-stack-info-frame");
         case StackListArguments:
-            command = QStringLiteral("stack-list-arguments");
-            break;
+            return QStringLiteral("-stack-list-arguments");
         case StackListFrames:
-            command = QStringLiteral("stack-list-frames");
-            break;
+            return QStringLiteral("-stack-list-frames");
         case StackListLocals:
-            command = QStringLiteral("stack-list-locals");
-            break;
+            return QStringLiteral("-stack-list-locals");
         case StackSelectFrame:
-            command = QStringLiteral("stack-select-frame");
-            break;
+            return QStringLiteral("-stack-select-frame");
 
         case SymbolListLines:
-            command = QStringLiteral("symbol-list-lines");
-            break;
+            return QStringLiteral("-symbol-list-lines");
 
         case TargetAttach:
-            command = QStringLiteral("target-attach");
-            break;
+            return QStringLiteral("-target-attach");
         case TargetDetach:
-            command = QStringLiteral("target-detach");//"detach"
-            break;
+            return QStringLiteral("-target-detach");//"detach"
         case TargetDisconnect:
-            command = QStringLiteral("target-disconnect");//"disconnect"
-            break;
+            return QStringLiteral("-target-disconnect");//"disconnect"
         case TargetDownload:
-            command = QStringLiteral("target-download");
-            break;
+            return QStringLiteral("-target-download");
         case TargetSelect:
-            command = QStringLiteral("target-select");
-            break;
+            return QStringLiteral("-target-select");
 
         case ThreadInfo:
-            command = QStringLiteral("thread-info");
-            break;
+            return QStringLiteral("-thread-info");
         case ThreadListIds:
-            command = QStringLiteral("thread-list-ids");
-            break;
+            return QStringLiteral("-thread-list-ids");
         case ThreadSelect:
-            command = QStringLiteral("thread-select");
-            break;
+            return QStringLiteral("-thread-select");
 
         case TraceFind:
-            command = QStringLiteral("trace-find");
-            break;
+            return QStringLiteral("-trace-find");
         case TraceStart:
-            command = QStringLiteral("trace-start");
-            break;
+            return QStringLiteral("-trace-start");
         case TraceStop:
-            command = QStringLiteral("trace-stop");
-            break;
+            return QStringLiteral("-trace-stop");
 
         case VarAssign:
-            command = QStringLiteral("var-assign");
-            break;
+            return QStringLiteral("-var-assign");
         case VarCreate:
-            command = QStringLiteral("var-create");
-            break;
+            return QStringLiteral("-var-create");
         case VarDelete:
-            command = QStringLiteral("var-delete");
-            break;
+            return QStringLiteral("-var-delete");
         case VarEvaluateExpression:
-            command = QStringLiteral("var-evaluate-expression");
-            break;
+            return QStringLiteral("-var-evaluate-expression");
         case VarInfoPathExpression:
-            command = QStringLiteral("var-info-path-expression");
-            break;
+            return QStringLiteral("-var-info-path-expression");
         case VarInfoNumChildren:
-            command = QStringLiteral("var-info-num-children");
-            break;
+            return QStringLiteral("-var-info-num-children");
         case VarInfoType:
-            command = QStringLiteral("var-info-type");
-            break;
+            return QStringLiteral("-var-info-type");
         case VarListChildren:
-            command = QStringLiteral("var-list-children");
-            break;
+            return QStringLiteral("-var-list-children");
         case VarSetFormat:
-            command = QStringLiteral("var-set-format");
-            break;
+            return QStringLiteral("-var-set-format");
         case VarSetFrozen:
-            command = QStringLiteral("var-set-frozen");
-            break;
+            return QStringLiteral("-var-set-frozen");
         case VarShowAttributes:
-            command = QStringLiteral("var-show-attributes");
-            break;
+            return QStringLiteral("-var-show-attributes");
         case VarShowFormat:
-            command = QStringLiteral("var-show-format");
-            break;
+            return QStringLiteral("-var-show-format");
         case VarUpdate:
-            command = QStringLiteral("var-update");
-            break;
-
-        default:
-            command = QStringLiteral("unknown");
-            break;
+            return QStringLiteral("-var-update");
     }
 
-    return '-' + command;
+    return QStringLiteral("-unknown");
 }
 
 CommandType MICommand::type() const
diff --git a/plugins/debuggercommon/midebugger.cpp b/plugins/debuggercommon/midebugger.cpp
--- a/plugins/debuggercommon/midebugger.cpp
+++ b/plugins/debuggercommon/midebugger.cpp
@@ -281,9 +281,6 @@
                 // On-going status information about progress of a slow operation; may be ignored
                 break;
             }
-
-            default:
-                Q_ASSERT(false);
             }
             break;
         }
diff --git a/plugins/debuggercommon/widgets/disassemblewidget.cpp b/plugins/debuggercommon/widgets/disassemblewidget.cpp
--- a/plugins/debuggercommon/widgets/disassemblewidget.cpp
+++ b/plugins/debuggercommon/widgets/disassemblewidget.cpp
@@ -134,7 +134,6 @@
 {
     switch(flavor)
     {
-    default:
     case DisassemblyFlavorUnknown:
         m_disassemblyFlavorAtt->setChecked(false);
         m_disassemblyFlavorIntel->setChecked(false);
diff --git a/plugins/documentview/kdevdocumentmodel.cpp b/plugins/documentview/kdevdocumentmodel.cpp
--- a/plugins/documentview/kdevdocumentmodel.cpp
+++ b/plugins/documentview/kdevdocumentmodel.cpp
@@ -45,9 +45,8 @@
         return QIcon::fromTheme(QStringLiteral("document-revert"));
     case IDocument::DirtyAndModified:
         return QIcon::fromTheme(QStringLiteral("edit-delete"));
-    default:
-        return QIcon();
     }
+    Q_UNREACHABLE();
 }
 
 IDocument::DocumentState KDevDocumentItem::documentState() const
diff --git a/plugins/filetemplates/overridespage.cpp b/plugins/filetemplates/overridespage.cpp
--- a/plugins/filetemplates/overridespage.cpp
+++ b/plugins/filetemplates/overridespage.cpp
@@ -51,11 +51,8 @@
         return i18n("Protected");
     case Declaration::Private:
         return i18n("Private");
-    default:
-        qCritical("Unexpected value for Declaration::AccessPolicy: %d", accessPolicy);
-        Q_ASSERT(false);
-        return QString();
     }
+    Q_UNREACHABLE();
 }
 
 static QString functionPropertiesToString(ClassFunctionDeclaration* decl)
diff --git a/plugins/testview/testview.cpp b/plugins/testview/testview.cpp
--- a/plugins/testview/testview.cpp
+++ b/plugins/testview/testview.cpp
@@ -217,10 +217,8 @@
 
         case TestResult::Error:
             return QIcon::fromTheme(QStringLiteral("dialog-cancel"));
-
-        default:
-            return QIcon::fromTheme(QLatin1String(""));
     }
+    Q_UNREACHABLE();
 }
 
 QStandardItem* TestView::itemForSuite(ITestSuite* suite)