Port to new Q_UNREACHABLE_RETURN()

This is a semantic patch using ClangTidyTransformator to convert
sequences of Q_UNREACHABLE() + return into Q_UNREACHABLE_RETURN(),
newly added to qtbase.

    const std::string unr = "unr", val = "val", ret = "ret";
    auto makeUnreachableReturn = cat("Q_UNREACHABLE_RETURN(",
                                    ifBound(val, cat(node(val)), cat("")),
                                    ")");
    auto ignoringSwitchCases = [](auto stmt) {
        return anyOf(stmt, switchCase(subStmt(stmt)));
    };

    makeRule(stmt(ignoringSwitchCases(stmt(isExpandedFromMacro("Q_UNREACHABLE")).bind(unr)),
                  nextStmt(returnStmt(optionally(hasReturnValue(expr().bind(val)))).bind(ret))),
             {changeTo(node(unr), cat(makeUnreachableReturn,
                                      ";")), // TODO: why is the ; lost w/o this?
              changeTo(node(ret), cat(""))},
             cat("use ", makeUnreachableReturn));

a.k.a qt-use-unreachable-return.

subStmt() and nextStmt() are non-standard matchers.

There was one false positive, suppressed it with NOLINTNEXTLINE.

It's not really a false positiive, it's just that Clang sees the world
in one way and if conditonal compilation (#if) differs for other
compilers, Clang doesn't know better. This is an artifact of matching
two consecutive statements.

Change-Id: I3855b2dc8523db1ea860f72ad9818738162495c6
Reviewed-by: Qt CI Bot <[email protected]>
Reviewed-by: Fabian Kosmale <[email protected]>

36 files changed, 84 insertions, 161 deletions

diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewfileengine.cpp b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewfileengine.cpp
index 3afdaa53f1..fef0773613 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewfileengine.cpp
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewfileengine.cpp
@@ -113,8 +113,7 @@ bool QQmlPreviewFileEngine::open(QIODevice::OpenMode flags,
     case QQmlPreviewFileLoader::Fallback:
         return m_fallback->open(flags, permissions);
     default:
-        Q_UNREACHABLE();
-        return false;
+        Q_UNREACHABLE_RETURN(false);
     }
 }
 
@@ -129,8 +128,7 @@ bool QQmlPreviewFileEngine::close()
     case QQmlPreviewFileLoader::Directory:
         return false;
     default:
-        Q_UNREACHABLE();
-        return false;
+        Q_UNREACHABLE_RETURN(false);
     }
 }
 
@@ -293,8 +291,7 @@ bool QQmlPreviewFileEngine::setSize(qint64 size)
     case QQmlPreviewFileLoader::Directory:
         return false;
     default:
-        Q_UNREACHABLE();
-        return false;
+        Q_UNREACHABLE_RETURN(false);
     }
 }
 
diff --git a/src/qml/common/qv4staticvalue_p.h b/src/qml/common/qv4staticvalue_p.h
index 1c2343013b..001666d08a 100644
--- a/src/qml/common/qv4staticvalue_p.h
+++ b/src/qml/common/qv4staticvalue_p.h
@@ -366,8 +366,7 @@ struct StaticValue
             return 0; // Coercion of NaN to int, results in 0;
         }
 
-        Q_UNREACHABLE();
-        return 0;
+        Q_UNREACHABLE_RETURN(0);
     }
 
     ReturnedValue *data_ptr() { return &_val; }
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 8ed900e9e1..fbaf34abe1 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -483,8 +483,7 @@ QString IRBuilder::signalNameFromSignalPropertyName(const QString &signalPropert
         }
     }
 
-    Q_UNREACHABLE();
-    return QString();
+    Q_UNREACHABLE_RETURN(QString());
 }
 
 bool IRBuilder::visit(QQmlJS::AST::UiArrayMemberList *ast)
@@ -803,8 +802,7 @@ private:
             return Pragma::FunctionSignatureBehavior;
         }
 
-        Q_UNREACHABLE();
-        return Pragma::PragmaType(-1);
+        Q_UNREACHABLE_RETURN(Pragma::PragmaType(-1));
     }
 
     static bool assign(Pragma *pragma, QStringView value)
@@ -869,8 +867,7 @@ private:
         default:
             break;
         }
-        Q_UNREACHABLE();
-        return QLatin1StringView();
+        Q_UNREACHABLE_RETURN(QLatin1StringView());
     }
 };
 
diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 2f5a9bd55f..6f8e572702 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -759,86 +759,72 @@ void Codegen::destructurePattern(Pattern *p, const Reference &rhs)
 
 bool Codegen::visit(ArgumentList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(CaseBlock *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(CaseClause *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(CaseClauses *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(Catch *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(DefaultClause *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(Elision *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(Finally *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(FormalParameterList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(Program *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(PatternElement *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(PatternElementList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(PatternProperty *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(PatternPropertyList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(ExportDeclaration *ast)
@@ -879,68 +865,57 @@ bool Codegen::visit(TypeAnnotation *ast)
 
 bool Codegen::visit(StatementList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiArrayMemberList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiImport *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiHeaderItemList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiPragma *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiObjectInitializer *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiObjectMemberList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiParameterList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiProgram *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(UiQualifiedId *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(VariableDeclarationList *)
 {
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 bool Codegen::visit(ClassExpression *ast)
@@ -4473,8 +4448,7 @@ void Codegen::Reference::storeAccumulator() const
     }
     switch (type) {
     case Super:
-        Q_UNREACHABLE();
-        return;
+        Q_UNREACHABLE_RETURN();
     case SuperProperty:
         Instruction::StoreSuperProperty store;
         store.property = property.stackSlot();
@@ -4562,8 +4536,7 @@ void Codegen::Reference::loadInAccumulator() const
     case Accumulator:
         return;
     case Super:
-        Q_UNREACHABLE();
-        return;
+        Q_UNREACHABLE_RETURN();
     case SuperProperty:
         tdzCheckStackSlot(property, subscriptRequiresTDZCheck);
         Instruction::LoadSuperProperty load;
diff --git a/src/qml/jsapi/qjsmanagedvalue.cpp b/src/qml/jsapi/qjsmanagedvalue.cpp
index 8ae1ef3dd2..eeadf875de 100644
--- a/src/qml/jsapi/qjsmanagedvalue.cpp
+++ b/src/qml/jsapi/qjsmanagedvalue.cpp
@@ -634,8 +634,7 @@ QVariant QJSManagedValue::toVariant() const
     if (d->as<QV4::Managed>())
         return QV4::ExecutionEngine::toVariant(*d, QMetaType{}, true);
 
-    Q_UNREACHABLE();
-    return QVariant();
+    Q_UNREACHABLE_RETURN(QVariant());
 }
 
 /*!
diff --git a/src/qml/jsapi/qjsprimitivevalue.h b/src/qml/jsapi/qjsprimitivevalue.h
index bc32d554ae..9ac12dc86a 100644
--- a/src/qml/jsapi/qjsprimitivevalue.h
+++ b/src/qml/jsapi/qjsprimitivevalue.h
@@ -227,8 +227,7 @@ public:
         case String: return asString();
         }
 
-        Q_UNREACHABLE();
-        return QString();
+        Q_UNREACHABLE_RETURN(QString());
     }
 
     QVariant toVariant() const
@@ -242,8 +241,7 @@ public:
         case String:    return QVariant(asString());
         }
 
-        Q_UNREACHABLE();
-        return QVariant();
+        Q_UNREACHABLE_RETURN(QVariant());
     }
 
     friend inline QJSPrimitiveValue operator+(const QJSPrimitiveValue &lhs,
@@ -629,8 +627,7 @@ private:
             break;
         }
 
-        Q_UNREACHABLE();
-        return QJSPrimitiveUndefined();
+        Q_UNREACHABLE_RETURN(QJSPrimitiveUndefined());
     }
 
     constexpr bool isNanOrUndefined() const
@@ -742,8 +739,7 @@ private:
             else if constexpr (std::is_same_v<T, QString>)
                 return getString();
 
-            Q_UNREACHABLE();
-            return T();
+            Q_UNREACHABLE_RETURN(T());
         }
 
     private:
diff --git a/src/qml/jsapi/qjsvalue.cpp b/src/qml/jsapi/qjsvalue.cpp
index 5c864f9928..3f51b902b9 100644
--- a/src/qml/jsapi/qjsvalue.cpp
+++ b/src/qml/jsapi/qjsvalue.cpp
@@ -371,8 +371,7 @@ QJSValue::ErrorType QJSValue::errorType() const
     case QV4::Heap::ErrorObject::URIError:
         return URIError;
     }
-    Q_UNREACHABLE();
-    return NoError;
+    Q_UNREACHABLE_RETURN(NoError);
 }
 
 /*!
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index bb89dd87b2..e83c111251 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -316,8 +316,7 @@ static OptionalReturnedValue getPropertyFromImports(
                                          v4, qobj, qmlContext->imports(), r.importNamespace,
                                          Heap::QQmlTypeWrapper::ExcludeEnums));
     }
-    Q_UNREACHABLE();
-    return OptionalReturnedValue();
+    Q_UNREACHABLE_RETURN(OptionalReturnedValue());
 }
 
 ReturnedValue QObjectWrapper::getQmlProperty(
diff --git a/src/qml/jsruntime/qv4value.cpp b/src/qml/jsruntime/qv4value.cpp
index 8962932a66..223a004602 100644
--- a/src/qml/jsruntime/qv4value.cpp
+++ b/src/qml/jsruntime/qv4value.cpp
@@ -91,8 +91,7 @@ static QString primitiveToQString(const Value *value)
     switch (value->type()) {
     case Value::Empty_Type:
         Q_ASSERT(!"empty Value encountered");
-        Q_UNREACHABLE();
-        return QString();
+        Q_UNREACHABLE_RETURN(QString());
     case Value::Undefined_Type:
         return QStringLiteral("undefined");
     case Value::Null_Type:
@@ -103,8 +102,7 @@ static QString primitiveToQString(const Value *value)
         else
             return QStringLiteral("false");
     case Value::Managed_Type:
-        Q_UNREACHABLE();
-        return QString();
+        Q_UNREACHABLE_RETURN(QString());
     case Value::Integer_Type: {
         QString str;
         RuntimeHelpers::numberToString(&str, (double)value->int_32(), 10);
@@ -117,8 +115,7 @@ static QString primitiveToQString(const Value *value)
     }
     } // switch
 
-    Q_UNREACHABLE();
-    return QString();
+    Q_UNREACHABLE_RETURN(QString());
 }
 
 
diff --git a/src/qml/qml/qqml.cpp b/src/qml/qml/qqml.cpp
index 68cf1dc130..d5e98f1805 100644
--- a/src/qml/qml/qqml.cpp
+++ b/src/qml/qml/qqml.cpp
@@ -1411,8 +1411,7 @@ bool AOTCompiledContext::loadScopeObjectPropertyLookup(uint index, void *target)
         return true;
     }
 
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 void AOTCompiledContext::initLoadScopeObjectPropertyLookup(uint index, QMetaType type) const
@@ -1595,8 +1594,7 @@ bool AOTCompiledContext::getObjectLookup(uint index, QObject *object, void *targ
         return true;
     }
 
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 void AOTCompiledContext::initGetObjectLookup(uint index, QObject *object, QMetaType type) const
@@ -1701,8 +1699,7 @@ bool AOTCompiledContext::setObjectLookup(uint index, QObject *object, void *valu
         return true;
     }
 
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 void AOTCompiledContext::initSetObjectLookup(uint index, QObject *object, QMetaType type) const
diff --git a/src/qml/qml/qqmltypedata.cpp b/src/qml/qml/qqmltypedata.cpp
index 43354dac6d..dd70af34bf 100644
--- a/src/qml/qml/qqmltypedata.cpp
+++ b/src/qml/qml/qqmltypedata.cpp
@@ -75,8 +75,8 @@ QV4::ExecutableCompilationUnit *QQmlTypeData::compilationUnitForInlineComponent(
             return m_inlineComponentToCompiledData[icIt->nameIndex].data();
         }
     }
-    Q_UNREACHABLE();
-    return nullptr; // make integrity happy
+    Q_UNREACHABLE_RETURN(nullptr);
+    // make integrity happy
 }
 
 void QQmlTypeData::registerCallback(TypeDataCallback *callback)
diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index 7b763030f3..9a575d4986 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -725,12 +725,10 @@ bool QQmlTypeLoader::Blob::addImport(
     case QV4::CompiledData::Import::ImportScript:
         return addScriptImport(import);
     case QV4::CompiledData::Import::ImportInlineComponent:
-        Q_UNREACHABLE(); // addImport is never called with an inline component import
-        return false;
+        Q_UNREACHABLE_RETURN(false); // addImport is never called with an inline component import
     }
 
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 void QQmlTypeLoader::Blob::dependencyComplete(QQmlDataBlob *blob)
diff --git a/src/qml/qml/qqmlvme_p.h b/src/qml/qml/qqmlvme_p.h
index d5b2329395..ac0694354d 100644
--- a/src/qml/qml/qqmlvme_p.h
+++ b/src/qml/qml/qqmlvme_p.h
@@ -115,8 +115,7 @@ bool QQmlInstantiationInterrupt::shouldInterrupt() const
     case Flag:
         return !runWhile->load(std::memory_order_acquire) || (nsecs && timer.nsecsElapsed() > nsecs);
     }
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 QT_END_NAMESPACE
diff --git a/src/qmlcompiler/qqmljsmetatypes.cpp b/src/qmlcompiler/qqmljsmetatypes.cpp
index 235662ca64..9a205bec01 100644
--- a/src/qmlcompiler/qqmljsmetatypes.cpp
+++ b/src/qmlcompiler/qqmljsmetatypes.cpp
@@ -112,8 +112,8 @@ QSharedPointer<const QQmlJSScope> QQmlJSMetaPropertyBinding::literalType(const Q
     default:
         return {};
     }
-    Q_UNREACHABLE();
-    return {}; // needed on some compilers which do not see that every case in the switch returns
+    Q_UNREACHABLE_RETURN({});
+    // needed on some compilers which do not see that every case in the switch returns
 }
 
 QT_END_NAMESPACE
diff --git a/src/qmlcompiler/qqmljsregistercontent.cpp b/src/qmlcompiler/qqmljsregistercontent.cpp
index aec772ca5b..60f51bc302 100644
--- a/src/qmlcompiler/qqmljsregistercontent.cpp
+++ b/src/qmlcompiler/qqmljsregistercontent.cpp
@@ -54,8 +54,7 @@ QString QQmlJSRegisterContent::descriptiveName() const
                     std::get<ConvertedTypes>(m_content).result->internalName());
     }
     }
-    Q_UNREACHABLE();
-    return result + u"wat?"_s;
+    Q_UNREACHABLE_RETURN(result + u"wat?"_s);
 }
 
 bool QQmlJSRegisterContent::isList() const
diff --git a/src/qmlcompiler/qqmljsregistercontent_p.h b/src/qmlcompiler/qqmljsregistercontent_p.h
index 4e8c2f44b6..1ca44fd0c3 100644
--- a/src/qmlcompiler/qqmljsregistercontent_p.h
+++ b/src/qmlcompiler/qqmljsregistercontent_p.h
@@ -134,8 +134,7 @@ public:
             return qHash(std::get<ConvertedTypes>(registerContent.m_content), seed);
         }
 
-        Q_UNREACHABLE();
-        return seed;
+        Q_UNREACHABLE_RETURN(seed);
     }
 
     static QQmlJSRegisterContent create(const QQmlJSScope::ConstPtr &storedType,
diff --git a/src/qmlcompiler/qqmljstyperesolver.cpp b/src/qmlcompiler/qqmljstyperesolver.cpp
index 5eb9980ca1..db06d926fc 100644
--- a/src/qmlcompiler/qqmljstyperesolver.cpp
+++ b/src/qmlcompiler/qqmljstyperesolver.cpp
@@ -330,8 +330,7 @@ QQmlJSTypeResolver::containedType(const QQmlJSRegisterContent &container) const
     if (container.isConversion())
         return container.conversionResult();
 
-    Q_UNREACHABLE();
-    return {};
+    Q_UNREACHABLE_RETURN({});
 }
 
 void QQmlJSTypeResolver::trackListPropertyType(
@@ -411,8 +410,7 @@ QQmlJSRegisterContent QQmlJSTypeResolver::transformed(
                     origin.variant(), (this->*op)(origin.scopeType()));
     }
 
-    Q_UNREACHABLE();
-    return {};
+    Q_UNREACHABLE_RETURN({});
 }
 
 QQmlJSRegisterContent QQmlJSTypeResolver::referenceTypeForName(
@@ -804,8 +802,7 @@ static QQmlJSRegisterContent::ContentVariant scopeContentVariant(QQmlJSScope::Ex
     case QQmlJSScope::ExtensionNamespace:
         break;
     }
-    Q_UNREACHABLE();
-    return QQmlJSRegisterContent::Unknown;
+    Q_UNREACHABLE_RETURN(QQmlJSRegisterContent::Unknown);
 }
 
 static bool isRevisionAllowed(int memberRevision, const QQmlJSScope::ConstPtr &scope)
@@ -1201,8 +1198,7 @@ QQmlJSRegisterContent QQmlJSTypeResolver::memberType(const QQmlJSRegisterContent
         return result.isValid() ? result : memberEnumType(type.scopeType(), name);
     }
 
-    Q_UNREACHABLE();
-    return {};
+    Q_UNREACHABLE_RETURN({});
 }
 
 QQmlJSRegisterContent QQmlJSTypeResolver::valueType(const QQmlJSRegisterContent &list) const
diff --git a/src/qmldebug/qqmlprofilerevent.cpp b/src/qmldebug/qqmlprofilerevent.cpp
index 0cea64b41f..59e9eb4ebd 100644
--- a/src/qmldebug/qqmlprofilerevent.cpp
+++ b/src/qmldebug/qqmlprofilerevent.cpp
@@ -67,8 +67,7 @@ static inline Number readNumber(QDataStream &stream, qint8 type)
         return static_cast<Number>(value);
     }
     default:
-        Q_UNREACHABLE();
-        return 0;
+        Q_UNREACHABLE_RETURN(0);
     }
 }
 
diff --git a/src/qmldebug/qqmlprofilerevent_p.h b/src/qmldebug/qqmlprofilerevent_p.h
index 88aec820cf..9870e47897 100644
--- a/src/qmldebug/qqmlprofilerevent_p.h
+++ b/src/qmldebug/qqmlprofilerevent_p.h
@@ -175,8 +175,7 @@ QT_WARNING_POP
         case Inline8Bit:
             return QString::fromUtf8(m_data.internalChar, m_dataLength);
         default:
-            Q_UNREACHABLE();
-            return QString();
+            Q_UNREACHABLE_RETURN(QString());
         }
     }
 
diff --git a/src/qmlmodels/qqmllistaccessor.cpp b/src/qmlmodels/qqmllistaccessor.cpp
index 0e57c3c4e9..f1728d5e6c 100644
--- a/src/qmlmodels/qqmllistaccessor.cpp
+++ b/src/qmlmodels/qqmllistaccessor.cpp
@@ -117,8 +117,7 @@ qsizetype QQmlListAccessor::count() const
     case Invalid:
         return 0;
     }
-    Q_UNREACHABLE();
-    return 0;
+    Q_UNREACHABLE_RETURN(0);
 }
 
 QVariant QQmlListAccessor::at(qsizetype idx) const
@@ -159,8 +158,7 @@ QVariant QQmlListAccessor::at(qsizetype idx) const
     case Invalid:
         return QVariant();
     }
-    Q_UNREACHABLE();
-    return QVariant();
+    Q_UNREACHABLE_RETURN(QVariant());
 }
 
 bool QQmlListAccessor::isValid() const
diff --git a/src/qmlmodels/qqmlobjectmodel.cpp b/src/qmlmodels/qqmlobjectmodel.cpp
index 970a1e541f..4921010911 100644
--- a/src/qmlmodels/qqmlobjectmodel.cpp
+++ b/src/qmlmodels/qqmlobjectmodel.cpp
@@ -422,8 +422,7 @@ bool QQmlInstanceModel::setRequiredProperty(int index, const QString &name, cons
     Q_UNUSED(value);
     // The view should not call this function, unless
     // it's actually handled in a subclass.
-    Q_UNREACHABLE();
-    return false;
+    Q_UNREACHABLE_RETURN(false);
 }
 
 QT_END_NAMESPACE
diff --git a/src/qmlmodels/qqmltableinstancemodel_p.h b/src/qmlmodels/qqmltableinstancemodel_p.h
index 8fa2b30c14..6d3f455adc 100644
--- a/src/qmlmodels/qqmltableinstancemodel_p.h
+++ b/src/qmlmodels/qqmltableinstancemodel_p.h
@@ -85,9 +85,9 @@ public:
 
     bool setRequiredProperty(int index, const QString &name, const QVariant &value) final;
 
-    QVariant variantValue(int, const QString &) override { Q_UNREACHABLE(); return QVariant(); }
+    QVariant variantValue(int, const QString &) override { Q_UNREACHABLE_RETURN(QVariant()); }
     void setWatchedRoles(const QList<QByteArray> &) override { Q_UNREACHABLE(); }
-    int indexOf(QObject *, QObject *) const override { Q_UNREACHABLE(); return 0; }
+    int indexOf(QObject *, QObject *) const override { Q_UNREACHABLE_RETURN(0); }
 
 private:
     enum DestructionMode {
diff --git a/src/quick/items/qquickpalette.cpp b/src/quick/items/qquickpalette.cpp
index 9a72807fe1..07d1e61b59 100644
--- a/src/quick/items/qquickpalette.cpp
+++ b/src/quick/items/qquickpalette.cpp
@@ -23,9 +23,9 @@ static constexpr bool is_valid(QPalette::ColorGroup cg) noexcept
 
     // GCC 8.x does not tread __builtin_unreachable() as constexpr
 #if defined(Q_CC_INTEL) || defined(Q_CC_CLANG) || (defined(Q_CC_GNU) && Q_CC_GNU >= 900)
+    // NOLINTNEXTLINE(qt-use-unreachable-return): Triggers on Clang, breaking GCC 8
     Q_UNREACHABLE();
 #endif
-
     return false;
 }
 
diff --git a/src/quick/items/qquickpaletteproviderprivatebase_p.h b/src/quick/items/qquickpaletteproviderprivatebase_p.h
index 0b701f777b..a0e0302ea9 100644
--- a/src/quick/items/qquickpaletteproviderprivatebase_p.h
+++ b/src/quick/items/qquickpaletteproviderprivatebase_p.h
@@ -323,8 +323,7 @@ void QQuickPaletteProviderPrivateBase<I, Impl>::updateChildrenPalettes(const QPa
          * nothing in this instantiation of updateChildrenPalettes and instead add an override in
          * QQuickWindowPrivate, which does the correct thing.
          */
-        Q_UNREACHABLE(); // You are not supposed to call this function
-        return;
+        Q_UNREACHABLE_RETURN(); // You are not supposed to call this function
     } else {
         if (auto root = rootItem(*itemWithPalette())) {
             for (auto &&child : root->childItems()) {
diff --git a/src/quick/items/qquicktextutil_p.h b/src/quick/items/qquicktextutil_p.h
index 58da5e4947..212c488c73 100644
--- a/src/quick/items/qquicktextutil_p.h
+++ b/src/quick/items/qquicktextutil_p.h
@@ -101,8 +101,7 @@ typename T::RenderType QQuickTextUtil::textRenderType()
         return T::NativeRendering;
     }
 
-    Q_UNREACHABLE();
-    return T::QtRendering;
+    Q_UNREACHABLE_RETURN(T::QtRendering);
 }
 
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
index bab9bff07e..874d2f08e7 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
@@ -115,8 +115,7 @@ QRhiVertexInputAttribute::Format qsg_vertexInputFormat(const QSGGeometry::Attrib
         break;
     }
     qWarning("Unsupported attribute type 0x%x with %d components", a.type, a.tupleSize);
-    Q_UNREACHABLE();
-    return QRhiVertexInputAttribute::Float;
+    Q_UNREACHABLE_RETURN(QRhiVertexInputAttribute::Float);
 }
 
 static QRhiVertexInputLayout calculateVertexInputLayout(const QSGMaterialShader *s, const QSGGeometry *geometry, bool batchable)
@@ -169,8 +168,7 @@ QRhiCommandBuffer::IndexFormat qsg_indexFormat(const QSGGeometry *geometry)
         return QRhiCommandBuffer::IndexUInt32;
         break;
     default:
-        Q_UNREACHABLE();
-        return QRhiCommandBuffer::IndexUInt16;
+        Q_UNREACHABLE_RETURN(QRhiCommandBuffer::IndexUInt16);
     }
 }
 
diff --git a/src/quick/scenegraph/coreapi/qsgmaterialshader.cpp b/src/quick/scenegraph/coreapi/qsgmaterialshader.cpp
index 268f34d77b..b4090eb9cd 100644
--- a/src/quick/scenegraph/coreapi/qsgmaterialshader.cpp
+++ b/src/quick/scenegraph/coreapi/qsgmaterialshader.cpp
@@ -336,8 +336,7 @@ static inline QShader::Stage toShaderStage(QSGMaterialShader::Stage stage)
     case QSGMaterialShader::FragmentStage:
         return QShader::FragmentStage;
     default:
-        Q_UNREACHABLE();
-        return QShader::VertexStage;
+        Q_UNREACHABLE_RETURN(QShader::VertexStage);
     }
 }
 
diff --git a/src/quickcontrols2/material/qquickmaterialstyle.cpp b/src/quickcontrols2/material/qquickmaterialstyle.cpp
index 9114462828..dbe7347acc 100644
--- a/src/quickcontrols2/material/qquickmaterialstyle.cpp
+++ b/src/quickcontrols2/material/qquickmaterialstyle.cpp
@@ -1156,8 +1156,7 @@ QColor QQuickMaterialStyle::shade(const QColor &color, Shade shade) const
     case ShadeA700:
         return darkerShade(color, m_theme == Light ? 0.12 : 0.38);
     default:
-        Q_UNREACHABLE();
-        return QColor();
+        Q_UNREACHABLE_RETURN(QColor());
     }
 }
 
diff --git a/src/quickshapes/qquickshapegenericrenderer.cpp b/src/quickshapes/qquickshapegenericrenderer.cpp
index b91f2d59a1..680bd6c60f 100644
--- a/src/quickshapes/qquickshapegenericrenderer.cpp
+++ b/src/quickshapes/qquickshapegenericrenderer.cpp
@@ -564,8 +564,7 @@ void QQuickShapeGenericRenderer::updateFillNode(ShapePathData *d, QQuickShapeGen
             gradMat = QQuickShapeGenericStrokeFillNode::MatConicalGradient;
             break;
         default:
-            Q_UNREACHABLE();
-            return;
+            Q_UNREACHABLE_RETURN();
         }
         n->activateMaterial(m_item->window(), gradMat);
         if (d->effectiveDirty & DirtyFillGradient) {
diff --git a/src/quicktemplates2/qquickpopup.cpp b/src/quicktemplates2/qquickpopup.cpp
index 596eb7103e..f13d5e8de8 100644
--- a/src/quicktemplates2/qquickpopup.cpp
+++ b/src/quicktemplates2/qquickpopup.cpp
@@ -393,8 +393,7 @@ bool QQuickPopupPrivate::handleMouseEvent(QQuickItem *item, QMouseEvent *event)
     case QEvent::MouseButtonRelease:
         return handleRelease(item, event->scenePosition(), event->timestamp());
     default:
-        Q_UNREACHABLE();
-        return false;
+        Q_UNREACHABLE_RETURN(false);
     }
 }
 
@@ -406,8 +405,7 @@ bool QQuickPopupPrivate::handleHoverEvent(QQuickItem *item, QHoverEvent *event)
     case QEvent::HoverLeave:
         return blockInput(item, event->scenePosition());
     default:
-        Q_UNREACHABLE();
-        return false;
+        Q_UNREACHABLE_RETURN(false);
     }
 }
 
diff --git a/tests/auto/qml/qjsprimitivevalue/tst_qjsprimitivevalue.cpp b/tests/auto/qml/qjsprimitivevalue/tst_qjsprimitivevalue.cpp
index ea17eeae89..0c46fc9f6b 100644
--- a/tests/auto/qml/qjsprimitivevalue/tst_qjsprimitivevalue.cpp
+++ b/tests/auto/qml/qjsprimitivevalue/tst_qjsprimitivevalue.cpp
@@ -97,8 +97,7 @@ QString toString(BinaryOperator op) {
     case Mod:  return "%";
     }
 
-    Q_UNREACHABLE();
-    return QString();
+    Q_UNREACHABLE_RETURN(QString());
 }
 
 template<typename Result>
@@ -239,8 +238,7 @@ QString toString(UnaryOperator op) {
         return "--";
     }
 
-    Q_UNREACHABLE();
-    return QString();
+    Q_UNREACHABLE_RETURN(QString());
 }
 
 template<typename Result, UnaryOperator Operator>
diff --git a/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp b/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
index 3d942648fd..1a0d211989 100644
--- a/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
+++ b/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
@@ -2624,8 +2624,7 @@ double jsEval(double arg1, double arg2, const QString &op, QJSEngine *engine)
         return evalBinaryConst(u"<<"_s);
 
     qDebug() << op;
-    Q_UNREACHABLE();
-    return 0;
+    Q_UNREACHABLE_RETURN(0);
 }
 
 void tst_QmlCppCodegen::mathOperations()
diff --git a/tests/auto/qml/qqmllanguage/testtypes.h b/tests/auto/qml/qqmllanguage/testtypes.h
index 060c867a27..9ba5132bb4 100644
--- a/tests/auto/qml/qqmllanguage/testtypes.h
+++ b/tests/auto/qml/qqmllanguage/testtypes.h
@@ -1818,8 +1818,7 @@ public:
 
     int c()
     {
-        Q_UNREACHABLE();
-        return 1111;
+        Q_UNREACHABLE_RETURN(1111);
     }
 };
 
diff --git a/tools/qmljsrootgen/main.cpp b/tools/qmljsrootgen/main.cpp
index 77abd1be54..2bd54692d1 100644
--- a/tools/qmljsrootgen/main.cpp
+++ b/tools/qmljsrootgen/main.cpp
@@ -86,8 +86,7 @@ static QString findClassName(const QJSManagedValue &value)
     if (QV4::ScopedValue scoped(scope, asManaged(value)); scoped->isManaged())
         return scoped->managed()->vtable()->className;
 
-    Q_UNREACHABLE();
-    return QString();
+    Q_UNREACHABLE_RETURN(QString());
 }
 
 static QString buildClass(const QJSManagedValue &value, QJsonArray *classes,
diff --git a/tools/qmlscene/main.cpp b/tools/qmlscene/main.cpp
index 891b7534bd..123844ebb3 100644
--- a/tools/qmlscene/main.cpp
+++ b/tools/qmlscene/main.cpp
@@ -397,8 +397,7 @@ static QQuickWindow::TextRenderType parseTextRenderType(const QString &renderTyp
 
     usage();
 
-    Q_UNREACHABLE();
-    return QQuickWindow::QtTextRendering;
+    Q_UNREACHABLE_RETURN(QQuickWindow::QtTextRendering);
 }
 
 int main(int argc, char ** argv)
diff --git a/tools/qmltc/qmltcvisitor.cpp b/tools/qmltc/qmltcvisitor.cpp
index c36290a360..504ccbf159 100644
--- a/tools/qmltc/qmltcvisitor.cpp
+++ b/tools/qmltc/qmltcvisitor.cpp
@@ -352,8 +352,7 @@ QQmlJSScope::ConstPtr fetchType(const QQmlJSMetaPropertyBinding &binding)
     }
     // coverity complains about the unreachable return below,
     // some compilers; some compilers complain without it
-    Q_UNREACHABLE();
-    return {};
+    Q_UNREACHABLE_RETURN({});
 }
 
 template<typename Predicate>