init variables where they are declared when possible (clang-tidy)

clang-tidy -p compile_commands.json $file -checks='-*,modernize-use-default-member-init,readability-redundant-member-init'
 -config='{CheckOptions: [{key: modernize-use-default-member-init.UseAssignment, value: "1"}]}' -header-filter='qtdeclarative' -fix

Change-Id: I705f3235ff129ba68b0d8dad54a083e29fcead5f
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

61 files changed, 359 insertions, 528 deletions

diff --git a/src/imports/settings/qqmlsettings.cpp b/src/imports/settings/qqmlsettings.cpp
index b00876440d..2271774643 100644
--- a/src/imports/settings/qqmlsettings.cpp
+++ b/src/imports/settings/qqmlsettings.cpp
@@ -254,18 +254,15 @@ public:
     void _q_propertyChanged();
     QVariant readProperty(const QMetaProperty &property) const;
 
-    QQmlSettings *q_ptr;
-    int timerId;
-    bool initialized;
+    QQmlSettings *q_ptr = nullptr;
+    int timerId = 0;
+    bool initialized = false;
     QString category;
     mutable QPointer<QSettings> settings;
     QHash<const char *, QVariant> changedProperties;
 };
 
-QQmlSettingsPrivate::QQmlSettingsPrivate()
-    : q_ptr(nullptr), timerId(0), initialized(false)
-{
-}
+QQmlSettingsPrivate::QQmlSettingsPrivate() {}
 
 QSettings *QQmlSettingsPrivate::instance() const
 {
diff --git a/src/imports/sharedimage/qsharedimageloader.cpp b/src/imports/sharedimage/qsharedimageloader.cpp
index ee862b6a77..4672ded376 100644
--- a/src/imports/sharedimage/qsharedimageloader.cpp
+++ b/src/imports/sharedimage/qsharedimageloader.cpp
@@ -88,9 +88,7 @@ class QSharedImageLoaderPrivate : public QObjectPrivate
     Q_DECLARE_PUBLIC(QSharedImageLoader)
 
 public:
-    QSharedImageLoaderPrivate()
-        : QObjectPrivate()
-    {}
+    QSharedImageLoaderPrivate() {}
 
     QImage load(const QString &path, QSharedImageLoader::ImageParameters *params);
 
diff --git a/src/particles/qquickparticlesystem_p.h b/src/particles/qquickparticlesystem_p.h
index 6671cec4f8..73351fb99a 100644
--- a/src/particles/qquickparticlesystem_p.h
+++ b/src/particles/qquickparticlesystem_p.h
@@ -137,10 +137,7 @@ class Q_QUICKPARTICLES_PRIVATE_EXPORT QQuickParticleGroupData {
     class FreeList
     {
     public:
-        FreeList()
-            : firstUnused(UINT_MAX)
-            , allocated(0)
-        {}
+        FreeList() {}
 
         void resize(int newSize)
         {
@@ -189,8 +186,8 @@ class Q_QUICKPARTICLES_PRIVATE_EXPORT QQuickParticleGroupData {
 
     private:
         QV4::BitVector isUnused;
-        unsigned firstUnused;
-        int allocated;
+        unsigned firstUnused = UINT_MAX;
+        int allocated = 0;
     };
 
 public: // types
diff --git a/src/plugins/qmltooling/qmldbg_local/qlocalclientconnection.cpp b/src/plugins/qmltooling/qmldbg_local/qlocalclientconnection.cpp
index 28cfabc44b..dd0e4c6a04 100644
--- a/src/plugins/qmltooling/qmldbg_local/qlocalclientconnection.cpp
+++ b/src/plugins/qmltooling/qmldbg_local/qlocalclientconnection.cpp
@@ -71,18 +71,13 @@ private:
     void connectionEstablished();
     bool connectToServer();
 
-    bool m_block;
+    bool m_block = false;
     QString m_filename;
-    QLocalSocket *m_socket;
-    QQmlDebugServer *m_debugServer;
+    QLocalSocket *m_socket = nullptr;
+    QQmlDebugServer *m_debugServer = nullptr;
 };
 
-QLocalClientConnection::QLocalClientConnection() :
-    m_block(false),
-    m_socket(nullptr),
-    m_debugServer(nullptr)
-{
-}
+QLocalClientConnection::QLocalClientConnection() { }
 
 QLocalClientConnection::~QLocalClientConnection()
 {
diff --git a/src/plugins/qmltooling/qmldbg_tcp/qtcpserverconnection.cpp b/src/plugins/qmltooling/qmldbg_tcp/qtcpserverconnection.cpp
index 4006bf17ff..32ce820ea8 100644
--- a/src/plugins/qmltooling/qmldbg_tcp/qtcpserverconnection.cpp
+++ b/src/plugins/qmltooling/qmldbg_tcp/qtcpserverconnection.cpp
@@ -70,24 +70,16 @@ private:
     void newConnection();
     bool listen();
 
-    int m_portFrom;
-    int m_portTo;
-    bool m_block;
+    int m_portFrom = 0;
+    int m_portTo = 0;
+    bool m_block = false;
     QString m_hostaddress;
-    QTcpSocket *m_socket;
-    QTcpServer *m_tcpServer;
-    QQmlDebugServer *m_debugServer;
+    QTcpSocket *m_socket = nullptr;
+    QTcpServer *m_tcpServer = nullptr;
+    QQmlDebugServer *m_debugServer = nullptr;
 };
 
-QTcpServerConnection::QTcpServerConnection() :
-    m_portFrom(0),
-    m_portTo(0),
-    m_block(false),
-    m_socket(nullptr),
-    m_tcpServer(nullptr),
-    m_debugServer(nullptr)
-{
-}
+QTcpServerConnection::QTcpServerConnection() {}
 
 QTcpServerConnection::~QTcpServerConnection()
 {
diff --git a/src/qml/animations/qanimationgroupjob_p.h b/src/qml/animations/qanimationgroupjob_p.h
index 26965c0264..42a73aa77b 100644
--- a/src/qml/animations/qanimationgroupjob_p.h
+++ b/src/qml/animations/qanimationgroupjob_p.h
@@ -90,8 +90,8 @@ protected:
 
 private:
     //definition
-    QAbstractAnimationJob *m_firstChild;
-    QAbstractAnimationJob *m_lastChild;
+    QAbstractAnimationJob *m_firstChild = nullptr;
+    QAbstractAnimationJob *m_lastChild = nullptr;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/animations/qcontinuinganimationgroupjob.cpp b/src/qml/animations/qcontinuinganimationgroupjob.cpp
index 02dcaf1313..10096bf19c 100644
--- a/src/qml/animations/qcontinuinganimationgroupjob.cpp
+++ b/src/qml/animations/qcontinuinganimationgroupjob.cpp
@@ -43,7 +43,6 @@
 QT_BEGIN_NAMESPACE
 
 QContinuingAnimationGroupJob::QContinuingAnimationGroupJob()
-    : QAnimationGroupJob()
 {
 }
 
diff --git a/src/qml/animations/qparallelanimationgroupjob_p.h b/src/qml/animations/qparallelanimationgroupjob_p.h
index 358b95ce53..67ba626247 100644
--- a/src/qml/animations/qparallelanimationgroupjob_p.h
+++ b/src/qml/animations/qparallelanimationgroupjob_p.h
@@ -76,8 +76,8 @@ private:
     void applyGroupState(QAbstractAnimationJob *animation);
 
     //state
-    int m_previousLoop;
-    int m_previousCurrentTime;
+    int m_previousLoop = 0;
+    int m_previousCurrentTime = 0;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/animations/qpauseanimationjob.cpp b/src/qml/animations/qpauseanimationjob.cpp
index 27175580dc..0652ed578b 100644
--- a/src/qml/animations/qpauseanimationjob.cpp
+++ b/src/qml/animations/qpauseanimationjob.cpp
@@ -42,8 +42,7 @@
 QT_BEGIN_NAMESPACE
 
 QPauseAnimationJob::QPauseAnimationJob(int duration)
-    : QAbstractAnimationJob()
-    , m_duration(duration)
+    : m_duration(duration)
 {
     m_isPause = true;
 }
diff --git a/src/qml/animations/qsequentialanimationgroupjob_p.h b/src/qml/animations/qsequentialanimationgroupjob_p.h
index c7023b77c6..800f0c3b90 100644
--- a/src/qml/animations/qsequentialanimationgroupjob_p.h
+++ b/src/qml/animations/qsequentialanimationgroupjob_p.h
@@ -77,12 +77,12 @@ protected:
 private:
     struct AnimationIndex
     {
-        AnimationIndex() : afterCurrent(false), timeOffset(0), animation(nullptr) {}
+        AnimationIndex() {}
         // AnimationIndex points to the animation at timeOffset, skipping 0 duration animations.
         // Note that the index semantic is slightly different depending on the direction.
-        bool afterCurrent;  //whether animation is before or after m_currentAnimation   //TODO: make enum Before/After/Same
-        int timeOffset; // time offset when the animation at index starts.
-        QAbstractAnimationJob *animation; //points to the animation at timeOffset
+        bool afterCurrent = false;  //whether animation is before or after m_currentAnimation   //TODO: make enum Before/After/Same
+        int timeOffset = 0; // time offset when the animation at index starts.
+        QAbstractAnimationJob *animation = nullptr; //points to the animation at timeOffset
     };
 
     int animationActualTotalDuration(QAbstractAnimationJob *anim) const;
@@ -103,8 +103,8 @@ private:
     void advanceForwards(const AnimationIndex &newAnimationIndex);
 
     //state
-    QAbstractAnimationJob *m_currentAnimation;
-    int m_previousLoop;
+    QAbstractAnimationJob *m_currentAnimation = nullptr;
+    int m_previousLoop = 0;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/compiler/qqmlirbuilder_p.h b/src/qml/compiler/qqmlirbuilder_p.h
index 673bc2c481..7f2cf40611 100644
--- a/src/qml/compiler/qqmlirbuilder_p.h
+++ b/src/qml/compiler/qqmlirbuilder_p.h
@@ -82,12 +82,11 @@ struct PoolList
     PoolList()
         : first(nullptr)
         , last(nullptr)
-        , count(0)
     {}
 
     T *first;
     T *last;
-    int count;
+    int count = 0;
 
     int append(T *item) {
         item->next = nullptr;
@@ -205,11 +204,11 @@ class FixedPoolArray
 {
     T *data;
 public:
-    int count;
+    int count = 0;
 
     FixedPoolArray()
         : data(nullptr)
-        , count(0)
+
     {}
 
     void allocate(QQmlJS::MemoryPool *pool, int size)
@@ -343,21 +342,16 @@ struct Function
 struct Q_QML_PRIVATE_EXPORT CompiledFunctionOrExpression
 {
     CompiledFunctionOrExpression()
-        : node(nullptr)
-        , nameIndex(0)
-        , disableAcceleratedLookups(false)
-        , next(nullptr)
+
     {}
     CompiledFunctionOrExpression(QQmlJS::AST::Node *n)
         : node(n)
-        , nameIndex(0)
-        , disableAcceleratedLookups(false)
-        , next(nullptr)
+
     {}
-    QQmlJS::AST::Node *node; // FunctionDeclaration, Statement or Expression
-    quint32 nameIndex;
-    bool disableAcceleratedLookups;
-    CompiledFunctionOrExpression *next;
+    QQmlJS::AST::Node *node = nullptr; // FunctionDeclaration, Statement or Expression
+    quint32 nameIndex = 0;
+    bool disableAcceleratedLookups = false;
+    CompiledFunctionOrExpression *next = nullptr;
 };
 
 struct Q_QML_PRIVATE_EXPORT Object
diff --git a/src/qml/compiler/qv4codegen_p.h b/src/qml/compiler/qv4codegen_p.h
index 27c8e96e16..a46d47cb67 100644
--- a/src/qml/compiler/qv4codegen_p.h
+++ b/src/qml/compiler/qv4codegen_p.h
@@ -191,10 +191,7 @@ public:
         bool isLValue() const { return !isReadonly; }
 
         Reference(Codegen *cg, Type type = Invalid) : type(type), codegen(cg) {}
-        Reference()
-            : type(Invalid)
-            , codegen(nullptr)
-        {}
+        Reference() {}
         Reference(const Reference &other);
 
         Reference &operator =(const Reference &other);
@@ -367,7 +364,7 @@ public:
         bool stackSlotIsLocalOrArgument = false;
         bool isVolatile = false;
         bool global = false;
-        Codegen *codegen;
+        Codegen *codegen = nullptr;
 
     private:
         void storeAccumulator() const;
@@ -386,16 +383,12 @@ public:
     };
 
     struct ObjectPropertyValue {
-        ObjectPropertyValue()
-            : getter(-1)
-            , setter(-1)
-            , keyAsIndex(UINT_MAX)
-        {}
+        ObjectPropertyValue() {}
 
         Reference rvalue;
-        int getter; // index in _module->functions or -1 if not set
-        int setter;
-        uint keyAsIndex;
+        int getter = -1; // index in _module->functions or -1 if not set
+        int setter = -1;
+        uint keyAsIndex = UINT_MAX;
 
         bool hasGetter() const { return getter >= 0; }
         bool hasSetter() const { return setter >= 0; }
@@ -406,34 +399,26 @@ protected:
     class Result {
         Reference _result;
 
-        const BytecodeGenerator::Label *_iftrue;
-        const BytecodeGenerator::Label *_iffalse;
-        Format _format;
+        const BytecodeGenerator::Label *_iftrue = nullptr;
+        const BytecodeGenerator::Label *_iffalse = nullptr;
+        Format _format = ex;
         Format _requested;
         bool _trueBlockFollowsCondition = false;
 
     public:
         explicit Result(const Reference &lrvalue)
             : _result(lrvalue)
-            , _iftrue(nullptr)
-            , _iffalse(nullptr)
-            , _format(ex)
             , _requested(ex)
-        {
-        }
+        {}
 
         explicit Result(Format requested = ex)
-            : _iftrue(nullptr)
-            , _iffalse(nullptr)
-            , _format(ex)
-            , _requested(requested) {}
+            : _requested(requested) {}
 
         explicit Result(const BytecodeGenerator::Label *iftrue,
                         const BytecodeGenerator::Label *iffalse,
                         bool trueBlockFollowsCondition)
             : _iftrue(iftrue)
             , _iffalse(iffalse)
-            , _format(ex)
             , _requested(cx)
             , _trueBlockFollowsCondition(trueBlockFollowsCondition)
         {
diff --git a/src/qml/compiler/qv4compilercontext_p.h b/src/qml/compiler/qv4compilercontext_p.h
index d375942d0e..a78a66db52 100644
--- a/src/qml/compiler/qv4compilercontext_p.h
+++ b/src/qml/compiler/qv4compilercontext_p.h
@@ -173,10 +173,10 @@ struct Context {
     // Map from meta property index (existence implies dependency) to notify signal index
     struct KeyValuePair
     {
-        quint32 _key;
-        quint32 _value;
+        quint32 _key = 0;
+        quint32 _value = 0;
 
-        KeyValuePair(): _key(0), _value(0) {}
+        KeyValuePair() {}
         KeyValuePair(quint32 key, quint32 value): _key(key), _value(value) {}
 
         quint32 key() const { return _key; }
diff --git a/src/qml/jsruntime/qv4executableallocator_p.h b/src/qml/jsruntime/qv4executableallocator_p.h
index 2984a89df5..375c9a365f 100644
--- a/src/qml/jsruntime/qv4executableallocator_p.h
+++ b/src/qml/jsruntime/qv4executableallocator_p.h
@@ -82,11 +82,8 @@ public:
     struct Allocation
     {
         Allocation()
-            : addr(0)
-            , size(0)
+            : size(0)
             , free(true)
-            , next(nullptr)
-            , prev(nullptr)
         {}
 
         void *start() const;
@@ -103,11 +100,11 @@ public:
         bool mergeNext(ExecutableAllocator *allocator);
         bool mergePrevious(ExecutableAllocator *allocator);
 
-        quintptr addr;
+        quintptr addr = 0;
         uint size : 31; // More than 2GB of function code? nah :)
         uint free : 1;
-        Allocation *next;
-        Allocation *prev;
+        Allocation *next = nullptr;
+        Allocation *prev = nullptr;
     };
 
     // for debugging / unit-testing
@@ -117,13 +114,12 @@ public:
     struct ChunkOfPages
     {
         ChunkOfPages()
-            : pages(nullptr)
-            , firstAllocation(nullptr)
+
         {}
         ~ChunkOfPages();
 
-        WTF::PageAllocation *pages;
-        Allocation *firstAllocation;
+        WTF::PageAllocation *pages = nullptr;
+        Allocation *firstAllocation = nullptr;
 
         bool contains(Allocation *alloc) const;
     };
diff --git a/src/qml/jsruntime/qv4identifier_p.h b/src/qml/jsruntime/qv4identifier_p.h
index 21e4e8ea66..82346d5f68 100644
--- a/src/qml/jsruntime/qv4identifier_p.h
+++ b/src/qml/jsruntime/qv4identifier_p.h
@@ -95,9 +95,9 @@ struct IdentifierHashData
 struct IdentifierHash
 {
 
-    IdentifierHashData *d;
+    IdentifierHashData *d = nullptr;
 
-    IdentifierHash() : d(nullptr) {}
+    IdentifierHash() {}
     IdentifierHash(ExecutionEngine *engine);
     inline IdentifierHash(const IdentifierHash &other);
     inline ~IdentifierHash();
diff --git a/src/qml/jsruntime/qv4persistent_p.h b/src/qml/jsruntime/qv4persistent_p.h
index 5a0b2389e1..55e8eefcb7 100644
--- a/src/qml/jsruntime/qv4persistent_p.h
+++ b/src/qml/jsruntime/qv4persistent_p.h
@@ -94,7 +94,7 @@ private:
 class Q_QML_EXPORT PersistentValue
 {
 public:
-    PersistentValue() : val(nullptr) {}
+    PersistentValue() {}
     PersistentValue(const PersistentValue &other);
     PersistentValue &operator=(const PersistentValue &other);
     PersistentValue &operator=(const WeakValue &other);
@@ -142,13 +142,13 @@ public:
     bool isEmpty() { return !val; }
 
 private:
-    Value *val;
+    Value *val = nullptr;
 };
 
 class Q_QML_EXPORT WeakValue
 {
 public:
-    WeakValue() : val(nullptr) {}
+    WeakValue() {}
     WeakValue(const WeakValue &other);
     WeakValue(ExecutionEngine *engine, const Value &value);
     WeakValue &operator=(const WeakValue &other);
@@ -206,7 +206,7 @@ public:
     void markOnce(MarkStack *markStack);
 
 private:
-    Value *val;
+    Value *val = nullptr;
 
 private:
     Q_NEVER_INLINE void allocVal(ExecutionEngine *engine);
diff --git a/src/qml/parser/qqmljsast_p.h b/src/qml/parser/qqmljsast_p.h
index acbd88d466..ed3c83badf 100644
--- a/src/qml/parser/qqmljsast_p.h
+++ b/src/qml/parser/qqmljsast_p.h
@@ -224,8 +224,7 @@ public:
         Kind_UiEnumMemberList
     };
 
-    inline Node()
-        : kind(Kind_Undefined) {}
+    inline Node() {}
 
     // NOTE: node destructors are never called,
     //       instead we block free the memory
@@ -248,7 +247,7 @@ public:
     virtual SourceLocation lastSourceLocation() const = 0;
 
 // attributes
-    int kind;
+    int kind = Kind_Undefined;
 };
 
 class QML_PARSER_EXPORT ExpressionNode: public Node
@@ -489,8 +488,8 @@ class QML_PARSER_EXPORT ObjectLiteral: public ExpressionNode
 public:
     QQMLJS_DECLARE_AST_NODE(ObjectLiteral)
 
-    ObjectLiteral():
-        properties (nullptr) { kind = K; }
+    ObjectLiteral()
+        { kind = K; }
 
     ObjectLiteral(PropertyAssignmentList *plist):
         properties (plist) { kind = K; }
@@ -504,7 +503,7 @@ public:
     { return rbraceToken; }
 
 // attributes
-    PropertyAssignmentList *properties;
+    PropertyAssignmentList *properties = nullptr;
     SourceLocation lbraceToken;
     SourceLocation rbraceToken;
 };
diff --git a/src/qml/parser/qqmljsengine_p.h b/src/qml/parser/qqmljsengine_p.h
index 8cbe69a0ba..af26bac0ff 100644
--- a/src/qml/parser/qqmljsengine_p.h
+++ b/src/qml/parser/qqmljsengine_p.h
@@ -71,8 +71,7 @@ class QML_PARSER_EXPORT DiagnosticMessage
 public:
     enum Kind { Warning, Error };
 
-    DiagnosticMessage()
-        : kind(Error) {}
+    DiagnosticMessage() {}
 
     DiagnosticMessage(Kind kind, const AST::SourceLocation &loc, const QString &message)
         : kind(kind), loc(loc), message(message) {}
@@ -83,7 +82,7 @@ public:
     bool isError() const
     { return kind == Error; }
 
-    Kind kind;
+    Kind kind = Error;
     AST::SourceLocation loc;
     QString message;
 };
diff --git a/src/qml/parser/qqmljsmemorypool_p.h b/src/qml/parser/qqmljsmemorypool_p.h
index 5682d66f45..ef443d96bc 100644
--- a/src/qml/parser/qqmljsmemorypool_p.h
+++ b/src/qml/parser/qqmljsmemorypool_p.h
@@ -71,13 +71,7 @@ class QML_PARSER_EXPORT MemoryPool : public QSharedData
     void operator =(const MemoryPool &other);
 
 public:
-    MemoryPool()
-        : _blocks(nullptr),
-          _allocatedBlocks(0),
-          _blockCount(-1),
-          _ptr(nullptr),
-          _end(nullptr)
-    { }
+    MemoryPool() {}
 
     ~MemoryPool()
     {
@@ -144,11 +138,11 @@ private:
     }
 
 private:
-    char **_blocks;
-    int _allocatedBlocks;
-    int _blockCount;
-    char *_ptr;
-    char *_end;
+    char **_blocks = nullptr;
+    int _allocatedBlocks = 0;
+    int _blockCount = -1;
+    char *_ptr = nullptr;
+    char *_end = nullptr;
 
     enum
     {
diff --git a/src/qml/qml/ftw/qflagpointer_p.h b/src/qml/qml/ftw/qflagpointer_p.h
index 6954a8f09c..91ce74bec9 100644
--- a/src/qml/qml/ftw/qflagpointer_p.h
+++ b/src/qml/qml/ftw/qflagpointer_p.h
@@ -83,7 +83,7 @@ public:
     inline T *data() const;
 
 private:
-    quintptr ptr_value;
+    quintptr ptr_value = 0;
 
     static const quintptr FlagBit = 0x1;
     static const quintptr Flag2Bit = 0x2;
@@ -115,7 +115,7 @@ public:
     inline T2 *asT2() const;
 
 private:
-    quintptr ptr_value;
+    quintptr ptr_value = 0;
 
     static const quintptr FlagBit = 0x1;
     static const quintptr Flag2Bit = 0x2;
@@ -124,7 +124,6 @@ private:
 
 template<typename T>
 QFlagPointer<T>::QFlagPointer()
-: ptr_value(0)
 {
 }
 
@@ -233,7 +232,6 @@ T *QFlagPointer<T>::data() const
 
 template<typename T, typename T2>
 QBiPointer<T, T2>::QBiPointer()
-: ptr_value(0)
 {
 }
 
diff --git a/src/qml/qml/ftw/qhashedstring_p.h b/src/qml/qml/ftw/qhashedstring_p.h
index bd2c9fbdb7..2d6c25bdd3 100644
--- a/src/qml/qml/ftw/qhashedstring_p.h
+++ b/src/qml/qml/ftw/qhashedstring_p.h
@@ -94,7 +94,7 @@ private:
     friend class QStringHashNode;
 
     inline void computeHash() const;
-    mutable quint32 m_hash;
+    mutable quint32 m_hash = 0;
 };
 
 class QHashedCStringRef;
@@ -142,9 +142,9 @@ private:
 
     inline void computeHash() const;
 
-    const QChar *m_data;
-    int m_length;
-    mutable quint32 m_hash;
+    const QChar *m_data = nullptr;
+    int m_length = 0;
+    mutable quint32 m_hash = 0;
 };
 
 class Q_AUTOTEST_EXPORT QHashedCStringRef
@@ -169,9 +169,9 @@ private:
 
     inline void computeHash() const;
 
-    const char *m_data;
-    int m_length;
-    mutable quint32 m_hash;
+    const char *m_data = nullptr;
+    int m_length = 0;
+    mutable quint32 m_hash = 0;
 };
 
 class QStringHashData;
@@ -179,7 +179,7 @@ class Q_AUTOTEST_EXPORT QStringHashNode
 {
 public:
     QStringHashNode()
-    : length(0), hash(0), symbolId(0), ckey(nullptr)
+    : ckey(nullptr)
     {
     }
 
@@ -210,9 +210,9 @@ public:
 
     QFlagPointer<QStringHashNode> next;
 
-    qint32 length;
-    quint32 hash;
-    quint32 symbolId;
+    qint32 length = 0;
+    quint32 hash = 0;
+    quint32 symbolId = 0;
 
     union {
         const char *ckey;
@@ -276,25 +276,20 @@ public:
 class Q_AUTOTEST_EXPORT QStringHashData
 {
 public:
-    QStringHashData()
-    : buckets(nullptr), numBuckets(0), size(0), numBits(0)
-#ifdef QSTRINGHASH_LINK_DEBUG
-      , linkCount(0)
-#endif
-    {}
+    QStringHashData() {}
 
-    QStringHashNode **buckets;
-    int numBuckets;
-    int size;
-    short numBits;
+    QStringHashNode **buckets = nullptr;
+    int numBuckets = 0;
+    int size = 0;
+    short numBits = 0;
 #ifdef QSTRINGHASH_LINK_DEBUG
-    int linkCount;
+    int linkCount = 0;
 #endif
 
     struct IteratorData {
-        IteratorData() : n(nullptr), p(nullptr) {}
-        QStringHashNode *n;
-        void *p;
+        IteratorData() {}
+        QStringHashNode *n = nullptr;
+        void *p = nullptr;
     };
     void rehashToBits(short);
     void rehashToSize(int);
@@ -369,10 +364,10 @@ public:
     };
     struct ReservedNodePool
     {
-        ReservedNodePool() : count(0), used(0), nodes(nullptr) {}
+        ReservedNodePool() : nodes(nullptr) {}
         ~ReservedNodePool() { delete [] nodes; }
-        int count;
-        int used;
+        int count = 0;
+        int used = 0;
         Node *nodes;
     };
 
@@ -1038,7 +1033,7 @@ inline uint qHash(const QHashedStringRef &string)
 }
 
 QHashedString::QHashedString()
-: QString(), m_hash(0)
+: QString()
 {
 }
 
@@ -1089,7 +1084,6 @@ quint32 QHashedString::existingHash() const
 }
 
 QHashedStringRef::QHashedStringRef()
-: m_data(nullptr), m_length(0), m_hash(0)
 {
 }
 
@@ -1236,7 +1230,6 @@ quint32 QHashedStringRef::hash() const
 }
 
 QHashedCStringRef::QHashedCStringRef()
-: m_data(nullptr), m_length(0), m_hash(0)
 {
 }
 
diff --git a/src/qml/qml/ftw/qintrusivelist_p.h b/src/qml/qml/ftw/qintrusivelist_p.h
index c3b16f5b8c..8992be9f93 100644
--- a/src/qml/qml/ftw/qintrusivelist_p.h
+++ b/src/qml/qml/ftw/qintrusivelist_p.h
@@ -95,7 +95,7 @@ public:
 private:
     static inline N *nodeToN(QIntrusiveListNode *node);
 
-    QIntrusiveListNode *__first;
+    QIntrusiveListNode *__first = nullptr;
 };
 
 class QIntrusiveListNode
@@ -107,8 +107,8 @@ public:
     inline void remove();
     inline bool isInList() const;
 
-    QIntrusiveListNode *_next;
-    QIntrusiveListNode**_prev;
+    QIntrusiveListNode *_next = nullptr;
+    QIntrusiveListNode**_prev = nullptr;
 };
 
 template<class N, QIntrusiveListNode N::*member>
@@ -165,7 +165,7 @@ typename QIntrusiveList<N, member>::iterator &QIntrusiveList<N, member>::iterato
 
 template<class N, QIntrusiveListNode N::*member>
 QIntrusiveList<N, member>::QIntrusiveList()
-: __first(nullptr)
+
 {
 }
 
@@ -245,7 +245,6 @@ N *QIntrusiveList<N, member>::nodeToN(QIntrusiveListNode *node)
 }
 
 QIntrusiveListNode::QIntrusiveListNode()
-: _next(nullptr), _prev(nullptr)
 {
 }
 
diff --git a/src/qml/qml/ftw/qqmlnullablevalue_p.h b/src/qml/qml/ftw/qqmlnullablevalue_p.h
index 7a9e4d7b8a..5b3d2fc456 100644
--- a/src/qml/qml/ftw/qqmlnullablevalue_p.h
+++ b/src/qml/qml/ftw/qqmlnullablevalue_p.h
@@ -57,7 +57,7 @@ template<typename T>
 struct QQmlNullableValue
 {
     QQmlNullableValue()
-    : isNull(true), value(T()) {}
+    : value(T()) {}
     QQmlNullableValue(const QQmlNullableValue<T> &o)
     : isNull(o.isNull), value(o.value) {}
     QQmlNullableValue(const T &t)
@@ -70,7 +70,7 @@ struct QQmlNullableValue
 
     void invalidate() { isNull = true; }
     bool isValid() const { return !isNull; }
-    bool isNull;
+    bool isNull = true;
     T value;
 };
 
diff --git a/src/qml/qml/qqmlabstractbinding_p.h b/src/qml/qml/qqmlabstractbinding_p.h
index bea2d253e4..fc53be3e7b 100644
--- a/src/qml/qml/qqmlabstractbinding_p.h
+++ b/src/qml/qml/qqmlabstractbinding_p.h
@@ -95,8 +95,8 @@ public:
     { return m_nextBinding.flag2(); }
 
     struct RefCount {
-        RefCount() : refCount(0) {}
-        int refCount;
+        RefCount() {}
+        int refCount = 0;
         void ref() { ++refCount; }
         int deref() { return --refCount; }
         operator int() const { return refCount; }
diff --git a/src/qml/qml/qqmlboundsignalexpressionpointer_p.h b/src/qml/qml/qqmlboundsignalexpressionpointer_p.h
index 685e0160a3..eabe6666b4 100644
--- a/src/qml/qml/qqmlboundsignalexpressionpointer_p.h
+++ b/src/qml/qml/qqmlboundsignalexpressionpointer_p.h
@@ -58,7 +58,7 @@ class QQmlBoundSignalExpression;
 class Q_QML_PRIVATE_EXPORT QQmlBoundSignalExpressionPointer
 {
 public:
-    inline QQmlBoundSignalExpressionPointer() : o(nullptr) {}
+    inline QQmlBoundSignalExpressionPointer() {}
     QQmlBoundSignalExpressionPointer(QQmlBoundSignalExpression *);
     QQmlBoundSignalExpressionPointer(const QQmlBoundSignalExpressionPointer &);
     ~QQmlBoundSignalExpressionPointer();
@@ -73,7 +73,7 @@ public:
     QQmlBoundSignalExpressionPointer &take(QQmlBoundSignalExpression *);
 
 private:
-    QQmlBoundSignalExpression *o;
+    QQmlBoundSignalExpression *o = nullptr;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmldirparser_p.h b/src/qml/qml/qqmldirparser_p.h
index 1530b7a6cf..95370398ad 100644
--- a/src/qml/qml/qqmldirparser_p.h
+++ b/src/qml/qml/qqmldirparser_p.h
@@ -91,8 +91,7 @@ public:
 
     struct Component
     {
-        Component()
-            : majorVersion(0), minorVersion(0), internal(false), singleton(false) {}
+        Component() {}
 
         Component(const QString &typeName, const QString &fileName, int majorVersion, int minorVersion)
             : typeName(typeName), fileName(fileName), majorVersion(majorVersion), minorVersion(minorVersion),
@@ -100,24 +99,23 @@ public:
 
         QString typeName;
         QString fileName;
-        int majorVersion;
-        int minorVersion;
-        bool internal;
-        bool singleton;
+        int majorVersion = 0;
+        int minorVersion = 0;
+        bool internal = false;
+        bool singleton = false;
     };
 
     struct Script
     {
-        Script()
-            : majorVersion(0), minorVersion(0) {}
+        Script() {}
 
         Script(const QString &nameSpace, const QString &fileName, int majorVersion, int minorVersion)
             : nameSpace(nameSpace), fileName(fileName), majorVersion(majorVersion), minorVersion(minorVersion) {}
 
         QString nameSpace;
         QString fileName;
-        int majorVersion;
-        int minorVersion;
+        int majorVersion = 0;
+        int minorVersion = 0;
     };
 
     QHash<QString,Component> components() const;
diff --git a/src/qml/qml/qqmlglobal_p.h b/src/qml/qml/qqmlglobal_p.h
index 53f5dbed02..302fdd56c4 100644
--- a/src/qml/qml/qqmlglobal_p.h
+++ b/src/qml/qml/qqmlglobal_p.h
@@ -368,12 +368,12 @@ public:
 
 struct QQmlSourceLocation
 {
-    QQmlSourceLocation() : line(0), column(0) {}
+    QQmlSourceLocation() {}
     QQmlSourceLocation(const QString &sourceFile, quint16 line, quint16 column)
         : sourceFile(sourceFile), line(line), column(column) {}
     QString sourceFile;
-    quint16 line;
-    quint16 column;
+    quint16 line = 0;
+    quint16 column = 0;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlguard_p.h b/src/qml/qml/qqmlguard_p.h
index 87c3677d29..808bf4c709 100644
--- a/src/qml/qml/qqmlguard_p.h
+++ b/src/qml/qml/qqmlguard_p.h
@@ -65,9 +65,9 @@ public:
     inline QQmlGuardImpl(const QQmlGuardImpl &);
     inline ~QQmlGuardImpl();
 
-    QObject *o;
-    QQmlGuardImpl  *next;
-    QQmlGuardImpl **prev;
+    QObject *o = nullptr;
+    QQmlGuardImpl  *next = nullptr;
+    QQmlGuardImpl **prev = nullptr;
 
     inline void addGuard();
     inline void remGuard();
@@ -113,18 +113,17 @@ Q_DECLARE_METATYPE(QQmlGuard<QObject>)
 QT_BEGIN_NAMESPACE
 
 QQmlGuardImpl::QQmlGuardImpl()
-: o(nullptr), next(nullptr), prev(nullptr)
 {
 }
 
 QQmlGuardImpl::QQmlGuardImpl(QObject *g)
-: o(g), next(nullptr), prev(nullptr)
+: o(g)
 {
     if (o) addGuard();
 }
 
 QQmlGuardImpl::QQmlGuardImpl(const QQmlGuardImpl &g)
-: o(g.o), next(nullptr), prev(nullptr)
+: o(g.o)
 {
     if (o) addGuard();
 }
diff --git a/src/qml/qml/qqmllist.h b/src/qml/qml/qqmllist.h
index 4c6ae0cb8f..90ec57c911 100644
--- a/src/qml/qml/qqmllist.h
+++ b/src/qml/qml/qqmllist.h
@@ -61,20 +61,15 @@ public:
     typedef void (*ClearFunction)(QQmlListProperty<T> *);
 
     QQmlListProperty()
-        : object(nullptr),
-          data(nullptr),
-          append(nullptr),
+        : append(nullptr),
           count(nullptr),
           at(nullptr),
-          clear(nullptr),
-          dummy1(nullptr),
-          dummy2(nullptr)
+          clear(nullptr)
     {}
     QQmlListProperty(QObject *o, QList<T *> &list)
         : object(o), data(&list), append(qlist_append), count(qlist_count), at(qlist_at),
-          clear(qlist_clear),
-          dummy1(nullptr),
-          dummy2(nullptr)
+          clear(qlist_clear)
+
     {}
     QQmlListProperty(QObject *o, void *d, AppendFunction a, CountFunction c, AtFunction t,
                     ClearFunction r )
@@ -83,18 +78,15 @@ public:
           append(a),
           count(c),
           at(t),
-          clear(r),
-          dummy1(nullptr),
-          dummy2(nullptr)
+          clear(r)
+
     {}
     QQmlListProperty(QObject *o, void *d, CountFunction c, AtFunction t)
         : object(o),
           data(d),
           append(nullptr),
           count(c), at(t),
-          clear(nullptr),
-          dummy1(nullptr),
-          dummy2(nullptr)
+          clear(nullptr)
     {}
     bool operator==(const QQmlListProperty &o) const {
         return object == o.object &&
@@ -105,8 +97,8 @@ public:
                clear == o.clear;
     }
 
-    QObject *object;
-    void *data;
+    QObject *object = nullptr;
+    void *data = nullptr;
 
     AppendFunction append;
 
@@ -115,8 +107,8 @@ public:
 
     ClearFunction clear;
 
-    void *dummy1;
-    void *dummy2;
+    void *dummy1 = nullptr;
+    void *dummy2 = nullptr;
 
 private:
     static void qlist_append(QQmlListProperty *p, T *v) {
diff --git a/src/qml/qml/qqmlnotifier_p.h b/src/qml/qml/qqmlnotifier_p.h
index 39761875bf..d77e314de5 100644
--- a/src/qml/qml/qqmlnotifier_p.h
+++ b/src/qml/qml/qqmlnotifier_p.h
@@ -73,7 +73,7 @@ private:
     friend class QQmlThreadNotifierProxyObject;
 
     static void emitNotify(QQmlNotifierEndpoint *, void **a);
-    QQmlNotifierEndpoint *endpoints;
+    QQmlNotifierEndpoint *endpoints = nullptr;
 };
 
 class QQmlEngine;
@@ -129,7 +129,6 @@ private:
 };
 
 QQmlNotifier::QQmlNotifier()
-: endpoints(nullptr)
 {
 }
 
diff --git a/src/qml/qml/qqmlpropertycache_p.h b/src/qml/qml/qqmlpropertycache_p.h
index 22be6ba60c..7b04ba11b8 100644
--- a/src/qml/qml/qqmlpropertycache_p.h
+++ b/src/qml/qml/qqmlpropertycache_p.h
@@ -376,10 +376,10 @@ private:
 
 struct QQmlEnumValue
 {
-    QQmlEnumValue() : value(-1) {}
+    QQmlEnumValue() {}
     QQmlEnumValue(const QString &n, int v) : namedValue(n), value(v) {}
     QString namedValue;
-    int value;
+    int value = -1;
 };
 
 struct QQmlEnumData
diff --git a/src/qml/types/qqmltimer.cpp b/src/qml/types/qqmltimer.cpp
index 2037c4f6cd..6554010f36 100644
--- a/src/qml/types/qqmltimer.cpp
+++ b/src/qml/types/qqmltimer.cpp
@@ -57,7 +57,7 @@ class QQmlTimerPrivate : public QObjectPrivate, public QAnimationJobChangeListen
     Q_DECLARE_PUBLIC(QQmlTimer)
 public:
     QQmlTimerPrivate()
-        : interval(1000), running(false), repeating(false), triggeredOnStart(false)
+        : running(false), repeating(false), triggeredOnStart(false)
         , classBegun(false), componentComplete(false), firstTick(true), awaitingTick(false) {}
 
     void animationFinished(QAbstractAnimationJob *) override;
@@ -71,7 +71,7 @@ public:
         }
     }
 
-    int interval;
+    int interval = 1000;
     QPauseAnimationJob pause;
     bool running : 1;
     bool repeating : 1;
diff --git a/src/qml/util/qqmlchangeset_p.h b/src/qml/util/qqmlchangeset_p.h
index 8bc13f1b67..8347a3ff19 100644
--- a/src/qml/util/qqmlchangeset_p.h
+++ b/src/qml/util/qqmlchangeset_p.h
@@ -62,10 +62,10 @@ class Q_QML_PRIVATE_EXPORT QQmlChangeSet
 public:
     struct MoveKey
     {
-        MoveKey() : moveId(-1), offset(0) {}
+        MoveKey() {}
         MoveKey(int moveId, int offset) : moveId(moveId), offset(offset) {}
-        int moveId;
-        int offset;
+        int moveId = -1;
+        int offset = 0;
     };
 
     // The storrage for Change (below). This struct is trivial, which it has to be in order to store
diff --git a/src/qml/util/qqmllistcompositor_p.h b/src/qml/util/qqmllistcompositor_p.h
index d5723889e1..172040559c 100644
--- a/src/qml/util/qqmllistcompositor_p.h
+++ b/src/qml/util/qqmllistcompositor_p.h
@@ -87,17 +87,17 @@ public:
     class Range
     {
     public:
-        Range() : next(this), previous(this), list(nullptr), index(0), count(0), flags(0) {}
+        Range() : next(this), previous(this) {}
         Range(Range *next, void *list, int index, int count, uint flags)
             : next(next), previous(next->previous), list(list), index(index), count(count), flags(flags) {
             next->previous = this; previous->next = this; }
 
         Range *next;
         Range *previous;
-        void *list;
-        int index;
-        int count;
-        uint flags;
+        void *list = nullptr;
+        int index = 0;
+        int count = 0;
+        uint flags = 0;
 
         inline int start() const { return index; }
         inline int end() const { return index + count; }
@@ -145,11 +145,11 @@ public:
 
         void setGroup(Group g) { group = g; groupFlag = 1 << g; }
 
-        Range *range;
-        int offset;
-        Group group;
+        Range *range = nullptr;
+        int offset = 0;
+        Group group = Default;
         int groupFlag;
-        int groupCount;
+        int groupCount = 0;
         union {
             struct {
                 int cacheIndex;
@@ -308,8 +308,7 @@ Q_DECLARE_TYPEINFO(QQmlListCompositor::Change, Q_PRIMITIVE_TYPE);
 Q_DECLARE_TYPEINFO(QQmlListCompositor::Remove, Q_PRIMITIVE_TYPE);
 Q_DECLARE_TYPEINFO(QQmlListCompositor::Insert, Q_PRIMITIVE_TYPE);
 
-inline QQmlListCompositor::iterator::iterator()
-    : range(nullptr), offset(0), group(Default), groupCount(0) {}
+inline QQmlListCompositor::iterator::iterator() {}
 inline QQmlListCompositor::iterator::iterator(const iterator &it)
     : range(it.range)
     , offset(it.offset)
diff --git a/src/qmldebug/qqmldebugconnection.cpp b/src/qmldebug/qqmldebugconnection.cpp
index 1f40cab049..67bad8d812 100644
--- a/src/qmldebug/qqmldebugconnection.cpp
+++ b/src/qmldebug/qqmldebugconnection.cpp
@@ -63,15 +63,15 @@ class QQmlDebugConnectionPrivate : public QObjectPrivate
 
 public:
     QQmlDebugConnectionPrivate();
-    QPacketProtocol *protocol;
-    QIODevice *device;
-    QLocalServer *server;
+    QPacketProtocol *protocol = nullptr;
+    QIODevice *device = nullptr;
+    QLocalServer *server = nullptr;
     QEventLoop handshakeEventLoop;
     QTimer handshakeTimer;
 
-    bool gotHello;
-    int currentDataStreamVersion;
-    int maximumDataStreamVersion;
+    bool gotHello = false;
+    int currentDataStreamVersion = QDataStream::Qt_4_7;
+    int maximumDataStreamVersion = QDataStream::Qt_DefaultCompiledVersion;
     QHash <QString, float> serverPlugins;
     QHash<QString, QQmlDebugClient *> plugins;
     QStringList removedPlugins;
@@ -81,10 +81,7 @@ public:
     void flush();
 };
 
-QQmlDebugConnectionPrivate::QQmlDebugConnectionPrivate() :
-    protocol(nullptr), device(nullptr), server(nullptr), gotHello(false),
-    currentDataStreamVersion(QDataStream::Qt_4_7),
-    maximumDataStreamVersion(QDataStream::Qt_DefaultCompiledVersion)
+QQmlDebugConnectionPrivate::QQmlDebugConnectionPrivate()
 {
     handshakeTimer.setSingleShot(true);
     handshakeTimer.setInterval(3000);
diff --git a/src/quick/items/qquickanchors_p_p.h b/src/quick/items/qquickanchors_p_p.h
index db929f99f3..0a834276ae 100644
--- a/src/quick/items/qquickanchors_p_p.h
+++ b/src/quick/items/qquickanchors_p_p.h
@@ -60,15 +60,15 @@ QT_BEGIN_NAMESPACE
 class QQuickAnchorLine
 {
 public:
-    QQuickAnchorLine() : item(nullptr), anchorLine(QQuickAnchors::InvalidAnchor) {}
+    QQuickAnchorLine() {}
     QQuickAnchorLine(QQuickItem *i, QQuickAnchors::Anchor l) : item(i), anchorLine(l) {}
     QQuickAnchorLine(QQuickItem *i, uint l)
         : item(i)
         , anchorLine(static_cast<QQuickAnchors::Anchor>(l))
     { Q_ASSERT(l < ((QQuickAnchors::BaselineAnchor << 1) - 1)); }
 
-    QQuickItem *item;
-    QQuickAnchors::Anchor anchorLine;
+    QQuickItem *item = nullptr;
+    QQuickAnchors::Anchor anchorLine = QQuickAnchors::InvalidAnchor;
 };
 
 inline bool operator==(const QQuickAnchorLine& a, const QQuickAnchorLine& b)
diff --git a/src/quick/items/qquickevents_p_p.h b/src/quick/items/qquickevents_p_p.h
index d6aca87f84..e430832fe7 100644
--- a/src/quick/items/qquickevents_p_p.h
+++ b/src/quick/items/qquickevents_p_p.h
@@ -135,8 +135,8 @@ class Q_QUICK_PRIVATE_EXPORT QQuickMouseEvent : public QObject
 
 public:
     QQuickMouseEvent()
-      : _x(0), _y(0), _button(Qt::NoButton), _buttons(Qt::NoButton), _modifiers(Qt::NoModifier)
-      , _source(Qt::MouseEventNotSynthesized), _wasHeld(false), _isClick(false), _accepted(false)
+      : _buttons(Qt::NoButton), _modifiers(Qt::NoModifier)
+      , _wasHeld(false), _isClick(false), _accepted(false)
       , _flags(Qt::MouseEventFlags(nullptr))
     {}
 
@@ -175,12 +175,12 @@ public:
     void setAccepted(bool accepted) { _accepted = accepted; }
     int flags() const { return _flags; }
 private:
-    qreal _x;
-    qreal _y;
-    Qt::MouseButton _button;
+    qreal _x = 0;
+    qreal _y = 0;
+    Qt::MouseButton _button = Qt::NoButton;
     Qt::MouseButtons _buttons;
     Qt::KeyboardModifiers _modifiers;
-    Qt::MouseEventSource _source;
+    Qt::MouseEventSource _source = Qt::MouseEventNotSynthesized;
     bool _wasHeld : 1;
     bool _isClick : 1;
     bool _accepted : 1;
@@ -201,8 +201,7 @@ class QQuickWheelEvent : public QObject
 
 public:
     QQuickWheelEvent()
-      : _x(0), _y(0), _buttons(Qt::NoButton), _modifiers(Qt::NoModifier)
-      , _inverted(false), _accepted(false)
+      : _buttons(Qt::NoButton), _modifiers(Qt::NoModifier)
     {}
 
     void reset(qreal x, qreal y, const QPoint &angleDelta, const QPoint &pixelDelta,
@@ -229,14 +228,14 @@ public:
     void setAccepted(bool accepted) { _accepted = accepted; }
 
 private:
-    qreal _x;
-    qreal _y;
+    qreal _x = 0;
+    qreal _y = 0;
     QPoint _angleDelta;
     QPoint _pixelDelta;
     Qt::MouseButtons _buttons;
     Qt::KeyboardModifiers _modifiers;
-    bool _inverted;
-    bool _accepted;
+    bool _inverted = false;
+    bool _accepted = false;
 };
 
 class Q_QUICK_PRIVATE_EXPORT QQuickCloseEvent : public QObject
@@ -245,14 +244,13 @@ class Q_QUICK_PRIVATE_EXPORT QQuickCloseEvent : public QObject
     Q_PROPERTY(bool accepted READ isAccepted WRITE setAccepted)
 
 public:
-    QQuickCloseEvent()
-        : _accepted(true) {}
+    QQuickCloseEvent() {}
 
     bool isAccepted() { return _accepted; }
     void setAccepted(bool accepted) { _accepted = accepted; }
 
 private:
-    bool _accepted;
+    bool _accepted = true;
 };
 
 class Q_QUICK_PRIVATE_EXPORT QQuickEventPoint : public QObject
@@ -394,10 +392,8 @@ public:
     QQuickPointerEvent(QObject *parent = nullptr, QQuickPointerDevice *device = nullptr)
       : QObject(parent)
       , m_device(device)
-      , m_event(nullptr)
-      , m_button(Qt::NoButton)
       , m_pressedButtons(Qt::NoButton)
-    { }
+    {}
 
     virtual ~QQuickPointerEvent();
 
@@ -441,8 +437,8 @@ public: // helpers for C++ only (during event delivery)
 
 protected:
     QQuickPointerDevice *m_device;
-    QInputEvent *m_event; // original event as received by QQuickWindow
-    Qt::MouseButton m_button;
+    QInputEvent *m_event = nullptr; // original event as received by QQuickWindow
+    Qt::MouseButton m_button = Qt::NoButton;
     Qt::MouseButtons m_pressedButtons;
 
     Q_DISABLE_COPY(QQuickPointerEvent)
@@ -487,9 +483,8 @@ class Q_QUICK_PRIVATE_EXPORT QQuickPointerTouchEvent : public QQuickPointerEvent
 public:
     QQuickPointerTouchEvent(QObject *parent = nullptr, QQuickPointerDevice *device = nullptr)
         : QQuickPointerEvent(parent, device)
-        , m_pointCount(0)
         , m_synthMouseEvent(QEvent::MouseMove, QPointF(), Qt::NoButton, Qt::NoButton, Qt::NoModifier)
-    { }
+    {}
 
     QQuickPointerEvent *reset(QEvent *) override;
     void localize(QQuickItem *target) override;
@@ -515,7 +510,7 @@ public:
     QTouchEvent *asTouchEvent() const;
 
 private:
-    int m_pointCount;
+    int m_pointCount = 0;
     QVector<QQuickEventTouchPoint *> m_touchPoints;
     mutable QMouseEvent m_synthMouseEvent;
 
diff --git a/src/quick/items/qquickitem_p.h b/src/quick/items/qquickitem_p.h
index 2e91e2111c..1a3be437af 100644
--- a/src/quick/items/qquickitem_p.h
+++ b/src/quick/items/qquickitem_p.h
@@ -661,17 +661,15 @@ class QQuickKeyNavigationAttachedPrivate : public QObjectPrivate
 {
 public:
     QQuickKeyNavigationAttachedPrivate()
-        : QObjectPrivate(),
-          left(nullptr), right(nullptr), up(nullptr), down(nullptr), tab(nullptr), backtab(nullptr),
-          leftSet(false), rightSet(false), upSet(false), downSet(false),
+        : leftSet(false), rightSet(false), upSet(false), downSet(false),
           tabSet(false), backtabSet(false) {}
 
-    QQuickItem *left;
-    QQuickItem *right;
-    QQuickItem *up;
-    QQuickItem *down;
-    QQuickItem *tab;
-    QQuickItem *backtab;
+    QQuickItem *left = nullptr;
+    QQuickItem *right = nullptr;
+    QQuickItem *up = nullptr;
+    QQuickItem *down = nullptr;
+    QQuickItem *tab = nullptr;
+    QQuickItem *backtab = nullptr;
     bool leftSet : 1;
     bool rightSet : 1;
     bool upSet : 1;
@@ -782,8 +780,7 @@ class QQuickKeysAttachedPrivate : public QObjectPrivate
 {
 public:
     QQuickKeysAttachedPrivate()
-        : QObjectPrivate(), inPress(false), inRelease(false)
-        , inIM(false), enabled(true), imeItem(nullptr), item(nullptr)
+        : inPress(false), inRelease(false), inIM(false), enabled(true)
     {}
 
     //loop detection
@@ -793,9 +790,9 @@ public:
 
     bool enabled : 1;
 
-    QQuickItem *imeItem;
+    QQuickItem *imeItem = nullptr;
     QList<QQuickItem *> targets;
-    QQuickItem *item;
+    QQuickItem *item = nullptr;
     QQuickKeyEvent theKeyEvent;
 };
 
diff --git a/src/quick/items/qquickmultipointtoucharea_p.h b/src/quick/items/qquickmultipointtoucharea_p.h
index a6acdfc97d..f1550b4ac6 100644
--- a/src/quick/items/qquickmultipointtoucharea_p.h
+++ b/src/quick/items/qquickmultipointtoucharea_p.h
@@ -86,16 +86,7 @@ class Q_AUTOTEST_EXPORT QQuickTouchPoint : public QObject
 
 public:
     QQuickTouchPoint(bool qmlDefined = true)
-        : _id(0),
-          _x(0.0), _y(0.0),
-          _pressure(0.0),
-          _rotation(0),
-          _qmlDefined(qmlDefined),
-          _inUse(false),
-          _pressed(false),
-          _startX(0.0), _startY(0.0),
-          _previousX(0.0), _previousY(0.0),
-          _sceneX(0.0), _sceneY(0.0)
+        : _qmlDefined(qmlDefined)
     {}
 
     int pointId() const { return _id; }
@@ -171,23 +162,23 @@ Q_SIGNALS:
 
 private:
     friend class QQuickMultiPointTouchArea;
-    int _id;
-    qreal _x;
-    qreal _y;
-    qreal _pressure;
-    qreal _rotation;
+    int _id = 0;
+    qreal _x = 0.0;
+    qreal _y = 0.0;
+    qreal _pressure = 0.0;
+    qreal _rotation = 0;
     QSizeF _ellipseDiameters;
     QVector2D _velocity;
     QRectF _area;
     bool _qmlDefined;
-    bool _inUse;    //whether the point is currently in use (only valid when _qmlDefined == true)
-    bool _pressed;
-    qreal _startX;
-    qreal _startY;
-    qreal _previousX;
-    qreal _previousY;
-    qreal _sceneX;
-    qreal _sceneY;
+    bool _inUse = false;    //whether the point is currently in use (only valid when _qmlDefined == true)
+    bool _pressed = false;
+    qreal _startX = 0.0;
+    qreal _startY = 0.0;
+    qreal _previousX = 0.0;
+    qreal _previousY = 0.0;
+    qreal _sceneX = 0.0;
+    qreal _sceneY = 0.0;
     QPointingDeviceUniqueId _uniqueId;
 };
 
@@ -197,7 +188,7 @@ class QQuickGrabGestureEvent : public QObject
     Q_PROPERTY(QQmlListProperty<QObject> touchPoints READ touchPoints)
     Q_PROPERTY(qreal dragThreshold READ dragThreshold)
 public:
-    QQuickGrabGestureEvent() : _grab(false), _dragThreshold(QGuiApplication::styleHints()->startDragDistance()) {}
+    QQuickGrabGestureEvent() : _dragThreshold(QGuiApplication::styleHints()->startDragDistance()) {}
 
     Q_INVOKABLE void grab() { _grab = true; }
     bool wantsGrab() const { return _grab; }
@@ -209,7 +200,7 @@ public:
 
 private:
     friend class QQuickMultiPointTouchArea;
-    bool _grab;
+    bool _grab = false;
     qreal _dragThreshold;
     QList<QObject*> _touchPoints;
 };
diff --git a/src/quick/items/qquickspriteengine_p.h b/src/quick/items/qquickspriteengine_p.h
index 416e6611b5..d6d22b05d8 100644
--- a/src/quick/items/qquickspriteengine_p.h
+++ b/src/quick/items/qquickspriteengine_p.h
@@ -83,9 +83,6 @@ class Q_QUICK_PRIVATE_EXPORT QQuickStochasticState : public QObject //Currently
 public:
     QQuickStochasticState(QObject* parent = nullptr)
         : QObject(parent)
-        , m_duration(-1)
-        , m_durationVariation(0)
-        , m_randomStart(false)
     {
     }
 
@@ -179,11 +176,11 @@ public Q_SLOTS:
 private:
     QString m_name;
     QVariantMap m_to;
-    int m_duration;
-    int m_durationVariation;
+    int m_duration = -1;
+    int m_durationVariation = 0;
 
     friend class QQuickStochasticEngine;
-    bool m_randomStart;
+    bool m_randomStart = false;
 };
 
 class Q_QUICK_PRIVATE_EXPORT QQuickStochasticEngine : public QObject
diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h b/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
index 46753e8087..918f3ce82c 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
@@ -125,7 +125,6 @@ template <typename Type, int PageSize> class Allocator
 {
 public:
     Allocator()
-        : m_freePage(0)
     {
         pages.push_back(new AllocatorPage<Type, PageSize>());
     }
@@ -209,7 +208,7 @@ public:
     }
 
     QVector<AllocatorPage<Type, PageSize> *> pages;
-    int m_freePage;
+    int m_freePage = 0;
 };
 
 
@@ -306,12 +305,7 @@ struct Buffer {
 struct Element {
 
     Element()
-        : node(nullptr)
-        , batch(nullptr)
-        , nextInBatch(nullptr)
-        , root(nullptr)
-        , order(0)
-        , boundsComputed(false)
+        : boundsComputed(false)
         , boundsOutsideFloatRange(false)
         , translateOnlyToRoot(false)
         , removed(false)
@@ -332,14 +326,14 @@ struct Element {
     }
     void computeBounds();
 
-    QSGGeometryNode *node;
-    Batch *batch;
-    Element *nextInBatch;
-    Node *root;
+    QSGGeometryNode *node = nullptr;
+    Batch *batch = nullptr;
+    Element *nextInBatch = nullptr;
+    Node *root = nullptr;
 
     Rect bounds; // in device coordinates
 
-    int order;
+    int order = 0;
 
     uint boundsComputed : 1;
     uint boundsOutsideFloatRange : 1;
@@ -362,12 +356,12 @@ struct RenderNodeElement : public Element {
 };
 
 struct BatchRootInfo {
-    BatchRootInfo() : parentRoot(nullptr), lastOrder(-1), firstOrder(-1), availableOrders(0) { }
+    BatchRootInfo() {}
     QSet<Node *> subRoots;
-    Node *parentRoot;
-    int lastOrder;
-    int firstOrder;
-    int availableOrders;
+    Node *parentRoot = nullptr;
+    int lastOrder = -1;
+    int firstOrder = -1;
+    int availableOrders = 0;
 };
 
 struct ClipBatchRootInfo : public BatchRootInfo
@@ -381,14 +375,13 @@ struct DrawSet
         : vertices(v)
         , zorders(z)
         , indices(i)
-        , indexCount(0)
     {
     }
-    DrawSet() : vertices(0), zorders(0), indices(0), indexCount(0) {}
-    int vertices;
-    int zorders;
-    int indices;
-    int indexCount;
+    DrawSet() {}
+    int vertices = 0;
+    int zorders = 0;
+    int indices = 0;
+    int indexCount = 0;
 };
 
 enum BatchCompatibility
diff --git a/src/quick/scenegraph/coreapi/qsgnode.cpp b/src/quick/scenegraph/coreapi/qsgnode.cpp
index 10d4e2a3eb..9717862baa 100644
--- a/src/quick/scenegraph/coreapi/qsgnode.cpp
+++ b/src/quick/scenegraph/coreapi/qsgnode.cpp
@@ -244,14 +244,7 @@ static void qt_print_node_count()
  * Constructs a new node
  */
 QSGNode::QSGNode()
-    : m_parent(nullptr)
-    , m_type(BasicNodeType)
-    , m_firstChild(nullptr)
-    , m_lastChild(nullptr)
-    , m_nextSibling(nullptr)
-    , m_previousSibling(nullptr)
-    , m_subtreeRenderableCount(0)
-    , m_nodeFlags(OwnedByParent)
+    : m_nodeFlags(OwnedByParent)
     , m_dirtyState(nullptr)
 {
     init();
@@ -870,10 +863,6 @@ void QSGBasicGeometryNode::setGeometry(QSGGeometry *geometry)
 
 QSGGeometryNode::QSGGeometryNode()
     : QSGBasicGeometryNode(GeometryNodeType)
-    , m_render_order(0)
-    , m_material(nullptr)
-    , m_opaque_material(nullptr)
-    , m_opacity(1)
 {
 }
 
@@ -1326,8 +1315,6 @@ void QSGRootNode::notifyNodeChange(QSGNode *node, DirtyState state)
   */
 QSGOpacityNode::QSGOpacityNode()
     : QSGNode(OpacityNodeType)
-    , m_opacity(1)
-    , m_combined_opacity(1)
 {
 }
 
diff --git a/src/quick/scenegraph/coreapi/qsgnode.h b/src/quick/scenegraph/coreapi/qsgnode.h
index cd9d689dc1..528f100f8e 100644
--- a/src/quick/scenegraph/coreapi/qsgnode.h
+++ b/src/quick/scenegraph/coreapi/qsgnode.h
@@ -168,13 +168,13 @@ private:
     void init();
     void destroy();
 
-    QSGNode *m_parent;
-    NodeType m_type;
-    QSGNode *m_firstChild;
-    QSGNode *m_lastChild;
-    QSGNode *m_nextSibling;
-    QSGNode *m_previousSibling;
-    int m_subtreeRenderableCount;
+    QSGNode *m_parent = nullptr;
+    NodeType m_type = BasicNodeType;
+    QSGNode *m_firstChild = nullptr;
+    QSGNode *m_lastChild = nullptr;
+    QSGNode *m_nextSibling = nullptr;
+    QSGNode *m_previousSibling = nullptr;
+    int m_subtreeRenderableCount = 0;
 
     Flags m_nodeFlags;
     DirtyState m_dirtyState; // Obsolete, remove in Qt 6
@@ -246,11 +246,11 @@ protected:
 private:
     friend class QSGNodeUpdater;
 
-    int m_render_order;
-    QSGMaterial *m_material;
-    QSGMaterial *m_opaque_material;
+    int m_render_order = 0;
+    QSGMaterial *m_material = nullptr;
+    QSGMaterial *m_opaque_material = nullptr;
 
-    qreal m_opacity;
+    qreal m_opacity = 1;
 };
 
 class Q_QUICK_EXPORT QSGClipNode : public QSGBasicGeometryNode
@@ -323,8 +323,8 @@ public:
     bool isSubtreeBlocked() const override;
 
 private:
-    qreal m_opacity;
-    qreal m_combined_opacity;
+    qreal m_opacity = 1;
+    qreal m_combined_opacity = 1;
 };
 
 class Q_QUICK_EXPORT QSGNodeVisitor {
diff --git a/src/quick/scenegraph/coreapi/qsgnode_p.h b/src/quick/scenegraph/coreapi/qsgnode_p.h
index 84d5477085..f81128f51a 100644
--- a/src/quick/scenegraph/coreapi/qsgnode_p.h
+++ b/src/quick/scenegraph/coreapi/qsgnode_p.h
@@ -78,18 +78,14 @@ public:
 class QSGBasicGeometryNodePrivate : public QSGNodePrivate
 {
 public:
-    QSGBasicGeometryNodePrivate()
-        : QSGNodePrivate()
-    {}
+    QSGBasicGeometryNodePrivate() {}
 };
 
 
 class QSGGeometryNodePrivate: public QSGBasicGeometryNodePrivate
 {
 public:
-    QSGGeometryNodePrivate()
-        : QSGBasicGeometryNodePrivate()
-    {}
+    QSGGeometryNodePrivate() {}
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/coreapi/qsgrenderer_p.h b/src/quick/scenegraph/coreapi/qsgrenderer_p.h
index b890728fd8..d4ff6ea9fe 100644
--- a/src/quick/scenegraph/coreapi/qsgrenderer_p.h
+++ b/src/quick/scenegraph/coreapi/qsgrenderer_p.h
@@ -162,12 +162,12 @@ class Q_QUICK_PRIVATE_EXPORT QSGNodeDumper : public QSGNodeVisitor {
 public:
     static void dump(QSGNode *n);
 
-    QSGNodeDumper() : m_indent(0) {}
+    QSGNodeDumper() {}
     void visitNode(QSGNode *n) override;
     void visitChildren(QSGNode *n) override;
 
 private:
-    int m_indent;
+    int m_indent = 0;
 };
 
 
diff --git a/src/quick/scenegraph/qsgadaptationlayer_p.h b/src/quick/scenegraph/qsgadaptationlayer_p.h
index f1d8493e85..9c88b8272c 100644
--- a/src/quick/scenegraph/qsgadaptationlayer_p.h
+++ b/src/quick/scenegraph/qsgadaptationlayer_p.h
@@ -266,19 +266,19 @@ public:
             Texture // for APIs with separate texture and sampler objects
         };
         struct InputParameter {
-            InputParameter() : semanticIndex(0) { }
+            InputParameter() {}
             // Semantics use the D3D keys (POSITION, TEXCOORD).
             // Attribute name based APIs can map based on pre-defined names.
             QByteArray semanticName;
-            int semanticIndex;
+            int semanticIndex = 0;
         };
         struct Variable {
-            Variable() : type(Constant), offset(0), size(0), bindPoint(0) { }
-            VariableType type;
+            Variable() {}
+            VariableType type = Constant;
             QByteArray name;
-            uint offset; // for cbuffer members
-            uint size; // for cbuffer members
-            int bindPoint; // for textures and samplers; for register-based APIs
+            uint offset = 0; // for cbuffer members
+            uint size = 0; // for cbuffer members
+            int bindPoint = 0; // for textures and samplers; for register-based APIs
         };
 
         QByteArray blob; // source or bytecode
@@ -329,8 +329,8 @@ public:
     };
 
     struct ShaderData {
-        ShaderData() : hasShaderCode(false) { }
-        bool hasShaderCode;
+        ShaderData() {}
+        bool hasShaderCode = false;
         QSGGuiThreadShaderEffectManager::ShaderInfo shaderInfo;
         QVector<VariableData> varData;
     };
@@ -373,7 +373,7 @@ public:
         HighQualitySubPixelAntialiasing
     };
 
-    QSGGlyphNode() : m_ownerElement(nullptr) {}
+    QSGGlyphNode() {}
 
     virtual void setGlyphs(const QPointF &position, const QGlyphRun &glyphs) = 0;
     virtual void setColor(const QColor &color) = 0;
@@ -394,7 +394,7 @@ public:
     void accept(QSGNodeVisitorEx *visitor) override { if (visitor->visit(this)) visitor->visitChildren(this); visitor->endVisit(this); }
 protected:
     QRectF m_bounding_rect;
-    QQuickItem *m_ownerElement;
+    QQuickItem *m_ownerElement = nullptr;
 };
 
 class Q_QUICK_PRIVATE_EXPORT QSGDistanceFieldGlyphConsumer
@@ -421,24 +421,24 @@ public:
     };
 
     struct TexCoord {
-        qreal x;
-        qreal y;
-        qreal width;
-        qreal height;
-        qreal xMargin;
-        qreal yMargin;
+        qreal x = 0;
+        qreal y = 0;
+        qreal width = -1;
+        qreal height = -1;
+        qreal xMargin = 0;
+        qreal yMargin = 0;
 
-        TexCoord() : x(0), y(0), width(-1), height(-1), xMargin(0), yMargin(0) { }
+        TexCoord() {}
 
         bool isNull() const { return width <= 0 || height <= 0; }
         bool isValid() const { return width >= 0 && height >= 0; }
     };
 
     struct Texture {
-        uint textureId;
+        uint textureId = 0;
         QSize size;
 
-        Texture() : textureId(0), size(QSize()) { }
+        Texture() : size(QSize()) { }
         bool operator == (const Texture &other) const { return textureId == other.textureId; }
     };
 
@@ -478,13 +478,13 @@ protected:
     };
 
     struct GlyphData {
-        Texture *texture;
+        Texture *texture = nullptr;
         TexCoord texCoord;
         QRectF boundingRect;
         QPainterPath path;
-        quint32 ref;
+        quint32 ref = 0;
 
-        GlyphData() : texture(nullptr), ref(0) { }
+        GlyphData() {}
     };
 
     virtual void requestGlyphs(const QSet<glyph_t> &glyphs) = 0;
diff --git a/src/quick/scenegraph/qsgcontextplugin.cpp b/src/quick/scenegraph/qsgcontextplugin.cpp
index a697c315a3..628619fa46 100644
--- a/src/quick/scenegraph/qsgcontextplugin.cpp
+++ b/src/quick/scenegraph/qsgcontextplugin.cpp
@@ -74,8 +74,8 @@ struct QSGAdaptationBackendData
 {
     QSGAdaptationBackendData();
 
-    bool tried;
-    QSGContextFactoryInterface *factory;
+    bool tried = false;
+    QSGContextFactoryInterface *factory = nullptr;
     QString name;
     QSGContextFactoryInterface::Flags flags;
 
@@ -85,9 +85,7 @@ struct QSGAdaptationBackendData
 };
 
 QSGAdaptationBackendData::QSGAdaptationBackendData()
-    : tried(false)
-    , factory(nullptr)
-    , flags(nullptr)
+    : flags(nullptr)
 {
     // Fill in the table with the built-in adaptations.
     builtIns.append(new QSGSoftwareAdaptation);
diff --git a/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache_p.h b/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache_p.h
index fe365495c2..76c0d20647 100644
--- a/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache_p.h
+++ b/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache_p.h
@@ -91,10 +91,9 @@ private:
         QSize size;
         QRect allocatedArea;
         QDistanceField image;
-        int padding;
+        int padding = -1;
 
-        TextureInfo(const QRect &preallocRect = QRect()) : texture(0), allocatedArea(preallocRect), padding(-1)
-        { }
+        TextureInfo(const QRect &preallocRect = QRect()) : texture(0), allocatedArea(preallocRect) { }
     };
 
     void createTexture(TextureInfo * texInfo, int width, int height);
diff --git a/src/quick/scenegraph/qsgdefaultinternalimagenode.cpp b/src/quick/scenegraph/qsgdefaultinternalimagenode.cpp
index 7e6d6d0d07..5dd6eaa4ca 100644
--- a/src/quick/scenegraph/qsgdefaultinternalimagenode.cpp
+++ b/src/quick/scenegraph/qsgdefaultinternalimagenode.cpp
@@ -83,7 +83,6 @@ QSGMaterialShader *QSGSmoothTextureMaterial::createShader() const
 }
 
 SmoothTextureMaterialShader::SmoothTextureMaterialShader()
-    : QSGTextureMaterialShader()
 {
     setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/smoothtexture.vert"));
     setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/smoothtexture.frag"));
diff --git a/src/quick/scenegraph/qsgdefaultinternalrectanglenode.cpp b/src/quick/scenegraph/qsgdefaultinternalrectanglenode.cpp
index ef8a13931e..fd0dcebd57 100644
--- a/src/quick/scenegraph/qsgdefaultinternalrectanglenode.cpp
+++ b/src/quick/scenegraph/qsgdefaultinternalrectanglenode.cpp
@@ -67,7 +67,6 @@ private:
 };
 
 SmoothColorMaterialShader::SmoothColorMaterialShader()
-    : QSGMaterialShader()
 {
     setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/smoothcolor.vert"));
     setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/smoothcolor.frag"));
diff --git a/src/quick/scenegraph/qsgdefaultspritenode.cpp b/src/quick/scenegraph/qsgdefaultspritenode.cpp
index c9a9625f2b..8761d99c1f 100644
--- a/src/quick/scenegraph/qsgdefaultspritenode.cpp
+++ b/src/quick/scenegraph/qsgdefaultspritenode.cpp
@@ -70,26 +70,18 @@ public:
         return this - static_cast<const QQuickSpriteMaterial *>(other);
     }
 
-    QSGTexture *texture;
-
-    float animT;
-    float animX1;
-    float animY1;
-    float animX2;
-    float animY2;
-    float animW;
-    float animH;
+    QSGTexture *texture = nullptr;
+
+    float animT = 0.0f;
+    float animX1 = 0.0f;
+    float animY1 = 0.0f;
+    float animX2 = 0.0f;
+    float animY2 = 0.0f;
+    float animW = 1.0f;
+    float animH = 1.0f;
 };
 
 QQuickSpriteMaterial::QQuickSpriteMaterial()
-    : texture(nullptr)
-    , animT(0.0f)
-    , animX1(0.0f)
-    , animY1(0.0f)
-    , animX2(0.0f)
-    , animY2(0.0f)
-    , animW(1.0f)
-    , animH(1.0f)
 {
     setFlag(Blending, true);
 }
@@ -103,7 +95,6 @@ class SpriteMaterialData : public QSGMaterialShader
 {
 public:
     SpriteMaterialData()
-        : QSGMaterialShader()
     {
         setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/sprite.vert"));
         setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/sprite.frag"));
diff --git a/src/quick/scenegraph/qsgdistancefieldglyphnode_p.cpp b/src/quick/scenegraph/qsgdistancefieldglyphnode_p.cpp
index dd2d787495..aa58218505 100644
--- a/src/quick/scenegraph/qsgdistancefieldglyphnode_p.cpp
+++ b/src/quick/scenegraph/qsgdistancefieldglyphnode_p.cpp
@@ -61,19 +61,19 @@ protected:
     void updateColor(const QVector4D &c);
     void updateTextureScale(const QVector2D &ts);
 
-    float m_fontScale;
-    float m_matrixScale;
+    float m_fontScale = 1.0;
+    float m_matrixScale = 1.0;
 
-    int m_matrix_id;
-    int m_textureScale_id;
-    int m_alphaMin_id;
-    int m_alphaMax_id;
-    int m_color_id;
+    int m_matrix_id = -1;
+    int m_textureScale_id = -1;
+    int m_alphaMin_id = -1;
+    int m_alphaMax_id = -1;
+    int m_color_id = -1;
 
     QVector2D m_lastTextureScale;
     QVector4D m_lastColor;
-    float m_lastAlphaMin;
-    float m_lastAlphaMax;
+    float m_lastAlphaMin = -1;
+    float m_lastAlphaMax = -1;
 };
 
 char const *const *QSGDistanceFieldTextMaterialShader::attributeNames() const {
@@ -82,16 +82,6 @@ char const *const *QSGDistanceFieldTextMaterialShader::attributeNames() const {
 }
 
 QSGDistanceFieldTextMaterialShader::QSGDistanceFieldTextMaterialShader()
-    : QSGMaterialShader(),
-      m_fontScale(1.0)
-    , m_matrixScale(1.0)
-    , m_matrix_id(-1)
-    , m_textureScale_id(-1)
-    , m_alphaMin_id(-1)
-    , m_alphaMax_id(-1)
-    , m_color_id(-1)
-    , m_lastAlphaMin(-1)
-    , m_lastAlphaMax(-1)
 {
     setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/distancefieldtext.vert"));
     setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/distancefieldtext.frag"));
@@ -288,12 +278,11 @@ public:
 protected:
     void initialize() override;
 
-    int m_styleColor_id;
+    int m_styleColor_id = -1;
 };
 
 DistanceFieldStyledTextMaterialShader::DistanceFieldStyledTextMaterialShader()
     : QSGDistanceFieldTextMaterialShader()
-    , m_styleColor_id(-1)
 {
 }
 
@@ -358,14 +347,12 @@ protected:
 
     void updateOutlineAlphaRange(int dfRadius);
 
-    int m_outlineAlphaMax0_id;
-    int m_outlineAlphaMax1_id;
+    int m_outlineAlphaMax0_id = -1;
+    int m_outlineAlphaMax1_id = -1;
 };
 
 DistanceFieldOutlineTextMaterialShader::DistanceFieldOutlineTextMaterialShader()
     : DistanceFieldStyledTextMaterialShader()
-    , m_outlineAlphaMax0_id(-1)
-    , m_outlineAlphaMax1_id(-1)
 {
     setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/distancefieldoutlinetext.frag"));
 }
@@ -438,12 +425,11 @@ protected:
 
     void updateShift(qreal fontScale, const QPointF& shift);
 
-    int m_shift_id;
+    int m_shift_id = -1;
 };
 
 DistanceFieldShiftedStyleTextMaterialShader::DistanceFieldShiftedStyleTextMaterialShader()
     : DistanceFieldStyledTextMaterialShader()
-    , m_shift_id(-1)
 {
     setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/distancefieldshiftedtext.vert"));
     setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/distancefieldshiftedtext.frag"));
@@ -516,14 +502,12 @@ public:
     void updateState(const RenderState &state, QSGMaterial *newEffect, QSGMaterial *oldEffect) override;
 
 private:
-    int m_fontScale_id;
-    int m_vecDelta_id;
+    int m_fontScale_id = -1;
+    int m_vecDelta_id = -1;
 };
 
 QSGHiQSubPixelDistanceFieldTextMaterialShader::QSGHiQSubPixelDistanceFieldTextMaterialShader()
     : QSGDistanceFieldTextMaterialShader()
-    , m_fontScale_id(-1)
-    , m_vecDelta_id(-1)
 {
     setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/hiqsubpixeldistancefieldtext.vert"));
     setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/hiqsubpixeldistancefieldtext.frag"));
diff --git a/src/quick/scenegraph/util/qsgsimpletexturenode.cpp b/src/quick/scenegraph/util/qsgsimpletexturenode.cpp
index 6ce37de7cb..0c49ca9aa5 100644
--- a/src/quick/scenegraph/util/qsgsimpletexturenode.cpp
+++ b/src/quick/scenegraph/util/qsgsimpletexturenode.cpp
@@ -47,8 +47,7 @@ class QSGSimpleTextureNodePrivate : public QSGGeometryNodePrivate
 {
 public:
     QSGSimpleTextureNodePrivate()
-        : QSGGeometryNodePrivate()
-        , texCoordMode(QSGSimpleTextureNode::NoTransform)
+        : texCoordMode(QSGSimpleTextureNode::NoTransform)
         , isAtlasTexture(false)
         , ownsTexture(false)
     {}
diff --git a/src/quick/scenegraph/util/qsgtexturematerial.cpp b/src/quick/scenegraph/util/qsgtexturematerial.cpp
index 70a8b321d8..7b1d5abb26 100644
--- a/src/quick/scenegraph/util/qsgtexturematerial.cpp
+++ b/src/quick/scenegraph/util/qsgtexturematerial.cpp
@@ -57,7 +57,6 @@ inline static bool isPowerOfTwo(int x)
 QSGMaterialType QSGOpaqueTextureMaterialShader::type;
 
 QSGOpaqueTextureMaterialShader::QSGOpaqueTextureMaterialShader()
-    : QSGMaterialShader()
 {
 #if QT_CONFIG(opengl)
     setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/opaquetexture.vert"));
diff --git a/src/quick/scenegraph/util/qsgvertexcolormaterial.cpp b/src/quick/scenegraph/util/qsgvertexcolormaterial.cpp
index f1ad73af1b..cb61430e2e 100644
--- a/src/quick/scenegraph/util/qsgvertexcolormaterial.cpp
+++ b/src/quick/scenegraph/util/qsgvertexcolormaterial.cpp
@@ -64,7 +64,6 @@ private:
 QSGMaterialType QSGVertexColorMaterialShader::type;
 
 QSGVertexColorMaterialShader::QSGVertexColorMaterialShader()
-    : QSGMaterialShader()
 {
 #if QT_CONFIG(opengl)
     setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/vertexcolor.vert"));
diff --git a/src/quick/util/qquickfontloader.cpp b/src/quick/util/qquickfontloader.cpp
index 72b9149886..2da541304d 100644
--- a/src/quick/util/qquickfontloader.cpp
+++ b/src/quick/util/qquickfontloader.cpp
@@ -77,8 +77,8 @@ Q_SIGNALS:
     void fontDownloaded(const QString&, QQuickFontLoader::Status);
 
 private:
-    int redirectCount;
-    QNetworkReply *reply;
+    int redirectCount = 0;
+    QNetworkReply *reply = nullptr;
 
 private Q_SLOTS:
     void replyFinished();
@@ -91,13 +91,8 @@ public:
 };
 
 QQuickFontObject::QQuickFontObject(int _id)
-    : QObject(nullptr)
-#if QT_CONFIG(qml_network)
-    ,redirectCount(0), reply(nullptr)
-#endif
-    ,id(_id)
+    : QObject(nullptr), id(_id)
 {
-
 }
 
 #if QT_CONFIG(qml_network)
@@ -148,11 +143,11 @@ class QQuickFontLoaderPrivate : public QObjectPrivate
     Q_DECLARE_PUBLIC(QQuickFontLoader)
 
 public:
-    QQuickFontLoaderPrivate() : status(QQuickFontLoader::Null) {}
+    QQuickFontLoaderPrivate() {}
 
     QUrl url;
     QString name;
-    QQuickFontLoader::Status status;
+    QQuickFontLoader::Status status = QQuickFontLoader::Null;
 };
 
 static void q_QFontLoaderFontsStaticReset();
diff --git a/src/quick/util/qquickimageprovider.cpp b/src/quick/util/qquickimageprovider.cpp
index e7891a6612..1a13f6395a 100644
--- a/src/quick/util/qquickimageprovider.cpp
+++ b/src/quick/util/qquickimageprovider.cpp
@@ -515,15 +515,12 @@ class QQuickImageProviderOptionsPrivate : public QSharedData
 {
 public:
     QQuickImageProviderOptionsPrivate()
-     : autoTransform(QQuickImageProviderOptions::UsePluginDefaultTransform)
-     , preserveAspectRatioCrop(false)
-     , preserveAspectRatioFit(false)
     {
     }
 
-    QQuickImageProviderOptions::AutoTransform autoTransform;
-    bool preserveAspectRatioCrop;
-    bool preserveAspectRatioFit;
+    QQuickImageProviderOptions::AutoTransform autoTransform = QQuickImageProviderOptions::UsePluginDefaultTransform;
+    bool preserveAspectRatioCrop = false;
+    bool preserveAspectRatioFit = false;
 };
 
 /*!
diff --git a/src/quick/util/qquickpath_p.h b/src/quick/util/qquickpath_p.h
index 06f6800a0e..f8b67ef945 100644
--- a/src/quick/util/qquickpath_p.h
+++ b/src/quick/util/qquickpath_p.h
@@ -90,7 +90,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickPathAttribute : public QQuickPathElement
     Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged)
     Q_PROPERTY(qreal value READ value WRITE setValue NOTIFY valueChanged)
 public:
-    QQuickPathAttribute(QObject *parent=nullptr) : QQuickPathElement(parent), _value(0) {}
+    QQuickPathAttribute(QObject *parent=nullptr) : QQuickPathElement(parent) {}
 
 
     QString name() const;
@@ -105,7 +105,7 @@ Q_SIGNALS:
 
 private:
     QString _name;
-    qreal _value;
+    qreal _value = 0;
 };
 
 class Q_QUICK_PRIVATE_EXPORT QQuickCurve : public QQuickPathElement
@@ -177,7 +177,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickPathQuad : public QQuickCurve
     Q_PROPERTY(qreal relativeControlX READ relativeControlX WRITE setRelativeControlX NOTIFY relativeControlXChanged)
     Q_PROPERTY(qreal relativeControlY READ relativeControlY WRITE setRelativeControlY NOTIFY relativeControlYChanged)
 public:
-    QQuickPathQuad(QObject *parent=nullptr) : QQuickCurve(parent), _controlX(0), _controlY(0) {}
+    QQuickPathQuad(QObject *parent=nullptr) : QQuickCurve(parent) {}
 
     qreal controlX() const;
     void setControlX(qreal x);
@@ -202,8 +202,8 @@ Q_SIGNALS:
     void relativeControlYChanged();
 
 private:
-    qreal _controlX;
-    qreal _controlY;
+    qreal _controlX = 0;
+    qreal _controlY = 0;
     QQmlNullableValue<qreal> _relativeControlX;
     QQmlNullableValue<qreal> _relativeControlY;
 };
@@ -221,7 +221,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickPathCubic : public QQuickCurve
     Q_PROPERTY(qreal relativeControl2X READ relativeControl2X WRITE setRelativeControl2X NOTIFY relativeControl2XChanged)
     Q_PROPERTY(qreal relativeControl2Y READ relativeControl2Y WRITE setRelativeControl2Y NOTIFY relativeControl2YChanged)
 public:
-    QQuickPathCubic(QObject *parent=nullptr) : QQuickCurve(parent), _control1X(0), _control1Y(0), _control2X(0), _control2Y(0) {}
+    QQuickPathCubic(QObject *parent=nullptr) : QQuickCurve(parent) {}
 
     qreal control1X() const;
     void setControl1X(qreal x);
@@ -264,10 +264,10 @@ Q_SIGNALS:
     void relativeControl2YChanged();
 
 private:
-    qreal _control1X;
-    qreal _control1Y;
-    qreal _control2X;
-    qreal _control2Y;
+    qreal _control1X = 0;
+    qreal _control1Y = 0;
+    qreal _control2X = 0;
+    qreal _control2Y = 0;
     QQmlNullableValue<qreal> _relativeControl1X;
     QQmlNullableValue<qreal> _relativeControl1Y;
     QQmlNullableValue<qreal> _relativeControl2X;
@@ -294,7 +294,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickPathArc : public QQuickCurve
 
 public:
     QQuickPathArc(QObject *parent=nullptr)
-        : QQuickCurve(parent), _radiusX(0), _radiusY(0), _useLargeArc(false), _direction(Clockwise), _xAxisRotation(0) {}
+        : QQuickCurve(parent) {}
 
     enum ArcDirection { Clockwise, Counterclockwise };
     Q_ENUM(ArcDirection)
@@ -324,11 +324,11 @@ Q_SIGNALS:
     Q_REVISION(2) void xAxisRotationChanged();
 
 private:
-    qreal _radiusX;
-    qreal _radiusY;
-    bool _useLargeArc;
-    ArcDirection _direction;
-    qreal _xAxisRotation;
+    qreal _radiusX = 0;
+    qreal _radiusY = 0;
+    bool _useLargeArc = false;
+    ArcDirection _direction = Clockwise;
+    qreal _xAxisRotation = 0;
 };
 
 class Q_QUICK_PRIVATE_EXPORT QQuickPathAngleArc : public QQuickCurve
@@ -344,7 +344,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickPathAngleArc : public QQuickCurve
 
 public:
     QQuickPathAngleArc(QObject *parent=nullptr)
-        : QQuickCurve(parent), _centerX(0), _centerY(0), _radiusX(0), _radiusY(0), _startAngle(0), _sweepAngle(0), _moveToStart(true) {}
+        : QQuickCurve(parent) {}
 
     qreal centerX() const;
     void setCenterX(qreal);
@@ -379,13 +379,13 @@ Q_SIGNALS:
     void moveToStartChanged();
 
 private:
-    qreal _centerX;
-    qreal _centerY;
-    qreal _radiusX;
-    qreal _radiusY;
-    qreal _startAngle;
-    qreal _sweepAngle;
-    bool _moveToStart;
+    qreal _centerX = 0;
+    qreal _centerY = 0;
+    qreal _radiusX = 0;
+    qreal _radiusY = 0;
+    qreal _startAngle = 0;
+    qreal _sweepAngle = 0;
+    bool _moveToStart = true;
 };
 
 class Q_QUICK_PRIVATE_EXPORT QQuickPathSvg : public QQuickCurve
@@ -412,7 +412,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickPathPercent : public QQuickPathElement
     Q_OBJECT
     Q_PROPERTY(qreal value READ value WRITE setValue NOTIFY valueChanged)
 public:
-    QQuickPathPercent(QObject *parent=nullptr) : QQuickPathElement(parent), _value(0) {}
+    QQuickPathPercent(QObject *parent=nullptr) : QQuickPathElement(parent) {}
 
     qreal value() const;
     void setValue(qreal value);
@@ -421,18 +421,18 @@ Q_SIGNALS:
     void valueChanged();
 
 private:
-    qreal _value;
+    qreal _value = 0;
 };
 
 struct QQuickCachedBezier
 {
-    QQuickCachedBezier() : isValid(false) {}
+    QQuickCachedBezier() {}
     QBezier bezier;
     int element;
     qreal bezLength;
     qreal currLength;
     qreal p;
-    bool isValid;
+    bool isValid = false;
 };
 
 class QQuickPathPrivate;
@@ -494,15 +494,15 @@ private Q_SLOTS:
 
 private:
     struct AttributePoint {
-        AttributePoint() : percent(0), scale(1), origpercent(0) {}
+        AttributePoint() {}
         AttributePoint(const AttributePoint &other)
             : percent(other.percent), scale(other.scale), origpercent(other.origpercent), values(other.values) {}
         AttributePoint &operator=(const AttributePoint &other) {
             percent = other.percent; scale = other.scale; origpercent = other.origpercent; values = other.values; return *this;
         }
-        qreal percent;      //massaged percent along the painter path
-        qreal scale;
-        qreal origpercent;  //'real' percent along the painter path
+        qreal percent = 0;      //massaged percent along the painter path
+        qreal scale = 1;
+        qreal origpercent = 0;  //'real' percent along the painter path
         QHash<QString, qreal> values;
     };
 
diff --git a/src/quick/util/qquickpath_p_p.h b/src/quick/util/qquickpath_p_p.h
index f5c9664223..9735d51264 100644
--- a/src/quick/util/qquickpath_p_p.h
+++ b/src/quick/util/qquickpath_p_p.h
@@ -72,7 +72,7 @@ public:
     static QQuickPathPrivate* get(QQuickPath *path) { return path->d_func(); }
     static const QQuickPathPrivate* get(const QQuickPath *path) { return path->d_func(); }
 
-    QQuickPathPrivate() : pathLength(0), closed(false), componentComplete(true), isShapePath(false) { }
+    QQuickPathPrivate() {}
 
     QPainterPath _path;
     QList<QQuickPathElement*> _pathElements;
@@ -83,10 +83,10 @@ public:
     mutable QQuickCachedBezier prevBez;
     QQmlNullableValue<qreal> startX;
     QQmlNullableValue<qreal> startY;
-    qreal pathLength;
-    bool closed;
-    bool componentComplete;
-    bool isShapePath;
+    qreal pathLength = 0;
+    bool closed = false;
+    bool componentComplete = true;
+    bool isShapePath = false;
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/util/qquickstyledtext_p.h b/src/quick/util/qquickstyledtext_p.h
index 821f95b6bf..51f1b7d8f9 100644
--- a/src/quick/util/qquickstyledtext_p.h
+++ b/src/quick/util/qquickstyledtext_p.h
@@ -67,9 +67,7 @@ class QQmlContext;
 class Q_AUTOTEST_EXPORT QQuickStyledTextImgTag
 {
 public:
-    QQuickStyledTextImgTag()
-        : position(0), offset(0.0), align(QQuickStyledTextImgTag::Bottom), pix(nullptr)
-    { }
+    QQuickStyledTextImgTag() { }
 
     ~QQuickStyledTextImgTag() { delete pix; }
 
@@ -82,10 +80,10 @@ public:
     QUrl url;
     QPointF pos;
     QSize size;
-    int position;
-    qreal offset; // this offset allows us to compensate for flooring reserved space
-    Align align;
-    QQuickPixmap *pix;
+    int position = 0;
+    qreal offset = 0.0; // this offset allows us to compensate for flooring reserved space
+    Align align = QQuickStyledTextImgTag::Bottom;
+    QQuickPixmap *pix = nullptr;
 };
 
 class Q_AUTOTEST_EXPORT QQuickStyledText
diff --git a/src/quick/util/qquicktimeline.cpp b/src/quick/util/qquicktimeline.cpp
index 93284c0685..ac9f75979e 100644
--- a/src/quick/util/qquicktimeline.cpp
+++ b/src/quick/util/qquicktimeline.cpp
@@ -104,11 +104,11 @@ struct QQuickTimeLinePrivate
     };
     struct TimeLine
     {
-        TimeLine() : length(0), consumedOpLength(0), base(0.) {}
+        TimeLine() {}
         QList<Op> ops;
-        int length;
-        int consumedOpLength;
-        qreal base;
+        int length = 0;
+        int consumedOpLength = 0;
+        qreal base = 0.;
     };
 
     int length;