QML: Change storage types of QQmlPropertyRawData fields

By getting rid of the unions, all "features" (like accessors and notify
indices) can now be used for all properties or functions. Other fields
are trimmed to the size as used in other parts of QML.

Now the size of QQmlPropertyRawData is 24 bytes on 32bit platforms, and
32 bytes on 64bit platforms.

Change-Id: Ie2f22eb60e6119c93e3d3ea32a2974a718d45e91
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 55 insertions, 41 deletions

diff --git a/src/qml/qml/qqmlpropertycache_p.h b/src/qml/qml/qqmlpropertycache_p.h
index 8a1f3810aa..480f1dcf40 100644
--- a/src/qml/qml/qqmlpropertycache_p.h
+++ b/src/qml/qml/qqmlpropertycache_p.h
@@ -168,20 +168,45 @@ public:
     bool isCloned() const { return _flags.isCloned; }
     bool isConstructor() const { return _flags.isConstructor; }
 
-    bool hasOverride() const { return !(_flags.hasAccessors) &&
-                                      overrideIndex() >= 0; }
-    bool hasRevision() const { return !(_flags.hasAccessors) && revision() != 0; }
+    bool hasOverride() const { return overrideIndex() >= 0; }
+    bool hasRevision() const { return revision() != 0; }
 
     bool isFullyResolved() const { return !_flags.notFullyResolved; }
 
     int propType() const { Q_ASSERT(isFullyResolved()); return _propType; }
-    void setPropType(int pt) { _propType = pt; }
+    void setPropType(int pt)
+    {
+        Q_ASSERT(pt >= 0);
+        Q_ASSERT(pt <= std::numeric_limits<qint16>::max());
+        _propType = quint16(pt);
+    }
 
     int notifyIndex() const { return _notifyIndex; }
-    void setNotifyIndex(int idx) { _notifyIndex = idx; }
+    void setNotifyIndex(int idx)
+    {
+        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
+        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
+        _notifyIndex = qint16(idx);
+    }
 
-    QQmlPropertyCacheMethodArguments *arguments() const { return _arguments; }
-    void setArguments(QQmlPropertyCacheMethodArguments *args) { _arguments = args; }
+    bool overrideIndexIsProperty() const { return _flags.overrideIndexIsProperty; }
+    void setOverrideIndexIsProperty(bool onoff) { _flags.overrideIndexIsProperty = onoff; }
+
+    int overrideIndex() const { return _overrideIndex; }
+    void setOverrideIndex(int idx)
+    {
+        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
+        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
+        _overrideIndex = qint16(idx);
+    }
+
+    int coreIndex() const { return _coreIndex; }
+    void setCoreIndex(int idx)
+    {
+        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
+        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
+        _coreIndex = qint16(idx);
+    }
 
     int revision() const { return _revision; }
     void setRevision(int rev)
@@ -191,6 +216,9 @@ public:
         _revision = qint16(rev);
     }
 
+    QQmlPropertyCacheMethodArguments *arguments() const { return _arguments; }
+    void setArguments(QQmlPropertyCacheMethodArguments *args) { _arguments = args; }
+
     int metaObjectOffset() const { return _metaObjectOffset; }
     void setMetaObjectOffset(int off)
     {
@@ -199,51 +227,35 @@ public:
         _metaObjectOffset = qint16(off);
     }
 
-    bool overrideIndexIsProperty() const { return _flags.overrideIndexIsProperty; }
-    void setOverrideIndexIsProperty(bool onoff) { _flags.overrideIndexIsProperty = onoff; }
-
-    int overrideIndex() const { return _overrideIndex; }
-    void setOverrideIndex(int idx)
-    {
-        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
-        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
-        _overrideIndex = idx;
-    }
-
     QQmlAccessors *accessors() const { return _accessors; }
     void setAccessors(QQmlAccessors *acc) { _accessors = acc; }
 
-    int coreIndex() const { return _coreIndex; }
-    void setCoreIndex(int idx) { _coreIndex = idx; }
-
 private:
-    int _propType;             // When !NotFullyResolved
-    union {
-        // The notify index is in the range returned by QObjectPrivate::signalIndex().
-        // This is different from QMetaMethod::methodIndex().
-        int _notifyIndex;  // When !IsFunction
-        QQmlPropertyCacheMethodArguments *_arguments;  // When IsFunction && HasArguments
-    };
+    Flags _flags;
+    qint16 _coreIndex;
+    quint16 _propType;
 
-    union {
-        struct { // When !HasAccessors
-            qint16 _revision;
-            qint16 _metaObjectOffset;
+    // The notify index is in the range returned by QObjectPrivate::signalIndex().
+    // This is different from QMetaMethod::methodIndex().
+    qint16 _notifyIndex;
+    qint16 _overrideIndex;
 
-            signed int _overrideIndex; // When !IsValueTypeVirtual
-        };
-        struct { // When HasAccessors
-            QQmlAccessors *_accessors;
-        };
-    };
+    qint16 _revision;
+    qint16 _metaObjectOffset;
 
-    int _coreIndex;
-    Flags _flags;
+    QQmlPropertyCacheMethodArguments *_arguments;
+    QQmlAccessors *_accessors;
 
     friend class QQmlPropertyData;
     friend class QQmlPropertyCache;
 };
 
+#if QT_POINTER_SIZE == 4
+Q_STATIC_ASSERT(sizeof(QQmlPropertyRawData) == 24);
+#else // QT_POINTER_SIZE == 8
+Q_STATIC_ASSERT(sizeof(QQmlPropertyRawData) == 32);
+#endif
+
 class QQmlPropertyData : public QQmlPropertyRawData
 {
 public:
@@ -619,12 +631,14 @@ void QQmlPropertyRawData::Flags::copyPropertyTypeFlags(QQmlPropertyRawData::Flag
 
 QQmlPropertyData::QQmlPropertyData()
 {
+    setCoreIndex(-1);
     setPropType(0);
     setNotifyIndex(-1);
     setOverrideIndex(-1);
     setRevision(0);
     setMetaObjectOffset(-1);
-    setCoreIndex(-1);
+    setArguments(nullptr);
+    setAccessors(nullptr);
 }
 
 QQmlPropertyData::QQmlPropertyData(const QQmlPropertyRawData &d)