De-duplicate vtables, part I: exported private classes

By making the destructor (usually the first non-inline, non-pure,
virtual function, and therefore the trigger for most compilers to
emit the vtable and type_info structures for the class in that TU)
out-of-line, vtables and, more importantly, type_info structures for
the class are pinned to a single TU. This prevents false negative
dynamic_cast and catch evaluation.

In this first batch, we de-inline destructors of exported private
classes.

Since they are already exported, users of these classes are unaffected
by the change, and since it's private API, we don't need to avoid
adding code to the out-of-line destructor until Qt 6.

Change-Id: I450707877d2cb6a77f79ae1dd355facb98d6c517
Reported-by: Volker Krause <volker.krause@kdab.com>
Task-number: QTBUG-45582
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

4 files changed, 10 insertions, 0 deletions

diff --git a/src/widgets/effects/qgraphicseffect.cpp b/src/widgets/effects/qgraphicseffect.cpp
index f53804e494..5a97be3d96 100644
--- a/src/widgets/effects/qgraphicseffect.cpp
+++ b/src/widgets/effects/qgraphicseffect.cpp
@@ -111,6 +111,10 @@
 #ifndef QT_NO_GRAPHICSEFFECT
 QT_BEGIN_NAMESPACE
 
+QGraphicsEffectPrivate::~QGraphicsEffectPrivate()
+{
+}
+
 /*!
     \internal
     \class QGraphicsEffectSource
diff --git a/src/widgets/effects/qgraphicseffect_p.h b/src/widgets/effects/qgraphicseffect_p.h
index 6e990cc52e..35264c0d30 100644
--- a/src/widgets/effects/qgraphicseffect_p.h
+++ b/src/widgets/effects/qgraphicseffect_p.h
@@ -142,6 +142,7 @@ class Q_WIDGETS_EXPORT QGraphicsEffectPrivate : public QObjectPrivate
     Q_DECLARE_PUBLIC(QGraphicsEffect)
 public:
     QGraphicsEffectPrivate() : source(0), isEnabled(1) {}
+    ~QGraphicsEffectPrivate();
 
     inline void setGraphicsEffectSource(QGraphicsEffectSource *newSource)
     {
diff --git a/src/widgets/graphicsview/qgraphicsview.cpp b/src/widgets/graphicsview/qgraphicsview.cpp
index c270c4be88..decb455988 100644
--- a/src/widgets/graphicsview/qgraphicsview.cpp
+++ b/src/widgets/graphicsview/qgraphicsview.cpp
@@ -362,6 +362,10 @@ QGraphicsViewPrivate::QGraphicsViewPrivate()
     styleOptions.reserve(QGRAPHICSVIEW_PREALLOC_STYLE_OPTIONS);
 }
 
+QGraphicsViewPrivate::~QGraphicsViewPrivate()
+{
+}
+
 /*!
     \internal
 */
diff --git a/src/widgets/graphicsview/qgraphicsview_p.h b/src/widgets/graphicsview/qgraphicsview_p.h
index fec8336695..dcbffb1c39 100644
--- a/src/widgets/graphicsview/qgraphicsview_p.h
+++ b/src/widgets/graphicsview/qgraphicsview_p.h
@@ -63,6 +63,7 @@ class Q_WIDGETS_EXPORT QGraphicsViewPrivate : public QAbstractScrollAreaPrivate
     Q_DECLARE_PUBLIC(QGraphicsView)
 public:
     QGraphicsViewPrivate();
+    ~QGraphicsViewPrivate();
 
     void recalculateContentSize();
     void centerView(QGraphicsView::ViewportAnchor anchor);