extend the QObjectPrivate::connectedSignals bitfield to make space

for all the required NOTIFY signals we need for QML bindings.
An additional internal function QMetaObject::isConnected() allows
to query the bits, or you use connectedSignals[0] if you know that
the signal in question has a QMetaObject::indexOfSignal() < 32.

Authored-by: mae
Reviewed-by: Aaron Kennedy

3 files changed, 66 insertions, 16 deletions

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 6503ab0..e5cc375 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -139,7 +139,8 @@ QObjectPrivate::QObjectPrivate(int version)
     receiveChildEvents = true;
     postedEvents = 0;
     extraData = 0;
-    connectedSignals = 0;
+    for (uint i = 0; i < (sizeof connectedSignals / sizeof connectedSignals[0]); ++i)
+        connectedSignals[i] = 0;
     inEventHandler = false;
     inThreadChangeEvent = false;
     deleteWatch = 0;
@@ -2849,10 +2850,16 @@ bool QMetaObject::connect(const QObject *sender, int signal_index,
 
     s->d_func()->addConnection(signal_index, c);
 
-    if (signal_index < 0)
-        sender->d_func()->connectedSignals = ~0u;
-    else if (signal_index < 32)
-        sender->d_func()->connectedSignals |= (1 << signal_index);
+    if (signal_index < 0) {
+        for (uint i = 0; i < (sizeof sender->d_func()->connectedSignals
+                              / sizeof sender->d_func()->connectedSignals[0] ); ++i)
+            sender->d_func()->connectedSignals[i] = ~0u;
+    } else if (signal_index < (int)sizeof sender->d_func()->connectedSignals * 8) {
+        uint n = (signal_index / (8 * sizeof sender->d_func()->connectedSignals[0]));
+        sender->d_func()->connectedSignals[n] |= (1 << (signal_index - n * 8
+                                                        * sizeof sender->d_func()->connectedSignals[0]));
+    }
+
 
     return true;
 }
@@ -3192,11 +3199,12 @@ void QMetaObject::activate(QObject *sender, int from_signal_index, int to_signal
  */
 void QMetaObject::activate(QObject *sender, int signal_index, void **argv)
 {
-    if (signal_index < 32
+    if (signal_index < (int)sizeof(sender->d_func()->connectedSignals) * 8
         && !qt_signal_spy_callback_set.signal_begin_callback
         && !qt_signal_spy_callback_set.signal_end_callback) {
-        uint signal_mask = 1 << signal_index;
-        if ((sender->d_func()->connectedSignals & signal_mask) == 0)
+        uint n = (signal_index / (8 * sizeof sender->d_func()->connectedSignals[0]));
+        uint m = 1 << (signal_index - n * 8 * sizeof sender->d_func()->connectedSignals[0]);
+        if ((sender->d_func()->connectedSignals[n] & m) == 0)
             // nothing connected to these signals, and no spy
             return;
     }
@@ -3209,11 +3217,12 @@ void QMetaObject::activate(QObject *sender, const QMetaObject *m, int local_sign
                            void **argv)
 {
     int signal_index = m->methodOffset() + local_signal_index;
-    if (signal_index < 32
+    if (signal_index < (int)sizeof(sender->d_func()->connectedSignals) * 8
         && !qt_signal_spy_callback_set.signal_begin_callback
         && !qt_signal_spy_callback_set.signal_end_callback) {
-        uint signal_mask = 1 << signal_index;
-        if ((sender->d_func()->connectedSignals & signal_mask) == 0)
+        uint n = (signal_index / (8 * sizeof sender->d_func()->connectedSignals[0]));
+        uint m = 1 << (signal_index - n * 8 * sizeof sender->d_func()->connectedSignals[0]);
+        if ((sender->d_func()->connectedSignals[n] & m) == 0)
             // nothing connected to these signals, and no spy
             return;
     }
@@ -3225,21 +3234,59 @@ void QMetaObject::activate(QObject *sender, const QMetaObject *m, int local_sign
 void QMetaObject::activate(QObject *sender, const QMetaObject *m,
                            int from_local_signal_index, int to_local_signal_index, void **argv)
 {
+    Q_ASSERT(from_local_signal_index <= to_local_signal_index);
     int offset = m->methodOffset();
     int from_signal_index = offset + from_local_signal_index;
     int to_signal_index = offset + to_local_signal_index;
-    if (to_signal_index < 32
+
+    if (to_signal_index < (int)sizeof(sender->d_func()->connectedSignals) * 8
         && !qt_signal_spy_callback_set.signal_begin_callback
         && !qt_signal_spy_callback_set.signal_end_callback) {
-        uint signal_mask = (1 << (to_signal_index + 1)) - 1;
-        signal_mask ^= (1 << from_signal_index) - 1;
-        if ((sender->d_func()->connectedSignals & signal_mask) == 0)
+
+        uint n = (from_signal_index / (8 * sizeof sender->d_func()->connectedSignals[0]));
+        uint m = 1 << (from_signal_index - n * 8 * sizeof sender->d_func()->connectedSignals[0]);
+        uint nt = (to_signal_index / (8 * sizeof sender->d_func()->connectedSignals[0]));
+        uint mt = 1 << (to_signal_index - n * 8 * sizeof sender->d_func()->connectedSignals[0]);
+        bool connected = false;
+        quint32 *connectedSignals = sender->d_func()->connectedSignals;
+        for (uint i = 0; !connected && i < (sizeof sender->d_func()->connectedSignals
+                                            / sizeof sender->d_func()->connectedSignals[0]); ++i) {
+            uint mask = 0;
+            if (i > n)
+                mask = ~0u;
+            else if (i == n)
+                mask = ~(m -1);
+            if (i > nt)
+                mask = 0;
+            else if (i == nt)
+                mask &= (mt << 1) - 1;
+            connected = connectedSignals[i] & mask;
+        }
+        if (!connected)
             // nothing connected to these signals, and no spy
             return;
     }
     activate(sender, from_signal_index, to_signal_index, argv);
 }
 
+/*! \internal
+
+  Returns true if the signal with index \a signal_index from object \a sender is connected.
+  Signals with indices above a certain range are always considered connected (see connectedSignals
+  in QObjectPrivate). If a signal spy is installed, all signals are considered connected.
+*/
+bool QMetaObject::isConnected(QObject *sender, int signal_index) {
+    if (signal_index < (int)sizeof(sender->d_func()->connectedSignals) * 8
+        && !qt_signal_spy_callback_set.signal_begin_callback
+        && !qt_signal_spy_callback_set.signal_end_callback) {
+        uint n = (signal_index / (8 * sizeof sender->d_func()->connectedSignals[0]));
+        uint m = 1 << (signal_index - n * 8 * sizeof sender->d_func()->connectedSignals[0]);
+        if ((sender->d_func()->connectedSignals[n] & m) == 0)
+            // nothing connected to these signals, and no spy
+            return false;
+    }
+    return true;
+}
 
 /*****************************************************************************
   Properties
diff --git a/src/corelib/kernel/qobject_p.h b/src/corelib/kernel/qobject_p.h
index 07c397f..6a20040 100644
--- a/src/corelib/kernel/qobject_p.h
+++ b/src/corelib/kernel/qobject_p.h
@@ -140,7 +140,7 @@ public:
         QList<QVariant> propertyValues;
     };
     ExtraData *extraData;
-    mutable quint32 connectedSignals;
+    mutable quint32 connectedSignals[2];
 
     QString objectName;
 
diff --git a/src/corelib/kernel/qobjectdefs.h b/src/corelib/kernel/qobjectdefs.h
index 9187765..300e9fa 100644
--- a/src/corelib/kernel/qobjectdefs.h
+++ b/src/corelib/kernel/qobjectdefs.h
@@ -334,6 +334,9 @@ struct Q_CORE_EXPORT QMetaObject
     static void activate(QObject *sender, int from_signal_index, int to_signal_index, void **argv);
     static void activate(QObject *sender, const QMetaObject *, int local_signal_index, void **argv);
     static void activate(QObject *sender, const QMetaObject *, int from_local_signal_index, int to_local_signal_index, void **argv);
+
+    static bool isConnected(QObject *sender, int signal_index);
+
     // internal guarded pointers
     static void addGuard(QObject **ptr);
     static void removeGuard(QObject **ptr);