Make QPropertyBindingPrivate accessible to QtQml

QtQml needs the private just for one detail which nobody else should
need it for: Tracking additional dependencies and marking the binding as
dirty. Exporting the private requires hiding some variables and
providing accessors, to compile with MSVC - including the removal of
QVarLengthArray usage. Upside: The binding structure shrinks by 8 bytes
and the encapsulation makes it a little easier to change things without
breaking declarative, ... in the unlikely event ;-)

Also remove setDirty() from the public API as it's not needed by QtQml
and using it is dangerous, because it means that there's a risk of
somebody keeping a reference (count) to the untyped binding from within
the binding closure, which introduces a memory leak.

Change-Id: I43bd56f4bdf218efb54fa23e2d627ad3acfafeb5
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 3 insertions, 5 deletions

diff --git a/tests/auto/corelib/kernel/qproperty/tst_qproperty.cpp b/tests/auto/corelib/kernel/qproperty/tst_qproperty.cpp
index 942865f3a3..d4c5741814 100644
--- a/tests/auto/corelib/kernel/qproperty/tst_qproperty.cpp
+++ b/tests/auto/corelib/kernel/qproperty/tst_qproperty.cpp
@@ -220,13 +220,11 @@ void tst_QProperty::avoidDependencyAllocationAfterFirstEval()
     QCOMPARE(propWithBinding.value(), int(11));
 
     QVERIFY(QPropertyBasePointer::get(propWithBinding).bindingPtr());
-    QCOMPARE(QPropertyBasePointer::get(propWithBinding).bindingPtr()->dependencyObservers.size(), 2);
-    QVERIFY(QPropertyBasePointer::get(propWithBinding).bindingPtr()->dependencyObservers.capacity() >= 2);
+    QCOMPARE(QPropertyBasePointer::get(propWithBinding).bindingPtr()->dependencyObserverCount, 2);
 
     firstDependency = 100;
     QCOMPARE(propWithBinding.value(), int(110));
-    QCOMPARE(QPropertyBasePointer::get(propWithBinding).bindingPtr()->dependencyObservers.size(), 2);
-    QVERIFY(QPropertyBasePointer::get(propWithBinding).bindingPtr()->dependencyObservers.capacity() >= 2);
+    QCOMPARE(QPropertyBasePointer::get(propWithBinding).bindingPtr()->dependencyObserverCount, 2);
 }
 
 void tst_QProperty::propertyArrays()
@@ -493,7 +491,7 @@ void tst_QProperty::bindingSourceLocation()
 #if defined(QT_PROPERTY_COLLECT_BINDING_LOCATION)
     auto bindingLine = std::experimental::source_location::current().line() + 1;
     auto binding = Qt::makePropertyBinding([]() { return 42; });
-    QCOMPARE(QPropertyBindingPrivate::get(binding)->location.line, bindingLine);
+    QCOMPARE(QPropertyBindingPrivate::get(binding)->sourceLocation().line, bindingLine);
 #else
     QSKIP("Skipping this in the light of missing binding source location support");
 #endif