diff options
| author | Olivier JG <olivier.de.gaalon@kdab.com> | 2016-12-16 09:57:37 -0600 |
|---|---|---|
| committer | Giuseppe D'Angelo <giuseppe.dangelo@kdab.com> | 2017-05-17 09:23:39 +0000 |
| commit | 4425d6f9b637e7404379b611cef4b22929acbe62 (patch) | |
| tree | ceaa670ee0efc6ed3a455aa18a6ec0784854629d /src/qml/jsruntime | |
| parent | dc3015e891e903e6f701f1abc303be9f2efc2e5a (diff) | |
QML: emit messages when breaking bindings
Add a new logging category that can be used to debug issues with
unexpected binding breakages caused by assignment to previously bound
properties. If enabled, outputs a message when a binding is broken with
detailed location and property/value information.
[ChangeLog][QtQml] The QML engine can now emit informational messages
(in the "qt.qml.binding.removal" logging category) whenever a binding is
lost due to an imperative assignment. This can be used to debug issues
due to broken bindings.
Change-Id: Ie31e5a198450b6f998c1266acfc97e8f33a92e3d
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Diffstat (limited to 'src/qml/jsruntime')
| -rw-r--r-- | src/qml/jsruntime/qv4qobjectwrapper.cpp | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp index e4fb54f0ff..83730d632a 100644 --- a/src/qml/jsruntime/qv4qobjectwrapper.cpp +++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp @@ -75,10 +75,13 @@ #include <QtCore/qatomic.h> #include <QtCore/qmetaobject.h> #include <QtCore/qabstractitemmodel.h> +#include <QtCore/qloggingcategory.h> #include <vector> QT_BEGIN_NAMESPACE +Q_LOGGING_CATEGORY(lcBindingRemoval, "qt.qml.binding.removal", QtWarningMsg) + // The code in this file does not violate strict aliasing, but GCC thinks it does // so turn off the warnings for us to have a clean build QT_WARNING_DISABLE_GCC("-Wstrict-aliasing") @@ -458,10 +461,23 @@ void QObjectWrapper::setProperty(ExecutionEngine *engine, QObject *object, QQmlP } } - if (newBinding) + if (newBinding) { QQmlPropertyPrivate::setBinding(newBinding); - else + } else { + if (Q_UNLIKELY(lcBindingRemoval().isInfoEnabled())) { + if (auto binding = QQmlPropertyPrivate::binding(object, QQmlPropertyIndex(property->coreIndex()))) { + Q_ASSERT(!binding->isValueTypeProxy()); + const auto qmlBinding = static_cast<const QQmlBinding*>(binding); + const auto stackFrame = engine->currentStackFrame(); + qCInfo(lcBindingRemoval, + "Overwriting binding on %s::%s at %s:%d that was initially bound at %s", + object->metaObject()->className(), qPrintable(property->name(object)), + qPrintable(stackFrame.source), stackFrame.line, + qPrintable(qmlBinding->expressionIdentifier())); + } + } QQmlPropertyPrivate::removeBinding(object, QQmlPropertyIndex(property->coreIndex())); + } if (!newBinding && property->isVarProperty()) { // allow assignment of "special" values (null, undefined, function) to var properties |