Provide methods to query and remove a dynamically loaded plugin

This may be necessary in some corner cases in order to manually manage
memmory for loaded libraries. Also, clear the (static) plugins on
qmlClearTypeRegistrations if !QT_CONFIG(library).

Task-number: QTBUG-76074
Change-Id: Id33d2a4acd7ca94efad53353f8bcb020576c4010
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

2 files changed, 37 insertions, 1 deletions

diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index 79e3585202..af6d067fbb 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -2141,6 +2141,40 @@ bool QQmlImportDatabase::importDynamicPlugin(const QString &filePath, const QStr
     return true;
 }
 
+bool QQmlImportDatabase::removeDynamicPlugin(const QString &filePath)
+{
+    StringRegisteredPluginMap *plugins = qmlEnginePluginsWithRegisteredTypes();
+    QMutexLocker lock(&plugins->mutex);
+
+    auto it = plugins->find(QFileInfo(filePath).absoluteFilePath());
+    if (it == plugins->end())
+        return false;
+
+    QPluginLoader *loader = it->loader;
+    if (!loader)
+        return false;
+
+    if (!loader->unload()) {
+        qWarning("Unloading %s failed: %s", qPrintable(it->uri),
+                 qPrintable(loader->errorString()));
+    }
+
+    delete loader;
+    plugins->erase(it);
+    return true;
+}
+
+QStringList QQmlImportDatabase::dynamicPlugins() const
+{
+    StringRegisteredPluginMap *plugins = qmlEnginePluginsWithRegisteredTypes();
+    QMutexLocker lock(&plugins->mutex);
+    QStringList results;
+    for (auto it = plugins->constBegin(), end = plugins->constEnd(); it != end; ++it) {
+        if (it->loader != nullptr)
+            results.append(it.key());
+    }
+    return results;
+}
 #endif // QT_CONFIG(library)
 
 void QQmlImportDatabase::clearDirCache()
diff --git a/src/qml/qml/qqmlimport_p.h b/src/qml/qml/qqmlimport_p.h
index 7f781d2eb7..30d7c56a3e 100644
--- a/src/qml/qml/qqmlimport_p.h
+++ b/src/qml/qml/qqmlimport_p.h
@@ -203,7 +203,7 @@ private:
     QQmlImportsPrivate *d;
 };
 
-class QQmlImportDatabase
+class Q_QML_PRIVATE_EXPORT QQmlImportDatabase
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlImportDatabase)
 public:
@@ -214,6 +214,8 @@ public:
 
 #if QT_CONFIG(library)
     bool importDynamicPlugin(const QString &filePath, const QString &uri, const QString &importNamespace, int vmaj, QList<QQmlError> *errors);
+    bool removeDynamicPlugin(const QString &filePath);
+    QStringList dynamicPlugins() const;
 #endif
 
     QStringList importPathList(PathType type = LocalOrRemote) const;