qmllint: Defer resolution of types read from QML files

When importing a directory we most likely don't need all of the files in
the directory. Therefore we now parse them only when they are accessed.
This speeds up the execution and will allow us to process imports
recursively without running into infinite recursion.

Change-Id: I0c79313de792249e6bb86144b5014a7787dbdc5b
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 181 insertions, 0 deletions

diff --git a/src/qmlcompiler/qdeferredpointer_p.h b/src/qmlcompiler/qdeferredpointer_p.h
new file mode 100644
index 0000000000..07875013fa
--- /dev/null
+++ b/src/qmlcompiler/qdeferredpointer_p.h
@@ -0,0 +1,181 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the tools applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QDEFERREDPOINTER_P_H
+#define QDEFERREDPOINTER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+
+#include <QtCore/qglobal.h>
+#include <QtCore/qsharedpointer.h>
+
+QT_BEGIN_NAMESPACE
+
+template<typename T>
+class QDeferredFactory
+{
+public:
+    T create() const;
+    bool isValid() const;
+    void clear();
+};
+
+template<typename T>
+class QDeferredWeakPointer;
+
+template<typename T>
+class QDeferredSharedPointer
+{
+public:
+    using Factory = QDeferredFactory<std::remove_const_t<T>>;
+
+    QDeferredSharedPointer() = default;
+
+    QDeferredSharedPointer(QSharedPointer<T> data)
+        : m_data(data)
+    {}
+
+    QDeferredSharedPointer(QWeakPointer<T> data)
+        : m_data(data)
+    {}
+
+    QDeferredSharedPointer(QSharedPointer<T> data, QSharedPointer<Factory> factory)
+        : m_data(data), m_factory(factory)
+    {}
+
+    operator QSharedPointer<T>() const
+    {
+        if (m_factory && m_factory->isValid()) {
+            const_cast<std::remove_const_t<T> &>(*m_data) = m_factory->create();
+            m_factory->clear();
+        }
+        return m_data;
+    }
+
+    operator QDeferredSharedPointer<const T>() const { return { m_data, m_factory }; }
+
+    T &operator*() const { return QSharedPointer<T>(*this).operator*(); }
+    T *operator->() const { return QSharedPointer<T>(*this).operator->(); }
+
+    bool isNull() const { return m_data.isNull(); }
+    explicit operator bool() const noexcept { return !isNull(); }
+    bool operator !() const noexcept { return isNull(); }
+
+    T *data() const { return QSharedPointer<T>(*this).data(); }
+
+    friend qsizetype qHash(const QDeferredSharedPointer &ptr, qsizetype seed = 0)
+    {
+        return qHashMulti(seed, ptr.m_factory, ptr.m_data);
+    }
+
+    friend bool operator==(const QDeferredSharedPointer &a, const QDeferredSharedPointer &b)
+    {
+        return a.m_factory == b.m_factory && a.m_data == b.m_data;
+    }
+
+private:
+    friend class QDeferredWeakPointer<T>;
+
+    QSharedPointer<T> m_data;
+    QSharedPointer<Factory> m_factory;
+};
+
+template<typename T>
+class QDeferredWeakPointer
+{
+public:
+    using Factory = QDeferredFactory<std::remove_const_t<T>>;
+
+    QDeferredWeakPointer() = default;
+
+    QDeferredWeakPointer(const QDeferredSharedPointer<T> &strong)
+        : m_data(strong.m_data), m_factory(strong.m_factory)
+    {
+    }
+
+    QDeferredWeakPointer(QWeakPointer<T> data, QWeakPointer<Factory> factory)
+        : m_data(data), m_factory(factory)
+    {}
+
+    operator QWeakPointer<T>() const
+    {
+        if (m_factory) {
+            auto factory = m_factory.toStrongRef();
+            if (factory->isValid()) {
+                const_cast<std::remove_const_t<T> &>(*(m_data.toStrongRef())) = factory->create();
+                factory->clear();
+            }
+        }
+        return m_data;
+    }
+
+    operator QDeferredSharedPointer<T>() const
+    {
+        return QDeferredSharedPointer<T>(m_data.toStrongRef(), m_factory.toStrongRef());
+    }
+
+    operator QDeferredWeakPointer<const T>() const { return {m_data, m_factory}; }
+
+    QSharedPointer<T> toStrongRef() const
+    {
+        return QWeakPointer<T>(*this).toStrongRef();
+    }
+
+    bool isNull() const { return m_data.isNull(); }
+    explicit operator bool() const noexcept { return !isNull(); }
+    bool operator !() const noexcept { return isNull(); }
+
+    T *data() const { return QWeakPointer<T>(*this).data(); }
+
+    friend qsizetype qHash(const QDeferredWeakPointer &ptr, qsizetype seed = 0)
+    {
+        return qHashMulti(seed, ptr.m_factory, ptr.m_data);
+    }
+
+    friend bool operator==(const QDeferredWeakPointer &a, const QDeferredWeakPointer &b)
+    {
+        return a.m_factory == b.m_factory && a.m_data == b.m_data;
+    }
+
+private:
+    QWeakPointer<T> m_data;
+    QWeakPointer<Factory> m_factory;
+};
+
+
+QT_END_NAMESPACE
+
+#endif // QDEFERREDPOINTER_P_H