1 files changed, 70 insertions, 0 deletions
diff --git a/src/qmlcompiler/qqmljsshadowcheck_p.h b/src/qmlcompiler/qqmljsshadowcheck_p.h
new file mode 100644
index 0000000000..dfa00134cb
--- /dev/null
+++ b/src/qmlcompiler/qqmljsshadowcheck_p.h
@@ -0,0 +1,70 @@
+// Copyright (C) 2021 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#ifndef QQMLJSSHADOWCHECK_P_H
+#define QQMLJSSHADOWCHECK_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 <private/qqmljscompilepass_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class Q_QMLCOMPILER_EXPORT QQmlJSShadowCheck : public QQmlJSCompilePass
+{
+public:
+    QQmlJSShadowCheck(const QV4::Compiler::JSUnitGenerator *jsUnitGenerator,
+                      const QQmlJSTypeResolver *typeResolver, QQmlJSLogger *logger,
+                      BasicBlocks basicBlocks, InstructionAnnotations annotations)
+        : QQmlJSCompilePass(jsUnitGenerator, typeResolver, logger, basicBlocks, annotations)
+    {}
+
+    ~QQmlJSShadowCheck() = default;
+
+    BlocksAndAnnotations run(const Function *function, QQmlJS::DiagnosticMessage *error);
+
+private:
+    struct ResettableStore {
+        QQmlJSRegisterContent accumulatorIn;
+        int instructionOffset = -1;
+    };
+
+    void handleStore(int base, const QString &memberName);
+
+    void generate_LoadProperty(int nameIndex) override;
+    void generate_GetLookup(int index) override;
+    void generate_GetOptionalLookup(int index, int offset) override;
+    void generate_StoreProperty(int nameIndex, int base) override;
+    void generate_SetLookup(int index, int base) override;
+    void generate_CallProperty(int nameIndex, int base, int argc, int argv) override;
+    void generate_CallPropertyLookup(int nameIndex, int base, int argc, int argv) override;
+
+    QV4::Moth::ByteCodeHandler::Verdict startInstruction(QV4::Moth::Instr::Type) override;
+    void endInstruction(QV4::Moth::Instr::Type) override;
+
+    enum Shadowability { NotShadowable, Shadowable };
+    Shadowability checkShadowing(
+            const QQmlJSRegisterContent &baseType, const QString &propertyName, int baseRegister);
+
+    void checkResettable(const QQmlJSRegisterContent &accumulatorIn, int instructionOffset);
+
+    Shadowability checkBaseType(const QQmlJSRegisterContent &baseType);
+
+    QList<ResettableStore> m_resettableStores;
+    QList<QQmlJSRegisterContent> m_baseTypes;
+    QSet<QQmlJSRegisterContent> m_adjustedTypes;
+
+    State m_state;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLJSSHADOWCHECK_P_H