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// Copyright (C) 2018 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#ifndef QV4PROPERTYKEY_H
#define QV4PROPERTYKEY_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/qv4writebarrier_p.h>
#include <private/qv4global_p.h>
#include <private/qv4staticvalue_p.h>
#include <QtCore/qhashfunctions.h>
QT_BEGIN_NAMESPACE
class QString;
namespace QV4 {
struct PropertyKey
{
private:
// Property keys are Strings, Symbols or unsigned integers.
// For convenience we derive them from Values, allowing us to store them
// on the JS stack
//
// They do however behave somewhat different than a Value:
// * If the key is a String, the pointer to the string is stored in the identifier
// table and thus unique.
// * If the key is a Symbol it simply points to the referenced symbol object
// * if the key is an array index (a uint < UINT_MAX), it's encoded as an
// integer value
QV4::StaticValue val;
inline bool isManaged() const { return val.isManaged(); }
inline quint32 value() const { return val.value(); }
public:
static PropertyKey invalid()
{
PropertyKey key;
key.val = StaticValue::undefinedValue();
return key;
}
static PropertyKey fromArrayIndex(uint idx)
{
PropertyKey key;
key.val.setInt_32(idx);
return key;
}
bool isStringOrSymbol() const { return isManaged(); }
uint asArrayIndex() const
{
Q_ASSERT(isArrayIndex());
return value();
}
bool isArrayIndex() const { return val.isInteger(); }
bool isValid() const { return !val.isUndefined(); }
// We cannot #include the declaration of Heap::StringOrSymbol here.
// Therefore we do some gymnastics to enforce the type safety.
template<typename StringOrSymbol = Heap::StringOrSymbol, typename Engine = QV4::EngineBase>
static PropertyKey fromStringOrSymbol(Engine *engine, StringOrSymbol *b)
{
static_assert(std::is_base_of_v<Heap::StringOrSymbol, StringOrSymbol>);
PropertyKey key;
QV4::WriteBarrier::markCustom(engine, [&](QV4::MarkStack *stack) {
if constexpr (QV4::WriteBarrier::isInsertionBarrier) {
// treat this as an insertion - the StringOrSymbol becomes reachable
// via the propertykey, so we consequently need to mark it durnig gc
b->mark(stack);
}
});
key.val.setM(b);
Q_ASSERT(key.isManaged());
return key;
}
template<typename StringOrSymbol = Heap::StringOrSymbol>
StringOrSymbol *asStringOrSymbol() const
{
static_assert(std::is_base_of_v<Heap::StringOrSymbol, StringOrSymbol>);
if (!isManaged())
return nullptr;
return static_cast<StringOrSymbol *>(val.m());
}
Q_QML_EXPORT bool isString() const;
Q_QML_EXPORT bool isSymbol() const;
bool isCanonicalNumericIndexString() const;
Q_QML_EXPORT QString toQString() const;
Heap::StringOrSymbol *toStringOrSymbol(ExecutionEngine *e);
quint64 id() const { return val._val; }
static PropertyKey fromId(quint64 id) {
PropertyKey key; key.val._val = id; return key;
}
enum FunctionNamePrefix {
None,
Getter,
Setter
};
Heap::String *asFunctionName(ExecutionEngine *e, FunctionNamePrefix prefix) const;
bool operator ==(const PropertyKey &other) const { return val._val == other.val._val; }
bool operator !=(const PropertyKey &other) const { return val._val != other.val._val; }
bool operator <(const PropertyKey &other) const { return val._val < other.val._val; }
friend size_t qHash(const PropertyKey &key, size_t seed = 0) { return qHash(key.val._val, seed); }
};
}
QT_END_NAMESPACE
#endif
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