AK: Rename RetainPtr.h => RefPtr.h, Retained.h => NonnullRefPtr.h.

AK/NonnullRefPtr.h

@@ -0,0 +1,225 @@
+#pragma once
+
+#include <AK/Assertions.h>
+#include <AK/Types.h>
+
+#ifdef __clang__
+#    define CONSUMABLE(initial_state) __attribute__((consumable(initial_state)))
+#    define CALLABLE_WHEN(...) __attribute__((callable_when(__VA_ARGS__)))
+#    define SET_TYPESTATE(state) __attribute__((set_typestate(state)))
+#    define RETURN_TYPESTATE(state) __attribute__((return_typestate(state)))
+#else
+#    define CONSUMABLE(initial_state)
+#    define CALLABLE_WHEN(state)
+#    define SET_TYPESTATE(state)
+#    define RETURN_TYPESTATE(state)
+#endif
+
+namespace AK {
+
+template<typename T>
+inline void ref_if_not_null(T* ptr)
+{
+    if (ptr)
+        ptr->ref();
+}
+
+template<typename T>
+inline void deref_if_not_null(T* ptr)
+{
+    if (ptr)
+        ptr->deref();
+}
+
+template<typename T>
+class CONSUMABLE(unconsumed) NonnullRefPtr {
+public:
+    enum AdoptTag {
+        Adopt
+    };
+
+    RETURN_TYPESTATE(unconsumed)
+    NonnullRefPtr(const T& object)
+        : m_ptr(const_cast<T*>(&object))
+    {
+        m_ptr->ref();
+    }
+    template<typename U>
+    RETURN_TYPESTATE(unconsumed)
+    NonnullRefPtr(const U& object)
+        : m_ptr(&const_cast<T&>(static_cast<const T&>(object)))
+    {
+        m_ptr->ref();
+    }
+    RETURN_TYPESTATE(unconsumed)
+    NonnullRefPtr(AdoptTag, T& object)
+        : m_ptr(&object)
+    {
+    }
+    RETURN_TYPESTATE(unconsumed)
+    NonnullRefPtr(NonnullRefPtr& other)
+        : m_ptr(&other.copy_ref().leak_ref())
+    {
+    }
+    RETURN_TYPESTATE(unconsumed)
+    NonnullRefPtr(NonnullRefPtr&& other)
+        : m_ptr(&other.leak_ref())
+    {
+    }
+    template<typename U>
+    RETURN_TYPESTATE(unconsumed)
+    NonnullRefPtr(NonnullRefPtr<U>&& other)
+        : m_ptr(static_cast<T*>(&other.leak_ref()))
+    {
+    }
+    RETURN_TYPESTATE(unconsumed)
+    NonnullRefPtr(const NonnullRefPtr& other)
+        : m_ptr(&const_cast<NonnullRefPtr&>(other).copy_ref().leak_ref())
+    {
+    }
+    template<typename U>
+    RETURN_TYPESTATE(unconsumed)
+    NonnullRefPtr(const NonnullRefPtr<U>& other)
+        : m_ptr(&const_cast<NonnullRefPtr<U>&>(other).copy_ref().leak_ref())
+    {
+    }
+    ~NonnullRefPtr()
+    {
+        deref_if_not_null(m_ptr);
+        m_ptr = nullptr;
+#ifdef SANITIZE_PTRS
+        if constexpr (sizeof(T*) == 8)
+            m_ptr = (T*)(0xb0b0b0b0b0b0b0b0);
+        else
+            m_ptr = (T*)(0xb0b0b0b0);
+#endif
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    NonnullRefPtr& operator=(NonnullRefPtr&& other)
+    {
+        if (this != &other) {
+            deref_if_not_null(m_ptr);
+            m_ptr = &other.leak_ref();
+        }
+        return *this;
+    }
+
+    template<typename U>
+    CALLABLE_WHEN(unconsumed)
+    NonnullRefPtr& operator=(NonnullRefPtr<U>&& other)
+    {
+        if (this != static_cast<void*>(&other)) {
+            deref_if_not_null(m_ptr);
+            m_ptr = &other.leak_ref();
+        }
+        return *this;
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    NonnullRefPtr& operator=(T& object)
+    {
+        if (m_ptr != &object)
+            deref_if_not_null(m_ptr);
+        m_ptr = &object;
+        m_ptr->ref();
+        return *this;
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    NonnullRefPtr copy_ref() const
+    {
+        return NonnullRefPtr(*m_ptr);
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    SET_TYPESTATE(consumed)
+    T& leak_ref()
+    {
+        ASSERT(m_ptr);
+        T* leakedPtr = m_ptr;
+        m_ptr = nullptr;
+        return *leakedPtr;
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    T* ptr()
+    {
+        ASSERT(m_ptr);
+        return m_ptr;
+    }
+    CALLABLE_WHEN(unconsumed)
+    const T* ptr() const
+    {
+        ASSERT(m_ptr);
+        return m_ptr;
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    T* operator->()
+    {
+        ASSERT(m_ptr);
+        return m_ptr;
+    }
+    CALLABLE_WHEN(unconsumed)
+    const T* operator->() const
+    {
+        ASSERT(m_ptr);
+        return m_ptr;
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    T& operator*()
+    {
+        ASSERT(m_ptr);
+        return *m_ptr;
+    }
+    CALLABLE_WHEN(unconsumed)
+    const T& operator*() const
+    {
+        ASSERT(m_ptr);
+        return *m_ptr;
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    operator T*()
+    {
+        ASSERT(m_ptr);
+        return m_ptr;
+    }
+    CALLABLE_WHEN(unconsumed)
+    operator const T*() const
+    {
+        ASSERT(m_ptr);
+        return m_ptr;
+    }
+
+    CALLABLE_WHEN(unconsumed)
+    operator T&()
+    {
+        ASSERT(m_ptr);
+        return *m_ptr;
+    }
+    CALLABLE_WHEN(unconsumed)
+    operator const T&() const
+    {
+        ASSERT(m_ptr);
+        return *m_ptr;
+    }
+
+private:
+    NonnullRefPtr() {}
+
+    T* m_ptr { nullptr };
+};
+
+template<typename T>
+inline NonnullRefPtr<T> adopt(T& object)
+{
+    return NonnullRefPtr<T>(NonnullRefPtr<T>::Adopt, object);
+}
+
+}
+
+using AK::adopt;
+using AK::NonnullRefPtr;