1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include "JSCJSValue.h"
29#include <wtf/StdLibExtras.h>
30
31namespace JSC {
32
33namespace Wasm {
34class Callee;
35}
36
37class JSCell;
38
39class CalleeBits {
40public:
41 CalleeBits() = default;
42 CalleeBits(void* ptr) : m_ptr(ptr) { }
43
44 CalleeBits& operator=(JSCell* cell)
45 {
46 m_ptr = cell;
47 ASSERT(isCell());
48 return *this;
49 }
50
51#if ENABLE(WEBASSEMBLY)
52 static void* boxWasm(Wasm::Callee* callee)
53 {
54 CalleeBits result(reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(callee) | TagBitsWasm));
55 ASSERT(result.isWasm());
56 return result.rawPtr();
57 }
58#endif
59
60 bool isWasm() const
61 {
62#if ENABLE(WEBASSEMBLY)
63 return (reinterpret_cast<uintptr_t>(m_ptr) & TagWasmMask) == TagBitsWasm;
64#else
65 return false;
66#endif
67 }
68 bool isCell() const { return !isWasm(); }
69
70 JSCell* asCell() const
71 {
72 ASSERT(!isWasm());
73 return static_cast<JSCell*>(m_ptr);
74 }
75
76#if ENABLE(WEBASSEMBLY)
77 Wasm::Callee* asWasmCallee() const
78 {
79 ASSERT(isWasm());
80 return reinterpret_cast<Wasm::Callee*>(reinterpret_cast<uintptr_t>(m_ptr) & ~TagBitsWasm);
81 }
82#endif
83
84 void* rawPtr() const { return m_ptr; }
85
86private:
87 void* m_ptr { nullptr };
88};
89
90} // namespace JSC
91