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 "WasmName.h"
29#include "WasmNameSection.h"
30#include <wtf/RefPtr.h>
31#include <wtf/StdLibExtras.h>
32#include <wtf/text/WTFString.h>
33
34namespace JSC { namespace Wasm {
35
36struct NameSection;
37
38struct IndexOrName {
39 typedef size_t Index;
40
41 IndexOrName() { m_indexName.index = emptyTag; }
42 IndexOrName(Index, std::pair<const Name*, RefPtr<NameSection>>&&);
43 bool isEmpty() const { return bitwise_cast<Index>(m_indexName) & emptyTag; }
44 bool isIndex() const { return bitwise_cast<Index>(m_indexName) & indexTag; }
45 bool isName() const { return !(isEmpty() || isName()); }
46 NameSection* nameSection() const { return m_nameSection.get(); }
47
48 friend String makeString(const IndexOrName&);
49
50private:
51 union {
52 Index index;
53 const Name* name;
54 } m_indexName;
55 RefPtr<NameSection> m_nameSection;
56
57 // Use the top bits as tags. Neither pointers nor the function index space should use them.
58 static constexpr Index indexTag = 1ull << (CHAR_BIT * sizeof(Index) - 1);
59 static constexpr Index emptyTag = 1ull << (CHAR_BIT * sizeof(Index) - 2);
60 static constexpr Index allTags = indexTag | emptyTag;
61};
62
63String makeString(const IndexOrName&);
64
65} } // namespace JSC::Wasm
66