summaryrefslogtreecommitdiff
path: root/Source/JavaScriptCore/wasm/WasmSignature.h
blob: 4d43ffcfce61598e3ccee47622ee7f416d7ec0e7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/*
 * Copyright (C) 2016 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#if ENABLE(WEBASSEMBLY)

#include "B3Type.h"
#include "WasmOps.h"
#include <cstdint>
#include <cstring>
#include <wtf/HashMap.h>
#include <wtf/HashTraits.h>
#include <wtf/StdLibExtras.h>
#include <wtf/Vector.h>

namespace WTF {
class PrintStream;
}

namespace JSC {

class VM;

namespace Wasm {

typedef uint32_t SignatureArgCount;
typedef uint32_t SignatureIndex;

class Signature {
    static const constexpr SignatureArgCount s_retCount = 1;
    typedef uint64_t allocationSizeRoundsUpTo;

    Signature() = delete;
    Signature(const Signature&) = delete;
    Signature(SignatureArgCount argCount)
        : m_argCount(argCount)
    {
    }

    Type* storage(SignatureArgCount i)
    {
        return i + reinterpret_cast<Type*>(reinterpret_cast<char*>(this) + sizeof(Signature));
    }
    Type* storage(SignatureArgCount i) const { return const_cast<Signature*>(this)->storage(i); }
    static uint32_t allocatedSize(SignatureArgCount argCount)
    {
        return WTF::roundUpToMultipleOf<sizeof(allocationSizeRoundsUpTo)>(sizeof(Signature) + (s_retCount + argCount) * sizeof(Type));
    }

public:
    Type& returnType() { return *storage(0); }
    Type returnType() const { return *storage(0); }
    SignatureArgCount returnCount() const { return s_retCount; }
    SignatureArgCount argumentCount() const { return m_argCount; }
    Type& argument(SignatureArgCount i)
    {
        ASSERT(i < argumentCount());
        return *storage(returnCount() + i);
    }
    Type argument(SignatureArgCount i) const { return const_cast<Signature*>(this)->argument(i); }

    WTF::String toString() const;
    void dump(WTF::PrintStream& out) const;
    bool operator==(const Signature& rhs) const
    {
        return allocatedSize(argumentCount()) == allocatedSize(rhs.argumentCount()) && !memcmp(this, &rhs, allocatedSize(argumentCount()));
    }
    unsigned hash() const;

    static Signature* create(SignatureArgCount);
    static void destroy(Signature*);

    // Signatures are uniqued and, for call_indirect, validated at runtime. Tables can create invalid SignatureIndex values which cause call_indirect to fail. We use 0 as the invalidIndex so that the codegen can easily test for it and trap, and we add a token invalid entry in SignatureInformation.
    static const constexpr SignatureIndex invalidIndex = 0;

private:
    friend class SignatureInformation;
    static Signature* createInvalid();
    SignatureArgCount m_argCount;
    // Return Type and arguments are stored here.
};

struct SignatureHash {
    const Signature* key;
    static const Signature* empty() { return nullptr; }
    static const Signature* deleted() { return reinterpret_cast<const Signature*>(1); }
    SignatureHash()
        : key(empty())
    {
    }
    explicit SignatureHash(const Signature* key)
        : key(key)
    {
        ASSERT(key != empty());
        ASSERT(key != deleted());
    }
    explicit SignatureHash(WTF::HashTableDeletedValueType)
        : key(deleted())
    {
    }
    bool operator==(const SignatureHash& rhs) const { return equal(*this, rhs); }
    static bool equal(const SignatureHash& lhs, const SignatureHash& rhs) { return lhs.key == rhs.key || (lhs.key && rhs.key && *lhs.key == *rhs.key); }
    static unsigned hash(const SignatureHash& signature) { return signature.key->hash(); }
    static const bool safeToCompareToEmptyOrDeleted = false;
    bool isHashTableDeletedValue() const { return key == deleted(); }
};

} } // namespace JSC::Wasm


namespace WTF {

template<typename T> struct DefaultHash;
template<> struct DefaultHash<JSC::Wasm::SignatureHash> {
    typedef JSC::Wasm::SignatureHash Hash;
};

template<typename T> struct HashTraits;
template<> struct HashTraits<JSC::Wasm::SignatureHash> : SimpleClassHashTraits<JSC::Wasm::SignatureHash> {
    static const bool emptyValueIsZero = true;
};

} // namespace WTF


namespace JSC { namespace Wasm {

// Signature information is held globally on VM to allow all signatures to be unique. This is required when wasm calls another wasm instance.
// Note: signatures are never removed from VM because that would require accounting for all WebAssembly.Module and which signatures they use. The maximum number of signatures is bounded, and isn't worth the counting overhead. We could clear everything when we reach zero outstanding WebAssembly.Module. https://bugs.webkit.org/show_bug.cgi?id=166037
class SignatureInformation {
    HashMap<Wasm::SignatureHash, Wasm::SignatureIndex> m_signatureMap;
    Vector<Signature*> m_signatures;
    Lock m_lock;
    static SignatureInformation* get(VM*);
    SignatureInformation();
    SignatureInformation(const SignatureInformation&) = delete;

public:
    ~SignatureInformation();
    static SignatureIndex WARN_UNUSED_RETURN adopt(VM*, Signature*);
    static const Signature* WARN_UNUSED_RETURN get(VM*, SignatureIndex);
};

} } // namespace JSC::Wasm

#endif // ENABLE(WEBASSEMBLY)