1/*
2 * Copyright (C) 2012-2018 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 "JSCPtrTag.h"
29#include "JSFunction.h"
30#include "MacroAssemblerCodeRef.h"
31#include <wtf/SentinelLinkedList.h>
32
33namespace JSC {
34
35struct Instruction;
36
37class LLIntCallLinkInfo : public PackedRawSentinelNode<LLIntCallLinkInfo> {
38public:
39 friend class LLIntOffsetsExtractor;
40
41 static constexpr uintptr_t unlinkedBit = 0x1;
42
43 LLIntCallLinkInfo() = default;
44
45 ~LLIntCallLinkInfo()
46 {
47 if (isOnList())
48 remove();
49 }
50
51 bool isLinked() const { return !(m_calleeOrLastSeenCalleeWithLinkBit & unlinkedBit); }
52
53
54 void link(VM& vm, JSCell* owner, JSObject* callee, MacroAssemblerCodePtr<JSEntryPtrTag> codePtr)
55 {
56 if (isOnList())
57 remove();
58 m_calleeOrLastSeenCalleeWithLinkBit = bitwise_cast<uintptr_t>(callee);
59 vm.heap.writeBarrier(owner, callee);
60 m_machineCodeTarget = codePtr;
61 }
62
63 void unlink()
64 {
65 // Make link invalidated. It works because LLInt tests the given callee with this pointer. But it is still valid as lastSeenCallee!
66 m_calleeOrLastSeenCalleeWithLinkBit |= unlinkedBit;
67 m_machineCodeTarget = MacroAssemblerCodePtr<JSEntryPtrTag>();
68 if (isOnList())
69 remove();
70 }
71
72 JSObject* callee() const
73 {
74 if (!isLinked())
75 return nullptr;
76 return bitwise_cast<JSObject*>(m_calleeOrLastSeenCalleeWithLinkBit);
77 }
78
79 JSObject* lastSeenCallee() const
80 {
81 return bitwise_cast<JSObject*>(m_calleeOrLastSeenCalleeWithLinkBit & ~unlinkedBit);
82 }
83
84 void clearLastSeenCallee()
85 {
86 m_calleeOrLastSeenCalleeWithLinkBit = unlinkedBit;
87 }
88
89 ArrayProfile m_arrayProfile;
90
91private:
92 uintptr_t m_calleeOrLastSeenCalleeWithLinkBit { unlinkedBit };
93 MacroAssemblerCodePtr<JSEntryPtrTag> m_machineCodeTarget;
94};
95
96} // namespace JSC
97