1/*
2 * Copyright (C) 2016 Yusuke Suzuki <utatane.tea@gmail.com>
3 * Copyright (C) 2016-2017 Apple Inc. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
15 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
16 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
18 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
20 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
21 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
22 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
23 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
24 * THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "config.h"
28#include "BytecodeRewriter.h"
29
30#include "JSCInlines.h"
31#include "PreciseJumpTargetsInlines.h"
32#include <wtf/BubbleSort.h>
33
34namespace JSC {
35
36void BytecodeRewriter::applyModification()
37{
38 for (size_t insertionIndex = m_insertions.size(); insertionIndex--;) {
39 Insertion& insertion = m_insertions[insertionIndex];
40 if (insertion.type == Insertion::Type::Remove)
41 m_writer.m_instructions.remove(insertion.index.bytecodeOffset, insertion.length());
42 else {
43 if (insertion.includeBranch == IncludeBranch::Yes) {
44 int finalOffset = insertion.index.bytecodeOffset + calculateDifference(m_insertions.begin(), m_insertions.begin() + insertionIndex);
45 adjustJumpTargetsInFragment(finalOffset, insertion);
46 }
47 m_writer.m_instructions.insertVector(insertion.index.bytecodeOffset, insertion.instructions.m_instructions);
48 }
49 }
50 m_insertions.clear();
51}
52
53void BytecodeRewriter::execute()
54{
55 WTF::bubbleSort(m_insertions.begin(), m_insertions.end(), [] (const Insertion& lhs, const Insertion& rhs) {
56 return lhs.index < rhs.index;
57 });
58
59 m_codeBlock->applyModification(*this, m_writer);
60}
61
62void BytecodeRewriter::adjustJumpTargetsInFragment(unsigned finalOffset, Insertion& insertion)
63{
64 for (auto& instruction : insertion.instructions) {
65 if (isBranch(instruction->opcodeID())) {
66 unsigned bytecodeOffset = finalOffset + instruction.offset();
67 updateStoredJumpTargetsForInstruction(m_codeBlock, finalOffset, instruction, [&](int32_t label) {
68 int absoluteOffset = adjustAbsoluteOffset(label);
69 return absoluteOffset - static_cast<int>(bytecodeOffset);
70 });
71 }
72 }
73}
74
75void BytecodeRewriter::insertImpl(InsertionPoint insertionPoint, IncludeBranch includeBranch, InstructionStreamWriter&& writer)
76{
77 ASSERT(insertionPoint.position == Position::Before || insertionPoint.position == Position::After);
78 m_insertions.append(Insertion {
79 insertionPoint,
80 Insertion::Type::Insert,
81 includeBranch,
82 0,
83 WTFMove(writer)
84 });
85}
86
87int32_t BytecodeRewriter::adjustJumpTarget(InsertionPoint startPoint, InsertionPoint jumpTargetPoint)
88{
89 if (startPoint < jumpTargetPoint) {
90 int jumpTarget = jumpTargetPoint.bytecodeOffset;
91 auto start = std::lower_bound(m_insertions.begin(), m_insertions.end(), startPoint, [&] (const Insertion& insertion, InsertionPoint startPoint) {
92 return insertion.index < startPoint;
93 });
94 if (start != m_insertions.end()) {
95 auto end = std::lower_bound(m_insertions.begin(), m_insertions.end(), jumpTargetPoint, [&] (const Insertion& insertion, InsertionPoint jumpTargetPoint) {
96 return insertion.index < jumpTargetPoint;
97 });
98 jumpTarget += calculateDifference(start, end);
99 }
100 return jumpTarget - startPoint.bytecodeOffset;
101 }
102
103 if (startPoint == jumpTargetPoint)
104 return 0;
105
106 return -adjustJumpTarget(jumpTargetPoint, startPoint);
107}
108
109// FIXME: unit test the logic in this method
110// https://bugs.webkit.org/show_bug.cgi?id=190950
111void BytecodeRewriter::adjustJumpTargets()
112{
113 auto currentInsertion = m_insertions.begin();
114 auto outOfLineJumpTargets = m_codeBlock->replaceOutOfLineJumpTargets();
115
116 int offset = 0;
117 for (InstructionStream::Offset i = 0; i < m_writer.size();) {
118 int before = 0;
119 int after = 0;
120 int remove = 0;
121 while (currentInsertion != m_insertions.end() && static_cast<InstructionStream::Offset>(currentInsertion->index.bytecodeOffset) == i) {
122 auto size = currentInsertion->length();
123 if (currentInsertion->type == Insertion::Type::Remove)
124 remove += size;
125 else if (currentInsertion->index.position == Position::Before)
126 before += size;
127 else if (currentInsertion->index.position == Position::After)
128 after += size;
129 ++currentInsertion;
130 }
131
132 offset += before;
133
134 if (!remove) {
135 auto instruction = m_writer.ref(i);
136 updateStoredJumpTargetsForInstruction(m_codeBlock, offset, instruction, [&](int32_t relativeOffset) {
137 return adjustJumpTarget(instruction.offset(), instruction.offset() + relativeOffset);
138 }, outOfLineJumpTargets);
139 i += instruction->size();
140 } else {
141 offset -= remove;
142 i += remove;
143 }
144
145 offset += after;
146 }
147}
148
149} // namespace JSC
150