webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

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diff --git a/Source/JavaScriptCore/bytecode/BytecodeRewriter.cpp b/Source/JavaScriptCore/bytecode/BytecodeRewriter.cpp
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+++ b/Source/JavaScriptCore/bytecode/BytecodeRewriter.cpp
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+/*
+ * Copyright (C) 2016 Yusuke Suzuki <utatane.tea@gmail.com>
+ * 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. AND ITS CONTRIBUTORS ``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 ITS 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.
+ */
+
+#include "config.h"
+#include "BytecodeRewriter.h"
+
+#include "HeapInlines.h"
+#include "PreciseJumpTargetsInlines.h"
+#include <wtf/BubbleSort.h>
+
+namespace JSC {
+
+void BytecodeRewriter::applyModification()
+{
+    for (size_t insertionIndex = m_insertions.size(); insertionIndex--;) {
+        Insertion& insertion = m_insertions[insertionIndex];
+        if (insertion.type == Insertion::Type::Remove)
+            m_graph.instructions().remove(insertion.index.bytecodeOffset, insertion.length());
+        else {
+            if (insertion.includeBranch == IncludeBranch::Yes) {
+                int finalOffset = insertion.index.bytecodeOffset + calculateDifference(m_insertions.begin(), m_insertions.begin() + insertionIndex);
+                adjustJumpTargetsInFragment(finalOffset, insertion);
+            }
+            m_graph.instructions().insertVector(insertion.index.bytecodeOffset, insertion.instructions);
+        }
+    }
+    m_insertions.clear();
+}
+
+void BytecodeRewriter::execute()
+{
+    WTF::bubbleSort(m_insertions.begin(), m_insertions.end(), [] (const Insertion& lhs, const Insertion& rhs) {
+        return lhs.index < rhs.index;
+    });
+
+    UnlinkedCodeBlock* codeBlock = m_graph.codeBlock();
+    codeBlock->applyModification(*this);
+}
+
+void BytecodeRewriter::adjustJumpTargetsInFragment(unsigned finalOffset, Insertion& insertion)
+{
+    auto& fragment = insertion.instructions;
+    UnlinkedInstruction* instructionsBegin = fragment.data();
+    for (unsigned fragmentOffset = 0, fragmentCount = fragment.size(); fragmentOffset < fragmentCount;) {
+        UnlinkedInstruction& instruction = fragment[fragmentOffset];
+        OpcodeID opcodeID = instruction.u.opcode;
+        if (isBranch(opcodeID)) {
+            unsigned bytecodeOffset = finalOffset + fragmentOffset;
+            UnlinkedCodeBlock* codeBlock = m_graph.codeBlock();
+            extractStoredJumpTargetsForBytecodeOffset(codeBlock, codeBlock->vm()->interpreter, instructionsBegin, fragmentOffset, [&](int32_t& label) {
+                int absoluteOffset = adjustAbsoluteOffset(label);
+                label = absoluteOffset - static_cast<int>(bytecodeOffset);
+            });
+        }
+        fragmentOffset += opcodeLength(opcodeID);
+    }
+}
+
+void BytecodeRewriter::insertImpl(InsertionPoint insertionPoint, IncludeBranch includeBranch, Vector<UnlinkedInstruction>&& fragment)
+{
+    ASSERT(insertionPoint.position == Position::Before || insertionPoint.position == Position::After);
+    m_insertions.append(Insertion {
+        insertionPoint,
+        Insertion::Type::Insert,
+        includeBranch,
+        0,
+        WTFMove(fragment)
+    });
+}
+
+int BytecodeRewriter::adjustJumpTarget(InsertionPoint startPoint, InsertionPoint jumpTargetPoint)
+{
+    if (startPoint < jumpTargetPoint) {
+        int jumpTarget = jumpTargetPoint.bytecodeOffset;
+        auto start = std::lower_bound(m_insertions.begin(), m_insertions.end(), startPoint, [&] (const Insertion& insertion, InsertionPoint startPoint) {
+            return insertion.index < startPoint;
+        });
+        if (start != m_insertions.end()) {
+            auto end = std::lower_bound(m_insertions.begin(), m_insertions.end(), jumpTargetPoint, [&] (const Insertion& insertion, InsertionPoint jumpTargetPoint) {
+                return insertion.index < jumpTargetPoint;
+            });
+            jumpTarget += calculateDifference(start, end);
+        }
+        return jumpTarget - startPoint.bytecodeOffset;
+    }
+
+    if (startPoint == jumpTargetPoint)
+        return 0;
+
+    return -adjustJumpTarget(jumpTargetPoint, startPoint);
+}
+
+} // namespace JSC