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diff --git a/Source/JavaScriptCore/assembler/LinkBuffer.h b/Source/JavaScriptCore/assembler/LinkBuffer.h
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+/*
+ * Copyright (C) 2009, 2010, 2012-2015 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. 
+ */
+
+#ifndef LinkBuffer_h
+#define LinkBuffer_h
+
+#if ENABLE(ASSEMBLER)
+
+#define DUMP_LINK_STATISTICS 0
+#define DUMP_CODE 0
+
+#define GLOBAL_THUNK_ID reinterpret_cast<void*>(static_cast<intptr_t>(-1))
+#define REGEXP_CODE_ID reinterpret_cast<void*>(static_cast<intptr_t>(-2))
+#define CSS_CODE_ID reinterpret_cast<void*>(static_cast<intptr_t>(-3))
+
+#include "JITCompilationEffort.h"
+#include "MacroAssembler.h"
+#include <wtf/DataLog.h>
+#include <wtf/FastMalloc.h>
+#include <wtf/Noncopyable.h>
+
+namespace JSC {
+
+class CodeBlock;
+class VM;
+
+// LinkBuffer:
+//
+// This class assists in linking code generated by the macro assembler, once code generation
+// has been completed, and the code has been copied to is final location in memory.  At this
+// time pointers to labels within the code may be resolved, and relative offsets to external
+// addresses may be fixed.
+//
+// Specifically:
+//   * Jump objects may be linked to external targets,
+//   * The address of Jump objects may taken, such that it can later be relinked.
+//   * The return address of a Call may be acquired.
+//   * The address of a Label pointing into the code may be resolved.
+//   * The value referenced by a DataLabel may be set.
+//
+class LinkBuffer {
+    WTF_MAKE_NONCOPYABLE(LinkBuffer); WTF_MAKE_FAST_ALLOCATED;
+    
+    typedef MacroAssemblerCodeRef CodeRef;
+    typedef MacroAssemblerCodePtr CodePtr;
+    typedef MacroAssembler::Label Label;
+    typedef MacroAssembler::Jump Jump;
+    typedef MacroAssembler::PatchableJump PatchableJump;
+    typedef MacroAssembler::JumpList JumpList;
+    typedef MacroAssembler::Call Call;
+    typedef MacroAssembler::DataLabelCompact DataLabelCompact;
+    typedef MacroAssembler::DataLabel32 DataLabel32;
+    typedef MacroAssembler::DataLabelPtr DataLabelPtr;
+    typedef MacroAssembler::ConvertibleLoadLabel ConvertibleLoadLabel;
+#if ENABLE(BRANCH_COMPACTION)
+    typedef MacroAssembler::LinkRecord LinkRecord;
+    typedef MacroAssembler::JumpLinkType JumpLinkType;
+#endif
+
+public:
+    LinkBuffer(VM& vm, MacroAssembler& macroAssembler, void* ownerUID, JITCompilationEffort effort = JITCompilationMustSucceed)
+        : m_size(0)
+#if ENABLE(BRANCH_COMPACTION)
+        , m_initialSize(0)
+#endif
+        , m_didAllocate(false)
+        , m_code(0)
+        , m_vm(&vm)
+#ifndef NDEBUG
+        , m_completed(false)
+#endif
+    {
+        linkCode(macroAssembler, ownerUID, effort);
+    }
+
+    LinkBuffer(VM& vm, MacroAssembler& macroAssembler, void* code, size_t size)
+        : m_size(size)
+#if ENABLE(BRANCH_COMPACTION)
+        , m_initialSize(0)
+#endif
+        , m_didAllocate(false)
+        , m_code(code)
+        , m_vm(&vm)
+#ifndef NDEBUG
+        , m_completed(false)
+#endif
+    {
+        linkCode(macroAssembler, 0, JITCompilationCanFail);
+    }
+
+    ~LinkBuffer()
+    {
+    }
+    
+    bool didFailToAllocate() const
+    {
+        return !m_didAllocate;
+    }
+
+    bool isValid() const
+    {
+        return !didFailToAllocate();
+    }
+    
+    // These methods are used to link or set values at code generation time.
+
+    void link(Call call, FunctionPtr function)
+    {
+        ASSERT(call.isFlagSet(Call::Linkable));
+        call.m_label = applyOffset(call.m_label);
+        MacroAssembler::linkCall(code(), call, function);
+    }
+    
+    void link(Call call, CodeLocationLabel label)
+    {
+        link(call, FunctionPtr(label.executableAddress()));
+    }
+    
+    void link(Jump jump, CodeLocationLabel label)
+    {
+        jump.m_label = applyOffset(jump.m_label);
+        MacroAssembler::linkJump(code(), jump, label);
+    }
+
+    void link(JumpList list, CodeLocationLabel label)
+    {
+        for (unsigned i = 0; i < list.m_jumps.size(); ++i)
+            link(list.m_jumps[i], label);
+    }
+
+    void patch(DataLabelPtr label, void* value)
+    {
+        AssemblerLabel target = applyOffset(label.m_label);
+        MacroAssembler::linkPointer(code(), target, value);
+    }
+
+    void patch(DataLabelPtr label, CodeLocationLabel value)
+    {
+        AssemblerLabel target = applyOffset(label.m_label);
+        MacroAssembler::linkPointer(code(), target, value.executableAddress());
+    }
+
+    // These methods are used to obtain handles to allow the code to be relinked / repatched later.
+    
+    CodeLocationLabel entrypoint()
+    {
+        return CodeLocationLabel(code());
+    }
+
+    CodeLocationCall locationOf(Call call)
+    {
+        ASSERT(call.isFlagSet(Call::Linkable));
+        ASSERT(!call.isFlagSet(Call::Near));
+        return CodeLocationCall(MacroAssembler::getLinkerAddress(code(), applyOffset(call.m_label)));
+    }
+
+    CodeLocationNearCall locationOfNearCall(Call call)
+    {
+        ASSERT(call.isFlagSet(Call::Linkable));
+        ASSERT(call.isFlagSet(Call::Near));
+        return CodeLocationNearCall(MacroAssembler::getLinkerAddress(code(), applyOffset(call.m_label)));
+    }
+
+    CodeLocationLabel locationOf(PatchableJump jump)
+    {
+        return CodeLocationLabel(MacroAssembler::getLinkerAddress(code(), applyOffset(jump.m_jump.m_label)));
+    }
+
+    CodeLocationLabel locationOf(Label label)
+    {
+        return CodeLocationLabel(MacroAssembler::getLinkerAddress(code(), applyOffset(label.m_label)));
+    }
+
+    CodeLocationDataLabelPtr locationOf(DataLabelPtr label)
+    {
+        return CodeLocationDataLabelPtr(MacroAssembler::getLinkerAddress(code(), applyOffset(label.m_label)));
+    }
+
+    CodeLocationDataLabel32 locationOf(DataLabel32 label)
+    {
+        return CodeLocationDataLabel32(MacroAssembler::getLinkerAddress(code(), applyOffset(label.m_label)));
+    }
+    
+    CodeLocationDataLabelCompact locationOf(DataLabelCompact label)
+    {
+        return CodeLocationDataLabelCompact(MacroAssembler::getLinkerAddress(code(), applyOffset(label.m_label)));
+    }
+
+    CodeLocationConvertibleLoad locationOf(ConvertibleLoadLabel label)
+    {
+        return CodeLocationConvertibleLoad(MacroAssembler::getLinkerAddress(code(), applyOffset(label.m_label)));
+    }
+
+    // This method obtains the return address of the call, given as an offset from
+    // the start of the code.
+    unsigned returnAddressOffset(Call call)
+    {
+        call.m_label = applyOffset(call.m_label);
+        return MacroAssembler::getLinkerCallReturnOffset(call);
+    }
+
+    uint32_t offsetOf(Label label)
+    {
+        return applyOffset(label.m_label).m_offset;
+    }
+
+    unsigned offsetOf(PatchableJump jump)
+    {
+        return applyOffset(jump.m_jump.m_label).m_offset;
+    }
+
+    // Upon completion of all patching 'FINALIZE_CODE()' should be called once to
+    // complete generation of the code. Alternatively, call
+    // finalizeCodeWithoutDisassembly() directly if you have your own way of
+    // displaying disassembly.
+    
+    JS_EXPORT_PRIVATE CodeRef finalizeCodeWithoutDisassembly();
+    JS_EXPORT_PRIVATE CodeRef finalizeCodeWithDisassembly(const char* format, ...) WTF_ATTRIBUTE_PRINTF(2, 3);
+
+    CodePtr trampolineAt(Label label)
+    {
+        return CodePtr(MacroAssembler::AssemblerType_T::getRelocatedAddress(code(), applyOffset(label.m_label)));
+    }
+
+    void* debugAddress()
+    {
+        return m_code;
+    }
+
+    // FIXME: this does not account for the AssemblerData size!
+    size_t size()
+    {
+        return m_size;
+    }
+    
+    bool wasAlreadyDisassembled() const { return m_alreadyDisassembled; }
+    void didAlreadyDisassemble() { m_alreadyDisassembled = true; }
+
+private:
+#if ENABLE(BRANCH_COMPACTION)
+    int executableOffsetFor(int location)
+    {
+        if (!location)
+            return 0;
+        return bitwise_cast<int32_t*>(m_assemblerStorage.buffer())[location / sizeof(int32_t) - 1];
+    }
+#endif
+    
+    template <typename T> T applyOffset(T src)
+    {
+#if ENABLE(BRANCH_COMPACTION)
+        src.m_offset -= executableOffsetFor(src.m_offset);
+#endif
+        return src;
+    }
+    
+    // Keep this private! - the underlying code should only be obtained externally via finalizeCode().
+    void* code()
+    {
+        return m_code;
+    }
+    
+    void allocate(size_t initialSize, void* ownerUID, JITCompilationEffort);
+    void shrink(size_t newSize);
+
+    JS_EXPORT_PRIVATE void linkCode(MacroAssembler&, void* ownerUID, JITCompilationEffort);
+#if ENABLE(BRANCH_COMPACTION)
+    template <typename InstructionType>
+    void copyCompactAndLinkCode(MacroAssembler&, void* ownerUID, JITCompilationEffort);
+#endif
+
+    void performFinalization();
+
+#if DUMP_LINK_STATISTICS
+    static void dumpLinkStatistics(void* code, size_t initialSize, size_t finalSize);
+#endif
+    
+#if DUMP_CODE
+    static void dumpCode(void* code, size_t);
+#endif
+    
+    RefPtr<ExecutableMemoryHandle> m_executableMemory;
+    size_t m_size;
+#if ENABLE(BRANCH_COMPACTION)
+    size_t m_initialSize;
+    AssemblerData m_assemblerStorage;
+#endif
+    bool m_didAllocate;
+    void* m_code;
+    VM* m_vm;
+#ifndef NDEBUG
+    bool m_completed;
+#endif
+    bool m_alreadyDisassembled { false };
+};
+
+#define FINALIZE_CODE_IF(condition, linkBufferReference, dataLogFArgumentsForHeading)  \
+    (UNLIKELY((condition))                                              \
+     ? ((linkBufferReference).finalizeCodeWithDisassembly dataLogFArgumentsForHeading) \
+     : (linkBufferReference).finalizeCodeWithoutDisassembly())
+
+bool shouldShowDisassemblyFor(CodeBlock*);
+
+#define FINALIZE_CODE_FOR(codeBlock, linkBufferReference, dataLogFArgumentsForHeading)  \
+    FINALIZE_CODE_IF(shouldShowDisassemblyFor(codeBlock) || Options::asyncDisassembly(), linkBufferReference, dataLogFArgumentsForHeading)
+
+// Use this to finalize code, like so:
+//
+// CodeRef code = FINALIZE_CODE(linkBuffer, ("my super thingy number %d", number));
+//
+// Which, in disassembly mode, will print:
+//
+// Generated JIT code for my super thingy number 42:
+//     Code at [0x123456, 0x234567]:
+//         0x123456: mov $0, 0
+//         0x12345a: ret
+//
+// ... and so on.
+//
+// Note that the dataLogFArgumentsForHeading are only evaluated when showDisassembly
+// is true, so you can hide expensive disassembly-only computations inside there.
+
+#define FINALIZE_CODE(linkBufferReference, dataLogFArgumentsForHeading)  \
+    FINALIZE_CODE_IF(JSC::Options::asyncDisassembly() || JSC::Options::showDisassembly(), linkBufferReference, dataLogFArgumentsForHeading)
+
+#define FINALIZE_DFG_CODE(linkBufferReference, dataLogFArgumentsForHeading)  \
+    FINALIZE_CODE_IF(JSC::Options::asyncDisassembly() || JSC::Options::showDisassembly() || Options::showDFGDisassembly(), linkBufferReference, dataLogFArgumentsForHeading)
+
+} // namespace JSC
+
+#endif // ENABLE(ASSEMBLER)
+
+#endif // LinkBuffer_h