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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.
*/
#pragma once
#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)
, m_didAllocate(false)
, m_code(0)
, m_vm(&vm)
#ifndef NDEBUG
, m_completed(false)
#endif
{
linkCode(macroAssembler, ownerUID, effort);
}
LinkBuffer(MacroAssembler& macroAssembler, void* code, size_t size, JITCompilationEffort effort = JITCompilationMustSucceed, bool shouldPerformBranchCompaction = true)
: m_size(size)
, m_didAllocate(false)
, m_code(code)
, m_vm(0)
#ifndef NDEBUG
, m_completed(false)
#endif
{
#if ENABLE(BRANCH_COMPACTION)
m_shouldPerformBranchCompaction = shouldPerformBranchCompaction;
#else
UNUSED_PARAM(shouldPerformBranchCompaction);
#endif
linkCode(macroAssembler, 0, effort);
}
~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(const JumpList& list, CodeLocationLabel label)
{
for (const Jump& jump : list.jumps())
link(jump, 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)),
call.isFlagSet(Call::Tail) ? NearCallMode::Tail : NearCallMode::Regular);
}
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;
}
size_t size() const { return m_size; }
bool wasAlreadyDisassembled() const { return m_alreadyDisassembled; }
void didAlreadyDisassemble() { m_alreadyDisassembled = true; }
VM& vm() { return *m_vm; }
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(MacroAssembler&, void* ownerUID, JITCompilationEffort);
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)
AssemblerData m_assemblerStorage;
bool m_shouldPerformBranchCompaction { true };
#endif
bool m_didAllocate;
void* m_code;
VM* m_vm;
#ifndef NDEBUG
bool m_completed;
#endif
bool m_alreadyDisassembled { false };
Vector<RefPtr<SharedTask<void(LinkBuffer&)>>> m_linkTasks;
};
#define FINALIZE_CODE_IF(condition, linkBufferReference, dataLogFArgumentsForHeading) \
(UNLIKELY((condition)) \
? ((linkBufferReference).finalizeCodeWithDisassembly dataLogFArgumentsForHeading) \
: (linkBufferReference).finalizeCodeWithoutDisassembly())
bool shouldDumpDisassemblyFor(CodeBlock*);
#define FINALIZE_CODE_FOR(codeBlock, linkBufferReference, dataLogFArgumentsForHeading) \
FINALIZE_CODE_IF(shouldDumpDisassemblyFor(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 dumpDisassembly
// 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::dumpDisassembly(), linkBufferReference, dataLogFArgumentsForHeading)
#define FINALIZE_DFG_CODE(linkBufferReference, dataLogFArgumentsForHeading) \
FINALIZE_CODE_IF(JSC::Options::asyncDisassembly() || JSC::Options::dumpDisassembly() || Options::dumpDFGDisassembly(), linkBufferReference, dataLogFArgumentsForHeading)
} // namespace JSC
#endif // ENABLE(ASSEMBLER)