#ifndef LinkBuffer_h
#define LinkBuffer_h
#if ENABLE(ASSEMBLER)
#include <MacroAssembler.h>
#include <wtf/Noncopyable.h>
namespace JSC {
class LinkBuffer : public Noncopyable {
typedef MacroAssemblerCodeRef CodeRef;
typedef MacroAssemblerCodePtr CodePtr;
typedef MacroAssembler::Label Label;
typedef MacroAssembler::Jump Jump;
typedef MacroAssembler::JumpList JumpList;
typedef MacroAssembler::Call Call;
typedef MacroAssembler::DataLabel32 DataLabel32;
typedef MacroAssembler::DataLabelPtr DataLabelPtr;
typedef MacroAssembler::JmpDst JmpDst;
#if ENABLE(BRANCH_COMPACTION)
typedef MacroAssembler::LinkRecord LinkRecord;
typedef MacroAssembler::JumpLinkType JumpLinkType;
#endif
public:
LinkBuffer(MacroAssembler* masm, PassRefPtr<ExecutablePool> executablePool, void* linkOffset)
: m_executablePool(executablePool)
, m_size(0)
, m_code(0)
, m_assembler(masm)
#ifndef NDEBUG
, m_completed(false)
#endif
{
linkCode(linkOffset);
}
~LinkBuffer()
{
ASSERT(m_completed);
}
void link(Call call, FunctionPtr function)
{
ASSERT(call.isFlagSet(Call::Linkable));
call.m_jmp = applyOffset(call.m_jmp);
MacroAssembler::linkCall(code(), call, function);
}
void link(Jump jump, CodeLocationLabel label)
{
jump.m_jmp = applyOffset(jump.m_jmp);
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)
{
JmpDst target = applyOffset(label.m_label);
MacroAssembler::linkPointer(code(), target, value);
}
void patch(DataLabelPtr label, CodeLocationLabel value)
{
JmpDst target = applyOffset(label.m_label);
MacroAssembler::linkPointer(code(), target, value.executableAddress());
}
CodeLocationCall locationOf(Call call)
{
ASSERT(call.isFlagSet(Call::Linkable));
ASSERT(!call.isFlagSet(Call::Near));
return CodeLocationCall(MacroAssembler::getLinkerAddress(code(), applyOffset(call.m_jmp)));
}
CodeLocationNearCall locationOfNearCall(Call call)
{
ASSERT(call.isFlagSet(Call::Linkable));
ASSERT(call.isFlagSet(Call::Near));
return CodeLocationNearCall(MacroAssembler::getLinkerAddress(code(), applyOffset(call.m_jmp)));
}
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)));
}
unsigned returnAddressOffset(Call call)
{
call.m_jmp = applyOffset(call.m_jmp);
return MacroAssembler::getLinkerCallReturnOffset(call);
}
CodeRef finalizeCode()
{
performFinalization();
return CodeRef(m_code, m_executablePool, m_size);
}
CodeLocationLabel finalizeCodeAddendum()
{
performFinalization();
return CodeLocationLabel(code());
}
CodePtr trampolineAt(Label label)
{
return CodePtr(MacroAssembler::AssemblerType_T::getRelocatedAddress(code(), applyOffset(label.m_label)));
}
private:
template <typename T> T applyOffset(T src)
{
#if ENABLE(BRANCH_COMPACTION)
src.m_offset -= m_assembler->executableOffsetFor(src.m_offset);
#endif
return src;
}
void* code()
{
return m_code;
}
void linkCode(void* linkOffset)
{
UNUSED_PARAM(linkOffset);
ASSERT(!m_code);
#if !ENABLE(BRANCH_COMPACTION)
m_code = m_assembler->m_assembler.executableCopy(m_executablePool.get());
m_size = m_assembler->size();
#else
size_t initialSize = m_assembler->size();
m_code = (uint8_t*)m_executablePool->alloc(initialSize);
if (!m_code)
return;
ExecutableAllocator::makeWritable(m_code, m_assembler->size());
uint8_t* inData = (uint8_t*)m_assembler->unlinkedCode();
uint8_t* outData = reinterpret_cast<uint8_t*>(m_code);
const uint8_t* linkBase = linkOffset ? reinterpret_cast<uint8_t*>(linkOffset) : outData;
int readPtr = 0;
int writePtr = 0;
Vector<LinkRecord>& jumpsToLink = m_assembler->jumpsToLink();
unsigned jumpCount = jumpsToLink.size();
for (unsigned i = 0; i < jumpCount; ++i) {
int offset = readPtr - writePtr;
ASSERT(!(offset & 1));
size_t regionSize = jumpsToLink[i].from() - readPtr;
memcpy(outData + writePtr, inData + readPtr, regionSize);
m_assembler->recordLinkOffsets(readPtr, jumpsToLink[i].from(), offset);
readPtr += regionSize;
writePtr += regionSize;
const uint8_t* target;
if (jumpsToLink[i].to() >= jumpsToLink[i].from())
target = linkBase + jumpsToLink[i].to() - offset; else
target = linkBase + jumpsToLink[i].to() - m_assembler->executableOffsetFor(jumpsToLink[i].to());
JumpLinkType jumpLinkType = m_assembler->computeJumpType(jumpsToLink[i], linkBase + writePtr, target);
if (m_assembler->canCompact(jumpsToLink[i].type())) {
int32_t delta = m_assembler->jumpSizeDelta(jumpsToLink[i].type(), jumpLinkType);
if (delta) {
writePtr -= delta;
m_assembler->recordLinkOffsets(jumpsToLink[i].from() - delta, readPtr, readPtr - writePtr);
}
}
jumpsToLink[i].setFrom(writePtr);
}
memcpy(outData + writePtr, inData + readPtr, m_assembler->size() - readPtr);
m_assembler->recordLinkOffsets(readPtr, m_assembler->size(), readPtr - writePtr);
if (!linkOffset) {
for (unsigned i = 0; i < jumpCount; ++i) {
uint8_t* location = outData + jumpsToLink[i].from();
uint8_t* target = outData + jumpsToLink[i].to() - m_assembler->executableOffsetFor(jumpsToLink[i].to());
m_assembler->link(jumpsToLink[i], location, target);
}
}
jumpsToLink.clear();
m_size = writePtr + m_assembler->size() - readPtr;
m_executablePool->tryShrink(m_code, initialSize, m_size);
#endif
}
void performFinalization()
{
#ifndef NDEBUG
ASSERT(!m_completed);
m_completed = true;
#endif
ExecutableAllocator::makeExecutable(code(), m_size);
ExecutableAllocator::cacheFlush(code(), m_size);
}
RefPtr<ExecutablePool> m_executablePool;
size_t m_size;
void* m_code;
MacroAssembler* m_assembler;
#ifndef NDEBUG
bool m_completed;
#endif
};
}
#endif // ENABLE(ASSEMBLER)
#endif // LinkBuffer_h