{

performFinalization();

ASSERT(m_didAllocate);

CodeRef<LinkBufferPtrTag> codeRef(m_executableMemory ? CodeRef<LinkBufferPtrTag>(*m_executableMemory) : CodeRef<LinkBufferPtrTag>::createSelfManagedCodeRef(m_code));

logJITCodeForJITDump(codeRef, simpleName);

return codeRef;

{

if (!Options::useJITDump() && !Options::useGdbJITInfo()) [[likely]]

return;

if (m_isRewriting)

return;

auto dumpSimpleName = [&](StringPrintStream& out, ASCIILiteral simpleName) {

if (simpleName.isNull())

out.print("unspecified");

else

out.print(simpleName);

};

StringPrintStream out;

out.print("JSC-", profileName(m_profile), ": ");

switch (m_profile) {

case Profile::Baseline:

case Profile::DFG:

case Profile::FTL: {

if (m_ownerUID)

static_cast<CodeBlock*>(m_ownerUID)->dumpSimpleName(out);

else

dumpSimpleName(out, simpleName);

break;

}

#if ENABLE(WEBASSEMBLY)

case Profile::WasmOMG:

case Profile::WasmBBQ: {

if (m_ownerUID)

uncheckedDowncast<Wasm::Callee>(reinterpret_cast<NativeCallee*>(m_ownerUID))->dumpSimpleName(out);

else

dumpSimpleName(out, simpleName);

break;

}

#endif

#if ENABLE(YARR_JIT)

case Profile::YarrJIT: {

if (m_ownerUID)

static_cast<Yarr::YarrCodeBlock*>(m_ownerUID)->dumpSimpleName(out);

else

dumpSimpleName(out, simpleName);

break;

}

#endif

default:

dumpSimpleName(out, simpleName);

break;

}

auto finalName = out.toCString();

if (Options::useGdbJITInfo()) [[unlikely]]

GdbJIT::log(finalName, codeRef);

if (Options::useJITDump()) [[unlikely]]

PerfLog::log(finalName, codeRef, WTF::move(m_irDumpDebugInfo), WTF::move(m_sourceCodeDebugInfo));

{

CodeRef<LinkBufferPtrTag> result = finalizeCodeWithoutDisassemblyImpl(simpleName);

if (!dumpDisassembly && !Options::logJIT())

return result;

bool justDumpingHeader = !dumpDisassembly || m_alreadyDisassembled;

ScopedPrintStream out;

out.printf("Generated JIT code for ");

va_list argList;

va_start(argList, format);

if (m_isThunk) {

va_list preflightArgs;

va_copy(preflightArgs, argList);

size_t stringLength = vsnprintf(nullptr, 0, format, preflightArgs);

va_end(preflightArgs);

constexpr auto prefix = "thunk: "_s;

std::span<char> buffer;

size_t length = stringLength + prefix.length() + 1;

CString label = CString::newUninitialized(length, buffer);

memcpySpan(buffer, prefix.span8());

vsnprintf(buffer.subspan(prefix.length()).data(), stringLength + 1, format, argList);

out.printf("%s", buffer.data());

registerLabel(result.code().untaggedPtr(), WTF::move(label));

} else

out.vprintf(format, argList);

va_end(argList);

uint8_t* executableAddress = result.code().untaggedPtr<uint8_t*>();

out.printf(": [%p, %p) %zu bytes%s\n", executableAddress, executableAddress + result.size(), result.size(), justDumpingHeader ? "." : ":");

if (justDumpingHeader) {

if (!Options::logJIT())

out.reset();

return result;

}

void* codeStart = entrypoint<DisassemblyPtrTag>().untaggedPtr();

void* codeEnd = std::bit_cast<uint8_t*>(codeStart) + size();

disassemble(result.retaggedCode<DisassemblyPtrTag>(), m_size, codeStart, codeEnd, " ", out);

return result;

WTF_MAKE_NONCOPYABLE(BranchCompactionLinkBuffer);

BranchCompactionLinkBuffer()

{

}

BranchCompactionLinkBuffer(size_t size, uint8_t* userBuffer = nullptr)

{

if (userBuffer) {

m_data = userBuffer;

m_size = size;

m_bufferProvided = true;

return;

}

auto& threadSpecific = threadSpecificBranchCompactionLinkBuffer();

if (threadSpecific->size() >= size)

takeBufferIfLarger(*threadSpecific);

else {

m_size = size;

m_data = static_cast<uint8_t*>(BranchCompactionLinkBufferMalloc::malloc(size));

}

}

~BranchCompactionLinkBuffer()

{

if (m_bufferProvided)

return;

auto& threadSpecific = threadSpecificBranchCompactionLinkBuffer();

threadSpecific->takeBufferIfLarger(*this);

if (m_data)

BranchCompactionLinkBufferMalloc::free(m_data);

}

uint8_t* NODELETE data()

{

return m_data;

}

void takeBufferIfLarger(BranchCompactionLinkBuffer& other)

{

if (size() >= other.size())

return;

if (m_data)

BranchCompactionLinkBufferMalloc::free(m_data);

m_data = other.m_data;

m_size = other.m_size;

other.m_data = nullptr;

other.m_size = 0;

}

size_t size()

{

return m_size;

}

uint8_t* m_data { nullptr };

size_t m_size { 0 };

bool m_bufferProvided { false };

{

#if OS(DARWIN)

memset_pattern4(std::bit_cast<uint8_t*>(assemblerData.buffer()) + regionStart, &offset, regionEnd - regionStart);

#else

int32_t ptr = regionStart / sizeof(int32_t);

const int32_t end = regionEnd / sizeof(int32_t);

int32_t* offsets = reinterpret_cast_ptr<int32_t*>(assemblerData.buffer());

while (ptr < end)

offsets[ptr++] = offset;

#endif

{

allocate(macroAssembler, effort);

const size_t initialSize = macroAssembler.m_assembler.codeSize();

if (didFailToAllocate())

return;

auto& jumpsToLink = macroAssembler.jumpsToLink();

m_assemblerStorage = macroAssembler.m_assembler.buffer().releaseAssemblerData();

uint8_t* inData = std::bit_cast<uint8_t*>(m_assemblerStorage.buffer());

#if ENABLE(JIT_SIGN_ASSEMBLER_BUFFER)

ARM64EHash<ShouldSign::No> verifyUncompactedHash;

m_assemblerHashesStorage = macroAssembler.m_assembler.buffer().releaseAssemblerHashes();

uint32_t* inHashes = std::bit_cast<uint32_t*>(m_assemblerHashesStorage.buffer());

#endif

uint8_t* codeOutData = m_code.dataLocation<uint8_t*>();

#define shouldCopyDirectlyToJITRegion (!m_shouldPerformBranchCompaction || g_jscConfig.useFastJITPermissions)

BranchCompactionLinkBuffer outBuffer(m_size, shouldCopyDirectlyToJITRegion ? codeOutData : 0);

uint8_t* outData = outBuffer.data();

#if CPU(ARM64)

RELEASE_ASSERT(roundUpToMultipleOf<sizeof(unsigned)>(outData) == outData);

RELEASE_ASSERT(roundUpToMultipleOf<sizeof(unsigned)>(codeOutData) == codeOutData);

#endif

int readPtr = 0;

int writePtr = 0;

unsigned jumpCount = jumpsToLink.size();

auto read = [&](const InstructionType* ptr) -> InstructionType {

InstructionType value = *ptr;

#if ENABLE(JIT_SIGN_ASSEMBLER_BUFFER)

unsigned index = (std::bit_cast<uint8_t*>(ptr) - inData) / 4;

uint32_t hash = verifyUncompactedHash.update(value, index);

RELEASE_ASSERT(inHashes[index] == hash);

#endif

return value;

};

if (g_jscConfig.useFastJITPermissions)

threadSelfRestrict<MemoryRestriction::kRwxToRw>();

#if ENABLE(MPROTECT_RX_TO_RWX)

ExecutableAllocator::singleton().startWriting(outData, initialSize);

#endif

if (m_shouldPerformBranchCompaction) {

for (unsigned i = 0; i < jumpCount; ++i) {

auto& linkRecord = jumpsToLink[i];

int offset = readPtr - writePtr;

ASSERT(!(offset & 1));

// Copy the instructions from the last jump to the current one.

size_t regionSize = linkRecord.from() - readPtr;

InstructionType* copySource = reinterpret_cast_ptr<InstructionType*>(inData + readPtr);

InstructionType* copyEnd = reinterpret_cast_ptr<InstructionType*>(inData + readPtr + regionSize);

InstructionType* copyDst = reinterpret_cast_ptr<InstructionType*>(outData + writePtr);

ASSERT(!(regionSize % 2));

ASSERT(!(readPtr % 2));

ASSERT(!(writePtr % 2));

while (copySource != copyEnd) {

InstructionType insn = read(copySource++);

*copyDst++ = insn;

}

recordLinkOffsets(m_assemblerStorage, readPtr, linkRecord.from(), offset);

readPtr += regionSize;

writePtr += regionSize;

// Calculate absolute address of the jump target, in the case of backwards

// branches we need to be precise, forward branches we are pessimistic

const uint8_t* target;

const intptr_t to = linkRecord.to(&macroAssembler.m_assembler);

if (linkRecord.isThunk())

target = std::bit_cast<uint8_t*>(to);

else if (to >= linkRecord.from())

target = codeOutData + to - offset; // Compensate for what we have collapsed so far

else

target = codeOutData + to - executableOffsetFor(to);

JumpLinkType jumpLinkType = MacroAssembler::computeJumpType(linkRecord, codeOutData + writePtr, target);

// Compact branch if we can...

if (MacroAssembler::canCompact(linkRecord.type())) {

// Step back in the write stream

int32_t delta = MacroAssembler::jumpSizeDelta(linkRecord.type(), jumpLinkType);

if (delta) {

writePtr -= delta;

recordLinkOffsets(m_assemblerStorage, linkRecord.from() - delta, readPtr, readPtr - writePtr);

}

}

linkRecord.setFrom(&macroAssembler.m_assembler, writePtr);

}

} else {

if (ASSERT_ENABLED) {

for (unsigned i = 0; i < jumpCount; ++i)

ASSERT(!MacroAssembler::canCompact(jumpsToLink[i].type()));

}

}

// Copy everything after the last jump

{

InstructionType* dst = std::bit_cast<InstructionType*>(outData + writePtr);

InstructionType* src = std::bit_cast<InstructionType*>(inData + readPtr);

size_t bytes = initialSize - readPtr;

RELEASE_ASSERT(!(std::bit_cast<uintptr_t>(dst) % sizeof(InstructionType)));

RELEASE_ASSERT(!(std::bit_cast<uintptr_t>(src) % sizeof(InstructionType)));

RELEASE_ASSERT(!(bytes % sizeof(InstructionType)));

for (size_t i = 0; i < bytes; i += sizeof(InstructionType)) {

InstructionType insn = read(src++);

*dst++ = insn;

}

}

recordLinkOffsets(m_assemblerStorage, readPtr, initialSize, readPtr - writePtr);

for (unsigned i = 0; i < jumpCount; ++i) {

auto& linkRecord = jumpsToLink[i];

uint8_t* location = codeOutData + linkRecord.from();

const intptr_t to = linkRecord.to(&macroAssembler.m_assembler);

uint8_t* target = nullptr;

if (linkRecord.isThunk())

target = std::bit_cast<uint8_t*>(to);

else

target = codeOutData + to - executableOffsetFor(to);

if (shouldCopyDirectlyToJITRegion)

MacroAssembler::link<memcpyRepatch>(linkRecord, outData + linkRecord.from(), location, target);

else

MacroAssembler::link<jitMemcpyRepatch>(linkRecord, outData + linkRecord.from(), location, target);

}

size_t compactSize = writePtr + initialSize - readPtr;

if (!m_executableMemory) {

size_t nopSizeInBytes = initialSize - compactSize;

if (shouldCopyDirectlyToJITRegion)

Assembler::fillNops<memcpyRepatch>(outData + compactSize, nopSizeInBytes);

else

Assembler::fillNops<jitMemcpyRepatch>(outData + compactSize, nopSizeInBytes);

}

if (g_jscConfig.useFastJITPermissions)

threadSelfRestrict<MemoryRestriction::kRwxToRx>();

if (m_executableMemory) {

m_size = compactSize;

m_executableMemory->shrink(m_size);

}

#undef shouldCopyDirectlyToJITRegion

#if ENABLE(JIT)

if (g_jscConfig.useFastJITPermissions) {

ASSERT(codeOutData == outData);

if (Options::dumpJITMemoryPath()) [[unlikely]]

dumpJITMemory(outData, outData, m_size);

} else {

ASSERT(codeOutData != outData);

performJITMemcpy<jitMemcpyRepatch>(codeOutData, outData, m_size);

}

#else

ASSERT(codeOutData != outData);

performJITMemcpy<jitMemcpyRepatch>(codeOutData, outData, m_size);

#endif

#if ENABLE(MPROTECT_RX_TO_RWX)

ExecutableAllocator::singleton().finishWriting(outData, initialSize);

#endif

jumpsToLink.clear();

#if DUMP_LINK_STATISTICS

dumpLinkStatistics(codeOutData, initialSize, m_size);

#endif

#if DUMP_CODE

dumpCode(codeOutData, m_size);

#endif

{

// Ensure that the end of the last invalidation point does not extend beyond the end of the buffer.

macroAssembler.label();

#if ENABLE(JIT)

#if !ENABLE(BRANCH_COMPACTION)

#if defined(ASSEMBLER_HAS_CONSTANT_POOL) && ASSEMBLER_HAS_CONSTANT_POOL

macroAssembler.m_assembler.buffer().flushConstantPool(false);

#endif

allocate(macroAssembler, effort);

if (!m_didAllocate)

return;

ASSERT(m_code);

AssemblerBuffer& buffer = macroAssembler.m_assembler.buffer();

void* code = m_code.dataLocation();

#if CPU(ARM64)

RELEASE_ASSERT(roundUpToMultipleOf<Assembler::instructionSize>(code) == code);

#endif

performJITMemcpy<jitMemcpyRepatch>(code, buffer.data(), buffer.codeSize());

#elif CPU(ARM_THUMB2)

copyCompactAndLinkCode<uint16_t>(macroAssembler, effort);

#elif CPU(ARM64)

copyCompactAndLinkCode<uint32_t>(macroAssembler, effort);

#endif // !ENABLE(BRANCH_COMPACTION)

#else // ENABLE(JIT)

UNUSED_PARAM(effort);

#endif // ENABLE(JIT)

m_linkTasks = WTF::move(macroAssembler.m_linkTasks);

m_lateLinkTasks = WTF::move(macroAssembler.m_lateLinkTasks);

linkComments(macroAssembler);

{

size_t initialSize = macroAssembler.m_assembler.codeSize();

if (m_code) {

if (initialSize > m_size)

return;

size_t nopsToFillInBytes = m_size - initialSize;

macroAssembler.emitNops(nopsToFillInBytes);

m_didAllocate = true;

return;

}

while (initialSize % jitAllocationGranule) {

macroAssembler.breakpoint();

initialSize = macroAssembler.m_assembler.codeSize();

}

#if ENABLE(JIT_SIGN_ASSEMBLER_BUFFER)

macroAssembler.m_assembler.buffer().arm64eHash().deallocatePinForCurrentThread();

#endif

m_executableMemory = ExecutableAllocator::singleton().allocate(initialSize, effort);

if (!m_executableMemory)

return;

m_code = CodePtr<LinkBufferPtrTag>(m_executableMemory->start().retaggedPtr<LinkBufferPtrTag>());

m_size = initialSize;

m_didAllocate = true;

{

if (!Options::needDisassemblySupport()) [[likely]]

return;

if (!m_executableMemory)

return;

AssemblyCommentRegistry::CommentMap map;

for (auto& comment : assembler.m_comments) {

void* commentLocation = locationOf<DisassemblyPtrTag>(comment.first).dataLocation();

auto key = reinterpret_cast<uintptr_t>(commentLocation);

auto& string = comment.second;

auto addResult = map.ensure(key, [&] {

return string.isolatedCopy();

});

if (!addResult.isNewEntry)

addResult.iterator->value = makeString(addResult.iterator->value, "\n; "_s, string);

}

AssemblyCommentRegistry::singleton().registerCodeRange(m_executableMemory->start().untaggedPtr(), m_executableMemory->end().untaggedPtr(), WTF::move(map));

{

#if ENABLE(MPROTECT_RX_TO_RWX)

ExecutableAllocator::singleton().startWriting(code(), m_size);

#endif

for (auto& task : m_linkTasks)

task->run(*this);

for (auto& task : m_lateLinkTasks)

task->run(*this);

#if ENABLE(MPROTECT_RX_TO_RWX)

ExecutableAllocator::singleton().finishWriting(code(), m_size);

#endif

#ifndef NDEBUG

ASSERT(!m_completed);

ASSERT(isValid());

m_completed = true;

#endif

s_profileCummulativeLinkedSizes[static_cast<unsigned>(m_profile)] += m_size;

s_profileCummulativeLinkedCounts[static_cast<unsigned>(m_profile)]++;

MacroAssembler::cacheFlush(code(), m_size);

{

static unsigned linkCount = 0;

static unsigned totalInitialSize = 0;

static unsigned totalFinalSize = 0;

linkCount++;

totalInitialSize += initialSize;

totalFinalSize += finalSize;

dataLogF("link %p: orig %u, compact %u (delta %u, %.2f%%)\n",

code, static_cast<unsigned>(initialSize), static_cast<unsigned>(finalSize),

static_cast<unsigned>(initialSize - finalSize),

100.0 * (initialSize - finalSize) / initialSize);

dataLogF("\ttotal %u: orig %u, compact %u (delta %u, %.2f%%)\n",

linkCount, totalInitialSize, totalFinalSize, totalInitialSize - totalFinalSize,

100.0 * (totalInitialSize - totalFinalSize) / totalInitialSize);

{

#if CPU(ARM_THUMB2)

// Dump the generated code in an asm file format that can be assembled and then disassembled

// for debugging purposes. For example, save this output as jit.s:

// gcc -arch armv7 -c jit.s

// otool -tv jit.o

static unsigned codeCount = 0;

unsigned short* tcode = static_cast<unsigned short*>(code);

size_t tsize = size / sizeof(short);

char nameBuf[128];

snprintf(nameBuf, sizeof(nameBuf), "_jsc_jit%u", codeCount++);

dataLogF("\t.syntax unified\n"

"\t.section\t__TEXT,__text,regular,pure_instructions\n"

"\t.globl\t%s\n"

"\t.align 2\n"

"\t.code 16\n"

"\t.thumb_func\t%s\n"

"# %p\n"

"%s:\n", nameBuf, nameBuf, code, nameBuf);

for (unsigned i = 0; i < tsize; i++)

dataLogF("\t.short\t0x%x\n", tcode[i]);

#endif

{

for (unsigned i = 0; i < numberOfProfiles; ++i) {

s_profileCummulativeLinkedSizes[i] = 0;

s_profileCummulativeLinkedCounts[i] = 0;

}

{

struct Stat {

Profile profile;

size_t size;

size_t count;

};

Stat sortedStats[numberOfProfiles];

PrintStream& out = outStream ? *outStream.value() : WTF::dataFile();

size_t totalOfAllProfilesSize = 0;

auto dumpStat = [&] (const Stat& stat) {

char formattedName[21];

snprintf(formattedName, 21, "%20s", profileName(stat.profile));

const char* largerUnit = nullptr;

double sizeInLargerUnit = stat.size;

if (stat.size > 1 * MB) {

largerUnit = "MB";

sizeInLargerUnit = sizeInLargerUnit / MB;

} else if (stat.size > 1 * KB) {

largerUnit = "KB";

sizeInLargerUnit = sizeInLargerUnit / KB;

}

if (largerUnit)

out.print(" ", formattedName, ": ", stat.size, " (", sizeInLargerUnit, " ", largerUnit, ")");

else

out.print(" ", formattedName, ": ", stat.size);

if (!stat.count)

out.println();

else

out.println(" count ", stat.count, " avg size ", (stat.size / stat.count));

};

for (unsigned i = 0; i < numberOfProfiles; ++i) {

sortedStats[i].profile = static_cast<Profile>(i);

sortedStats[i].size = s_profileCummulativeLinkedSizes[i];

sortedStats[i].count = s_profileCummulativeLinkedCounts[i];

totalOfAllProfilesSize += s_profileCummulativeLinkedSizes[i];

}

sortedStats[static_cast<unsigned>(Profile::Total)].size = totalOfAllProfilesSize;

std::sort(&sortedStats[0], &sortedStats[numberOfProfilesExcludingTotal],

[] (Stat& a, Stat& b) -> bool {

return a.size > b.size;

});

out.println("Cummulative LinkBuffer profile sizes:");

for (unsigned i = 0; i < numberOfProfiles; ++i)

dumpStat(sortedStats[i]);