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1//===-- ABISysV_arc.cpp ---------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "ABISysV_arc.h"10 11// C Includes12// C++ Includes13#include <array>14#include <limits>15#include <type_traits>16 17// Other libraries and framework includes18#include "llvm/IR/DerivedTypes.h"19#include "llvm/Support/MathExtras.h"20#include "llvm/TargetParser/Triple.h"21 22#include "lldb/Core/Module.h"23#include "lldb/Core/PluginManager.h"24#include "lldb/Core/Value.h"25#include "lldb/Symbol/UnwindPlan.h"26#include "lldb/Target/Process.h"27#include "lldb/Target/RegisterContext.h"28#include "lldb/Target/StackFrame.h"29#include "lldb/Target/Target.h"30#include "lldb/Target/Thread.h"31#include "lldb/Utility/ConstString.h"32#include "lldb/Utility/RegisterValue.h"33#include "lldb/Utility/Status.h"34#include "lldb/ValueObject/ValueObjectConstResult.h"35#include "lldb/ValueObject/ValueObjectMemory.h"36#include "lldb/ValueObject/ValueObjectRegister.h"37 38#define DEFINE_REG_NAME(reg_num)      ConstString(#reg_num).GetCString()39#define DEFINE_REG_NAME_STR(reg_name) ConstString(reg_name).GetCString()40 41// The ABI is not a source of such information as size, offset, encoding, etc.42// of a register. Just provides correct dwarf and eh_frame numbers.43 44#define DEFINE_GENERIC_REGISTER_STUB(dwarf_num, str_name, generic_num)        \45  {                                                                           \46    DEFINE_REG_NAME(dwarf_num), DEFINE_REG_NAME_STR(str_name),                \47    0, 0, eEncodingInvalid, eFormatDefault,                                   \48    { dwarf_num, dwarf_num, generic_num, LLDB_INVALID_REGNUM, dwarf_num },    \49    nullptr, nullptr, nullptr,                                                \50  }51 52#define DEFINE_REGISTER_STUB(dwarf_num, str_name) \53  DEFINE_GENERIC_REGISTER_STUB(dwarf_num, str_name, LLDB_INVALID_REGNUM)54 55using namespace lldb;56using namespace lldb_private;57 58LLDB_PLUGIN_DEFINE_ADV(ABISysV_arc, ABIARC)59 60namespace {61namespace dwarf {62enum regnums {63  r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16,64  r17, r18, r19, r20, r21, r22, r23, r24, r25, r26,65  r27, fp = r27, r28, sp = r28, r29, r30, r31, blink = r31,66  r32, r33, r34, r35, r36, r37, r38, r39, r40, r41, r42, r43, r44, r45, r46,67  r47, r48, r49, r50, r51, r52, r53, r54, r55, r56, r57, r58, r59, r60,68  /*reserved,*/ /*limm indicator,*/ r63 = 63, pc = 70, status32 = 7469};70 71static const std::array<RegisterInfo, 64> g_register_infos = { {72    DEFINE_GENERIC_REGISTER_STUB(r0, nullptr, LLDB_REGNUM_GENERIC_ARG1),73    DEFINE_GENERIC_REGISTER_STUB(r1, nullptr, LLDB_REGNUM_GENERIC_ARG2),74    DEFINE_GENERIC_REGISTER_STUB(r2, nullptr, LLDB_REGNUM_GENERIC_ARG3),75    DEFINE_GENERIC_REGISTER_STUB(r3, nullptr, LLDB_REGNUM_GENERIC_ARG4),76    DEFINE_GENERIC_REGISTER_STUB(r4, nullptr, LLDB_REGNUM_GENERIC_ARG5),77    DEFINE_GENERIC_REGISTER_STUB(r5, nullptr, LLDB_REGNUM_GENERIC_ARG6),78    DEFINE_GENERIC_REGISTER_STUB(r6, nullptr, LLDB_REGNUM_GENERIC_ARG7),79    DEFINE_GENERIC_REGISTER_STUB(r7, nullptr, LLDB_REGNUM_GENERIC_ARG8),80    DEFINE_REGISTER_STUB(r8, nullptr),81    DEFINE_REGISTER_STUB(r9, nullptr),82    DEFINE_REGISTER_STUB(r10, nullptr),83    DEFINE_REGISTER_STUB(r11, nullptr),84    DEFINE_REGISTER_STUB(r12, nullptr),85    DEFINE_REGISTER_STUB(r13, nullptr),86    DEFINE_REGISTER_STUB(r14, nullptr),87    DEFINE_REGISTER_STUB(r15, nullptr),88    DEFINE_REGISTER_STUB(r16, nullptr),89    DEFINE_REGISTER_STUB(r17, nullptr),90    DEFINE_REGISTER_STUB(r18, nullptr),91    DEFINE_REGISTER_STUB(r19, nullptr),92    DEFINE_REGISTER_STUB(r20, nullptr),93    DEFINE_REGISTER_STUB(r21, nullptr),94    DEFINE_REGISTER_STUB(r22, nullptr),95    DEFINE_REGISTER_STUB(r23, nullptr),96    DEFINE_REGISTER_STUB(r24, nullptr),97    DEFINE_REGISTER_STUB(r25, nullptr),98    DEFINE_REGISTER_STUB(r26, "gp"),99    DEFINE_GENERIC_REGISTER_STUB(r27, "fp", LLDB_REGNUM_GENERIC_FP),100    DEFINE_GENERIC_REGISTER_STUB(r28, "sp", LLDB_REGNUM_GENERIC_SP),101    DEFINE_REGISTER_STUB(r29, "ilink"),102    DEFINE_REGISTER_STUB(r30, nullptr),103    DEFINE_GENERIC_REGISTER_STUB(r31, "blink", LLDB_REGNUM_GENERIC_RA),104    DEFINE_REGISTER_STUB(r32, nullptr),105    DEFINE_REGISTER_STUB(r33, nullptr),106    DEFINE_REGISTER_STUB(r34, nullptr),107    DEFINE_REGISTER_STUB(r35, nullptr),108    DEFINE_REGISTER_STUB(r36, nullptr),109    DEFINE_REGISTER_STUB(r37, nullptr),110    DEFINE_REGISTER_STUB(r38, nullptr),111    DEFINE_REGISTER_STUB(r39, nullptr),112    DEFINE_REGISTER_STUB(r40, nullptr),113    DEFINE_REGISTER_STUB(r41, nullptr),114    DEFINE_REGISTER_STUB(r42, nullptr),115    DEFINE_REGISTER_STUB(r43, nullptr),116    DEFINE_REGISTER_STUB(r44, nullptr),117    DEFINE_REGISTER_STUB(r45, nullptr),118    DEFINE_REGISTER_STUB(r46, nullptr),119    DEFINE_REGISTER_STUB(r47, nullptr),120    DEFINE_REGISTER_STUB(r48, nullptr),121    DEFINE_REGISTER_STUB(r49, nullptr),122    DEFINE_REGISTER_STUB(r50, nullptr),123    DEFINE_REGISTER_STUB(r51, nullptr),124    DEFINE_REGISTER_STUB(r52, nullptr),125    DEFINE_REGISTER_STUB(r53, nullptr),126    DEFINE_REGISTER_STUB(r54, nullptr),127    DEFINE_REGISTER_STUB(r55, nullptr),128    DEFINE_REGISTER_STUB(r56, nullptr),129    DEFINE_REGISTER_STUB(r57, nullptr),130    DEFINE_REGISTER_STUB(r58, "accl"),131    DEFINE_REGISTER_STUB(r59, "acch"),132    DEFINE_REGISTER_STUB(r60, "lp_count"),133    DEFINE_REGISTER_STUB(r63, "pcl"),134    DEFINE_GENERIC_REGISTER_STUB(pc, nullptr, LLDB_REGNUM_GENERIC_PC),135    DEFINE_GENERIC_REGISTER_STUB(status32, nullptr, LLDB_REGNUM_GENERIC_FLAGS)} };136} // namespace dwarf137} // namespace138 139const RegisterInfo *ABISysV_arc::GetRegisterInfoArray(uint32_t &count) {140  count = dwarf::g_register_infos.size();141  return dwarf::g_register_infos.data();142}143 144size_t ABISysV_arc::GetRedZoneSize() const { return 0; }145 146bool ABISysV_arc::IsRegisterFileReduced(RegisterContext &reg_ctx) const {147  if (!m_is_reg_file_reduced) {148    const auto *const rf_build_reg = reg_ctx.GetRegisterInfoByName("rf_build");149 150    const auto reg_value = reg_ctx.ReadRegisterAsUnsigned(rf_build_reg,151                                                          /*fail_value*/ 0);152    // RF_BUILD "Number of Entries" bit.153    const uint32_t rf_entries_bit = 1U << 9U;154    m_is_reg_file_reduced = (reg_value & rf_entries_bit) != 0;155  }156 157  return m_is_reg_file_reduced.value_or(false);158}159 160//------------------------------------------------------------------161// Static Functions162//------------------------------------------------------------------163 164ABISP ABISysV_arc::CreateInstance(ProcessSP process_sp, const ArchSpec &arch) {165  return llvm::Triple::arc == arch.GetTriple().getArch() ?166      ABISP(new ABISysV_arc(std::move(process_sp), MakeMCRegisterInfo(arch))) :167      ABISP();168}169 170static const size_t word_size = 4U;171static const size_t reg_size = word_size;172 173static inline size_t AugmentArgSize(size_t size_in_bytes) {174  return llvm::alignTo(size_in_bytes, word_size);175}176 177static size_t178TotalArgsSizeInWords(const llvm::ArrayRef<ABI::CallArgument> &args) {179  size_t total_size = 0;180  for (const auto &arg : args)181    total_size +=182        (ABI::CallArgument::TargetValue == arg.type ? AugmentArgSize(arg.size)183                                                    : reg_size) /184        word_size;185 186  return total_size;187}188 189bool ABISysV_arc::PrepareTrivialCall(Thread &thread, addr_t sp,190                                     addr_t func_addr, addr_t return_addr,191                                     llvm::ArrayRef<addr_t> args) const {192  // We don't use the traditional trivial call specialized for jit.193  return false;194}195 196bool ABISysV_arc::PrepareTrivialCall(Thread &thread, addr_t sp, addr_t pc,197    addr_t ra, llvm::Type &prototype,198    llvm::ArrayRef<ABI::CallArgument> args) const {199  auto reg_ctx = thread.GetRegisterContext();200  if (!reg_ctx)201    return false;202 203  uint32_t pc_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(204      eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);205  if (pc_reg == LLDB_INVALID_REGNUM)206    return false;207 208  uint32_t ra_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(209      eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA);210  if (ra_reg == LLDB_INVALID_REGNUM)211    return false;212 213  uint32_t sp_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(214      eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);215  if (sp_reg == LLDB_INVALID_REGNUM)216    return false;217 218  Status error;219  ProcessSP process = thread.GetProcess();220  if (!process)221    return false;222 223  // Push host data onto target.224  for (const auto &arg : args) {225    // Skip over target values.226    if (arg.type == ABI::CallArgument::TargetValue)227      continue;228 229    // Create space on the stack for this data 4-byte aligned.230    sp -= AugmentArgSize(arg.size);231 232    if (process->WriteMemory(sp, arg.data_up.get(), arg.size, error) < arg.size233        || error.Fail())234      return false;235 236    // Update the argument with the target pointer.237    *const_cast<addr_t *>(&arg.value) = sp;238  }239 240  // Make sure number of parameters matches prototype.241  assert(!prototype.isFunctionVarArg());242  assert(prototype.getFunctionNumParams() == args.size());243 244  const size_t regs_for_args_count = IsRegisterFileReduced(*reg_ctx) ? 4U : 8U;245 246  // Number of arguments passed on stack.247  auto args_size = TotalArgsSizeInWords(args);248  auto on_stack =249      args_size <= regs_for_args_count ? 0 : args_size - regs_for_args_count;250  auto offset = on_stack * word_size;251 252  uint8_t reg_value[reg_size];253  size_t reg_index = LLDB_REGNUM_GENERIC_ARG1;254 255  for (const auto &arg : args) {256    auto value = reinterpret_cast<const uint8_t *>(&arg.value);257    auto size =258        ABI::CallArgument::TargetValue == arg.type ? arg.size : reg_size;259 260    // Pass arguments via registers.261    while (size > 0 && reg_index < regs_for_args_count) {262      size_t byte_index = 0;263      auto end = size < reg_size ? size : reg_size;264 265      while (byte_index < end) {266        reg_value[byte_index++] = *(value++);267        --size;268      }269 270      while (byte_index < reg_size) {271        reg_value[byte_index++] = 0;272      }273 274      RegisterValue reg_val_obj(llvm::ArrayRef(reg_value, reg_size),275                                eByteOrderLittle);276      if (!reg_ctx->WriteRegister(277            reg_ctx->GetRegisterInfo(eRegisterKindGeneric, reg_index),278            reg_val_obj))279        return false;280 281      // NOTE: It's unsafe to iterate through LLDB_REGNUM_GENERICs.282      ++reg_index;283    }284 285    if (reg_index < regs_for_args_count || size == 0)286      continue;287 288    // Remaining arguments are passed on the stack.289    if (process->WriteMemory(sp - offset, value, size, error) < size ||290        !error.Success())291      return false;292 293    offset -= AugmentArgSize(size);294  }295 296  // Set stack pointer immediately below arguments.297  sp -= on_stack * word_size;298 299  // Update registers with current function call state.300  reg_ctx->WriteRegisterFromUnsigned(pc_reg, pc);301  reg_ctx->WriteRegisterFromUnsigned(ra_reg, ra);302  reg_ctx->WriteRegisterFromUnsigned(sp_reg, sp);303 304  return true;305}306 307bool ABISysV_arc::GetArgumentValues(Thread &thread, ValueList &values) const {308  return false;309}310 311Status ABISysV_arc::SetReturnValueObject(StackFrameSP &frame_sp,312                                         ValueObjectSP &new_value_sp) {313  Status result;314  if (!new_value_sp) {315    result = Status::FromErrorString("Empty value object for return value.");316    return result;317  }318 319  CompilerType compiler_type = new_value_sp->GetCompilerType();320  if (!compiler_type) {321    result = Status::FromErrorString("Null clang type for return value.");322    return result;323  }324 325  auto &reg_ctx = *frame_sp->GetThread()->GetRegisterContext();326 327  bool is_signed = false;328  if (!compiler_type.IsIntegerOrEnumerationType(is_signed) &&329      !compiler_type.IsPointerType()) {330    result = Status::FromErrorString(331        "We don't support returning other types at present");332    return result;333  }334 335  DataExtractor data;336  size_t num_bytes = new_value_sp->GetData(data, result);337 338  if (result.Fail()) {339    result = Status::FromErrorStringWithFormat(340        "Couldn't convert return value to raw data: %s", result.AsCString());341    return result;342  }343 344  if (num_bytes <= 2 * reg_size) {345    offset_t offset = 0;346    uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);347 348    auto reg_info =349        reg_ctx.GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);350    if (!reg_ctx.WriteRegisterFromUnsigned(reg_info, raw_value)) {351      result = Status::FromErrorStringWithFormat(352          "Couldn't write value to register %s", reg_info->name);353      return result;354    }355 356    if (num_bytes <= reg_size)357      return result; // Successfully written.358 359    raw_value >>= 32;360    reg_info =361        reg_ctx.GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);362    if (!reg_ctx.WriteRegisterFromUnsigned(reg_info, raw_value)) {363      result = Status::FromErrorStringWithFormat(364          "Couldn't write value to register %s", reg_info->name);365    }366 367    return result;368  }369 370  result = Status::FromErrorString(371      "We don't support returning large integer values at present.");372  return result;373}374 375template <typename T>376static void SetInteger(Scalar &scalar, uint64_t raw_value, bool is_signed) {377  raw_value &= std::numeric_limits<T>::max();378  if (is_signed)379    scalar = static_cast<typename std::make_signed<T>::type>(raw_value);380  else381    scalar = static_cast<T>(raw_value);382}383 384static bool SetSizedInteger(Scalar &scalar, uint64_t raw_value,385                            uint8_t size_in_bytes, bool is_signed) {386  switch (size_in_bytes) {387  default:388    return false;389 390  case sizeof(uint64_t):391    SetInteger<uint64_t>(scalar, raw_value, is_signed);392    break;393 394  case sizeof(uint32_t):395    SetInteger<uint32_t>(scalar, raw_value, is_signed);396    break;397 398  case sizeof(uint16_t):399    SetInteger<uint16_t>(scalar, raw_value, is_signed);400    break;401 402  case sizeof(uint8_t):403    SetInteger<uint8_t>(scalar, raw_value, is_signed);404    break;405  }406 407  return true;408}409 410static bool SetSizedFloat(Scalar &scalar, uint64_t raw_value,411                          uint8_t size_in_bytes) {412  switch (size_in_bytes) {413  default:414    return false;415 416  case sizeof(uint64_t):417    scalar = *reinterpret_cast<double *>(&raw_value);418    break;419 420  case sizeof(uint32_t):421    scalar = *reinterpret_cast<float *>(&raw_value);422    break;423  }424 425  return true;426}427 428static uint64_t ReadRawValue(const RegisterContextSP &reg_ctx,429                             uint8_t size_in_bytes) {430  auto reg_info_r0 =431      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);432 433  // Extract the register context so we can read arguments from registers.434  uint64_t raw_value =435      reg_ctx->ReadRegisterAsUnsigned(reg_info_r0, 0) & UINT32_MAX;436 437  if (sizeof(uint64_t) == size_in_bytes)438    raw_value |= (reg_ctx->ReadRegisterAsUnsigned(439                      reg_ctx->GetRegisterInfo(eRegisterKindGeneric,440                                               LLDB_REGNUM_GENERIC_ARG2), 0) &441                  UINT64_MAX) << 32U;442 443  return raw_value;444}445 446ValueObjectSP447ABISysV_arc::GetReturnValueObjectSimple(Thread &thread,448                                        CompilerType &compiler_type) const {449  if (!compiler_type)450    return ValueObjectSP();451 452  auto reg_ctx = thread.GetRegisterContext();453  if (!reg_ctx)454    return ValueObjectSP();455 456  Value value;457  value.SetCompilerType(compiler_type);458 459  const uint32_t type_flags = compiler_type.GetTypeInfo();460  // Integer return type.461  if (type_flags & eTypeIsInteger) {462    const size_t byte_size =463        llvm::expectedToOptional(compiler_type.GetByteSize(&thread))464            .value_or(0);465    auto raw_value = ReadRawValue(reg_ctx, byte_size);466 467    const bool is_signed = (type_flags & eTypeIsSigned) != 0;468    if (!SetSizedInteger(value.GetScalar(), raw_value, byte_size, is_signed))469      return ValueObjectSP();470 471    value.SetValueType(Value::ValueType::Scalar);472  }473  // Pointer return type.474  else if (type_flags & eTypeIsPointer) {475    auto reg_info_r0 = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,476                                                LLDB_REGNUM_GENERIC_ARG1);477    value.GetScalar() = reg_ctx->ReadRegisterAsUnsigned(reg_info_r0, 0);478 479    value.SetValueType(Value::ValueType::Scalar);480  }481  // Floating point return type.482  else if (type_flags & eTypeIsFloat) {483    bool is_complex = false;484 485    if (compiler_type.IsFloatingPointType(is_complex) &&486        !compiler_type.IsVectorType() && !is_complex) {487      const size_t byte_size =488          llvm::expectedToOptional(compiler_type.GetByteSize(&thread))489              .value_or(0);490      auto raw_value = ReadRawValue(reg_ctx, byte_size);491 492      if (!SetSizedFloat(value.GetScalar(), raw_value, byte_size))493        return ValueObjectSP();494    }495  }496  // Unsupported return type.497  else498    return ValueObjectSP();499 500  return ValueObjectConstResult::Create(thread.GetStackFrameAtIndex(0).get(),501                                        value, ConstString(""));502}503 504ValueObjectSP ABISysV_arc::GetReturnValueObjectImpl(505    Thread &thread, CompilerType &return_compiler_type) const {506  ValueObjectSP return_valobj_sp;507 508  if (!return_compiler_type)509    return return_valobj_sp;510 511  ExecutionContext exe_ctx(thread.shared_from_this());512  return GetReturnValueObjectSimple(thread, return_compiler_type);513}514 515ValueObjectSP ABISysV_arc::GetReturnValueObjectImpl(Thread &thread,516                                                    llvm::Type &retType) const {517  auto reg_ctx = thread.GetRegisterContext();518  if (!reg_ctx)519    return ValueObjectSP();520 521  Value value;522  // Void return type.523  if (retType.isVoidTy()) {524    value.GetScalar() = 0;525  }526  // Integer return type.527  else if (retType.isIntegerTy()) {528    size_t byte_size = retType.getPrimitiveSizeInBits();529    if (1 != byte_size) // For boolean type.530      byte_size /= CHAR_BIT;531 532    auto raw_value = ReadRawValue(reg_ctx, byte_size);533 534    const bool is_signed = false; // IR Type doesn't provide this info.535    if (!SetSizedInteger(value.GetScalar(), raw_value, byte_size, is_signed))536      return ValueObjectSP();537  }538  // Pointer return type.539  else if (retType.isPointerTy()) {540    auto reg_info_r0 = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,541                                                LLDB_REGNUM_GENERIC_ARG1);542    value.GetScalar() = reg_ctx->ReadRegisterAsUnsigned(reg_info_r0, 0);543    value.SetValueType(Value::ValueType::Scalar);544  }545  // Floating point return type.546  else if (retType.isFloatingPointTy()) {547    const size_t byte_size = retType.getPrimitiveSizeInBits() / CHAR_BIT;548    auto raw_value = ReadRawValue(reg_ctx, byte_size);549 550    if (!SetSizedFloat(value.GetScalar(), raw_value, byte_size))551      return ValueObjectSP();552  }553  // Unsupported return type.554  else555    return ValueObjectSP();556 557  return ValueObjectConstResult::Create(thread.GetStackFrameAtIndex(0).get(),558                                        value, ConstString(""));559}560 561UnwindPlanSP ABISysV_arc::CreateFunctionEntryUnwindPlan() {562  UnwindPlan::Row row;563 564  // Our Call Frame Address is the stack pointer value.565  row.GetCFAValue().SetIsRegisterPlusOffset(dwarf::sp, 0);566 567  // The previous PC is in the BLINK, all other registers are the same.568  row.SetRegisterLocationToRegister(dwarf::pc, dwarf::blink, true);569 570  auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);571  plan_sp->AppendRow(std::move(row));572  plan_sp->SetSourceName("arc at-func-entry default");573  plan_sp->SetSourcedFromCompiler(eLazyBoolNo);574  return plan_sp;575}576 577UnwindPlanSP ABISysV_arc::CreateDefaultUnwindPlan() { return nullptr; }578 579bool ABISysV_arc::RegisterIsVolatile(const RegisterInfo *reg_info) {580  if (nullptr == reg_info)581    return false;582 583  // Volatile registers are: r0..r12.584  uint32_t regnum = reg_info->kinds[eRegisterKindDWARF];585  if (regnum <= 12)586    return true;587 588  static const std::string ra_reg_name = "blink";589  return ra_reg_name == reg_info->name;590}591 592void ABISysV_arc::Initialize() {593  PluginManager::RegisterPlugin(GetPluginNameStatic(),594                                "System V ABI for ARC targets", CreateInstance);595}596 597void ABISysV_arc::Terminate() {598  PluginManager::UnregisterPlugin(CreateInstance);599}600