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1//===-- ABISysV_arm64.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_arm64.h"10 11#include <optional>12#include <vector>13 14#include "llvm/ADT/STLExtras.h"15#include "llvm/TargetParser/Triple.h"16 17#include "lldb/Core/Module.h"18#include "lldb/Core/PluginManager.h"19#include "lldb/Core/Value.h"20#include "lldb/Symbol/UnwindPlan.h"21#include "lldb/Target/Process.h"22#include "lldb/Target/RegisterContext.h"23#include "lldb/Target/Target.h"24#include "lldb/Target/Thread.h"25#include "lldb/Utility/ConstString.h"26#include "lldb/Utility/LLDBLog.h"27#include "lldb/Utility/Log.h"28#include "lldb/Utility/RegisterValue.h"29#include "lldb/Utility/Scalar.h"30#include "lldb/Utility/Status.h"31#include "lldb/ValueObject/ValueObjectConstResult.h"32 33using namespace lldb;34using namespace lldb_private;35 36bool ABISysV_arm64::GetPointerReturnRegister(const char *&name) {37  name = "x0";38  return true;39}40 41size_t ABISysV_arm64::GetRedZoneSize() const { return 128; }42 43// Static Functions44 45ABISP46ABISysV_arm64::CreateInstance(lldb::ProcessSP process_sp, const ArchSpec &arch) {47  const llvm::Triple::ArchType arch_type = arch.GetTriple().getArch();48  const llvm::Triple::VendorType vendor_type = arch.GetTriple().getVendor();49 50  if (vendor_type != llvm::Triple::Apple) {51    if (arch_type == llvm::Triple::aarch64 ||52        arch_type == llvm::Triple::aarch64_32) {53      return ABISP(54          new ABISysV_arm64(std::move(process_sp), MakeMCRegisterInfo(arch)));55    }56  }57 58  return ABISP();59}60 61static Status PushToLinuxGuardedControlStack(addr_t return_addr,62                                             RegisterContext *reg_ctx,63                                             Thread &thread) {64  Status err;65 66  // If the Guarded Control Stack extension is present we may need to put the67  // return address onto that stack.68  const RegisterInfo *gcs_features_enabled_info =69      reg_ctx->GetRegisterInfoByName("gcs_features_enabled");70  if (!gcs_features_enabled_info)71    return err;72 73  uint64_t gcs_features_enabled = reg_ctx->ReadRegisterAsUnsigned(74      gcs_features_enabled_info, LLDB_INVALID_ADDRESS);75  if (gcs_features_enabled == LLDB_INVALID_ADDRESS)76    return Status("Could not read GCS features enabled register.");77 78  // Only attempt this if GCS is enabled. If it's not enabled then gcspr_el079  // may point to unmapped memory.80  if ((gcs_features_enabled & 1) == 0)81    return err;82 83  const RegisterInfo *gcspr_el0_info =84      reg_ctx->GetRegisterInfoByName("gcspr_el0");85  if (!gcspr_el0_info)86    return Status("Could not get register info for gcspr_el0.");87 88  uint64_t gcspr_el0 =89      reg_ctx->ReadRegisterAsUnsigned(gcspr_el0_info, LLDB_INVALID_ADDRESS);90  if (gcspr_el0 == LLDB_INVALID_ADDRESS)91    return Status("Could not read gcspr_el0.");92 93  // A link register entry on the GCS is 8 bytes.94  gcspr_el0 -= 8;95  if (!reg_ctx->WriteRegisterFromUnsigned(gcspr_el0_info, gcspr_el0))96    return Status(97        "Attempted to decrement gcspr_el0, but could not write to it.");98 99  Status error;100  size_t wrote = thread.GetProcess()->WriteMemory(gcspr_el0, &return_addr,101                                                  sizeof(return_addr), error);102  if ((wrote != sizeof(return_addr) || error.Fail())) {103    // gcspr_el0 will be restored by the ThreadPlan's DoTakedown.104    return Status("Failed to write new Guarded Control Stack entry.");105  }106 107  Log *log = GetLog(LLDBLog::Expressions);108  LLDB_LOGF(log,109            "Pushed return address 0x%" PRIx64 " to Guarded Control Stack. "110            "gcspr_el0 was 0%" PRIx64 ", is now 0x%" PRIx64 ".",111            return_addr, gcspr_el0 - 8, gcspr_el0);112 113  // gcspr_el0 will be restored to the original value by lldb-server after114  // the call has finished, which serves as the "pop".115 116  return err;117}118 119bool ABISysV_arm64::PrepareTrivialCall(Thread &thread, addr_t sp,120                                       addr_t func_addr, addr_t return_addr,121                                       llvm::ArrayRef<addr_t> args) const {122  RegisterContext *reg_ctx = thread.GetRegisterContext().get();123  if (!reg_ctx)124    return false;125 126  Log *log = GetLog(LLDBLog::Expressions);127 128  if (log) {129    StreamString s;130    s.Printf("ABISysV_arm64::PrepareTrivialCall (tid = 0x%" PRIx64131             ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64132             ", return_addr = 0x%" PRIx64,133             thread.GetID(), (uint64_t)sp, (uint64_t)func_addr,134             (uint64_t)return_addr);135 136    for (size_t i = 0; i < args.size(); ++i)137      s.Printf(", arg%d = 0x%" PRIx64, static_cast<int>(i + 1), args[i]);138    s.PutCString(")");139    log->PutString(s.GetString());140  }141 142  // x0 - x7 contain first 8 simple args143  if (args.size() > 8)144    return false;145 146  if (GetProcessSP()->GetTarget().GetArchitecture().GetTriple().isOSLinux()) {147    Status err = PushToLinuxGuardedControlStack(return_addr, reg_ctx, thread);148    // If we could not manage the GCS, the expression will certainly fail,149    // and if we just carried on, that failure would be a lot more cryptic.150    if (err.Fail()) {151      LLDB_LOGF(log, "Failed to setup Guarded Call Stack: %s", err.AsCString());152      return false;153    }154  }155 156  for (size_t i = 0; i < args.size(); ++i) {157    const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(158        eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + i);159    LLDB_LOGF(log, "About to write arg%d (0x%" PRIx64 ") into %s",160              static_cast<int>(i + 1), args[i], reg_info->name);161    if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))162      return false;163  }164 165  // Set "lr" to the return address166  if (!reg_ctx->WriteRegisterFromUnsigned(167          reg_ctx->GetRegisterInfo(eRegisterKindGeneric,168                                   LLDB_REGNUM_GENERIC_RA),169          return_addr))170    return false;171 172  // Set "sp" to the requested value173  if (!reg_ctx->WriteRegisterFromUnsigned(174          reg_ctx->GetRegisterInfo(eRegisterKindGeneric,175                                   LLDB_REGNUM_GENERIC_SP),176          sp))177    return false;178 179  // Set "pc" to the address requested180  if (!reg_ctx->WriteRegisterFromUnsigned(181          reg_ctx->GetRegisterInfo(eRegisterKindGeneric,182                                   LLDB_REGNUM_GENERIC_PC),183          func_addr))184    return false;185 186  return true;187}188 189// TODO: We dont support fp/SIMD arguments in v0-v7190bool ABISysV_arm64::GetArgumentValues(Thread &thread, ValueList &values) const {191  uint32_t num_values = values.GetSize();192 193  ExecutionContext exe_ctx(thread.shared_from_this());194 195  // Extract the register context so we can read arguments from registers196 197  RegisterContext *reg_ctx = thread.GetRegisterContext().get();198 199  if (!reg_ctx)200    return false;201 202  addr_t sp = 0;203 204  for (uint32_t value_idx = 0; value_idx < num_values; ++value_idx) {205    // We currently only support extracting values with Clang QualTypes. Do we206    // care about others?207    Value *value = values.GetValueAtIndex(value_idx);208 209    if (!value)210      return false;211 212    CompilerType value_type = value->GetCompilerType();213    if (value_type) {214      bool is_signed = false;215      size_t bit_width = 0;216      std::optional<uint64_t> bit_size =217          llvm::expectedToOptional(value_type.GetBitSize(&thread));218      if (!bit_size)219        return false;220      if (value_type.IsIntegerOrEnumerationType(is_signed)) {221        bit_width = *bit_size;222      } else if (value_type.IsPointerOrReferenceType()) {223        bit_width = *bit_size;224      } else {225        // We only handle integer, pointer and reference types currently...226        return false;227      }228 229      if (bit_width <= (exe_ctx.GetProcessRef().GetAddressByteSize() * 8)) {230        if (value_idx < 8) {231          // Arguments 1-8 are in x0-x7...232          const RegisterInfo *reg_info = nullptr;233          reg_info = reg_ctx->GetRegisterInfo(234              eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + value_idx);235 236          if (reg_info) {237            RegisterValue reg_value;238 239            if (reg_ctx->ReadRegister(reg_info, reg_value)) {240              if (is_signed)241                reg_value.SignExtend(bit_width);242              if (!reg_value.GetScalarValue(value->GetScalar()))243                return false;244              continue;245            }246          }247          return false;248        } else {249          // TODO: Verify for stack layout for SysV250          if (sp == 0) {251            // Read the stack pointer if we already haven't read it252            sp = reg_ctx->GetSP(0);253            if (sp == 0)254              return false;255          }256 257          // Arguments 5 on up are on the stack258          const uint32_t arg_byte_size = (bit_width + (8 - 1)) / 8;259          Status error;260          if (!exe_ctx.GetProcessRef().ReadScalarIntegerFromMemory(261                  sp, arg_byte_size, is_signed, value->GetScalar(), error))262            return false;263 264          sp += arg_byte_size;265          // Align up to the next 8 byte boundary if needed266          if (sp % 8) {267            sp >>= 3;268            sp += 1;269            sp <<= 3;270          }271        }272      }273    }274  }275  return true;276}277 278Status ABISysV_arm64::SetReturnValueObject(lldb::StackFrameSP &frame_sp,279                                           lldb::ValueObjectSP &new_value_sp) {280  Status error;281  if (!new_value_sp) {282    error = Status::FromErrorString("Empty value object for return value.");283    return error;284  }285 286  CompilerType return_value_type = new_value_sp->GetCompilerType();287  if (!return_value_type) {288    error = Status::FromErrorString("Null clang type for return value.");289    return error;290  }291 292  Thread *thread = frame_sp->GetThread().get();293 294  RegisterContext *reg_ctx = thread->GetRegisterContext().get();295 296  if (reg_ctx) {297    DataExtractor data;298    Status data_error;299    const uint64_t byte_size = new_value_sp->GetData(data, data_error);300    if (data_error.Fail()) {301      error = Status::FromErrorStringWithFormat(302          "Couldn't convert return value to raw data: %s",303          data_error.AsCString());304      return error;305    }306 307    const uint32_t type_flags = return_value_type.GetTypeInfo(nullptr);308    if (type_flags & eTypeIsScalar || type_flags & eTypeIsPointer) {309      if (type_flags & eTypeIsInteger || type_flags & eTypeIsPointer) {310        // Extract the register context so we can read arguments from registers311        lldb::offset_t offset = 0;312        if (byte_size <= 16) {313          const RegisterInfo *x0_info = reg_ctx->GetRegisterInfo(314              eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);315          if (byte_size <= 8) {316            uint64_t raw_value = data.GetMaxU64(&offset, byte_size);317 318            if (!reg_ctx->WriteRegisterFromUnsigned(x0_info, raw_value))319              error = Status::FromErrorString("failed to write register x0");320          } else {321            uint64_t raw_value = data.GetMaxU64(&offset, 8);322 323            if (reg_ctx->WriteRegisterFromUnsigned(x0_info, raw_value)) {324              const RegisterInfo *x1_info = reg_ctx->GetRegisterInfo(325                  eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);326              raw_value = data.GetMaxU64(&offset, byte_size - offset);327 328              if (!reg_ctx->WriteRegisterFromUnsigned(x1_info, raw_value))329                error = Status::FromErrorString("failed to write register x1");330            }331          }332        } else {333          error = Status::FromErrorString(334              "We don't support returning longer than 128 bit "335              "integer values at present.");336        }337      } else if (type_flags & eTypeIsFloat) {338        if (type_flags & eTypeIsComplex) {339          // Don't handle complex yet.340          error = Status::FromErrorString(341              "returning complex float values are not supported");342        } else {343          const RegisterInfo *v0_info = reg_ctx->GetRegisterInfoByName("v0", 0);344 345          if (v0_info) {346            if (byte_size <= 16) {347              RegisterValue reg_value;348              error = reg_value.SetValueFromData(*v0_info, data, 0, true);349              if (error.Success())350                if (!reg_ctx->WriteRegister(v0_info, reg_value))351                  error =352                      Status::FromErrorString("failed to write register v0");353            } else {354              error = Status::FromErrorString(355                  "returning float values longer than 128 "356                  "bits are not supported");357            }358          } else359            error = Status::FromErrorString(360                "v0 register is not available on this target");361        }362      }363    } else if (type_flags & eTypeIsVector) {364      if (byte_size > 0) {365        const RegisterInfo *v0_info = reg_ctx->GetRegisterInfoByName("v0", 0);366 367        if (v0_info) {368          if (byte_size <= v0_info->byte_size) {369            RegisterValue reg_value;370            error = reg_value.SetValueFromData(*v0_info, data, 0, true);371            if (error.Success()) {372              if (!reg_ctx->WriteRegister(v0_info, reg_value))373                error = Status::FromErrorString("failed to write register v0");374            }375          }376        }377      }378    }379  } else {380    error = Status::FromErrorString("no registers are available");381  }382 383  return error;384}385 386// AAPCS64 (Procedure Call Standard for the ARM 64-bit Architecture) says387// registers x19 through x28 and sp are callee preserved. v8-v15 are non-388// volatile (and specifically only the lower 8 bytes of these regs), the rest389// of the fp/SIMD registers are volatile.390 391// We treat x29 as callee preserved also, else the unwinder won't try to392// retrieve fp saves.393 394bool ABISysV_arm64::RegisterIsVolatile(const RegisterInfo *reg_info) {395  if (reg_info) {396    const char *name = reg_info->name;397 398    // Sometimes we'll be called with the "alternate" name for these registers;399    // recognize them as non-volatile.400 401    if (name[0] == 'p' && name[1] == 'c') // pc402      return false;403    if (name[0] == 'f' && name[1] == 'p') // fp404      return false;405    if (name[0] == 's' && name[1] == 'p') // sp406      return false;407    if (name[0] == 'l' && name[1] == 'r') // lr408      return false;409 410    if (name[0] == 'x' || name[0] == 'r') {411      // Volatile registers: x0-x18412      // Although documentation says only x19-28 + sp are callee saved We ll413      // also have to treat x30 as non-volatile. Each dwarf frame has its own414      // value of lr. Return false for the non-volatile gpr regs, true for415      // everything else416      switch (name[1]) {417      case '1':418        switch (name[2]) {419        case '9':420          return false; // x19 is non-volatile421        default:422          return true;423        }424        break;425      case '2':426        switch (name[2]) {427        case '0':428        case '1':429        case '2':430        case '3':431        case '4':432        case '5':433        case '6':434        case '7':435        case '8':436          return false; // x20 - 28 are non-volatile437        case '9':438          return false; // x29 aka fp treat as non-volatile439        default:440          return true;441        }442      case '3': // x30 (lr) and x31 (sp) treat as non-volatile443        if (name[2] == '0' || name[2] == '1')444          return false;445        break;446      default:447        return true; // all volatile cases not handled above fall here.448      }449    } else if (name[0] == 'v' || name[0] == 's' || name[0] == 'd') {450      // Volatile registers: v0-7, v16-v31451      // Return false for non-volatile fp/SIMD regs, true for everything else452      switch (name[1]) {453      case '8':454      case '9':455        return false; // v8-v9 are non-volatile456      case '1':457        switch (name[2]) {458        case '0':459        case '1':460        case '2':461        case '3':462        case '4':463        case '5':464          return false; // v10-v15 are non-volatile465        default:466          return true;467        }468      default:469        return true;470      }471    }472  }473  return true;474}475 476static bool LoadValueFromConsecutiveGPRRegisters(477    ExecutionContext &exe_ctx, RegisterContext *reg_ctx,478    const CompilerType &value_type,479    bool is_return_value, // false => parameter, true => return value480    uint32_t &NGRN,       // NGRN (see ABI documentation)481    uint32_t &NSRN,       // NSRN (see ABI documentation)482    DataExtractor &data) {483  std::optional<uint64_t> byte_size = llvm::expectedToOptional(484      value_type.GetByteSize(exe_ctx.GetBestExecutionContextScope()));485 486  if (byte_size || *byte_size == 0)487    return false;488 489  std::unique_ptr<DataBufferHeap> heap_data_up(490      new DataBufferHeap(*byte_size, 0));491  const ByteOrder byte_order = exe_ctx.GetProcessRef().GetByteOrder();492  Status error;493 494  CompilerType base_type;495  const uint32_t homogeneous_count =496      value_type.IsHomogeneousAggregate(&base_type);497  if (homogeneous_count > 0 && homogeneous_count <= 8) {498    // Make sure we have enough registers499    if (NSRN < 8 && (8 - NSRN) >= homogeneous_count) {500      if (!base_type)501        return false;502      std::optional<uint64_t> base_byte_size = llvm::expectedToOptional(503          base_type.GetByteSize(exe_ctx.GetBestExecutionContextScope()));504      if (!base_byte_size)505        return false;506      uint32_t data_offset = 0;507 508      for (uint32_t i = 0; i < homogeneous_count; ++i) {509        char v_name[8];510        ::snprintf(v_name, sizeof(v_name), "v%u", NSRN);511        const RegisterInfo *reg_info =512            reg_ctx->GetRegisterInfoByName(v_name, 0);513        if (reg_info == nullptr)514          return false;515 516        if (*base_byte_size > reg_info->byte_size)517          return false;518 519        RegisterValue reg_value;520 521        if (!reg_ctx->ReadRegister(reg_info, reg_value))522          return false;523 524        // Make sure we have enough room in "heap_data_up"525        if ((data_offset + *base_byte_size) <= heap_data_up->GetByteSize()) {526          const size_t bytes_copied = reg_value.GetAsMemoryData(527              *reg_info, heap_data_up->GetBytes() + data_offset,528              *base_byte_size, byte_order, error);529          if (bytes_copied != *base_byte_size)530            return false;531          data_offset += bytes_copied;532          ++NSRN;533        } else534          return false;535      }536      data.SetByteOrder(byte_order);537      data.SetAddressByteSize(exe_ctx.GetProcessRef().GetAddressByteSize());538      data.SetData(DataBufferSP(heap_data_up.release()));539      return true;540    }541  }542 543  const size_t max_reg_byte_size = 16;544  if (*byte_size <= max_reg_byte_size) {545    size_t bytes_left = *byte_size;546    uint32_t data_offset = 0;547    while (data_offset < *byte_size) {548      if (NGRN >= 8)549        return false;550 551      const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(552          eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + NGRN);553      if (reg_info == nullptr)554        return false;555 556      RegisterValue reg_value;557 558      if (!reg_ctx->ReadRegister(reg_info, reg_value))559        return false;560 561      const size_t curr_byte_size = std::min<size_t>(8, bytes_left);562      const size_t bytes_copied = reg_value.GetAsMemoryData(563          *reg_info, heap_data_up->GetBytes() + data_offset, curr_byte_size,564          byte_order, error);565      if (bytes_copied == 0)566        return false;567      if (bytes_copied >= bytes_left)568        break;569      data_offset += bytes_copied;570      bytes_left -= bytes_copied;571      ++NGRN;572    }573  } else {574    const RegisterInfo *reg_info = nullptr;575    if (is_return_value) {576      // The SysV arm64 ABI doesn't require you to write the return location 577      // back to x8 before returning from the function the way the x86_64 ABI 578      // does.  It looks like all the users of this ABI currently choose not to579      // do that, and so we can't reconstruct stack based returns on exit 580      // from the function.581      return false;582    } else {583      // We are assuming we are stopped at the first instruction in a function584      // and that the ABI is being respected so all parameters appear where585      // they should be (functions with no external linkage can legally violate586      // the ABI).587      if (NGRN >= 8)588        return false;589 590      reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,591                                          LLDB_REGNUM_GENERIC_ARG1 + NGRN);592      if (reg_info == nullptr)593        return false;594      ++NGRN;595    }596 597    const lldb::addr_t value_addr =598        reg_ctx->ReadRegisterAsUnsigned(reg_info, LLDB_INVALID_ADDRESS);599 600    if (value_addr == LLDB_INVALID_ADDRESS)601      return false;602 603    if (exe_ctx.GetProcessRef().ReadMemory(604            value_addr, heap_data_up->GetBytes(), heap_data_up->GetByteSize(),605            error) != heap_data_up->GetByteSize()) {606      return false;607    }608  }609 610  data.SetByteOrder(byte_order);611  data.SetAddressByteSize(exe_ctx.GetProcessRef().GetAddressByteSize());612  data.SetData(DataBufferSP(heap_data_up.release()));613  return true;614}615 616ValueObjectSP ABISysV_arm64::GetReturnValueObjectImpl(617    Thread &thread, CompilerType &return_compiler_type) const {618  ValueObjectSP return_valobj_sp;619  Value value;620 621  ExecutionContext exe_ctx(thread.shared_from_this());622  if (exe_ctx.GetTargetPtr() == nullptr || exe_ctx.GetProcessPtr() == nullptr)623    return return_valobj_sp;624 625  // value.SetContext (Value::eContextTypeClangType, return_compiler_type);626  value.SetCompilerType(return_compiler_type);627 628  RegisterContext *reg_ctx = thread.GetRegisterContext().get();629  if (!reg_ctx)630    return return_valobj_sp;631 632  std::optional<uint64_t> byte_size =633      llvm::expectedToOptional(return_compiler_type.GetByteSize(&thread));634  if (!byte_size)635    return return_valobj_sp;636 637  const uint32_t type_flags = return_compiler_type.GetTypeInfo(nullptr);638  if (type_flags & eTypeIsScalar || type_flags & eTypeIsPointer) {639    value.SetValueType(Value::ValueType::Scalar);640 641    bool success = false;642    if (type_flags & eTypeIsInteger || type_flags & eTypeIsPointer) {643      // Extract the register context so we can read arguments from registers644      if (*byte_size <= 8) {645        const RegisterInfo *x0_reg_info = nullptr;646        x0_reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,647                                               LLDB_REGNUM_GENERIC_ARG1);648        if (x0_reg_info) {649          uint64_t raw_value =650              thread.GetRegisterContext()->ReadRegisterAsUnsigned(x0_reg_info,651                                                                  0);652          const bool is_signed = (type_flags & eTypeIsSigned) != 0;653          switch (*byte_size) {654          default:655            break;656          case 16: // uint128_t657            // In register x0 and x1658            {659              const RegisterInfo *x1_reg_info = nullptr;660              x1_reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,661                                                     LLDB_REGNUM_GENERIC_ARG2);662 663              if (x1_reg_info) {664                if (*byte_size <=665                    x0_reg_info->byte_size + x1_reg_info->byte_size) {666                  std::unique_ptr<DataBufferHeap> heap_data_up(667                      new DataBufferHeap(*byte_size, 0));668                  const ByteOrder byte_order =669                      exe_ctx.GetProcessRef().GetByteOrder();670                  RegisterValue x0_reg_value;671                  RegisterValue x1_reg_value;672                  if (reg_ctx->ReadRegister(x0_reg_info, x0_reg_value) &&673                      reg_ctx->ReadRegister(x1_reg_info, x1_reg_value)) {674                    Status error;675                    if (x0_reg_value.GetAsMemoryData(676                            *x0_reg_info, heap_data_up->GetBytes() + 0, 8,677                            byte_order, error) &&678                        x1_reg_value.GetAsMemoryData(679                            *x1_reg_info, heap_data_up->GetBytes() + 8, 8,680                            byte_order, error)) {681                      DataExtractor data(682                          DataBufferSP(heap_data_up.release()), byte_order,683                          exe_ctx.GetProcessRef().GetAddressByteSize());684 685                      return_valobj_sp = ValueObjectConstResult::Create(686                          &thread, return_compiler_type, ConstString(""), data);687                      return return_valobj_sp;688                    }689                  }690                }691              }692            }693            break;694          case sizeof(uint64_t):695            if (is_signed)696              value.GetScalar() = (int64_t)(raw_value);697            else698              value.GetScalar() = (uint64_t)(raw_value);699            success = true;700            break;701 702          case sizeof(uint32_t):703            if (is_signed)704              value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);705            else706              value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);707            success = true;708            break;709 710          case sizeof(uint16_t):711            if (is_signed)712              value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);713            else714              value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);715            success = true;716            break;717 718          case sizeof(uint8_t):719            if (is_signed)720              value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);721            else722              value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);723            success = true;724            break;725          }726        }727      }728    } else if (type_flags & eTypeIsFloat) {729      if (type_flags & eTypeIsComplex) {730        // Don't handle complex yet.731      } else {732        if (*byte_size <= sizeof(long double)) {733          const RegisterInfo *v0_reg_info =734              reg_ctx->GetRegisterInfoByName("v0", 0);735          RegisterValue v0_value;736          if (reg_ctx->ReadRegister(v0_reg_info, v0_value)) {737            DataExtractor data;738            if (v0_value.GetData(data)) {739              lldb::offset_t offset = 0;740              if (*byte_size == sizeof(float)) {741                value.GetScalar() = data.GetFloat(&offset);742                success = true;743              } else if (*byte_size == sizeof(double)) {744                value.GetScalar() = data.GetDouble(&offset);745                success = true;746              } else if (*byte_size == sizeof(long double)) {747                value.GetScalar() = data.GetLongDouble(&offset);748                success = true;749              }750            }751          }752        }753      }754    }755 756    if (success)757      return_valobj_sp = ValueObjectConstResult::Create(758          thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));759  } else if (type_flags & eTypeIsVector && *byte_size <= 16) {760    if (*byte_size > 0) {761      const RegisterInfo *v0_info = reg_ctx->GetRegisterInfoByName("v0", 0);762 763      if (v0_info) {764        std::unique_ptr<DataBufferHeap> heap_data_up(765            new DataBufferHeap(*byte_size, 0));766        const ByteOrder byte_order = exe_ctx.GetProcessRef().GetByteOrder();767        RegisterValue reg_value;768        if (reg_ctx->ReadRegister(v0_info, reg_value)) {769          Status error;770          if (reg_value.GetAsMemoryData(*v0_info, heap_data_up->GetBytes(),771                                        heap_data_up->GetByteSize(), byte_order,772                                        error)) {773            DataExtractor data(DataBufferSP(heap_data_up.release()), byte_order,774                               exe_ctx.GetProcessRef().GetAddressByteSize());775            return_valobj_sp = ValueObjectConstResult::Create(776                &thread, return_compiler_type, ConstString(""), data);777          }778        }779      }780    }781  } else if (type_flags & eTypeIsStructUnion || type_flags & eTypeIsClass ||782             (type_flags & eTypeIsVector && *byte_size > 16)) {783    DataExtractor data;784 785    uint32_t NGRN = 0; // Search ABI docs for NGRN786    uint32_t NSRN = 0; // Search ABI docs for NSRN787    const bool is_return_value = true;788    if (LoadValueFromConsecutiveGPRRegisters(789            exe_ctx, reg_ctx, return_compiler_type, is_return_value, NGRN, NSRN,790            data)) {791      return_valobj_sp = ValueObjectConstResult::Create(792          &thread, return_compiler_type, ConstString(""), data);793    }794  }795  return return_valobj_sp;796}797 798lldb::addr_t ABISysV_arm64::FixAddress(addr_t pc, addr_t mask) {799  if (mask == LLDB_INVALID_ADDRESS_MASK)800    return pc;801  lldb::addr_t pac_sign_extension = 0x0080000000000000ULL;802  return (pc & pac_sign_extension) ? pc | mask : pc & (~mask);803}804 805// Reads code or data address mask for the current Linux process.806static lldb::addr_t ReadLinuxProcessAddressMask(lldb::ProcessSP process_sp,807                                                llvm::StringRef reg_name) {808  // LLDB_INVALID_ADDRESS_MASK means there isn't a mask or it has not been read809  // yet. We do not return the top byte mask unless thread_sp is valid. This810  // prevents calls to this function before the thread is setup locking in the811  // value to just the top byte mask, in cases where pointer authentication812  // might also be active.813  uint64_t address_mask = LLDB_INVALID_ADDRESS_MASK;814  lldb::ThreadSP thread_sp = process_sp->GetThreadList().GetSelectedThread();815  if (thread_sp) {816    // Linux configures user-space virtual addresses with top byte ignored.817    // We set default value of mask such that top byte is masked out.818    address_mask = ~((1ULL << 56) - 1);819    // If Pointer Authentication feature is enabled then Linux exposes820    // PAC data and code mask register. Try reading relevant register821    // below and merge it with default address mask calculated above.822    lldb::RegisterContextSP reg_ctx_sp = thread_sp->GetRegisterContext();823    if (reg_ctx_sp) {824      const RegisterInfo *reg_info =825          reg_ctx_sp->GetRegisterInfoByName(reg_name, 0);826      if (reg_info) {827        lldb::addr_t mask_reg_val = reg_ctx_sp->ReadRegisterAsUnsigned(828            reg_info->kinds[eRegisterKindLLDB], LLDB_INVALID_ADDRESS);829        if (mask_reg_val != LLDB_INVALID_ADDRESS)830          address_mask |= mask_reg_val;831      }832    }833  }834  return address_mask;835}836 837lldb::addr_t ABISysV_arm64::FixCodeAddress(lldb::addr_t pc) {838  if (lldb::ProcessSP process_sp = GetProcessSP()) {839    if (process_sp->GetTarget().GetArchitecture().GetTriple().isOSLinux() &&840        process_sp->GetCodeAddressMask() == LLDB_INVALID_ADDRESS_MASK)841      process_sp->SetCodeAddressMask(842          ReadLinuxProcessAddressMask(process_sp, "code_mask"));843 844    // b55 is the highest bit outside TBI (if it's enabled), use845    // it to determine if the high bits are set to 0 or 1.846    const addr_t pac_sign_extension = 0x0080000000000000ULL;847    addr_t mask = process_sp->GetCodeAddressMask();848    // Test if the high memory mask has been overriden separately849    if (pc & pac_sign_extension &&850        process_sp->GetHighmemCodeAddressMask() != LLDB_INVALID_ADDRESS_MASK)851      mask = process_sp->GetHighmemCodeAddressMask();852 853    return FixAddress(pc, mask);854  }855  return pc;856}857 858lldb::addr_t ABISysV_arm64::FixDataAddress(lldb::addr_t pc) {859  if (lldb::ProcessSP process_sp = GetProcessSP()) {860    if (process_sp->GetTarget().GetArchitecture().GetTriple().isOSLinux() &&861        process_sp->GetDataAddressMask() == LLDB_INVALID_ADDRESS_MASK)862      process_sp->SetDataAddressMask(863          ReadLinuxProcessAddressMask(process_sp, "data_mask"));864 865    // b55 is the highest bit outside TBI (if it's enabled), use866    // it to determine if the high bits are set to 0 or 1.867    const addr_t pac_sign_extension = 0x0080000000000000ULL;868    addr_t mask = process_sp->GetDataAddressMask();869    // Test if the high memory mask has been overriden separately870    if (pc & pac_sign_extension &&871        process_sp->GetHighmemDataAddressMask() != LLDB_INVALID_ADDRESS_MASK)872      mask = process_sp->GetHighmemDataAddressMask();873 874    return FixAddress(pc, mask);875  }876  return pc;877}878 879void ABISysV_arm64::Initialize() {880  PluginManager::RegisterPlugin(GetPluginNameStatic(),881                                "SysV ABI for AArch64 targets", CreateInstance);882}883 884void ABISysV_arm64::Terminate() {885  PluginManager::UnregisterPlugin(CreateInstance);886}887