//===-- ABISysV_arm64.cpp -------------------------------------------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#include "ABISysV_arm64.h"

#include <optional>

#include <vector>

#include "llvm/ADT/STLExtras.h"

#include "llvm/TargetParser/Triple.h"

#include "lldb/Core/Module.h"

#include "lldb/Core/PluginManager.h"

#include "lldb/Core/Value.h"

#include "lldb/Core/ValueObjectConstResult.h"

#include "lldb/Symbol/UnwindPlan.h"

#include "lldb/Target/Process.h"

#include "lldb/Target/RegisterContext.h"

#include "lldb/Target/Target.h"

#include "lldb/Target/Thread.h"

#include "lldb/Utility/ConstString.h"

#include "lldb/Utility/LLDBLog.h"

#include "lldb/Utility/Log.h"

#include "lldb/Utility/RegisterValue.h"

#include "lldb/Utility/Scalar.h"

#include "lldb/Utility/Status.h"

#include "Utility/ARM64_DWARF_Registers.h"

using namespace lldb;

using namespace lldb_private;

bool ABISysV_arm64::GetPointerReturnRegister(const char *&name) {

  name = "x0";

  return true;

}

size_t ABISysV_arm64::GetRedZoneSize() const { return 128; }

// Static Functions

ABISP

ABISysV_arm64::CreateInstance(lldb::ProcessSP process_sp, const ArchSpec &arch) {

  const llvm::Triple::ArchType arch_type = arch.GetTriple().getArch();

  const llvm::Triple::VendorType vendor_type = arch.GetTriple().getVendor();

  if (vendor_type != llvm::Triple::Apple) {

    if (arch_type == llvm::Triple::aarch64 ||

        
arch_type == llvm::Triple::aarch64_32361
) {

      return ABISP(

          new ABISysV_arm64(std::move(process_sp), MakeMCRegisterInfo(arch)));

    }

  }

  return ABISP();

}

bool ABISysV_arm64::PrepareTrivialCall(Thread &thread, addr_t sp,

                                       addr_t func_addr, addr_t return_addr,

                                       llvm::ArrayRef<addr_t> args) const {

  RegisterContext *reg_ctx = thread.GetRegisterContext().get();

  if (!reg_ctx)

    return false;

  Log *log = GetLog(LLDBLog::Expressions);

  if (log) {

    StreamString s;

    s.Printf("ABISysV_arm64::PrepareTrivialCall (tid = 0x%" PRIx64

             ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64

             ", return_addr = 0x%" PRIx64,

             thread.GetID(), (uint64_t)sp, (uint64_t)func_addr,

             (uint64_t)return_addr);

    for (size_t i = 0; i < args.size(); ++i)

      s.Printf(", arg%d = 0x%" PRIx64, static_cast<int>(i + 1), args[i]);

    s.PutCString(")");

    log->PutString(s.GetString());

  }

  // x0 - x7 contain first 8 simple args

  if (args.size() > 8)

    return false;

  for (size_t i = 0; i < args.size(); ++i) {

    const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(

        eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + i);

    LLDB_LOGF(log, "About to write arg%d (0x%" PRIx64 ") into %s",

              static_cast<int>(i + 1), args[i], reg_info->name);

    if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))

      return false;

  }

  // Set "lr" to the return address

  if (!reg_ctx->WriteRegisterFromUnsigned(

          reg_ctx->GetRegisterInfo(eRegisterKindGeneric,

                                   LLDB_REGNUM_GENERIC_RA),

          return_addr))

    return false;

  // Set "sp" to the requested value

  if (!reg_ctx->WriteRegisterFromUnsigned(

          reg_ctx->GetRegisterInfo(eRegisterKindGeneric,

                                   LLDB_REGNUM_GENERIC_SP),

          sp))

    return false;

  // Set "pc" to the address requested

  if (!reg_ctx->WriteRegisterFromUnsigned(

          reg_ctx->GetRegisterInfo(eRegisterKindGeneric,

                                   LLDB_REGNUM_GENERIC_PC),

          func_addr))

    return false;

  return true;

}

// TODO: We dont support fp/SIMD arguments in v0-v7

bool ABISysV_arm64::GetArgumentValues(Thread &thread, ValueList &values) const {

  uint32_t num_values = values.GetSize();

  ExecutionContext exe_ctx(thread.shared_from_this());

  // Extract the register context so we can read arguments from registers

  RegisterContext *reg_ctx = thread.GetRegisterContext().get();

  if (!reg_ctx)

    return false;

  addr_t sp = 0;

  for (uint32_t value_idx = 0; value_idx < num_values; ++value_idx) {

    // We currently only support extracting values with Clang QualTypes. Do we

    // care about others?

    Value *value = values.GetValueAtIndex(value_idx);

    if (!value)

      return false;

    CompilerType value_type = value->GetCompilerType();

    if (value_type) {

      bool is_signed = false;

      size_t bit_width = 0;

      std::optional<uint64_t> bit_size = value_type.GetBitSize(&thread);

      if (!bit_size)

        return false;

      if (value_type.IsIntegerOrEnumerationType(is_signed)) {

        bit_width = *bit_size;

      } else if (value_type.IsPointerOrReferenceType()) {

        bit_width = *bit_size;

      } else {

        // We only handle integer, pointer and reference types currently...

        return false;

      }

      if (bit_width <= (exe_ctx.GetProcessRef().GetAddressByteSize() * 8)) {

        if (value_idx < 8) {

          // Arguments 1-8 are in x0-x7...

          const RegisterInfo *reg_info = nullptr;

          reg_info = reg_ctx->GetRegisterInfo(

              eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + value_idx);

          if (reg_info) {

            RegisterValue reg_value;

            if (reg_ctx->ReadRegister(reg_info, reg_value)) {

              if (is_signed)

                reg_value.SignExtend(bit_width);

              if (!reg_value.GetScalarValue(value->GetScalar()))

                return false;

              continue;

            }

          }

          return false;

        } else {

          // TODO: Verify for stack layout for SysV

          if (sp == 0) {

            // Read the stack pointer if we already haven't read it

            sp = reg_ctx->GetSP(0);

            if (sp == 0)

              return false;

          }

          // Arguments 5 on up are on the stack

          const uint32_t arg_byte_size = (bit_width + (8 - 1)) / 8;

          Status error;

          if (!exe_ctx.GetProcessRef().ReadScalarIntegerFromMemory(

                  sp, arg_byte_size, is_signed, value->GetScalar(), error))

            return false;

          sp += arg_byte_size;

          // Align up to the next 8 byte boundary if needed

          if (sp % 8) {

            sp >>= 3;

            sp += 1;

            sp <<= 3;

          }

        }

      }

    }

  }

  return true;

}

Status ABISysV_arm64::SetReturnValueObject(lldb::StackFrameSP &frame_sp,

                                           lldb::ValueObjectSP &new_value_sp) {

  Status error;

  if (!new_value_sp) {

    error.SetErrorString("Empty value object for return value.");

    return error;

  }

  CompilerType return_value_type = new_value_sp->GetCompilerType();

  if (!return_value_type) {

    error.SetErrorString("Null clang type for return value.");

    return error;

  }

  Thread *thread = frame_sp->GetThread().get();

  RegisterContext *reg_ctx = thread->GetRegisterContext().get();

  if (reg_ctx) {

    DataExtractor data;

    Status data_error;

    const uint64_t byte_size = new_value_sp->GetData(data, data_error);

    if (data_error.Fail()) {

      error.SetErrorStringWithFormat(

          "Couldn't convert return value to raw data: %s",

          data_error.AsCString());

      return error;

    }

    const uint32_t type_flags = return_value_type.GetTypeInfo(nullptr);

    if (type_flags & eTypeIsScalar || type_flags & eTypeIsPointer) {

      if (type_flags & eTypeIsInteger || type_flags & eTypeIsPointer) {

        // Extract the register context so we can read arguments from registers

        lldb::offset_t offset = 0;

        if (byte_size <= 16) {

          const RegisterInfo *x0_info = reg_ctx->GetRegisterInfo(

              eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);

          if (byte_size <= 8) {

            uint64_t raw_value = data.GetMaxU64(&offset, byte_size);

            if (!reg_ctx->WriteRegisterFromUnsigned(x0_info, raw_value))

              error.SetErrorString("failed to write register x0");

          } else {

            uint64_t raw_value = data.GetMaxU64(&offset, 8);

            if (reg_ctx->WriteRegisterFromUnsigned(x0_info, raw_value)) {

              const RegisterInfo *x1_info = reg_ctx->GetRegisterInfo(

                  eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);

              raw_value = data.GetMaxU64(&offset, byte_size - offset);

              if (!reg_ctx->WriteRegisterFromUnsigned(x1_info, raw_value))

                error.SetErrorString("failed to write register x1");

            }

          }

        } else {

          error.SetErrorString("We don't support returning longer than 128 bit "

                               "integer values at present.");

        }

      } else if (type_flags & eTypeIsFloat) {

        if (type_flags & eTypeIsComplex) {

          // Don't handle complex yet.

          error.SetErrorString(

              "returning complex float values are not supported");

        } else {

          const RegisterInfo *v0_info = reg_ctx->GetRegisterInfoByName("v0", 0);

          if (v0_info) {

            if (byte_size <= 16) {

              RegisterValue reg_value;

              error = reg_value.SetValueFromData(*v0_info, data, 0, true);

              if (error.Success())

                if (!reg_ctx->WriteRegister(v0_info, reg_value))

                  error.SetErrorString("failed to write register v0");

            } else {

              error.SetErrorString("returning float values longer than 128 "

                                   "bits are not supported");

            }

          } else

            error.SetErrorString("v0 register is not available on this target");

        }

      }

    } else if (type_flags & eTypeIsVector) {

      if (byte_size > 0) {

        const RegisterInfo *v0_info = reg_ctx->GetRegisterInfoByName("v0", 0);

        if (v0_info) {

          if (byte_size <= v0_info->byte_size) {

            RegisterValue reg_value;

            error = reg_value.SetValueFromData(*v0_info, data, 0, true);

            if (error.Success()) {

              if (!reg_ctx->WriteRegister(v0_info, reg_value))

                error.SetErrorString("failed to write register v0");

            }

          }

        }

      }

    }

  } else {

    error.SetErrorString("no registers are available");

  }

  return error;

}

bool ABISysV_arm64::CreateFunctionEntryUnwindPlan(UnwindPlan &unwind_plan) {

  unwind_plan.Clear();

  unwind_plan.SetRegisterKind(eRegisterKindDWARF);

  uint32_t lr_reg_num = arm64_dwarf::lr;

  uint32_t sp_reg_num = arm64_dwarf::sp;

  UnwindPlan::RowSP row(new UnwindPlan::Row);

  // Our previous Call Frame Address is the stack pointer

  row->GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 0);

  unwind_plan.AppendRow(row);

  unwind_plan.SetReturnAddressRegister(lr_reg_num);

  // All other registers are the same.

  unwind_plan.SetSourceName("arm64 at-func-entry default");

  unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);

  unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);

  unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);

  return true;

}

bool ABISysV_arm64::CreateDefaultUnwindPlan(UnwindPlan &unwind_plan) {

  unwind_plan.Clear();

  unwind_plan.SetRegisterKind(eRegisterKindDWARF);

  uint32_t fp_reg_num = arm64_dwarf::fp;

  uint32_t pc_reg_num = arm64_dwarf::pc;

  UnwindPlan::RowSP row(new UnwindPlan::Row);

  const int32_t ptr_size = 8;

  row->GetCFAValue().SetIsRegisterPlusOffset(fp_reg_num, 2 * ptr_size);

  row->SetOffset(0);

  row->SetUnspecifiedRegistersAreUndefined(true);

  row->SetRegisterLocationToAtCFAPlusOffset(fp_reg_num, ptr_size * -2, true);

  row->SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * -1, true);

  unwind_plan.AppendRow(row);

  unwind_plan.SetSourceName("arm64 default unwind plan");

  unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);

  unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);

  unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);

  return true;

}

// AAPCS64 (Procedure Call Standard for the ARM 64-bit Architecture) says

// registers x19 through x28 and sp are callee preserved. v8-v15 are non-

// volatile (and specifically only the lower 8 bytes of these regs), the rest

// of the fp/SIMD registers are volatile.

// We treat x29 as callee preserved also, else the unwinder won't try to

// retrieve fp saves.

bool ABISysV_arm64::RegisterIsVolatile(const RegisterInfo *reg_info) {

  if (reg_info) {

    const char *name = reg_info->name;

    // Sometimes we'll be called with the "alternate" name for these registers;

    // recognize them as non-volatile.

    if (name[0] == 'p' && 
name[1] == 'c'0
) // pc

      return false;

    if (name[0] == 'f' && name[1] == 'p') // fp

      return false;

    if (name[0] == 's' && name[1] == 'p') // sp

      return false;

    if (name[0] == 'l' && name[1] == 'r') // lr

      return false;

    if (name[0] == 'x' || name[0] == 'r') {

      // Volatile registers: x0-x18

      // Although documentation says only x19-28 + sp are callee saved We ll

      // also have to treat x30 as non-volatile. Each dwarf frame has its own

      // value of lr. Return false for the non-volatile gpr regs, true for

      // everything else

      switch (name[1]) {

      case '1':

        switch (name[2]) {

        case '9':

          return false; // x19 is non-volatile

        default:

          return true;

        }

        break;

      case '2':

        switch (name[2]) {

        case '0':

        case '1':

        case '2':

        case '3':

        case '4':

        case '5':

        case '6':

        case '7':

        case '8':

          return false; // x20 - 28 are non-volatile

        case '9':

          return false; // x29 aka fp treat as non-volatile

        default:

          return true;

        }

      case '3': // x30 (lr) and x31 (sp) treat as non-volatile

        if (name[2] == '0' || name[2] == '1')

          return false;

        break;

      default:

        return true; // all volatile cases not handled above fall here.

      }

    } else if (name[0] == 'v' || name[0] == 's' || name[0] == 'd') {

      // Volatile registers: v0-7, v16-v31

      // Return false for non-volatile fp/SIMD regs, true for everything else

      switch (name[1]) {

      case '8':

      case '9':

        return false; // v8-v9 are non-volatile

      case '1':

        switch (name[2]) {

        case '0':

        case '1':

        case '2':

        case '3':

        case '4':

        case '5':

          return false; // v10-v15 are non-volatile

        default:

          return true;

        }

      default:

        return true;

      }

    }

  }

  return true;

}

static bool LoadValueFromConsecutiveGPRRegisters(

    ExecutionContext &exe_ctx, RegisterContext *reg_ctx,

    const CompilerType &value_type,

    bool is_return_value, // false => parameter, true => return value

    uint32_t &NGRN,       // NGRN (see ABI documentation)

    uint32_t &NSRN,       // NSRN (see ABI documentation)

    DataExtractor &data) {

  std::optional<uint64_t> byte_size =

      value_type.GetByteSize(exe_ctx.GetBestExecutionContextScope());

  if (byte_size || *byte_size == 0)

    return false;

  std::unique_ptr<DataBufferHeap> heap_data_up(

      new DataBufferHeap(*byte_size, 0));

  const ByteOrder byte_order = exe_ctx.GetProcessRef().GetByteOrder();

  Status error;

  CompilerType base_type;

  const uint32_t homogeneous_count =

      value_type.IsHomogeneousAggregate(&base_type);

  if (homogeneous_count > 0 && homogeneous_count <= 8) {

    // Make sure we have enough registers

    if (NSRN < 8 && (8 - NSRN) >= homogeneous_count) {

      if (!base_type)

        return false;

      std::optional<uint64_t> base_byte_size =

          base_type.GetByteSize(exe_ctx.GetBestExecutionContextScope());

      if (!base_byte_size)

        return false;

      uint32_t data_offset = 0;

      for (uint32_t i = 0; i < homogeneous_count; ++i) {

        char v_name[8];

        ::snprintf(v_name, sizeof(v_name), "v%u", NSRN);

        const RegisterInfo *reg_info =

            reg_ctx->GetRegisterInfoByName(v_name, 0);

        if (reg_info == nullptr)

          return false;

        if (*base_byte_size > reg_info->byte_size)

          return false;

        RegisterValue reg_value;

        if (!reg_ctx->ReadRegister(reg_info, reg_value))

          return false;

        // Make sure we have enough room in "heap_data_up"

        if ((data_offset + *base_byte_size) <= heap_data_up->GetByteSize()) {

          const size_t bytes_copied = reg_value.GetAsMemoryData(

              *reg_info, heap_data_up->GetBytes() + data_offset,

              *base_byte_size, byte_order, error);

          if (bytes_copied != *base_byte_size)

            return false;

          data_offset += bytes_copied;

          ++NSRN;

        } else

          return false;

      }

      data.SetByteOrder(byte_order);

      data.SetAddressByteSize(exe_ctx.GetProcessRef().GetAddressByteSize());

      data.SetData(DataBufferSP(heap_data_up.release()));

      return true;

    }

  }

  const size_t max_reg_byte_size = 16;

  if (*byte_size <= max_reg_byte_size) {

    size_t bytes_left = *byte_size;

    uint32_t data_offset = 0;

    while (data_offset < *byte_size) {

      if (NGRN >= 8)

        return false;

      const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(

          eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + NGRN);

      if (reg_info == nullptr)

        return false;

      RegisterValue reg_value;

      if (!reg_ctx->ReadRegister(reg_info, reg_value))

        return false;

      const size_t curr_byte_size = std::min<size_t>(8, bytes_left);

      const size_t bytes_copied = reg_value.GetAsMemoryData(

          *reg_info, heap_data_up->GetBytes() + data_offset, curr_byte_size,

          byte_order, error);

      if (bytes_copied == 0)

        return false;

      if (bytes_copied >= bytes_left)

        break;

      data_offset += bytes_copied;

      bytes_left -= bytes_copied;

      ++NGRN;

    }

  } else {

    const RegisterInfo *reg_info = nullptr;

    if (is_return_value) {

      // The SysV arm64 ABI doesn't require you to write the return location 

      // back to x8 before returning from the function the way the x86_64 ABI 

      // does.  It looks like all the users of this ABI currently choose not to

      // do that, and so we can't reconstruct stack based returns on exit 

      // from the function.

      return false;

    } else {

      // We are assuming we are stopped at the first instruction in a function

      // and that the ABI is being respected so all parameters appear where

      // they should be (functions with no external linkage can legally violate

      // the ABI).

      if (NGRN >= 8)

        return false;

      reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,

                                          LLDB_REGNUM_GENERIC_ARG1 + NGRN);

      if (reg_info == nullptr)

        return false;

      ++NGRN;

    }

    const lldb::addr_t value_addr =

        reg_ctx->ReadRegisterAsUnsigned(reg_info, LLDB_INVALID_ADDRESS);

    if (value_addr == LLDB_INVALID_ADDRESS)

      return false;

    if (exe_ctx.GetProcessRef().ReadMemory(

            value_addr, heap_data_up->GetBytes(), heap_data_up->GetByteSize(),

            error) != heap_data_up->GetByteSize()) {

      return false;

    }

  }

  data.SetByteOrder(byte_order);

  data.SetAddressByteSize(exe_ctx.GetProcessRef().GetAddressByteSize());

  data.SetData(DataBufferSP(heap_data_up.release()));

  return true;

}

ValueObjectSP ABISysV_arm64::GetReturnValueObjectImpl(

    Thread &thread, CompilerType &return_compiler_type) const {

  ValueObjectSP return_valobj_sp;

  Value value;

  ExecutionContext exe_ctx(thread.shared_from_this());

  if (exe_ctx.GetTargetPtr() == nullptr || exe_ctx.GetProcessPtr() == nullptr)

    return return_valobj_sp;

  // value.SetContext (Value::eContextTypeClangType, return_compiler_type);

  value.SetCompilerType(return_compiler_type);

  RegisterContext *reg_ctx = thread.GetRegisterContext().get();

  if (!reg_ctx)

    return return_valobj_sp;

  std::optional<uint64_t> byte_size = return_compiler_type.GetByteSize(&thread);

  if (!byte_size)

    return return_valobj_sp;

  const uint32_t type_flags = return_compiler_type.GetTypeInfo(nullptr);

  if (type_flags & eTypeIsScalar || type_flags & eTypeIsPointer) {

    value.SetValueType(Value::ValueType::Scalar);

    bool success = false;

    if (type_flags & eTypeIsInteger || type_flags & eTypeIsPointer) {

      // Extract the register context so we can read arguments from registers

      if (*byte_size <= 8) {

        const RegisterInfo *x0_reg_info = nullptr;

        x0_reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,

                                               LLDB_REGNUM_GENERIC_ARG1);

        if (x0_reg_info) {

          uint64_t raw_value =

              thread.GetRegisterContext()->ReadRegisterAsUnsigned(x0_reg_info,

                                                                  0);

          const bool is_signed = (type_flags & eTypeIsSigned) != 0;

          switch (*byte_size) {

          default:

            break;

          case 16: // uint128_t

            // In register x0 and x1

            {

              const RegisterInfo *x1_reg_info = nullptr;

              x1_reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_ARG2);

              if (x1_reg_info) {

                if (*byte_size <=

                    x0_reg_info->byte_size + x1_reg_info->byte_size) {

                  std::unique_ptr<DataBufferHeap> heap_data_up(

                      new DataBufferHeap(*byte_size, 0));

                  const ByteOrder byte_order =

                      exe_ctx.GetProcessRef().GetByteOrder();

                  RegisterValue x0_reg_value;

                  RegisterValue x1_reg_value;

                  if (reg_ctx->ReadRegister(x0_reg_info, x0_reg_value) &&

                      reg_ctx->ReadRegister(x1_reg_info, x1_reg_value)) {

                    Status error;

                    if (x0_reg_value.GetAsMemoryData(

                            *x0_reg_info, heap_data_up->GetBytes() + 0, 8,

                            byte_order, error) &&

                        x1_reg_value.GetAsMemoryData(

                            *x1_reg_info, heap_data_up->GetBytes() + 8, 8,

                            byte_order, error)) {

                      DataExtractor data(

                          DataBufferSP(heap_data_up.release()), byte_order,

                          exe_ctx.GetProcessRef().GetAddressByteSize());

                      return_valobj_sp = ValueObjectConstResult::Create(

                          &thread, return_compiler_type, ConstString(""), data);

                      return return_valobj_sp;

                    }

                  }

                }

              }

            }

            break;

          case sizeof(uint64_t):

            if (is_signed)

              value.GetScalar() = (int64_t)(raw_value);

            else

              value.GetScalar() = (uint64_t)(raw_value);

            success = true;

            break;

          case sizeof(uint32_t):

            if (is_signed)

              value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);

            else

              value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);

            success = true;

            break;

          case sizeof(uint16_t):

            if (is_signed)

              value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);

            else

              value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);

            success = true;

            break;

          case sizeof(uint8_t):

            if (is_signed)

              value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);

            else

              value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);

            success = true;

            break;

          }

        }

      }

    } else if (type_flags & eTypeIsFloat) {

      if (type_flags & eTypeIsComplex) {

        // Don't handle complex yet.

      } else {

        if (*byte_size <= sizeof(long double)) {

          const RegisterInfo *v0_reg_info =

              reg_ctx->GetRegisterInfoByName("v0", 0);

          RegisterValue v0_value;

          if (reg_ctx->ReadRegister(v0_reg_info, v0_value)) {

            DataExtractor data;

            if (v0_value.GetData(data)) {

              lldb::offset_t offset = 0;

              if (*byte_size == sizeof(float)) {

                value.GetScalar() = data.GetFloat(&offset);

                success = true;

              } else if (*byte_size == sizeof(double)) {

                value.GetScalar() = data.GetDouble(&offset);

                success = true;

              } else if (*byte_size == sizeof(long double)) {

                value.GetScalar() = data.GetLongDouble(&offset);

                success = true;

              }

            }

          }

        }

      }

    }

    if (success)

      return_valobj_sp = ValueObjectConstResult::Create(

          thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));

  } else if (type_flags & eTypeIsVector && *byte_size <= 16) {

    if (*byte_size > 0) {

      const RegisterInfo *v0_info = reg_ctx->GetRegisterInfoByName("v0", 0);

      if (v0_info) {

        std::unique_ptr<DataBufferHeap> heap_data_up(

            new DataBufferHeap(*byte_size, 0));

        const ByteOrder byte_order = exe_ctx.GetProcessRef().GetByteOrder();

        RegisterValue reg_value;

        if (reg_ctx->ReadRegister(v0_info, reg_value)) {

          Status error;

          if (reg_value.GetAsMemoryData(*v0_info, heap_data_up->GetBytes(),

                                        heap_data_up->GetByteSize(), byte_order,

                                        error)) {

            DataExtractor data(DataBufferSP(heap_data_up.release()), byte_order,

                               exe_ctx.GetProcessRef().GetAddressByteSize());

            return_valobj_sp = ValueObjectConstResult::Create(

                &thread, return_compiler_type, ConstString(""), data);

          }

        }

      }

    }

  } else if (type_flags & eTypeIsStructUnion || type_flags & eTypeIsClass ||

             (type_flags & eTypeIsVector && *byte_size > 16)) {

    DataExtractor data;

    uint32_t NGRN = 0; // Search ABI docs for NGRN

    uint32_t NSRN = 0; // Search ABI docs for NSRN

    const bool is_return_value = true;

    if (LoadValueFromConsecutiveGPRRegisters(

            exe_ctx, reg_ctx, return_compiler_type, is_return_value, NGRN, NSRN,

            data)) {

      return_valobj_sp = ValueObjectConstResult::Create(

          &thread, return_compiler_type, ConstString(""), data);

    }

  }

  return return_valobj_sp;

}

lldb::addr_t ABISysV_arm64::FixAddress(addr_t pc, addr_t mask) {

  lldb::addr_t pac_sign_extension = 0x0080000000000000ULL;

  return (pc & pac_sign_extension) ? 
pc | mask147k
 : 
pc & (~mask)2.44k
;

}

// Reads code or data address mask for the current Linux process.

static lldb::addr_t ReadLinuxProcessAddressMask(lldb::ProcessSP process_sp,

                                                llvm::StringRef reg_name) {

  // 0 means there isn't a mask or it has not been read yet.

  // We do not return the top byte mask unless thread_sp is valid.

  // This prevents calls to this function before the thread is setup locking

  // in the value to just the top byte mask, in cases where pointer

  // authentication might also be active.

  uint64_t address_mask = 0;

  lldb::ThreadSP thread_sp = process_sp->GetThreadList().GetSelectedThread();

  if (thread_sp) {

    // Linux configures user-space virtual addresses with top byte ignored.

    // We set default value of mask such that top byte is masked out.

    address_mask = ~((1ULL << 56) - 1);

    // If Pointer Authentication feature is enabled then Linux exposes

    // PAC data and code mask register. Try reading relevant register

    // below and merge it with default address mask calculated above.

    lldb::RegisterContextSP reg_ctx_sp = thread_sp->GetRegisterContext();

    if (reg_ctx_sp) {

      const RegisterInfo *reg_info =

          reg_ctx_sp->GetRegisterInfoByName(reg_name, 0);

      if (reg_info) {

        lldb::addr_t mask_reg_val = reg_ctx_sp->ReadRegisterAsUnsigned(

            reg_info->kinds[eRegisterKindLLDB], LLDB_INVALID_ADDRESS);

        if (mask_reg_val != LLDB_INVALID_ADDRESS)

          address_mask |= mask_reg_val;

      }

    }

  }

  return address_mask;

}

lldb::addr_t ABISysV_arm64::FixCodeAddress(lldb::addr_t pc) {

  if (lldb::ProcessSP process_sp = GetProcessSP()) {

    if (process_sp->GetTarget().GetArchitecture().GetTriple().isOSLinux() &&

        
!process_sp->GetCodeAddressMask()135
)

      process_sp->SetCodeAddressMask(

          ReadLinuxProcessAddressMask(process_sp, "code_mask"));

    return FixAddress(pc, process_sp->GetCodeAddressMask());

  }

  return pc;

}

lldb::addr_t ABISysV_arm64::FixDataAddress(lldb::addr_t pc) {

  if (lldb::ProcessSP process_sp = GetProcessSP()) {

    if (process_sp->GetTarget().GetArchitecture().GetTriple().isOSLinux() &&

        
!process_sp->GetDataAddressMask()1.11k
)

      process_sp->SetDataAddressMask(

          ReadLinuxProcessAddressMask(process_sp, "data_mask"));

    return FixAddress(pc, process_sp->GetDataAddressMask());

  }

  return pc;

}

void ABISysV_arm64::Initialize() {

  PluginManager::RegisterPlugin(GetPluginNameStatic(),

                                "SysV ABI for AArch64 targets", CreateInstance);

}

void ABISysV_arm64::Terminate() {

  PluginManager::UnregisterPlugin(CreateInstance);

}