//===-- NativeRegisterContext.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 "lldb/Host/common/NativeRegisterContext.h"

#include "lldb/Utility/LLDBLog.h"

#include "lldb/Utility/RegisterValue.h"

#include "lldb/Host/PosixApi.h"

#include "lldb/Host/common/NativeProcessProtocol.h"

#include "lldb/Host/common/NativeThreadProtocol.h"

using namespace lldb;

using namespace lldb_private;

NativeRegisterContext::NativeRegisterContext(NativeThreadProtocol &thread)

    : m_thread(thread) {}

// Destructor

NativeRegisterContext::~NativeRegisterContext() = default;

// FIXME revisit invalidation, process stop ids, etc.  Right now we don't

// support caching in NativeRegisterContext.  We can do this later by utilizing

// NativeProcessProtocol::GetStopID () and adding a stop id to

// NativeRegisterContext.

// void

// NativeRegisterContext::InvalidateIfNeeded (bool force) {

//     ProcessSP process_sp (m_thread.GetProcess());

//     bool invalidate = force;

//     uint32_t process_stop_id = UINT32_MAX;

//     if (process_sp)

//         process_stop_id = process_sp->GetStopID();

//     else

//         invalidate = true;

//     if (!invalidate)

//         invalidate = process_stop_id != GetStopID();

//     if (invalidate)

//     {

//         InvalidateAllRegisters ();

//         SetStopID (process_stop_id);

//     }

// }

const RegisterInfo *

NativeRegisterContext::GetRegisterInfoByName(llvm::StringRef reg_name,

                                             uint32_t start_idx) {

  if (reg_name.empty())

    return nullptr;

  // Generic register names take precedence over specific register names.

  // For example, on x86 we want "sp" to refer to the complete RSP/ESP register

  // rather than the 16-bit SP pseudo-register.

  uint32_t generic_reg = Args::StringToGenericRegister(reg_name);

  if (generic_reg != LLDB_INVALID_REGNUM) {

    const RegisterInfo *reg_info =

        GetRegisterInfo(eRegisterKindGeneric, generic_reg);

    if (reg_info)

      return reg_info;

  }

  const uint32_t num_registers = GetRegisterCount();

  for (uint32_t reg = start_idx; reg < num_registers; ++reg) {

    const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg);

    if (reg_name.equals_insensitive(reg_info->name) ||

        reg_name.equals_insensitive(reg_info->alt_name))

      return reg_info;

  }

  return nullptr;

}

const RegisterInfo *NativeRegisterContext::GetRegisterInfo(uint32_t kind,

                                                           uint32_t num) {

  const uint32_t reg_num = ConvertRegisterKindToRegisterNumber(kind, num);

  if (reg_num == LLDB_INVALID_REGNUM)

    return nullptr;

  return GetRegisterInfoAtIndex(reg_num);

}

const char *NativeRegisterContext::GetRegisterName(uint32_t reg) {

  const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg);

  if (reg_info)

    return reg_info->name;

  return nullptr;

}

const char *NativeRegisterContext::GetRegisterSetNameForRegisterAtIndex(

    uint32_t reg_index) const {

  const RegisterInfo *const reg_info = GetRegisterInfoAtIndex(reg_index);

  if (!reg_info)

    return nullptr;

  for (uint32_t set_index = 0; set_index < GetRegisterSetCount(); ++set_index) {

    const RegisterSet *const reg_set = GetRegisterSet(set_index);

    if (!reg_set)

      continue;

    for (uint32_t reg_num_index = 0; reg_num_index < reg_set->num_registers;

         ++reg_num_index) {

      const uint32_t reg_num = reg_set->registers[reg_num_index];

      // FIXME double check we're checking the right register kind here.

      if (reg_info->kinds[RegisterKind::eRegisterKindLLDB] == reg_num) {

        // The given register is a member of this register set.  Return the

        // register set name.

        return reg_set->name;

      }

    }

  }

  // Didn't find it.

  return nullptr;

}

lldb::addr_t NativeRegisterContext::GetPC(lldb::addr_t fail_value) {

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

  uint32_t reg = ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_PC);

  LLDB_LOGF(log, "Using reg index %" PRIu32 " (default %" PRIu64 ")", reg,

            fail_value);

  const uint64_t retval = ReadRegisterAsUnsigned(reg, fail_value);

  LLDB_LOGF(log, PRIu32 " retval %" PRIu64, retval);

  return retval;

}

lldb::addr_t

NativeRegisterContext::GetPCfromBreakpointLocation(lldb::addr_t fail_value) {

  return GetPC(fail_value);

}

Status NativeRegisterContext::SetPC(lldb::addr_t pc) {

  uint32_t reg = ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_PC);

  return WriteRegisterFromUnsigned(reg, pc);

}

lldb::addr_t NativeRegisterContext::GetSP(lldb::addr_t fail_value) {

  uint32_t reg = ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_SP);

  return ReadRegisterAsUnsigned(reg, fail_value);

}

Status NativeRegisterContext::SetSP(lldb::addr_t sp) {

  uint32_t reg = ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_SP);

  return WriteRegisterFromUnsigned(reg, sp);

}

lldb::addr_t NativeRegisterContext::GetFP(lldb::addr_t fail_value) {

  uint32_t reg = ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_FP);

  return ReadRegisterAsUnsigned(reg, fail_value);

}

Status NativeRegisterContext::SetFP(lldb::addr_t fp) {

  uint32_t reg = ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_FP);

  return WriteRegisterFromUnsigned(reg, fp);

}

lldb::addr_t NativeRegisterContext::GetReturnAddress(lldb::addr_t fail_value) {

  uint32_t reg = ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_RA);

  return ReadRegisterAsUnsigned(reg, fail_value);

}

lldb::addr_t NativeRegisterContext::GetFlags(lldb::addr_t fail_value) {

  uint32_t reg = ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,

                                                     LLDB_REGNUM_GENERIC_FLAGS);

  return ReadRegisterAsUnsigned(reg, fail_value);

}

lldb::addr_t

NativeRegisterContext::ReadRegisterAsUnsigned(uint32_t reg,

                                              lldb::addr_t fail_value) {

  if (reg != LLDB_INVALID_REGNUM)

    return ReadRegisterAsUnsigned(GetRegisterInfoAtIndex(reg), fail_value);

  return fail_value;

}

uint64_t

NativeRegisterContext::ReadRegisterAsUnsigned(const RegisterInfo *reg_info,

                                              lldb::addr_t fail_value) {

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

  if (reg_info) {

    RegisterValue value;

    Status error = ReadRegister(reg_info, value);

    if (error.Success()) {

      LLDB_LOGF(log,

                "Read register succeeded: value "

                "%" PRIu64,

                value.GetAsUInt64());

      return value.GetAsUInt64();

    } else {

      LLDB_LOGF(log, "Read register failed: error %s", error.AsCString());

    }

  } else {

    LLDB_LOGF(log, "Read register failed: null reg_info");

  }

  return fail_value;

}

Status NativeRegisterContext::WriteRegisterFromUnsigned(uint32_t reg,

                                                        uint64_t uval) {

  if (reg == LLDB_INVALID_REGNUM)

    return Status("Write register failed: reg is invalid");

  return WriteRegisterFromUnsigned(GetRegisterInfoAtIndex(reg), uval);

}

Status

NativeRegisterContext::WriteRegisterFromUnsigned(const RegisterInfo *reg_info,

                                                 uint64_t uval) {

  assert(reg_info);

  if (!reg_info)

    return Status("reg_info is nullptr");

  RegisterValue value;

  if (!value.SetUInt(uval, reg_info->byte_size))

    return Status("RegisterValue::SetUInt () failed");

  return WriteRegister(reg_info, value);

}

lldb::tid_t NativeRegisterContext::GetThreadID() const {

  return m_thread.GetID();

}

uint32_t NativeRegisterContext::NumSupportedHardwareBreakpoints() { return 0; }

uint32_t NativeRegisterContext::SetHardwareBreakpoint(lldb::addr_t addr,

                                                      size_t size) {

  return LLDB_INVALID_INDEX32;

}

Status NativeRegisterContext::ClearAllHardwareBreakpoints() {

  return Status("not implemented");

}

bool NativeRegisterContext::ClearHardwareBreakpoint(uint32_t hw_idx) {

  return false;

}

Status NativeRegisterContext::GetHardwareBreakHitIndex(uint32_t &bp_index,

                                                       lldb::addr_t trap_addr) {

  bp_index = LLDB_INVALID_INDEX32;

  return Status("not implemented");

}

uint32_t NativeRegisterContext::NumSupportedHardwareWatchpoints() { return 0; }

uint32_t NativeRegisterContext::SetHardwareWatchpoint(lldb::addr_t addr,

                                                      size_t size,

                                                      uint32_t watch_flags) {

  return LLDB_INVALID_INDEX32;

}

bool NativeRegisterContext::ClearHardwareWatchpoint(uint32_t hw_index) {

  return false;

}

Status NativeRegisterContext::ClearWatchpointHit(uint32_t hw_index) {

  return Status("not implemented");

}

Status NativeRegisterContext::ClearAllHardwareWatchpoints() {

  return Status("not implemented");

}

Status NativeRegisterContext::IsWatchpointHit(uint32_t wp_index, bool &is_hit) {

  is_hit = false;

  return Status("not implemented");

}

Status NativeRegisterContext::GetWatchpointHitIndex(uint32_t &wp_index,

                                                    lldb::addr_t trap_addr) {

  wp_index = LLDB_INVALID_INDEX32;

  return Status("not implemented");

}

Status NativeRegisterContext::IsWatchpointVacant(uint32_t wp_index,

                                                 bool &is_vacant) {

  is_vacant = false;

  return Status("not implemented");

}

lldb::addr_t NativeRegisterContext::GetWatchpointAddress(uint32_t wp_index) {

  return LLDB_INVALID_ADDRESS;

}

lldb::addr_t NativeRegisterContext::GetWatchpointHitAddress(uint32_t wp_index) {

  return LLDB_INVALID_ADDRESS;

}

bool NativeRegisterContext::HardwareSingleStep(bool enable) { return false; }

Status NativeRegisterContext::ReadRegisterValueFromMemory(

    const RegisterInfo *reg_info, lldb::addr_t src_addr, size_t src_len,

    RegisterValue &reg_value) {

  Status error;

  if (reg_info == nullptr) {

    error.SetErrorString("invalid register info argument.");

    return error;

  }

  // Moving from addr into a register

  //

  // Case 1: src_len == dst_len

  //

  //   |AABBCCDD| Address contents

  //   |AABBCCDD| Register contents

  //

  // Case 2: src_len > dst_len

  //

  //   Status!  (The register should always be big enough to hold the data)

  //

  // Case 3: src_len < dst_len

  //

  //   |AABB| Address contents

  //   |AABB0000| Register contents [on little-endian hardware]

  //   |0000AABB| Register contents [on big-endian hardware]

  const size_t dst_len = reg_info->byte_size;

  if (src_len > dst_len) {

    error.SetErrorStringWithFormat(

        "%" PRIu64 " bytes is too big to store in register %s (%" PRIu64

        " bytes)",

        static_cast<uint64_t>(src_len), reg_info->name,

        static_cast<uint64_t>(dst_len));

    return error;

  }

  NativeProcessProtocol &process = m_thread.GetProcess();

  RegisterValue::BytesContainer src(src_len);

  // Read the memory

  size_t bytes_read;

  error = process.ReadMemory(src_addr, src.data(), src_len, bytes_read);

  if (error.Fail())

    return error;

  // Make sure the memory read succeeded...

  if (bytes_read != src_len) {

    // This might happen if we read _some_ bytes but not all

    error.SetErrorStringWithFormat("read %" PRIu64 " of %" PRIu64 " bytes",

                                   static_cast<uint64_t>(bytes_read),

                                   static_cast<uint64_t>(src_len));

    return error;

  }

  // We now have a memory buffer that contains the part or all of the register

  // value. Set the register value using this memory data.

  // TODO: we might need to add a parameter to this function in case the byte

  // order of the memory data doesn't match the process. For now we are

  // assuming they are the same.

  reg_value.SetFromMemoryData(*reg_info, src.data(), src_len,

                              process.GetByteOrder(), error);

  return error;

}

Status NativeRegisterContext::WriteRegisterValueToMemory(

    const RegisterInfo *reg_info, lldb::addr_t dst_addr, size_t dst_len,

    const RegisterValue &reg_value) {

  Status error;

  if (reg_info == nullptr) {

    error.SetErrorString("Invalid register info argument.");

    return error;

  }

  RegisterValue::BytesContainer dst(dst_len);

  NativeProcessProtocol &process = m_thread.GetProcess();

  // TODO: we might need to add a parameter to this function in case the byte

  // order of the memory data doesn't match the process. For now we are

  // assuming they are the same.

  const size_t bytes_copied = reg_value.GetAsMemoryData(

      *reg_info, dst.data(), dst_len, process.GetByteOrder(), error);

  if (error.Success()) {

    if (bytes_copied == 0) {

      error.SetErrorString("byte copy failed.");

    } else {

      size_t bytes_written;

      error = process.WriteMemory(dst_addr, dst.data(), bytes_copied,

                                  bytes_written);

      if (error.Fail())

        return error;

      if (bytes_written != bytes_copied) {

        // This might happen if we read _some_ bytes but not all

        error.SetErrorStringWithFormat("only wrote %" PRIu64 " of %" PRIu64

                                       " bytes",

                                       static_cast<uint64_t>(bytes_written),

                                       static_cast<uint64_t>(bytes_copied));

      }

    }

  }

  return error;

}

uint32_t

NativeRegisterContext::ConvertRegisterKindToRegisterNumber(uint32_t kind,

                                                           uint32_t num) const {

  const uint32_t num_regs = GetRegisterCount();

  assert(kind < kNumRegisterKinds);

  for (uint32_t reg_idx = 0; reg_idx < num_regs; ++reg_idx) {

    const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg_idx);

    if (reg_info->kinds[kind] == num)

      return reg_idx;

  }

  return LLDB_INVALID_REGNUM;

}

std::vector<uint32_t>

NativeRegisterContext::GetExpeditedRegisters(ExpeditedRegs expType) const {

  if (expType == ExpeditedRegs::Minimal) {

    // Expedite only a minimum set of important generic registers.

    static const uint32_t k_expedited_registers[] = {

        LLDB_REGNUM_GENERIC_PC, LLDB_REGNUM_GENERIC_SP, LLDB_REGNUM_GENERIC_FP,

        LLDB_REGNUM_GENERIC_RA};

    std::vector<uint32_t> expedited_reg_nums;

    for (uint32_t gen_reg : k_expedited_registers) {

      uint32_t reg_num =

          ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric, gen_reg);

      if (reg_num == LLDB_INVALID_REGNUM)

        continue; // Target does not support the given register.

      else

        expedited_reg_nums.push_back(reg_num);

    }

    return expedited_reg_nums;

  }

  if (GetRegisterSetCount() > 0 && expType == ExpeditedRegs::Full)

    return std::vector<uint32_t>(GetRegisterSet(0)->registers,

                                 GetRegisterSet(0)->registers +

                                     GetRegisterSet(0)->num_registers);

  return std::vector<uint32_t>();

}