src/developer/debug/debug_agent/general_registers.h

// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SRC_DEVELOPER_DEBUG_DEBUG_AGENT_GENERAL_REGISTERS_H_
#define SRC_DEVELOPER_DEBUG_DEBUG_AGENT_GENERAL_REGISTERS_H_

#include <optional>
#include <vector>

#include "src/developer/debug/debug_agent/arch.h"
#include "src/developer/debug/shared/register_id.h"
#include "src/developer/debug/shared/register_value.h"

namespace debug_agent {

// Wrapper around the general thread registers to allow them to be accessed uniformly regardless
// of the platform.
class GeneralRegisters {
 public:
  GeneralRegisters() : regs_() {}
  explicit GeneralRegisters(const arch::PlatformGeneralRegisters& r) : regs_(r) {}

#if defined(__x86_64__)
  // Instruction pointer.
  uint64_t ip() const { return regs_.rip; }
  void set_ip(uint64_t ip) { regs_.rip = ip; }

  // Stack pointer.
  uint64_t sp() const { return regs_.rsp; }
  void set_sp(uint64_t sp) { regs_.rsp = sp; }
#elif defined(__aarch64__)
  uint64_t ip() const { return regs_.pc; }
  void set_ip(uint64_t ip) { regs_.pc = ip; }

  // Stack pointer.
  uint64_t sp() const { return regs_.sp; }
  void set_sp(uint64_t sp) { regs_.sp = sp; }
#endif

  // Appends the current general registers to the given high-level register record.
  void CopyTo(std::vector<debug::RegisterValue>& dest) const;

  arch::PlatformGeneralRegisters& GetNativeRegisters() { return regs_; }
  const arch::PlatformGeneralRegisters& GetNativeRegisters() const { return regs_; }

  // TODO: Maintain a better id <-> platform register mapping and use here and in the arch files to
  // avoid this unnecessary std::vector creation and unify with the arch::SaveGeneralRegisters()
  // implementation.
  std::optional<uint64_t> GetRegister(debug::RegisterID reg_id) const;

 private:
  arch::PlatformGeneralRegisters regs_;
};

}  // namespace debug_agent

#endif  // SRC_DEVELOPER_DEBUG_DEBUG_AGENT_GENERAL_REGISTERS_H_