exception_states.h

#pragma once
 
#include "libmicroemu/exception_type.h"
#include "libmicroemu/types.h"
#include <array>
 
namespace libmicroemu {
 
using ExceptionFlagsSet = u8;
 
enum class ExceptionFlags : ExceptionFlagsSet {
  kPending = 1U << 0U,
  kActive = 1U << 1U,
};
 
static constexpr i16 kLowestExceptionPriority = 255U;

struct SingleExceptionState {
  explicit constexpr SingleExceptionState(u8 number) : number_{number}, priority_{0}, flags_{0U} {}

  inline void ClearFlags() noexcept { flags_ = 0U; }

  inline bool IsPending() const noexcept {
    return (flags_ & static_cast<ExceptionFlagsSet>(ExceptionFlags::kPending)) != 0U;
  }

  inline void ClearPending() noexcept {
    flags_ &= ~static_cast<ExceptionFlagsSet>(ExceptionFlags::kPending);
  }

  inline void SetPending() noexcept {
    flags_ |= static_cast<ExceptionFlagsSet>(ExceptionFlags::kPending);
  }

  inline bool IsActive() const noexcept {
    return (flags_ & static_cast<ExceptionFlagsSet>(ExceptionFlags::kActive)) != 0U;
  }

  inline void ClearActive() noexcept {
    flags_ &= ~static_cast<ExceptionFlagsSet>(ExceptionFlags::kActive);
  }

  inline void SetActive() noexcept {
    flags_ |= static_cast<ExceptionFlagsSet>(ExceptionFlags::kActive);
  }

  inline i16 GetPriority() const noexcept { return priority_; }

  inline void SetPriority(i16 priority) noexcept { priority_ = priority; }

  inline u8 GetNumber() const noexcept { return number_; }
 
private:
  const u8 number_;
  i16 priority_;
  ExceptionFlagsSet flags_;
};
 
template <std::size_t... Indices>
constexpr auto MakeExceptionArray(std::index_sequence<Indices...>) {
  return std::array<SingleExceptionState, sizeof...(Indices)>{
      SingleExceptionState(static_cast<u8>(Indices))...};
}
 
struct ExceptionStates {
  ExceptionStates()
      : exception{MakeExceptionArray(std::make_index_sequence<CountExceptions()>())} {}
 
  u32 pending_exceptions{0U};
  std::array<SingleExceptionState, CountExceptions()> exception;
};
 
} // namespace libmicroemu