// vi:ft=cpp
/**
 * \file
 * \brief   Error helper.
 */
/*
 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
 *               Alexander Warg <warg@os.inf.tu-dresden.de>,
 *               Torsten Frenzel <frenzel@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * This file is part of TUD:OS and distributed under the terms of the
 * GNU General Public License 2.
 * Please see the COPYING-GPL-2 file for details.
 *
 * As a special exception, you may use this file as part of a free software
 * library without restriction.  Specifically, if other files instantiate
 * templates or use macros or inline functions from this file, or you compile
 * this file and link it with other files to produce an executable, this
 * file does not by itself cause the resulting executable to be covered by
 * the GNU General Public License.  This exception does not however
 * invalidate any other reasons why the executable file might be covered by
 * the GNU General Public License.
 */
#pragma once

#include <l4/sys/types.h>
#include <l4/cxx/exceptions>
#include <l4/sys/err.h>

namespace L4Re {

#ifdef __EXCEPTIONS
namespace Priv {
inline long __attribute__((__noreturn__)) __runtime_error(long err, char const *extra);

inline long __runtime_error(long err, char const *extra)
{
  switch (err)
    {
    case -L4_ENOENT: throw (L4::Element_not_found(extra));
    case -L4_ENOMEM: throw (L4::Out_of_memory(extra));
    case -L4_EEXIST: throw (L4::Element_already_exists(extra));
    case -L4_ERANGE: throw (L4::Bounds_error(extra));
    default: throw (L4::Runtime_error(err, extra));
    }
}

}

/**
 * \brief Generate C++ exception on error
 *
 * \param err   Error value, if negative exception will be thrown
 * \param extra Optional text for exception (default "")
 * \param ret   Optional value for exception, default is error value (err)
 *
 * This function throws an exception if the err is negative and
 * otherwise returns err.
 */
inline
long chksys(long err, char const *extra = "", long ret = 0)
{
  if (L4_UNLIKELY(err < 0))
    Priv::__runtime_error(ret ? ret : err, extra);

  return err;
}

/**
 * \brief Generate C++ exception on error
 *
 * \param t     Message tag.
 * \param extra Optional text for exception (default "")
 * \param utcb  Option UTCB
 * \param ret   Optional value for exception, default is error value (err)
 *
 * This function throws an exception if the message tag contains an error or
 * the label in the message tag is negative. Otherwise the label in the
 * message tag is returned.
 */
inline
long chksys(l4_msgtag_t const &t, char const *extra = "",
            l4_utcb_t *utcb = l4_utcb(), long ret = 0)
{
  if (L4_UNLIKELY(t.has_error()))
    Priv::__runtime_error(ret ? ret : l4_error_u(t, utcb), extra);
  else if (L4_UNLIKELY(t.label() < 0))
    throw L4::Runtime_error(ret ? ret: t.label(), extra);

  return t.label();
}

/**
 * \brief Generate C++ exception on error
 *
 * \param t     Message tag.
 * \param utcb  UTCB.
 * \param extra Optional text for exception (default "")
 *
 * This function throws an exception if the message tag contains an error or
 * the label in the message tag is negative. Otherwise the label in the
 * message tag is returned.
 */
inline
long chksys(l4_msgtag_t const &t, l4_utcb_t *utcb, char const *extra = "")
{ return chksys(t, extra, utcb); }

#if 0
inline
long chksys(long ret, long err, char const *extra = "")
{
  if (L4_UNLIKELY(ret < 0))
    Priv::__runtime_error(err, extra);

  return ret;
}
#endif

/**
 * Check for valid capability or raise C++ exception
 *
 * \tparam T  Type of object to check, must be capability-like
 *            (L4::Cap, L4Re::Util::Auto_cap etc.)
 *
 * \param cap    Capability value to check.
 * \param extra  Optional text for exception.
 * \param err    Error value for exception or 0 if the capability value
 *               should be used.
 *
 * This function checks whether the capability is valid. If the capability
 * is invalid an C++ exception is generated, using err if err is not zero,
 * otherwise the capability value is used. A valid capability will just be
 * returned.
 */
template<typename T>
inline
#if __cplusplus >= 201103L
T chkcap(T &&cap, char const *extra = "", long err = -L4_ENOMEM)
#else
T chkcap(T cap, char const *extra = "", long err = -L4_ENOMEM)
#endif
{
  if (L4_UNLIKELY(!cap.is_valid()))
    Priv::__runtime_error(err ? err : cap.cap(), extra);

  return cap;
}
#endif

}