// vim:set ft=cpp: -*- Mode: C++ -*-
/**
 * \file
 * L4::Cap related definitions.
 *
 * \author Alexander Warg <alexander.warg@os.inf.tu-dresden.de>
 *
 */
/*
 * (c) 2008-2009,2015 Author(s)
 *     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/consts.h>
#include <l4/sys/types.h>
#include <l4/sys/kobject>
#include <l4/sys/task.h>

namespace L4
{

/* Forward declarations for our kernel object classes. */
class Task;
class Thread;
class Factory;
class Irq;
class Log;
class Vm;
class Kobject;

/**
 * Disable copy of a class.
 *
 * \param _class  Name of the class that shall not have value copy semantics.
 *
 * The typical use of this is:
 * ~~~
 * class Non_value
 * {
 *   L4_DISABLE_COPY(Non_value)
 *
 *   ...
 * }
 * ~~~
 */
#if __cplusplus >= 201103L
#  define L4_DISABLE_COPY(_class)                \
  public:                                        \
    _class(_class const &) = delete;             \
    _class operator = (_class const &) = delete; \
  private:
#else
#  define L4_DISABLE_COPY(_class)       \
  private:                              \
    _class(_class const &);             \
    _class operator = (_class const &);
#endif


#define L4_KOBJECT_DISABLE_COPY(_class) \
  protected:                            \
    _class();                           \
  L4_DISABLE_COPY(_class)


#define L4_KOBJECT(_class) L4_KOBJECT_DISABLE_COPY(_class)

inline l4_msgtag_t
Cap_base::validate(Cap<Task> task, l4_utcb_t *u) const noexcept
{
  return is_valid() ? l4_task_cap_valid_u(task.cap(), _c, u)
                    : l4_msgtag(0, 0, 0, 0);
}

inline l4_msgtag_t
Cap_base::validate(l4_utcb_t *u) const noexcept
{
  return is_valid() ? l4_task_cap_valid_u(L4_BASE_TASK_CAP, _c, u)
                    : l4_msgtag(0, 0, 0, 0);
}

}; // namespace L4

#include <l4/sys/meta>

namespace L4 {

/**
 * `dynamic_cast` for capabilities.
 *
 * \tparam T  The target type of the capability.
 * \tparam F  The source type (is usually implicitly set).
 * \param  c  The source capability that shall be casted.
 *
 * \retval Cap<T>          Capability of target interface `T`.
 * \retval L4_INVALID_CAP  `c` does not support the target interface `T` or the
 *                         L4::Meta interface.
 *
 * The use of this cast operator is similar to the `dynamic_cast<>()` for
 * C++ pointers.  It also induces overhead, because it uses the meta interface
 * (L4::Meta) to do runtime type checking.
 *
 * Example code:
 *
 *     L4::Cap<L4::Kobject> obj = ... ;
 *     L4::Cap<L4::Icu> icu = L4::cap_dynamic_cast<L4::Icu>(obj);
 *
 */
template< typename T, typename F >
inline
Cap<T> cap_dynamic_cast(Cap<F> const &c) noexcept
{
  if (!c.is_valid())
    return Cap<T>::Invalid;

  Cap<Meta> mc = cap_reinterpret_cast<Meta>(c);
  Type_info const *m = kobject_typeid<T>();
  if (m->proto() && l4_error(mc->supports(m->proto())) > 0)
    return Cap<T>(c.cap());

  // FIXME: use generic checker
#if 0
  if (l4_error(mc->supports(T::kobject_proto())) > 0)
    return Cap<T>(c.cap());
#endif

  return Cap<T>::Invalid;
}

}