luabind/exception_handler.hpp

   1 // Copyright Daniel Wallin 2005. Use, modification and distribution is
   2 // subject to the Boost Software License, Version 1.0. (See accompanying
   3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   4
   5 #ifndef LUABIND_EXCEPTION_HANDLER_050601_HPP
   6 # define LUABIND_EXCEPTION_HANDLER_050601_HPP
   7
   8 # include <luabind/lua_include.hpp>
   9 # include <luabind/config.hpp>
  10 # include <boost/optional.hpp>
  11 # include <boost/type.hpp>
  12
  13 # if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
  14 #  include <boost/mpl/if.hpp>
  15 #  include <boost/type_traits/is_pointer.hpp>
  16 # endif
  17
  18 namespace luabind {
  19
  20 # ifndef LUABIND_NO_EXCEPTIONS
  21
  22 namespace detail
  23 {
  24
  25   struct LUABIND_API exception_handler_base
  26   {
  27       exception_handler_base()
  28         : next(0)
  29       {}
  30
  31       virtual ~exception_handler_base() {}
  32       virtual void handle(lua_State*) const = 0;
  33
  34       void try_next(lua_State*) const;
  35
  36       exception_handler_base* next;
  37   };
  38
  39   namespace mpl = boost::mpl;
  40
  41   template<class E, class Handler>
  42   struct exception_handler : exception_handler_base
  43   {
  44 #  if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
  45       typedef typename mpl::if_<
  46           boost::is_pointer<E>, E, E const&
  47       >::type argument;
  48 #  else
  49       typedef E const& argument;
  50 #  endif
  51
  52       exception_handler(Handler handler)
  53         : handler(handler)
  54       {}
  55
  56       void handle(lua_State* L) const
  57       {
  58           try
  59           {
  60               try_next(L);
  61           }
  62           catch (argument e)
  63           {
  64               handler(L, e);
  65           }
  66       }
  67
  68       Handler handler;
  69   };
  70
  71   LUABIND_API void handle_exception_aux(lua_State* L);
  72   LUABIND_API void register_exception_handler(exception_handler_base*);
  73
  74 } // namespace detail
  75
  76 # endif
  77
  78 template<class E, class Handler>
  79 void register_exception_handler(Handler handler, boost::type<E>* = 0)
  80 {
  81 # ifndef LUABIND_NO_EXCEPTIONS
  82     detail::register_exception_handler(
  83         new detail::exception_handler<E, Handler>(handler)
  84     );
  85 # endif
  86 }
  87
  88 template<class R, class F>
  89 boost::optional<R> handle_exceptions(lua_State* L, F fn, boost::type<R>* = 0)
  90 {
  91 # ifndef LUABIND_NO_EXCEPTIONS
  92     try
  93     {
  94         return fn();
  95     }
  96     catch (...)
  97     {
  98         detail::handle_exception_aux(L);
  99     }
 100
 101     return boost::optional<R>();
 102 # else
 103     return fn();
 104 # endif
 105 }
 106
 107 } // namespace luabind
 108
 109 #endif // LUABIND_EXCEPTION_HANDLER_050601_HPP
 110