boost/serialization/export.hpp

   1 #ifndef BOOST_SERIALIZATION_EXPORT_HPP
   2 #define BOOST_SERIALIZATION_EXPORT_HPP
   3
   4 // MS compatible compilers support #pragma once
   5 #if defined(_MSC_VER)
   6 # pragma once
   7 #endif
   8
   9 /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
  10 // export.hpp: set traits of classes to be serialized
  11
  12 // (C) Copyright 2002 Robert Ramey - http://www.rrsd.com .
  13 // Use, modification and distribution is subject to the Boost Software
  14 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  15 // http://www.boost.org/LICENSE_1_0.txt)
  16
  17 //  See http://www.boost.org for updates, documentation, and revision history.
  18
  19 // (C) Copyright 2006 David Abrahams - http://www.boost.org.
  20 // implementation of class export functionality.  This is an alternative to
  21 // "forward declaration" method to provoke instantiation of derived classes
  22 // that are to be serialized through pointers.
  23
  24 #include <utility>
  25 #include <cstddef> // NULL
  26
  27 #include <boost/config.hpp>
  28 #include <boost/static_assert.hpp>
  29 #include <boost/preprocessor/stringize.hpp>
  30 #include <boost/type_traits/is_polymorphic.hpp>
  31
  32 #include <boost/mpl/assert.hpp>
  33 #include <boost/mpl/and.hpp>
  34 #include <boost/mpl/not.hpp>
  35 #include <boost/mpl/bool.hpp>
  36
  37 #include <boost/serialization/extended_type_info.hpp> // for guid_defined only
  38 #include <boost/serialization/static_warning.hpp>
  39 #include <boost/serialization/assume_abstract.hpp>
  40 #include <boost/serialization/force_include.hpp>
  41 #include <boost/serialization/singleton.hpp>
  42
  43 #include <boost/archive/detail/register_archive.hpp>
  44
  45 #include <iostream>
  46
  47 namespace boost {
  48 namespace archive {
  49 namespace detail {
  50
  51 class basic_pointer_iserializer;
  52 class basic_pointer_oserializer;
  53
  54 template<class Archive, class T>
  55 class pointer_iserializer;
  56 template<class Archive, class T>
  57 class pointer_oserializer;
  58
  59 template <class Archive, class Serializable>
  60 struct export_impl
  61 {
  62     static const basic_pointer_iserializer &
  63     enable_load(mpl::true_){
  64         return boost::serialization::singleton<
  65             pointer_iserializer<Archive, Serializable>
  66         >::get_const_instance();
  67     }
  68
  69     static const basic_pointer_oserializer &
  70     enable_save(mpl::true_){
  71         return boost::serialization::singleton<
  72             pointer_oserializer<Archive, Serializable>
  73         >::get_const_instance();
  74     }
  75     inline static void enable_load(mpl::false_) {}
  76     inline static void enable_save(mpl::false_) {}
  77 };
  78
  79 // On many platforms, naming a specialization of this template is
  80 // enough to cause its argument to be instantiated.
  81 template <void(*)()>
  82 struct instantiate_function {};
  83
  84 template <class Archive, class Serializable>
  85 struct ptr_serialization_support
  86 {
  87 # if defined(BOOST_MSVC) || defined(__SUNPRO_CC)
  88     virtual BOOST_DLLEXPORT void instantiate() BOOST_USED;
  89 # elif defined(__BORLANDC__)
  90     static BOOST_DLLEXPORT void instantiate() BOOST_USED;
  91     enum { x = sizeof(instantiate(),3) };
  92 # else
  93     static BOOST_DLLEXPORT void instantiate() BOOST_USED;
  94     typedef instantiate_function<
  95         &ptr_serialization_support::instantiate
  96     > x;
  97 # endif
  98 };
  99
 100 template <class Archive, class Serializable>
 101 BOOST_DLLEXPORT void
 102 ptr_serialization_support<Archive,Serializable>::instantiate()
 103 {
 104     export_impl<Archive,Serializable>::enable_save(
 105         #if ! defined(__BORLANDC__)
 106         typename
 107         #endif
 108         Archive::is_saving()
 109     );
 110
 111     export_impl<Archive,Serializable>::enable_load(
 112         #if ! defined(__BORLANDC__)
 113         typename
 114         #endif
 115         Archive::is_loading()
 116     );
 117 }
 118
 119 // Note INTENTIONAL usage of anonymous namespace in header.
 120 // This was made this way so that export.hpp could be included
 121 // in other headers.  This is still under study.
 122
 123 namespace extra_detail {
 124
 125 template<class T>
 126 struct guid_initializer
 127 {
 128     void export_guid(mpl::false_) const {
 129         // generates the statically-initialized objects whose constructors
 130         // register the information allowing serialization of T objects
 131         // through pointers to their base classes.
 132         instantiate_ptr_serialization((T*)0, 0, adl_tag());
 133     }
 134     void export_guid(mpl::true_) const {
 135     }
 136     guid_initializer const & export_guid() const {
 137         BOOST_STATIC_WARNING(boost::is_polymorphic< T >::value);
 138         // note: exporting an abstract base class will have no effect
 139         // and cannot be used to instantitiate serialization code
 140         // (one might be using this in a DLL to instantiate code)
 141         //BOOST_STATIC_WARNING(! boost::serialization::is_abstract< T >::value);
 142         export_guid(boost::serialization::is_abstract< T >());
 143         return *this;
 144     }
 145 };
 146
 147 template<typename T>
 148 struct init_guid;
 149
 150 } // anonymous
 151 } // namespace detail
 152 } // namespace archive
 153 } // namespace boost
 154
 155 #define BOOST_CLASS_EXPORT_IMPLEMENT(T)                      \
 156     namespace boost {                                        \
 157     namespace archive {                                      \
 158     namespace detail {                                       \
 159     namespace extra_detail {                                 \
 160     template<>                                               \
 161     struct init_guid< T > {                                  \
 162         static guid_initializer< T > const & g;              \
 163     };                                                       \
 164     guid_initializer< T > const & init_guid< T >::g =        \
 165         ::boost::serialization::singleton<                   \
 166             guid_initializer< T >                            \
 167         >::get_mutable_instance().export_guid();             \
 168     }}}}                                                     \
 169 /**/
 170
 171 #define BOOST_CLASS_EXPORT_KEY2(T, K)          \
 172 namespace boost {                              \
 173 namespace serialization {                      \
 174 template<>                                     \
 175 struct guid_defined< T > : boost::mpl::true_ {}; \
 176 template<>                                     \
 177 inline const char * guid< T >(){                 \
 178     return K;                                  \
 179 }                                              \
 180 } /* serialization */                          \
 181 } /* boost */                                  \
 182 /**/
 183
 184 #define BOOST_CLASS_EXPORT_KEY(T)                                      \
 185     BOOST_CLASS_EXPORT_KEY2(T, BOOST_PP_STRINGIZE(T))                                                                  \
 186 /**/
 187
 188 #define BOOST_CLASS_EXPORT_GUID(T, K)                                  \
 189 BOOST_CLASS_EXPORT_KEY2(T, K)                                          \
 190 BOOST_CLASS_EXPORT_IMPLEMENT(T)                                        \
 191 /**/
 192
 193 #if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3205))
 194
 195 // CodeWarrior fails to construct static members of class templates
 196 // when they are instantiated from within templates, so on that
 197 // compiler we ask users to specifically register base/derived class
 198 // relationships for exported classes.  On all other compilers, use of
 199 // this macro is entirely optional.
 200 # define BOOST_SERIALIZATION_MWERKS_BASE_AND_DERIVED(Base,Derived)             \
 201 namespace {                                                                    \
 202   static int BOOST_PP_CAT(boost_serialization_mwerks_init_, __LINE__) =        \
 203   (::boost::archive::detail::instantiate_ptr_serialization((Derived*)0,0), 3); \
 204   static int BOOST_PP_CAT(boost_serialization_mwerks_init2_, __LINE__) = (     \
 205       ::boost::serialization::void_cast_register((Derived*)0,(Base*)0)         \
 206     , 3);                                                                      \
 207 }
 208
 209 #else
 210
 211 # define BOOST_SERIALIZATION_MWERKS_BASE_AND_DERIVED(Base,Derived)
 212
 213 #endif
 214
 215 // check for unnecessary export.  T isn't polymorphic so there is no
 216 // need to export it.
 217 #define BOOST_CLASS_EXPORT_CHECK(T)                              \
 218     BOOST_STATIC_WARNING(                                        \
 219         boost::is_polymorphic<U>::value                          \
 220     );                                                           \
 221     /**/
 222
 223 // the default exportable class identifier is the class name
 224 // the default list of archives types for which code id generated
 225 // are the originally included with this serialization system
 226 #define BOOST_CLASS_EXPORT(T)                   \
 227     BOOST_CLASS_EXPORT_GUID(                    \
 228         T,                                      \
 229         BOOST_PP_STRINGIZE(T)                   \
 230     )                                           \
 231     /**/
 232
 233 #endif // BOOST_SERIALIZATION_EXPORT_HPP
 234