external_libraries/boost/libs/exception/src/clone_current_exception_non_intrusive.cpp

   1 //Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc.
   2
   3 //Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 //file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 //This MSVC-specific cpp file implements non-intrusive cloning of exception objects.
   7 //Based on an exception_ptr implementation by Anthony Williams.
   8
   9 #ifdef BOOST_NO_EXCEPTIONS
  10 #error This file requires exception handling to be enabled.
  11 #endif
  12
  13 #include <boost/exception/detail/clone_current_exception.hpp>
  14
  15 #if defined(BOOST_ENABLE_NON_INTRUSIVE_EXCEPTION_PTR) && defined(_MSC_VER) && defined(_M_IX86) && !defined(_M_X64)
  16
  17 //Non-intrusive cloning support implemented below, only for MSVC versions mentioned above.
  18 //Thanks Anthony Williams!
  19
  20 #include <boost/exception/exception.hpp>
  21 #include <boost/shared_ptr.hpp>
  22 #ifndef BOOST_NO_RTTI
  23 #include <typeinfo>
  24 #endif
  25 #include <windows.h>
  26 #include <malloc.h>
  27
  28 namespace
  29     {
  30     unsigned const exception_maximum_parameters=15;
  31     unsigned const exception_noncontinuable=1;
  32
  33 #if _MSC_VER==1310
  34     int const exception_info_offset=0x74;
  35 #elif (_MSC_VER==1400 || _MSC_VER==1500)
  36     int const exception_info_offset=0x80;
  37 #else
  38     int const exception_info_offset=-1;
  39 #endif
  40
  41     struct
  42     exception_record
  43         {
  44         unsigned long ExceptionCode;
  45         unsigned long ExceptionFlags;
  46         exception_record * ExceptionRecord;
  47         void * ExceptionAddress;
  48         unsigned long NumberParameters;
  49         ULONG_PTR ExceptionInformation[exception_maximum_parameters];
  50         };
  51
  52     struct
  53     exception_pointers
  54         {
  55         exception_record * ExceptionRecord;
  56         void * ContextRecord;
  57         };
  58
  59     unsigned const cpp_exception_code=0xE06D7363;
  60     unsigned const cpp_exception_magic_flag=0x19930520;
  61     unsigned const cpp_exception_parameter_count=3;
  62
  63     struct
  64     dummy_exception_type
  65         {
  66         };
  67
  68     typedef int(dummy_exception_type::*normal_copy_constructor_ptr)(void * src);
  69     typedef int(dummy_exception_type::*copy_constructor_with_virtual_base_ptr)(void * src,void * dst);
  70     typedef void (dummy_exception_type::*destructor_ptr)();
  71
  72     union
  73     cpp_copy_constructor
  74         {
  75         normal_copy_constructor_ptr normal_copy_constructor;
  76         copy_constructor_with_virtual_base_ptr copy_constructor_with_virtual_base;
  77         };
  78
  79     enum
  80     cpp_type_flags
  81         {
  82         class_is_simple_type=1,
  83         class_has_virtual_base=4
  84         };
  85
  86     struct
  87     cpp_type_info
  88         {
  89         unsigned flags;
  90 #ifndef BOOST_NO_RTTI
  91         void const * type_info;
  92 #else
  93         std::type_info * type_info;
  94 #endif
  95         int this_offset;
  96         int vbase_descr;
  97         int vbase_offset;
  98         unsigned long size;
  99         cpp_copy_constructor copy_constructor;
 100         };
 101
 102     struct
 103     cpp_type_info_table
 104         {
 105         unsigned count;
 106         const cpp_type_info * info[1];
 107         };
 108
 109     struct
 110     cpp_exception_type
 111         {
 112         unsigned flags;
 113         destructor_ptr destructor;
 114         void(*custom_handler)();
 115         cpp_type_info_table const * type_info_table;
 116         };
 117
 118     struct
 119     exception_object_deleter
 120         {
 121         cpp_exception_type const & et_;
 122
 123         exception_object_deleter( cpp_exception_type const & et ):
 124             et_(et)
 125             {
 126             }
 127
 128         void
 129         operator()( void * obj )
 130             {
 131             BOOST_ASSERT(obj!=0);
 132             dummy_exception_type * dummy_exception_ptr=reinterpret_cast<dummy_exception_type *>(obj);
 133             (dummy_exception_ptr->*(et_.destructor))();
 134             free(obj);
 135             }
 136         };
 137
 138     cpp_type_info const &
 139     get_cpp_type_info( cpp_exception_type const & et )
 140         {
 141         cpp_type_info const * ti = et.type_info_table->info[0];
 142         BOOST_ASSERT(ti!=0);
 143         return *ti;
 144         }
 145
 146     void
 147     copy_msvc_exception( void * dst, void * src, cpp_type_info const & ti )
 148         {
 149         if( !(ti.flags & class_is_simple_type) && ti.copy_constructor.normal_copy_constructor )
 150             {
 151             dummy_exception_type * dummy_exception_ptr = reinterpret_cast<dummy_exception_type *>(dst);
 152             if( ti.flags & class_has_virtual_base )
 153                 (dummy_exception_ptr->*(ti.copy_constructor.copy_constructor_with_virtual_base))(src,dst);
 154             else
 155                 (dummy_exception_ptr->*(ti.copy_constructor.normal_copy_constructor))(src);
 156             }
 157         else
 158             memmove(dst,src,ti.size);
 159         }
 160
 161     boost::shared_ptr<void>
 162     clone_msvc_exception( void * src, cpp_exception_type const & et )
 163         {
 164         assert(src!=0);
 165         cpp_type_info const & ti=get_cpp_type_info(et);
 166         if( void * dst = malloc(ti.size) )
 167             {
 168             try
 169                 {
 170                 copy_msvc_exception(dst,src,ti);
 171                 }
 172             catch(
 173             ... )
 174                 {
 175                 free(dst);
 176                 throw;
 177                 }
 178             return boost::shared_ptr<void>(dst,exception_object_deleter(et));
 179             }
 180         else
 181             throw std::bad_alloc();
 182         }
 183
 184     class
 185     cloned_exception:
 186         public boost::exception_detail::clone_base
 187         {
 188         cloned_exception( cloned_exception const & );
 189         cloned_exception & operator=( cloned_exception const & );
 190
 191         cpp_exception_type const & et_;
 192         boost::shared_ptr<void> exc_;
 193
 194         public:
 195
 196         cloned_exception( void * exc, cpp_exception_type const & et ):
 197             et_(et),
 198             exc_(clone_msvc_exception(exc,et_))
 199             {
 200             }
 201
 202         ~cloned_exception() throw()
 203             {
 204             }
 205
 206         boost::exception_detail::clone_base const *
 207         clone() const
 208             {
 209             return new cloned_exception(exc_.get(),et_);
 210             }
 211
 212         void
 213         rethrow() const
 214             {
 215             cpp_type_info const & ti=get_cpp_type_info(et_);
 216             void * dst = _alloca(ti.size);
 217             copy_msvc_exception(dst,exc_.get(),ti);
 218             ULONG_PTR args[cpp_exception_parameter_count];
 219             args[0]=cpp_exception_magic_flag;
 220             args[1]=reinterpret_cast<ULONG_PTR>(dst);
 221             args[2]=reinterpret_cast<ULONG_PTR>(&et_);
 222             RaiseException(cpp_exception_code,EXCEPTION_NONCONTINUABLE,cpp_exception_parameter_count,args);
 223             }
 224         };
 225
 226     bool
 227     is_cpp_exception( EXCEPTION_RECORD const * record )
 228         {
 229         return record &&
 230             (record->ExceptionCode==cpp_exception_code) &&
 231             (record->NumberParameters==cpp_exception_parameter_count) &&
 232             (record->ExceptionInformation[0]==cpp_exception_magic_flag);
 233         }
 234
 235     unsigned long
 236     exception_cloning_filter( int & result, boost::exception_detail::clone_base const * & ptr, void * info_ )
 237         {
 238         BOOST_ASSERT(exception_info_offset>=0);
 239         BOOST_ASSERT(info_!=0);
 240         EXCEPTION_POINTERS * info=reinterpret_cast<EXCEPTION_POINTERS *>(info_);
 241         EXCEPTION_RECORD * record=info->ExceptionRecord;
 242         if( is_cpp_exception(record) )
 243             {
 244             if( !record->ExceptionInformation[2] )
 245                 record = *reinterpret_cast<EXCEPTION_RECORD * *>(reinterpret_cast<char *>(_errno())+exception_info_offset);
 246             if( is_cpp_exception(record) && record->ExceptionInformation[2] )
 247                 try
 248                     {
 249                     ptr = new cloned_exception(
 250                             reinterpret_cast<void *>(record->ExceptionInformation[1]),
 251                             *reinterpret_cast<cpp_exception_type const *>(record->ExceptionInformation[2]));
 252                     result = boost::exception_detail::clone_current_exception_result::success;
 253                     }
 254                 catch(
 255                 std::bad_alloc & )
 256                     {
 257                     result = boost::exception_detail::clone_current_exception_result::bad_alloc;
 258                     }
 259                 catch(
 260                 ... )
 261                     {
 262                     result = boost::exception_detail::clone_current_exception_result::bad_exception;
 263                     }
 264             }
 265         return EXCEPTION_EXECUTE_HANDLER;
 266         }
 267     }
 268
 269 namespace
 270 boost
 271     {
 272     namespace
 273     exception_detail
 274         {
 275         int
 276         clone_current_exception_non_intrusive( clone_base const * & cloned )
 277             {
 278             BOOST_ASSERT(!cloned);
 279             int result = clone_current_exception_result::not_supported;
 280             if( exception_info_offset>=0 )
 281                 {
 282                  clone_base const * ptr=0;
 283                 __try
 284                     {
 285                     throw;
 286                     }
 287                 __except(exception_cloning_filter(result,ptr,GetExceptionInformation()))
 288                     {
 289                     }
 290                 if( result==clone_current_exception_result::success )
 291                     cloned=ptr;
 292                 }
 293             BOOST_ASSERT(result!=clone_current_exception_result::success || cloned);
 294             return result;
 295             }
 296         }
 297     }
 298
 299 #else
 300
 301 //On all other compilers, return clone_current_exception_result::not_supported.
 302 //On such platforms, only the intrusive enable_current_exception() cloning will work.
 303
 304 #include <boost/config.hpp>
 305
 306 namespace
 307 boost
 308     {
 309     namespace
 310     exception_detail
 311         {
 312         int
 313         clone_current_exception_non_intrusive( clone_base const * & )
 314             {
 315             return clone_current_exception_result::not_supported;
 316             }
 317         }
 318     }
 319
 320 #endif