kernel/src/bbtkRTTI.cxx

   1 #include "bbtkRTTI.h"
   2 #include "bbtkMessageManager.h"
   3
   4
   5
   6 namespace bbtk
   7 {
   8   // Adapted from https://savannah.cern.ch/support/download.php?file_id=1972
   9
  10   // Something to which we can cast the void*s, to allow finding the
  11   // dynamic typeid.
  12   struct Dummy {
  13     virtual ~Dummy() {}
  14   };
  15
  16
  17  void*  run_time_up_or_down_cast( const std::type_info& target_type,
  18                                const std::type_info& source_type,
  19                                const void*  source_pointer
  20                                )
  21  {
  22    return run_time_up_or_down_cast(target_type,
  23                                    source_type,
  24                                    const_cast<void*>(source_pointer));
  25  }
  26
  27   void*   run_time_up_or_down_cast( const std::type_info& target_type,
  28                                const std::type_info& source_type,
  29                                void*  source_pointer
  30                                )
  31   {
  32     bbtkDebugMessage("Data",5,
  33                      "run_time_up_or_down_cast : Casting pointer to '"
  34                      << TypeName(typeid(*(Dummy*)source_pointer))
  35                      << "' from " << TypeName(source_type)
  36                      << " to " << TypeName(target_type) << std::endl);
  37
  38     void* target_pointer = 0;
  39 #if __GNUC__ > 3 ||                                     \
  40   (__GNUC__ == 3 && (__GNUC_MINOR__ > 1 ||              \
  41                      (__GNUC_MINOR__ == 1 &&            \
  42                       __GNUC_PATCHLEVEL__ > 0)))
  43
  44     const abi::__class_type_info* targetTI =
  45       (const abi::__class_type_info *)( &(target_type));
  46
  47     bbtkDebugMessage("Data",7," * source   = "<<source_pointer<<std::endl);
  48
  49     void* tmp = source_pointer;
  50     if (source_type.__do_upcast(targetTI,&tmp))
  51       {
  52         target_pointer = tmp;
  53       }
  54     else
  55       {
  56         bbtkDebugMessage("Data",7,
  57                          " * upcast failed : trying dynamic down cast"
  58                          <<std::endl);
  59         const abi::__class_type_info* sourceTI =
  60           (const abi::__class_type_info *)( &(source_type));
  61
  62
  63         target_pointer = abi::__dynamic_cast(source_pointer,
  64                                              sourceTI,
  65                                              targetTI,
  66                                              -1);
  67       }
  68
  69     bbtkDebugMessage("Data",7," * target   = "<<target_pointer<<std::endl);
  70
  71 #else
  72     bbtkWarning("run_time_up_or_down_cast not impl. on Win : to do");
  73     // target_pointer = __RTDynamicCast(source_pointer, 0, source_type, target_type, 0);
  74 #endif
  75     return target_pointer;
  76
  77   }
  78
  79 }
  80