lib/c++/orb.cc

   1 #include <System.h>
   2 #include <util/radix.h>
   3
   4 namespace System {
   5 namespace RunTime {
   6         using namespace ::System::Exceptions::Std;
   7
   8         // This function could be made to do a binary search if we can
   9         // manage to somehow sort the IFaceTables...
  10         uintptr_t downcast(::System::_i_Object *obj,
  11                            const unsigned long *new_guid)
  12         {
  13                 if (!obj)
  14                         return 0;
  15
  16                 void unsupported_long_size();
  17
  18                 if (sizeof(long) != 4 && sizeof(long) != 8)
  19                         unsupported_long_size();
  20
  21                 IFaceTable *tbl = obj->info->concrete_IFaceTable;
  22                 unsigned long new_guid_first = *new_guid;
  23
  24                 // This doesn't use guids_equal(), as that would eliminate the
  25                 // ability to cache the first word of new_guid.  The compiler
  26                 // *might* do it anyway, but this code was written before
  27                 // guids_equal existed, and I don't want to risk removing an
  28                 // optimization by changing it now without testing how GCC
  29                 // behaves.
  30
  31                 while (true) {
  32                         if (tbl->info->guid[0] == new_guid_first &&
  33                             tbl->info->guid[1] == new_guid[1] &&
  34                             (sizeof(long) == 8 ||
  35                              (tbl->info->guid[2] == new_guid[2] &&
  36                               tbl->info->guid[3] == new_guid[3])))
  37                                 break;
  38
  39                         tbl++;
  40                         if (__builtin_expect(!tbl->info->guid, 0))
  41                                 return 0;
  42                 }
  43
  44                 uintptr_t ptr = reinterpret_cast<uintptr_t>(obj);
  45
  46                 ptr += obj->info->concrete;
  47                 ptr += tbl->offset;
  48
  49                 return ptr;
  50         };
  51
  52         namespace Priv {
  53                 typedef void (*MethodEntry)(ParamInfoBlock *pib);
  54
  55                 struct Object {
  56                         MethodEntry entry;
  57                         void *ptr; // pointer to the class interface
  58                 };
  59
  60                 typedef ::Util::RadixTree<Object, ID, 6> ObjTable;
  61                 ObjTable objtable;
  62
  63                 unsigned long get_pc()
  64                 {
  65                         return reinterpret_cast<unsigned long>(__builtin_return_address(0));
  66                 }
  67
  68                 void exception_to_array(::System::VStruct *ex, Array<uint8_t> *ar)
  69                 {
  70                         // FIXME: marshall struct
  71                 }
  72
  73                 void handle_message(ParamInfoBlock *pib)
  74                 {
  75                         Message *msg = reinterpret_cast<Message *>(pib->segments[0].ptr);
  76
  77                         switch (msg->seg0.opcode) {
  78                                 case Segment0::InvokeMethod: {
  79                                         if (pib->segments[0].len < sizeof(InvokeMethod))
  80                                                 throw_idl(ShortMessage, 0, pib->segments[0].len,
  81                                                           sizeof(InvokeMethod));
  82
  83 //                                      ID obj = pib->objlist[0];
  84                                         break;
  85                                 }
  86
  87                                 default:
  88                                         throw_idl(InvalidOpcode, msg->seg0.opcode);
  89                         }
  90                 }
  91         }
  92 }}
  93
  94 extern "C" void abort();
  95
  96 extern "C" void handle_message(::System::RunTime::ParamInfoBlock *pib,
  97                                ::System::RunTime::Array<uint8_t> *ex_arr)
  98 {
  99         try {
 100                 ::System::RunTime::Priv::handle_message(pib);
 101         }
 102
 103         catch (::System::Exceptions::Exception &ex) {
 104                 ::System::RunTime::Priv::exception_to_array(&ex, ex_arr);
 105         }
 106
 107         catch (...) {
 108                 abort();
 109         }
 110 }