Separating transitions from descriptors.

src/objects-printer.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 255 matching lines @@
           break;
         }
         case CONSTANT_FUNCTION:
           descs->GetConstantFunction(i)->ShortPrint(out);
           PrintF(out, " (constant function)\n");
           break;
         case CALLBACKS:
           descs->GetCallbacksObject(i)->ShortPrint(out);
           PrintF(out, " (callback)\n");
           break;
-        case MAP_TRANSITION:
-          PrintF(out, "(map transition)\n");
-          break;
-        case CONSTANT_TRANSITION:
-          PrintF(out, "(constant transition)\n");
-          break;
         case NORMAL:  // only in slow mode
         case HANDLER:  // only in lookup results, not in descriptors
         case INTERCEPTOR:  // only in lookup results, not in descriptors
+        // There are no transitions in the descriptor array.
+        case TRANSITION:
         case NONEXISTENT:
           UNREACHABLE();
           break;
       }
     }
   } else {
     property_dictionary()->Print(out);
   }
 }
 
@@ skipping 106 matching lines @@
         PrintF(out, "   %d: ", i);
         p->get(i)->ShortPrint(out);
         PrintF(out, "\n");
       }
       break;
     }
   }
 }
 
 
+void JSObject::PrintTransitions(FILE* out) {
+  if (!map()->HasTransitionArray()) return;
+  TransitionArray* transitions = map()->transitions();
+  for (int i = 0; i < transitions->number_of_transitions(); i++) {
+    PrintF(out, "   ");
+    transitions->GetKey(i)->StringPrint(out);
+    PrintF(out, ": ");
+    switch (transitions->GetTargetDetails(i).type()) {
+      case FIELD: {
+        PrintF(out, " (transition to field)\n");
+        break;
+      }
+      case CONSTANT_FUNCTION:
+        PrintF(out, " (transition to constant function)\n");
+        break;
+      case CALLBACKS:
+        PrintF(out, " (transition to callback)\n");
+        break;
+      // Values below are never in the target descriptor array.
+      case NORMAL:
+      case HANDLER:
+      case INTERCEPTOR:
+      case TRANSITION:
+      case NONEXISTENT:
+        UNREACHABLE();
+        break;
+    }
+  }
+}
+
+
 void JSObject::JSObjectPrint(FILE* out) {
   PrintF(out, "%p: [JSObject]\n", reinterpret_cast<void*>(this));
   PrintF(out, " - map = %p [", reinterpret_cast<void*>(map()));
   // Don't call GetElementsKind, its validation code can cause the printer to
   // fail when debugging.
   PrintElementsKind(out, this->map()->elements_kind());
   PrintF(out,
          "]\n - prototype = %p\n",
          reinterpret_cast<void*>(GetPrototype()));
-  PrintF(out,
-         " - elements transition to = %p\n",
-         reinterpret_cast<void*>(map()->elements_transition_map()));
   PrintF(out, " {\n");
   PrintProperties(out);
+  PrintTransitions(out);
   PrintElements(out);
   PrintF(out, " }\n");
 }
 
 
 void JSModule::JSModulePrint(FILE* out) {
   HeapObject::PrintHeader(out, "JSModule");
   PrintF(out, " - map = 0x%p\n", reinterpret_cast<void*>(map()));
   PrintF(out, " - context = ");
   context()->Print(out);
@@ skipping 95 matching lines @@
     PrintF(out, " - undetectable\n");
   }
   if (has_instance_call_handler()) {
     PrintF(out, " - instance_call_handler\n");
   }
   if (is_access_check_needed()) {
     PrintF(out, " - access_check_needed\n");
   }
   PrintF(out, " - instance descriptors: ");
   instance_descriptors()->ShortPrint(out);
+  PrintF(out, "\n - transitions: ");
+  transitions()->ShortPrint(out);
   PrintF(out, "\n - prototype: ");
   prototype()->ShortPrint(out);
   PrintF(out, "\n - constructor: ");
   constructor()->ShortPrint(out);
   PrintF(out, "\n - code cache: ");
   code_cache()->ShortPrint(out);
   PrintF(out, "\n");
 }
 
 
@@ skipping 467 matching lines @@
   for (int i = 0; i < number_of_descriptors(); i++) {
     PrintF(out, " %d: ", i);
     Descriptor desc;
     Get(i, &desc);
     desc.Print(out);
   }
   PrintF(out, "\n");
 }
 
 
+void TransitionArray::PrintTransitions(FILE* out) {
+  PrintF(out, "Transition array  %d\n", number_of_transitions());
+  for (int i = 0; i < number_of_transitions(); i++) {
+    PrintF(out, " %d: ", i);
+    GetKey(i)->StringPrint(out);
+    PrintF(out, ": ");
+    switch (GetTargetDetails(i).type()) {
+      case FIELD: {
+        PrintF(out, " (transition to field)\n");
+        break;
+      }
+      case CONSTANT_FUNCTION:
+        PrintF(out, " (transition to constant function)\n");
+        break;
+      case CALLBACKS:
+        PrintF(out, " (transition to callback)\n");
+        break;
+      // Values below are never in the target descriptor array.
+      case NORMAL:
+      case HANDLER:
+      case INTERCEPTOR:
+      case TRANSITION:
+      case NONEXISTENT:
+        UNREACHABLE();
+        break;
+    }
+  }
+  PrintF(out, "\n");
+}
+
+
 #endif  // OBJECT_PRINT
 
 
 } }  // namespace v8::internal