Reland "Enable map dependency to in-flight compilation info."

src/mark-compact.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 2486 matching lines @@
 }
 
 
 void MarkCompactCollector::ClearAndDeoptimizeDependentCode(Map* map) {
   DisallowHeapAllocation no_allocation;
   DependentCode* entries = map->dependent_code();
   DependentCode::GroupStartIndexes starts(entries);
   int number_of_entries = starts.number_of_entries();
   if (number_of_entries == 0) return;
   for (int i = 0; i < number_of_entries; i++) {
+    // If the entry is compilation info then the map must be alive,
+    // and ClearAndDeoptimizeDependentCode shouldn't be called.
+    ASSERT(entries->is_code_at(i));
     Code* code = entries->code_at(i);
     if (IsMarked(code) && !code->marked_for_deoptimization()) {
       code->set_marked_for_deoptimization(true);
     }
-    entries->clear_code_at(i);
+    entries->clear_at(i);
   }
   map->set_dependent_code(DependentCode::cast(heap()->empty_fixed_array()));
 }
 
 
 void MarkCompactCollector::ClearNonLiveDependentCode(Map* map) {
   DisallowHeapAllocation no_allocation;
   DependentCode* entries = map->dependent_code();
   DependentCode::GroupStartIndexes starts(entries);
   int number_of_entries = starts.number_of_entries();
   if (number_of_entries == 0) return;
   int new_number_of_entries = 0;
   // Go through all groups, remove dead codes and compact.
   for (int g = 0; g < DependentCode::kGroupCount; g++) {
     int group_number_of_entries = 0;
     for (int i = starts.at(g); i < starts.at(g + 1); i++) {
-      Code* code = entries->code_at(i);
-      if (IsMarked(code) && !code->marked_for_deoptimization()) {
+      Object* obj = entries->object_at(i);
+      ASSERT(obj->IsCode() || IsMarked(obj));
+      if (IsMarked(obj) &&
+          (!obj->IsCode() || !Code::cast(obj)->marked_for_deoptimization())) {
         if (new_number_of_entries + group_number_of_entries != i) {
-          entries->set_code_at(new_number_of_entries +
-                               group_number_of_entries, code);
+          entries->set_object_at(
+              new_number_of_entries + group_number_of_entries, obj);
         }
-        Object** slot = entries->code_slot_at(new_number_of_entries +
-                                              group_number_of_entries);
-        RecordSlot(slot, slot, code);
+        Object** slot = entries->slot_at(new_number_of_entries +
+                                         group_number_of_entries);
+        RecordSlot(slot, slot, obj);
         group_number_of_entries++;
       }
     }
     entries->set_number_of_entries(
         static_cast<DependentCode::DependencyGroup>(g),
         group_number_of_entries);
     new_number_of_entries += group_number_of_entries;
   }
   for (int i = new_number_of_entries; i < number_of_entries; i++) {
-    entries->clear_code_at(i);
+    entries->clear_at(i);
   }
 }
 
 
 void MarkCompactCollector::ProcessWeakMaps() {
   GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_WEAKMAP_PROCESS);
   Object* weak_map_obj = encountered_weak_maps();
   while (weak_map_obj != Smi::FromInt(0)) {
     ASSERT(MarkCompactCollector::IsMarked(HeapObject::cast(weak_map_obj)));
     JSWeakMap* weak_map = reinterpret_cast<JSWeakMap*>(weak_map_obj);
@@ skipping 1708 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal