Introduce global contexts to represent lexical global scope(s).

src/heap.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 2421 matching lines @@
   set_block_context_map(Map::cast(obj));
 
   { MaybeObject* maybe_obj =
         AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel);
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   set_module_context_map(Map::cast(obj));
 
   { MaybeObject* maybe_obj =
         AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel);
     if (!maybe_obj->ToObject(&obj)) return false;

[Sven Panne, 2012/08/27 06:24:54]

Consider templatized 'To'

[rossberg, 2012/08/27 09:07:16]

Yeah, none of the other functions around here does, so I'd thought I'd rather be
consistent. Cleaning all that up is a separate gardening todo.

   }
+  set_global_context_map(Map::cast(obj));
+
+  { MaybeObject* maybe_obj =
+        AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel);
+    if (!maybe_obj->ToObject(&obj)) return false;
+  }
   Map* native_context_map = Map::cast(obj);
   native_context_map->set_dictionary_map(true);
   native_context_map->set_visitor_id(StaticVisitorBase::kVisitNativeContext);
   set_native_context_map(native_context_map);
 
   { MaybeObject* maybe_obj = AllocateMap(SHARED_FUNCTION_INFO_TYPE,
                                          SharedFunctionInfo::kAlignedSize);
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   set_shared_function_info_map(Map::cast(obj));
@@ skipping 2444 matching lines @@
   }
   Context* context = reinterpret_cast<Context*>(result);
   context->set_map_no_write_barrier(native_context_map());
   context->set_js_array_maps(undefined_value());
   ASSERT(context->IsNativeContext());
   ASSERT(result->IsContext());
   return result;
 }
 
 
+MaybeObject* Heap::AllocateGlobalContext(JSFunction* function,
+                                         ScopeInfo* scope_info) {
+  Object* result;
+  { MaybeObject* maybe_result =
+        AllocateFixedArray(scope_info->ContextLength(), TENURED);
+    if (!maybe_result->ToObject(&result)) return maybe_result;
+  }
+  Context* context = reinterpret_cast<Context*>(result);
+  context->set_map_no_write_barrier(global_context_map());
+  context->set_closure(function);
+  context->set_extension(scope_info);
+  ASSERT(context->IsGlobalContext());
+  ASSERT(result->IsContext());
+  return context;
+}
+
+
 MaybeObject* Heap::AllocateModuleContext(ScopeInfo* scope_info) {
   Object* result;
   { MaybeObject* maybe_result =
         AllocateFixedArray(scope_info->ContextLength(), TENURED);
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
   Context* context = reinterpret_cast<Context*>(result);
   context->set_map_no_write_barrier(module_context_map());
   // Context links will be set later.
   context->set_extension(Smi::FromInt(0));
@@ skipping 2344 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   memcpy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   memcpy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal