[modules] Factor out cell load into helper function.

src/objects.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 20129 matching lines @@
 
   Handle<ObjectHashTable> exports(module->exports(), isolate);
   for (int i = 0, n = names->length(); i < n; ++i) {
     Handle<String> name(String::cast(names->get(i)), isolate);
     DCHECK(exports->Lookup(name)->IsTheHole(isolate));
     exports = ObjectHashTable::Put(exports, name, cell);
   }
   module->set_exports(*exports);
 }
 
-Handle<Object> Module::LoadVariable(Handle<Module> module, int cell_index) {
-  Isolate* isolate = module->GetIsolate();
-  Handle<Object> object;
+Cell* Module::GetCell(int cell_index) {
+  DisallowHeapAllocation no_gc;
+  Object* cell;

[Michael Starzinger, 2017/05/03 17:08:02]

nit: I have the sneaking suspicion that some compilers will complain about the
"cell" variable not being initialized on all paths in some configurations.

   switch (ModuleDescriptor::GetCellIndexKind(cell_index)) {
     case ModuleDescriptor::kImport:
-      object = handle(module->regular_imports()->get(ImportIndex(cell_index)),
-                      isolate);
+      cell = regular_imports()->get(ImportIndex(cell_index));
       break;
     case ModuleDescriptor::kExport:
-      object = handle(module->regular_exports()->get(ExportIndex(cell_index)),
-                      isolate);
+      cell = regular_exports()->get(ExportIndex(cell_index));
       break;
     case ModuleDescriptor::kInvalid:
       UNREACHABLE();
       break;
   }
-  return handle(Handle<Cell>::cast(object)->value(), isolate);
+  return Cell::cast(cell);
+}
+
+Handle<Object> Module::LoadVariable(Handle<Module> module, int cell_index) {
+  Isolate* isolate = module->GetIsolate();
+  return handle(module->GetCell(cell_index)->value(), isolate);
 }
 
 void Module::StoreVariable(Handle<Module> module, int cell_index,
                            Handle<Object> value) {
-  Isolate* isolate = module->GetIsolate();
   DCHECK_EQ(ModuleDescriptor::GetCellIndexKind(cell_index),
             ModuleDescriptor::kExport);
-  Handle<Object> object(module->regular_exports()->get(ExportIndex(cell_index)),
-                        isolate);
-  Handle<Cell>::cast(object)->set_value(*value);
+  module->GetCell(cell_index)->set_value(*value);
 }
 
 MaybeHandle<Cell> Module::ResolveImport(Handle<Module> module,
                                         Handle<String> name, int module_request,
                                         MessageLocation loc, bool must_resolve,
                                         Module::ResolveSet* resolve_set) {
   Isolate* isolate = module->GetIsolate();
   Handle<Module> requested_module(
       Module::cast(module->requested_modules()->get(module_request)), isolate);
   return Module::ResolveExport(requested_module, name, loc, must_resolve,
@@ skipping 483 matching lines @@
       // depend on this.
       return DICTIONARY_ELEMENTS;
     }
     DCHECK_LE(kind, LAST_ELEMENTS_KIND);
     return kind;
   }
 }
 
 }  // namespace internal
 }  // namespace v8