Implement rudimentary module linking.

src/objects-debug.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 117 matching lines @@
     case CODE_TYPE:
       Code::cast(this)->CodeVerify();
       break;
     case ODDBALL_TYPE:
       Oddball::cast(this)->OddballVerify();
       break;
     case JS_OBJECT_TYPE:
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
       JSObject::cast(this)->JSObjectVerify();
       break;
+    case JS_MODULE_TYPE:
+      JSModule::cast(this)->JSModuleVerify();
+      break;
     case JS_VALUE_TYPE:
       JSValue::cast(this)->JSValueVerify();
       break;
     case JS_DATE_TYPE:
       JSDate::cast(this)->JSDateVerify();
       break;
     case JS_FUNCTION_TYPE:
       JSFunction::cast(this)->JSFunctionVerify();
       break;
     case JS_GLOBAL_PROXY_TYPE:
@@ skipping 211 matching lines @@
       double value = get_scalar(i);
       ASSERT(!isnan(value) ||
              (BitCast<uint64_t>(value) ==
               BitCast<uint64_t>(canonical_not_the_hole_nan_as_double())) ||
              ((BitCast<uint64_t>(value) & Double::kSignMask) != 0));
     }
   }
 }
 
 
+void JSModule::JSModuleVerify() {
+  Object* v = context();
+  if (v->IsHeapObject()) {
+    VerifyHeapPointer(v);
+  }
+  CHECK(v->IsUndefined() || v->IsModuleContext());
+}
+
+
 void JSValue::JSValueVerify() {
   Object* v = value();
   if (v->IsHeapObject()) {
     VerifyHeapPointer(v);
   }
 }
 
 
 void JSDate::JSDateVerify() {
   if (value()->IsHeapObject()) {
@@ skipping 539 matching lines @@
         ASSERT(e->IsUndefined());
       }
     }
   }
 }
 
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal