[modules] Support star exports.

src/objects.h

 // 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 7944 matching lines @@
   static Handle<Object> LoadExport(Handle<Module> module, Handle<String> name);
   static void StoreExport(Handle<Module> module, Handle<String> name,
                           Handle<Object> value);
 
   static void CreateIndirectExport(Handle<Module> module, Handle<String> name,
                                    Handle<ModuleInfoEntry> entry);
 
   static Handle<Object> LoadImport(Handle<Module> module, Handle<String> name,
                                    int module_request);
 
+  // The [must_resolve] argument indicates whether or not an exception should be
+  // thrown if the module does not provide an export named [name].
+  // Currently, an exception is always thrown in the case of a cycle and in the
+  // case of conflicting star exports.  TODO(neis): Make that spec-compliant.
+  static MUST_USE_RESULT MaybeHandle<Cell> ResolveExport(Handle<Module> module,
+                                                         Handle<String> name,
+                                                         bool must_resolve);
   static MUST_USE_RESULT MaybeHandle<Cell> ResolveImport(Handle<Module> module,
                                                          Handle<String> name,
-                                                         int module_request);
-  static MUST_USE_RESULT MaybeHandle<Cell> ResolveExport(Handle<Module> module,
-                                                         Handle<String> name);
+                                                         int module_request,
+                                                         bool must_resolve);
 
   static const int kCodeOffset = HeapObject::kHeaderSize;
   static const int kExportsOffset = kCodeOffset + kPointerSize;
   static const int kRequestedModulesOffset = kExportsOffset + kPointerSize;
   static const int kFlagsOffset = kRequestedModulesOffset + kPointerSize;
   static const int kEmbedderDataOffset = kFlagsOffset + kPointerSize;
   static const int kSize = kEmbedderDataOffset + kPointerSize;
 
  private:
   enum { kEvaluatedBit };
 
+  // Helper for ResolveExport.

[adamk, 2016/09/24 01:01:00]

Please document the fact that you have to check the isolate for exceptions. I'm
still not loving this though.

+  static MUST_USE_RESULT MaybeHandle<Cell> ResolveExportUsingStarExports(
+      Handle<Module> module, Handle<String> name, bool must_resolve);
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(Module);
 };
 
 // JSBoundFunction describes a bound function exotic object.
 class JSBoundFunction : public JSObject {
  public:
   // [bound_target_function]: The wrapped function object.
   DECL_ACCESSORS(bound_target_function, JSReceiver)
 
   // [bound_this]: The value that is always passed as the this value when
@@ skipping 3426 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_