[modules] Basic support of exports

src/contexts.cc

 // Copyright 2011 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/contexts.h"
 
 #include "src/bootstrapper.h"
 #include "src/debug/debug.h"
 #include "src/isolate-inl.h"
 
@@ skipping 92 matching lines @@
 
 
 JSReceiver* Context::extension_receiver() {
   DCHECK(IsNativeContext() || IsWithContext() ||
          IsFunctionContext() || IsBlockContext());
   return IsWithContext() ? JSReceiver::cast(extension()) : extension_object();
 }
 
 
 ScopeInfo* Context::scope_info() {
-  DCHECK(IsModuleContext() || IsScriptContext() || IsBlockContext());
+  DCHECK(IsScriptContext() || IsBlockContext());
   HeapObject* object = extension();
   if (object->IsSloppyBlockWithEvalContextExtension()) {
     DCHECK(IsBlockContext());
     object = SloppyBlockWithEvalContextExtension::cast(object)->scope_info();
   }
   return ScopeInfo::cast(object);
 }
 
 
+JSModule* Context::module() {
+  Context* current = this;
+  while (!current->IsModuleContext()) {
+    current = current->previous();
+    DCHECK_NOT_NULL(current);  // XXX

[adamk, 2016/09/01 23:13:34]

In our offline discussion I said this was a bit bogus because of how objects
work, but I do see that the bootstrapper actually _does_ set this to NULL. That
seems really wrong to me, though, so I'd prefer to leave out this DCHECK, as
it'll start failing if we ever fix the bootstrapper.

[neis, 2016/09/02 11:32:58]

Done.

+  }
+  return JSModule::cast(current->extension());
+}
+
+
 String* Context::catch_name() {
   DCHECK(IsCatchContext());
   return String::cast(extension());
 }
 
 
 JSGlobalObject* Context::global_object() {
   return JSGlobalObject::cast(native_context()->extension());
 }
 
@@ skipping 45 matching lines @@
 
 static PropertyAttributes GetAttributesForMode(VariableMode mode) {
   DCHECK(IsDeclaredVariableMode(mode));
   return mode == CONST ? READ_ONLY : NONE;
 }
 
 Handle<Object> Context::Lookup(Handle<String> name, ContextLookupFlags flags,
                                int* index, PropertyAttributes* attributes,
                                InitializationFlag* init_flag,
                                VariableMode* variable_mode) {
+  DCHECK(!IsModuleContext());
   Isolate* isolate = GetIsolate();
   Handle<Context> context(this, isolate);
 
   bool follow_context_chain = (flags & FOLLOW_CONTEXT_CHAIN) != 0;
   bool failed_whitelist = false;
   *index = kNotFound;
   *attributes = ABSENT;
   *init_flag = kCreatedInitialized;
   *variable_mode = VAR;
 
@@ skipping 357 matching lines @@
 
   int previous_value = errors_thrown()->value();
   set_errors_thrown(Smi::FromInt(previous_value + 1));
 }
 
 
 int Context::GetErrorsThrown() { return errors_thrown()->value(); }
 
 }  // namespace internal
 }  // namespace v8