[modules] Implement namespace imports.

src/interpreter/bytecode-generator.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/interpreter/bytecode-generator.h"
 
 #include "src/ast/compile-time-value.h"
 #include "src/ast/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compilation-info.h"
@@ skipping 656 matching lines @@
   VisitNewTargetVariable(scope()->new_target_var());
 
   // TODO(rmcilroy): Emit tracing call if requested to do so.
   if (FLAG_trace) {
     UNIMPLEMENTED();
   }
 
   // Visit declarations within the function scope.
   VisitDeclarations(scope()->declarations());
 
+  VisitModuleNamespaceImports();

[Michael Starzinger, 2016/10/05 13:07:30]

nit: Please add "// Visit module imports if needed." to indicate that it might
be a no-op.

[neis, 2016/10/06 08:56:44]

Done.

+
   // Perform a stack-check before the body.
   builder()->StackCheck(info()->literal()->start_position());
 
   // Visit statements in the function body.
   VisitStatements(info()->literal()->body());
 }
 
 void BytecodeGenerator::BuildIndexedJump(Register index, size_t start_index,
                                          size_t size,
                                          ZoneVector<BytecodeLabel>& targets) {
@@ skipping 179 matching lines @@
     case VariableLocation::MODULE:
       DCHECK_EQ(variable->mode(), LET);
       DCHECK(variable->IsExport());
       VisitForAccumulatorValue(decl->fun());
       VisitVariableAssignment(variable, Token::INIT,
                               FeedbackVectorSlot::Invalid());
       break;
   }
 }
 
+void BytecodeGenerator::VisitModuleNamespaceImports() {
+  if (!scope()->is_module_scope()) return;
+
+  RegisterAllocationScope register_scope(this);
+  Register module_request = register_allocator()->NewRegister();
+
+  ModuleDescriptor* descriptor = scope()->AsModuleScope()->module();
+  for (auto entry : descriptor->namespace_imports()) {
+    builder()
+        ->LoadLiteral(Smi::FromInt(entry->module_request))
+        .StoreAccumulatorInRegister(module_request)
+        .CallRuntime(Runtime::kGetModuleNamespace, module_request);
+    Variable* var = scope()->LookupLocal(entry->local_name);
+    DCHECK_NOT_NULL(var);
+    VisitVariableAssignment(var, Token::INIT, FeedbackVectorSlot::Invalid());
+  }
+}
+
 void BytecodeGenerator::VisitDeclarations(
     ZoneList<Declaration*>* declarations) {
   RegisterAllocationScope register_scope(this);
   DCHECK(globals_builder()->empty());
   for (int i = 0; i < declarations->length(); i++) {
     RegisterAllocationScope register_scope(this);
     Visit(declarations->at(i));
   }
   if (globals_builder()->empty()) return;
 
@@ skipping 2260 matching lines @@
 }
 
 Runtime::FunctionId BytecodeGenerator::StoreKeyedToSuperRuntimeId() {
   return is_strict(language_mode()) ? Runtime::kStoreKeyedToSuper_Strict
                                     : Runtime::kStoreKeyedToSuper_Sloppy;
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8