Separate Scope into DeclarationScope and Scope

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/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-flags.h"
@@ skipping 638 matching lines @@
   // contain jumps to unbound labels (resume points that will never be used).
   // We bind these now.
   for (auto& label : generator_resume_points_) {
     if (!label.is_bound()) builder()->Bind(&label);
   }
 
   builder()->EnsureReturn();
 }
 
 void BytecodeGenerator::GenerateBytecodeBody() {
+  DCHECK_EQ(scope(), info()->scope());

[Michael Starzinger, 2016/08/03 13:02:19]

nit: Can we change BytecodeGenerator::scope() to return a "DeclarationScope"
instead of a "Scope" and leave the rest of this function untouched?

   // Build the arguments object if it is used.
-  VisitArgumentsObject(scope()->arguments());
+  VisitArgumentsObject(info()->scope()->arguments());
 
   // Build rest arguments array if it is used.
   int rest_index;
-  Variable* rest_parameter = scope()->rest_parameter(&rest_index);
+  Variable* rest_parameter = info()->scope()->rest_parameter(&rest_index);
   VisitRestArgumentsArray(rest_parameter);
 
   // Build assignment to {.this_function} variable if it is used.
-  VisitThisFunctionVariable(scope()->this_function_var());
+  VisitThisFunctionVariable(info()->scope()->this_function_var());
 
   // Build assignment to {new.target} variable if it is used.
-  VisitNewTargetVariable(scope()->new_target_var());
+  VisitNewTargetVariable(info()->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());
+  VisitDeclarations(info()->scope()->declarations());
 
   // 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,
@@ skipping 2319 matching lines @@
         .StoreAccumulatorInRegister(scope_info)
         .CallRuntime(Runtime::kNewScriptContext, closure, 2);
   } else {
     builder()->CallRuntime(Runtime::kNewFunctionContext,
                            Register::function_closure(), 1);
   }
   execution_result()->SetResultInAccumulator();
 }
 
 void BytecodeGenerator::VisitBuildLocalActivationContext() {
-  Scope* scope = this->scope();
+  DeclarationScope* scope = this->scope()->AsDeclarationScope();

[Michael Starzinger, 2016/08/03 13:02:19]

nit: See comment above.

 
   if (scope->has_this_declaration() && scope->receiver()->IsContextSlot()) {
     Variable* variable = scope->receiver();
     Register receiver(builder()->Parameter(0));
     // Context variable (at bottom of the context chain).
     DCHECK_EQ(0, scope->ContextChainLength(variable->scope()));
     builder()->LoadAccumulatorWithRegister(receiver).StoreContextSlot(
         execution_context()->reg(), variable->index());
   }
 
@@ skipping 128 matching lines @@
 void BytecodeGenerator::VisitNewTargetVariable(Variable* variable) {
   if (variable == nullptr) return;
 
   // Store the new target we were called with in the given variable.
   builder()->LoadAccumulatorWithRegister(Register::new_target());
   VisitVariableAssignment(variable, Token::INIT, FeedbackVectorSlot::Invalid());
 }
 
 void BytecodeGenerator::VisitFunctionClosureForContext() {
   AccumulatorResultScope accumulator_execution_result(this);
-  Scope* closure_scope = execution_context()->scope()->ClosureScope();
+  DeclarationScope* closure_scope =
+      execution_context()->scope()->GetClosureScope();
   if (closure_scope->is_script_scope() ||
       closure_scope->is_module_scope()) {
     // Contexts nested in the native context have a canonical empty function as
     // their closure, not the anonymous closure containing the global code.
     Register native_context = register_allocator()->NewRegister();
     builder()
         ->LoadContextSlot(execution_context()->reg(),
                           Context::NATIVE_CONTEXT_INDEX)
         .StoreAccumulatorInRegister(native_context)
         .LoadContextSlot(native_context, Context::CLOSURE_INDEX);
@@ skipping 57 matching lines @@
   return execution_context()->scope()->language_mode();
 }
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return TypeFeedbackVector::GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8