[turbofan] Implement top-level lookup slot declaration.

src/compiler/ast-graph-builder.cc

 // Copyright 2014 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/compiler/ast-graph-builder.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
@@ skipping 1096 matching lines @@
         environment()->Bind(variable, value);
       }
       break;
     case VariableLocation::CONTEXT:
       if (hole_init) {
         Node* value = jsgraph()->TheHoleConstant();
         const Operator* op = javascript()->StoreContext(0, variable->index());
         NewNode(op, current_context(), value);
       }
       break;
-    case VariableLocation::LOOKUP:
-      // TODO(mstarzinger): Implement this case.
-      SetStackOverflow();
+    case VariableLocation::LOOKUP: {
+      Node* name = jsgraph()->Constant(variable->name());
+      // For variables we must not push an initial value (such as 'undefined')
+      // because we may have a (legal) redeclaration and we must not destroy
+      // the current value.
+      Node* value =
+          hole_init ? jsgraph()->TheHoleConstant()
+                    : jsgraph()->ZeroConstant();  // Indicates no initial value.
+      Node* attr =
+          jsgraph()->Constant(variable->DeclarationPropertyAttributes());
+      const Operator* op =
+          javascript()->CallRuntime(Runtime::kDeclareLookupSlot);
+      Node* store = NewNode(op, name, value, attr);
+      PrepareFrameState(store, decl->proxy()->id());
       break;
+    }
   }
 }
 
 
 void AstGraphBuilder::VisitFunctionDeclaration(FunctionDeclaration* decl) {
   Variable* variable = decl->proxy()->var();
   switch (variable->location()) {
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED: {
       Handle<SharedFunctionInfo> function = Compiler::GetSharedFunctionInfo(
@@ skipping 11 matching lines @@
       environment()->Bind(variable, value);
       break;
     }
     case VariableLocation::CONTEXT: {
       VisitForValue(decl->fun());
       Node* value = environment()->Pop();
       const Operator* op = javascript()->StoreContext(0, variable->index());
       NewNode(op, current_context(), value);
       break;
     }
-    case VariableLocation::LOOKUP:
-      // TODO(mstarzinger): Implement this case.
-      SetStackOverflow();
+    case VariableLocation::LOOKUP: {
+      VisitForValue(decl->fun());
+      Node* value = environment()->Pop();
+      Node* name = jsgraph()->Constant(variable->name());
+      Node* attr =
+          jsgraph()->Constant(variable->DeclarationPropertyAttributes());
+      const Operator* op =
+          javascript()->CallRuntime(Runtime::kDeclareLookupSlot);
+      Node* store = NewNode(op, name, value, attr);
+      PrepareFrameState(store, decl->proxy()->id());
       break;
+    }
   }
 }
 
 
 void AstGraphBuilder::VisitImportDeclaration(ImportDeclaration* decl) {
   UNREACHABLE();
 }
 
 
 void AstGraphBuilder::VisitExportDeclaration(ExportDeclaration* decl) {
@@ skipping 3177 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8