Make closures optimizable by Crankshaft compiler.

src/scopes.cc

Index: src/scopes.cc
diff --git a/src/scopes.cc b/src/scopes.cc
index 3565e11b58f710e280f1080c0fb479e5e01376f9..6aa682571d6c53082829ea4626e24f25af011faf 100644
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -135,7 +135,8 @@ Scope::Scope(Type type)
     outer_scope_is_eval_scope_(false),
     force_eager_compilation_(false),
     num_stack_slots_(0),
-    num_heap_slots_(0) {
+    num_heap_slots_(0),
+    resolved_(false) {
 }
 
 
@@ -162,7 +163,8 @@ Scope::Scope(Scope* outer_scope, Type type)
     outer_scope_is_eval_scope_(false),
     force_eager_compilation_(false),
     num_stack_slots_(0),
-    num_heap_slots_(0) {
+    num_heap_slots_(0),
+    resolved_(false) {
   // At some point we might want to provide outer scopes to
   // eval scopes (by walking the stack and reading the scope info).
   // In that case, the ASSERT below needs to be adjusted.
@@ -210,7 +212,7 @@ void Scope::Initialize(bool inside_with) {
   Variable* var =
       variables_.Declare(this, Factory::this_symbol(), Variable::VAR,
                          false, Variable::THIS);
-  var->rewrite_ = new Slot(var, Slot::PARAMETER, -1);
+  var->set_rewrite(new Slot(var, Slot::PARAMETER, -1));
   receiver_ = var;
 
   if (is_function_scope()) {
@@ -550,7 +552,7 @@ Variable* Scope::NonLocal(Handle<String> name, Variable::Mode mode) {
     // Declare a new non-local.
     var = map->Declare(NULL, name, mode, true, Variable::NORMAL);
     // Allocate it by giving it a dynamic lookup.
-    var->rewrite_ = new Slot(var, Slot::LOOKUP, -1);
+    var->set_rewrite(new Slot(var, Slot::LOOKUP, -1));
   }
   return var;
 }
@@ -612,8 +614,9 @@ Variable* Scope::LookupRecursive(Handle<String> name,
   ASSERT(var != NULL);
 
   // If this is a lookup from an inner scope, mark the variable.
-  if (inner_lookup)
-    var->is_accessed_from_inner_scope_ = true;
+  if (inner_lookup) {
+    var->MarkAsAccessedFromInnerScope();
+  }
 
   // If the variable we have found is just a guess, invalidate the
   // result. If the found variable is local, record that fact so we
@@ -753,7 +756,7 @@ bool Scope::MustAllocate(Variable* var) {
   // via an eval() call.  This is only possible if the variable has a
   // visible name.
   if ((var->is_this() || var->name()->length() > 0) &&
-      (var->is_accessed_from_inner_scope_ ||
+      (var->is_accessed_from_inner_scope() ||
        scope_calls_eval_ || inner_scope_calls_eval_ ||
        scope_contains_with_)) {
     var->set_is_used(true);
@@ -771,7 +774,7 @@ bool Scope::MustAllocateInContext(Variable* var) {
   // context.
   return
     var->mode() != Variable::TEMPORARY &&
-    (var->is_accessed_from_inner_scope_ ||
+    (var->is_accessed_from_inner_scope() ||
      scope_calls_eval_ || inner_scope_calls_eval_ ||
      scope_contains_with_ || var->is_global());
 }
@@ -787,12 +790,12 @@ bool Scope::HasArgumentsParameter() {
 
 
 void Scope::AllocateStackSlot(Variable* var) {
-  var->rewrite_ = new Slot(var, Slot::LOCAL, num_stack_slots_++);
+  var->set_rewrite(new Slot(var, Slot::LOCAL, num_stack_slots_++));
 }
 
 
 void Scope::AllocateHeapSlot(Variable* var) {
-  var->rewrite_ = new Slot(var, Slot::CONTEXT, num_heap_slots_++);
+  var->set_rewrite(new Slot(var, Slot::CONTEXT, num_heap_slots_++));
 }
 
 
@@ -857,7 +860,7 @@ void Scope::AllocateParameterLocals() {
           // It is ok to set this only now, because arguments is a local
           // variable that is allocated after the parameters have been
           // allocated.
-          arguments_shadow_->is_accessed_from_inner_scope_ = true;
+          arguments_shadow_->MarkAsAccessedFromInnerScope();
         }
         Property* rewrite =
             new Property(new VariableProxy(arguments_shadow_),
@@ -865,7 +868,7 @@ void Scope::AllocateParameterLocals() {
                          RelocInfo::kNoPosition,
                          Property::SYNTHETIC);
         rewrite->set_is_arguments_access(true);
-        var->rewrite_ = rewrite;
+        var->set_rewrite(rewrite);
       }
     }
 
@@ -880,23 +883,23 @@ void Scope::AllocateParameterLocals() {
       ASSERT(var->scope() == this);
       if (MustAllocate(var)) {
         if (MustAllocateInContext(var)) {
-          ASSERT(var->rewrite_ == NULL ||
+          ASSERT(var->rewrite() == NULL ||
                  (var->AsSlot() != NULL &&
                   var->AsSlot()->type() == Slot::CONTEXT));
-          if (var->rewrite_ == NULL) {
+          if (var->rewrite() == NULL) {
             // Only set the heap allocation if the parameter has not
             // been allocated yet.
             AllocateHeapSlot(var);
           }
         } else {
-          ASSERT(var->rewrite_ == NULL ||
+          ASSERT(var->rewrite() == NULL ||
                  (var->AsSlot() != NULL &&
                   var->AsSlot()->type() == Slot::PARAMETER));
           // Set the parameter index always, even if the parameter
           // was seen before! (We need to access the actual parameter
           // supplied for the last occurrence of a multiply declared
           // parameter.)
-          var->rewrite_ = new Slot(var, Slot::PARAMETER, i);
+          var->set_rewrite(new Slot(var, Slot::PARAMETER, i));
         }
       }
     }
@@ -906,10 +909,10 @@ void Scope::AllocateParameterLocals() {
 
 void Scope::AllocateNonParameterLocal(Variable* var) {
   ASSERT(var->scope() == this);
-  ASSERT(var->rewrite_ == NULL ||
+  ASSERT(var->rewrite() == NULL ||
          (!var->IsVariable(Factory::result_symbol())) ||
          (var->AsSlot() == NULL || var->AsSlot()->type() != Slot::LOCAL));
-  if (var->rewrite_ == NULL && MustAllocate(var)) {
+  if (var->rewrite() == NULL && MustAllocate(var)) {
     if (MustAllocateInContext(var)) {
       AllocateHeapSlot(var);
     } else {
@@ -943,15 +946,18 @@ void Scope::AllocateNonParameterLocals() {
 
 
 void Scope::AllocateVariablesRecursively() {
-  // The number of slots required for variables.
-  num_stack_slots_ = 0;
-  num_heap_slots_ = Context::MIN_CONTEXT_SLOTS;
-
   // Allocate variables for inner scopes.
   for (int i = 0; i < inner_scopes_.length(); i++) {
     inner_scopes_[i]->AllocateVariablesRecursively();
   }
 
+  // If scope is already resolved, we still need to allocate
+  // variables in inner scopes which might not had been resolved yet.
+  if (resolved_) return;
+  // The number of slots required for variables.
+  num_stack_slots_ = 0;
+  num_heap_slots_ = Context::MIN_CONTEXT_SLOTS;
+
   // Allocate variables for this scope.
   // Parameters must be allocated first, if any.
   if (is_function_scope()) AllocateParameterLocals();