Strawman: check strong mode free variables against the global object.

src/scopes.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/accessors.h"
 #include "src/bootstrapper.h"
 #include "src/messages.h"
 #include "src/parser.h"
@@ skipping 575 matching lines @@
   static int Compare(const VarAndOrder* a, const VarAndOrder* b) {
     return a->order_ - b->order_;
   }
 
  private:
   Variable* var_;
   int order_;
 };
 
 
-void Scope::CollectStackAndContextLocals(ZoneList<Variable*>* stack_locals,
-                                         ZoneList<Variable*>* context_locals) {
+void Scope::CollectStackAndContextLocals(
+    ZoneList<Variable*>* stack_locals, ZoneList<Variable*>* context_locals,
+    ZoneList<Variable*>* strong_mode_free_variables) {
   DCHECK(stack_locals != NULL);
   DCHECK(context_locals != NULL);
 
   // Collect internals which are always allocated on the heap.
   for (int i = 0; i < internals_.length(); i++) {
     Variable* var = internals_[i];
     if (var->is_used()) {
       DCHECK(var->IsContextSlot());
       context_locals->Add(var, zone());
     }
@@ skipping 13 matching lines @@
       }
     }
   }
 
   // Collect declared local variables.
   ZoneList<VarAndOrder> vars(variables_.occupancy(), zone());
   for (VariableMap::Entry* p = variables_.Start();
        p != NULL;
        p = variables_.Next(p)) {
     Variable* var = reinterpret_cast<Variable*>(p->value);
+    if (strong_mode_free_variables && var->has_strong_mode_reference() &&
+        var->mode() == DYNAMIC_GLOBAL) {
+      strong_mode_free_variables->Add(var, zone());
+    }
+
     if (var->is_used()) {
       vars.Add(VarAndOrder(var, p->order), zone());
     }
   }
   vars.Sort(VarAndOrder::Compare);
   int var_count = vars.length();
   for (int i = 0; i < var_count; i++) {
     Variable* var = vars[i].var();
     if (var->IsStackLocal()) {
       stack_locals->Add(var, zone());
@@ skipping 467 matching lines @@
 
     case DYNAMIC_LOOKUP:
       // The variable could not be resolved statically.
       var = NonLocal(proxy->raw_name(), DYNAMIC);
       break;
   }
 
   DCHECK(var != NULL);
   if (proxy->is_assigned()) var->set_maybe_assigned();
 
+  if (is_strong(language_mode())) {
+    // Record that the variable is referred to from strong mode. Also, record
+    // the position.
+    var->RecordStrongModeReference(proxy->position(), proxy->end_position());
+  }
+
   proxy->BindTo(var);
 
   return true;
 }
 
 
 bool Scope::CheckStrongModeDeclaration(VariableProxy* proxy, Variable* var) {
   // Check for declaration-after use (for variables) in strong mode. Note that
   // we can only do this in the case where we have seen the declaration. And we
   // always allow referencing functions (for now).
@@ skipping 330 matching lines @@
       (function_ != NULL && function_->proxy()->var()->IsStackLocal() ? 1 : 0);
 }
 
 
 int Scope::ContextLocalCount() const {
   if (num_heap_slots() == 0) return 0;
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS -
       (function_ != NULL && function_->proxy()->var()->IsContextSlot() ? 1 : 0);
 }
 } }  // namespace v8::internal