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

src/scopeinfo.cc

Index: src/scopeinfo.cc
diff --git a/src/scopeinfo.cc b/src/scopeinfo.cc
index d62bc4129588196d3f3faf6d7c1fd035b39bbaa6..ed4705465e0e293b0baad49035bfdb38e1e32141 100644
--- a/src/scopeinfo.cc
+++ b/src/scopeinfo.cc
@@ -18,9 +18,14 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone,
   // Collect stack and context locals.
   ZoneList<Variable*> stack_locals(scope->StackLocalCount(), zone);
   ZoneList<Variable*> context_locals(scope->ContextLocalCount(), zone);
-  scope->CollectStackAndContextLocals(&stack_locals, &context_locals);
+  ZoneList<Variable*> strong_mode_free_variables(0, zone);
+
+  scope->CollectStackAndContextLocals(&stack_locals, &context_locals,
+                                      &strong_mode_free_variables);
   const int stack_local_count = stack_locals.length();
   const int context_local_count = context_locals.length();
+  const int strong_mode_free_variable_count =
+      strong_mode_free_variables.length();
   // Make sure we allocate the correct amount.
   DCHECK(scope->StackLocalCount() == stack_local_count);
   DCHECK(scope->ContextLocalCount() == context_local_count);
@@ -49,9 +54,9 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone,
 
   const bool has_function_name = function_name_info != NONE;
   const int parameter_count = scope->num_parameters();
-  const int length = kVariablePartIndex
-      + parameter_count + stack_local_count + 2 * context_local_count
-      + (has_function_name ? 2 : 0);
+  const int length = kVariablePartIndex + parameter_count + stack_local_count +
+                     2 * context_local_count + (has_function_name ? 2 : 0) +
+                     strong_mode_free_variable_count;
 
   Factory* factory = isolate->factory();
   Handle<ScopeInfo> scope_info = factory->NewScopeInfo(length);
@@ -71,6 +76,7 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone,
   scope_info->SetParameterCount(parameter_count);
   scope_info->SetStackLocalCount(stack_local_count);
   scope_info->SetContextLocalCount(context_local_count);
+  scope_info->SetStrongModeFreeVariableCount(strong_mode_free_variable_count);
 
   int index = kVariablePartIndex;
   // Add parameters.
@@ -113,6 +119,11 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone,
     scope_info->set(index++, Smi::FromInt(value));
   }
 
+  DCHECK(index == scope_info->StrongModeFreeVariableEntriesIndex());
+  for (int i = 0; i < strong_mode_free_variable_count; ++i) {
+    scope_info->set(index++, *strong_mode_free_variables[i]->name());
+  }
+
   // If present, add the function variable name and its index.
   DCHECK(index == scope_info->FunctionNameEntryIndex());
   if (has_function_name) {
@@ -285,6 +296,13 @@ bool ScopeInfo::LocalIsSynthetic(int var) {
 }
 
 
+String* ScopeInfo::StrongModeFreeVariableName(int var) {
+  DCHECK(0 <= var && var < StrongModeFreeVariableCount());
+  int info_index = StrongModeFreeVariableEntriesIndex() + var;
+  return String::cast(get(info_index));
+}
+
+
 int ScopeInfo::StackSlotIndex(String* name) {
   DCHECK(name->IsInternalizedString());
   if (length() > 0) {
@@ -432,11 +450,16 @@ int ScopeInfo::ContextLocalInfoEntriesIndex() {
 }
 
 
-int ScopeInfo::FunctionNameEntryIndex() {
+int ScopeInfo::StrongModeFreeVariableEntriesIndex() {
   return ContextLocalInfoEntriesIndex() + ContextLocalCount();
 }
 
 
+int ScopeInfo::FunctionNameEntryIndex() {
+  return StrongModeFreeVariableEntriesIndex() + StrongModeFreeVariableCount();
+}
+
+
 int ContextSlotCache::Hash(Object* data, String* name) {
   // Uses only lower 32 bits if pointers are larger.
   uintptr_t addr_hash =