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

src/objects.h

 // 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 4288 matching lines @@
   // Return the initialization flag of the given context local.
   InitializationFlag ContextLocalInitFlag(int var);
 
   // Return the initialization flag of the given context local.
   MaybeAssignedFlag ContextLocalMaybeAssignedFlag(int var);
 
   // Return true if this local was introduced by the compiler, and should not be
   // exposed to the user in a debugger.
   bool LocalIsSynthetic(int var);
 
+  String* StrongModeFreeVariableName(int var);
+  int StrongModeFreeVariableStartPosition(int var);
+  int StrongModeFreeVariableEndPosition(int var);
+
   // Lookup support for serialized scope info. Returns the
   // the stack slot index for a given slot name if the slot is
   // present; otherwise returns a value < 0. The name must be an internalized
   // string.
   int StackSlotIndex(String* name);
 
   // Lookup support for serialized scope info. Returns the
   // context slot index for a given slot name if the slot is present; otherwise
   // returns a value < 0. The name must be an internalized string.
   // If the slot is present and mode != NULL, sets *mode to the corresponding
@@ skipping 32 matching lines @@
 #endif
 
   // The layout of the static part of a ScopeInfo is as follows. Each entry is
   // numeric and occupies one array slot.
   // 1. A set of properties of the scope
   // 2. The number of parameters. This only applies to function scopes. For
   //    non-function scopes this is 0.
   // 3. The number of non-parameter variables allocated on the stack.
   // 4. The number of non-parameter and parameter variables allocated in the
   //    context.
-#define FOR_EACH_NUMERIC_FIELD(V)          \
-  V(Flags)                                 \
-  V(ParameterCount)                        \
-  V(StackLocalCount)                       \
-  V(ContextLocalCount)
+#define FOR_EACH_NUMERIC_FIELD(V) \
+  V(Flags)                        \
+  V(ParameterCount)               \
+  V(StackLocalCount)              \
+  V(ContextLocalCount)            \
+  V(StrongModeFreeVariableCount)
 
 #define FIELD_ACCESSORS(name)                            \
   void Set##name(int value) {                            \
     set(k##name, Smi::FromInt(value));                   \
   }                                                      \
   int name() {                                           \
     if (length() > 0) {                                  \
       return Smi::cast(get(k##name))->value();           \
     } else {                                             \
       return 0;                                          \
@@ skipping 26 matching lines @@
   //    Contains the names of local variables and parameters that are allocated
   //    in the context. They are stored in increasing order of the context slot
   //    index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per
   //    context local, so in total this part occupies ContextLocalCount() slots
   //    in the array.
   // 4. ContextLocalInfoEntries:
   //    Contains the variable modes and initialization flags corresponding to
   //    the context locals in ContextLocalNameEntries. One slot is used per
   //    context local, so in total this part occupies ContextLocalCount()
   //    slots in the array.
-  // 5. FunctionNameEntryIndex:
+  // 5. StrongModeFreeVariableNameEntries:
+  //    Stores the names of strong mode free variables.
+  // 6. StrongModeFreeVariablePositionEntries:
+  //    Stores the locations (start and end position) of strong mode free
+  //    variables.
+  // 7. FunctionNameEntryIndex:
   //    If the scope belongs to a named function expression this part contains
   //    information about the function variable. It always occupies two array
   //    slots:  a. The name of the function variable.
   //            b. The context or stack slot index for the variable.
   int ParameterEntriesIndex();
   int StackLocalEntriesIndex();
   int ContextLocalNameEntriesIndex();
   int ContextLocalInfoEntriesIndex();
+  int StrongModeFreeVariableNameEntriesIndex();
+  int StrongModeFreeVariablePositionEntriesIndex();
   int FunctionNameEntryIndex();
 
   // Location of the function variable for named function expressions.
   enum FunctionVariableInfo {
     NONE,     // No function name present.
     STACK,    // Function
     CONTEXT,
     UNUSED
   };
 
@@ skipping 6561 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_