Implement TDZ in StoreIC for top-level lexicals.

src/ic/ic.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/api.h"
 #include "src/arguments.h"
 #include "src/base/bits.h"
@@ skipping 1540 matching lines @@
         global->native_context()->script_context_table());
 
     ScriptContextTable::LookupResult lookup_result;
     if (ScriptContextTable::Lookup(script_contexts, str_name, &lookup_result)) {
       Handle<Context> script_context = ScriptContextTable::GetContext(
           script_contexts, lookup_result.context_index);
       if (lookup_result.mode == CONST) {
         return TypeError("const_assign", object, name);
       }
 
+      Handle<Object> previous_value =
+          FixedArray::get(script_context, lookup_result.slot_index);
+
+      if (*previous_value == *isolate()->factory()->the_hole_value()) {
+        // Do not install stubs and stay pre-monomorphic for
+        // uninitialized accesses.
+        return ReferenceError("not_defined", name);
+      }
+
       if (FLAG_use_ic &&
           StoreScriptContextFieldStub::Accepted(&lookup_result)) {
         StoreScriptContextFieldStub stub(isolate(), &lookup_result);
         PatchCache(name, stub.GetCode());
       }
 
       script_context->set(lookup_result.slot_index, *value);
       return value;
     }
   }
@@ skipping 1484 matching lines @@
 static const Address IC_utilities[] = {
 #define ADDR(name) FUNCTION_ADDR(name),
     IC_UTIL_LIST(ADDR) NULL
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) { return IC_utilities[id]; }
 }
 }  // namespace v8::internal