Take the scope info of the direct outer scope as outer scope info

src/ast/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/ast/scopes.h"
 
 #include <set>
 
 #include "src/accessors.h"
 #include "src/ast/ast.h"
@@ skipping 1069 matching lines @@
     }
   }
   return nullptr;
 }
 
 void DeclarationScope::AllocateVariables(ParseInfo* info, AnalyzeMode mode) {
   ResolveVariablesRecursively(info);
   AllocateVariablesRecursively();
 
   MaybeHandle<ScopeInfo> outer_scope;
-  for (const Scope* s = outer_scope_; s != nullptr; s = s->outer_scope_) {
-    if (s->scope_info_.is_null()) continue;
-    outer_scope = s->scope_info_;
-    break;
-  }
+  if (outer_scope_ != nullptr) outer_scope = outer_scope_->scope_info_;

[jochen (gone - plz use gerrit), 2016/10/17 09:55:51]

DCHECK that scope_info_ is not null?

[Toon Verwaest, 2016/10/17 10:34:37]

That scope info isn't guaranteed to be non-null. We can have a module scope with
an outer script scope, both of which were freshly created for this compile.

+
   AllocateScopeInfosRecursively(info->isolate(), outer_scope);
   if (mode == AnalyzeMode::kDebugger) {
     AllocateDebuggerScopeInfos(info->isolate(), outer_scope);
   }
   // The debugger expects all shared function infos to contain a scope info.
   // Since the top-most scope will end up in a shared function info, make sure
   // it has one, even if it doesn't need a scope info.
   // TODO(jochen|yangguo): Remove this requirement.
   if (scope_info_.is_null()) {
     scope_info_ = ScopeInfo::Create(info->isolate(), zone(), this, outer_scope);
@@ skipping 871 matching lines @@
   Variable* function =
       is_function_scope() ? AsDeclarationScope()->function_var() : nullptr;
   bool is_function_var_in_context =
       function != nullptr && function->IsContextSlot();
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS -
          (is_function_var_in_context ? 1 : 0);
 }
 
 }  // namespace internal
 }  // namespace v8