Infer whether a variable is assigned

src/variables.cc

 // Copyright 2011 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/ast.h"
 #include "src/scopes.h"
 #include "src/variables.h"
 
@@ skipping 32 matching lines @@
     name_(name),
     mode_(mode),
     kind_(kind),
     location_(UNALLOCATED),
     index_(-1),
     initializer_position_(RelocInfo::kNoPosition),
     local_if_not_shadowed_(NULL),
     is_valid_ref_(is_valid_ref),
     force_context_allocation_(false),
     is_used_(false),
+    maybe_assigned_(false),
     initialization_flag_(initialization_flag),
     interface_(interface) {
   // Names must be canonicalized for fast equality checks.
   ASSERT(name->IsInternalizedString());
   // Var declared variables never need initialization.
   ASSERT(!(mode == VAR && initialization_flag == kNeedsInitialization));
 }
 
 
 bool Variable::IsGlobalObjectProperty() const {
   // Temporaries are never global, they must always be allocated in the
   // activation frame.
   return (IsDynamicVariableMode(mode_) ||
           (IsDeclaredVariableMode(mode_) && !IsLexicalVariableMode(mode_)))
       && scope_ != NULL && scope_->is_global_scope();
 }
 
 
 int Variable::CompareIndex(Variable* const* v, Variable* const* w) {
   int x = (*v)->index();
   int y = (*w)->index();
   // Consider sorting them according to type as well?
   return x - y;
 }
 
 } }  // namespace v8::internal