Propagate reaching definitions to the instuctions of a block.

src/ast.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 85 matching lines @@
 
 #define AST_NODE_LIST(V)                        \
   V(Declaration)                                \
   STATEMENT_NODE_LIST(V)                        \
   EXPRESSION_NODE_LIST(V)
 
 // Forward declarations
 class TargetCollector;
 class MaterializedLiteral;
 class DefinitionInfo;
+class BitVector;
 
 #define DEF_FORWARD_DECLARATION(type) class type;
 AST_NODE_LIST(DEF_FORWARD_DECLARATION)
 #undef DEF_FORWARD_DECLARATION
 
 
 // Typedef only introduced to avoid unreadable code.
 // Please do appreciate the required space in "> >".
 typedef ZoneList<Handle<String> > ZoneStringList;
 typedef ZoneList<Handle<Object> > ZoneObjectList;
@@ skipping 909 matching lines @@
     return (variable == NULL) ? false : variable->is_arguments();
   }
 
   Handle<String> name() const  { return name_; }
   Variable* var() const  { return var_; }
   bool is_this() const  { return is_this_; }
   bool inside_with() const  { return inside_with_; }
   bool is_trivial() { return is_trivial_; }
   void set_is_trivial(bool b) { is_trivial_ = b; }
 
+  BitVector* reaching_definitions() { return reaching_definitions_; }
+  void set_reaching_definitions(BitVector* rd) { reaching_definitions_ = rd; }
+
   // Bind this proxy to the variable var.
   void BindTo(Variable* var);
 
  protected:
   Handle<String> name_;
   Variable* var_;  // resolved variable, or NULL
   bool is_this_;
   bool inside_with_;
   bool is_trivial_;
+  BitVector* reaching_definitions_;
 
   VariableProxy(Handle<String> name, bool is_this, bool inside_with);
   explicit VariableProxy(bool is_this);
 
   friend class Scope;
 };
 
 
 class VariableProxySentinel: public VariableProxy {
  public:
@@ skipping 925 matching lines @@
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_