Compute expected type for variables

src/variables.h

 // Copyright 2011 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 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_VARIABLES_H_
 #define V8_VARIABLES_H_
 
 #include "zone.h"
+#include "types.h"
 #include "interface.h"
 
 namespace v8 {
 namespace internal {
 
 // The AST refers to variables via VariableProxies - placeholders for the actual
 // variables. Variables themselves are never directly referred to from the AST,
 // they are maintained by scopes, and referred to from VariableProxies and Slots
 // after binding and variable allocation.
 
@@ skipping 94 matching lines @@
 
   Variable* local_if_not_shadowed() const {
     ASSERT(mode_ == DYNAMIC_LOCAL && local_if_not_shadowed_ != NULL);
     return local_if_not_shadowed_;
   }
 
   void set_local_if_not_shadowed(Variable* local) {
     local_if_not_shadowed_ = local;
   }
 
+  Handle<Type> expected_type() { return expected_type_; }
+  void set_expected_type(Handle<Type> type) { expected_type_ = type; }
+
   Location location() const { return location_; }
   int index() const { return index_; }
   InitializationFlag initialization_flag() const {
     return initialization_flag_;
   }
   Interface* interface() const { return interface_; }
 
   void AllocateTo(Location location, int index) {
     location_ = location;
     index_ = index;
   }
 
   static int CompareIndex(Variable* const* v, Variable* const* w);
 
  private:
   Scope* scope_;
   Handle<String> name_;
   VariableMode mode_;
   Kind kind_;
+  Handle<Type> expected_type_;  // Intersection of all reads

[Jakob Kummerow, 2013/07/09 16:01:50]

nit: trailing full stop. And, uhm, "Union" ;-)

   Location location_;
   int index_;
   int initializer_position_;
 
   // If this field is set, this variable references the stored locally bound
   // variable, but it might be shadowed by variable bindings introduced by
   // non-strict 'eval' calls between the reference scope (inclusive) and the
   // binding scope (exclusive).
   Variable* local_if_not_shadowed_;
 
   // Valid as a LHS? (const and this are not valid LHS, for example)
   bool is_valid_LHS_;
 
   // Usage info.
   bool force_context_allocation_;  // set by variable resolver
   bool is_used_;
   InitializationFlag initialization_flag_;
 
   // Module type info.
   Interface* interface_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_VARIABLES_H_