clean out checks for reference_to expressions

This has no know users.

Author: Daniel Kroening

src/analyses/invariant_set.cpp

@@ -134,8 +134,7 @@ std::string inv_object_storet::build_string(const exprt &expr) const
       return integer2string(*i);
   }
 
-  // we also like "address_of" and "reference_to"
-  // if the object is constant
+  // we also like "address_of" if the object is constant
   // we don't know what mode (language) we are in, so we rely on the default
   // language to be reasonable for from_expr
   if(is_constant_address(expr))

src/pointer-analysis/goto_program_dereference.cpp

@@ -96,7 +96,7 @@ void goto_program_dereferencet::dereference_failure(
   }
 }
 
-/// Turn subexpression of `expr` of the form `&*p` or `reference_to(*p)` to p
+/// Turn subexpression of `expr` of the form `&*p` into p
 /// and use `dereference` on subexpressions of the form `*p`
 /// \param expr: expression in which to remove dereferences
 /// \param guard: boolean expression assumed to hold when dereferencing
@@ -172,8 +172,7 @@ void goto_program_dereferencet::dereference_rec(
     return;
   }
 
-  if(expr.id()==ID_address_of ||
-     expr.id()=="reference_to")
+  if(expr.id() == ID_address_of)
   {
     // turn &*p to p
     // this has *no* side effect!

src/pointer-analysis/value_set.cpp

@@ -493,31 +493,6 @@ void value_sett::get_value_set_rec(
       }
     }
   }
-  else if(expr.id()=="reference_to")
-  {
-    // old stuff, will go away
-    object_mapt reference_set;
-
-    get_reference_set(expr, reference_set, ns);
-
-    const object_map_dt &object_map=reference_set.read();
-
-    if(object_map.begin()==object_map.end())
-      insert(dest, exprt(ID_unknown, original_type));
-    else
-    {
-      for(object_map_dt::const_iterator
-          it=object_map.begin();
-          it!=object_map.end();
-          it++)
-      {
-        /// Do not take a reference to object_numbering's storage as we may call
-        /// object_numbering.number(), which may reallocate it.
-        const exprt object=object_numbering[it->first];
-        get_value_set_rec(object, dest, suffix, original_type, ns);
-      }
-    }
-  }
   else if(expr.is_constant())
   {
     // check if NULL

src/pointer-analysis/value_set_fi.cpp

@@ -499,26 +499,6 @@ void value_set_fit::get_value_set_rec(
       return;
     }
   }
-  else if(expr.id()=="reference_to")
-  {
-    object_mapt reference_set;
-
-    get_reference_set_sharing(expr, reference_set, ns);
-
-    const object_map_dt &object_map=reference_set.read();
-
-    if(object_map.begin()!=object_map.end())
-    {
-      forall_objects(it, object_map)
-      {
-        const exprt &object=object_numbering[it->first];
-        get_value_set_rec(object, dest, suffix,
-                          original_type, ns, recursion_set);
-      }
-
-      return;
-    }
-  }
   else if(expr.is_constant())
   {
     // check if NULL

src/pointer-analysis/value_set_fivr.cpp

@@ -615,26 +615,6 @@ void value_set_fivrt::get_value_set_rec(
       return;
     }
   }
-  else if(expr.id()=="reference_to")
-  {
-    object_mapt reference_set;
-
-    get_reference_set_sharing(expr, reference_set, ns);
-
-    const object_map_dt &object_map=reference_set.read();
-
-    if(object_map.begin()!=object_map.end())
-    {
-      forall_objects(it, object_map)
-      {
-        const exprt &object=object_numbering[it->first];
-        get_value_set_rec(object, dest, suffix,
-                          original_type, ns, recursion_set);
-      }
-
-      return;
-    }
-  }
   else if(expr.is_constant())
   {
     // check if NULL

src/pointer-analysis/value_set_fivrns.cpp

@@ -405,26 +405,6 @@ void value_set_fivrnst::get_value_set_rec(
       return;
     }
   }
-  else if(expr.id()=="reference_to")
-  {
-    object_mapt reference_set;
-
-    get_reference_set(expr, reference_set, ns);
-
-    const object_map_dt &object_map=reference_set.read();
-
-    if(object_map.begin()!=object_map.end())
-    {
-      forall_objects(it, object_map)
-      {
-        const exprt &object=object_numbering[it->first];
-        get_value_set_rec(object, dest, suffix,
-                          original_type, ns);
-      }
-
-      return;
-    }
-  }
   else if(expr.is_constant())
   {
     // check if NULL