Move heap object creation off into object factory.

This feels like the right place for this, and also gives future options
for configuration/customisation.

Author: jezhiggins

src/analyses/variable-sensitivity/abstract_environment.cpp

@@ -88,13 +88,10 @@ abstract_environmentt::eval(const exprt &expr, const namespacet &ns) const
     simplified_id == ID_side_effect &&
     (simplified_expr.get(ID_statement) == ID_allocate))
   {
-    auto dynamic_object = exprt(ID_dynamic_object);
-    dynamic_object.set(ID_identifier, "allocated-on-heap");
-    auto heap_symbol =
-      unary_exprt(ID_address_of, dynamic_object, simplified_expr.type());
-    auto heap_pointer =
-      abstract_object_factory(simplified_expr.type(), heap_symbol, ns);
-    return heap_pointer;
+    return abstract_object_factory(
+      typet(ID_dynamic_object),
+      exprt(ID_dynamic_object, simplified_expr.type()),
+      ns);
   }
 
   // No special handling required by the abstract environment

src/analyses/variable-sensitivity/variable_sensitivity_configuration.h

@@ -31,7 +31,8 @@ enum ABSTRACT_OBJECT_TYPET
   STRUCT_INSENSITIVE,
   // TODO: plug in UNION_SENSITIVE HERE
   UNION_INSENSITIVE,
-  VALUE_SET
+  VALUE_SET,
+  HEAP_ALLOCATION
 };
 
 enum class flow_sensitivityt

src/analyses/variable-sensitivity/variable_sensitivity_object_factory.cpp

@@ -114,6 +114,10 @@ variable_sensitivity_object_factoryt::get_abstract_object_type(
   {
     return configuration.union_abstract_type;
   }
+  else if(type.id() == ID_dynamic_object)
+  {
+    return HEAP_ALLOCATION;
+  }
 
   return abstract_object_type;
 }
@@ -174,6 +178,16 @@ variable_sensitivity_object_factoryt::get_abstract_object(
     return initialize_abstract_object<two_value_union_abstract_objectt>(
       followed_type, top, bottom, e, environment, ns, configuration);
 
+  case HEAP_ALLOCATION:
+  {
+    auto dynamic_object = exprt(ID_dynamic_object);
+    dynamic_object.set(ID_identifier, "allocated-on-heap");
+    auto heap_symbol = unary_exprt(ID_address_of, dynamic_object, e.type());
+    auto heap_pointer =
+      get_abstract_object(e.type(), false, false, heap_symbol, environment, ns);
+    return heap_pointer;
+  }
+
   default:
     UNREACHABLE;
     return initialize_abstract_object<abstract_objectt>(