Merge pull request diffblue#218 from diffblue/issue178

Fix pointer types when converting write_stacks to expressions

Author: chrisr-diffblue

src/analyses/variable-sensitivity/write_stack.cpp

@@ -187,6 +187,10 @@ exprt write_stackt::to_expression() const
         new_expr.operands().resize(1);
       }
       new_expr.op0()=access_expr;
+      // also need to update the type of new_expr because the index_exprt
+      // will have been constructed with a nil op0 and therefore will not
+      // have had its type constructed properly.
+      new_expr.type()=access_expr.type().subtype();
 
       access_expr=new_expr;
     }

src/analyses/variable-sensitivity/write_stack_entry.cpp

@@ -46,8 +46,11 @@ offset_entryt::offset_entryt(abstract_object_pointert offset_value):
 }
 
 /// Get the expression part needed to read this stack entry. For offset entries
-/// this is an index expression with the index() part the offset
-/// \return The expression to read this part of the stack
+/// this is an index expression with the index() part the offset.
+/// It is important to note that the returned index_exprt does not have a type,
+/// so it will be necessary for the caller to update the type whenever the index
+/// expression is completed.
+/// \return The untyped expression to read this part of the stack
 exprt offset_entryt::get_access_expr() const
 {
   return index_exprt(exprt(), offset->to_constant());