goto_symex_can_forward_propagate.h

Go to the documentation of this file.

/*******************************************************************\
 
Module: Symbolic Execution Constant Propagation
 
Author: Michael Tautschig, tautschn@amazon.com
 
\*******************************************************************/

 
#ifndef CPROVER_GOTO_SYMEX_GOTO_SYMEX_CAN_FORWARD_PROPAGATE_H
#define CPROVER_GOTO_SYMEX_GOTO_SYMEX_CAN_FORWARD_PROPAGATE_H
 
#include <util/expr.h>
#include <util/expr_util.h>
 
class goto_symex_can_forward_propagatet : public can_forward_propagatet
{
public:
  explicit goto_symex_can_forward_propagatet(const namespacet &ns)
    : can_forward_propagatet(ns)
  {
  }
 
protected:
  bool is_constant(const exprt &expr) const override
  {
    if(expr.id() == ID_mult)
    {
      bool found_non_constant = false;
 
      // propagate stuff with sizeof in it
      for(const auto &op : expr.operands())
      {
        if(op.find(ID_C_c_sizeof_type).is_not_nil())
          return true;
        else if(!is_constant(op))
          found_non_constant = true;
      }
 
      return !found_non_constant;
    }
    else if(expr.id() == ID_with)
    {
      // this is bad
#if 0
      for(const auto &op : expr.operands())
      {
        if(!is_constant(op))
          return false;
      }
 
      return true;
#else
      return false;
#endif
    }
 
    return can_forward_propagatet::is_constant(expr);
  }
};
 
#endif // CPROVER_GOTO_SYMEX_GOTO_SYMEX_CAN_FORWARD_PROPAGATE_H