havoc_utils.cpp

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/*******************************************************************\
 
Module: Utilities for building havoc code for expressions.
 
Author: Saswat Padhi, saspadhi@amazon.com
 
Date: July 2021
 
\*******************************************************************/
 
 
#include "havoc_utils.h"
 
#include <util/arith_tools.h>
#include <util/c_types.h>
#include <util/pointer_expr.h>
#include <util/std_code.h>
 
void havoc_utilst::append_full_havoc_code(
  const source_locationt location,
  goto_programt &dest) const
{
  for(const auto &expr : assigns)
    append_havoc_code_for_expr(location, expr, dest);
}
 
void havoc_utilst::append_havoc_code_for_expr(
  const source_locationt location,
  const exprt &expr,
  goto_programt &dest) const
{
  if(expr.id() == ID_index || expr.id() == ID_dereference)
  {
    address_of_exprt address_of_expr(expr);
    if(!is_constant(address_of_expr))
    {
      append_object_havoc_code_for_expr(location, address_of_expr, dest);
      return;
    }
  }
  append_scalar_havoc_code_for_expr(location, expr, dest);
}
 
void havoc_utilst::append_object_havoc_code_for_expr(
  const source_locationt location,
  const exprt &expr,
  goto_programt &dest) const
{
  codet havoc(ID_havoc_object);
  havoc.add_source_location() = location;
  havoc.add_to_operands(expr);
  dest.add(goto_programt::make_other(havoc, location));
}
 
void havoc_utilst::append_scalar_havoc_code_for_expr(
  const source_locationt location,
  const exprt &expr,
  goto_programt &dest) const
{
  side_effect_expr_nondett rhs(expr.type(), location);
  goto_programt::targett t =
    dest.add(goto_programt::make_assignment(expr, std::move(rhs), location));
  t->code_nonconst().add_source_location() = location;
}