boolbv_struct.cpp

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/*******************************************************************\
 
Module:
 
Author: Daniel Kroening, kroening@kroening.com
 
\*******************************************************************/
 
#include "boolbv.h"
 
#include <util/namespace.h>
 
bvt boolbvt::convert_struct(const struct_exprt &expr)
{
  const struct_typet &struct_type =
    expr.type().id() == ID_struct_tag
      ? ns.follow_tag(to_struct_tag_type(expr.type()))
      : to_struct_type(expr.type());
 
  std::size_t width=boolbv_width(struct_type);
 
  const struct_typet::componentst &components=struct_type.components();
 
  DATA_INVARIANT_WITH_DIAGNOSTICS(
    expr.operands().size() == components.size(),
    "number of operands of a struct expression shall equal the number of"
    "components as indicated by its type",
    expr.find_source_location());
 
  bvt bv;
  bv.resize(width);
 
  std::size_t bit_idx = 0;
 
  exprt::operandst::const_iterator op_it=expr.operands().begin();
  for(const auto &comp : components)
  {
    const typet &subtype=comp.type();
    const exprt &op=*op_it;
 
    DATA_INVARIANT_WITH_DIAGNOSTICS(
      subtype == op.type(),
      "type of a struct expression operand shall equal the type of the "
      "corresponding struct component",
      expr.find_source_location(),
      subtype.pretty(),
      op.type().pretty());
 
    std::size_t subtype_width=boolbv_width(subtype);
 
    if(subtype_width!=0)
    {
      const bvt &op_bv = convert_bv(op, subtype_width);
 
      INVARIANT(
        bit_idx + op_bv.size() <= width, "bit index shall be within bounds");
 
      for(const auto &bit : op_bv)
      {
        bv[bit_idx] = bit;
        bit_idx++;
      }
    }
 
    ++op_it;
  }
 
  INVARIANT(
    bit_idx == width, "all bits in the bitvector shall have been assigned");
 
  return bv;
}