solver_factory.cpp

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/*******************************************************************\
 
Module: Solver Factory
 
Author: Daniel Kroening, Peter Schrammel
 
\*******************************************************************/
 
 
#include "solver_factory.h"
 
#include <util/cmdline.h>
#include <util/exception_utils.h>
#include <util/exit_codes.h>
#include <util/message.h>
#include <util/options.h>
#include <util/unicode.h>
#include <util/version.h>
 
#include <goto-symex/solver_hardness.h>
#include <solvers/flattening/bv_dimacs.h>
#include <solvers/prop/prop.h>
#include <solvers/prop/solver_resource_limits.h>
#include <solvers/refinement/bv_refinement.h>
#include <solvers/sat/dimacs_cnf.h>
#include <solvers/sat/external_sat.h>
#include <solvers/sat/satcheck.h>
#include <solvers/smt2_incremental/smt2_incremental_decision_procedure.h>
#include <solvers/smt2_incremental/smt_solver_process.h>
#include <solvers/strings/string_refinement.h>
 
#include <iostream>
#include <vector>
 
solver_factoryt::solver_factoryt(
  const optionst &_options,
  const namespacet &_ns,
  message_handlert &_message_handler,
  bool _output_xml_in_refinement)
  : options(_options),
    ns(_ns),
    message_handler(_message_handler),
    output_xml_in_refinement(_output_xml_in_refinement)
{
}
 
solver_factoryt::solvert::solvert(std::unique_ptr<stack_decision_proceduret> p)
  : decision_procedure_ptr(std::move(p))
{
}
 
solver_factoryt::solvert::solvert(
  std::unique_ptr<stack_decision_proceduret> p1,
  std::unique_ptr<propt> p2)
  : prop_ptr(std::move(p2)), decision_procedure_ptr(std::move(p1))
{
}
 
solver_factoryt::solvert::solvert(
  std::unique_ptr<stack_decision_proceduret> p1,
  std::unique_ptr<std::ofstream> p2)
  : ofstream_ptr(std::move(p2)), decision_procedure_ptr(std::move(p1))
{
}
 
solver_factoryt::solvert::solvert(
  std::unique_ptr<boolbvt> p1,
  std::unique_ptr<propt> p2)
  : prop_ptr(std::move(p2)), decision_procedure_is_boolbvt_ptr(std::move(p1))
{
}
 
solver_factoryt::solvert::solvert(
  std::unique_ptr<boolbvt> p1,
  std::unique_ptr<propt> p2,
  std::unique_ptr<std::ofstream> p3)
  : ofstream_ptr(std::move(p3)),
    prop_ptr(std::move(p2)),
    decision_procedure_is_boolbvt_ptr(std::move(p1))
{
}
 
stack_decision_proceduret &solver_factoryt::solvert::decision_procedure() const
{
  PRECONDITION(
    (decision_procedure_ptr != nullptr) !=
    (decision_procedure_is_boolbvt_ptr != nullptr));
  if(decision_procedure_ptr)
    return *decision_procedure_ptr;
  else
    return *decision_procedure_is_boolbvt_ptr;
}
 
boolbvt &solver_factoryt::solvert::boolbv_decision_procedure() const
{
  PRECONDITION(decision_procedure_is_boolbvt_ptr != nullptr);
  return *decision_procedure_is_boolbvt_ptr;
}
 
void solver_factoryt::set_decision_procedure_time_limit(
  solver_resource_limitst &decision_procedure)
{
  const int timeout_seconds =
    options.get_signed_int_option("solver-time-limit");
 
  if(timeout_seconds > 0)
    decision_procedure.set_time_limit_seconds(timeout_seconds);
}
 
std::unique_ptr<solver_factoryt::solvert> solver_factoryt::get_solver()
{
  if(options.get_bool_option("dimacs"))
    return get_dimacs();
  if(options.is_set("external-sat-solver"))
    return get_external_sat();
  if(
    options.get_bool_option("refine") &&
    !options.get_bool_option("refine-strings"))
  {
    return get_bv_refinement();
  }
  else if(options.get_bool_option("refine-strings"))
    return get_string_refinement();
  const auto incremental_smt2_solver =
    options.get_option("incremental-smt2-solver");
  if(!incremental_smt2_solver.empty())
    return get_incremental_smt2(incremental_smt2_solver);
  if(options.get_bool_option("smt2"))
    return get_smt2(get_smt2_solver_type());
  return get_default();
}
 
smt2_dect::solvert solver_factoryt::get_smt2_solver_type() const
{
  // we shouldn't get here if this option isn't set
  PRECONDITION(options.get_bool_option("smt2"));
 
  smt2_dect::solvert s = smt2_dect::solvert::GENERIC;
 
  if(options.get_bool_option("bitwuzla"))
    s = smt2_dect::solvert::BITWUZLA;
  else if(options.get_bool_option("boolector"))
    s = smt2_dect::solvert::BOOLECTOR;
  else if(options.get_bool_option("cprover-smt2"))
    s = smt2_dect::solvert::CPROVER_SMT2;
  else if(options.get_bool_option("mathsat"))
    s = smt2_dect::solvert::MATHSAT;
  else if(options.get_bool_option("cvc5"))
    s = smt2_dect::solvert::CVC5;
  else if(options.get_bool_option("yices"))
    s = smt2_dect::solvert::YICES;
  else if(options.get_bool_option("z3"))
    s = smt2_dect::solvert::Z3;
  else if(options.get_bool_option("generic"))
    s = smt2_dect::solvert::GENERIC;
 
  return s;
}
 
static void emit_solver_warning(
  message_handlert &message_handler,
  const std::string &solver)
{
  messaget log(message_handler);
  log.warning() << "The specified solver, '" << solver
                << "', is not available. "
                << "The default solver will be used instead." << messaget::eom;
}
 
template <typename SatcheckT>
static typename std::enable_if<
  !std::is_base_of<hardness_collectort, SatcheckT>::value,
  std::unique_ptr<SatcheckT>>::type
make_satcheck_prop(message_handlert &message_handler, const optionst &options)
{
  auto satcheck = std::make_unique<SatcheckT>(message_handler);
  if(options.is_set("write-solver-stats-to"))
  {
    messaget log(message_handler);
    log.warning()
      << "Configured solver does not support --write-solver-stats-to. "
      << "Solver stats will not be written." << messaget::eom;
  }
  return satcheck;
}
 
template <typename SatcheckT>
static typename std::enable_if<
  std::is_base_of<hardness_collectort, SatcheckT>::value,
  std::unique_ptr<SatcheckT>>::type
make_satcheck_prop(message_handlert &message_handler, const optionst &options)
{
  auto satcheck = std::make_unique<SatcheckT>(message_handler);
  if(options.is_set("write-solver-stats-to"))
  {
    std::unique_ptr<solver_hardnesst> solver_hardness =
      std::make_unique<solver_hardnesst>();
    solver_hardness->set_outfile(options.get_option("write-solver-stats-to"));
    satcheck->solver_hardness = std::move(solver_hardness);
  }
  return satcheck;
}
 
static std::unique_ptr<propt>
get_sat_solver(message_handlert &message_handler, const optionst &options)
{
  const bool no_simplifier = options.get_bool_option("beautify") ||
                             !options.get_bool_option("sat-preprocessor") ||
                             options.get_bool_option("refine-strings");
 
  if(options.is_set("sat-solver"))
  {
    const std::string &solver_option = options.get_option("sat-solver");
    if(solver_option == "zchaff")
    {
#if defined SATCHECK_ZCHAFF
      return make_satcheck_prop<satcheck_zchafft>(message_handler, options);
#else
      emit_solver_warning(message_handler, "zchaff");
#endif
    }
    else if(solver_option == "booleforce")
    {
#if defined SATCHECK_BOOLERFORCE
      return make_satcheck_prop<satcheck_booleforcet>(message_handler, options);
#else
      emit_solver_warning(message_handler, "booleforce");
#endif
    }
    else if(solver_option == "minisat1")
    {
#if defined SATCHECK_MINISAT1
      return make_satcheck_prop<satcheck_minisat1t>(message_handler, options);
#else
      emit_solver_warning(message_handler, "minisat1");
#endif
    }
    else if(solver_option == "minisat2")
    {
#if defined SATCHECK_MINISAT2
      if(no_simplifier)
      {
        // simplifier won't work with beautification
        return make_satcheck_prop<satcheck_minisat_no_simplifiert>(
          message_handler, options);
      }
      else // with simplifier
      {
        return make_satcheck_prop<satcheck_minisat_simplifiert>(
          message_handler, options);
      }
#else
      emit_solver_warning(message_handler, "minisat2");
#endif
    }
    else if(solver_option == "ipasir")
    {
#if defined SATCHECK_IPASIR
      return make_satcheck_prop<satcheck_ipasirt>(message_handler, options);
#else
      emit_solver_warning(message_handler, "ipasir");
#endif
    }
    else if(solver_option == "picosat")
    {
#if defined SATCHECK_PICOSAT
      return make_satcheck_prop<satcheck_picosatt>(message_handler, options);
#else
      emit_solver_warning(message_handler, "picosat");
#endif
    }
    else if(solver_option == "lingeling")
    {
#if defined SATCHECK_LINGELING
      return make_satcheck_prop<satcheck_lingelingt>(message_handler, options);
#else
      emit_solver_warning(message_handler, "lingeling");
#endif
    }
    else if(solver_option == "glucose")
    {
#if defined SATCHECK_GLUCOSE
      if(no_simplifier)
      {
        // simplifier won't work with beautification
        return make_satcheck_prop<satcheck_glucose_no_simplifiert>(
          message_handler, options);
      }
      else // with simplifier
      {
        return make_satcheck_prop<satcheck_glucose_simplifiert>(
          message_handler, options);
      }
#else
      emit_solver_warning(message_handler, "glucose");
#endif
    }
    else if(solver_option == "cadical")
    {
#if defined SATCHECK_CADICAL
      return make_satcheck_prop<satcheck_cadical_no_preprocessingt>(
        message_handler, options);
#else
      emit_solver_warning(message_handler, "cadical");
#endif
    }
    else
    {
      messaget log(message_handler);
      log.error() << "unknown solver '" << solver_option << "'"
                  << messaget::eom;
      exit(CPROVER_EXIT_USAGE_ERROR);
    }
  }
 
  // default solver
  if(no_simplifier)
  {
    // simplifier won't work with beautification
    return make_satcheck_prop<satcheck_no_simplifiert>(
      message_handler, options);
  }
  else // with simplifier
  {
    return make_satcheck_prop<satcheckt>(message_handler, options);
  }
}
 
static std::unique_ptr<std::ofstream> open_outfile_and_check(
  const std::string &filename,
  message_handlert &message_handler,
  const std::string &arg_name)
{
  if(filename.empty())
    return nullptr;
 
  auto out = std::make_unique<std::ofstream>(widen_if_needed(filename));
 
  if(!*out)
  {
    throw invalid_command_line_argument_exceptiont(
      "failed to open file: " + filename, arg_name);
  }
 
  messaget log(message_handler);
  log.status() << "Outputting formula to file: " << filename << messaget::eom;
  return out;
}
 
std::unique_ptr<solver_factoryt::solvert> solver_factoryt::get_default()
{
  auto sat_solver = get_sat_solver(message_handler, options);
 
  bool get_array_constraints =
    options.get_bool_option("show-array-constraints");
  auto bv_pointers = std::make_unique<bv_pointerst>(
    ns, *sat_solver, message_handler, get_array_constraints);
 
  if(options.get_option("arrays-uf") == "never")
    bv_pointers->unbounded_array = bv_pointerst::unbounded_arrayt::U_NONE;
  else if(options.get_option("arrays-uf") == "always")
    bv_pointers->unbounded_array = bv_pointerst::unbounded_arrayt::U_ALL;
 
  set_decision_procedure_time_limit(*bv_pointers);
 
  std::unique_ptr<boolbvt> boolbv = std::move(bv_pointers);
  return std::make_unique<solvert>(std::move(boolbv), std::move(sat_solver));
}
 
std::unique_ptr<solver_factoryt::solvert> solver_factoryt::get_dimacs()
{
  no_beautification();
  no_incremental_check();
 
  auto prop = std::make_unique<dimacs_cnft>(message_handler);
 
  std::string filename = options.get_option("outfile");
 
  if(filename.empty() || filename == "-")
  {
    std::unique_ptr<boolbvt> bv_dimacs =
      std::make_unique<bv_dimacst>(ns, *prop, message_handler, std::cout);
 
    return std::make_unique<solvert>(std::move(bv_dimacs), std::move(prop));
  }
 
  auto outfile = open_outfile_and_check(filename, message_handler, "--outfile");
 
  std::unique_ptr<boolbvt> bv_dimacs =
    std::make_unique<bv_dimacst>(ns, *prop, message_handler, *outfile);
 
  return std::make_unique<solvert>(
    std::move(bv_dimacs), std::move(prop), std::move(outfile));
}
 
std::unique_ptr<solver_factoryt::solvert> solver_factoryt::get_external_sat()
{
  no_beautification();
  no_incremental_check();
 
  std::string external_sat_solver = options.get_option("external-sat-solver");
  auto prop =
    std::make_unique<external_satt>(message_handler, external_sat_solver);
 
  std::unique_ptr<boolbvt> bv_pointers =
    std::make_unique<bv_pointerst>(ns, *prop, message_handler);
 
  return std::make_unique<solvert>(std::move(bv_pointers), std::move(prop));
}
 
std::unique_ptr<solver_factoryt::solvert> solver_factoryt::get_bv_refinement()
{
  std::unique_ptr<propt> prop = get_sat_solver(message_handler, options);
 
  bv_refinementt::infot info;
  info.ns = &ns;
  info.prop = prop.get();
  info.output_xml = output_xml_in_refinement;
 
  // we allow setting some parameters
  if(options.get_bool_option("max-node-refinement"))
    info.max_node_refinement =
      options.get_unsigned_int_option("max-node-refinement");
 
  info.refine_arrays = options.get_bool_option("refine-arrays");
  info.refine_arithmetic = options.get_bool_option("refine-arithmetic");
  info.message_handler = &message_handler;
 
  std::unique_ptr<boolbvt> decision_procedure =
    std::make_unique<bv_refinementt>(info);
  set_decision_procedure_time_limit(*decision_procedure);
  return std::make_unique<solvert>(
    std::move(decision_procedure), std::move(prop));
}
 
std::unique_ptr<solver_factoryt::solvert>
solver_factoryt::get_string_refinement()
{
  string_refinementt::infot info;
  info.ns = &ns;
  auto prop = get_sat_solver(message_handler, options);
  info.prop = prop.get();
  info.refinement_bound = DEFAULT_MAX_NB_REFINEMENT;
  info.output_xml = output_xml_in_refinement;
  if(options.get_bool_option("max-node-refinement"))
    info.max_node_refinement =
      options.get_unsigned_int_option("max-node-refinement");
  info.refine_arrays = options.get_bool_option("refine-arrays");
  info.refine_arithmetic = options.get_bool_option("refine-arithmetic");
  info.message_handler = &message_handler;
 
  std::unique_ptr<boolbvt> decision_procedure =
    std::make_unique<string_refinementt>(info);
  set_decision_procedure_time_limit(*decision_procedure);
  return std::make_unique<solvert>(
    std::move(decision_procedure), std::move(prop));
}
 
std::unique_ptr<solver_factoryt::solvert>
solver_factoryt::get_incremental_smt2(std::string solver_command)
{
  no_beautification();
 
  const std::string outfile_arg = options.get_option("outfile");
  const std::string dump_smt_formula = options.get_option("dump-smt-formula");
 
  if(!outfile_arg.empty() && !dump_smt_formula.empty())
  {
    throw invalid_command_line_argument_exceptiont(
      "Argument --outfile is incompatible with --dump-smt-formula. ",
      "--outfile");
  }
 
  std::unique_ptr<smt_base_solver_processt> solver_process = nullptr;
 
  if(!outfile_arg.empty())
  {
    bool on_std_out = outfile_arg == "-";
    std::unique_ptr<std::ostream> outfile =
      on_std_out
        ? nullptr
        : open_outfile_and_check(outfile_arg, message_handler, "--outfile");
    solver_process = std::make_unique<smt_incremental_dry_run_solvert>(
      message_handler, on_std_out ? std::cout : *outfile, std::move(outfile));
  }
  else
  {
    const auto out_filename = options.get_option("dump-smt-formula");
 
    // If no out_filename is provided `open_outfile_and_check` will return
    // `nullptr`, and the solver will work normally without any logging.
    solver_process = std::make_unique<smt_piped_solver_processt>(
      std::move(solver_command),
      message_handler,
      open_outfile_and_check(
        out_filename, message_handler, "--dump-smt-formula"));
  }
 
  return std::make_unique<solvert>(
    std::make_unique<smt2_incremental_decision_proceduret>(
      ns, std::move(solver_process), message_handler));
}
 
std::unique_ptr<solver_factoryt::solvert>
solver_factoryt::get_smt2(smt2_dect::solvert solver)
{
  no_beautification();
 
  const std::string &filename = options.get_option("outfile");
 
  if(filename.empty())
  {
    if(solver == smt2_dect::solvert::GENERIC)
    {
      throw invalid_command_line_argument_exceptiont(
        "required filename not provided",
        "--outfile",
        "provide a filename with --outfile");
    }
 
    auto smt2_dec = std::make_unique<smt2_dect>(
      ns,
      "cbmc",
      std::string("Generated by CBMC ") + CBMC_VERSION,
      "QF_AUFBV",
      solver,
      options.get_option("external-smt2-solver"),
      message_handler);
 
    if(options.get_bool_option("fpa"))
      smt2_dec->use_FPA_theory = true;
 
    return std::make_unique<solvert>(std::move(smt2_dec));
  }
  else if(filename == "-")
  {
    auto smt2_conv = std::make_unique<smt2_convt>(
      ns,
      "cbmc",
      std::string("Generated by CBMC ") + CBMC_VERSION,
      "QF_AUFBV",
      solver,
      std::cout);
 
    if(options.get_bool_option("fpa"))
      smt2_conv->use_FPA_theory = true;
 
    return std::make_unique<solvert>(std::move(smt2_conv));
  }
  else
  {
    auto out = open_outfile_and_check(filename, message_handler, "--outfile");
 
    auto smt2_conv = std::make_unique<smt2_convt>(
      ns,
      "cbmc",
      std::string("Generated by CBMC ") + CBMC_VERSION,
      "QF_AUFBV",
      solver,
      *out);
 
    if(options.get_bool_option("fpa"))
      smt2_conv->use_FPA_theory = true;
 
    return std::make_unique<solvert>(std::move(smt2_conv), std::move(out));
  }
}
 
void solver_factoryt::no_beautification()
{
  if(options.get_bool_option("beautify"))
  {
    throw invalid_command_line_argument_exceptiont(
      "the chosen solver does not support beautification", "--beautify");
  }
}
 
void solver_factoryt::no_incremental_check()
{
  const bool all_properties = options.get_bool_option("all-properties");
  const bool cover = options.is_set("cover");
  const bool incremental_loop = options.is_set("incremental-loop");
 
  if(all_properties)
  {
    throw invalid_command_line_argument_exceptiont(
      "the chosen solver does not support incremental solving",
      "--all_properties");
  }
  else if(cover)
  {
    throw invalid_command_line_argument_exceptiont(
      "the chosen solver does not support incremental solving", "--cover");
  }
  else if(incremental_loop)
  {
    throw invalid_command_line_argument_exceptiont(
      "the chosen solver does not support incremental solving",
      "--incremental-loop");
  }
}
 
static void parse_sat_options(const cmdlinet &cmdline, optionst &options)
{
  if(cmdline.isset("external-sat-solver"))
  {
    options.set_option(
      "external-sat-solver", cmdline.get_value("external-sat-solver"));
  }
 
  options.set_option("sat-preprocessor", !cmdline.isset("no-sat-preprocessor"));
 
  if(cmdline.isset("dimacs"))
    options.set_option("dimacs", true);
 
  if(cmdline.isset("sat-solver"))
    options.set_option("sat-solver", cmdline.get_value("sat-solver"));
}
 
static void parse_smt2_options(const cmdlinet &cmdline, optionst &options)
{
  if(cmdline.isset("smt2"))
    options.set_option("smt2", true);
 
  if(cmdline.isset("fpa"))
    options.set_option("fpa", true);
 
  bool solver_set = false;
 
  if(cmdline.isset("bitwuzla"))
  {
    options.set_option("bitwuzla", true), solver_set = true;
    options.set_option("smt2", true);
  }
 
  if(cmdline.isset("boolector"))
  {
    options.set_option("boolector", true), solver_set = true;
    options.set_option("smt2", true);
  }
 
  if(cmdline.isset("cprover-smt2"))
  {
    options.set_option("cprover-smt2", true), solver_set = true;
    options.set_option("smt2", true);
  }
 
  if(cmdline.isset("mathsat"))
  {
    options.set_option("mathsat", true), solver_set = true;
    options.set_option("smt2", true);
  }
 
  if(cmdline.isset("cvc5"))
  {
    options.set_option("cvc5", true), solver_set = true;
    options.set_option("smt2", true);
  }
 
  if(cmdline.isset("incremental-smt2-solver"))
  {
    options.set_option(
      "incremental-smt2-solver", cmdline.get_value("incremental-smt2-solver")),
      solver_set = true;
  }
 
  if(cmdline.isset("yices"))
  {
    options.set_option("yices", true), solver_set = true;
    options.set_option("smt2", true);
  }
 
  if(cmdline.isset("z3"))
  {
    options.set_option("z3", true), solver_set = true;
    options.set_option("smt2", true);
  }
 
  if(cmdline.isset("external-smt2-solver"))
  {
    options.set_option(
      "external-smt2-solver", cmdline.get_value("external-smt2-solver"));
    solver_set = true;
    options.set_option("smt2", true);
  }
 
  if(cmdline.isset("smt2") && !solver_set)
  {
    if(cmdline.isset("outfile"))
    {
      // outfile and no solver should give standard compliant SMT-LIB
      options.set_option("generic", true);
    }
    else
    {
      // the default smt2 solver
      options.set_option("z3", true);
    }
  }
}
 
void parse_solver_options(const cmdlinet &cmdline, optionst &options)
{
  parse_sat_options(cmdline, options);
  parse_smt2_options(cmdline, options);
 
  // Detect conflicting solver backend selections. The solver categories
  // are mutually exclusive: DIMACS output, an external SAT solver, an
  // SMT2 solver (including --smt2, solver-specific flags like --z3, and
  // --external-smt2-solver), and the incremental SMT2 solver.
  std::vector<std::string> solver_flags;
 
  if(cmdline.isset("dimacs"))
    solver_flags.push_back("--dimacs");
 
  if(cmdline.isset("external-sat-solver"))
    solver_flags.push_back("--external-sat-solver");
 
  // All SMT2-related flags are in the same category (at most one
  // reported in the conflict message).
  for(const char *smt2_flag :
      {"smt2",
       "bitwuzla",
       "boolector",
       "cprover-smt2",
       "mathsat",
       "cvc5",
       "yices",
       "z3",
       "external-smt2-solver"})
  {
    if(cmdline.isset(smt2_flag))
    {
      solver_flags.push_back(std::string("--") + smt2_flag);
      break;
    }
  }
 
  if(cmdline.isset("incremental-smt2-solver"))
    solver_flags.push_back("--incremental-smt2-solver");
 
  if(solver_flags.size() > 1)
  {
    throw invalid_command_line_argument_exceptiont(
      "conflicting solver options: " + solver_flags[0] + " and " +
        solver_flags[1] + " must not be given together",
      solver_flags[0] + " " + solver_flags[1]);
  }
 
  // --fpa is not supported with the incremental SMT2 solver
  if(cmdline.isset("incremental-smt2-solver") && cmdline.isset("fpa"))
  {
    throw invalid_command_line_argument_exceptiont(
      "--fpa is not supported with --incremental-smt2-solver",
      "--fpa --incremental-smt2-solver");
  }
 
  if(cmdline.isset("outfile"))
    options.set_option("outfile", cmdline.get_value("outfile"));
 
  if(cmdline.isset("dump-smt-formula"))
    options.set_option(
      "dump-smt-formula", cmdline.get_value("dump-smt-formula"));
 
  if(cmdline.isset("write-solver-stats-to"))
  {
    options.set_option(
      "write-solver-stats-to", cmdline.get_value("write-solver-stats-to"));
  }
 
  if(cmdline.isset("beautify"))
    options.set_option("beautify", true);
 
  if(cmdline.isset("refine-arrays"))
  {
    options.set_option("refine", true);
    options.set_option("refine-arrays", true);
  }
 
  if(cmdline.isset("refine-arithmetic"))
  {
    options.set_option("refine", true);
    options.set_option("refine-arithmetic", true);
  }
 
  if(cmdline.isset("refine"))
  {
    options.set_option("refine", true);
    options.set_option("refine-arrays", true);
    options.set_option("refine-arithmetic", true);
  }
 
  if(cmdline.isset("max-node-refinement"))
  {
    options.set_option(
      "max-node-refinement", cmdline.get_value("max-node-refinement"));
  }
}