on-restart-benchmarks/solvers/fzn/fzn_solverinstance.cpp

/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */

/*
 *  Main authors:
 *     Guido Tack <guido.tack@monash.edu>
 */

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#endif

#ifdef _WIN32
#define NOMINMAX  // Need this before all (implicit) include's of Windows.h
#endif

#include <minizinc/builtins.hh>
#include <minizinc/eval_par.hh>
#include <minizinc/parser.hh>
#include <minizinc/pathfileprinter.hh>
#include <minizinc/prettyprinter.hh>
#include <minizinc/process.hh>
#include <minizinc/solvers/fzn_solverinstance.hh>
#include <minizinc/timer.hh>
#include <minizinc/typecheck.hh>

#include <cstdio>
#include <fstream>

#ifdef _WIN32
#undef ERROR
#endif

using namespace std;

namespace MiniZinc {

FZN_SolverFactory::FZN_SolverFactory(void) {
  SolverConfig sc("org.minizinc.mzn-fzn",
                  MZN_VERSION_MAJOR "." MZN_VERSION_MINOR "." MZN_VERSION_PATCH);
  sc.name("Generic FlatZinc driver");
  sc.mznlibVersion(1);
  sc.description("MiniZinc generic FlatZinc solver plugin");
  sc.requiredFlags({"--fzn-cmd"});
  sc.stdFlags({"-a", "-n", "-f", "-p", "-s", "-r", "-v"});
  sc.tags({"__internal__"});
  SolverConfigs::registerBuiltinSolver(sc);
}

string FZN_SolverFactory::getDescription(SolverInstanceBase::Options*) {
  string v = "FZN solver plugin, compiled  " __DATE__ "  " __TIME__;
  return v;
}

string FZN_SolverFactory::getVersion(SolverInstanceBase::Options*) { return MZN_VERSION_MAJOR; }

string FZN_SolverFactory::getId() { return "org.minizinc.mzn-fzn"; }

void FZN_SolverFactory::printHelp(ostream& os) {
  os << "MZN-FZN plugin options:" << std::endl
     << "  --fzn-cmd , --flatzinc-cmd <exe>\n     the backend solver filename.\n"
     << "  -b, --backend, --solver-backend <be>\n     the backend codename. Currently passed to "
        "the solver.\n"
     << "  --fzn-flags <options>, --flatzinc-flags <options>\n     Specify option to be passed to "
        "the FlatZinc interpreter.\n"
     << "  --fzn-flag <option>, --flatzinc-flag <option>\n     As above, but for a single option "
        "string that need to be quoted in a shell.\n"
     << "  -n <n>, --num-solutions <n>\n     An upper bound on the number of solutions to output. "
        "The default should be 1.\n"
     << "  -t <ms>, --solver-time-limit <ms>, --fzn-time-limit <ms>\n     Set time limit (in "
        "milliseconds) for solving.\n"
     << "  --fzn-sigint\n     Send SIGINT instead of SIGTERM.\n"
     << "  -a, --all, --all-solns, --all-solutions\n     Print all solutions.\n"
     << "  -p <n>, --parallel <n>\n     Use <n> threads during search. The default is "
        "solver-dependent.\n"
     << "  -k, --keep-files\n     For compatibility only: to produce .ozn and .fzn, use mzn2fzn\n"
        "     or <this_exe> --fzn ..., --ozn ...\n"
     << "  -r <n>, --seed <n>, --random-seed <n>\n     For compatibility only: use solver flags "
        "instead.\n";
}

SolverInstanceBase::Options* FZN_SolverFactory::createOptions(void) { return new FZNSolverOptions; }

SolverInstanceBase* FZN_SolverFactory::doCreateSI(std::ostream& log,
                                                  SolverInstanceBase::Options* opt) {
  return new FZNSolverInstance(log, opt);
}

bool FZN_SolverFactory::processOption(SolverInstanceBase::Options* opt, int& i,
                                      std::vector<std::string>& argv) {
  FZNSolverOptions& _opt = static_cast<FZNSolverOptions&>(*opt);
  CLOParser cop(i, argv);
  string buffer;
  int nn = -1;

  if (cop.getOption("--fzn-cmd --flatzinc-cmd", &buffer)) {
    _opt.fzn_solver = buffer;
  } else if (cop.getOption("-b --backend --solver-backend", &buffer)) {
    _opt.backend = buffer;
  } else if (cop.getOption("--fzn-flags --flatzinc-flags", &buffer)) {
    std::vector<std::string> cmdLine = FileUtils::parseCmdLine(buffer);
    for (auto& s : cmdLine) {
      _opt.fzn_flags.push_back(s);
    }
  } else if (cop.getOption("-t --solver-time-limit --fzn-time-limit", &nn)) {
    _opt.fzn_time_limit_ms = nn;
    if (_opt.supports_t) {
      _opt.solver_time_limit_ms = nn;
      _opt.fzn_time_limit_ms += 1000;  // kill 1 second after solver should have stopped
    }
  } else if (cop.getOption("--fzn-sigint")) {
    _opt.fzn_sigint = true;
  } else if (cop.getOption("--fzn-needs-paths")) {
    _opt.fzn_needs_paths = true;
  } else if (cop.getOption("--fzn-output-passthrough")) {
    _opt.fzn_output_passthrough = true;
  } else if (cop.getOption("--fzn-flag --flatzinc-flag", &buffer)) {
    _opt.fzn_flags.push_back(buffer);
  } else if (_opt.supports_n && cop.getOption("-n --num-solutions", &nn)) {
    _opt.numSols = nn;
  } else if (_opt.supports_a && cop.getOption("-a --all --all-solns --all-solutions")) {
    _opt.allSols = true;
  } else if (cop.getOption("-p --parallel", &nn)) {
    if (_opt.supports_p) _opt.parallel = to_string(nn);
  } else if (cop.getOption("-k --keep-files")) {
  } else if (cop.getOption("-r --seed --random-seed", &buffer)) {
    if (_opt.supports_r) {
      _opt.fzn_flags.push_back("-r");
      _opt.fzn_flags.push_back(buffer);
    }
  } else if (cop.getOption("-s --solver-statistics")) {
    if (_opt.supports_s) {
      _opt.printStatistics = true;
    }
  } else if (cop.getOption("-v --verbose-solving")) {
    _opt.verbose = true;
  } else if (cop.getOption("-f --free-search")) {
    if (_opt.supports_f) _opt.fzn_flags.push_back("-f");
  } else {
    for (auto& fznf : _opt.fzn_solver_flags) {
      if (fznf.t == MZNFZNSolverFlag::FT_ARG && cop.getOption(fznf.n.c_str(), &buffer)) {
        _opt.fzn_flags.push_back(fznf.n);
        _opt.fzn_flags.push_back(buffer);
        return true;
      } else if (fznf.t == MZNFZNSolverFlag::FT_NOARG && cop.getOption(fznf.n.c_str())) {
        _opt.fzn_flags.push_back(fznf.n);
        return true;
      }
    }

    return false;
  }
  return true;
}

void FZN_SolverFactory::setAcceptedFlags(SolverInstanceBase::Options* opt,
                                         const std::vector<MZNFZNSolverFlag>& flags) {
  FZNSolverOptions& _opt = static_cast<FZNSolverOptions&>(*opt);
  _opt.fzn_solver_flags.clear();
  for (auto& f : flags) {
    if (f.n == "-a") {
      _opt.supports_a = true;
    } else if (f.n == "-n") {
      _opt.supports_n = true;
    } else if (f.n == "-f") {
      _opt.supports_f = true;
    } else if (f.n == "-p") {
      _opt.supports_p = true;
    } else if (f.n == "-s") {
      _opt.supports_s = true;
    } else if (f.n == "-r") {
      _opt.supports_r = true;
    } else if (f.n == "-v") {
      _opt.supports_v = true;
    } else if (f.n == "-t") {
      _opt.supports_t = true;
    } else {
      _opt.fzn_solver_flags.push_back(f);
    }
  }
}

FZNSolverInstance::FZNSolverInstance(std::ostream& log, SolverInstanceBase::Options* options)
    : SolverInstanceBase(log, options), _model(new Model()), env(_model) {}

FZNSolverInstance::~FZNSolverInstance(void) {}

void FZNSolverInstance::addFunction(FunctionI* fi) {
  _model->addItem(fi);
  _model->registerFn(env.envi(), fi);
}

VarDecl* FZNSolverInstance::add_var_to_model(int ident, TypeInst* ti, bool view, bool isOutput) {
  VarDecl* vd;
  if (!view) {
    vd = new VarDecl(Location().introduce(), ti, ident);

    if (isOutput) {
      vd->addAnnotation(constants().ann.output_var);
      bool is_bool = ti->type().isbool();
      auto output_ti =
          new TypeInst(Location().introduce(), is_bool ? Type::parbool() : Type::parint(), nullptr);
      auto output_vd = new VarDecl(Location().introduce(), output_ti, ident);
      env.output()->addItem(new VarDeclI(Location().introduce(), output_vd));
    }
  } else {
    vd = new VarDecl(Location().introduce(), ti, "view_" + std::to_string(ident));
  }
  auto vdi = new VarDeclI(Location().introduce(), vd);
  _model->addItem(vdi);
  return vd;
}

Expression* FZNSolverInstance::val_to_expr(Type ty, Val v) {
  v = Val::follow_alias(v);
  if (v.isInt()) {
    if (ty.isbool()) {
      return v == 0 ? constants().lit_false : constants().lit_true;
    }
    return IntLit::a(v.toIntVal());
  } else if (v.isVar()) {
    auto it = vdmap.find(v.timestamp());
    assert(it != vdmap.end());
    VarStore& vs = it->second;
    if (ty.isbool()) {
      if (vs.used_bool) {
        return vs.bool_var()->cast<VarDecl>()->id();
      }
      vs.used_bool = true;

      auto ti = new TypeInst(Location().introduce(), Type::varbool());
      VarDecl* vd = add_var_to_model(v.timestamp(), ti, vs.used_int);
      vs.bool_var = KeepAlive(vd);

      if (vs.used_int) {
        _model->addItem(new ConstraintI(
            Location().introduce(),
            new Call(Location().introduce(), constants().ids.bool2int,
                     {vs.bool_var()->cast<VarDecl>()->id(), vs.int_var()->cast<VarDecl>()->id()})));
      } else {
        uninitialised_vars.erase(v.timestamp());
      }
      return vs.bool_var()->cast<VarDecl>()->id();
    }
    if (vs.used_int) {
      return vs.int_var()->cast<VarDecl>()->id();
    }
    vs.used_int = true;

    SetLit* dom_set = new SetLit(Location().introduce(), IntSetVal::a(0, 1));
    auto ti = new TypeInst(Location().introduce(), Type::varint(), dom_set);
    VarDecl* vd = add_var_to_model(v.timestamp(), ti, vs.used_bool);
    vs.int_var = KeepAlive(vd);

    if (vs.used_bool) {
      _model->addItem(new ConstraintI(
          Location().introduce(),
          new Call(Location().introduce(), constants().ids.bool2int,
                   {vs.bool_var()->cast<VarDecl>()->id(), vs.int_var()->cast<VarDecl>()->id()})));
    } else {
      uninitialised_vars.erase(v.timestamp());
    }

    return vs.int_var()->cast<VarDecl>()->id();
  } else {
    assert(v.isVec());
    if (ty.is_set()) {
      std::vector<IntSetVal::Range> ranges;
      Vec* vec = v.toVec();
      for (int i = 0; i < vec->size(); i += 2) {
        ranges.push_back(IntSetVal::Range((*vec)[i].toIntVal(), (*vec)[i + 1].toIntVal()));
      }
      auto sl = new SetLit(Location().introduce(), IntSetVal::a(ranges));
      return sl;
    } else {
      // this is an array
      Val vec = v.toVec()->raw_data();
      std::vector<Expression*> evec(vec.size());
      bool par = true;
      for (int i = 0; i < vec.size(); ++i) {
        assert(!vec[i].isVec());
        Type nty = ty;
        nty.dim(0);
        evec[i] = val_to_expr(nty, vec[i]);
        par = par && evec[i]->type().ispar();
      }
      auto al = new ArrayLit(Location().introduce(), evec);
      al->type(par ? Type::parint(1) : Type::varint(1));
      return al;
    }
  }
}

void FZNSolverInstance::addConstraint(const std::vector<BytecodeProc>& bs, Constraint* c) {
  GCLock lock;
  const BytecodeProc& proc = bs[c->pred()];
  const std::string& name = proc.name;
  if (name == "solve_this") {
    IntVal solve_mode = c->arg(0).toIntVal();
    Val obj = c->arg(1);
    SolveI* si;
    if (solve_mode == 0) {
      si = SolveI::sat(Location().introduce());
    } else if (solve_mode == 1) {
      si = SolveI::min(Location().introduce(), val_to_expr(Type::varint(), obj));
    } else {
      assert(solve_mode == 2);
      si = SolveI::max(Location().introduce(), val_to_expr(Type::varint(), obj));
    }
    if (c->size() == 5) {
      Val search_a = c->arg(2);
      IntVal var_sel = c->arg(3).toIntVal();
      IntVal val_sel = c->arg(4).toIntVal();
      if (search_a.isVec() && search_a.size() > 0 && var_sel > 0 && val_sel > 0) {
        Expression* search_vars = val_to_expr(Type::varint(1), search_a);
        ASTString var_sel_s(var_sel == 1 ? "input_order" : "first_fail");
        ASTString val_sel_s(val_sel == 1 ? "indomain_min" : "indomain_max");
        Id* var_sel_id = new Id(Location().introduce(), var_sel_s, nullptr);
        Id* val_sel_id = new Id(Location().introduce(), val_sel_s, nullptr);
        Id* complete_id = new Id(Location().introduce(), "complete", nullptr);
        si->ann().add(new Call(Location().introduce(), ASTString("int_search"),
                               {search_vars, var_sel_id, val_sel_id, complete_id}));
      }
    }
    _model->addItem(si);
    return;
  }
  auto fnit = _model->fnmap.find(ASTString(name));
  assert(fnit != _model->fnmap.end());
  assert(fnit->second.size() == 1);
  std::vector<Type>& tys = fnit->second[0].t;
  assert(tys.size() == c->size());
  std::vector<Expression*> args(proc.nargs);
  for (int i = 0; i < proc.nargs; ++i) {
    args[i] = val_to_expr(tys[i], c->arg(i));
  }
  auto call = new Call(Location().introduce(), name, args);
  auto ci = new ConstraintI(Location().introduce(), call);
  _model->addItem(ci);
};

void FZNSolverInstance::addVariable(Variable* var, bool isOutput) {
  GCLock lock;
  Vec* dom = var->domain();
  assert(dom->size() >= 2 && dom->size() % 2 == 0);

  if (!isOutput && dom->size() == 2 && (*dom)[0] == 0 && (*dom)[1] == 1) {
    vdmap.emplace(std::piecewise_construct, std::forward_as_tuple(var->timestamp()),
                  std::forward_as_tuple(nullptr, nullptr, false, false));
    uninitialised_vars.insert(var->timestamp());
    return;
  }

  std::vector<IntSetVal::Range> ranges;
  for (int i = 0; i < dom->size(); i += 2) {
    ranges.emplace_back((*dom)[i].toIntVal(), (*dom)[i + 1].toIntVal());
  }
  SetLit* dom_set = new SetLit(Location().introduce(), IntSetVal::a(ranges));
  auto ti = new TypeInst(Location().introduce(), Type::varint(), dom_set);
  VarDecl* vd = add_var_to_model(var->timestamp(), ti, false, isOutput);
  vdmap.emplace(std::piecewise_construct, std::forward_as_tuple(var->timestamp()),
                std::forward_as_tuple(vd, nullptr, true, false));
}

Val FZNSolverInstance::getSolutionValue(Variable* var) {
  GCLock lock;
  Id ident(Location().introduce(), var->timestamp(), nullptr);
  auto de = getSolns2Out()->findOutputVar(ident.str());
  assert(de.first->e());  // A solution must have been assigned
  return Val::fromIntVal(eval_int(env.envi(), de.first->e()));
};

void FZNSolverInstance::pushState() { stack.emplace_back(_model->size()); }

void FZNSolverInstance::popState() {
  for (auto i = stack.back(); i < _model->size(); ++i) {
    Item* it = (*_model)[i];
    if (!it->isa<FunctionI>()) {
      it->remove();
    }
  }
  _model->compact();
  stack.pop_back();
}

void FZNSolverInstance::printStatistics(bool fLegend) {
  FlatModelStatistics stats = statistics(_model);
  auto& out = getSolns2Out()->getOutput();

  if (stats.n_bool_vars) {
    out << "%%%mzn-stat: flatBoolVars=" << stats.n_bool_vars << endl;
  }
  if (stats.n_int_vars) {
    out << "%%%mzn-stat: flatIntVars=" << stats.n_int_vars << endl;
  }
  if (stats.n_float_vars) {
    out << "%%%mzn-stat: flatFloatVars=" << stats.n_float_vars << endl;
  }
  if (stats.n_set_vars) {
    out << "%%%mzn-stat: flatSetVars=" << stats.n_set_vars << endl;
  }

  if (stats.n_bool_ct) {
    out << "%%%mzn-stat: flatBoolConstraints=" << stats.n_bool_ct << endl;
  }
  if (stats.n_int_ct) {
    out << "%%%mzn-stat: flatIntConstraints=" << stats.n_int_ct << endl;
  }
  if (stats.n_float_ct) {
    out << "%%%mzn-stat: flatFloatConstraints=" << stats.n_float_ct << endl;
  }
  if (stats.n_set_ct) {
    out << "%%%mzn-stat: flatSetConstraints=" << stats.n_set_ct << endl;
  }

  if (stats.n_reif_ct) {
    out << "%%%mzn-stat: evaluatedReifiedConstraints=" << stats.n_reif_ct << endl;
  }
  if (stats.n_imp_ct) {
    out << "%%%mzn-stat: evaluatedHalfReifiedConstraints=" << stats.n_imp_ct << endl;
  }

  if (stats.n_imp_del) {
    out << "%%%mzn-stat: eliminatedImplications=" << stats.n_imp_del << endl;
  }
  if (stats.n_lin_del) {
    out << "%%%mzn-stat: eliminatedLinearConstraints=" << stats.n_lin_del << endl;
  }

  /// Objective / SAT. These messages are used by mzn-test.py.
  SolveI* solveItem = _model->solveItem();
  if (solveItem && solveItem->st() != SolveI::SolveType::ST_SAT) {
    if (solveItem->st() == SolveI::SolveType::ST_MAX) {
      out << "%%%mzn-stat: method=\"maximize\"" << endl;
    } else {
      out << "%%%mzn-stat: method=\"minimize\"" << endl;
    }
  } else {
    out << "%%%mzn-stat: method=\"satisfy\"" << endl;
  }
  out << "%%%mzn-stat-end" << endl << endl;
}
void FZNSolverInstance::printFlatZincToFile(std::string filename) {
  std::ofstream os(filename);
  Printer p(os, 0, true);
  for (FunctionIterator it = _model->begin_functions(); it != _model->end_functions(); ++it) {
    if (!it->removed()) {
      Item& item = *it;
      p.print(&item);
    }
  }
  for (VarDeclIterator it = _model->begin_vardecls(); it != _model->end_vardecls(); ++it) {
    if (!it->removed()) {
      Item& item = *it;
      p.print(&item);
    }
  }
  for (ConstraintIterator it = _model->begin_constraints(); it != _model->end_constraints(); ++it) {
    if (!it->removed()) {
      Item& item = *it;
      p.print(&item);
    }
  }
  if (_model->solveItem()) {
    p.print(_model->solveItem());
  } else {
    GCLock lock;
    auto si = SolveI::sat(Location().introduce());
    p.print(si);
  }
}
void FZNSolverInstance::printOutputToFile(std::string filename) {
  Model* output = env.output();
  std::ofstream os(filename);
  Printer p(os, 0, true);
  p.print(output);
}
void FZNSolverInstance::outputArray(Vec* arr) {
  GCLock lock;
  std::vector<Expression*> content;
  for (int i = 0; i < arr->size(); ++i) {
    Val real = Val::follow_alias((*arr)[i]);
    content.push_back(val_to_expr(Type::parint(), real));
  }
  auto* al = new ArrayLit(Location().introduce(), content);
  std::vector<Expression*> sarg = {new Call(Location().introduce(), constants().ids.show, {al})};
  auto* sal = new ArrayLit(Location().introduce(), sarg);
  env.output()->addItem(new OutputI(Location().introduce(), sal));
}
void FZNSolverInstance::outputDict(Variable* start) {
  GCLock lock;
  std::vector<Expression*> content;
  auto* open = new StringLit(Location().introduce(), "{");
  auto* close = new StringLit(Location().introduce(), "}");
  auto* comma = new StringLit(Location().introduce(), ",");
  auto* quote = new StringLit(Location().introduce(), "\"");
  auto* quote_colon = new StringLit(Location().introduce(), "\":");
  auto* var_start = new StringLit(Location().introduce(), "X_INTRODUCED_");

  content.push_back(open);
  Variable* v = start->next();  // Skip root node
  bool first = true;
  while (v != start) {
    if (!first) {
      content.push_back(comma);
    }
    Val real = Val::follow_alias(Val(v));
    content.push_back(quote);
    content.push_back(var_start);
    content.push_back(new StringLit(Location().introduce(), std::to_string(v->timestamp())));
    content.push_back(quote_colon);
    content.push_back(new Call(Location().introduce(), constants().ids.show,
                               {val_to_expr(Type::parint(), real)}));
    v = v->next();
    first = false;
  };
  content.push_back(close);
  auto* al = new ArrayLit(Location().introduce(), content);
  env.output()->addItem(new OutputI(Location().introduce(), al));
}

SolverInstance::Status FZNSolverInstance::solve(void) {
  {
    // Add all remaining variables to the model
    GCLock lock;
    auto ti = new TypeInst(Location().introduce(), Type::varbool());
    for (int var : uninitialised_vars) {
      add_var_to_model(var, ti);
    }
  }

  FZNSolverOptions& opt = static_cast<FZNSolverOptions&>(*_options);
  if (opt.fzn_solver.empty()) {
    throw InternalError("No FlatZinc solver specified");
  }
  /// Passing options to solver
  vector<string> cmd_line;
  cmd_line.push_back(opt.fzn_solver);
  string sBE = opt.backend;
  if (sBE.size()) {
    cmd_line.push_back("-b");
    cmd_line.push_back(sBE);
  }
  for (auto& f : opt.fzn_flags) {
    cmd_line.push_back(f);
  }
  if (opt.numSols != 1) {
    cmd_line.push_back("-n");
    ostringstream oss;
    oss << opt.numSols;
    cmd_line.push_back(oss.str());
  }
  if (opt.allSols) {
    cmd_line.push_back("-a");
  }
  if (opt.parallel.size()) {
    cmd_line.push_back("-p");
    ostringstream oss;
    oss << opt.parallel;
    cmd_line.push_back(oss.str());
  }
  if (opt.printStatistics) {
    cmd_line.push_back("-s");
  }
  if (opt.solver_time_limit_ms != 0) {
    cmd_line.push_back("-t");
    std::ostringstream oss;
    oss << opt.solver_time_limit_ms;
    cmd_line.push_back(oss.str());
  }
  if (opt.verbose) {
    if (opt.supports_v) cmd_line.push_back("-v");
    std::cerr << "Using FZN solver " << cmd_line[0] << " for solving, parameters: ";
    for (int i = 1; i < cmd_line.size(); ++i) cerr << "" << cmd_line[i] << " ";
    cerr << std::endl;
  }
  int timelimit = opt.fzn_time_limit_ms;
  bool sigint = opt.fzn_sigint;

  FileUtils::TmpFile fznFile(".fzn");
  printFlatZincToFile(fznFile.name());
  cmd_line.push_back(fznFile.name());

  FileUtils::TmpFile* pathsFile = NULL;
  // if(opt.fzn_needs_paths) {
  //   pathsFile = new FileUtils::TmpFile(".paths");
  //   std::ofstream ofs(pathsFile->name());
  //   PathFilePrinter pfp(ofs, _env.envi());
  //   pfp.print(_fzn);

  //   cmd_line.push_back("--paths");
  //   cmd_line.push_back(pathsFile->name());
  // }
  getSolns2Out()->initFromEnv(&env);

  if (!opt.fzn_output_passthrough) {
    Process<Solns2Out> proc(cmd_line, getSolns2Out(), timelimit, sigint);
    int exitStatus = proc.run();
    delete pathsFile;
    return exitStatus == 0 ? getSolns2Out()->status : SolverInstance::ERROR;
  } else {
    Solns2Log s2l(getSolns2Out()->getOutput(), _log);
    Process<Solns2Log> proc(cmd_line, &s2l, timelimit, sigint);
    int exitStatus = proc.run();
    delete pathsFile;
    return exitStatus == 0 ? SolverInstance::NONE : SolverInstance::ERROR;
  }
}

void FZNSolverInstance::processFlatZinc(void) {}

void FZNSolverInstance::resetSolver(void) {}

Expression* FZNSolverInstance::getSolutionValue(Id* id) {
  assert(false);
  return NULL;
}
}  // namespace MiniZinc