smt.cpp

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#include "hal_core/python_bindings/python_bindings.h"
 
namespace hal
{
    void smt_init(py::module& m)
    {
        auto py_smt = m.def_submodule("SMT", R"(
            SMT solver functions.
        )");
 
        py::enum_<SMT::SolverType> py_smt_solver_type(py_smt, "SolverType", R"(
            Identifier for the SMT solver type.
        )");
 
        py_smt_solver_type.value("Z3", SMT::SolverType::Z3, R"(Z3 SMT solver.)")
            .value("Boolector", SMT::SolverType::Boolector, R"(Boolector SMT solver.)")
            .value("Bitwuzla", SMT::SolverType::Bitwuzla, R"(Bitwuzla SMT solver.)")
            .value("Unknown", SMT::SolverType::Unknown, R"(Unknown (unsupported) SMT solver.)")
            .export_values();
 
        py::enum_<SMT::SolverCall> py_smt_solver_call(py_smt, "SolverCall", R"(
            Identifier for how the SMT solver is invoked.
        )");
 
        py_smt_solver_call.value("Binary", SMT::SolverCall::Binary, R"(Call the solver binary in a subprocess.)")
            .value("Library", SMT::SolverCall::Library, R"(Call the solver through the library linked into HAL.)")
            .export_values();
 
        py::class_<SMT::QueryConfig> py_smt_query_config(py_smt, "QueryConfig", R"(
            Represents the data structure to configure an SMT query.
        )");
 
        py_smt_query_config.def(py::init<>(), R"(
            Constructs a new query configuration.
        )");
 
        py_smt_query_config.def_readwrite("solver", &SMT::QueryConfig::solver, R"(
            The SMT solver identifier.
 
            :type: hal_py.SMT.SolverType
        )");
 
        py_smt_query_config.def_readwrite("local", &SMT::QueryConfig::local, R"(
            Controls whether the SMT query is performed on a local or a remote machine.
 
            :type: bool
        )");
 
        py_smt_query_config.def_readwrite("generate_model", &SMT::QueryConfig::generate_model, R"(
            Controls whether the SMT solver should generate a model in case formula is satisfiable.
 
            :type: bool
        )");
 
        py_smt_query_config.def_readwrite("timeout_in_seconds", &SMT::QueryConfig::timeout_in_seconds, R"(
            The timeout after which the SMT solver is killed in seconds.
 
            :type: int
        )");
 
        py_smt_query_config.def("with_solver", &SMT::QueryConfig::with_solver, py::arg("solver"), R"(
            Sets the solver type to the desired SMT solver.
 
            :param hal_py.SMT.SolverType solver: The solver type identifier.
            :returns: The updated SMT query configuration.
            :rtype: hal_py.SMT.QueryConfig
        )");
 
        py_smt_query_config.def("with_call", &SMT::QueryConfig::with_call, py::arg("call"), R"(
            Sets the call type to the desired target.
 
            :param hal_py.SMT.SolverCall call: The solver call.
            :returns: The updated SMT query configuration.
            :rtype: hal_py.SMT.QueryConfig
        )");
 
        py_smt_query_config.def("with_local_solver", &SMT::QueryConfig::with_local_solver, R"(
            Activates local SMT solver execution.
 
            :returns: The updated SMT query configuration.
            :rtype: hal_py.SMT.QueryConfig
        )");
 
        py_smt_query_config.def("with_remote_solver", &SMT::QueryConfig::with_remote_solver, R"(
            Indicates that the SMT solver runs on a remote machine.
 
            :returns: The updated SMT query configuration.
            :rtype: hal_py.SMT.QueryConfig
        )");
 
        py_smt_query_config.def("with_model_generation", &SMT::QueryConfig::with_model_generation, R"(
            Indicates that the SMT solver should generate a model in case the formula is satisfiable.
 
            :returns: The updated SMT query configuration.
            :rtype: hal_py.SMT.QueryConfig
        )");
 
        py_smt_query_config.def("without_model_generation", &SMT::QueryConfig::without_model_generation, R"(
            Indicates that the SMT solver should not generate a model.
 
            :returns: The updated SMT query configuration.
            :rtype: hal_py.SMT.QueryConfig
        )");
 
        py_smt_query_config.def("with_timeout", &SMT::QueryConfig::with_timeout, py::arg("seconds"), R"(
            Sets a timeout in seconds that terminates an SMT query after the specified time has passed.
 
            :param int seconds: The timeout in seconds.
            :returns: The updated SMT query configuration.
            :rtype: hal_py.SMT.QueryConfig
        )");
 
        py_smt_query_config.def("to_string", &SMT::QueryConfig::to_string, R"(
            Translates the SMT query configuration into its string representation.
 
            :returns: A string representing the SMT query configuration.
            :rtype: str
        )");
 
        py_smt_query_config.def("__str__", [](const SMT::QueryConfig& config) { return config.to_string(); }, R"(
            Translates the SMT query configuration into its string representation.
 
            :returns: A string representing the SMT query configuration.
            :rtype: str
        )");
 
        py::class_<SMT::Constraint> py_smt_constraint(py_smt, "Constraint", R"(
            Represents a constraint to the SMT query.
            A constraint is either an assignment of two Boolean functions or a single Boolean function, e.g., an equality check or similar.
        )");
 
        py_smt_constraint.def_readwrite("constraint", &SMT::Constraint::constraint, R"(
            A constraint that is either an assignment of two Boolean functions or a single Boolean function, e.g., an equality check or similar.
 
            :type: hal_py.BooleanFunction or tuple(hal_py.BooleanFunction, hal_py.BooleanFunction)  
        )");
 
        py_smt_constraint.def(py::init([](BooleanFunction constraint) { return new SMT::Constraint(std::move(constraint)); }), py::arg("constraint"), R"(
            Constructs a new constraint from one Boolean function that evaluates to a single bit.
 
            :param hal_py.BooleanFunction constraint: The constraint function.
        )");
 
        py_smt_constraint.def(py::init([](BooleanFunction lhs, BooleanFunction rhs) { return new SMT::Constraint(std::move(lhs), std::move(rhs)); }), py::arg("lhs"), py::arg("rhs"), R"(
            Constructs a new equality constraint from two Boolean functions.
 
            :param hal_py.BooleanFunction lhs: The left-hand side of the equality constraint.
            :param hal_py.BooleanFunction rhs: The right-hand side of the equality constraint.
        )");
 
        py_smt_constraint.def("is_assignment", &SMT::Constraint::is_assignment, R"(
            Checks whether the constraint is an assignment constraint.
        
            :returns: ``True`` if the constraint is an assignment, ``False`` otherwise.
            :rtype: bool
        )");
 
        py_smt_constraint.def(
            "get_assignment",
            [](const SMT::Constraint& self) -> std::optional<std::pair<BooleanFunction, BooleanFunction>> {
                auto res = self.get_assignment();
                if (res.is_ok())
                {
                    return *res.get();
                }
                else
                {
                    log_error("python_context", "{}", res.get_error().get());
                    return std::nullopt;
                }
            },
            R"(
            Returns the assignment constraint as a pair of Boolean functions.
 
            :returns: The assignment constraint on success, ``None`` otherwise.
            :rtype: tuple(hal_py.BooleanFunction,hal_py.BooleanFunction) or None
        )");
 
        py_smt_constraint.def(
            "get_function",
            [](const SMT::Constraint& self) -> std::optional<const BooleanFunction*> {
                auto res = self.get_function();
                if (res.is_ok())
                {
                    return res.get();
                }
                else
                {
                    log_error("python_context", "{}", res.get_error().get());
                    return std::nullopt;
                }
            },
            R"(
            Returns the function constraint.
 
            :returns: The function constraint on success, ``None`` otherwise.
            :rtype: hal_py.BooleanFunction or None
        )");
 
        py_smt_constraint.def("to_string", &SMT::Constraint::to_string, R"(
            Translates the SMT constraint into its string representation.
 
            :returns: A string representing the SMT constraint.
            :rtype: str
        )");
 
        py_smt_constraint.def("__str__", [](const SMT::Constraint& constraint) { return constraint.to_string(); }, R"(
            Translates the SMT constraint into its string representation.
 
            :returns: A string representing the SMT constraint.
            :rtype: str
        )");
 
        py::enum_<SMT::SolverResultType> py_smt_result_type(py_smt, "SolverResultType", R"(
            Result type of an SMT solver query.
        )");
 
        py_smt_result_type.value("Sat", SMT::SolverResultType::Sat, R"(The list of constraints is satisfiable.)")
            .value("UnSat", SMT::SolverResultType::UnSat, R"(The list of constraints is not satisfiable.)")
            .value("Unknown", SMT::SolverResultType::Unknown, R"(A result could not be obtained, e.g., due to a time-out.)")
            .export_values();
 
        py::class_<SMT::Model> py_smt_model(py_smt, "Model", R"(
            Represents a list of assignments for variable nodes that yield a satisfiable assignment for a given list of constraints.
        )");
 
        py_smt_model.def(py::init<const std::map<std::string, std::tuple<u64, u16>>&>(), py::arg("model") = std::map<std::string, std::tuple<u64, u16>>(), R"(
            Constructs a new model from a map of variable names to value and bit-size.
 
            :param dict[str,tuple(int,int)] model: A dict from variable name to value and bit-size.
        )");
 
        py_smt_model.def(py::self == py::self, R"(
            Checks whether two SMT models are equal.
 
            :returns: ``True`` if both models are equal, ``False`` otherwise.
            :rtype: bool
        )");
 
        py_smt_model.def(py::self != py::self, R"(
            Checks whether two SMT models are unequal.
 
            :returns: ``True`` if both models are unequal, ``False`` otherwise.
            :rtype: bool
        )");
 
        py_smt_model.def_readwrite("model", &SMT::Model::model, R"(
            A dict from variable identifiers to a (1) value and (2) its bit-size.
 
            :type: dict(str,tuple(int,int))
        )");
 
        py_smt_model.def_static(
            "parse",
            [](const std::string& model_str, const SMT::SolverType& solver) -> std::optional<SMT::Model> {
                auto res = SMT::Model::parse(model_str, solver);
                if (res.is_ok())
                {
                    return res.get();
                }
                else
                {
                    log_error("python_context", "{}", res.get_error().get());
                    return std::nullopt;
                }
            },
            py::arg("model_str"),
            py::arg("solver"),
            R"(
            Parses an SMT-Lib model from a string output by a solver of the given type.
 
            :param str model_str: The SMT-Lib model string.
            :param hal_py.SMT.SolverType solver: The solver that computed the model.
            :returns: The model on success, ``None`` otherwise.
            :rtype: hal_py.SMT.Model or None
        )");
 
        py_smt_model.def(
            "evaluate",
            [](const SMT::Model& self, const BooleanFunction& bf) -> std::optional<BooleanFunction> {
                auto res = self.evaluate(bf);
                if (res.is_ok())
                {
                    return res.get();
                }
                else
                {
                    log_error("python_context", "{}", res.get_error().get());
                    return std::nullopt;
                }
            },
            py::arg("bf"),
            R"(
            Evaluates the given Boolean function by replacing all variables contained in the model with their corresponding value and simplifying the result.
 
            :param hal_py.BooleanFunction bf: The Boolean function to evaluate.
            :returns: The evaluated function on success, ``None`` otherwise.
            :rtype: hal_py.BooleanFunction or None
        )");
 
        py_smt_model.def("to_string", &SMT::Model::to_string, R"(
            Translates the SMT model into its string representation.
 
            :returns: A string representing the SMT model.
            :rtype: str
        )");
 
        py_smt_model.def("__str__", [](const SMT::Model& model) { return model.to_string(); }, R"(
            Translates the SMT model into its string representation.
 
            :returns: A string representing the SMT model.
            :rtype: str
        )");
 
        py::class_<SMT::SolverResult> py_smt_result(py_smt, "SolverResult", R"(
            Represents the result of an SMT query.
        )");
 
        py_smt_result.def_readwrite("type", &SMT::SolverResult::type, R"(
            Result type of the SMT query.
 
            :type: hal_py.SMT.ResultType
        )");
 
        py_smt_result.def_readwrite("model", &SMT::SolverResult::model, R"(
            The (optional) model that is only available if type == SMT.ResultType.Sat and model generation is enabled.
 
            :type: hal_py.SMT.Model
        )");
 
        py_smt_result.def_static("Sat", &SMT::SolverResult::Sat, py::arg("model") = std::optional<SMT::Model>(), R"(
            Creates a satisfiable result with an optional model.
 
            :param hal_py.SMT.Model model: Optional model for satisfiable formula.
            :returns: The result.
            :rtype: hal_py.SMT.SolverResult
        )");
 
        py_smt_result.def_static("UnSat", &SMT::SolverResult::UnSat, R"(
            Creates an unsatisfiable result.
 
            :returns: The result.
            :rtype: hal_py.SMT.SolverResult
        )");
 
        py_smt_result.def_static("Unknown", &SMT::SolverResult::Unknown, R"(
            Creates an unknown result.
 
            :returns: The result.
            :rtype: hal_py.SMT.SolverResult
        )");
 
        py_smt_result.def("is", &SMT::SolverResult::is, py::arg("type"), R"(
            Checks whether the result is of a specific type.
 
            :param hal_py.SMT.ResultType type: The type to check.
            :returns: ``True`` in case result matches the given type, ``False`` otherwise.
            :rtype: bool
        )");
 
        py_smt_result.def("is_sat", &SMT::SolverResult::is_sat, R"(
            Checks whether the result is satisfiable.
 
            :returns: ``True`` in case result is satisfiable, ``False`` otherwise.
            :rtype: bool
        )");
 
        py_smt_result.def("is_unsat", &SMT::SolverResult::is_unsat, R"(
            Checks whether the result is unsatisfiable.
 
            :returns: ``True`` in case result is unsatisfiable, ``False`` otherwise.
            :rtype: bool
        )");
 
        py_smt_result.def("is_unknown", &SMT::SolverResult::is_unknown, R"(
            Checks whether the result is unknown.
 
            :returns: ``True`` in case result is unknown, ``False`` otherwise.
            :rtype: bool
        )");
 
        py_smt_result.def("to_string", &SMT::SolverResult::to_string, R"(
            Translates the SMT result into its string representation.
 
            :returns: A string representing the SMT result.
            :rtype: str
        )");
 
        py_smt_result.def("__str__", [](const SMT::SolverResult& result) { return result.to_string(); }, R"(
            Translates the SMT result into its string representation.
 
            :returns: A string representing the SMT result.
            :rtype: str
        )");
 
        py::class_<SMT::Solver> py_smt_solver(py_smt, "Solver", R"(
            Provides an interface to query SMT solvers for a list of constraints, i.e. statements that have to be equal. To this end, we translate constraints to a SMT-LIB v2 string representation and query solvers with a defined configuration, i.e., chosen solver, model generation etc.
        )");
 
        py_smt_solver.def(py::init<std::vector<SMT::Constraint>>(), py::arg("constraints") = std::vector<SMT::Constraint>(), R"(
            Constructs an solver with an optional list of constraints.
 
            :param list[hal_py.SMT.Constraint] constraints: The (optional) list of constraints.
        )");
 
        py_smt_solver.def_property_readonly("constraints", &SMT::Solver::get_constraints, R"(
            The list of constraints.
 
            :type: list[hal_py.SMT.Constraint]
        )");
 
        py_smt_solver.def("get_constraints", &SMT::Solver::get_constraints, R"(
            Returns the list of constraints.
 
            :returns: The list of constraints.
            :rtype: list[hal_py.SMT.Constraint]
        )");
 
        py_smt_solver.def("with_constraint", &SMT::Solver::with_constraint, py::arg("constraint"), R"(
            Adds a constraint to the SMT solver.
 
            :param hal_py.SMT.Constraint constraint: The constraint.
            :returns: The updated SMT solver.
            :rtype: hal_py.SMT.Solver
        )");
 
        py_smt_solver.def("with_constraints", &SMT::Solver::with_constraints, py::arg("constraints"), R"(
            Adds a list of constraints to the SMT solver.
 
            :param list[hal_py.SMT.Constraint] constraints: The constraints.
            :returns: The updated SMT solver.
            :rtype: hal_py.SMT.Solver
        )");
 
        py_smt_solver.def_static("has_local_solver_for", &SMT::Solver::has_local_solver_for, py::arg("type"), py::arg("call"), R"(
            Checks whether a SMT solver of the given type is available on the local machine.
 
            :param hal_py.SMT.SolverType type: The SMT solver type.
            :param hal_py.SMT.SolverCall call: The solver call.
            :returns: ``True`` if an SMT solver of the requested type is available, ``False`` otherwise.
            :rtype: bool
        )");
 
        py_smt_solver.def(
            "query",
            [](const SMT::Solver& self, const SMT::QueryConfig& config = SMT::QueryConfig()) -> std::optional<SMT::SolverResult> {
                auto res = self.query(config);
                if (res.is_ok())
                {
                    return res.get();
                }
                else
                {
                    log_error("python_context", "{}", res.get_error().get());
                    return std::nullopt;
                }
            },
            py::arg("config") = SMT::QueryConfig(),
            R"(
            Queries an SMT solver with the specified query configuration.
 
            :param hal_py.SMT.QueryConfig config: The SMT solver query configuration.
            :returns: The result on success, a string error message otherwise.
            :rtype: hal_py.SMT.Result or str
        )");
 
        py_smt_solver.def(
            "query_local",
            [](const SMT::Solver& self, const SMT::QueryConfig& config) -> std::optional<SMT::SolverResult> {
                auto res = self.query_local(config);
                if (res.is_ok())
                {
                    return res.get();
                }
                else
                {
                    log_error("python_context", "{}", res.get_error().get());
                    return std::nullopt;
                }
            },
            py::arg("config"),
            R"(
            Queries a local SMT solver with the specified query configuration.
 
            :param hal_py.SMT.QueryConfig config: The SMT solver query configuration.
            :returns: The result on success, a string error message otherwise.
            :rtype: hal_py.SMT.Result or str
        )");
 
        py_smt_solver.def(
            "to_smt2",
            [](const SMT::Solver& self, const SMT::QueryConfig& config) -> std::optional<std::string> {
                auto res = self.to_smt2(config);
                if (res.is_ok())
                {
                    return res.get();
                }
                log_error("python_context", "{}", res.get_error().get());
                return std::nullopt;
            },
            py::arg("config"),
            R"(
            Translate the constraints of the solver into an smt2 representation of the query.
 
            :param hal_py.SMT.QueryConfig config: The SMT solver query configuration.
            :returns: The smt2 representation on success, ``None`` otherwise.
            :rtype: str or None
        )");
 
        py_smt_solver.def_static(
            "query_local_with_smt2",
            [](const SMT::QueryConfig& config, const std::string& smt2) -> std::optional<SMT::SolverResult> {
                auto res = SMT::Solver::query_local_with_smt2(config, smt2);
                if (res.is_ok())
                {
                    return res.get();
                }
                else
                {
                    log_error("python_context", "{}", res.get_error().get());
                    return std::nullopt;
                }
            },
            py::arg("config"),
            py::arg("smt2"),
            R"(
            Queries a local SMT solver with the specified query configuration and the provided smt2 representation of the query.
 
            :param hal_py.SMT.QueryConfig config: The SMT solver query configuration.
            :param str smt2: The SMT solver query as smt2 string.
            :returns: The result on success, a string error message otherwise.
            :rtype: hal_py.SMT.Result or str
        )");
 
        py_smt_solver.def("query_remote", &SMT::Solver::query_remote, py::arg("config"), R"(
            Queries a remote SMT solver with the specified query configuration.
 
            WARNING: This function is not yet implemented.
 
            :param hal_py.SMT.QueryConfig config: The SMT solver query configuration.
            :returns: The result on success, a string error message otherwise.
            :rtype: hal_py.SMT.Result or str
        )");
 
        py::class_<SMT::SymbolicState> py_smt_symbolic_state(py_smt, "SymbolicState", R"(
           Represents the data structure that keeps track of symbolic variable values (e.g., required for symbolic simplification).
        )");
 
        py_smt_symbolic_state.def(py::init<const std::vector<BooleanFunction>&>(), py::arg("variables") = std::vector<BooleanFunction>(), R"(
            Constructs a symbolic state and (optionally) initializes the variables.
 
            :param list[hal_py.BooleanFunction] variables: The (optional) list of variables.
        )");
 
        py_smt_symbolic_state.def("get", &SMT::SymbolicState::get, py::arg("key"), R"(
            Looks up a Boolean function in the symbolic state.
 
            :param hal_py.BooleanFunction key: The Boolean function to look up.
            :returns: The Boolean function from the symbolic state or the key itself if it is not contained in the symbolic state.
            :rtype: hal_py.BooleanFunction
        )");
 
        py_smt_symbolic_state.def("set", &SMT::SymbolicState::set, py::arg("key"), py::arg("value"), R"(
            Sets a Boolean function equivalent in the symbolic state.
 
            :param hal_py.BooleanFunction key: The Boolean function.
            :param hal_py.BooleanFunction value: The equivalent Boolean function.
        )");
 
        py::class_<SMT::SymbolicExecution> py_smt_symbolic_execution(py_smt, "SymbolicExecution", R"(
           Represents the symbolic execution engine that handles the evaluation and simplification of Boolean function abstract syntax trees.
        )");
 
        py_smt_symbolic_execution.def_readwrite("state", &SMT::SymbolicExecution::state, R"(
            The current symbolic state.
 
            :type: hal_py.SMT.SymbolicState
        )");
 
        py_smt_symbolic_execution.def(py::init<const std::vector<BooleanFunction>&>(), py::arg("variables") = std::vector<BooleanFunction>(), R"(
            Creates a symbolic execution engine and (optionally) initializes the variables.
 
            :param list[hal_py.BooleanFunction] variables: The (optional) list of variables.
        )");
 
        py_smt_symbolic_execution.def(
            "evaluate",
            [](const SMT::SymbolicExecution& self, const BooleanFunction& function) -> std::optional<BooleanFunction> {
                auto res = self.evaluate(function);
                if (res.is_ok())
                {
                    return res.get();
                }
                log_error("python_context", "{}", res.get_error().get());
                return std::nullopt;
            },
            py::arg("function"),
            R"(
            Evaluates a Boolean function within the symbolic state of the symbolic execution.
 
            :param hal_py.BooleanFunction function: The Boolean function to evaluate.
            :returns: The evaluated Boolean function on success, ``None`` otherwise.
            :rtype: hal_py.BooleanFunction or None
        )");
 
        py_smt_symbolic_execution.def(
            "evaluate",
            [](SMT::SymbolicExecution& self, const SMT::Constraint& constraint) -> bool {
                auto res = self.evaluate(constraint);
                if (res.is_ok())
                {
                    return true;
                }
                log_error("python_context", "{}", res.get_error().get());
                return false;
            },
            py::arg("constraint"),
            R"(
            Evaluates an equality constraint and applies it to the symbolic state of the symbolic execution.
 
            :param hal_py.SMT.Constraint constraint: The equality constraint to evaluate.
            :returns: ``True`` on success, ``False`` otherwise.
            :rtype: bool
        )");
    }
}    // namespace hal