solver factories, cleanup solver API, simplified strategic solver, added combined solver

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/cmd_context/cmd_context.cpp

@@ -582,8 +582,8 @@ void cmd_context::init_manager_core(bool new_manager) {
         // it prevents clashes with builtin types.
         insert(pm().mk_plist_decl());
     }
-    if (m_solver) {
-        init_solver_options(m_solver.get());
+    if (m_solver_factory) {
+        mk_solver();
     }
     m_check_logic.set_logic(m(), m_logic);
 }
@@ -1119,7 +1119,7 @@ void cmd_context::reset(bool finalize) {
     reset_func_decls();
     restore_assertions(0);
     if (m_solver)
-        m_solver->reset();
+        m_solver = 0;
     m_pp_env = 0;
     m_dt_eh  = 0;
     if (m_manager) {
@@ -1441,17 +1441,18 @@ void cmd_context::validate_model() {
     }
 }
 
-void cmd_context::init_solver_options(solver * s) {
+void cmd_context::mk_solver() {
+    bool proofs_enabled, models_enabled, unsat_core_enabled;
     params_ref p;
-    m_params.init_solver_params(m(), *m_solver, p);
-    m_solver->init(m(), m_logic);
+    m_params.get_solver_params(m(), p, proofs_enabled, models_enabled, unsat_core_enabled);
+    m_solver = (*m_solver_factory)(m(), p, proofs_enabled, models_enabled, unsat_core_enabled, m_logic);
 }
 
-void cmd_context::set_solver(solver * s) {
+void cmd_context::set_solver_factory(solver_factory * f) {
+    m_solver_factory   = f;
     m_check_sat_result = 0;
-    m_solver = s;
-    if (has_manager() && s != 0) {
-        init_solver_options(s);
+    if (has_manager() && f != 0) {
+        mk_solver();
         // assert formulas and create scopes in the new solver.
         unsigned lim = 0;
         svector<scope>::iterator it  = m_scopes.begin();

src/cmd_context/cmd_context.h

@@ -185,6 +185,7 @@ protected:
     };
 
     svector<scope>               m_scopes;
+    scoped_ptr<solver_factory>   m_solver_factory;
     ref<solver>                  m_solver;
     ref<check_sat_result>        m_check_sat_result;
 
@@ -243,7 +244,7 @@ protected:
     void print_unsupported_msg() { regular_stream() << "unsupported" << std::endl; }
     void print_unsupported_info(symbol const& s) { if (s != symbol::null) diagnostic_stream() << "; " << s << std::endl;}
 
-    void init_solver_options(solver * s);
+    void mk_solver();
 
 public:
     cmd_context(bool main_ctx = true, ast_manager * m = 0, symbol const & l = symbol::null);
@@ -289,8 +290,7 @@ public:
     pdecl_manager & pm() const { if (!m_pmanager) const_cast<cmd_context*>(this)->init_manager(); return *m_pmanager; }
     sexpr_manager & sm() const { if (!m_sexpr_manager) const_cast<cmd_context*>(this)->m_sexpr_manager = alloc(sexpr_manager); return *m_sexpr_manager; }
  
-    void set_solver(solver * s);
-    solver * get_solver() const { return m_solver.get(); }
+    void set_solver_factory(solver_factory * s);
     void set_check_sat_result(check_sat_result * r) { m_check_sat_result = r; }
     check_sat_result * get_check_sat_result() const { return m_check_sat_result.get(); }
     check_sat_state cs_state() const;

src/cmd_context/context_params.cpp

@@ -131,11 +131,11 @@ params_ref context_params::merge_default_params(params_ref const & p) {
     }
 }
 
-void context_params::init_solver_params(ast_manager & m, solver & s, params_ref const & p) {
-    s.set_produce_proofs(m.proofs_enabled() && m_proof);
-    s.set_produce_models(p.get_bool("model", m_model));
-    s.set_produce_unsat_cores(p.get_bool("unsat_core", m_unsat_core));
-    s.updt_params(merge_default_params(p));
+void context_params::get_solver_params(ast_manager const & m, params_ref & p, bool & proofs_enabled, bool & models_enabled, bool & unsat_core_enabled) {
+    proofs_enabled     = m.proofs_enabled() && p.get_bool("proof", m_proof);
+    models_enabled     = p.get_bool("model", m_model);
+    unsat_core_enabled = p.get_bool("unsat_core", m_unsat_core);
+    p = merge_default_params(p);
 }
 
 ast_manager * context_params::mk_ast_manager() {

src/cmd_context/context_params.h

@@ -22,7 +22,6 @@ Notes:
 
 #include"params.h"
 class ast_manager;
-class solver;
 
 class context_params {
     void set_bool(bool & opt, char const * param, char const * value);
@@ -50,13 +49,9 @@ public:
     */
     
     /**
-       \brief Goodie for updating the solver params
-       based on the configuration of the context_params object.
-
-       This method is used when creating solvers from the
-       cmd_context and API.
+       \brief Goodies for extracting parameters for creating a solver object.
     */
-    void init_solver_params(ast_manager & m, solver & s, params_ref const & p);
+    void get_solver_params(ast_manager const & m, params_ref & p, bool & proofs_enabled, bool & models_enabled, bool & unsat_core_enabled);
 
     /**
        \brief Include in p parameters derived from this context_params.