adding dump facility for cancelation #2095, easing dimacs in/out

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/solver/CMakeLists.txt

@@ -16,5 +16,7 @@ z3_add_component(solver
   PYG_FILES
     combined_solver_params.pyg
     parallel_params.pyg
+  PYG_FILES
+    solver_params.pyg
 
 )

src/solver/combined_solver.cpp

@@ -218,7 +218,7 @@ public:
         return l_undef;
     }
 
-    lbool check_sat(unsigned num_assumptions, expr * const * assumptions) override {
+    lbool check_sat_core(unsigned num_assumptions, expr * const * assumptions) override {
         m_check_sat_executed  = true;        
         m_use_solver1_results = false;
 
@@ -227,13 +227,13 @@ public:
             m_ignore_solver1)  {
             // must use incremental solver
             switch_inc_mode();
-            return m_solver2->check_sat(num_assumptions, assumptions);
+            return m_solver2->check_sat_core(num_assumptions, assumptions);
         }
         
         if (m_inc_mode) {
             if (m_inc_timeout == UINT_MAX) {
                 IF_VERBOSE(PS_VB_LVL, verbose_stream() << "(combined-solver \"using solver 2 (without a timeout)\")\n";);            
-                lbool r = m_solver2->check_sat(num_assumptions, assumptions);
+                lbool r = m_solver2->check_sat_core(num_assumptions, assumptions);
                 if (r != l_undef || !use_solver1_when_undef() || get_manager().canceled()) {
                     return r;
                 }
@@ -244,7 +244,7 @@ public:
                 lbool r = l_undef;
                 try {
                     scoped_timer timer(m_inc_timeout, &eh);
-                    r = m_solver2->check_sat(num_assumptions, assumptions);
+                    r = m_solver2->check_sat_core(num_assumptions, assumptions);
                 }
                 catch (z3_exception&) {
                     if (!eh.m_canceled) {
@@ -260,7 +260,7 @@ public:
         
         IF_VERBOSE(PS_VB_LVL, verbose_stream() << "(combined-solver \"using solver 1\")\n";);
         m_use_solver1_results = true;
-        return m_solver1->check_sat(num_assumptions, assumptions);
+        return m_solver1->check_sat_core(num_assumptions, assumptions);
     }
     
     void set_progress_callback(progress_callback * callback) override {

src/solver/solver.cpp

@@ -3,7 +3,7 @@ Copyright (c) 2011 Microsoft Corporation
 
 Module Name:
 
-    solver.h
+    solver.cpp
 
 Abstract:
 
@@ -21,25 +21,25 @@ Notes:
 #include "ast/ast_util.h"
 #include "ast/ast_pp.h"
 #include "ast/ast_pp_util.h"
+#include "ast/display_dimacs.h"
 #include "tactic/model_converter.h"
 #include "solver/solver.h"
+#include "solver/solver_params.hpp"
 #include "model/model_evaluator.h"
 
 
 unsigned solver::get_num_assertions() const {
-    NOT_IMPLEMENTED_YET();
+    UNREACHABLE();
     return 0;
 }
 
 expr * solver::get_assertion(unsigned idx) const {
-    NOT_IMPLEMENTED_YET();
+    UNREACHABLE();
     return nullptr;
 }
 
 std::ostream& solver::display(std::ostream & out, unsigned n, expr* const* assumptions) const {
     expr_ref_vector fmls(get_manager());
-    stopwatch sw;
-    sw.start();
     get_assertions(fmls);    
     ast_pp_util visitor(get_manager());
     model_converter_ref mc = get_model_converter();
@@ -57,6 +57,12 @@ std::ostream& solver::display(std::ostream & out, unsigned n, expr* const* assum
     return out;
 }
 
+std::ostream& solver::display_dimacs(std::ostream& out) const {
+    expr_ref_vector fmls(get_manager());
+    get_assertions(fmls);    
+    return ::display_dimacs(out, fmls);
+}
+
 void solver::get_assertions(expr_ref_vector& fmls) const {
     unsigned sz = get_num_assertions();
     for (unsigned i = 0; i < sz; ++i) {
@@ -232,12 +238,16 @@ void solver::collect_param_descrs(param_descrs & r) {
 
 void solver::reset_params(params_ref const & p) {
     m_params = p;
-    m_enforce_model_conversion = m_params.get_bool("solver.enforce_model_conversion", false);
+    solver_params sp(m_params);
+    m_enforce_model_conversion = sp.enforce_model_conversion();
+    m_cancel_backup_file = sp.cancel_backup_file();
 }
 
 void solver::updt_params(params_ref const & p) {
     m_params.copy(p);
-    m_enforce_model_conversion = m_params.get_bool("solver.enforce_model_conversion", false);
+    solver_params sp(m_params);
+    m_enforce_model_conversion = sp.enforce_model_conversion();
+    m_cancel_backup_file = sp.cancel_backup_file();
 }
 
 
@@ -309,3 +319,28 @@ expr_ref_vector solver::get_non_units(ast_manager& m) {
     }
     return result;
 }
+
+lbool solver::check_sat(unsigned num_assumptions, expr * const * assumptions) {
+    lbool r = l_undef;
+    try {
+        r = check_sat_core(num_assumptions, assumptions);
+    }
+    catch (...) {
+        if (get_manager().canceled()) {
+            dump_state(num_assumptions, assumptions);
+        }
+        throw;
+    }
+    if (r == l_undef && get_manager().canceled()) {
+        dump_state(num_assumptions, assumptions);        
+    }
+    return r;
+}
+
+void solver::dump_state(unsigned sz, expr* const* assumptions) {
+    std::string file = m_cancel_backup_file.str();
+    if (file != "") {
+        std::ofstream ous(file);
+        display(ous, sz, assumptions);
+    }
+}

src/solver/solver.h

@@ -44,8 +44,9 @@ public:
      - results based on check_sat_result API
 */
 class solver : public check_sat_result {
-    params_ref m_params;
-    bool       m_enforce_model_conversion;
+    params_ref  m_params;
+    bool        m_enforce_model_conversion;
+    symbol      m_cancel_backup_file;
 public:
     solver(): m_enforce_model_conversion(false) {}
     ~solver() override {}
@@ -140,7 +141,8 @@ public:
        
        If it is unsatisfiable, and unsat-core generation is enabled. Then, the unsat-core is a subset of these assumptions.
     */
-    virtual lbool check_sat(unsigned num_assumptions, expr * const * assumptions) = 0;
+
+    lbool check_sat(unsigned num_assumptions, expr * const * assumptions);
 
     lbool check_sat(expr_ref_vector const& asms) { return check_sat(asms.size(), asms.c_ptr()); }
     
@@ -227,6 +229,11 @@ public:
     */
     virtual std::ostream& display(std::ostream & out, unsigned n = 0, expr* const* assumptions = nullptr) const;
 
+    /**
+       \brief Display the content of this solver in DIMACS format
+    */
+    std::ostream& display_dimacs(std::ostream & out) const;
+
     /**
        \brief expose model converter when solver produces partially reduced set of assertions.
      */
@@ -249,14 +256,17 @@ public:
         void disable_pop() { m_nopop = true; }
     };
 
+    virtual lbool check_sat_core(unsigned num_assumptions, expr * const * assumptions) = 0;
  
 protected:
 
     virtual lbool get_consequences_core(expr_ref_vector const& asms, expr_ref_vector const& vars, expr_ref_vector& consequences);
 
+    void dump_state(unsigned sz, expr* const* assumptions);
 
     bool is_literal(ast_manager& m, expr* e);
 
+
 };
 
 typedef ref<solver> solver_ref;

src/solver/solver_na2as.cpp

@@ -61,10 +61,10 @@ struct append_assumptions {
     }
 };
 
-lbool solver_na2as::check_sat(unsigned num_assumptions, expr * const * assumptions) {
+lbool solver_na2as::check_sat_core(unsigned num_assumptions, expr * const * assumptions) {
     append_assumptions app(m_assumptions, num_assumptions, assumptions);
     TRACE("solver_na2as", display(tout););
-    return check_sat_core(m_assumptions.size(), m_assumptions.c_ptr());
+    return check_sat_core2(m_assumptions.size(), m_assumptions.c_ptr());
 }
 
 lbool solver_na2as::check_sat_cc(const expr_ref_vector &assumptions, vector<expr_ref_vector> const &clauses) {

src/solver/solver_na2as.h

@@ -35,10 +35,9 @@ public:
     ~solver_na2as() override;
 
     void assert_expr_core2(expr * t, expr * a) override;
-    // virtual void assert_expr_core(expr * t) = 0;
 
     // Subclasses of solver_na2as should redefine the following *_core methods instead of these ones.
-    lbool check_sat(unsigned num_assumptions, expr * const * assumptions) override;
+    lbool check_sat_core(unsigned num_assumptions, expr * const * assumptions) override;
     lbool check_sat_cc(const expr_ref_vector &assumptions, vector<expr_ref_vector> const &clauses) override;
     void push() override;
     void pop(unsigned n) override;
@@ -49,7 +48,7 @@ public:
     lbool get_consequences(expr_ref_vector const& asms, expr_ref_vector const& vars, expr_ref_vector& consequences) override;
     lbool find_mutexes(expr_ref_vector const& vars, vector<expr_ref_vector>& mutexes) override;
 protected:
-    virtual lbool check_sat_core(unsigned num_assumptions, expr * const * assumptions) = 0;
+    virtual lbool check_sat_core2(unsigned num_assumptions, expr * const * assumptions) = 0;
     virtual lbool check_sat_cc_core(const expr_ref_vector &assumptions, vector<expr_ref_vector> const &clauses) { NOT_IMPLEMENTED_YET(); }
     virtual void push_core() = 0;
     virtual void pop_core(unsigned n) = 0;

src/solver/solver_params.pyg

@@ -0,0 +1,8 @@
+
+def_module_params('solver', 
+                  description='solver parameters',
+                  export=True,
+                  params=(('enforce_model_conversion', BOOL, False, "apply model transformation on new assertions"),
+                          ('cancel_backup_file', SYMBOL, '', "file to save partial search state if search is canceled"),
+                          ))
+                

src/solver/solver_pool.cpp

@@ -119,7 +119,7 @@ public:
         }
     }
 
-    lbool check_sat_core(unsigned num_assumptions, expr * const * assumptions) override {
+    lbool check_sat_core2(unsigned num_assumptions, expr * const * assumptions) override {
         SASSERT(!m_pushed || get_scope_level() > 0);
         m_proof.reset();
         scoped_watch _t_(m_pool.m_check_watch);

src/solver/tactic2solver.cpp

@@ -62,7 +62,7 @@ public:
 
     void push_core() override;
     void pop_core(unsigned n) override;
-    lbool check_sat_core(unsigned num_assumptions, expr * const * assumptions) override;
+    lbool check_sat_core2(unsigned num_assumptions, expr * const * assumptions) override;
 
     void collect_statistics(statistics & st) const override;
     void get_unsat_core(expr_ref_vector & r) override;
@@ -136,7 +136,7 @@ void tactic2solver::pop_core(unsigned n) {
     m_result = nullptr;
 }
 
-lbool tactic2solver::check_sat_core(unsigned num_assumptions, expr * const * assumptions) {
+lbool tactic2solver::check_sat_core2(unsigned num_assumptions, expr * const * assumptions) {
     if (m_tactic.get() == nullptr)
         return l_false;
     ast_manager & m = m_assertions.m();