fixing cancellation code paths for inc_sat_solver

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

src/ast/rewriter/bit_blaster/bit_blaster_rewriter.cpp

@@ -165,6 +165,10 @@ struct blaster_rewriter_cfg : public default_rewriter_cfg {
         m_keyval_lim.push_back(m_keys.size());
     }
 
+    unsigned get_num_scopes() const {
+        return m_keyval_lim.size();
+    }
+
     void pop(unsigned num_scopes) {
         if (num_scopes > 0) {
             SASSERT(num_scopes <= m_keyval_lim.size());
@@ -637,6 +641,7 @@ struct bit_blaster_rewriter::imp : public rewriter_tpl<blaster_rewriter_cfg> {
     }
     void push() { m_cfg.push(); }
     void pop(unsigned s) { m_cfg.pop(s); }
+    unsigned get_num_scopes() const { return m_cfg.get_num_scopes(); }
 };
 
 bit_blaster_rewriter::bit_blaster_rewriter(ast_manager & m, params_ref const & p):
@@ -680,3 +685,7 @@ void bit_blaster_rewriter::operator()(expr * e, expr_ref & result, proof_ref & r
     m_imp->operator()(e, result, result_proof);
 }
 
+unsigned bit_blaster_rewriter::get_num_scopes() const {
+    return m_imp->get_num_scopes();
+}
+

src/ast/rewriter/bit_blaster/bit_blaster_rewriter.h

@@ -37,6 +37,7 @@ public:
     void operator()(expr * e, expr_ref & result, proof_ref & result_proof);
     void push();
     void pop(unsigned num_scopes);
+    unsigned get_num_scopes() const;
 };
 
 #endif

src/sat/sat_solver.cpp

@@ -3158,7 +3158,14 @@ namespace sat {
         init_search();
         propagate(false);
         if (inconsistent()) return l_false;
-        init_assumptions(asms.size(), asms.c_ptr(), 0, 0);
+        if (asms.empty()) {
+            bool_var v = mk_var(true, false);
+            literal lit(v, false);
+            init_assumptions(1, &lit, 0, 0);
+        }
+        else {
+            init_assumptions(asms.size(), asms.c_ptr(), 0, 0);
+        }
         propagate(false);
         if (check_inconsistent()) return l_false;
        
@@ -3169,6 +3176,7 @@ namespace sat {
             checkpoint();
             literal_set::iterator it = vars.begin(), end = vars.end();
             unsigned num_resolves = 0;
+            lbool is_sat = l_true;
             for (; it != end; ++it) {
                 literal lit = *it;
                 if (value(lit) != l_undef) {
@@ -3179,8 +3187,10 @@ namespace sat {
                 propagate(false);
                 while (inconsistent()) {      
                     if (!resolve_conflict()) {
-                        TRACE("sat", tout << "inconsistent\n";);
-                        return l_false;
+                        TRACE("sat", display(tout << "inconsistent\n"););
+                        m_inconsistent = false;
+                        is_sat = l_undef;
+                        break;
                     }
                     propagate(false);                    
                     ++num_resolves;
@@ -3189,17 +3199,16 @@ namespace sat {
                     break;
                 }
             }
-            lbool is_sat;
-            while (true) {
+            if (is_sat == l_true) {
                 if (scope_lvl() == 1 && num_resolves > 0) {
                     is_sat = l_undef;
-                    break;
                 }
-                is_sat = bounded_search();
-                if (is_sat == l_undef) {
-                    restart();      
+                else {
+                    is_sat = bounded_search();
+                    if (is_sat == l_undef) {
+                        restart();      
+                    }
                 }
-                break;
             }
             if (is_sat == l_false) {
                 TRACE("sat", tout << "unsat\n";);

src/sat/sat_solver/inc_sat_solver.cpp

@@ -234,6 +234,7 @@ public:
     }
 
     virtual lbool get_consequences_core(expr_ref_vector const& assumptions, expr_ref_vector const& vars, expr_ref_vector& conseq) {
+        init_preprocess();
         TRACE("sat", tout << assumptions << "\n" << vars << "\n";);
         sat::literal_vector asms;
         sat::bool_var_vector bvars;
@@ -341,7 +342,7 @@ public:
                      mk_bit_blaster_tactic(m, m_bb_rewriter.get()),
                      //mk_aig_tactic(),
                      using_params(mk_simplify_tactic(m), simp2_p));
-        for (unsigned i = 0; i < m_num_scopes; ++i) {
+        while (m_bb_rewriter->get_num_scopes() < m_num_scopes) {
             m_bb_rewriter->push();
         }
         m_preprocess->reset();
@@ -364,6 +365,7 @@ private:
         }
         catch (tactic_exception & ex) {
             IF_VERBOSE(0, verbose_stream() << "exception in tactic " << ex.msg() << "\n";);
+            TRACE("sat", tout << "exception: " << ex.msg() << "\n";);
             m_preprocess = 0;
             m_bb_rewriter = 0;
             return l_undef;
@@ -518,10 +520,14 @@ private:
         }
         dep2asm_t dep2asm;
         goal_ref g = alloc(goal, m, true, false); // models, maybe cores are enabled
-        for (; m_fmls_head < m_fmls.size(); ++m_fmls_head) {
-            g->assert_expr(m_fmls[m_fmls_head].get());
+        for (unsigned i = 0 ; i < m_fmls.size(); ++i) {
+            g->assert_expr(m_fmls[i].get());
         }
-        return internalize_goal(g, dep2asm);
+        lbool res = internalize_goal(g, dep2asm);
+        if (res != l_undef) {
+            m_fmls_head = m_fmls.size();
+        }
+        return res;
     }
 
     void extract_assumptions(unsigned sz, expr* const* asms, dep2asm_t& dep2asm) {

src/tactic/portfolio/bounded_int2bv_solver.cpp

@@ -247,8 +247,9 @@ private:
                 expr_ref t(m.mk_const(fbv), m);
                 t = m_bv.mk_bv2int(t);
                 if (!offset.is_zero()) {
-                    t = m_arith.mk_add(t, m_arith.mk_numeral(lo, true));
+                    t = m_arith.mk_add(t, m_arith.mk_numeral(offset, true));
                 }
+                TRACE("pb", tout << lo << " <= " << hi << " offset: " << offset << "\n"; tout << mk_pp(e, m) << " |-> " << t << "\n";);
                 sub.insert(e, t);
             }
             else {