fix #3557

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

src/muz/base/dl_context.h

@@ -497,7 +497,7 @@ namespace datalog {
         // -----------------------------------
 
         bool canceled() {
-            return m.canceled() && (m_last_status = CANCELED, true);
+            return !m.inc() && (m_last_status = CANCELED, true);
         }
 
         void cleanup();

src/muz/base/hnf.cpp

@@ -172,7 +172,7 @@ public:
     }
 
     bool checkpoint() {
-        return !m.canceled();
+        return m.inc();
     }
 
     void set_name(symbol const& n) {

src/muz/bmc/dl_bmc_engine.cpp

@@ -26,6 +26,7 @@ Revision History:
 #include "ast/scoped_proof.h"
 #include "smt/smt_solver.h"
 #include "tactic/fd_solver/fd_solver.h"
+#include "tactic/tactic.h"
 #include "muz/base/dl_context.h"
 #include "muz/base/dl_rule_transformer.h"
 #include "muz/bmc/dl_bmc_engine.h"
@@ -35,6 +36,7 @@ Revision History:
 #include "muz/transforms/dl_mk_rule_inliner.h"
 #include "muz/base/fp_params.hpp"
 
+
 namespace datalog {
 
     // ---------------------------------------------------------------------------
@@ -485,7 +487,7 @@ namespace datalog {
         }
 
         proof_ref get_proof(model_ref& md, func_decl* pred, app* prop, unsigned level) {
-            if (m.canceled()) {
+            if (!m.inc()) {
                 return proof_ref(nullptr, m);
             }
             TRACE("bmc", tout << "Predicate: " << pred->get_name() << "\n";);
@@ -1173,7 +1175,7 @@ namespace datalog {
     private:
 
         void get_model(unsigned level) {
-            if (m.canceled()) {
+            if (!m.inc()) {
                 return;
             }
             rule_manager& rm = b.m_ctx.get_rule_manager();
@@ -1520,9 +1522,7 @@ namespace datalog {
     }
 
     void bmc::checkpoint() {
-        if (m.canceled()) {
-            throw default_exception(Z3_CANCELED_MSG);
-        }
+        tactic::checkpoint(m);
     }
 
     void bmc::display_certificate(std::ostream& out) const {

src/muz/spacer/spacer_context.cpp

@@ -2759,11 +2759,8 @@ lbool context::solve(unsigned from_lvl)
 }
 
 
-void context::checkpoint()
-{
-    if (m.canceled ()) {
-        throw default_exception("spacer canceled");
-    }
+void context::checkpoint() {
+    tactic::checkpoint(m);
 }
 
 unsigned context::get_cex_depth()

src/muz/tab/tab_context.cpp

@@ -581,7 +581,7 @@ namespace tb {
 
         // extract pre_cond => post_cond validation obligation from match.
         bool find_match(unsigned& subsumer) {
-            for (unsigned i = 0; !m.canceled() && i < m_index.size(); ++i) {
+            for (unsigned i = 0; m.inc() && i < m_index.size(); ++i) {
                 if (match_rule(i)) {
                     subsumer = m_index[i]->get_seqno();
                     return true;
@@ -618,7 +618,7 @@ namespace tb {
 
             app* q = g.get_predicate(predicate_index);
 
-            for (unsigned i = 0; !m.canceled() && i < m_preds.size(); ++i) {
+            for (unsigned i = 0; m.inc() && i < m_preds.size(); ++i) {
                 app* p = m_preds[i].get();
                 m_subst.push_scope();
                 unsigned limit = m_sideconds.size();
@@ -647,7 +647,7 @@ namespace tb {
             expr_ref_vector fmls(m_sideconds);
             m_subst.reset_cache();
 
-            for (unsigned i = 0; !m.canceled() && i < fmls.size(); ++i) {
+            for (unsigned i = 0; m.inc() && i < fmls.size(); ++i) {
                 m_subst.apply(2, deltas, expr_offset(fmls[i].get(), 0), q);
                 fmls[i] = q;
             }
@@ -664,7 +664,7 @@ namespace tb {
                 }
             }
             m_rw.mk_and(fmls.size(), fmls.c_ptr(), postcond);
-            if (m.canceled()) {
+            if (!m.inc()) {
                 return false;
             }
             if (m.is_false(postcond)) {
@@ -1493,7 +1493,7 @@ namespace datalog {
             m_status      = l_undef;
             while (true) {
                 IF_VERBOSE(2, verbose_stream() << m_instruction << "\n";);
-                if (m.canceled()) {
+                if (!m.inc()) {
                     cleanup();
                     return l_undef;
                 }

src/muz/transforms/dl_mk_karr_invariants.cpp

@@ -214,7 +214,7 @@ namespace datalog {
 
         get_invariants(*src_loop);
 
-        if (m.canceled()) {
+        if (!m.inc()) {
             return nullptr;
         }