tgba_digraph: add a copy constructor, and obsolete dupexp

* src/tgba/tgbagraph.hh, src/tgba/tgbagraph.cc: Add a copy constructor,
and some method to purge unreachable states.
* src/graph/graph.hh (defrag_states): Erase transition of removed
states.
* src/tgbaalgos/complete.cc, src/tgbaalgos/compsusp.cc,
src/tgbaalgos/dtgbacomp.cc, src/tgbaalgos/simulation.cc,
src/tgbatest/checkpsl.cc, src/tgbatest/emptchk.cc,
src/tgbatest/ltl2tgba.cc: Adjust to use make_tgba_digraph() instead
of tgba_dupexp_dfs() or tgba_dupexp_bfs().
* src/tgbaalgos/dupexp.cc, src/tgbaalgos/dupexp.hh: Use
make_tgba_digraph() when possible.
* src/tgbatest/det.test, src/tgbatest/sim.test: Adjust expected results.

src/tgbaalgos/complete.cc

@@ -18,7 +18,6 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "complete.hh"
-#include "dupexp.hh"
 
 namespace spot
 {
@@ -105,7 +104,12 @@ namespace spot
 
   tgba_digraph_ptr tgba_complete(const const_tgba_ptr& aut)
   {
-    tgba_digraph_ptr res = tgba_dupexp_dfs(aut);
+    auto res = make_tgba_digraph(aut);
+    res->prop_copy(aut,
+		   true, 	// state based
+		   true, 	// single acc
+		   true, 	// inherently_weak
+		   true);	// deterministic
     tgba_complete_here(res);
     return res;
   }

src/tgbaalgos/compsusp.cc

@@ -25,7 +25,6 @@
 #include "minimize.hh"
 #include "simulation.hh"
 #include "safety.hh"
-#include "dupexp.hh"
 #include "ltlast/allnodes.hh"
 #include "ltlvisit/tostring.hh"
 #include "ltlvisit/clone.hh"

src/tgbaalgos/dtgbacomp.cc

@@ -18,7 +18,6 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "dtgbacomp.hh"
-#include "dupexp.hh"
 #include "sccinfo.hh"
 
 namespace spot
@@ -26,9 +25,12 @@ namespace spot
   tgba_digraph_ptr dtgba_complement_nonweak(const const_tgba_ptr& aut)
   {
     // Clone the original automaton.
-    tgba_digraph_ptr res = tgba_dupexp_dfs(aut);
-
-
+    auto res = make_tgba_digraph(aut);
+    res->prop_copy(aut,
+		   false, 	// state based
+		   false, 	// single acc
+		   false, 	// inherently_weak
+		   false);	// deterministic
     // Copy the old acceptance condition before we replace it.
     acc_cond oldacc = aut->acc(); // Copy it!
 
@@ -36,6 +38,9 @@ namespace spot
     // automaton will only have one acceptance set.
     // This changes aut->acc();
     res->set_single_acceptance_set();
+    // The resulting automaton is weak.
+    res->prop_inherently_weak();
+    res->prop_state_based_acc();
 
     unsigned num_sets = oldacc.num_sets();
     unsigned n = res->num_states();
@@ -108,8 +113,7 @@ namespace spot
   tgba_digraph_ptr dtgba_complement_weak(const const_tgba_ptr& aut)
   {
     // Clone the original automaton.
-    tgba_digraph_ptr res = tgba_dupexp_dfs(aut);
-
+    auto res = make_tgba_digraph(aut);
     res->prop_copy(aut,
 		   true, 	// state based
 		   true, 	// single acc

src/tgbaalgos/dupexp.cc

@@ -21,10 +21,12 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "dupexp.hh"
+#include "tgba/tgbagraph.hh"
 #include <sstream>
 #include <string>
 #include <map>
 #include "reachiter.hh"
+#include "dotty.hh"
 
 namespace spot
 {
@@ -119,6 +121,20 @@ namespace spot
   tgba_digraph_ptr
   tgba_dupexp_dfs(const const_tgba_ptr& aut, std::vector<const state*>& rel)
   {
+    auto aa = std::dynamic_pointer_cast<const spot::tgba_digraph>(aut);
+    if (aa)
+      {
+	aa->get_init_state_number(); // Create an initial state if needed.
+	auto res = make_tgba_digraph(aa);
+	unsigned ns = aa->num_states();
+	rel.reserve(ns);
+	// The state numbers are common to both automata, but
+	// the state pointers are to the older one.
+	for (unsigned n = 0; n < ns; ++n)
+	  rel.push_back(aa->state_from_number(n));
+	return res;
+      }
+
     dupexp_iter_save<tgba_reachable_iterator_depth_first> di(aut, rel);
     di.run();
     return di.result();

src/tgbaalgos/dupexp.hh

@@ -23,7 +23,10 @@
 #ifndef SPOT_TGBAALGOS_DUPEXP_HH
 # define SPOT_TGBAALGOS_DUPEXP_HH
 
-# include "tgba/tgbagraph.hh"
+# include "misc/common.hh"
+# include "tgba/fwd.hh"
+# include "tgba/tgba.hh"
+# include <vector>
 
 namespace spot
 {

src/tgbaalgos/simulation.cc

@@ -256,7 +256,6 @@ namespace spot
         scc_info_.reset(new scc_info(a_));
         old_a_ = a_;
 
-
 	// Replace all the acceptance conditions by their complements.
 	// (In the case of Cosimulation, we also flip the transitions.)
 	{
@@ -298,6 +297,8 @@ namespace spot
 		  else
 		    t.acc = acc;
 		}
+	      if (Cosimulation)
+		a_->set_init_state(old_a_->get_init_state_number());
 	    }
 	  size_a_ = ns;
 	}
@@ -435,7 +436,7 @@ namespace spot
 
         // When we Cosimulate, we add a special flag to differentiate
         // the initial state from the other.
-        if (Cosimulation && src == 0)
+        if (Cosimulation && src == a_->get_init_state_number())
           res |= bdd_initial;
 
         return res;
@@ -696,6 +697,8 @@ namespace spot
 	      }
 	  }
 
+	res->purge_unreachable_states();
+
 	delete gb;
 	res->prop_copy(original_,
 		       false, // state-based acc forced below
@@ -835,6 +838,8 @@ namespace spot
         bdd res = bddfalse;
 
         unsigned scc = scc_info_->scc_of(src);
+	if (scc == -1U)		// Unreachable
+	  return bddfalse;
         bool sccacc = scc_info_->is_accepting_scc(scc);
 
 	for (auto& t: a_->out(src))
@@ -1353,12 +1358,13 @@ namespace spot
 
         direct_simulation<true, Sba> cosimul(res);
 	res = cosimul.run();
-        next.set_size(res);
 
 	if (Sba)
 	  res = scc_filter_states(res);
 	else
 	  res = scc_filter(res, false);
+
+        next.set_size(res);
       }
     while (prev != next);
     return res;