Replace prune_scc() by scc_filter().

prune_scc() leaked memory and failed to remove chains of useless SCCs.

* src/tgbaalgos/reductgba_sim.cc (reduc_tgba_sim): Call
scc_filter() instead of prune_scc(), and do it before running
any simulation-based reduction.
* src/tgbaalgos/reductgba_sim.hh (reduc_tgba_sim): Return a const
tgba*.
* src/tgbatest/ltl2tgba.cc: Call scc_filter() instead of
prune_scc().
* src/tgbatest/scc.test: Add two more tests that failed with
prune_scc().

ChangeLog

@@ -1,3 +1,19 @@
+2009-11-18  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
+
+	Replace prune_scc() by scc_filter().
+
+	prune_scc() leaked memory and failed to remove chains of useless SCCs.
+
+	* src/tgbaalgos/reductgba_sim.cc (reduc_tgba_sim): Call
+	scc_filter() instead of prune_scc(), and do it before running
+	any simulation-based reduction.
+	* src/tgbaalgos/reductgba_sim.hh (reduc_tgba_sim): Return a const
+	tgba*.
+	* src/tgbatest/ltl2tgba.cc, src/tgbatest/reductgba.cc: Call
+	scc_filter() instead of prune_scc().
+	* src/tgbatest/scc.test: Add two more tests that failed with
+	prune_scc().
+
 2009-11-18  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 
 	Quick implementation of a "useless SCC" filter using scc_map.

src/tgbaalgos/reductgba_sim.cc

@@ -1,6 +1,6 @@
-// Copyright (C) 2004, 2005, 2007  Laboratoire d'Informatique de Paris 6 (LIP6),
+// Copyright (C) 2004, 2005, 2007, 2009 Laboratoire d'Informatique de
-// département Systèmes Répartis Coopératifs (SRC), Université Pierre
+// Paris 6 (LIP6), département Systèmes Répartis Coopératifs (SRC),
-// et Marie Curie.
+// Université Pierre et Marie Curie.
 //
 // This file is part of Spot, a model checking library.
 //
@@ -21,6 +21,7 @@
 
 #include "reductgba_sim.hh"
 #include "tgba/bddprint.hh"
+#include "sccfilter.hh"
 
 namespace spot
 {
@@ -663,11 +664,24 @@ namespace spot
     return false;
   }
 
-  tgba*
+  const tgba*
   reduc_tgba_sim(const tgba* f, int opt)
   {
+    if (opt & Reduce_Scc)
+      {
+	f = scc_filter(f);
+
+	// No more reduction requested? Return the automaton as-is.
+	if (opt == Reduce_Scc)
+	  return f;
+      }
+
     spot::tgba_reduc* automatareduc = new  spot::tgba_reduc(f);
 
+    // Destroy the automaton created by scc_filter.
+    if (opt & Reduce_Scc)
+      delete f;
+
     if (opt & (Reduce_quotient_Dir_Sim | Reduce_transition_Dir_Sim))
       {
 	direct_simulation_relation* rel
@@ -696,11 +710,6 @@ namespace spot
 	  free_relation_simulation(rel);
 	}
 
-    if (opt & Reduce_Scc)
-      {
-	automatareduc->prune_scc();
-      }
-
     return automatareduc;
   }
 

src/tgbaalgos/reductgba_sim.hh

@@ -1,4 +1,4 @@
-// Copyright (C) 2004, 2005  Laboratoire d'Informatique de Paris 6 (LIP6),
+// Copyright (C) 2004, 2005, 2009  Laboratoire d'Informatique de Paris 6 (LIP6),
 // département Systèmes Répartis Coopératifs (SRC), Université Pierre
 // et Marie Curie.
 //
@@ -61,7 +61,7 @@ namespace spot
   /// \param opt a conjonction of spot::reduce_tgba_options specifying
   ///             which optimizations to apply.
   /// \return the reduced automata.
-  tgba* reduc_tgba_sim(const tgba* a, int opt = Reduce_All);
+  const tgba* reduc_tgba_sim(const tgba* a, int opt = Reduce_All);
 
   /// \brief Compute a direct simulation relation on state of tgba \a f.
   direct_simulation_relation* get_direct_relation_simulation(const tgba* a,

src/tgbatest/ltl2tgba.cc

@@ -48,6 +48,7 @@
 #include "tgbaalgos/reductgba_sim.hh"
 #include "tgbaalgos/replayrun.hh"
 #include "tgbaalgos/rundotdec.hh"
+#include "tgbaalgos/sccfilter.hh"
 #include "misc/timer.hh"
 
 #include "tgbaalgos/stats.hh"
@@ -715,13 +716,21 @@ main(int argc, char** argv)
       }
 
       spot::tgba_reduc* aut_red = 0;
+      spot::tgba* aut_scc = 0;
       if (reduc_aut != spot::Reduce_None)
 	{
-	  tm.start("reducing formula automaton");
-	  a = aut_red = new spot::tgba_reduc(a);
 
 	  if (reduc_aut & spot::Reduce_Scc)
-	    aut_red->prune_scc();
+	    {
+	      tm.start("reducing formula aut. w/ SCC");
+	      a = aut_scc = spot::scc_filter(a);
+	      tm.start("reducing formula aut. w/ SCC");
+	    }
+
+	  if (reduc_aut & !spot::Reduce_Scc)
+	    {
+	      tm.start("reducing formula aut. w/ sim.");
+	      a = aut_red = new spot::tgba_reduc(a);
 
 	      if (reduc_aut & (spot::Reduce_quotient_Dir_Sim |
 			       spot::Reduce_transition_Dir_Sim |
@@ -735,18 +744,16 @@ main(int argc, char** argv)
 				   spot::Reduce_transition_Dir_Sim))
 		    {
 		      rel_dir =
-		    spot::get_direct_relation_simulation(a,
+			spot::get_direct_relation_simulation
-							 std::cout,
+			  (a, std::cout, display_parity_game);
-							 display_parity_game);
 		      assert(rel_dir);
 		    }
 		  if (reduc_aut & (spot::Reduce_quotient_Del_Sim |
 					spot::Reduce_transition_Del_Sim))
 		    {
 		      rel_del =
-		    spot::get_delayed_relation_simulation(a,
+			spot::get_delayed_relation_simulation
-							  std::cout,
+			  (a, std::cout, display_parity_game);
-							  display_parity_game);
 		      assert(rel_del);
 		    }
 
@@ -772,7 +779,8 @@ main(int argc, char** argv)
 		  if (rel_del)
 		    spot::free_relation_simulation(rel_del);
 		}
-	  tm.stop("reducing formula automaton");
+	      tm.stop("reducing formula aut. w/ sim.");
+	    }
 	}
 
       spot::tgba_explicit* expl = 0;
@@ -1021,6 +1029,7 @@ main(int argc, char** argv)
       delete system;
       delete expl;
       delete aut_red;
+      delete aut_scc;
       delete degeneralized;
       delete state_labeled;
       delete to_free;

src/tgbatest/reductgba.cc

@@ -40,6 +40,7 @@
 #include "tgbaparse/public.hh"
 #include "tgbaalgos/dupexp.hh"
 #include "tgbaalgos/neverclaim.hh"
+#include "tgbaalgos/sccfilter.hh"
 
 #include "misc/escape.hh"
 
@@ -148,21 +149,18 @@ main(int argc, char** argv)
       spot::free_relation_simulation(rel_del);
     }
 
+  spot::tgba* res = automatareduc;
+
   if (o & spot::Reduce_Scc)
     {
-      automatareduc->prune_scc();
+      res = spot::scc_filter(automatareduc);
-      //automatareduc->display_scc(std::cout);
-    }
-
-  if (automatareduc != 0)
-    {
-      spot::dotty_reachable(std::cout, automatareduc);
-    }
-
-  if (automata != 0)
-    delete automata;
-  if (automatareduc != 0)
       delete automatareduc;
+    }
+
+  spot::dotty_reachable(std::cout, res);
+
+  delete automata;
+  delete res;
 #ifndef REDUCCMP
   if (f != 0)
     f->destroy();

src/tgbatest/scc.test

@@ -48,3 +48,27 @@ accepting paths: 2
 dead paths: 1
 EOF
 diff stdout expected
+
+run 0 ../ltl2tgba -f -R3 -k '(b U a) | (GFa & XG!a)' >stdout
+cat >expected <<EOF
+transitions: 5
+states: 3
+total SCCs: 3
+accepting SCCs: 1
+dead SCCs: 0
+accepting paths: 2
+dead paths: 0
+EOF
+diff stdout expected
+
+run 0 ../ltl2tgba -f -R3 -k 'XXXX(0)' >stdout
+cat >expected <<EOF
+transitions: 0
+states: 1
+total SCCs: 1
+accepting SCCs: 0
+dead SCCs: 1
+accepting paths: 0
+dead paths: 1
+EOF
+diff stdout expected