rename src/tgbaalgos/ as src/twaalgos/

Automatic mass renaming.

* src/tgbaalgos/: Rename as...
* src/twaalgos/: ... this.
* README, configure.ac, iface/ltsmin/modelcheck.cc, src/Makefile.am,
src/bin/autfilt.cc, src/bin/common_aoutput.cc,
src/bin/common_aoutput.hh, src/bin/common_output.hh,
src/bin/common_post.hh, src/bin/dstar2tgba.cc, src/bin/ltl2tgba.cc,
src/bin/ltl2tgta.cc, src/bin/ltlcross.cc, src/bin/ltldo.cc,
src/bin/ltlfilt.cc, src/bin/randaut.cc, src/dstarparse/dra2ba.cc,
src/dstarparse/nra2nba.cc, src/dstarparse/nsa2tgba.cc,
src/graphtest/twagraph.cc, src/kripke/kripkeprint.cc,
src/ltlvisit/contain.cc, src/ltlvisit/contain.hh,
src/ltlvisit/exclusive.cc, src/taalgos/emptinessta.hh,
src/tgbatest/checkpsl.cc, src/tgbatest/checkta.cc,
src/tgbatest/complementation.cc, src/tgbatest/emptchk.cc,
src/tgbatest/ltl2tgba.cc, src/tgbatest/ltlprod.cc,
src/tgbatest/randtgba.cc, src/tgbatest/taatgba.cc, src/twa/twa.cc,
src/twa/twagraph.hh, src/twa/twasafracomplement.cc,
wrap/python/spot_impl.i: Adjust.

src/twaalgos/isweakscc.cc

@@ -0,0 +1,120 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2012, 2013, 2014, 2015 Laboratoire de Recherche et
+// Developpement de l'Epita (LRDE).
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+//
+// Spot is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+// License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "cycles.hh"
+#include "ltlast/formula.hh"
+#include "isweakscc.hh"
+
+namespace spot
+{
+  namespace
+  {
+    // Look for a non-accepting cycle.
+    class weak_checker final : public enumerate_cycles
+    {
+    public:
+      bool result;
+
+      weak_checker(const scc_info& map)
+	: enumerate_cycles(map), result(true)
+      {
+      }
+
+      virtual bool
+      cycle_found(unsigned start) override
+      {
+	dfs_stack::const_reverse_iterator i = dfs_.rbegin();
+	acc_cond::mark_t acc = 0U;
+	for (;;)
+	  {
+	    acc |= aut_->trans_storage(i->succ).acc;
+	    if (i->s == start)
+	      break;
+	    ++i;
+	    // The const cast is here to please old g++ versions.
+	    // At least version 4.0 needs it.
+	    assert(i != const_cast<const dfs_stack&>(dfs_).rend());
+	  }
+	if (!aut_->acc().accepting(acc))
+	  {
+	    // We have found an non-accepting cycle, so the SCC is not
+	    // weak.
+	    result = false;
+	    return false;
+	  }
+	return true;
+      }
+
+    };
+  }
+
+  bool
+  is_inherently_weak_scc(scc_info& map, unsigned scc)
+  {
+     // Weak SCCs are inherently weak.
+    if (is_weak_scc(map, scc))
+      return true;
+    // If the SCC is accepting, but one cycle is not, the SCC is not
+    // weak.
+    weak_checker w(map);
+    w.run(scc);
+    return w.result;
+  }
+
+  bool
+  is_weak_scc(scc_info& map, unsigned scc)
+  {
+    // Rejecting SCCs are weak.
+    if (map.is_rejecting_scc(scc))
+      return true;
+    // If all transitions use the same acceptance set, the SCC is weak.
+    return map.used_acc_of(scc).size() == 1;
+  }
+
+  bool
+  is_complete_scc(scc_info& map, unsigned scc)
+  {
+    auto a = map.get_aut();
+    for (auto s: map.states_of(scc))
+      {
+	bool has_succ = false;
+	bdd sumall = bddfalse;
+	for (auto& t: a->out(s))
+	  {
+	    has_succ = true;
+	    if (map.scc_of(t.dst) == scc)
+	      sumall |= t.cond;
+	    if (sumall == bddtrue)
+	      break;
+	  }
+	if (!has_succ || sumall != bddtrue)
+	  return false;
+      }
+    return true;
+  }
+
+  bool
+  is_terminal_scc(scc_info& map, unsigned scc)
+  {
+    // If all transitions use all acceptance conditions, the SCC is weak.
+    return (map.is_accepting_scc(scc)
+	    && map.used_acc_of(scc).size() == 1
+	    && is_complete_scc(map, scc));
+  }
+}