Add Testing Automata Product & Emptiness Check

* src/taalgos/stats.hh, src/taalgos/stats.cc: Compute statistics for a
automaton.
* src/ta/ta.hh, src/ta/ta.cc: Abstract representation of a Testing
Automata(TA)
* src/ta/taexplicit.hh, src/ta/taexplicit.cc: Explicit representation of
a Testing Automata (TA)
* src/taalgos/dotty.cc: Print a TA in dot format.
* src/taalgos/reachiter.hh, src/taalgos/reachiter.cc: Iterate over all
reachable states of a TA
* src/taalgos/sba2ta.cc: implements the construction of a TA from a BA
(Buchi Automata)
* src/tgbatest/ltl2tgba.cc: add commands to test the TA implementation
* src/taalgos/emptinessta.hh, src/taalgos/emptinessta.cc: implementation
 of the TA emptiness-check algorithm
* src/ta/taproduct.hh, src/ta/taproduct.cc: representation of the
product (automaton) between a TA and a Kripke structure.
* src/ta/Makefile.am, src/taalgos/Makefile.am: add them

src/taalgos/emptinessta.hh

@@ -0,0 +1,94 @@
+// Copyright (C) 2008 Laboratoire de Recherche et Development de
+// l'Epita (LRDE).
+// Copyright (C) 2003, 2004, 2005, 2006 Laboratoire d'Informatique de
+// Paris 6 (LIP6), département Systèmes Répartis Coopératifs (SRC),
+// Université Pierre et Marie Curie.
+//
+// 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 2 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 Spot; see the file COPYING.  If not, write to the Free
+// Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+
+#ifndef SPOT_TAALGOS_EMPTINESS_HH
+# define SPOT_TAALGOS_EMPTINESS_HH
+
+#include "ta/ta.hh"
+#include "misc/optionmap.hh"
+#include "tgbaalgos/gtec/nsheap.hh"
+#include "tgbaalgos/emptiness_stats.hh"
+#include <stack>
+
+namespace spot
+{
+
+  namespace
+  {
+    typedef std::pair<spot::state*, ta_succ_iterator*> pair_state_iter;
+  }
+  /// \brief An implementation of the ta emptiness-check algorithm.
+  ///
+  /// See the documentation for spot::ta.
+  class ta_check : public ec_statistics
+  {
+  public:
+    ta_check(const ta* a, option_map o = option_map());
+    virtual
+    ~ta_check();
+
+    /// Check whether the automaton's language is empty.
+    virtual bool
+    check();
+
+    virtual bool
+    livelock_detection(const ta* t);
+
+    virtual std::ostream&
+    print_stats(std::ostream& os) const;
+
+    /// \brief Return the status of the emptiness-check.
+    ///
+    /// When check() succeed, the status should be passed along
+    /// to spot::counter_example.
+    ///
+    /// This status should not be deleted, it is a pointer
+    /// to a member of this class that will be deleted when
+    /// the ta object is deleted.
+    //  const tgba_check_status* result() const;
+
+  protected:
+    void
+    clear(numbered_state_heap* h, std::stack<pair_state_iter> todo, std::stack<
+        spot::state*> init_set);
+    bool
+    heuristic_livelock_detection(const state * stuttering_succ,
+        numbered_state_heap* h, int h_livelock_root, std::set<const state*,
+            state_ptr_less_than> liveset_curr);
+    const ta* a_; ///< The automaton.
+    option_map o_; ///< The options
+
+    bool is_full_2_pass_;
+
+    // * scc: a stack of strongly connected components (SCC)
+    scc_stack_ta scc;
+
+    // * sscc: a stack of strongly stuttering-connected components (SSCC)
+    scc_stack_ta sscc;
+
+  };
+
+/// @}
+}
+
+#endif // SPOT_TAALGOS_EMPTINESS_HH