remove wdbacomp.cc and wdbacomp.hh

The weak complementation is now implemented by dtgba_complement(), with
dispatch based on the automaton property.

* src/tgba/wdbacomp.cc, src/tgba/wdbacomp.hh: Remove.
* src/tgba/Makefile.am: Adjust.
* src/tgbaalgos/dtgbacomp.cc: Implement the weak version.
* src/tgbaalgos/dtgbacomp.hh: Document it.
* src/tgbaalgos/minimize.cc: Use dtgba_complement() instead.

src/tgba/Makefile.am

@@ -38,8 +38,7 @@ tgba_HEADERS = \
   tgbaproxy.hh \
   tgbaproduct.hh \
   tgbasgba.hh \
-  tgbasafracomplement.hh \
-  wdbacomp.hh
+  tgbasafracomplement.hh
 
 noinst_LTLIBRARIES = libtgba.la
 libtgba_la_SOURCES = \
@@ -54,5 +53,4 @@ libtgba_la_SOURCES = \
   tgbamask.cc \
   tgbaproxy.cc \
   tgbasafracomplement.cc \
-  tgbasgba.cc \
-  wdbacomp.cc
+  tgbasgba.cc

src/tgba/wdbacomp.cc

-// -*- coding: utf-8 -*-
-// Copyright (C) 2011, 2012, 2013, 2014 Laboratoire de Recherche et
-// Développement de l'Epita.
-//
-// 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 "wdbacomp.hh"
-#include "ltlast/constant.hh"
-
-namespace spot
-{
-  namespace
-  {
-    class state_wdba_comp_proxy : public state
-    {
-    public:
-      state_wdba_comp_proxy(state* s) : s_(s)
-      {
-      }
-
-      /// Copy constructor
-      state_wdba_comp_proxy(const state_wdba_comp_proxy& o)
-	: state(),
-	  s_(o.real_state())
-      {
-	if (s_)
-	  s_ = s_->clone();
-      }
-
-      virtual
-      ~state_wdba_comp_proxy()
-      {
-	if (s_)
-	  s_->destroy();
-      }
-
-      state*
-      real_state() const
-      {
-	return s_;
-      }
-
-      virtual int
-      compare(const state* other) const
-      {
-	const state_wdba_comp_proxy* o =
-	  down_cast<const state_wdba_comp_proxy*>(other);
-	assert(o);
-	const state* oo = o->real_state();
-	if (s_ == 0)
-	  return oo ? 1 : 0;
-	if (oo == 0)
-	  return -1;
-
-	return s_->compare(oo);
-      }
-
-      virtual size_t
-      hash() const
-      {
-	if (s_)
-	  return s_->hash();
-	return 0;
-      }
-
-      virtual
-      state_wdba_comp_proxy* clone() const
-      {
-	return new state_wdba_comp_proxy(*this);
-      }
-
-    private:
-      state* s_; // 0 if sink-state.
-    };
-
-    class tgba_wdba_comp_proxy_succ_iterator: public tgba_succ_iterator
-    {
-    public:
-      tgba_wdba_comp_proxy_succ_iterator(tgba_succ_iterator* it,
-					 bdd the_acceptance_cond)
-	: it_(it), the_acceptance_cond_(the_acceptance_cond), left_(bddtrue)
-      {
-      }
-
-      void recycle(const const_tgba_ptr& a, tgba_succ_iterator* it)
-      {
-	a->release_iter(it_);
-	it_ = it;
-      }
-
-      virtual
-      ~tgba_wdba_comp_proxy_succ_iterator()
-      {
-	delete it_;
-      }
-
-      // iteration
-
-      bool
-      first()
-      {
-	left_ = bddtrue;
-	if (it_)
-	  it_->first();
-	// Return true even if it_ is done, because
-	// we have to build a sink state.
-	return true;
-      }
-
-      bool
-      next()
-      {
-	if (!it_ || it_->done())
-	  {
-	    left_ = bddfalse;
-	    return false;
-	  }
-	left_ -= it_->current_condition();
-	if (left_ == bddfalse)
-	  return false;
-	it_->next();
-	// Return true even if it_ is done, because
-	// we have to build a sink state.
-	return true;
-      }
-
-      bool
-      done() const
-      {
-	return left_ == bddfalse;
-      }
-
-      // inspection
-
-      state_wdba_comp_proxy*
-      current_state() const
-      {
-	if (!it_ || it_->done())
-	  return new state_wdba_comp_proxy(0);
-	return new state_wdba_comp_proxy(it_->current_state());
-      }
-
-      bdd
-      current_condition() const
-      {
-	if (!it_ || it_->done())
-	  return left_;
-	return it_->current_condition();
-      }
-
-      bdd
-      current_acceptance_conditions() const
-      {
-	if (!it_ || it_->done())
-	  // The sink state is accepting in the negated automaton.
-	  return the_acceptance_cond_;
-
-	if (it_->current_acceptance_conditions() == bddfalse)
-	  return the_acceptance_cond_;
-	else
-	  return bddfalse;
-      }
-
-    protected:
-      tgba_succ_iterator* it_;
-      const bdd the_acceptance_cond_;
-      bdd left_;
-    };
-
-    class tgba_wdba_comp_proxy: public tgba
-    {
-    public:
-      tgba_wdba_comp_proxy(const const_tgba_ptr& a)
-	: a_(a), the_acceptance_cond_(a->all_acceptance_conditions())
-      {
-	if (the_acceptance_cond_ == bddfalse)
-	  {
-	    int v = get_dict()
-	      ->register_acceptance_variable(ltl::constant::true_instance(),
-					     this);
-	    the_acceptance_cond_ = bdd_ithvar(v);
-	  }
-      }
-
-      virtual ~tgba_wdba_comp_proxy()
-      {
-	get_dict()->unregister_all_my_variables(this);
-      }
-
-      virtual state* get_init_state() const
-      {
-	return new state_wdba_comp_proxy(a_->get_init_state());
-      }
-
-      virtual tgba_succ_iterator*
-      succ_iter(const state* st) const
-      {
-	const state_wdba_comp_proxy* s =
-	  down_cast<const state_wdba_comp_proxy*>(st);
-	assert(s);
-
-	const state* o = s->real_state();
-	tgba_succ_iterator* it = nullptr;
-	if (o)
-	  it = a_->succ_iter(s->real_state());
-	if (iter_cache_)
-	  {
-	    tgba_wdba_comp_proxy_succ_iterator* res =
-	      down_cast<tgba_wdba_comp_proxy_succ_iterator*>(iter_cache_);
-	    res->recycle(a_, it);
-	    iter_cache_ = nullptr;
-	    return res;
-	  }
-	return new tgba_wdba_comp_proxy_succ_iterator(it, the_acceptance_cond_);
-      }
-
-      virtual bdd_dict_ptr
-      get_dict() const
-      {
-	return a_->get_dict();
-      }
-
-      virtual std::string
-      format_state(const state* ostate) const
-      {
-	const state_wdba_comp_proxy* s =
-	  down_cast<const state_wdba_comp_proxy*>(ostate);
-	assert(s);
-	const state* rs = s->real_state();
-	if (rs)
-	  return a_->format_state(s->real_state());
-	else
-	  return "(*)"; // sink state
-      }
-
-      virtual state*
-      project_state(const state* s, const const_tgba_ptr& t) const
-      {
-	const state_wdba_comp_proxy* s2 =
-	  down_cast<const state_wdba_comp_proxy*>(s);
-	assert(s2);
-	if (t.get() == this)
-	  return s2->clone();
-	return a_->project_state(s2->real_state(), t);
-      }
-
-      virtual bdd
-      all_acceptance_conditions() const
-      {
-	return the_acceptance_cond_;
-      }
-
-      virtual bdd
-      neg_acceptance_conditions() const
-      {
-	return !the_acceptance_cond_;
-      }
-
-    protected:
-      virtual bdd
-      compute_support_conditions(const state*) const
-      {
-	// The automaton is complete, so we always support all variables.
-	return bddtrue;
-      }
-
-      const_tgba_ptr a_;
-    private:
-      bdd the_acceptance_cond_;
-
-      // Disallow copy.
-      tgba_wdba_comp_proxy(const tgba_wdba_comp_proxy&) SPOT_DELETED;
-      tgba_wdba_comp_proxy& operator=(const tgba_wdba_comp_proxy&) SPOT_DELETED;
-    };
-
-  }
-
-  const_tgba_ptr
-  wdba_complement(const const_tgba_ptr& aut)
-  {
-    return std::make_shared<tgba_wdba_comp_proxy>(aut);
-  }
-}

src/tgba/wdbacomp.hh

-// -*- coding: utf-8 -*-
-// Copyright (C) 2011, 2013, 2014 Laboratoire de Recherche et Développement
-// de l'Epita.
-//
-// 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/>.
-
-#ifndef SPOT_TGBA_WDBACOMP_HH
-# define SPOT_TGBA_WDBACOMP_HH
-
-#include "tgba.hh"
-
-namespace spot
-{
-  /// \ingroup tgba_on_the_fly_algorithms
-  /// \brief Complement a weak deterministic Büchi automaton
-  /// \param aut a weak deterministic Büchi automaton to complement
-  /// \return a new automaton that recognizes the complement language
-  SPOT_API const_tgba_ptr
-  wdba_complement(const const_tgba_ptr& aut);
-}
-
-#endif

src/tgbaalgos/dtgbacomp.cc

@@ -19,10 +19,11 @@
 
 #include "dtgbacomp.hh"
 #include "dupexp.hh"
+#include "sccinfo.hh"
 
 namespace spot
 {
-  tgba_digraph_ptr dtgba_complement(const const_tgba_ptr& aut)
+  tgba_digraph_ptr dtgba_complement_nonweak(const const_tgba_ptr& aut)
   {
     // Clone the original automaton.
     tgba_digraph_ptr res = tgba_dupexp_dfs(aut);
@@ -50,7 +51,7 @@ namespace spot
 	bdd missingcond = bddtrue;
 	for (auto& t: res->out(src))
 	  {
-	    if (t.dst >= n)	// Ignore transition we added.
+	    if (t.dst >= n)	// Ignore transitions we added.
 	      break;
 	    missingcond -= t.cond;
 	    bdd curacc = t.acc;
@@ -121,4 +122,65 @@ namespace spot
     // FIXME: Remove unreachable states.
     return res;
   }
+
+  tgba_digraph_ptr dtgba_complement_weak(const const_tgba_ptr& aut)
+  {
+    // Clone the original automaton.
+    tgba_digraph_ptr res = tgba_dupexp_dfs(aut);
+
+    res->prop_copy(aut,
+		   true, 	// state based
+		   true, 	// single acc
+		   true, 	// inherently_weak
+		   true);	// deterministic
+
+    bdd oldaccs = aut->all_acceptance_conditions();
+    bdd oldnegs = aut->neg_acceptance_conditions();
+
+    scc_info si(res);
+
+    // We will modify res in place, and the resulting
+    // automaton will only have one acceptance set.
+    bdd all_acc = res->set_single_acceptance_set();
+    res->prop_state_based_acc();
+
+    unsigned sink = res->num_states();
+
+    for (unsigned src = 0; src < sink; ++src)
+      {
+	bdd acc = bddfalse;
+	unsigned scc = si.scc_of(src);
+	if (!si.is_accepting_scc(scc) && !si.is_trivial(scc))
+	  acc = all_acc;
+
+	// Keep track of all conditions on transition leaving state
+	// SRC, so we can complete it.
+	bdd missingcond = bddtrue;
+	for (auto& t: res->out(src))
+	  {
+	    missingcond -= t.cond;
+	    t.acc = acc;
+	  }
+	// Complete the original automaton.
+	if (missingcond != bddfalse)
+	  {
+	    if (res->num_states() == sink)
+	      {
+		res->new_state();
+		res->new_acc_transition(sink, sink, bddtrue);
+	      }
+	    res->new_transition(src, sink, missingcond);
+	  }
+      }
+    //res->merge_transitions();
+    return res;
+  }
+
+  tgba_digraph_ptr dtgba_complement(const const_tgba_ptr& aut)
+  {
+    if (aut->is_inherently_weak())
+      return dtgba_complement_weak(aut);
+    else
+      return dtgba_complement_nonweak(aut);
+  }
 }

src/tgbaalgos/dtgbacomp.hh

 // -*- coding: utf-8 -*-
-// Copyright (C) 2013 Laboratoire de Recherche et Développement
+// Copyright (C) 2013, 2014 Laboratoire de Recherche et Développement
 // de l'Epita.
 //
 // This file is part of Spot, a model checking library.
@@ -28,8 +28,9 @@ namespace spot
   ///
   /// The automaton \a aut should be deterministic.  It does no need
   /// to be complete.  Acceptance can be transition-based, or
-  /// state-based.  The resulting automaton is very unlikely to be
-  /// deterministic.
+  /// state-based.  Unless the input automaton is marked as weak (in
+  /// which case the output will also be weak and deterministic) the
+  /// resulting automaton is very unlikely to be deterministic.
   SPOT_API tgba_digraph_ptr
   dtgba_complement(const const_tgba_ptr& aut);
 }

src/tgbaalgos/minimize.cc

@@ -37,7 +37,6 @@
 #include "misc/hash.hh"
 #include "misc/bddlt.hh"
 #include "tgba/tgbaproduct.hh"
-#include "tgba/wdbacomp.hh"
 #include "tgbaalgos/powerset.hh"
 #include "tgbaalgos/gtec/gtec.hh"
 #include "tgbaalgos/safety.hh"
@@ -671,7 +670,8 @@ namespace spot
     if (product(min_aut_f, aut_neg_f)->is_empty())
       {
 	// Complement the minimized WDBA.
-	auto neg_min_aut_f = wdba_complement(min_aut_f);
+	assert(min_aut_f->is_inherently_weak());
+	auto neg_min_aut_f = dtgba_complement(min_aut_f);
 	if (product(aut_f, neg_min_aut_f)->is_empty())
 	  // Finally, we are now sure that it was safe
 	  // to minimize the automaton.