Add a visitor to relabel the atomic proposition in formulas.

* src/ltlvisit/relabel.cc, src/ltlvisit/relabel.hh: New files.
* src/ltlvisit/Makefile.am: Add them.
* src/ltlvisit/clone.cc (recurse): Don't call clone(), nobody
needs that.  Instead, really recurse.
* src/bin/ltlfilt.cc: Add a --relabel option.
* src/bin/genltl.cc: Relabel formulas if --lbt is used.
* src/sanity/style.test: Tweak detection of i++.

src/ltlvisit/Makefile.am

@@ -42,6 +42,7 @@ ltlvisit_HEADERS = \
   postfix.hh \
   randomltl.hh \
   reduce.hh \
+  relabel.hh \
   simpfg.hh \
   simplify.hh \
   snf.hh \
@@ -65,6 +66,7 @@ libltlvisit_la_SOURCES = \
   postfix.cc \
   randomltl.cc \
   reduce.cc \
+  relabel.cc \
   simpfg.cc \
   simplify.cc \
   snf.cc \

src/ltlvisit/clone.cc

@@ -70,8 +70,9 @@ namespace spot
     void
     clone_visitor::visit(const binop* bo)
     {
+      const formula* first = recurse(bo->first());
       result_ = binop::instance(bo->op(),
-				recurse(bo->first()), recurse(bo->second()));
+				first, recurse(bo->second()));
     }
 
     void
@@ -96,7 +97,8 @@ namespace spot
     const formula*
     clone_visitor::recurse(const formula* f)
     {
-      return f->clone();
+      f->accept(*this);
+      return result_;
     }
 
     const formula*

src/ltlvisit/relabel.cc

@@ -0,0 +1,118 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2012 Laboratoire de Recherche et
+// Développement 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 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.
+
+#include <relabel.hh>
+#include <sstream>
+#include "clone.hh"
+#include "misc/hash.hh"
+#include "ltlenv/defaultenv.hh"
+
+namespace spot
+{
+  namespace ltl
+  {
+    namespace
+    {
+      class relabeler: public clone_visitor
+      {
+      public:
+	typedef Sgi::hash_map<const atomic_prop*, const formula*,
+			      ptr_hash<atomic_prop> > map;
+	map newname;
+
+	void
+	visit(const atomic_prop* ap)
+	{
+	  map::const_iterator it = newname.find(ap);
+	  if (it != newname.end())
+	    result_ = it->second->clone();
+	  else
+	    newname[ap] = result_ = next();
+	}
+
+	virtual const formula* next() = 0;
+      };
+
+      class relabeler_pnn: public relabeler
+      {
+      public:
+	relabeler_pnn()
+	  : nn(0)
+	{
+	}
+
+	unsigned nn;
+
+	const formula* next()
+	{
+	  std::ostringstream s;
+	  s << "p" << nn++;
+	  return default_environment::instance().require(s.str());
+	}
+      };
+
+      class relabeler_abc: public relabeler
+      {
+      public:
+	relabeler_abc()
+	  : nn(0)
+	{
+	}
+
+	unsigned nn;
+
+	const formula* next()
+	{
+	  std::string s;
+	  unsigned n = nn++;
+	  do
+	    {
+	      s.push_back('a' + (n % 26));
+	      n /= 26;
+	    }
+	  while (n);
+
+	  return default_environment::instance().require(s);
+	}
+      };
+    }
+
+
+    const formula*
+    relabel(const formula* f, relabeling_style style)
+    {
+      relabeler* rel = 0;
+      switch (style)
+	{
+	case Pnn:
+	  rel = new relabeler_pnn;
+	  break;
+	case Abc:
+	  rel = new relabeler_abc;
+	  break;
+	}
+      f->accept(*rel);
+      const formula* res = rel->result();
+      delete rel;
+      return res;
+    }
+  }
+}

src/ltlvisit/relabel.hh

@@ -0,0 +1,42 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2012 Laboratoire de Recherche et
+// Développement 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 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_LTLVISIT_RELABEL_HH
+# define SPOT_LTLVISIT_RELABEL_HH
+
+#include <ltlast/formula.hh>
+
+namespace spot
+{
+  namespace ltl
+  {
+    enum relabeling_style { Abc, Pnn };
+
+    /// \brief Relabel the atomic proposition in a formula.
+    ///
+    /// \ingroup ltl_rewriting
+    const formula* relabel(const formula* f, relabeling_style style);
+  }
+}
+
+
+
+#endif // SPOT_LTLVISIT_RELABEL_HH