spot/spot/twaalgos/bfssteps.cc
Alexandre Duret-Lutz 0b25820211 ignore false edges in emptiness checks and scc_info
Based on reports by Florian Renkin and Jens Kreber.

* spot/twaalgos/bfssteps.cc, spot/twaalgos/couvreurnew.cc,
spot/twaalgos/gtec/gtec.cc, spot/twaalgos/gv04.cc,
spot/twaalgos/magic.cc, spot/twaalgos/sccinfo.cc
spot/twaalgos/se05.cc, spot/twaalgos/tau03.cc: Ignore bddfalse edges.
* spot/twaalgos/gtec/gtec.hh: Remove debugging function.
* tests/core/neverclaimread.test: Adjust.
* tests/python/ecfalse.py: New test file.
* tests/Makefile.am: Add it.
* NEWS: Mention the bug.
2020-04-11 11:24:55 +02:00

113 lines
3.1 KiB
C++

// -*- coding: utf-8 -*-
// Copyright (C) 2014, 2015, 2018, 2020 Laboratoire de Recherche et
// Développement de l'Epita (LRDE)
// Copyright (C) 2004 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 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 "config.h"
#include <deque>
#include <utility>
#include <spot/twa/twa.hh>
#include <spot/twaalgos/bfssteps.hh>
namespace spot
{
bfs_steps::bfs_steps(const const_twa_ptr& a)
: a_(a)
{
}
bfs_steps::~bfs_steps()
{
}
void
bfs_steps::finalize(const std::map<const state*, twa_run::step,
state_ptr_less_than>& father, const twa_run::step& s,
const state* start, twa_run::steps& l)
{
twa_run::steps p;
twa_run::step current = s;
for (;;)
{
twa_run::step tmp = current;
tmp.s = tmp.s->clone();
p.push_front(tmp);
if (current.s == start)
break;
std::map<const state*, twa_run::step,
state_ptr_less_than>::const_iterator it = father.find(current.s);
assert(it != father.end());
current = it->second;
}
l.splice(l.end(), p);
}
const state*
bfs_steps::search(const state* start, twa_run::steps& l)
{
// Records backlinks to parent state during the BFS.
// (This also stores the propositions of this link.)
std::map<const state*, twa_run::step,
state_ptr_less_than> father;
// BFS queue.
std::deque<const state*> todo;
// Initial state.
todo.emplace_back(start);
while (!todo.empty())
{
const state* src = todo.front();
todo.pop_front();
for (auto i: a_->succ(src))
{
// skip false transitions
if (SPOT_UNLIKELY(i->cond() == bddfalse))
continue;
const state* dest = filter(i->dst());
if (!dest)
continue;
bdd cond = i->cond();
acc_cond::mark_t acc = i->acc();
twa_run::step s = { src, cond, acc };
if (match(s, dest))
{
// Found it!
finalize(father, s, start, l);
return dest;
}
// Common case: record backlinks and continue BFS
// for unvisited states.
if (father.find(dest) == father.end())
{
todo.emplace_back(dest);
father[dest] = s;
}
}
}
return nullptr;
}
}