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/* Template classes for directed graphs.
Copyright (C) 2019-2024 Free Software Foundation, Inc.
Contributed by David Malcolm <dmalcolm@redhat.com>.
This file is part of GCC.
GCC 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, or (at your option)
any later version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "diagnostic.h"
#include "graphviz.h"
#include "digraph.h"
#include "shortest-paths.h"
#include "selftest.h"
#if CHECKING_P
namespace selftest {
/* A family of digraph classes for writing selftests. */
struct test_node;
struct test_edge;
struct test_graph;
struct test_dump_args_t {};
struct test_cluster;
struct test_graph_traits
{
typedef test_node node_t;
typedef test_edge edge_t;
typedef test_graph graph_t;
typedef test_dump_args_t dump_args_t;
typedef test_cluster cluster_t;
};
struct test_node : public dnode<test_graph_traits>
{
test_node (const char *name, int index) : m_name (name), m_index (index) {}
void dump_dot (graphviz_out *, const dump_args_t &) const override
{
}
const char *m_name;
int m_index;
};
struct test_edge : public dedge<test_graph_traits>
{
test_edge (node_t *src, node_t *dest)
: dedge<test_graph_traits> (src, dest)
{}
void dump_dot (graphviz_out *gv, const dump_args_t &) const override
{
gv->println ("%s %s %s%c", m_src->m_name, "->", m_dest->m_name, ';');
}
};
struct test_graph : public digraph<test_graph_traits>
{
test_node *add_test_node (const char *name)
{
test_node *result = new test_node (name, m_nodes.length ());
add_node (result);
return result;
}
test_edge *add_test_edge (test_node *src, test_node *dst)
{
test_edge *result = new test_edge (src, dst);
add_edge (result);
return result;
}
};
struct test_cluster : public cluster<test_graph_traits>
{
};
struct test_path
{
auto_vec<const test_edge *> m_edges;
};
/* Smoketest of digraph dumping. */
static void
test_dump_to_dot ()
{
test_graph g;
test_node *a = g.add_test_node ("a");
test_node *b = g.add_test_node ("b");
g.add_test_edge (a, b);
pretty_printer pp;
pp.buffer->stream = NULL;
test_dump_args_t dump_args;
g.dump_dot_to_pp (&pp, NULL, dump_args);
ASSERT_STR_CONTAINS (pp_formatted_text (&pp),
"a -> b;\n");
}
/* Test shortest paths from A in this digraph,
where edges run top-to-bottom if not otherwise labeled:
A
/ \
B C-->D
| |
E |
\ /
F. */
static void
test_shortest_paths ()
{
test_graph g;
test_node *a = g.add_test_node ("a");
test_node *b = g.add_test_node ("b");
test_node *c = g.add_test_node ("d");
test_node *d = g.add_test_node ("d");
test_node *e = g.add_test_node ("e");
test_node *f = g.add_test_node ("f");
test_edge *ab = g.add_test_edge (a, b);
test_edge *ac = g.add_test_edge (a, c);
test_edge *cd = g.add_test_edge (c, d);
test_edge *be = g.add_test_edge (b, e);
test_edge *ef = g.add_test_edge (e, f);
test_edge *cf = g.add_test_edge (c, f);
/* Use "A" as the origin; all nodes should be reachable. */
{
shortest_paths<test_graph_traits, test_path> sp (g, a,
SPS_FROM_GIVEN_ORIGIN);
test_path path_to_a = sp.get_shortest_path (a);
ASSERT_EQ (path_to_a.m_edges.length (), 0); /* Trivial path. */
test_path path_to_b = sp.get_shortest_path (b);
ASSERT_EQ (path_to_b.m_edges.length (), 1);
ASSERT_EQ (path_to_b.m_edges[0], ab);
test_path path_to_c = sp.get_shortest_path (c);
ASSERT_EQ (path_to_c.m_edges.length (), 1);
ASSERT_EQ (path_to_c.m_edges[0], ac);
test_path path_to_d = sp.get_shortest_path (d);
ASSERT_EQ (path_to_d.m_edges.length (), 2);
ASSERT_EQ (path_to_d.m_edges[0], ac);
ASSERT_EQ (path_to_d.m_edges[1], cd);
test_path path_to_e = sp.get_shortest_path (e);
ASSERT_EQ (path_to_e.m_edges.length (), 2);
ASSERT_EQ (path_to_e.m_edges[0], ab);
ASSERT_EQ (path_to_e.m_edges[1], be);
test_path path_to_f = sp.get_shortest_path (f);
ASSERT_EQ (path_to_f.m_edges.length (), 2);
ASSERT_EQ (path_to_f.m_edges[0], ac);
ASSERT_EQ (path_to_f.m_edges[1], cf);
}
/* Verify that we gracefully handle an origin from which some nodes
aren't reachable. */
/* Use "B" as the origin, so only E and F are reachable. */
{
shortest_paths<test_graph_traits, test_path> sp (g, b,
SPS_FROM_GIVEN_ORIGIN);
test_path path_to_a = sp.get_shortest_path (a);
ASSERT_EQ (path_to_a.m_edges.length (), 0); /* No path. */
test_path path_to_b = sp.get_shortest_path (b);
ASSERT_EQ (path_to_b.m_edges.length (), 0); /* Trivial path. */
test_path path_to_c = sp.get_shortest_path (c);
ASSERT_EQ (path_to_c.m_edges.length (), 0); /* No path. */
test_path path_to_d = sp.get_shortest_path (d);
ASSERT_EQ (path_to_d.m_edges.length (), 0); /* No path. */
test_path path_to_e = sp.get_shortest_path (e);
ASSERT_EQ (path_to_e.m_edges.length (), 1);
ASSERT_EQ (path_to_e.m_edges[0], be);
test_path path_to_f = sp.get_shortest_path (f);
ASSERT_EQ (path_to_f.m_edges.length (), 2);
ASSERT_EQ (path_to_f.m_edges[0], be);
ASSERT_EQ (path_to_f.m_edges[1], ef);
}
/* Use "C" as the origin, so only D and F are reachable. */
{
shortest_paths<test_graph_traits, test_path> sp (g, c,
SPS_FROM_GIVEN_ORIGIN);
test_path path_to_a = sp.get_shortest_path (a);
ASSERT_EQ (path_to_a.m_edges.length (), 0); /* No path. */
test_path path_to_b = sp.get_shortest_path (b);
ASSERT_EQ (path_to_b.m_edges.length (), 0); /* No path. */
test_path path_to_c = sp.get_shortest_path (c);
ASSERT_EQ (path_to_c.m_edges.length (), 0); /* Trivial path. */
test_path path_to_d = sp.get_shortest_path (d);
ASSERT_EQ (path_to_d.m_edges.length (), 1);
ASSERT_EQ (path_to_d.m_edges[0], cd);
test_path path_to_e = sp.get_shortest_path (e);
ASSERT_EQ (path_to_e.m_edges.length (), 0); /* No path. */
test_path path_to_f = sp.get_shortest_path (f);
ASSERT_EQ (path_to_f.m_edges.length (), 1);
ASSERT_EQ (path_to_f.m_edges[0], cf);
}
/* Test of SPS_TO_GIVEN_TARGET. Use "F" as the target. */
{
shortest_paths<test_graph_traits, test_path> sp (g, f,
SPS_TO_GIVEN_TARGET);
test_path path_to_a = sp.get_shortest_path (a);
ASSERT_EQ (path_to_a.m_edges.length (), 2);
ASSERT_EQ (path_to_a.m_edges[0], ac);
ASSERT_EQ (path_to_a.m_edges[1], cf);
test_path path_to_b = sp.get_shortest_path (b);
ASSERT_EQ (path_to_b.m_edges.length (), 2);
ASSERT_EQ (path_to_b.m_edges[0], be);
ASSERT_EQ (path_to_b.m_edges[1], ef);
test_path path_to_c = sp.get_shortest_path (c);
ASSERT_EQ (path_to_c.m_edges.length (), 1);
ASSERT_EQ (path_to_c.m_edges[0], cf);
test_path path_to_d = sp.get_shortest_path (d);
ASSERT_EQ (path_to_d.m_edges.length (), 0); /* No path. */
test_path path_to_e = sp.get_shortest_path (e);
ASSERT_EQ (path_to_e.m_edges.length (), 1);
ASSERT_EQ (path_to_e.m_edges[0], ef);
test_path path_to_f = sp.get_shortest_path (f);
ASSERT_EQ (path_to_f.m_edges.length (), 0);
}
}
/* Run all of the selftests within this file. */
void
digraph_cc_tests ()
{
test_dump_to_dot ();
test_shortest_paths ();
}
} // namespace selftest
#endif /* #if CHECKING_P */