1/* A graph for exploring trees of feasible paths through the egraph.
2 Copyright (C) 2021-2024 Free Software Foundation, Inc.
3 Contributed by David Malcolm <dmalcolm@redhat.com>.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it
8under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 3, or (at your option)
10any later version.
11
12GCC is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3. If not see
19<http://www.gnu.org/licenses/>. */
20
21#ifndef GCC_ANALYZER_FEASIBLE_GRAPH_H
22#define GCC_ANALYZER_FEASIBLE_GRAPH_H
23
24#include "analyzer/exploded-graph.h"
25
26namespace ana {
27
28/* Forward decls. */
29
30class base_feasible_node;
31 class feasible_node;
32 class infeasible_node;
33class base_feasible_edge;
34 class feasible_edge;
35 class infeasible_edge;
36class feasible_graph;
37class feasible_cluster;
38
39/* A traits class for feasible_graph. */
40
41struct fg_traits
42{
43 typedef base_feasible_node node_t;
44 typedef base_feasible_edge edge_t;
45 typedef feasible_graph graph_t;
46 struct dump_args_t
47 {
48 typedef typename eg_traits::dump_args_t inner_args_t;
49
50 dump_args_t (const inner_args_t &inner_args)
51 : m_inner_args (inner_args)
52 {
53 }
54
55 const inner_args_t &m_inner_args;
56 };
57 typedef feasible_cluster cluster_t;
58};
59
60/* Base class of node within a feasible_graph.
61 There can be 0 or more base_feasible_nodes per exploded_node. */
62
63class base_feasible_node : public dnode<fg_traits>
64{
65 public:
66 void dump_dot_id (pretty_printer *pp) const;
67
68 const exploded_node *get_inner_node () const { return m_inner_node; }
69 unsigned get_index () const { return m_index; }
70
71 protected:
72 base_feasible_node (const exploded_node *inner_node, unsigned index)
73 : m_inner_node (inner_node), m_index (index)
74 {}
75
76 const exploded_node *m_inner_node;
77 unsigned m_index;
78};
79
80/* Subclass of base_feasible_node for a node that is reachable via a
81 feasible path, with a particular state. */
82
83class feasible_node : public base_feasible_node
84{
85public:
86 feasible_node (const exploded_node *inner_node, unsigned index,
87 const feasibility_state &state,
88 unsigned path_length)
89 : base_feasible_node (inner_node, index),
90 m_state (state),
91 m_path_length (path_length)
92 {
93 }
94
95 void dump_dot (graphviz_out *gv,
96 const dump_args_t &args) const final override;
97
98 const feasibility_state &get_state () const { return m_state; }
99 const region_model &get_model () const { return m_state.get_model (); }
100 const auto_sbitmap &get_snodes_visited () const
101 {
102 return m_state.get_snodes_visited ();
103 }
104
105 unsigned get_path_length () const { return m_path_length; }
106
107 bool get_state_at_stmt (const gimple *target_stmt,
108 region_model *out) const;
109
110private:
111 feasibility_state m_state;
112 unsigned m_path_length;
113};
114
115/* Subclass of base_feasible_node for a node that requires following
116 an infeasible edge to reach (and thus terminating this part of the
117 exploration). */
118
119class infeasible_node : public base_feasible_node
120{
121public:
122 infeasible_node (const exploded_node *inner_node, unsigned index,
123 std::unique_ptr<rejected_constraint> rc)
124 : base_feasible_node (inner_node, index),
125 m_rc (std::move (rc))
126 {
127 }
128
129 void dump_dot (graphviz_out *gv,
130 const dump_args_t &args) const final override;
131
132private:
133 std::unique_ptr<rejected_constraint> m_rc;
134};
135
136/* Base class of edge within a feasible_graph. */
137
138class base_feasible_edge : public dedge<fg_traits>
139{
140 public:
141 void dump_dot (graphviz_out *gv,
142 const dump_args_t &args) const final override;
143
144 const exploded_edge *get_inner_edge () const { return m_inner_edge; }
145
146 protected:
147 base_feasible_edge (base_feasible_node *src, base_feasible_node *dest,
148 const exploded_edge *inner_edge)
149 : dedge<fg_traits> (src, dest), m_inner_edge (inner_edge)
150 {
151 }
152
153 const exploded_edge *m_inner_edge;
154};
155
156/* Subclass of base_feasible_edge for connecting two feasible_nodes. */
157
158class feasible_edge : public base_feasible_edge
159{
160 public:
161 feasible_edge (feasible_node *src, feasible_node *dest,
162 const exploded_edge *inner_edge)
163 : base_feasible_edge (src, dest, inner_edge)
164 {
165 }
166};
167
168/* Subclass of base_feasible_edge for connecting a feasible_node
169 to an infeasible_node (and thus terminating this part of the
170 exploration). */
171
172class infeasible_edge : public base_feasible_edge
173{
174 public:
175 infeasible_edge (feasible_node *src, infeasible_node *dest,
176 const exploded_edge *inner_edge)
177 : base_feasible_edge (src, dest, inner_edge)
178 {
179 }
180};
181
182/* A digraph subclass for exploring trees of feasible paths through
183 the egraph. This is actually a tree.
184
185 The paths within the graph of feasible_nodes express feasible paths
186 through the graph, and it also captures known infeasible edges,
187 which is invaluable for debugging. */
188
189class feasible_graph : public digraph <fg_traits>
190{
191 public:
192 feasible_graph ();
193
194 feasible_node *add_node (const exploded_node *enode,
195 const feasibility_state &state,
196 unsigned path_length);
197
198 void add_feasibility_problem (feasible_node *src_fnode,
199 const exploded_edge *eedge,
200 std::unique_ptr<rejected_constraint> rc);
201
202 std::unique_ptr<exploded_path> make_epath (feasible_node *fnode) const;
203
204 void dump_feasible_path (const feasible_node &dst_fnode,
205 const char *filename) const;
206
207 unsigned get_num_infeasible () const { return m_num_infeasible; }
208
209 void log_stats (logger *logger) const;
210
211private:
212 void dump_feasible_path (const feasible_node &dst_fnode,
213 pretty_printer *pp) const;
214
215 unsigned m_num_infeasible;
216};
217
218class feasible_cluster : public cluster <fg_traits>
219{
220};
221
222} // namespace ana
223
224#endif /* GCC_ANALYZER_FEASIBLE_GRAPH_H */
225

source code of gcc/analyzer/feasible-graph.h