Mercurial > hg > CbC > CbC_gcc

comparison gcc/analyzer/constraint-manager.h @ 145:1830386684a0

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
gcc-9.2.0
author anatofuz
date Thu, 13 Feb 2020 11:34:05 +0900
parents
children
comparison
equal deleted inserted replaced
131:84e7813d76e9 145:1830386684a0
1 /* Tracking equivalence classes and constraints at a point on an execution path.
2 Copyright (C) 2019-2020 Free Software Foundation, Inc.
3 Contributed by David Malcolm <dmalcolm@redhat.com>.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11
12 GCC is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 #ifndef GCC_ANALYZER_CONSTRAINT_MANAGER_H
22 #define GCC_ANALYZER_CONSTRAINT_MANAGER_H
23
24 namespace ana {
25
26 class constraint_manager;
27
28 /* Abstract base class for specifying how state should be purged. */
29
30 class purge_criteria
31 {
32 public:
33 virtual ~purge_criteria () {}
34 virtual bool should_purge_p (svalue_id sid) const = 0;
35 };
36
37 /* An equivalence class within a constraint manager: a set of
38 svalue_ids that are known to all be equal to each other,
39 together with an optional tree constant that they are equal to. */
40
41 class equiv_class
42 {
43 public:
44 equiv_class ();
45 equiv_class (const equiv_class &other);
46
47 hashval_t hash () const;
48 bool operator== (const equiv_class &other);
49
50 void add (svalue_id sid, const constraint_manager &cm);
51 bool del (svalue_id sid);
52
53 tree get_any_constant () const { return m_constant; }
54
55 svalue_id get_representative () const;
56
57 void remap_svalue_ids (const svalue_id_map &map);
58
59 void canonicalize ();
60
61 void print (pretty_printer *pp) const;
62
63 /* An equivalence class can contain multiple constants (e.g. multiple
64 different zeroes, for different types); these are just for the last
65 constant added. */
66 tree m_constant;
67 svalue_id m_cst_sid;
68
69 // TODO: should this be a set rather than a vec?
70 auto_vec<svalue_id> m_vars;
71 };
72
73 /* The various kinds of constraint. */
74
75 enum constraint_op
76 {
77 CONSTRAINT_NE,
78 CONSTRAINT_LT,
79 CONSTRAINT_LE
80 };
81
82 const char *constraint_op_code (enum constraint_op c_op);
83
84 /* An ID for an equiv_class within a constraint_manager. Internally, this
85 is an index into a vector of equiv_class * within the constraint_manager. */
86
87 class equiv_class_id
88 {
89 public:
90 static equiv_class_id null () { return equiv_class_id (-1); }
91
92 equiv_class_id (unsigned idx) : m_idx (idx) {}
93 const equiv_class &get_obj (const constraint_manager &cm) const;
94 equiv_class &get_obj (constraint_manager &cm) const;
95
96 bool operator== (const equiv_class_id &other) const
97 {
98 return m_idx == other.m_idx;
99 }
100 bool operator!= (const equiv_class_id &other) const
101 {
102 return m_idx != other.m_idx;
103 }
104
105 bool null_p () const { return m_idx == -1; }
106
107 static equiv_class_id from_int (int idx) { return equiv_class_id (idx); }
108 int as_int () const { return m_idx; }
109
110 void print (pretty_printer *pp) const;
111
112 void update_for_removal (equiv_class_id other)
113 {
114 if (m_idx > other.m_idx)
115 m_idx--;
116 }
117
118 int m_idx;
119 };
120
121 /* A relationship between two equivalence classes in a constraint_manager. */
122
123 class constraint
124 {
125 public:
126 constraint (equiv_class_id lhs, enum constraint_op c_op, equiv_class_id rhs)
127 : m_lhs (lhs), m_op (c_op), m_rhs (rhs)
128 {
129 gcc_assert (!lhs.null_p ());
130 gcc_assert (!rhs.null_p ());
131 }
132
133 void print (pretty_printer *pp, const constraint_manager &cm) const;
134
135 hashval_t hash () const;
136 bool operator== (const constraint &other) const;
137
138 /* Is this an ordering, rather than a "!=". */
139 bool is_ordering_p () const
140 {
141 return m_op != CONSTRAINT_NE;
142 }
143
144 equiv_class_id m_lhs;
145 enum constraint_op m_op;
146 equiv_class_id m_rhs;
147 };
148
149 /* An abstract base class for use with constraint_manager::for_each_fact. */
150
151 class fact_visitor
152 {
153 public:
154 virtual ~fact_visitor () {}
155 virtual void on_fact (svalue_id lhs, enum tree_code, svalue_id rhs) = 0;
156 };
157
158 /* A collection of equivalence classes and constraints on them.
159
160 Given N svalues, this can be thought of as representing a subset of
161 N-dimensional space. When we call add_constraint,
162 we are effectively taking an intersection with that constraint. */
163
164 class constraint_manager
165 {
166 public:
167 constraint_manager () {}
168 constraint_manager (const constraint_manager &other);
169 virtual ~constraint_manager () {}
170
171 virtual constraint_manager *clone (region_model *) const = 0;
172 virtual tree maybe_get_constant (svalue_id sid) const = 0;
173 virtual svalue_id get_sid_for_constant (tree cst) const = 0;
174 virtual int get_num_svalues () const = 0;
175
176 constraint_manager& operator= (const constraint_manager &other);
177
178 hashval_t hash () const;
179 bool operator== (const constraint_manager &other) const;
180 bool operator!= (const constraint_manager &other) const
181 {
182 return !(*this == other);
183 }
184
185 void print (pretty_printer *pp) const;
186 void dump_to_pp (pretty_printer *pp) const;
187 void dump (FILE *fp) const;
188 void dump () const;
189
190 const equiv_class &get_equiv_class_by_index (unsigned idx) const
191 {
192 return *m_equiv_classes[idx];
193 }
194 equiv_class &get_equiv_class_by_index (unsigned idx)
195 {
196 return *m_equiv_classes[idx];
197 }
198
199 equiv_class &get_equiv_class (svalue_id sid)
200 {
201 equiv_class_id ec_id = get_or_add_equiv_class (sid);
202 return ec_id.get_obj (*this);
203 }
204
205 bool add_constraint (svalue_id lhs, enum tree_code op, svalue_id rhs);
206
207 bool add_constraint (equiv_class_id lhs_ec_id,
208 enum tree_code op,
209 equiv_class_id rhs_ec_id);
210
211 bool get_equiv_class_by_sid (svalue_id sid, equiv_class_id *out) const;
212 equiv_class_id get_or_add_equiv_class (svalue_id sid);
213 tristate eval_condition (equiv_class_id lhs,
214 enum tree_code op,
215 equiv_class_id rhs);
216 tristate eval_condition (svalue_id lhs,
217 enum tree_code op,
218 svalue_id rhs);
219
220 void purge (const purge_criteria &p, purge_stats *stats);
221
222 void remap_svalue_ids (const svalue_id_map &map);
223
224 void canonicalize (unsigned num_svalue_ids);
225
226 static void merge (const constraint_manager &cm_a,
227 const constraint_manager &cm_b,
228 constraint_manager *out,
229 const model_merger &merger);
230
231 void for_each_fact (fact_visitor *) const;
232
233 void validate () const;
234
235 auto_delete_vec<equiv_class> m_equiv_classes;
236 auto_vec<constraint> m_constraints;
237
238 private:
239 static void clean_merger_input (const constraint_manager &cm_in,
240 const one_way_svalue_id_map &map_sid_to_m,
241 constraint_manager *out);
242
243 void add_constraint_internal (equiv_class_id lhs_id,
244 enum constraint_op c_op,
245 equiv_class_id rhs_id);
246 };
247
248 } // namespace ana
249
250 #endif /* GCC_ANALYZER_CONSTRAINT_MANAGER_H */