1 | /* A type-safe hash set. |
2 | Copyright (C) 2014-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | |
21 | #ifndef hash_set_h |
22 | #define hash_set_h |
23 | |
24 | /* Class hash_set is a hash-value based container for objects of |
25 | KeyId type. |
26 | KeyId may be a non-trivial (non-POD) type provided a suitabe Traits |
27 | class. Default Traits specializations are provided for basic types |
28 | such as integers, pointers, and std::pair. Inserted elements are |
29 | value-initialized either to zero for POD types or by invoking their |
30 | default ctor. Removed elements are destroyed by invoking their dtor. |
31 | On hash_set destruction all elements are removed. Objects of |
32 | hash_set type are copy-constructible but not assignable. */ |
33 | |
34 | template<typename KeyId, bool Lazy = false, |
35 | typename Traits = default_hash_traits<KeyId> > |
36 | class hash_set |
37 | { |
38 | public: |
39 | typedef typename Traits::value_type Key; |
40 | explicit hash_set (size_t n = 13, bool ggc = false CXX_MEM_STAT_INFO) |
41 | : m_table (n, ggc, true, GATHER_STATISTICS, HASH_SET_ORIGIN PASS_MEM_STAT) {} |
42 | |
43 | /* Create a hash_set in gc memory with space for at least n elements. */ |
44 | |
45 | static hash_set * |
46 | create_ggc (size_t n) |
47 | { |
48 | hash_set *set = ggc_alloc<hash_set> (); |
49 | new (set) hash_set (n, true); |
50 | return set; |
51 | } |
52 | |
53 | /* If key k isn't already in the map add it to the map, and |
54 | return false. Otherwise return true. */ |
55 | |
56 | bool add (const Key &k) |
57 | { |
58 | Key *e = m_table.find_slot_with_hash (k, Traits::hash (k), INSERT); |
59 | bool existed = !Traits::is_empty (*e); |
60 | if (!existed) |
61 | { |
62 | new (e) Key (k); |
63 | // Catch attempts to insert e.g. a NULL pointer. |
64 | gcc_checking_assert (!Traits::is_empty (*e) |
65 | && !Traits::is_deleted (*e)); |
66 | } |
67 | |
68 | return existed; |
69 | } |
70 | |
71 | /* if the passed in key is in the map return its value otherwise NULL. */ |
72 | |
73 | bool contains (const Key &k) |
74 | { |
75 | if (Lazy) |
76 | return (m_table.find_slot_with_hash (k, Traits::hash (k), NO_INSERT) |
77 | != NULL); |
78 | Key &e = m_table.find_with_hash (k, Traits::hash (k)); |
79 | return !Traits::is_empty (e); |
80 | } |
81 | |
82 | void remove (const Key &k) |
83 | { |
84 | m_table.remove_elt_with_hash (k, Traits::hash (k)); |
85 | } |
86 | |
87 | /* Call the call back on each pair of key and value with the passed in |
88 | arg. */ |
89 | |
90 | template<typename Arg, bool (*f)(const typename Traits::value_type &, Arg)> |
91 | void traverse (Arg a) const |
92 | { |
93 | for (typename hash_table<Traits, Lazy>::iterator iter = m_table.begin (); |
94 | iter != m_table.end (); ++iter) |
95 | f (*iter, a); |
96 | } |
97 | |
98 | /* Return the number of elements in the set. */ |
99 | |
100 | size_t elements () const { return m_table.elements (); } |
101 | |
102 | /* Clear the hash table. */ |
103 | |
104 | void empty () { m_table.empty (); } |
105 | |
106 | /* Return true when there are no elements in this hash set. */ |
107 | bool is_empty () const { return m_table.is_empty (); } |
108 | |
109 | class iterator |
110 | { |
111 | public: |
112 | explicit iterator (const typename hash_table<Traits, |
113 | Lazy>::iterator &iter) : |
114 | m_iter (iter) {} |
115 | |
116 | iterator &operator++ () |
117 | { |
118 | ++m_iter; |
119 | return *this; |
120 | } |
121 | |
122 | Key |
123 | operator* () |
124 | { |
125 | return *m_iter; |
126 | } |
127 | |
128 | bool |
129 | operator != (const iterator &other) const |
130 | { |
131 | return m_iter != other.m_iter; |
132 | } |
133 | |
134 | private: |
135 | typename hash_table<Traits, Lazy>::iterator m_iter; |
136 | }; |
137 | |
138 | /* Standard iterator retrieval methods. */ |
139 | |
140 | iterator begin () const { return iterator (m_table.begin ()); } |
141 | iterator end () const { return iterator (m_table.end ()); } |
142 | |
143 | |
144 | private: |
145 | |
146 | template<typename T, typename U> |
147 | friend void gt_ggc_mx (hash_set<T, false, U> *); |
148 | template<typename T, typename U> |
149 | friend void gt_pch_nx (hash_set<T, false, U> *); |
150 | template<typename T, typename U> |
151 | friend void gt_pch_nx (hash_set<T, false, U> *, gt_pointer_operator, void *); |
152 | |
153 | hash_table<Traits, Lazy> m_table; |
154 | }; |
155 | |
156 | /* Generic hash_set<TYPE> debug helper. |
157 | |
158 | This needs to be instantiated for each hash_set<TYPE> used throughout |
159 | the compiler like this: |
160 | |
161 | DEFINE_DEBUG_HASH_SET (TYPE) |
162 | |
163 | The reason we have a debug_helper() is because GDB can't |
164 | disambiguate a plain call to debug(some_hash), and it must be called |
165 | like debug<TYPE>(some_hash). */ |
166 | template<typename T> |
167 | void |
168 | debug_helper (hash_set<T> &ref) |
169 | { |
170 | for (typename hash_set<T>::iterator it = ref.begin (); |
171 | it != ref.end (); ++it) |
172 | { |
173 | debug_slim (*it); |
174 | fputc (c: '\n', stderr); |
175 | } |
176 | } |
177 | |
178 | #define DEFINE_DEBUG_HASH_SET(T) \ |
179 | template void debug_helper (hash_set<T> &); \ |
180 | DEBUG_FUNCTION void \ |
181 | debug (hash_set<T> &ref) \ |
182 | { \ |
183 | debug_helper <T> (ref); \ |
184 | } \ |
185 | DEBUG_FUNCTION void \ |
186 | debug (hash_set<T> *ptr) \ |
187 | { \ |
188 | if (ptr) \ |
189 | debug (*ptr); \ |
190 | else \ |
191 | fprintf (stderr, "<nil>\n"); \ |
192 | } |
193 | |
194 | /* ggc marking routines. */ |
195 | |
196 | template<typename K, typename H> |
197 | inline void |
198 | gt_ggc_mx (hash_set<K, false, H> *h) |
199 | { |
200 | gt_ggc_mx (&h->m_table); |
201 | } |
202 | |
203 | template<typename K, typename H> |
204 | inline void |
205 | gt_pch_nx (hash_set<K, false, H> *h) |
206 | { |
207 | gt_pch_nx (&h->m_table); |
208 | } |
209 | |
210 | template<typename K, typename H> |
211 | inline void |
212 | gt_pch_nx (hash_set<K, false, H> *h, gt_pointer_operator op, void *cookie) |
213 | { |
214 | op (&h->m_table.m_entries, NULL, cookie); |
215 | } |
216 | |
217 | #endif |
218 | |