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1 | /* A type-safe hash set. | |
2 | Copyright (C) 2014-2025 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 ('\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 |