1 /* A type-safe hash set.
2 Copyright (C) 2014-2018 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 template<typename KeyId, typename Traits = default_hash_traits<KeyId> >
25 class hash_set
26 {
27 public:
28 typedef typename Traits::value_type Key;
29 explicit hash_set (size_t n = 13, bool ggc = false CXX_MEM_STAT_INFO)
m_table(n,ggc,GATHER_STATISTICS,HASH_SET_ORIGIN PASS_MEM_STAT)30 : m_table (n, ggc, GATHER_STATISTICS, HASH_SET_ORIGIN PASS_MEM_STAT) {}
31
32 /* Create a hash_set in gc memory with space for at least n elements. */
33
34 static hash_set *
create_ggc(size_t n)35 create_ggc (size_t n)
36 {
37 hash_set *set = ggc_alloc<hash_set> ();
38 new (set) hash_set (n, true);
39 return set;
40 }
41
42 /* If key k isn't already in the map add it to the map, and
43 return false. Otherwise return true. */
44
add(const Key & k)45 bool add (const Key &k)
46 {
47 Key *e = m_table.find_slot_with_hash (k, Traits::hash (k), INSERT);
48 bool existed = !Traits::is_empty (*e);
49 if (!existed)
50 *e = k;
51
52 return existed;
53 }
54
55 /* if the passed in key is in the map return its value otherwise NULL. */
56
contains(const Key & k)57 bool contains (const Key &k)
58 {
59 Key &e = m_table.find_with_hash (k, Traits::hash (k));
60 return !Traits::is_empty (e);
61 }
62
remove(const Key & k)63 void remove (const Key &k)
64 {
65 m_table.remove_elt_with_hash (k, Traits::hash (k));
66 }
67
68 /* Call the call back on each pair of key and value with the passed in
69 arg. */
70
71 template<typename Arg, bool (*f)(const typename Traits::value_type &, Arg)>
traverse(Arg a)72 void traverse (Arg a) const
73 {
74 for (typename hash_table<Traits>::iterator iter = m_table.begin ();
75 iter != m_table.end (); ++iter)
76 f (*iter, a);
77 }
78
79 /* Return the number of elements in the set. */
80
elements()81 size_t elements () const { return m_table.elements (); }
82
83 /* Clear the hash table. */
84
empty()85 void empty () { m_table.empty (); }
86
87 class iterator
88 {
89 public:
iterator(const typename hash_table<Traits>::iterator & iter)90 explicit iterator (const typename hash_table<Traits>::iterator &iter) :
91 m_iter (iter) {}
92
93 iterator &operator++ ()
94 {
95 ++m_iter;
96 return *this;
97 }
98
99 Key
100 operator* ()
101 {
102 return *m_iter;
103 }
104
105 bool
106 operator != (const iterator &other) const
107 {
108 return m_iter != other.m_iter;
109 }
110
111 private:
112 typename hash_table<Traits>::iterator m_iter;
113 };
114
115 /* Standard iterator retrieval methods. */
116
begin()117 iterator begin () const { return iterator (m_table.begin ()); }
end()118 iterator end () const { return iterator (m_table.end ()); }
119
120
121 private:
122
123 template<typename T, typename U> friend void gt_ggc_mx (hash_set<T, U> *);
124 template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *);
125 template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *, gt_pointer_operator, void *);
126
127 hash_table<Traits> m_table;
128 };
129
130 /* Generic hash_set<TYPE> debug helper.
131
132 This needs to be instantiated for each hash_set<TYPE> used throughout
133 the compiler like this:
134
135 DEFINE_DEBUG_HASH_SET (TYPE)
136
137 The reason we have a debug_helper() is because GDB can't
138 disambiguate a plain call to debug(some_hash), and it must be called
139 like debug<TYPE>(some_hash). */
140 template<typename T>
141 void
debug_helper(hash_set<T> & ref)142 debug_helper (hash_set<T> &ref)
143 {
144 for (typename hash_set<T>::iterator it = ref.begin ();
145 it != ref.end (); ++it)
146 {
147 debug_slim (*it);
148 fputc ('\n', stderr);
149 }
150 }
151
152 #define DEFINE_DEBUG_HASH_SET(T) \
153 template void debug_helper (hash_set<T> &); \
154 DEBUG_FUNCTION void \
155 debug (hash_set<T> &ref) \
156 { \
157 debug_helper <T> (ref); \
158 } \
159 DEBUG_FUNCTION void \
160 debug (hash_set<T> *ptr) \
161 { \
162 if (ptr) \
163 debug (*ptr); \
164 else \
165 fprintf (stderr, "<nil>\n"); \
166 }
167
168 /* ggc marking routines. */
169
170 template<typename K, typename H>
171 static inline void
gt_ggc_mx(hash_set<K,H> * h)172 gt_ggc_mx (hash_set<K, H> *h)
173 {
174 gt_ggc_mx (&h->m_table);
175 }
176
177 template<typename K, typename H>
178 static inline void
gt_pch_nx(hash_set<K,H> * h)179 gt_pch_nx (hash_set<K, H> *h)
180 {
181 gt_pch_nx (&h->m_table);
182 }
183
184 template<typename K, typename H>
185 static inline void
gt_pch_nx(hash_set<K,H> * h,gt_pointer_operator op,void * cookie)186 gt_pch_nx (hash_set<K, H> *h, gt_pointer_operator op, void *cookie)
187 {
188 op (&h->m_table.m_entries, cookie);
189 }
190
191 #endif
192