1 /* A type-safe hash set. 2 Copyright (C) 2014-2020 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 new (e) Key (k); 62 63 return existed; 64 } 65 66 /* if the passed in key is in the map return its value otherwise NULL. */ 67 68 bool contains (const Key &k) 69 { 70 if (Lazy) 71 return (m_table.find_slot_with_hash (k, Traits::hash (k), NO_INSERT) 72 != NULL); 73 Key &e = m_table.find_with_hash (k, Traits::hash (k)); 74 return !Traits::is_empty (e); 75 } 76 77 void remove (const Key &k) 78 { 79 m_table.remove_elt_with_hash (k, Traits::hash (k)); 80 } 81 82 /* Call the call back on each pair of key and value with the passed in 83 arg. */ 84 85 template<typename Arg, bool (*f)(const typename Traits::value_type &, Arg)> 86 void traverse (Arg a) const 87 { 88 for (typename hash_table<Traits, Lazy>::iterator iter = m_table.begin (); 89 iter != m_table.end (); ++iter) 90 f (*iter, a); 91 } 92 93 /* Return the number of elements in the set. */ 94 95 size_t elements () const { return m_table.elements (); } 96 97 /* Clear the hash table. */ 98 99 void empty () { m_table.empty (); } 100 101 /* Return true when there are no elements in this hash set. */ 102 bool is_empty () const { return m_table.is_empty (); } 103 104 class iterator 105 { 106 public: 107 explicit iterator (const typename hash_table<Traits, 108 Lazy>::iterator &iter) : 109 m_iter (iter) {} 110 111 iterator &operator++ () 112 { 113 ++m_iter; 114 return *this; 115 } 116 117 Key 118 operator* () 119 { 120 return *m_iter; 121 } 122 123 bool 124 operator != (const iterator &other) const 125 { 126 return m_iter != other.m_iter; 127 } 128 129 private: 130 typename hash_table<Traits, Lazy>::iterator m_iter; 131 }; 132 133 /* Standard iterator retrieval methods. */ 134 135 iterator begin () const { return iterator (m_table.begin ()); } 136 iterator end () const { return iterator (m_table.end ()); } 137 138 139 private: 140 141 template<typename T, typename U> 142 friend void gt_ggc_mx (hash_set<T, false, U> *); 143 template<typename T, typename U> 144 friend void gt_pch_nx (hash_set<T, false, U> *); 145 template<typename T, typename U> 146 friend void gt_pch_nx (hash_set<T, false, U> *, gt_pointer_operator, void *); 147 148 hash_table<Traits, Lazy> m_table; 149 }; 150 151 /* Generic hash_set<TYPE> debug helper. 152 153 This needs to be instantiated for each hash_set<TYPE> used throughout 154 the compiler like this: 155 156 DEFINE_DEBUG_HASH_SET (TYPE) 157 158 The reason we have a debug_helper() is because GDB can't 159 disambiguate a plain call to debug(some_hash), and it must be called 160 like debug<TYPE>(some_hash). */ 161 template<typename T> 162 void 163 debug_helper (hash_set<T> &ref) 164 { 165 for (typename hash_set<T>::iterator it = ref.begin (); 166 it != ref.end (); ++it) 167 { 168 debug_slim (*it); 169 fputc ('\n', stderr); 170 } 171 } 172 173 #define DEFINE_DEBUG_HASH_SET(T) \ 174 template void debug_helper (hash_set<T> &); \ 175 DEBUG_FUNCTION void \ 176 debug (hash_set<T> &ref) \ 177 { \ 178 debug_helper <T> (ref); \ 179 } \ 180 DEBUG_FUNCTION void \ 181 debug (hash_set<T> *ptr) \ 182 { \ 183 if (ptr) \ 184 debug (*ptr); \ 185 else \ 186 fprintf (stderr, "<nil>\n"); \ 187 } 188 189 /* ggc marking routines. */ 190 191 template<typename K, typename H> 192 static inline void 193 gt_ggc_mx (hash_set<K, false, H> *h) 194 { 195 gt_ggc_mx (&h->m_table); 196 } 197 198 template<typename K, typename H> 199 static inline void 200 gt_pch_nx (hash_set<K, false, H> *h) 201 { 202 gt_pch_nx (&h->m_table); 203 } 204 205 template<typename K, typename H> 206 static inline void 207 gt_pch_nx (hash_set<K, false, H> *h, gt_pointer_operator op, void *cookie) 208 { 209 op (&h->m_table.m_entries, cookie); 210 } 211 212 #endif 213