gcc/hash-set.h

   1 /* A type-safe hash set.
   2    Copyright (C) 2014-2019 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)
  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 *
  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
  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
  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
  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)>
  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
  81   size_t elements () const { return m_table.elements (); }
  82
  83   /* Clear the hash table.  */
  84
  85   void empty () { m_table.empty (); }
  86
  87   class iterator
  88   {
  89   public:
  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
 117   iterator begin () const { return iterator (m_table.begin ()); }
 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
 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
 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
 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
 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