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, bool Lazy = false,
  25          typename Traits = default_hash_traits<KeyId> >
  26 class hash_set
  27 {
  28 public:
  29   typedef typename Traits::value_type Key;
  30   explicit hash_set (size_t n = 13, bool ggc = false CXX_MEM_STAT_INFO)
  31     : m_table (n, ggc, true, GATHER_STATISTICS, HASH_SET_ORIGIN PASS_MEM_STAT) {}
  32
  33   /* Create a hash_set in gc memory with space for at least n elements.  */
  34
  35   static hash_set *
  36   create_ggc (size_t n)
  37     {
  38       hash_set *set = ggc_alloc<hash_set> ();
  39       new (set) hash_set (n, true);
  40       return set;
  41     }
  42
  43   /* If key k isn't already in the map add it to the map, and
  44      return false.  Otherwise return true.  */
  45
  46   bool add (const Key &k)
  47     {
  48       Key *e = m_table.find_slot_with_hash (k, Traits::hash (k), INSERT);
  49       bool existed = !Traits::is_empty (*e);
  50       if (!existed)
  51         *e = k;
  52
  53       return existed;
  54     }
  55
  56   /* if the passed in key is in the map return its value otherwise NULL.  */
  57
  58   bool contains (const Key &k)
  59     {
  60       if (Lazy)
  61         return (m_table.find_slot_with_hash (k, Traits::hash (k), NO_INSERT)
  62                 != NULL);
  63       Key &e = m_table.find_with_hash (k, Traits::hash (k));
  64       return !Traits::is_empty (e);
  65     }
  66
  67   void remove (const Key &k)
  68     {
  69       m_table.remove_elt_with_hash (k, Traits::hash (k));
  70     }
  71
  72   /* Call the call back on each pair of key and value with the passed in
  73      arg.  */
  74
  75   template<typename Arg, bool (*f)(const typename Traits::value_type &, Arg)>
  76   void traverse (Arg a) const
  77     {
  78       for (typename hash_table<Traits, Lazy>::iterator iter = m_table.begin ();
  79            iter != m_table.end (); ++iter)
  80         f (*iter, a);
  81     }
  82
  83   /* Return the number of elements in the set.  */
  84
  85   size_t elements () const { return m_table.elements (); }
  86
  87   /* Clear the hash table.  */
  88
  89   void empty () { m_table.empty (); }
  90
  91   /* Return true when there are no elements in this hash set.  */
  92   bool is_empty () const { return m_table.is_empty (); }
  93
  94   class iterator
  95   {
  96   public:
  97     explicit iterator (const typename hash_table<Traits,
  98                                                  Lazy>::iterator &iter) :
  99       m_iter (iter) {}
 100
 101     iterator &operator++ ()
 102       {
 103         ++m_iter;
 104         return *this;
 105       }
 106
 107     Key
 108     operator* ()
 109       {
 110         return *m_iter;
 111       }
 112
 113     bool
 114     operator != (const iterator &other) const
 115       {
 116         return m_iter != other.m_iter;
 117       }
 118
 119   private:
 120     typename hash_table<Traits, Lazy>::iterator m_iter;
 121   };
 122
 123   /* Standard iterator retrieval methods.  */
 124
 125   iterator begin () const { return iterator (m_table.begin ()); }
 126   iterator end () const { return iterator (m_table.end ()); }
 127
 128
 129 private:
 130
 131   template<typename T, typename U>
 132   friend void gt_ggc_mx (hash_set<T, false, U> *);
 133   template<typename T, typename U>
 134   friend void gt_pch_nx (hash_set<T, false, U> *);
 135   template<typename T, typename U>
 136   friend void gt_pch_nx (hash_set<T, false, U> *, gt_pointer_operator, void *);
 137
 138   hash_table<Traits, Lazy> m_table;
 139 };
 140
 141 /* Generic hash_set<TYPE> debug helper.
 142
 143    This needs to be instantiated for each hash_set<TYPE> used throughout
 144    the compiler like this:
 145
 146     DEFINE_DEBUG_HASH_SET (TYPE)
 147
 148    The reason we have a debug_helper() is because GDB can't
 149    disambiguate a plain call to debug(some_hash), and it must be called
 150    like debug<TYPE>(some_hash).  */
 151 template<typename T>
 152 void
 153 debug_helper (hash_set<T> &ref)
 154 {
 155   for (typename hash_set<T>::iterator it = ref.begin ();
 156        it != ref.end (); ++it)
 157     {
 158       debug_slim (*it);
 159       fputc ('\n', stderr);
 160     }
 161 }
 162
 163 #define DEFINE_DEBUG_HASH_SET(T) \
 164   template void debug_helper (hash_set<T> &);           \
 165   DEBUG_FUNCTION void                                   \
 166   debug (hash_set<T> &ref)                              \
 167   {                                                     \
 168     debug_helper <T> (ref);                             \
 169   }                                                     \
 170   DEBUG_FUNCTION void                                   \
 171   debug (hash_set<T> *ptr)                              \
 172   {                                                     \
 173     if (ptr)                                            \
 174       debug (*ptr);                                     \
 175     else                                                \
 176       fprintf (stderr, "<nil>\n");                      \
 177   }
 178
 179 /* ggc marking routines.  */
 180
 181 template<typename K, typename H>
 182 static inline void
 183 gt_ggc_mx (hash_set<K, false, H> *h)
 184 {
 185   gt_ggc_mx (&h->m_table);
 186 }
 187
 188 template<typename K, typename H>
 189 static inline void
 190 gt_pch_nx (hash_set<K, false, H> *h)
 191 {
 192   gt_pch_nx (&h->m_table);
 193 }
 194
 195 template<typename K, typename H>
 196 static inline void
 197 gt_pch_nx (hash_set<K, false, H> *h, gt_pointer_operator op, void *cookie)
 198 {
 199   op (&h->m_table.m_entries, cookie);
 200 }
 201
 202 #endif