sdcc/support/cpp/gcc/hash-set.h

   1 /* A type-safe hash set.
   2    Copyright (C) 2014-2022 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 #include "hash-table.h" // sdcpp
  25 #include "hash-traits.h" // sdcpp
  26
  27 /* Class hash_set is a hash-value based container for objects of
  28    KeyId type.
  29    KeyId may be a non-trivial (non-POD) type provided a suitabe Traits
  30    class.  Default Traits specializations are provided for basic types
  31    such as integers, pointers, and std::pair.  Inserted elements are
  32    value-initialized either to zero for POD types or by invoking their
  33    default ctor.  Removed elements are destroyed by invoking their dtor.
  34    On hash_set destruction all elements are removed.  Objects of
  35    hash_set type are copy-constructible but not assignable.  */
  36
  37 template<typename KeyId, bool Lazy = false,
  38          typename Traits = default_hash_traits<KeyId> >
  39 class hash_set
  40 {
  41 public:
  42   typedef typename Traits::value_type Key;
  43   explicit hash_set (size_t n = 13, bool ggc = false CXX_MEM_STAT_INFO)
  44     : m_table (n, ggc, true, GATHER_STATISTICS, HASH_SET_ORIGIN PASS_MEM_STAT) {}
  45
  46   /* Create a hash_set in gc memory with space for at least n elements.  */
  47
  48   static hash_set *
  49   create_ggc (size_t n)
  50     {
  51       hash_set *set = ggc_alloc<hash_set> ();
  52       new (set) hash_set (n, true);
  53       return set;
  54     }
  55
  56   /* If key k isn't already in the map add it to the map, and
  57      return false.  Otherwise return true.  */
  58
  59   bool add (const Key &k)
  60     {
  61       Key *e = m_table.find_slot_with_hash (k, Traits::hash (k), INSERT);
  62       bool existed = !Traits::is_empty (*e);
  63       if (!existed)
  64         new (e) Key (k);
  65
  66       return existed;
  67     }
  68
  69   /* if the passed in key is in the map return its value otherwise NULL.  */
  70
  71   bool contains (const Key &k)
  72     {
  73       if (Lazy)
  74         return (m_table.find_slot_with_hash (k, Traits::hash (k), NO_INSERT)
  75                 != NULL);
  76       Key &e = m_table.find_with_hash (k, Traits::hash (k));
  77       return !Traits::is_empty (e);
  78     }
  79
  80   void remove (const Key &k)
  81     {
  82       m_table.remove_elt_with_hash (k, Traits::hash (k));
  83     }
  84
  85   /* Call the call back on each pair of key and value with the passed in
  86      arg.  */
  87
  88   template<typename Arg, bool (*f)(const typename Traits::value_type &, Arg)>
  89   void traverse (Arg a) const
  90     {
  91       for (typename hash_table<Traits, Lazy>::iterator iter = m_table.begin ();
  92            iter != m_table.end (); ++iter)
  93         f (*iter, a);
  94     }
  95
  96   /* Return the number of elements in the set.  */
  97
  98   size_t elements () const { return m_table.elements (); }
  99
 100   /* Clear the hash table.  */
 101
 102   void empty () { m_table.empty (); }
 103
 104   /* Return true when there are no elements in this hash set.  */
 105   bool is_empty () const { return m_table.is_empty (); }
 106
 107   class iterator
 108   {
 109   public:
 110     explicit iterator (const typename hash_table<Traits,
 111                                                  Lazy>::iterator &iter) :
 112       m_iter (iter) {}
 113
 114     iterator &operator++ ()
 115       {
 116         ++m_iter;
 117         return *this;
 118       }
 119
 120     Key
 121     operator* ()
 122       {
 123         return *m_iter;
 124       }
 125
 126     bool
 127     operator != (const iterator &other) const
 128       {
 129         return m_iter != other.m_iter;
 130       }
 131
 132   private:
 133     typename hash_table<Traits, Lazy>::iterator m_iter;
 134   };
 135
 136   /* Standard iterator retrieval methods.  */
 137
 138   iterator begin () const { return iterator (m_table.begin ()); }
 139   iterator end () const { return iterator (m_table.end ()); }
 140
 141
 142 private:
 143
 144   template<typename T, typename U>
 145   friend void gt_ggc_mx (hash_set<T, false, U> *);
 146   template<typename T, typename U>
 147   friend void gt_pch_nx (hash_set<T, false, U> *);
 148   template<typename T, typename U>
 149   friend void gt_pch_nx (hash_set<T, false, U> *, gt_pointer_operator, void *);
 150
 151   hash_table<Traits, Lazy> m_table;
 152 };
 153
 154 /* Generic hash_set<TYPE> debug helper.
 155
 156    This needs to be instantiated for each hash_set<TYPE> used throughout
 157    the compiler like this:
 158
 159     DEFINE_DEBUG_HASH_SET (TYPE)
 160
 161    The reason we have a debug_helper() is because GDB can't
 162    disambiguate a plain call to debug(some_hash), and it must be called
 163    like debug<TYPE>(some_hash).  */
 164 template<typename T>
 165 void
 166 debug_helper (hash_set<T> &ref)
 167 {
 168   for (typename hash_set<T>::iterator it = ref.begin ();
 169        it != ref.end (); ++it)
 170     {
 171       debug_slim (*it);
 172       fputc ('\n', stderr);
 173     }
 174 }
 175
 176 #define DEFINE_DEBUG_HASH_SET(T) \
 177   template void debug_helper (hash_set<T> &);           \
 178   DEBUG_FUNCTION void                                   \
 179   debug (hash_set<T> &ref)                              \
 180   {                                                     \
 181     debug_helper <T> (ref);                             \
 182   }                                                     \
 183   DEBUG_FUNCTION void                                   \
 184   debug (hash_set<T> *ptr)                              \
 185   {                                                     \
 186     if (ptr)                                            \
 187       debug (*ptr);                                     \
 188     else                                                \
 189       fprintf (stderr, "<nil>\n");                      \
 190   }
 191
 192 /* ggc marking routines.  */
 193
 194 template<typename K, typename H>
 195 static inline void
 196 gt_ggc_mx (hash_set<K, false, H> *h)
 197 {
 198   gt_ggc_mx (&h->m_table);
 199 }
 200
 201 template<typename K, typename H>
 202 static inline void
 203 gt_pch_nx (hash_set<K, false, H> *h)
 204 {
 205   gt_pch_nx (&h->m_table);
 206 }
 207
 208 template<typename K, typename H>
 209 static inline void
 210 gt_pch_nx (hash_set<K, false, H> *h, gt_pointer_operator op, void *cookie)
 211 {
 212   op (&h->m_table.m_entries, NULL, cookie);
 213 }
 214
 215 #endif