xref: /dragonfly/contrib/gcc-8.0/gcc/hash-set.h (revision 8bf5b238)
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)
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
192