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/* A type-safe hash set.
Copyright (C) 2014-2022 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#ifndef hash_set_h
#define hash_set_h
/* Class hash_set is a hash-value based container for objects of
KeyId type.
KeyId may be a non-trivial (non-POD) type provided a suitabe Traits
class. Default Traits specializations are provided for basic types
such as integers, pointers, and std::pair. Inserted elements are
value-initialized either to zero for POD types or by invoking their
default ctor. Removed elements are destroyed by invoking their dtor.
On hash_set destruction all elements are removed. Objects of
hash_set type are copy-constructible but not assignable. */
template<typename KeyId, bool Lazy = false,
typename Traits = default_hash_traits<KeyId> >
class hash_set
{
public:
typedef typename Traits::value_type Key;
explicit hash_set (size_t n = 13, bool ggc = false CXX_MEM_STAT_INFO)
: m_table (n, ggc, true, GATHER_STATISTICS, HASH_SET_ORIGIN PASS_MEM_STAT) {}
/* Create a hash_set in gc memory with space for at least n elements. */
static hash_set *
create_ggc (size_t n)
{
hash_set *set = ggc_alloc<hash_set> ();
new (set) hash_set (n, true);
return set;
}
/* If key k isn't already in the map add it to the map, and
return false. Otherwise return true. */
bool add (const Key &k)
{
Key *e = m_table.find_slot_with_hash (k, Traits::hash (k), INSERT);
bool existed = !Traits::is_empty (*e);
if (!existed)
new (e) Key (k);
return existed;
}
/* if the passed in key is in the map return its value otherwise NULL. */
bool contains (const Key &k)
{
if (Lazy)
return (m_table.find_slot_with_hash (k, Traits::hash (k), NO_INSERT)
!= NULL);
Key &e = m_table.find_with_hash (k, Traits::hash (k));
return !Traits::is_empty (e);
}
void remove (const Key &k)
{
m_table.remove_elt_with_hash (k, Traits::hash (k));
}
/* Call the call back on each pair of key and value with the passed in
arg. */
template<typename Arg, bool (*f)(const typename Traits::value_type &, Arg)>
void traverse (Arg a) const
{
for (typename hash_table<Traits, Lazy>::iterator iter = m_table.begin ();
iter != m_table.end (); ++iter)
f (*iter, a);
}
/* Return the number of elements in the set. */
size_t elements () const { return m_table.elements (); }
/* Clear the hash table. */
void empty () { m_table.empty (); }
/* Return true when there are no elements in this hash set. */
bool is_empty () const { return m_table.is_empty (); }
class iterator
{
public:
explicit iterator (const typename hash_table<Traits,
Lazy>::iterator &iter) :
m_iter (iter) {}
iterator &operator++ ()
{
++m_iter;
return *this;
}
Key
operator* ()
{
return *m_iter;
}
bool
operator != (const iterator &other) const
{
return m_iter != other.m_iter;
}
private:
typename hash_table<Traits, Lazy>::iterator m_iter;
};
/* Standard iterator retrieval methods. */
iterator begin () const { return iterator (m_table.begin ()); }
iterator end () const { return iterator (m_table.end ()); }
private:
template<typename T, typename U>
friend void gt_ggc_mx (hash_set<T, false, U> *);
template<typename T, typename U>
friend void gt_pch_nx (hash_set<T, false, U> *);
template<typename T, typename U>
friend void gt_pch_nx (hash_set<T, false, U> *, gt_pointer_operator, void *);
hash_table<Traits, Lazy> m_table;
};
/* Generic hash_set<TYPE> debug helper.
This needs to be instantiated for each hash_set<TYPE> used throughout
the compiler like this:
DEFINE_DEBUG_HASH_SET (TYPE)
The reason we have a debug_helper() is because GDB can't
disambiguate a plain call to debug(some_hash), and it must be called
like debug<TYPE>(some_hash). */
template<typename T>
void
debug_helper (hash_set<T> &ref)
{
for (typename hash_set<T>::iterator it = ref.begin ();
it != ref.end (); ++it)
{
debug_slim (*it);
fputc ('\n', stderr);
}
}
#define DEFINE_DEBUG_HASH_SET(T) \
template void debug_helper (hash_set<T> &); \
DEBUG_FUNCTION void \
debug (hash_set<T> &ref) \
{ \
debug_helper <T> (ref); \
} \
DEBUG_FUNCTION void \
debug (hash_set<T> *ptr) \
{ \
if (ptr) \
debug (*ptr); \
else \
fprintf (stderr, "<nil>\n"); \
}
/* ggc marking routines. */
template<typename K, typename H>
static inline void
gt_ggc_mx (hash_set<K, false, H> *h)
{
gt_ggc_mx (&h->m_table);
}
template<typename K, typename H>
static inline void
gt_pch_nx (hash_set<K, false, H> *h)
{
gt_pch_nx (&h->m_table);
}
template<typename K, typename H>
static inline void
gt_pch_nx (hash_set<K, false, H> *h, gt_pointer_operator op, void *cookie)
{
op (&h->m_table.m_entries, NULL, cookie);
}
#endif