--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/objc/objc-map.h	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,309 @@
+/* objc-map.h -- Implementation of map data structures for ObjC compiler
+   Copyright (C) 2011-2017 Free Software Foundation, Inc.
+   Written by Nicola Pero <nicola.pero@meta-innovation.com>
+
+This program is free software; you can redistribute it and/or modify it
+under the terms of the GNU Lesser Public License as published by the
+Free Software Foundation; either version 3, or (at your option) any
+later version.
+
+This program 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 Lesser Public License for more details.
+
+You should have received a copy of the GNU Lesser Public License
+along with this program; if not, write to the Free Software
+Foundation, 51 Franklin Street - Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+#ifndef OBJC_MAP_H
+#define OBJC_MAP_H
+
+/* A map is a data structure that maps a key to a value.  In this file
+   we currently have maps that can map a GCC identifier (a tree) to
+   some other GCC tree.  This is what the ObjC frontend mostly needs:
+   being able to look up an identifier into an ObjC data structure.  A
+   typical usage is mapping ObjC class names (as identifiers) to a
+   tree representing the class.
+
+   This implementation is fast.  :-) */
+
+/**
+ ** Private definitions.
+ **/
+
+/* We include private declaration and definitions that are required to
+   provide the implementation of inline functions.  You should ignore
+   these definitions (and the implementation of the inline functions)
+   as they are not part of the public API and may change.  */
+typedef unsigned int objc_map_private_hash_t;
+
+/* This is used as sentinel.  */
+#define OBJC_MAP_PRIVATE_EMPTY_SLOT (tree)0
+
+struct GTY(()) objc_map_private {
+  /* Total number of slots.  This is the maximum number of elements
+     that can be currently stored in the map before resizing.  This is
+     the number of slots in the C array.  Important: this is
+     guaranteed to be a power of 2.  When we create (or resize) the
+     map, we round up the size to the next power of 2.  This allows us
+     to convert a hash to a position in the hashtable by simply doing
+     "position = hash & mask", where mask is number_of_slots - 1
+     instead of using a modulo (which requires a division).  */
+  size_t number_of_slots;
+
+  /* This is number_of_slots - 1, precomputed.  */
+  size_t mask;
+
+  /* Number of slots that are not empty (ie, that are active).  We
+     keep counts using this variable which can easily be checked
+     against max_number_of_non_empty_slots.  */
+  size_t number_of_non_empty_slots;
+
+  /* This is the load factor limit.  When the number of non empty
+     slots equals this number, we need to resize the array.  This is
+     calculated once, when the slots are resized, and then kept cached
+     so it can be compared quickly when elements are added.  */
+  size_t max_number_of_non_empty_slots;
+
+  /* The maximum load factor.  */
+  int maximum_load_factor;
+
+  /* These are the keys.  */
+  tree * GTY ((length ("%h.number_of_slots"))) slots;
+
+  /* These are the values.  values[i] is the value corresponding
+     to slots[i].  */
+  tree * GTY ((length ("%h.number_of_slots"))) values;
+};
+
+/* Private functions used to resize the map.  They may be called by
+   the inline functions when adding elements.  */
+extern void
+objc_map_private_grow (struct objc_map_private *map);
+
+
+/**
+ ** The definition of a map.
+ **/
+typedef struct objc_map_private *objc_map_t;
+
+
+/**
+ ** Creating a map.
+ **/
+
+/* objc_map_alloc_ggc() creates a new map which is under GGC.  The initial
+   capacity must be specified as an argument; this is used to size the map
+   when it is created.  */
+objc_map_t objc_map_alloc_ggc (size_t initial_capacity);
+
+/**
+ ** Performance tuning.
+ **/
+
+/* Set a maximum load factor for the data structure.  This is the main
+   tuning parameter to improve performance (at the expense of
+   memory).  */
+void objc_map_set_maximum_load_factor (objc_map_t map, int number_between_zero_and_one_hundred);
+
+/* Read the maximum load factor.  */
+int objc_map_maximum_load_factor (objc_map_t map);
+
+
+/**
+ ** Getting the value corresponding to a key.
+ **/
+
+/* This is the value returned by objc_map_get() when the value
+   corresponding to a key is not found.  */
+#define OBJC_MAP_NOT_FOUND (tree)1
+
+/* objc_map_get() returns the value associated with a certain key,
+   or OBJC_MAP_NOT_FOUND if there is no value associated with that key.
+   Note that you can also use it to simply check if the map contains a
+   pair with a certain key; just compare the result of calling
+   objc_map_get() to OBJC_MAP_NOT_FOUND.
+
+   It is essential to always check the results of the call to make
+   sure it is not OBJC_MAP_NOT_FOUND.
+
+   NULL is a valid value, so a key can be inserted into a map with
+   value NULL, and objc_map_get() will return NULL in that case.
+   So a result of NULL means that they key *was* found, and the value
+   associated with it was NULL.  */
+static inline tree
+objc_map_get (objc_map_t map, /* struct tree_identifier * */tree key)
+{
+  /* The inline implementation is private and may change without notice.  */
+  objc_map_private_hash_t hash = IDENTIFIER_HASH_VALUE (key);
+  size_t i = hash & map->mask;
+  size_t j = 1;
+
+  if (map->slots[i] == OBJC_MAP_PRIVATE_EMPTY_SLOT)
+    return OBJC_MAP_NOT_FOUND;
+
+  if (map->slots[i] == key)
+    return map->values[i];
+  
+  while (1)
+    {
+      i = (i + j) & map->mask;
+      
+      if (map->slots[i] == OBJC_MAP_PRIVATE_EMPTY_SLOT)
+	return OBJC_MAP_NOT_FOUND;
+      
+      if (map->slots[i] == key)
+	return map->values[i];
+
+      j++;
+    }
+}
+
+/* objc_map_put() puts a key/value pair into the map.  If the map does
+   not contain the key, it is added to it with the specified value.
+   If the map already contains the key, the previous value is replaced
+   with the new one.
+
+   You can use any identifier as key, with the exception of NULL.
+
+   You can use any tree as value, including NULL.  */
+static inline
+void objc_map_put (objc_map_t map, /*struct tree_identifier * */tree key, tree value)
+{
+  /* The inline implementation is private and may change without notice.  */
+  objc_map_private_hash_t hash = IDENTIFIER_HASH_VALUE (key);
+  size_t i, j = 0;
+
+  if (map->number_of_non_empty_slots == map->max_number_of_non_empty_slots)
+    objc_map_private_grow (map);
+
+  i = hash & map->mask;
+    
+  while (1)
+    {
+      if (map->slots[i] == OBJC_MAP_PRIVATE_EMPTY_SLOT)
+	{
+	  map->number_of_non_empty_slots++;
+	  map->slots[i] = key;
+	  map->values[i] = value;
+	  return;
+	}
+      if (map->slots[i] == key)
+	{
+	  map->values[i] = value;
+	  return;
+	}
+
+      j++;
+      i = (i + j) & map->mask;
+    }
+}
+
+/**
+ ** Iterating over a map using an iterator.
+ **/
+
+/* When using iterators you can iterate directly on the elements in
+   the map, and take an action over each one.
+
+   Here is how you iterate over a hmap_pointer using iterators:
+
+   objc_map_iterator_t i;
+
+   objc_map_iterator_initialize (map, &i);
+
+   while (objc_map_iterator_move_to_next (map, &i))
+     {
+       tree p = objc_map_iterator_current_key (map, i);
+       tree q = objc_map_iterator_current_value (map, i);
+
+       ... do something with p and q ...
+     }
+
+   You'll notice that the functions that modify the iterator (to
+   initialize it, or move it to the next element) take a pointer to it
+   as argument (as in "&i"), while the functions that only read its
+   state (to read the current key/value, or remove the current
+   key/value from the map) take it as a direct argument (as in "i").
+
+   Note that all the objc_map_iterator_*() functions are inline and if
+   you follow the pattern above, the compiler should be able to inline
+   everything into a very efficient loop, roughly equivalent to
+   hand-writing a C loop that iterates directly onto the hmap_pointer
+   internal data structures.  */
+
+/* A objc_map_iterator_t variable encapsulates the state of an
+   iteration.  The fact that this is actually a size_t (pointing to
+   the index of the slot that we return next) is an internal, private
+   detail of the implementation and may change without notice.  */
+typedef size_t objc_map_iterator_t;
+
+/* Initialize an iterator to iterate over the specified objc_map.  You
+   must use this before starting the iteration, to get a working
+   iterator.  */
+static inline
+void
+objc_map_iterator_initialize (objc_map_t map ATTRIBUTE_UNUSED, objc_map_iterator_t *i)
+{
+  /* The inline implementation is private and may change without notice.  */
+  /* This is trivial, but the same API would work to initialize more
+     complicated iterators.  */
+  *i = 0;
+}
+
+#define OBJC_MAP_FAILURE 0
+#define OBJC_MAP_SUCCESS 1
+
+/* Move the iterator to the next key/value pair, and return
+   OBJC_MAP_SUCCESS if there is such a key/value pair, and
+   OBJC_MAP_FAILURE if there are no more ones.  The iterator must have
+   been initialized using objc_map_iterator_initialize().  Note that
+   because this function is modifying the iterator, you need to pass a
+   pointer to it.  */
+static inline
+int
+objc_map_iterator_move_to_next (objc_map_t map, objc_map_iterator_t *i)
+{
+  /* The inline implementation is private and may change without notice.  */
+  while (1)
+    {
+      void *slot;
+      if (*i == map->number_of_slots)
+	return OBJC_MAP_FAILURE;
+      
+      slot = map->slots[*i];
+      *i = *i + 1;
+      if (slot != OBJC_MAP_PRIVATE_EMPTY_SLOT)
+	return OBJC_MAP_SUCCESS;
+    }
+}
+
+/* Return the current key.  You can only call it after you have called
+   objc_map_iterator_move_to_next() at least once (to move to the
+   first element), and only if the last call returned
+   OBJC_MAP_SUCCESS.  The behavior is otherwise undefined, probably a
+   segmentation fault.  */
+static inline
+tree
+objc_map_iterator_current_key (objc_map_t map, objc_map_iterator_t i)
+{
+  /* The inline implementation is private and may change without notice.  */
+  return map->slots[i - 1];
+}
+
+/* Return the current value.  You can only call it after you have
+   called objc_map_iterator_move_to_next() at least once (to move to
+   the first element), and only if the last call returned
+   OBJC_MAP_SUCCESS.  The behavior is otherwise undefined, probably a
+   segmentation fault.  */
+static inline
+tree
+objc_map_iterator_current_value (objc_map_t map, objc_map_iterator_t i)
+{
+  /* The inline implementation is private and may change without notice.  */
+  return map->values[i - 1];
+}
+
+#endif /* OBJC_MAP_H */