gdb: add target_ops::supports_displaced_step
[deliverable/binutils-gdb.git] / libiberty / splay-tree.c
index d7ed86813dc553007827b3208590e8e9ffff9b0a..3b7b810388ce67b15b419cfb7d165f03b7552890 100644 (file)
@@ -1,5 +1,5 @@
 /* A splay-tree datatype.  
-   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1998-2020 Free Software Foundation, Inc.
    Contributed by Mark Mitchell (mark@markmitchell.com).
 
 This file is part of GNU CC.
@@ -31,6 +31,9 @@ Boston, MA 02110-1301, USA.  */
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h>
 #endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
 
 #include <stdio.h>
 
@@ -43,7 +46,7 @@ static inline void rotate_left (splay_tree_node *,
 static inline void rotate_right (splay_tree_node *,
                                splay_tree_node, splay_tree_node);
 static void splay_tree_splay (splay_tree, splay_tree_key);
-static int splay_tree_foreach_helper (splay_tree, splay_tree_node,
+static int splay_tree_foreach_helper (splay_tree_node,
                                       splay_tree_foreach_fn, void*);
 
 /* Deallocate NODE (a member of SP), and all its sub-trees.  */
@@ -203,25 +206,51 @@ splay_tree_splay (splay_tree sp, splay_tree_key key)
    value is returned.  Otherwise, this function returns 0.  */
 
 static int
-splay_tree_foreach_helper (splay_tree sp, splay_tree_node node,
+splay_tree_foreach_helper (splay_tree_node node,
                            splay_tree_foreach_fn fn, void *data)
 {
   int val;
+  splay_tree_node *stack;
+  int stack_ptr, stack_size;
 
-  if (!node)
-    return 0;
+  /* A non-recursive implementation is used to avoid filling the stack
+     for large trees.  Splay trees are worst case O(n) in the depth of
+     the tree.  */
+
+#define INITIAL_STACK_SIZE 100
+  stack_size = INITIAL_STACK_SIZE;
+  stack_ptr = 0;
+  stack = XNEWVEC (splay_tree_node, stack_size);
+  val = 0;
+
+  for (;;)
+    {
+      while (node != NULL)
+       {
+         if (stack_ptr == stack_size)
+           {
+             stack_size *= 2;
+             stack = XRESIZEVEC (splay_tree_node, stack, stack_size);
+           }
+         stack[stack_ptr++] = node;
+         node = node->left;
+       }
 
-  val = splay_tree_foreach_helper (sp, node->left, fn, data);
-  if (val)
-    return val;
+      if (stack_ptr == 0)
+       break;
 
-  val = (*fn)(node, data);
-  if (val)
-    return val;
+      node = stack[--stack_ptr];
 
-  return splay_tree_foreach_helper (sp, node->right, fn, data);
-}
+      val = (*fn) (node, data);
+      if (val)
+       break;
+
+      node = node->right;
+    }
 
+  XDELETEVEC (stack);
+  return val;
+}
 
 /* An allocator and deallocator based on xmalloc.  */
 static void *
@@ -265,13 +294,57 @@ splay_tree_new_with_allocator (splay_tree_compare_fn compare_fn,
                                splay_tree_deallocate_fn deallocate_fn,
                                void *allocate_data)
 {
-  splay_tree sp = (splay_tree) (*allocate_fn) (sizeof (struct splay_tree_s),
-                                               allocate_data);
+  return
+    splay_tree_new_typed_alloc (compare_fn, delete_key_fn, delete_value_fn,
+                               allocate_fn, allocate_fn, deallocate_fn,
+                               allocate_data);
+}
+
+/*
+
+@deftypefn Supplemental splay_tree splay_tree_new_with_typed_alloc @
+(splay_tree_compare_fn @var{compare_fn}, @
+splay_tree_delete_key_fn @var{delete_key_fn}, @
+splay_tree_delete_value_fn @var{delete_value_fn}, @
+splay_tree_allocate_fn @var{tree_allocate_fn}, @
+splay_tree_allocate_fn @var{node_allocate_fn}, @
+splay_tree_deallocate_fn @var{deallocate_fn}, @
+void * @var{allocate_data})
+
+This function creates a splay tree that uses two different allocators
+@var{tree_allocate_fn} and @var{node_allocate_fn} to use for allocating the
+tree itself and its nodes respectively.  This is useful when variables of
+different types need to be allocated with different allocators.
+
+The splay tree will use @var{compare_fn} to compare nodes,
+@var{delete_key_fn} to deallocate keys, and @var{delete_value_fn} to
+deallocate values.  Keys and values will be deallocated when the
+tree is deleted using splay_tree_delete or when a node is removed
+using splay_tree_remove.  splay_tree_insert will release the previously
+inserted key and value using @var{delete_key_fn} and @var{delete_value_fn}
+if the inserted key is already found in the tree.
+
+@end deftypefn
+
+*/
+
+splay_tree
+splay_tree_new_typed_alloc (splay_tree_compare_fn compare_fn,
+                           splay_tree_delete_key_fn delete_key_fn,
+                           splay_tree_delete_value_fn delete_value_fn,
+                           splay_tree_allocate_fn tree_allocate_fn,
+                           splay_tree_allocate_fn node_allocate_fn,
+                           splay_tree_deallocate_fn deallocate_fn,
+                           void * allocate_data)
+{
+  splay_tree sp = (splay_tree) (*tree_allocate_fn)
+    (sizeof (struct splay_tree_s), allocate_data);
+
   sp->root = 0;
   sp->comp = compare_fn;
   sp->delete_key = delete_key_fn;
   sp->delete_value = delete_value_fn;
-  sp->allocate = allocate_fn;
+  sp->allocate = node_allocate_fn;
   sp->deallocate = deallocate_fn;
   sp->allocate_data = allocate_data;
 
@@ -303,20 +376,23 @@ splay_tree_insert (splay_tree sp, splay_tree_key key, splay_tree_value value)
 
   if (sp->root && comparison == 0)
     {
-      /* If the root of the tree already has the indicated KEY, just
-        replace the value with VALUE.  */
+      /* If the root of the tree already has the indicated KEY, delete
+         the old key and old value, and replace them with KEY and  VALUE.  */
+      if (sp->delete_key)
+       (*sp->delete_key) (sp->root->key);
       if (sp->delete_value)
        (*sp->delete_value)(sp->root->value);
+      sp->root->key = key;
       sp->root->value = value;
     } 
   else 
     {
       /* Create a new node, and insert it at the root.  */
       splay_tree_node node;
-      
+
       node = ((splay_tree_node)
-              (*sp->allocate) (sizeof (struct splay_tree_node_s),
-                               sp->allocate_data));
+             (*sp->allocate) (sizeof (struct splay_tree_node_s),
+                              sp->allocate_data));
       node->key = key;
       node->value = value;
       
@@ -356,6 +432,8 @@ splay_tree_remove (splay_tree sp, splay_tree_key key)
       right = sp->root->right;
 
       /* Delete the root node itself.  */
+      if (sp->delete_key)
+       (*sp->delete_key) (sp->root->key);
       if (sp->delete_value)
        (*sp->delete_value) (sp->root->value);
       (*sp->deallocate) (sp->root, sp->allocate_data);
@@ -496,7 +574,7 @@ splay_tree_successor (splay_tree sp, splay_tree_key key)
 int
 splay_tree_foreach (splay_tree sp, splay_tree_foreach_fn fn, void *data)
 {
-  return splay_tree_foreach_helper (sp, sp->root, fn, data);
+  return splay_tree_foreach_helper (sp->root, fn, data);
 }
 
 /* Splay-tree comparison function, treating the keys as ints.  */
@@ -524,3 +602,19 @@ splay_tree_compare_pointers (splay_tree_key k1, splay_tree_key k2)
   else 
     return 0;
 }
+
+/* Splay-tree comparison function, treating the keys as strings.  */
+
+int
+splay_tree_compare_strings (splay_tree_key k1, splay_tree_key k2)
+{
+  return strcmp ((char *) k1, (char *) k2);
+}
+
+/* Splay-tree delete function, simply using free.  */
+
+void
+splay_tree_delete_pointers (splay_tree_value value)
+{
+  free ((void *) value);
+}
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