libobjc/objc-foreach.c

   1 /* GNU Objective C Runtime 'fast enumeration' implementation
   2    Copyright (C) 2010-2017 Free Software Foundation, Inc.
   3    Contributed by Nicola Pero <nicola.pero@meta-innovation.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under the
   8 terms of the GNU General Public License as published by the Free Software
   9 Foundation; either version 3, or (at your option) any later 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 FITNESS
  13 FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  14 details.
  15
  16 Under Section 7 of GPL version 3, you are granted additional
  17 permissions described in the GCC Runtime Library Exception, version
  18 3.1, as published by the Free Software Foundation.
  19
  20 You should have received a copy of the GNU General Public License and
  21 a copy of the GCC Runtime Library Exception along with this program;
  22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 <http://www.gnu.org/licenses/>.  */
  24
  25 /* This file implements objc_enumeration_mutation() and
  26    objc_set_enumeration_mutation_handler(), the two functions required
  27    to handle mutations during a fast enumeration.  */
  28 #include "objc-private/common.h"
  29 #include "objc-private/error.h"     /* For _objc_abort() */
  30 #include "objc/runtime.h"           /* For objc_enumerationMutation() and objc_set_enumeration_mutation_handler() */
  31
  32 /* The enumeration mutation handler currently in use.  */
  33 static void (*__objc_enumeration_mutation_handler)(id) = NULL;
  34
  35 void
  36 objc_setEnumerationMutationHandler (void (*handler)(id))
  37 {
  38   __objc_enumeration_mutation_handler = handler;
  39 }
  40
  41 void
  42 objc_enumerationMutation (id collection)
  43 {
  44   if (__objc_enumeration_mutation_handler != NULL)
  45     (*__objc_enumeration_mutation_handler) (collection);
  46
  47   /* We always abort if we get here; there is no point in going on as
  48      the next iteration in the fast enumeration would probably go
  49      deeply wrong.  */
  50   _objc_abort ("Collection %p mutated during fast enumeration", collection);
  51 }