lib/qsort_r.c

   1 /* Reentrant sort function.
   2
   3    Copyright 2014-2021 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License along
  16    with this program; if not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Paul Eggert.  */
  19
  20 #include <config.h>
  21
  22 #include <stdlib.h>
  23
  24 /* This file is compiled only when the system has a qsort_r that needs
  25    to be replaced because it has the BSD signature rather than the GNU
  26    signature.  */
  27
  28 struct thunk
  29 {
  30   int (*cmp) (void const *, void const *, void *);
  31   void *arg;
  32 };
  33
  34 static int
  35 thunk_cmp (void *thunk, void const *a, void const *b)
  36 {
  37   struct thunk *th = thunk;
  38   return th->cmp (a, b, th->arg);
  39 }
  40
  41 void
  42 qsort_r (void *base, size_t nmemb, size_t size,
  43          int (*cmp) (void const *, void const *, void *),
  44          void *arg)
  45 {
  46 # undef qsort_r
  47   struct thunk thunk;
  48   thunk.cmp = cmp;
  49   thunk.arg = arg;
  50   qsort_r (base, nmemb, size, &thunk, thunk_cmp);
  51 }