# tsearch.m4 serial 6

dnl Copyright (C) 2006-2017 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_TSEARCH],

[

  AC_REQUIRE([gl_SEARCH_H_DEFAULTS])

  AC_CHECK_FUNCS([tsearch])

  if test $ac_cv_func_tsearch = yes; then

    dnl On OpenBSD 4.0, the return value of tdelete() is incorrect.

    AC_REQUIRE([AC_PROG_CC])

    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

    AC_CACHE_CHECK([whether tdelete works], [gl_cv_func_tdelete_works],

      [

        AC_RUN_IFELSE([AC_LANG_SOURCE([[

#include <stddef.h>

#include <search.h>

static int

cmp_fn (const void *a, const void *b)

{

  return *(const int *) a - *(const int *) b;

}

int

main ()

{

  int result = 0;

  int x = 0;

  void *root = NULL;

  if (!(tfind (&x, &root, cmp_fn) == NULL))

    result |= 1;

  tsearch (&x, &root, cmp_fn);

  if (!(tfind (&x, &root, cmp_fn) != NULL))

    result |= 2;

  if (!(tdelete (&x, &root, cmp_fn) != NULL))

    result |= 4;

  return result;

}]])], [gl_cv_func_tdelete_works=yes], [gl_cv_func_tdelete_works=no],

            [case "$host_os" in

               openbsd*) gl_cv_func_tdelete_works="guessing no";;

               *)        gl_cv_func_tdelete_works="guessing yes";;

             esac

            ])

      ])

    case "$gl_cv_func_tdelete_works" in

      *no)

        REPLACE_TSEARCH=1

        ;;

    esac

  else

    HAVE_TSEARCH=0

  fi

])

# Prerequisites of lib/tsearch.c.

AC_DEFUN([gl_PREREQ_TSEARCH], [

  :

])