1# fdatasync.m4 serial 5
2dnl Copyright (C) 2008-2021 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7AC_DEFUN([gl_FUNC_FDATASYNC],
8[
9  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
10  AC_REQUIRE([AC_CANONICAL_HOST])
11
12  dnl Using AC_CHECK_FUNCS_ONCE would break our subsequent AC_SEARCH_LIBS
13  AC_CHECK_DECLS_ONCE([fdatasync])
14  LIB_FDATASYNC=
15  AC_SUBST([LIB_FDATASYNC])
16
17  if test $ac_cv_have_decl_fdatasync = no; then
18    HAVE_DECL_FDATASYNC=0
19    dnl Mac OS X 10.7 has fdatasync but does not declare it.
20    AC_CHECK_FUNCS([fdatasync])
21    if test $ac_cv_func_fdatasync = no; then
22      HAVE_FDATASYNC=0
23    fi
24  else
25    case "$host_os" in
26      solaris*)
27        dnl Solaris <= 2.6 has fdatasync() in libposix4.
28        dnl Solaris 7..10 has it in librt.
29        gl_saved_libs=$LIBS
30        AC_SEARCH_LIBS([fdatasync], [rt posix4],
31          [test "$ac_cv_search_fdatasync" = "none required" ||
32           LIB_FDATASYNC=$ac_cv_search_fdatasync])
33        LIBS=$gl_saved_libs
34        ;;
35      *)
36        dnl Android 4.3 does not have fdatasync but declares it.
37        AC_CHECK_FUNCS([fdatasync])
38        if test $ac_cv_func_fdatasync = no; then
39          HAVE_FDATASYNC=0
40        fi
41        ;;
42    esac
43  fi
44])
45