Assume Autoconf >= 2.63.

* DEPENDENCIES: Mention the requirement.

* gnulib-tool (DEFAULT_AUTOCONF_MINVERSION): Bump to 2.63.
(func_get_filelist): Don't list m4/onceonly.m4 any more.
* pygnulib/GLModuleSystem.py (getFiles): Likewise.
* m4/onceonly.m4: Remove file.

* m4/openmp.m4: Remove file.
* modules/openmp (Files): Remove m4/openmp.m4.

* m4/configmake.m4 (gl_CONFIGMAKE_PREP): Don't set datarootdir, docdir,
htmldir, dvidir, pdfdir, psdir, localedir.
* m4/po.m4 (AM_PO_SUBDIRS): Don't set localedir.

* m4/gnulib-common.m4 (m4_foreach_w): Remove fallback for
Autoconf < 2.60.
(AC_PROG_MKDIR_P): Remove definition for Autoconf < 2.62.
(AC_PROG_SED): Remove fallback for Autoconf < 2.60.

* m4/errno_h.m4 (AC_COMPUTE_INT): Remove fallback for Autoconf < 2.61.
* m4/size_max.m4 (AC_COMPUTE_INT): Likewise.
* m4/stdint.m4 (AC_COMPUTE_INT): Likewise.

* m4/fcntl-o.m4 (gl_FCNTL_O_FLAGS): Assume AC_USE_SYSTEM_EXTENSIONS
exists.
* m4/threadlib.m4 (gl_THREADLIB_EARLY_BODY): Likewise,

* m4/lib-link.m4 (AC_LIB_LINKFLAGS_BODY): Remove workaround for
Autoconf < 2.61.

* m4/lib-prefix.m4 (AC_LIB_ARG_WITH): Remove macro.
(AC_LIB_PREFIX): Use AC_ARG_WITH, assuming semantics of
Autoconf >= 2.52.

* m4/longlong.m4: Require Autoconf >= 2.62. Update comments.
* m4/ls-mntd-fs.m4: Require Autoconf >= 2.60. Update comments.
* m4/gettext.m4 (AM_GNU_GETTEXT): Update comment.

20 files changed, 96 insertions, 419 deletions

diff --git a/ChangeLog b/ChangeLog
index 455e1ca407..7dbfd38102 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,46 @@
 2018-10-22  Bruno Haible  <bruno@clisp.org>
 
+	Assume Autoconf >= 2.63.
+	* DEPENDENCIES: Mention the requirement.
+
+	* gnulib-tool (DEFAULT_AUTOCONF_MINVERSION): Bump to 2.63.
+	(func_get_filelist): Don't list m4/onceonly.m4 any more.
+	* pygnulib/GLModuleSystem.py (getFiles): Likewise.
+	* m4/onceonly.m4: Remove file.
+
+	* m4/openmp.m4: Remove file.
+	* modules/openmp (Files): Remove m4/openmp.m4.
+
+	* m4/configmake.m4 (gl_CONFIGMAKE_PREP): Don't set datarootdir, docdir,
+	htmldir, dvidir, pdfdir, psdir, localedir.
+	* m4/po.m4 (AM_PO_SUBDIRS): Don't set localedir.
+
+	* m4/gnulib-common.m4 (m4_foreach_w): Remove fallback for
+	Autoconf < 2.60.
+	(AC_PROG_MKDIR_P): Remove definition for Autoconf < 2.62.
+	(AC_PROG_SED): Remove fallback for Autoconf < 2.60.
+
+	* m4/errno_h.m4 (AC_COMPUTE_INT): Remove fallback for Autoconf < 2.61.
+	* m4/size_max.m4 (AC_COMPUTE_INT): Likewise.
+	* m4/stdint.m4 (AC_COMPUTE_INT): Likewise.
+
+	* m4/fcntl-o.m4 (gl_FCNTL_O_FLAGS): Assume AC_USE_SYSTEM_EXTENSIONS
+	exists.
+	* m4/threadlib.m4 (gl_THREADLIB_EARLY_BODY): Likewise,
+
+	* m4/lib-link.m4 (AC_LIB_LINKFLAGS_BODY): Remove workaround for
+	Autoconf < 2.61.
+
+	* m4/lib-prefix.m4 (AC_LIB_ARG_WITH): Remove macro.
+	(AC_LIB_PREFIX): Use AC_ARG_WITH, assuming semantics of
+	Autoconf >= 2.52.
+
+	* m4/longlong.m4: Require Autoconf >= 2.62. Update comments.
+	* m4/ls-mntd-fs.m4: Require Autoconf >= 2.60. Update comments.
+	* m4/gettext.m4 (AM_GNU_GETTEXT): Update comment.
+
+2018-10-22  Bruno Haible  <bruno@clisp.org>
+
 	Assume Automake >= 1.11.
 	* m4/configmake.m4: Update comments.
 	* m4/lib-link.m4 (AC_LIB_RPATH): Assume AC_REQUIRE_AUX_FILE exists.
diff --git a/DEPENDENCIES b/DEPENDENCIES
index f9b6aa0cf1..a7ca044eae 100644
--- a/DEPENDENCIES
+++ b/DEPENDENCIES
@@ -31,7 +31,7 @@ at any time.
   + Download:
     https://ftp.gnu.org/gnu/m4/
 
-* Autoconf 2.60 or newer.
+* Autoconf 2.63 or newer.
   + Mandatory.
   + Homepage:
     https://www.gnu.org/software/autoconf/
diff --git a/gnulib-tool b/gnulib-tool
index 6ef8793615..498e4791e8 100755
--- a/gnulib-tool
+++ b/gnulib-tool
@@ -25,11 +25,11 @@ nl='
 '
 IFS=" ""	$nl"
 
-# You can set AUTOCONFPATH to empty if autoconf 2.57 is already in your PATH.
+# You can set AUTOCONFPATH to empty if autoconf 2.63 is already in your PATH.
 AUTOCONFPATH=
 #case $USER in
 #  bruno )
-#    AUTOCONFBINDIR=/packages/gnu-inst-autoconf/2.57/bin
+#    AUTOCONFBINDIR=/arch/x86-linux/gnu-inst-autoconf/2.63/bin
 #    AUTOCONFPATH="eval env PATH=${AUTOCONFBINDIR}:\$PATH "
 #    ;;
 #esac
@@ -1513,7 +1513,7 @@ func_determine_path_separator
 
   # Determine the minimum supported autoconf version from the project's
   # configure.ac.
-  DEFAULT_AUTOCONF_MINVERSION="2.59"
+  DEFAULT_AUTOCONF_MINVERSION="2.63"
   autoconf_minversion=
   configure_ac=
   if case "$mode" in import | add-import | remove-import | update) true;; *) false;; esac \
@@ -1560,8 +1560,8 @@ func_determine_path_separator
     autoconf_minversion=$DEFAULT_AUTOCONF_MINVERSION
   fi
   case "$autoconf_minversion" in
-    1.* | 2.[0-4]* | 2.5[0-8]*)
-      func_fatal_error "minimum supported autoconf version is 2.59. Try adding AC_PREREQ([$DEFAULT_AUTOCONF_MINVERSION]) to your configure.ac." ;;
+    1.* | 2.[0-5]* | 2.6[0-2]*)
+      func_fatal_error "minimum supported autoconf version is 2.63. Try adding AC_PREREQ([$DEFAULT_AUTOCONF_MINVERSION]) to your configure.ac." ;;
   esac
 
   # Remove trailing slashes from the directory names. This is necessary for
@@ -2240,11 +2240,6 @@ func_get_filelist ()
   fi
   echo m4/00gnulib.m4
   echo m4/gnulib-common.m4
-  case "$autoconf_minversion" in
-    2.59)
-      echo m4/onceonly.m4
-      ;;
-  esac
 }
 
 # func_filter_filelist outputvar separator filelist prefix suffix removed_prefix removed_suffix [added_prefix [added_suffix]]
diff --git a/m4/configmake.m4 b/m4/configmake.m4
index a4285f8add..78a96fd8f6 100644
--- a/m4/configmake.m4
+++ b/m4/configmake.m4
@@ -4,46 +4,19 @@ 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_PREREQ([2.60])
+
 # gl_CONFIGMAKE_PREP
 # ------------------
 # Guarantee all of the standard directory variables, even when used with
-# autoconf 2.59 (datarootdir wasn't supported until 2.59c, and runstatedir
-# in 2.70) or automake 1.11 (runstatedir isn't supported even in 1.16.1).
+# autoconf 2.63 (runstatedir wasn't supported before 2.70) or
+# automake 1.11 (runstatedir isn't supported even in 1.16.1).
 AC_DEFUN([gl_CONFIGMAKE_PREP],
 [
-  dnl Technically, datadir should default to datarootdir.  But if
-  dnl autoconf is too old to provide datarootdir, then reversing the
-  dnl definition is a reasonable compromise.  Only AC_SUBST a variable
-  dnl if it was not already defined earlier by autoconf.
-  if test "x$datarootdir" = x; then
-    AC_SUBST([datarootdir], ['${datadir}'])
-  fi
-  dnl Copy the approach used in autoconf 2.60.
-  if test "x$docdir" = x; then
-    AC_SUBST([docdir], [m4_ifset([AC_PACKAGE_TARNAME],
-      ['${datarootdir}/doc/${PACKAGE_TARNAME}'],
-      ['${datarootdir}/doc/${PACKAGE}'])])
-  fi
-  dnl The remaining variables missing from autoconf 2.59 are easier.
-  if test "x$htmldir" = x; then
-    AC_SUBST([htmldir], ['${docdir}'])
-  fi
-  if test "x$dvidir" = x; then
-    AC_SUBST([dvidir], ['${docdir}'])
-  fi
-  if test "x$pdfdir" = x; then
-    AC_SUBST([pdfdir], ['${docdir}'])
-  fi
-  if test "x$psdir" = x; then
-    AC_SUBST([psdir], ['${docdir}'])
-  fi
   if test "x$lispdir" = x; then
     AC_SUBST([lispdir], ['${datarootdir}/emacs/site-lisp'])
   fi
-  if test "x$localedir" = x; then
-    AC_SUBST([localedir], ['${datarootdir}/locale'])
-  fi
-  dnl Added in autoconf 2.70
+  dnl Added in autoconf 2.70.
   if test "x$runstatedir" = x; then
     AC_SUBST([runstatedir], ['${localstatedir}/run'])
   fi
diff --git a/m4/errno_h.m4 b/m4/errno_h.m4
index 9dbdedd505..e1ae295126 100644
--- a/m4/errno_h.m4
+++ b/m4/errno_h.m4
@@ -1,9 +1,11 @@
-# errno_h.m4 serial 12
+# errno_h.m4 serial 13
 dnl Copyright (C) 2004, 2006, 2008-2018 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_PREREQ([2.61])
+
 AC_DEFUN_ONCE([gl_HEADER_ERRNO_H],
 [
   AC_REQUIRE([AC_PROG_CC])
@@ -129,9 +131,3 @@ yes
     AC_SUBST($1[_VALUE])
   fi
 ])
-
-dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
-dnl Remove this when we can assume autoconf >= 2.61.
-m4_ifdef([AC_COMPUTE_INT], [], [
-  AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
-])
diff --git a/m4/fcntl-o.m4 b/m4/fcntl-o.m4
index 4dc3daa2fa..cffb9de176 100644
--- a/m4/fcntl-o.m4
+++ b/m4/fcntl-o.m4
@@ -1,4 +1,4 @@
-# fcntl-o.m4 serial 5
+# fcntl-o.m4 serial 6
 dnl Copyright (C) 2006, 2009-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -6,17 +6,15 @@ dnl with or without modifications, as long as this notice is preserved.
 
 dnl Written by Paul Eggert.
 
+AC_PREREQ([2.60])
+
 # Test whether the flags O_NOATIME and O_NOFOLLOW actually work.
 # Define HAVE_WORKING_O_NOATIME to 1 if O_NOATIME works, or to 0 otherwise.
 # Define HAVE_WORKING_O_NOFOLLOW to 1 if O_NOFOLLOW works, or to 0 otherwise.
 AC_DEFUN([gl_FCNTL_O_FLAGS],
 [
   dnl Persuade glibc <fcntl.h> to define O_NOATIME and O_NOFOLLOW.
-  dnl AC_USE_SYSTEM_EXTENSIONS was introduced in autoconf 2.60 and obsoletes
-  dnl AC_GNU_SOURCE.
-  m4_ifdef([AC_USE_SYSTEM_EXTENSIONS],
-    [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])],
-    [AC_REQUIRE([AC_GNU_SOURCE])])
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
 
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CHECK_HEADERS_ONCE([unistd.h])
diff --git a/m4/gettext.m4 b/m4/gettext.m4
index eef5073b32..a91c4dab5b 100644
--- a/m4/gettext.m4
+++ b/m4/gettext.m4
@@ -1,5 +1,5 @@
-# gettext.m4 serial 68 (gettext-0.19.8)
-dnl Copyright (C) 1995-2014, 2016 Free Software Foundation, Inc.
+# gettext.m4 serial 69 (gettext-0.19.9)
+dnl Copyright (C) 1995-2014, 2016, 2018 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.
@@ -91,8 +91,7 @@ AC_DEFUN([AM_GNU_GETTEXT],
   dnl again, outside any 'if'. There are two solutions:
   dnl - Invoke AM_ICONV_LINKFLAGS_BODY here, outside any 'if'.
   dnl - Control the expansions in more detail using AC_PROVIDE_IFELSE.
-  dnl Since AC_PROVIDE_IFELSE is only in autoconf >= 2.52 and not
-  dnl documented, we avoid it.
+  dnl Since AC_PROVIDE_IFELSE is not documented, we avoid it.
   ifelse(gt_included_intl, yes, , [
     AC_REQUIRE([AM_ICONV_LINKFLAGS_BODY])
   ])
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index 5f07855acf..1b8cdd567c 100644
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,9 +1,11 @@
-# gnulib-common.m4 serial 39
+# gnulib-common.m4 serial 40
 dnl Copyright (C) 2007-2018 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_PREREQ([2.62])
+
 # gl_COMMON
 # is expanded unconditionally through gnulib-tool magic.
 AC_DEFUN([gl_COMMON], [
@@ -214,13 +216,6 @@ AC_DEFUN([gl_FEATURES_H],
   AC_SUBST([HAVE_FEATURES_H])
 ])
 
-# m4_foreach_w
-# is a backport of autoconf-2.59c's m4_foreach_w.
-# Remove this macro when we can assume autoconf >= 2.60.
-m4_ifndef([m4_foreach_w],
-  [m4_define([m4_foreach_w],
-    [m4_foreach([$1], m4_split(m4_normalize([$2]), [ ]), [$3])])])
-
 # AS_VAR_IF(VAR, VALUE, [IF-MATCH], [IF-NOT-MATCH])
 # ----------------------------------------------------
 # Backport of autoconf-2.63b's macro.
@@ -233,7 +228,6 @@ m4_ifndef([AS_VAR_IF],
 # Modifies the value of the shell variable CC in an attempt to make $CC
 # understand ISO C99 source code.
 # This is like AC_PROG_CC_C99, except that
-# - AC_PROG_CC_C99 did not exist in Autoconf versions < 2.60,
 # - AC_PROG_CC_C99 does not mix well with AC_PROG_CC_STDC
 #   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00367.html>,
 #   but many more packages use AC_PROG_CC_STDC than AC_PROG_CC_C99
@@ -322,25 +316,6 @@ Amsterdam
   AC_SUBST([RANLIB])
 ])
 
-# AC_PROG_MKDIR_P
-# is a backport of autoconf-2.60's AC_PROG_MKDIR_P, with a fix
-# for interoperability with automake-1.9.6 from autoconf-2.62.
-# Remove this macro when we can assume autoconf >= 2.62 or
-# autoconf >= 2.60 && automake >= 1.10.
-# AC_AUTOCONF_VERSION was introduced in 2.62, so use that as the witness.
-m4_ifndef([AC_AUTOCONF_VERSION],[
-m4_ifdef([AC_PROG_MKDIR_P], [
-  dnl For automake-1.9.6 && autoconf < 2.62: Ensure MKDIR_P is AC_SUBSTed.
-  m4_define([AC_PROG_MKDIR_P],
-    m4_defn([AC_PROG_MKDIR_P])[
-    AC_SUBST([MKDIR_P])])], [
-  dnl For autoconf < 2.60: Backport of AC_PROG_MKDIR_P.
-  AC_DEFUN_ONCE([AC_PROG_MKDIR_P],
-    [AC_REQUIRE([AM_PROG_MKDIR_P])dnl defined by automake
-     MKDIR_P='$(mkdir_p)'
-     AC_SUBST([MKDIR_P])])])
-])
-
 # AC_C_RESTRICT
 # This definition is copied from post-2.69 Autoconf and overrides the
 # AC_C_RESTRICT macro from autoconf 2.60..2.69.  It can be removed
@@ -414,61 +389,3 @@ AC_DEFUN([gl_CACHE_VAL_SILENT],
 # AS_VAR_COPY was added in autoconf 2.63b
 m4_define_default([AS_VAR_COPY],
 [AS_LITERAL_IF([$1[]$2], [$1=$$2], [eval $1=\$$2])])
-
-# AC_PROG_SED was added in autoconf 2.59b
-m4_ifndef([AC_PROG_SED],
-[AC_DEFUN([AC_PROG_SED],
-[AC_CACHE_CHECK([for a sed that does not truncate output], ac_cv_path_SED,
-    [dnl ac_script should not contain more than 99 commands (for HP-UX sed),
-     dnl but more than about 7000 bytes, to catch a limit in Solaris 8 /usr/ucb/sed.
-     ac_script=s/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/
-     for ac_i in 1 2 3 4 5 6 7; do
-       ac_script="$ac_script$as_nl$ac_script"
-     done
-     echo "$ac_script" 2>/dev/null | sed 99q >conftest.sed
-     AS_UNSET([ac_script])
-     if test -z "$SED"; then
-       ac_path_SED_found=false
-       _AS_PATH_WALK([], [
-         for ac_prog in sed gsed; do
-           for ac_exec_ext in '' $ac_executable_extensions; do
-             ac_path_SED="$as_dir/$ac_prog$ac_exec_ext"
-             AS_EXECUTABLE_P(["$ac_path_SED"]) || continue
-             case `"$ac_path_SED" --version 2>&1` in
-               *GNU*) ac_cv_path_SED=$ac_path_SED ac_path_SED_found=:;;
-               *)
-                 ac_count=0
-                 _AS_ECHO_N([0123456789]) >conftest.in
-                 while :
-                 do
-                   cat conftest.in conftest.in >conftest.tmp
-                   mv conftest.tmp conftest.in
-                   cp conftest.in conftest.nl
-                   echo >> conftest.nl
-                   "$ac_path_SED" -f conftest.sed <conftest.nl >conftest.out 2>/dev/null || break
-                   diff conftest.out conftest.nl >/dev/null 2>&1 || break
-                   ac_count=`expr $ac_count + 1`
-                   if test $ac_count -gt ${ac_path_SED_max-0}; then
-                     # Best so far, but keep looking for better
-                     ac_cv_path_SED=$ac_path_SED
-                     ac_path_SED_max=$ac_count
-                   fi
-                   test $ac_count -gt 10 && break
-                 done
-                 rm -f conftest.in conftest.tmp conftest.nl conftest.out;;
-             esac
-             $ac_path_SED_found && break 3
-           done
-         done])
-       if test -z "$ac_cv_path_SED"; then
-         AC_ERROR([no acceptable sed could be found in \$PATH])
-       fi
-     else
-       ac_cv_path_SED=$SED
-     fi
-    ])
- SED="$ac_cv_path_SED"
- AC_SUBST([SED])dnl
- rm -f conftest.sed
-])
-])
diff --git a/m4/lib-link.m4 b/m4/lib-link.m4
index a2e7ab3fc8..dee3300d03 100644
--- a/m4/lib-link.m4
+++ b/m4/lib-link.m4
@@ -1,4 +1,4 @@
-# lib-link.m4 serial 27
+# lib-link.m4 serial 28
 dnl Copyright (C) 2001-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -6,7 +6,7 @@ dnl with or without modifications, as long as this notice is preserved.
 
 dnl From Bruno Haible.
 
-AC_PREREQ([2.54])
+AC_PREREQ([2.61])
 
 dnl AC_LIB_LINKFLAGS(name [, dependencies]) searches for libname and
 dnl the libraries corresponding to explicit and implicit dependencies.
@@ -187,17 +187,15 @@ AC_DEFUN([AC_LIB_LINKFLAGS_BODY],
   pushdef([PACKUP],[m4_translit(PACK,[abcdefghijklmnopqrstuvwxyz./+-],
                                      [ABCDEFGHIJKLMNOPQRSTUVWXYZ____])])
   pushdef([PACKLIBS],[m4_ifdef([acl_frompackage_]NAME, [acl_libsinpackage_]PACKUP, lib[$1])])
-  dnl Autoconf >= 2.61 supports dots in --with options.
-  pushdef([P_A_C_K],[m4_if(m4_version_compare(m4_defn([m4_PACKAGE_VERSION]),[2.61]),[-1],[m4_translit(PACK,[.],[_])],PACK)])
   dnl By default, look in $includedir and $libdir.
   use_additional=yes
   AC_LIB_WITH_FINAL_PREFIX([
     eval additional_includedir=\"$includedir\"
     eval additional_libdir=\"$libdir\"
   ])
-  AC_ARG_WITH(P_A_C_K[-prefix],
-[[  --with-]]P_A_C_K[[-prefix[=DIR]  search for ]PACKLIBS[ in DIR/include and DIR/lib
-  --without-]]P_A_C_K[[-prefix     don't search for ]PACKLIBS[ in includedir and libdir]],
+  AC_ARG_WITH(PACK[-prefix],
+[[  --with-]]PACK[[-prefix[=DIR]  search for ]PACKLIBS[ in DIR/include and DIR/lib
+  --without-]]PACK[[-prefix     don't search for ]PACKLIBS[ in includedir and libdir]],
 [
     if test "X$withval" = "Xno"; then
       use_additional=no
@@ -670,7 +668,6 @@ AC_DEFUN([AC_LIB_LINKFLAGS_BODY],
       LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-R$found_dir"
     done
   fi
-  popdef([P_A_C_K])
   popdef([PACKLIBS])
   popdef([PACKUP])
   popdef([PACK])
diff --git a/m4/lib-prefix.m4 b/m4/lib-prefix.m4
index 16b26fb2a8..5abf4e6990 100644
--- a/m4/lib-prefix.m4
+++ b/m4/lib-prefix.m4
@@ -1,4 +1,4 @@
-# lib-prefix.m4 serial 11
+# lib-prefix.m4 serial 12
 dnl Copyright (C) 2001-2005, 2008-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -6,13 +6,6 @@ dnl with or without modifications, as long as this notice is preserved.
 
 dnl From Bruno Haible.
 
-dnl AC_LIB_ARG_WITH is synonymous to AC_ARG_WITH in autoconf-2.13, and
-dnl similar to AC_ARG_WITH in autoconf 2.52...2.57 except that is doesn't
-dnl require excessive bracketing.
-ifdef([AC_HELP_STRING],
-[AC_DEFUN([AC_LIB_ARG_WITH], [AC_ARG_WITH([$1],[[$2]],[$3],[$4])])],
-[AC_DEFUN([AC_][LIB_ARG_WITH], [AC_ARG_WITH([$1],[$2],[$3],[$4])])])
-
 dnl AC_LIB_PREFIX adds to the CPPFLAGS and LDFLAGS the flags that are needed
 dnl to access previously installed libraries. The basic assumption is that
 dnl a user will want packages to use other packages he previously installed
@@ -32,9 +25,9 @@ AC_DEFUN([AC_LIB_PREFIX],
     eval additional_includedir=\"$includedir\"
     eval additional_libdir=\"$libdir\"
   ])
-  AC_LIB_ARG_WITH([lib-prefix],
-[  --with-lib-prefix[=DIR] search for libraries in DIR/include and DIR/lib
-  --without-lib-prefix    don't search for libraries in includedir and libdir],
+  AC_ARG_WITH([lib-prefix],
+[[  --with-lib-prefix[=DIR] search for libraries in DIR/include and DIR/lib
+  --without-lib-prefix    don't search for libraries in includedir and libdir]],
 [
     if test "X$withval" = "Xno"; then
       use_additional=no
diff --git a/m4/longlong.m4 b/m4/longlong.m4
index 27e63265a8..322d79b66c 100644
--- a/m4/longlong.m4
+++ b/m4/longlong.m4
@@ -1,4 +1,4 @@
-# longlong.m4 serial 17
+# longlong.m4 serial 18
 dnl Copyright (C) 1999-2007, 2009-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -6,9 +6,10 @@ dnl with or without modifications, as long as this notice is preserved.
 
 dnl From Paul Eggert.
 
+AC_PREREQ([2.62])
+
 # Define HAVE_LONG_LONG_INT if 'long long int' works.
-# This fixes a bug in Autoconf 2.61, and can be faster
-# than what's in Autoconf 2.62 through 2.68.
+# This can be faster than what's in Autoconf 2.62 through 2.68.
 
 # Note: If the type 'long long int' exists but is only 32 bits large
 # (as on some very old compilers), HAVE_LONG_LONG_INT will not be
@@ -56,8 +57,7 @@ AC_DEFUN([AC_TYPE_LONG_LONG_INT],
 ])
 
 # Define HAVE_UNSIGNED_LONG_LONG_INT if 'unsigned long long int' works.
-# This fixes a bug in Autoconf 2.61, and can be faster
-# than what's in Autoconf 2.62 through 2.68.
+# This fixes can be faster than what's in Autoconf 2.62 through 2.68.
 
 # Note: If the type 'unsigned long long int' exists but is only 32 bits
 # large (as on some very old compilers), AC_TYPE_UNSIGNED_LONG_LONG_INT
diff --git a/m4/ls-mntd-fs.m4 b/m4/ls-mntd-fs.m4
index 8ce748ce4a..4d4fbf4384 100644
--- a/m4/ls-mntd-fs.m4
+++ b/m4/ls-mntd-fs.m4
@@ -1,4 +1,4 @@
-# serial 35
+# serial 36
 # How to list mounted file systems.
 
 # Copyright (C) 1998-2004, 2006, 2009-2018 Free Software Foundation, Inc.
@@ -8,14 +8,14 @@
 # with or without modifications, as long as this notice is preserved.
 
 dnl From Jim Meyering.
-dnl
+
+AC_PREREQ([2.60])
+
 dnl This is not pretty.  I've just taken the autoconf code and wrapped
 dnl it in an AC_DEFUN and made some other fixes.
-dnl
 
-# Replace Autoconf's AC_FUNC_GETMNTENT to work around a bug in Autoconf
-# through Autoconf 2.59.  We can remove this once we assume Autoconf 2.60
-# or later.
+# Replace Autoconf's AC_FUNC_GETMNTENT to omit checks that are unnecessary
+# nowadays.
 AC_DEFUN([AC_FUNC_GETMNTENT],
 [
   # getmntent is in the standard C library on UNICOS, in -lsun on Irix 4,
diff --git a/m4/onceonly.m4 b/m4/onceonly.m4
deleted file mode 100644
index 5ab3dd7d3a..0000000000
--- a/m4/onceonly.m4
+++ /dev/null
@@ -1,104 +0,0 @@
-# onceonly.m4 serial 9
-dnl Copyright (C) 2002-2003, 2005-2006, 2008-2018 Free Software Foundation,
-dnl Inc.
-dnl
-dnl This file is free software; you can redistribute it and/or modify
-dnl it under the terms of the GNU General Public License as published by
-dnl the Free Software Foundation; either version 3 of the License, or
-dnl (at your option) any later version.
-dnl
-dnl This file is distributed in the hope that it will be useful,
-dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
-dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-dnl GNU General Public License for more details.
-dnl
-dnl You should have received a copy of the GNU General Public License
-dnl along with this file.  If not, see <https://www.gnu.org/licenses/>.
-dnl
-dnl As a special exception to the GNU General Public License,
-dnl this file may be distributed as part of a program
-dnl that contains a configuration script generated by Autoconf, under
-dnl the same distribution terms as the rest of that program.
-
-dnl This file defines some "once only" variants of standard autoconf macros.
-dnl   AC_CHECK_HEADERS_ONCE          like  AC_CHECK_HEADERS
-dnl   AC_CHECK_FUNCS_ONCE            like  AC_CHECK_FUNCS
-dnl   AC_CHECK_DECLS_ONCE            like  AC_CHECK_DECLS
-dnl   AC_REQUIRE([AC_FUNC_STRCOLL])  like  AC_FUNC_STRCOLL
-dnl The advantage is that the check for each of the headers/functions/decls
-dnl will be put only once into the 'configure' file. It keeps the size of
-dnl the 'configure' file down, and avoids redundant output when 'configure'
-dnl is run.
-dnl The drawback is that the checks cannot be conditionalized. If you write
-dnl   if some_condition; then gl_CHECK_HEADERS(stdlib.h); fi
-dnl inside an AC_DEFUNed function, the gl_CHECK_HEADERS macro call expands to
-dnl empty, and the check will be inserted before the body of the AC_DEFUNed
-dnl function.
-
-dnl The original code implemented AC_CHECK_HEADERS_ONCE and AC_CHECK_FUNCS_ONCE
-dnl in terms of AC_DEFUN and AC_REQUIRE. This implementation uses diversions to
-dnl named sections DEFAULTS and INIT_PREPARE in order to check all requested
-dnl headers at once, thus reducing the size of 'configure'. It is known to work
-dnl with autoconf 2.57..2.62 at least . The size reduction is ca. 9%.
-
-dnl Autoconf version 2.59 plus gnulib is required; this file is not needed
-dnl with Autoconf 2.60 or greater. But note that autoconf's implementation of
-dnl AC_CHECK_DECLS_ONCE expects a comma-separated list of symbols as first
-dnl argument!
-AC_PREREQ([2.59])
-
-# AC_CHECK_HEADERS_ONCE(HEADER1 HEADER2 ...) is a once-only variant of
-# AC_CHECK_HEADERS(HEADER1 HEADER2 ...).
-AC_DEFUN([AC_CHECK_HEADERS_ONCE], [
-  :
-  m4_foreach_w([gl_HEADER_NAME], [$1], [
-    AC_DEFUN([gl_CHECK_HEADER_]m4_quote(m4_translit(gl_HEADER_NAME,
-                                                    [./-], [___])), [
-      m4_divert_text([INIT_PREPARE],
-        [gl_header_list="$gl_header_list gl_HEADER_NAME"])
-      gl_HEADERS_EXPANSION
-      AH_TEMPLATE(AS_TR_CPP([HAVE_]m4_defn([gl_HEADER_NAME])),
-        [Define to 1 if you have the <]m4_defn([gl_HEADER_NAME])[> header file.])
-    ])
-    AC_REQUIRE([gl_CHECK_HEADER_]m4_quote(m4_translit(gl_HEADER_NAME,
-                                                      [./-], [___])))
-  ])
-])
-m4_define([gl_HEADERS_EXPANSION], [
-  m4_divert_text([DEFAULTS], [gl_header_list=])
-  AC_CHECK_HEADERS([$gl_header_list])
-  m4_define([gl_HEADERS_EXPANSION], [])
-])
-
-# AC_CHECK_FUNCS_ONCE(FUNC1 FUNC2 ...) is a once-only variant of
-# AC_CHECK_FUNCS(FUNC1 FUNC2 ...).
-AC_DEFUN([AC_CHECK_FUNCS_ONCE], [
-  :
-  m4_foreach_w([gl_FUNC_NAME], [$1], [
-    AC_DEFUN([gl_CHECK_FUNC_]m4_defn([gl_FUNC_NAME]), [
-      m4_divert_text([INIT_PREPARE],
-        [gl_func_list="$gl_func_list gl_FUNC_NAME"])
-      gl_FUNCS_EXPANSION
-      AH_TEMPLATE(AS_TR_CPP([HAVE_]m4_defn([gl_FUNC_NAME])),
-        [Define to 1 if you have the ']m4_defn([gl_FUNC_NAME])[' function.])
-    ])
-    AC_REQUIRE([gl_CHECK_FUNC_]m4_defn([gl_FUNC_NAME]))
-  ])
-])
-m4_define([gl_FUNCS_EXPANSION], [
-  m4_divert_text([DEFAULTS], [gl_func_list=])
-  AC_CHECK_FUNCS([$gl_func_list])
-  m4_define([gl_FUNCS_EXPANSION], [])
-])
-
-# AC_CHECK_DECLS_ONCE(DECL1 DECL2 ...) is a once-only variant of
-# AC_CHECK_DECLS(DECL1, DECL2, ...).
-AC_DEFUN([AC_CHECK_DECLS_ONCE], [
-  :
-  m4_foreach_w([gl_DECL_NAME], [$1], [
-    AC_DEFUN([gl_CHECK_DECL_]m4_defn([gl_DECL_NAME]), [
-      AC_CHECK_DECLS(m4_defn([gl_DECL_NAME]))
-    ])
-    AC_REQUIRE([gl_CHECK_DECL_]m4_defn([gl_DECL_NAME]))
-  ])
-])
diff --git a/m4/openmp.m4 b/m4/openmp.m4
deleted file mode 100644
index ef681cbb34..0000000000
--- a/m4/openmp.m4
+++ /dev/null
@@ -1,109 +0,0 @@
-# openmp.m4 serial 9
-dnl Copyright (C) 2006-2018 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.
-
-dnl This file can be removed once we assume autoconf >= 2.62.
-
-dnl Expand to nothing in autoconf >= 2.62. m4_copy has a different
-dnl semantic in autoconf > 2.63.
-m4_ifdef([AC_OPENMP], [], [
-
-# _AC_LANG_OPENMP
-# ---------------
-# Expands to some language dependent source code for testing the presence of
-# OpenMP.
-AC_DEFUN([_AC_LANG_OPENMP],
-[_AC_LANG_DISPATCH([$0], _AC_LANG, $@)])
-
-# _AC_LANG_OPENMP(C)
-# ------------------
-m4_define([_AC_LANG_OPENMP(C)],
-[
-#ifndef _OPENMP
- choke me
-#endif
-#include <omp.h>
-int main () { return omp_get_num_threads (); }
-])
-
-# _AC_LANG_OPENMP(C++)
-# --------------------
-m4_copy([_AC_LANG_OPENMP(C)], [_AC_LANG_OPENMP(C++)])
-
-# _AC_LANG_OPENMP(Fortran 77)
-# ---------------------------
-m4_define([_AC_LANG_OPENMP(Fortran 77)],
-[
-      program main
-      implicit none
-!$    integer tid
-      tid = 42
-      call omp_set_num_threads(2)
-      end
-])
-
-# _AC_LANG_OPENMP(Fortran)
-# ---------------------------
-m4_copy([_AC_LANG_OPENMP(Fortran 77)], [_AC_LANG_OPENMP(Fortran)])
-
-# AC_OPENMP
-# ---------
-# Check which options need to be passed to the C compiler to support OpenMP.
-# Set the OPENMP_CFLAGS / OPENMP_CXXFLAGS / OPENMP_FFLAGS variable to these
-# options.
-# The options are necessary at compile time (so the #pragmas are understood)
-# and at link time (so the appropriate library is linked with).
-# This macro takes care to not produce redundant options if $CC $CFLAGS already
-# supports OpenMP. It also is careful to not pass options to compilers that
-# misinterpret them; for example, most compilers accept "-openmp" and create
-# an output file called 'penmp' rather than activating OpenMP support.
-AC_DEFUN([AC_OPENMP],
-[
-  OPENMP_[]_AC_LANG_PREFIX[]FLAGS=
-  AC_ARG_ENABLE([openmp],
-    [AS_HELP_STRING([--disable-openmp], [do not use OpenMP])])
-  if test "$enable_openmp" != no; then
-    AC_CACHE_CHECK([for $CC option to support OpenMP],
-      [ac_cv_prog_[]_AC_LANG_ABBREV[]_openmp],
-      [AC_LINK_IFELSE([_AC_LANG_OPENMP],
-         [ac_cv_prog_[]_AC_LANG_ABBREV[]_openmp='none needed'],
-         [ac_cv_prog_[]_AC_LANG_ABBREV[]_openmp='unsupported'
-          dnl Try these flags:
-          dnl   GCC >= 4.2           -fopenmp
-          dnl   SunPRO C             -xopenmp
-          dnl   Intel C              -openmp
-          dnl   SGI C, PGI C         -mp
-          dnl   Tru64 Compaq C       -omp
-          dnl   IBM C (AIX, Linux)   -qsmp=omp
-          dnl   Cray CCE             -homp
-          dnl   NEC SX               -Popenmp
-          dnl   Lahey Fortran (Linux)  --openmp
-          dnl If in this loop a compiler is passed an option that it doesn't
-          dnl understand or that it misinterprets, the AC_LINK_IFELSE test
-          dnl will fail (since we know that it failed without the option),
-          dnl therefore the loop will continue searching for an option, and
-          dnl no output file called 'penmp' or 'mp' is created.
-          for ac_option in -fopenmp -xopenmp -openmp -mp -omp -qsmp=omp -homp \
-                           -Popenmp --openmp; do
-            ac_save_[]_AC_LANG_PREFIX[]FLAGS=$[]_AC_LANG_PREFIX[]FLAGS
-            _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $ac_option"
-            AC_LINK_IFELSE([_AC_LANG_OPENMP],
-              [ac_cv_prog_[]_AC_LANG_ABBREV[]_openmp=$ac_option])
-            _AC_LANG_PREFIX[]FLAGS=$ac_save_[]_AC_LANG_PREFIX[]FLAGS
-            if test "$ac_cv_prog_[]_AC_LANG_ABBREV[]_openmp" != unsupported; then
-              break
-            fi
-          done])])
-    case $ac_cv_prog_[]_AC_LANG_ABBREV[]_openmp in #(
-      "none needed" | unsupported)
-        ;; #(
-      *)
-        OPENMP_[]_AC_LANG_PREFIX[]FLAGS=$ac_cv_prog_[]_AC_LANG_ABBREV[]_openmp ;;
-    esac
-  fi
-  AC_SUBST([OPENMP_]_AC_LANG_PREFIX[FLAGS])
-])
-
-])
diff --git a/m4/po.m4 b/m4/po.m4
index 4650c18050..d77f3aa4bc 100644
--- a/m4/po.m4
+++ b/m4/po.m4
@@ -1,4 +1,4 @@
-# po.m4 serial 25
+# po.m4 serial 24a
 dnl Copyright (C) 1995-2014, 2016, 2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -83,12 +83,6 @@ changequote([,])dnl
   AM_PATH_PROG_WITH_TEST(MSGMERGE, msgmerge,
     [$ac_dir/$ac_word --update -q /dev/null /dev/null >&]AS_MESSAGE_LOG_FD[ 2>&1], :)
 
-  dnl Installation directories.
-  dnl Autoconf >= 2.60 defines localedir. For older versions of autoconf, we
-  dnl have to define it here, so that it can be used in po/Makefile.
-  test -n "$localedir" || localedir='${datadir}/locale'
-  AC_SUBST([localedir])
-
   dnl Support for AM_XGETTEXT_OPTION.
   test -n "${XGETTEXT_EXTRA_OPTIONS+set}" || XGETTEXT_EXTRA_OPTIONS=
   AC_SUBST([XGETTEXT_EXTRA_OPTIONS])
diff --git a/m4/size_max.m4 b/m4/size_max.m4
index 2b770e6ca3..3e3986e15e 100644
--- a/m4/size_max.m4
+++ b/m4/size_max.m4
@@ -1,4 +1,4 @@
-# size_max.m4 serial 10
+# size_max.m4 serial 11
 dnl Copyright (C) 2003, 2005-2006, 2008-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -6,6 +6,8 @@ dnl with or without modifications, as long as this notice is preserved.
 
 dnl From Bruno Haible.
 
+AC_PREREQ([2.61])
+
 AC_DEFUN([gl_SIZE_MAX],
 [
   AC_CHECK_HEADERS([stdint.h])
@@ -71,9 +73,3 @@ Found it
 # undef SIZE_MAX
 #endif])
 ])
-
-dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
-dnl Remove this when we can assume autoconf >= 2.61.
-m4_ifdef([AC_COMPUTE_INT], [], [
-  AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
-])
diff --git a/m4/stdint.m4 b/m4/stdint.m4
index 38dbbedffe..81d065f655 100644
--- a/m4/stdint.m4
+++ b/m4/stdint.m4
@@ -1,4 +1,4 @@
-# stdint.m4 serial 52
+# stdint.m4 serial 53
 dnl Copyright (C) 2001-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,6 +7,8 @@ dnl with or without modifications, as long as this notice is preserved.
 dnl From Paul Eggert and Bruno Haible.
 dnl Test whether <stdint.h> is supported or must be substituted.
 
+AC_PREREQ([2.61])
+
 AC_DEFUN_ONCE([gl_STDINT_H],
 [
   AC_PREREQ([2.59])dnl
@@ -540,9 +542,3 @@ AC_DEFUN([gl_STDINT_TYPE_PROPERTIES],
     BITSIZEOF_WINT_T=32
   fi
 ])
-
-dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
-dnl Remove this when we can assume autoconf >= 2.61.
-m4_ifdef([AC_COMPUTE_INT], [], [
-  AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
-])
diff --git a/m4/threadlib.m4 b/m4/threadlib.m4
index 54a57e9ba1..ed6ebd5117 100644
--- a/m4/threadlib.m4
+++ b/m4/threadlib.m4
@@ -1,4 +1,4 @@
-# threadlib.m4 serial 14
+# threadlib.m4 serial 15
 dnl Copyright (C) 2005-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -6,6 +6,8 @@ dnl with or without modifications, as long as this notice is preserved.
 
 dnl From Bruno Haible.
 
+AC_PREREQ([2.60])
+
 dnl gl_THREADLIB
 dnl ------------
 dnl Tests for a multithreading library to be used.
@@ -43,11 +45,7 @@ AC_DEFUN([gl_THREADLIB_EARLY_BODY],
 
   AC_REQUIRE([AC_CANONICAL_HOST])
   dnl _GNU_SOURCE is needed for pthread_rwlock_t on glibc systems.
-  dnl AC_USE_SYSTEM_EXTENSIONS was introduced in autoconf 2.60 and obsoletes
-  dnl AC_GNU_SOURCE.
-  m4_ifdef([AC_USE_SYSTEM_EXTENSIONS],
-    [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])],
-    [AC_REQUIRE([AC_GNU_SOURCE])])
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
   dnl Check for multithreading.
   m4_ifdef([gl_THREADLIB_DEFAULT_NO],
     [m4_divert_text([DEFAULTS], [gl_use_threads_default=no])],
diff --git a/modules/openmp b/modules/openmp
index 13dc9a5588..76f012d2d6 100644
--- a/modules/openmp
+++ b/modules/openmp
@@ -2,7 +2,6 @@ Description:
 Detection of OpenMP support.
 
 Files:
-m4/openmp.m4
 
 Depends-on:
 
diff --git a/pygnulib/GLModuleSystem.py b/pygnulib/GLModuleSystem.py
index 59109cce7e..f2f9df4ac9 100644
--- a/pygnulib/GLModuleSystem.py
+++ b/pygnulib/GLModuleSystem.py
@@ -545,8 +545,6 @@ Include:|Link:|License:|Maintainer:)'
                 result = [part.strip() for part in parts if part.strip()]
             result += [joinpath('m4', '00gnulib.m4')]
             result += [joinpath('m4', 'gnulib-common.m4')]
-            if ac_version == 2.59:
-                result += [joinpath('m4', 'onceonly.m4')]
             self.cache['files'] = list(result)
         return(list(self.cache['files']))