Revert "Import posix_spawn from Gnulib."

This reverts commit 3ba34141da77a24c251ee6530f3f72a366fe556e.
It breaks the MinGW build and should be first tested on a
branch.

7 files changed, 0 insertions, 1141 deletions

diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index e2a44efe621..0971636c33d 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -139,18 +139,6 @@ AC_DEFUN([gl_EARLY],
   # Code from module openat-h:
   # Code from module pathmax:
   # Code from module pipe2:
-  # Code from module posix_spawn:
-  # Code from module posix_spawn-internal:
-  # Code from module posix_spawn_file_actions_addchdir:
-  # Code from module posix_spawn_file_actions_adddup2:
-  # Code from module posix_spawn_file_actions_destroy:
-  # Code from module posix_spawn_file_actions_init:
-  # Code from module posix_spawnattr_destroy:
-  # Code from module posix_spawnattr_init:
-  # Code from module posix_spawnattr_setflags:
-  # Code from module posix_spawnattr_setpgroup:
-  # Code from module posix_spawnattr_setsigdefault:
-  # Code from module posix_spawnattr_setsigmask:
   # Code from module pselect:
   # Code from module pthread_sigmask:
   # Code from module qcopy-acl:
@@ -159,9 +147,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module readlinkat:
   # Code from module regex:
   # Code from module root-uid:
-  # Code from module sched:
   # Code from module scratch_buffer:
-  # Code from module sh-filename:
   # Code from module sig2str:
   # Code from module sigdescr_np:
   # Code from module signal-h:
@@ -170,7 +156,6 @@ AC_DEFUN([gl_EARLY],
   # Code from module snippet/c++defs:
   # Code from module snippet/warn-on-use:
   # Code from module socklen:
-  # Code from module spawn:
   # Code from module ssize_t:
   # Code from module stat-time:
   # Code from module std-gnu11:
@@ -180,7 +165,6 @@ AC_DEFUN([gl_EARLY],
   # Code from module stdio:
   # Code from module stdlib:
   # Code from module stpcpy:
-  # Code from module strchrnul:
   # Code from module string:
   # Code from module strnlen:
   # Code from module strtoimax:
@@ -419,61 +403,6 @@ AC_DEFUN([gl_INIT],
   gl_PATHMAX
   gl_FUNC_PIPE2
   gl_UNISTD_MODULE_INDICATOR([pipe2])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawn])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawn])
-  gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1 || test $HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR = 0 || test $REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR = 1; then
-    AC_LIBOBJ([spawn_faction_addchdir])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawn_file_actions_addchdir])
-  gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1 || test $REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2 = 1; then
-    AC_LIBOBJ([spawn_faction_adddup2])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawn_file_actions_adddup2])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawn_faction_destroy])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawn_file_actions_destroy])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawn_faction_init])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawn_file_actions_init])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawnattr_destroy])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_destroy])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawnattr_init])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_init])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawnattr_setflags])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_setflags])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawnattr_setpgroup])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_setpgroup])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawnattr_setdefault])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_setsigdefault])
-  gl_POSIX_SPAWN
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_LIBOBJ([spawnattr_setsigmask])
-  fi
-  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_setsigmask])
   gl_FUNC_PSELECT
   if test $HAVE_PSELECT = 0 || test $REPLACE_PSELECT = 1; then
     AC_LIBOBJ([pselect])
@@ -501,7 +430,6 @@ AC_DEFUN([gl_INIT],
     AC_LIBOBJ([regex])
     gl_PREREQ_REGEX
   fi
-  gl_SCHED_H
   gl_FUNC_SIG2STR
   if test $ac_cv_func_sig2str = no; then
     AC_LIBOBJ([sig2str])
@@ -514,7 +442,6 @@ AC_DEFUN([gl_INIT],
   gl_STRING_MODULE_INDICATOR([sigdescr_np])
   gl_SIGNAL_H
   gl_TYPE_SOCKLEN_T
-  gl_SPAWN_H
   gt_TYPE_SSIZE_T
   gl_STAT_TIME
   gl_STAT_BIRTHTIME
@@ -601,12 +528,9 @@ AC_DEFUN([gl_INIT],
   gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31=false
   gl_gnulib_enabled_open=false
   gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=false
-  gl_gnulib_enabled_332607f759618fb73dfc3076748afea7=false
   gl_gnulib_enabled_rawmemchr=false
   gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=false
   gl_gnulib_enabled_scratch_buffer=false
-  gl_gnulib_enabled_cdeb0f2aaf9d280baa6526bfa1b07f70=false
-  gl_gnulib_enabled_strchrnul=false
   gl_gnulib_enabled_strtoll=false
   gl_gnulib_enabled_utimens=false
   gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=false
@@ -761,20 +685,6 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=true
     fi
   }
-  func_gl_gnulib_m4code_332607f759618fb73dfc3076748afea7 ()
-  {
-    if ! $gl_gnulib_enabled_332607f759618fb73dfc3076748afea7; then
-      gl_POSIX_SPAWN
-      if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-        AC_LIBOBJ([spawni])
-        gl_PREREQ_POSIX_SPAWN_INTERNAL
-      fi
-      gl_gnulib_enabled_332607f759618fb73dfc3076748afea7=true
-      func_gl_gnulib_m4code_open
-      func_gl_gnulib_m4code_cdeb0f2aaf9d280baa6526bfa1b07f70
-      func_gl_gnulib_m4code_strchrnul
-    fi
-  }
   func_gl_gnulib_m4code_rawmemchr ()
   {
     if ! $gl_gnulib_enabled_rawmemchr; then
@@ -799,28 +709,6 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_scratch_buffer=true
     fi
   }
-  func_gl_gnulib_m4code_cdeb0f2aaf9d280baa6526bfa1b07f70 ()
-  {
-    if ! $gl_gnulib_enabled_cdeb0f2aaf9d280baa6526bfa1b07f70; then
-      gl_SH_FILENAME
-      gl_gnulib_enabled_cdeb0f2aaf9d280baa6526bfa1b07f70=true
-    fi
-  }
-  func_gl_gnulib_m4code_strchrnul ()
-  {
-    if ! $gl_gnulib_enabled_strchrnul; then
-      gl_FUNC_STRCHRNUL
-      if test $HAVE_STRCHRNUL = 0 || test $REPLACE_STRCHRNUL = 1; then
-        AC_LIBOBJ([strchrnul])
-        gl_PREREQ_STRCHRNUL
-      fi
-      gl_STRING_MODULE_INDICATOR([strchrnul])
-      gl_gnulib_enabled_strchrnul=true
-      if test $HAVE_STRCHRNUL = 0 || test $REPLACE_STRCHRNUL = 1; then
-        func_gl_gnulib_m4code_rawmemchr
-      fi
-    fi
-  }
   func_gl_gnulib_m4code_strtoll ()
   {
     if ! $gl_gnulib_enabled_strtoll; then
@@ -903,12 +791,6 @@ AC_DEFUN([gl_INIT],
   if case $host_os in mingw*) false;; *) test $HAVE_GETRANDOM = 0 || test $REPLACE_GETRANDOM = 1;; esac; then
     func_gl_gnulib_m4code_open
   fi
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
-    func_gl_gnulib_m4code_332607f759618fb73dfc3076748afea7
-  fi
-  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1 || test $REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2 = 1; then
-    func_gl_gnulib_m4code_getdtablesize
-  fi
   if test $HAVE_READLINKAT = 0 || test $REPLACE_READLINKAT = 1; then
     func_gl_gnulib_m4code_260941c0e5dc67ec9e87d1fb321c300b
   fi
@@ -948,12 +830,9 @@ AC_DEFUN([gl_INIT],
   AM_CONDITIONAL([gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31], [$gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_open], [$gl_gnulib_enabled_open])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7], [$gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7])
-  AM_CONDITIONAL([gl_GNULIB_ENABLED_332607f759618fb73dfc3076748afea7], [$gl_gnulib_enabled_332607f759618fb73dfc3076748afea7])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_rawmemchr], [$gl_gnulib_enabled_rawmemchr])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c], [$gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_scratch_buffer], [$gl_gnulib_enabled_scratch_buffer])
-  AM_CONDITIONAL([gl_GNULIB_ENABLED_cdeb0f2aaf9d280baa6526bfa1b07f70], [$gl_gnulib_enabled_cdeb0f2aaf9d280baa6526bfa1b07f70])
-  AM_CONDITIONAL([gl_GNULIB_ENABLED_strchrnul], [$gl_gnulib_enabled_strchrnul])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_strtoll], [$gl_gnulib_enabled_strtoll])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_utimens], [$gl_gnulib_enabled_utimens])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_682e609604ccaac6be382e4ee3a4eaec], [$gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec])
@@ -1234,7 +1113,6 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/regex_internal.h
   lib/regexec.c
   lib/root-uid.h
-  lib/sched.in.h
   lib/scratch_buffer.h
   lib/set-permissions.c
   lib/sha1.c
@@ -1247,20 +1125,6 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/sig2str.h
   lib/sigdescr_np.c
   lib/signal.in.h
-  lib/spawn.c
-  lib/spawn.in.h
-  lib/spawn_faction_addchdir.c
-  lib/spawn_faction_adddup2.c
-  lib/spawn_faction_destroy.c
-  lib/spawn_faction_init.c
-  lib/spawn_int.h
-  lib/spawnattr_destroy.c
-  lib/spawnattr_init.c
-  lib/spawnattr_setdefault.c
-  lib/spawnattr_setflags.c
-  lib/spawnattr_setpgroup.c
-  lib/spawnattr_setsigmask.c
-  lib/spawni.c
   lib/stat-time.c
   lib/stat-time.h
   lib/stdalign.in.h
@@ -1271,8 +1135,6 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/stdlib.in.h
   lib/stpcpy.c
   lib/str-two-way.h
-  lib/strchrnul.c
-  lib/strchrnul.valgrind
   lib/strftime.h
   lib/string.in.h
   lib/strnlen.c
@@ -1386,16 +1248,12 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/pathmax.m4
   m4/pid_t.m4
   m4/pipe2.m4
-  m4/posix_spawn.m4
-  m4/posix_spawn_faction_addchdir.m4
   m4/pselect.m4
   m4/pthread_sigmask.m4
   m4/rawmemchr.m4
   m4/readlink.m4
   m4/readlinkat.m4
   m4/regex.m4
-  m4/sched_h.m4
-  m4/sh-filename.m4
   m4/sha1.m4
   m4/sha256.m4
   m4/sha512.m4
@@ -1403,7 +1261,6 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/sigdescr_np.m4
   m4/signal_h.m4
   m4/socklen.m4
-  m4/spawn_h.m4
   m4/ssize_t.m4
   m4/stat-time.m4
   m4/std-gnu11.m4
@@ -1413,7 +1270,6 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/stdio_h.m4
   m4/stdlib_h.m4
   m4/stpcpy.m4
-  m4/strchrnul.m4
   m4/string_h.m4
   m4/strnlen.m4
   m4/strtoimax.m4
diff --git a/m4/posix_spawn.m4 b/m4/posix_spawn.m4
deleted file mode 100644
index 59e56fcb5f2..00000000000
--- a/m4/posix_spawn.m4
+++ /dev/null
@@ -1,678 +0,0 @@
-# posix_spawn.m4 serial 19
-dnl Copyright (C) 2008-2020 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 Tests whether the entire posix_spawn facility is available.
-AC_DEFUN([gl_POSIX_SPAWN],
-[
-  AC_REQUIRE([gl_POSIX_SPAWN_BODY])
-])
-
-AC_DEFUN([gl_POSIX_SPAWN_BODY],
-[
-  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
-  AC_REQUIRE([gl_HAVE_POSIX_SPAWN])
-  dnl Assume that when the main function exists, all the others,
-  dnl except posix_spawnattr_{get,set}sched*, are available as well.
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnp])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_init])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addclose])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_adddup2])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addopen])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_destroy])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_init])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getflags])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setflags])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getpgroup])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setpgroup])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getsigdefault])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setsigdefault])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getsigmask])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setsigmask])
-  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_destroy])
-  if test $ac_cv_func_posix_spawn = yes; then
-    m4_ifdef([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR],
-      [dnl Module 'posix_spawn_file_actions_addchdir' is present.
-       AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addchdir_np])
-       if test $ac_cv_func_posix_spawn_file_actions_addchdir_np = no; then
-         dnl In order to implement the posix_spawn_file_actions_addchdir
-         dnl function, we need to replace the entire posix_spawn facility.
-         REPLACE_POSIX_SPAWN=1
-       fi
-      ])
-    m4_ifdef([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDFCHDIR],
-      [dnl Module 'posix_spawn_file_actions_addfchdir' is present.
-       AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addfchdir_np])
-       if test $ac_cv_func_posix_spawn_file_actions_addfchdir_np = no; then
-         dnl In order to implement the posix_spawn_file_actions_addfchdir
-         dnl function, we need to replace the entire posix_spawn facility.
-         REPLACE_POSIX_SPAWN=1
-       fi
-      ])
-    if test $REPLACE_POSIX_SPAWN = 0; then
-      gl_POSIX_SPAWN_WORKS
-      case "$gl_cv_func_posix_spawn_works" in
-        *yes) ;;
-        *) REPLACE_POSIX_SPAWN=1 ;;
-      esac
-    fi
-    if test $REPLACE_POSIX_SPAWN = 0; then
-      gl_POSIX_SPAWN_SECURE
-      case "$gl_cv_func_posix_spawn_secure_exec" in
-        *yes) ;;
-        *) REPLACE_POSIX_SPAWN=1 ;;
-      esac
-      case "$gl_cv_func_posix_spawnp_secure_exec" in
-        *yes) ;;
-        *) REPLACE_POSIX_SPAWN=1 ;;
-      esac
-    fi
-    if test $REPLACE_POSIX_SPAWN = 0; then
-      dnl Assume that these functions are available if POSIX_SPAWN_SETSCHEDULER
-      dnl evaluates to nonzero.
-      dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getschedpolicy])
-      dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setschedpolicy])
-      AC_CACHE_CHECK([whether posix_spawnattr_setschedpolicy is supported],
-        [gl_cv_func_spawnattr_setschedpolicy],
-        [AC_EGREP_CPP([POSIX scheduling supported], [
-#include <spawn.h>
-#if POSIX_SPAWN_SETSCHEDULER
- POSIX scheduling supported
-#endif
-],
-           [gl_cv_func_spawnattr_setschedpolicy=yes],
-           [gl_cv_func_spawnattr_setschedpolicy=no])
-        ])
-      dnl Assume that these functions are available if POSIX_SPAWN_SETSCHEDPARAM
-      dnl evaluates to nonzero.
-      dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getschedparam])
-      dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setschedparam])
-      AC_CACHE_CHECK([whether posix_spawnattr_setschedparam is supported],
-        [gl_cv_func_spawnattr_setschedparam],
-        [AC_EGREP_CPP([POSIX scheduling supported], [
-#include <spawn.h>
-#if POSIX_SPAWN_SETSCHEDPARAM
- POSIX scheduling supported
-#endif
-],
-           [gl_cv_func_spawnattr_setschedparam=yes],
-           [gl_cv_func_spawnattr_setschedparam=no])
-        ])
-    fi
-  fi
-  if test $ac_cv_func_posix_spawn != yes || test $REPLACE_POSIX_SPAWN = 1; then
-    AC_DEFINE([REPLACE_POSIX_SPAWN], [1],
-      [Define if gnulib uses its own posix_spawn and posix_spawnp functions.])
-  fi
-])
-
-dnl Test whether posix_spawn actually works.
-dnl posix_spawn on AIX 5.3..6.1 has two bugs:
-dnl 1) When it fails to execute the program, the child process exits with
-dnl    exit() rather than _exit(), which causes the stdio buffers to be
-dnl    flushed. Reported by Rainer Tammer.
-dnl 2) The posix_spawn_file_actions_addopen function does not support file
-dnl    names that contain a '*'.
-dnl posix_spawn on AIX 5.3..6.1 has also a third bug: It does not work
-dnl when POSIX threads are used. But we don't test against this bug here.
-AC_DEFUN([gl_POSIX_SPAWN_WORKS],
-[
-  AC_REQUIRE([AC_PROG_CC])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  AC_CACHE_CHECK([whether posix_spawn works], [gl_cv_func_posix_spawn_works],
-    [if test $cross_compiling = no; then
-       AC_LINK_IFELSE([AC_LANG_SOURCE([[
-#include <errno.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <spawn.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-]GL_MDA_DEFINES[
-
-extern char **environ;
-
-#ifndef STDIN_FILENO
-# define STDIN_FILENO 0
-#endif
-#ifndef STDOUT_FILENO
-# define STDOUT_FILENO 1
-#endif
-#ifndef STDERR_FILENO
-# define STDERR_FILENO 2
-#endif
-
-#ifndef WTERMSIG
-# define WTERMSIG(x) ((x) & 0x7f)
-#endif
-#ifndef WIFEXITED
-# define WIFEXITED(x) (WTERMSIG (x) == 0)
-#endif
-#ifndef WEXITSTATUS
-# define WEXITSTATUS(x) (((x) >> 8) & 0xff)
-#endif
-
-#define CHILD_PROGRAM_FILENAME "/non/exist/ent"
-
-static int
-fd_safer (int fd)
-{
-  if (0 <= fd && fd <= 2)
-    {
-      int f = fd_safer (dup (fd));
-      int e = errno;
-      close (fd);
-      errno = e;
-      fd = f;
-    }
-
-  return fd;
-}
-
-int
-main ()
-{
-  char *argv[2] = { CHILD_PROGRAM_FILENAME, NULL };
-  int ofd[2];
-  sigset_t blocked_signals;
-  sigset_t fatal_signal_set;
-  posix_spawn_file_actions_t actions;
-  bool actions_allocated;
-  posix_spawnattr_t attrs;
-  bool attrs_allocated;
-  int err;
-  pid_t child;
-  int status;
-  int exitstatus;
-
-  setvbuf (stdout, NULL, _IOFBF, 0);
-  puts ("This should be seen only once.");
-  if (pipe (ofd) < 0 || (ofd[1] = fd_safer (ofd[1])) < 0)
-    {
-      perror ("cannot create pipe");
-      exit (1);
-    }
-  sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
-  sigemptyset (&fatal_signal_set);
-  sigaddset (&fatal_signal_set, SIGINT);
-  sigaddset (&fatal_signal_set, SIGTERM);
-  sigaddset (&fatal_signal_set, SIGHUP);
-  sigaddset (&fatal_signal_set, SIGPIPE);
-  sigprocmask (SIG_BLOCK, &fatal_signal_set, NULL);
-  actions_allocated = false;
-  attrs_allocated = false;
-  if ((err = posix_spawn_file_actions_init (&actions)) != 0
-      || (actions_allocated = true,
-          (err = posix_spawn_file_actions_adddup2 (&actions, ofd[0], STDIN_FILENO)) != 0
-          || (err = posix_spawn_file_actions_addclose (&actions, ofd[0])) != 0
-          || (err = posix_spawn_file_actions_addclose (&actions, ofd[1])) != 0
-          || (err = posix_spawnattr_init (&attrs)) != 0
-          || (attrs_allocated = true,
-              (err = posix_spawnattr_setsigmask (&attrs, &blocked_signals)) != 0
-              || (err = posix_spawnattr_setflags (&attrs, POSIX_SPAWN_SETSIGMASK)) != 0)
-          || (err = posix_spawnp (&child, CHILD_PROGRAM_FILENAME, &actions, &attrs, argv, environ)) != 0))
-    {
-      if (actions_allocated)
-        posix_spawn_file_actions_destroy (&actions);
-      if (attrs_allocated)
-        posix_spawnattr_destroy (&attrs);
-      sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
-      if (err == ENOENT)
-        return 0;
-      else
-        {
-          errno = err;
-          perror ("subprocess failed");
-          exit (1);
-        }
-    }
-  posix_spawn_file_actions_destroy (&actions);
-  posix_spawnattr_destroy (&attrs);
-  sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
-  close (ofd[0]);
-  close (ofd[1]);
-  status = 0;
-  while (waitpid (child, &status, 0) != child)
-    ;
-  if (!WIFEXITED (status))
-    {
-      fprintf (stderr, "subprocess terminated with unexpected wait status %d\n", status);
-      exit (1);
-    }
-  exitstatus = WEXITSTATUS (status);
-  if (exitstatus != 127)
-    {
-      fprintf (stderr, "subprocess terminated with unexpected exit status %d\n", exitstatus);
-      exit (1);
-    }
-  return 0;
-}
-]])],
-         [if test -s conftest$ac_exeext \
-             && ./conftest$ac_exeext > conftest.out \
-             && echo 'This should be seen only once.' > conftest.ok \
-             && cmp conftest.out conftest.ok >/dev/null 2>&1; then
-            gl_cv_func_posix_spawn_works=yes
-          else
-            gl_cv_func_posix_spawn_works=no
-          fi],
-         [gl_cv_func_posix_spawn_works=no])
-       if test $gl_cv_func_posix_spawn_works = yes; then
-         AC_RUN_IFELSE([AC_LANG_SOURCE([[
-/* Test whether posix_spawn_file_actions_addopen supports filename arguments
-   that contain special characters such as '*'.  */
-
-#include <errno.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <spawn.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-]GL_MDA_DEFINES[
-
-extern char **environ;
-
-#ifndef STDIN_FILENO
-# define STDIN_FILENO 0
-#endif
-#ifndef STDOUT_FILENO
-# define STDOUT_FILENO 1
-#endif
-#ifndef STDERR_FILENO
-# define STDERR_FILENO 2
-#endif
-
-#ifndef WTERMSIG
-# define WTERMSIG(x) ((x) & 0x7f)
-#endif
-#ifndef WIFEXITED
-# define WIFEXITED(x) (WTERMSIG (x) == 0)
-#endif
-#ifndef WEXITSTATUS
-# define WEXITSTATUS(x) (((x) >> 8) & 0xff)
-#endif
-
-#define CHILD_PROGRAM_FILENAME "conftest"
-#define DATA_FILENAME "conftest%=*#?"
-
-static int
-parent_main (void)
-{
-  FILE *fp;
-  char *argv[3] = { CHILD_PROGRAM_FILENAME, "-child", NULL };
-  posix_spawn_file_actions_t actions;
-  bool actions_allocated;
-  int err;
-  pid_t child;
-  int status;
-  int exitstatus;
-
-  /* Create a data file with specific contents.  */
-  fp = fopen (DATA_FILENAME, "wb");
-  if (fp == NULL)
-    {
-      perror ("cannot create data file");
-      return 1;
-    }
-  fwrite ("Halle Potta", 1, 11, fp);
-  if (fflush (fp) || fclose (fp))
-    {
-      perror ("cannot prepare data file");
-      return 2;
-    }
-
-  /* Avoid reading from our stdin, as it could block.  */
-  freopen ("/dev/null", "rb", stdin);
-
-  /* Test whether posix_spawn_file_actions_addopen with this file name
-     actually works, but spawning a child that reads from this file.  */
-  actions_allocated = false;
-  if ((err = posix_spawn_file_actions_init (&actions)) != 0
-      || (actions_allocated = true,
-          (err = posix_spawn_file_actions_addopen (&actions, STDIN_FILENO, DATA_FILENAME, O_RDONLY, 0600)) != 0
-          || (err = posix_spawn (&child, CHILD_PROGRAM_FILENAME, &actions, NULL, argv, environ)) != 0))
-    {
-      if (actions_allocated)
-        posix_spawn_file_actions_destroy (&actions);
-      errno = err;
-      perror ("subprocess failed");
-      return 3;
-    }
-  posix_spawn_file_actions_destroy (&actions);
-  status = 0;
-  while (waitpid (child, &status, 0) != child)
-    ;
-  if (!WIFEXITED (status))
-    {
-      fprintf (stderr, "subprocess terminated with unexpected wait status %d\n", status);
-      return 4;
-    }
-  exitstatus = WEXITSTATUS (status);
-  if (exitstatus != 0)
-    {
-      fprintf (stderr, "subprocess terminated with unexpected exit status %d\n", exitstatus);
-      return 5;
-    }
-  return 0;
-}
-
-static int
-child_main (void)
-{
-  char buf[1024];
-
-  /* See if reading from STDIN_FILENO yields the expected contents.  */
-  if (fread (buf, 1, sizeof (buf), stdin) == 11
-      && memcmp (buf, "Halle Potta", 11) == 0)
-    return 0;
-  else
-    return 8;
-}
-
-static void
-cleanup_then_die (int sig)
-{
-  /* Clean up data file.  */
-  unlink (DATA_FILENAME);
-
-  /* Re-raise the signal and die from it.  */
-  signal (sig, SIG_DFL);
-  raise (sig);
-}
-
-int
-main (int argc, char *argv[])
-{
-  int exitstatus;
-
-  if (!(argc > 1 && strcmp (argv[1], "-child") == 0))
-    {
-      /* This is the parent process.  */
-      signal (SIGINT, cleanup_then_die);
-      signal (SIGTERM, cleanup_then_die);
-      #ifdef SIGHUP
-      signal (SIGHUP, cleanup_then_die);
-      #endif
-
-      exitstatus = parent_main ();
-    }
-  else
-    {
-      /* This is the child process.  */
-
-      exitstatus = child_main ();
-    }
-  unlink (DATA_FILENAME);
-  return exitstatus;
-}
-]])],
-           [],
-           [gl_cv_func_posix_spawn_works=no])
-       fi
-     else
-       case "$host_os" in
-         aix*) gl_cv_func_posix_spawn_works="guessing no";;
-         *)    gl_cv_func_posix_spawn_works="guessing yes";;
-       esac
-     fi
-    ])
-])
-
-dnl Test whether posix_spawn and posix_spawnp are secure.
-AC_DEFUN([gl_POSIX_SPAWN_SECURE],
-[
-  AC_REQUIRE([AC_PROG_CC])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  dnl On many platforms, posix_spawn or posix_spawnp allow executing a
-  dnl script without a '#!' marker as a shell script. This is unsecure.
-  AC_CACHE_CHECK([whether posix_spawn rejects scripts without shebang],
-    [gl_cv_func_posix_spawn_secure_exec],
-    [echo ':' > conftest.scr
-     chmod a+x conftest.scr
-     AC_RUN_IFELSE([AC_LANG_SOURCE([[
-       #include <errno.h>
-       #include <spawn.h>
-       #include <stddef.h>
-       #include <sys/types.h>
-       #include <sys/wait.h>
-       int
-       main ()
-       {
-         const char *prog_path = "./conftest.scr";
-         const char *prog_argv[2] = { prog_path, NULL };
-         const char *environment[2] = { "PATH=.", NULL };
-         pid_t child;
-         int status;
-         int err = posix_spawn (&child, prog_path, NULL, NULL,
-                                (char **) prog_argv, (char **) environment);
-         if (err == ENOEXEC)
-           return 0;
-         if (err != 0)
-           return 1;
-         status = 0;
-         while (waitpid (child, &status, 0) != child)
-           ;
-         if (!WIFEXITED (status))
-           return 2;
-         if (WEXITSTATUS (status) != 127)
-           return 3;
-         return 0;
-       }
-       ]])],
-       [gl_cv_func_posix_spawn_secure_exec=yes],
-       [gl_cv_func_posix_spawn_secure_exec=no],
-       [case "$host_os" in
-          # Guess no on GNU/Hurd.
-          gnu*)
-            gl_cv_func_posix_spawn_secure_exec="guessing no" ;;
-          # Guess yes on all other platforms.
-          *)
-            gl_cv_func_posix_spawn_secure_exec="guessing yes" ;;
-        esac
-       ])
-     rm -f conftest.scr
-    ])
-  AC_CACHE_CHECK([whether posix_spawnp rejects scripts without shebang],
-    [gl_cv_func_posix_spawnp_secure_exec],
-    [echo ':' > conftest.scr
-     chmod a+x conftest.scr
-     AC_RUN_IFELSE([AC_LANG_SOURCE([[
-       #include <errno.h>
-       #include <spawn.h>
-       #include <stddef.h>
-       #include <sys/types.h>
-       #include <sys/wait.h>
-       int
-       main ()
-       {
-         const char *prog_path = "./conftest.scr";
-         const char *prog_argv[2] = { prog_path, NULL };
-         const char *environment[2] = { "PATH=.", NULL };
-         pid_t child;
-         int status;
-         int err = posix_spawnp (&child, prog_path, NULL, NULL,
-                                 (char **) prog_argv, (char **) environment);
-         if (err == ENOEXEC)
-           return 0;
-         if (err != 0)
-           return 1;
-         status = 0;
-         while (waitpid (child, &status, 0) != child)
-           ;
-         if (!WIFEXITED (status))
-           return 2;
-         if (WEXITSTATUS (status) != 127)
-           return 3;
-         return 0;
-       }
-       ]])],
-       [gl_cv_func_posix_spawnp_secure_exec=yes],
-       [gl_cv_func_posix_spawnp_secure_exec=no],
-       [case "$host_os" in
-          # Guess yes on glibc systems (glibc >= 2.15 actually) except GNU/Hurd,
-          # musl libc, NetBSD.
-          *-gnu* | *-musl* | netbsd*)
-            gl_cv_func_posix_spawnp_secure_exec="guessing yes" ;;
-          # Guess no on GNU/Hurd, macOS, FreeBSD, OpenBSD, AIX, Solaris, Cygwin.
-          gnu* | darwin* | freebsd* | dragonfly* | openbsd* | aix* | solaris* | cygwin*)
-            gl_cv_func_posix_spawnp_secure_exec="guessing no" ;;
-          # If we don't know, obey --enable-cross-guesses.
-          *)
-            gl_cv_func_posix_spawnp_secure_exec="$gl_cross_guess_normal" ;;
-        esac
-       ])
-     rm -f conftest.scr
-    ])
-])
-
-# Prerequisites of lib/spawni.c.
-AC_DEFUN([gl_PREREQ_POSIX_SPAWN_INTERNAL],
-[
-  AC_CHECK_HEADERS([paths.h])
-  AC_CHECK_FUNCS([confstr sched_setparam sched_setscheduler setegid seteuid vfork])
-])
-
-AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE],
-[
-  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
-  AC_REQUIRE([AC_PROG_CC])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  gl_POSIX_SPAWN
-  if test $REPLACE_POSIX_SPAWN = 1; then
-    REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE=1
-  else
-    dnl On musl libc and Solaris 11.0, posix_spawn_file_actions_addclose
-    dnl succeeds even if the fd argument is out of range.
-    AC_CACHE_CHECK([whether posix_spawn_file_actions_addclose works],
-      [gl_cv_func_posix_spawn_file_actions_addclose_works],
-      [AC_RUN_IFELSE(
-         [AC_LANG_SOURCE([[
-#include <spawn.h>
-int main ()
-{
-  posix_spawn_file_actions_t actions;
-  if (posix_spawn_file_actions_init (&actions) != 0)
-    return 1;
-  if (posix_spawn_file_actions_addclose (&actions, 10000000) == 0)
-    return 2;
-  return 0;
-}]])],
-         [gl_cv_func_posix_spawn_file_actions_addclose_works=yes],
-         [gl_cv_func_posix_spawn_file_actions_addclose_works=no],
-         [# Guess no on musl libc and Solaris, yes otherwise.
-          case "$host_os" in
-            *-musl*)  gl_cv_func_posix_spawn_file_actions_addclose_works="guessing no" ;;
-            solaris*) gl_cv_func_posix_spawn_file_actions_addclose_works="guessing no" ;;
-                      # Guess no on native Windows.
-            mingw*)   gl_cv_func_posix_spawn_file_actions_addclose_works="guessing no" ;;
-            *)        gl_cv_func_posix_spawn_file_actions_addclose_works="guessing yes" ;;
-          esac
-         ])
-      ])
-    case "$gl_cv_func_posix_spawn_file_actions_addclose_works" in
-      *yes) ;;
-      *) REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE=1 ;;
-    esac
-  fi
-])
-
-AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2],
-[
-  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
-  AC_REQUIRE([AC_PROG_CC])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  gl_POSIX_SPAWN
-  if test $REPLACE_POSIX_SPAWN = 1; then
-    REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2=1
-  else
-    dnl On musl libc and Solaris 11.0, posix_spawn_file_actions_adddup2
-    dnl succeeds even if the fd argument is out of range.
-    AC_CACHE_CHECK([whether posix_spawn_file_actions_adddup2 works],
-      [gl_cv_func_posix_spawn_file_actions_adddup2_works],
-      [AC_RUN_IFELSE(
-         [AC_LANG_SOURCE([[
-#include <spawn.h>
-int main ()
-{
-  posix_spawn_file_actions_t actions;
-  if (posix_spawn_file_actions_init (&actions) != 0)
-    return 1;
-  if (posix_spawn_file_actions_adddup2 (&actions, 10000000, 2) == 0)
-    return 2;
-  return 0;
-}]])],
-         [gl_cv_func_posix_spawn_file_actions_adddup2_works=yes],
-         [gl_cv_func_posix_spawn_file_actions_adddup2_works=no],
-         [# Guess no on musl libc and Solaris, yes otherwise.
-          case "$host_os" in
-            *-musl*)  gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing no";;
-            solaris*) gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing no";;
-                      # Guess no on native Windows.
-            mingw*)   gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing no" ;;
-            *)        gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing yes";;
-          esac
-         ])
-      ])
-    case "$gl_cv_func_posix_spawn_file_actions_adddup2_works" in
-      *yes) ;;
-      *) REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2=1 ;;
-    esac
-  fi
-])
-
-AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN],
-[
-  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
-  AC_REQUIRE([AC_PROG_CC])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  gl_POSIX_SPAWN
-  if test $REPLACE_POSIX_SPAWN = 1; then
-    REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN=1
-  else
-    dnl On musl libc and Solaris 11.0, posix_spawn_file_actions_addopen
-    dnl succeeds even if the fd argument is out of range.
-    AC_CACHE_CHECK([whether posix_spawn_file_actions_addopen works],
-      [gl_cv_func_posix_spawn_file_actions_addopen_works],
-      [AC_RUN_IFELSE(
-         [AC_LANG_SOURCE([[
-#include <spawn.h>
-#include <fcntl.h>
-int main ()
-{
-  posix_spawn_file_actions_t actions;
-  if (posix_spawn_file_actions_init (&actions) != 0)
-    return 1;
-  if (posix_spawn_file_actions_addopen (&actions, 10000000, "foo", 0, O_RDONLY)
-      == 0)
-    return 2;
-  return 0;
-}]])],
-         [gl_cv_func_posix_spawn_file_actions_addopen_works=yes],
-         [gl_cv_func_posix_spawn_file_actions_addopen_works=no],
-         [# Guess no on musl libc and Solaris, yes otherwise.
-          case "$host_os" in
-            *-musl*)  gl_cv_func_posix_spawn_file_actions_addopen_works="guessing no";;
-            solaris*) gl_cv_func_posix_spawn_file_actions_addopen_works="guessing no";;
-                      # Guess no on native Windows.
-            mingw*)   gl_cv_func_posix_spawn_file_actions_addopen_works="guessing no" ;;
-            *)        gl_cv_func_posix_spawn_file_actions_addopen_works="guessing yes";;
-          esac
-         ])
-      ])
-    case "$gl_cv_func_posix_spawn_file_actions_addopen_works" in
-      *yes) ;;
-      *) REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN=1 ;;
-    esac
-  fi
-])
diff --git a/m4/posix_spawn_faction_addchdir.m4 b/m4/posix_spawn_faction_addchdir.m4
deleted file mode 100644
index 1ce7153d1d1..00000000000
--- a/m4/posix_spawn_faction_addchdir.m4
+++ /dev/null
@@ -1,20 +0,0 @@
-# posix_spawn_faction_addchdir.m4 serial 1
-dnl Copyright (C) 2018-2020 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_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR],
-[
-  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
-  AC_REQUIRE([AC_PROG_CC])
-  gl_POSIX_SPAWN
-  AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addchdir posix_spawn_file_actions_addchdir_np])
-  if test $ac_cv_func_posix_spawn_file_actions_addchdir = yes; then
-    dnl This function is not yet standardized. Therefore override the
-    dnl system's implementation always.
-    REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR=1
-  else
-    HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR=0
-  fi
-])
diff --git a/m4/sched_h.m4 b/m4/sched_h.m4
deleted file mode 100644
index af0c43de079..00000000000
--- a/m4/sched_h.m4
+++ /dev/null
@@ -1,91 +0,0 @@
-# sched_h.m4 serial 12
-dnl Copyright (C) 2008-2020 Free Software Foundation, Inc.
-dnl This file is free software; the Free Software Foundation
-dnl gives unlimited permission to copy and/or distribute it,
-dnl with or without modifications, as long as this notice is preserved.
-
-dnl Written by Bruno Haible.
-
-AC_DEFUN([gl_SCHED_H],
-[
-  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
-  dnl once only, before all statements that occur in other macros.
-  AC_REQUIRE([gl_SCHED_H_DEFAULTS])
-
-  AC_REQUIRE([AC_CANONICAL_HOST])
-
-  AC_CHECK_HEADERS_ONCE([sys/cdefs.h])
-  AC_CHECK_HEADERS([sched.h], [], [],
-    [[#if HAVE_SYS_CDEFS_H
-       #include <sys/cdefs.h>
-      #endif
-    ]])
-  gl_NEXT_HEADERS([sched.h])
-
-  if test "$ac_cv_header_sched_h" = yes; then
-    HAVE_SCHED_H=1
-  else
-    HAVE_SCHED_H=0
-  fi
-  AC_SUBST([HAVE_SCHED_H])
-
-  if test "$HAVE_SCHED_H" = 1; then
-    AC_CHECK_TYPE([struct sched_param],
-      [HAVE_STRUCT_SCHED_PARAM=1], [HAVE_STRUCT_SCHED_PARAM=0],
-      [[#if HAVE_SYS_CDEFS_H
-         #include <sys/cdefs.h>
-        #endif
-        #include <sched.h>
-      ]])
-  else
-    HAVE_STRUCT_SCHED_PARAM=0
-    case "$host_os" in
-      os2*)
-        dnl On OS/2 kLIBC, struct sched_param is in spawn.h.
-        AC_CHECK_TYPE([struct sched_param],
-          [HAVE_STRUCT_SCHED_PARAM=1], [],
-          [#include <spawn.h>])
-        ;;
-      vms)
-        dnl On OpenVMS 7.2 or newer, struct sched_param is in pthread.h.
-        AC_CHECK_TYPE([struct sched_param],
-          [HAVE_STRUCT_SCHED_PARAM=1], [],
-          [#include <pthread.h>])
-        ;;
-    esac
-  fi
-  AC_SUBST([HAVE_STRUCT_SCHED_PARAM])
-
-  if test "$ac_cv_header_sys_cdefs_h" = yes; then
-    HAVE_SYS_CDEFS_H=1
-  else
-    HAVE_SYS_CDEFS_H=0
-  fi
-  AC_SUBST([HAVE_SYS_CDEFS_H])
-
-  dnl Ensure the type pid_t gets defined.
-  AC_REQUIRE([AC_TYPE_PID_T])
-
-  dnl Check for declarations of anything we want to poison if the
-  dnl corresponding gnulib module is not in use, if it is not common
-  dnl enough to be declared everywhere.
-  gl_WARN_ON_USE_PREPARE([[#include <sched.h>
-    ]], [sched_yield])
-])
-
-AC_DEFUN([gl_SCHED_MODULE_INDICATOR],
-[
-  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
-  AC_REQUIRE([gl_SCHED_H_DEFAULTS])
-  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
-  dnl Define it also as a C macro, for the benefit of the unit tests.
-  gl_MODULE_INDICATOR_FOR_TESTS([$1])
-])
-
-AC_DEFUN([gl_SCHED_H_DEFAULTS],
-[
-  GNULIB_SCHED_YIELD=0;  AC_SUBST([GNULIB_SCHED_YIELD])
-  dnl Assume proper GNU behavior unless another module says otherwise.
-  HAVE_SCHED_YIELD=1;    AC_SUBST([HAVE_SCHED_YIELD])
-  REPLACE_SCHED_YIELD=0; AC_SUBST([REPLACE_SCHED_YIELD])
-])
diff --git a/m4/sh-filename.m4 b/m4/sh-filename.m4
deleted file mode 100644
index f7b31548e0d..00000000000
--- a/m4/sh-filename.m4
+++ /dev/null
@@ -1,22 +0,0 @@
-# sh-filename.m4 serial 2
-dnl Copyright (C) 2018-2020 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 From Bruno Haible.
-
-AC_DEFUN([gl_SH_FILENAME],
-[
-  AH_VERBATIM([SH_FILENAME],
-[/* File name of the Bourne shell.  */
-#if defined __CYGWIN__ || defined __ANDROID__
-/* Omit the directory part because
-   - For 32-bit Cygwin programs in a 64-bit Cygwin environment, the Cygwin
-     mounts are not visible.
-   - On Android, /bin/sh does not exist. It's /system/bin/sh instead.  */
-# define BOURNE_SHELL "sh"
-#else
-# define BOURNE_SHELL "/bin/sh"
-#endif])
-])
diff --git a/m4/spawn_h.m4 b/m4/spawn_h.m4
deleted file mode 100644
index 781f9f49652..00000000000
--- a/m4/spawn_h.m4
+++ /dev/null
@@ -1,136 +0,0 @@
-# spawn_h.m4 serial 18
-dnl Copyright (C) 2008-2020 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 Written by Bruno Haible.
-
-AC_DEFUN([gl_SPAWN_H],
-[
-  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
-  dnl once only, before all statements that occur in other macros.
-  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
-
-  dnl <spawn.h> is always overridden, because of GNULIB_POSIXCHECK.
-  gl_CHECK_NEXT_HEADERS([spawn.h])
-
-  if test $ac_cv_header_spawn_h = yes; then
-    HAVE_SPAWN_H=1
-    AC_CHECK_TYPES([posix_spawnattr_t], [], [HAVE_POSIX_SPAWNATTR_T=0], [[
-#include <spawn.h>
-      ]])
-    AC_CHECK_TYPES([posix_spawn_file_actions_t], [],
-      [HAVE_POSIX_SPAWN_FILE_ACTIONS_T=0], [[
-#include <spawn.h>
-      ]])
-  else
-    HAVE_SPAWN_H=0
-    HAVE_POSIX_SPAWNATTR_T=0
-    HAVE_POSIX_SPAWN_FILE_ACTIONS_T=0
-  fi
-  AC_SUBST([HAVE_SPAWN_H])
-
-  dnl Ensure the type pid_t gets defined.
-  AC_REQUIRE([AC_TYPE_PID_T])
-
-  dnl Ensure the type mode_t gets defined.
-  AC_REQUIRE([AC_TYPE_MODE_T])
-
-  AC_REQUIRE([gl_HAVE_POSIX_SPAWN])
-
-  AC_REQUIRE([AC_C_RESTRICT])
-
-  dnl Check for declarations of anything we want to poison if the
-  dnl corresponding gnulib module is not in use.
-  gl_WARN_ON_USE_PREPARE([[#include <spawn.h>
-    ]], [posix_spawn posix_spawnp posix_spawnattr_init posix_spawnattr_destroy
-    posix_spawnattr_getsigdefault posix_spawnattr_setsigdefault
-    posix_spawnattr_getsigmask posix_spawnattr_setsigmask
-    posix_spawnattr_getflags posix_spawnattr_setflags
-    posix_spawnattr_getpgroup posix_spawnattr_setpgroup
-    posix_spawnattr_getschedpolicy posix_spawnattr_setschedpolicy
-    posix_spawnattr_getschedparam posix_spawnattr_setschedparam
-    posix_spawn_file_actions_init posix_spawn_file_actions_destroy
-    posix_spawn_file_actions_addopen posix_spawn_file_actions_addclose
-    posix_spawn_file_actions_adddup2 posix_spawn_file_actions_addchdir
-    posix_spawn_file_actions_addfchdir])
-])
-
-dnl Checks whether the system has the functions posix_spawn.
-dnl Sets ac_cv_func_posix_spawn and HAVE_POSIX_SPAWN.
-AC_DEFUN([gl_HAVE_POSIX_SPAWN],
-[
-  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
-  dnl once only, before all statements that occur in other macros.
-  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
-
-  LIB_POSIX_SPAWN=
-  AC_SUBST([LIB_POSIX_SPAWN])
-  gl_saved_libs=$LIBS
-    AC_SEARCH_LIBS([posix_spawn], [rt],
-                   [test "$ac_cv_search_posix_spawn" = "none required" ||
-                    LIB_POSIX_SPAWN=$ac_cv_search_posix_spawn])
-    AC_CHECK_FUNCS([posix_spawn])
-  LIBS=$gl_saved_libs
-
-  if test $ac_cv_func_posix_spawn != yes; then
-    HAVE_POSIX_SPAWN=0
-  fi
-])
-
-AC_DEFUN([gl_SPAWN_MODULE_INDICATOR],
-[
-  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
-  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
-  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
-  dnl Define it also as a C macro, for the benefit of the unit tests.
-  gl_MODULE_INDICATOR_FOR_TESTS([$1])
-])
-
-AC_DEFUN([gl_SPAWN_H_DEFAULTS],
-[
-  GNULIB_POSIX_SPAWN=0;                        AC_SUBST([GNULIB_POSIX_SPAWN])
-  GNULIB_POSIX_SPAWNP=0;                       AC_SUBST([GNULIB_POSIX_SPAWNP])
-  GNULIB_POSIX_SPAWN_FILE_ACTIONS_INIT=0;      AC_SUBST([GNULIB_POSIX_SPAWN_FILE_ACTIONS_INIT])
-  GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR=0;  AC_SUBST([GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR])
-  GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE=0;  AC_SUBST([GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE])
-  GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2=0;   AC_SUBST([GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2])
-  GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDFCHDIR=0; AC_SUBST([GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDFCHDIR])
-  GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN=0;   AC_SUBST([GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN])
-  GNULIB_POSIX_SPAWN_FILE_ACTIONS_DESTROY=0;   AC_SUBST([GNULIB_POSIX_SPAWN_FILE_ACTIONS_DESTROY])
-  GNULIB_POSIX_SPAWNATTR_INIT=0;               AC_SUBST([GNULIB_POSIX_SPAWNATTR_INIT])
-  GNULIB_POSIX_SPAWNATTR_GETFLAGS=0;           AC_SUBST([GNULIB_POSIX_SPAWNATTR_GETFLAGS])
-  GNULIB_POSIX_SPAWNATTR_SETFLAGS=0;           AC_SUBST([GNULIB_POSIX_SPAWNATTR_SETFLAGS])
-  GNULIB_POSIX_SPAWNATTR_GETPGROUP=0;          AC_SUBST([GNULIB_POSIX_SPAWNATTR_GETPGROUP])
-  GNULIB_POSIX_SPAWNATTR_SETPGROUP=0;          AC_SUBST([GNULIB_POSIX_SPAWNATTR_SETPGROUP])
-  GNULIB_POSIX_SPAWNATTR_GETSCHEDPARAM=0;      AC_SUBST([GNULIB_POSIX_SPAWNATTR_GETSCHEDPARAM])
-  GNULIB_POSIX_SPAWNATTR_SETSCHEDPARAM=0;      AC_SUBST([GNULIB_POSIX_SPAWNATTR_SETSCHEDPARAM])
-  GNULIB_POSIX_SPAWNATTR_GETSCHEDPOLICY=0;     AC_SUBST([GNULIB_POSIX_SPAWNATTR_GETSCHEDPOLICY])
-  GNULIB_POSIX_SPAWNATTR_SETSCHEDPOLICY=0;     AC_SUBST([GNULIB_POSIX_SPAWNATTR_SETSCHEDPOLICY])
-  GNULIB_POSIX_SPAWNATTR_GETSIGDEFAULT=0;      AC_SUBST([GNULIB_POSIX_SPAWNATTR_GETSIGDEFAULT])
-  GNULIB_POSIX_SPAWNATTR_SETSIGDEFAULT=0;      AC_SUBST([GNULIB_POSIX_SPAWNATTR_SETSIGDEFAULT])
-  GNULIB_POSIX_SPAWNATTR_GETSIGMASK=0;         AC_SUBST([GNULIB_POSIX_SPAWNATTR_GETSIGMASK])
-  GNULIB_POSIX_SPAWNATTR_SETSIGMASK=0;         AC_SUBST([GNULIB_POSIX_SPAWNATTR_SETSIGMASK])
-  GNULIB_POSIX_SPAWNATTR_DESTROY=0;            AC_SUBST([GNULIB_POSIX_SPAWNATTR_DESTROY])
-  dnl Assume proper GNU behavior unless another module says otherwise.
-  HAVE_POSIX_SPAWN=1;        AC_SUBST([HAVE_POSIX_SPAWN])
-  HAVE_POSIX_SPAWNATTR_T=1;  AC_SUBST([HAVE_POSIX_SPAWNATTR_T])
-  HAVE_POSIX_SPAWN_FILE_ACTIONS_T=1;
-                             AC_SUBST([HAVE_POSIX_SPAWN_FILE_ACTIONS_T])
-  HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR=1;
-                             AC_SUBST([HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR])
-  HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDFCHDIR=1;
-                             AC_SUBST([HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDFCHDIR])
-  REPLACE_POSIX_SPAWN=0;     AC_SUBST([REPLACE_POSIX_SPAWN])
-  REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR=0;
-                             AC_SUBST([REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR])
-  REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE=0;
-                             AC_SUBST([REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE])
-  REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2=0;
-                             AC_SUBST([REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2])
-  REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDFCHDIR=0;
-                             AC_SUBST([REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDFCHDIR])
-  REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN=0;
-                             AC_SUBST([REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN])
-])
diff --git a/m4/strchrnul.m4 b/m4/strchrnul.m4
deleted file mode 100644
index a18f0935a51..00000000000
--- a/m4/strchrnul.m4
+++ /dev/null
@@ -1,50 +0,0 @@
-# strchrnul.m4 serial 9
-dnl Copyright (C) 2003, 2007, 2009-2020 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_STRCHRNUL],
-[
-  dnl Persuade glibc <string.h> to declare strchrnul().
-  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
-
-  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
-  AC_CHECK_FUNCS([strchrnul])
-  if test $ac_cv_func_strchrnul = no; then
-    HAVE_STRCHRNUL=0
-  else
-    AC_CACHE_CHECK([whether strchrnul works],
-      [gl_cv_func_strchrnul_works],
-      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
-#include <string.h> /* for strchrnul */
-]], [[const char *buf = "a";
-      return strchrnul (buf, 'b') != buf + 1;
-    ]])],
-        [gl_cv_func_strchrnul_works=yes],
-        [gl_cv_func_strchrnul_works=no],
-        [dnl Cygwin 1.7.9 introduced strchrnul, but it was broken until 1.7.10
-         AC_EGREP_CPP([Lucky user],
-           [
-#if defined __CYGWIN__
- #include <cygwin/version.h>
- #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 9)
-  Lucky user
- #endif
-#else
-  Lucky user
-#endif
-           ],
-           [gl_cv_func_strchrnul_works="guessing yes"],
-           [gl_cv_func_strchrnul_works="guessing no"])
-        ])
-      ])
-    case "$gl_cv_func_strchrnul_works" in
-      *yes) ;;
-      *) REPLACE_STRCHRNUL=1 ;;
-    esac
-  fi
-])
-
-# Prerequisites of lib/strchrnul.c.
-AC_DEFUN([gl_PREREQ_STRCHRNUL], [:])