Re: [PATCH] getopt-posix: port better to Alpine 3.20.0_rc1

[Bruno Haible]

Paul Eggert wrote:
> +     * m4/getopt.m4 (gl_GETOPT_SUBSTITUTE_HEADER):
> +     * m4/sched_h.m4 (gl_SCHED_H): Use the new macro
> +     gl_CHECK_HEADER_SYS_CDEFS_H instead of checking independently.
> +     * m4/sys_cdefs_h.m4: New file.

Running './bootstrap' in diffutils, I see a warning:

autoreconf: running: /darch/x86_64-linux-gnu/gnu/bin/autoconf --include=m4 
--force
configure.ac:43: warning: AC_REQUIRE: 'gl_CHECK_HEADER_SYS_CDEFS_H' was 
expanded before it was required
configure.ac:43: 
https://www.gnu.org/software/autoconf/manual/autoconf.html#Expanded-Before-Required
m4/gnulib-comp.m4:699: gl_INIT is expanded from...
configure.ac:43: the top level

This patch fixes it.


2024-05-21  Bruno Haible  <bruno@clisp.org>

        Fix "'gl_CHECK_HEADER_SYS_CDEFS_H' was expanded before it was required".
        * m4/sys_cdefs_h.m4 (gl_CHECK_HEADER_SYS_CDEFS_H): Define through
        AC_DEFUN_ONCE.

diff --git a/m4/sys_cdefs_h.m4 b/m4/sys_cdefs_h.m4
index 069146d438..22fa6c3849 100644
--- a/m4/sys_cdefs_h.m4
+++ b/m4/sys_cdefs_h.m4
@@ -1,5 +1,5 @@
 # sys_cdefs_h.m4 - Is <sys/cdefs.h> compatible enough with glibc?
-# serial 1
+# serial 2
 dnl Copyright 2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,7 +7,7 @@
 
 dnl Written by Paul Eggert.
 
-AC_DEFUN([gl_CHECK_HEADER_SYS_CDEFS_H],
+AC_DEFUN_ONCE([gl_CHECK_HEADER_SYS_CDEFS_H],
   [AC_CACHE_CHECK([for glibc-compatible sys/cdefs.h],
      [gl_cv_header_sys_cdefs_h],
      [AC_COMPILE_IFELSE(