stdio-windows: Prefer AC_CHECK_FUNCS_ONCE to AC_CHECK_FUNCS.

[Collin Funk]

Hi Bruno,

When running 'make check' I saw this error:

    modules/stdio-windows
    use AC_CHECK_FUNCS_ONCE, not AC_CHECK_FUNCS in modules/
    make: *** [Makefile:35: sc_prefer_ac_check_funcs_once] Error 1

Is there any reason for stdio-windows should be treated differently? I
assume not so I have attached the patch that fixes it, but I don't know
much about this module so figured I should ask before pushing.

Collin


>From 410913408ed713cbd152cc12db6c1be2b51e58be Mon Sep 17 00:00:00 2001
Message-ID: <410913408ed713cbd152cc12db6c1be2b51e58be.1773717794.git.collin.fu...@gmail.com>
From: Collin Funk <collin.fu...@gmail.com>
Date: Mon, 16 Mar 2026 20:22:48 -0700
Subject: [PATCH] stdio-windows: Prefer AC_CHECK_FUNCS_ONCE to AC_CHECK_FUNCS.

This fixes 'make sc_prefer_ac_check_funcs_once'.

* modules/stdio-windows (configure.ac): Use AC_CHECK_FUNCS_ONCE instead
of AC_CHECK_FUNCS when checking for vasprintf.
---
 ChangeLog             | 7 +++++++
 modules/stdio-windows | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 1032063da7..d2ba58f6f2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2026-03-16  Collin Funk  <collin.fu...@gmail.com>
+
+	stdio-windows: Prefer AC_CHECK_FUNCS_ONCE to AC_CHECK_FUNCS.
+	This fixes 'make sc_prefer_ac_check_funcs_once'.
+	* modules/stdio-windows (configure.ac): Use AC_CHECK_FUNCS_ONCE instead
+	of AC_CHECK_FUNCS when checking for vasprintf.
+
 2026-03-16  Paul Eggert  <egg...@cs.ucla.edu>
 
 	stdbit-h: don’t generate some dummy .o files
diff --git a/modules/stdio-windows b/modules/stdio-windows
index 8cbca1be1b..9a18fe58d1 100644
--- a/modules/stdio-windows
+++ b/modules/stdio-windows
@@ -23,7 +23,7 @@ case "$host_os" in
     ;;
 esac
 gl_CONDITIONAL([GL_COND_OBJ_STDIO_CONSOLESAFE], [test $USES_MSVCRT = 1])
-AC_CHECK_FUNCS([vasprintf])
+AC_CHECK_FUNCS_ONCE([vasprintf])
 
 Makefile.am:
 if GL_COND_OBJ_STDIO_CONSOLESAFE
-- 
2.53.0