Bruno Haible via Gnulib discussion list <bug-gnulib@gnu.org> writes:
> This patch fixes it.
After this patch I noticed some autoconf warnings when running
./bootstrap. Here is a simple way to reproduce:
$ gnulib-tool --create-testdir --dir testdir1 stddef-h
[...]
configure.ac:168: warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call
detected in body
./lib/autoconf/lang.m4:199: AC_LANG_CONFTEST is expanded from...
./lib/autoconf/general.m4:2821: _AC_COMPILE_IFELSE is expanded from...
./lib/autoconf/general.m4:2837: AC_COMPILE_IFELSE is expanded from...
lib/m4sugar/m4sh.m4:690: _AS_IF_ELSE is expanded from...
lib/m4sugar/m4sh.m4:697: AS_IF is expanded from...
./lib/autoconf/general.m4:2249: AC_CACHE_VAL is expanded from...
./lib/autoconf/general.m4:2270: AC_CACHE_CHECK is expanded from...
configure.ac:32: gl_INIT is expanded from...
configure.ac:168: the top level
I assume your patch is correct and these warnings are harmless since
building programs with GCC 14 and 15 worked fine for me.
But I have pushed the attached patch to prevent this warning from
causing confusion.
Collin
>From 0f9fb17a13956721aa0ab8553f13a1f736492abd Mon Sep 17 00:00:00 2001
From: Collin Funk <collin.fu...@gmail.com>
Date: Tue, 8 Apr 2025 21:20:39 -0700
Subject: [PATCH] stddef-h: Silence autoconf warnings introduced in previous
commit.
* m4/stddef_h.m4 (gl_STDDEF_H): Use AC_LANG_SOURCE inside call to
AC_COMPILE_IFELSE.
---
ChangeLog | 6 ++++++
m4/stddef_h.m4 | 7 ++++---
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index cf3e040ada..f213c4a4f9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2025-04-08 Collin Funk <collin.fu...@gmail.com>
+
+ stddef-h: Silence autoconf warnings introduced in previous commit.
+ * m4/stddef_h.m4 (gl_STDDEF_H): Use AC_LANG_SOURCE inside call to
+ AC_COMPILE_IFELSE.
+
2025-04-08 Bruno Haible <br...@clisp.org>
stddef-h: Make a configure test work with upcoming GCC 15.
diff --git a/m4/stddef_h.m4 b/m4/stddef_h.m4
index 13aff50e71..a6bc624314 100644
--- a/m4/stddef_h.m4
+++ b/m4/stddef_h.m4
@@ -1,5 +1,5 @@
# stddef_h.m4
-# serial 18
+# serial 19
dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -94,11 +94,12 @@ AC_DEFUN_ONCE([gl_STDDEF_H]
dnl affects GCC 13 and 14.
AC_CACHE_CHECK([whether <stddef.h> is idempotent],
[gl_cv_stddef_idempotent],
- [AC_COMPILE_IFELSE([
+ [AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+ [[
#if __GNUC__ == 13 || __GNUC__ == 14
#error "bug 114870 is present"
#endif
- ],
+ ]])],
[gl_cv_stddef_idempotent="guessing yes"],
[gl_cv_stddef_idempotent="guessing no"])
])
--
2.49.0
