Re: O_NOFOLLOW on NetBSD

[Bruno Haible]

Paul Eggert wrote:
> https://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/sys/sys/featuretest.h
> 
> says that defining _NETBSD_SOURCE should be helpful only if _ANSI_SOURCE, 
> _POSIX_SOURCE, _POSIX_C_SOURCE, or _XOPEN_SOURCE is defined. I suppose it 
> shouldn't hurt to define _NETBSD_SOURCE, to handle these (presumably rare) 
> configurations.

Yes, I agree. Our 'extensions' module does not define any of
_ANSI_SOURCE, _POSIX_SOURCE, _POSIX_C_SOURCE, or _XOPEN_SOURCE on NetBSD
(I checked it with NetBSD 7.0), therefore with the default CFLAGS and CPPFLAGS
this patch is a no-op. But when someone uses -D_XOPEN_SOURCE=500 or something
like that, gnulib would not operate properly without -D_NETBSD_SOURCE:
configure produces wrong findings for REPLACE_FCNTL, REPLACE_FSTATAT,
REPLACE_DUPLOCALE, REPLACE_RENAMEAT, HAVE_COPYSIGN, REPLACE_SYMLINKAT,
REPLACE_LINKAT, REPLACE_FCHOWNAT, REPLACE_UNSETENV, REPLACE_PTSNAME_R,
and so on.


2017-08-15  Bruno Haible  <address@hidden>

        extensions: Enable NetBSD specific extensions.
        * m4/extensions.m4 (AC_USE_SYSTEM_EXTENSIONS): Define _NETBSD_SOURCE.

diff --git a/m4/extensions.m4 b/m4/extensions.m4
index 0c16bb8..f854338 100644
--- a/m4/extensions.m4
+++ b/m4/extensions.m4
@@ -1,4 +1,4 @@
-# serial 16  -*- Autoconf -*-
+# serial 17  -*- Autoconf -*-
 # Enable extensions on systems that normally disable them.
 
 # Copyright (C) 2003, 2006-2017 Free Software Foundation, Inc.
@@ -68,6 +68,10 @@ dnl configure.ac when using autoheader 2.62.
 #ifndef _GNU_SOURCE
 # undef _GNU_SOURCE
 #endif
+/* Enable NetBSD extensions on NetBSD.  */
+#ifndef _NETBSD_SOURCE
+# undef _NETBSD_SOURCE
+#endif
 /* Enable OpenBSD extensions on NetBSD.  */
 #ifndef _OPENBSD_SOURCE
 # undef _OPENBSD_SOURCE
@@ -132,6 +136,7 @@ dnl configure.ac when using autoheader 2.62.
   AC_DEFINE([_ALL_SOURCE])
   AC_DEFINE([_DARWIN_C_SOURCE])
   AC_DEFINE([_GNU_SOURCE])
+  AC_DEFINE([_NETBSD_SOURCE])
   AC_DEFINE([_OPENBSD_SOURCE])
   AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
   AC_DEFINE([__STDC_WANT_IEC_60559_ATTRIBS_EXT__])