[committed 1/3] AC_USE_SYSTEM_EXTENSIONS now enables C23 Annex F

[Paul Eggert]

* lib/autoconf/specific.m4 (AC_USE_SYSTEM_EXTENSIONS):
Also define __STDC_WANT_IEC_60559_EXT__, for C23.
---
 NEWS                     | 3 +++
 doc/autoconf.texi        | 5 ++++-
 lib/autoconf/specific.m4 | 7 ++++++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index 7223fed6..33e1948c 100644
--- a/NEWS
+++ b/NEWS
@@ -21,6 +21,9 @@ GNU Autoconf NEWS - User visible changes.
   that you will get a confusing error message if you run autoconf on
   a configure.ac that neglects to use AC_INIT or AC_OUTPUT.
 
+*** AC_USE_SYSTEM_EXTENSIONS now enables C23 Annex F extensions
+  by defining __STDC_WANT_IEC_60559_EXT__.
+
 *** AC_SYS_LARGEFILE now arranges for 64-bit time_t if possible.
 
 *** m4sh diversions like BINSH have been renumbered.
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 7ae8ca64..5948902f 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -8926,12 +8926,15 @@ Enable extensions specified by ISO/IEC TS 18661-1:2014.
 @item __STDC_WANT_IEC_60559_DFP_EXT__
 @cvindex __STDC_WANT_IEC_60559_DFP_EXT__
 Enable extensions specified by ISO/IEC TS 18661-2:2015.
+@item __STDC_WANT_IEC_60559_EXT__
+@cvindex __STDC_WANT_IEC_60559_EXT__
+Enable extensions specified by C23 Annex F.
 @item __STDC_WANT_IEC_60559_FUNCS_EXT__
 @cvindex __STDC_WANT_IEC_60559_FUNCS_EXT__
 Enable extensions specified by ISO/IEC TS 18661-4:2015.
 @item __STDC_WANT_IEC_60559_TYPES_EXT__
 @cvindex __STDC_WANT_IEC_60559_TYPES_EXT__
-Enable extensions specified by ISO/IEC TS 18661-3:2015.
+Enable extensions specified by C23 Annex H and by ISO/IEC TS 18661-3:2015.
 @item __STDC_WANT_LIB_EXT2__
 @cvindex __STDC_WANT_LIB_EXT2__
 Enable extensions specified by ISO/IEC TR 24731-2:2010.
diff --git a/lib/autoconf/specific.m4 b/lib/autoconf/specific.m4
index 0a9adba5..576212a3 100644
--- a/lib/autoconf/specific.m4
+++ b/lib/autoconf/specific.m4
@@ -545,11 +545,15 @@ AH_VERBATIM([USE_SYSTEM_EXTENSIONS],
 #ifndef __STDC_WANT_IEC_60559_DFP_EXT__
 # undef __STDC_WANT_IEC_60559_DFP_EXT__
 #endif
+/* Enable extensions specified by C23 Annex F.  */
+#ifndef __STDC_WANT_IEC_60559_EXT__
+# undef __STDC_WANT_IEC_60559_EXT__
+#endif
 /* Enable extensions specified by ISO/IEC TS 18661-4:2015.  */
 #ifndef __STDC_WANT_IEC_60559_FUNCS_EXT__
 # undef __STDC_WANT_IEC_60559_FUNCS_EXT__
 #endif
-/* Enable extensions specified by ISO/IEC TS 18661-3:2015.  */
+/* Enable extensions specified by C23 Annex H and ISO/IEC TS 18661-3:2015.  */
 #ifndef __STDC_WANT_IEC_60559_TYPES_EXT__
 # undef __STDC_WANT_IEC_60559_TYPES_EXT__
 #endif
@@ -619,6 +623,7 @@ dnl it should only be defined when necessary.
   AC_DEFINE([__STDC_WANT_IEC_60559_ATTRIBS_EXT__])
   AC_DEFINE([__STDC_WANT_IEC_60559_BFP_EXT__])
   AC_DEFINE([__STDC_WANT_IEC_60559_DFP_EXT__])
+  AC_DEFINE([__STDC_WANT_IEC_60559_EXT__])
   AC_DEFINE([__STDC_WANT_IEC_60559_FUNCS_EXT__])
   AC_DEFINE([__STDC_WANT_IEC_60559_TYPES_EXT__])
   AC_DEFINE([__STDC_WANT_LIB_EXT2__])
-- 
2.38.1