Fix autoheader 2.62 regression on AC_DEFINE([__EXTENSIONS__]).

* lib/autoconf/specific.m4 (AC_USE_SYSTEM_EXTENSIONS): Use a
unique key for the AH_VERBATIM.
* tests/c.at (AC_USE_SYSTEM_EXTENSIONS): New test.
* NEWS: Mention the fix.
Reported by Andreas Schwab, analyzed by Stepan Kasal.

Signed-off-by: Eric Blake <ebb9@byu.net>

diff --git a/ChangeLog b/ChangeLog
index 60b3ee548f5aac9a6ff1c1012652e7260b0779ba..4c4cc3add6ca9327244131ebce131cfae62c966e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2008-08-06  Eric Blake  <ebb9@byu.net>
 
+       Fix autoheader 2.62 regression on AC_DEFINE([__EXTENSIONS__]).
+       * lib/autoconf/specific.m4 (AC_USE_SYSTEM_EXTENSIONS): Use a
+       unique key for the AH_VERBATIM.
+       * tests/c.at (AC_USE_SYSTEM_EXTENSIONS): New test.
+       * NEWS: Mention the fix.
+       Reported by Andreas Schwab, analyzed by Stepan Kasal.
+
        Add linear m4_cond for m4 1.4.x.
        * lib/m4sugar/m4sugar.m4 (m4_cond): Split into...
        (_m4_cond): ...this, for fewer macros per iteration.

diff --git a/NEWS b/NEWS
index efd7f46ecb64d16633d06237137a997b20793d10..dbff114c5a13dee2bdbcee07be7fe4b880e434ce 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,11 @@ GNU Autoconf NEWS - User visible changes.
 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
    library directories.
 
+** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
+   AC_DEFINE([__EXTENSIONS__]).  This fixes a regression introduced in
+   2.62 when using macros such as AC_AIX that were made obsolete in
+   favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
+
 ** Newly obsolete macros
    The following macro has been marked obsolete, since current porting
    targets can safely assume C89 semantics that signal handlers return

diff --git a/lib/autoconf/specific.m4 b/lib/autoconf/specific.m4
index d183d595c9d158d12565f64196f45eeac3e9f9b1..5fcfe377c82e98e500464657cbc5e27d3b592c8a 100644 (file)
--- a/lib/autoconf/specific.m4
+++ b/lib/autoconf/specific.m4
@@ -2,7 +2,8 @@
 # Macros that test for specific, unclassified, features.
 #
 # Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
-# 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+# 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation,
+# Inc.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -398,7 +399,9 @@ AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
       [Define to 1 if on MINIX.])
   fi
 
-  AH_VERBATIM([__EXTENSIONS__],
+dnl Use a different key than __EXTENSIONS__, as that name broke existing
+dnl configure.ac when using autoheader 2.62.
+  AH_VERBATIM([USE_SYSTEM_EXTENSIONS],
 [/* Enable extensions on AIX 3, Interix.  */
 #ifndef _ALL_SOURCE
 # undef _ALL_SOURCE

diff --git a/tests/c.at b/tests/c.at
index 39fcb181a436335b86d73bfb83181e11bebd7355..bc07c6ebc5e45f49a4de48ecfe58c17d5c681292 100644 (file)
--- a/tests/c.at
+++ b/tests/c.at
@@ -2,8 +2,8 @@
 
 AT_BANNER([C low level compiling/preprocessing macros.])
 
-# Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
-# Foundation, Inc.
+# Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2008 Free
+# Software Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -232,3 +232,26 @@ AT_CHECK_MACRO([AC_NO_EXECUTABLES (broken linker)],
 AC_NO_EXECUTABLES
 AC_PROG_CC
 ])
+
+
+## -------------------------- ##
+## AC_USE_SYSTEM_EXTENSIONS.  ##
+## -------------------------- ##
+
+AT_SETUP([AC_USE_SYSTEM_EXTENSIONS])
+
+# Some existing configure.ac mixed AC_AIX (now an alias for
+# AC_USE_SYSTEM_EXTENSIONS) and AC_DEFINE([__EXTENSIONS__]), which
+# broke autoheader in 2.62.  Test that this is supported.
+
+_AT_CHECK_AC_MACRO(
+[[AC_AIX
+AC_DEFINE([__EXTENSIONS__], [1], [Manually defined for Solaris])
+]])
+
+_AT_CHECK_AC_MACRO(
+[[AC_USE_SYSTEM_EXTENSIONS
+AC_DEFINE([__EXTENSIONS__], [1], [Manually defined for Solaris])
+]])
+
+AT_CLEANUP