From 8488c357ce4fc309d49c7b0224cf9574b68e8116 Mon Sep 17 00:00:00 2001
From: Kevin Buettner <kevinb@redhat.com>
Date: Thu, 18 Feb 2021 22:46:58 -0700
Subject: [PATCH] amd64-linux-siginfo.c: Adjust include order to avoid gnulib
 error

On Fedora rawhide, after updating to glibc-2.33, I'm seeing the
following build failure:

  CXX    nat/amd64-linux-siginfo.o
In file included from /usr/include/bits/sigstksz.h:24,
                 from /usr/include/signal.h:315,
                 from ../gnulib/import/signal.h:52,
                 from /ironwood1/sourceware-git/rawhide-gnulib/bld/../../worktree-gnulib/gdbserver/../gdb/nat/amd64-linux-siginfo.c:20:
../gnulib/import/unistd.h:663:3: error: #error "Please include config.h first."
  663 |  #error "Please include config.h first."
      |   ^~~~~

glibc-2.33 has changed signal.h to now include <bits/sigstksz.h> which,
in turn, includes <unistd.h>. For a gdb build, this causes the gnulib
version of unistd.h to be pulled in first.  The build failure shown
above happens because gnulib's config.h has not been included before
the include of <signal.h>.

The fix is simple - we just rearrange the order of the header file
includes to make sure that gdbsupport/commondefs.h is included before
attempting to include signal.h.  Note that gdbsupport/commondefs.h
includes <gnulib/config.h>.

Build and regression tested on Fedora 33.  On Fedora rawhide, GDB
builds again.

--- a/gdb/nat/amd64-linux-siginfo.c
+++ b/gdb/nat/amd64-linux-siginfo.c
@@ -17,8 +17,8 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <signal.h>
 #include "gdbsupport/common-defs.h"
+#include <signal.h>
 #include "amd64-linux-siginfo.h"
 
 #define GDB_SI_SIZE 128
-- 
2.27.0
