sim: switch config.h usage to defs.h

The defs.h header will take care of including the various config.h
headers.  For now, it's just config.h, but we'll add more when we
integrate gnulib in.

This header should be used instead of config.h, and should be the
first include in every .c file.  We won't rely on the old behavior
where we expected files to include the port's sim-main.h which then
includes the common sim-basics.h which then includes config.h.  We
have a ton of code that includes things before sim-main.h, and it
sometimes needs to be that way.  Creating a dedicated header avoids
the ordering mess and implicit inclusion that shows up otherwise.

1 files changed, 30 insertions, 0 deletions

diff --git a/sim/common/defs.h b/sim/common/defs.h
new file mode 100644
index 0000000..3a0737c
--- /dev/null
+++ b/sim/common/defs.h
@@ -0,0 +1,30 @@
+/* The configure generated header settings.
+
+   Copyright 2002-2021 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
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* This file should be included by every .c file before any other header.  */
+
+#ifndef DEFS_H
+#define DEFS_H
+
+#ifdef HAVE_CONFIG_H
+
+/* Include sim's various configure tests.  */
+#include "config.h"
+
+#endif
+
+#endif