From 7e9de36c3a524b63e0d21a8cc634b40404bb3200 Mon Sep 17 00:00:00 2001
From: Ed Maste <emaste@FreeBSD.org>
Date: Thu, 15 Dec 2016 12:57:03 +0000
Subject: [PATCH] newvers.sh: add option to eliminate kernel build metadata

Build metadata (username, hostname, etc.) prevents the FreeBSD kernel
from building reproducibly. Add an option to disable inclusion of that
metadata but retain the release information and SVN/git VCS details.
See https://reproducible-builds.org/ for additional background.

Reviewed by:	bapt
Obtained from:	NetBSD
MFC after:	1 month
Sponsored by:	Reproducible Builds World Summit 2, Berlin
Differential Revision:	https://reviews.freebsd.org/D4347
---
 sys/conf/newvers.sh | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/sys/conf/newvers.sh b/sys/conf/newvers.sh
index 72e9ae60610a..9e018f769f0e 100644
--- a/sys/conf/newvers.sh
+++ b/sys/conf/newvers.sh
@@ -30,6 +30,14 @@
 #	@(#)newvers.sh	8.1 (Berkeley) 4/20/94
 # $FreeBSD$
 
+# Command line options:
+#
+#     -r               Reproducible build.  Do not embed directory names, user
+#                      names, time stamps or other dynamic information into
+#                      the outuput file.  This is intended to allow two builds
+#                      done at different times and even by different people on
+#                      different hosts to produce identical output.
+
 TYPE="FreeBSD"
 REVISION="12.0"
 BRANCH="CURRENT"
@@ -250,10 +258,28 @@ if [ -n "$hg_cmd" ] ; then
 	fi
 fi
 
+include_metadata=true
+while getopts r opt; do
+	case "$opt" in
+	r)
+		include_metadata=
+		;;
+	esac
+done
+shift $((OPTIND - 1))
+
+if [ -z "${include_metadata}" ]; then
+	VERINFO="${VERSION} ${svn}${git}${hg}${p4version}"
+	VERSTR="${VERINFO}\\n"
+else
+	VERINFO="${VERSION} #${v}${svn}${git}${hg}${p4version}: ${t}"
+	VERSTR="${VERINFO}\\n    ${u}@${h}:${d}\\n"
+fi
+
 cat << EOF > vers.c
 $COPYRIGHT
-#define SCCSSTR "@(#)${VERSION} #${v}${svn}${git}${hg}${p4version}: ${t}"
-#define VERSTR "${VERSION} #${v}${svn}${git}${hg}${p4version}: ${t}\\n    ${u}@${h}:${d}\\n"
+#define SCCSSTR "@(#)${VERINFO}"
+#define VERSTR "${VERSTR}"
 #define RELSTR "${RELEASE}"
 
 char sccs[sizeof(SCCSSTR) > 128 ? sizeof(SCCSSTR) : 128] = SCCSSTR;