From 3f61e353424fb9ea3dce742022b94dfd7ea1ed9f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ulrich=20=C3=96lmann?= <u.oelmann@pengutronix.de>
Date: Thu, 4 Mar 2021 14:23:39 +0100
Subject: [PATCH] configure.ac: autodetect availability of systemd
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Import systemd's official suggestion [1] how this should be handled in packages
using autoconf. A side effect of this is the removal of the hardcoded fallback
path "/lib/systemd/system" which leaks build host information when cross
compiling v4l-utils and therefore defeats reproducible builds.

[1] https://www.freedesktop.org/software/systemd/man/daemon.html#Installing%20systemd%20Service%20Files

Upstream-Status: Backport [https://git.linuxtv.org/v4l-utils.git/commit/?id=3f61e353424fb9ea3dce742022b94dfd7ea1ed9f]

Signed-off-by: Ulrich Ölmann <u.oelmann@pengutronix.de>
Signed-off-by: Sean Young <sean@mess.org>
---
 configure.ac | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 727730c5ccf4..8470116df4b1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -388,7 +388,15 @@ AC_ARG_WITH(udevdir,
 AC_ARG_WITH(systemdsystemunitdir,
 	AS_HELP_STRING([--with-systemdsystemunitdir=DIR], [set systemd system unit directory]),
 	[],
-	[with_systemdsystemunitdir=`$PKG_CONFIG --variable=systemdsystemunitdir systemd || echo /lib/systemd/system`])
+	[with_systemdsystemunitdir=auto])
+AS_IF([test "x$with_systemdsystemunitdir" = "xyes" -o "x$with_systemdsystemunitdir" = "xauto"],
+      [def_systemdsystemunitdir=$($PKG_CONFIG --variable=systemdsystemunitdir systemd)
+       AS_IF([test "x$def_systemdsystemunitdir" = "x"],
+             [AS_IF([test "x$with_systemdsystemunitdir" = "xyes"],
+                    [AC_MSG_ERROR([systemd support requested but pkg-config unable to query systemd package])])
+              with_systemdsystemunitdir=no],
+             [with_systemdsystemunitdir="$def_systemdsystemunitdir"])])
+AM_CONDITIONAL([HAVE_SYSTEMD], [test "x$with_systemdsystemunitdir" != "xno"])
 
 # Generic check: works with most distributions
 def_gconv_dir=`for i in /lib64 /usr/lib64 /usr/local/lib64 /lib /usr/lib /usr/local/lib; do if @<:@ -d \$i/gconv @:>@; then echo \$i/gconv; break; fi; done`
-- 
2.29.2