build: ensure release year in copyright notice is up-to-date

From a suggestion by Eric Blake.  See automake bug#11356.
This is a follow-up to previous patch 'v1.12-12-gb99b5be'.

* configure.ac (RELEASE_YEAR): New AC_SUBST'd variable, should hold
the value of the current year.
* Makefile.am (update-copyright): Be sure to also update the
definition of 'RELEASE_YEAR' in configure.ac.
* lib/Automake/Config.in ($RELEASE_YEAR): New exported variable,
initialized from the value substituted for '@RELEASE_YEAR@'.
(@EXPORT): Add it.
* automake.in, aclocal.in: Use '$RELEASE_YEAR' (which will be
substituted at make time) instead of hard-coding the release
year.  This should ensure the copyright range in the version
message and in the generated files (Makefile.in and aclocal.m4)
are automatically kept up-to-date.
* bootstrap (dosubst): Update, also substitute '@RELEASE_YEAR@'.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/bootstrap b/bootstrap
index 814aedb51..1cede01aa 100755
--- a/bootstrap
+++ b/bootstrap
@@ -77,6 +77,8 @@ dosubst ()
 {
   rm -f $2
   in=`echo $1 | sed 's,^.*/,,'`
+  current_year=`date +%Y` && test -n "$current_year" \
+    || { echo "$me: cannot get current year" >&2; exit 1; }
   sed -e "s%@APIVERSION@%$APIVERSION%g" \
       -e "s%@PACKAGE@%$PACKAGE%g" \
       -e "s%@PERL@%$PERL%g" \
@@ -84,6 +86,7 @@ dosubst ()
       -e "s%@SHELL@%$BOOTSTRAP_SHELL%g" \
       -e "s%@VERSION@%$VERSION%g" \
       -e "s%@datadir@%$datadir%g" \
+      -e "s%@RELEASE_YEAR@%$current_year%g" \
       -e "s%@configure_input@%Generated from $in; do not edit by hand.%g" \
       $1 > $2
   chmod a-w $2