[PATCH v2] Use xz as the default tarball compression format

[PATCH v2] Use xz as the default tarball compression format

[Sam James]

xz is quite a common format for software to be distributed in nowadays
because of its size reductions.  With this patch, here is the result
on the master branch at db716e3b15912b7162def1faa704eb7823bbf34:

.rw-r--r--  406M sam   8 Nov 07:27   libabigail-2.2.tar.gz
.rw-r--r--  348M sam   8 Nov 07:26   libabigail-2.2.tar.xz

	* configure.ac: add dist-xz to AM_INIT_AUTOMAKE.
	* Makefile.am: adjust $(TARBALL) to new extension.
	* Makefile.am: pass XZ_OPT="-0" for distcheck-fast.

Signed-off-by: Sam James <sam@gentoo.org>
---
 Makefile.am  | 4 ++--
 configure.ac | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 65a1b121..0506256a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -53,7 +53,7 @@ check-valgrind-recursive:
 update-changelog:
 	python $(srcdir)/gen-changelog.py > $(srcdir)/ChangeLog
 
-TARBALL = $(PACKAGE_NAME)-$(VERSION).tar.gz
+TARBALL = $(PACKAGE_NAME)-$(VERSION).tar.xz $(PACKAGE_NAME)-$(VERSION).tar.gz
 RELEASED_BRANCH = master
 
 $(TARBALL): distcheck
@@ -86,7 +86,7 @@ tag-and-all: distcheck check-self-compare
 # the default for GZIP_ENV is --best, which is pretty slow for check runs
 # distcheck-fast therefore compresses with --fast instead
 distcheck-fast:
-	$(MAKE) distcheck GZIP_ENV="--fast"
+	$(MAKE) distcheck GZIP_ENV="--fast" XZ_OPT="-0"
 
 # This makes us compare libabigail.so against its own ABIXML
 # representation.  It's super slow (more than 5 minutes on one of my
diff --git a/configure.ac b/configure.ac
index 5aafed37..a2e5b33d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -57,7 +57,7 @@ dnl This one is to be able to run "make check-valgrind"
 dnl and have unit tests run under  der Valgrind.
 m4_include([autoconf-archive/ax_valgrind_check.m4])
 
-AM_INIT_AUTOMAKE([1.11.1 foreign subdir-objects tar-ustar parallel-tests])
+AM_INIT_AUTOMAKE([1.11.1 foreign subdir-objects dist-xz tar-ustar parallel-tests])
 AM_MAINTAINER_MODE([enable])
 
 AM_SILENT_RULES([yes])
-- 
2.38.1