[beast] BUILD: autogen.sh: speed up by some +40% by avoiding autoreconf

[Tim Janik <timj src gnome org>]

commit 471d8329bbab3e1d44da10bbfdc183a2244107ef
Author: Tim Janik <timj gnu org>
Date:   Thu Mar 16 00:40:53 2017 +0100

    BUILD: autogen.sh: speed up by some +40% by avoiding autoreconf
    
    Using autoreconf almost doubles the autotools runtime due to compatibility
    checks, m4 tracing and what not. Simply calling aclocal, libtoolize,
    autoconf, autoheader and automake directly means reducing a 14 second task
    down to 8 seconds.
    
    Signed-off-by: Tim Janik <timj gnu org>

 autogen.sh |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/autogen.sh b/autogen.sh
index ce80168..99525db 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -2,8 +2,16 @@
 
 set -xe # be verbose and abort on errors
 
-rm -rf autom4te.cache/ config.cache
+rm -rf autom4te.cache/ ./config.cache ./config.status
 
-autoreconf --verbose --force --symlink --install
+if false ; then # the autoreconf overhead almost doubles autotools runtime
+  autoreconf --verbose --force --symlink --install
+else
+  ${ACLOCAL:-aclocal}          --force                         # --verbose
+  ${LIBTOOLIZE:-libtoolize}    --force --install               # --verbose
+  ${AUTOCONF:-autoconf}                --force                         # --verbose
+  ${AUTOHEADER:-autoheader}    --force                         # --verbose
+  ${AUTOMAKE:-automake}                --add-missing --force-missing   # --verbose
+fi
 
 test -n "$NOCONFIGURE" || "./configure" "$@"