workaround incompatibilies of newer automake (+=) by adding AC_SUBST to configure...

[libt2n] / libt2n.m4

diff --git a/libt2n.m4 b/libt2n.m4
index 6d3ba22..0b7aed4 100644 (file)
--- a/libt2n.m4
+++ b/libt2n.m4
@@ -8,4 +8,21 @@ AC_DEFUN([LIBT2N_CHECK],
        LIBT2N_CLIENT_PCTEMPLATE="$LIBT2N_DATADIR/clientlib.pc.in"
        AC_SUBST(LIBT2N_CODEGEN)
        AC_SUBST(LIBT2N_CLIENT_PCTEMPLATE)
+
+       dnl newer automake versions do not allow to use += on undefined variables
+       dnl but we want to use += in codegen.make (s.a. examples-codegen/example1)
+       dnl as workaround we always define them
+       dnl see also:
+       dnl automake ml: subject: "automake conditional append"
+       dnl http://sourceware.org/ml/automake/2005-01/msg00019.html
+       dnl
+       dnl Note:
+       dnl if you update from libt2n 0.1 to 0.2 
+       dnl you must take care to pick up the right libt2n.m4
+
+       AC_SUBST([include_HEADERS], [''])
+       AC_SUBST([BUILT_SOURCES], [''])
+       AC_SUBST([CLEANFILES], [''])
+       AC_SUBST([DISTCLEANFILES], [''])
+       AC_SUBST([EXTRA_DIST], [''])
 ])