maint: update copyright

[gnulib.git] / m4 / bison.m4

diff --git a/m4/bison.m4 b/m4/bison.m4
index c4854b2..c003367 100644 (file)
--- a/m4/bison.m4
+++ b/m4/bison.m4
@@ -1,8 +1,24 @@
-#serial 3
+# serial 7
+
+# Copyright (C) 2002, 2005, 2009-2014 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
 
 AC_DEFUN([gl_BISON],
 [
-  # getdate.y works with bison only.
+  # parse-datetime.y works with bison only.
   : ${YACC='bison -y'}
-  AC_SUBST(YACC)
+dnl
+dnl Declaring YACC & YFLAGS precious will not be necessary after GNULIB
+dnl requires an Autoconf greater than 2.59c, but it will probably still be
+dnl useful to override the description of YACC in the --help output, re
+dnl parse-datetime.y assuming 'bison -y'.
+  AC_ARG_VAR([YACC],
+[The "Yet Another C Compiler" implementation to use.  Defaults to 'bison -y'.
+Values other than 'bison -y' will most likely break on most systems.])dnl
+  AC_ARG_VAR([YFLAGS],
+[YFLAGS contains the list arguments that will be passed by default to Bison.
+This script will default YFLAGS to the empty string to avoid a default value of
+'-d' given by some make applications.])dnl
 ])