Hi Berny,

> > 2019-07-19  Bruno Haible  <bruno@clisp.org>
> > 
> > 	parse-datetime: Require Bison 2.7 or newer.

Actually it requires Bison 2.4 or newer.

> > +    case $ac_prog_version in
> > +      '') ac_prog_version="v. ?.??, bad"; ac_verc_fail=yes;;
> > +      2.[7-9]* | [3-9].*)
> 
> This would run into a little problem in quite far future ...... when GNU Bison
> reaches version 10.x.  Maybe adjust to:
> 
> +      2.[7-9]* | [3-9].* | [1-9][0-9].*)

Good point. We don't know how the future version numbers will look like. The
only knowledge we have is on the version numbers of past releases.

Addressed in the first patch.

> During generation of parse-datetime.c, I'm getting these 2 new warnings:
> 
>   /home/berny/coreutils/./lib/parse-datetime.y:568.1-7: warning: POSIX Yacc does not support %define [-Wyacc]
>     568 | %define api.pure
>         | ^~~~~~~
>   /home/berny/coreutils/./lib/parse-datetime.y:573.1-7: warning: POSIX Yacc does not support %expect [-Wyacc]
>     573 | %expect 31
>         | ^~~~~~~
> 

Addressed in the second patch.

Thanks for these reports; I fixed the original code in GNU gettext as well.

Bruno


2019-07-19  Bruno Haible  <bruno@clisp.org>

	parse-datetime: Require Bison 2.4 or newer.
	* m4/parse-datetime.m4 (gl_PARSE_DATETIME): Set PARSE_DATETIME_BISON.
	Code taken from gettext's intl.m4.
	* modules/parse-datetime (Makefile.am): Use PARSE_DATETIME_BISON instead
	of YACC.

2019-07-19  Bruno Haible  <bruno@clisp.org>

	parse-datetime: Avoid warnings from bison versions >= 3.3.
	Reported by Bernhard Voelker <mail@bernhard-voelker.de>.
	* modules/parse-datetime (Makefile.am): Don't pass option '-y' to bison.