Re: [PATCH] add new AC_PROG_AR helper

[Mike Frysinger]

On 22 Feb 2021 11:26, Zack Weinberg wrote:
> On Mon, Feb 22, 2021 at 11:15 AM Mike Frysinger <vapier@gentoo.org> wrote:
> > This mirrors the existing RANLIB and related toolchain macros that
> > autoconf already exports.  Some projects assume `ar` is available
> > which isn't always safe, so provide a macro that probes the full
> > toolchain settings.
> >
> > This also makes it easier to use AC_REQUIRE with the macro instead
> > of duplicating the AC_CHECK_TOOL call in projects.
> 
> LGTM.  Could you please check whether there is code in automake and/or
> libtool that is now redundant to this macro?

automake has a AM_PROG_AR macro, but it does more than find/set $AR, and
provides an ar-lib wrapper script to handle additional `ar` interfaces.
i don't think it's something that would go into autoconf.  we should add
an AC_BEFORE call to it though as it calls similar code:
        AC_CHECK_TOOLS([AR], [ar lib "link -lib"], [false])

libtool has an internal _LT_PROG_AR macro that starts off with the same
logic, so it could be converted to use this new macro.
-mike