Re: 2.62 AT_SETUP limitations

[Joel E. Denny]

This message from Eric was never delivered to me, but I stumbled upon it 
in the bug-autoconf archives:

  http://lists.gnu.org/archive/html/bug-autoconf/2008-04/msg00064.html

Sorry to break threading with this forged reply.

On Wed, 23 Apr 2008, Eric Blake wrote:

> # example expanders
> m4_define([out0], [$1])              dnl raw echo
> m4_define([out1], [m4_quote($1)])    dnl probably what you meant
> m4_define([out2], [m4_dquote($1)])   dnl what you proposed
> m4_define([out3], [m4_expand([$1])]) dnl what AT_SETUP uses

> #length
> m4_len(out0([foo, bar]))
> m4_len(out1([foo, bar]))
> m4_len(out2([foo, bar]))
> m4_len(out3([foo, bar]))

I proposed that the result of m4_dquote be passed to m4_bpatsubst.  I 
didn't mean that the result of m4_dquote should be passed directly to 
m4_len.  After fixing the quoting (such as the underquoted comma) in the 
above example, out0 is appropriate.

> Thus, 
> using m4_expand provides a minimal-effort QoI improvement to cater to people 
> who don't know how to follow our advice of using proper quoting.

This is the answer I was really looking for.

> And thanks to Noah, we now have a working m4_expand implementation that still 
> permits quoted unbalanced () (I just hope you aren't trying to test files 
> named "-=<{(" or ")}>=-" ;).

I'm not too worried about Bison's test suite.

> So in the meantime, I've posted a patch to bug-bison (it should show up once 
> gmane lets me through) that allows you to re-enable your tests, even on 
> autoconf 2.62, by overriding the definition of m4_expand with the fixed 
> version 
> that once again allows unbalanced parentheses.

I'm afraid it may be a while before I get to it.

Thanks for all your time.