Re: Severe performance problem and proposed solution

[Akim Demaille]

>>>>> "Zack" == Zack Weinberg <address@hidden> writes:

Zack> Richard Henderson and I experimented with using echo instead of
Zack> here documents[1].  The trouble with this is of course that echo
Zack> may interpret backslashes and leading -, so both have to be
Zack> escaped.  We got a two-page gobbet of M4 that sort of worked,
Zack> but couldn't help at all with AC_DEFINE_UNQUOTED and the like.
Zack> I think this approach is a dead end.

Hi Zack,

We are aware of this issue, and this is one of the reason why we now
have configure re-exec'ing itself with a better shell, with `better'
being defined as `supports $LINENO'.

If this is enough, then we're good.  But we need someone to test it.

If it is not, then anyway the plan is to steal the technology Libtool
has wrt echo.  It means:

- augmenting the `better shell' check with some for of echo testing.
- moving Libtool's stuff into M4sh.

Then Autoconf will be able to use it.

But that's a tricky road.  First, we need evidence that the recent
re-execing is not enough.  Thanks!