Re: Severe performance problem and proposed solution

[Paul Eggert]

> From: Peter Eisentraut <address@hidden>
> Date: Sun, 24 Feb 2002 11:50:24 -0500 (EST)
> 
> Autoconf 2.53 will be able to automatically replace a different, more
> capable shell if the standard shell doesn't support a certain feature.
> I'm not sure how exactly you would test for the bug you are speaking of,
> but you might be able to convince Autoconf to skip certain suspicious
> candidates.

It might suffice simply to configure GCC with Autoconf 2.52f or later,
without changing Autoconf at all.  Most likely the shells with serious
performance problems will fail Autoconf's current test (which is to
test for proper support of $LINENO).  But, as you say, if this doesn't
suffice, we might be able to fix Autoconf to test for the performance
problem too.

Also, you should be able to work around the problem even if you
configure with Autoconf 2.52.  Ask installers to set
CONFIG_SHELL=/path/to/bash (or some other non-brain-damaged shell) in
their environment, and to execute configure with "$CONFIG_SHELL
configure" instead of "sh configure".