Re: Severe performance problem and proposed solution

[Peter Eisentraut]

Zack Weinberg writes:

> It's regularly reported to the GCC list that libstdc++'s configure
> script takes several hours to execute on certain proprietary Unixes,
> such as alpha-dec-osf4*.  This is due to a bug in the shell.  Some
> versions of the Bourne shell implement here documents by writing the
> text to a file in /tmp.  These files are not deleted until the shell
> exits.  When the shell spawns a subprocess from inside a conditional
> block, the child creates a hard link to every single scratch file
> which currently exists; when the child exits or execs, it unlinks them
> all first.  (No one is precisely sure why this is done, but we are
> certain that this is what happens.)

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.

At least this could be a much more near-term and less intrusive solution.

-- 
Peter Eisentraut   address@hidden