Re: "libtool" performance... / was: Re: Announcing Dolt, a drop-inLibtool replacement which cuts build timesin half

[Roland Mainz]

Daniel Stone wrote:
> On Fri, Apr 11, 2008 at 04:23:52PM +0200, Roland Mainz wrote:
> > Uhm... a while ago we hit the same problem and did some research on the
> > issue and  a diffent route by switching the shell used by libtool from
> > "bash" to "ksh93" and did some minor modifications (e.g. enable more
> > ksh93 builtin commands, replace some of the "sed" usage by
> > builtin-string operators (which are common between "bash" and "ksh93"
> > but libtool didn't use them) etc. (the resulting script no longer does
> > unneccesary |fork()|+|exec()| calls (since ksh93 doesn't |fork()| for
> > subshells&co.))) ... and as a result we hit a similar performance
> > improvement as seen with the "dolt" tool...
> 
> Thanks for the suggestion, but given the choice between forking a
> multi-thousand-line shell script

Erm.. I didn't really attempt to fork it, I just replaced the shell
which is used by libtool. The remaining changes, e.g. stuff like...
-- snip --
#!/usr/bin/ksh93
builtin basename
builtin dirname
builtin mkdir
builtin rmdir
# etc.
-- snip --
... was done to squish more performance out of the script.

> and replacing it with a ten line shell
> script, I think we'll stick with the one that isn't insane.

Ok... but "dolt" may been to be adopted to other compilers (like Sun
Workshop/Forte/Studio, icc etc.) and then it will be a bit more than the
10 lines (and adopting it for other POSIX-like shells may be nice, too -
"dolt" could greately benefit from "ksh93", too (using the same stuff as
used for "libtool" and by implementing some of the changes listed in
http://www.opensolaris.org/os/project/shell/shellstyle/)) ...

----

Bye,
Roland

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