karl@umb.umb.edu (Karl Berry.) (04/19/89)
The various GNU programs are not meant to necessarily be portable to other operating systems -- they are only supposed to work under GNU. Since GNU will support alloca(), any GNU program is free to use it. I don't know that it has anything in particular to do with garbage collection. That's the theory. In practice, no GNU kernel exists yet, and so the various GNU programs can only be run under ``foreign'' operating systems. I guess the ones that the author of grep (Mike Haertel, I believe) tried it under had a good enough alloca() to make his grep work, regardless of whether it is possible to implement correctly an alloca for all situations.