On Wed, 2008-07-09 at 13:45 +0200, Philipp Klaus Krause wrote: > Jonathan S. Shapiro schrieb: > > > If we want to use dynamic linking facilities, however (e.g. for code > > reuse), we need the ability to generate code at run time (more > > precisely: at dynamic link time). It is desirable to develop this > > capability anyway, since that capability can be used to support an > > interactive BitC environment. > > Wouldn't this be problematic for embedded systems? If there's only a few > KB of RAM and you want the program to live in a few dozen KB of ROM?
Philipp: I'm having trouble resolving what "this" you are referring to. Let me see if I can make a good enough guess to answer your question, but please ask again if this doesn't do it. I did not mean to say that all BitC implementations would be interactive. I was trying to say that we want to be able to have *some* BitC implementations that are interactive -- mainly because of the benefit for interactive development environments. It is very important for BitC to preserve the option for instantiation at static link time so that no further instantiation can possibly be required at run time. Hmm. Now that I think about it, perhaps there is a fourth desirable model: Instantiate everything at system build time. This is a specialization of static link time expansion, where you might have a bunch of programs running in a fixed system, and you want those programs to all share the same code space. If we assume that there is an "instantiate at system build time" model, then I think we have pushed about as far into the embedded space as any other general-purpose language can do. The remaining questions amount to "Can *any* 32-bit language reasonably be expected to function on a 4K-8K heap". I certainly imagine that the answer to this might be yes in some very special cases, and I think that BitC shouldn't be any different in this respect from any other 32-bit language. Now having said all of that, there may turn out to be a perverse middle ground. It is possible to imagine programs where a large amount of instantiation is required to execute the entire program, but most of that instantiation appears on rare paths. For such programs, run-time instantiation and code generation might provide a space savings. shap _______________________________________________ bitc-dev mailing list [email protected] http://www.coyotos.org/mailman/listinfo/bitc-dev
