Re: cni-changes documented?

[Andrew Haley <aph at redhat dot com>]

Adam Megacz writes:
 > 
 > Andrew Haley <aph@redhat.com> writes:
 > > I think so.  I exepct the only issue will be ABIs that pass single
 > > member structs in a different way from scalars.
 > 
 > How hard would it be to change GCC's internal representation of a
 > pointer to a pointer-to-a-pointer (handle)?

gcj, not gcc.  You can't do this with C.

 > Could this be done as a thin layer over the backend (ie a "filter"
 > over the code generator)?

It's doable.  It's not the back end though, but the front end.

 > Obviously this would carry a heavy performance penalty, but it
 > would be a quick-and-easy way to get precise GC with a copying
 > collector in the eden generation.  It would probably also be a
 > great "midway point" towards adding such functionality to Hans'
 > collector in the general (non-handle) case.  All the algorithms
 > could be tested in an environment where there is no ambiguity about
 > what/where to scan; once that code is stable and tested, more
 > complex scanning can be attempted without having to worry about the
 > correctness of the compacting algorithms.

Like anything else in free software, it's a matter of time and
motivation.

Andrew.