[m-dev.] Trailing

[Bart Demoen]

> you have no idea what the types of the entries are; this is a bit
> of a problem during garbage collection

I kept forgetting to point this out: I have no idea how gc in general
can figure out what the type is of things on the trail, so instead of

>         struct value_trail_entry {
>             Word *address;
>             Word value;
>         };

we probably need

        struct value_trail_entry {
            Word *address;
            Word value;
	    Type type;
        };

> In fact, you have no idea how to interpret the function argument.  It may be
> a C pointer to some structure that has a bunch of pointers into the heap.

it is already a problem for the C-interface (combined with native gc)
right now I think - is there a general plan on how to handle it
(independent of fancy trailing) ?

Bart