Re: Conservative GC isn't safe

[Pip Cet]

On Sat, Nov 26, 2016 at 8:11 AM, Daniel Colascione <address@hidden> wrote:
>   1) mark_maybe_pointer looks only for exact matches on object start. It's
> perfectly legal for the compiler to keep an interior object pointer and
> discard the pointer to the object start.

There's a new, currently undocumented, GCC option called
-fkeep-gc-roots-live, which I think addresses this problem. My
understanding is previous versions of GCC did not in practice break
conservative GC (except for strings, which we handle specially for
this reason).