Fwd: ScopeLayout hidden

Begin forwarded message:

> From: Mark Miller <[email protected]>
> Date: February 27, 2010 18:06:46 EST
> To: Kevin Reid <[email protected]>
> Cc: Thomas Leonard <tal-v5nx5w6akNyLE8xUarVfuPLx9OUvmyODWmv/[email protected]>
> Subject: ScopeLayout hidden
>
> Kevin, Besides the obvious change, this [patch] also does a bit of  
> comment
> reformatting. And it adds maximally restrictive safej files for
> ScopeLayout and EvalContext, just in case they leak by other means.
> See ENode#getScopeLayout() as such a leak that should probably be
> plugged more directly than just making ScopeLayouts opaque.
>
> Hi Thomas, I'm cc'ing you as our new committer. Welcome aboard! This
> is in reaction to the bug you reported. The underlying problem is that
> our taming system is too permissive. This doesn't fix this underlying
> problem, but only a symptom: It restricts Scope to not expose
> ScopeLayouts or EvalContexts, as these are really details of the
> implementation that shouldn't be visible from E. The specific bug you
> found came from exposing an internal optimization that relied to
> delicate invariants to E code which could violate these invariants.

-- 
Kevin Reid                                  <http://switchb.org/kpreid/>