On Nov 15, 2012, at 1:15 PM, David Herman <[email protected]> wrote:
> On Nov 15, 2012, at 1:04 PM, Allen Wirfs-Brock <[email protected]> wrote: > >> On Nov 15, 2012, at 12:37 PM, Andrea Giammarchi wrote: >> >>> I believe with is much more problematic than caller for all Engines out >>> there. A reference to "who is invoking" cannot be that bad ... is it? >> >> Yes it is! It is a capability leak. It give a callee access to functions >> that would otherwise be inaccessible to the callee. Who knows what mischief >> can be accomplished by calling such functions. > > What's more, it's totally inadequate as a stack walking tool. If any function > appears twice in a call stack (most commonly in the presence of recursion), > you can't walk the whole stack. You either have to detect the repeat and give > up, or loop infinitely. So in addition to being a security, performance, and > engineering nightmare, arguments.caller is pretty much useless. And to be clear, it *is* a problem for engines: it prevents proper tail calls (or even tail call optimization). Dave _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
