escaping addresses of ref parameters - not

[Jarrett Billingsley]

On Wed, Feb 11, 2009 at 8:19 AM, Christopher Wright <dhasenan at gmail.com> wrote:
> Bartosz Milewski wrote:
>>
>> What bothers me is that this is equivalent to saying that a seg fault
>> caused by null dereference can be caught only if the programmer puts
>> explicit runtime checks before it happens. I would say that reaks of C
>> philosophy, except that in most C++ implementation I've been working with
>> you can simply catch a seg fault. I wouldn't mind not being able to catch a
>> seg fault in a language where it's impossible to have an unitialized
>> reference. But both in Java and in D it's very easy to get into this
>> situation (in fact, it's easier in D) because of hidden reference semantics
>> of class objects. Which ties nicely with the discussion of nullable types.
>
> That is annoying, and there are libraries that fix it. It's already handled
> on Windows by default; why isn't it handled on Linux?

Probably because on Windows, segfaults are reported through the same
exception handling mechanism that the D compiler makes use of, while
on linux, they come in through signal handlers.  I don't know how easy
it is to start unwinding (or completely unwind) the call stack in the
signal handler but the impression I get is that it's not fun.