Warp schrieb:
> Invisible <voi### [at] devnull> wrote:
>> Their approach seems to be to "verify" each program before it runs, 
>> checking that it doesn't do any "bad" things.
> 
>   That's impossible. It can be proven that it's an unsolvable problem,
> exactly for the same reason as the halting problem is unsolvable. There's
> no way for any program to check if a piece of code is executed and how.
> 
>   It's also impossible for it to know, for example, the addresses of all
> pointers by simply examining the program (for example the address of a
> pointer could be calculated from user input).

If you only allow safe-mode managed code, pointer arithmethic is not 
possible. I don't see a big problem to validate managed code, ensuring 
it doesn't do anything "bad" for a fixed definition of "bad".

Manuel

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