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Subject: Re: [ub] Objectives and tasks for SG12
From: Nevin Liber (nevin_at_[hidden])
Date: 2013-05-29 15:36:15


On 29 May 2013 14:35, Jens Maurer <Jens.Maurer_at_[hidden]> wrote:

>
> (1) Is a compiler diagnostic acceptable? Yes.
> (2) Is a run-time abort acceptable? Yes.
> (3) Is an unspecified result value acceptable? Yes.
> (4) Is it acceptable that your compiler changes the behavior
> of unrelated code that follows the overflow? That's very surprising.
>
> Giving compilers latitude to choose among 1-3 (depending on the
> target audience) is fine, but, in my opinion, prohibiting option 4
> would be an improvement.
>

The counter argument is usually that (4) has a run time cost in that the
overflow must now be detected instead of just assumed that it cannot
happen. This effectively penalizes correct programs.

What does "behavior of unrelated code" even mean once we've invoked
undefined behavior?

-- 
 Nevin ":-)" Liber  <mailto:nevin_at_[hidden]>  (847) 691-1404



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