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Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."
On 2006-12-31 09:27:21 -0500, Robert Dewar wrote:
> As I said earlier in this thread, people seem to think that the
> standards committee invented something new here in making overflow
> undefined, but I don't think that's the case. I personally would
> have thought it more judicious to make it implementation defined,
> since I don't like undefined semantics anywhere in programming
> languages unless a hugely strong case can be made that providing
> or requiring a definition damages code (e.g. uninitialized variables
> have always been generally agreed to be in that class for C/Ada/Fortran
> level languages, but even there Ada 95 greatly reduced the damage
> that uninitialized variables can do, and introduced the notion of
> bounded error to replace many undefined (called erroneous) cases
> in Ada).
The compiler could have an optional mode where everything is defined.
So, this is more a problem with the compiler than with the language.
But this won't prevent from having bugs, possibly difficult to detect,
in particular if behavior is implementation-defined instead of being
fixed for every implementation.
--
Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
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Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)