Subject: Re: port-xen/29887: sysctl kern.consdev coredumps
To: Greywolf <>
From: Lennart Augustsson <>
List: tech-userlevel
Date: 06/20/2005 20:28:38
Greywolf wrote:
> der Mouse wrote:
>> Abstractly, the same thing is true of inlining bcopy (a transformation
>> with which this one was compared upthread).  As I see it, they were
>> just as abstractly wrong there; they got away with it in practice
>> because the historical behaviour matched the behaviour of the
>> transformed version closely enough.  (Core dumps are core dumps; the
>> major difference is that a frame is missing from the call stack, but
>> apparently that bothers few enough people to not matter.)
> Hm, no frame on the call stack =? inability to tell what went wrong 
> without compiling with
> full debugging enabled?  That's what it seems to imply.

Who says C has to be implemented with function calls at all?
Noone, as far as I know.

As a compiler writer I'll make the compiler do any transformations
I like as long as it doesn't change the semantics.  And when the
semantics is undefined, one undefined behaviour i a good a another.

It seems many people have some warped idea of the C semantics based
on historical precedence. :)

	-- Lennart