Re: Definition of BUG on x86

From: Ingo Molnar
Date: Thu Feb 19 2009 - 11:41:27 EST



* Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:

> Ingo Molnar wrote:
>> Well, the important question is thatGCC will optimize out whatever
>> comes after the __builtin_trap(), right? To guarantee an assert we can
>> do something like:
>>
>> __builtin_trap();
>> panic("should never get here");
>>
>> to guarantee a message. (But realistically GCC will at most generate a
>> build error.)
>
> Ah, right, I remember the problem. There's no guaranteed way
> of getting the address of the ud2a instruction __builtin_trap
> generates to put it into the bug table.

hm, indeed.

So that 2 byte overhead will be there for now, until gcc (or
some other compiler) is improved.

Ingo
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