Re: [PATCH] ARM: Convert BUG() to use unreachable()

Dave Korn
2009-12-22T13:52:44Z

Russell King - ARM Linux wrote:
> On Mon, Dec 21, 2009 at 11:30:43AM -0800, Richard Henderson wrote:
>> On 12/17/2009 10:17 AM, Russell King - ARM Linux wrote:
>>> How is "size-optimal trap" defined?
>> E.g. Sparc and MIPS have "tcc" instructions that trap based on the
>> condition codes, and so we eliminate the branch. That's the only
>> optimization we apply with __builtin_trap.
>>
>>> Let me put it another way: I want this function to terminate with an
>>> explicit NULL pointer dereference in every case.
>> Then just use that.
>
> That's precisely what we have been using for many years.

I don't understand. It should still work just fine; the original version
posted appears to simply lack 'volatile' on the (int *) cast.

cheers,
DaveK