[aarch64-port-dev ] RFR(XS): Provide information when hitting a HaltNode for architectures other than x86

[Christian Hagedorn]

Hi Andrew

On 06.05.20 16:38, Andrew Haley wrote:
> On 5/6/20 10:14 AM, Christian Hagedorn wrote:
>> On 06.05.20 10:40, Andrew Haley wrote:
>>> On 5/6/20 8:26 AM, Christian Hagedorn wrote
>>>> The fix was to
>>>> only do it if ShowMessageBoxOnError was set. So, I think it's indeed a
>>>> good idea to also do the same for other architectures.
>>> Really? Can't we fix stop() so that it generates only a tiny little bit
>>> of code? I can do it if you like.
>> This is probably what you've meant. I agree with you, the fewer
>> instructions emitted by stop() the better.
> 
> ShowMessageBoxOnError is completely the wrong thing to use. I run
> in GDB all the time, and I want accurate error messages, and I never
> use ShowMessageBoxOnError. If we get this right we can have near-zero
> code expansion, and keep this on at all times, even in production.

I like your suggestion of a trap solution as suggested in the other 
thread. This sounds much better than the original fix for HaltNodes on 
x86 which only had in mind to adapt stop() in such a way that it works 
with debug64() while avoiding the unnecessary regs[] and pc argument 
when ShowMessageBoxOnError is not set (which is probably not used much 
anyways). If a trap approach could get rid of all of it and emit minimal 
code, we should go for it.

Best regards,
Christian