Re: Patch for 96948

["Kirill Müller" <krlmlr+gcc@mailbox.org>]

Hi


Thanks for the explanation, this makes sense now.

I haven't actually tested if the cfa value (ms_context.Rsp) is valid, I 
also see no reason why it shouldn't be.

What does it take for your patch to be accepted? What's the minimum gcc 
version where it will be available?


Best regards

Kirill


On 08.09.20 17:34, Martin Storsjö wrote:
> Hi,
>
> On Tue, 8 Sep 2020, Kirill Müller wrote:
>
>> Thanks for the heads up. The coincidence is funny -- a file that 
>> hasn't been touched for years.
>
> I think we both may originally be triggered from the same guy asking 
> around in different places about implementations of _Unwind_Backtrace 
> for windows, actually.
>
>> I do believe that we need the logic around the `first` flag for 
>> consistency with the other unwind-*.c implementations.
>
> Yes, if you store ms_context.Rip/Rsp before the RtlVirtualUnwind step 
> - but my patch stores them afterwards; after RtlVirtualUnwind, before 
> calling the callback.
>
> The result should be the same, except if using the first flag 
> approach, I believe you're missing the last frame that is printed if 
> using my patch.
>
> // Martin