Re: Help with implementing Wine optimization experiment

[Daniel Santos <daniel dot santos at pobox dot com>]

On 08/15/2016 06:35 AM, André Hentschel wrote:
> Hi,
> Thanks for working on this, but I haven't seen some discussion on wine-devel recently.
> I'm also not an expert on that area, but isn't this risking to break copy protections and hotpatching.
> Just wanted to remind you about those two things, so the implementation will be usefull.

Thanks for your response! I've run into the hot-patching code a lot 
while working on this. Not breaking these should be easy since these 
functions are explicitly marked with the ms_hook_prologue attribute, so 
I can just skip altering these functions for now. This attribute is 
assigned in Wine via expansion of the macro DECLSPEC_HOTPATCH and I'm 
currently only counting 171 such functions.

I'm not sure about breaking copy protections however and I don't really 
know what the issues are pertaining to this. I'm mostly doing this as an 
experiment for now, and admittedly as an excuse to finally start hacking 
away at gcc, which I've been wanting to do for several years now. Until 
I know more about what the various copy protection mechanisms look for, 
I'm going to ignore it and address it later. Presuming that this 
experiment turns out to be useful, it might be implemented as a function 
attribute so that functions that need to appear a certain way to copy 
protection software can omit the optimization, similar to ms_hook_prologue.

Daniel