[PATCH] Cygwin: Adjust CWD magic to accommodate for the latest Windows previews

[Corinna Vinschen]

On Mar 18 10:45, Jeremy Drake via Cygwin-patches wrote:
> On Tue, 18 Mar 2025, Corinna Vinschen wrote:
> 
> > On Mar 17 17:39, Jeremy Drake via Cygwin-patches wrote:
> > > Since you kind of asked, here's a proof-of-concept that uses udis86 (I
> > > left a whole bunch of pointer<->integer warnings since this is a PoC).
> > > Tested on windows 11 and 8:
> >
> > Cool.  I like the idea.  But obviously, this can't make it into 3.6
> > anymore.
> 
> Right.  So the next thing to figure out is how to include udis86.  It is
> BSD 2-clause license, so that should be fine.  The way I see it, we could
> either static link it from a Cygwin/MSYS2 package, or vendor it.  I keep
> coming back to vendoring, there has not been any activity on the
> repository in years, there are only a few source files in the library part
> of the code, and of them several can be left out because we aren't
> intending to generate disassembly text output.  There is also a
> "standalone mode" macro that gets defined if built as part of the Linux
> kernel, which suggests we can define that if inside Cygwin also.  We can
> also reduce the size impact by removing/disabling the mappping of
> instruction mnemonic enum to string since we won't need that either.
> 
> If I want to try that, would it make more sense to drop these files in a
> subdirectory of winsup/cygwin, or winsup, or somewhere else?

Subdir of winsup/cygwin, probably.  What I'm most curious about is the
size it adds to the DLL.  I wonder if, say, an extra 32K is really
usefully spent, given it only checks a small part of ntdll.dll, and only
once per process tree, too.

> Should I be moving this discussion to cygwin-developers?  (that list
> doesn't seem to get much action, and the last time I used it I got
> redirected to the cygwin list).

We can discuss this on cygwin-developers.  It's pretty underused these
days.

That reminds me, I think we could use it for collecting ideas for 3.7 as
well.  There's a bit of stuff in the latest POSIX-1.2024 which might be
nice in Cygwin, too.


Corinna