Libstdc++ questions regarding Windows symlink patch

[Jonathan Wakely]

On Sun, 25 Jan 2026, 04:25 Adam Wood wrote:

> Hello,
>
> I have a couple questions regarding my patch titled "Add symlink support
> on Windows".
>
> First, who should I ask to review the Windows API parts of the patch?
>

I reviewed the v3 patch in October and had some questions. If I need more
help with the Windows parts I'll ask the mingw-w64 target maintainers to
look.


> Second, I am not sure that the approach I took regarding path
> normalization was correct. Windows will normalize paths with dot-dots
> before checking if the parent directory existed or was a symlink. For
> example, if you had the path "folder/doesntexist/.." on Linux, this is an
> error. Windows doesn't care about the non-existent folder, and the path is
> resolved to just "folder".
>
> I tried to circumvent this behavior in my patch so that functions like
> std::filesystem::canonical acted more like Linux so "folder/doesntexist/.."
> would throw an error on Windows as well. I now think I was wrong to do
> this. What are your thoughts?
>

How does the Microsoft implementation behave for that case? I think we
should follow that, because whatever behaviour they implemented is probably
what windows users expect.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://gcc.gnu.org/pipermail/libstdc++/attachments/20260125/591e27c4/attachment.htm>