[cfe-dev] "devirtualizing" files in the VFS

[Sam McCall via cfe-dev]

On Tue, Nov 27, 2018 at 7:01 PM Jonas Devlieghere <jdevlieghere at apple.com>
wrote:

> Hi Sam,
>
> Does extending the status with a path sound reasonable? This would work
> similar to the current Name field, which is controlled by UseExternalName.
>
> Please let me know what you think.
>
> Thanks,
> Jonas
>

Design-wise, adding a second Name field to Status doesn't seem
significantly different than adding a "getOtherName" field to VFS.
I don't think it's really reasonable to have this in the VFS interfaces,
because using it in any way means you're coupled to particular
implementations.

Implementation-wise, it seems the only way to do that would be to add an
extra string to Status, and some applications probably keep a lot of Status
objects. So it doesn't seem like an improvement vs the VFS method.

Overall I think if LLDB wants to wants to break abstraction and use the
native filesystem sometimes, it should have concrete private
implementations with wider interfaces, and bridge to common code by having
them implement the VFS interfaces. The contract of VFS may have been "real
filesystem with some redirected files", but I don't think it has been for
several years, and people rely on this.

I'm not an owner here though. I don't really know how these decisions get
made, and would like to hear more opinions.
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