Re: [PATCH RFC 1/9] libxl idl: add comments to error enum

[Ian Campbell <ian.campbell@citrix.com>]

On Fri, 2015-06-26 at 14:12 +0000, Rob Hoes wrote:
> >> +    # General failure; code should be avoided (used only in "xl")
> >>     (-7, "BADFAIL"),
> > 
> > Maybe it should be renamed.
> 
> Perhaps ERROR_INTERNAL_XL?

It would be a bit wrong to have an application specific error code in
the library space.

Perhaps we should declare some ranges which for specific uses. For
instance perhaps 0x7FFF0000..0x7FFFFFFF could be set aside for the
application, so xl can define itself some errors which it can use for
its own needs without needing to handle two separate error spaces. xl
could then define these codes itself.

Likewise perhaps libxl internal errors should be given their own range,
which the application can legitimately expect never to see.

I was originally think about this in the context of the xenstore patch
in this series, i.e. declaring that some range is used for the existing
XS error codes (e.g. 0x3000xxxx is a xenstore code). I'm not sure if
that's a good idea or not.

Ian.