Add warning when open file outside workspace

[edwin0cheng]

When file is not found in ra_vfs but exist, use LspError for warning instead of error_fmt to bail out error,

Temporarily fix #967 .

edit: typo

[matklad]

Excellent idea!

We probably shouldn't be checking specifically if the path exists: VSCode can send us in-memory files. In general, we should interract with fs only via vfs.

[edwin0cheng]

Fixed 👍

[edwin0cheng]

We probably shouldn't be checking specifically if the path exists: VSCode can send us in-memory files. In general, we should interract with fs only via vfs.

If we only handle files via vfs, what is the proper way to handle this error ? Currently even we pass this error back to vscode, when the user do other actions, it will send the warnings again and again, and is still very annoying. Should we add some kind of cached mechanism which suppress the warning (cancel the action) when it happens before ?

On the other hand, could it possible to add a new api which allow us to add a new Roots in ra_vfs after initialization ? If so, we can check whether file exists and the file's ancestor directory is a cargo workspace And then we add that directory in the new roots.

[matklad]

bors r+

Ideally, this should not be an error at all: we should just add the file to some kind of "default" VFS root. According to the protocol, it is valid for the client to send arbitrary files to the server.

However in practice, if we get a lot of such warnings, that probably means that something is misconfigurated on our side (as opposed to client genuinelly sending us random files)

[bors]

Build succeeded

• continuous-integration/travis-ci/push