Re: cc-mode fontification feels random

[Jim Porter]

On Fri, Jun 4, 2021 at 12:53 PM Eli Zaretskii <eliz@gnu.org> wrote:
>
> > From: Jim Porter <jporterbugs@gmail.com>
> > Date: Fri, 4 Jun 2021 12:41:56 -0700
> > Cc: joaotavora@gmail.com, theo@thornhill.no, dancol@dancol.org,
> >       ubolonton@gmail.com, emacs-devel@gnu.org
> >
> > Currently, the way Eglot works for remote files is that it
> > runs the LSP server on the remote host via TRAMP.
>
> Why does it do that?  Does the LSP server have to access the file
> itself?  We have all the contents of that file locally in a buffer, so
> we could hand it to LSP locally.

I'm not an expert on the internals of LSP servers, but it's my
understanding that for a language server like clangd, it needs access
not just to the current file, but the entire source tree[1]. That
allows for things like completion of member function names of classes
defined in another file, etc. For clangd in particular, it might be
possible to run a local clangd that pulls from a remote index[2], but
I don't know if every LSP server has such capabilities.

Moreover, in my own usage of Eglot, I find it very convenient that it
runs the LSP server remotely. I often find myself files remotely over
TRAMP from a local machine with a minimal set of devtools. While I
could install all the LSP servers I need on all the machines I connect
from, it's less effort to rely on the fact that the machine that'll be
doing the compilation has all the devtools I need.

- Jim

[1] As well as instructions about how to *build* the source, contained
in `compile_commands.json'.
[2] https://clangd.llvm.org/remote-index.html