Validation deps for Rust Clippy?

[Łukasz Anforowicz]

Hello @gn-dev,

In a document here, I've tried to explore what options there may be for "eagerly" invoking Rust Clippy during incremental Chromium builds.  It seems that one option may be adding GN support for ninja validation deps - a new kind of a dependency edge mentioned in a slide of @agrieve's Google-internal presentation here, and publicly documented in (a bit sparse) ninja docs here.

Are there any previous thoughts or design documents about implementing validation deps support in GN?  Should I just try implementing it (how hard can it be 😱).

Am I possibly missing any other options?

Thanks,

Lukasz

[Dirk Pranke]

I have not read the linked docs yet in any detail, and I can't access the Google-internal presentation, so I am withholding full blessing until I can do so -- or give up on the idea of getting around to it :) -- but it seems like a reasonable thing to explore. 

I don't recall any previous (public) discussions on this idea, nor any Google-internal discussions w/ me from when I was there.

(a) I would, however, largely defer to Andrew on this if he's thought about this a bunch

(b) I feel like it would be good if there was a way to bypass the validations if you wanted to do so, e.g., a `ninja --skip-validations` flag or something. I don't immediately see any such flag, nor do I remember any discussion about this on the ninja list. Do you know if there were discussions of such a thing somewhere?

-- Dirk