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	id 1m5jTS-004gFn-9R; Tue, 20 Jul 2021 08:43:27 +0200
Message-ID: <bf6c049af2f51ca584d1c134d4402272651c08f5.camel@sipsolutions.net>
Subject: Re: [TECH TOPIC] Rust for Linux
From: Johannes Berg <johannes@sipsolutions.net>
To: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>, Arnd Bergmann
	 <arnd@arndb.de>
Cc: Linus Walleij <linus.walleij@linaro.org>, Wedson Almeida Filho
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 <jack@suse.cz>, James Bottomley <James.Bottomley@hansenpartnership.com>, 
 Julia Lawall <julia.lawall@inria.fr>, Laurent Pinchart
 <laurent.pinchart@ideasonboard.com>, Roland Dreier <roland@kernel.org>,
 ksummit@lists.linux.dev, Viresh Kumar <viresh.kumar@linaro.org>
Date: Tue, 20 Jul 2021 08:43:22 +0200
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On Tue, 2021-07-20 at 03:46 +0200, Miguel Ojeda wrote:
> On Mon, Jul 19, 2021 at 11:33 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > 
> > I'm worried that this makes things harder to grep for, and to document,
> > when the same structure is used in both Rust and C.
> 
> For the former, by grepping you should find the Rust abstractions that
> use the C structures, because binding generation does not change the
> names or their case. Of course, the Rust abstractions on top of that
> is a different matter, but those do not exist in C anyway. So, at
> least for the use case of searching Rust abstractions that use a given
> C structure or API, it should be fine.

Keep in mind though that there are at least two different use cases for
grep:

1) I need to change the API here, need to find all the users - I agree
   this is covered here.

2) I need to change the semantics (e.g. locking) and for this I need to
   find all the users and analyse their use (e.g. locking-wise), which
   now becomes an exercise in digging through the abstractions and doing
   a kind of "indirect" grep for the next level.
   Not that this doesn't exist today (e.g. some netlink APIs I changed
   in the past have some abstractions in some subsystems), but it does
   make it more complex.


johannes