Message-ID: <066e7233-e248-aad5-7db9-63d009eafa19@gmail.com>
Date:   Mon, 27 Feb 2023 10:59:10 -0300
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Subject: Re: [PATCH 5/5] rust: error: Add from_kernel_result!() macro
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To:     Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>
Cc:     Gary Guo <gary@garyguo.net>, Asahi Lina <lina@asahilina.net>,
        Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        =?UTF-8?Q?Bj=c3=b6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        Sven Van Asbroeck <thesven73@gmail.com>,
        Fox Chen <foxhlchen@gmail.com>, rust-for-linux@vger.kernel.org,
        linux-kernel@vger.kernel.org, asahi@lists.linux.dev
References: <20230224-rust-error-v1-0-f8f9a9a87303@asahilina.net>
 <20230224-rust-error-v1-5-f8f9a9a87303@asahilina.net>
 <Y/lOlcSpc+d9ytq/@boqun-archlinux> <20230225222340.34d749ee.gary@garyguo.net>
 <Y/rCU1S+GDgIojNf@boqun-archlinux> <20230226133606.583cd1d8.gary@garyguo.net>
 <Y/uiAfZnfbbMrQuD@boqun-archlinux>
 <CANiq72kTiHF76T0AycM43qj4rUgQpHzBqXujdvk+H2qoDz22AQ@mail.gmail.com>
From:   Martin Rodriguez Reboredo <yakoyoku@gmail.com>
In-Reply-To: <CANiq72kTiHF76T0AycM43qj4rUgQpHzBqXujdvk+H2qoDz22AQ@mail.gmail.com>
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On 2/26/23 17:59, Miguel Ojeda wrote:
> On Sun, Feb 26, 2023 at 7:17 PM Boqun Feng <boqun.feng@gmail.com> wrote:
>>
>> My preference to function instead of macro here is because I want to
>> avoid the extra level of abstraction and make things explict, so that
>> users and reviewers can understand the API behavior solely based on
>> Rust's types, functions and closures: they are simpler than macros, at
>> least to me ;-)
> 
> There is one extra problem with the macro: `rustfmt` does not format
> the contents if called with braces (as we currently do).
> 
> So when I was cleaning some things up for v8, one of the things I did
> was run manually `rustfmt` on the blocks by removing the macro
> invocation, in commit 77a1a8c952e1 ("rust: kernel: apply `rustfmt` to
> `from_kernel_result!` blocks").
> 
> Having said that, it does format it when called with parenthesis
> wrapping the block, so we could do that if we end up with the macro.

Also rust-analyzer can't analyze the insides of a from_kernel_result!
block. Only thing it can do is to suggest a macro expansion. Plus, this
macro triggers a clippy lint on a redundant call on a closure. So it's a
bit annoying to work with.