rust-lang / rust-lang/rust-clippy

`uninlined_format_args` main error message doesn't take specific macro into account

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C-bug
Dominant language
Rust
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Description

Summary

The first error message for uninlined args references the format! macro, even when it's not the format! macro that's being invoked.

Reproducer

I tried this code (playground):

pub fn foo(mut w: impl std::io::Write) -> std::io::Result<()> {
    let x = 5;
    write!(w, "{}", x)?;
    Ok(())
}

I expected to see this happen: a warning about the use of a variable that could be inlined in write!

Instead, this happened: a warning about the use of a variable that could be inlined in format!

warning: variables can be used directly in the `format!` string
 --> src/lib.rs:3:5
  |
3 |     write!(w, "{}", x)?;
  |     ^^^^^^^^^^^^^^^^^^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
  = note: `#[warn(clippy::uninlined_format_args)]` on by default
help: change this to
  |
3 -     write!(w, "{}", x)?;
3 +     write!(w, "{x}")?;
  |
Version
clippy: 0.1.66 (2022-10-24 758f196)
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First steps

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start at the uninlined_format_args lint entry point and reproduce the write! example from the issue. The change is complete when the diagnostic names the invoked macro instead of always referring to format!, while preserving the suggested {x} rewrite.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
devtools
Issue type
Bug
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
45/100

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