rust-lang/rust-clippy

`use_debug` lint should not trigger on `debug!()` log macro calls

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#2,132 opened on Oct 12, 2017

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 (7 comments) (1 reaction) (0 assignees)Rust (1,391 forks)batch import
C-enhancementT-middlegood first issue

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Description

Example use-case:

#![cfg_attr(feature = "cargo-clippy", warn(use_debug))]

#[macro_use]
extern crate log;

pub fn euclid_steps(mut x: u64, mut y: u64) -> Vec<u64> {
    debug!("x = {}, y = {}", x, y);

    let mut steps = vec![];

    loop {
        let tmp = x % y;

        if tmp == 0 {
            debug!("Steps performed in Euclidean algorithm: {:?}", steps);
            return steps;
        }

        steps.push(tmp);
        x = y;
        y = tmp;
    }
}

Placing #![cfg_attr(feature = "cargo-clippy", allow(use_debug))] before each debug!() usage seems tedious to me when there are several dozens of them; and turning it off (even if locally) defeats the purpose of the lint.

Contributor guide

Research direction
Look at how `use debug` lint is implemented in clippy, specifically the check that triggers on `debug!()` macro. Add a check to skip the lint when the call is from the log crate's `debug!` macro.
Tech stack
rust
Domain
tooling
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Rust
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65