From e266708c42dd3d9489586e65b9c6cd1bee0046d5 Mon Sep 17 00:00:00 2001 From: Aleksei Latyshev Date: Wed, 4 Nov 2020 21:16:25 +0300 Subject: [PATCH] do not trigger MATCH_LIKE_MATCHES_MACRO lint with attrs - it can't be solved completely for attrs evaluated into `false` - change applicability to MaybeIncorrect and mention it in docs --- clippy_lints/src/matches.rs | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/clippy_lints/src/matches.rs b/clippy_lints/src/matches.rs index d695af4de..c49abbf78 100644 --- a/clippy_lints/src/matches.rs +++ b/clippy_lints/src/matches.rs @@ -459,7 +459,8 @@ declare_clippy_lint! { /// /// **Why is this bad?** Readability and needless complexity. /// - /// **Known problems:** None + /// **Known problems:** It can be FP triggered, when some arms have `cfg` + /// attributes, which evaluate into `false`. /// /// **Example:** /// ```rust @@ -1167,13 +1168,16 @@ fn find_matches_sugg(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr if b0 != b1; let if_guard = &b0_arms[0].guard; if if_guard.is_none() || b0_arms.len() == 1; + if b0_arms[0].attrs.is_empty(); if b0_arms[1..].iter() .all(|arm| { find_bool_lit(&arm.body.kind, desugared).map_or(false, |b| b == b0) && - arm.guard.is_none() + arm.guard.is_none() && arm.attrs.is_empty() }); then { - let mut applicability = Applicability::MachineApplicable; + // The suggestion may be incorrect, because some arms can have `cfg` attributes + // evaluated into `false` and so such arms will be stripped before. + let mut applicability = Applicability::MaybeIncorrect; let pat = { use itertools::Itertools as _; b0_arms.iter()