diff --git a/clippy_lints/src/matches/redundant_guards.rs b/clippy_lints/src/matches/redundant_guards.rs index 6383326aa38..29af4812351 100644 --- a/clippy_lints/src/matches/redundant_guards.rs +++ b/clippy_lints/src/matches/redundant_guards.rs @@ -2,6 +2,7 @@ use clippy_utils::path_to_local; use clippy_utils::source::snippet_with_applicability; use clippy_utils::visitors::{for_each_expr, is_local_used}; +use rustc_ast::LitKind; use rustc_errors::Applicability; use rustc_hir::def::{DefKind, Res}; use rustc_hir::{Arm, BinOpKind, Expr, ExprKind, Guard, MatchSource, Node, Pat, PatKind}; @@ -160,6 +161,11 @@ fn emit_redundant_guards<'tcx>( } /// Checks if the given `Expr` can also be represented as a `Pat`. +/// +/// All literals generally also work as patterns, however float literals are special. +/// They are currently (as of 2023/08/08) still allowed in patterns, but that will become +/// an error in the future, and rustc already actively warns against this (see rust#41620), +/// so we don't consider those as usable within patterns for linting purposes. fn expr_can_be_pat(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { for_each_expr(expr, |expr| { if match expr.kind { @@ -177,8 +183,8 @@ fn expr_can_be_pat(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { ExprKind::AddrOf(..) | ExprKind::Array(..) | ExprKind::Tup(..) - | ExprKind::Struct(..) - | ExprKind::Lit(..) => true, + | ExprKind::Struct(..) => true, + ExprKind::Lit(lit) if !matches!(lit.node, LitKind::Float(..)) => true, _ => false, } { return ControlFlow::Continue(()); diff --git a/tests/ui/redundant_guards.fixed b/tests/ui/redundant_guards.fixed index 77ac7666864..49d7336ee37 100644 --- a/tests/ui/redundant_guards.fixed +++ b/tests/ui/redundant_guards.fixed @@ -15,6 +15,19 @@ struct B { struct C(u32, u32); +#[derive(PartialEq)] +struct FloatWrapper(f32); +fn issue11304() { + match 0.1 { + x if x == 0.0 => todo!(), + _ => todo!(), + } + match FloatWrapper(0.1) { + x if x == FloatWrapper(0.0) => todo!(), + _ => todo!(), + } +} + fn main() { let c = C(1, 2); match c { diff --git a/tests/ui/redundant_guards.rs b/tests/ui/redundant_guards.rs index b072e4ea14d..87761010de2 100644 --- a/tests/ui/redundant_guards.rs +++ b/tests/ui/redundant_guards.rs @@ -15,6 +15,19 @@ struct B { struct C(u32, u32); +#[derive(PartialEq)] +struct FloatWrapper(f32); +fn issue11304() { + match 0.1 { + x if x == 0.0 => todo!(), + _ => todo!(), + } + match FloatWrapper(0.1) { + x if x == FloatWrapper(0.0) => todo!(), + _ => todo!(), + } +} + fn main() { let c = C(1, 2); match c { diff --git a/tests/ui/redundant_guards.stderr b/tests/ui/redundant_guards.stderr index c2a92071d1d..5bdf43d23c5 100644 --- a/tests/ui/redundant_guards.stderr +++ b/tests/ui/redundant_guards.stderr @@ -1,5 +1,5 @@ error: redundant guard - --> $DIR/redundant_guards.rs:21:20 + --> $DIR/redundant_guards.rs:34:20 | LL | C(x, y) if let 1 = y => .., | ^^^^^^^^^ @@ -12,7 +12,7 @@ LL + C(x, 1) => .., | error: redundant guard - --> $DIR/redundant_guards.rs:27:20 + --> $DIR/redundant_guards.rs:40:20 | LL | Some(x) if matches!(x, Some(1) if true) => .., | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -23,7 +23,7 @@ LL | Some(Some(1)) if true => .., | ~~~~~~~ ~~~~~~~ error: redundant guard - --> $DIR/redundant_guards.rs:28:20 + --> $DIR/redundant_guards.rs:41:20 | LL | Some(x) if matches!(x, Some(1)) => { | ^^^^^^^^^^^^^^^^^^^^ @@ -35,7 +35,7 @@ LL + Some(Some(1)) => { | error: redundant guard - --> $DIR/redundant_guards.rs:32:20 + --> $DIR/redundant_guards.rs:45:20 | LL | Some(x) if let Some(1) = x => .., | ^^^^^^^^^^^^^^^ @@ -47,7 +47,7 @@ LL + Some(Some(1)) => .., | error: redundant guard - --> $DIR/redundant_guards.rs:33:20 + --> $DIR/redundant_guards.rs:46:20 | LL | Some(x) if x == Some(2) => .., | ^^^^^^^^^^^^ @@ -59,7 +59,7 @@ LL + Some(Some(2)) => .., | error: redundant guard - --> $DIR/redundant_guards.rs:56:20 + --> $DIR/redundant_guards.rs:69:20 | LL | B { e } if matches!(e, Some(A(2))) => .., | ^^^^^^^^^^^^^^^^^^^^^^^ @@ -71,7 +71,7 @@ LL + B { e: Some(A(2)) } => .., | error: redundant guard - --> $DIR/redundant_guards.rs:93:20 + --> $DIR/redundant_guards.rs:106:20 | LL | E::A(y) if y == "not from an or pattern" => {}, | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -83,7 +83,7 @@ LL + E::A("not from an or pattern") => {}, | error: redundant guard - --> $DIR/redundant_guards.rs:100:14 + --> $DIR/redundant_guards.rs:113:14 | LL | x if matches!(x, Some(0)) => .., | ^^^^^^^^^^^^^^^^^^^^