From 51b57723d18aec1b9dd26bbb1482d1f29f6d18cf Mon Sep 17 00:00:00 2001 From: Centri3 <114838443+Centri3@users.noreply.github.com> Date: Wed, 14 Jun 2023 13:51:31 -0500 Subject: [PATCH] new lint `redundant_guards` --- CHANGELOG.md | 1 + clippy_lints/src/declared_lints.rs | 1 + clippy_lints/src/loops/utils.rs | 4 +- clippy_lints/src/matches/mod.rs | 33 +++ clippy_lints/src/matches/redundant_guards.rs | 190 ++++++++++++++++++ tests/ui/match_expr_like_matches_macro.fixed | 3 +- tests/ui/match_expr_like_matches_macro.rs | 3 +- tests/ui/match_expr_like_matches_macro.stderr | 28 +-- tests/ui/redundant_guards.fixed | 133 ++++++++++++ tests/ui/redundant_guards.rs | 133 ++++++++++++ tests/ui/redundant_guards.stderr | 98 +++++++++ tests/ui/shadow.rs | 7 +- tests/ui/shadow.stderr | 92 ++++----- tests/ui/single_match.fixed | 1 + tests/ui/single_match.rs | 1 + tests/ui/single_match.stderr | 36 ++-- 16 files changed, 681 insertions(+), 83 deletions(-) create mode 100644 clippy_lints/src/matches/redundant_guards.rs create mode 100644 tests/ui/redundant_guards.fixed create mode 100644 tests/ui/redundant_guards.rs create mode 100644 tests/ui/redundant_guards.stderr diff --git a/CHANGELOG.md b/CHANGELOG.md index 2b53f1df7c060..9118c0e634f4b 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -5190,6 +5190,7 @@ Released 2018-09-13 [`redundant_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_else [`redundant_feature_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_feature_names [`redundant_field_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names +[`redundant_guards`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_guards [`redundant_locals`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_locals [`redundant_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_pattern [`redundant_pattern_matching`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_pattern_matching diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index e92d9fa7f6372..189ca5b052e95 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -308,6 +308,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::matches::MATCH_WILDCARD_FOR_SINGLE_VARIANTS_INFO, crate::matches::MATCH_WILD_ERR_ARM_INFO, crate::matches::NEEDLESS_MATCH_INFO, + crate::matches::REDUNDANT_GUARDS_INFO, crate::matches::REDUNDANT_PATTERN_MATCHING_INFO, crate::matches::REST_PAT_IN_FULLY_BOUND_STRUCTS_INFO, crate::matches::SIGNIFICANT_DROP_IN_SCRUTINEE_INFO, diff --git a/clippy_lints/src/loops/utils.rs b/clippy_lints/src/loops/utils.rs index 28ee24309cc46..6edca2d55f649 100644 --- a/clippy_lints/src/loops/utils.rs +++ b/clippy_lints/src/loops/utils.rs @@ -76,7 +76,7 @@ impl<'a, 'tcx> Visitor<'tcx> for IncrementVisitor<'a, 'tcx> { ExprKind::Assign(lhs, _, _) if lhs.hir_id == expr.hir_id => { *state = IncrementVisitorVarState::DontWarn; }, - ExprKind::AddrOf(BorrowKind::Ref, mutability, _) if mutability == Mutability::Mut => { + ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, _) => { *state = IncrementVisitorVarState::DontWarn; }, _ => (), @@ -226,7 +226,7 @@ impl<'a, 'tcx> Visitor<'tcx> for InitializeVisitor<'a, 'tcx> { InitializeVisitorState::DontWarn } }, - ExprKind::AddrOf(BorrowKind::Ref, mutability, _) if mutability == Mutability::Mut => { + ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, _) => { self.state = InitializeVisitorState::DontWarn; }, _ => (), diff --git a/clippy_lints/src/matches/mod.rs b/clippy_lints/src/matches/mod.rs index d1061171e4d69..6d16d18875408 100644 --- a/clippy_lints/src/matches/mod.rs +++ b/clippy_lints/src/matches/mod.rs @@ -16,6 +16,7 @@ mod match_wild_enum; mod match_wild_err_arm; mod needless_match; mod overlapping_arms; +mod redundant_guards; mod redundant_pattern_match; mod rest_pat_in_fully_bound_struct; mod significant_drop_in_scrutinee; @@ -936,6 +937,36 @@ declare_clippy_lint! { "reimplementation of `filter`" } +declare_clippy_lint! { + /// ### What it does + /// Checks for unnecessary guards in match expressions. + /// + /// ### Why is this bad? + /// It's more complex and much less readable. Making it part of the pattern can improve + /// exhaustiveness checking as well. + /// + /// ### Example + /// ```rust,ignore + /// match x { + /// Some(x) if matches!(x, Some(1)) => .., + /// Some(x) if x == Some(2) => .., + /// _ => todo!(), + /// } + /// ``` + /// Use instead: + /// ```rust,ignore + /// match x { + /// Some(Some(1)) => .., + /// Some(Some(2)) => .., + /// _ => todo!(), + /// } + /// ``` + #[clippy::version = "1.72.0"] + pub REDUNDANT_GUARDS, + complexity, + "checks for unnecessary guards in match expressions" +} + #[derive(Default)] pub struct Matches { msrv: Msrv, @@ -978,6 +1009,7 @@ impl_lint_pass!(Matches => [ TRY_ERR, MANUAL_MAP, MANUAL_FILTER, + REDUNDANT_GUARDS, ]); impl<'tcx> LateLintPass<'tcx> for Matches { @@ -1025,6 +1057,7 @@ impl<'tcx> LateLintPass<'tcx> for Matches { needless_match::check_match(cx, ex, arms, expr); match_on_vec_items::check(cx, ex); match_str_case_mismatch::check(cx, ex, arms); + redundant_guards::check(cx, arms); if !in_constant(cx, expr.hir_id) { manual_unwrap_or::check(cx, expr, ex, arms); diff --git a/clippy_lints/src/matches/redundant_guards.rs b/clippy_lints/src/matches/redundant_guards.rs new file mode 100644 index 0000000000000..6383326aa38df --- /dev/null +++ b/clippy_lints/src/matches/redundant_guards.rs @@ -0,0 +1,190 @@ +use clippy_utils::diagnostics::span_lint_and_then; +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_errors::Applicability; +use rustc_hir::def::{DefKind, Res}; +use rustc_hir::{Arm, BinOpKind, Expr, ExprKind, Guard, MatchSource, Node, Pat, PatKind}; +use rustc_lint::LateContext; +use rustc_span::Span; +use std::ops::ControlFlow; + +use super::REDUNDANT_GUARDS; + +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'tcx>]) { + for outer_arm in arms { + let Some(guard) = outer_arm.guard else { + continue; + }; + + // `Some(x) if matches!(x, y)` + if let Guard::If(if_expr) = guard + && let ExprKind::Match( + scrutinee, + [ + arm, + Arm { + pat: Pat { + kind: PatKind::Wild, + .. + }, + .. + }, + ], + MatchSource::Normal, + ) = if_expr.kind + { + emit_redundant_guards( + cx, + outer_arm, + if_expr.span, + scrutinee, + arm.pat.span, + arm.guard, + ); + } + // `Some(x) if let Some(2) = x` + else if let Guard::IfLet(let_expr) = guard { + emit_redundant_guards( + cx, + outer_arm, + let_expr.span, + let_expr.init, + let_expr.pat.span, + None, + ); + } + // `Some(x) if x == Some(2)` + else if let Guard::If(if_expr) = guard + && let ExprKind::Binary(bin_op, local, pat) = if_expr.kind + && matches!(bin_op.node, BinOpKind::Eq) + && expr_can_be_pat(cx, pat) + // Ensure they have the same type. If they don't, we'd need deref coercion which isn't + // possible (currently) in a pattern. In some cases, you can use something like + // `as_deref` or similar but in general, we shouldn't lint this as it'd create an + // extraordinary amount of FPs. + // + // This isn't necessary in the other two checks, as they must be a pattern already. + && cx.typeck_results().expr_ty(local) == cx.typeck_results().expr_ty(pat) + { + emit_redundant_guards( + cx, + outer_arm, + if_expr.span, + local, + pat.span, + None, + ); + } + } +} + +fn get_pat_binding<'tcx>(cx: &LateContext<'tcx>, guard_expr: &Expr<'_>, outer_arm: &Arm<'tcx>) -> Option<(Span, bool)> { + if let Some(local) = path_to_local(guard_expr) && !is_local_used(cx, outer_arm.body, local) { + let mut span = None; + let mut multiple_bindings = false; + // `each_binding` gives the `HirId` of the `Pat` itself, not the binding + outer_arm.pat.walk(|pat| { + if let PatKind::Binding(_, hir_id, _, _) = pat.kind + && hir_id == local + && span.replace(pat.span).is_some() + { + multiple_bindings = true; + return false; + } + + true + }); + + // Ignore bindings from or patterns, like `First(x) | Second(x, _) | Third(x, _, _)` + if !multiple_bindings { + return span.map(|span| { + ( + span, + !matches!(cx.tcx.hir().get_parent(local), Node::PatField(_)), + ) + }); + } + } + + None +} + +fn emit_redundant_guards<'tcx>( + cx: &LateContext<'tcx>, + outer_arm: &Arm<'tcx>, + guard_span: Span, + local: &Expr<'_>, + pat_span: Span, + inner_guard: Option>, +) { + let mut app = Applicability::MaybeIncorrect; + let Some((pat_binding, can_use_shorthand)) = get_pat_binding(cx, local, outer_arm) else { + return; + }; + + span_lint_and_then( + cx, + REDUNDANT_GUARDS, + guard_span.source_callsite(), + "redundant guard", + |diag| { + let binding_replacement = snippet_with_applicability(cx, pat_span, "", &mut app); + diag.multipart_suggestion_verbose( + "try", + vec![ + if can_use_shorthand { + (pat_binding, binding_replacement.into_owned()) + } else { + (pat_binding.shrink_to_hi(), format!(": {binding_replacement}")) + }, + ( + guard_span.source_callsite().with_lo(outer_arm.pat.span.hi()), + inner_guard.map_or_else(String::new, |guard| { + let (prefix, span) = match guard { + Guard::If(e) => ("if", e.span), + Guard::IfLet(l) => ("if let", l.span), + }; + + format!( + " {prefix} {}", + snippet_with_applicability(cx, span, "", &mut app), + ) + }), + ), + ], + app, + ); + }, + ); +} + +/// Checks if the given `Expr` can also be represented as a `Pat`. +fn expr_can_be_pat(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { + for_each_expr(expr, |expr| { + if match expr.kind { + ExprKind::ConstBlock(..) => cx.tcx.features().inline_const_pat, + ExprKind::Call(c, ..) if let ExprKind::Path(qpath) = c.kind => { + // Allow ctors + matches!(cx.qpath_res(&qpath, c.hir_id), Res::Def(DefKind::Ctor(..), ..)) + }, + ExprKind::Path(qpath) => { + matches!( + cx.qpath_res(&qpath, expr.hir_id), + Res::Def(DefKind::Struct | DefKind::Enum | DefKind::Ctor(..), ..), + ) + }, + ExprKind::AddrOf(..) + | ExprKind::Array(..) + | ExprKind::Tup(..) + | ExprKind::Struct(..) + | ExprKind::Lit(..) => true, + _ => false, + } { + return ControlFlow::Continue(()); + } + + ControlFlow::Break(()) + }) + .is_none() +} diff --git a/tests/ui/match_expr_like_matches_macro.fixed b/tests/ui/match_expr_like_matches_macro.fixed index 60f590661735c..f19149cf9def9 100644 --- a/tests/ui/match_expr_like_matches_macro.fixed +++ b/tests/ui/match_expr_like_matches_macro.fixed @@ -5,7 +5,8 @@ unreachable_patterns, dead_code, clippy::equatable_if_let, - clippy::needless_borrowed_reference + clippy::needless_borrowed_reference, + clippy::redundant_guards )] fn main() { diff --git a/tests/ui/match_expr_like_matches_macro.rs b/tests/ui/match_expr_like_matches_macro.rs index afdf1069f5e4a..8f4e58981ea6a 100644 --- a/tests/ui/match_expr_like_matches_macro.rs +++ b/tests/ui/match_expr_like_matches_macro.rs @@ -5,7 +5,8 @@ unreachable_patterns, dead_code, clippy::equatable_if_let, - clippy::needless_borrowed_reference + clippy::needless_borrowed_reference, + clippy::redundant_guards )] fn main() { diff --git a/tests/ui/match_expr_like_matches_macro.stderr b/tests/ui/match_expr_like_matches_macro.stderr index c8c1e5da05fe0..b57b26284ff36 100644 --- a/tests/ui/match_expr_like_matches_macro.stderr +++ b/tests/ui/match_expr_like_matches_macro.stderr @@ -1,5 +1,5 @@ error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:15:14 + --> $DIR/match_expr_like_matches_macro.rs:16:14 | LL | let _y = match x { | ______________^ @@ -11,7 +11,7 @@ LL | | }; = note: `-D clippy::match-like-matches-macro` implied by `-D warnings` error: redundant pattern matching, consider using `is_some()` - --> $DIR/match_expr_like_matches_macro.rs:21:14 + --> $DIR/match_expr_like_matches_macro.rs:22:14 | LL | let _w = match x { | ______________^ @@ -23,7 +23,7 @@ LL | | }; = note: `-D clippy::redundant-pattern-matching` implied by `-D warnings` error: redundant pattern matching, consider using `is_none()` - --> $DIR/match_expr_like_matches_macro.rs:27:14 + --> $DIR/match_expr_like_matches_macro.rs:28:14 | LL | let _z = match x { | ______________^ @@ -33,7 +33,7 @@ LL | | }; | |_____^ help: try: `x.is_none()` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:33:15 + --> $DIR/match_expr_like_matches_macro.rs:34:15 | LL | let _zz = match x { | _______________^ @@ -43,13 +43,13 @@ LL | | }; | |_____^ help: try: `!matches!(x, Some(r) if r == 0)` error: if let .. else expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:39:16 + --> $DIR/match_expr_like_matches_macro.rs:40:16 | LL | let _zzz = if let Some(5) = x { true } else { false }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `matches!(x, Some(5))` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:63:20 + --> $DIR/match_expr_like_matches_macro.rs:64:20 | LL | let _ans = match x { | ____________________^ @@ -60,7 +60,7 @@ LL | | }; | |_________^ help: try: `matches!(x, E::A(_) | E::B(_))` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:73:20 + --> $DIR/match_expr_like_matches_macro.rs:74:20 | LL | let _ans = match x { | ____________________^ @@ -73,7 +73,7 @@ LL | | }; | |_________^ help: try: `matches!(x, E::A(_) | E::B(_))` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:83:20 + --> $DIR/match_expr_like_matches_macro.rs:84:20 | LL | let _ans = match x { | ____________________^ @@ -84,7 +84,7 @@ LL | | }; | |_________^ help: try: `!matches!(x, E::B(_) | E::C)` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:143:18 + --> $DIR/match_expr_like_matches_macro.rs:144:18 | LL | let _z = match &z { | __________________^ @@ -94,7 +94,7 @@ LL | | }; | |_________^ help: try: `matches!(z, Some(3))` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:152:18 + --> $DIR/match_expr_like_matches_macro.rs:153:18 | LL | let _z = match &z { | __________________^ @@ -104,7 +104,7 @@ LL | | }; | |_________^ help: try: `matches!(&z, Some(3))` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:169:21 + --> $DIR/match_expr_like_matches_macro.rs:170:21 | LL | let _ = match &z { | _____________________^ @@ -114,7 +114,7 @@ LL | | }; | |_____________^ help: try: `matches!(&z, AnEnum::X)` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:183:20 + --> $DIR/match_expr_like_matches_macro.rs:184:20 | LL | let _res = match &val { | ____________________^ @@ -124,7 +124,7 @@ LL | | }; | |_________^ help: try: `matches!(&val, &Some(ref _a))` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:195:20 + --> $DIR/match_expr_like_matches_macro.rs:196:20 | LL | let _res = match &val { | ____________________^ @@ -134,7 +134,7 @@ LL | | }; | |_________^ help: try: `matches!(&val, &Some(ref _a))` error: match expression looks like `matches!` macro - --> $DIR/match_expr_like_matches_macro.rs:253:14 + --> $DIR/match_expr_like_matches_macro.rs:254:14 | LL | let _y = match Some(5) { | ______________^ diff --git a/tests/ui/redundant_guards.fixed b/tests/ui/redundant_guards.fixed new file mode 100644 index 0000000000000..77ac76668649b --- /dev/null +++ b/tests/ui/redundant_guards.fixed @@ -0,0 +1,133 @@ +//@run-rustfix +//@aux-build:proc_macros.rs:proc-macro +#![feature(if_let_guard)] +#![allow(clippy::no_effect, unused)] +#![warn(clippy::redundant_guards)] + +#[macro_use] +extern crate proc_macros; + +struct A(u32); + +struct B { + e: Option, +} + +struct C(u32, u32); + +fn main() { + let c = C(1, 2); + match c { + C(x, 1) => .., + _ => todo!(), + }; + + let x = Some(Some(1)); + match x { + Some(Some(1)) if true => .., + Some(Some(1)) => { + println!("a"); + .. + }, + Some(Some(1)) => .., + Some(Some(2)) => .., + // Don't lint, since x is used in the body + Some(x) if let Some(1) = x => { + x; + .. + } + _ => todo!(), + }; + let y = 1; + match x { + // Don't inline these, since y is not from the pat + Some(x) if matches!(y, 1 if true) => .., + Some(x) if let 1 = y => .., + Some(x) if y == 2 => .., + _ => todo!(), + }; + let a = A(1); + match a { + _ if a.0 == 1 => {}, + _ => todo!(), + } + let b = B { e: Some(A(0)) }; + match b { + B { e: Some(A(2)) } => .., + _ => todo!(), + }; + // Do not lint, since we cannot represent this as a pattern (at least, without a conversion) + let v = Some(vec![1u8, 2, 3]); + match v { + Some(x) if x == [1] => {}, + _ => {}, + } + + external! { + let x = Some(Some(1)); + match x { + Some(x) if let Some(1) = x => .., + _ => todo!(), + }; + } + with_span! { + span + let x = Some(Some(1)); + match x { + Some(x) if let Some(1) = x => .., + _ => todo!(), + }; + } +} + +enum E { + A(&'static str), + B(&'static str), + C(&'static str), +} + +fn i() { + match E::A("") { + // Do not lint + E::A(x) | E::B(x) | E::C(x) if x == "from an or pattern" => {}, + E::A("not from an or pattern") => {}, + _ => {}, + }; +} + +fn h(v: Option) { + match v { + Some(0) => .., + _ => .., + }; +} + +// Do not lint + +fn f(s: Option) { + match s { + Some(x) if x == "a" => {}, + _ => {}, + } +} + +struct S { + a: usize, +} + +impl PartialEq for S { + fn eq(&self, _: &Self) -> bool { + true + } +} + +impl Eq for S {} + +static CONST_S: S = S { a: 1 }; + +fn g(opt_s: Option) { + match opt_s { + Some(x) if x == CONST_S => {}, + _ => {}, + } +} diff --git a/tests/ui/redundant_guards.rs b/tests/ui/redundant_guards.rs new file mode 100644 index 0000000000000..b072e4ea14d1d --- /dev/null +++ b/tests/ui/redundant_guards.rs @@ -0,0 +1,133 @@ +//@run-rustfix +//@aux-build:proc_macros.rs:proc-macro +#![feature(if_let_guard)] +#![allow(clippy::no_effect, unused)] +#![warn(clippy::redundant_guards)] + +#[macro_use] +extern crate proc_macros; + +struct A(u32); + +struct B { + e: Option, +} + +struct C(u32, u32); + +fn main() { + let c = C(1, 2); + match c { + C(x, y) if let 1 = y => .., + _ => todo!(), + }; + + let x = Some(Some(1)); + match x { + Some(x) if matches!(x, Some(1) if true) => .., + Some(x) if matches!(x, Some(1)) => { + println!("a"); + .. + }, + Some(x) if let Some(1) = x => .., + Some(x) if x == Some(2) => .., + // Don't lint, since x is used in the body + Some(x) if let Some(1) = x => { + x; + .. + } + _ => todo!(), + }; + let y = 1; + match x { + // Don't inline these, since y is not from the pat + Some(x) if matches!(y, 1 if true) => .., + Some(x) if let 1 = y => .., + Some(x) if y == 2 => .., + _ => todo!(), + }; + let a = A(1); + match a { + _ if a.0 == 1 => {}, + _ => todo!(), + } + let b = B { e: Some(A(0)) }; + match b { + B { e } if matches!(e, Some(A(2))) => .., + _ => todo!(), + }; + // Do not lint, since we cannot represent this as a pattern (at least, without a conversion) + let v = Some(vec![1u8, 2, 3]); + match v { + Some(x) if x == [1] => {}, + _ => {}, + } + + external! { + let x = Some(Some(1)); + match x { + Some(x) if let Some(1) = x => .., + _ => todo!(), + }; + } + with_span! { + span + let x = Some(Some(1)); + match x { + Some(x) if let Some(1) = x => .., + _ => todo!(), + }; + } +} + +enum E { + A(&'static str), + B(&'static str), + C(&'static str), +} + +fn i() { + match E::A("") { + // Do not lint + E::A(x) | E::B(x) | E::C(x) if x == "from an or pattern" => {}, + E::A(y) if y == "not from an or pattern" => {}, + _ => {}, + }; +} + +fn h(v: Option) { + match v { + x if matches!(x, Some(0)) => .., + _ => .., + }; +} + +// Do not lint + +fn f(s: Option) { + match s { + Some(x) if x == "a" => {}, + _ => {}, + } +} + +struct S { + a: usize, +} + +impl PartialEq for S { + fn eq(&self, _: &Self) -> bool { + true + } +} + +impl Eq for S {} + +static CONST_S: S = S { a: 1 }; + +fn g(opt_s: Option) { + match opt_s { + Some(x) if x == CONST_S => {}, + _ => {}, + } +} diff --git a/tests/ui/redundant_guards.stderr b/tests/ui/redundant_guards.stderr new file mode 100644 index 0000000000000..c2a92071d1dfb --- /dev/null +++ b/tests/ui/redundant_guards.stderr @@ -0,0 +1,98 @@ +error: redundant guard + --> $DIR/redundant_guards.rs:21:20 + | +LL | C(x, y) if let 1 = y => .., + | ^^^^^^^^^ + | + = note: `-D clippy::redundant-guards` implied by `-D warnings` +help: try + | +LL - C(x, y) if let 1 = y => .., +LL + C(x, 1) => .., + | + +error: redundant guard + --> $DIR/redundant_guards.rs:27:20 + | +LL | Some(x) if matches!(x, Some(1) if true) => .., + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: try + | +LL | Some(Some(1)) if true => .., + | ~~~~~~~ ~~~~~~~ + +error: redundant guard + --> $DIR/redundant_guards.rs:28:20 + | +LL | Some(x) if matches!(x, Some(1)) => { + | ^^^^^^^^^^^^^^^^^^^^ + | +help: try + | +LL - Some(x) if matches!(x, Some(1)) => { +LL + Some(Some(1)) => { + | + +error: redundant guard + --> $DIR/redundant_guards.rs:32:20 + | +LL | Some(x) if let Some(1) = x => .., + | ^^^^^^^^^^^^^^^ + | +help: try + | +LL - Some(x) if let Some(1) = x => .., +LL + Some(Some(1)) => .., + | + +error: redundant guard + --> $DIR/redundant_guards.rs:33:20 + | +LL | Some(x) if x == Some(2) => .., + | ^^^^^^^^^^^^ + | +help: try + | +LL - Some(x) if x == Some(2) => .., +LL + Some(Some(2)) => .., + | + +error: redundant guard + --> $DIR/redundant_guards.rs:56:20 + | +LL | B { e } if matches!(e, Some(A(2))) => .., + | ^^^^^^^^^^^^^^^^^^^^^^^ + | +help: try + | +LL - B { e } if matches!(e, Some(A(2))) => .., +LL + B { e: Some(A(2)) } => .., + | + +error: redundant guard + --> $DIR/redundant_guards.rs:93:20 + | +LL | E::A(y) if y == "not from an or pattern" => {}, + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: try + | +LL - E::A(y) if y == "not from an or pattern" => {}, +LL + E::A("not from an or pattern") => {}, + | + +error: redundant guard + --> $DIR/redundant_guards.rs:100:14 + | +LL | x if matches!(x, Some(0)) => .., + | ^^^^^^^^^^^^^^^^^^^^ + | +help: try + | +LL - x if matches!(x, Some(0)) => .., +LL + Some(0) => .., + | + +error: aborting due to 8 previous errors + diff --git a/tests/ui/shadow.rs b/tests/ui/shadow.rs index 4d22b7d2ad0dd..1b40a43d01962 100644 --- a/tests/ui/shadow.rs +++ b/tests/ui/shadow.rs @@ -1,7 +1,12 @@ //@aux-build:proc_macro_derive.rs:proc-macro #![warn(clippy::shadow_same, clippy::shadow_reuse, clippy::shadow_unrelated)] -#![allow(clippy::let_unit_value, clippy::needless_if, clippy::redundant_locals)] +#![allow( + clippy::let_unit_value, + clippy::needless_if, + clippy::redundant_guards, + clippy::redundant_locals +)] extern crate proc_macro_derive; diff --git a/tests/ui/shadow.stderr b/tests/ui/shadow.stderr index 8321f6df224cf..88b02f53be12e 100644 --- a/tests/ui/shadow.stderr +++ b/tests/ui/shadow.stderr @@ -1,278 +1,278 @@ error: `x` is shadowed by itself in `x` - --> $DIR/shadow.rs:19:9 + --> $DIR/shadow.rs:24:9 | LL | let x = x; | ^ | note: previous binding is here - --> $DIR/shadow.rs:18:9 + --> $DIR/shadow.rs:23:9 | LL | let x = 1; | ^ = note: `-D clippy::shadow-same` implied by `-D warnings` error: `mut x` is shadowed by itself in `&x` - --> $DIR/shadow.rs:20:13 + --> $DIR/shadow.rs:25:13 | LL | let mut x = &x; | ^ | note: previous binding is here - --> $DIR/shadow.rs:19:9 + --> $DIR/shadow.rs:24:9 | LL | let x = x; | ^ error: `x` is shadowed by itself in `&mut x` - --> $DIR/shadow.rs:21:9 + --> $DIR/shadow.rs:26:9 | LL | let x = &mut x; | ^ | note: previous binding is here - --> $DIR/shadow.rs:20:9 + --> $DIR/shadow.rs:25:9 | LL | let mut x = &x; | ^^^^^ error: `x` is shadowed by itself in `*x` - --> $DIR/shadow.rs:22:9 + --> $DIR/shadow.rs:27:9 | LL | let x = *x; | ^ | note: previous binding is here - --> $DIR/shadow.rs:21:9 + --> $DIR/shadow.rs:26:9 | LL | let x = &mut x; | ^ error: `x` is shadowed - --> $DIR/shadow.rs:27:9 + --> $DIR/shadow.rs:32:9 | LL | let x = x.0; | ^ | note: previous binding is here - --> $DIR/shadow.rs:26:9 + --> $DIR/shadow.rs:31:9 | LL | let x = ([[0]], ()); | ^ = note: `-D clippy::shadow-reuse` implied by `-D warnings` error: `x` is shadowed - --> $DIR/shadow.rs:28:9 + --> $DIR/shadow.rs:33:9 | LL | let x = x[0]; | ^ | note: previous binding is here - --> $DIR/shadow.rs:27:9 + --> $DIR/shadow.rs:32:9 | LL | let x = x.0; | ^ error: `x` is shadowed - --> $DIR/shadow.rs:29:10 + --> $DIR/shadow.rs:34:10 | LL | let [x] = x; | ^ | note: previous binding is here - --> $DIR/shadow.rs:28:9 + --> $DIR/shadow.rs:33:9 | LL | let x = x[0]; | ^ error: `x` is shadowed - --> $DIR/shadow.rs:30:9 + --> $DIR/shadow.rs:35:9 | LL | let x = Some(x); | ^ | note: previous binding is here - --> $DIR/shadow.rs:29:10 + --> $DIR/shadow.rs:34:10 | LL | let [x] = x; | ^ error: `x` is shadowed - --> $DIR/shadow.rs:31:9 + --> $DIR/shadow.rs:36:9 | LL | let x = foo(x); | ^ | note: previous binding is here - --> $DIR/shadow.rs:30:9 + --> $DIR/shadow.rs:35:9 | LL | let x = Some(x); | ^ error: `x` is shadowed - --> $DIR/shadow.rs:32:9 + --> $DIR/shadow.rs:37:9 | LL | let x = || x; | ^ | note: previous binding is here - --> $DIR/shadow.rs:31:9 + --> $DIR/shadow.rs:36:9 | LL | let x = foo(x); | ^ error: `x` is shadowed - --> $DIR/shadow.rs:33:9 + --> $DIR/shadow.rs:38:9 | LL | let x = Some(1).map(|_| x)?; | ^ | note: previous binding is here - --> $DIR/shadow.rs:32:9 + --> $DIR/shadow.rs:37:9 | LL | let x = || x; | ^ error: `y` is shadowed - --> $DIR/shadow.rs:35:9 + --> $DIR/shadow.rs:40:9 | LL | let y = match y { | ^ | note: previous binding is here - --> $DIR/shadow.rs:34:9 + --> $DIR/shadow.rs:39:9 | LL | let y = 1; | ^ error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:50:9 + --> $DIR/shadow.rs:55:9 | LL | let x = 2; | ^ | note: previous binding is here - --> $DIR/shadow.rs:49:9 + --> $DIR/shadow.rs:54:9 | LL | let x = 1; | ^ = note: `-D clippy::shadow-unrelated` implied by `-D warnings` error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:55:13 + --> $DIR/shadow.rs:60:13 | LL | let x = 1; | ^ | note: previous binding is here - --> $DIR/shadow.rs:54:10 + --> $DIR/shadow.rs:59:10 | LL | fn f(x: u32) { | ^ error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:60:14 + --> $DIR/shadow.rs:65:14 | LL | Some(x) => { | ^ | note: previous binding is here - --> $DIR/shadow.rs:57:9 + --> $DIR/shadow.rs:62:9 | LL | let x = 1; | ^ error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:61:17 + --> $DIR/shadow.rs:66:17 | LL | let x = 1; | ^ | note: previous binding is here - --> $DIR/shadow.rs:60:14 + --> $DIR/shadow.rs:65:14 | LL | Some(x) => { | ^ error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:65:17 + --> $DIR/shadow.rs:70:17 | LL | if let Some(x) = Some(1) {} | ^ | note: previous binding is here - --> $DIR/shadow.rs:57:9 + --> $DIR/shadow.rs:62:9 | LL | let x = 1; | ^ error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:66:20 + --> $DIR/shadow.rs:71:20 | LL | while let Some(x) = Some(1) {} | ^ | note: previous binding is here - --> $DIR/shadow.rs:57:9 + --> $DIR/shadow.rs:62:9 | LL | let x = 1; | ^ error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:67:15 + --> $DIR/shadow.rs:72:15 | LL | let _ = |[x]: [u32; 1]| { | ^ | note: previous binding is here - --> $DIR/shadow.rs:57:9 + --> $DIR/shadow.rs:62:9 | LL | let x = 1; | ^ error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:68:13 + --> $DIR/shadow.rs:73:13 | LL | let x = 1; | ^ | note: previous binding is here - --> $DIR/shadow.rs:67:15 + --> $DIR/shadow.rs:72:15 | LL | let _ = |[x]: [u32; 1]| { | ^ error: `y` is shadowed - --> $DIR/shadow.rs:71:17 + --> $DIR/shadow.rs:76:17 | LL | if let Some(y) = y {} | ^ | note: previous binding is here - --> $DIR/shadow.rs:70:9 + --> $DIR/shadow.rs:75:9 | LL | let y = Some(1); | ^ error: `_b` shadows a previous, unrelated binding - --> $DIR/shadow.rs:107:9 + --> $DIR/shadow.rs:112:9 | LL | let _b = _a; | ^^ | note: previous binding is here - --> $DIR/shadow.rs:106:28 + --> $DIR/shadow.rs:111:28 | LL | pub async fn foo2(_a: i32, _b: i64) { | ^^ error: `x` shadows a previous, unrelated binding - --> $DIR/shadow.rs:113:21 + --> $DIR/shadow.rs:118:21 | LL | if let Some(x) = Some(1) { x } else { 1 } | ^ | note: previous binding is here - --> $DIR/shadow.rs:112:13 + --> $DIR/shadow.rs:117:13 | LL | let x = 1; | ^ diff --git a/tests/ui/single_match.fixed b/tests/ui/single_match.fixed index e7b1fd6a85f22..163ba94aff802 100644 --- a/tests/ui/single_match.fixed +++ b/tests/ui/single_match.fixed @@ -4,6 +4,7 @@ unused, clippy::uninlined_format_args, clippy::needless_if, + clippy::redundant_guards, clippy::redundant_pattern_matching )] fn dummy() {} diff --git a/tests/ui/single_match.rs b/tests/ui/single_match.rs index 1515a7053e5dd..0dcdb125ffd8a 100644 --- a/tests/ui/single_match.rs +++ b/tests/ui/single_match.rs @@ -4,6 +4,7 @@ unused, clippy::uninlined_format_args, clippy::needless_if, + clippy::redundant_guards, clippy::redundant_pattern_matching )] fn dummy() {} diff --git a/tests/ui/single_match.stderr b/tests/ui/single_match.stderr index 76f7e78958985..d35361599493e 100644 --- a/tests/ui/single_match.stderr +++ b/tests/ui/single_match.stderr @@ -1,5 +1,5 @@ error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:14:5 + --> $DIR/single_match.rs:15:5 | LL | / match x { LL | | Some(y) => { @@ -18,7 +18,7 @@ LL ~ }; | error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:22:5 + --> $DIR/single_match.rs:23:5 | LL | / match x { LL | | // Note the missing block braces. @@ -30,7 +30,7 @@ LL | | } | |_____^ help: try: `if let Some(y) = x { println!("{:?}", y) }` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:31:5 + --> $DIR/single_match.rs:32:5 | LL | / match z { LL | | (2..=3, 7..=9) => dummy(), @@ -39,7 +39,7 @@ LL | | }; | |_____^ help: try: `if let (2..=3, 7..=9) = z { dummy() }` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:60:5 + --> $DIR/single_match.rs:61:5 | LL | / match x { LL | | Some(y) => dummy(), @@ -48,7 +48,7 @@ LL | | }; | |_____^ help: try: `if let Some(y) = x { dummy() }` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:65:5 + --> $DIR/single_match.rs:66:5 | LL | / match y { LL | | Ok(y) => dummy(), @@ -57,7 +57,7 @@ LL | | }; | |_____^ help: try: `if let Ok(y) = y { dummy() }` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:72:5 + --> $DIR/single_match.rs:73:5 | LL | / match c { LL | | Cow::Borrowed(..) => dummy(), @@ -66,7 +66,7 @@ LL | | }; | |_____^ help: try: `if let Cow::Borrowed(..) = c { dummy() }` error: you seem to be trying to use `match` for an equality check. Consider using `if` - --> $DIR/single_match.rs:93:5 + --> $DIR/single_match.rs:94:5 | LL | / match x { LL | | "test" => println!(), @@ -75,7 +75,7 @@ LL | | } | |_____^ help: try: `if x == "test" { println!() }` error: you seem to be trying to use `match` for an equality check. Consider using `if` - --> $DIR/single_match.rs:106:5 + --> $DIR/single_match.rs:107:5 | LL | / match x { LL | | Foo::A => println!(), @@ -84,7 +84,7 @@ LL | | } | |_____^ help: try: `if x == Foo::A { println!() }` error: you seem to be trying to use `match` for an equality check. Consider using `if` - --> $DIR/single_match.rs:112:5 + --> $DIR/single_match.rs:113:5 | LL | / match x { LL | | FOO_C => println!(), @@ -93,7 +93,7 @@ LL | | } | |_____^ help: try: `if x == FOO_C { println!() }` error: you seem to be trying to use `match` for an equality check. Consider using `if` - --> $DIR/single_match.rs:117:5 + --> $DIR/single_match.rs:118:5 | LL | / match &&x { LL | | Foo::A => println!(), @@ -102,7 +102,7 @@ LL | | } | |_____^ help: try: `if x == Foo::A { println!() }` error: you seem to be trying to use `match` for an equality check. Consider using `if` - --> $DIR/single_match.rs:123:5 + --> $DIR/single_match.rs:124:5 | LL | / match &x { LL | | Foo::A => println!(), @@ -111,7 +111,7 @@ LL | | } | |_____^ help: try: `if x == &Foo::A { println!() }` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:140:5 + --> $DIR/single_match.rs:141:5 | LL | / match x { LL | | Bar::A => println!(), @@ -120,7 +120,7 @@ LL | | } | |_____^ help: try: `if let Bar::A = x { println!() }` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:148:5 + --> $DIR/single_match.rs:149:5 | LL | / match x { LL | | None => println!(), @@ -129,7 +129,7 @@ LL | | }; | |_____^ help: try: `if let None = x { println!() }` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:170:5 + --> $DIR/single_match.rs:171:5 | LL | / match x { LL | | (Some(_), _) => {}, @@ -138,7 +138,7 @@ LL | | } | |_____^ help: try: `if let (Some(_), _) = x {}` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:176:5 + --> $DIR/single_match.rs:177:5 | LL | / match x { LL | | (Some(E::V), _) => todo!(), @@ -147,7 +147,7 @@ LL | | } | |_____^ help: try: `if let (Some(E::V), _) = x { todo!() }` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:182:5 + --> $DIR/single_match.rs:183:5 | LL | / match (Some(42), Some(E::V), Some(42)) { LL | | (.., Some(E::V), _) => {}, @@ -156,7 +156,7 @@ LL | | } | |_____^ help: try: `if let (.., Some(E::V), _) = (Some(42), Some(E::V), Some(42)) {}` error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:254:5 + --> $DIR/single_match.rs:255:5 | LL | / match bar { LL | | Some(v) => unsafe { @@ -176,7 +176,7 @@ LL + } } | error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let` - --> $DIR/single_match.rs:262:5 + --> $DIR/single_match.rs:263:5 | LL | / match bar { LL | | #[rustfmt::skip]