From 94e4b5ec316993200d75276b4e7c16a059bf3a57 Mon Sep 17 00:00:00 2001 From: Vardan Margaryan Date: Sun, 10 May 2020 00:08:41 +0300 Subject: [PATCH 1/8] Add the redundant_wildcard_enum_match lint --- CHANGELOG.md | 1 + clippy_lints/src/lib.rs | 2 + clippy_lints/src/matches.rs | 48 +++++++++++++++++++ src/lintlist/mod.rs | 7 +++ .../match_wildcard_for_single_variants.fixed | 18 +++++++ .../ui/match_wildcard_for_single_variants.rs | 18 +++++++ .../match_wildcard_for_single_variants.stderr | 10 ++++ 7 files changed, 104 insertions(+) create mode 100644 tests/ui/match_wildcard_for_single_variants.fixed create mode 100644 tests/ui/match_wildcard_for_single_variants.rs create mode 100644 tests/ui/match_wildcard_for_single_variants.stderr diff --git a/CHANGELOG.md b/CHANGELOG.md index b25ef0493568..d6298fec65a4 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1439,6 +1439,7 @@ Released 2018-09-13 [`match_same_arms`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_same_arms [`match_single_binding`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_single_binding [`match_wild_err_arm`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_wild_err_arm +[`match_wildcard_for_single_variants`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_wildcard_for_single_variants [`maybe_infinite_iter`]: https://rust-lang.github.io/rust-clippy/master/index.html#maybe_infinite_iter [`mem_discriminant_non_enum`]: https://rust-lang.github.io/rust-clippy/master/index.html#mem_discriminant_non_enum [`mem_forget`]: https://rust-lang.github.io/rust-clippy/master/index.html#mem_forget diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 0c4daeb731f9..41046c18ed25 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -641,6 +641,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &matches::MATCH_OVERLAPPING_ARM, &matches::MATCH_REF_PATS, &matches::MATCH_SINGLE_BINDING, + &matches::MATCH_WILDCARD_FOR_SINGLE_VARIANTS, &matches::MATCH_WILD_ERR_ARM, &matches::REST_PAT_IN_FULLY_BOUND_STRUCTS, &matches::SINGLE_MATCH, @@ -1147,6 +1148,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(¯o_use::MACRO_USE_IMPORTS), LintId::of(&match_on_vec_items::MATCH_ON_VEC_ITEMS), LintId::of(&matches::MATCH_BOOL), + LintId::of(&matches::MATCH_WILDCARD_FOR_SINGLE_VARIANTS), LintId::of(&matches::SINGLE_MATCH_ELSE), LintId::of(&methods::FILTER_MAP), LintId::of(&methods::FILTER_MAP_NEXT), diff --git a/clippy_lints/src/matches.rs b/clippy_lints/src/matches.rs index 8f86535ef1e0..42a6c4166194 100644 --- a/clippy_lints/src/matches.rs +++ b/clippy_lints/src/matches.rs @@ -229,6 +229,40 @@ declare_clippy_lint! { "a wildcard enum match arm using `_`" } +declare_clippy_lint! { + /// **What it does:** Checks for wildcard enum matches for a single variant. + /// + /// **Why is this bad?** New enum variants added by library updates can be missed. + /// + /// **Known problems:** Suggested replacements may not use correct path to enum + /// if it's not present in the current scope. + /// + /// **Example:** + /// + /// ```rust + /// # enum Foo { A, B, C } + /// # let x = Foo::B; + /// match x { + /// Foo::A => {}, + /// Foo::B => {}, + /// _ => {}, + /// } + /// ``` + /// Use instead: + /// ```rust + /// # enum Foo { A, B, C } + /// # let x = Foo::B; + /// match x { + /// Foo::A => {}, + /// Foo::B => {}, + /// Foo::C => {}, + /// } + /// ``` + pub MATCH_WILDCARD_FOR_SINGLE_VARIANTS, + pedantic, + "a wildcard enum match for a single variant" +} + declare_clippy_lint! { /// **What it does:** Checks for wildcard pattern used with others patterns in same match arm. /// @@ -356,6 +390,7 @@ impl_lint_pass!(Matches => [ MATCH_WILD_ERR_ARM, MATCH_AS_REF, WILDCARD_ENUM_MATCH_ARM, + MATCH_WILDCARD_FOR_SINGLE_VARIANTS, WILDCARD_IN_OR_PATTERNS, MATCH_SINGLE_BINDING, INFALLIBLE_DESTRUCTURING_MATCH, @@ -766,6 +801,19 @@ fn check_wild_enum_match(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_ } } + if suggestion.len() == 1 { + // No need to check for non-exhaustive enum as in that case len would be greater than 1 + span_lint_and_sugg( + cx, + MATCH_WILDCARD_FOR_SINGLE_VARIANTS, + wildcard_span, + message, + "try this", + suggestion[0].clone(), + Applicability::MachineApplicable, + ) + }; + span_lint_and_sugg( cx, WILDCARD_ENUM_MATCH_ARM, diff --git a/src/lintlist/mod.rs b/src/lintlist/mod.rs index e1a6d4bdd31f..250a7c09f781 100644 --- a/src/lintlist/mod.rs +++ b/src/lintlist/mod.rs @@ -1200,6 +1200,13 @@ pub static ref ALL_LINTS: Vec = vec![ deprecation: None, module: "matches", }, + Lint { + name: "match_wildcard_for_single_variants", + group: "pedantic", + desc: "a wildcard enum match for a single variant", + deprecation: None, + module: "matches", + }, Lint { name: "maybe_infinite_iter", group: "pedantic", diff --git a/tests/ui/match_wildcard_for_single_variants.fixed b/tests/ui/match_wildcard_for_single_variants.fixed new file mode 100644 index 000000000000..5f1a559f5914 --- /dev/null +++ b/tests/ui/match_wildcard_for_single_variants.fixed @@ -0,0 +1,18 @@ +// run-rustfix + +#![warn(clippy::match_wildcard_for_single_variants)] +#![allow(dead_code)] + +enum Foo { + A, + B, + C, +} + +fn main() { + match Foo::A { + Foo::A => {}, + Foo::B => {}, + Foo::C => {}, + } +} diff --git a/tests/ui/match_wildcard_for_single_variants.rs b/tests/ui/match_wildcard_for_single_variants.rs new file mode 100644 index 000000000000..1159f9e722d7 --- /dev/null +++ b/tests/ui/match_wildcard_for_single_variants.rs @@ -0,0 +1,18 @@ +// run-rustfix + +#![warn(clippy::match_wildcard_for_single_variants)] +#![allow(dead_code)] + +enum Foo { + A, + B, + C, +} + +fn main() { + match Foo::A { + Foo::A => {}, + Foo::B => {}, + _ => {}, + } +} diff --git a/tests/ui/match_wildcard_for_single_variants.stderr b/tests/ui/match_wildcard_for_single_variants.stderr new file mode 100644 index 000000000000..128dd4808bf7 --- /dev/null +++ b/tests/ui/match_wildcard_for_single_variants.stderr @@ -0,0 +1,10 @@ +error: wildcard match will miss any future added variants + --> $DIR/match_wildcard_for_single_variants.rs:16:9 + | +LL | _ => {}, + | ^ help: try this: `Foo::C` + | + = note: `-D clippy::match-wildcard-for-single-variants` implied by `-D warnings` + +error: aborting due to previous error + From 0ad9f7d651b52de4be6384c9b6dc893b389fd557 Mon Sep 17 00:00:00 2001 From: Vardan Margaryan Date: Sun, 10 May 2020 18:33:12 +0300 Subject: [PATCH 2/8] Fix trivial cases of new match_wildcard_for_single_variants lint --- clippy_lints/src/float_literal.rs | 2 +- clippy_lints/src/misc_early.rs | 2 +- clippy_lints/src/missing_const_for_fn.rs | 2 +- clippy_lints/src/needless_pass_by_value.rs | 2 +- clippy_lints/src/trivially_copy_pass_by_ref.rs | 2 +- tests/compile-test.rs | 2 +- 6 files changed, 6 insertions(+), 6 deletions(-) diff --git a/clippy_lints/src/float_literal.rs b/clippy_lints/src/float_literal.rs index 3a52b1d3fc20..4c604cd01075 100644 --- a/clippy_lints/src/float_literal.rs +++ b/clippy_lints/src/float_literal.rs @@ -77,7 +77,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FloatLiteral { let type_suffix = match lit_float_ty { LitFloatType::Suffixed(FloatTy::F32) => Some("f32"), LitFloatType::Suffixed(FloatTy::F64) => Some("f64"), - _ => None + LitFloatType::Unsuffixed => None }; let (is_whole, mut float_str) = match fty { FloatTy::F32 => { diff --git a/clippy_lints/src/misc_early.rs b/clippy_lints/src/misc_early.rs index 62ee051624b4..552222eba2ee 100644 --- a/clippy_lints/src/misc_early.rs +++ b/clippy_lints/src/misc_early.rs @@ -379,7 +379,7 @@ impl EarlyLintPass for MiscEarlyLints { let left_binding = match left { BindingMode::ByRef(Mutability::Mut) => "ref mut ", BindingMode::ByRef(Mutability::Not) => "ref ", - _ => "", + BindingMode::ByValue(..) => "", }; if let PatKind::Wild = right.kind { diff --git a/clippy_lints/src/missing_const_for_fn.rs b/clippy_lints/src/missing_const_for_fn.rs index 4301157e1644..9cfc8d191349 100644 --- a/clippy_lints/src/missing_const_for_fn.rs +++ b/clippy_lints/src/missing_const_for_fn.rs @@ -113,7 +113,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingConstForFn { return; } }, - _ => return, + FnKind::Closure(..) => return, } let mir = cx.tcx.optimized_mir(def_id); diff --git a/clippy_lints/src/needless_pass_by_value.rs b/clippy_lints/src/needless_pass_by_value.rs index a21818701dac..c099c5533339 100644 --- a/clippy_lints/src/needless_pass_by_value.rs +++ b/clippy_lints/src/needless_pass_by_value.rs @@ -86,7 +86,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NeedlessPassByValue { } }, FnKind::Method(..) => (), - _ => return, + FnKind::Closure(..) => return, } // Exclude non-inherent impls diff --git a/clippy_lints/src/trivially_copy_pass_by_ref.rs b/clippy_lints/src/trivially_copy_pass_by_ref.rs index 2c101220c5d6..8e0cb94317af 100644 --- a/clippy_lints/src/trivially_copy_pass_by_ref.rs +++ b/clippy_lints/src/trivially_copy_pass_by_ref.rs @@ -161,7 +161,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TriviallyCopyPassByRef { } }, FnKind::Method(..) => (), - _ => return, + FnKind::Closure(..) => return, } // Exclude non-inherent impls diff --git a/tests/compile-test.rs b/tests/compile-test.rs index de2cf6d7873f..a3df9d5ccbd1 100644 --- a/tests/compile-test.rs +++ b/tests/compile-test.rs @@ -44,7 +44,7 @@ fn third_party_crates() -> String { for entry in fs::read_dir(dep_dir).unwrap() { let path = match entry { Ok(entry) => entry.path(), - _ => continue, + Err(_) => continue, }; if let Some(name) = path.file_name().and_then(OsStr::to_str) { for dep in CRATES { From 494830797744c09d6de3b2b2452ab185d2204005 Mon Sep 17 00:00:00 2001 From: Vardan Margaryan Date: Sun, 10 May 2020 18:34:29 +0300 Subject: [PATCH 3/8] Fix cases of match_wildcard_for_single_variants lint when it is spanned on Option --- clippy_lints/src/consts.rs | 9 +++++---- clippy_lints/src/escape.rs | 4 ++-- clippy_lints/src/floating_point_arithmetic.rs | 2 +- clippy_lints/src/loops.rs | 2 +- clippy_lints/src/misc.rs | 2 +- clippy_lints/src/modulo_arithmetic.rs | 1 + clippy_lints/src/utils/mod.rs | 2 ++ 7 files changed, 13 insertions(+), 9 deletions(-) diff --git a/clippy_lints/src/consts.rs b/clippy_lints/src/consts.rs index 81ddc8c0067c..efb424bcb7bf 100644 --- a/clippy_lints/src/consts.rs +++ b/clippy_lints/src/consts.rs @@ -139,6 +139,7 @@ impl Constant { .find(|r| r.map_or(true, |o| o != Ordering::Equal)) .unwrap_or_else(|| Some(l.len().cmp(&r.len()))), (&Self::Repeat(ref lv, ref ls), &Self::Repeat(ref rv, ref rs)) => { + #[allow(clippy::match_wildcard_for_single_variants)] match Self::partial_cmp(tcx, cmp_type, lv, rv) { Some(Equal) => Some(ls.cmp(rs)), x => x, @@ -354,14 +355,14 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> { (Some(Constant::Vec(vec)), Some(Constant::Int(index))) => match vec.get(index as usize) { Some(Constant::F32(x)) => Some(Constant::F32(*x)), Some(Constant::F64(x)) => Some(Constant::F64(*x)), - _ => None, + Some(_) | None => None, }, (Some(Constant::Vec(vec)), _) => { if !vec.is_empty() && vec.iter().all(|x| *x == vec[0]) { match vec.get(0) { Some(Constant::F32(x)) => Some(Constant::F32(*x)), Some(Constant::F64(x)) => Some(Constant::F64(*x)), - _ => None, + Some(_) | None => None, } } else { None @@ -532,7 +533,7 @@ pub fn miri_to_const(result: &ty::Const<'_>) -> Option { }) .collect::>>() .map(Constant::Vec), - _ => None, + Some(_) | None => None, }, ty::Float(FloatTy::F64) => match miri_to_const(len) { Some(Constant::Int(len)) => alloc @@ -546,7 +547,7 @@ pub fn miri_to_const(result: &ty::Const<'_>) -> Option { }) .collect::>>() .map(Constant::Vec), - _ => None, + Some(_) | None => None, }, // FIXME: implement other array type conversions. _ => None, diff --git a/clippy_lints/src/escape.rs b/clippy_lints/src/escape.rs index 1ec60a0e6e67..615afee33ef9 100644 --- a/clippy_lints/src/escape.rs +++ b/clippy_lints/src/escape.rs @@ -95,12 +95,12 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BoxedLocal { fn is_argument(map: rustc_middle::hir::map::Map<'_>, id: HirId) -> bool { match map.find(id) { Some(Node::Binding(_)) => (), - _ => return false, + Some(_) | None => return false, } match map.find(map.get_parent_node(id)) { Some(Node::Param(_)) => true, - _ => false, + Some(_) | None => false, } } diff --git a/clippy_lints/src/floating_point_arithmetic.rs b/clippy_lints/src/floating_point_arithmetic.rs index 86317fb8bd5c..8c61b2f86643 100644 --- a/clippy_lints/src/floating_point_arithmetic.rs +++ b/clippy_lints/src/floating_point_arithmetic.rs @@ -410,7 +410,7 @@ fn is_zero(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { Some(Constant::Int(i)) => i == 0, Some(Constant::F32(f)) => f == 0.0, Some(Constant::F64(f)) => f == 0.0, - _ => false, + Some(_) | None => false, } } diff --git a/clippy_lints/src/loops.rs b/clippy_lints/src/loops.rs index 0bc6b70855ba..39908bff5ed4 100644 --- a/clippy_lints/src/loops.rs +++ b/clippy_lints/src/loops.rs @@ -2154,7 +2154,7 @@ fn is_loop_nested(cx: &LateContext<'_, '_>, loop_expr: &Expr<'_>, iter_expr: &Ex } }, Some(Node::Stmt(_)) => (), - _ => { + Some(_) | None => { return false; }, } diff --git a/clippy_lints/src/misc.rs b/clippy_lints/src/misc.rs index e1d524c2231e..38c2645d36e4 100644 --- a/clippy_lints/src/misc.rs +++ b/clippy_lints/src/misc.rs @@ -509,7 +509,7 @@ fn is_allowed<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) -> boo Constant::F64(f) => *f == 0.0 || (*f).is_infinite(), _ => false, }), - _ => false, + Some(_) | None => false, } } diff --git a/clippy_lints/src/modulo_arithmetic.rs b/clippy_lints/src/modulo_arithmetic.rs index 4ca90455bc4d..3bb3eb15d9c2 100644 --- a/clippy_lints/src/modulo_arithmetic.rs +++ b/clippy_lints/src/modulo_arithmetic.rs @@ -37,6 +37,7 @@ struct OperandInfo { } fn analyze_operand(operand: &Expr<'_>, cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Option { + #[allow(clippy::match_wildcard_for_single_variants)] match constant(cx, cx.tables, operand) { Some((Constant::Int(v), _)) => match cx.tables.expr_ty(expr).kind { ty::Int(ity) => { diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs index 3b8ef18bfab8..7bc8be492e82 100644 --- a/clippy_lints/src/utils/mod.rs +++ b/clippy_lints/src/utils/mod.rs @@ -370,6 +370,7 @@ pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'_, 'tcx>, hir_id: HirId) -> O /// Checks whether this type implements `Drop`. pub fn has_drop<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool { + #[allow(clippy::match_wildcard_for_single_variants)] match ty.ty_adt_def() { Some(def) => def.has_dtor(cx.tcx), _ => false, @@ -444,6 +445,7 @@ pub fn is_entrypoint_fn(cx: &LateContext<'_, '_>, def_id: DefId) -> bool { /// Gets the name of the item the expression is in, if available. pub fn get_item_name(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Option { let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id); + #[allow(clippy::match_wildcard_for_single_variants)] match cx.tcx.hir().find(parent_id) { Some( Node::Item(Item { ident, .. }) From 749619cfe34be1ee591f3af748fbdd4d2f54d3f0 Mon Sep 17 00:00:00 2001 From: Vardan Margaryan Date: Thu, 14 May 2020 22:40:33 +0300 Subject: [PATCH 4/8] Apply suggestions from PR review --- clippy_lints/src/matches.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/clippy_lints/src/matches.rs b/clippy_lints/src/matches.rs index 42a6c4166194..444f5bb0db6c 100644 --- a/clippy_lints/src/matches.rs +++ b/clippy_lints/src/matches.rs @@ -810,7 +810,7 @@ fn check_wild_enum_match(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_ message, "try this", suggestion[0].clone(), - Applicability::MachineApplicable, + Applicability::MaybeIncorrect, ) }; @@ -821,7 +821,7 @@ fn check_wild_enum_match(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_ message, "try this", suggestion.join(" | "), - Applicability::MachineApplicable, + Applicability::MaybeIncorrect, ) } } From 1c59cd5f2110ff90a256f0948f05716403e84b85 Mon Sep 17 00:00:00 2001 From: Vardan Margaryan Date: Thu, 14 May 2020 22:41:05 +0300 Subject: [PATCH 5/8] Fix example code of wildcard_enum_match_arm lint --- clippy_lints/src/matches.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clippy_lints/src/matches.rs b/clippy_lints/src/matches.rs index 444f5bb0db6c..6fdb4cf9cd74 100644 --- a/clippy_lints/src/matches.rs +++ b/clippy_lints/src/matches.rs @@ -220,7 +220,7 @@ declare_clippy_lint! { /// # enum Foo { A(usize), B(usize) } /// # let x = Foo::B(1); /// match x { - /// A => {}, + /// Foo::A(_) => {}, /// _ => {}, /// } /// ``` From 10313a2631efa6a01dc86199d554ce5a7c1bb51a Mon Sep 17 00:00:00 2001 From: Vardan Margaryan Date: Fri, 15 May 2020 22:33:37 +0300 Subject: [PATCH 6/8] Revert "Fix cases of match_wildcard_for_single_variants lint when it is spanned on Option" This reverts commit 494830797744c09d6de3b2b2452ab185d2204005. --- clippy_lints/src/consts.rs | 9 ++++----- clippy_lints/src/escape.rs | 4 ++-- clippy_lints/src/floating_point_arithmetic.rs | 2 +- clippy_lints/src/loops.rs | 2 +- clippy_lints/src/misc.rs | 2 +- clippy_lints/src/modulo_arithmetic.rs | 1 - clippy_lints/src/utils/mod.rs | 2 -- 7 files changed, 9 insertions(+), 13 deletions(-) diff --git a/clippy_lints/src/consts.rs b/clippy_lints/src/consts.rs index efb424bcb7bf..81ddc8c0067c 100644 --- a/clippy_lints/src/consts.rs +++ b/clippy_lints/src/consts.rs @@ -139,7 +139,6 @@ impl Constant { .find(|r| r.map_or(true, |o| o != Ordering::Equal)) .unwrap_or_else(|| Some(l.len().cmp(&r.len()))), (&Self::Repeat(ref lv, ref ls), &Self::Repeat(ref rv, ref rs)) => { - #[allow(clippy::match_wildcard_for_single_variants)] match Self::partial_cmp(tcx, cmp_type, lv, rv) { Some(Equal) => Some(ls.cmp(rs)), x => x, @@ -355,14 +354,14 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> { (Some(Constant::Vec(vec)), Some(Constant::Int(index))) => match vec.get(index as usize) { Some(Constant::F32(x)) => Some(Constant::F32(*x)), Some(Constant::F64(x)) => Some(Constant::F64(*x)), - Some(_) | None => None, + _ => None, }, (Some(Constant::Vec(vec)), _) => { if !vec.is_empty() && vec.iter().all(|x| *x == vec[0]) { match vec.get(0) { Some(Constant::F32(x)) => Some(Constant::F32(*x)), Some(Constant::F64(x)) => Some(Constant::F64(*x)), - Some(_) | None => None, + _ => None, } } else { None @@ -533,7 +532,7 @@ pub fn miri_to_const(result: &ty::Const<'_>) -> Option { }) .collect::>>() .map(Constant::Vec), - Some(_) | None => None, + _ => None, }, ty::Float(FloatTy::F64) => match miri_to_const(len) { Some(Constant::Int(len)) => alloc @@ -547,7 +546,7 @@ pub fn miri_to_const(result: &ty::Const<'_>) -> Option { }) .collect::>>() .map(Constant::Vec), - Some(_) | None => None, + _ => None, }, // FIXME: implement other array type conversions. _ => None, diff --git a/clippy_lints/src/escape.rs b/clippy_lints/src/escape.rs index 615afee33ef9..1ec60a0e6e67 100644 --- a/clippy_lints/src/escape.rs +++ b/clippy_lints/src/escape.rs @@ -95,12 +95,12 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BoxedLocal { fn is_argument(map: rustc_middle::hir::map::Map<'_>, id: HirId) -> bool { match map.find(id) { Some(Node::Binding(_)) => (), - Some(_) | None => return false, + _ => return false, } match map.find(map.get_parent_node(id)) { Some(Node::Param(_)) => true, - Some(_) | None => false, + _ => false, } } diff --git a/clippy_lints/src/floating_point_arithmetic.rs b/clippy_lints/src/floating_point_arithmetic.rs index 8c61b2f86643..86317fb8bd5c 100644 --- a/clippy_lints/src/floating_point_arithmetic.rs +++ b/clippy_lints/src/floating_point_arithmetic.rs @@ -410,7 +410,7 @@ fn is_zero(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { Some(Constant::Int(i)) => i == 0, Some(Constant::F32(f)) => f == 0.0, Some(Constant::F64(f)) => f == 0.0, - Some(_) | None => false, + _ => false, } } diff --git a/clippy_lints/src/loops.rs b/clippy_lints/src/loops.rs index 39908bff5ed4..0bc6b70855ba 100644 --- a/clippy_lints/src/loops.rs +++ b/clippy_lints/src/loops.rs @@ -2154,7 +2154,7 @@ fn is_loop_nested(cx: &LateContext<'_, '_>, loop_expr: &Expr<'_>, iter_expr: &Ex } }, Some(Node::Stmt(_)) => (), - Some(_) | None => { + _ => { return false; }, } diff --git a/clippy_lints/src/misc.rs b/clippy_lints/src/misc.rs index 38c2645d36e4..e1d524c2231e 100644 --- a/clippy_lints/src/misc.rs +++ b/clippy_lints/src/misc.rs @@ -509,7 +509,7 @@ fn is_allowed<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) -> boo Constant::F64(f) => *f == 0.0 || (*f).is_infinite(), _ => false, }), - Some(_) | None => false, + _ => false, } } diff --git a/clippy_lints/src/modulo_arithmetic.rs b/clippy_lints/src/modulo_arithmetic.rs index 3bb3eb15d9c2..4ca90455bc4d 100644 --- a/clippy_lints/src/modulo_arithmetic.rs +++ b/clippy_lints/src/modulo_arithmetic.rs @@ -37,7 +37,6 @@ struct OperandInfo { } fn analyze_operand(operand: &Expr<'_>, cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Option { - #[allow(clippy::match_wildcard_for_single_variants)] match constant(cx, cx.tables, operand) { Some((Constant::Int(v), _)) => match cx.tables.expr_ty(expr).kind { ty::Int(ity) => { diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs index 7bc8be492e82..3b8ef18bfab8 100644 --- a/clippy_lints/src/utils/mod.rs +++ b/clippy_lints/src/utils/mod.rs @@ -370,7 +370,6 @@ pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'_, 'tcx>, hir_id: HirId) -> O /// Checks whether this type implements `Drop`. pub fn has_drop<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool { - #[allow(clippy::match_wildcard_for_single_variants)] match ty.ty_adt_def() { Some(def) => def.has_dtor(cx.tcx), _ => false, @@ -445,7 +444,6 @@ pub fn is_entrypoint_fn(cx: &LateContext<'_, '_>, def_id: DefId) -> bool { /// Gets the name of the item the expression is in, if available. pub fn get_item_name(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Option { let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id); - #[allow(clippy::match_wildcard_for_single_variants)] match cx.tcx.hir().find(parent_id) { Some( Node::Item(Item { ident, .. }) From 2620d2449da851171773f7bec1396af11babe278 Mon Sep 17 00:00:00 2001 From: Vardan Margaryan Date: Sat, 16 May 2020 00:06:52 +0300 Subject: [PATCH 7/8] Fix check for missing enum variants from match expressions TupleStruct matches are checked for exhaustiveness --- clippy_lints/src/matches.rs | 16 ++++++++++++++-- clippy_lints/src/utils/mod.rs | 2 +- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/clippy_lints/src/matches.rs b/clippy_lints/src/matches.rs index 6fdb4cf9cd74..7d722820800c 100644 --- a/clippy_lints/src/matches.rs +++ b/clippy_lints/src/matches.rs @@ -764,9 +764,21 @@ fn check_wild_enum_match(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_ if let QPath::Resolved(_, p) = path { missing_variants.retain(|e| e.ctor_def_id != Some(p.res.def_id())); } - } else if let PatKind::TupleStruct(ref path, ..) = arm.pat.kind { + } else if let PatKind::TupleStruct(ref path, ref patterns, ..) = arm.pat.kind { if let QPath::Resolved(_, p) = path { - missing_variants.retain(|e| e.ctor_def_id != Some(p.res.def_id())); + // Some simple checks for exhaustive patterns. + // There is a room for improvements to detect more cases, + // but it can be more expensive to do so. + let is_pattern_exhaustive = |pat: &&Pat<'_>| { + if let PatKind::Wild | PatKind::Binding(.., None) = pat.kind { + true + } else { + false + } + }; + if patterns.iter().all(is_pattern_exhaustive) { + missing_variants.retain(|e| e.ctor_def_id != Some(p.res.def_id())); + } } } } diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs index 3b8ef18bfab8..7545235e6467 100644 --- a/clippy_lints/src/utils/mod.rs +++ b/clippy_lints/src/utils/mod.rs @@ -372,7 +372,7 @@ pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'_, 'tcx>, hir_id: HirId) -> O pub fn has_drop<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool { match ty.ty_adt_def() { Some(def) => def.has_dtor(cx.tcx), - _ => false, + None => false, } } From d90625385e8ed0a9030e3ab2ea0990fce39c28bf Mon Sep 17 00:00:00 2001 From: Vardan Margaryan Date: Sat, 16 May 2020 00:19:30 +0300 Subject: [PATCH 8/8] Add more test cases for match_wildcard_for_single_variants --- .../match_wildcard_for_single_variants.fixed | 43 ++++++++++++++++++- .../ui/match_wildcard_for_single_variants.rs | 43 ++++++++++++++++++- .../match_wildcard_for_single_variants.stderr | 22 +++++++++- 3 files changed, 104 insertions(+), 4 deletions(-) diff --git a/tests/ui/match_wildcard_for_single_variants.fixed b/tests/ui/match_wildcard_for_single_variants.fixed index 5f1a559f5914..519200977a79 100644 --- a/tests/ui/match_wildcard_for_single_variants.fixed +++ b/tests/ui/match_wildcard_for_single_variants.fixed @@ -9,10 +9,51 @@ enum Foo { C, } +enum Color { + Red, + Green, + Blue, + Rgb(u8, u8, u8), +} + fn main() { - match Foo::A { + let f = Foo::A; + match f { Foo::A => {}, Foo::B => {}, Foo::C => {}, } + + let color = Color::Red; + + // check exhaustive bindings + match color { + Color::Red => {}, + Color::Green => {}, + Color::Rgb(_r, _g, _b) => {}, + Color::Blue => {}, + } + + // check exhaustive wild + match color { + Color::Red => {}, + Color::Green => {}, + Color::Rgb(..) => {}, + Color::Blue => {}, + } + match color { + Color::Red => {}, + Color::Green => {}, + Color::Rgb(_, _, _) => {}, + Color::Blue => {}, + } + + // shouldn't lint as there is one missing variant + // and one that isn't exhaustively covered + match color { + Color::Red => {}, + Color::Green => {}, + Color::Rgb(255, _, _) => {}, + _ => {}, + } } diff --git a/tests/ui/match_wildcard_for_single_variants.rs b/tests/ui/match_wildcard_for_single_variants.rs index 1159f9e722d7..1df917e085c7 100644 --- a/tests/ui/match_wildcard_for_single_variants.rs +++ b/tests/ui/match_wildcard_for_single_variants.rs @@ -9,10 +9,51 @@ enum Foo { C, } +enum Color { + Red, + Green, + Blue, + Rgb(u8, u8, u8), +} + fn main() { - match Foo::A { + let f = Foo::A; + match f { Foo::A => {}, Foo::B => {}, _ => {}, } + + let color = Color::Red; + + // check exhaustive bindings + match color { + Color::Red => {}, + Color::Green => {}, + Color::Rgb(_r, _g, _b) => {}, + _ => {}, + } + + // check exhaustive wild + match color { + Color::Red => {}, + Color::Green => {}, + Color::Rgb(..) => {}, + _ => {}, + } + match color { + Color::Red => {}, + Color::Green => {}, + Color::Rgb(_, _, _) => {}, + _ => {}, + } + + // shouldn't lint as there is one missing variant + // and one that isn't exhaustively covered + match color { + Color::Red => {}, + Color::Green => {}, + Color::Rgb(255, _, _) => {}, + _ => {}, + } } diff --git a/tests/ui/match_wildcard_for_single_variants.stderr b/tests/ui/match_wildcard_for_single_variants.stderr index 128dd4808bf7..82790aa9e80b 100644 --- a/tests/ui/match_wildcard_for_single_variants.stderr +++ b/tests/ui/match_wildcard_for_single_variants.stderr @@ -1,10 +1,28 @@ error: wildcard match will miss any future added variants - --> $DIR/match_wildcard_for_single_variants.rs:16:9 + --> $DIR/match_wildcard_for_single_variants.rs:24:9 | LL | _ => {}, | ^ help: try this: `Foo::C` | = note: `-D clippy::match-wildcard-for-single-variants` implied by `-D warnings` -error: aborting due to previous error +error: wildcard match will miss any future added variants + --> $DIR/match_wildcard_for_single_variants.rs:34:9 + | +LL | _ => {}, + | ^ help: try this: `Color::Blue` + +error: wildcard match will miss any future added variants + --> $DIR/match_wildcard_for_single_variants.rs:42:9 + | +LL | _ => {}, + | ^ help: try this: `Color::Blue` + +error: wildcard match will miss any future added variants + --> $DIR/match_wildcard_for_single_variants.rs:48:9 + | +LL | _ => {}, + | ^ help: try this: `Color::Blue` + +error: aborting due to 4 previous errors