diff options
| -rw-r--r-- | clippy_lints/src/lib.register_all.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/lib.register_complexity.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/lib.register_lints.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/lib.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/methods/mod.rs | 29 | ||||
| -rw-r--r-- | clippy_lints/src/methods/needless_option_as_deref.rs | 37 | ||||
| -rw-r--r-- | clippy_lints/src/needless_option_as_deref.rs | 65 | ||||
| -rw-r--r-- | tests/ui/needless_option_as_deref.fixed | 30 | ||||
| -rw-r--r-- | tests/ui/needless_option_as_deref.rs | 30 | ||||
| -rw-r--r-- | tests/ui/needless_option_as_deref.stderr | 12 |
10 files changed, 136 insertions, 75 deletions
diff --git a/clippy_lints/src/lib.register_all.rs b/clippy_lints/src/lib.register_all.rs index 1fb3ca1fd9b..341c7e397d3 100644 --- a/clippy_lints/src/lib.register_all.rs +++ b/clippy_lints/src/lib.register_all.rs @@ -176,6 +176,7 @@ store.register_group(true, "clippy::all", Some("clippy_all"), vec![ LintId::of(methods::MAP_COLLECT_RESULT_UNIT), LintId::of(methods::MAP_FLATTEN), LintId::of(methods::MAP_IDENTITY), + LintId::of(methods::NEEDLESS_OPTION_AS_DEREF), LintId::of(methods::NEEDLESS_SPLITN), LintId::of(methods::NEW_RET_NO_SELF), LintId::of(methods::OK_EXPECT), @@ -225,7 +226,6 @@ store.register_group(true, "clippy::all", Some("clippy_all"), vec![ LintId::of(needless_bool::NEEDLESS_BOOL), LintId::of(needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE), LintId::of(needless_late_init::NEEDLESS_LATE_INIT), - LintId::of(needless_option_as_deref::NEEDLESS_OPTION_AS_DEREF), LintId::of(needless_question_mark::NEEDLESS_QUESTION_MARK), LintId::of(needless_update::NEEDLESS_UPDATE), LintId::of(neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD), diff --git a/clippy_lints/src/lib.register_complexity.rs b/clippy_lints/src/lib.register_complexity.rs index a2ce69065f9..10369a855ae 100644 --- a/clippy_lints/src/lib.register_complexity.rs +++ b/clippy_lints/src/lib.register_complexity.rs @@ -44,6 +44,7 @@ store.register_group(true, "clippy::complexity", Some("clippy_complexity"), vec! LintId::of(methods::MANUAL_SPLIT_ONCE), LintId::of(methods::MAP_FLATTEN), LintId::of(methods::MAP_IDENTITY), + LintId::of(methods::NEEDLESS_OPTION_AS_DEREF), LintId::of(methods::NEEDLESS_SPLITN), LintId::of(methods::OPTION_AS_REF_DEREF), LintId::of(methods::OPTION_FILTER_MAP), @@ -60,7 +61,6 @@ store.register_group(true, "clippy::complexity", Some("clippy_complexity"), vec! LintId::of(needless_bool::BOOL_COMPARISON), LintId::of(needless_bool::NEEDLESS_BOOL), LintId::of(needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE), - LintId::of(needless_option_as_deref::NEEDLESS_OPTION_AS_DEREF), LintId::of(needless_question_mark::NEEDLESS_QUESTION_MARK), LintId::of(needless_update::NEEDLESS_UPDATE), LintId::of(neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD), diff --git a/clippy_lints/src/lib.register_lints.rs b/clippy_lints/src/lib.register_lints.rs index bba3cae45f5..e5f5c6cd31c 100644 --- a/clippy_lints/src/lib.register_lints.rs +++ b/clippy_lints/src/lib.register_lints.rs @@ -315,6 +315,7 @@ store.register_lints(&[ methods::MAP_FLATTEN, methods::MAP_IDENTITY, methods::MAP_UNWRAP_OR, + methods::NEEDLESS_OPTION_AS_DEREF, methods::NEEDLESS_SPLITN, methods::NEW_RET_NO_SELF, methods::OK_EXPECT, @@ -386,7 +387,6 @@ store.register_lints(&[ needless_continue::NEEDLESS_CONTINUE, needless_for_each::NEEDLESS_FOR_EACH, needless_late_init::NEEDLESS_LATE_INIT, - needless_option_as_deref::NEEDLESS_OPTION_AS_DEREF, needless_pass_by_value::NEEDLESS_PASS_BY_VALUE, needless_question_mark::NEEDLESS_QUESTION_MARK, needless_update::NEEDLESS_UPDATE, diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 8dab039f24f..a9a77f5ae04 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -308,7 +308,6 @@ mod needless_borrowed_ref; mod needless_continue; mod needless_for_each; mod needless_late_init; -mod needless_option_as_deref; mod needless_pass_by_value; mod needless_question_mark; mod needless_update; @@ -536,7 +535,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|| Box::new(ptr::Ptr)); store.register_late_pass(|| Box::new(ptr_eq::PtrEq)); store.register_late_pass(|| Box::new(needless_bool::NeedlessBool)); - store.register_late_pass(|| Box::new(needless_option_as_deref::OptionNeedlessDeref)); store.register_late_pass(|| Box::new(needless_bool::BoolComparison)); store.register_late_pass(|| Box::new(needless_for_each::NeedlessForEach)); store.register_late_pass(|| Box::new(misc::MiscLints)); diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index c5c871c9d29..4a2bcca13b4 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -41,6 +41,7 @@ mod map_collect_result_unit; mod map_flatten; mod map_identity; mod map_unwrap_or; +mod needless_option_as_deref; mod ok_expect; mod option_as_ref_deref; mod option_map_or_none; @@ -2106,6 +2107,30 @@ declare_clippy_lint! { "using `.collect::<Vec<String>>().join(\"\")` on an iterator" } +declare_clippy_lint! { + /// ### What it does + /// Checks for no-op uses of `Option::{as_deref, as_deref_mut}`, + /// for example, `Option<&T>::as_deref()` returns the same type. + /// + /// ### Why is this bad? + /// Redundant code and improving readability. + /// + /// ### Example + /// ```rust + /// let a = Some(&1); + /// let b = a.as_deref(); // goes from Option<&i32> to Option<&i32> + /// ``` + /// Could be written as: + /// ```rust + /// let a = Some(&1); + /// let b = a; + /// ``` + #[clippy::version = "1.57.0"] + pub NEEDLESS_OPTION_AS_DEREF, + complexity, + "no-op use of `deref` or `deref_mut` method to `Option`." +} + pub struct Methods { avoid_breaking_exported_api: bool, msrv: Option<RustcVersion>, @@ -2193,6 +2218,7 @@ impl_lint_pass!(Methods => [ UNNECESSARY_TO_OWNED, UNNECESSARY_JOIN, ERR_EXPECT, + NEEDLESS_OPTION_AS_DEREF, ]); /// Extracts a method call name, args, and `Span` of the method name. @@ -2425,6 +2451,9 @@ fn check_methods<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, msrv: Optio unnecessary_lazy_eval::check(cx, expr, recv, arg, "and"); } }, + ("as_deref" | "as_deref_mut", []) => { + needless_option_as_deref::check(cx, expr, recv, name); + }, ("as_mut", []) => useless_asref::check(cx, expr, "as_mut", recv), ("as_ref", []) => useless_asref::check(cx, expr, "as_ref", recv), ("assume_init", []) => uninit_assumed_init::check(cx, expr, recv), diff --git a/clippy_lints/src/methods/needless_option_as_deref.rs b/clippy_lints/src/methods/needless_option_as_deref.rs new file mode 100644 index 00000000000..7030baf19ff --- /dev/null +++ b/clippy_lints/src/methods/needless_option_as_deref.rs @@ -0,0 +1,37 @@ +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::path_res; +use clippy_utils::source::snippet_opt; +use clippy_utils::ty::is_type_diagnostic_item; +use clippy_utils::usage::local_used_after_expr; +use rustc_errors::Applicability; +use rustc_hir::def::Res; +use rustc_hir::Expr; +use rustc_lint::LateContext; +use rustc_span::sym; + +use super::NEEDLESS_OPTION_AS_DEREF; + +pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, name: &str) { + let typeck = cx.typeck_results(); + let outer_ty = typeck.expr_ty(expr); + + if is_type_diagnostic_item(cx, outer_ty, sym::Option) && outer_ty == typeck.expr_ty(recv) { + if name == "as_deref_mut" && recv.is_syntactic_place_expr() { + let Res::Local(binding_id) = path_res(cx, recv) else { return }; + + if local_used_after_expr(cx, binding_id, recv) { + return; + } + } + + span_lint_and_sugg( + cx, + NEEDLESS_OPTION_AS_DEREF, + expr.span, + "derefed type is same as origin", + "try this", + snippet_opt(cx, recv.span).unwrap(), + Applicability::MachineApplicable, + ); + } +} diff --git a/clippy_lints/src/needless_option_as_deref.rs b/clippy_lints/src/needless_option_as_deref.rs deleted file mode 100644 index 9d3d7d1f24c..00000000000 --- a/clippy_lints/src/needless_option_as_deref.rs +++ /dev/null @@ -1,65 +0,0 @@ -use clippy_utils::diagnostics::span_lint_and_sugg; -use clippy_utils::source::snippet_opt; -use clippy_utils::ty::is_type_diagnostic_item; -use rustc_errors::Applicability; -use rustc_hir::{Expr, ExprKind}; -use rustc_lint::{LateContext, LateLintPass}; -use rustc_session::{declare_lint_pass, declare_tool_lint}; -use rustc_span::symbol::sym; - -declare_clippy_lint! { - /// ### What it does - /// Checks for no-op uses of Option::{as_deref,as_deref_mut}, - /// for example, `Option<&T>::as_deref()` returns the same type. - /// - /// ### Why is this bad? - /// Redundant code and improving readability. - /// - /// ### Example - /// ```rust - /// let a = Some(&1); - /// let b = a.as_deref(); // goes from Option<&i32> to Option<&i32> - /// ``` - /// Could be written as: - /// ```rust - /// let a = Some(&1); - /// let b = a; - /// ``` - #[clippy::version = "1.57.0"] - pub NEEDLESS_OPTION_AS_DEREF, - complexity, - "no-op use of `deref` or `deref_mut` method to `Option`." -} - -declare_lint_pass!(OptionNeedlessDeref=> [ - NEEDLESS_OPTION_AS_DEREF, -]); - -impl<'tcx> LateLintPass<'tcx> for OptionNeedlessDeref { - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { - if expr.span.from_expansion() { - return; - } - let typeck = cx.typeck_results(); - let outer_ty = typeck.expr_ty(expr); - - if_chain! { - if is_type_diagnostic_item(cx,outer_ty,sym::Option); - if let ExprKind::MethodCall(path, [sub_expr], _) = expr.kind; - let symbol = path.ident.as_str(); - if symbol == "as_deref" || symbol == "as_deref_mut"; - if outer_ty == typeck.expr_ty(sub_expr); - then{ - span_lint_and_sugg( - cx, - NEEDLESS_OPTION_AS_DEREF, - expr.span, - "derefed type is same as origin", - "try this", - snippet_opt(cx,sub_expr.span).unwrap(), - Applicability::MachineApplicable - ); - } - } - } -} diff --git a/tests/ui/needless_option_as_deref.fixed b/tests/ui/needless_option_as_deref.fixed index d721452ae88..c09b07db3dc 100644 --- a/tests/ui/needless_option_as_deref.fixed +++ b/tests/ui/needless_option_as_deref.fixed @@ -1,13 +1,41 @@ // run-rustfix -#[warn(clippy::needless_option_as_deref)] +#![allow(unused)] +#![warn(clippy::needless_option_as_deref)] fn main() { // should lint let _: Option<&usize> = Some(&1); let _: Option<&mut usize> = Some(&mut 1); + let mut y = 0; + let mut x = Some(&mut y); + let _ = x; + // should not lint let _ = Some(Box::new(1)).as_deref(); let _ = Some(Box::new(1)).as_deref_mut(); + + // #7846 + let mut i = 0; + let mut opt_vec = vec![Some(&mut i)]; + opt_vec[0].as_deref_mut().unwrap(); + + let mut i = 0; + let x = &mut Some(&mut i); + (*x).as_deref_mut(); + + // #8047 + let mut y = 0; + let mut x = Some(&mut y); + x.as_deref_mut(); + dbg!(x); +} + +struct S<'a> { + opt: Option<&'a mut usize>, +} + +fn from_field<'a>(s: &'a mut S<'a>) -> Option<&'a mut usize> { + s.opt.as_deref_mut() } diff --git a/tests/ui/needless_option_as_deref.rs b/tests/ui/needless_option_as_deref.rs index bb15512adf6..c3ba27ecccf 100644 --- a/tests/ui/needless_option_as_deref.rs +++ b/tests/ui/needless_option_as_deref.rs @@ -1,13 +1,41 @@ // run-rustfix -#[warn(clippy::needless_option_as_deref)] +#![allow(unused)] +#![warn(clippy::needless_option_as_deref)] fn main() { // should lint let _: Option<&usize> = Some(&1).as_deref(); let _: Option<&mut usize> = Some(&mut 1).as_deref_mut(); + let mut y = 0; + let mut x = Some(&mut y); + let _ = x.as_deref_mut(); + // should not lint let _ = Some(Box::new(1)).as_deref(); let _ = Some(Box::new(1)).as_deref_mut(); + + // #7846 + let mut i = 0; + let mut opt_vec = vec![Some(&mut i)]; + opt_vec[0].as_deref_mut().unwrap(); + + let mut i = 0; + let x = &mut Some(&mut i); + (*x).as_deref_mut(); + + // #8047 + let mut y = 0; + let mut x = Some(&mut y); + x.as_deref_mut(); + dbg!(x); +} + +struct S<'a> { + opt: Option<&'a mut usize>, +} + +fn from_field<'a>(s: &'a mut S<'a>) -> Option<&'a mut usize> { + s.opt.as_deref_mut() } diff --git a/tests/ui/needless_option_as_deref.stderr b/tests/ui/needless_option_as_deref.stderr index 5dd507b4a71..bc07db5b38e 100644 --- a/tests/ui/needless_option_as_deref.stderr +++ b/tests/ui/needless_option_as_deref.stderr @@ -1,5 +1,5 @@ error: derefed type is same as origin - --> $DIR/needless_option_as_deref.rs:7:29 + --> $DIR/needless_option_as_deref.rs:8:29 | LL | let _: Option<&usize> = Some(&1).as_deref(); | ^^^^^^^^^^^^^^^^^^^ help: try this: `Some(&1)` @@ -7,10 +7,16 @@ LL | let _: Option<&usize> = Some(&1).as_deref(); = note: `-D clippy::needless-option-as-deref` implied by `-D warnings` error: derefed type is same as origin - --> $DIR/needless_option_as_deref.rs:8:33 + --> $DIR/needless_option_as_deref.rs:9:33 | LL | let _: Option<&mut usize> = Some(&mut 1).as_deref_mut(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `Some(&mut 1)` -error: aborting due to 2 previous errors +error: derefed type is same as origin + --> $DIR/needless_option_as_deref.rs:13:13 + | +LL | let _ = x.as_deref_mut(); + | ^^^^^^^^^^^^^^^^ help: try this: `x` + +error: aborting due to 3 previous errors |