From d2f7ae70ae07f039321b35a1f9f48585e8ddc9bd Mon Sep 17 00:00:00 2001 From: Manish Goregaokar Date: Mon, 15 Apr 2019 14:32:39 -0700 Subject: [PATCH] Suggest .copied() instead of .cloned() in map_clone when dealing with references --- clippy_lints/src/map_clone.rs | 47 +++++++++++++++++++++++------------ tests/ui/map_clone.fixed | 5 ++-- tests/ui/map_clone.rs | 1 + tests/ui/map_clone.stderr | 16 ++++++------ 4 files changed, 43 insertions(+), 26 deletions(-) diff --git a/clippy_lints/src/map_clone.rs b/clippy_lints/src/map_clone.rs index 4a309264096..27b5a2968b8 100644 --- a/clippy_lints/src/map_clone.rs +++ b/clippy_lints/src/map_clone.rs @@ -73,14 +73,14 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass { hir::BindingAnnotation::Unannotated, .., name, None ) = inner.node { if ident_eq(name, closure_expr) { - lint(cx, e.span, args[0].span); + lint(cx, e.span, args[0].span, true); } }, hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, .., name, None) => { match closure_expr.node { hir::ExprKind::Unary(hir::UnOp::UnDeref, ref inner) => { if ident_eq(name, inner) && !cx.tables.expr_ty(inner).is_box() { - lint(cx, e.span, args[0].span); + lint(cx, e.span, args[0].span, true); } }, hir::ExprKind::MethodCall(ref method, _, ref obj) => { @@ -89,7 +89,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass { let obj_ty = cx.tables.expr_ty(&obj[0]); if let ty::Ref(..) = obj_ty.sty { - lint(cx, e.span, args[0].span); + lint(cx, e.span, args[0].span, false); } else { lint_needless_cloning(cx, e.span, args[0].span); } @@ -125,18 +125,33 @@ fn lint_needless_cloning(cx: &LateContext<'_, '_>, root: Span, receiver: Span) { ) } -fn lint(cx: &LateContext<'_, '_>, replace: Span, root: Span) { +fn lint(cx: &LateContext<'_, '_>, replace: Span, root: Span, copied: bool) { let mut applicability = Applicability::MachineApplicable; - span_lint_and_sugg( - cx, - MAP_CLONE, - replace, - "You are using an explicit closure for cloning elements", - "Consider calling the dedicated `cloned` method", - format!( - "{}.cloned()", - snippet_with_applicability(cx, root, "..", &mut applicability) - ), - applicability, - ) + if copied { + span_lint_and_sugg( + cx, + MAP_CLONE, + replace, + "You are using an explicit closure for copying elements", + "Consider calling the dedicated `copied` method", + format!( + "{}.copied()", + snippet_with_applicability(cx, root, "..", &mut applicability) + ), + applicability, + ) + } else { + span_lint_and_sugg( + cx, + MAP_CLONE, + replace, + "You are using an explicit closure for cloning elements", + "Consider calling the dedicated `cloned` method", + format!( + "{}.cloned()", + snippet_with_applicability(cx, root, "..", &mut applicability) + ), + applicability, + ) + } } diff --git a/tests/ui/map_clone.fixed b/tests/ui/map_clone.fixed index d804e838d5a..14d456b1433 100644 --- a/tests/ui/map_clone.fixed +++ b/tests/ui/map_clone.fixed @@ -4,11 +4,12 @@ #![allow(clippy::clone_on_copy)] #![allow(clippy::missing_docs_in_private_items)] #![allow(clippy::redundant_closure)] +#![feature(iter_copied)] fn main() { - let _: Vec = vec![5_i8; 6].iter().cloned().collect(); + let _: Vec = vec![5_i8; 6].iter().copied().collect(); let _: Vec = vec![String::new()].iter().cloned().collect(); - let _: Vec = vec![42, 43].iter().cloned().collect(); + let _: Vec = vec![42, 43].iter().copied().collect(); let _: Option = Some(Box::new(16)).map(|b| *b); // Don't lint these diff --git a/tests/ui/map_clone.rs b/tests/ui/map_clone.rs index d98cd939d8c..a0160662ed4 100644 --- a/tests/ui/map_clone.rs +++ b/tests/ui/map_clone.rs @@ -4,6 +4,7 @@ #![allow(clippy::clone_on_copy)] #![allow(clippy::missing_docs_in_private_items)] #![allow(clippy::redundant_closure)] +#![feature(iter_copied)] fn main() { let _: Vec = vec![5_i8; 6].iter().map(|x| *x).collect(); diff --git a/tests/ui/map_clone.stderr b/tests/ui/map_clone.stderr index db7fa4f52fc..8fe7f05f99f 100644 --- a/tests/ui/map_clone.stderr +++ b/tests/ui/map_clone.stderr @@ -1,25 +1,25 @@ -error: You are using an explicit closure for cloning elements - --> $DIR/map_clone.rs:9:22 +error: You are using an explicit closure for copying elements + --> $DIR/map_clone.rs:10:22 | LL | let _: Vec = vec![5_i8; 6].iter().map(|x| *x).collect(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![5_i8; 6].iter().cloned()` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `copied` method: `vec![5_i8; 6].iter().copied()` | = note: `-D clippy::map-clone` implied by `-D warnings` error: You are using an explicit closure for cloning elements - --> $DIR/map_clone.rs:10:26 + --> $DIR/map_clone.rs:11:26 | LL | let _: Vec = vec![String::new()].iter().map(|x| x.clone()).collect(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![String::new()].iter().cloned()` -error: You are using an explicit closure for cloning elements - --> $DIR/map_clone.rs:11:23 +error: You are using an explicit closure for copying elements + --> $DIR/map_clone.rs:12:23 | LL | let _: Vec = vec![42, 43].iter().map(|&x| x).collect(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![42, 43].iter().cloned()` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `copied` method: `vec![42, 43].iter().copied()` error: You are needlessly cloning iterator elements - --> $DIR/map_clone.rs:23:29 + --> $DIR/map_clone.rs:24:29 | LL | let _ = std::env::args().map(|v| v.clone()); | ^^^^^^^^^^^^^^^^^^^ help: Remove the map call