diff --git a/clippy_lints/src/manual_map.rs b/clippy_lints/src/manual_map.rs index 78dc0d54f28..bc6544ee79e 100644 --- a/clippy_lints/src/manual_map.rs +++ b/clippy_lints/src/manual_map.rs @@ -2,13 +2,17 @@ use crate::{ map_unit_fn::OPTION_MAP_UNIT_FN, matches::MATCH_AS_REF, utils::{ - is_allowed, is_type_diagnostic_item, match_def_path, match_var, paths, peel_hir_expr_refs, - peel_mid_ty_refs_is_mutable, snippet_with_applicability, span_lint_and_sugg, + can_partially_move_ty, is_allowed, is_type_diagnostic_item, match_def_path, match_var, paths, + peel_hir_expr_refs, peel_mid_ty_refs_is_mutable, snippet_with_applicability, span_lint_and_sugg, }, }; use rustc_ast::util::parser::PREC_POSTFIX; use rustc_errors::Applicability; -use rustc_hir::{Arm, BindingAnnotation, Block, Expr, ExprKind, Mutability, Pat, PatKind, QPath}; +use rustc_hir::{ + def::Res, + intravisit::{walk_expr, ErasedMap, NestedVisitorMap, Visitor}, + Arm, BindingAnnotation, Block, Expr, ExprKind, Mutability, Pat, PatKind, Path, QPath, +}; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::lint::in_external_macro; use rustc_session::{declare_lint_pass, declare_tool_lint}; @@ -99,6 +103,10 @@ impl LateLintPass<'_> for ManualMap { return; } + if !can_move_expr_to_closure(cx, some_expr) { + return; + } + // Determine which binding mode to use. let explicit_ref = some_pat.contains_explicit_ref_binding(); let binding_ref = explicit_ref.or_else(|| (ty_ref_count != pat_ref_count).then(|| ty_mutability)); @@ -171,6 +179,46 @@ impl LateLintPass<'_> for ManualMap { } } +// Checks if the expression can be moved into a closure as is. +fn can_move_expr_to_closure(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool { + struct V<'cx, 'tcx> { + cx: &'cx LateContext<'tcx>, + make_closure: bool, + } + impl Visitor<'tcx> for V<'_, 'tcx> { + type Map = ErasedMap<'tcx>; + fn nested_visit_map(&mut self) -> NestedVisitorMap { + NestedVisitorMap::None + } + + fn visit_expr(&mut self, e: &'tcx Expr<'_>) { + match e.kind { + ExprKind::Break(..) | ExprKind::Continue(_) | ExprKind::Ret(_) => { + self.make_closure = false; + }, + // Accessing a field of a local value can only be done if the type isn't + // partially moved. + ExprKind::Field(base_expr, _) + if matches!( + base_expr.kind, + ExprKind::Path(QPath::Resolved(_, Path { res: Res::Local(_), .. })) + ) && can_partially_move_ty(self.cx, self.cx.typeck_results().expr_ty(base_expr)) => + { + // TODO: check if the local has been partially moved. Assume it has for now. + self.make_closure = false; + return; + } + _ => (), + }; + walk_expr(self, e); + } + } + + let mut v = V { cx, make_closure: true }; + v.visit_expr(expr); + v.make_closure +} + // Checks whether the expression could be passed as a function, or whether a closure is needed. // Returns the function to be passed to `map` if it exists. fn can_pass_as_func(cx: &LateContext<'tcx>, binding: Ident, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> { diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs index 8e5cf5dc654..05523943511 100644 --- a/clippy_utils/src/lib.rs +++ b/clippy_utils/src/lib.rs @@ -456,6 +456,18 @@ pub fn has_drop<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool { } } +/// Checks whether a type can be partially moved. +pub fn can_partially_move_ty(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool { + if has_drop(cx, ty) || is_copy(cx, ty) { + return false; + } + match ty.kind() { + ty::Param(_) => false, + ty::Adt(def, subs) => def.all_fields().any(|f| !is_copy(cx, f.ty(cx.tcx, subs))), + _ => true, + } +} + /// Returns the method names and argument list of nested method call expressions that make up /// `expr`. method/span lists are sorted with the most recent call first. pub fn method_calls<'tcx>( diff --git a/tests/ui/manual_map_option.fixed b/tests/ui/manual_map_option.fixed index 19350906758..428aac43940 100644 --- a/tests/ui/manual_map_option.fixed +++ b/tests/ui/manual_map_option.fixed @@ -1,7 +1,13 @@ // run-rustfix #![warn(clippy::manual_map)] -#![allow(clippy::no_effect, clippy::map_identity, clippy::unit_arg, clippy::match_ref_pats)] +#![allow( + clippy::no_effect, + clippy::map_identity, + clippy::unit_arg, + clippy::match_ref_pats, + dead_code +)] fn main() { Some(0).map(|_| 2); @@ -67,4 +73,41 @@ fn main() { Some(Some((x, 1))) => Some(x), _ => None, }; + + // #6795 + fn f1() -> Result<(), ()> { + let _ = match Some(Ok(())) { + Some(x) => Some(x?), + None => None, + }; + Ok(()) + } + + for &x in Some(Some(true)).iter() { + let _ = match x { + Some(x) => Some(if x { continue } else { x }), + None => None, + }; + } + + // #6797 + let x1 = (Some(String::new()), 0); + let x2 = x1.0; + match x2 { + Some(x) => Some((x, x1.1)), + None => None, + }; + + struct S1 { + x: Option, + y: u32, + } + impl S1 { + fn f(self) -> Option<(String, u32)> { + match self.x { + Some(x) => Some((x, self.y)), + None => None, + } + } + } } diff --git a/tests/ui/manual_map_option.rs b/tests/ui/manual_map_option.rs index 8b8187db0a9..0f4a5bb2eb7 100644 --- a/tests/ui/manual_map_option.rs +++ b/tests/ui/manual_map_option.rs @@ -1,7 +1,13 @@ // run-rustfix #![warn(clippy::manual_map)] -#![allow(clippy::no_effect, clippy::map_identity, clippy::unit_arg, clippy::match_ref_pats)] +#![allow( + clippy::no_effect, + clippy::map_identity, + clippy::unit_arg, + clippy::match_ref_pats, + dead_code +)] fn main() { match Some(0) { @@ -119,4 +125,41 @@ fn main() { Some(Some((x, 1))) => Some(x), _ => None, }; + + // #6795 + fn f1() -> Result<(), ()> { + let _ = match Some(Ok(())) { + Some(x) => Some(x?), + None => None, + }; + Ok(()) + } + + for &x in Some(Some(true)).iter() { + let _ = match x { + Some(x) => Some(if x { continue } else { x }), + None => None, + }; + } + + // #6797 + let x1 = (Some(String::new()), 0); + let x2 = x1.0; + match x2 { + Some(x) => Some((x, x1.1)), + None => None, + }; + + struct S1 { + x: Option, + y: u32, + } + impl S1 { + fn f(self) -> Option<(String, u32)> { + match self.x { + Some(x) => Some((x, self.y)), + None => None, + } + } + } } diff --git a/tests/ui/manual_map_option.stderr b/tests/ui/manual_map_option.stderr index 210a30d05d4..49a51737784 100644 --- a/tests/ui/manual_map_option.stderr +++ b/tests/ui/manual_map_option.stderr @@ -1,5 +1,5 @@ error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:7:5 + --> $DIR/manual_map_option.rs:13:5 | LL | / match Some(0) { LL | | Some(_) => Some(2), @@ -10,7 +10,7 @@ LL | | }; = note: `-D clippy::manual-map` implied by `-D warnings` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:12:5 + --> $DIR/manual_map_option.rs:18:5 | LL | / match Some(0) { LL | | Some(x) => Some(x + 1), @@ -19,7 +19,7 @@ LL | | }; | |_____^ help: try this: `Some(0).map(|x| x + 1)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:17:5 + --> $DIR/manual_map_option.rs:23:5 | LL | / match Some("") { LL | | Some(x) => Some(x.is_empty()), @@ -28,7 +28,7 @@ LL | | }; | |_____^ help: try this: `Some("").map(|x| x.is_empty())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:22:5 + --> $DIR/manual_map_option.rs:28:5 | LL | / if let Some(x) = Some(0) { LL | | Some(!x) @@ -38,7 +38,7 @@ LL | | }; | |_____^ help: try this: `Some(0).map(|x| !x)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:29:5 + --> $DIR/manual_map_option.rs:35:5 | LL | / match Some(0) { LL | | Some(x) => { Some(std::convert::identity(x)) } @@ -47,7 +47,7 @@ LL | | }; | |_____^ help: try this: `Some(0).map(std::convert::identity)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:34:5 + --> $DIR/manual_map_option.rs:40:5 | LL | / match Some(&String::new()) { LL | | Some(x) => Some(str::len(x)), @@ -56,7 +56,7 @@ LL | | }; | |_____^ help: try this: `Some(&String::new()).map(|x| str::len(x))` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:44:5 + --> $DIR/manual_map_option.rs:50:5 | LL | / match &Some([0, 1]) { LL | | Some(x) => Some(x[0]), @@ -65,7 +65,7 @@ LL | | }; | |_____^ help: try this: `Some([0, 1]).as_ref().map(|x| x[0])` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:49:5 + --> $DIR/manual_map_option.rs:55:5 | LL | / match &Some(0) { LL | | &Some(x) => Some(x * 2), @@ -74,7 +74,7 @@ LL | | }; | |_____^ help: try this: `Some(0).map(|x| x * 2)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:54:5 + --> $DIR/manual_map_option.rs:60:5 | LL | / match Some(String::new()) { LL | | Some(ref x) => Some(x.is_empty()), @@ -83,7 +83,7 @@ LL | | }; | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:59:5 + --> $DIR/manual_map_option.rs:65:5 | LL | / match &&Some(String::new()) { LL | | Some(x) => Some(x.len()), @@ -92,7 +92,7 @@ LL | | }; | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:64:5 + --> $DIR/manual_map_option.rs:70:5 | LL | / match &&Some(0) { LL | | &&Some(x) => Some(x + x), @@ -101,7 +101,7 @@ LL | | }; | |_____^ help: try this: `Some(0).map(|x| x + x)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:77:9 + --> $DIR/manual_map_option.rs:83:9 | LL | / match &mut Some(String::new()) { LL | | Some(x) => Some(x.push_str("")), @@ -110,7 +110,7 @@ LL | | }; | |_________^ help: try this: `Some(String::new()).as_mut().map(|x| x.push_str(""))` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:83:5 + --> $DIR/manual_map_option.rs:89:5 | LL | / match &mut Some(String::new()) { LL | | Some(ref x) => Some(x.len()), @@ -119,7 +119,7 @@ LL | | }; | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:88:5 + --> $DIR/manual_map_option.rs:94:5 | LL | / match &mut &Some(String::new()) { LL | | Some(x) => Some(x.is_empty()), @@ -128,7 +128,7 @@ LL | | }; | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:93:5 + --> $DIR/manual_map_option.rs:99:5 | LL | / match Some((0, 1, 2)) { LL | | Some((x, y, z)) => Some(x + y + z), @@ -137,7 +137,7 @@ LL | | }; | |_____^ help: try this: `Some((0, 1, 2)).map(|(x, y, z)| x + y + z)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:98:5 + --> $DIR/manual_map_option.rs:104:5 | LL | / match Some([1, 2, 3]) { LL | | Some([first, ..]) => Some(first), @@ -146,7 +146,7 @@ LL | | }; | |_____^ help: try this: `Some([1, 2, 3]).map(|[first, ..]| first)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:103:5 + --> $DIR/manual_map_option.rs:109:5 | LL | / match &Some((String::new(), "test")) { LL | | Some((x, y)) => Some((y, x)),