diff options
| -rw-r--r-- | clippy_utils/src/lib.rs | 176 | ||||
| -rw-r--r-- | tests/ui/ignored_unit_patterns.fixed | 7 | ||||
| -rw-r--r-- | tests/ui/ignored_unit_patterns.rs | 7 | ||||
| -rw-r--r-- | tests/ui/ignored_unit_patterns.stderr | 18 | ||||
| -rw-r--r-- | tests/ui/needless_borrow.fixed | 3 | ||||
| -rw-r--r-- | tests/ui/needless_borrow.rs | 3 | ||||
| -rw-r--r-- | tests/ui/needless_borrow.stderr | 20 |
7 files changed, 112 insertions, 122 deletions
diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs index 7a14c64f5ef..a87fae10249 100644 --- a/clippy_utils/src/lib.rs +++ b/clippy_utils/src/lib.rs @@ -1,5 +1,6 @@ #![feature(array_chunks)] #![feature(box_patterns)] +#![feature(control_flow_enum)] #![feature(if_let_guard)] #![feature(let_chains)] #![feature(lint_reasons)] @@ -2508,26 +2509,30 @@ pub fn is_test_module_or_function(tcx: TyCtxt<'_>, item: &Item<'_>) -> bool { && item.ident.name.as_str().split('_').any(|a| a == "test" || a == "tests") } -/// Walks the HIR tree from the given expression, up to the node where the value produced by the -/// expression is consumed. Calls the function for every node encountered this way until it returns -/// `Some`. +/// Walks up the HIR tree from the given expression in an attempt to find where the value is +/// consumed. /// -/// This allows walking through `if`, `match`, `break`, block expressions to find where the value -/// produced by the expression is consumed. +/// Termination has three conditions: +/// - The given function returns `Break`. This function will return the value. +/// - The consuming node is found. This function will return `Continue(use_node, child_id)`. +/// - No further parent nodes are found. This will trigger a debug assert or return `None`. +/// +/// This allows walking through `if`, `match`, `break`, and block expressions to find where the +/// value produced by the expression is consumed. pub fn walk_to_expr_usage<'tcx, T>( cx: &LateContext<'tcx>, e: &Expr<'tcx>, - mut f: impl FnMut(Node<'tcx>, HirId) -> Option<T>, -) -> Option<T> { + mut f: impl FnMut(HirId, Node<'tcx>, HirId) -> ControlFlow<T>, +) -> Option<ControlFlow<T, (Node<'tcx>, HirId)>> { let map = cx.tcx.hir(); let mut iter = map.parent_iter(e.hir_id); let mut child_id = e.hir_id; while let Some((parent_id, parent)) = iter.next() { - if let Some(x) = f(parent, child_id) { - return Some(x); + if let ControlFlow::Break(x) = f(parent_id, parent, child_id) { + return Some(ControlFlow::Break(x)); } - let parent = match parent { + let parent_expr = match parent { Node::Expr(e) => e, Node::Block(Block { expr: Some(body), .. }) | Node::Arm(Arm { body, .. }) if body.hir_id == child_id => { child_id = parent_id; @@ -2537,18 +2542,19 @@ pub fn walk_to_expr_usage<'tcx, T>( child_id = parent_id; continue; }, - _ => return None, + _ => return Some(ControlFlow::Continue((parent, child_id))), }; - match parent.kind { + match parent_expr.kind { ExprKind::If(child, ..) | ExprKind::Match(child, ..) if child.hir_id != child_id => child_id = parent_id, ExprKind::Break(Destination { target_id: Ok(id), .. }, _) => { child_id = id; iter = map.parent_iter(id); }, - ExprKind::Block(..) => child_id = parent_id, - _ => return None, + ExprKind::Block(..) | ExprKind::DropTemps(_) => child_id = parent_id, + _ => return Some(ControlFlow::Continue((parent, child_id))), } } + debug_assert!(false, "no parent node found for `{child_id:?}`"); None } @@ -2592,6 +2598,8 @@ pub enum ExprUseNode<'tcx> { Callee, /// Access of a field. FieldAccess(Ident), + Expr, + Other, } impl<'tcx> ExprUseNode<'tcx> { /// Checks if the value is returned from the function. @@ -2668,144 +2676,104 @@ impl<'tcx> ExprUseNode<'tcx> { let sig = cx.tcx.fn_sig(id).skip_binder(); Some(DefinedTy::Mir(cx.tcx.param_env(id).and(sig.input(i)))) }, - Self::Local(_) | Self::FieldAccess(..) | Self::Callee => None, + Self::Local(_) | Self::FieldAccess(..) | Self::Callee | Self::Expr | Self::Other => None, } } } /// Gets the context an expression's value is used in. -#[expect(clippy::too_many_lines)] pub fn expr_use_ctxt<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> Option<ExprUseCtxt<'tcx>> { let mut adjustments = [].as_slice(); let mut is_ty_unified = false; let mut moved_before_use = false; let ctxt = e.span.ctxt(); - walk_to_expr_usage(cx, e, &mut |parent, child_id| { - // LocalTableInContext returns the wrong lifetime, so go use `expr_adjustments` instead. + walk_to_expr_usage(cx, e, &mut |parent_id, parent, child_id| { if adjustments.is_empty() && let Node::Expr(e) = cx.tcx.hir().get(child_id) { adjustments = cx.typeck_results().expr_adjustments(e); } - match parent { - Node::Local(l) if l.span.ctxt() == ctxt => Some(ExprUseCtxt { - node: ExprUseNode::Local(l), - adjustments, - is_ty_unified, - moved_before_use, - }), + if !cx.tcx.hir().opt_span(parent_id).is_some_and(|x| x.ctxt() == ctxt) { + return ControlFlow::Break(()); + } + if let Node::Expr(e) = parent { + match e.kind { + ExprKind::If(e, _, _) | ExprKind::Match(e, _, _) if e.hir_id != child_id => { + is_ty_unified = true; + moved_before_use = true; + }, + ExprKind::Block(_, Some(_)) | ExprKind::Break(..) => { + is_ty_unified = true; + moved_before_use = true; + }, + ExprKind::Block(..) => moved_before_use = true, + _ => {}, + } + } + ControlFlow::Continue(()) + })? + .continue_value() + .map(|(use_node, child_id)| { + let node = match use_node { + Node::Local(l) => ExprUseNode::Local(l), + Node::ExprField(field) => ExprUseNode::Field(field), + Node::Item(&Item { kind: ItemKind::Static(..) | ItemKind::Const(..), owner_id, - span, .. }) | Node::TraitItem(&TraitItem { kind: TraitItemKind::Const(..), owner_id, - span, .. }) | Node::ImplItem(&ImplItem { kind: ImplItemKind::Const(..), owner_id, - span, .. - }) if span.ctxt() == ctxt => Some(ExprUseCtxt { - node: ExprUseNode::ConstStatic(owner_id), - adjustments, - is_ty_unified, - moved_before_use, - }), + }) => ExprUseNode::ConstStatic(owner_id), Node::Item(&Item { kind: ItemKind::Fn(..), owner_id, - span, .. }) | Node::TraitItem(&TraitItem { kind: TraitItemKind::Fn(..), owner_id, - span, .. }) | Node::ImplItem(&ImplItem { kind: ImplItemKind::Fn(..), owner_id, - span, .. - }) if span.ctxt() == ctxt => Some(ExprUseCtxt { - node: ExprUseNode::Return(owner_id), - adjustments, - is_ty_unified, - moved_before_use, - }), - - Node::ExprField(field) if field.span.ctxt() == ctxt => Some(ExprUseCtxt { - node: ExprUseNode::Field(field), - adjustments, - is_ty_unified, - moved_before_use, - }), + }) => ExprUseNode::Return(owner_id), - Node::Expr(parent) if parent.span.ctxt() == ctxt => match parent.kind { - ExprKind::Ret(_) => Some(ExprUseCtxt { - node: ExprUseNode::Return(OwnerId { - def_id: cx.tcx.hir().body_owner_def_id(cx.enclosing_body.unwrap()), - }), - adjustments, - is_ty_unified, - moved_before_use, - }), - ExprKind::Closure(closure) => Some(ExprUseCtxt { - node: ExprUseNode::Return(OwnerId { def_id: closure.def_id }), - adjustments, - is_ty_unified, - moved_before_use, - }), - ExprKind::Call(func, args) => Some(ExprUseCtxt { - node: match args.iter().position(|arg| arg.hir_id == child_id) { - Some(i) => ExprUseNode::FnArg(func, i), - None => ExprUseNode::Callee, - }, - adjustments, - is_ty_unified, - moved_before_use, + Node::Expr(use_expr) => match use_expr.kind { + ExprKind::Ret(_) => ExprUseNode::Return(OwnerId { + def_id: cx.tcx.hir().body_owner_def_id(cx.enclosing_body.unwrap()), }), - ExprKind::MethodCall(name, _, args, _) => Some(ExprUseCtxt { - node: ExprUseNode::MethodArg( - parent.hir_id, - name.args, - args.iter().position(|arg| arg.hir_id == child_id).map_or(0, |i| i + 1), - ), - adjustments, - is_ty_unified, - moved_before_use, - }), - ExprKind::Field(child, name) if child.hir_id == e.hir_id => Some(ExprUseCtxt { - node: ExprUseNode::FieldAccess(name), - adjustments, - is_ty_unified, - moved_before_use, - }), - ExprKind::If(e, _, _) | ExprKind::Match(e, _, _) if e.hir_id != child_id => { - is_ty_unified = true; - moved_before_use = true; - None - }, - ExprKind::Block(_, Some(_)) | ExprKind::Break(..) => { - is_ty_unified = true; - moved_before_use = true; - None + ExprKind::Closure(closure) => ExprUseNode::Return(OwnerId { def_id: closure.def_id }), + ExprKind::Call(func, args) => match args.iter().position(|arg| arg.hir_id == child_id) { + Some(i) => ExprUseNode::FnArg(func, i), + None => ExprUseNode::Callee, }, - ExprKind::Block(..) => { - moved_before_use = true; - None - }, - _ => None, + ExprKind::MethodCall(name, _, args, _) => ExprUseNode::MethodArg( + use_expr.hir_id, + name.args, + args.iter().position(|arg| arg.hir_id == child_id).map_or(0, |i| i + 1), + ), + ExprKind::Field(child, name) if child.hir_id == e.hir_id => ExprUseNode::FieldAccess(name), + _ => ExprUseNode::Expr, }, - _ => None, + _ => ExprUseNode::Other, + }; + ExprUseCtxt { + node, + adjustments, + is_ty_unified, + moved_before_use, } }) } diff --git a/tests/ui/ignored_unit_patterns.fixed b/tests/ui/ignored_unit_patterns.fixed index 707a0e76e4e..118f0b48895 100644 --- a/tests/ui/ignored_unit_patterns.fixed +++ b/tests/ui/ignored_unit_patterns.fixed @@ -1,6 +1,11 @@ //@aux-build:proc_macro_derive.rs #![warn(clippy::ignored_unit_patterns)] -#![allow(clippy::let_unit_value, clippy::redundant_pattern_matching, clippy::single_match)] +#![allow( + clippy::let_unit_value, + clippy::redundant_pattern_matching, + clippy::single_match, + clippy::needless_borrow +)] fn foo() -> Result<(), ()> { unimplemented!() diff --git a/tests/ui/ignored_unit_patterns.rs b/tests/ui/ignored_unit_patterns.rs index 544f2b8f692..92feb9e6c28 100644 --- a/tests/ui/ignored_unit_patterns.rs +++ b/tests/ui/ignored_unit_patterns.rs @@ -1,6 +1,11 @@ //@aux-build:proc_macro_derive.rs #![warn(clippy::ignored_unit_patterns)] -#![allow(clippy::let_unit_value, clippy::redundant_pattern_matching, clippy::single_match)] +#![allow( + clippy::let_unit_value, + clippy::redundant_pattern_matching, + clippy::single_match, + clippy::needless_borrow +)] fn foo() -> Result<(), ()> { unimplemented!() diff --git a/tests/ui/ignored_unit_patterns.stderr b/tests/ui/ignored_unit_patterns.stderr index 05c8f281e55..18ca7ebbcf2 100644 --- a/tests/ui/ignored_unit_patterns.stderr +++ b/tests/ui/ignored_unit_patterns.stderr @@ -1,5 +1,5 @@ error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:11:12 + --> $DIR/ignored_unit_patterns.rs:16:12 | LL | Ok(_) => {}, | ^ help: use `()` instead of `_`: `()` @@ -8,49 +8,49 @@ LL | Ok(_) => {}, = help: to override `-D warnings` add `#[allow(clippy::ignored_unit_patterns)]` error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:12:13 + --> $DIR/ignored_unit_patterns.rs:17:13 | LL | Err(_) => {}, | ^ help: use `()` instead of `_`: `()` error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:14:15 + --> $DIR/ignored_unit_patterns.rs:19:15 | LL | if let Ok(_) = foo() {} | ^ help: use `()` instead of `_`: `()` error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:16:28 + --> $DIR/ignored_unit_patterns.rs:21:28 | LL | let _ = foo().map_err(|_| todo!()); | ^ help: use `()` instead of `_`: `()` error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:22:16 + --> $DIR/ignored_unit_patterns.rs:27:16 | LL | Ok(_) => {}, | ^ help: use `()` instead of `_`: `()` error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:24:17 + --> $DIR/ignored_unit_patterns.rs:29:17 | LL | Err(_) => {}, | ^ help: use `()` instead of `_`: `()` error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:36:9 + --> $DIR/ignored_unit_patterns.rs:41:9 | LL | let _ = foo().unwrap(); | ^ help: use `()` instead of `_`: `()` error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:45:13 + --> $DIR/ignored_unit_patterns.rs:50:13 | LL | (1, _) => unimplemented!(), | ^ help: use `()` instead of `_`: `()` error: matching over `()` is more explicit - --> $DIR/ignored_unit_patterns.rs:52:13 + --> $DIR/ignored_unit_patterns.rs:57:13 | LL | for (x, _) in v { | ^ help: use `()` instead of `_`: `()` diff --git a/tests/ui/needless_borrow.fixed b/tests/ui/needless_borrow.fixed index ff1e2dc8875..23e8bf8a468 100644 --- a/tests/ui/needless_borrow.fixed +++ b/tests/ui/needless_borrow.fixed @@ -131,6 +131,9 @@ fn main() { 0 } } + + // issue #11786 + let x: (&str,) = ("",); } #[allow(clippy::needless_borrowed_reference)] diff --git a/tests/ui/needless_borrow.rs b/tests/ui/needless_borrow.rs index 597021539ac..27771a8f15b 100644 --- a/tests/ui/needless_borrow.rs +++ b/tests/ui/needless_borrow.rs @@ -131,6 +131,9 @@ fn main() { 0 } } + + // issue #11786 + let x: (&str,) = (&"",); } #[allow(clippy::needless_borrowed_reference)] diff --git a/tests/ui/needless_borrow.stderr b/tests/ui/needless_borrow.stderr index 44552ee6abe..a21ed8382c1 100644 --- a/tests/ui/needless_borrow.stderr +++ b/tests/ui/needless_borrow.stderr @@ -121,41 +121,47 @@ error: this expression creates a reference which is immediately dereferenced by LL | (&&5).foo(); | ^^^^^ help: change this to: `(&5)` +error: this expression creates a reference which is immediately dereferenced by the compiler + --> $DIR/needless_borrow.rs:136:23 + | +LL | let x: (&str,) = (&"",); + | ^^^ help: change this to: `""` + error: this expression borrows a value the compiler would automatically borrow - --> $DIR/needless_borrow.rs:175:13 + --> $DIR/needless_borrow.rs:178:13 | LL | (&self.f)() | ^^^^^^^^^ help: change this to: `(self.f)` error: this expression borrows a value the compiler would automatically borrow - --> $DIR/needless_borrow.rs:184:13 + --> $DIR/needless_borrow.rs:187:13 | LL | (&mut self.f)() | ^^^^^^^^^^^^^ help: change this to: `(self.f)` error: this expression borrows a value the compiler would automatically borrow - --> $DIR/needless_borrow.rs:221:22 + --> $DIR/needless_borrow.rs:224:22 | LL | let _ = &mut (&mut { x.u }).x; | ^^^^^^^^^^^^^^ help: change this to: `{ x.u }` error: this expression borrows a value the compiler would automatically borrow - --> $DIR/needless_borrow.rs:228:22 + --> $DIR/needless_borrow.rs:231:22 | LL | let _ = &mut (&mut { x.u }).x; | ^^^^^^^^^^^^^^ help: change this to: `{ x.u }` error: this expression borrows a value the compiler would automatically borrow - --> $DIR/needless_borrow.rs:232:22 + --> $DIR/needless_borrow.rs:235:22 | LL | let _ = &mut (&mut x.u).x; | ^^^^^^^^^^ help: change this to: `x.u` error: this expression borrows a value the compiler would automatically borrow - --> $DIR/needless_borrow.rs:233:22 + --> $DIR/needless_borrow.rs:236:22 | LL | let _ = &mut (&mut { x.u }).x; | ^^^^^^^^^^^^^^ help: change this to: `{ x.u }` -error: aborting due to 26 previous errors +error: aborting due to 27 previous errors |