diff options
| -rw-r--r-- | clippy_lints/src/casts/ref_as_ptr.rs | 4 | ||||
| -rw-r--r-- | clippy_lints/src/dereference.rs | 46 | ||||
| -rw-r--r-- | clippy_lints/src/needless_borrows_for_generic_args.rs | 8 | ||||
| -rw-r--r-- | clippy_utils/src/lib.rs | 164 |
4 files changed, 120 insertions, 102 deletions
diff --git a/clippy_lints/src/casts/ref_as_ptr.rs b/clippy_lints/src/casts/ref_as_ptr.rs index f42bafce4dd..5f48b8bd206 100644 --- a/clippy_lints/src/casts/ref_as_ptr.rs +++ b/clippy_lints/src/casts/ref_as_ptr.rs @@ -22,9 +22,9 @@ pub(super) fn check<'tcx>( if matches!(cast_from.kind(), ty::Ref(..)) && let ty::RawPtr(_, to_mutbl) = cast_to.kind() - && let Some(use_cx) = expr_use_ctxt(cx, expr) + && let use_cx = expr_use_ctxt(cx, expr) // TODO: only block the lint if `cast_expr` is a temporary - && !matches!(use_cx.node, ExprUseNode::LetStmt(_) | ExprUseNode::ConstStatic(_)) + && !matches!(use_cx.use_node(cx), ExprUseNode::LetStmt(_) | ExprUseNode::ConstStatic(_)) { let core_or_std = if is_no_std_crate(cx) { "core" } else { "std" }; let fn_name = match to_mutbl { diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index d60320d8282..3c137b6b70f 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -260,18 +260,13 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { (None, kind) => { let expr_ty = typeck.expr_ty(expr); let use_cx = expr_use_ctxt(cx, expr); - let adjusted_ty = match &use_cx { - Some(use_cx) => match use_cx.adjustments { - [.., a] => a.target, - _ => expr_ty, - }, - _ => typeck.expr_ty_adjusted(expr), - }; + let adjusted_ty = use_cx.adjustments.last().map_or(expr_ty, |a| a.target); - match (use_cx, kind) { - (Some(use_cx), RefOp::Deref) => { + match kind { + RefOp::Deref if use_cx.same_ctxt => { + let use_node = use_cx.use_node(cx); let sub_ty = typeck.expr_ty(sub_expr); - if let ExprUseNode::FieldAccess(name) = use_cx.node + if let ExprUseNode::FieldAccess(name) = use_node && !use_cx.moved_before_use && !ty_contains_field(sub_ty, name.name) { @@ -288,9 +283,9 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { } else if sub_ty.is_ref() // Linting method receivers would require verifying that name lookup // would resolve the same way. This is complicated by trait methods. - && !use_cx.node.is_recv() - && let Some(ty) = use_cx.node.defined_ty(cx) - && TyCoercionStability::for_defined_ty(cx, ty, use_cx.node.is_return()).is_deref_stable() + && !use_node.is_recv() + && let Some(ty) = use_node.defined_ty(cx) + && TyCoercionStability::for_defined_ty(cx, ty, use_node.is_return()).is_deref_stable() { self.state = Some(( State::ExplicitDeref { mutability: None }, @@ -301,7 +296,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { )); } }, - (_, RefOp::Method { mutbl, is_ufcs }) + RefOp::Method { mutbl, is_ufcs } if !is_lint_allowed(cx, EXPLICIT_DEREF_METHODS, expr.hir_id) // Allow explicit deref in method chains. e.g. `foo.deref().bar()` && (is_ufcs || !in_postfix_position(cx, expr)) => @@ -319,7 +314,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { }, )); }, - (Some(use_cx), RefOp::AddrOf(mutability)) => { + RefOp::AddrOf(mutability) if use_cx.same_ctxt => { // Find the number of times the borrow is auto-derefed. let mut iter = use_cx.adjustments.iter(); let mut deref_count = 0usize; @@ -338,10 +333,11 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { }; }; - let stability = use_cx.node.defined_ty(cx).map_or(TyCoercionStability::None, |ty| { - TyCoercionStability::for_defined_ty(cx, ty, use_cx.node.is_return()) + let use_node = use_cx.use_node(cx); + let stability = use_node.defined_ty(cx).map_or(TyCoercionStability::None, |ty| { + TyCoercionStability::for_defined_ty(cx, ty, use_node.is_return()) }); - let can_auto_borrow = match use_cx.node { + let can_auto_borrow = match use_node { ExprUseNode::FieldAccess(_) if !use_cx.moved_before_use && matches!(sub_expr.kind, ExprKind::Field(..)) => { @@ -353,7 +349,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { // deref through `ManuallyDrop<_>` will not compile. !adjust_derefs_manually_drop(use_cx.adjustments, expr_ty) }, - ExprUseNode::Callee | ExprUseNode::FieldAccess(_) => true, + ExprUseNode::Callee | ExprUseNode::FieldAccess(_) if !use_cx.moved_before_use => true, ExprUseNode::MethodArg(hir_id, _, 0) if !use_cx.moved_before_use => { // Check for calls to trait methods where the trait is implemented // on a reference. @@ -363,9 +359,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { // priority. if let Some(fn_id) = typeck.type_dependent_def_id(hir_id) && let Some(trait_id) = cx.tcx.trait_of_item(fn_id) - && let arg_ty = cx - .tcx - .erase_regions(use_cx.adjustments.last().map_or(expr_ty, |a| a.target)) + && let arg_ty = cx.tcx.erase_regions(adjusted_ty) && let ty::Ref(_, sub_ty, _) = *arg_ty.kind() && let args = typeck.node_args_opt(hir_id).map(|args| &args[1..]).unwrap_or_default() @@ -443,7 +437,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { count: deref_count - required_refs, msg, stability, - for_field_access: if let ExprUseNode::FieldAccess(name) = use_cx.node + for_field_access: if let ExprUseNode::FieldAccess(name) = use_node && !use_cx.moved_before_use { Some(name.name) @@ -453,7 +447,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { }), StateData { first_expr: expr, - adjusted_ty: use_cx.adjustments.last().map_or(expr_ty, |a| a.target), + adjusted_ty, }, )); } else if stability.is_deref_stable() @@ -465,12 +459,12 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { State::Borrow { mutability }, StateData { first_expr: expr, - adjusted_ty: use_cx.adjustments.last().map_or(expr_ty, |a| a.target), + adjusted_ty, }, )); } }, - (None, _) | (_, RefOp::Method { .. }) => (), + _ => {}, } }, ( diff --git a/clippy_lints/src/needless_borrows_for_generic_args.rs b/clippy_lints/src/needless_borrows_for_generic_args.rs index 4f99eaa40c2..9c3ead855a7 100644 --- a/clippy_lints/src/needless_borrows_for_generic_args.rs +++ b/clippy_lints/src/needless_borrows_for_generic_args.rs @@ -80,11 +80,13 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrowsForGenericArgs<'tcx> { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { if matches!(expr.kind, ExprKind::AddrOf(..)) && !expr.span.from_expansion() - && let Some(use_cx) = expr_use_ctxt(cx, expr) + && let use_cx = expr_use_ctxt(cx, expr) + && use_cx.same_ctxt && !use_cx.is_ty_unified - && let Some(DefinedTy::Mir(ty)) = use_cx.node.defined_ty(cx) + && let use_node = use_cx.use_node(cx) + && let Some(DefinedTy::Mir(ty)) = use_node.defined_ty(cx) && let ty::Param(ty) = *ty.value.skip_binder().kind() - && let Some((hir_id, fn_id, i)) = match use_cx.node { + && let Some((hir_id, fn_id, i)) = match use_node { ExprUseNode::MethodArg(_, _, 0) => None, ExprUseNode::MethodArg(hir_id, None, i) => cx .typeck_results() diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs index 7dc341ec8d7..fda870f435a 100644 --- a/clippy_utils/src/lib.rs +++ b/clippy_utils/src/lib.rs @@ -1,6 +1,7 @@ #![feature(array_chunks)] #![feature(box_patterns)] #![feature(control_flow_enum)] +#![feature(exhaustive_patterns)] #![feature(if_let_guard)] #![feature(let_chains)] #![feature(lint_reasons)] @@ -2664,13 +2665,80 @@ pub enum DefinedTy<'tcx> { /// The context an expressions value is used in. pub struct ExprUseCtxt<'tcx> { /// The parent node which consumes the value. - pub node: ExprUseNode<'tcx>, + pub node: Node<'tcx>, + /// The child id of the node the value came from. + pub child_id: HirId, /// Any adjustments applied to the type. pub adjustments: &'tcx [Adjustment<'tcx>], - /// Whether or not the type must unify with another code path. + /// Whether the type must unify with another code path. pub is_ty_unified: bool, - /// Whether or not the value will be moved before it's used. + /// Whether the value will be moved before it's used. pub moved_before_use: bool, + /// Whether the use site has the same `SyntaxContext` as the value. + pub same_ctxt: bool, +} +impl<'tcx> ExprUseCtxt<'tcx> { + pub fn use_node(&self, cx: &LateContext<'tcx>) -> ExprUseNode<'tcx> { + match self.node { + Node::LetStmt(l) => ExprUseNode::LetStmt(l), + Node::ExprField(field) => ExprUseNode::Field(field), + + Node::Item(&Item { + kind: ItemKind::Static(..) | ItemKind::Const(..), + owner_id, + .. + }) + | Node::TraitItem(&TraitItem { + kind: TraitItemKind::Const(..), + owner_id, + .. + }) + | Node::ImplItem(&ImplItem { + kind: ImplItemKind::Const(..), + owner_id, + .. + }) => ExprUseNode::ConstStatic(owner_id), + + Node::Item(&Item { + kind: ItemKind::Fn(..), + owner_id, + .. + }) + | Node::TraitItem(&TraitItem { + kind: TraitItemKind::Fn(..), + owner_id, + .. + }) + | Node::ImplItem(&ImplItem { + kind: ImplItemKind::Fn(..), + owner_id, + .. + }) => ExprUseNode::Return(owner_id), + + 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::Closure(closure) => ExprUseNode::Return(OwnerId { def_id: closure.def_id }), + ExprKind::Call(func, args) => match args.iter().position(|arg| arg.hir_id == self.child_id) { + Some(i) => ExprUseNode::FnArg(func, i), + None => ExprUseNode::Callee, + }, + ExprKind::MethodCall(name, _, args, _) => ExprUseNode::MethodArg( + use_expr.hir_id, + name.args, + args.iter() + .position(|arg| arg.hir_id == self.child_id) + .map_or(0, |i| i + 1), + ), + ExprKind::Field(_, name) => ExprUseNode::FieldAccess(name), + ExprKind::AddrOf(kind, mutbl, _) => ExprUseNode::AddrOf(kind, mutbl), + _ => ExprUseNode::Other, + }, + _ => ExprUseNode::Other, + } + } } /// The node which consumes a value. @@ -2691,7 +2759,8 @@ pub enum ExprUseNode<'tcx> { Callee, /// Access of a field. FieldAccess(Ident), - Expr, + /// Borrow expression. + AddrOf(ast::BorrowKind, Mutability), Other, } impl<'tcx> ExprUseNode<'tcx> { @@ -2768,26 +2837,25 @@ 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::LetStmt(_) | Self::FieldAccess(..) | Self::Callee | Self::Expr | Self::Other => None, + Self::LetStmt(_) | Self::FieldAccess(..) | Self::Callee | Self::Other | Self::AddrOf(..) => None, } } } /// Gets the context an expression's value is used in. -pub fn expr_use_ctxt<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> Option<ExprUseCtxt<'tcx>> { +pub fn expr_use_ctxt<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> ExprUseCtxt<'tcx> { let mut adjustments = [].as_slice(); let mut is_ty_unified = false; let mut moved_before_use = false; + let mut same_ctxt = true; let ctxt = e.span.ctxt(); - walk_to_expr_usage(cx, e, &mut |parent_id, parent, child_id| { + let node = walk_to_expr_usage(cx, e, &mut |parent_id, parent, child_id| -> ControlFlow<!> { if adjustments.is_empty() && let Node::Expr(e) = cx.tcx.hir_node(child_id) { adjustments = cx.typeck_results().expr_adjustments(e); } - if cx.tcx.hir().span(parent_id).ctxt() != ctxt { - return ControlFlow::Break(()); - } + same_ctxt &= cx.tcx.hir().span(parent_id).ctxt() == ctxt; if let Node::Expr(e) = parent { match e.kind { ExprKind::If(e, _, _) | ExprKind::Match(e, _, _) if e.hir_id != child_id => { @@ -2803,71 +2871,25 @@ pub fn expr_use_ctxt<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> Optio } } ControlFlow::Continue(()) - })? - .continue_value() - .map(|(use_node, child_id)| { - let node = match use_node { - Node::LetStmt(l) => ExprUseNode::LetStmt(l), - Node::ExprField(field) => ExprUseNode::Field(field), - - Node::Item(&Item { - kind: ItemKind::Static(..) | ItemKind::Const(..), - owner_id, - .. - }) - | Node::TraitItem(&TraitItem { - kind: TraitItemKind::Const(..), - owner_id, - .. - }) - | Node::ImplItem(&ImplItem { - kind: ImplItemKind::Const(..), - owner_id, - .. - }) => ExprUseNode::ConstStatic(owner_id), - - Node::Item(&Item { - kind: ItemKind::Fn(..), - owner_id, - .. - }) - | Node::TraitItem(&TraitItem { - kind: TraitItemKind::Fn(..), - owner_id, - .. - }) - | Node::ImplItem(&ImplItem { - kind: ImplItemKind::Fn(..), - owner_id, - .. - }) => ExprUseNode::Return(owner_id), - - 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::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::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, - }, - _ => ExprUseNode::Other, - }; - ExprUseCtxt { + }); + match node { + Some(ControlFlow::Continue((node, child_id))) => ExprUseCtxt { node, + child_id, adjustments, is_ty_unified, moved_before_use, - } - }) + same_ctxt, + }, + None => ExprUseCtxt { + node: Node::Crate(cx.tcx.hir().root_module()), + child_id: HirId::INVALID, + adjustments: &[], + is_ty_unified: true, + moved_before_use: true, + same_ctxt: false, + }, + } } /// Tokenizes the input while keeping the text associated with each token. |