diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index 6c333afac..b2ed81219 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -3,7 +3,7 @@ use clippy_utils::mir::{enclosing_mir, expr_local, local_assignments, used_exact use clippy_utils::msrvs::{self, Msrv}; use clippy_utils::source::{snippet_with_applicability, snippet_with_context}; use clippy_utils::sugg::has_enclosing_paren; -use clippy_utils::ty::{expr_sig, is_copy, peel_mid_ty_refs, ty_sig, variant_of_res}; +use clippy_utils::ty::{adt_and_variant_of_res, expr_sig, is_copy, peel_mid_ty_refs, ty_sig}; use clippy_utils::{ fn_def_id, get_parent_expr, get_parent_expr_for_hir, is_lint_allowed, path_to_local, walk_to_expr_usage, }; @@ -26,8 +26,8 @@ use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::mir::{Rvalue, StatementKind}; use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability}; use rustc_middle::ty::{ - self, Binder, BoundVariableKind, Clause, EarlyBinder, FnSig, GenericArgKind, List, ParamTy, PredicateKind, - ProjectionPredicate, Ty, TyCtxt, TypeVisitable, TypeckResults, + self, Binder, BoundVariableKind, Clause, EarlyBinder, FnSig, GenericArgKind, List, ParamEnv, ParamTy, + PredicateKind, ProjectionPredicate, Ty, TyCtxt, TypeVisitable, TypeckResults, }; use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::{symbol::sym, Span, Symbol}; @@ -736,7 +736,7 @@ fn walk_parents<'tcx>( .. }) if span.ctxt() == ctxt => { let ty = cx.tcx.type_of(owner_id.def_id); - Some(ty_auto_deref_stability(cx, ty, precedence).position_for_result(cx)) + Some(ty_auto_deref_stability(cx.tcx, cx.param_env, ty, precedence).position_for_result(cx)) }, Node::Item(&Item { @@ -760,7 +760,7 @@ fn walk_parents<'tcx>( let output = cx .tcx .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).subst_identity().output()); - Some(ty_auto_deref_stability(cx, output, precedence).position_for_result(cx)) + Some(ty_auto_deref_stability(cx.tcx, cx.param_env, output, precedence).position_for_result(cx)) }, Node::ExprField(field) if field.span.ctxt() == ctxt => match get_parent_expr_for_hir(cx, field.hir_id) { @@ -768,10 +768,23 @@ fn walk_parents<'tcx>( hir_id, kind: ExprKind::Struct(path, ..), .. - }) => variant_of_res(cx, cx.qpath_res(path, *hir_id)) - .and_then(|variant| variant.fields.iter().find(|f| f.name == field.ident.name)) - .map(|field_def| { - ty_auto_deref_stability(cx, cx.tcx.type_of(field_def.did), precedence).position_for_arg() + }) => adt_and_variant_of_res(cx, cx.qpath_res(path, *hir_id)) + .and_then(|(adt, variant)| { + variant + .fields + .iter() + .find(|f| f.name == field.ident.name) + .map(|f| (adt, f)) + }) + .map(|(adt, field_def)| { + ty_auto_deref_stability( + cx.tcx, + // Use the param_env of the target type. + cx.tcx.param_env(adt.did()), + cx.tcx.type_of(field_def.did), + precedence, + ) + .position_for_arg() }), _ => None, }, @@ -792,7 +805,7 @@ fn walk_parents<'tcx>( let output = cx .tcx .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).subst_identity().output()); - ty_auto_deref_stability(cx, output, precedence).position_for_result(cx) + ty_auto_deref_stability(cx.tcx, cx.param_env, output, precedence).position_for_result(cx) }, ) }, @@ -835,15 +848,20 @@ fn walk_parents<'tcx>( msrv, ) } else { - ty_auto_deref_stability(cx, cx.tcx.erase_late_bound_regions(ty), precedence) - .position_for_arg() + ty_auto_deref_stability( + cx.tcx, + // Use the param_env of the target function. + sig.predicates_id().map_or(ParamEnv::empty(), |id| cx.tcx.param_env(id)), + cx.tcx.erase_late_bound_regions(ty), + precedence + ).position_for_arg() } }, } }) }), ExprKind::MethodCall(method, receiver, args, _) => { - let id = cx.typeck_results().type_dependent_def_id(parent.hir_id).unwrap(); + let fn_id = cx.typeck_results().type_dependent_def_id(parent.hir_id).unwrap(); if receiver.hir_id == child_id { // Check for calls to trait methods where the trait is implemented on a reference. // Two cases need to be handled: @@ -852,13 +870,17 @@ fn walk_parents<'tcx>( // priority. if e.hir_id != child_id { return Some(Position::ReborrowStable(precedence)) - } else if let Some(trait_id) = cx.tcx.trait_of_item(id) + } else if let Some(trait_id) = cx.tcx.trait_of_item(fn_id) && let arg_ty = cx.tcx.erase_regions(cx.typeck_results().expr_ty_adjusted(e)) && let ty::Ref(_, sub_ty, _) = *arg_ty.kind() && let subs = cx .typeck_results() .node_substs_opt(parent.hir_id).map(|subs| &subs[1..]).unwrap_or_default() - && let impl_ty = if cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[0].is_ref() { + && let impl_ty = if cx.tcx.fn_sig(fn_id) + .subst_identity() + .skip_binder() + .inputs()[0].is_ref() + { // Trait methods taking `&self` sub_ty } else { @@ -879,10 +901,13 @@ fn walk_parents<'tcx>( return Some(Position::MethodReceiver); } args.iter().position(|arg| arg.hir_id == child_id).map(|i| { - let ty = cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[i + 1]; + let ty = cx.tcx.fn_sig(fn_id).subst_identity().input(i + 1); // `e.hir_id == child_id` for https://github.com/rust-lang/rust-clippy/issues/9739 // `method.args.is_none()` for https://github.com/rust-lang/rust-clippy/issues/9782 - if e.hir_id == child_id && method.args.is_none() && let ty::Param(param_ty) = ty.kind() { + if e.hir_id == child_id + && method.args.is_none() + && let ty::Param(param_ty) = ty.skip_binder().kind() + { needless_borrow_impl_arg_position( cx, possible_borrowers, @@ -895,8 +920,10 @@ fn walk_parents<'tcx>( ) } else { ty_auto_deref_stability( - cx, - cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).subst_identity().input(i + 1)), + cx.tcx, + // Use the param_env of the target function. + cx.tcx.param_env(fn_id), + cx.tcx.erase_late_bound_regions(ty), precedence, ) .position_for_arg() @@ -1378,11 +1405,18 @@ impl<'tcx> TyPosition<'tcx> { } // Checks whether a type is stable when switching to auto dereferencing, -fn ty_auto_deref_stability<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, precedence: i8) -> TyPosition<'tcx> { +fn ty_auto_deref_stability<'tcx>( + tcx: TyCtxt<'tcx>, + param_env: ParamEnv<'tcx>, + ty: Ty<'tcx>, + precedence: i8, +) -> TyPosition<'tcx> { let ty::Ref(_, mut ty, _) = *ty.kind() else { return Position::Other(precedence).into(); }; + ty = tcx.try_normalize_erasing_regions(param_env, ty).unwrap_or(ty); + loop { break match *ty.kind() { ty::Ref(_, ref_ty, _) => { @@ -1423,9 +1457,7 @@ fn ty_auto_deref_stability<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, precedenc | ty::Closure(..) | ty::Never | ty::Tuple(_) - | ty::Alias(ty::Projection, _) => { - Position::DerefStable(precedence, ty.is_sized(cx.tcx, cx.param_env.without_caller_bounds())).into() - }, + | ty::Alias(ty::Projection, _) => Position::DerefStable(precedence, ty.is_sized(tcx, param_env)).into(), }; } } diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs index c48d27b05..99ebfa8fe 100644 --- a/clippy_utils/src/ty.rs +++ b/clippy_utils/src/ty.rs @@ -894,16 +894,29 @@ impl AdtVariantInfo { } /// Gets the struct or enum variant from the given `Res` -pub fn variant_of_res<'tcx>(cx: &LateContext<'tcx>, res: Res) -> Option<&'tcx VariantDef> { +pub fn adt_and_variant_of_res<'tcx>(cx: &LateContext<'tcx>, res: Res) -> Option<(AdtDef<'tcx>, &'tcx VariantDef)> { match res { - Res::Def(DefKind::Struct, id) => Some(cx.tcx.adt_def(id).non_enum_variant()), - Res::Def(DefKind::Variant, id) => Some(cx.tcx.adt_def(cx.tcx.parent(id)).variant_with_id(id)), - Res::Def(DefKind::Ctor(CtorOf::Struct, _), id) => Some(cx.tcx.adt_def(cx.tcx.parent(id)).non_enum_variant()), + Res::Def(DefKind::Struct, id) => { + let adt = cx.tcx.adt_def(id); + Some((adt, adt.non_enum_variant())) + }, + Res::Def(DefKind::Variant, id) => { + let adt = cx.tcx.adt_def(cx.tcx.parent(id)); + Some((adt, adt.variant_with_id(id))) + }, + Res::Def(DefKind::Ctor(CtorOf::Struct, _), id) => { + let adt = cx.tcx.adt_def(cx.tcx.parent(id)); + Some((adt, adt.non_enum_variant())) + }, Res::Def(DefKind::Ctor(CtorOf::Variant, _), id) => { let var_id = cx.tcx.parent(id); - Some(cx.tcx.adt_def(cx.tcx.parent(var_id)).variant_with_id(var_id)) + let adt = cx.tcx.adt_def(cx.tcx.parent(var_id)); + Some((adt, adt.variant_with_id(var_id))) + }, + Res::SelfCtor(id) => { + let adt = cx.tcx.type_of(id).ty_adt_def().unwrap(); + Some((adt, adt.non_enum_variant())) }, - Res::SelfCtor(id) => Some(cx.tcx.type_of(id).ty_adt_def().unwrap().non_enum_variant()), _ => None, } } diff --git a/tests/ui/explicit_auto_deref.fixed b/tests/ui/explicit_auto_deref.fixed index 475fae5e8..5d40c8504 100644 --- a/tests/ui/explicit_auto_deref.fixed +++ b/tests/ui/explicit_auto_deref.fixed @@ -269,6 +269,9 @@ fn main() { trait WithAssoc { type Assoc: ?Sized; + fn to_assoc(&self) -> &Self::Assoc { + panic!() + } } impl WithAssoc for String { type Assoc = str; @@ -281,4 +284,15 @@ fn main() { // Issue #9901 fn takes_ref(_: &i32) {} takes_ref(*Box::new(&0i32)); + + // Issue #10384 + impl<'a> WithAssoc for &'a u32 { + type Assoc = dyn core::fmt::Display; + fn to_assoc(&self) -> &Self::Assoc { + *self + } + } + fn return_dyn_assoc<'a>(x: &'a &'a u32) -> &'a <&'a u32 as WithAssoc>::Assoc { + *x + } } diff --git a/tests/ui/explicit_auto_deref.rs b/tests/ui/explicit_auto_deref.rs index c1894258f..79e03f4d7 100644 --- a/tests/ui/explicit_auto_deref.rs +++ b/tests/ui/explicit_auto_deref.rs @@ -269,6 +269,9 @@ fn main() { trait WithAssoc { type Assoc: ?Sized; + fn to_assoc(&self) -> &Self::Assoc { + panic!() + } } impl WithAssoc for String { type Assoc = str; @@ -281,4 +284,15 @@ fn main() { // Issue #9901 fn takes_ref(_: &i32) {} takes_ref(*Box::new(&0i32)); + + // Issue #10384 + impl<'a> WithAssoc for &'a u32 { + type Assoc = dyn core::fmt::Display; + fn to_assoc(&self) -> &Self::Assoc { + *self + } + } + fn return_dyn_assoc<'a>(x: &'a &'a u32) -> &'a <&'a u32 as WithAssoc>::Assoc { + *x + } }