diff --git a/clippy_lints/src/non_copy_const.rs b/clippy_lints/src/non_copy_const.rs index 28c68a2b68c..bb44eeb6adc 100644 --- a/clippy_lints/src/non_copy_const.rs +++ b/clippy_lints/src/non_copy_const.rs @@ -9,8 +9,7 @@ use rustc_hir::{Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, Node, Tr use rustc_infer::traits::specialization_graph; use rustc_lint::{LateContext, LateLintPass, Lint}; use rustc_middle::ty::adjustment::Adjust; -use rustc_middle::ty::fold::TypeFoldable as _; -use rustc_middle::ty::{AssocKind, Ty, TypeFlags}; +use rustc_middle::ty::{AssocKind, Ty}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::{InnerSpan, Span, DUMMY_SP}; use rustc_typeck::hir_ty_to_ty; @@ -178,15 +177,18 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst { if let Some(of_trait_def_id) = of_trait_ref.trait_def_id(); if let Some(of_assoc_item) = specialization_graph::Node::Trait(of_trait_def_id) .item(cx.tcx, impl_item.ident, AssocKind::Const, of_trait_def_id); - if cx.tcx - // Normalize assoc types because ones originated from generic params - // bounded other traits could have their bound at the trait defs; - // and, in that case, the definition is *not* generic. - .normalize_erasing_regions( - cx.tcx.param_env(of_trait_def_id), - cx.tcx.type_of(of_assoc_item.def_id), - ) - .has_type_flags(TypeFlags::HAS_PROJECTION | TypeFlags::HAS_TY_PARAM); + if cx + .tcx + .layout_of(cx.tcx.param_env(of_trait_def_id).and( + // Normalize assoc types because ones originated from generic params + // bounded other traits could have their bound at the trait defs; + // and, in that case, the definition is *not* generic. + cx.tcx.normalize_erasing_regions( + cx.tcx.param_env(of_trait_def_id), + cx.tcx.type_of(of_assoc_item.def_id), + ), + )) + .is_err(); then { let ty = hir_ty_to_ty(cx.tcx, hir_ty); let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty); diff --git a/tests/ui/declare_interior_mutable_const.rs b/tests/ui/declare_interior_mutable_const.rs index 7471b360540..646d3ec8b47 100644 --- a/tests/ui/declare_interior_mutable_const.rs +++ b/tests/ui/declare_interior_mutable_const.rs @@ -34,64 +34,135 @@ static STATIC_TUPLE: (AtomicUsize, String) = (ATOMIC, STRING); #[allow(clippy::declare_interior_mutable_const)] const ONCE_INIT: Once = Once::new(); -struct Wrapper(T); - -trait Trait> { - type AssocType; - type AssocType2; - type AssocType3; - +// a constant whose type is a concrete type should be linted at the definition site. +trait ConcreteTypes { const ATOMIC: AtomicUsize; //~ ERROR interior mutable const INTEGER: u64; const STRING: String; - const SELF: Self; - const INPUT: T; - const INPUT_ASSOC: T::AssocType4; - const INPUT_ASSOC_2: T::AssocType5; //~ ERROR interior mutable - const ASSOC: Self::AssocType; - const ASSOC_2: Self::AssocType2; - const WRAPPED_ASSOC_2: Wrapper; - const WRAPPED_ASSOC_3: Wrapper; - - const AN_INPUT: T = Self::INPUT; - declare_const!(ANOTHER_INPUT: T = Self::INPUT); declare_const!(ANOTHER_ATOMIC: AtomicUsize = Self::ATOMIC); //~ ERROR interior mutable } -trait Trait2 { - type AssocType4; - type AssocType5; - - const SELF_2: Self; - const ASSOC_4: Self::AssocType4; -} - -impl> Trait for u64 { - type AssocType = u16; - type AssocType2 = AtomicUsize; - type AssocType3 = T; - +impl ConcreteTypes for u64 { const ATOMIC: AtomicUsize = AtomicUsize::new(9); const INTEGER: u64 = 10; const STRING: String = String::new(); - const SELF: Self = 11; - const INPUT: T = T::SELF_2; - const INPUT_ASSOC: T::AssocType4 = T::ASSOC_4; - const INPUT_ASSOC_2: T::AssocType5 = AtomicUsize::new(16); - const ASSOC: Self::AssocType = 13; - const ASSOC_2: Self::AssocType2 = AtomicUsize::new(15); //~ ERROR interior mutable - const WRAPPED_ASSOC_2: Wrapper = Wrapper(AtomicUsize::new(16)); //~ ERROR interior mutable - const WRAPPED_ASSOC_3: Wrapper = Wrapper(T::SELF_2); } -struct Local(T, U); +// a helper trait used below +trait ConstDefault { + const DEFAULT: Self; +} -impl, U: Trait2> Local { - const ASSOC_5: AtomicUsize = AtomicUsize::new(14); //~ ERROR interior mutable +// a constant whose type is a generic type should be linted at the implementation site. +trait GenericTypes { + const TO_REMAIN_GENERIC: T; + const TO_BE_CONCRETE: U; + + const HAVING_DEFAULT: T = Self::TO_REMAIN_GENERIC; + declare_const!(IN_MACRO: T = Self::TO_REMAIN_GENERIC); +} + +impl GenericTypes for u64 { + const TO_REMAIN_GENERIC: T = T::DEFAULT; + const TO_BE_CONCRETE: AtomicUsize = AtomicUsize::new(11); //~ ERROR interior mutable +} + +// a helper type used below +struct Wrapper(T); + +// a constant whose type is an associated type should be linted at the implementation site, too. +trait AssocTypes { + type ToBeFrozen; + type ToBeUnfrozen; + type ToBeGenericParam; + + const TO_BE_FROZEN: Self::ToBeFrozen; + const TO_BE_UNFROZEN: Self::ToBeUnfrozen; + const WRAPPED_TO_BE_UNFROZEN: Wrapper; + // to ensure it can handle things when a generic type remains after normalization. + const WRAPPED_TO_BE_GENERIC_PARAM: Wrapper; +} + +impl AssocTypes for Vec { + type ToBeFrozen = u16; + type ToBeUnfrozen = AtomicUsize; + type ToBeGenericParam = T; + + const TO_BE_FROZEN: Self::ToBeFrozen = 12; + const TO_BE_UNFROZEN: Self::ToBeUnfrozen = AtomicUsize::new(13); //~ ERROR interior mutable + const WRAPPED_TO_BE_UNFROZEN: Wrapper = Wrapper(AtomicUsize::new(14)); //~ ERROR interior mutable + const WRAPPED_TO_BE_GENERIC_PARAM: Wrapper = Wrapper(T::DEFAULT); +} + +// a helper trait used below +trait AssocTypesHelper { + type NotToBeBounded; + type ToBeBounded; + + const NOT_TO_BE_BOUNDED: Self::NotToBeBounded; +} + +// a constant whose type is an assoc type originated from a generic param bounded at the definition +// site should be linted at there. +trait AssocTypesFromGenericParam +where + T: AssocTypesHelper, +{ + const NOT_BOUNDED: T::NotToBeBounded; + const BOUNDED: T::ToBeBounded; //~ ERROR interior mutable +} + +impl AssocTypesFromGenericParam for u64 +where + T: AssocTypesHelper, +{ + // an associated type could remain unknown in a trait impl. + const NOT_BOUNDED: T::NotToBeBounded = T::NOT_TO_BE_BOUNDED; + const BOUNDED: T::ToBeBounded = AtomicUsize::new(15); +} + +trait SelfType { + const SELF: Self; +} + +impl SelfType for u64 { + const SELF: Self = 16; +} + +impl SelfType for AtomicUsize { + // this (interior mutable `Self` const) exists in `parking_lot`. + // `const_trait_impl` will replace it in the future, hopefully. + const SELF: Self = AtomicUsize::new(17); //~ ERROR interior mutable +} + +// Even though a constant contains a generic type, if it also have a interior mutable type, +// it should be linted at the definition site. +trait BothOfCellAndGeneric { + // this is a false negative in the current implementation. + const DIRECT: Cell; + const INDIRECT: Cell<*const T>; //~ ERROR interior mutable +} + +impl BothOfCellAndGeneric for u64 { + const DIRECT: Cell = Cell::new(T::DEFAULT); + const INDIRECT: Cell<*const T> = Cell::new(std::ptr::null()); +} + +struct Local(T); + +// a constant in an inherent impl are essentially the same as a normal const item +// except there can be a generic or associated type. +impl Local +where + T: ConstDefault + AssocTypesHelper, +{ + const ATOMIC: AtomicUsize = AtomicUsize::new(18); //~ ERROR interior mutable const COW: Cow<'static, str> = Cow::Borrowed("tuvwxy"); - const U_SELF: U = U::SELF_2; - const T_ASSOC: T::AssocType = T::ASSOC; - const U_ASSOC: U::AssocType5 = AtomicUsize::new(17); //~ ERROR interior mutable + + const GENERIC_TYPE: T = T::DEFAULT; + + const ASSOC_TYPE: T::NotToBeBounded = T::NOT_TO_BE_BOUNDED; + const BOUNDED_ASSOC_TYPE: T::ToBeBounded = AtomicUsize::new(19); //~ ERROR interior mutable } fn main() {} diff --git a/tests/ui/declare_interior_mutable_const.stderr b/tests/ui/declare_interior_mutable_const.stderr index 0fcb726db46..0a0b818b8b7 100644 --- a/tests/ui/declare_interior_mutable_const.stderr +++ b/tests/ui/declare_interior_mutable_const.stderr @@ -36,17 +36,11 @@ LL | declare_const!(_ONCE: Once = Once::new()); //~ ERROR interior mutable = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info) error: a `const` item should never be interior mutable - --> $DIR/declare_interior_mutable_const.rs:44:5 + --> $DIR/declare_interior_mutable_const.rs:39:5 | LL | const ATOMIC: AtomicUsize; //~ ERROR interior mutable | ^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: a `const` item should never be interior mutable - --> $DIR/declare_interior_mutable_const.rs:50:5 - | -LL | const INPUT_ASSOC_2: T::AssocType5; //~ ERROR interior mutable - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - error: a `const` item should never be interior mutable --> $DIR/declare_interior_mutable_const.rs:16:9 | @@ -59,28 +53,52 @@ LL | declare_const!(ANOTHER_ATOMIC: AtomicUsize = Self::ATOMIC); //~ ERROR i = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info) error: a `const` item should never be interior mutable - --> $DIR/declare_interior_mutable_const.rs:82:5 + --> $DIR/declare_interior_mutable_const.rs:67:5 | -LL | const ASSOC_2: Self::AssocType2 = AtomicUsize::new(15); //~ ERROR interior mutable - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | const TO_BE_CONCRETE: AtomicUsize = AtomicUsize::new(11); //~ ERROR interior mutable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: a `const` item should never be interior mutable - --> $DIR/declare_interior_mutable_const.rs:83:5 + --> $DIR/declare_interior_mutable_const.rs:92:5 | -LL | const WRAPPED_ASSOC_2: Wrapper = Wrapper(AtomicUsize::new(16)); //~ ERROR interior mutable - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | const TO_BE_UNFROZEN: Self::ToBeUnfrozen = AtomicUsize::new(13); //~ ERROR interior mutable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: a `const` item should never be interior mutable - --> $DIR/declare_interior_mutable_const.rs:90:5 + --> $DIR/declare_interior_mutable_const.rs:93:5 | -LL | const ASSOC_5: AtomicUsize = AtomicUsize::new(14); //~ ERROR interior mutable - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | const WRAPPED_TO_BE_UNFROZEN: Wrapper = Wrapper(AtomicUsize::new(14)); //~ ERROR interior mutable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: a `const` item should never be interior mutable - --> $DIR/declare_interior_mutable_const.rs:94:5 + --> $DIR/declare_interior_mutable_const.rs:112:5 | -LL | const U_ASSOC: U::AssocType5 = AtomicUsize::new(17); //~ ERROR interior mutable - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | const BOUNDED: T::ToBeBounded; //~ ERROR interior mutable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: aborting due to 11 previous errors +error: a `const` item should never be interior mutable + --> $DIR/declare_interior_mutable_const.rs:135:5 + | +LL | const SELF: Self = AtomicUsize::new(17); //~ ERROR interior mutable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: a `const` item should never be interior mutable + --> $DIR/declare_interior_mutable_const.rs:143:5 + | +LL | const INDIRECT: Cell<*const T>; //~ ERROR interior mutable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: a `const` item should never be interior mutable + --> $DIR/declare_interior_mutable_const.rs:159:5 + | +LL | const ATOMIC: AtomicUsize = AtomicUsize::new(18); //~ ERROR interior mutable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: a `const` item should never be interior mutable + --> $DIR/declare_interior_mutable_const.rs:165:5 + | +LL | const BOUNDED_ASSOC_TYPE: T::ToBeBounded = AtomicUsize::new(19); //~ ERROR interior mutable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 14 previous errors