diff --git a/compiler/rustc_error_codes/src/error_codes/E0152.md b/compiler/rustc_error_codes/src/error_codes/E0152.md index 120c96b421104..ef17b8b4c75c9 100644 --- a/compiler/rustc_error_codes/src/error_codes/E0152.md +++ b/compiler/rustc_error_codes/src/error_codes/E0152.md @@ -6,7 +6,7 @@ Erroneous code example: #![feature(lang_items)] #[lang = "owned_box"] -struct Foo; // error: duplicate lang item found: `owned_box` +struct Foo(T); // error: duplicate lang item found: `owned_box` ``` Lang items are already implemented in the standard library. Unless you are diff --git a/compiler/rustc_hir/src/lang_items.rs b/compiler/rustc_hir/src/lang_items.rs index 55000ae7e59d4..b85ed0cb4bbe5 100644 --- a/compiler/rustc_hir/src/lang_items.rs +++ b/compiler/rustc_hir/src/lang_items.rs @@ -38,7 +38,7 @@ macro_rules! expand_group { // So you probably just want to nip down to the end. macro_rules! language_item_table { ( - $( $(#[$attr:meta])* $variant:ident $($group:expr)?, $module:ident :: $name:ident, $method:ident, $target:expr; )* + $( $(#[$attr:meta])* $variant:ident $($group:expr)?, $module:ident :: $name:ident, $method:ident, $target:expr, $generics:expr; )* ) => { enum_from_u32! { @@ -72,6 +72,12 @@ macro_rules! language_item_table { $( LangItem::$variant => expand_group!($($group)*), )* } } + + pub fn required_generics(&self) -> GenericRequirement { + match self { + $( LangItem::$variant => $generics, )* + } + } } /// All of the language items, defined or not. @@ -165,108 +171,108 @@ where } language_item_table! { -// Variant name, Name, Method name, Target; - Bool, sym::bool, bool_impl, Target::Impl; - Char, sym::char, char_impl, Target::Impl; - Str, sym::str, str_impl, Target::Impl; - Array, sym::array, array_impl, Target::Impl; - Slice, sym::slice, slice_impl, Target::Impl; - SliceU8, sym::slice_u8, slice_u8_impl, Target::Impl; - StrAlloc, sym::str_alloc, str_alloc_impl, Target::Impl; - SliceAlloc, sym::slice_alloc, slice_alloc_impl, Target::Impl; - SliceU8Alloc, sym::slice_u8_alloc, slice_u8_alloc_impl, Target::Impl; - ConstPtr, sym::const_ptr, const_ptr_impl, Target::Impl; - MutPtr, sym::mut_ptr, mut_ptr_impl, Target::Impl; - ConstSlicePtr, sym::const_slice_ptr, const_slice_ptr_impl, Target::Impl; - MutSlicePtr, sym::mut_slice_ptr, mut_slice_ptr_impl, Target::Impl; - I8, sym::i8, i8_impl, Target::Impl; - I16, sym::i16, i16_impl, Target::Impl; - I32, sym::i32, i32_impl, Target::Impl; - I64, sym::i64, i64_impl, Target::Impl; - I128, sym::i128, i128_impl, Target::Impl; - Isize, sym::isize, isize_impl, Target::Impl; - U8, sym::u8, u8_impl, Target::Impl; - U16, sym::u16, u16_impl, Target::Impl; - U32, sym::u32, u32_impl, Target::Impl; - U64, sym::u64, u64_impl, Target::Impl; - U128, sym::u128, u128_impl, Target::Impl; - Usize, sym::usize, usize_impl, Target::Impl; - F32, sym::f32, f32_impl, Target::Impl; - F64, sym::f64, f64_impl, Target::Impl; - F32Runtime, sym::f32_runtime, f32_runtime_impl, Target::Impl; - F64Runtime, sym::f64_runtime, f64_runtime_impl, Target::Impl; - - Sized, sym::sized, sized_trait, Target::Trait; - Unsize, sym::unsize, unsize_trait, Target::Trait; +// Variant name, Name, Method name, Target Generic requirements; + Bool, sym::bool, bool_impl, Target::Impl, GenericRequirement::None; + Char, sym::char, char_impl, Target::Impl, GenericRequirement::None; + Str, sym::str, str_impl, Target::Impl, GenericRequirement::None; + Array, sym::array, array_impl, Target::Impl, GenericRequirement::None; + Slice, sym::slice, slice_impl, Target::Impl, GenericRequirement::None; + SliceU8, sym::slice_u8, slice_u8_impl, Target::Impl, GenericRequirement::None; + StrAlloc, sym::str_alloc, str_alloc_impl, Target::Impl, GenericRequirement::None; + SliceAlloc, sym::slice_alloc, slice_alloc_impl, Target::Impl, GenericRequirement::None; + SliceU8Alloc, sym::slice_u8_alloc, slice_u8_alloc_impl, Target::Impl, GenericRequirement::None; + ConstPtr, sym::const_ptr, const_ptr_impl, Target::Impl, GenericRequirement::None; + MutPtr, sym::mut_ptr, mut_ptr_impl, Target::Impl, GenericRequirement::None; + ConstSlicePtr, sym::const_slice_ptr, const_slice_ptr_impl, Target::Impl, GenericRequirement::None; + MutSlicePtr, sym::mut_slice_ptr, mut_slice_ptr_impl, Target::Impl, GenericRequirement::None; + I8, sym::i8, i8_impl, Target::Impl, GenericRequirement::None; + I16, sym::i16, i16_impl, Target::Impl, GenericRequirement::None; + I32, sym::i32, i32_impl, Target::Impl, GenericRequirement::None; + I64, sym::i64, i64_impl, Target::Impl, GenericRequirement::None; + I128, sym::i128, i128_impl, Target::Impl, GenericRequirement::None; + Isize, sym::isize, isize_impl, Target::Impl, GenericRequirement::None; + U8, sym::u8, u8_impl, Target::Impl, GenericRequirement::None; + U16, sym::u16, u16_impl, Target::Impl, GenericRequirement::None; + U32, sym::u32, u32_impl, Target::Impl, GenericRequirement::None; + U64, sym::u64, u64_impl, Target::Impl, GenericRequirement::None; + U128, sym::u128, u128_impl, Target::Impl, GenericRequirement::None; + Usize, sym::usize, usize_impl, Target::Impl, GenericRequirement::None; + F32, sym::f32, f32_impl, Target::Impl, GenericRequirement::None; + F64, sym::f64, f64_impl, Target::Impl, GenericRequirement::None; + F32Runtime, sym::f32_runtime, f32_runtime_impl, Target::Impl, GenericRequirement::None; + F64Runtime, sym::f64_runtime, f64_runtime_impl, Target::Impl, GenericRequirement::None; + + Sized, sym::sized, sized_trait, Target::Trait, GenericRequirement::Exact(0); + Unsize, sym::unsize, unsize_trait, Target::Trait, GenericRequirement::Minimum(1); /// Trait injected by `#[derive(PartialEq)]`, (i.e. "Partial EQ"). - StructuralPeq, sym::structural_peq, structural_peq_trait, Target::Trait; + StructuralPeq, sym::structural_peq, structural_peq_trait, Target::Trait, GenericRequirement::None; /// Trait injected by `#[derive(Eq)]`, (i.e. "Total EQ"; no, I will not apologize). - StructuralTeq, sym::structural_teq, structural_teq_trait, Target::Trait; - Copy, sym::copy, copy_trait, Target::Trait; - Clone, sym::clone, clone_trait, Target::Trait; - Sync, sym::sync, sync_trait, Target::Trait; - DiscriminantKind, sym::discriminant_kind, discriminant_kind_trait, Target::Trait; + StructuralTeq, sym::structural_teq, structural_teq_trait, Target::Trait, GenericRequirement::None; + Copy, sym::copy, copy_trait, Target::Trait, GenericRequirement::Exact(0); + Clone, sym::clone, clone_trait, Target::Trait, GenericRequirement::None; + Sync, sym::sync, sync_trait, Target::Trait, GenericRequirement::Exact(0); + DiscriminantKind, sym::discriminant_kind, discriminant_kind_trait, Target::Trait, GenericRequirement::None; /// The associated item of the [`DiscriminantKind`] trait. - Discriminant, sym::discriminant_type, discriminant_type, Target::AssocTy; - - PointeeTrait, sym::pointee_trait, pointee_trait, Target::Trait; - Metadata, sym::metadata_type, metadata_type, Target::AssocTy; - DynMetadata, sym::dyn_metadata, dyn_metadata, Target::Struct; - - Freeze, sym::freeze, freeze_trait, Target::Trait; - - Drop, sym::drop, drop_trait, Target::Trait; - - CoerceUnsized, sym::coerce_unsized, coerce_unsized_trait, Target::Trait; - DispatchFromDyn, sym::dispatch_from_dyn, dispatch_from_dyn_trait, Target::Trait; - - Add(Op), sym::add, add_trait, Target::Trait; - Sub(Op), sym::sub, sub_trait, Target::Trait; - Mul(Op), sym::mul, mul_trait, Target::Trait; - Div(Op), sym::div, div_trait, Target::Trait; - Rem(Op), sym::rem, rem_trait, Target::Trait; - Neg(Op), sym::neg, neg_trait, Target::Trait; - Not(Op), sym::not, not_trait, Target::Trait; - BitXor(Op), sym::bitxor, bitxor_trait, Target::Trait; - BitAnd(Op), sym::bitand, bitand_trait, Target::Trait; - BitOr(Op), sym::bitor, bitor_trait, Target::Trait; - Shl(Op), sym::shl, shl_trait, Target::Trait; - Shr(Op), sym::shr, shr_trait, Target::Trait; - AddAssign(Op), sym::add_assign, add_assign_trait, Target::Trait; - SubAssign(Op), sym::sub_assign, sub_assign_trait, Target::Trait; - MulAssign(Op), sym::mul_assign, mul_assign_trait, Target::Trait; - DivAssign(Op), sym::div_assign, div_assign_trait, Target::Trait; - RemAssign(Op), sym::rem_assign, rem_assign_trait, Target::Trait; - BitXorAssign(Op), sym::bitxor_assign, bitxor_assign_trait, Target::Trait; - BitAndAssign(Op), sym::bitand_assign, bitand_assign_trait, Target::Trait; - BitOrAssign(Op), sym::bitor_assign, bitor_assign_trait, Target::Trait; - ShlAssign(Op), sym::shl_assign, shl_assign_trait, Target::Trait; - ShrAssign(Op), sym::shr_assign, shr_assign_trait, Target::Trait; - Index(Op), sym::index, index_trait, Target::Trait; - IndexMut(Op), sym::index_mut, index_mut_trait, Target::Trait; - - UnsafeCell, sym::unsafe_cell, unsafe_cell_type, Target::Struct; - VaList, sym::va_list, va_list, Target::Struct; - - Deref, sym::deref, deref_trait, Target::Trait; - DerefMut, sym::deref_mut, deref_mut_trait, Target::Trait; - DerefTarget, sym::deref_target, deref_target, Target::AssocTy; - Receiver, sym::receiver, receiver_trait, Target::Trait; - - Fn, kw::Fn, fn_trait, Target::Trait; - FnMut, sym::fn_mut, fn_mut_trait, Target::Trait; - FnOnce, sym::fn_once, fn_once_trait, Target::Trait; - - FnOnceOutput, sym::fn_once_output, fn_once_output, Target::AssocTy; - - Future, sym::future_trait, future_trait, Target::Trait; - GeneratorState, sym::generator_state, gen_state, Target::Enum; - Generator, sym::generator, gen_trait, Target::Trait; - Unpin, sym::unpin, unpin_trait, Target::Trait; - Pin, sym::pin, pin_type, Target::Struct; - - PartialEq, sym::eq, eq_trait, Target::Trait; - PartialOrd, sym::partial_ord, partial_ord_trait, Target::Trait; + Discriminant, sym::discriminant_type, discriminant_type, Target::AssocTy, GenericRequirement::None; + + PointeeTrait, sym::pointee_trait, pointee_trait, Target::Trait, GenericRequirement::None; + Metadata, sym::metadata_type, metadata_type, Target::AssocTy, GenericRequirement::None; + DynMetadata, sym::dyn_metadata, dyn_metadata, Target::Struct, GenericRequirement::None; + + Freeze, sym::freeze, freeze_trait, Target::Trait, GenericRequirement::Exact(0); + + Drop, sym::drop, drop_trait, Target::Trait, GenericRequirement::None; + + CoerceUnsized, sym::coerce_unsized, coerce_unsized_trait, Target::Trait, GenericRequirement::Minimum(1); + DispatchFromDyn, sym::dispatch_from_dyn, dispatch_from_dyn_trait, Target::Trait, GenericRequirement::Minimum(1); + + Add(Op), sym::add, add_trait, Target::Trait, GenericRequirement::Exact(1); + Sub(Op), sym::sub, sub_trait, Target::Trait, GenericRequirement::Exact(1); + Mul(Op), sym::mul, mul_trait, Target::Trait, GenericRequirement::Exact(1); + Div(Op), sym::div, div_trait, Target::Trait, GenericRequirement::Exact(1); + Rem(Op), sym::rem, rem_trait, Target::Trait, GenericRequirement::Exact(1); + Neg(Op), sym::neg, neg_trait, Target::Trait, GenericRequirement::Exact(0); + Not(Op), sym::not, not_trait, Target::Trait, GenericRequirement::Exact(0); + BitXor(Op), sym::bitxor, bitxor_trait, Target::Trait, GenericRequirement::Exact(1); + BitAnd(Op), sym::bitand, bitand_trait, Target::Trait, GenericRequirement::Exact(1); + BitOr(Op), sym::bitor, bitor_trait, Target::Trait, GenericRequirement::Exact(1); + Shl(Op), sym::shl, shl_trait, Target::Trait, GenericRequirement::Exact(1); + Shr(Op), sym::shr, shr_trait, Target::Trait, GenericRequirement::Exact(1); + AddAssign(Op), sym::add_assign, add_assign_trait, Target::Trait, GenericRequirement::Exact(1); + SubAssign(Op), sym::sub_assign, sub_assign_trait, Target::Trait, GenericRequirement::Exact(1); + MulAssign(Op), sym::mul_assign, mul_assign_trait, Target::Trait, GenericRequirement::Exact(1); + DivAssign(Op), sym::div_assign, div_assign_trait, Target::Trait, GenericRequirement::Exact(1); + RemAssign(Op), sym::rem_assign, rem_assign_trait, Target::Trait, GenericRequirement::Exact(1); + BitXorAssign(Op), sym::bitxor_assign, bitxor_assign_trait, Target::Trait, GenericRequirement::Exact(1); + BitAndAssign(Op), sym::bitand_assign, bitand_assign_trait, Target::Trait, GenericRequirement::Exact(1); + BitOrAssign(Op), sym::bitor_assign, bitor_assign_trait, Target::Trait, GenericRequirement::Exact(1); + ShlAssign(Op), sym::shl_assign, shl_assign_trait, Target::Trait, GenericRequirement::Exact(1); + ShrAssign(Op), sym::shr_assign, shr_assign_trait, Target::Trait, GenericRequirement::Exact(1); + Index(Op), sym::index, index_trait, Target::Trait, GenericRequirement::Exact(1); + IndexMut(Op), sym::index_mut, index_mut_trait, Target::Trait, GenericRequirement::Exact(1); + + UnsafeCell, sym::unsafe_cell, unsafe_cell_type, Target::Struct, GenericRequirement::None; + VaList, sym::va_list, va_list, Target::Struct, GenericRequirement::None; + + Deref, sym::deref, deref_trait, Target::Trait, GenericRequirement::Exact(0); + DerefMut, sym::deref_mut, deref_mut_trait, Target::Trait, GenericRequirement::Exact(0); + DerefTarget, sym::deref_target, deref_target, Target::AssocTy, GenericRequirement::None; + Receiver, sym::receiver, receiver_trait, Target::Trait, GenericRequirement::None; + + Fn, kw::Fn, fn_trait, Target::Trait, GenericRequirement::Exact(1); + FnMut, sym::fn_mut, fn_mut_trait, Target::Trait, GenericRequirement::Exact(1); + FnOnce, sym::fn_once, fn_once_trait, Target::Trait, GenericRequirement::Exact(1); + + FnOnceOutput, sym::fn_once_output, fn_once_output, Target::AssocTy, GenericRequirement::None; + + Future, sym::future_trait, future_trait, Target::Trait, GenericRequirement::Exact(0); + GeneratorState, sym::generator_state, gen_state, Target::Enum, GenericRequirement::None; + Generator, sym::generator, gen_trait, Target::Trait, GenericRequirement::Minimum(1); + Unpin, sym::unpin, unpin_trait, Target::Trait, GenericRequirement::None; + Pin, sym::pin, pin_type, Target::Struct, GenericRequirement::None; + + PartialEq, sym::eq, eq_trait, Target::Trait, GenericRequirement::Exact(1); + PartialOrd, sym::partial_ord, partial_ord_trait, Target::Trait, GenericRequirement::Exact(1); // A number of panic-related lang items. The `panic` item corresponds to divide-by-zero and // various panic cases with `match`. The `panic_bounds_check` item is for indexing arrays. @@ -275,80 +281,86 @@ language_item_table! { // in the sense that a crate is not required to have it defined to use it, but a final product // is required to define it somewhere. Additionally, there are restrictions on crates that use // a weak lang item, but do not have it defined. - Panic, sym::panic, panic_fn, Target::Fn; - PanicFmt, sym::panic_fmt, panic_fmt, Target::Fn; - PanicStr, sym::panic_str, panic_str, Target::Fn; - ConstPanicFmt, sym::const_panic_fmt, const_panic_fmt, Target::Fn; - PanicBoundsCheck, sym::panic_bounds_check, panic_bounds_check_fn, Target::Fn; - PanicInfo, sym::panic_info, panic_info, Target::Struct; - PanicLocation, sym::panic_location, panic_location, Target::Struct; - PanicImpl, sym::panic_impl, panic_impl, Target::Fn; + Panic, sym::panic, panic_fn, Target::Fn, GenericRequirement::None; + PanicFmt, sym::panic_fmt, panic_fmt, Target::Fn, GenericRequirement::None; + PanicStr, sym::panic_str, panic_str, Target::Fn, GenericRequirement::None; + ConstPanicFmt, sym::const_panic_fmt, const_panic_fmt, Target::Fn, GenericRequirement::None; + PanicBoundsCheck, sym::panic_bounds_check, panic_bounds_check_fn, Target::Fn, GenericRequirement::None; + PanicInfo, sym::panic_info, panic_info, Target::Struct, GenericRequirement::None; + PanicLocation, sym::panic_location, panic_location, Target::Struct, GenericRequirement::None; + PanicImpl, sym::panic_impl, panic_impl, Target::Fn, GenericRequirement::None; /// libstd panic entry point. Necessary for const eval to be able to catch it - BeginPanic, sym::begin_panic, begin_panic_fn, Target::Fn; - BeginPanicFmt, sym::begin_panic_fmt, begin_panic_fmt, Target::Fn; + BeginPanic, sym::begin_panic, begin_panic_fn, Target::Fn, GenericRequirement::None; + BeginPanicFmt, sym::begin_panic_fmt, begin_panic_fmt, Target::Fn, GenericRequirement::None; - ExchangeMalloc, sym::exchange_malloc, exchange_malloc_fn, Target::Fn; - BoxFree, sym::box_free, box_free_fn, Target::Fn; - DropInPlace, sym::drop_in_place, drop_in_place_fn, Target::Fn; - Oom, sym::oom, oom, Target::Fn; - AllocLayout, sym::alloc_layout, alloc_layout, Target::Struct; + ExchangeMalloc, sym::exchange_malloc, exchange_malloc_fn, Target::Fn, GenericRequirement::None; + BoxFree, sym::box_free, box_free_fn, Target::Fn, GenericRequirement::Minimum(1); + DropInPlace, sym::drop_in_place, drop_in_place_fn, Target::Fn, GenericRequirement::Minimum(1); + Oom, sym::oom, oom, Target::Fn, GenericRequirement::None; + AllocLayout, sym::alloc_layout, alloc_layout, Target::Struct, GenericRequirement::None; - Start, sym::start, start_fn, Target::Fn; + Start, sym::start, start_fn, Target::Fn, GenericRequirement::None; - EhPersonality, sym::eh_personality, eh_personality, Target::Fn; - EhCatchTypeinfo, sym::eh_catch_typeinfo, eh_catch_typeinfo, Target::Static; + EhPersonality, sym::eh_personality, eh_personality, Target::Fn, GenericRequirement::None; + EhCatchTypeinfo, sym::eh_catch_typeinfo, eh_catch_typeinfo, Target::Static, GenericRequirement::None; - OwnedBox, sym::owned_box, owned_box, Target::Struct; + OwnedBox, sym::owned_box, owned_box, Target::Struct, GenericRequirement::Minimum(1); - PhantomData, sym::phantom_data, phantom_data, Target::Struct; + PhantomData, sym::phantom_data, phantom_data, Target::Struct, GenericRequirement::Exact(1); - ManuallyDrop, sym::manually_drop, manually_drop, Target::Struct; + ManuallyDrop, sym::manually_drop, manually_drop, Target::Struct, GenericRequirement::None; - MaybeUninit, sym::maybe_uninit, maybe_uninit, Target::Union; + MaybeUninit, sym::maybe_uninit, maybe_uninit, Target::Union, GenericRequirement::None; /// Align offset for stride != 1; must not panic. - AlignOffset, sym::align_offset, align_offset_fn, Target::Fn; + AlignOffset, sym::align_offset, align_offset_fn, Target::Fn, GenericRequirement::None; - Termination, sym::termination, termination, Target::Trait; + Termination, sym::termination, termination, Target::Trait, GenericRequirement::None; - Try, sym::Try, try_trait, Target::Trait; + Try, sym::Try, try_trait, Target::Trait, GenericRequirement::None; - SliceLen, sym::slice_len_fn, slice_len_fn, Target::Method(MethodKind::Inherent); + SliceLen, sym::slice_len_fn, slice_len_fn, Target::Method(MethodKind::Inherent), GenericRequirement::None; // Language items from AST lowering - TryTraitFromResidual, sym::from_residual, from_residual_fn, Target::Method(MethodKind::Trait { body: false }); - TryTraitFromOutput, sym::from_output, from_output_fn, Target::Method(MethodKind::Trait { body: false }); - TryTraitBranch, sym::branch, branch_fn, Target::Method(MethodKind::Trait { body: false }); + TryTraitFromResidual, sym::from_residual, from_residual_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None; + TryTraitFromOutput, sym::from_output, from_output_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None; + TryTraitBranch, sym::branch, branch_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None; + + PollReady, sym::Ready, poll_ready_variant, Target::Variant, GenericRequirement::None; + PollPending, sym::Pending, poll_pending_variant, Target::Variant, GenericRequirement::None; - PollReady, sym::Ready, poll_ready_variant, Target::Variant; - PollPending, sym::Pending, poll_pending_variant, Target::Variant; + FromGenerator, sym::from_generator, from_generator_fn, Target::Fn, GenericRequirement::None; + GetContext, sym::get_context, get_context_fn, Target::Fn, GenericRequirement::None; - FromGenerator, sym::from_generator, from_generator_fn, Target::Fn; - GetContext, sym::get_context, get_context_fn, Target::Fn; + FuturePoll, sym::poll, future_poll_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None; - FuturePoll, sym::poll, future_poll_fn, Target::Method(MethodKind::Trait { body: false }); + FromFrom, sym::from, from_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None; - FromFrom, sym::from, from_fn, Target::Method(MethodKind::Trait { body: false }); + OptionSome, sym::Some, option_some_variant, Target::Variant, GenericRequirement::None; + OptionNone, sym::None, option_none_variant, Target::Variant, GenericRequirement::None; - OptionSome, sym::Some, option_some_variant, Target::Variant; - OptionNone, sym::None, option_none_variant, Target::Variant; + ResultOk, sym::Ok, result_ok_variant, Target::Variant, GenericRequirement::None; + ResultErr, sym::Err, result_err_variant, Target::Variant, GenericRequirement::None; - ResultOk, sym::Ok, result_ok_variant, Target::Variant; - ResultErr, sym::Err, result_err_variant, Target::Variant; + ControlFlowContinue, sym::Continue, cf_continue_variant, Target::Variant, GenericRequirement::None; + ControlFlowBreak, sym::Break, cf_break_variant, Target::Variant, GenericRequirement::None; - ControlFlowContinue, sym::Continue, cf_continue_variant, Target::Variant; - ControlFlowBreak, sym::Break, cf_break_variant, Target::Variant; + IntoIterIntoIter, sym::into_iter, into_iter_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None; + IteratorNext, sym::next, next_fn, Target::Method(MethodKind::Trait { body: false}), GenericRequirement::None; - IntoIterIntoIter, sym::into_iter, into_iter_fn, Target::Method(MethodKind::Trait { body: false }); - IteratorNext, sym::next, next_fn, Target::Method(MethodKind::Trait { body: false}); + PinNewUnchecked, sym::new_unchecked, new_unchecked_fn, Target::Method(MethodKind::Inherent), GenericRequirement::None; - PinNewUnchecked, sym::new_unchecked, new_unchecked_fn, Target::Method(MethodKind::Inherent); + RangeFrom, sym::RangeFrom, range_from_struct, Target::Struct, GenericRequirement::None; + RangeFull, sym::RangeFull, range_full_struct, Target::Struct, GenericRequirement::None; + RangeInclusiveStruct, sym::RangeInclusive, range_inclusive_struct, Target::Struct, GenericRequirement::None; + RangeInclusiveNew, sym::range_inclusive_new, range_inclusive_new_method, Target::Method(MethodKind::Inherent), GenericRequirement::None; + Range, sym::Range, range_struct, Target::Struct, GenericRequirement::None; + RangeToInclusive, sym::RangeToInclusive, range_to_inclusive_struct, Target::Struct, GenericRequirement::None; + RangeTo, sym::RangeTo, range_to_struct, Target::Struct, GenericRequirement::None; +} - RangeFrom, sym::RangeFrom, range_from_struct, Target::Struct; - RangeFull, sym::RangeFull, range_full_struct, Target::Struct; - RangeInclusiveStruct, sym::RangeInclusive, range_inclusive_struct, Target::Struct; - RangeInclusiveNew, sym::range_inclusive_new, range_inclusive_new_method, Target::Method(MethodKind::Inherent); - Range, sym::Range, range_struct, Target::Struct; - RangeToInclusive, sym::RangeToInclusive, range_to_inclusive_struct, Target::Struct; - RangeTo, sym::RangeTo, range_to_struct, Target::Struct; +pub enum GenericRequirement { + None, + Minimum(usize), + Exact(usize), } diff --git a/compiler/rustc_passes/src/lang_items.rs b/compiler/rustc_passes/src/lang_items.rs index 62f9bcfdc4729..77ff8dc5b4aee 100644 --- a/compiler/rustc_passes/src/lang_items.rs +++ b/compiler/rustc_passes/src/lang_items.rs @@ -18,7 +18,7 @@ use rustc_errors::{pluralize, struct_span_err}; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_hir::itemlikevisit::ItemLikeVisitor; -use rustc_hir::lang_items::{extract, ITEM_REFS}; +use rustc_hir::lang_items::{extract, GenericRequirement, ITEM_REFS}; use rustc_hir::{HirId, LangItem, LanguageItems, Target}; use rustc_span::Span; @@ -183,97 +183,39 @@ impl LanguageItemCollector<'tcx> { } // Like collect_item() above, but also checks whether the lang item is declared - // with the right number of generic arguments if it is a trait. + // with the right number of generic arguments. fn collect_item_extended(&mut self, item_index: usize, hir_id: HirId, span: Span) { let item_def_id = self.tcx.hir().local_def_id(hir_id).to_def_id(); let lang_item = LangItem::from_u32(item_index as u32).unwrap(); let name = lang_item.name(); - self.collect_item(item_index, item_def_id); - // Now check whether the lang_item has the expected number of generic - // arguments if it is a trait. Generally speaking, binary and indexing - // operations have one (for the RHS/index), unary operations have none, - // and the rest also have none except for the closure traits (one for - // the argument list), generators (one for the resume argument), - // ordering/equality relations (one for the RHS), and various conversion - // traits. - - let expected_num = match lang_item { - // Binary operations - LangItem::Add - | LangItem::Sub - | LangItem::Mul - | LangItem::Div - | LangItem::Rem - | LangItem::BitXor - | LangItem::BitAnd - | LangItem::BitOr - | LangItem::Shl - | LangItem::Shr - | LangItem::AddAssign - | LangItem::SubAssign - | LangItem::MulAssign - | LangItem::DivAssign - | LangItem::RemAssign - | LangItem::BitXorAssign - | LangItem::BitAndAssign - | LangItem::BitOrAssign - | LangItem::ShlAssign - | LangItem::ShrAssign - | LangItem::Index - | LangItem::IndexMut - - // Miscellaneous - | LangItem::Unsize - | LangItem::CoerceUnsized - | LangItem::DispatchFromDyn - | LangItem::Fn - | LangItem::FnMut - | LangItem::FnOnce - | LangItem::Generator - | LangItem::PartialEq - | LangItem::PartialOrd - => Some(1), - - // Unary operations - LangItem::Neg - | LangItem::Not - - // Miscellaneous - | LangItem::Deref - | LangItem::DerefMut - | LangItem::Sized - | LangItem::StructuralPeq - | LangItem::StructuralTeq - | LangItem::Copy - | LangItem::Clone - | LangItem::Sync - | LangItem::DiscriminantKind - | LangItem::PointeeTrait - | LangItem::Freeze - | LangItem::Drop - | LangItem::Receiver - | LangItem::Future - | LangItem::Unpin - | LangItem::Termination - | LangItem::Try - => Some(0), + // arguments. Generally speaking, binary and indexing operations have + // one (for the RHS/index), unary operations have none, the closure + // traits have one for the argument list, generators have one for the + // resume argument, and ordering/equality relations have one for the RHS + // Some other types like Box and various functions like drop_in_place + // have minimum requirements. - // Not a trait - _ => None, - }; + if let hir::Node::Item(hir::Item { kind, span: item_span, .. }) = self.tcx.hir().get(hir_id) + { + let (actual_num, generics_span) = match kind.generics() { + Some(generics) => (generics.params.len(), generics.span), + None => (0, *item_span), + }; - if let Some(expected_num) = expected_num { - let (actual_num, generics_span) = match self.tcx.hir().get(hir_id) { - hir::Node::Item(hir::Item { - kind: hir::ItemKind::Trait(_, _, generics, ..), - .. - }) => (generics.params.len(), generics.span), - _ => bug!("op/index/deref lang item target is not a trait: {:?}", lang_item), + let required = match lang_item.required_generics() { + GenericRequirement::Exact(num) if num != actual_num => { + Some((format!("{}", num), pluralize!(num))) + } + GenericRequirement::Minimum(num) if actual_num < num => { + Some((format!("at least {}", num), pluralize!(num))) + } + // If the number matches, or there is no requirement, handle it normally + _ => None, }; - if expected_num != actual_num { + if let Some((range_str, pluralized)) = required { // We are issuing E0718 "incorrect target" here, because while the // item kind of the target is correct, the target is still wrong // because of the wrong number of generic arguments. @@ -281,23 +223,29 @@ impl LanguageItemCollector<'tcx> { self.tcx.sess, span, E0718, - "`{}` language item must be applied to a trait with {} generic argument{}", + "`{}` language item must be applied to a {} with {} generic argument{}", name, - expected_num, - pluralize!(expected_num) + kind.descr(), + range_str, + pluralized, ) .span_label( generics_span, format!( - "this trait has {} generic argument{}, not {}", + "this {} has {} generic argument{}", + kind.descr(), actual_num, pluralize!(actual_num), - expected_num ), ) .emit(); + + // return early to not collect the lang item + return; } } + + self.collect_item(item_index, item_def_id); } } diff --git a/src/test/ui/error-codes/E0152.rs b/src/test/ui/error-codes/E0152.rs index d716ca1a14fdf..ee8e5e6dffee3 100644 --- a/src/test/ui/error-codes/E0152.rs +++ b/src/test/ui/error-codes/E0152.rs @@ -2,7 +2,7 @@ #![feature(lang_items)] #[lang = "owned_box"] -struct Foo; //~ ERROR E0152 +struct Foo(T); //~ ERROR E0152 fn main() { } diff --git a/src/test/ui/error-codes/E0152.stderr b/src/test/ui/error-codes/E0152.stderr index 7445c2880af1c..5cdfe1cc5562d 100644 --- a/src/test/ui/error-codes/E0152.stderr +++ b/src/test/ui/error-codes/E0152.stderr @@ -1,8 +1,8 @@ error[E0152]: found duplicate lang item `owned_box` --> $DIR/E0152.rs:5:1 | -LL | struct Foo; - | ^^^^^^^^^^^ +LL | struct Foo(T); + | ^^^^^^^^^^^^^^^^^ | = note: the lang item is first defined in crate `alloc` (which `std` depends on) = note: first definition in `alloc` loaded from SYSROOT/liballoc-*.rlib diff --git a/src/test/ui/lang-items/lang-item-correct-generics.rs b/src/test/ui/lang-items/lang-item-correct-generics.rs new file mode 100644 index 0000000000000..a3287db74e733 --- /dev/null +++ b/src/test/ui/lang-items/lang-item-correct-generics.rs @@ -0,0 +1,28 @@ +// build-pass + +#![feature(lang_items,no_core)] +#![no_core] +#![crate_type="lib"] + +#[lang = "sized"] +trait MySized {} + +#[lang = "copy"] +trait MyCopy {} + +#[lang = "drop"] +trait MyDrop {} + +struct S; + +impl MyDrop for S {} + +#[lang = "i32"] +impl<'a> i32 { + fn foo() {} +} + +fn bar() { + i32::foo(); + S; +} diff --git a/src/test/ui/lang-items/lang-item-generic-requirements.rs b/src/test/ui/lang-items/lang-item-generic-requirements.rs new file mode 100644 index 0000000000000..d785749afc9c2 --- /dev/null +++ b/src/test/ui/lang-items/lang-item-generic-requirements.rs @@ -0,0 +1,44 @@ +// Checks whether declaring a lang item with the wrong number +// of generic arguments crashes the compiler (issue #83893, #87573, and part of #9307). + +#![feature(lang_items, no_core)] +#![no_core] +#![crate_type = "lib"] + +#[lang = "sized"] +trait MySized {} + +#[lang = "add"] +trait MyAdd<'a, T> {} +//~^^ ERROR: `add` language item must be applied to a trait with 1 generic argument [E0718] + +#[lang = "drop_in_place"] +//~^ ERROR `drop_in_place` language item must be applied to a function with at least 1 generic +fn my_ptr_drop() {} + +#[lang = "index"] +trait MyIndex<'a, T> {} +//~^^ ERROR: `index` language item must be applied to a trait with 1 generic argument [E0718] + +#[lang = "phantom_data"] +//~^ ERROR `phantom_data` language item must be applied to a struct with 1 generic argument +struct MyPhantomData; +//~^ ERROR parameter `T` is never used +//~| ERROR parameter `U` is never used + +fn ice() { + // Use add + let r = 5; + let a = 6; + r + a; + + // Use drop in place + my_ptr_drop(); + + // Use index + let arr = [0; 5]; + let _ = arr[2]; + + // Use phantomdata + let _ = MyPhantomData::<(), i32>; +} diff --git a/src/test/ui/lang-items/lang-item-generic-requirements.stderr b/src/test/ui/lang-items/lang-item-generic-requirements.stderr new file mode 100644 index 0000000000000..add5938811c28 --- /dev/null +++ b/src/test/ui/lang-items/lang-item-generic-requirements.stderr @@ -0,0 +1,56 @@ +error[E0718]: `add` language item must be applied to a trait with 1 generic argument + --> $DIR/lang-item-generic-requirements.rs:11:1 + | +LL | #[lang = "add"] + | ^^^^^^^^^^^^^^^ +LL | trait MyAdd<'a, T> {} + | ------- this trait has 2 generic arguments + +error[E0718]: `drop_in_place` language item must be applied to a function with at least 1 generic argument + --> $DIR/lang-item-generic-requirements.rs:15:1 + | +LL | #[lang = "drop_in_place"] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | +LL | fn my_ptr_drop() {} + | - this function has 0 generic arguments + +error[E0718]: `index` language item must be applied to a trait with 1 generic argument + --> $DIR/lang-item-generic-requirements.rs:19:1 + | +LL | #[lang = "index"] + | ^^^^^^^^^^^^^^^^^ +LL | trait MyIndex<'a, T> {} + | ------- this trait has 2 generic arguments + +error[E0718]: `phantom_data` language item must be applied to a struct with 1 generic argument + --> $DIR/lang-item-generic-requirements.rs:23:1 + | +LL | #[lang = "phantom_data"] + | ^^^^^^^^^^^^^^^^^^^^^^^^ +LL | +LL | struct MyPhantomData; + | ------ this struct has 2 generic arguments + +error[E0392]: parameter `T` is never used + --> $DIR/lang-item-generic-requirements.rs:25:22 + | +LL | struct MyPhantomData; + | ^ unused parameter + | + = help: consider removing `T` or referring to it in a field + = help: if you intended `T` to be a const parameter, use `const T: usize` instead + +error[E0392]: parameter `U` is never used + --> $DIR/lang-item-generic-requirements.rs:25:25 + | +LL | struct MyPhantomData; + | ^ unused parameter + | + = help: consider removing `U` or referring to it in a field + = help: if you intended `U` to be a const parameter, use `const U: usize` instead + +error: aborting due to 6 previous errors + +Some errors have detailed explanations: E0392, E0718. +For more information about an error, try `rustc --explain E0392`. diff --git a/src/test/ui/lang-items/wrong-number-generic-args-add.rs b/src/test/ui/lang-items/wrong-number-generic-args-add.rs deleted file mode 100644 index 9f4f2464a1e65..0000000000000 --- a/src/test/ui/lang-items/wrong-number-generic-args-add.rs +++ /dev/null @@ -1,20 +0,0 @@ -// Checks whether declaring a lang item with the wrong number -// of generic arguments crashes the compiler (issue #83893). - -#![feature(lang_items,no_core)] -#![no_core] -#![crate_type="lib"] - -#[lang = "sized"] -trait MySized {} - -#[lang = "add"] -trait MyAdd<'a, T> {} -//~^^ ERROR: `add` language item must be applied to a trait with 1 generic argument [E0718] - -fn ice() { - let r = 5; - let a = 6; - r + a - //~^ ERROR: cannot add `{integer}` to `{integer}` [E0369] -} diff --git a/src/test/ui/lang-items/wrong-number-generic-args-add.stderr b/src/test/ui/lang-items/wrong-number-generic-args-add.stderr deleted file mode 100644 index 6f89441fd285d..0000000000000 --- a/src/test/ui/lang-items/wrong-number-generic-args-add.stderr +++ /dev/null @@ -1,20 +0,0 @@ -error[E0718]: `add` language item must be applied to a trait with 1 generic argument - --> $DIR/wrong-number-generic-args-add.rs:11:1 - | -LL | #[lang = "add"] - | ^^^^^^^^^^^^^^^ -LL | trait MyAdd<'a, T> {} - | ------- this trait has 2 generic arguments, not 1 - -error[E0369]: cannot add `{integer}` to `{integer}` - --> $DIR/wrong-number-generic-args-add.rs:18:7 - | -LL | r + a - | - ^ - {integer} - | | - | {integer} - -error: aborting due to 2 previous errors - -Some errors have detailed explanations: E0369, E0718. -For more information about an error, try `rustc --explain E0369`. diff --git a/src/test/ui/lang-items/wrong-number-generic-args-index.rs b/src/test/ui/lang-items/wrong-number-generic-args-index.rs deleted file mode 100644 index 1d90e63dc5470..0000000000000 --- a/src/test/ui/lang-items/wrong-number-generic-args-index.rs +++ /dev/null @@ -1,19 +0,0 @@ -// Checks whether declaring a lang item with the wrong number -// of generic arguments crashes the compiler (issue #83893). - -#![feature(lang_items,no_core)] -#![no_core] -#![crate_type="lib"] - -#[lang = "sized"] -trait MySized {} - -#[lang = "index"] -trait MyIndex<'a, T> {} -//~^^ ERROR: `index` language item must be applied to a trait with 1 generic argument [E0718] - -fn ice() { - let arr = [0; 5]; - let _ = arr[2]; - //~^ ERROR: cannot index into a value of type `[{integer}; 5]` [E0608] -} diff --git a/src/test/ui/lang-items/wrong-number-generic-args-index.stderr b/src/test/ui/lang-items/wrong-number-generic-args-index.stderr deleted file mode 100644 index bc3f19ff27623..0000000000000 --- a/src/test/ui/lang-items/wrong-number-generic-args-index.stderr +++ /dev/null @@ -1,18 +0,0 @@ -error[E0718]: `index` language item must be applied to a trait with 1 generic argument - --> $DIR/wrong-number-generic-args-index.rs:11:1 - | -LL | #[lang = "index"] - | ^^^^^^^^^^^^^^^^^ -LL | trait MyIndex<'a, T> {} - | ------- this trait has 2 generic arguments, not 1 - -error[E0608]: cannot index into a value of type `[{integer}; 5]` - --> $DIR/wrong-number-generic-args-index.rs:17:13 - | -LL | let _ = arr[2]; - | ^^^^^^ - -error: aborting due to 2 previous errors - -Some errors have detailed explanations: E0608, E0718. -For more information about an error, try `rustc --explain E0608`.