From 0336dd132b50af57389aa222793aff3c38b88daf Mon Sep 17 00:00:00 2001 From: Nilstrieb <48135649+Nilstrieb@users.noreply.github.com> Date: Tue, 16 May 2023 19:40:02 +0200 Subject: [PATCH] Add derive for `core::marker::ConstParamTy` This makes it easier to implement it for a type, just like `Copy`. --- .../src/deriving/bounds.rs | 23 +++++++++++++ compiler/rustc_builtin_macros/src/lib.rs | 1 + compiler/rustc_span/src/symbol.rs | 1 + library/core/src/marker.rs | 8 +++++ .../adt_const_params/const_param_ty_good.rs | 10 ++++++ .../const_param_ty_impl_bad_field.rs | 4 +++ .../const_param_ty_impl_bad_field.stderr | 13 +++++++- .../const_param_ty_impl_no_structural_eq.rs | 4 +++ ...onst_param_ty_impl_no_structural_eq.stderr | 12 ++++++- .../const_param_ty_impl_union.rs | 33 +++++++++++++++++++ .../const_param_ty_impl_union.stderr | 8 +++++ 11 files changed, 115 insertions(+), 2 deletions(-) create mode 100644 tests/ui/const-generics/adt_const_params/const_param_ty_impl_union.rs create mode 100644 tests/ui/const-generics/adt_const_params/const_param_ty_impl_union.stderr diff --git a/compiler/rustc_builtin_macros/src/deriving/bounds.rs b/compiler/rustc_builtin_macros/src/deriving/bounds.rs index 0481a118906..2c8e6f99c67 100644 --- a/compiler/rustc_builtin_macros/src/deriving/bounds.rs +++ b/compiler/rustc_builtin_macros/src/deriving/bounds.rs @@ -27,3 +27,26 @@ pub fn expand_deriving_copy( trait_def.expand(cx, mitem, item, push); } + +pub fn expand_deriving_const_param_ty( + cx: &mut ExtCtxt<'_>, + span: Span, + mitem: &MetaItem, + item: &Annotatable, + push: &mut dyn FnMut(Annotatable), + is_const: bool, +) { + let trait_def = TraitDef { + span, + path: path_std!(marker::ConstParamTy), + skip_path_as_bound: false, + needs_copy_as_bound_if_packed: false, + additional_bounds: Vec::new(), + supports_unions: false, + methods: Vec::new(), + associated_types: Vec::new(), + is_const, + }; + + trait_def.expand(cx, mitem, item, push); +} diff --git a/compiler/rustc_builtin_macros/src/lib.rs b/compiler/rustc_builtin_macros/src/lib.rs index 4e5edb4d6b1..ebf1448f55c 100644 --- a/compiler/rustc_builtin_macros/src/lib.rs +++ b/compiler/rustc_builtin_macros/src/lib.rs @@ -115,6 +115,7 @@ pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand) { register_derive! { Clone: clone::expand_deriving_clone, Copy: bounds::expand_deriving_copy, + ConstParamTy: bounds::expand_deriving_const_param_ty, Debug: debug::expand_deriving_debug, Default: default::expand_deriving_default, Eq: eq::expand_deriving_eq, diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 60efcb768cb..b3e54b10900 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -164,6 +164,7 @@ symbols! { Capture, Center, Clone, + ConstParamTy, Context, Continue, Copy, diff --git a/library/core/src/marker.rs b/library/core/src/marker.rs index 97f9d01e016..ede0e5db50c 100644 --- a/library/core/src/marker.rs +++ b/library/core/src/marker.rs @@ -991,6 +991,14 @@ pub trait PointerLike {} #[rustc_on_unimplemented(message = "`{Self}` can't be used as a const parameter type")] pub trait ConstParamTy: StructuralEq {} +/// Derive macro generating an impl of the trait `Copy`. +#[rustc_builtin_macro] +#[unstable(feature = "adt_const_params", issue = "95174")] +#[cfg(not(bootstrap))] +pub macro ConstParamTy($item:item) { + /* compiler built-in */ +} + // FIXME(generic_const_parameter_types): handle `ty::FnDef`/`ty::Closure` // FIXME(generic_const_parameter_types): handle `ty::Tuple` marker_impls! { diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_good.rs b/tests/ui/const-generics/adt_const_params/const_param_ty_good.rs index a1b711a3024..87ae83dd966 100644 --- a/tests/ui/const-generics/adt_const_params/const_param_ty_good.rs +++ b/tests/ui/const-generics/adt_const_params/const_param_ty_good.rs @@ -11,6 +11,13 @@ struct S { impl ConstParamTy for S {} +#[derive(PartialEq, Eq, ConstParamTy)] +struct D { + field: u8, + gen: T, +} + + fn check() {} fn main() { @@ -39,5 +46,8 @@ fn main() { check::>(); check::>(); + check::>(); + check::>(); + // FIXME: test tuples } diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_bad_field.rs b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_bad_field.rs index 07fd243737e..74283a37afc 100644 --- a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_bad_field.rs +++ b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_bad_field.rs @@ -10,4 +10,8 @@ struct CantParam(NotParam); impl std::marker::ConstParamTy for CantParam {} //~^ error: the trait `ConstParamTy` cannot be implemented for this type +#[derive(std::marker::ConstParamTy, Eq, PartialEq)] +//~^ error: the trait `ConstParamTy` cannot be implemented for this type +struct CantParamDerive(NotParam); + fn main() {} diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_bad_field.stderr b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_bad_field.stderr index c8e065848b1..52b65d6061a 100644 --- a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_bad_field.stderr +++ b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_bad_field.stderr @@ -7,6 +7,17 @@ LL | LL | impl std::marker::ConstParamTy for CantParam {} | ^^^^^^^^^ -error: aborting due to previous error +error[E0204]: the trait `ConstParamTy` cannot be implemented for this type + --> $DIR/const_param_ty_impl_bad_field.rs:13:10 + | +LL | #[derive(std::marker::ConstParamTy, Eq, PartialEq)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | +LL | struct CantParamDerive(NotParam); + | -------- this field does not implement `ConstParamTy` + | + = note: this error originates in the derive macro `std::marker::ConstParamTy` (in Nightly builds, run with -Z macro-backtrace for more info) + +error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0204`. diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_no_structural_eq.rs b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_no_structural_eq.rs index 17ef396164e..37986de481f 100644 --- a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_no_structural_eq.rs +++ b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_no_structural_eq.rs @@ -10,6 +10,10 @@ struct CantParam(ImplementsConstParamTy); impl std::marker::ConstParamTy for CantParam {} //~^ error: the type `CantParam` does not `#[derive(Eq)]` +#[derive(std::marker::ConstParamTy)] +//~^ error: the type `CantParamDerive` does not `#[derive(Eq)]` +struct CantParamDerive(ImplementsConstParamTy); + fn check() {} fn main() { diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_no_structural_eq.stderr b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_no_structural_eq.stderr index ca5abf5e254..52701d55914 100644 --- a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_no_structural_eq.stderr +++ b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_no_structural_eq.stderr @@ -7,6 +7,16 @@ LL | impl std::marker::ConstParamTy for CantParam {} note: required by a bound in `ConstParamTy` --> $SRC_DIR/core/src/marker.rs:LL:COL -error: aborting due to previous error +error[E0277]: the type `CantParamDerive` does not `#[derive(Eq)]` + --> $DIR/const_param_ty_impl_no_structural_eq.rs:13:10 + | +LL | #[derive(std::marker::ConstParamTy)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `StructuralEq` is not implemented for `CantParamDerive` + | +note: required by a bound in `ConstParamTy` + --> $SRC_DIR/core/src/marker.rs:LL:COL + = note: this error originates in the derive macro `std::marker::ConstParamTy` (in Nightly builds, run with -Z macro-backtrace for more info) + +error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_union.rs b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_union.rs new file mode 100644 index 00000000000..d70377a20c1 --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_union.rs @@ -0,0 +1,33 @@ +#![allow(incomplete_features)] +#![feature(adt_const_params, structural_match)] + +union Union { + a: u8, +} + +impl PartialEq for Union { + fn eq(&self, other: &Union) -> bool { + true + } +} +impl Eq for Union {} +impl std::marker::StructuralEq for Union {} + +impl std::marker::ConstParamTy for Union {} + +#[derive(std::marker::ConstParamTy)] +//~^ ERROR this trait cannot be derived for unions +union UnionDerive { + a: u8, +} + +impl PartialEq for UnionDerive { + fn eq(&self, other: &UnionDerive) -> bool { + true + } +} +impl Eq for UnionDerive {} +impl std::marker::StructuralEq for UnionDerive {} + + +fn main() {} diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_impl_union.stderr b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_union.stderr new file mode 100644 index 00000000000..29370304605 --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/const_param_ty_impl_union.stderr @@ -0,0 +1,8 @@ +error: this trait cannot be derived for unions + --> $DIR/const_param_ty_impl_union.rs:18:10 + | +LL | #[derive(std::marker::ConstParamTy)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to previous error +