diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index d2eb7a52f78a0..d6a80e22602dc 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -1773,6 +1773,22 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { { span_mirbug!(self, constant, "bad static type {:?} ({:?})", constant, terr); } + } else if let Const::Ty(_, ct) = constant.const_ + && let ty::ConstKind::Param(p) = ct.kind() + { + let body_def_id = self.universal_regions.defining_ty.def_id(); + let const_param = tcx.generics_of(body_def_id).const_param(p, tcx); + self.ascribe_user_type( + constant.const_.ty(), + ty::UserType::new(ty::UserTypeKind::TypeOf( + const_param.def_id, + UserArgs { + args: self.universal_regions.defining_ty.args(), + user_self_ty: None, + }, + )), + locations.span(self.body), + ); } if let ty::FnDef(def_id, args) = *constant.const_.ty().kind() { diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs index cfac9b36832fd..994a5ad32b308 100644 --- a/compiler/rustc_borrowck/src/universal_regions.rs +++ b/compiler/rustc_borrowck/src/universal_regions.rs @@ -184,6 +184,20 @@ impl<'tcx> DefiningTy<'tcx> { | DefiningTy::GlobalAsm(def_id) => def_id, } } + + /// Returns the args of the `DefiningTy`. These are equivalent to the identity + /// substs of the body, but replaced with region vids. + pub(crate) fn args(&self) -> ty::GenericArgsRef<'tcx> { + match *self { + DefiningTy::Closure(_, args) + | DefiningTy::Coroutine(_, args) + | DefiningTy::CoroutineClosure(_, args) + | DefiningTy::FnDef(_, args) + | DefiningTy::Const(_, args) + | DefiningTy::InlineConst(_, args) => args, + DefiningTy::GlobalAsm(_) => ty::List::empty(), + } + } } #[derive(Debug)] diff --git a/tests/ui/const-generics/adt_const_params/check-type-in-mir.rs b/tests/ui/const-generics/adt_const_params/check-type-in-mir.rs new file mode 100644 index 0000000000000..bec485b001c04 --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/check-type-in-mir.rs @@ -0,0 +1,16 @@ +// Ensure that we actually treat `N`'s type as `Invariant<'static>` in MIR typeck. + +#![feature(adt_const_params)] + +use std::marker::ConstParamTy; +use std::ops::Deref; + +#[derive(ConstParamTy, PartialEq, Eq)] +struct Invariant<'a>(<&'a () as Deref>::Target); + +fn test<'a, const N: Invariant<'static>>() { + let x: Invariant<'a> = N; + //~^ ERROR lifetime may not live long enough +} + +fn main() {} diff --git a/tests/ui/const-generics/adt_const_params/check-type-in-mir.stderr b/tests/ui/const-generics/adt_const_params/check-type-in-mir.stderr new file mode 100644 index 0000000000000..7e265f33f35bd --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/check-type-in-mir.stderr @@ -0,0 +1,14 @@ +error: lifetime may not live long enough + --> $DIR/check-type-in-mir.rs:12:28 + | +LL | fn test<'a, const N: Invariant<'static>>() { + | -- lifetime `'a` defined here +LL | let x: Invariant<'a> = N; + | ^ assignment requires that `'a` must outlive `'static` + | + = note: requirement occurs because of the type `Invariant<'_>`, which makes the generic argument `'_` invariant + = note: the struct `Invariant<'a>` is invariant over the parameter `'a` + = help: see for more information about variance + +error: aborting due to 1 previous error + diff --git a/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.rs b/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.rs new file mode 100644 index 0000000000000..d3bc544ed6c58 --- /dev/null +++ b/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.rs @@ -0,0 +1,12 @@ +// Ensure that we actually treat `N`'s type as `&'a u32` in MIR typeck. + +#![feature(unsized_const_params, adt_const_params, generic_const_parameter_types)] +//~^ WARN the feature `unsized_const_params` is incomplete +//~| WARN the feature `generic_const_parameter_types` is incomplete + +fn foo<'a, const N: &'a u32>() { + let b: &'static u32 = N; + //~^ ERROR lifetime may not live long enough +} + +fn main() {} diff --git a/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.stderr b/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.stderr new file mode 100644 index 0000000000000..3dc7ce438fa93 --- /dev/null +++ b/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.stderr @@ -0,0 +1,27 @@ +warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes + --> $DIR/check-type-in-mir.rs:3:12 + | +LL | #![feature(unsized_const_params, adt_const_params, generic_const_parameter_types)] + | ^^^^^^^^^^^^^^^^^^^^ + | + = note: see issue #95174 for more information + = note: `#[warn(incomplete_features)]` on by default + +warning: the feature `generic_const_parameter_types` is incomplete and may not be safe to use and/or cause compiler crashes + --> $DIR/check-type-in-mir.rs:3:52 + | +LL | #![feature(unsized_const_params, adt_const_params, generic_const_parameter_types)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: see issue #137626 for more information + +error: lifetime may not live long enough + --> $DIR/check-type-in-mir.rs:8:12 + | +LL | fn foo<'a, const N: &'a u32>() { + | -- lifetime `'a` defined here +LL | let b: &'static u32 = N; + | ^^^^^^^^^^^^ type annotation requires that `'a` must outlive `'static` + +error: aborting due to 1 previous error; 2 warnings emitted +