From 2743df848b0970ad9d97b6ce8222d4fd64898b61 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Sun, 12 Jan 2025 20:52:30 +0000
Subject: [PATCH] Enforce syntactical stability of const traits in HIR
---
compiler/rustc_middle/src/middle/stability.rs | 89 ++++++++++++++++++-
compiler/rustc_passes/src/stability.rs | 36 +++++++-
compiler/rustc_resolve/src/macros.rs | 1 +
library/core/src/intrinsics/fallback.rs | 1 +
library/core/src/marker.rs | 1 +
library/core/src/ops/arith.rs | 1 +
library/core/src/ops/deref.rs | 2 +
library/core/src/ops/drop.rs | 1 +
tests/ui/consts/promoted-const-drop.rs | 2 +-
tests/ui/consts/promoted_const_call.rs | 16 ++--
tests/ui/consts/promoted_const_call.stderr | 39 ++++----
.../missing-const-stability.rs | 1 +
.../missing-const-stability.stderr | 14 ++-
.../const-traits/auxiliary/staged-api.rs | 1 +
.../call-const-trait-method-pass.rs | 2 +-
.../const-traits/const-and-non-const-impl.rs | 2 +-
tests/ui/traits/const-traits/generic-bound.rs | 2 +-
.../const-traits/syntactical-unstable.rs | 34 +++++++
.../const-traits/syntactical-unstable.stderr | 67 ++++++++++++++
.../trait-default-body-stability.rs | 1 +
.../trait-default-body-stability.stderr | 4 +-
21 files changed, 279 insertions(+), 38 deletions(-)
create mode 100644 tests/ui/traits/const-traits/syntactical-unstable.rs
create mode 100644 tests/ui/traits/const-traits/syntactical-unstable.stderr
diff --git a/compiler/rustc_middle/src/middle/stability.rs b/compiler/rustc_middle/src/middle/stability.rs
index 84c3c2eb49e..75ca289056e 100644
--- a/compiler/rustc_middle/src/middle/stability.rs
+++ b/compiler/rustc_middle/src/middle/stability.rs
@@ -30,6 +30,14 @@ pub enum StabilityLevel {
Stable,
}
+#[derive(Copy, Clone)]
+pub enum UnstableKind {
+ /// Enforcing regular stability of an item
+ Regular,
+ /// Enforcing const stability of an item
+ Const(Span),
+}
+
/// An entry in the `depr_map`.
#[derive(Copy, Clone, HashStable, Debug, Encodable, Decodable)]
pub struct DeprecationEntry {
@@ -108,10 +116,16 @@ pub fn report_unstable(
is_soft: bool,
span: Span,
soft_handler: impl FnOnce(&'static Lint, Span, String),
+ kind: UnstableKind,
) {
+ let qual = match kind {
+ UnstableKind::Regular => "",
+ UnstableKind::Const(_) => " const",
+ };
+
let msg = match reason {
- Some(r) => format!("use of unstable library feature `{feature}`: {r}"),
- None => format!("use of unstable library feature `{feature}`"),
+ Some(r) => format!("use of unstable{qual} library feature `{feature}`: {r}"),
+ None => format!("use of unstable{qual} library feature `{feature}`"),
};
if is_soft {
@@ -121,6 +135,9 @@ pub fn report_unstable(
if let Some((inner_types, msg, sugg, applicability)) = suggestion {
err.span_suggestion(inner_types, msg, sugg, applicability);
}
+ if let UnstableKind::Const(kw) = kind {
+ err.span_label(kw, "trait is not stable as const yet");
+ }
err.emit();
}
}
@@ -587,6 +604,7 @@ impl<'tcx> TyCtxt<'tcx> {
is_soft,
span,
soft_handler,
+ UnstableKind::Regular,
),
EvalResult::Unmarked => unmarked(span, def_id),
}
@@ -594,6 +612,73 @@ impl<'tcx> TyCtxt<'tcx> {
is_allowed
}
+ /// This function is analogous to `check_optional_stability` but with the logic in
+ /// `eval_stability_allow_unstable` inlined, and which operating on const stability
+ /// instead of regular stability.
+ ///
+ /// This enforces *syntactical* const stability of const traits. In other words,
+ /// it enforces the ability to name `~const`/`const` traits in trait bounds in various
+ /// syntax positions in HIR (including in the trait of an impl header).
+ pub fn check_const_stability(self, def_id: DefId, span: Span, const_kw_span: Span) {
+ let is_staged_api = self.lookup_stability(def_id.krate.as_def_id()).is_some();
+ if !is_staged_api {
+ return;
+ }
+
+ // Only the cross-crate scenario matters when checking unstable APIs
+ let cross_crate = !def_id.is_local();
+ if !cross_crate {
+ return;
+ }
+
+ let stability = self.lookup_const_stability(def_id);
+ debug!(
+ "stability: \
+ inspecting def_id={:?} span={:?} of stability={:?}",
+ def_id, span, stability
+ );
+
+ match stability {
+ Some(ConstStability {
+ level: attr::StabilityLevel::Unstable { reason, issue, is_soft, implied_by, .. },
+ feature,
+ ..
+ }) => {
+ assert!(!is_soft);
+
+ if span.allows_unstable(feature) {
+ debug!("body stability: skipping span={:?} since it is internal", span);
+ return;
+ }
+ if self.features().enabled(feature) {
+ return;
+ }
+
+ // If this item was previously part of a now-stabilized feature which is still
+ // enabled (i.e. the user hasn't removed the attribute for the stabilized feature
+ // yet) then allow use of this item.
+ if let Some(implied_by) = implied_by
+ && self.features().enabled(implied_by)
+ {
+ return;
+ }
+
+ report_unstable(
+ self.sess,
+ feature,
+ reason.to_opt_reason(),
+ issue,
+ None,
+ false,
+ span,
+ |_, _, _| {},
+ UnstableKind::Const(const_kw_span),
+ );
+ }
+ Some(_) | None => {}
+ }
+ }
+
pub fn lookup_deprecation(self, id: DefId) -> Option<Deprecation> {
self.lookup_deprecation_entry(id).map(|depr| depr.attr)
}
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index 30f9e698521..aabc33b015e 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -593,9 +593,11 @@ impl<'tcx> MissingStabilityAnnotations<'tcx> {
}
fn check_missing_const_stability(&self, def_id: LocalDefId, span: Span) {
- let is_const = self.tcx.is_const_fn(def_id.to_def_id());
+ let is_const = self.tcx.is_const_fn(def_id.to_def_id())
+ || (self.tcx.def_kind(def_id.to_def_id()) == DefKind::Trait
+ && self.tcx.is_const_trait(def_id.to_def_id()));
- // Reachable const fn must have a stability attribute.
+ // Reachable const fn/trait must have a stability attribute.
if is_const
&& self.effective_visibilities.is_reachable(def_id)
&& self.tcx.lookup_const_stability(def_id).is_none()
@@ -772,7 +774,13 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
// For implementations of traits, check the stability of each item
// individually as it's possible to have a stable trait with unstable
// items.
- hir::ItemKind::Impl(hir::Impl { of_trait: Some(ref t), self_ty, items, .. }) => {
+ hir::ItemKind::Impl(hir::Impl {
+ of_trait: Some(ref t),
+ self_ty,
+ items,
+ constness,
+ ..
+ }) => {
let features = self.tcx.features();
if features.staged_api() {
let attrs = self.tcx.hir().attrs(item.hir_id());
@@ -814,6 +822,16 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
}
}
+ match constness {
+ rustc_hir::Constness::Const => {
+ if let Some(def_id) = t.trait_def_id() {
+ // FIXME(const_trait_impl): Improve the span here.
+ self.tcx.check_const_stability(def_id, t.path.span, t.path.span);
+ }
+ }
+ rustc_hir::Constness::NotConst => {}
+ }
+
for impl_item_ref in *items {
let impl_item = self.tcx.associated_item(impl_item_ref.id.owner_id);
@@ -829,6 +847,18 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
intravisit::walk_item(self, item);
}
+ fn visit_poly_trait_ref(&mut self, t: &'tcx hir::PolyTraitRef<'tcx>) {
+ match t.modifiers.constness {
+ hir::BoundConstness::Always(span) | hir::BoundConstness::Maybe(span) => {
+ if let Some(def_id) = t.trait_ref.trait_def_id() {
+ self.tcx.check_const_stability(def_id, t.trait_ref.path.span, span);
+ }
+ }
+ hir::BoundConstness::Never => {}
+ }
+ intravisit::walk_poly_trait_ref(self, t);
+ }
+
fn visit_path(&mut self, path: &hir::Path<'tcx>, id: hir::HirId) {
if let Some(def_id) = path.res.opt_def_id() {
let method_span = path.segments.last().map(|s| s.ident.span);
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index b24e343c58d..25e35fead7e 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -1031,6 +1031,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
is_soft,
span,
soft_handler,
+ stability::UnstableKind::Regular,
);
}
}
diff --git a/library/core/src/intrinsics/fallback.rs b/library/core/src/intrinsics/fallback.rs
index 1779126b180..70484e4d0f2 100644
--- a/library/core/src/intrinsics/fallback.rs
+++ b/library/core/src/intrinsics/fallback.rs
@@ -8,6 +8,7 @@
#![allow(missing_docs)]
#[const_trait]
+#[rustc_const_unstable(feature = "core_intrinsics_fallbacks", issue = "none")]
pub trait CarryingMulAdd: Copy + 'static {
type Unsigned: Copy + 'static;
fn carrying_mul_add(
diff --git a/library/core/src/marker.rs b/library/core/src/marker.rs
index 4af9b666e54..01af964a83e 100644
--- a/library/core/src/marker.rs
+++ b/library/core/src/marker.rs
@@ -952,6 +952,7 @@ marker_impls! {
/// This should be used for `~const` bounds,
/// as non-const bounds will always hold for every type.
#[unstable(feature = "const_destruct", issue = "133214")]
+#[rustc_const_unstable(feature = "const_destruct", issue = "133214")]
#[lang = "destruct"]
#[rustc_on_unimplemented(message = "can't drop `{Self}`", append_const_msg)]
#[rustc_deny_explicit_impl]
diff --git a/library/core/src/ops/arith.rs b/library/core/src/ops/arith.rs
index 810b906b871..fe7ff2d9ede 100644
--- a/library/core/src/ops/arith.rs
+++ b/library/core/src/ops/arith.rs
@@ -65,6 +65,7 @@
/// ```
#[lang = "add"]
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
#[rustc_on_unimplemented(
on(all(_Self = "{integer}", Rhs = "{float}"), message = "cannot add a float to an integer",),
on(all(_Self = "{float}", Rhs = "{integer}"), message = "cannot add an integer to a float",),
diff --git a/library/core/src/ops/deref.rs b/library/core/src/ops/deref.rs
index ed0d30a0f50..11490ea2bfc 100644
--- a/library/core/src/ops/deref.rs
+++ b/library/core/src/ops/deref.rs
@@ -134,6 +134,7 @@
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_diagnostic_item = "Deref"]
#[const_trait]
+#[rustc_const_unstable(feature = "const_deref", issue = "88955")]
pub trait Deref {
/// The resulting type after dereferencing.
#[stable(feature = "rust1", since = "1.0.0")]
@@ -263,6 +264,7 @@ impl<T: ?Sized> const Deref for &mut T {
#[doc(alias = "*")]
#[stable(feature = "rust1", since = "1.0.0")]
#[const_trait]
+#[rustc_const_unstable(feature = "const_deref", issue = "88955")]
pub trait DerefMut: ~const Deref {
/// Mutably dereferences the value.
#[stable(feature = "rust1", since = "1.0.0")]
diff --git a/library/core/src/ops/drop.rs b/library/core/src/ops/drop.rs
index 78b5252195f..e024b7fb4d3 100644
--- a/library/core/src/ops/drop.rs
+++ b/library/core/src/ops/drop.rs
@@ -204,6 +204,7 @@
#[lang = "drop"]
#[stable(feature = "rust1", since = "1.0.0")]
#[const_trait]
+#[rustc_const_unstable(feature = "const_destruct", issue = "133214")]
pub trait Drop {
/// Executes the destructor for this type.
///
diff --git a/tests/ui/consts/promoted-const-drop.rs b/tests/ui/consts/promoted-const-drop.rs
index e09c30ea785..1d1897e15d4 100644
--- a/tests/ui/consts/promoted-const-drop.rs
+++ b/tests/ui/consts/promoted-const-drop.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl)]
+#![feature(const_trait_impl, const_destruct)]
struct A();
diff --git a/tests/ui/consts/promoted_const_call.rs b/tests/ui/consts/promoted_const_call.rs
index c3920ff7241..79cb2ea2a02 100644
--- a/tests/ui/consts/promoted_const_call.rs
+++ b/tests/ui/consts/promoted_const_call.rs
@@ -1,6 +1,4 @@
-//@ known-bug: #103507
-
-#![feature(const_trait_impl)]
+#![feature(const_trait_impl, const_destruct)]
struct Panic;
impl const Drop for Panic { fn drop(&mut self) { panic!(); } }
@@ -8,15 +6,15 @@ impl const Drop for Panic { fn drop(&mut self) { panic!(); } }
pub const fn id<T>(x: T) -> T { x }
pub const C: () = {
let _: &'static _ = &id(&Panic);
- //FIXME ~^ ERROR: temporary value dropped while borrowed
- //FIXME ~| ERROR: temporary value dropped while borrowed
+ //~^ ERROR: temporary value dropped while borrowed
+ //~| ERROR: temporary value dropped while borrowed
};
fn main() {
let _: &'static _ = &id(&Panic);
- //FIXME ~^ ERROR: temporary value dropped while borrowed
- //FIXME ~| ERROR: temporary value dropped while borrowed
+ //~^ ERROR: temporary value dropped while borrowed
+ //~| ERROR: temporary value dropped while borrowed
let _: &'static _ = &&(Panic, 0).1;
- //FIXME~^ ERROR: temporary value dropped while borrowed
- //FIXME~| ERROR: temporary value dropped while borrowed
+ //~^ ERROR: temporary value dropped while borrowed
+ //~| ERROR: temporary value dropped while borrowed
}
diff --git a/tests/ui/consts/promoted_const_call.stderr b/tests/ui/consts/promoted_const_call.stderr
index 40c6d083b06..7a9cdd68704 100644
--- a/tests/ui/consts/promoted_const_call.stderr
+++ b/tests/ui/consts/promoted_const_call.stderr
@@ -1,17 +1,25 @@
-error[E0493]: destructor of `Panic` cannot be evaluated at compile-time
- --> $DIR/promoted_const_call.rs:10:30
+error[E0716]: temporary value dropped while borrowed
+ --> $DIR/promoted_const_call.rs:8:26
|
LL | let _: &'static _ = &id(&Panic);
- | ^^^^^ - value is dropped here
- | |
- | the destructor for this type cannot be evaluated in constants
- |
- = note: see issue #133214 <https://github.com/rust-lang/rust/issues/133214> for more information
- = help: add `#![feature(const_destruct)]` to the crate attributes to enable
- = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+ | ---------- ^^^^^^^^^^ creates a temporary value which is freed while still in use
+ | |
+ | type annotation requires that borrow lasts for `'static`
+...
+LL | };
+ | - temporary value is freed at the end of this statement
error[E0716]: temporary value dropped while borrowed
- --> $DIR/promoted_const_call.rs:16:26
+ --> $DIR/promoted_const_call.rs:8:30
+ |
+LL | let _: &'static _ = &id(&Panic);
+ | ---------- ^^^^^ - temporary value is freed at the end of this statement
+ | | |
+ | | creates a temporary value which is freed while still in use
+ | type annotation requires that borrow lasts for `'static`
+
+error[E0716]: temporary value dropped while borrowed
+ --> $DIR/promoted_const_call.rs:14:26
|
LL | let _: &'static _ = &id(&Panic);
| ---------- ^^^^^^^^^^ creates a temporary value which is freed while still in use
@@ -22,7 +30,7 @@ LL | }
| - temporary value is freed at the end of this statement
error[E0716]: temporary value dropped while borrowed
- --> $DIR/promoted_const_call.rs:16:30
+ --> $DIR/promoted_const_call.rs:14:30
|
LL | let _: &'static _ = &id(&Panic);
| ---------- ^^^^^ - temporary value is freed at the end of this statement
@@ -31,7 +39,7 @@ LL | let _: &'static _ = &id(&Panic);
| type annotation requires that borrow lasts for `'static`
error[E0716]: temporary value dropped while borrowed
- --> $DIR/promoted_const_call.rs:19:26
+ --> $DIR/promoted_const_call.rs:17:26
|
LL | let _: &'static _ = &&(Panic, 0).1;
| ---------- ^^^^^^^^^^^^^ creates a temporary value which is freed while still in use
@@ -42,7 +50,7 @@ LL | }
| - temporary value is freed at the end of this statement
error[E0716]: temporary value dropped while borrowed
- --> $DIR/promoted_const_call.rs:19:27
+ --> $DIR/promoted_const_call.rs:17:27
|
LL | let _: &'static _ = &&(Panic, 0).1;
| ---------- ^^^^^^^^^^ creates a temporary value which is freed while still in use
@@ -52,7 +60,6 @@ LL | let _: &'static _ = &&(Panic, 0).1;
LL | }
| - temporary value is freed at the end of this statement
-error: aborting due to 5 previous errors
+error: aborting due to 6 previous errors
-Some errors have detailed explanations: E0493, E0716.
-For more information about an error, try `rustc --explain E0493`.
+For more information about this error, try `rustc --explain E0716`.
diff --git a/tests/ui/stability-attribute/missing-const-stability.rs b/tests/ui/stability-attribute/missing-const-stability.rs
index 19820730736..c3e72e83948 100644
--- a/tests/ui/stability-attribute/missing-const-stability.rs
+++ b/tests/ui/stability-attribute/missing-const-stability.rs
@@ -22,6 +22,7 @@ impl Foo {
#[stable(feature = "stable", since = "1.0.0")]
#[const_trait]
pub trait Bar {
+//~^ ERROR trait has missing const stability attribute
#[stable(feature = "stable", since = "1.0.0")]
fn fun();
}
diff --git a/tests/ui/stability-attribute/missing-const-stability.stderr b/tests/ui/stability-attribute/missing-const-stability.stderr
index baa4c34af06..09461e6fb54 100644
--- a/tests/ui/stability-attribute/missing-const-stability.stderr
+++ b/tests/ui/stability-attribute/missing-const-stability.stderr
@@ -4,8 +4,18 @@ error: function has missing const stability attribute
LL | pub const fn foo() {}
| ^^^^^^^^^^^^^^^^^^^^^
+error: trait has missing const stability attribute
+ --> $DIR/missing-const-stability.rs:24:1
+ |
+LL | / pub trait Bar {
+LL | |
+LL | | #[stable(feature = "stable", since = "1.0.0")]
+LL | | fn fun();
+LL | | }
+ | |_^
+
error: function has missing const stability attribute
- --> $DIR/missing-const-stability.rs:36:1
+ --> $DIR/missing-const-stability.rs:37:1
|
LL | pub const unsafe fn size_of_val<T>(x: *const T) -> usize { 42 }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -16,5 +26,5 @@ error: associated function has missing const stability attribute
LL | pub const fn foo() {}
| ^^^^^^^^^^^^^^^^^^^^^
-error: aborting due to 3 previous errors
+error: aborting due to 4 previous errors
diff --git a/tests/ui/traits/const-traits/auxiliary/staged-api.rs b/tests/ui/traits/const-traits/auxiliary/staged-api.rs
index abe22db702c..933a25769dc 100644
--- a/tests/ui/traits/const-traits/auxiliary/staged-api.rs
+++ b/tests/ui/traits/const-traits/auxiliary/staged-api.rs
@@ -4,6 +4,7 @@
#![stable(feature = "rust1", since = "1.0.0")]
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "unstable", issue = "none")]
#[const_trait]
pub trait MyTrait {
#[stable(feature = "rust1", since = "1.0.0")]
diff --git a/tests/ui/traits/const-traits/call-const-trait-method-pass.rs b/tests/ui/traits/const-traits/call-const-trait-method-pass.rs
index b854b422b3a..3004647ede0 100644
--- a/tests/ui/traits/const-traits/call-const-trait-method-pass.rs
+++ b/tests/ui/traits/const-traits/call-const-trait-method-pass.rs
@@ -1,6 +1,6 @@
//@ known-bug: #110395
-#![feature(const_trait_impl)]
+#![feature(const_trait_impl, const_ops)]
struct Int(i32);
diff --git a/tests/ui/traits/const-traits/const-and-non-const-impl.rs b/tests/ui/traits/const-traits/const-and-non-const-impl.rs
index 6b96fcf0ae3..85e2c5d3df6 100644
--- a/tests/ui/traits/const-traits/const-and-non-const-impl.rs
+++ b/tests/ui/traits/const-traits/const-and-non-const-impl.rs
@@ -1,6 +1,6 @@
//@ known-bug: #110395
-#![feature(const_trait_impl)]
+#![feature(const_trait_impl, const_ops)]
pub struct Int(i32);
diff --git a/tests/ui/traits/const-traits/generic-bound.rs b/tests/ui/traits/const-traits/generic-bound.rs
index 5eb236acde2..99de21471b2 100644
--- a/tests/ui/traits/const-traits/generic-bound.rs
+++ b/tests/ui/traits/const-traits/generic-bound.rs
@@ -1,6 +1,6 @@
//@ check-pass
-#![feature(const_trait_impl)]
+#![feature(const_trait_impl, const_ops)]
use std::marker::PhantomData;
diff --git a/tests/ui/traits/const-traits/syntactical-unstable.rs b/tests/ui/traits/const-traits/syntactical-unstable.rs
new file mode 100644
index 00000000000..e192e80fabd
--- /dev/null
+++ b/tests/ui/traits/const-traits/syntactical-unstable.rs
@@ -0,0 +1,34 @@
+//@ aux-build:staged-api.rs
+
+// Ensure that we enforce const stability of traits in `~const`/`const` bounds.
+
+#![feature(const_trait_impl)]
+
+use std::ops::Deref;
+
+extern crate staged_api;
+use staged_api::MyTrait;
+
+#[const_trait]
+trait Foo: ~const MyTrait {
+ //~^ ERROR use of unstable const library feature `unstable`
+ type Item: ~const MyTrait;
+ //~^ ERROR use of unstable const library feature `unstable`
+}
+
+const fn where_clause<T>() where T: ~const MyTrait {}
+//~^ ERROR use of unstable const library feature `unstable`
+
+const fn nested<T>() where T: Deref<Target: ~const MyTrait> {}
+//~^ ERROR use of unstable const library feature `unstable`
+
+const fn rpit() -> impl ~const MyTrait { Local }
+//~^ ERROR use of unstable const library feature `unstable`
+
+struct Local;
+impl const MyTrait for Local {
+//~^ ERROR use of unstable const library feature `unstable`
+ fn func() {}
+}
+
+fn main() {}
diff --git a/tests/ui/traits/const-traits/syntactical-unstable.stderr b/tests/ui/traits/const-traits/syntactical-unstable.stderr
new file mode 100644
index 00000000000..a2ce2f2b6e9
--- /dev/null
+++ b/tests/ui/traits/const-traits/syntactical-unstable.stderr
@@ -0,0 +1,67 @@
+error[E0658]: use of unstable const library feature `unstable`
+ --> $DIR/syntactical-unstable.rs:13:19
+ |
+LL | trait Foo: ~const MyTrait {
+ | ------ ^^^^^^^
+ | |
+ | trait is not stable as const yet
+ |
+ = help: add `#![feature(unstable)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable const library feature `unstable`
+ --> $DIR/syntactical-unstable.rs:19:44
+ |
+LL | const fn where_clause<T>() where T: ~const MyTrait {}
+ | ------ ^^^^^^^
+ | |
+ | trait is not stable as const yet
+ |
+ = help: add `#![feature(unstable)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable const library feature `unstable`
+ --> $DIR/syntactical-unstable.rs:22:52
+ |
+LL | const fn nested<T>() where T: Deref<Target: ~const MyTrait> {}
+ | ------ ^^^^^^^
+ | |
+ | trait is not stable as const yet
+ |
+ = help: add `#![feature(unstable)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable const library feature `unstable`
+ --> $DIR/syntactical-unstable.rs:25:32
+ |
+LL | const fn rpit() -> impl ~const MyTrait { Local }
+ | ------ ^^^^^^^
+ | |
+ | trait is not stable as const yet
+ |
+ = help: add `#![feature(unstable)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable const library feature `unstable`
+ --> $DIR/syntactical-unstable.rs:29:12
+ |
+LL | impl const MyTrait for Local {
+ | ^^^^^^^ trait is not stable as const yet
+ |
+ = help: add `#![feature(unstable)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable const library feature `unstable`
+ --> $DIR/syntactical-unstable.rs:15:23
+ |
+LL | type Item: ~const MyTrait;
+ | ------ ^^^^^^^
+ | |
+ | trait is not stable as const yet
+ |
+ = help: add `#![feature(unstable)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 6 previous errors
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/traits/const-traits/trait-default-body-stability.rs b/tests/ui/traits/const-traits/trait-default-body-stability.rs
index 5f7486eb176..567f1b3c284 100644
--- a/tests/ui/traits/const-traits/trait-default-body-stability.rs
+++ b/tests/ui/traits/const-traits/trait-default-body-stability.rs
@@ -38,6 +38,7 @@ impl const FromResidual for T {
}
#[stable(feature = "foo", since = "1.0")]
+#[rustc_const_unstable(feature = "const_tr", issue = "none")]
#[const_trait]
pub trait Tr {
#[stable(feature = "foo", since = "1.0")]
diff --git a/tests/ui/traits/const-traits/trait-default-body-stability.stderr b/tests/ui/traits/const-traits/trait-default-body-stability.stderr
index 77b81211e81..a13d9a1e075 100644
--- a/tests/ui/traits/const-traits/trait-default-body-stability.stderr
+++ b/tests/ui/traits/const-traits/trait-default-body-stability.stderr
@@ -17,7 +17,7 @@ LL | impl const FromResidual for T {
= note: adding a non-const method body in the future would be a breaking change
error[E0015]: `?` is not allowed on `T` in constant functions
- --> $DIR/trait-default-body-stability.rs:45:9
+ --> $DIR/trait-default-body-stability.rs:46:9
|
LL | T?
| ^^
@@ -25,7 +25,7 @@ LL | T?
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
error[E0015]: `?` is not allowed on `T` in constant functions
- --> $DIR/trait-default-body-stability.rs:45:9
+ --> $DIR/trait-default-body-stability.rs:46:9
|
LL | T?
| ^^