diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index fe1d190b4ec1a..3879d6052922a 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -2751,6 +2751,15 @@ pub enum Constness {
NotConst,
}
+impl fmt::Display for Constness {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.write_str(match *self {
+ Self::Const => "const",
+ Self::NotConst => "non-const",
+ })
+ }
+}
+
#[derive(Copy, Clone, Encodable, Debug, HashStable_Generic)]
pub struct FnHeader {
pub unsafety: Unsafety,
@@ -3252,8 +3261,13 @@ impl<'hir> Node<'hir> {
}
}
- /// Returns `Constness::Const` when this node is a const fn/impl.
- pub fn constness(&self) -> Constness {
+ /// Returns `Constness::Const` when this node is a const fn/impl/item,
+ ///
+ /// HACK(fee1-dead): or an associated type in a trait. This works because
+ /// only typeck cares about const trait predicates, so although the predicates
+ /// query would return const predicates when it does not need to be const,
+ /// it wouldn't have any effect.
+ pub fn constness_for_typeck(&self) -> Constness {
match self {
Node::Item(Item {
kind: ItemKind::Fn(FnSig { header: FnHeader { constness, .. }, .. }, ..),
@@ -3269,6 +3283,11 @@ impl<'hir> Node<'hir> {
})
| Node::Item(Item { kind: ItemKind::Impl(Impl { constness, .. }), .. }) => *constness,
+ Node::Item(Item { kind: ItemKind::Const(..), .. })
+ | Node::TraitItem(TraitItem { kind: TraitItemKind::Const(..), .. })
+ | Node::TraitItem(TraitItem { kind: TraitItemKind::Type(..), .. })
+ | Node::ImplItem(ImplItem { kind: ImplItemKind::Const(..), .. }) => Constness::Const,
+
_ => Constness::NotConst,
}
}
diff --git a/compiler/rustc_infer/src/traits/engine.rs b/compiler/rustc_infer/src/traits/engine.rs
index 2710debea9478..d60388b31c13c 100644
--- a/compiler/rustc_infer/src/traits/engine.rs
+++ b/compiler/rustc_infer/src/traits/engine.rs
@@ -1,5 +1,6 @@
use crate::infer::InferCtxt;
use crate::traits::Obligation;
+use rustc_hir as hir;
use rustc_hir::def_id::DefId;
use rustc_middle::ty::{self, ToPredicate, Ty, WithConstness};
@@ -49,11 +50,28 @@ pub trait TraitEngine<'tcx>: 'tcx {
infcx: &InferCtxt<'_, 'tcx>,
) -> Result<(), Vec<FulfillmentError<'tcx>>>;
+ fn select_all_with_constness_or_error(
+ &mut self,
+ infcx: &InferCtxt<'_, 'tcx>,
+ _constness: hir::Constness,
+ ) -> Result<(), Vec<FulfillmentError<'tcx>>> {
+ self.select_all_or_error(infcx)
+ }
+
fn select_where_possible(
&mut self,
infcx: &InferCtxt<'_, 'tcx>,
) -> Result<(), Vec<FulfillmentError<'tcx>>>;
+ // FIXME this should not provide a default body for chalk as chalk should be updated
+ fn select_with_constness_where_possible(
+ &mut self,
+ infcx: &InferCtxt<'_, 'tcx>,
+ _constness: hir::Constness,
+ ) -> Result<(), Vec<FulfillmentError<'tcx>>> {
+ self.select_where_possible(infcx)
+ }
+
fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>>;
}
diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs
index ce1445f8a4746..3139e12116373 100644
--- a/compiler/rustc_infer/src/traits/util.rs
+++ b/compiler/rustc_infer/src/traits/util.rs
@@ -124,7 +124,7 @@ impl Elaborator<'tcx> {
let bound_predicate = obligation.predicate.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(data, _) => {
+ ty::PredicateKind::Trait(data) => {
// Get predicates declared on the trait.
let predicates = tcx.super_predicates_of(data.def_id());
diff --git a/compiler/rustc_lint/src/traits.rs b/compiler/rustc_lint/src/traits.rs
index e713ce7c71bec..2c039b6d05d29 100644
--- a/compiler/rustc_lint/src/traits.rs
+++ b/compiler/rustc_lint/src/traits.rs
@@ -87,7 +87,7 @@ impl<'tcx> LateLintPass<'tcx> for DropTraitConstraints {
let predicates = cx.tcx.explicit_predicates_of(item.def_id);
for &(predicate, span) in predicates.predicates {
let trait_predicate = match predicate.kind().skip_binder() {
- Trait(trait_predicate, _constness) => trait_predicate,
+ Trait(trait_predicate) => trait_predicate,
_ => continue,
};
let def_id = trait_predicate.trait_ref.def_id;
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index 2b580452a60eb..2d2897f3f9899 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -211,7 +211,7 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
let mut has_emitted = false;
for &(predicate, _) in cx.tcx.explicit_item_bounds(def) {
// We only look at the `DefId`, so it is safe to skip the binder here.
- if let ty::PredicateKind::Trait(ref poly_trait_predicate, _) =
+ if let ty::PredicateKind::Trait(ref poly_trait_predicate) =
predicate.kind().skip_binder()
{
let def_id = poly_trait_predicate.trait_ref.def_id;
diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs
index ab085175762ab..924568a01a7de 100644
--- a/compiler/rustc_middle/src/traits/select.rs
+++ b/compiler/rustc_middle/src/traits/select.rs
@@ -12,12 +12,12 @@ use rustc_hir::def_id::DefId;
use rustc_query_system::cache::Cache;
pub type SelectionCache<'tcx> = Cache<
- ty::ParamEnvAnd<'tcx, ty::TraitRef<'tcx>>,
+ ty::ConstnessAnd<ty::ParamEnvAnd<'tcx, ty::TraitRef<'tcx>>>,
SelectionResult<'tcx, SelectionCandidate<'tcx>>,
>;
pub type EvaluationCache<'tcx> =
- Cache<ty::ParamEnvAnd<'tcx, ty::PolyTraitRef<'tcx>>, EvaluationResult>;
+ Cache<ty::ParamEnvAnd<'tcx, ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>>, EvaluationResult>;
/// The selection process begins by considering all impls, where
/// clauses, and so forth that might resolve an obligation. Sometimes
diff --git a/compiler/rustc_middle/src/ty/assoc.rs b/compiler/rustc_middle/src/ty/assoc.rs
index 2d177551664f6..5cb2b90fe1116 100644
--- a/compiler/rustc_middle/src/ty/assoc.rs
+++ b/compiler/rustc_middle/src/ty/assoc.rs
@@ -16,6 +16,13 @@ pub enum AssocItemContainer {
}
impl AssocItemContainer {
+ pub fn impl_def_id(&self) -> Option<DefId> {
+ match *self {
+ ImplContainer(id) => Some(id),
+ _ => None,
+ }
+ }
+
/// Asserts that this is the `DefId` of an associated item declared
/// in a trait, and returns the trait `DefId`.
pub fn assert_trait(&self) -> DefId {
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index ef0392e51970b..106b443ee3c14 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -2169,7 +2169,7 @@ impl<'tcx> TyCtxt<'tcx> {
let generic_predicates = self.super_predicates_of(trait_did);
for (predicate, _) in generic_predicates.predicates {
- if let ty::PredicateKind::Trait(data, _) = predicate.kind().skip_binder() {
+ if let ty::PredicateKind::Trait(data) = predicate.kind().skip_binder() {
if set.insert(data.def_id()) {
stack.push(data.def_id());
}
diff --git a/compiler/rustc_middle/src/ty/error.rs b/compiler/rustc_middle/src/ty/error.rs
index f1c7c1ea852a2..3846d9ffdbae5 100644
--- a/compiler/rustc_middle/src/ty/error.rs
+++ b/compiler/rustc_middle/src/ty/error.rs
@@ -33,6 +33,7 @@ impl<T> ExpectedFound<T> {
#[derive(Clone, Debug, TypeFoldable)]
pub enum TypeError<'tcx> {
Mismatch,
+ ConstnessMismatch(ExpectedFound<hir::Constness>),
UnsafetyMismatch(ExpectedFound<hir::Unsafety>),
AbiMismatch(ExpectedFound<abi::Abi>),
Mutability,
@@ -106,6 +107,9 @@ impl<'tcx> fmt::Display for TypeError<'tcx> {
CyclicTy(_) => write!(f, "cyclic type of infinite size"),
CyclicConst(_) => write!(f, "encountered a self-referencing constant"),
Mismatch => write!(f, "types differ"),
+ ConstnessMismatch(values) => {
+ write!(f, "expected {} fn, found {} fn", values.expected, values.found)
+ }
UnsafetyMismatch(values) => {
write!(f, "expected {} fn, found {} fn", values.expected, values.found)
}
@@ -213,9 +217,11 @@ impl<'tcx> TypeError<'tcx> {
pub fn must_include_note(&self) -> bool {
use self::TypeError::*;
match self {
- CyclicTy(_) | CyclicConst(_) | UnsafetyMismatch(_) | Mismatch | AbiMismatch(_)
- | FixedArraySize(_) | ArgumentSorts(..) | Sorts(_) | IntMismatch(_)
- | FloatMismatch(_) | VariadicMismatch(_) | TargetFeatureCast(_) => false,
+ CyclicTy(_) | CyclicConst(_) | UnsafetyMismatch(_) | ConstnessMismatch(_)
+ | Mismatch | AbiMismatch(_) | FixedArraySize(_) | ArgumentSorts(..) | Sorts(_)
+ | IntMismatch(_) | FloatMismatch(_) | VariadicMismatch(_) | TargetFeatureCast(_) => {
+ false
+ }
Mutability
| ArgumentMutability(_)
diff --git a/compiler/rustc_middle/src/ty/flags.rs b/compiler/rustc_middle/src/ty/flags.rs
index 9faa172a4973f..391c8292bd542 100644
--- a/compiler/rustc_middle/src/ty/flags.rs
+++ b/compiler/rustc_middle/src/ty/flags.rs
@@ -216,7 +216,7 @@ impl FlagComputation {
fn add_predicate_atom(&mut self, atom: ty::PredicateKind<'_>) {
match atom {
- ty::PredicateKind::Trait(trait_pred, _constness) => {
+ ty::PredicateKind::Trait(trait_pred) => {
self.add_substs(trait_pred.trait_ref.substs);
}
ty::PredicateKind::RegionOutlives(ty::OutlivesPredicate(a, b)) => {
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index a6aff42479069..6ea44789c7a38 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -456,7 +456,7 @@ pub enum PredicateKind<'tcx> {
/// A trait predicate will have `Constness::Const` if it originates
/// from a bound on a `const fn` without the `?const` opt-out (e.g.,
/// `const fn foobar<Foo: Bar>() {}`).
- Trait(TraitPredicate<'tcx>, Constness),
+ Trait(TraitPredicate<'tcx>),
/// `where 'a: 'b`
RegionOutlives(RegionOutlivesPredicate<'tcx>),
@@ -612,6 +612,11 @@ impl<'tcx> Predicate<'tcx> {
#[derive(HashStable, TypeFoldable)]
pub struct TraitPredicate<'tcx> {
pub trait_ref: TraitRef<'tcx>,
+
+ /// A trait predicate will have `Constness::Const` if it originates
+ /// from a bound on a `const fn` without the `?const` opt-out (e.g.,
+ /// `const fn foobar<Foo: Bar>() {}`).
+ pub constness: hir::Constness,
}
pub type PolyTraitPredicate<'tcx> = ty::Binder<'tcx, TraitPredicate<'tcx>>;
@@ -745,8 +750,11 @@ impl ToPredicate<'tcx> for PredicateKind<'tcx> {
impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<TraitRef<'tcx>> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
- PredicateKind::Trait(ty::TraitPredicate { trait_ref: self.value }, self.constness)
- .to_predicate(tcx)
+ PredicateKind::Trait(ty::TraitPredicate {
+ trait_ref: self.value,
+ constness: self.constness,
+ })
+ .to_predicate(tcx)
}
}
@@ -754,15 +762,15 @@ impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<PolyTraitRef<'tcx>> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
self.value
.map_bound(|trait_ref| {
- PredicateKind::Trait(ty::TraitPredicate { trait_ref }, self.constness)
+ PredicateKind::Trait(ty::TraitPredicate { trait_ref, constness: self.constness })
})
.to_predicate(tcx)
}
}
-impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<PolyTraitPredicate<'tcx>> {
+impl<'tcx> ToPredicate<'tcx> for PolyTraitPredicate<'tcx> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
- self.value.map_bound(|value| PredicateKind::Trait(value, self.constness)).to_predicate(tcx)
+ self.map_bound(PredicateKind::Trait).to_predicate(tcx)
}
}
@@ -788,8 +796,8 @@ impl<'tcx> Predicate<'tcx> {
pub fn to_opt_poly_trait_ref(self) -> Option<ConstnessAnd<PolyTraitRef<'tcx>>> {
let predicate = self.kind();
match predicate.skip_binder() {
- PredicateKind::Trait(t, constness) => {
- Some(ConstnessAnd { constness, value: predicate.rebind(t.trait_ref) })
+ PredicateKind::Trait(t) => {
+ Some(ConstnessAnd { constness: t.constness, value: predicate.rebind(t.trait_ref) })
}
PredicateKind::Projection(..)
| PredicateKind::Subtype(..)
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index dc94124e62ab6..c96621338f574 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -630,7 +630,7 @@ pub trait PrettyPrinter<'tcx>:
for (predicate, _) in bounds {
let predicate = predicate.subst(self.tcx(), substs);
let bound_predicate = predicate.kind();
- if let ty::PredicateKind::Trait(pred, _) = bound_predicate.skip_binder() {
+ if let ty::PredicateKind::Trait(pred) = bound_predicate.skip_binder() {
let trait_ref = bound_predicate.rebind(pred.trait_ref);
// Don't print +Sized, but rather +?Sized if absent.
if Some(trait_ref.def_id()) == self.tcx().lang_items().sized_trait() {
@@ -2264,10 +2264,7 @@ define_print_and_forward_display! {
ty::PredicateKind<'tcx> {
match *self {
- ty::PredicateKind::Trait(ref data, constness) => {
- if let hir::Constness::Const = constness {
- p!("const ");
- }
+ ty::PredicateKind::Trait(ref data) => {
p!(print(data))
}
ty::PredicateKind::Subtype(predicate) => p!(print(predicate)),
diff --git a/compiler/rustc_middle/src/ty/relate.rs b/compiler/rustc_middle/src/ty/relate.rs
index a4c36be21992b..9c48f05617e09 100644
--- a/compiler/rustc_middle/src/ty/relate.rs
+++ b/compiler/rustc_middle/src/ty/relate.rs
@@ -200,6 +200,33 @@ impl<'tcx> Relate<'tcx> for ty::FnSig<'tcx> {
}
}
+impl<'tcx> Relate<'tcx> for ast::Constness {
+ fn relate<R: TypeRelation<'tcx>>(
+ relation: &mut R,
+ a: ast::Constness,
+ b: ast::Constness,
+ ) -> RelateResult<'tcx, ast::Constness> {
+ if a != b {
+ Err(TypeError::ConstnessMismatch(expected_found(relation, a, b)))
+ } else {
+ Ok(a)
+ }
+ }
+}
+
+impl<'tcx, T: Relate<'tcx>> Relate<'tcx> for ty::ConstnessAnd<T> {
+ fn relate<R: TypeRelation<'tcx>>(
+ relation: &mut R,
+ a: ty::ConstnessAnd<T>,
+ b: ty::ConstnessAnd<T>,
+ ) -> RelateResult<'tcx, ty::ConstnessAnd<T>> {
+ Ok(ty::ConstnessAnd {
+ constness: relation.relate(a.constness, b.constness)?,
+ value: relation.relate(a.value, b.value)?,
+ })
+ }
+}
+
impl<'tcx> Relate<'tcx> for ast::Unsafety {
fn relate<R: TypeRelation<'tcx>>(
relation: &mut R,
@@ -767,7 +794,10 @@ impl<'tcx> Relate<'tcx> for ty::TraitPredicate<'tcx> {
a: ty::TraitPredicate<'tcx>,
b: ty::TraitPredicate<'tcx>,
) -> RelateResult<'tcx, ty::TraitPredicate<'tcx>> {
- Ok(ty::TraitPredicate { trait_ref: relation.relate(a.trait_ref, b.trait_ref)? })
+ Ok(ty::TraitPredicate {
+ trait_ref: relation.relate(a.trait_ref, b.trait_ref)?,
+ constness: relation.relate(a.constness, b.constness)?,
+ })
}
}
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index 7290c41d615df..62397752db2fc 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -155,6 +155,9 @@ impl fmt::Debug for ty::ParamConst {
impl fmt::Debug for ty::TraitPredicate<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ if let hir::Constness::Const = self.constness {
+ write!(f, "const ")?;
+ }
write!(f, "TraitPredicate({:?})", self.trait_ref)
}
}
@@ -174,12 +177,7 @@ impl fmt::Debug for ty::Predicate<'tcx> {
impl fmt::Debug for ty::PredicateKind<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
- ty::PredicateKind::Trait(ref a, constness) => {
- if let hir::Constness::Const = constness {
- write!(f, "const ")?;
- }
- a.fmt(f)
- }
+ ty::PredicateKind::Trait(ref a) => a.fmt(f),
ty::PredicateKind::Subtype(ref pair) => pair.fmt(f),
ty::PredicateKind::RegionOutlives(ref pair) => pair.fmt(f),
ty::PredicateKind::TypeOutlives(ref pair) => pair.fmt(f),
@@ -366,7 +364,8 @@ impl<'a, 'tcx> Lift<'tcx> for ty::ExistentialPredicate<'a> {
impl<'a, 'tcx> Lift<'tcx> for ty::TraitPredicate<'a> {
type Lifted = ty::TraitPredicate<'tcx>;
fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<ty::TraitPredicate<'tcx>> {
- tcx.lift(self.trait_ref).map(|trait_ref| ty::TraitPredicate { trait_ref })
+ tcx.lift(self.trait_ref)
+ .map(|trait_ref| ty::TraitPredicate { trait_ref, constness: self.constness })
}
}
@@ -419,9 +418,7 @@ impl<'a, 'tcx> Lift<'tcx> for ty::PredicateKind<'a> {
type Lifted = ty::PredicateKind<'tcx>;
fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
match self {
- ty::PredicateKind::Trait(data, constness) => {
- tcx.lift(data).map(|data| ty::PredicateKind::Trait(data, constness))
- }
+ ty::PredicateKind::Trait(data) => tcx.lift(data).map(ty::PredicateKind::Trait),
ty::PredicateKind::Subtype(data) => tcx.lift(data).map(ty::PredicateKind::Subtype),
ty::PredicateKind::RegionOutlives(data) => {
tcx.lift(data).map(ty::PredicateKind::RegionOutlives)
@@ -584,6 +581,7 @@ impl<'a, 'tcx> Lift<'tcx> for ty::error::TypeError<'a> {
Some(match self {
Mismatch => Mismatch,
+ ConstnessMismatch(x) => ConstnessMismatch(x),
UnsafetyMismatch(x) => UnsafetyMismatch(x),
AbiMismatch(x) => AbiMismatch(x),
Mutability => Mutability,
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 6a7e349819afd..a1edb8071c459 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -876,7 +876,10 @@ impl<'tcx> PolyTraitRef<'tcx> {
}
pub fn to_poly_trait_predicate(&self) -> ty::PolyTraitPredicate<'tcx> {
- self.map_bound(|trait_ref| ty::TraitPredicate { trait_ref })
+ self.map_bound(|trait_ref| ty::TraitPredicate {
+ trait_ref,
+ constness: hir::Constness::NotConst,
+ })
}
}
diff --git a/compiler/rustc_mir/src/borrow_check/type_check/mod.rs b/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
index f69d08a6d5942..86dcb9c9c1b7a 100644
--- a/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
+++ b/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
@@ -1084,11 +1084,12 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
span_mirbug!(
self,
user_annotation,
- "bad user type AscribeUserType({:?}, {:?} {:?}): {:?}",
+ "bad user type AscribeUserType({:?}, {:?} {:?}, type_of={:?}): {:?}",
inferred_ty,
def_id,
user_substs,
- terr
+ self.tcx().type_of(def_id),
+ terr,
);
}
}
@@ -2688,10 +2689,10 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
category: ConstraintCategory,
) {
self.prove_predicates(
- Some(ty::PredicateKind::Trait(
- ty::TraitPredicate { trait_ref },
- hir::Constness::NotConst,
- )),
+ Some(ty::PredicateKind::Trait(ty::TraitPredicate {
+ trait_ref,
+ constness: hir::Constness::NotConst,
+ })),
locations,
category,
);
diff --git a/compiler/rustc_mir/src/transform/check_consts/check.rs b/compiler/rustc_mir/src/transform/check_consts/check.rs
index 109da59aa4380..48fd63b258ca7 100644
--- a/compiler/rustc_mir/src/transform/check_consts/check.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/check.rs
@@ -423,7 +423,7 @@ impl Checker<'mir, 'tcx> {
ty::PredicateKind::Subtype(_) => {
bug!("subtype predicate on function: {:#?}", predicate)
}
- ty::PredicateKind::Trait(pred, _constness) => {
+ ty::PredicateKind::Trait(pred) => {
if Some(pred.def_id()) == tcx.lang_items().sized_trait() {
continue;
}
@@ -817,7 +817,10 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> {
let obligation = Obligation::new(
ObligationCause::dummy(),
param_env,
- Binder::dummy(TraitPredicate { trait_ref }),
+ Binder::dummy(TraitPredicate {
+ trait_ref,
+ constness: hir::Constness::Const,
+ }),
);
let implsrc = tcx.infer_ctxt().enter(|infcx| {
diff --git a/compiler/rustc_mir/src/transform/function_item_references.rs b/compiler/rustc_mir/src/transform/function_item_references.rs
index 8d02ac6d9b774..26fe796cb916f 100644
--- a/compiler/rustc_mir/src/transform/function_item_references.rs
+++ b/compiler/rustc_mir/src/transform/function_item_references.rs
@@ -132,7 +132,7 @@ impl<'a, 'tcx> FunctionItemRefChecker<'a, 'tcx> {
/// If the given predicate is the trait `fmt::Pointer`, returns the bound parameter type.
fn is_pointer_trait(&self, bound: &PredicateKind<'tcx>) -> Option<Ty<'tcx>> {
- if let ty::PredicateKind::Trait(predicate, _) = bound {
+ if let ty::PredicateKind::Trait(predicate) = bound {
if self.tcx.is_diagnostic_item(sym::pointer_trait, predicate.def_id()) {
Some(predicate.trait_ref.self_ty())
} else {
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index 1a0510d23cf13..3df8ade216925 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -122,7 +122,7 @@ where
fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ControlFlow<V::BreakTy> {
match predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(ty::TraitPredicate { trait_ref }, _) => {
+ ty::PredicateKind::Trait(ty::TraitPredicate { trait_ref, constness: _ }) => {
self.visit_trait(trait_ref)
}
ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, ty }) => {
diff --git a/compiler/rustc_resolve/src/late/lifetimes.rs b/compiler/rustc_resolve/src/late/lifetimes.rs
index e18dae0b8eebb..d79fd910b7e78 100644
--- a/compiler/rustc_resolve/src/late/lifetimes.rs
+++ b/compiler/rustc_resolve/src/late/lifetimes.rs
@@ -2657,7 +2657,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
let obligations = predicates.predicates.iter().filter_map(|&(pred, _)| {
let bound_predicate = pred.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(data, _) => {
+ ty::PredicateKind::Trait(data) => {
// The order here needs to match what we would get from `subst_supertrait`
let pred_bound_vars = bound_predicate.bound_vars();
let mut all_bound_vars = bound_vars.clone();
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index f54eb0914a5a7..282502cfa0d3d 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -285,6 +285,7 @@ impl AutoTraitFinder<'tcx> {
def_id: trait_did,
substs: infcx.tcx.mk_substs_trait(ty, &[]),
},
+ constness: hir::Constness::NotConst,
}));
let computed_preds = param_env.caller_bounds().iter();
@@ -344,10 +345,7 @@ impl AutoTraitFinder<'tcx> {
Err(SelectionError::Unimplemented) => {
if self.is_param_no_infer(pred.skip_binder().trait_ref.substs) {
already_visited.remove(&pred);
- self.add_user_pred(
- &mut user_computed_preds,
- pred.without_const().to_predicate(self.tcx),
- );
+ self.add_user_pred(&mut user_computed_preds, pred.to_predicate(self.tcx));
predicates.push_back(pred);
} else {
debug!(
@@ -414,10 +412,8 @@ impl AutoTraitFinder<'tcx> {
) {
let mut should_add_new = true;
user_computed_preds.retain(|&old_pred| {
- if let (
- ty::PredicateKind::Trait(new_trait, _),
- ty::PredicateKind::Trait(old_trait, _),
- ) = (new_pred.kind().skip_binder(), old_pred.kind().skip_binder())
+ if let (ty::PredicateKind::Trait(new_trait), ty::PredicateKind::Trait(old_trait)) =
+ (new_pred.kind().skip_binder(), old_pred.kind().skip_binder())
{
if new_trait.def_id() == old_trait.def_id() {
let new_substs = new_trait.trait_ref.substs;
@@ -638,7 +634,7 @@ impl AutoTraitFinder<'tcx> {
let bound_predicate = predicate.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(p, _) => {
+ ty::PredicateKind::Trait(p) => {
// Add this to `predicates` so that we end up calling `select`
// with it. If this predicate ends up being unimplemented,
// then `evaluate_predicates` will handle adding it the `ParamEnv`
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index ac07cc1f03439..2f91666ca641d 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -277,7 +277,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
let bound_predicate = obligation.predicate.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(trait_predicate, _) => {
+ ty::PredicateKind::Trait(trait_predicate) => {
let trait_predicate = bound_predicate.rebind(trait_predicate);
let trait_predicate = self.resolve_vars_if_possible(trait_predicate);
@@ -518,8 +518,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
);
trait_pred
});
- let unit_obligation =
- obligation.with(predicate.without_const().to_predicate(tcx));
+ let unit_obligation = obligation.with(predicate.to_predicate(tcx));
if self.predicate_may_hold(&unit_obligation) {
err.note("this trait is implemented for `()`.");
err.note(
@@ -1148,7 +1147,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
// FIXME: It should be possible to deal with `ForAll` in a cleaner way.
let bound_error = error.kind();
let (cond, error) = match (cond.kind().skip_binder(), bound_error.skip_binder()) {
- (ty::PredicateKind::Trait(..), ty::PredicateKind::Trait(error, _)) => {
+ (ty::PredicateKind::Trait(..), ty::PredicateKind::Trait(error)) => {
(cond, bound_error.rebind(error))
}
_ => {
@@ -1159,7 +1158,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
for obligation in super::elaborate_predicates(self.tcx, std::iter::once(cond)) {
let bound_predicate = obligation.predicate.kind();
- if let ty::PredicateKind::Trait(implication, _) = bound_predicate.skip_binder() {
+ if let ty::PredicateKind::Trait(implication) = bound_predicate.skip_binder() {
let error = error.to_poly_trait_ref();
let implication = bound_predicate.rebind(implication.trait_ref);
// FIXME: I'm just not taking associated types at all here.
@@ -1536,7 +1535,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
let bound_predicate = predicate.kind();
let mut err = match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(data, _) => {
+ ty::PredicateKind::Trait(data) => {
let trait_ref = bound_predicate.rebind(data.trait_ref);
debug!("trait_ref {:?}", trait_ref);
@@ -1803,7 +1802,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
match (obligation.predicate.kind().skip_binder(), obligation.cause.code.peel_derives())
{
(
- ty::PredicateKind::Trait(pred, _),
+ ty::PredicateKind::Trait(pred),
&ObligationCauseCode::BindingObligation(item_def_id, span),
) => (pred, item_def_id, span),
_ => return,
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index b6ee51cfc1a47..269560843657d 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -1386,7 +1386,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
// bound was introduced. At least one generator should be present for this diagnostic to be
// modified.
let (mut trait_ref, mut target_ty) = match obligation.predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(p, _) => (Some(p.trait_ref), Some(p.self_ty())),
+ ty::PredicateKind::Trait(p) => (Some(p.trait_ref), Some(p.self_ty())),
_ => (None, None),
};
let mut generator = None;
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
index 9ec1dd5c2ee3b..7048f0dbedcb6 100644
--- a/compiler/rustc_trait_selection/src/traits/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -3,6 +3,7 @@ use rustc_data_structures::obligation_forest::ProcessResult;
use rustc_data_structures::obligation_forest::{Error, ForestObligation, Outcome};
use rustc_data_structures::obligation_forest::{ObligationForest, ObligationProcessor};
use rustc_errors::ErrorReported;
+use rustc_hir as hir;
use rustc_infer::traits::{SelectionError, TraitEngine, TraitEngineExt as _, TraitObligation};
use rustc_middle::mir::abstract_const::NotConstEvaluatable;
use rustc_middle::mir::interpret::ErrorHandled;
@@ -228,6 +229,22 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
if errors.is_empty() { Ok(()) } else { Err(errors) }
}
+ fn select_all_with_constness_or_error(
+ &mut self,
+ infcx: &InferCtxt<'_, 'tcx>,
+ constness: rustc_hir::Constness,
+ ) -> Result<(), Vec<FulfillmentError<'tcx>>> {
+ self.select_with_constness_where_possible(infcx, constness)?;
+
+ let errors: Vec<_> = self
+ .predicates
+ .to_errors(CodeAmbiguity)
+ .into_iter()
+ .map(to_fulfillment_error)
+ .collect();
+ if errors.is_empty() { Ok(()) } else { Err(errors) }
+ }
+
fn select_where_possible(
&mut self,
infcx: &InferCtxt<'_, 'tcx>,
@@ -236,6 +253,15 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
self.select(&mut selcx)
}
+ fn select_with_constness_where_possible(
+ &mut self,
+ infcx: &InferCtxt<'_, 'tcx>,
+ constness: hir::Constness,
+ ) -> Result<(), Vec<FulfillmentError<'tcx>>> {
+ let mut selcx = SelectionContext::with_constness(infcx, constness);
+ self.select(&mut selcx)
+ }
+
fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> {
self.predicates.map_pending_obligations(|o| o.obligation.clone())
}
@@ -352,7 +378,7 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
// Evaluation will discard candidates using the leak check.
// This means we need to pass it the bound version of our
// predicate.
- ty::PredicateKind::Trait(trait_ref, _constness) => {
+ ty::PredicateKind::Trait(trait_ref) => {
let trait_obligation = obligation.with(binder.rebind(trait_ref));
self.process_trait_obligation(
@@ -388,7 +414,7 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
}
},
Some(pred) => match pred {
- ty::PredicateKind::Trait(data, _) => {
+ ty::PredicateKind::Trait(data) => {
let trait_obligation = obligation.with(Binder::dummy(data));
self.process_trait_obligation(
@@ -623,7 +649,12 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
if obligation.predicate.is_global() {
// no type variables present, can use evaluation for better caching.
// FIXME: consider caching errors too.
- if infcx.predicate_must_hold_considering_regions(obligation) {
+ //
+ // If the predicate is considered const, then we cannot use this because
+ // it will cause false negatives in the ui tests.
+ if !self.selcx.is_predicate_const(obligation.predicate)
+ && infcx.predicate_must_hold_considering_regions(obligation)
+ {
debug!(
"selecting trait at depth {} evaluated to holds",
obligation.recursion_depth
@@ -677,7 +708,12 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
if obligation.predicate.is_global() {
// no type variables present, can use evaluation for better caching.
// FIXME: consider caching errors too.
- if self.selcx.infcx().predicate_must_hold_considering_regions(obligation) {
+ //
+ // If the predicate is considered const, then we cannot use this because
+ // it will cause false negatives in the ui tests.
+ if !self.selcx.is_predicate_const(obligation.predicate)
+ && self.selcx.infcx().predicate_must_hold_considering_regions(obligation)
+ {
return ProcessResult::Changed(vec![]);
} else {
tracing::debug!("Does NOT hold: {:?}", obligation);
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index 7ebef7f8883ae..04bc689d51161 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -280,7 +280,7 @@ fn predicate_references_self(
let self_ty = tcx.types.self_param;
let has_self_ty = |arg: &GenericArg<'_>| arg.walk().any(|arg| arg == self_ty.into());
match predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(ref data, _) => {
+ ty::PredicateKind::Trait(ref data) => {
// In the case of a trait predicate, we can skip the "self" type.
if data.trait_ref.substs[1..].iter().any(has_self_ty) { Some(sp) } else { None }
}
@@ -331,7 +331,7 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
let predicates = predicates.instantiate_identity(tcx).predicates;
elaborate_predicates(tcx, predicates.into_iter()).any(|obligation| {
match obligation.predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(ref trait_pred, _) => {
+ ty::PredicateKind::Trait(ref trait_pred) => {
trait_pred.def_id() == sized_def_id && trait_pred.self_ty().is_param(0)
}
ty::PredicateKind::Projection(..)
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
index de538c62c5e39..02e9b4d0f0e72 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
@@ -15,7 +15,7 @@ impl<'tcx> super::QueryTypeOp<'tcx> for ProvePredicate<'tcx> {
// `&T`, accounts for about 60% percentage of the predicates
// we have to prove. No need to canonicalize and all that for
// such cases.
- if let ty::PredicateKind::Trait(trait_ref, _) = key.value.predicate.kind().skip_binder() {
+ if let ty::PredicateKind::Trait(trait_ref) = key.value.predicate.kind().skip_binder() {
if let Some(sized_def_id) = tcx.lang_items().sized_trait() {
if trait_ref.def_id() == sized_def_id {
if trait_ref.self_ty().is_trivially_sized(tcx) {
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index c7bf1f2a94319..4312cc9468242 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -144,7 +144,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// Instead, we select the right impl now but report "`Bar` does
// not implement `Clone`".
if candidates.len() == 1 {
- return self.filter_negative_and_reservation_impls(candidates.pop().unwrap());
+ return self.filter_impls(candidates.pop().unwrap(), stack.obligation);
}
// Winnow, but record the exact outcome of evaluation, which
@@ -217,7 +217,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
// Just one candidate left.
- self.filter_negative_and_reservation_impls(candidates.pop().unwrap().candidate)
+ self.filter_impls(candidates.pop().unwrap().candidate, stack.obligation)
}
pub(super) fn assemble_candidates<'o>(
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 95611ebc8188c..dcf5ac63b78ea 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -41,8 +41,9 @@ use rustc_middle::ty::fast_reject;
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_middle::ty::relate::TypeRelation;
use rustc_middle::ty::subst::{GenericArgKind, Subst, SubstsRef};
+use rustc_middle::ty::WithConstness;
use rustc_middle::ty::{self, PolyProjectionPredicate, ToPolyTraitRef, ToPredicate};
-use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable, WithConstness};
+use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable};
use rustc_span::symbol::sym;
use std::cell::{Cell, RefCell};
@@ -129,6 +130,9 @@ pub struct SelectionContext<'cx, 'tcx> {
/// and a negative impl
allow_negative_impls: bool,
+ /// Do we only want const impls when we have a const trait predicate?
+ const_impls_required: bool,
+
/// The mode that trait queries run in, which informs our error handling
/// policy. In essence, canonicalized queries need their errors propagated
/// rather than immediately reported because we do not have accurate spans.
@@ -141,7 +145,7 @@ struct TraitObligationStack<'prev, 'tcx> {
/// The trait ref from `obligation` but "freshened" with the
/// selection-context's freshener. Used to check for recursion.
- fresh_trait_ref: ty::PolyTraitRef<'tcx>,
+ fresh_trait_ref: ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>,
/// Starts out equal to `depth` -- if, during evaluation, we
/// encounter a cycle, then we will set this flag to the minimum
@@ -220,6 +224,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
intercrate: false,
intercrate_ambiguity_causes: None,
allow_negative_impls: false,
+ const_impls_required: false,
query_mode: TraitQueryMode::Standard,
}
}
@@ -231,6 +236,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
intercrate: true,
intercrate_ambiguity_causes: None,
allow_negative_impls: false,
+ const_impls_required: false,
query_mode: TraitQueryMode::Standard,
}
}
@@ -246,6 +252,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
intercrate: false,
intercrate_ambiguity_causes: None,
allow_negative_impls,
+ const_impls_required: false,
query_mode: TraitQueryMode::Standard,
}
}
@@ -261,10 +268,26 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
intercrate: false,
intercrate_ambiguity_causes: None,
allow_negative_impls: false,
+ const_impls_required: false,
query_mode,
}
}
+ pub fn with_constness(
+ infcx: &'cx InferCtxt<'cx, 'tcx>,
+ constness: hir::Constness,
+ ) -> SelectionContext<'cx, 'tcx> {
+ SelectionContext {
+ infcx,
+ freshener: infcx.freshener_keep_static(),
+ intercrate: false,
+ intercrate_ambiguity_causes: None,
+ allow_negative_impls: false,
+ const_impls_required: matches!(constness, hir::Constness::Const),
+ query_mode: TraitQueryMode::Standard,
+ }
+ }
+
/// Enables tracking of intercrate ambiguity causes. These are
/// used in coherence to give improved diagnostics. We don't do
/// this until we detect a coherence error because it can lead to
@@ -293,6 +316,18 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
self.infcx.tcx
}
+ /// returns `true` if the predicate is considered `const` to
+ /// this selection context.
+ pub fn is_predicate_const(&self, pred: ty::Predicate<'_>) -> bool {
+ match pred.kind().skip_binder() {
+ ty::PredicateKind::Trait(ty::TraitPredicate {
+ constness: hir::Constness::Const,
+ ..
+ }) if self.const_impls_required => true,
+ _ => false,
+ }
+ }
+
///////////////////////////////////////////////////////////////////////////
// Selection
//
@@ -454,7 +489,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
let result = ensure_sufficient_stack(|| {
let bound_predicate = obligation.predicate.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(t, _) => {
+ ty::PredicateKind::Trait(t) => {
let t = bound_predicate.rebind(t);
debug_assert!(!t.has_escaping_bound_vars());
let obligation = obligation.with(t);
@@ -762,8 +797,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// if the regions match exactly.
let cycle = stack.iter().skip(1).take_while(|s| s.depth >= cycle_depth);
let tcx = self.tcx();
- let cycle =
- cycle.map(|stack| stack.obligation.predicate.without_const().to_predicate(tcx));
+ let cycle = cycle.map(|stack| stack.obligation.predicate.to_predicate(tcx));
if self.coinductive_match(cycle) {
debug!("evaluate_stack --> recursive, coinductive");
Some(EvaluatedToOk)
@@ -805,7 +839,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// terms of `Fn` etc, but we could probably make this more
// precise still.
let unbound_input_types =
- stack.fresh_trait_ref.skip_binder().substs.types().any(|ty| ty.is_fresh());
+ stack.fresh_trait_ref.value.skip_binder().substs.types().any(|ty| ty.is_fresh());
// This check was an imperfect workaround for a bug in the old
// intercrate mode; it should be removed when that goes away.
if unbound_input_types && self.intercrate {
@@ -873,7 +907,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
fn coinductive_predicate(&self, predicate: ty::Predicate<'tcx>) -> bool {
let result = match predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(ref data, _) => self.tcx().trait_is_auto(data.def_id()),
+ ty::PredicateKind::Trait(ref data) => self.tcx().trait_is_auto(data.def_id()),
_ => false,
};
debug!(?predicate, ?result, "coinductive_predicate");
@@ -926,7 +960,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
fn check_evaluation_cache(
&self,
param_env: ty::ParamEnv<'tcx>,
- trait_ref: ty::PolyTraitRef<'tcx>,
+ trait_ref: ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>,
) -> Option<EvaluationResult> {
let tcx = self.tcx();
if self.can_use_global_caches(param_env) {
@@ -940,7 +974,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
fn insert_evaluation_cache(
&mut self,
param_env: ty::ParamEnv<'tcx>,
- trait_ref: ty::PolyTraitRef<'tcx>,
+ trait_ref: ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>,
dep_node: DepNodeIndex,
result: EvaluationResult,
) {
@@ -1016,13 +1050,44 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
(result, dep_node)
}
- // Treat negative impls as unimplemented, and reservation impls as ambiguity.
- fn filter_negative_and_reservation_impls(
+ #[instrument(level = "debug", skip(self))]
+ fn filter_impls(
&mut self,
candidate: SelectionCandidate<'tcx>,
+ obligation: &TraitObligation<'tcx>,
) -> SelectionResult<'tcx, SelectionCandidate<'tcx>> {
+ let tcx = self.tcx();
+ // Respect const trait obligations
+ if self.const_impls_required {
+ if let hir::Constness::Const = obligation.predicate.skip_binder().constness {
+ if Some(obligation.predicate.skip_binder().trait_ref.def_id)
+ != tcx.lang_items().sized_trait()
+ // const Sized bounds are skipped
+ {
+ match candidate {
+ // const impl
+ ImplCandidate(def_id)
+ if tcx.impl_constness(def_id) == hir::Constness::Const => {}
+ // const param
+ ParamCandidate(ty::ConstnessAnd {
+ constness: hir::Constness::Const,
+ ..
+ }) => {}
+ // auto trait impl
+ AutoImplCandidate(..) => {}
+ // generator, this will raise error in other places
+ // or ignore error with const_async_blocks feature
+ GeneratorCandidate => {}
+ _ => {
+ // reject all other types of candidates
+ return Err(Unimplemented);
+ }
+ }
+ }
+ }
+ }
+ // Treat negative impls as unimplemented, and reservation impls as ambiguity.
if let ImplCandidate(def_id) = candidate {
- let tcx = self.tcx();
match tcx.impl_polarity(def_id) {
ty::ImplPolarity::Negative if !self.allow_negative_impls => {
return Err(Unimplemented);
@@ -1036,7 +1101,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
let value = attr.and_then(|a| a.value_str());
if let Some(value) = value {
debug!(
- "filter_negative_and_reservation_impls: \
+ "filter_impls: \
reservation impl ambiguity on {:?}",
def_id
);
@@ -1103,13 +1168,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
cache_fresh_trait_pred: ty::PolyTraitPredicate<'tcx>,
) -> Option<SelectionResult<'tcx, SelectionCandidate<'tcx>>> {
let tcx = self.tcx();
- let trait_ref = &cache_fresh_trait_pred.skip_binder().trait_ref;
+ let pred = &cache_fresh_trait_pred.skip_binder();
+ let trait_ref = pred.trait_ref;
if self.can_use_global_caches(param_env) {
- if let Some(res) = tcx.selection_cache.get(¶m_env.and(*trait_ref), tcx) {
+ if let Some(res) = tcx
+ .selection_cache
+ .get(¶m_env.and(trait_ref).with_constness(pred.constness), tcx)
+ {
return Some(res);
}
}
- self.infcx.selection_cache.get(¶m_env.and(*trait_ref), tcx)
+ self.infcx
+ .selection_cache
+ .get(¶m_env.and(trait_ref).with_constness(pred.constness), tcx)
}
/// Determines whether can we safely cache the result
@@ -1146,7 +1217,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
candidate: SelectionResult<'tcx, SelectionCandidate<'tcx>>,
) {
let tcx = self.tcx();
- let trait_ref = cache_fresh_trait_pred.skip_binder().trait_ref;
+ let pred = cache_fresh_trait_pred.skip_binder();
+ let trait_ref = pred.trait_ref;
if !self.can_cache_candidate(&candidate) {
debug!(?trait_ref, ?candidate, "insert_candidate_cache - candidate is not cacheable");
@@ -1160,14 +1232,22 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
if !candidate.needs_infer() {
debug!(?trait_ref, ?candidate, "insert_candidate_cache global");
// This may overwrite the cache with the same value.
- tcx.selection_cache.insert(param_env.and(trait_ref), dep_node, candidate);
+ tcx.selection_cache.insert(
+ param_env.and(trait_ref).with_constness(pred.constness),
+ dep_node,
+ candidate,
+ );
return;
}
}
}
debug!(?trait_ref, ?candidate, "insert_candidate_cache local");
- self.infcx.selection_cache.insert(param_env.and(trait_ref), dep_node, candidate);
+ self.infcx.selection_cache.insert(
+ param_env.and(trait_ref).with_constness(pred.constness),
+ dep_node,
+ candidate,
+ );
}
/// Matches a predicate against the bounds of its self type.
@@ -1213,7 +1293,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
.enumerate()
.filter_map(|(idx, bound)| {
let bound_predicate = bound.kind();
- if let ty::PredicateKind::Trait(pred, _) = bound_predicate.skip_binder() {
+ if let ty::PredicateKind::Trait(pred) = bound_predicate.skip_binder() {
let bound = bound_predicate.rebind(pred.trait_ref);
if self.infcx.probe(|_| {
match self.match_normalize_trait_ref(
@@ -1997,8 +2077,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
fn match_fresh_trait_refs(
&self,
- previous: ty::PolyTraitRef<'tcx>,
- current: ty::PolyTraitRef<'tcx>,
+ previous: ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>,
+ current: ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>,
param_env: ty::ParamEnv<'tcx>,
) -> bool {
let mut matcher = ty::_match::Match::new(self.tcx(), param_env);
@@ -2010,8 +2090,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
previous_stack: TraitObligationStackList<'o, 'tcx>,
obligation: &'o TraitObligation<'tcx>,
) -> TraitObligationStack<'o, 'tcx> {
- let fresh_trait_ref =
- obligation.predicate.to_poly_trait_ref().fold_with(&mut self.freshener);
+ let fresh_trait_ref = obligation
+ .predicate
+ .to_poly_trait_ref()
+ .fold_with(&mut self.freshener)
+ .with_constness(obligation.predicate.skip_binder().constness);
let dfn = previous_stack.cache.next_dfn();
let depth = previous_stack.depth() + 1;
@@ -2290,7 +2373,7 @@ struct ProvisionalEvaluationCache<'tcx> {
/// - then we determine that `E` is in error -- we will then clear
/// all cache values whose DFN is >= 4 -- in this case, that
/// means the cached value for `F`.
- map: RefCell<FxHashMap<ty::PolyTraitRef<'tcx>, ProvisionalEvaluation>>,
+ map: RefCell<FxHashMap<ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>, ProvisionalEvaluation>>,
}
/// A cache value for the provisional cache: contains the depth-first
@@ -2322,7 +2405,7 @@ impl<'tcx> ProvisionalEvaluationCache<'tcx> {
/// `reached_depth` (from the returned value).
fn get_provisional(
&self,
- fresh_trait_ref: ty::PolyTraitRef<'tcx>,
+ fresh_trait_ref: ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>,
) -> Option<ProvisionalEvaluation> {
debug!(
?fresh_trait_ref,
@@ -2340,7 +2423,7 @@ impl<'tcx> ProvisionalEvaluationCache<'tcx> {
&self,
from_dfn: usize,
reached_depth: usize,
- fresh_trait_ref: ty::PolyTraitRef<'tcx>,
+ fresh_trait_ref: ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>,
result: EvaluationResult,
) {
debug!(?from_dfn, ?fresh_trait_ref, ?result, "insert_provisional");
@@ -2418,7 +2501,7 @@ impl<'tcx> ProvisionalEvaluationCache<'tcx> {
fn on_completion(
&self,
dfn: usize,
- mut op: impl FnMut(ty::PolyTraitRef<'tcx>, EvaluationResult),
+ mut op: impl FnMut(ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>, EvaluationResult),
) {
debug!(?dfn, "on_completion");
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index 27c8e00c5596c..9c9664d7b5e84 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -108,7 +108,7 @@ pub fn predicate_obligations<'a, 'tcx>(
// It's ok to skip the binder here because wf code is prepared for it
match predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(t, _) => {
+ ty::PredicateKind::Trait(t) => {
wf.compute_trait_ref(&t.trait_ref, Elaborate::None);
}
ty::PredicateKind::RegionOutlives(..) => {}
@@ -226,7 +226,7 @@ fn extend_cause_with_original_assoc_item_obligation<'tcx>(
}
}
}
- ty::PredicateKind::Trait(pred, _) => {
+ ty::PredicateKind::Trait(pred) => {
// An associated item obligation born out of the `trait` failed to be met. An example
// can be seen in `ui/associated-types/point-at-type-on-obligation-failure-2.rs`.
debug!("extended_cause_with_original_assoc_item_obligation trait proj {:?}", pred);
diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs
index a838172d664c3..974755e9e2669 100644
--- a/compiler/rustc_traits/src/chalk/lowering.rs
+++ b/compiler/rustc_traits/src/chalk/lowering.rs
@@ -87,7 +87,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'
ty::PredicateKind::TypeWellFormedFromEnv(ty) => {
chalk_ir::DomainGoal::FromEnv(chalk_ir::FromEnv::Ty(ty.lower_into(interner)))
}
- ty::PredicateKind::Trait(predicate, _) => chalk_ir::DomainGoal::FromEnv(
+ ty::PredicateKind::Trait(predicate) => chalk_ir::DomainGoal::FromEnv(
chalk_ir::FromEnv::Trait(predicate.trait_ref.lower_into(interner)),
),
ty::PredicateKind::RegionOutlives(predicate) => chalk_ir::DomainGoal::Holds(
@@ -137,7 +137,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predi
collect_bound_vars(interner, interner.tcx, self.kind());
let value = match predicate {
- ty::PredicateKind::Trait(predicate, _) => {
+ ty::PredicateKind::Trait(predicate) => {
chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::Holds(
chalk_ir::WhereClause::Implemented(predicate.trait_ref.lower_into(interner)),
))
@@ -569,7 +569,7 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_ir::QuantifiedWhereClause<RustInterner<'
let (predicate, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, self.kind());
let value = match predicate {
- ty::PredicateKind::Trait(predicate, _) => {
+ ty::PredicateKind::Trait(predicate) => {
Some(chalk_ir::WhereClause::Implemented(predicate.trait_ref.lower_into(interner)))
}
ty::PredicateKind::RegionOutlives(predicate) => {
@@ -702,7 +702,7 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_solve::rust_ir::QuantifiedInlineBound<Ru
let (predicate, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, self.kind());
match predicate {
- ty::PredicateKind::Trait(predicate, _) => Some(chalk_ir::Binders::new(
+ ty::PredicateKind::Trait(predicate) => Some(chalk_ir::Binders::new(
binders,
chalk_solve::rust_ir::InlineBound::TraitBound(
predicate.trait_ref.lower_into(interner),
diff --git a/compiler/rustc_traits/src/type_op.rs b/compiler/rustc_traits/src/type_op.rs
index 2c55ea7f5c14e..f4a0cc6767f09 100644
--- a/compiler/rustc_traits/src/type_op.rs
+++ b/compiler/rustc_traits/src/type_op.rs
@@ -6,7 +6,9 @@ use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
use rustc_infer::traits::TraitEngineExt as _;
use rustc_middle::ty::query::Providers;
use rustc_middle::ty::subst::{GenericArg, Subst, UserSelfTy, UserSubsts};
-use rustc_middle::ty::{self, FnSig, Lift, PolyFnSig, Ty, TyCtxt, TypeFoldable, Variance};
+use rustc_middle::ty::{
+ self, FnSig, Lift, PolyFnSig, PredicateKind, Ty, TyCtxt, TypeFoldable, Variance,
+};
use rustc_middle::ty::{ParamEnv, ParamEnvAnd, Predicate, ToPredicate};
use rustc_span::DUMMY_SP;
use rustc_trait_selection::infer::InferCtxtBuilderExt;
@@ -85,7 +87,16 @@ impl AscribeUserTypeCx<'me, 'tcx> {
Ok(())
}
- fn prove_predicate(&mut self, predicate: Predicate<'tcx>) {
+ fn prove_predicate(&mut self, mut predicate: Predicate<'tcx>) {
+ if let PredicateKind::Trait(mut tr) = predicate.kind().skip_binder() {
+ if let hir::Constness::Const = tr.constness {
+ // FIXME check if we actually want to prove const predicates inside AscribeUserType
+ tr.constness = hir::Constness::NotConst;
+ predicate =
+ predicate.kind().rebind(PredicateKind::Trait(tr)).to_predicate(self.tcx());
+ }
+ }
+
self.fulfill_cx.register_predicate_obligation(
self.infcx,
Obligation::new(ObligationCause::dummy(), self.param_env, predicate),
@@ -126,6 +137,7 @@ impl AscribeUserTypeCx<'me, 'tcx> {
// outlives" error messages.
let instantiated_predicates =
self.tcx().predicates_of(def_id).instantiate(self.tcx(), substs);
+ debug!(?instantiated_predicates.predicates);
for instantiated_predicate in instantiated_predicates.predicates {
let instantiated_predicate = self.normalize(instantiated_predicate);
self.prove_predicate(instantiated_predicate);
diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs
index 92583f2b0ea9b..3f72a431bd155 100644
--- a/compiler/rustc_typeck/src/astconv/mod.rs
+++ b/compiler/rustc_typeck/src/astconv/mod.rs
@@ -1340,7 +1340,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
let bound_predicate = obligation.predicate.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(pred, _) => {
+ ty::PredicateKind::Trait(pred) => {
let pred = bound_predicate.rebind(pred);
associated_types.entry(span).or_default().extend(
tcx.associated_items(pred.def_id())
diff --git a/compiler/rustc_typeck/src/check/_match.rs b/compiler/rustc_typeck/src/check/_match.rs
index 10c3a97e73a5a..4f8c8ca899f90 100644
--- a/compiler/rustc_typeck/src/check/_match.rs
+++ b/compiler/rustc_typeck/src/check/_match.rs
@@ -606,16 +606,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let mut suggest_box = !obligations.is_empty();
for o in obligations {
match o.predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(t, constness) => {
- let pred = ty::PredicateKind::Trait(
- ty::TraitPredicate {
- trait_ref: ty::TraitRef {
- def_id: t.def_id(),
- substs: self.infcx.tcx.mk_substs_trait(outer_ty, &[]),
- },
+ ty::PredicateKind::Trait(t) => {
+ let pred = ty::PredicateKind::Trait(ty::TraitPredicate {
+ trait_ref: ty::TraitRef {
+ def_id: t.def_id(),
+ substs: self.infcx.tcx.mk_substs_trait(outer_ty, &[]),
},
- constness,
- );
+ constness: t.constness,
+ });
let obl = Obligation::new(
o.cause.clone(),
self.param_env,
diff --git a/compiler/rustc_typeck/src/check/coercion.rs b/compiler/rustc_typeck/src/check/coercion.rs
index a83b39a110834..208eb27c84406 100644
--- a/compiler/rustc_typeck/src/check/coercion.rs
+++ b/compiler/rustc_typeck/src/check/coercion.rs
@@ -587,9 +587,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
debug!("coerce_unsized resolve step: {:?}", obligation);
let bound_predicate = obligation.predicate.kind();
let trait_pred = match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(trait_pred, _)
- if traits.contains(&trait_pred.def_id()) =>
- {
+ ty::PredicateKind::Trait(trait_pred) if traits.contains(&trait_pred.def_id()) => {
if unsize_did == trait_pred.def_id() {
let self_ty = trait_pred.self_ty();
let unsize_ty = trait_pred.trait_ref.substs[1].expect_ty();
diff --git a/compiler/rustc_typeck/src/check/compare_method.rs b/compiler/rustc_typeck/src/check/compare_method.rs
index d35868881558e..316a097556aec 100644
--- a/compiler/rustc_typeck/src/check/compare_method.rs
+++ b/compiler/rustc_typeck/src/check/compare_method.rs
@@ -1292,7 +1292,13 @@ pub fn check_type_bounds<'tcx>(
};
tcx.infer_ctxt().enter(move |infcx| {
- let inh = Inherited::new(infcx, impl_ty.def_id.expect_local());
+ let constness = impl_ty
+ .container
+ .impl_def_id()
+ .map(|did| tcx.impl_constness(did))
+ .unwrap_or(hir::Constness::NotConst);
+
+ let inh = Inherited::with_constness(infcx, impl_ty.def_id.expect_local(), constness);
let infcx = &inh.infcx;
let mut selcx = traits::SelectionContext::new(&infcx);
@@ -1334,7 +1340,9 @@ pub fn check_type_bounds<'tcx>(
// Check that all obligations are satisfied by the implementation's
// version.
- if let Err(ref errors) = inh.fulfillment_cx.borrow_mut().select_all_or_error(&infcx) {
+ if let Err(ref errors) =
+ inh.fulfillment_cx.borrow_mut().select_all_with_constness_or_error(&infcx, constness)
+ {
infcx.report_fulfillment_errors(errors, None, false);
return Err(ErrorReported);
}
diff --git a/compiler/rustc_typeck/src/check/dropck.rs b/compiler/rustc_typeck/src/check/dropck.rs
index 17f5020300d40..c34dd705bef7b 100644
--- a/compiler/rustc_typeck/src/check/dropck.rs
+++ b/compiler/rustc_typeck/src/check/dropck.rs
@@ -229,7 +229,7 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
let predicate = predicate.kind();
let p = p.kind();
match (predicate.skip_binder(), p.skip_binder()) {
- (ty::PredicateKind::Trait(a, _), ty::PredicateKind::Trait(b, _)) => {
+ (ty::PredicateKind::Trait(a), ty::PredicateKind::Trait(b)) => {
relator.relate(predicate.rebind(a), p.rebind(b)).is_ok()
}
(ty::PredicateKind::Projection(a), ty::PredicateKind::Projection(b)) => {
diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs
index b84a79b768c9a..c13901ae8be2b 100644
--- a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs
+++ b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs
@@ -714,7 +714,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
pub(in super::super) fn select_all_obligations_or_error(&self) {
debug!("select_all_obligations_or_error");
- if let Err(errors) = self.fulfillment_cx.borrow_mut().select_all_or_error(&self) {
+ if let Err(errors) = self
+ .fulfillment_cx
+ .borrow_mut()
+ .select_all_with_constness_or_error(&self, self.inh.constness)
+ {
self.report_fulfillment_errors(&errors, self.inh.body_id, false);
}
}
@@ -725,7 +729,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
fallback_has_occurred: bool,
mutate_fulfillment_errors: impl Fn(&mut Vec<traits::FulfillmentError<'tcx>>),
) {
- let result = self.fulfillment_cx.borrow_mut().select_where_possible(self);
+ let result = self
+ .fulfillment_cx
+ .borrow_mut()
+ .select_with_constness_where_possible(self, self.inh.constness);
if let Err(mut errors) = result {
mutate_fulfillment_errors(&mut errors);
self.report_fulfillment_errors(&errors, self.inh.body_id, fallback_has_occurred);
@@ -796,7 +803,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
bound_predicate.rebind(data).required_poly_trait_ref(self.tcx),
obligation,
)),
- ty::PredicateKind::Trait(data, _) => {
+ ty::PredicateKind::Trait(data) => {
Some((bound_predicate.rebind(data).to_poly_trait_ref(), obligation))
}
ty::PredicateKind::Subtype(..) => None,
diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
index f65cc429fbd48..9952413353fa9 100644
--- a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
+++ b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
@@ -923,7 +923,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
continue;
}
- if let ty::PredicateKind::Trait(predicate, _) =
+ if let ty::PredicateKind::Trait(predicate) =
error.obligation.predicate.kind().skip_binder()
{
// Collect the argument position for all arguments that could have caused this
@@ -974,7 +974,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
if let hir::ExprKind::Path(qpath) = &path.kind {
if let hir::QPath::Resolved(_, path) = &qpath {
for error in errors {
- if let ty::PredicateKind::Trait(predicate, _) =
+ if let ty::PredicateKind::Trait(predicate) =
error.obligation.predicate.kind().skip_binder()
{
// If any of the type arguments in this path segment caused the
diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs b/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs
index 13686cfec809a..c0ecee155c6dd 100644
--- a/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs
+++ b/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs
@@ -174,7 +174,7 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
}
fn default_constness_for_trait_bounds(&self) -> hir::Constness {
- self.tcx.hir().get(self.body_id).constness()
+ self.tcx.hir().get(self.body_id).constness_for_typeck()
}
fn get_type_parameter_bounds(
@@ -194,7 +194,7 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
predicates: tcx.arena.alloc_from_iter(
self.param_env.caller_bounds().iter().filter_map(|predicate| {
match predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(data, _) if data.self_ty().is_param(index) => {
+ ty::PredicateKind::Trait(data) if data.self_ty().is_param(index) => {
// HACK(eddyb) should get the original `Span`.
let span = tcx.def_span(def_id);
Some((predicate, span))
diff --git a/compiler/rustc_typeck/src/check/inherited.rs b/compiler/rustc_typeck/src/check/inherited.rs
index fb7beae70ba1e..6006c8f7513d7 100644
--- a/compiler/rustc_typeck/src/check/inherited.rs
+++ b/compiler/rustc_typeck/src/check/inherited.rs
@@ -52,6 +52,9 @@ pub struct Inherited<'a, 'tcx> {
pub(super) deferred_generator_interiors:
RefCell<Vec<(hir::BodyId, Ty<'tcx>, hir::GeneratorKind)>>,
+ /// Reports whether this is in a const context.
+ pub(super) constness: hir::Constness,
+
pub(super) body_id: Option<hir::BodyId>,
}
@@ -93,6 +96,16 @@ impl<'tcx> InheritedBuilder<'tcx> {
impl Inherited<'a, 'tcx> {
pub(super) fn new(infcx: InferCtxt<'a, 'tcx>, def_id: LocalDefId) -> Self {
+ let tcx = infcx.tcx;
+ let item_id = tcx.hir().local_def_id_to_hir_id(def_id);
+ Self::with_constness(infcx, def_id, tcx.hir().get(item_id).constness_for_typeck())
+ }
+
+ pub(super) fn with_constness(
+ infcx: InferCtxt<'a, 'tcx>,
+ def_id: LocalDefId,
+ constness: hir::Constness,
+ ) -> Self {
let tcx = infcx.tcx;
let item_id = tcx.hir().local_def_id_to_hir_id(def_id);
let body_id = tcx.hir().maybe_body_owned_by(item_id);
@@ -108,6 +121,7 @@ impl Inherited<'a, 'tcx> {
deferred_call_resolutions: RefCell::new(Default::default()),
deferred_cast_checks: RefCell::new(Vec::new()),
deferred_generator_interiors: RefCell::new(Vec::new()),
+ constness,
body_id,
}
}
diff --git a/compiler/rustc_typeck/src/check/method/confirm.rs b/compiler/rustc_typeck/src/check/method/confirm.rs
index 3aceaba882d6c..88be49e96e7be 100644
--- a/compiler/rustc_typeck/src/check/method/confirm.rs
+++ b/compiler/rustc_typeck/src/check/method/confirm.rs
@@ -507,7 +507,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
traits::elaborate_predicates(self.tcx, predicates.predicates.iter().copied())
// We don't care about regions here.
.filter_map(|obligation| match obligation.predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(trait_pred, _) if trait_pred.def_id() == sized_def_id => {
+ ty::PredicateKind::Trait(trait_pred) if trait_pred.def_id() == sized_def_id => {
let span = iter::zip(&predicates.predicates, &predicates.spans)
.find_map(
|(p, span)| {
diff --git a/compiler/rustc_typeck/src/check/method/probe.rs b/compiler/rustc_typeck/src/check/method/probe.rs
index 9037ffe49a9a2..c6e6c8c5d70e2 100644
--- a/compiler/rustc_typeck/src/check/method/probe.rs
+++ b/compiler/rustc_typeck/src/check/method/probe.rs
@@ -832,7 +832,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
let bounds = self.param_env.caller_bounds().iter().filter_map(|predicate| {
let bound_predicate = predicate.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(trait_predicate, _) => {
+ ty::PredicateKind::Trait(trait_predicate) => {
match *trait_predicate.trait_ref.self_ty().kind() {
ty::Param(p) if p == param_ty => {
Some(bound_predicate.rebind(trait_predicate.trait_ref))
diff --git a/compiler/rustc_typeck/src/check/method/suggest.rs b/compiler/rustc_typeck/src/check/method/suggest.rs
index c7a7462668aa5..1d5a9e3e1f968 100644
--- a/compiler/rustc_typeck/src/check/method/suggest.rs
+++ b/compiler/rustc_typeck/src/check/method/suggest.rs
@@ -683,7 +683,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let mut collect_type_param_suggestions =
|self_ty: Ty<'tcx>, parent_pred: &ty::Predicate<'tcx>, obligation: &str| {
// We don't care about regions here, so it's fine to skip the binder here.
- if let (ty::Param(_), ty::PredicateKind::Trait(p, _)) =
+ if let (ty::Param(_), ty::PredicateKind::Trait(p)) =
(self_ty.kind(), parent_pred.kind().skip_binder())
{
if let ty::Adt(def, _) = p.trait_ref.self_ty().kind() {
@@ -763,7 +763,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
bound_span_label(projection_ty.self_ty(), &obligation, &quiet);
Some((obligation, projection_ty.self_ty()))
}
- ty::PredicateKind::Trait(poly_trait_ref, _) => {
+ ty::PredicateKind::Trait(poly_trait_ref) => {
let p = poly_trait_ref.trait_ref;
let self_ty = p.self_ty();
let path = p.print_only_trait_path();
@@ -1200,7 +1200,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
match p.kind().skip_binder() {
// Hide traits if they are present in predicates as they can be fixed without
// having to implement them.
- ty::PredicateKind::Trait(t, _) => t.def_id() == info.def_id,
+ ty::PredicateKind::Trait(t) => t.def_id() == info.def_id,
ty::PredicateKind::Projection(p) => {
p.projection_ty.item_def_id == info.def_id
}
diff --git a/compiler/rustc_typeck/src/check/mod.rs b/compiler/rustc_typeck/src/check/mod.rs
index 92c162c4861b1..d1e583ed1845a 100644
--- a/compiler/rustc_typeck/src/check/mod.rs
+++ b/compiler/rustc_typeck/src/check/mod.rs
@@ -689,7 +689,7 @@ fn bounds_from_generic_predicates<'tcx>(
debug!("predicate {:?}", predicate);
let bound_predicate = predicate.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(trait_predicate, _) => {
+ ty::PredicateKind::Trait(trait_predicate) => {
let entry = types.entry(trait_predicate.self_ty()).or_default();
let def_id = trait_predicate.def_id();
if Some(def_id) != tcx.lang_items().sized_trait() {
diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index eb94fde21099b..9fbf5ab85334f 100644
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -364,7 +364,7 @@ impl AstConv<'tcx> for ItemCtxt<'tcx> {
}
fn default_constness_for_trait_bounds(&self) -> hir::Constness {
- self.node().constness()
+ self.node().constness_for_typeck()
}
fn get_type_parameter_bounds(
@@ -640,7 +640,7 @@ fn type_param_predicates(
)
.into_iter()
.filter(|(predicate, _)| match predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(data, _) => data.self_ty().is_param(index),
+ ty::PredicateKind::Trait(data) => data.self_ty().is_param(index),
_ => false,
}),
);
@@ -1198,7 +1198,7 @@ fn super_predicates_that_define_assoc_type(
// which will, in turn, reach indirect supertraits.
for &(pred, span) in superbounds {
debug!("superbound: {:?}", pred);
- if let ty::PredicateKind::Trait(bound, _) = pred.kind().skip_binder() {
+ if let ty::PredicateKind::Trait(bound) = pred.kind().skip_binder() {
tcx.at(span).super_predicates_of(bound.def_id());
}
}
@@ -2439,7 +2439,7 @@ fn explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicat
.iter()
.copied()
.filter(|(pred, _)| match pred.kind().skip_binder() {
- ty::PredicateKind::Trait(tr, _) => !is_assoc_item_ty(tr.self_ty()),
+ ty::PredicateKind::Trait(tr) => !is_assoc_item_ty(tr.self_ty()),
ty::PredicateKind::Projection(proj) => {
!is_assoc_item_ty(proj.projection_ty.self_ty())
}
diff --git a/compiler/rustc_typeck/src/collect/item_bounds.rs b/compiler/rustc_typeck/src/collect/item_bounds.rs
index a5b36445aae2e..1d08c4450afcf 100644
--- a/compiler/rustc_typeck/src/collect/item_bounds.rs
+++ b/compiler/rustc_typeck/src/collect/item_bounds.rs
@@ -38,7 +38,7 @@ fn associated_type_bounds<'tcx>(
let bounds_from_parent = trait_predicates.predicates.iter().copied().filter(|(pred, _)| {
match pred.kind().skip_binder() {
- ty::PredicateKind::Trait(tr, _) => tr.self_ty() == item_ty,
+ ty::PredicateKind::Trait(tr) => tr.self_ty() == item_ty,
ty::PredicateKind::Projection(proj) => proj.projection_ty.self_ty() == item_ty,
ty::PredicateKind::TypeOutlives(outlives) => outlives.0 == item_ty,
_ => false,
diff --git a/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs b/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs
index 505d9a59d9c2f..d5d81603fc516 100644
--- a/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs
@@ -366,7 +366,10 @@ fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, predicate: ty::Predicate<'tc
_ if predicate.is_global() => (),
// We allow specializing on explicitly marked traits with no associated
// items.
- ty::PredicateKind::Trait(pred, hir::Constness::NotConst) => {
+ ty::PredicateKind::Trait(ty::TraitPredicate {
+ trait_ref,
+ constness: hir::Constness::NotConst,
+ }) => {
if !matches!(
trait_predicate_kind(tcx, predicate),
Some(TraitSpecializationKind::Marker)
@@ -376,7 +379,7 @@ fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, predicate: ty::Predicate<'tc
span,
&format!(
"cannot specialize on trait `{}`",
- tcx.def_path_str(pred.def_id()),
+ tcx.def_path_str(trait_ref.def_id),
),
)
.emit()
@@ -394,10 +397,11 @@ fn trait_predicate_kind<'tcx>(
predicate: ty::Predicate<'tcx>,
) -> Option<TraitSpecializationKind> {
match predicate.kind().skip_binder() {
- ty::PredicateKind::Trait(pred, hir::Constness::NotConst) => {
- Some(tcx.trait_def(pred.def_id()).specialization_kind)
- }
- ty::PredicateKind::Trait(_, hir::Constness::Const)
+ ty::PredicateKind::Trait(ty::TraitPredicate {
+ trait_ref,
+ constness: hir::Constness::NotConst,
+ }) => Some(tcx.trait_def(trait_ref.def_id).specialization_kind),
+ ty::PredicateKind::Trait(_)
| ty::PredicateKind::RegionOutlives(_)
| ty::PredicateKind::TypeOutlives(_)
| ty::PredicateKind::Projection(_)
diff --git a/library/alloc/src/collections/btree/map/tests.rs b/library/alloc/src/collections/btree/map/tests.rs
index 1e61692b7c63c..17e538483431c 100644
--- a/library/alloc/src/collections/btree/map/tests.rs
+++ b/library/alloc/src/collections/btree/map/tests.rs
@@ -1786,13 +1786,6 @@ fn test_ord_absence() {
}
}
-#[allow(dead_code)]
-fn test_const() {
- const MAP: &'static BTreeMap<(), ()> = &BTreeMap::new();
- const LEN: usize = MAP.len();
- const IS_EMPTY: bool = MAP.is_empty();
-}
-
#[test]
fn test_occupied_entry_key() {
let mut a = BTreeMap::new();
diff --git a/library/alloc/src/collections/btree/set/tests.rs b/library/alloc/src/collections/btree/set/tests.rs
index de7a10dca7b8c..5d590a26281d2 100644
--- a/library/alloc/src/collections/btree/set/tests.rs
+++ b/library/alloc/src/collections/btree/set/tests.rs
@@ -16,13 +16,6 @@ fn test_clone_eq() {
assert_eq!(m.clone(), m);
}
-#[allow(dead_code)]
-fn test_const() {
- const SET: &'static BTreeSet<()> = &BTreeSet::new();
- const LEN: usize = SET.len();
- const IS_EMPTY: bool = SET.is_empty();
-}
-
#[test]
fn test_iter_min_max() {
let mut a = BTreeSet::new();
diff --git a/library/alloc/tests/const_fns.rs b/library/alloc/tests/const_fns.rs
new file mode 100644
index 0000000000000..02e8f8f40228f
--- /dev/null
+++ b/library/alloc/tests/const_fns.rs
@@ -0,0 +1,53 @@
+// Test several functions can be used for constants
+// 1. Vec::new()
+// 2. String::new()
+// 3. BTreeMap::new()
+// 4. BTreeSet::new()
+
+#[allow(dead_code)]
+pub const MY_VEC: Vec<usize> = Vec::new();
+
+#[allow(dead_code)]
+pub const MY_STRING: String = String::new();
+
+// FIXME remove this struct once we put `K: ?const Ord` on BTreeMap::new.
+#[derive(PartialEq, Eq, PartialOrd)]
+pub struct MyType;
+
+impl const Ord for MyType {
+ fn cmp(&self, _: &Self) -> Ordering {
+ Ordering::Equal
+ }
+
+ fn max(self, _: Self) -> Self {
+ Self
+ }
+
+ fn min(self, _: Self) -> Self {
+ Self
+ }
+
+ fn clamp(self, _: Self, _: Self) -> Self {
+ Self
+ }
+}
+
+use core::cmp::Ordering;
+use std::collections::{BTreeMap, BTreeSet};
+
+pub const MY_BTREEMAP: BTreeMap<MyType, MyType> = BTreeMap::new();
+pub const MAP: &'static BTreeMap<MyType, MyType> = &MY_BTREEMAP;
+pub const MAP_LEN: usize = MAP.len();
+pub const MAP_IS_EMPTY: bool = MAP.is_empty();
+
+pub const MY_BTREESET: BTreeSet<MyType> = BTreeSet::new();
+pub const SET: &'static BTreeSet<MyType> = &MY_BTREESET;
+pub const SET_LEN: usize = SET.len();
+pub const SET_IS_EMPTY: bool = SET.is_empty();
+
+#[test]
+fn test_const() {
+ assert_eq!(MAP_LEN, 0);
+ assert_eq!(SET_LEN, 0);
+ assert!(MAP_IS_EMPTY && SET_IS_EMPTY)
+}
diff --git a/library/alloc/tests/lib.rs b/library/alloc/tests/lib.rs
index 8fca2662fc304..f7d68b5a89e99 100644
--- a/library/alloc/tests/lib.rs
+++ b/library/alloc/tests/lib.rs
@@ -23,6 +23,10 @@
#![feature(slice_partition_dedup)]
#![feature(vec_spare_capacity)]
#![feature(string_remove_matches)]
+#![feature(const_btree_new)]
+#![feature(const_trait_impl)]
+// FIXME remove this when const_trait_impl is not incomplete anymore
+#![allow(incomplete_features)]
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};
@@ -32,6 +36,7 @@ mod binary_heap;
mod borrow;
mod boxed;
mod btree_set_hash;
+mod const_fns;
mod cow_str;
mod fmt;
mod heap;
diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index e479d162b8ffb..58a87673241f5 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -316,7 +316,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
let bound_predicate = pred.kind();
let tcx = self.cx.tcx;
let regions = match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(poly_trait_pred, _) => {
+ ty::PredicateKind::Trait(poly_trait_pred) => {
tcx.collect_referenced_late_bound_regions(&bound_predicate.rebind(poly_trait_pred))
}
ty::PredicateKind::Projection(poly_proj_pred) => {
@@ -463,7 +463,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
.filter(|p| {
!orig_bounds.contains(p)
|| match p.kind().skip_binder() {
- ty::PredicateKind::Trait(pred, _) => pred.def_id() == sized_trait,
+ ty::PredicateKind::Trait(pred) => pred.def_id() == sized_trait,
_ => false,
}
})
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 3d65fcedaf4e5..02cfea914209b 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -325,7 +325,7 @@ impl<'a> Clean<Option<WherePredicate>> for ty::Predicate<'a> {
fn clean(&self, cx: &mut DocContext<'_>) -> Option<WherePredicate> {
let bound_predicate = self.kind();
match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(pred, _) => Some(bound_predicate.rebind(pred).clean(cx)),
+ ty::PredicateKind::Trait(pred) => Some(bound_predicate.rebind(pred).clean(cx)),
ty::PredicateKind::RegionOutlives(pred) => pred.clean(cx),
ty::PredicateKind::TypeOutlives(pred) => pred.clean(cx),
ty::PredicateKind::Projection(pred) => Some(pred.clean(cx)),
@@ -637,7 +637,7 @@ impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics, ty::GenericPredicates<'tcx
let param_idx = (|| {
let bound_p = p.kind();
match bound_p.skip_binder() {
- ty::PredicateKind::Trait(pred, _constness) => {
+ ty::PredicateKind::Trait(pred) => {
if let ty::Param(param) = pred.self_ty().kind() {
return Some(param.index);
}
@@ -1555,9 +1555,7 @@ impl<'tcx> Clean<Type> for Ty<'tcx> {
.filter_map(|bound| {
let bound_predicate = bound.kind();
let trait_ref = match bound_predicate.skip_binder() {
- ty::PredicateKind::Trait(tr, _constness) => {
- bound_predicate.rebind(tr.trait_ref)
- }
+ ty::PredicateKind::Trait(tr) => bound_predicate.rebind(tr.trait_ref),
ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(_ty, reg)) => {
if let Some(r) = reg.clean(cx) {
regions.push(GenericBound::Outlives(r));
diff --git a/src/librustdoc/clean/simplify.rs b/src/librustdoc/clean/simplify.rs
index 3ec0a22a2c09a..c0d52d349280f 100644
--- a/src/librustdoc/clean/simplify.rs
+++ b/src/librustdoc/clean/simplify.rs
@@ -139,7 +139,7 @@ fn trait_is_same_or_supertrait(cx: &DocContext<'_>, child: DefId, trait_: DefId)
.predicates
.iter()
.filter_map(|(pred, _)| {
- if let ty::PredicateKind::Trait(pred, _) = pred.kind().skip_binder() {
+ if let ty::PredicateKind::Trait(pred) = pred.kind().skip_binder() {
if pred.trait_ref.self_ty() == self_ty { Some(pred.def_id()) } else { None }
} else {
None
diff --git a/src/test/ui/collections-const-new.rs b/src/test/ui/collections-const-new.rs
deleted file mode 100644
index 978f25f9a9344..0000000000000
--- a/src/test/ui/collections-const-new.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-// check-pass
-
-// Test several functions can be used for constants
-// 1. Vec::new()
-// 2. String::new()
-// 3. BTreeMap::new()
-// 4. BTreeSet::new()
-
-#![feature(const_btree_new)]
-
-const MY_VEC: Vec<usize> = Vec::new();
-
-const MY_STRING: String = String::new();
-
-use std::collections::{BTreeMap, BTreeSet};
-const MY_BTREEMAP: BTreeMap<u32, u32> = BTreeMap::new();
-
-const MY_BTREESET: BTreeSet<u32> = BTreeSet::new();
-
-fn main() {}
diff --git a/src/test/ui/consts/const-eval/issue-49296.rs b/src/test/ui/consts/const-eval/issue-49296.rs
index ba0885532f113..bb8113e53f9c1 100644
--- a/src/test/ui/consts/const-eval/issue-49296.rs
+++ b/src/test/ui/consts/const-eval/issue-49296.rs
@@ -1,8 +1,10 @@
// issue-49296: Unsafe shenigans in constants can result in missing errors
#![feature(const_fn_trait_bound)]
+#![feature(const_trait_bound_opt_out)]
+#![allow(incomplete_features)]
-const unsafe fn transmute<T: Copy, U: Copy>(t: T) -> U {
+const unsafe fn transmute<T: ?const Copy, U: ?const Copy>(t: T) -> U {
#[repr(C)]
union Transmute<T: Copy, U: Copy> {
from: T,
diff --git a/src/test/ui/consts/const-eval/issue-49296.stderr b/src/test/ui/consts/const-eval/issue-49296.stderr
index e87ef160b8278..28fdcb7c48637 100644
--- a/src/test/ui/consts/const-eval/issue-49296.stderr
+++ b/src/test/ui/consts/const-eval/issue-49296.stderr
@@ -1,5 +1,5 @@
error[E0080]: evaluation of constant value failed
- --> $DIR/issue-49296.rs:18:16
+ --> $DIR/issue-49296.rs:20:16
|
LL | const X: u64 = *wat(42);
| ^^^^^^^^ pointer to alloc2 was dereferenced after this allocation got freed
diff --git a/src/test/ui/generic-associated-types/projection-bound-cycle-generic.stderr b/src/test/ui/generic-associated-types/projection-bound-cycle-generic.stderr
index 345e2b3fcb12c..e7f801a7bd4b1 100644
--- a/src/test/ui/generic-associated-types/projection-bound-cycle-generic.stderr
+++ b/src/test/ui/generic-associated-types/projection-bound-cycle-generic.stderr
@@ -1,8 +1,8 @@
error[E0275]: overflow evaluating the requirement `<T as Foo>::Item: Sized`
--> $DIR/projection-bound-cycle-generic.rs:44:18
|
-LL | struct OnlySized<T> where T: Sized { f: T }
- | - required by this bound in `OnlySized`
+LL | type Item: Sized where <Self as Foo>::Item: Sized;
+ | ----- required by this bound in `Foo::Item`
...
LL | type Assoc = OnlySized<<T as Foo>::Item>;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/generic-associated-types/projection-bound-cycle.stderr b/src/test/ui/generic-associated-types/projection-bound-cycle.stderr
index eefc09fa78863..67195c65d36e6 100644
--- a/src/test/ui/generic-associated-types/projection-bound-cycle.stderr
+++ b/src/test/ui/generic-associated-types/projection-bound-cycle.stderr
@@ -1,8 +1,8 @@
error[E0275]: overflow evaluating the requirement `<T as Foo>::Item: Sized`
--> $DIR/projection-bound-cycle.rs:46:18
|
-LL | struct OnlySized<T> where T: Sized { f: T }
- | - required by this bound in `OnlySized`
+LL | type Item: Sized where <Self as Foo>::Item: Sized;
+ | ----- required by this bound in `Foo::Item`
...
LL | type Assoc = OnlySized<<T as Foo>::Item>;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs b/src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs
index 4a1bd5da98b8a..1dbd000afd73e 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs
@@ -1,9 +1,7 @@
-// ignore-test
-
-// FIXME: This test should fail since, within a const impl of `Foo`, the bound on `Foo::Bar` should
-// require a const impl of `Add` for the associated type.
-
+// FIXME(fee1-dead): this should have a better error message
#![feature(const_trait_impl)]
+#![feature(const_trait_bound_opt_out)]
+#![allow(incomplete_features)]
struct NonConstAdd(i32);
@@ -21,6 +19,15 @@ trait Foo {
impl const Foo for NonConstAdd {
type Bar = NonConstAdd;
+ //~^ ERROR
+}
+
+trait Baz {
+ type Qux: ?const std::ops::Add;
+}
+
+impl const Baz for NonConstAdd {
+ type Qux = NonConstAdd; // OK
}
fn main() {}
diff --git a/src/test/ui/rfc-2632-const-trait-impl/assoc-type.stderr b/src/test/ui/rfc-2632-const-trait-impl/assoc-type.stderr
new file mode 100644
index 0000000000000..f690d95cc589b
--- /dev/null
+++ b/src/test/ui/rfc-2632-const-trait-impl/assoc-type.stderr
@@ -0,0 +1,18 @@
+error[E0277]: cannot add `NonConstAdd` to `NonConstAdd`
+ --> $DIR/assoc-type.rs:21:5
+ |
+LL | type Bar: std::ops::Add;
+ | ------------- required by this bound in `Foo::Bar`
+...
+LL | type Bar = NonConstAdd;
+ | ^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `NonConstAdd + NonConstAdd`
+ |
+ = help: the trait `Add` is not implemented for `NonConstAdd`
+help: consider introducing a `where` bound, but there might be an alternative better way to express this requirement
+ |
+LL | impl const Foo for NonConstAdd where NonConstAdd: Add {
+ | ++++++++++++++++++++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs b/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs
index 087f8fbdcd1ea..8343974f8c7e7 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs
@@ -1,7 +1,5 @@
-// FIXME(jschievink): this is not rejected correctly (only when the non-const impl is actually used)
-// ignore-test
-
#![feature(const_trait_impl)]
+#![feature(const_fn_trait_bound)]
struct S;
diff --git a/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-nonconst.stderr b/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-nonconst.stderr
new file mode 100644
index 0000000000000..75c7cab362147
--- /dev/null
+++ b/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-nonconst.stderr
@@ -0,0 +1,14 @@
+error[E0277]: can't compare `S` with `S`
+ --> $DIR/call-generic-method-nonconst.rs:19:34
+ |
+LL | const fn equals_self<T: PartialEq>(t: &T) -> bool {
+ | --------- required by this bound in `equals_self`
+...
+LL | pub const EQ: bool = equals_self(&S);
+ | ^^ no implementation for `S == S`
+ |
+ = help: the trait `PartialEq` is not implemented for `S`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/tools/clippy/clippy_lints/src/future_not_send.rs b/src/tools/clippy/clippy_lints/src/future_not_send.rs
index 0be03969bcbe2..3e35ada7b2a1c 100644
--- a/src/tools/clippy/clippy_lints/src/future_not_send.rs
+++ b/src/tools/clippy/clippy_lints/src/future_not_send.rs
@@ -93,7 +93,7 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
cx.tcx.infer_ctxt().enter(|infcx| {
for FulfillmentError { obligation, .. } in send_errors {
infcx.maybe_note_obligation_cause_for_async_await(db, &obligation);
- if let Trait(trait_pred, _) = obligation.predicate.kind().skip_binder() {
+ if let Trait(trait_pred) = obligation.predicate.kind().skip_binder() {
db.note(&format!(
"`{}` doesn't implement `{}`",
trait_pred.self_ty(),
diff --git a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
index 03eeb54d8d1c2..5e559991c1697 100644
--- a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
@@ -121,7 +121,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
.filter_map(|obligation| {
// Note that we do not want to deal with qualified predicates here.
match obligation.predicate.kind().no_bound_vars() {
- Some(ty::PredicateKind::Trait(pred, _)) if pred.def_id() != sized_trait => Some(pred),
+ Some(ty::PredicateKind::Trait(pred)) if pred.def_id() != sized_trait => Some(pred),
_ => None,
}
})
diff --git a/src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs b/src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs
index 900d453176071..ee675838c4cb3 100644
--- a/src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs
+++ b/src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs
@@ -45,7 +45,7 @@ fn get_trait_predicates_for_trait_id<'tcx>(
let mut preds = Vec::new();
for (pred, _) in generics.predicates {
if_chain! {
- if let PredicateKind::Trait(poly_trait_pred, _) = pred.kind().skip_binder();
+ if let PredicateKind::Trait(poly_trait_pred) = pred.kind().skip_binder();
let trait_pred = cx.tcx.erase_late_bound_regions(pred.kind().rebind(poly_trait_pred));
if let Some(trait_def_id) = trait_id;
if trait_def_id == trait_pred.trait_ref.def_id;
diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
index 0e6ead675c247..dee9d487c78ea 100644
--- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
+++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
@@ -36,7 +36,7 @@ pub fn is_min_const_fn(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, msrv: Option<&Ru
ty::PredicateKind::ObjectSafe(_) => panic!("object safe predicate on function: {:#?}", predicate),
ty::PredicateKind::ClosureKind(..) => panic!("closure kind predicate on function: {:#?}", predicate),
ty::PredicateKind::Subtype(_) => panic!("subtype predicate on function: {:#?}", predicate),
- ty::PredicateKind::Trait(pred, _) => {
+ ty::PredicateKind::Trait(pred) => {
if Some(pred.def_id()) == tcx.lang_items().sized_trait() {
continue;
}
diff --git a/src/tools/clippy/clippy_utils/src/ty.rs b/src/tools/clippy/clippy_utils/src/ty.rs
index 4f9aaf396b806..a2221a0b283b0 100644
--- a/src/tools/clippy/clippy_utils/src/ty.rs
+++ b/src/tools/clippy/clippy_utils/src/ty.rs
@@ -157,7 +157,7 @@ pub fn is_must_use_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
ty::Tuple(substs) => substs.types().any(|ty| is_must_use_ty(cx, ty)),
ty::Opaque(ref def_id, _) => {
for (predicate, _) in cx.tcx.explicit_item_bounds(*def_id) {
- if let ty::PredicateKind::Trait(trait_predicate, _) = predicate.kind().skip_binder() {
+ if let ty::PredicateKind::Trait(trait_predicate) = predicate.kind().skip_binder() {
if must_use_attr(cx.tcx.get_attrs(trait_predicate.trait_ref.def_id)).is_some() {
return true;
}