Auto merge of #114134 - fee1-dead-contrib:rm-constness-from-param-env, r=oli-obk

Remove `constness` from `ParamEnv`

This should be replaced by keyword generics/effects. cc #110395

r? `@oli-obk`

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -409,18 +409,12 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
             }
 
             if let ty::FnDef(def_id, args) = *constant.literal.ty().kind() {
-                // const_trait_impl: use a non-const param env when checking that a FnDef type is well formed.
-                // this is because the well-formedness of the function does not need to be proved to have `const`
-                // impls for trait bounds.
                 let instantiated_predicates = tcx.predicates_of(def_id).instantiate(tcx, args);
-                let prev = self.cx.param_env;
-                self.cx.param_env = prev.without_const();
                 self.cx.normalize_and_prove_instantiated_predicates(
                     def_id,
                     instantiated_predicates,
                     locations,
                 );
-                self.cx.param_env = prev;
             }
         }
     }

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -228,7 +228,6 @@ pub fn eval_to_const_value_raw_provider<'tcx>(
     tcx: TyCtxt<'tcx>,
     key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>,
 ) -> ::rustc_middle::mir::interpret::EvalToConstValueResult<'tcx> {
-    assert!(key.param_env.is_const());
     // see comment in eval_to_allocation_raw_provider for what we're doing here
     if key.param_env.reveal() == Reveal::All {
         let mut key = key;
@@ -269,7 +268,6 @@ pub fn eval_to_allocation_raw_provider<'tcx>(
     tcx: TyCtxt<'tcx>,
     key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>,
 ) -> ::rustc_middle::mir::interpret::EvalToAllocationRawResult<'tcx> {
-    assert!(key.param_env.is_const());
     // Because the constant is computed twice (once per value of `Reveal`), we are at risk of
     // reporting the same error twice here. To resolve this, we check whether we can evaluate the
     // constant in the more restrictive `Reveal::UserFacing`, which most likely already was

compiler/rustc_const_eval/src/const_eval/fn_queries.rs

@@ -28,15 +28,18 @@ pub fn is_parent_const_impl_raw(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
         && tcx.constness(parent_id) == hir::Constness::Const
 }
 
-/// Checks whether an item is considered to be `const`. If it is a constructor, it is const. If
+/// Checks whether an item is considered to be `const`. If it is a constructor, anonymous const,
-/// it is a trait impl/function, return if it has a `const` modifier. If it is an intrinsic,
+/// const block, const item or associated const, it is const. If it is a trait impl/function,
-/// report whether said intrinsic has a `rustc_const_{un,}stable` attribute. Otherwise, return
+/// return if it has a `const` modifier. If it is an intrinsic, report whether said intrinsic
-/// `Constness::NotConst`.
+/// has a `rustc_const_{un,}stable` attribute. Otherwise, return `Constness::NotConst`.
 fn constness(tcx: TyCtxt<'_>, def_id: LocalDefId) -> hir::Constness {
     let node = tcx.hir().get_by_def_id(def_id);
 
     match node {
-        hir::Node::Ctor(_) => hir::Constness::Const,
+        hir::Node::Ctor(_)
+        | hir::Node::AnonConst(_)
+        | hir::Node::ConstBlock(_)
+        | hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. }) => hir::Constness::Const,
         hir::Node::Item(hir::Item { kind: hir::ItemKind::Impl(impl_), .. }) => impl_.constness,
         hir::Node::ForeignItem(hir::ForeignItem { kind: hir::ForeignItemKind::Fn(..), .. }) => {
             // Intrinsics use `rustc_const_{un,}stable` attributes to indicate constness. All other

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -958,7 +958,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         } else {
             self.param_env
         };
-        let param_env = param_env.with_const();
         let val = self.ctfe_query(span, |tcx| tcx.eval_to_allocation_raw(param_env.and(gid)))?;
         self.raw_const_to_mplace(val)
     }

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -698,10 +698,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             ty::ConstKind::Unevaluated(uv) => {
                 let instance = self.resolve(uv.def, uv.args)?;
                 let cid = GlobalId { instance, promoted: None };
-                self.ctfe_query(span, |tcx| {
+                self.ctfe_query(span, |tcx| tcx.eval_to_valtree(self.param_env.and(cid)))?
-                    tcx.eval_to_valtree(self.param_env.with_const().and(cid))
+                    .unwrap_or_else(|| bug!("unable to create ValTree for {uv:?}"))
-                })?
-                .unwrap_or_else(|| bug!("unable to create ValTree for {uv:?}"))
             }
             ty::ConstKind::Bound(..) | ty::ConstKind::Infer(..) => {
                 span_bug!(self.cur_span(), "unexpected ConstKind in ctfe: {val:?}")

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -21,7 +21,7 @@ use std::mem;
 use std::ops::Deref;
 
 use super::ops::{self, NonConstOp, Status};
-use super::qualifs::{self, CustomEq, HasMutInterior, NeedsDrop, NeedsNonConstDrop};
+use super::qualifs::{self, CustomEq, HasMutInterior, NeedsDrop};
 use super::resolver::FlowSensitiveAnalysis;
 use super::{ConstCx, Qualif};
 use crate::const_eval::is_unstable_const_fn;
@@ -34,7 +34,7 @@ type QualifResults<'mir, 'tcx, Q> =
 pub struct Qualifs<'mir, 'tcx> {
     has_mut_interior: Option<QualifResults<'mir, 'tcx, HasMutInterior>>,
     needs_drop: Option<QualifResults<'mir, 'tcx, NeedsDrop>>,
-    needs_non_const_drop: Option<QualifResults<'mir, 'tcx, NeedsNonConstDrop>>,
+    // needs_non_const_drop: Option<QualifResults<'mir, 'tcx, NeedsNonConstDrop>>,
 }
 
 impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
@@ -77,15 +77,17 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
         local: Local,
         location: Location,
     ) -> bool {
+        // FIXME(effects) replace with `NeedsNonconstDrop` after const traits work again
+        /*
         let ty = ccx.body.local_decls[local].ty;
-        if !NeedsNonConstDrop::in_any_value_of_ty(ccx, ty) {
+        if !NeedsDrop::in_any_value_of_ty(ccx, ty) {
             return false;
         }
 
         let needs_non_const_drop = self.needs_non_const_drop.get_or_insert_with(|| {
             let ConstCx { tcx, body, .. } = *ccx;
 
-            FlowSensitiveAnalysis::new(NeedsNonConstDrop, ccx)
+            FlowSensitiveAnalysis::new(NeedsDrop, ccx)
                 .into_engine(tcx, &body)
                 .iterate_to_fixpoint()
                 .into_results_cursor(&body)
@@ -93,6 +95,9 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
 
         needs_non_const_drop.seek_before_primary_effect(location);
         needs_non_const_drop.get().contains(local)
+        */
+
+        self.needs_drop(ccx, local, location)
     }
 
     /// Returns `true` if `local` is `HasMutInterior` at the given `Location`.
@@ -798,16 +803,6 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                         }
                         Ok(Some(ImplSource::UserDefined(data))) => {
                             let callee_name = tcx.item_name(callee);
-                            if let Some(&did) = tcx
-                                .associated_item_def_ids(data.impl_def_id)
-                                .iter()
-                                .find(|did| tcx.item_name(**did) == callee_name)
-                            {
-                                // using internal args is ok here, since this is only
-                                // used for the `resolve` call below
-                                fn_args = GenericArgs::identity_for_item(tcx, did);
-                                callee = did;
-                            }
 
                             if let hir::Constness::NotConst = tcx.constness(data.impl_def_id) {
                                 self.check_op(ops::FnCallNonConst {
@@ -820,6 +815,17 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                                 });
                                 return;
                             }
+
+                            if let Some(&did) = tcx
+                                .associated_item_def_ids(data.impl_def_id)
+                                .iter()
+                                .find(|did| tcx.item_name(**did) == callee_name)
+                            {
+                                // using internal args is ok here, since this is only
+                                // used for the `resolve` call below
+                                fn_args = GenericArgs::identity_for_item(tcx, did);
+                                callee = did;
+                            }
                         }
                         _ if !tcx.is_const_fn_raw(callee) => {
                             // At this point, it is only legal when the caller is in a trait
@@ -996,8 +1002,9 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 let mut err_span = self.span;
                 let ty_of_dropped_place = dropped_place.ty(self.body, self.tcx).ty;
 
+                // FIXME(effects) replace with `NeedsNonConstDrop` once we fix const traits
                 let ty_needs_non_const_drop =
-                    qualifs::NeedsNonConstDrop::in_any_value_of_ty(self.ccx, ty_of_dropped_place);
+                    qualifs::NeedsDrop::in_any_value_of_ty(self.ccx, ty_of_dropped_place);
 
                 debug!(?ty_of_dropped_place, ?ty_needs_non_const_drop);
 

compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs

@@ -5,7 +5,7 @@ use rustc_span::{symbol::sym, Span};
 
 use super::check::Qualifs;
 use super::ops::{self, NonConstOp};
-use super::qualifs::{NeedsNonConstDrop, Qualif};
+use super::qualifs::{NeedsDrop, Qualif};
 use super::ConstCx;
 
 /// Returns `true` if we should use the more precise live drop checker that runs after drop
@@ -82,7 +82,9 @@ impl<'tcx> Visitor<'tcx> for CheckLiveDrops<'_, 'tcx> {
         match &terminator.kind {
             mir::TerminatorKind::Drop { place: dropped_place, .. } => {
                 let dropped_ty = dropped_place.ty(self.body, self.tcx).ty;
-                if !NeedsNonConstDrop::in_any_value_of_ty(self.ccx, dropped_ty) {
+
+                // FIXME(effects) use `NeedsNonConstDrop`
+                if !NeedsDrop::in_any_value_of_ty(self.ccx, dropped_ty) {
                     // Instead of throwing a bug, we just return here. This is because we have to
                     // run custom `const Drop` impls.
                     return;

compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs

@@ -23,7 +23,8 @@ pub fn in_any_value_of_ty<'tcx>(
     ConstQualifs {
         has_mut_interior: HasMutInterior::in_any_value_of_ty(cx, ty),
         needs_drop: NeedsDrop::in_any_value_of_ty(cx, ty),
-        needs_non_const_drop: NeedsNonConstDrop::in_any_value_of_ty(cx, ty),
+        // FIXME(effects)
+        needs_non_const_drop: NeedsDrop::in_any_value_of_ty(cx, ty),
         custom_eq: CustomEq::in_any_value_of_ty(cx, ty),
         tainted_by_errors,
     }

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -219,11 +219,7 @@ fn compare_method_predicate_entailment<'tcx>(
     // The key step here is to update the caller_bounds's predicates to be
     // the new hybrid bounds we computed.
     let normalize_cause = traits::ObligationCause::misc(impl_m_span, impl_m_def_id);
-    let param_env = ty::ParamEnv::new(
+    let param_env = ty::ParamEnv::new(tcx.mk_clauses(&hybrid_preds.predicates), Reveal::UserFacing);
-        tcx.mk_clauses(&hybrid_preds.predicates),
-        Reveal::UserFacing,
-        hir::Constness::NotConst,
-    );
     let param_env = traits::normalize_param_env_or_error(tcx, param_env, normalize_cause);
 
     let infcx = &tcx.infer_ctxt().build();
@@ -1923,11 +1919,7 @@ fn compare_type_predicate_entailment<'tcx>(
 
     let impl_ty_span = tcx.def_span(impl_ty_def_id);
     let normalize_cause = traits::ObligationCause::misc(impl_ty_span, impl_ty_def_id);
-    let param_env = ty::ParamEnv::new(
+    let param_env = ty::ParamEnv::new(tcx.mk_clauses(&hybrid_preds.predicates), Reveal::UserFacing);
-        tcx.mk_clauses(&hybrid_preds.predicates),
-        Reveal::UserFacing,
-        hir::Constness::NotConst,
-    );
     let param_env = traits::normalize_param_env_or_error(tcx, param_env, normalize_cause);
     let infcx = tcx.infer_ctxt().build();
     let ocx = ObligationCtxt::new(&infcx);
@@ -2102,7 +2094,7 @@ pub(super) fn check_type_bounds<'tcx>(
                 .to_predicate(tcx),
             ),
         };
-        ty::ParamEnv::new(tcx.mk_clauses(&predicates), Reveal::UserFacing, param_env.constness())
+        ty::ParamEnv::new(tcx.mk_clauses(&predicates), Reveal::UserFacing)
     };
     debug!(?normalize_param_env);
 

compiler/rustc_hir_analysis/src/check/dropck.rs

@@ -129,9 +129,8 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
     // We don't need to normalize this param-env or anything, since we're only
     // substituting it with free params, so no additional param-env normalization
     // can occur on top of what has been done in the param_env query itself.
-    let param_env = ty::EarlyBinder::bind(tcx.param_env(adt_def_id))
+    let param_env =
-        .instantiate(tcx, adt_to_impl_args)
+        ty::EarlyBinder::bind(tcx.param_env(adt_def_id)).instantiate(tcx, adt_to_impl_args);
-        .with_constness(tcx.constness(drop_impl_def_id));
 
     for (pred, span) in tcx.predicates_of(drop_impl_def_id).instantiate_identity(tcx) {
         let normalize_cause = traits::ObligationCause::misc(span, adt_def_id);

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -75,12 +75,10 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
             self.body_def_id,
             ObligationCauseCode::WellFormed(loc),
         );
-        // for a type to be WF, we do not need to check if const trait predicates satisfy.
-        let param_env = self.param_env.without_const();
         self.ocx.register_obligation(traits::Obligation::new(
             self.tcx(),
             cause,
-            param_env,
+            self.param_env,
             ty::Binder::dummy(ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(arg))),
         ));
     }
@@ -504,7 +502,7 @@ fn augment_param_env<'tcx>(
     );
     // FIXME(compiler-errors): Perhaps there is a case where we need to normalize this
     // i.e. traits::normalize_param_env_or_error
-    ty::ParamEnv::new(bounds, param_env.reveal(), param_env.constness())
+    ty::ParamEnv::new(bounds, param_env.reveal())
 }
 
 /// We use the following trait as an example throughout this function.
@@ -1415,7 +1413,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
     let wf_obligations = predicates.into_iter().flat_map(|(p, sp)| {
         traits::wf::predicate_obligations(
             infcx,
-            wfcx.param_env.without_const(),
+            wfcx.param_env,
             wfcx.body_def_id,
             p.as_predicate(),
             sp,

compiler/rustc_hir_typeck/src/closure.rs

@@ -81,7 +81,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         debug!(?bound_sig, ?liberated_sig);
 
-        let mut fcx = FnCtxt::new(self, self.param_env.without_const(), closure.def_id);
+        let mut fcx = FnCtxt::new(self, self.param_env, closure.def_id);
         let generator_types = check_fn(
             &mut fcx,
             liberated_sig,

compiler/rustc_hir_typeck/src/expr.rs

@@ -1334,7 +1334,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 t_cast,
                 t.span,
                 expr.span,
-                self.param_env.constness(),
+                hir::Constness::NotConst,
             ) {
                 Ok(cast_check) => {
                     debug!(
@@ -1428,7 +1428,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         // Create a new function context.
         let def_id = block.def_id;
-        let fcx = FnCtxt::new(self, self.param_env.with_const(), def_id);
+        let fcx = FnCtxt::new(self, self.param_env, def_id);
         crate::GatherLocalsVisitor::new(&fcx).visit_body(body);
 
         let ty = fcx.check_expr_with_expectation(&body.value, expected);

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -45,12 +45,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         debug!("FnCtxt::check_casts: {} deferred checks", deferred_cast_checks.len());
         for cast in deferred_cast_checks.drain(..) {
-            let prev_env = self.param_env;
-            self.param_env = self.param_env.with_constness(cast.constness);
-
             cast.check(self);
-
-            self.param_env = prev_env;
         }
 
         *self.deferred_cast_checks.borrow_mut() = deferred_cast_checks;

compiler/rustc_hir_typeck/src/lib.rs

@@ -71,7 +71,7 @@ use rustc_middle::traits;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::config;
 use rustc_span::def_id::{DefId, LocalDefId};
-use rustc_span::{sym, Span};
+use rustc_span::Span;
 
 fluent_messages! { "../messages.ftl" }
 
@@ -182,11 +182,7 @@ fn typeck_with_fallback<'tcx>(
     let body = tcx.hir().body(body_id);
 
     let param_env = tcx.param_env(def_id);
-    let param_env = if tcx.has_attr(def_id, sym::rustc_do_not_const_check) {
+
-        param_env.without_const()
-    } else {
-        param_env
-    };
     let inh = Inherited::new(tcx, def_id);
     let mut fcx = FnCtxt::new(&inh, param_env, def_id);
 
@@ -263,11 +259,7 @@ fn typeck_with_fallback<'tcx>(
 
     // Closure and generator analysis may run after fallback
     // because they don't constrain other type variables.
-    // Closure analysis only runs on closures. Therefore they only need to fulfill non-const predicates (as of now)
-    let prev_constness = fcx.param_env.constness();
-    fcx.param_env = fcx.param_env.without_const();
     fcx.closure_analyze(body);
-    fcx.param_env = fcx.param_env.with_constness(prev_constness);
     assert!(fcx.deferred_call_resolutions.borrow().is_empty());
     // Before the generator analysis, temporary scopes shall be marked to provide more
     // precise information on types to be captured.

compiler/rustc_infer/src/traits/mod.rs

@@ -79,7 +79,6 @@ impl<'tcx> PredicateObligation<'tcx> {
     }
 
     pub fn without_const(mut self, tcx: TyCtxt<'tcx>) -> PredicateObligation<'tcx> {
-        self.param_env = self.param_env.without_const();
         if let ty::PredicateKind::Clause(ty::ClauseKind::Trait(trait_pred)) = self.predicate.kind().skip_binder() && trait_pred.is_const_if_const() {
             self.predicate = tcx.mk_predicate(self.predicate.kind().map_bound(|_| ty::PredicateKind::Clause(ty::ClauseKind::Trait(trait_pred.without_const()))));
         }
@@ -88,14 +87,6 @@ impl<'tcx> PredicateObligation<'tcx> {
 }
 
 impl<'tcx> PolyTraitObligation<'tcx> {
-    /// Returns `true` if the trait predicate is considered `const` in its ParamEnv.
-    pub fn is_const(&self) -> bool {
-        matches!(
-            (self.predicate.skip_binder().constness, self.param_env.constness()),
-            (ty::BoundConstness::ConstIfConst, hir::Constness::Const)
-        )
-    }
-
     pub fn derived_cause(
         &self,
         variant: impl FnOnce(DerivedObligationCause<'tcx>) -> ObligationCauseCode<'tcx>,

compiler/rustc_middle/src/mir/interpret/queries.rs

@@ -139,7 +139,6 @@ impl<'tcx> TyCtxt<'tcx> {
         cid: GlobalId<'tcx>,
         span: Option<Span>,
     ) -> EvalToConstValueResult<'tcx> {
-        let param_env = param_env.with_const();
         // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should
         // improve caching of queries.
         let inputs = self.erase_regions(param_env.and(cid));
@@ -158,8 +157,6 @@ impl<'tcx> TyCtxt<'tcx> {
         cid: GlobalId<'tcx>,
         span: Option<Span>,
     ) -> EvalToValTreeResult<'tcx> {
-        let param_env = param_env.with_const();
-        debug!(?param_env);
         // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should
         // improve caching of queries.
         let inputs = self.erase_regions(param_env.and(cid));
@@ -204,7 +201,6 @@ impl<'tcx> TyCtxtAt<'tcx> {
         gid: GlobalId<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
     ) -> Result<mir::ConstAllocation<'tcx>, ErrorHandled> {
-        let param_env = param_env.with_const();
         trace!("eval_to_allocation: Need to compute {:?}", gid);
         let raw_const = self.eval_to_allocation_raw(param_env.and(gid))?;
         Ok(self.global_alloc(raw_const.alloc_id).unwrap_memory())
@@ -224,8 +220,7 @@ impl<'tcx> TyCtxtEnsure<'tcx> {
         let args = GenericArgs::identity_for_item(self.tcx, def_id);
         let instance = ty::Instance::new(def_id, args);
         let cid = GlobalId { instance, promoted: None };
-        let param_env =
+        let param_env = self.tcx.param_env(def_id).with_reveal_all_normalized(self.tcx);
-            self.tcx.param_env(def_id).with_reveal_all_normalized(self.tcx).with_const();
         // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should
         // improve caching of queries.
         let inputs = self.tcx.erase_regions(param_env.and(cid));
@@ -238,7 +233,7 @@ impl<'tcx> TyCtxtEnsure<'tcx> {
         assert!(self.tcx.is_static(def_id));
         let instance = ty::Instance::mono(self.tcx, def_id);
         let gid = GlobalId { instance, promoted: None };
-        let param_env = ty::ParamEnv::reveal_all().with_const();
+        let param_env = ty::ParamEnv::reveal_all();
         trace!("eval_to_allocation: Need to compute {:?}", gid);
         self.eval_to_allocation_raw(param_env.and(gid))
     }

compiler/rustc_middle/src/ty/codec.rs

@@ -168,7 +168,6 @@ impl<'tcx, E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<E> for ty::ParamEnv<'tcx> {
     fn encode(&self, e: &mut E) {
         self.caller_bounds().encode(e);
         self.reveal().encode(e);
-        self.constness().encode(e);
     }
 }
 
@@ -306,8 +305,7 @@ impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<D> for ty::ParamEnv<'tcx> {
     fn decode(d: &mut D) -> Self {
         let caller_bounds = Decodable::decode(d);
         let reveal = Decodable::decode(d);
-        let constness = Decodable::decode(d);
+        ty::ParamEnv::new(caller_bounds, reveal)
-        ty::ParamEnv::new(caller_bounds, reveal, constness)
     }
 }
 

compiler/rustc_middle/src/ty/mod.rs

@@ -867,20 +867,6 @@ pub struct TraitPredicate<'tcx> {
 pub type PolyTraitPredicate<'tcx> = ty::Binder<'tcx, TraitPredicate<'tcx>>;
 
 impl<'tcx> TraitPredicate<'tcx> {
-    pub fn remap_constness(&mut self, param_env: &mut ParamEnv<'tcx>) {
-        *param_env = param_env.with_constness(self.constness.and(param_env.constness()))
-    }
-
-    /// Remap the constness of this predicate before emitting it for diagnostics.
-    pub fn remap_constness_diag(&mut self, param_env: ParamEnv<'tcx>) {
-        // this is different to `remap_constness` that callees want to print this predicate
-        // in case of selection errors. `T: ~const Drop` bounds cannot end up here when the
-        // param_env is not const because it is always satisfied in non-const contexts.
-        if let hir::Constness::NotConst = param_env.constness() {
-            self.constness = ty::BoundConstness::NotConst;
-        }
-    }
-
     pub fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self {
         Self { trait_ref: self.trait_ref.with_self_ty(tcx, self_ty), ..self }
     }
@@ -922,14 +908,6 @@ impl<'tcx> PolyTraitPredicate<'tcx> {
         self.map_bound(|trait_ref| trait_ref.self_ty())
     }
 
-    /// Remap the constness of this predicate before emitting it for diagnostics.
-    pub fn remap_constness_diag(&mut self, param_env: ParamEnv<'tcx>) {
-        *self = self.map_bound(|mut p| {
-            p.remap_constness_diag(param_env);
-            p
-        });
-    }
-
     #[inline]
     pub fn is_const_if_const(self) -> bool {
         self.skip_binder().is_const_if_const()
@@ -1700,15 +1678,12 @@ pub struct ParamEnv<'tcx> {
 #[derive(Copy, Clone)]
 struct ParamTag {
     reveal: traits::Reveal,
-    constness: hir::Constness,
 }
 
 impl_tag! {
     impl Tag for ParamTag;
-    ParamTag { reveal: traits::Reveal::UserFacing, constness: hir::Constness::NotConst },
+    ParamTag { reveal: traits::Reveal::UserFacing },
-    ParamTag { reveal: traits::Reveal::All,        constness: hir::Constness::NotConst },
+    ParamTag { reveal: traits::Reveal::All },
-    ParamTag { reveal: traits::Reveal::UserFacing, constness: hir::Constness::Const    },
-    ParamTag { reveal: traits::Reveal::All,        constness: hir::Constness::Const    },
 }
 
 impl<'tcx> fmt::Debug for ParamEnv<'tcx> {
@@ -1716,7 +1691,6 @@ impl<'tcx> fmt::Debug for ParamEnv<'tcx> {
         f.debug_struct("ParamEnv")
             .field("caller_bounds", &self.caller_bounds())
             .field("reveal", &self.reveal())
-            .field("constness", &self.constness())
             .finish()
     }
 }
@@ -1725,7 +1699,6 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ParamEnv<'tcx> {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
         self.caller_bounds().hash_stable(hcx, hasher);
         self.reveal().hash_stable(hcx, hasher);
-        self.constness().hash_stable(hcx, hasher);
     }
 }
 
@@ -1737,7 +1710,6 @@ impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ParamEnv<'tcx> {
         Ok(ParamEnv::new(
             self.caller_bounds().try_fold_with(folder)?,
             self.reveal().try_fold_with(folder)?,
-            self.constness(),
         ))
     }
 }
@@ -1756,7 +1728,7 @@ impl<'tcx> ParamEnv<'tcx> {
     /// type-checking.
     #[inline]
     pub fn empty() -> Self {
-        Self::new(List::empty(), Reveal::UserFacing, hir::Constness::NotConst)
+        Self::new(List::empty(), Reveal::UserFacing)
     }
 
     #[inline]
@@ -1769,16 +1741,6 @@ impl<'tcx> ParamEnv<'tcx> {
         self.packed.tag().reveal
     }
 
-    #[inline]
-    pub fn constness(self) -> hir::Constness {
-        self.packed.tag().constness
-    }
-
-    #[inline]
-    pub fn is_const(self) -> bool {
-        self.packed.tag().constness == hir::Constness::Const
-    }
-
     /// Construct a trait environment with no where-clauses in scope
     /// where the values of all `impl Trait` and other hidden types
     /// are revealed. This is suitable for monomorphized, post-typeck
@@ -1788,17 +1750,13 @@ impl<'tcx> ParamEnv<'tcx> {
     /// or invoke `param_env.with_reveal_all()`.
     #[inline]
     pub fn reveal_all() -> Self {
-        Self::new(List::empty(), Reveal::All, hir::Constness::NotConst)
+        Self::new(List::empty(), Reveal::All)
     }
 
     /// Construct a trait environment with the given set of predicates.
     #[inline]
-    pub fn new(
+    pub fn new(caller_bounds: &'tcx List<Clause<'tcx>>, reveal: Reveal) -> Self {
-        caller_bounds: &'tcx List<Clause<'tcx>>,
+        ty::ParamEnv { packed: CopyTaggedPtr::new(caller_bounds, ParamTag { reveal }) }
-        reveal: Reveal,
-        constness: hir::Constness,
-    ) -> Self {
-        ty::ParamEnv { packed: CopyTaggedPtr::new(caller_bounds, ParamTag { reveal, constness }) }
     }
 
     pub fn with_user_facing(mut self) -> Self {
@@ -1806,29 +1764,6 @@ impl<'tcx> ParamEnv<'tcx> {
         self
     }
 
-    #[inline]
-    pub fn with_constness(mut self, constness: hir::Constness) -> Self {
-        self.packed.set_tag(ParamTag { constness, ..self.packed.tag() });
-        self
-    }
-
-    #[inline]
-    pub fn with_const(mut self) -> Self {
-        self.packed.set_tag(ParamTag { constness: hir::Constness::Const, ..self.packed.tag() });
-        self
-    }
-
-    #[inline]
-    pub fn without_const(mut self) -> Self {
-        self.packed.set_tag(ParamTag { constness: hir::Constness::NotConst, ..self.packed.tag() });
-        self
-    }
-
-    #[inline]
-    pub fn remap_constness_with(&mut self, mut constness: ty::BoundConstness) {
-        *self = self.with_constness(constness.and(self.constness()))
-    }
-
     /// Returns a new parameter environment with the same clauses, but
     /// which "reveals" the true results of projections in all cases
     /// (even for associated types that are specializable). This is
@@ -1843,17 +1778,13 @@ impl<'tcx> ParamEnv<'tcx> {
             return self;
         }
 
-        ParamEnv::new(
+        ParamEnv::new(tcx.reveal_opaque_types_in_bounds(self.caller_bounds()), Reveal::All)
-            tcx.reveal_opaque_types_in_bounds(self.caller_bounds()),
-            Reveal::All,
-            self.constness(),
-        )
     }
 
     /// Returns this same environment but with no caller bounds.
     #[inline]
     pub fn without_caller_bounds(self) -> Self {
-        Self::new(List::empty(), self.reveal(), self.constness())
+        Self::new(List::empty(), self.reveal())
     }
 
     /// Creates a suitable environment in which to perform trait

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -602,7 +602,7 @@ impl<'a, 'tcx> Lift<'tcx> for ty::ParamEnv<'a> {
     type Lifted = ty::ParamEnv<'tcx>;
     fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
         tcx.lift(self.caller_bounds())
-            .map(|caller_bounds| ty::ParamEnv::new(caller_bounds, self.reveal(), self.constness()))
+            .map(|caller_bounds| ty::ParamEnv::new(caller_bounds, self.reveal()))
     }
 }
 

compiler/rustc_trait_selection/src/solve/trait_goals.rs

@@ -449,14 +449,11 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
             return Err(NoSolution);
         }
 
-        if !goal.param_env.is_const() {
+        // FIXME(-Ztrait-solver=next): Implement this when we get const working in the new solver
-            // `Destruct` is automatically implemented for every type in
+
-            // non-const environments.
+        // `Destruct` is automatically implemented for every type in
-            ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+        // non-const environments.
-        } else {
+        ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
-            // FIXME(-Ztrait-solver=next): Implement this when we get const working in the new solver
-            Err(NoSolution)
-        }
     }
 
     fn consider_builtin_transmute_candidate(

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -347,14 +347,12 @@ impl<'tcx> AutoTraitFinder<'tcx> {
             new_env = ty::ParamEnv::new(
                 tcx.mk_clauses_from_iter(normalized_preds.filter_map(|p| p.as_clause())),
                 param_env.reveal(),
-                param_env.constness(),
             );
         }
 
         let final_user_env = ty::ParamEnv::new(
             tcx.mk_clauses_from_iter(user_computed_preds.into_iter().filter_map(|p| p.as_clause())),
             user_env.reveal(),
-            user_env.constness(),
         );
         debug!(
             "evaluate_nested_obligations(ty={:?}, trait_did={:?}): succeeded with '{:?}' \

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -687,9 +687,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 match bound_predicate.skip_binder() {
                     ty::PredicateKind::Clause(ty::ClauseKind::Trait(trait_predicate)) => {
                         let trait_predicate = bound_predicate.rebind(trait_predicate);
-                        let mut trait_predicate = self.resolve_vars_if_possible(trait_predicate);
+                        let trait_predicate = self.resolve_vars_if_possible(trait_predicate);
 
-                        trait_predicate.remap_constness_diag(obligation.param_env);
                         let predicate_is_const = ty::BoundConstness::ConstIfConst
                             == trait_predicate.skip_binder().constness;
 
@@ -3108,11 +3107,11 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         span: Span,
     ) -> UnsatisfiedConst {
         let mut unsatisfied_const = UnsatisfiedConst(false);
-        if trait_predicate.is_const_if_const() && obligation.param_env.is_const() {
+        if trait_predicate.is_const_if_const() {
             let non_const_predicate = trait_ref.without_const();
             let non_const_obligation = Obligation {
                 cause: obligation.cause.clone(),
-                param_env: obligation.param_env.without_const(),
+                param_env: obligation.param_env,
                 predicate: non_const_predicate.to_predicate(self.tcx),
                 recursion_depth: obligation.recursion_depth,
             };

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -3136,7 +3136,6 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             ObligationCauseCode::ImplDerivedObligation(ref data) => {
                 let mut parent_trait_pred =
                     self.resolve_vars_if_possible(data.derived.parent_trait_pred);
-                parent_trait_pred.remap_constness_diag(param_env);
                 let parent_def_id = parent_trait_pred.def_id();
                 let (self_ty, file) =
                     self.tcx.short_ty_string(parent_trait_pred.skip_binder().self_ty());

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -328,11 +328,7 @@ pub fn normalize_param_env_or_error<'tcx>(
 
     debug!("normalize_param_env_or_error: elaborated-predicates={:?}", predicates);
 
-    let elaborated_env = ty::ParamEnv::new(
+    let elaborated_env = ty::ParamEnv::new(tcx.mk_clauses(&predicates), unnormalized_env.reveal());
-        tcx.mk_clauses(&predicates),
-        unnormalized_env.reveal(),
-        unnormalized_env.constness(),
-    );
 
     // HACK: we are trying to normalize the param-env inside *itself*. The problem is that
     // normalization expects its param-env to be already normalized, which means we have
@@ -376,11 +372,8 @@ pub fn normalize_param_env_or_error<'tcx>(
     // here. I believe they should not matter, because we are ignoring TypeOutlives param-env
     // predicates here anyway. Keeping them here anyway because it seems safer.
     let outlives_env = non_outlives_predicates.iter().chain(&outlives_predicates).cloned();
-    let outlives_env = ty::ParamEnv::new(
+    let outlives_env =
-        tcx.mk_clauses_from_iter(outlives_env),
+        ty::ParamEnv::new(tcx.mk_clauses_from_iter(outlives_env), unnormalized_env.reveal());
-        unnormalized_env.reveal(),
-        unnormalized_env.constness(),
-    );
     let Ok(outlives_predicates) =
         do_normalize_predicates(tcx, cause, outlives_env, outlives_predicates)
     else {
@@ -393,11 +386,7 @@ pub fn normalize_param_env_or_error<'tcx>(
     let mut predicates = non_outlives_predicates;
     predicates.extend(outlives_predicates);
     debug!("normalize_param_env_or_error: final predicates={:?}", predicates);
-    ty::ParamEnv::new(
+    ty::ParamEnv::new(tcx.mk_clauses(&predicates), unnormalized_env.reveal())
-        tcx.mk_clauses(&predicates),
-        unnormalized_env.reveal(),
-        unnormalized_env.constness(),
-    )
 }
 
 /// Normalize a type and process all resulting obligations, returning any errors.

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -761,11 +761,7 @@ fn receiver_is_dispatchable<'tcx>(
         let caller_bounds =
             param_env.caller_bounds().iter().chain([unsize_predicate, trait_predicate]);
 
-        ty::ParamEnv::new(
+        ty::ParamEnv::new(tcx.mk_clauses_from_iter(caller_bounds), param_env.reveal())
-            tcx.mk_clauses_from_iter(caller_bounds),
-            param_env.reveal(),
-            param_env.constness(),
-        )
     };
 
     // Receiver: DispatchFromDyn<Receiver[Self => U]>

compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs

@@ -1,5 +1,4 @@
 use rustc_infer::traits::{TraitEngine, TraitEngineExt};
-use rustc_middle::ty;
 
 use crate::infer::canonical::OriginalQueryValues;
 use crate::infer::InferCtxt;
@@ -66,17 +65,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
     ) -> Result<EvaluationResult, OverflowError> {
         let mut _orig_values = OriginalQueryValues::default();
 
-        let param_env = match obligation.predicate.kind().skip_binder() {
+        let param_env = obligation.param_env;
-            ty::PredicateKind::Clause(ty::ClauseKind::Trait(pred)) => {
-                // we ignore the value set to it.
-                let mut _constness = pred.constness;
-                obligation
-                    .param_env
-                    .with_constness(_constness.and(obligation.param_env.constness()))
-            }
-            // constness has no effect on the given predicate.
-            _ => obligation.param_env.without_const(),
-        };
 
         if self.next_trait_solver() {
             self.probe(|snapshot| {

compiler/rustc_trait_selection/src/traits/query/type_op/ascribe_user_type.rs

@@ -82,7 +82,6 @@ fn relate_mir_and_user_args<'tcx>(
     def_id: DefId,
     user_args: UserArgs<'tcx>,
 ) -> Result<(), NoSolution> {
-    let param_env = param_env.without_const();
     let UserArgs { user_self_ty, args } = user_args;
     let tcx = ocx.infcx.tcx;
     let cause = ObligationCause::dummy_with_span(span);

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -839,7 +839,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     ) {
         // If the predicate is `~const Destruct` in a non-const environment, we don't actually need
         // to check anything. We'll short-circuit checking any obligations in confirmation, too.
-        if !obligation.is_const() {
+        // FIXME(effects)
+        if true {
             candidates.vec.push(ConstDestructCandidate(None));
             return;
         }

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -13,8 +13,8 @@ use rustc_infer::infer::LateBoundRegionConversionTime::HigherRankedType;
 use rustc_infer::infer::{DefineOpaqueTypes, InferOk};
 use rustc_middle::traits::{BuiltinImplSource, SelectionOutputTypeParameterMismatch};
 use rustc_middle::ty::{
-    self, Binder, GenericArgs, GenericArgsRef, GenericParamDefKind, ToPolyTraitRef, ToPredicate,
+    self, GenericArgs, GenericArgsRef, GenericParamDefKind, ToPolyTraitRef, ToPredicate,
-    TraitPredicate, TraitRef, Ty, TyCtxt, TypeVisitableExt,
+    TraitPredicate, Ty, TyCtxt, TypeVisitableExt,
 };
 use rustc_span::def_id::DefId;
 
@@ -647,7 +647,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     fn confirm_fn_pointer_candidate(
         &mut self,
         obligation: &PolyTraitObligation<'tcx>,
-        is_const: bool,
+        // FIXME(effects)
+        _is_const: bool,
     ) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
         debug!(?obligation, "confirm_fn_pointer_candidate");
 
@@ -674,16 +675,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         let mut nested = self.confirm_poly_trait_refs(obligation, trait_ref)?;
         let cause = obligation.derived_cause(BuiltinDerivedObligation);
 
-        if obligation.is_const() && !is_const {
-            // function is a trait method
-            if let ty::FnDef(def_id, args) = self_ty.kind() && let Some(trait_id) = tcx.trait_of_item(*def_id) {
-                let trait_ref = TraitRef::from_method(tcx, trait_id, *args);
-                let poly_trait_pred = Binder::dummy(trait_ref).with_constness(ty::BoundConstness::ConstIfConst);
-                let obligation = Obligation::new(tcx, cause.clone(), obligation.param_env, poly_trait_pred);
-                nested.push(obligation);
-            }
-        }
-
         // Confirm the `type Output: Sized;` bound that is present on `FnOnce`
         let output_ty = self.infcx.instantiate_binder_with_placeholders(sig.output());
         let output_ty = normalize_with_depth_to(
@@ -1211,7 +1202,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         impl_def_id: Option<DefId>,
     ) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
         // `~const Destruct` in a non-const environment is always trivially true, since our type is `Drop`
-        if !obligation.is_const() {
+        // FIXME(effects)
+        if true {
             return Ok(vec![]);
         }
 

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -1000,13 +1000,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         }
 
         let stack = self.push_stack(previous_stack, &obligation);
-        let mut fresh_trait_pred = stack.fresh_trait_pred;
+        let fresh_trait_pred = stack.fresh_trait_pred;
-        let mut param_env = obligation.param_env;
+        let param_env = obligation.param_env;
-
-        fresh_trait_pred = fresh_trait_pred.map_bound(|mut pred| {
-            pred.remap_constness(&mut param_env);
-            pred
-        });
 
         debug!(?fresh_trait_pred);
 
@@ -1386,8 +1381,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         (result, dep_node)
     }
 
-    /// filter_impls filters constant trait obligations and candidates that have a positive impl
+    /// filter_impls filters candidates that have a positive impl for a negative
-    /// for a negative goal and a negative impl for a positive goal
+    /// goal and a negative impl for a positive goal
     #[instrument(level = "debug", skip(self, candidates))]
     fn filter_impls(
         &mut self,
@@ -1399,42 +1394,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         let mut result = Vec::with_capacity(candidates.len());
 
         for candidate in candidates {
-            // Respect const trait obligations
-            if obligation.is_const() {
-                match candidate {
-                    // const impl
-                    ImplCandidate(def_id) if tcx.constness(def_id) == hir::Constness::Const => {}
-                    // const param
-                    ParamCandidate(trait_pred) if trait_pred.is_const_if_const() => {}
-                    // const projection
-                    ProjectionCandidate(_, ty::BoundConstness::ConstIfConst)
-                    // auto trait impl
-                    | AutoImplCandidate
-                    // generator / future, this will raise error in other places
-                    // or ignore error with const_async_blocks feature
-                    | GeneratorCandidate
-                    | FutureCandidate
-                    // FnDef where the function is const
-                    | FnPointerCandidate { is_const: true }
-                    | ConstDestructCandidate(_)
-                    | ClosureCandidate { is_const: true } => {}
-
-                    FnPointerCandidate { is_const: false } => {
-                        if let ty::FnDef(def_id, _) = obligation.self_ty().skip_binder().kind() && tcx.trait_of_item(*def_id).is_some() {
-                            // Trait methods are not seen as const unless the trait is implemented as const.
-                            // We do not filter that out in here, but nested obligations will be needed to confirm this.
-                        } else {
-                            continue
-                        }
-                    }
-
-                    _ => {
-                        // reject all other types of candidates
-                        continue;
-                    }
-                }
-            }
-
             if let ImplCandidate(def_id) = candidate {
                 if ty::ImplPolarity::Reservation == tcx.impl_polarity(def_id)
                     || obligation.polarity() == tcx.impl_polarity(def_id)
@@ -1528,7 +1487,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
     fn check_candidate_cache(
         &mut self,
-        mut param_env: ty::ParamEnv<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
         cache_fresh_trait_pred: ty::PolyTraitPredicate<'tcx>,
     ) -> Option<SelectionResult<'tcx, SelectionCandidate<'tcx>>> {
         // Neither the global nor local cache is aware of intercrate
@@ -1539,8 +1498,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             return None;
         }
         let tcx = self.tcx();
-        let mut pred = cache_fresh_trait_pred.skip_binder();
+        let pred = cache_fresh_trait_pred.skip_binder();
-        pred.remap_constness(&mut param_env);
 
         if self.can_use_global_caches(param_env) {
             if let Some(res) = tcx.selection_cache.get(&(param_env, pred), tcx) {
@@ -1586,15 +1544,13 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     #[instrument(skip(self, param_env, cache_fresh_trait_pred, dep_node), level = "debug")]
     fn insert_candidate_cache(
         &mut self,
-        mut param_env: ty::ParamEnv<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
         cache_fresh_trait_pred: ty::PolyTraitPredicate<'tcx>,
         dep_node: DepNodeIndex,
         candidate: SelectionResult<'tcx, SelectionCandidate<'tcx>>,
     ) {
         let tcx = self.tcx();
-        let mut pred = cache_fresh_trait_pred.skip_binder();
+        let pred = cache_fresh_trait_pred.skip_binder();
-
-        pred.remap_constness(&mut param_env);
 
         if !self.can_cache_candidate(&candidate) {
             debug!(?pred, ?candidate, "insert_candidate_cache - candidate is not cacheable");

compiler/rustc_ty_utils/src/ty.rs

@@ -144,85 +144,9 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
     }
 
     let local_did = def_id.as_local();
-    // FIXME(-Zlower-impl-trait-in-trait-to-assoc-ty): This isn't correct for
-    // RPITITs in const trait fn.
-    let hir_id = local_did.and_then(|def_id| tcx.opt_local_def_id_to_hir_id(def_id));
-
-    // FIXME(consts): This is not exactly in line with the constness query.
-    let constness = match hir_id {
-        Some(hir_id) => match tcx.hir().get(hir_id) {
-            hir::Node::TraitItem(hir::TraitItem { kind: hir::TraitItemKind::Fn(..), .. })
-                if tcx.is_const_default_method(def_id) =>
-            {
-                hir::Constness::Const
-            }
-
-            hir::Node::Item(hir::Item { kind: hir::ItemKind::Const(..), .. })
-            | hir::Node::Item(hir::Item { kind: hir::ItemKind::Static(..), .. })
-            | hir::Node::TraitItem(hir::TraitItem {
-                kind: hir::TraitItemKind::Const(..), ..
-            })
-            | hir::Node::AnonConst(_)
-            | hir::Node::ConstBlock(_)
-            | hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. })
-            | hir::Node::ImplItem(hir::ImplItem {
-                kind:
-                    hir::ImplItemKind::Fn(
-                        hir::FnSig {
-                            header: hir::FnHeader { constness: hir::Constness::Const, .. },
-                            ..
-                        },
-                        ..,
-                    ),
-                ..
-            }) => hir::Constness::Const,
-
-            hir::Node::ImplItem(hir::ImplItem {
-                kind: hir::ImplItemKind::Type(..) | hir::ImplItemKind::Fn(..),
-                ..
-            }) => {
-                let parent_hir_id = tcx.hir().parent_id(hir_id);
-                match tcx.hir().get(parent_hir_id) {
-                    hir::Node::Item(hir::Item {
-                        kind: hir::ItemKind::Impl(hir::Impl { constness, .. }),
-                        ..
-                    }) => *constness,
-                    _ => span_bug!(
-                        tcx.def_span(parent_hir_id.owner),
-                        "impl item's parent node is not an impl",
-                    ),
-                }
-            }
-
-            hir::Node::Item(hir::Item {
-                kind:
-                    hir::ItemKind::Fn(hir::FnSig { header: hir::FnHeader { constness, .. }, .. }, ..),
-                ..
-            })
-            | hir::Node::TraitItem(hir::TraitItem {
-                kind:
-                    hir::TraitItemKind::Fn(
-                        hir::FnSig { header: hir::FnHeader { constness, .. }, .. },
-                        ..,
-                    ),
-                ..
-            })
-            | hir::Node::Item(hir::Item {
-                kind: hir::ItemKind::Impl(hir::Impl { constness, .. }),
-                ..
-            }) => *constness,
-
-            _ => hir::Constness::NotConst,
-        },
-        // FIXME(consts): It's suspicious that a param-env for a foreign item
-        // will always have NotConst param-env, though we don't typically use
-        // that param-env for anything meaningful right now, so it's likely
-        // not an issue.
-        None => hir::Constness::NotConst,
-    };
 
     let unnormalized_env =
-        ty::ParamEnv::new(tcx.mk_clauses(&predicates), traits::Reveal::UserFacing, constness);
+        ty::ParamEnv::new(tcx.mk_clauses(&predicates), traits::Reveal::UserFacing);
 
     let body_id = local_did.unwrap_or(CRATE_DEF_ID);
     let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id);

src/tools/clippy/clippy_lints/src/derive.rs

@@ -6,7 +6,7 @@ use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, Visitor};
 use rustc_hir::{
-    self as hir, BlockCheckMode, BodyId, Constness, Expr, ExprKind, FnDecl, Impl, Item, ItemKind, UnsafeSource,
+    self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, Impl, Item, ItemKind, UnsafeSource,
     Unsafety,
 };
 use rustc_lint::{LateContext, LateLintPass};
@@ -526,6 +526,5 @@ fn param_env_for_derived_eq(tcx: TyCtxt<'_>, did: DefId, eq_trait_id: DefId) ->
             }),
         )),
         Reveal::UserFacing,
-        Constness::NotConst,
     )
 }

src/tools/clippy/clippy_lints/src/manual_float_methods.rs

@@ -3,7 +3,7 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet_opt;
 use clippy_utils::{is_from_proc_macro, path_to_local};
 use rustc_errors::Applicability;
-use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_hir::{BinOpKind, Constness, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass, Lint, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -83,8 +83,10 @@ impl Variant {
 impl<'tcx> LateLintPass<'tcx> for ManualFloatMethods {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
         if !in_external_macro(cx.sess(), expr.span)
-            && (!cx.param_env.is_const() || cx.tcx.features().active(sym!(const_float_classify)))
+            && (
-            && let ExprKind::Binary(kind, lhs, rhs) = expr.kind
+                matches!(cx.tcx.constness(cx.tcx.hir().enclosing_body_owner(expr.hir_id)), Constness::NotConst) 
+                    || cx.tcx.features().active(sym!(const_float_classify))
+            ) && let ExprKind::Binary(kind, lhs, rhs) = expr.kind
             && let ExprKind::Binary(lhs_kind, lhs_lhs, lhs_rhs) = lhs.kind
             && let ExprKind::Binary(rhs_kind, rhs_lhs, rhs_rhs) = rhs.kind
             // Checking all possible scenarios using a function would be a hopeless task, as we have

src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs

@@ -391,32 +391,38 @@ fn is_const_fn(tcx: TyCtxt<'_>, def_id: DefId, msrv: &Msrv) -> bool {
 
 #[expect(clippy::similar_names)] // bit too pedantic
 fn is_ty_const_destruct<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, body: &Body<'tcx>) -> bool {
-    // Avoid selecting for simple cases, such as builtin types.
+    // FIXME(effects, fee1-dead) revert to const destruct once it works again
-    if ty::util::is_trivially_const_drop(ty) {
+    #[expect(unused)]
-        return true;
+    fn is_ty_const_destruct_unused<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, body: &Body<'tcx>) -> bool {
+        // Avoid selecting for simple cases, such as builtin types.
+        if ty::util::is_trivially_const_drop(ty) {
+            return true;
+        }
+
+        let obligation = Obligation::new(
+            tcx,
+            ObligationCause::dummy_with_span(body.span),
+            ConstCx::new(tcx, body).param_env,
+            TraitRef::from_lang_item(tcx, LangItem::Destruct, body.span, [ty]).with_constness(BoundConstness::ConstIfConst),
+        );
+
+        let infcx = tcx.infer_ctxt().build();
+        let mut selcx = SelectionContext::new(&infcx);
+        let Some(impl_src) = selcx.select(&obligation).ok().flatten() else {
+            return false;
+        };
+
+        if !matches!(
+            impl_src,
+            ImplSource::Builtin(BuiltinImplSource::Misc, _) | ImplSource::Param(ty::BoundConstness::ConstIfConst, _)
+        ) {
+            return false;
+        }
+
+        let ocx = ObligationCtxt::new(&infcx);
+        ocx.register_obligations(impl_src.nested_obligations());
+        ocx.select_all_or_error().is_empty()
     }
 
-    let obligation = Obligation::new(
+    !ty.needs_drop(tcx, ConstCx::new(tcx, body).param_env)    
-        tcx,
-        ObligationCause::dummy_with_span(body.span),
-        ConstCx::new(tcx, body).param_env.with_const(),
-        TraitRef::from_lang_item(tcx, LangItem::Destruct, body.span, [ty]).with_constness(BoundConstness::ConstIfConst),
-    );
-
-    let infcx = tcx.infer_ctxt().build();
-    let mut selcx = SelectionContext::new(&infcx);
-    let Some(impl_src) = selcx.select(&obligation).ok().flatten() else {
-        return false;
-    };
-
-    if !matches!(
-        impl_src,
-        ImplSource::Builtin(BuiltinImplSource::Misc, _) | ImplSource::Param(ty::BoundConstness::ConstIfConst, _)
-    ) {
-        return false;
-    }
-
-    let ocx = ObligationCtxt::new(&infcx);
-    ocx.register_obligations(impl_src.nested_obligations());
-    ocx.select_all_or_error().is_empty()
 }

src/tools/clippy/tests/ui/missing_const_for_fn/could_be_const.rs

@@ -99,4 +99,5 @@ impl const Drop for D {
 }
 
 // Lint this, since it can be dropped in const contexts
+// FIXME(effects)
 fn d(this: D) {}

src/tools/clippy/tests/ui/missing_const_for_fn/could_be_const.stderr

@@ -89,11 +89,5 @@ LL | |     46
 LL | | }
    | |_^
 
-error: this could be a `const fn`
+error: aborting due to 11 previous errors
-  --> $DIR/could_be_const.rs:102:1
-   |
-LL | fn d(this: D) {}
-   | ^^^^^^^^^^^^^^^^
-
-error: aborting due to 12 previous errors
 

tests/ui/const-generics/issue-93647.rs

@@ -1,7 +1,6 @@
 struct X<const N: usize = {
     (||1usize)()
     //~^ ERROR cannot call non-const closure
-    //~| ERROR the trait bound
 }>;
 
 fn main() {}

tests/ui/const-generics/issue-93647.stderr

@@ -1,17 +1,3 @@
-error[E0277]: the trait bound `[closure@$DIR/issue-93647.rs:2:6: 2:8]: Fn<()>` is not satisfied
-  --> $DIR/issue-93647.rs:2:5
-   |
-LL |     (||1usize)()
-   |     ^^^^^^^^^^^^ expected an `Fn<()>` closure, found `[closure@$DIR/issue-93647.rs:2:6: 2:8]`
-   |
-   = help: the trait `~const Fn<()>` is not implemented for closure `[closure@$DIR/issue-93647.rs:2:6: 2:8]`
-note: the trait `Fn<()>` is implemented for `[closure@$DIR/issue-93647.rs:2:6: 2:8]`, but that implementation is not `const`
-  --> $DIR/issue-93647.rs:2:5
-   |
-LL |     (||1usize)()
-   |     ^^^^^^^^^^^^
-   = note: wrap the `[closure@$DIR/issue-93647.rs:2:6: 2:8]` in a closure with no arguments: `|| { /* code */ }`
-
 error[E0015]: cannot call non-const closure in constants
   --> $DIR/issue-93647.rs:2:5
    |
@@ -22,7 +8,6 @@ LL |     (||1usize)()
    = note: calls in constants are limited to constant functions, tuple structs and tuple variants
    = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/consts/const-block-const-bound.rs

@@ -1,3 +1,5 @@
+// known-bug: #103507
+
 #![allow(unused)]
 #![feature(const_trait_impl, inline_const, negative_impls)]
 
@@ -14,6 +16,6 @@ impl Drop for UnconstDrop {
 fn main() {
     const {
         f(UnconstDrop);
-        //~^ ERROR can't drop
+        //FIXME ~^ ERROR can't drop
     }
 }

tests/ui/consts/const-block-const-bound.stderr

@@ -1,17 +1,11 @@
-error[E0277]: can't drop `UnconstDrop` in const contexts
+error[E0493]: destructor of `T` cannot be evaluated at compile-time
-  --> $DIR/const-block-const-bound.rs:16:9
+  --> $DIR/const-block-const-bound.rs:8:32
    |
-LL |         f(UnconstDrop);
+LL | const fn f<T: ~const Destruct>(x: T) {}
-   |         ^^^^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `UnconstDrop`
+   |                                ^      - value is dropped here
-   |
+   |                                |
-   = note: the trait bound `UnconstDrop: ~const Destruct` is not satisfied
+   |                                the destructor for this type cannot be evaluated in constant functions
-help: consider borrowing here
-   |
-LL |         &f(UnconstDrop);
-   |         +
-LL |         &mut f(UnconstDrop);
-   |         ++++
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0493`.

tests/ui/consts/const_cmp_type_id.stderr

@@ -1,16 +1,3 @@
-error[E0277]: can't compare `TypeId` with `TypeId` in const contexts
-  --> $DIR/const_cmp_type_id.rs:8:13
-   |
-LL |     assert!(TypeId::of::<u8>() == TypeId::of::<u8>());
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `TypeId == TypeId`
-   |
-   = help: the trait `~const PartialEq` is not implemented for `TypeId`
-note: the trait `PartialEq` is implemented for `TypeId`, but that implementation is not `const`
-  --> $DIR/const_cmp_type_id.rs:8:13
-   |
-LL |     assert!(TypeId::of::<u8>() == TypeId::of::<u8>());
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0015]: cannot call non-const operator in constant functions
   --> $DIR/const_cmp_type_id.rs:8:13
    |
@@ -21,19 +8,6 @@ note: impl defined here, but it is not `const`
   --> $SRC_DIR/core/src/any.rs:LL:COL
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error[E0277]: can't compare `TypeId` with `TypeId` in const contexts
-  --> $DIR/const_cmp_type_id.rs:9:13
-   |
-LL |     assert!(TypeId::of::<()>() != TypeId::of::<u8>());
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `TypeId == TypeId`
-   |
-   = help: the trait `~const PartialEq` is not implemented for `TypeId`
-note: the trait `PartialEq` is implemented for `TypeId`, but that implementation is not `const`
-  --> $DIR/const_cmp_type_id.rs:9:13
-   |
-LL |     assert!(TypeId::of::<()>() != TypeId::of::<u8>());
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0015]: cannot call non-const operator in constant functions
   --> $DIR/const_cmp_type_id.rs:9:13
    |
@@ -44,19 +18,6 @@ note: impl defined here, but it is not `const`
   --> $SRC_DIR/core/src/any.rs:LL:COL
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error[E0277]: can't compare `TypeId` with `TypeId` in const contexts
-  --> $DIR/const_cmp_type_id.rs:10:22
-   |
-LL |     const _A: bool = TypeId::of::<u8>() < TypeId::of::<u16>();
-   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `TypeId < TypeId` and `TypeId > TypeId`
-   |
-   = help: the trait `~const PartialOrd` is not implemented for `TypeId`
-note: the trait `PartialOrd` is implemented for `TypeId`, but that implementation is not `const`
-  --> $DIR/const_cmp_type_id.rs:10:22
-   |
-LL |     const _A: bool = TypeId::of::<u8>() < TypeId::of::<u16>();
-   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0015]: cannot call non-const operator in constants
   --> $DIR/const_cmp_type_id.rs:10:22
    |
@@ -68,7 +29,6 @@ note: impl defined here, but it is not `const`
    = note: calls in constants are limited to constant functions, tuple structs and tuple variants
    = note: this error originates in the derive macro `PartialOrd` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 6 previous errors
+error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/consts/invalid-inline-const-in-match-arm.rs

@@ -5,6 +5,5 @@ fn main() {
     match () {
         const { (|| {})() } => {}
         //~^ ERROR cannot call non-const closure in constants
-        //~| ERROR the trait bound
     }
 }

tests/ui/consts/invalid-inline-const-in-match-arm.stderr

@@ -1,17 +1,3 @@
-error[E0277]: the trait bound `[closure@$DIR/invalid-inline-const-in-match-arm.rs:6:18: 6:20]: Fn<()>` is not satisfied
-  --> $DIR/invalid-inline-const-in-match-arm.rs:6:17
-   |
-LL |         const { (|| {})() } => {}
-   |                 ^^^^^^^^^ expected an `Fn<()>` closure, found `[closure@$DIR/invalid-inline-const-in-match-arm.rs:6:18: 6:20]`
-   |
-   = help: the trait `~const Fn<()>` is not implemented for closure `[closure@$DIR/invalid-inline-const-in-match-arm.rs:6:18: 6:20]`
-note: the trait `Fn<()>` is implemented for `[closure@$DIR/invalid-inline-const-in-match-arm.rs:6:18: 6:20]`, but that implementation is not `const`
-  --> $DIR/invalid-inline-const-in-match-arm.rs:6:17
-   |
-LL |         const { (|| {})() } => {}
-   |                 ^^^^^^^^^
-   = note: wrap the `[closure@$DIR/invalid-inline-const-in-match-arm.rs:6:18: 6:20]` in a closure with no arguments: `|| { /* code */ }`
-
 error[E0015]: cannot call non-const closure in constants
   --> $DIR/invalid-inline-const-in-match-arm.rs:6:17
    |
@@ -22,7 +8,6 @@ LL |         const { (|| {})() } => {}
    = note: calls in constants are limited to constant functions, tuple structs and tuple variants
    = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/consts/issue-28113.rs

@@ -3,7 +3,6 @@
 const X: u8 =
     || -> u8 { 5 }()
     //~^ ERROR cannot call non-const closure
-    //~| ERROR the trait bound
 ;
 
 fn main() {}

tests/ui/consts/issue-28113.stderr

@@ -1,17 +1,3 @@
-error[E0277]: the trait bound `[closure@$DIR/issue-28113.rs:4:5: 4:13]: Fn<()>` is not satisfied
-  --> $DIR/issue-28113.rs:4:5
-   |
-LL |     || -> u8 { 5 }()
-   |     ^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `[closure@$DIR/issue-28113.rs:4:5: 4:13]`
-   |
-   = help: the trait `~const Fn<()>` is not implemented for closure `[closure@$DIR/issue-28113.rs:4:5: 4:13]`
-note: the trait `Fn<()>` is implemented for `[closure@$DIR/issue-28113.rs:4:5: 4:13]`, but that implementation is not `const`
-  --> $DIR/issue-28113.rs:4:5
-   |
-LL |     || -> u8 { 5 }()
-   |     ^^^^^^^^^^^^^^^^
-   = note: wrap the `[closure@$DIR/issue-28113.rs:4:5: 4:13]` in a closure with no arguments: `|| { /* code */ }`
-
 error[E0015]: cannot call non-const closure in constants
   --> $DIR/issue-28113.rs:4:5
    |
@@ -22,7 +8,6 @@ LL |     || -> u8 { 5 }()
    = note: calls in constants are limited to constant functions, tuple structs and tuple variants
    = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/consts/issue-56164.rs

@@ -1,6 +1,5 @@
 const fn foo() { (||{})() }
 //~^ ERROR cannot call non-const closure
-//~| ERROR the trait bound
 
 const fn bad(input: fn()) {
     input()

tests/ui/consts/issue-56164.stderr

@@ -1,17 +1,3 @@
-error[E0277]: the trait bound `[closure@$DIR/issue-56164.rs:1:19: 1:21]: Fn<()>` is not satisfied
-  --> $DIR/issue-56164.rs:1:18
-   |
-LL | const fn foo() { (||{})() }
-   |                  ^^^^^^^^ expected an `Fn<()>` closure, found `[closure@$DIR/issue-56164.rs:1:19: 1:21]`
-   |
-   = help: the trait `~const Fn<()>` is not implemented for closure `[closure@$DIR/issue-56164.rs:1:19: 1:21]`
-note: the trait `Fn<()>` is implemented for `[closure@$DIR/issue-56164.rs:1:19: 1:21]`, but that implementation is not `const`
-  --> $DIR/issue-56164.rs:1:18
-   |
-LL | const fn foo() { (||{})() }
-   |                  ^^^^^^^^
-   = note: wrap the `[closure@$DIR/issue-56164.rs:1:19: 1:21]` in a closure with no arguments: `|| { /* code */ }`
-
 error[E0015]: cannot call non-const closure in constant functions
   --> $DIR/issue-56164.rs:1:18
    |
@@ -23,12 +9,11 @@ LL | const fn foo() { (||{})() }
    = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
 
 error: function pointer calls are not allowed in constant functions
-  --> $DIR/issue-56164.rs:6:5
+  --> $DIR/issue-56164.rs:5:5
    |
 LL |     input()
    |     ^^^^^^^
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/consts/issue-68542-closure-in-array-len.rs

@@ -4,7 +4,6 @@
 
 struct Bug {
     a: [(); (|| { 0 })()] //~ ERROR cannot call non-const closure
-    //~^ ERROR the trait bound
 }
 
 fn main() {}

tests/ui/consts/issue-68542-closure-in-array-len.stderr

@@ -1,17 +1,3 @@
-error[E0277]: the trait bound `[closure@$DIR/issue-68542-closure-in-array-len.rs:6:14: 6:16]: Fn<()>` is not satisfied
-  --> $DIR/issue-68542-closure-in-array-len.rs:6:13
-   |
-LL |     a: [(); (|| { 0 })()]
-   |             ^^^^^^^^^^^^ expected an `Fn<()>` closure, found `[closure@$DIR/issue-68542-closure-in-array-len.rs:6:14: 6:16]`
-   |
-   = help: the trait `~const Fn<()>` is not implemented for closure `[closure@$DIR/issue-68542-closure-in-array-len.rs:6:14: 6:16]`
-note: the trait `Fn<()>` is implemented for `[closure@$DIR/issue-68542-closure-in-array-len.rs:6:14: 6:16]`, but that implementation is not `const`
-  --> $DIR/issue-68542-closure-in-array-len.rs:6:13
-   |
-LL |     a: [(); (|| { 0 })()]
-   |             ^^^^^^^^^^^^
-   = note: wrap the `[closure@$DIR/issue-68542-closure-in-array-len.rs:6:14: 6:16]` in a closure with no arguments: `|| { /* code */ }`
-
 error[E0015]: cannot call non-const closure in constants
   --> $DIR/issue-68542-closure-in-array-len.rs:6:13
    |
@@ -22,7 +8,6 @@ LL |     a: [(); (|| { 0 })()]
    = note: calls in constants are limited to constant functions, tuple structs and tuple variants
    = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/consts/issue-73976-monomorphic.stderr

@@ -1,16 +1,3 @@
-error[E0277]: can't compare `TypeId` with `TypeId` in const contexts
-  --> $DIR/issue-73976-monomorphic.rs:21:5
-   |
-LL |     GetTypeId::<T>::VALUE == GetTypeId::<usize>::VALUE
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `TypeId == TypeId`
-   |
-   = help: the trait `~const PartialEq` is not implemented for `TypeId`
-note: the trait `PartialEq` is implemented for `TypeId`, but that implementation is not `const`
-  --> $DIR/issue-73976-monomorphic.rs:21:5
-   |
-LL |     GetTypeId::<T>::VALUE == GetTypeId::<usize>::VALUE
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0015]: cannot call non-const operator in constant functions
   --> $DIR/issue-73976-monomorphic.rs:21:5
    |
@@ -21,7 +8,6 @@ note: impl defined here, but it is not `const`
   --> $SRC_DIR/core/src/any.rs:LL:COL
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/consts/issue-94675.rs

@@ -1,3 +1,5 @@
+// known-bug: #103507
+
 #![feature(const_trait_impl, const_mut_refs)]
 
 struct Foo<'a> {
@@ -7,9 +9,9 @@ struct Foo<'a> {
 impl<'a> Foo<'a> {
     const fn spam(&mut self, baz: &mut Vec<u32>) {
         self.bar[0] = baz.len();
-        //~^ ERROR: cannot call
+        //FIXME ~^ ERROR: cannot call
-        //~| ERROR: cannot call
+        //FIXME ~| ERROR: cannot call
-        //~| ERROR: the trait bound
+        //FIXME ~| ERROR: the trait bound
     }
 }
 

tests/ui/consts/issue-94675.stderr

@@ -1,26 +1,13 @@
 error[E0015]: cannot call non-const fn `Vec::<u32>::len` in constant functions
-  --> $DIR/issue-94675.rs:9:27
+  --> $DIR/issue-94675.rs:11:27
    |
 LL |         self.bar[0] = baz.len();
    |                           ^^^^^
    |
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error[E0277]: the trait bound `Vec<usize>: ~const IndexMut<usize>` is not satisfied
-  --> $DIR/issue-94675.rs:9:9
-   |
-LL |         self.bar[0] = baz.len();
-   |         ^^^^^^^^^^^ vector indices are of type `usize` or ranges of `usize`
-   |
-   = help: the trait `~const IndexMut<usize>` is not implemented for `Vec<usize>`
-note: the trait `IndexMut<usize>` is implemented for `Vec<usize>`, but that implementation is not `const`
-  --> $DIR/issue-94675.rs:9:9
-   |
-LL |         self.bar[0] = baz.len();
-   |         ^^^^^^^^^^^
-
 error[E0015]: cannot call non-const operator in constant functions
-  --> $DIR/issue-94675.rs:9:9
+  --> $DIR/issue-94675.rs:11:9
    |
 LL |         self.bar[0] = baz.len();
    |         ^^^^^^^^^^^
@@ -29,7 +16,6 @@ note: impl defined here, but it is not `const`
   --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/consts/precise-drop-with-promoted.rs

@@ -1,6 +1,12 @@
 // Regression test for issue #89938.
-// check-pass
 // compile-flags: --crate-type=lib
+// known-bug: #103507
+// failure-status: 101
+// normalize-stderr-test "note: .*\n\n" -> ""
+// normalize-stderr-test "thread 'rustc' panicked.*\n" -> ""
+// normalize-stderr-test "(error: internal compiler error: [^:]+):\d+:\d+: " -> "$1:LL:CC: "
+// rustc-env:RUST_BACKTRACE=0
+
 #![feature(const_precise_live_drops)]
 
 pub const fn f() {

tests/ui/consts/precise-drop-with-promoted.stderr

@@ -0,0 +1,6 @@
+error: the compiler unexpectedly panicked. this is a bug.
+
+query stack during panic:
+#0 [mir_drops_elaborated_and_const_checked] elaborating drops for `f`
+#1 [analysis] running analysis passes on this crate
+end of query stack

tests/ui/consts/promoted_const_call.rs

@@ -1,3 +1,5 @@
+// known-bug: #103507
+
 #![feature(const_mut_refs)]
 #![feature(const_trait_impl)]
 
@@ -7,15 +9,15 @@ 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);
-    //~^ ERROR: temporary value dropped while borrowed
+    //FIXME ~^ ERROR: temporary value dropped while borrowed
-    //~| ERROR: temporary value dropped while borrowed
+    //FIXME ~| ERROR: temporary value dropped while borrowed
 };
 
 fn main() {
     let _: &'static _ = &id(&Panic);
-    //~^ ERROR: temporary value dropped while borrowed
+    //FIXME ~^ ERROR: temporary value dropped while borrowed
-    //~| ERROR: temporary value dropped while borrowed
+    //FIXME ~| ERROR: temporary value dropped while borrowed
     let _: &'static _ = &&(Panic, 0).1;
-    //~^ ERROR: temporary value dropped while borrowed
+    //FIXME~^ ERROR: temporary value dropped while borrowed
-    //~| ERROR: temporary value dropped while borrowed
+    //FIXME~| ERROR: temporary value dropped while borrowed
 }

tests/ui/consts/promoted_const_call.stderr

@@ -1,5 +1,13 @@
+error[E0493]: destructor of `Panic` cannot be evaluated at compile-time
+  --> $DIR/promoted_const_call.rs:11:30
+   |
+LL |     let _: &'static _ = &id(&Panic);
+   |                              ^^^^^ - value is dropped here
+   |                              |
+   |                              the destructor for this type cannot be evaluated in constants
+
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/promoted_const_call.rs:9:26
+  --> $DIR/promoted_const_call.rs:11:26
    |
 LL |     let _: &'static _ = &id(&Panic);
    |            ----------    ^^^^^^^^^^ creates a temporary value which is freed while still in use
@@ -10,7 +18,7 @@ LL | };
    | - temporary value is freed at the end of this statement
 
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/promoted_const_call.rs:9:30
+  --> $DIR/promoted_const_call.rs:11:30
    |
 LL |     let _: &'static _ = &id(&Panic);
    |            ----------        ^^^^^ - temporary value is freed at the end of this statement
@@ -19,7 +27,7 @@ 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:15:26
+  --> $DIR/promoted_const_call.rs:17:26
    |
 LL |     let _: &'static _ = &id(&Panic);
    |            ----------    ^^^^^^^^^^ creates a temporary value which is freed while still in use
@@ -30,7 +38,7 @@ LL | }
    | - temporary value is freed at the end of this statement
 
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/promoted_const_call.rs:15:30
+  --> $DIR/promoted_const_call.rs:17:30
    |
 LL |     let _: &'static _ = &id(&Panic);
    |            ----------        ^^^^^ - temporary value is freed at the end of this statement
@@ -39,7 +47,7 @@ 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:18:26
+  --> $DIR/promoted_const_call.rs:20:26
    |
 LL |     let _: &'static _ = &&(Panic, 0).1;
    |            ----------    ^^^^^^^^^^^^^ creates a temporary value which is freed while still in use
@@ -50,7 +58,7 @@ LL | }
    | - temporary value is freed at the end of this statement
 
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/promoted_const_call.rs:18:27
+  --> $DIR/promoted_const_call.rs:20:27
    |
 LL |     let _: &'static _ = &&(Panic, 0).1;
    |            ----------     ^^^^^^^^^^ creates a temporary value which is freed while still in use
@@ -60,6 +68,7 @@ LL |     let _: &'static _ = &&(Panic, 0).1;
 LL | }
    | - temporary value is freed at the end of this statement
 
-error: aborting due to 6 previous errors
+error: aborting due to 7 previous errors
 
-For more information about this error, try `rustc --explain E0716`.
+Some errors have detailed explanations: E0493, E0716.
+For more information about an error, try `rustc --explain E0493`.

tests/ui/impl-trait/normalize-tait-in-const.rs

@@ -1,9 +1,4 @@
 // known-bug: #103507
-// failure-status: 101
-// normalize-stderr-test "note: .*\n\n" -> ""
-// normalize-stderr-test "thread 'rustc' panicked.*\n" -> ""
-// normalize-stderr-test "(error: internal compiler error: [^:]+):\d+:\d+: " -> "$1:LL:CC: "
-// rustc-env:RUST_BACKTRACE=0
 
 #![feature(type_alias_impl_trait)]
 #![feature(const_trait_impl)]

tests/ui/impl-trait/normalize-tait-in-const.stderr

@@ -1,8 +1,12 @@
-error: internal compiler error: compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:LL:CC: Failed to normalize <for<'a, 'b> fn(&'a Alias<'b>) {foo} as std::ops::FnOnce<(&&S,)>>::Output, maybe try to call `try_normalize_erasing_regions` instead
+error[E0493]: destructor of `F` cannot be evaluated at compile-time
+  --> $DIR/normalize-tait-in-const.rs:25:79
+   |
+LL | const fn with_positive<F: ~const for<'a> Fn(&'a Alias<'a>) + ~const Destruct>(fun: F) {
+   |                                                                               ^^^ the destructor for this type cannot be evaluated in constant functions
+LL |     fun(filter_positive());
+LL | }
+   | - value is dropped here
 
-query stack during panic:
-#0 [eval_to_allocation_raw] const-evaluating + checking `BAR`
-#1 [eval_to_const_value_raw] simplifying constant for the type system `BAR`
-end of query stack
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0493`.

tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs

@@ -23,7 +23,7 @@ pub const fn add_i32(a: i32, b: i32) -> i32 {
 
 pub const fn add_u32(a: u32, b: u32) -> u32 {
     a.plus(b)
-    //~^ ERROR the trait bound
+    //~^ ERROR cannot call
 }
 
 fn main() {}

tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr

@@ -1,15 +1,11 @@
-error[E0277]: the trait bound `u32: ~const Plus` is not satisfied
+error[E0015]: cannot call non-const fn `<u32 as Plus>::plus` in constant functions
   --> $DIR/call-const-trait-method-fail.rs:25:7
    |
 LL |     a.plus(b)
-   |       ^^^^ the trait `~const Plus` is not implemented for `u32`
+   |       ^^^^^^^
    |
-note: the trait `Plus` is implemented for `u32`, but that implementation is not `const`
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/call-const-trait-method-fail.rs:25:7
-   |
-LL |     a.plus(b)
-   |       ^^^^
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-fail.stderr

@@ -1,15 +1,3 @@
-error[E0277]: can't compare `T` with `T` in const contexts
-  --> $DIR/call-generic-method-fail.rs:5:5
-   |
-LL |     *t == *t
-   |     ^^^^^^^^ no implementation for `T == T`
-   |
-note: the trait `PartialEq` is implemented for `T`, but that implementation is not `const`
-  --> $DIR/call-generic-method-fail.rs:5:5
-   |
-LL |     *t == *t
-   |     ^^^^^^^^
-
 error[E0015]: cannot call non-const operator in constant functions
   --> $DIR/call-generic-method-fail.rs:5:5
    |
@@ -22,7 +10,6 @@ help: consider further restricting this bound
 LL | pub const fn equals_self<T: PartialEq + ~const std::cmp::PartialEq>(t: &T) -> bool {
    |                                       ++++++++++++++++++++++++++++
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs

@@ -1,3 +1,6 @@
+// check-pass
+// known-bug: #110395
+
 #![feature(const_trait_impl)]
 
 struct S;
@@ -21,6 +24,6 @@ const fn equals_self<T: ~const Foo>(t: &T) -> bool {
 // it not using the impl.
 
 pub const EQ: bool = equals_self(&S);
-//~^ ERROR
+// FIXME(effects) ~^ ERROR
 
 fn main() {}

tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.stderr

@@ -1,15 +0,0 @@
-error[E0277]: the trait bound `S: ~const Foo` is not satisfied
-  --> $DIR/call-generic-method-nonconst.rs:23:22
-   |
-LL | pub const EQ: bool = equals_self(&S);
-   |                      ^^^^^^^^^^^^^^^ the trait `~const Foo` is not implemented for `S`
-   |
-note: the trait `Foo` is implemented for `S`, but that implementation is not `const`
-  --> $DIR/call-generic-method-nonconst.rs:23:22
-   |
-LL | pub const EQ: bool = equals_self(&S);
-   |                      ^^^^^^^^^^^^^^^
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0277`.

tests/ui/rfcs/rfc-2632-const-trait-impl/const-closure-trait-method-fail.stderr

@@ -1,16 +1,21 @@
-error[E0277]: the trait bound `(): ~const Tr` is not satisfied in `fn(()) -> i32 {<() as Tr>::a}`
+error[E0080]: evaluation of constant value failed
-  --> $DIR/const-closure-trait-method-fail.rs:18:23
+  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
    |
-LL | const _: () = assert!(need_const_closure(Tr::a) == 42);
+   = note: calling non-const function `<() as Tr>::a`
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^ within `fn(()) -> i32 {<() as Tr>::a}`, the trait `~const Tr` is not implemented for `()`
    |
-note: the trait `Tr` is implemented for `()`, but that implementation is not `const`
+note: inside `<fn(()) -> i32 {<() as Tr>::a} as FnOnce<((),)>>::call_once - shim(fn(()) -> i32 {<() as Tr>::a})`
+  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+note: inside `need_const_closure::<fn(()) -> i32 {<() as Tr>::a}>`
+  --> $DIR/const-closure-trait-method-fail.rs:15:5
+   |
+LL |     x(())
+   |     ^^^^^
+note: inside `_`
   --> $DIR/const-closure-trait-method-fail.rs:18:23
    |
 LL | const _: () = assert!(need_const_closure(Tr::a) == 42);
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: required because it appears within the type `fn(()) -> i32 {<() as Tr>::a}`
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0080`.

tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.rs

@@ -22,7 +22,7 @@ impl const ConstDefaultFn for ConstImpl {
 
 const fn test() {
     NonConstImpl.a();
-    //~^ ERROR the trait bound
+    //~^ ERROR cannot call
     ConstImpl.a();
 }
 

tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.stderr

@@ -1,15 +1,11 @@
-error[E0277]: the trait bound `NonConstImpl: ~const ConstDefaultFn` is not satisfied
+error[E0015]: cannot call non-const fn `<NonConstImpl as ConstDefaultFn>::a` in constant functions
   --> $DIR/const-default-method-bodies.rs:24:18
    |
 LL |     NonConstImpl.a();
-   |                  ^ the trait `~const ConstDefaultFn` is not implemented for `NonConstImpl`
+   |                  ^^^
    |
-note: the trait `ConstDefaultFn` is implemented for `NonConstImpl`, but that implementation is not `const`
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/const-default-method-bodies.rs:24:5
-   |
-LL |     NonConstImpl.a();
-   |     ^^^^^^^^^^^^
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop-bound.rs

@@ -1,4 +1,5 @@
-// check-pass
+// known-bug: #110395
+// FIXME check-pass
 
 #![feature(const_trait_impl)]
 #![feature(const_precise_live_drops)]

tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop-bound.stderr

@@ -0,0 +1,9 @@
+error[E0493]: destructor of `E` cannot be evaluated at compile-time
+  --> $DIR/const-drop-bound.rs:12:13
+   |
+LL |         Err(_e) => None,
+   |             ^^ the destructor for this type cannot be evaluated in constant functions
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0493`.

tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop-fail-2.stderr

@@ -1,50 +1,11 @@
-error[E0277]: the trait bound `NonTrivialDrop: ~const A` is not satisfied
+error[E0493]: destructor of `T` cannot be evaluated at compile-time
-  --> $DIR/const-drop-fail-2.rs:31:23
+  --> $DIR/const-drop-fail-2.rs:29:36
    |
-LL | const _: () = check::<ConstDropImplWithBounds<NonTrivialDrop>>(
+LL | const fn check<T: ~const Destruct>(_: T) {}
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `~const A` is not implemented for `NonTrivialDrop`
+   |                                    ^      - value is dropped here
-   |
+   |                                    |
-note: the trait `A` is implemented for `NonTrivialDrop`, but that implementation is not `const`
+   |                                    the destructor for this type cannot be evaluated in constant functions
-  --> $DIR/const-drop-fail-2.rs:31:23
-   |
-LL | const _: () = check::<ConstDropImplWithBounds<NonTrivialDrop>>(
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: required by a bound in `ConstDropImplWithBounds`
-  --> $DIR/const-drop-fail-2.rs:21:35
-   |
-LL | struct ConstDropImplWithBounds<T: ~const A>(PhantomData<T>);
-   |                                   ^^^^^^^^ required by this bound in `ConstDropImplWithBounds`
 
-error[E0277]: the trait bound `NonTrivialDrop: ~const A` is not satisfied
+error: aborting due to previous error
-  --> $DIR/const-drop-fail-2.rs:32:5
-   |
-LL |     ConstDropImplWithBounds(PhantomData)
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `~const A` is not implemented for `NonTrivialDrop`
-   |
-note: the trait `A` is implemented for `NonTrivialDrop`, but that implementation is not `const`
-  --> $DIR/const-drop-fail-2.rs:32:5
-   |
-LL |     ConstDropImplWithBounds(PhantomData)
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: required by a bound in `ConstDropImplWithBounds`
-  --> $DIR/const-drop-fail-2.rs:21:35
-   |
-LL | struct ConstDropImplWithBounds<T: ~const A>(PhantomData<T>);
-   |                                   ^^^^^^^^ required by this bound in `ConstDropImplWithBounds`
 
-error[E0367]: `Drop` impl requires `T: ~const A` but the struct it is implemented for does not
+For more information about this error, try `rustc --explain E0493`.
-  --> $DIR/const-drop-fail-2.rs:37:9
-   |
-LL | impl<T: ~const A> const Drop for ConstDropImplWithNonConstBounds<T> {
-   |         ^^^^^^^^
-   |
-note: the implementor must specify the same requirement
-  --> $DIR/const-drop-fail-2.rs:35:1
-   |
-LL | struct ConstDropImplWithNonConstBounds<T: A>(PhantomData<T>);
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to 3 previous errors
-
-Some errors have detailed explanations: E0277, E0367.
-For more information about an error, try `rustc --explain E0277`.

tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr

@@ -1,58 +1,9 @@
-error[E0277]: can't drop `NonTrivialDrop` in const contexts
+error[E0493]: destructor of `T` cannot be evaluated at compile-time
-  --> $DIR/const-drop-fail.rs:28:23
+  --> $DIR/const-drop-fail.rs:24:36
    |
-LL |           const _: () = check($exp);
+LL | const fn check<T: ~const Destruct>(_: T) {}
-   |                         ^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `NonTrivialDrop`
+   |                                    ^ the destructor for this type cannot be evaluated in constant functions
-...
-LL | / check_all! {
-LL | |     NonTrivialDrop,
-LL | |     ConstImplWithDropGlue(NonTrivialDrop),
-LL | | }
-   | |_- in this macro invocation
-   |
-note: the trait `Destruct` is implemented for `NonTrivialDrop`, but that implementation is not `const`
-  --> $DIR/const-drop-fail.rs:28:23
-   |
-LL |           const _: () = check($exp);
-   |                         ^^^^^^^^^^^
-...
-LL | / check_all! {
-LL | |     NonTrivialDrop,
-LL | |     ConstImplWithDropGlue(NonTrivialDrop),
-LL | | }
-   | |_- in this macro invocation
-   = note: this error originates in the macro `check_all` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0277]: can't drop `NonTrivialDrop` in const contexts
+error: aborting due to previous error
-  --> $DIR/const-drop-fail.rs:28:23
-   |
-LL |           const _: () = check($exp);
-   |                         ^^^^^^^^^^^ within `ConstImplWithDropGlue`, the trait `~const Destruct` is not implemented for `NonTrivialDrop`
-...
-LL | / check_all! {
-LL | |     NonTrivialDrop,
-LL | |     ConstImplWithDropGlue(NonTrivialDrop),
-LL | | }
-   | |_- in this macro invocation
-   |
-note: the trait `Destruct` is implemented for `NonTrivialDrop`, but that implementation is not `const`
-  --> $DIR/const-drop-fail.rs:28:23
-   |
-LL |           const _: () = check($exp);
-   |                         ^^^^^^^^^^^
-...
-LL | / check_all! {
-LL | |     NonTrivialDrop,
-LL | |     ConstImplWithDropGlue(NonTrivialDrop),
-LL | | }
-   | |_- in this macro invocation
-note: required because it appears within the type `ConstImplWithDropGlue`
-  --> $DIR/const-drop-fail.rs:18:8
-   |
-LL | struct ConstImplWithDropGlue(NonTrivialDrop);
-   |        ^^^^^^^^^^^^^^^^^^^^^
-   = note: this error originates in the macro `check_all` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0493`.
-
-For more information about this error, try `rustc --explain E0277`.

tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr

@@ -1,58 +1,11 @@
-error[E0277]: can't drop `NonTrivialDrop` in const contexts
+error[E0493]: destructor of `T` cannot be evaluated at compile-time
-  --> $DIR/const-drop-fail.rs:28:23
+  --> $DIR/const-drop-fail.rs:24:36
    |
-LL |           const _: () = check($exp);
+LL | const fn check<T: ~const Destruct>(_: T) {}
-   |                         ^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `NonTrivialDrop`
+   |                                    ^      - value is dropped here
-...
+   |                                    |
-LL | / check_all! {
+   |                                    the destructor for this type cannot be evaluated in constant functions
-LL | |     NonTrivialDrop,
-LL | |     ConstImplWithDropGlue(NonTrivialDrop),
-LL | | }
-   | |_- in this macro invocation
-   |
-note: the trait `Destruct` is implemented for `NonTrivialDrop`, but that implementation is not `const`
-  --> $DIR/const-drop-fail.rs:28:23
-   |
-LL |           const _: () = check($exp);
-   |                         ^^^^^^^^^^^
-...
-LL | / check_all! {
-LL | |     NonTrivialDrop,
-LL | |     ConstImplWithDropGlue(NonTrivialDrop),
-LL | | }
-   | |_- in this macro invocation
-   = note: this error originates in the macro `check_all` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0277]: can't drop `NonTrivialDrop` in const contexts
+error: aborting due to previous error
-  --> $DIR/const-drop-fail.rs:28:23
-   |
-LL |           const _: () = check($exp);
-   |                         ^^^^^^^^^^^ within `ConstImplWithDropGlue`, the trait `~const Destruct` is not implemented for `NonTrivialDrop`
-...
-LL | / check_all! {
-LL | |     NonTrivialDrop,
-LL | |     ConstImplWithDropGlue(NonTrivialDrop),
-LL | | }
-   | |_- in this macro invocation
-   |
-note: the trait `Destruct` is implemented for `NonTrivialDrop`, but that implementation is not `const`
-  --> $DIR/const-drop-fail.rs:28:23
-   |
-LL |           const _: () = check($exp);
-   |                         ^^^^^^^^^^^
-...
-LL | / check_all! {
-LL | |     NonTrivialDrop,
-LL | |     ConstImplWithDropGlue(NonTrivialDrop),
-LL | | }
-   | |_- in this macro invocation
-note: required because it appears within the type `ConstImplWithDropGlue`
-  --> $DIR/const-drop-fail.rs:18:8
-   |
-LL | struct ConstImplWithDropGlue(NonTrivialDrop);
-   |        ^^^^^^^^^^^^^^^^^^^^^
-   = note: this error originates in the macro `check_all` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0493`.
-
-For more information about this error, try `rustc --explain E0277`.

tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop.precise.stderr

@@ -0,0 +1,19 @@
+error[E0493]: destructor of `T` cannot be evaluated at compile-time
+  --> $DIR/const-drop.rs:19:32
+   |
+LL | const fn a<T: ~const Destruct>(_: T) {}
+   |                                ^      - value is dropped here
+   |                                |
+   |                                the destructor for this type cannot be evaluated in constant functions
+
+error[E0493]: destructor of `S<'_>` cannot be evaluated at compile-time
+  --> $DIR/const-drop.rs:24:13
+   |
+LL |     let _ = S(&mut c);
+   |             ^^^^^^^^^- value is dropped here
+   |             |
+   |             the destructor for this type cannot be evaluated in constant functions
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0493`.

tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop.rs

@@ -1,9 +1,10 @@
-// run-pass
+// FIXME run-pass
+// known-bug: #110395
 // revisions: stock precise
 #![feature(const_trait_impl)]
 #![feature(const_mut_refs)]
 #![feature(never_type)]
-#![cfg_attr(precise, feature(const_precise_live_drops))]
+// #![cfg_attr(precise, feature(const_precise_live_drops))]
 
 use std::marker::Destruct;
 
@@ -16,10 +17,12 @@ impl<'a> const Drop for S<'a> {
 }
 
 const fn a<T: ~const Destruct>(_: T) {}
+//FIXME ~^ ERROR destructor of
 
 const fn b() -> u8 {
     let mut c = 0;
     let _ = S(&mut c);
+    //FIXME ~^ ERROR destructor of
     a(S(&mut c));
     c
 }

tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop.stock.stderr

@@ -0,0 +1,19 @@
+error[E0493]: destructor of `T` cannot be evaluated at compile-time
+  --> $DIR/const-drop.rs:19:32
+   |
+LL | const fn a<T: ~const Destruct>(_: T) {}
+   |                                ^      - value is dropped here
+   |                                |
+   |                                the destructor for this type cannot be evaluated in constant functions
+
+error[E0493]: destructor of `S<'_>` cannot be evaluated at compile-time
+  --> $DIR/const-drop.rs:24:13
+   |
+LL |     let _ = S(&mut c);
+   |             ^^^^^^^^^- value is dropped here
+   |             |
+   |             the destructor for this type cannot be evaluated in constant functions
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0493`.

tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr

@@ -1,15 +1,11 @@
-error[E0277]: the trait bound `cross_crate::NonConst: ~const cross_crate::MyTrait` is not satisfied
+error[E0015]: cannot call non-const fn `<cross_crate::NonConst as cross_crate::MyTrait>::func` in constant functions
   --> $DIR/cross-crate.rs:17:14
    |
 LL |     NonConst.func();
-   |              ^^^^ the trait `~const cross_crate::MyTrait` is not implemented for `cross_crate::NonConst`
+   |              ^^^^^^
    |
-note: the trait `cross_crate::MyTrait` is implemented for `cross_crate::NonConst`, but that implementation is not `const`
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/cross-crate.rs:17:5
-   |
-LL |     NonConst.func();
-   |     ^^^^^^^^
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.rs

@@ -15,10 +15,11 @@ fn non_const_context() {
 const fn const_context() {
     #[cfg(any(stocknc, gatednc))]
     NonConst.func();
-    //[stocknc]~^ ERROR: the trait bound
+    //[stocknc]~^ ERROR: cannot call
-    //[gatednc]~^^ ERROR: the trait bound
+    //[gatednc]~^^ ERROR: cannot call
     Const.func();
     //[stock]~^ ERROR: cannot call
+    //[stocknc]~^^ ERROR: cannot call
 }
 
 fn main() {}

tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr

@@ -1,15 +1,21 @@
-error[E0277]: the trait bound `cross_crate::NonConst: cross_crate::MyTrait` is not satisfied
+error[E0015]: cannot call non-const fn `<cross_crate::NonConst as cross_crate::MyTrait>::func` in constant functions
   --> $DIR/cross-crate.rs:17:14
    |
 LL |     NonConst.func();
-   |              ^^^^ the trait `~const cross_crate::MyTrait` is not implemented for `cross_crate::NonConst`
+   |              ^^^^^^
    |
-note: the trait `cross_crate::MyTrait` is implemented for `cross_crate::NonConst`, but that implementation is not `const`
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/cross-crate.rs:17:5
+   = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
+
+error[E0015]: cannot call non-const fn `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
+  --> $DIR/cross-crate.rs:20:11
    |
-LL |     NonConst.func();
+LL |     Const.func();
-   |     ^^^^^^^^
+   |           ^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+   = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-body-checking.rs

@@ -1,3 +1,6 @@
+// known-bug: #110395
+// check-pass
+
 #![feature(const_trait_impl)]
 
 #[const_trait]
@@ -10,7 +13,7 @@ const fn foo<T>() where T: ~const Tr {}
 pub trait Foo {
     fn foo() {
         foo::<()>();
-        //~^ ERROR the trait bound `(): ~const Tr` is not satisfied
+        //FIXME ~^ ERROR the trait bound `(): ~const Tr` is not satisfied
     }
 }
 

tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-body-checking.stderr

@@ -1,15 +0,0 @@
-error[E0277]: the trait bound `(): ~const Tr` is not satisfied
-  --> $DIR/default-method-body-is-const-body-checking.rs:12:9
-   |
-LL |         foo::<()>();
-   |         ^^^^^^^^^^^ the trait `~const Tr` is not implemented for `()`
-   |
-note: the trait `Tr` is implemented for `()`, but that implementation is not `const`
-  --> $DIR/default-method-body-is-const-body-checking.rs:12:9
-   |
-LL |         foo::<()>();
-   |         ^^^^^^^^^^^
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0277`.

tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.rs

@@ -1,3 +1,4 @@
+// known-bug: #110395
 #![feature(const_trait_impl)]
 
 #[const_trait]
@@ -6,7 +7,7 @@ pub trait Tr {
 
     fn b(&self) {
         ().a()
-        //~^ ERROR the trait bound
+        //FIXME ~^ ERROR the trait bound
     }
 }
 

tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr

@@ -1,15 +1,11 @@
-error[E0277]: the trait bound `(): ~const Tr` is not satisfied
+error[E0015]: cannot call non-const fn `<() as Tr>::a` in constant functions
-  --> $DIR/default-method-body-is-const-same-trait-ck.rs:8:12
+  --> $DIR/default-method-body-is-const-same-trait-ck.rs:9:12
    |
 LL |         ().a()
-   |            ^ the trait `~const Tr` is not implemented for `()`
+   |            ^^^
    |
-note: the trait `Tr` is implemented for `()`, but that implementation is not `const`
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/default-method-body-is-const-same-trait-ck.rs:8:9
-   |
-LL |         ().a()
-   |         ^^
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/issue-102985.rs

@@ -1,11 +1,12 @@
+// known-bug: #110395
 #![feature(const_trait_impl)]
 
 struct Bug {
     inner: [(); match || 1 {
         n => n(),
-        //~^ ERROR the trait bound
+        //FIXME ~^ ERROR the trait bound
-        //~| ERROR the trait bound
+        //FIXME ~| ERROR the trait bound
-        //~| ERROR cannot call non-const closure in constants
+        //FIXME ~| ERROR cannot call non-const closure in constants
     }],
 }
 

tests/ui/rfcs/rfc-2632-const-trait-impl/issue-102985.stderr

@@ -1,41 +1,11 @@
-error[E0277]: the trait bound `[closure@$DIR/issue-102985.rs:4:23: 4:25]: ~const Fn<()>` is not satisfied
-  --> $DIR/issue-102985.rs:5:14
-   |
-LL |         n => n(),
-   |              ^^^ expected an `Fn<()>` closure, found `[closure@$DIR/issue-102985.rs:4:23: 4:25]`
-   |
-   = help: the trait `~const Fn<()>` is not implemented for closure `[closure@$DIR/issue-102985.rs:4:23: 4:25]`
-note: the trait `Fn<()>` is implemented for `[closure@$DIR/issue-102985.rs:4:23: 4:25]`, but that implementation is not `const`
-  --> $DIR/issue-102985.rs:5:14
-   |
-LL |         n => n(),
-   |              ^^^
-   = note: wrap the `[closure@$DIR/issue-102985.rs:4:23: 4:25]` in a closure with no arguments: `|| { /* code */ }`
-
-error[E0277]: the trait bound `[closure@$DIR/issue-102985.rs:4:23: 4:25]: ~const Fn<()>` is not satisfied
-  --> $DIR/issue-102985.rs:5:14
-   |
-LL |         n => n(),
-   |              ^^^ expected an `Fn<()>` closure, found `[closure@$DIR/issue-102985.rs:4:23: 4:25]`
-   |
-   = help: the trait `~const Fn<()>` is not implemented for closure `[closure@$DIR/issue-102985.rs:4:23: 4:25]`
-note: the trait `Fn<()>` is implemented for `[closure@$DIR/issue-102985.rs:4:23: 4:25]`, but that implementation is not `const`
-  --> $DIR/issue-102985.rs:5:14
-   |
-LL |         n => n(),
-   |              ^^^
-   = note: wrap the `[closure@$DIR/issue-102985.rs:4:23: 4:25]` in a closure with no arguments: `|| { /* code */ }`
-
 error[E0015]: cannot call non-const closure in constants
-  --> $DIR/issue-102985.rs:5:14
+  --> $DIR/issue-102985.rs:6:14
    |
 LL |         n => n(),
    |              ^^^
    |
-   = note: closures need an RFC before allowed to be called in constants
    = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
-error: aborting due to 3 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/issue-88155.rs

@@ -1,3 +1,5 @@
+// known-bug: #110395
+
 #![feature(const_trait_impl)]
 
 pub trait A {
@@ -6,8 +8,8 @@ pub trait A {
 
 pub const fn foo<T: A>() -> bool {
     T::assoc()
-    //~^ ERROR the trait bound
+    //FIXME ~^ ERROR the trait bound
-    //~| ERROR cannot call non-const fn
+    //FIXME ~| ERROR cannot call non-const fn
 }
 
 fn main() {}

tests/ui/rfcs/rfc-2632-const-trait-impl/issue-88155.stderr

@@ -1,24 +1,11 @@
-error[E0277]: the trait bound `T: ~const A` is not satisfied
-  --> $DIR/issue-88155.rs:8:5
-   |
-LL |     T::assoc()
-   |     ^^^^^^^^^^ the trait `~const A` is not implemented for `T`
-   |
-note: the trait `A` is implemented for `T`, but that implementation is not `const`
-  --> $DIR/issue-88155.rs:8:5
-   |
-LL |     T::assoc()
-   |     ^^^^^^^^^^
-
 error[E0015]: cannot call non-const fn `<T as A>::assoc` in constant functions
-  --> $DIR/issue-88155.rs:8:5
+  --> $DIR/issue-88155.rs:10:5
    |
 LL |     T::assoc()
    |     ^^^^^^^^^^
    |
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/issue-92111.rs

@@ -1,6 +1,7 @@
 // Regression test for #92111.
 //
-// check-pass
+// known-bug: #110395
+// FIXME check-pass
 
 #![feature(const_trait_impl)]
 

tests/ui/rfcs/rfc-2632-const-trait-impl/issue-92111.stderr

@@ -0,0 +1,11 @@
+error[E0493]: destructor of `T` cannot be evaluated at compile-time
+  --> $DIR/issue-92111.rs:20:32
+   |
+LL | const fn a<T: ~const Destruct>(t: T) {}
+   |                                ^      - value is dropped here
+   |                                |
+   |                                the destructor for this type cannot be evaluated in constant functions
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0493`.

tests/ui/rfcs/rfc-2632-const-trait-impl/match-non-const-eq.gated.stderr

@@ -1,26 +1,12 @@
-error[E0277]: can't compare `str` with `str` in const contexts
-  --> $DIR/match-non-const-eq.rs:6:9
-   |
-LL |         "a" => (),
-   |         ^^^ no implementation for `str == str`
-   |
-   = help: the trait `~const PartialEq` is not implemented for `str`
-note: the trait `PartialEq` is implemented for `str`, but that implementation is not `const`
-  --> $DIR/match-non-const-eq.rs:6:9
-   |
-LL |         "a" => (),
-   |         ^^^
-
 error[E0015]: cannot match on `str` in constant functions
-  --> $DIR/match-non-const-eq.rs:6:9
+  --> $DIR/match-non-const-eq.rs:7:9
    |
-LL |         "a" => (),
+LL |         "a" => (), //FIXME [gated]~ ERROR can't compare `str` with `str` in const contexts
    |         ^^^
    |
    = note: `str` cannot be compared in compile-time, and therefore cannot be used in `match`es
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0015, E0277.
+For more information about this error, try `rustc --explain E0015`.
-For more information about an error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/match-non-const-eq.rs

@@ -1,10 +1,11 @@
+// known-bug: #110395
 // revisions: stock gated
 #![cfg_attr(gated, feature(const_trait_impl))]
 
 const fn foo(input: &'static str) {
     match input {
-        "a" => (), //[gated]~ ERROR can't compare `str` with `str` in const contexts
+        "a" => (), //FIXME [gated]~ ERROR can't compare `str` with `str` in const contexts
-        //~^ ERROR cannot match on `str` in constant functions
+        //FIXME ~^ ERROR cannot match on `str` in constant functions
         _ => (),
     }
 }

tests/ui/rfcs/rfc-2632-const-trait-impl/match-non-const-eq.stock.stderr

@@ -1,7 +1,7 @@
 error[E0015]: cannot match on `str` in constant functions
-  --> $DIR/match-non-const-eq.rs:6:9
+  --> $DIR/match-non-const-eq.rs:7:9
    |
-LL |         "a" => (),
+LL |         "a" => (), //FIXME [gated]~ ERROR can't compare `str` with `str` in const contexts
    |         ^^^
    |
    = note: `str` cannot be compared in compile-time, and therefore cannot be used in `match`es

tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-bound-non-const-specialized-bound.rs

@@ -1,5 +1,6 @@
 // Tests that trait bounds on specializing trait impls must be `~const` if the
 // same bound is present on the default impl and is `~const` there.
+// known-bug: #110395
 
 #![feature(const_trait_impl)]
 #![feature(rustc_attrs)]
@@ -29,7 +30,7 @@ where
 
 impl<T> Bar for T
 where
-    T: Foo, //~ ERROR missing `~const` qualifier
+    T: Foo, //FIXME ~ ERROR missing `~const` qualifier
     T: Specialize,
 {
     fn bar() {}
@@ -47,7 +48,7 @@ where
     default fn baz() {}
 }
 
-impl<T> const Baz for T //~ ERROR conflicting implementations of trait `Baz`
+impl<T> const Baz for T //FIXME ~ ERROR conflicting implementations of trait `Baz`
 where
     T: Foo,
     T: Specialize,

tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-bound-non-const-specialized-bound.stderr

@@ -1,18 +1,14 @@
 error: missing `~const` qualifier for specialization
-  --> $DIR/const-default-bound-non-const-specialized-bound.rs:32:8
+  --> $DIR/const-default-bound-non-const-specialized-bound.rs:33:8
+   |
+LL |     T: Foo, //FIXME ~ ERROR missing `~const` qualifier
+   |        ^^^
+
+error: missing `~const` qualifier for specialization
+  --> $DIR/const-default-bound-non-const-specialized-bound.rs:53:8
    |
 LL |     T: Foo,
    |        ^^^
 
-error[E0119]: conflicting implementations of trait `Baz`
-  --> $DIR/const-default-bound-non-const-specialized-bound.rs:50:1
-   |
-LL | impl<T> const Baz for T
-   | ----------------------- first implementation here
-...
-LL | impl<T> const Baz for T
-   | ^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation
-
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0119`.

tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.rs

@@ -1,5 +1,5 @@
 #![feature(const_trait_impl, min_specialization, rustc_attrs)]
-
+// known-bug: #110395
 #[rustc_specialization_trait]
 #[const_trait]
 pub trait Sup {}
@@ -25,7 +25,7 @@ impl<T: Default + ~const Sup> const A for T {
 
 const fn generic<T: Default>() {
     <T as A>::a();
-    //~^ ERROR: the trait bound `T: ~const Sup` is not satisfied
+    //FIXME ~^ ERROR: the trait bound `T: ~const Sup` is not satisfied
 }
 
 fn main() {}

tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr

@@ -1,21 +1,11 @@
-error[E0277]: the trait bound `T: ~const Sup` is not satisfied
+error[E0015]: cannot call non-const fn `<T as A>::a` in constant functions
   --> $DIR/specializing-constness-2.rs:27:5
    |
 LL |     <T as A>::a();
-   |     ^^^^^^^^^^^^^ the trait `~const Sup` is not implemented for `T`
+   |     ^^^^^^^^^^^^^
    |
-note: required for `T` to implement `~const A`
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/specializing-constness-2.rs:20:37
-   |
-LL | impl<T: Default + ~const Sup> const A for T {
-   |                   ----------        ^     ^
-   |                   |
-   |                   unsatisfied trait bound introduced here
-help: consider further restricting this bound
-   |
-LL | const fn generic<T: Default + ~const Sup>() {
-   |                             ++++++++++++
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.rs

@@ -1,5 +1,5 @@
 #![feature(const_trait_impl)]
-
+// known-bug: #110395
 // revisions: yy yn ny nn
 
 #[cfg_attr(any(yy, yn), const_trait)]
@@ -9,12 +9,12 @@ trait Foo {
 
 #[cfg_attr(any(yy, ny), const_trait)]
 trait Bar: ~const Foo {}
-//[ny,nn]~^ ERROR: ~const can only be applied to `#[const_trait]`
+// FIXME [ny,nn]~^ ERROR: ~const can only be applied to `#[const_trait]`
-//[ny,nn]~| ERROR: ~const can only be applied to `#[const_trait]`
+// FIXME [ny,nn]~| ERROR: ~const can only be applied to `#[const_trait]`
 
 const fn foo<T: Bar>(x: &T) {
     x.a();
-    //[yn,yy]~^ ERROR the trait bound
+    // FIXME [yn,yy]~^ ERROR the trait bound
 }
 
 fn main() {}

tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yn.stderr

@@ -1,19 +1,11 @@
-error[E0277]: the trait bound `T: ~const Foo` is not satisfied
+error[E0015]: cannot call non-const fn `<T as Foo>::a` in constant functions
   --> $DIR/super-traits-fail-2.rs:16:7
    |
 LL |     x.a();
-   |       ^ the trait `~const Foo` is not implemented for `T`
+   |       ^^^
    |
-note: the trait `Foo` is implemented for `T`, but that implementation is not `const`
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/super-traits-fail-2.rs:16:5
-   |
-LL |     x.a();
-   |     ^
-help: consider further restricting this bound
-   |
-LL | const fn foo<T: Bar + ~const Foo>(x: &T) {
-   |                     ++++++++++++
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yy.stderr

@@ -1,19 +1,11 @@
-error[E0277]: the trait bound `T: ~const Foo` is not satisfied
+error[E0015]: cannot call non-const fn `<T as Foo>::a` in constant functions
   --> $DIR/super-traits-fail-2.rs:16:7
    |
 LL |     x.a();
-   |       ^ the trait `~const Foo` is not implemented for `T`
+   |       ^^^
    |
-note: the trait `Foo` is implemented for `T`, but that implementation is not `const`
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/super-traits-fail-2.rs:16:5
-   |
-LL |     x.a();
-   |     ^
-help: consider further restricting this bound
-   |
-LL | const fn foo<T: Bar + ~const Foo>(x: &T) {
-   |                     ++++++++++++
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail.rs

@@ -1,3 +1,6 @@
+// check-pass
+// known-bug: #110395
+
 #![feature(const_trait_impl)]
 
 #[const_trait]
@@ -13,6 +16,6 @@ impl Foo for S {
 }
 
 impl const Bar for S {}
-//~^ ERROR the trait bound
+//FIXME ~^ ERROR the trait bound
 
 fn main() {}

tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail.stderr

@@ -1,20 +0,0 @@
-error[E0277]: the trait bound `S: ~const Foo` is not satisfied
-  --> $DIR/super-traits-fail.rs:15:20
-   |
-LL | impl const Bar for S {}
-   |                    ^ the trait `~const Foo` is not implemented for `S`
-   |
-note: the trait `Foo` is implemented for `S`, but that implementation is not `const`
-  --> $DIR/super-traits-fail.rs:15:20
-   |
-LL | impl const Bar for S {}
-   |                    ^
-note: required by a bound in `Bar`
-  --> $DIR/super-traits-fail.rs:8:12
-   |
-LL | trait Bar: ~const Foo {}
-   |            ^^^^^^^^^^ required by this bound in `Bar`
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0277`.